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Sample records for solution-deposited zinc-oxide-based semiconductors

  1. Photocatalysis of zinc oxide nanotip array/titanium oxide film heterojunction prepared by aqueous solution deposition

    Science.gov (United States)

    Lee, Ming-Kwei; Lee, Bo-Wei; Kao, Chen-Yu

    2017-05-01

    A TiO2 film was prepared on indium tin oxide (ITO)/glass by aqueous solution deposition (ASD) with precursors of ammonium hexafluoro-titanate and boric acid at 40 °C. The photocatalysis of annealed TiO2 film increases with increasing growth time and decreases with increasing growth times longer than 60 min. A ZnO nanotip array was prepared on ZnO seed layer/TiO2 film/glass by aqueous solution deposition with precursors of zinc nitrate and ammonium hydroxide at 70 °C. The photocatalysis of ASD-ZnO/ASD-TiO2 film/ITO glass can be better than that of P25.

  2. The kinetic of photoreactions in zinc oxide microrods

    Science.gov (United States)

    Fiedot, M.; Rac, O.; Suchorska-Woźniak, P.; Nawrot, W.; Teterycz, H.

    2016-01-01

    Zinc oxide is the oldest sensing material used in the chemical resistive gas sensors which allow to detect many gases, such as carbon oxide, nitrogen oxides and other. This material is also widely used in medicine and daily life as antibacterial agent. For this reason this semiconductor is often synthesized on the polymer substrates such as foils and textiles. In presented results zinc oxide was deposited on the surface of poly(ethylene terephthalate) foil to obtain antibacterial material. As synthesis method chemical bath deposition was chosen. The growth of zinc oxide structures was carried out in water solution of zinc nitrate (V) and hexamethylenetetramine in 90°C during 9 h. Because antibacterial properties of ZnO are strongly depended on photocatalytic and electric properties of this semiconductor impedance spectroscopy measurements were carried out. During the measurements material was tested with and without UV light to determinate the kinetic of photoreactions in zinc oxide. Moreover the composite was analyzed by XRD diffraction and scanning electron microscope. The X-ray analysis indicated that obtained material has the structure of wurtzite which is typical of zinc oxide. SEM images showed that on the PET foil microrods of ZnO were formed. The impedance spectroscopy measurements of ZnO layer showed that in UV light significant changes in the conductivity of the material are observed.

  3. The kinetic of photoreactions in zinc oxide microrods

    International Nuclear Information System (INIS)

    Fiedot, M; Rac, O; Suchorska-Woźniak, P; Nawrot, W; Teterycz, H

    2016-01-01

    Zinc oxide is the oldest sensing material used in the chemical resistive gas sensors which allow to detect many gases, such as carbon oxide, nitrogen oxides and other. This material is also widely used in medicine and daily life as antibacterial agent. For this reason this semiconductor is often synthesized on the polymer substrates such as foils and textiles. In presented results zinc oxide was deposited on the surface of poly(ethylene terephthalate) foil to obtain antibacterial material. As synthesis method chemical bath deposition was chosen. The growth of zinc oxide structures was carried out in water solution of zinc nitrate (V) and hexamethylenetetramine in 90°C during 9 h. Because antibacterial properties of ZnO are strongly depended on photocatalytic and electric properties of this semiconductor impedance spectroscopy measurements were carried out. During the measurements material was tested with and without UV light to determinate the kinetic of photoreactions in zinc oxide. Moreover the composite was analyzed by XRD diffraction and scanning electron microscope. The X-ray analysis indicated that obtained material has the structure of wurtzite which is typical of zinc oxide. SEM images showed that on the PET foil microrods of ZnO were formed. The impedance spectroscopy measurements of ZnO layer showed that in UV light significant changes in the conductivity of the material are observed

  4. Surface Preparation and Deposited Gate Oxides for Gallium Nitride Based Metal Oxide Semiconductor Devices

    Directory of Open Access Journals (Sweden)

    Paul C. McIntyre

    2012-07-01

    Full Text Available The literature on polar Gallium Nitride (GaN surfaces, surface treatments and gate dielectrics relevant to metal oxide semiconductor devices is reviewed. The significance of the GaN growth technique and growth parameters on the properties of GaN epilayers, the ability to modify GaN surface properties using in situ and ex situ processes and progress on the understanding and performance of GaN metal oxide semiconductor (MOS devices are presented and discussed. Although a reasonably consistent picture is emerging from focused studies on issues covered in each of these topics, future research can achieve a better understanding of the critical oxide-semiconductor interface by probing the connections between these topics. The challenges in analyzing defect concentrations and energies in GaN MOS gate stacks are discussed. Promising gate dielectric deposition techniques such as atomic layer deposition, which is already accepted by the semiconductor industry for silicon CMOS device fabrication, coupled with more advanced physical and electrical characterization methods will likely accelerate the pace of learning required to develop future GaN-based MOS technology.

  5. Signatures of Quantized Energy States in Solution-Processed Ultrathin Layers of Metal-Oxide Semiconductors and Their Devices

    KAUST Repository

    Labram, John G.

    2015-02-13

    Physical phenomena such as energy quantization have to-date been overlooked in solution-processed inorganic semiconducting layers, owing to heterogeneity in layer thickness uniformity unlike some of their vacuum-deposited counterparts. Recent reports of the growth of uniform, ultrathin (<5 nm) metal-oxide semiconductors from solution, however, have potentially opened the door to such phenomena manifesting themselves. Here, a theoretical framework is developed for energy quantization in inorganic semiconductor layers with appreciable surface roughness, as compared to the mean layer thickness, and present experimental evidence of the existence of quantized energy states in spin-cast layers of zinc oxide (ZnO). As-grown ZnO layers are found to be remarkably continuous and uniform with controllable thicknesses in the range 2-24 nm and exhibit a characteristic widening of the energy bandgap with reducing thickness in agreement with theoretical predictions. Using sequentially spin-cast layers of ZnO as the bulk semiconductor and quantum well materials, and gallium oxide or organic self-assembled monolayers as the barrier materials, two terminal electronic devices are demonstrated, the current-voltage characteristics of which resemble closely those of double-barrier resonant-tunneling diodes. As-fabricated all-oxide/hybrid devices exhibit a characteristic negative-differential conductance region with peak-to-valley ratios in the range 2-7.

  6. High performance solution-deposited amorphous indium gallium zinc oxide thin film transistors by oxygen plasma treatment

    KAUST Repository

    Nayak, Pradipta K.

    2012-05-16

    Solution-deposited amorphous indium gallium zinc oxide (a-IGZO) thin film transistors(TFTs) with high performance were fabricated using O2-plasma treatment of the films prior to high temperature annealing. The O2-plasma treatment resulted in a decrease in oxygen vacancy and residual hydrocarbon concentration in the a-IGZO films, as well as an improvement in the dielectric/channel interfacial roughness. As a result, the TFTs with O2-plasma treated a-IGZO channel layers showed three times higher linear field-effect mobility compared to the untreated a-IGZO over a range of processing temperatures. The O2-plasma treatment effectively reduces the required processing temperature of solution-deposited a-IGZO films to achieve the required performance.

  7. Zinc oxide based dye sensitized solar cell using eosin – Y as ...

    African Journals Online (AJOL)

    A zinc oxide based Dye sensitized Solar Cell (DSSC) has been fabricated, using Eosin-Y as the dye adsorbed on a nanocrystalline zinc oxide - fluorine doped tin oxide electrode, for the sensitization of the large band gap semiconductor. The absorption spectrum of Eosin-Y showed high absorption of visible light between ...

  8. Transparent conductive zinc-oxide-based films grown at low temperature by mist chemical vapor deposition

    International Nuclear Information System (INIS)

    Shirahata, Takahiro; Kawaharamura, Toshiyuki; Fujita, Shizuo; Orita, Hiroyuki

    2015-01-01

    Atmospheric pressure mist chemical vapor deposition (Mist–CVD) systems have been developed to grow zinc-oxide-based (ZnO-based) transparent conductive oxide (TCO) films. Low-resistive aluminum-doped ZnO (AZO) TCOs, showing resistivity of the order on 10"−"4 Ωcm, previously were grown using a safe source material zinc acetate [Zn(ac)_2], at a growth temperature as high as 500 °C. To grow superior TCOs at lower temperatures, we proposed the addition of NH_3 to accelerate the reaction of acetylacetonate compounds. As the result, we could grow gallium-doped ZnO (GZO) TCOs with a resistivity of 2.7 × 10"−"3 Ω cm and transmittance higher than 90% at 300 °C by using zinc acetylacetonate [Zn(acac)_2] as the Zn source. To grow boron-doped ZnO (BZO) TCOs at a lower growth temperature of 200 °C, we used boron doping along with a toluene solution of diethylzinc (DEZ), that maintained high reactivity without being flammable. These BZO TCOs showed a resistivity of 1.5 × 10"−"3 Ω cm and transmittance higher than 90%, despite the use of a non-vacuum-based open-air technology. - Highlights: • Introduction of Mist–CVD as a non-vacuum-based, safe, and cost-effective growth technology • Process evolution of the growth technology to lower the growth temperature. • Achievement of low resistive ZnO films at 200oC.

  9. Transparent conductive zinc-oxide-based films grown at low temperature by mist chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Shirahata, Takahiro [New Energy and Environmental Business Division, Toshiba Mitsubishi-Electric Industrial Systems Corporation, Kobe International Business Center (KIBC) 509, 5-5-2 Minatojima-Minami, Chuo-Ku, Kobe 650-0047 (Japan); Kawaharamura, Toshiyuki [Research Institute, Kochi University of Technology, Kami, Kochi 780-8502 (Japan); School of Systems Engineering, Kochi University of Technology, Kami, Kochi 780-8502 (Japan); Fujita, Shizuo, E-mail: fujitasz@kuee.kyoto-u.ac.jp [Photonics and Electronics Science and Engineering Center, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8520 (Japan); Orita, Hiroyuki [New Energy and Environmental Business Division, Toshiba Mitsubishi-Electric Industrial Systems Corporation, Kobe International Business Center (KIBC) 509, 5-5-2 Minatojima-Minami, Chuo-Ku, Kobe 650-0047 (Japan)

    2015-12-31

    Atmospheric pressure mist chemical vapor deposition (Mist–CVD) systems have been developed to grow zinc-oxide-based (ZnO-based) transparent conductive oxide (TCO) films. Low-resistive aluminum-doped ZnO (AZO) TCOs, showing resistivity of the order on 10{sup −4} Ωcm, previously were grown using a safe source material zinc acetate [Zn(ac){sub 2}], at a growth temperature as high as 500 °C. To grow superior TCOs at lower temperatures, we proposed the addition of NH{sub 3} to accelerate the reaction of acetylacetonate compounds. As the result, we could grow gallium-doped ZnO (GZO) TCOs with a resistivity of 2.7 × 10{sup −3} Ω cm and transmittance higher than 90% at 300 °C by using zinc acetylacetonate [Zn(acac){sub 2}] as the Zn source. To grow boron-doped ZnO (BZO) TCOs at a lower growth temperature of 200 °C, we used boron doping along with a toluene solution of diethylzinc (DEZ), that maintained high reactivity without being flammable. These BZO TCOs showed a resistivity of 1.5 × 10{sup −3} Ω cm and transmittance higher than 90%, despite the use of a non-vacuum-based open-air technology. - Highlights: • Introduction of Mist–CVD as a non-vacuum-based, safe, and cost-effective growth technology • Process evolution of the growth technology to lower the growth temperature. • Achievement of low resistive ZnO films at 200oC.

  10. Zinc oxide nanorod clusters deposited seaweed cellulose sheet for antimicrobial activity.

    Science.gov (United States)

    Bhutiya, Priyank L; Mahajan, Mayur S; Abdul Rasheed, M; Pandey, Manoj; Zaheer Hasan, S; Misra, Nirendra

    2018-06-01

    Seaweed cellulose was isolated from green seaweed Ulva fasciata using a common bleaching agent. Sheet containing porous mesh was prepared from the extracted seaweed crystalline cellulose along with zinc oxide (ZnO) nanorod clusters grown over the sheet by single step hydrothermal method. Seaweed cellulose and zinc oxide nanorod clusters deposited seaweed cellulose sheet was characterized by FT-IR, XRD, TGA, and SEM-EDX. Morphology showed that the diameter of zinc oxide nanorods were around 70nm. Zinc oxide nanorod clusters deposited on seaweed cellulose sheet gave remarkable antibacterial activity towards gram-positive (Staphylococcus aureus, Bacillus ceresus, Streptococcus thermophilis) and gram-negative (Escherichia coli, Pseudomonas aeruginous) microbes. Such deposited sheet has potential applications in pharmaceutical, biomedical, food packaging, water treatment and biotechnological industries. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Efficient indium-tin-oxide free inverted organic solar cells based on aluminum-doped zinc oxide cathode and low-temperature aqueous solution processed zinc oxide electron extraction layer

    International Nuclear Information System (INIS)

    Chen, Dazheng; Zhang, Chunfu; Wang, Zhizhe; Zhang, Jincheng; Tang, Shi; Wei, Wei; Sun, Li; Hao, Yue

    2014-01-01

    Indium-tin-oxide (ITO) free inverted organic solar cells (IOSCs) based on aluminum-doped zinc oxide (AZO) cathode, low-temperature aqueous solution processed zinc oxide (ZnO) electron extraction layer, and poly(3-hexylthiophene-2, 5-diyl):[6, 6]-phenyl C 61 butyric acid methyl ester blend were realized in this work. The resulted IOSC with ZnO annealed at 150 °C shows the superior power conversion efficiency (PCE) of 3.01%, if decreasing the ZnO annealing temperature to 100 °C, the obtained IOSC also shows a PCE of 2.76%, and no light soaking issue is observed. It is found that this ZnO film not only acts as an effective buffer layer but also slightly improves the optical transmittance of AZO substrates. Further, despite the relatively inferior air-stability, these un-encapsulated AZO/ZnO IOSCs show comparable PCEs to the referenced ITO/ZnO IOSCs, which demonstrates that the AZO cathode is a potential alternative to ITO in IOSCs. Meanwhile, this simple ZnO process is compatible with large area deposition and plastic substrates, and is promising to be widely used in IOSCs and other relative fields.

  12. Atmospheric pressure plasma enhanced chemical vapor deposition of zinc oxide and aluminum zinc oxide

    International Nuclear Information System (INIS)

    Johnson, Kyle W.; Guruvenket, Srinivasan; Sailer, Robert A.; Ahrenkiel, S. Phillip; Schulz, Douglas L.

    2013-01-01

    Zinc oxide (ZnO) and aluminum-doped zinc oxide (AZO) thin films were deposited via atmospheric pressure plasma enhanced chemical vapor deposition. A second-generation precursor, bis(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato)(N,N′-diethylethylenediamine) zinc, exhibited significant vapor pressure and good stability at one atmosphere where a vaporization temperature of 110 °C gave flux ∼ 7 μmol/min. Auger electron spectroscopy confirmed that addition of H 2 O to the carrier gas stream mitigated F contamination giving nearly 1:1 metal:oxide stoichiometries for both ZnO and AZO with little precursor-derived C contamination. ZnO and AZO thin film resistivities ranged from 14 to 28 Ω·cm for the former and 1.1 to 2.7 Ω·cm for the latter. - Highlights: • A second generation precursor was utilized for atmospheric pressure film growth. • Addition of water vapor to the carrier gas stream led to a marked reduction of ZnF 2 . • Carbonaceous contamination from the precursor was minimal

  13. Flexible substrate compatible solution processed P-N heterojunction diodes with indium-gallium-zinc oxide and copper oxide

    Energy Technology Data Exchange (ETDEWEB)

    Choudhary, Ishan; Deepak, E-mail: saboo@iitk.ac.in

    2017-04-15

    Highlights: • Both n and p-type semiconductors are solution processed. • Temperature compatibility with flexible substrates such as polyimide. • Compatibility of p-type film (CuO) on n-type film (IZO). • Diode with rectification ratio of 10{sup 4} and operating voltage <1.5 V. • Construction of band alignment using XPS. - Abstract: Printed electronics on flexible substrates requires low temperature and solution processed active inks. With n-type indium-gallium-zinc oxide (IGZO) based electronics maturing for thin film transistor (TFT), we here demonstrate its heterojunction diode with p-copper oxide, prepared by sol-gel method and processed at temperatures compatible with polyimide substrates. The phase obtained for copper oxide is CuO. When coated on n-type oxide, it is prone to develop morphological features, which are minimized by annealing treatment. Diodes of p-CuO films with IGZO are of poor quality due to its high resistivity while, conducting indium-zinc oxide (IZO) films yielded good diode with rectification ratio of 10{sup 4} and operating voltage <1.5 V. A detailed measurement at the interface by X-ray photoelectron spectroscopy and optical absorption ascertained the band alignment to be of staggered type. Consistently, the current in the diode is established to be due to electrons tunnelling from n-IZO to p-CuO.

  14. Deposition and Characterization of Silver Oxide from Solution of Silver, Cassava and Sugarcane Juice Effects

    Directory of Open Access Journals (Sweden)

    Uche E. Ekpunobi

    2013-06-01

    Full Text Available Silver oxide was deposited on metallic substrates (zinc and lead from silver solution with different additives at a pH of 5, dc current of 0.2A, 4V for 20seconds at 25°C. The additives were cassava solution and sugarcane juice. The metallic substrates served as cathode while a copper electrode serves as the anode. Compositions of the electrolytes were 50ml AgNO3, 50ml AgNO3 and 50ml of cassava solution or 50ml of sugarcane juice. Structural and textural characterizations were carried out on the deposits. The result showed that deposition using zinc substrate gave a better result than that of lead in that the deposits were pure without impurities. Using cassava solution as additive, a pure Ag2O3 deposit was obtained while sugarcane juice gave a pure intergrowth of Ag2O3 and Ag3O4 deposits both on zinc substrates.

  15. Zinc-oxide-based nanostructured materials for heterostructure solar cells

    International Nuclear Information System (INIS)

    Bobkov, A. A.; Maximov, A. I.; Moshnikov, V. A.; Somov, P. A.; Terukov, E. I.

    2015-01-01

    Results obtained in the deposition of nanostructured zinc-oxide layers by hydrothermal synthesis as the basic method are presented. The possibility of controlling the structure and morphology of the layers is demonstrated. The important role of the procedure employed to form the nucleating layer is noted. The faceted hexagonal nanoprisms obtained are promising for the fabrication of solar cells based on oxide heterostructures, and aluminum-doped zinc-oxide layers with petal morphology, for the deposition of an antireflection layer. The results are compatible and promising for application in flexible electronics

  16. Low-temperature solution-processed zinc oxide field effect transistor by blending zinc hydroxide and zinc oxide nanoparticle in aqueous solutions

    Science.gov (United States)

    Shin, Hyeonwoo; Kang, Chan-mo; Baek, Kyu-Ha; Kim, Jun Young; Do, Lee-Mi; Lee, Changhee

    2018-05-01

    We present a novel methods of fabricating low-temperature (180 °C), solution-processed zinc oxide (ZnO) transistors using a ZnO precursor that is blended with zinc hydroxide [Zn(OH)2] and zinc oxide hydrate (ZnO • H2O) in an ammonium solution. By using the proposed method, we successfully improved the electrical performance of the transistor in terms of the mobility (μ), on/off current ratio (I on/I off), sub-threshold swing (SS), and operational stability. Our new approach to forming a ZnO film was systematically compared with previously proposed methods. An atomic forced microscopic (AFM) image and an X-ray photoelectron spectroscopy (XPS) analysis showed that our method increases the ZnO crystallite size with less OH‑ impurities. Thus, we attribute the improved electrical performance to the better ZnO film formation using the blending methods.

  17. Multifunctional Organic-Semiconductor Interfacial Layers for Solution-Processed Oxide-Semiconductor Thin-Film Transistor.

    Science.gov (United States)

    Kwon, Guhyun; Kim, Keetae; Choi, Byung Doo; Roh, Jeongkyun; Lee, Changhee; Noh, Yong-Young; Seo, SungYong; Kim, Myung-Gil; Kim, Choongik

    2017-06-01

    The stabilization and control of the electrical properties in solution-processed amorphous-oxide semiconductors (AOSs) is crucial for the realization of cost-effective, high-performance, large-area electronics. In particular, impurity diffusion, electrical instability, and the lack of a general substitutional doping strategy for the active layer hinder the industrial implementation of copper electrodes and the fine tuning of the electrical parameters of AOS-based thin-film transistors (TFTs). In this study, the authors employ a multifunctional organic-semiconductor (OSC) interlayer as a solution-processed thin-film passivation layer and a charge-transfer dopant. As an electrically active impurity blocking layer, the OSC interlayer enhances the electrical stability of AOS TFTs by suppressing the adsorption of environmental gas species and copper-ion diffusion. Moreover, charge transfer between the organic interlayer and the AOS allows the fine tuning of the electrical properties and the passivation of the electrical defects in the AOS TFTs. The development of a multifunctional solution-processed organic interlayer enables the production of low-cost, high-performance oxide semiconductor-based circuits. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Inkjet printed ambipolar transistors and inverters based on carbon nanotube/zinc tin oxide heterostructures

    International Nuclear Information System (INIS)

    Kim, Bongjun; Jang, Seonpil; Dodabalapur, Ananth; Geier, Michael L.; Prabhumirashi, Pradyumna L.; Hersam, Mark C.

    2014-01-01

    We report ambipolar field-effect transistors (FETs) consisting of inkjet printed semiconductor bilayer heterostructures utilizing semiconducting single-walled carbon nanotubes (SWCNTs) and amorphous zinc tin oxide (ZTO). The bilayer structure allows for electron transport to occur principally in the amorphous oxide layer and hole transport to occur exclusively in the SWCNT layer. This results in balanced electron and hole mobilities exceeding 2 cm 2 V −1 s −1 at low operating voltages ( 10). This work provides a pathway for realizing solution processable, inkjet printable, large area electronic devices, and systems based on SWCNT-amorphous oxide heterostructures

  19. Characteristics of zinc oxide nanorod array/titanium oxide film heterojunction prepared by aqueous solution deposition

    Science.gov (United States)

    Lee, Ming-Kwei; Hong, Min-Hsuan; Li, Bo-Wei

    2016-07-01

    The characteristics of a ZnO nanorod array/TiO2 film heterojunction were investigated. A TiO2 film was prepared on glass by aqueous solution deposition with precursors of ammonium hexafluorotitanate and boric acid at 40 °C. Then, a ZnO seed layer was prepared on a TiO2 film/glass substrate by RF sputtering. A vertically oriented ZnO nanorod array was grown on a ZnO seed layer/TiO2 film/glass substrate by aqueous solution deposition with precursors of zinc nitrate and hexamethylenetetramine (HMT) at 70 °C. After thermal annealing in N2O ambient at 300 °C, this heterojunction used as an oxygen gas sensor shows much better rise time, decay time, and on/off current ratio than as-grown and annealed ZnO nanorods.

  20. Microwave assisted synthesis and characterisation of a zinc oxide/tobacco mosaic virus hybrid material. An active hybrid semiconductor in a field-effect transistor device

    Directory of Open Access Journals (Sweden)

    Shawn Sanctis

    2015-03-01

    Full Text Available Tobacco mosaic virus (TMV has been employed as a robust functional template for the fabrication of a TMV/zinc oxide field effect transistor (FET. A microwave based approach, under mild conditions was employed to synthesize stable zinc oxide (ZnO nanoparticles, employing a molecular precursor. Insightful studies of the decomposition of the precursor were done using NMR spectroscopy and material characterization of the hybrid material derived from the decomposition was achieved using dynamic light scattering (DLS, transmission electron microscopy (TEM, grazing incidence X-ray diffractometry (GI-XRD and atomic force microscopy (AFM. TEM and DLS data confirm the formation of crystalline ZnO nanoparticles tethered on top of the virus template. GI-XRD investigations exhibit an orientated nature of the deposited ZnO film along the c-axis. FET devices fabricated using the zinc oxide mineralized virus template material demonstrates an operational transistor performance which was achieved without any high-temperature post-processing steps. Moreover, a further improvement in FET performance was observed by adjusting an optimal layer thickness of the deposited ZnO on top of the TMV. Such a bio-inorganic nanocomposite semiconductor material accessible using a mild and straightforward microwave processing technique could open up new future avenues within the field of bio-electronics.

  1. Atomic Layer Deposited Thin Films for Dielectrics, Semiconductor Passivation, and Solid Oxide Fuel Cells

    Science.gov (United States)

    Xu, Runshen

    Atomic layer deposition (ALD) utilizes sequential precursor gas pulses to deposit one monolayer or sub-monolayer of material per cycle based on its self-limiting surface reaction, which offers advantages, such as precise thickness control, thickness uniformity, and conformality. ALD is a powerful means of fabricating nanoscale features in future nanoelectronics, such as contemporary sub-45 nm metal-oxide-semiconductor field effect transistors, photovoltaic cells, near- and far-infrared detectors, and intermediate temperature solid oxide fuel cells. High dielectric constant, kappa, materials have been recognized to be promising candidates to replace traditional SiO2 and SiON, because they enable good scalability of sub-45 nm MOSFET (metal-oxide-semiconductor field-effect transistor) without inducing additional power consumption and heat dissipation. In addition to high dielectric constant, high-kappa materials must meet a number of other requirements, such as low leakage current, high mobility, good thermal and structure stability with Si to withstand high-temperature source-drain activation annealing. In this thesis, atomic layer deposited Er2O3 doped TiO2 is studied and proposed as a thermally stable amorphous high-kappa dielectric on Si substrate. The stabilization of TiO2 in its amorphous state is found to achieve a high permittivity of 36, a hysteresis voltage of less than 10 mV, and a low leakage current density of 10-8 A/cm-2 at -1 MV/cm. In III-V semiconductors, issues including unsatisfied dangling bonds and native oxides often result in inferior surface quality that yields non-negligible leakage currents and degrades the long-term performance of devices. The traditional means for passivating the surface of III-V semiconductors are based on the use of sulfide solutions; however, that only offers good protection against oxidation for a short-term (i.e., one day). In this work, in order to improve the chemical passivation efficacy of III-V semiconductors

  2. The effect of the solution flow rate on the properties of zinc oxide (ZnO) thin films deposited by ultrasonic spray

    International Nuclear Information System (INIS)

    Attaf, A.; Benkhetta, Y.; Saidi, H.; Bouhdjar, A.; Bendjedidi, H.; Nouadji, M.; Lehraki, N.

    2015-01-01

    In this work, we used a system based on ultrasonic spray pyrolysis technique. By witch, we have deposited thin films of zinc oxide (ZnO) with the variation of solution flow rate from 50 ml / h to 150 ml / h, and set other parameters such as the concentration of the solution, the deposition time, substrate temperature and the nozzel -substrate distance. In order to study the influence of the solution flow rate on the properties of the films produced, we have several characterization techniques such as X-ray diffraction to determine the films structure, the scanning electron microscopy SEM for the morphology of the surfaces, EDS spectroscopy for the chemical composition, UV-Visible-Nir spectroscopy for determination the optical proprieties of thin films.The experimental results show that: the films have hexagonal structure at the type (wurtzite), the average size of grains varies from 20.11 to 32.45 nm, the transmittance of the films equals 80% in visible rang and the band gap is varied between 3.274 and 3.282 eV, when the solution flow rate increases from 50 to 150 ml/h

  3. The effect of the solution flow rate on the properties of zinc oxide (ZnO) thin films deposited by ultrasonic spray

    Science.gov (United States)

    Attaf, A.; Benkhetta, Y.; Saidi, H.; Bouhdjar, A.; Bendjedidi, H.; Nouadji, M.; Lehraki, N.

    2015-03-01

    In this work, we used a system based on ultrasonic spray pyrolysis technique. By witch, we have deposited thin films of zinc oxide (ZnO) with the variation of solution flow rate from 50 ml / h to 150 ml / h, and set other parameters such as the concentration of the solution, the deposition time, substrate temperature and the nozzel -substrate distance. In order to study the influence of the solution flow rate on the properties of the films produced, we have several characterization techniques such as X-ray diffraction to determine the films structure, the scanning electron microscopy SEM for the morphology of the surfaces, EDS spectroscopy for the chemical composition, UV-Visible-Nir spectroscopy for determination the optical proprieties of thin films.The experimental results show that: the films have hexagonal structure at the type (wurtzite), the average size of grains varies from 20.11 to 32.45 nm, the transmittance of the films equals 80% in visible rang and the band gap is varied between 3.274 and 3.282 eV, when the solution flow rate increases from 50 to 150 ml/h.

  4. Zinc oxide microcapsules obtained via a bio-inspired approach

    International Nuclear Information System (INIS)

    Lipowsky, Peter; Hirscher, Michael; Hoffmann, Rudolf C; Bill, Joachim; Aldinger, Fritz

    2007-01-01

    Hollow zinc oxide microcapsules have been synthesized by a sacrificial template route involving the chemical bath deposition of nanostructured zinc oxide thin films on sulfonate-modified polystyrene microspheres and subsequent removal of the polymer core by dissolution in a solvent or by thermolysis. Scanning electron micrographs show that uniform coating of the templates is achieved when ZnO is deposited from a solution containing zinc acetate, the polymer polyvinylpyrrolidone, and a base in methanol, and that the ZnO shells remain intact after removal of the cores. A focused ion beam is used to cut slices from the spheres and demonstrate their inner morphology and hollowness. X-ray diffraction yields evidence that the shells consist of nanocrystalline ZnO with the zincite structure

  5. Modeling drain current of indium zinc oxide thin film transistors prepared by solution deposition technique

    Science.gov (United States)

    Qiang, Lei; Liang, Xiaoci; Cai, Guangshuo; Pei, Yanli; Yao, Ruohe; Wang, Gang

    2018-06-01

    Indium zinc oxide (IZO) thin film transistor (TFT) deposited by solution method is of considerable technological interest as it is a key component for the fabrication of flexible and cheap transparent electronic devices. To obtain a principal understanding of physical properties of solution-processed IZO TFT, a new drain current model that account for the charge transport is proposed. The formulation is developed by incorporating the effect of gate voltage on mobility and threshold voltage with the carrier charges. It is demonstrated that in IZO TFTs the below threshold regime should be divided into two sections: EC - EF > 3kT and EC - EF ≤ 3kT, where kT is the thermal energy, EF and EC represent the Fermi level and the conduction band edge, respectively. Additionally, in order to describe conduction mechanisms more accurately, the extended mobility edge model is conjoined, which can also get rid of the complicated and lengthy computations. The good agreement between measured and calculated results confirms the efficiency of this model for the design of integrated large-area thin film circuits.

  6. Effect of Different Post Deposition Annealing Treatments on Properties of Zinc Oxide Thin Films

    Directory of Open Access Journals (Sweden)

    Arti Arora

    2010-06-01

    Full Text Available Two different post deposition annealing atmospheres of oxygen and forming gas have been investigated for the improvement of rf sputtered zinc oxide thin films. The results show that type of atmosphere (oxidant o reduction plays an important role in the changes observed in structural, electrical and optical properties. It has been found that the structural properties of rf sputtered zinc oxide films improve in all the annealing environments. The intensity and grain size increases as the annealing temperature increases. It has been found that films become stress free at lowest temperature in oxygen as compare to forming gas annealing. The zinc oxide films annealed in oxygen shows sufficient resistivity associated to high transmittance (83 % characteristics required for MEMS based acoustic devices.

  7. Soft solution synthesis and intense visible photoluminescence of lamellar zinc oxide hybrids

    International Nuclear Information System (INIS)

    Sağlam, Özge

    2013-01-01

    Graphical abstract: -- In this study, we demonstrate the synthesis of layered zinc oxide films intercalated with dodecyl sulphate ions by a simple soft solution process. The presence of potassium (K + ) and lithium (Li + ) ions in the precursor solution of layered zinc hydroxide resulted in lamellar hybrid zinc oxide films instead of layered zinc hydroxides. On the other hand, the addition of nickel phthalocyanine induces zinc hydroxide host layers which exhibit an intense blue emission. This is also promoted by K + and Li + ions

  8. Homostructured ZnO-based metal-oxide-semiconductor field-effect transistors deposited at low temperature by vapor cooling condensation system

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Tzu-Shun [Institute of Nanotechnology and Microsystems Engineering, National Cheng Kung University, 701 Tainan, Taiwan, ROC (China); Lee, Ching-Ting, E-mail: ctlee@ee.ncku.edu.tw [Institute of Nanotechnology and Microsystems Engineering, National Cheng Kung University, 701 Tainan, Taiwan, ROC (China); Institute of Microelectronics, Department of Electrical Engineering, Advanced Optoelectronic Technology Center, National Cheng Kung University, 701 Tainan, Taiwan, ROC (China)

    2015-11-01

    Highlights: • The vapor cooling condensation system was designed and used to deposit homostructured ZnO-based metal-oxide-semiconductor field-effect transistors. • The resulting homostructured ZnO-based MOSFETs operated at a reverse voltage of −6 V had a very low gate leakage current of 24 nA. • The associated I{sub DSS} and the g{sub m(max)} were 5.64 mA/mm and 1.31 mS/mm, respectively. - Abstract: The vapor cooling condensation system was designed and used to deposit homostructured ZnO-based metal-oxide-semiconductor field-effect transistors (MOSFETs) on sapphire substrates. Owing to the high quality of the deposited, various ZnO films and interfaces, the resulting MOSFETs manifested attractive characteristics, such as the low gate leakage current of 24 nA, the low average interface state density of 2.92 × 10{sup 11} cm{sup −2} eV{sup −1}, and the complete pinch-off performance. The saturation drain–source current, the maximum transconductance, and the gate voltage swing of the resulting homostructured ZnO-based MOSFETs were 5.64 mA/mm, 1.31 mS/mm, and 3.2 V, respectively.

  9. Atomic layer deposition of perovskite oxides and their epitaxial integration with Si, Ge, and other semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    McDaniel, Martin D.; Ngo, Thong Q.; Hu, Shen; Ekerdt, John G., E-mail: ekerdt@utexas.edu [Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Posadas, Agham; Demkov, Alexander A. [Department of Physics, The University of Texas at Austin, Austin, Texas 78712 (United States)

    2015-12-15

    Atomic layer deposition (ALD) is a proven technique for the conformal deposition of oxide thin films with nanoscale thickness control. Most successful industrial applications have been with binary oxides, such as Al{sub 2}O{sub 3} and HfO{sub 2}. However, there has been much effort to deposit ternary oxides, such as perovskites (ABO{sub 3}), with desirable properties for advanced thin film applications. Distinct challenges are presented by the deposition of multi-component oxides using ALD. This review is intended to highlight the research of the many groups that have deposited perovskite oxides by ALD methods. Several commonalities between the studies are discussed. Special emphasis is put on precursor selection, deposition temperatures, and specific property performance (high-k, ferroelectric, ferromagnetic, etc.). Finally, the monolithic integration of perovskite oxides with semiconductors by ALD is reviewed. High-quality epitaxial growth of oxide thin films has traditionally been limited to physical vapor deposition techniques (e.g., molecular beam epitaxy). However, recent studies have demonstrated that epitaxial oxide thin films may be deposited on semiconductor substrates using ALD. This presents an exciting opportunity to integrate functional perovskite oxides for advanced semiconductor applications in a process that is economical and scalable.

  10. Atomic layer deposition of perovskite oxides and their epitaxial integration with Si, Ge, and other semiconductors

    International Nuclear Information System (INIS)

    McDaniel, Martin D.; Ngo, Thong Q.; Hu, Shen; Ekerdt, John G.; Posadas, Agham; Demkov, Alexander A.

    2015-01-01

    Atomic layer deposition (ALD) is a proven technique for the conformal deposition of oxide thin films with nanoscale thickness control. Most successful industrial applications have been with binary oxides, such as Al 2 O 3 and HfO 2 . However, there has been much effort to deposit ternary oxides, such as perovskites (ABO 3 ), with desirable properties for advanced thin film applications. Distinct challenges are presented by the deposition of multi-component oxides using ALD. This review is intended to highlight the research of the many groups that have deposited perovskite oxides by ALD methods. Several commonalities between the studies are discussed. Special emphasis is put on precursor selection, deposition temperatures, and specific property performance (high-k, ferroelectric, ferromagnetic, etc.). Finally, the monolithic integration of perovskite oxides with semiconductors by ALD is reviewed. High-quality epitaxial growth of oxide thin films has traditionally been limited to physical vapor deposition techniques (e.g., molecular beam epitaxy). However, recent studies have demonstrated that epitaxial oxide thin films may be deposited on semiconductor substrates using ALD. This presents an exciting opportunity to integrate functional perovskite oxides for advanced semiconductor applications in a process that is economical and scalable

  11. The effect of substrate temperature on atomic layer deposited zinc tin oxide

    Energy Technology Data Exchange (ETDEWEB)

    Lindahl, Johan, E-mail: johan.lindahl@angstrom.uu.se; Hägglund, Carl, E-mail: carl.hagglund@angstrom.uu.se; Wätjen, J. Timo, E-mail: timo.watjen@angstrom.uu.se; Edoff, Marika, E-mail: marika.edoff@angstrom.uu.se; Törndahl, Tobias, E-mail: tobias.torndahl@angstrom.uu.se

    2015-07-01

    Zinc tin oxide (ZTO) thin films were deposited on glass substrates by atomic layer deposition (ALD), and the film properties were investigated for varying deposition temperatures in the range of 90 to 180 °C. It was found that the [Sn]/([Sn] + [Zn]) composition is only slightly temperature dependent, while properties such as growth rate, film density, material structure and band gap are more strongly affected. The growth rate dependence on deposition temperature varies with the relative number of zinc or tin containing precursor pulses and it correlates with the growth rate behavior of pure ZnO and SnO{sub x} ALD. In contrast to the pure ZnO phase, the density of the mixed ZTO films is found to depend on the deposition temperature and it increases linearly with about 1 g/cm{sup 3} in total over the investigated range. Characterization by transmission electron microscopy suggests that zinc rich ZTO films contain small (~ 10 nm) ZnO or ZnO(Sn) crystallites embedded in an amorphous matrix, and that these crystallites increase in size with increasing zinc content and deposition temperature. These crystallites are small enough for quantum confinement effects to reduce the optical band gap of the ZTO films as they grow in size with increasing deposition temperature. - Highlights: • Zinc tin oxide thin films were deposited by atomic layer deposition. • The structure and optical properties were studied at different growth temperatures. • The growth temperature had only a small effect on the composition of the films. • Small ZnO or ZnO(Sn) crystallites were observed by TEM in zinc rich ZTO films. • The growth temperature affects the crystallite size, which influences the band gap.

  12. The effect of substrate temperature on atomic layer deposited zinc tin oxide

    International Nuclear Information System (INIS)

    Lindahl, Johan; Hägglund, Carl; Wätjen, J. Timo; Edoff, Marika; Törndahl, Tobias

    2015-01-01

    Zinc tin oxide (ZTO) thin films were deposited on glass substrates by atomic layer deposition (ALD), and the film properties were investigated for varying deposition temperatures in the range of 90 to 180 °C. It was found that the [Sn]/([Sn] + [Zn]) composition is only slightly temperature dependent, while properties such as growth rate, film density, material structure and band gap are more strongly affected. The growth rate dependence on deposition temperature varies with the relative number of zinc or tin containing precursor pulses and it correlates with the growth rate behavior of pure ZnO and SnO x ALD. In contrast to the pure ZnO phase, the density of the mixed ZTO films is found to depend on the deposition temperature and it increases linearly with about 1 g/cm 3 in total over the investigated range. Characterization by transmission electron microscopy suggests that zinc rich ZTO films contain small (~ 10 nm) ZnO or ZnO(Sn) crystallites embedded in an amorphous matrix, and that these crystallites increase in size with increasing zinc content and deposition temperature. These crystallites are small enough for quantum confinement effects to reduce the optical band gap of the ZTO films as they grow in size with increasing deposition temperature. - Highlights: • Zinc tin oxide thin films were deposited by atomic layer deposition. • The structure and optical properties were studied at different growth temperatures. • The growth temperature had only a small effect on the composition of the films. • Small ZnO or ZnO(Sn) crystallites were observed by TEM in zinc rich ZTO films. • The growth temperature affects the crystallite size, which influences the band gap

  13. Color-selective photodetection from intermediate colloidal quantum dots buried in amorphous-oxide semiconductors.

    Science.gov (United States)

    Cho, Kyung-Sang; Heo, Keun; Baik, Chan-Wook; Choi, Jun Young; Jeong, Heejeong; Hwang, Sungwoo; Lee, Sang Yeol

    2017-10-10

    We report color-selective photodetection from intermediate, monolayered, quantum dots buried in between amorphous-oxide semiconductors. The proposed active channel in phototransistors is a hybrid configuration of oxide-quantum dot-oxide layers, where the gate-tunable electrical property of silicon-doped, indium-zinc-oxide layers is incorporated with the color-selective properties of quantum dots. A remarkably high detectivity (8.1 × 10 13 Jones) is obtained, along with three major findings: fast charge separation in monolayered quantum dots; efficient charge transport through high-mobility oxide layers (20 cm 2  V -1  s -1 ); and gate-tunable drain-current modulation. Particularly, the fast charge separation rate of 3.3 ns -1 measured with time-resolved photoluminescence is attributed to the intermediate quantum dots buried in oxide layers. These results facilitate the realization of efficient color-selective detection exhibiting a photoconductive gain of 10 7 , obtained using a room-temperature deposition of oxide layers and a solution process of quantum dots. This work offers promising opportunities in emerging applications for color detection with sensitivity, transparency, and flexibility.The development of highly sensitive photodetectors is important for image sensing and optical communication applications. Cho et al., report ultra-sensitive photodetectors based on monolayered quantum dots buried in between amorphous-oxide semiconductors and demonstrate color-detecting logic gates.

  14. Inkjet printed ambipolar transistors and inverters based on carbon nanotube/zinc tin oxide heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bongjun; Jang, Seonpil; Dodabalapur, Ananth, E-mail: ananth.dodabalapur@engr.utexas.edu [Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States); Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Geier, Michael L.; Prabhumirashi, Pradyumna L. [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Hersam, Mark C. [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Department of Chemistry, Northwestern University, Evanston, Illinois 60208 (United States); Department of Medicine, Northwestern University, Evanston, Illinois 60208 (United States)

    2014-02-10

    We report ambipolar field-effect transistors (FETs) consisting of inkjet printed semiconductor bilayer heterostructures utilizing semiconducting single-walled carbon nanotubes (SWCNTs) and amorphous zinc tin oxide (ZTO). The bilayer structure allows for electron transport to occur principally in the amorphous oxide layer and hole transport to occur exclusively in the SWCNT layer. This results in balanced electron and hole mobilities exceeding 2 cm{sup 2} V{sup −1} s{sup −1} at low operating voltages (<5 V) in air. We further show that the SWCNT-ZTO hybrid ambipolar FETs can be integrated into functional inverter circuits that display high peak gain (>10). This work provides a pathway for realizing solution processable, inkjet printable, large area electronic devices, and systems based on SWCNT-amorphous oxide heterostructures.

  15. Sputter deposition of indium tin oxide onto zinc pthalocyanine: Chemical and electronic properties of the interface studied by photoelectron spectroscopy

    Science.gov (United States)

    Gassmann, Jürgen; Brötz, Joachim; Klein, Andreas

    2012-02-01

    The interface chemistry and the energy band alignment at the interface formed during sputter deposition of transparent conducting indium tin oxide (ITO) onto the organic semiconductor zinc phtalocyanine (ZnPc), which is important for inverted, transparent, and stacked organic light emitting diodes, is studied by in situ photoelectron spectroscopy (XPS and UPS). ITO was sputtered at room temperature and a low power density with a face to face arrangement of the target and substrate. With these deposition conditions, no chemical reaction and a low barrier height for charge injection at this interface are observed. The barrier height is comparable to those observed for the reverse deposition sequence, which also confirms the absence of sputter damage.

  16. Plasma processes and film growth of expanding thermal plasma deposited textured zinc oxide

    NARCIS (Netherlands)

    Groenen, R.; Linden, J.L.; Sanden, van de M.C.M.

    2005-01-01

    Plasma processes and film growth of textured zinc oxide deposited from oxygen and diethyl zinc utilizing expanding thermal argon plasma created by a cascaded arc is discussed. In all conditions explored, an excess of argon ions and low temperature electrons is available, which represent the

  17. Magnetron sputtered transparent conductive zinc-oxide stabilized amorphous indium oxide thin films on polyethylene terephthalate substrates at ambient temperature

    International Nuclear Information System (INIS)

    Yan, Y.; Zhang, X.-F.; Ding, Y.-T.

    2013-01-01

    Amorphous transparent conducting zinc-oxide stabilized indium oxide thin films, named amorphous indium zinc oxide (a-IZO), were deposited by direct current magnetron sputtering at ambient temperature on flexible polyethylene terephthalate substrates. It has been demonstrated that the electrical resistivity could attain as low as ∼ 5 × 10 −4 Ω cm, which was noticeably lower than amorphous indium tin oxide films prepared at the same condition, while the visible transmittance exceeded 84% with the refractive index of 1.85–2.00. In our experiments, introduction of oxygen gas appeared to be beneficial to the improvement of the transparency and electrical conductivity. Both free carrier absorption and indirect transition were observed and Burstein–Moss effect proved a-IZO to be a degenerated amorphous semiconductor. However, the linear relation between the optical band gap and the band tail width which usually observed in covalent amorphous semiconductor such as a-Si:H was not conserved. Besides, porosity could greatly determine the resistivity and optical constants for the thickness variation at this deposition condition. Furthermore, a broad photoluminescence peak around 510 nm was identified when more than 1.5 sccm oxygen was introduced. - Highlights: ► Highly conducting amorphous zinc-oxide stabilized indium oxide thin films were prepared. ► The films were fabricated on polyethylene terephthalate at ambient temperature. ► Introduction of oxygen can improve the transparency and electrical conductivity. ► The linear relation between optical band gap and band tail width was not conserved

  18. All solution-processed high-resolution bottom-contact transparent metal-oxide thin film transistors

    International Nuclear Information System (INIS)

    Park, Sung Kyu; Kim, Yong-Hoon; Han, Jeong-In

    2009-01-01

    We report all solution-processed high-resolution bottom-contact indium-gallium-zinc-oxide (IGZO) thin film transistors (TFTs) using a simple surface patterning and dip-casting process. High-resolution nanoparticulate Ag source/drain electrodes and a sol-gel processed IGZO semiconductor were deposited by a simple dip-casting along with a photoresist-free, non-relief-pattern lithographic process. The deposited Ag and IGZO solution can be steered into the desired hydrophilic areas by a low surface energy self-assembled monolayer, resulting in source/drain electrodes and semiconducting layer, respectively. The all solution-processed bottom-contact IGZO TFTs including a channel length of 10 μm typically showed a mobility range 0.05-0.2 cm 2 V -1 s -1 with an on/off ratio of more than 10 6 .

  19. Characteristics of indium zinc oxide films deposited using the facing targets sputtering method for OLEDs applications

    International Nuclear Information System (INIS)

    Rim, Y.S.; Kim, H.J.; Kim, K.H.

    2010-01-01

    The amorphous indium zinc oxide (IZO) thin films were deposited on polyethersulfone (PES) and glass substrates using the facing targets sputtering (FTS) system. The electrical, optical and structural properties of the IZO thin films deposited as functions of sputtering parameters on the glass and PES substrates. An optimal IZO deposition condition is fabricated for organic light-emitting device (OLED) based on glass and PES. The amorphous IZO anode-based OLEDs show superior current density and luminance characteristics.

  20. Low Temperature Processed Complementary Metal Oxide Semiconductor (CMOS) Device by Oxidation Effect from Capping Layer

    KAUST Repository

    Wang, Zhenwei

    2015-04-20

    In this report, both p- and n-type tin oxide thin-film transistors (TFTs) were simultaneously achieved using single-step deposition of the tin oxide channel layer. The tuning of charge carrier polarity in the tin oxide channel is achieved by selectively depositing a copper oxide capping layer on top of tin oxide, which serves as an oxygen source, providing additional oxygen to form an n-type tin dioxide phase. The oxidation process can be realized by annealing at temperature as low as 190°C in air, which is significantly lower than the temperature generally required to form tin dioxide. Based on this approach, CMOS inverters based entirely on tin oxide TFTs were fabricated. Our method provides a solution to lower the process temperature for tin dioxide phase, which facilitates the application of this transparent oxide semiconductor in emerging electronic devices field.

  1. Highly transparent conductive electrode with ultra-low HAZE by grain boundary modification of aqueous solution fabricated alumina-doped zinc oxide nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Nian, Qiong; Cheng, Gary J. [Birck Nanotechnology Center and School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47906 (United States); Callahan, Michael; Bailey, John [Greentech Solutions, Inc., Hanson, Massachusetts 02341 (United States); Look, David [Semiconductor Research Center, Wright State University, Dayton, Ohio 45435 (United States); Efstathiadis, Harry [College of Nanoscale Science and Engineering (CNSE), University of Albany, Albany, New York 12203 (United States)

    2015-06-01

    Commercial production of transparent conducting oxide (TCO) polycrystalline films requires high electrical conductivity with minimal degradation in optical transparency. Aqueous solution deposited TCO films would reduce production costs of TCO films but suffer from low electrical mobility, which severely degrades both electrical conductivity and optical transparency in the visible spectrum. Here, we demonstrated that grain boundary modification by ultra-violet laser crystallization (UVLC) of solution deposited aluminium-doped zinc oxide (AZO) nanocrystals results in high Hall mobility, with a corresponding dramatic improvement in AZO electrical conductance. The AZO films after laser irradiation exhibit electrical mobility up to 18.1 cm{sup 2} V{sup −1} s{sup −1} with corresponding electrical resistivity and sheet resistances as low as 1 × 10{sup −3} Ω cm and 75 Ω/sq, respectively. The high mobility also enabled a high transmittance (T) of 88%-96% at 550 nm for the UVLC films. In addition, HAZE measurement shows AZO film scattering transmittance as low as 1.8%, which is superior over most other solution deposited transparent electrode alternatives such as silver nanowires. Thus, AZO films produced by the UVLC technique have a combined figure of merit for electrical conductivity, optical transparency, and optical HAZE higher than other solution based deposition techniques and comparable to vacuumed based deposition methods.

  2. Atomic layer deposition of high-mobility hydrogen-doped zinc oxide

    NARCIS (Netherlands)

    Macco, B.; Knoops, H.C.M.; Verheijen, M.A.; Beyer, W.; Creatore, M.; Kessels, W.M.M.

    2017-01-01

    In this work, atomic layer deposition (ALD) has been employed to prepare high-mobility H-doped zinc oxide (ZnO:H) films. Hydrogen doping was achieved by interleaving the ZnO ALD cycles with H2 plasma treatments. It has been shown that doping with H2 plasma offers key advantages over traditional

  3. Molecular-beam-deposited yttrium-oxide dielectrics in aluminum-gated metal - oxide - semiconductor field-effect transistors: Effective electron mobility

    International Nuclear Information System (INIS)

    Ragnarsson, L.-A degree.; Guha, S.; Copel, M.; Cartier, E.; Bojarczuk, N. A.; Karasinski, J.

    2001-01-01

    We report on high effective mobilities in yttrium-oxide-based n-channel metal - oxide - semiconductor field-effect transistors (MOSFETs) with aluminum gates. The yttrium oxide was grown in ultrahigh vacuum using a reactive atomic-beam-deposition system. Medium-energy ion-scattering studies indicate an oxide with an approximate composition of Y 2 O 3 on top of a thin layer of interfacial SiO 2 . The thickness of this interfacial oxide as well as the effective mobility are found to be dependent on the postgrowth anneal conditions. Optimum conditions result in mobilities approaching that of SiO 2 -based MOSFETs at higher fields with peak mobilities at approximately 210 cm 2 /Vs. [copyright] 2001 American Institute of Physics

  4. High performance solution processed zirconium oxide gate dielectric appropriate for low temperature device application

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Musarrat; Nguyen, Manh-Cuong; Kim, Hyojin; You, Seung-Won; Jeon, Yoon-Seok; Tong, Duc-Tai; Lee, Dong-Hwi; Jeong, Jae Kyeong; Choi, Rino, E-mail: rino.choi@inha.ac.kr

    2015-08-31

    This paper reports a solution processed electrical device with zirconium oxide gate dielectric that was fabricated at a low enough temperature appropriate for flexible electronics. Both inorganic dielectric and channel materials were synthesized in the same organic solvent. The dielectric constant achieved was 13 at 250 °C with a reasonably low leakage current. The bottom gate transistor devices showed the highest mobility of 75 cm{sup 2}/V s. The device is operated at low voltage with high-k dielectric with excellent transconductance and low threshold voltage. Overall, the results highlight the potential of low temperature solution based deposition in fabricating more complicated circuits for a range of applications. - Highlights: • We develop a low temperature inorganic dielectric deposition process. • We fabricate oxide semiconductor channel devices using all-solution processes. • Same solvent is used for dielectric and oxide semiconductor deposition.

  5. Transparent indium zinc oxide thin films used in photovoltaic cells based on polymer blends

    International Nuclear Information System (INIS)

    Besleaga, Cristina; Ion, L.; Ghenescu, Veta; Socol, G.; Radu, A.; Arghir, Iulia; Florica, Camelia; Antohe, S.

    2012-01-01

    Indium zinc oxide (IZO) thin films were obtained using pulsed laser deposition. The samples were prepared by ablation of targets with In concentrations, In/(In + Zn), of 80 at.%, at low substrate temperatures under reactive atmosphere. IZO films were used as transparent electrodes in polymer-based – poly(3-hexylthiophene) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C61 1:1 blend – photovoltaic cells. The action spectra measurements revealed that IZO-based photovoltaic structures have performances comparable with those using indium–tin–oxide as transparent electrode. - Highlights: ► Indium zinc oxide films were grown by pulsed laser deposition at room temperature. ► The films had large free carrier density and reasonably high mobility. ► These films fit for transparent electrodes in polymer-based photovoltaic cells.

  6. Smart methanol sensor based on silver oxide-doped zinc oxide nanoparticles deposited on microchips

    International Nuclear Information System (INIS)

    Rahman, Mohammed M.; Khan, Sher Bahadar; Asiri, Abdullah M.

    2014-01-01

    We have prepared calcined silver oxide-doped zinc oxide nanoparticles (NPs) by a hydrothermal method using reducing agents in alkaline medium. The doped NPs were characterized by UV/vis, FTIR, and X-ray photoelectron spectroscopy, and by X-ray powder diffraction and field-emission scanning electron microscopy. The NPs were deposited on microchips to result in a sensor that has a fast response to methanol in the liquid phase. Features include high sensitivity, low-sample volume, reliability, reproducibility, ease of integration, long-term stability, and enhanced electrochemical responses. The calibration plot is linear (r 2  = 0.9981) over the 0.25 mmolL −1 to 0.25 molL −1 methanol concentration range. The sensitivity is ∼7.917 μA cm −2 mmolL −2 , and the detection limit is 71.0 ± 0.5 μmolL −1 at a signal-to-noise-ratio of 3. (author)

  7. Tungsten oxide coatings deposited by plasma spray using powder and solution precursor for detection of nitrogen dioxide gas

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chao, E-mail: zhangc@yzu.edu.cn [College of Mechanical Engineering, Yangzhou University, Yangzhou 225127 (China); Wang, Jie [College of Mechanical Engineering, Yangzhou University, Yangzhou 225127 (China); Geng, Xin [College of Mechanical Engineering, Yangzhou University, Yangzhou 225127 (China); College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China)

    2016-05-25

    Increasing attention has been paid on preparation methods for resistive-type gas sensors based on semiconductor metal oxides. In this work, tungsten oxide (WO{sub 3}) coatings were prepared on alumina substrates and used as gas sensitive layers. The coatings were deposited by atmospheric plasma spray using powder, solution precursor, or a combination of both. Tungsten oxide powder through a powder port and ammonium tungstate aqueous solution through a liquid port were injected into plasma stream respectively or together to deposit WO{sub 3} coatings. Phase structures in the coatings were characterized by X-ray diffraction analyzer. The field-emission scanning electron microscopy images confirmed that the coatings were in microstructure, nanostructure or micro-nanostructure. The sensing properties of the sensors based on the coatings exposed to 1 ppm nitrogen dioxide gas were characterized in a home-made instrument. Sensing properties of the coatings were compared and discussed. The influences of gas humidity and working temperature on the sensor responses were further studied. - Highlights: • Porous gas sensitive coatings were deposited by plasma spray using powder and solution precursor. • Crystallized WO{sub 3} were obtained through hybrid plasma spray plus a pre-conditioned step. • Plasma power had an important influence on coating microstructure. • The particle size of atmospheric plasma-sprayed microstructured coating was stable. • Solution precursor plasma-sprayed WO{sub 3} coatings had nanostructure and showed good responses to 1 ppm NO{sub 2}.

  8. Deposition of zinc oxide thin films by reactive pulsed laser ablation

    Czech Academy of Sciences Publication Activity Database

    Bílková, Petra; Zemek, Josef; Mitu, B.; Marotta, V.; Orlando, S.

    2006-01-01

    Roč. 252, - (2006), s. 4604-4609 ISSN 0169-4332 Grant - others:NATO-CNR Outreach Fellowships Programm 2001(XE) 219.34 Institutional research plan: CEZ:AV0Z10100521 Keywords : reactive pulsed laser deposition * zinc oxide * thin films Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.436, year: 2006

  9. Effect of time and deposition method on quality of phosphonic acid modifier self-assembled monolayers on indium zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Sang, Lingzi [Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721 (United States); Knesting, Kristina M. [Department of Chemistry, University of Washington, Seattle, WA 98195-1700 (United States); Bulusu, Anuradha [School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Sigdel, Ajaya K. [National Renewable Energy Laboratory, Golden, CO 80401 (United States); Giordano, Anthony J.; Marder, Seth R. [School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, GA 30332-0400 (United States); Berry, Joseph J. [National Renewable Energy Laboratory, Golden, CO 80401 (United States); Graham, Samuel [School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Ginger, David S. [Department of Chemistry, University of Washington, Seattle, WA 98195-1700 (United States); Pemberton, Jeanne E., E-mail: pembertn@email.arizona.edu [Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721 (United States)

    2016-12-15

    Highlights: • Deposition of phosphonic acid monolayers on oxides from ethanol solutions occurs by rapid adsorption within 10 s with slower equilibration complete in 48 h. • The slower equilibration step involves molecular reorientation and vacancy filling on the oxide surface. • Soak-free deposition by spray coating and microcontact printing do not provide reproducible, fully-covered, uniform monolayers without substrate etching. • Adjustments to exposure time, substrate temperature, and solution/substrate contact efficiency are necessary to optimize soak-free methods. - Abstract: Phosphonic acid (PA) self-assembled monolayers (SAMs) are utilized at critical interfaces between transparent conductive oxides (TCO) and organic active layers in organic photovoltaic devices (OPVs). The effects of PA deposition method and time on the formation of close-packed, high-quality monolayers is investigated here for SAMs fabricated by solution deposition, micro-contact printing, and spray coating. The solution deposition isotherm for pentafluorinated benzylphosphonic acid (F{sub 5}BnPA) on indium-doped zinc oxide (IZO) is studied using polarization modulation-infrared reflection-absorption spectroscopy (PM-IRRAS) at room temperature as a model PA/IZO system. Fast surface adsorption occurs within the first min; however, well-oriented high-quality SAMs are reached only after ∼48 h, presumably through a continual process of molecular adsorption/desorption and monolayer filling accompanied by molecular reorientation. Two other rapid, soak-free deposition techniques, micro-contact printing and spray coating, are also explored. SAM quality is compared for deposition of phenyl phosphonic acid (PPA), F{sub 13}-octylphosphonic acid (F{sub 13}OPA), and pentafluorinated benzyl phosphonic acid (F{sub 5}BnPA) by solution deposition, micro-contact printing and spray coating using PM-IRRAS. In contrast to micro-contact printing and spray coating techniques, 48–168 h solution

  10. Selective UV–O3 treatment for indium zinc oxide thin film transistors with solution-based multiple active layer

    Science.gov (United States)

    Kim, Yu-Jung; Jeong, Jun-Kyo; Park, Jung-Hyun; Jeong, Byung-Jun; Lee, Hi-Deok; Lee, Ga-Won

    2018-06-01

    In this study, a method to control the electrical performance of solution-based indium zinc oxide (IZO) thin film transistors (TFTs) is proposed by ultraviolet–ozone (UV–O3) treatment on the selective layer during multiple IZO active layer depositions. The IZO film is composed of triple layers formed by spin coating and UV–O3 treatment only on the first layer or last layer. The IZO films are compared by X-ray photoelectron spectroscopy, and the results show that the atomic ratio of oxygen vacancy (VO) increases in the UV–O3 treatment on the first layer, while it decreases on last layer. The device characteristics of the bottom gated structure are also improved in the UV–O3 treatment on the first layer. This indicates that the selective UV–O3 treatment in a multi-stacking active layer is an effective method to optimize TFT properties by controlling the amount of VO in the IZO interface and surface independently.

  11. Reduction of Charge Traps and Stability Enhancement in Solution-Processed Organic Field-Effect Transistors Based on a Blended n-Type Semiconductor.

    Science.gov (United States)

    Campos, Antonio; Riera-Galindo, Sergi; Puigdollers, Joaquim; Mas-Torrent, Marta

    2018-05-09

    Solution-processed n-type organic field-effect transistors (OFETs) are essential elements for developing large-area, low-cost, and all organic logic/complementary circuits. Nonetheless, the development of air-stable n-type organic semiconductors (OSCs) lags behind their p-type counterparts. The trapping of electrons at the semiconductor-dielectric interface leads to a lower performance and operational stability. Herein, we report printed small-molecule n-type OFETs based on a blend with a binder polymer, which enhances the device stability due to the improvement of the semiconductor-dielectric interface quality and a self-encapsulation. Both combined effects prevent the fast deterioration of the OSC. Additionally, a complementary metal-oxide semiconductor-like inverter is fabricated depositing p-type and n-type OSCs simultaneously.

  12. Effect of Time and Deposition Method on Quality of Phosphonic Acid Modifier Self-Assembled Monolayers on Indium Zinc Oxide

    Energy Technology Data Exchange (ETDEWEB)

    Sang, Lingzi; Knesting, Kristina M.; Bulusu, Anuradha; Sigdel, Ajaya K.; Giordano, Anthony J.; Marder, Seth R.; Berry, Joseph J.; Graham, Samuel; Ginger, David S.; Pemberton, Jeanne E.

    2016-12-15

    Phosphonic acid (PA) self-assembled monolayers (SAMs) are utilized at critical interfaces between transparent conductive oxides (TCO) and organic active layers in organic photovoltaic devices (OPVs). The effects of PA deposition method and time on the formation of close-packed, high-quality monolayers is investigated here for SAMs fabricated by solution deposition, micro-contact printing, and spray coating. The solution deposition isotherm for pentafluorinated benzylphosphonic acid (F5BnPA) on indium-doped zinc oxide (IZO) is studied using polarization modulation-infrared reflection-absorption spectroscopy (PM-IRRAS) at room temperature as a model PA/IZO system. Fast surface adsorption occurs within the first min; however, well-oriented high-quality SAMs are reached only after -48 h, presumably through a continual process of molecular adsorption/desorption and monolayer filling accompanied by molecular reorientation. Two other rapid, soak-free deposition techniques, micro-contact printing and spray coating, are also explored. SAM quality is compared for deposition of phenyl phosphonic acid (PPA), F13-octylphosphonic acid (F13OPA), and pentafluorinated benzyl phosphonic acid (F5BnPA) by solution deposition, micro-contact printing and spray coating using PM-IRRAS. In contrast to micro-contact printing and spray coating techniques, 48-168 h solution deposition at both room temperature and 70 degrees C result in contamination- and surface etch-free close-packed monolayers with good reproducibility. SAMs fabricated by micro-contact printing and spray coating are much less well ordered.

  13. Ni-doped zinc oxide nanocombs and phonon spectra properties

    International Nuclear Information System (INIS)

    Zhang Bin; Zhang Xingtang; Gong Hechun; Wu Zhishen; Zhou Shaomin; Du Zuliang

    2008-01-01

    Ni-doped comb-like zinc oxide (ZnO) semiconductor nanostructures have been synthesized by a simple chemical vapor-deposition method (CVD) at relatively low temperature. The as-synthesized ZnO nanocombs consist of an array of very uniform, perfectly aligned, evenly spaced and long single-crystalline nanobelts (nanowires) with periods of about several tens of nanometers. X-ray diffraction and Raman spectra results provide the evidence that Ni is incorporated into the ZnO lattice at Zn site. Photoluminescence spectra of the as-obtained samples have been detected, in which the incorporation of donor Ni leads to the increases of the ultraviolet emission intensity and a blueshift of emission peak. This technique can be used to prepare other semiconductors and morphology-controlled doping nanocombs

  14. Antibacterial activity of zinc oxide-coated nanoporous alumina

    Energy Technology Data Exchange (ETDEWEB)

    Skoog, S.A. [Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Box 7115, Raleigh, NC 27695-7115 (United States); Bayati, M.R. [Department of Materials Science and Engineering, North Carolina State University, Box 7907, Raleigh, NC 27695-7907 (United States); Petrochenko, P.E. [Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Box 7115, Raleigh, NC 27695-7115 (United States); Division of Biology, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993 (United States); Stafslien, S.; Daniels, J.; Cilz, N. [Center for Nanoscale Science and Engineering, North Dakota State University, 1805 Research Park Drive, Fargo, ND 58102 (United States); Comstock, D.J.; Elam, J.W. [Energy Systems Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Narayan, R.J., E-mail: roger_narayan@msn.com [Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Box 7115, Raleigh, NC 27695-7115 (United States); Department of Materials Science and Engineering, North Carolina State University, Box 7907, Raleigh, NC 27695-7907 (United States)

    2012-07-25

    Highlights: Black-Right-Pointing-Pointer Atomic layer deposition was used to deposit ZnO on nanoporous alumina membranes. Black-Right-Pointing-Pointer Scanning electron microscopy showed continuous coatings of zinc oxide nanocrystals. Black-Right-Pointing-Pointer Activity against B. subtilis, E. coli, S. aureus, and S. epidermidis was shown. - Abstract: Nanoporous alumina membranes, also known as anodized aluminum oxide membranes, are being investigated for use in treatment of burn injuries and other skin wounds. In this study, atomic layer deposition was used for coating the surfaces of nanoporous alumina membranes with zinc oxide. Agar diffusion assays were used to show activity of zinc oxide-coated nanoporous alumina membranes against several bacteria found on the skin surface, including Bacillus subtilis, Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis. On the other hand, zinc oxide-coated nanoporous alumina membranes did not show activity against Pseudomonas aeruginosa, Enterococcus faecalis, and Candida albicans. These results suggest that zinc oxide-coated nanoporous alumina membranes have activity against some Gram-positive and Gram-negative bacteria that are associated with skin colonization and skin infection.

  15. TRANSPARENT CONDUCTING OXIDE SYNTHESIS OF ALUMINIUM DOPED ZINC OXIDES BY CHEMICAL COPRECIPITATION

    Directory of Open Access Journals (Sweden)

    Silvia Maioco

    2013-03-01

    Full Text Available Aluminium doped zinc oxides (AZO are promising replacements for tin doped indium oxides (ITO but thin films show a wide range of physical properties strongly dependent on deposition process conditions. Submicrometric 1% aluminum doped zinc oxide ceramics (AZO are examined, prepared by coprecipitation, from Zn(NO32 and Al(NO33 aqueous solutions, sintered at 1200°C and subsequently annealed in 10-16 atm controlled oxygen fugacity atmospheres, at 1000°C. Electrical resistivity diminishes by two orders of magnitude after two hours of annealing and the Seebeck coefficient gradually changes from -140 to -50 µV/K within 8 h. It is concluded that increased mobility is dominant over the increased carrier density, induced by changes in metal-oxygen stoichiometry

  16. Byproduct-free mass production of compound semiconductor nanowires: zinc phosphide

    Science.gov (United States)

    Chen, Yixi; Polinnaya, Rakesh; Vaddiraju, Sreeram

    2018-05-01

    A method for the mass production of compound semiconductor nanowires that involves the direct reaction of component elements in a chemical vapor deposition chamber (CVD) is presented. This method results in nanowires, without the associated production of any other byproducts such as nanoparticles or three-dimensional (3D) bulk crystals. Furthermore, no unreacted reactants remain mixed with the nanowire product in this method. This byproduct-free nanowire production thus circumvents the need to tediously purify and collect nanowires from a mixture of products/reactants after their synthesis. Demonstration made using zinc phosphide (Zn3P2) material system as an example indicated that the direct reaction of zinc microparticles with phosphorus supplied via the vapor phase results in the production of gram quantities of nanowires. To enhance thermal transport and achieve the complete reaction of zinc microparticles, while simultaneously ensuring that the microparticles do not agglomerate into macroscale zinc particles and partly remain unreacted (owing to diffusion limitations), pellets composed of mixtures of zinc and a sacrificial salt, NH4Cl, were employed as the starting material. The sublimation by decomposition of NH4Cl in the early stages of the reaction leaves a highly porous pellet of zinc composed of only zinc microparticles, which allows for inward diffusion of phosphorus/outward diffusion of zinc and the complete conversion of zinc into Zn3P2 nanowires. NH4Cl also aids in removal of any native oxide layer present on the zinc microparticles that may prevent their reaction with phosphorus. This method may be used to mass produce many other nanowires in a byproduct-free manner, besides Zn3P2.

  17. Assessing the antimicrobial activity of zinc oxide thin films using disk diffusion and biofilm reactor

    International Nuclear Information System (INIS)

    Gittard, Shaun D.; Perfect, John R.; Monteiro-Riviere, Nancy A.; Wei Wei; Jin Chunming; Narayan, Roger J.

    2009-01-01

    The electronic and chemical properties of semiconductor materials may be useful in preventing growth of microorganisms. In this article, in vitro methods for assessing microbial growth on semiconductor materials will be presented. The structural and biological properties of silicon wafers coated with zinc oxide thin films were evaluated using atomic force microscopy, X-ray photoelectron spectroscopy, and MTT viability assay. The antimicrobial properties of zinc oxide thin films were established using disk diffusion and CDC Biofilm Reactor studies. Our results suggest that zinc oxide and other semiconductor materials may play a leading role in providing antimicrobial functionality to the next-generation medical devices

  18. Influence of synthesis procedure on the formation and properties of zinc oxide

    International Nuclear Information System (INIS)

    Music, S.; Popovic, S.; Maljkovic, M.; Dragcevic, D.

    2002-01-01

    Formation and properties of zinc oxide were investigated in dependence on the synthesis procedure. Zinc oxide did not crystallize upon hydrothermal treatment of Zn(NO 3 ) 2 aqueous solutions containing urea, up to 160 deg. C. Hydrozincite was formed instead. Changes in the X-ray diffraction patterns and Fourier transform infrared (FT-IR) spectra were interpreted in terms of stacking disorder in hydrozincite crystals. Zinc oxide powder was obtained by thermal treatment in air of precipitated hydrozincite. The conditions for instantaneous synthesis of very fine zinc oxide particles were found. This procedure is based on addition of TMAH (tetramethylammonium hydroxide) solution to an ethanolic solution of zinc acetate dihydrate, up to pH∼14. On the other hand, addition of an equivalent volume of water to the ethanolic solution of zinc acetate dihydrate, prior to the addition of TMAH solution up to pH∼14, yielded ZnO flakes without any specific shape. All zinc oxide particles produced upon heating at 600 deg. C in air showed similar morphology and tendency to aggregation due to the sintering effect. The features of the FT-IR spectra of zinc oxide particles were related to their shapes

  19. Formation of solid solutions on the boundary of zinc oxidezinc telluride heterojunction

    International Nuclear Information System (INIS)

    Tsurkan, A.E.; Buzhor, L.V.

    1987-01-01

    Distribution of ZnO x Te 1-x alloy composition on the interface of zinc oxide-zinc telluride heterojunction depending on the production conditions is investigated. A regularity in the formation of an extended area with constant alloy composition is detected. The regularity is explained by the fact that electric Peltier field conditioned by contact of two heterogeneous semiconductors participates in the solid solution formation process. Peltier field levels off the composition at the end length section. So, a possibility of creating a section with the assigned minor thickness alloy constant composition controlled in the interface of heterojunction occurs

  20. Polycrystalline intrinsic zinc oxide to be used in transparent electronic devices

    International Nuclear Information System (INIS)

    Pimentel, A.; Fortunato, E.; Goncalves, A.; Marques, A.; Aguas, H.; Pereira, L.; Ferreira, I.; Martins, R.

    2005-01-01

    In this paper we present results of intrinsic/non-doped zinc oxide deposited at room temperature by radio frequency magnetron sputtering able to be used as a semiconductor material on electronic devices, like for example ozone gas sensors, ultra-violet detectors and thin film transistors. These films present a resistivity as high as 2.5x10 8 Ω cm with an optical transmittance of 90%. Concerning the structural properties, these films are polycrystalline presenting a uniform and very smooth surface

  1. Piezoelectric Zinc Oxide Based MEMS Acoustic Sensor

    Directory of Open Access Journals (Sweden)

    Aarti Arora

    2008-04-01

    Full Text Available An acoustic sensors exhibiting good sensitivity was fabricated using MEMS technology having piezoelectric zinc oxide as a dielectric between two plates of capacitor. Thin film zinc oxide has structural, piezoelectric and optical properties for surface acoustic wave (SAW and bulk acoustic wave (BAW devices. Oxygen effficient films are transparent and insulating having wide applications for sensors and transducers. A rf sputtered piezoelectric ZnO layer transforms the mechanical deflection of a thin etched silicon diaphragm into a piezoelectric charge. For 25-micron thin diaphragm Si was etched in tetramethylammonium hydroxide solution using bulk micromachining. This was followed by deposition of sandwiched structure composed of bottom aluminum electrode, sputtered 3 micron ZnO film and top aluminum electrode. A glass having 1 mm diameter hole was bonded on backside of device to compensate sound pressure in side the cavity. The measured value of central capacitance and dissipation factor of the fabricated MEMS acoustic sensor was found to be 82.4pF and 0.115 respectively, where as the value of ~176 pF was obtained for the rim capacitance with a dissipation factor of 0.138. The response of the acoustic sensors was reproducible for the devices prepared under similar processing conditions under different batches. The acoustic sensor was found to be working from 30Hz to 8KHz with a sensitivity of 139µV/Pa under varying acoustic pressure.

  2. Organic semiconductor rubrene thin films deposited by pulsed laser evaporation of solidified solutions

    Science.gov (United States)

    Majewska, N.; Gazda, M.; Jendrzejewski, R.; Majumdar, S.; Sawczak, M.; Śliwiński, G.

    2017-08-01

    Organic semiconductor rubrene (C42H28) belongs to most preferred spintronic materials because of the high charge carrier mobility up to 40 cm2(V·s)-1. However, the fabrication of a defect-free, polycrystalline rubrene for spintronic applications represents a difficult task. We report preparation and properties of rubrene thin films deposited by pulsed laser evaporation of solidified solutions. Samples of rubrene dissolved in aromatic solvents toluene, xylene, dichloromethane and 1,1-dichloroethane (0.23-1% wt) were cooled to temperatures in the range of 16.5-163 K and served as targets. The target ablation was provided by a pulsed 1064 nm or 266 nm laser. For films of thickness up to 100 nm deposited on Si, glass and ITO glass substrates, the Raman and AFM data show presence of the mixed crystalline and amorphous rubrene phases. Agglomerates of rubrene crystals are revealed by SEM observation too, and presence of oxide/peroxide (C42H28O2) in the films is concluded from matrix-assisted laser desorption/ionization time-of-flight spectroscopic analysis.

  3. Anisotropy-based crystalline oxide-on-semiconductor material

    Science.gov (United States)

    McKee, Rodney Allen; Walker, Frederick Joseph

    2000-01-01

    A semiconductor structure and device for use in a semiconductor application utilizes a substrate of semiconductor-based material, such as silicon, and a thin film of a crystalline oxide whose unit cells are capable of exhibiting anisotropic behavior overlying the substrate surface. Within the structure, the unit cells of the crystalline oxide are exposed to an in-plane stain which influences the geometric shape of the unit cells and thereby arranges a directional-dependent quality of the unit cells in a predisposed orientation relative to the substrate. This predisposition of the directional-dependent quality of the unit cells enables the device to take beneficial advantage of characteristics of the structure during operation. For example, in the instance in which the crystalline oxide of the structure is a perovskite, a spinel or an oxide of similarly-related cubic structure, the structure can, within an appropriate semiconductor device, exhibit ferroelectric, piezoelectric, pyroelectric, electro-optic, ferromagnetic, antiferromagnetic, magneto-optic or large dielectric properties that synergistically couple to the underlying semiconductor substrate.

  4. The effects of zinc on cobalt deposition in PWRs: summary report

    International Nuclear Information System (INIS)

    Bennet, Peter

    1996-01-01

    An experiment has been performed in a PWR loop of the Halden reactor to investigate the effects of the addition of 50 ppb zinc to the coolant on the incorporation of cobalt into the oxide films on primary circuit constructional materials. This report summarises the results from the three phases of the test. It was shown that zinc addition inhibits the corrosion of both new metal surfaces and surfaces with well-established oxides; this results in thinner oxide layers and reduced incorporation of cobalt into the oxide. Generally, there were no significant differences between the deposition of cobalt-60 onto pre-oxidised and new metal surfaces. In Phase 1 of the experiment, Co-60 deposition rates (normalised to the circulating Co-60 concentration) were lower than those measured in previous experiments in the loop by factors in the range from 5 to 10. In Phase 2, differences were observed in the behaviour of iron- and nickel-based alloys: larger decreases in the deposition rate compared with Phase 1 took place for stainless steel samples (i.e. factors > 20), whilst decreases on nickel-based coupons were generally less than a factor of 5. Co-60 deposition rates onto stainless steel coupons newly installed for Phase 3 of the experiment were greater by an order of magnitude than on coupons which had been exposed for all three phases; i.e. they were similar to those observed in Phase 1. The mechanisms by which zinc acts to inhibit corrosion and the incorporation of activity into oxide layers are not fully understood. More experimental data are required to resolve this issue, including information on the chemical form of the zinc within the oxide layer. (author)

  5. Indium zinc oxide films deposited on PET by LF magnetron sputtering

    International Nuclear Information System (INIS)

    Kim, Eun Lyoung; Jung, Sang Kooun; Sohn, Sang Ho; Park, Duck Kyu

    2007-01-01

    Indium zinc oxide (IZO) has attracted much attention recently for use in transparent oxide films compared with the ITO film. We carried out the deposition of IZO on a polyethylene terapthalate (PET) substrate at room temperature by a low-frequency (LF) magnetron sputtering system. These films have amorphous structures with excellent electrical stability, surface uniformity and high optical transmittance. The effects of LF applied voltage and O 2 flow rate were investigated. The electrical and optical properties were studied. At optimal deposition conditions, thin films of IZO with a sheet resistance of 32 Ω/sq and an optical transmittance of over 80% in the visible spectrum range were achieved. The IZO thin films fabricated by this method do not require substrate heating during the film preparation of any additional post-deposition annealing treatment. The experimental results show that films with good qualities of surface morphology, transmittance and electrical conduction can be grown by the LF magnetron sputtering method on PET which is recommendable

  6. Silver-zinc electrodeposition from a thiourea solution with added EDTA or HEDTA

    International Nuclear Information System (INIS)

    Oliveira, G.M. de; Carlos, I.A.

    2009-01-01

    This paper shows the study of silver-zinc electrodeposition from a thiourea solution with added (ethylenedinitrilo)tetraacetic acid (EDTA), disodium salt and N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA), trisodium salt. Voltammetric results indicated that silver-zinc alloy can be obtained applying overpotential higher than 0.495 V, in Tu solution containing 1.0 x 10 -1 mol L -1 Zn(NO 3 ) 2 + 2.5 x 10 -2 mol L -1 AgNO 3 . This was due to silver(I) ion complexation with thiourea, which shifted the silver deposition potential to more negative value and due to silver-zinc alloy deposition, which occurred at potentials more positive than the potential to zinc deposition alone. EDTA or HEDTA did not significantly affect the silver and zinc deposition potentials, but decreased the current density for silver-zinc deposition. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses of the silver-zinc deposits showed that the morphology and composition changed as a function of the conditions of deposition, viz, deposition potential (E d ), deposition charge density (q d ) and solution composition (silver, EDTA and HEDTA concentrations). EDS analysis of the deposits showed sulphur (S) incorporated into the silver-zinc deposit, while SEM images showed that this sulphur content seemed to improve the silver-zinc morphology, as did the presence of EDTA and HEDTA in the solution, which enhanced the sulphur incorporation into the silver-zinc deposit. X-ray diffraction (XRD) analysis of the silver-zinc deposit showed that it was amorphous, irrespective of its composition and morphology

  7. Optoelectronic properties of expanding thermal plasma deposited textured zinc oxide : effect of aluminum doping

    NARCIS (Netherlands)

    Groenen, R.; Kieft, E.R.; Linden, J.L.; Sanden, van de M.C.M.

    2006-01-01

    Aluminum-doped zinc oxide films exhibiting a rough surface morphol. are deposited on glass substrates utilizing expanding thermal plasma. Spectroscopic ellipsometry is used to evaluate optical and electronic film properties. The presence of aluminum donors in doped films is confirmed by a shift in

  8. Deposition and surface characterization of nanoparticles of zinc oxide using dense plasma focus device in nitrogen atmosphere

    International Nuclear Information System (INIS)

    Malhotra, Yashi; Srivastava, M P; Roy, Savita

    2010-01-01

    Nanoparticles of zinc oxide from zinc oxide pellets in the nitrogen plasma atmosphere are deposited on n and p type silicon substrates using Dense Plasma Focus device. The hot and dense nitrogen plasma formed during the focus phase ionizes the ZnO pellet, which then move upward in a fountain like shape and gets deposited on substrates which are placed above the top of the anode. Structural and surface properties of the deposited ZnO are investigated using X-ray diffraction and Atomic force microscope (AFM). X-ray spectra shows the diffraction plane (002) of ZnO nanoparticles deposited on Si with few shots in nitrogen atmosphere. AFM investigations revealed that there are nanoparticles of size between 15-80 nm on n-Si and p-Si substrates. The deposition on n-type Si is better than the p-type Si can be seen from AFM images, this may be due to different orientation of silicon.

  9. Polymer/metal oxide hybrid dielectrics for low voltage field-effect transistors with solution-processed, high-mobility semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Held, Martin; Schießl, Stefan P.; Gannott, Florentina [Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen D-91058 (Germany); Institute for Physical Chemistry, Universität Heidelberg, Heidelberg D-69120 (Germany); Miehler, Dominik [Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen D-91058 (Germany); Zaumseil, Jana, E-mail: zaumseil@uni-heidelberg.de [Institute for Physical Chemistry, Universität Heidelberg, Heidelberg D-69120 (Germany)

    2015-08-24

    Transistors for future flexible organic light-emitting diode (OLED) display backplanes should operate at low voltages and be able to sustain high currents over long times without degradation. Hence, high capacitance dielectrics with low surface trap densities are required that are compatible with solution-processable high-mobility semiconductors. Here, we combine poly(methyl methacrylate) (PMMA) and atomic layer deposition hafnium oxide (HfO{sub x}) into a bilayer hybrid dielectric for field-effect transistors with a donor-acceptor polymer (DPPT-TT) or single-walled carbon nanotubes (SWNTs) as the semiconductor and demonstrate substantially improved device performances for both. The ultra-thin PMMA layer ensures a low density of trap states at the semiconductor-dielectric interface while the metal oxide layer provides high capacitance, low gate leakage and superior barrier properties. Transistors with these thin (≤70 nm), high capacitance (100–300 nF/cm{sup 2}) hybrid dielectrics enable low operating voltages (<5 V), balanced charge carrier mobilities and low threshold voltages. Moreover, the hybrid layers substantially improve the bias stress stability of the transistors compared to those with pure PMMA and HfO{sub x} dielectrics.

  10. Atomic layer deposition precursor step repetition and surface plasma pretreatment influence on semiconductor–insulator–semiconductor heterojunction solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Talkenberg, Florian, E-mail: florian.talkenberg@ipht-jena.de; Illhardt, Stefan; Schmidl, Gabriele; Schleusener, Alexander; Sivakov, Vladimir [Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, D-07745 Jena (Germany); Radnóczi, György Zoltán; Pécz, Béla [Centre for Energy Research, Institute of Technical Physics and Materials Science, Konkoly-Thege Miklós u. 29-33, H-1121 Budapest (Hungary); Dikhanbayev, Kadyrjan; Mussabek, Gauhar [Department of Physics and Engineering, al-Farabi Kazakh National University, 71 al-Farabi Ave., 050040 Almaty (Kazakhstan); Gudovskikh, Alexander [Nanotechnology Research and Education Centre, St. Petersburg Academic University, Russian Academy of Sciences, Hlopina Str. 8/3, 194021 St. Petersburg (Russian Federation)

    2015-07-15

    Semiconductor–insulator–semiconductor heterojunction solar cells were prepared using atomic layer deposition (ALD) technique. The silicon surface was treated with oxygen and hydrogen plasma in different orders before dielectric layer deposition. A plasma-enhanced ALD process was applied to deposit dielectric Al{sub 2}O{sub 3} on the plasma pretreated n-type Si(100) substrate. Aluminum doped zinc oxide (Al:ZnO or AZO) was deposited by thermal ALD and serves as transparent conductive oxide. Based on transmission electron microscopy studies the presence of thin silicon oxide (SiO{sub x}) layer was detected at the Si/Al{sub 2}O{sub 3} interface. The SiO{sub x} formation depends on the initial growth behavior of Al{sub 2}O{sub 3} and has significant influence on solar cell parameters. The authors demonstrate that a hydrogen plasma pretreatment and a precursor dose step repetition of a single precursor improve the initial growth behavior of Al{sub 2}O{sub 3} and avoid the SiO{sub x} generation. Furthermore, it improves the solar cell performance, which indicates a change of the Si/Al{sub 2}O{sub 3} interface states.

  11. Rapid deposition process for zinc oxide film applications in pyroelectric devices

    International Nuclear Information System (INIS)

    Hsiao, Chun-Ching; Yu, Shih-Yuan

    2012-01-01

    Aerosol deposition (AD) is a rapid process for the deposition of films. Zinc oxide is a low toxicity and environmentally friendly material, and it possesses properties such as semiconductivity, pyroelectricity and piezoelectricity without the poling process. Therefore, AD is used to accelerate the manufacturing process for applications of ZnO films in pyroelectric devices. Increasing the temperature variation rate in pyroelectric films is a useful method for enhancing the responsivity of pyroelectric devices. In the present study, a porous ZnO film possessing the properties of large heat absorption and high temperature variation rate is successfully produced by the AD rapid process and laser annealing for application in pyroelectric devices. (paper)

  12. Temperature Dependence of the Seebeck Coefficient in Zinc Oxide Thin Films

    Science.gov (United States)

    Noori, Amirreza; Masoumi, Saeed; Hashemi, Najmeh

    2017-12-01

    Thermoelectric devices are reliable tools for converting waste heat into electricity as they last long, produce no noise or vibration, have no moving elements, and their light weight makes them suitable for the outer space usage. Materials with high thermoelectric figure of merit (zT) have the most important role in the fabrication of efficient thermoelectric devices. Metal oxide semiconductors, specially zinc oxide has recently received attention as a material suitable for sensor, optoelectronic and thermoelectric device applications because of their wide direct bandgap, chemical stability, high-energy radiation endurance, transparency and acceptable zT. Understanding the thermoelectric properties of the undoped ZnO thin films can help design better ZnO-based devices. Here, we report the results of our experimental work on the thermoelectric properties of the undoped polycrystalline ZnO thin films. These films are deposited on alumina substrates by thermal evaporation of zinc in vacuum followed by a controlled oxidation process in air carried out at the 350-500 °C temperature range. The experimental setup including gradient heaters, thermometry system and Seebeck voltage measurement equipment for high resistance samples is described. Seebeck voltage and electrical resistivity of the samples are measured at different conditions. The observed temperature dependence of the Seebeck coefficient is discussed.

  13. Preparation of Zinc Oxide (ZnO) Thin Film as Transparent Conductive Oxide (TCO) from Zinc Complex Compound on Thin Film Solar Cells: A Study of O2 Effect on Annealing Process

    Science.gov (United States)

    Muslih, E. Y.; Kim, K. H.

    2017-07-01

    Zinc oxide (ZnO) thin film as a transparent conductive oxide (TCO) for thin film solar cell application was successfully prepared through two step preparations which consisted of deposition by spin coating at 2000 rpm for 10 second and followed by annealing at 500 °C for 2 hours under O2 and ambient atmosphere. Zinc acetate dehydrate was used as a precursor which dissolved in ethanol and acetone (1:1 mol) mixture in order to make a zinc complex compound. In this work, we reported the O2 effect, reaction mechanism, structure, morphology, optical and electrical properties. ZnO thin film in this work shows a single phase of wurtzite, with n-type semiconductor and has band gap, carrier concentration, mobility, and resistivity as 3.18 eV, 1.21 × 10-19cm3, 11 cm2/Vs, 2.35 × 10-3 Ωcm respectively which is suitable for TCO at thin film solar cell.

  14. Influence of the Surface Layer on the Electrochemical Deposition of Metals and Semiconductors into Mesoporous Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Chubenko, E. B., E-mail: eugene.chubenko@gmail.com; Redko, S. V.; Sherstnyov, A. I.; Petrovich, V. A.; Kotov, D. A.; Bondarenko, V. P. [Belarusian State University of Information and RadioElectronics (Belarus)

    2016-03-15

    The influence of the surface layer on the process of the electrochemical deposition of metals and semiconductors into porous silicon is studied. It is shown that the surface layer differs in structure and electrical characteristics from the host porous silicon bulk. It is established that a decrease in the conductivity of silicon crystallites that form the surface layer of porous silicon has a positive effect on the process of the filling of porous silicon with metals and semiconductors. This is demonstrated by the example of nickel and zinc oxide. The effect can be used for the formation of nanocomposite materials on the basis of porous silicon and nanostructures with a high aspect ratio.

  15. Influence of the Surface Layer on the Electrochemical Deposition of Metals and Semiconductors into Mesoporous Silicon

    International Nuclear Information System (INIS)

    Chubenko, E. B.; Redko, S. V.; Sherstnyov, A. I.; Petrovich, V. A.; Kotov, D. A.; Bondarenko, V. P.

    2016-01-01

    The influence of the surface layer on the process of the electrochemical deposition of metals and semiconductors into porous silicon is studied. It is shown that the surface layer differs in structure and electrical characteristics from the host porous silicon bulk. It is established that a decrease in the conductivity of silicon crystallites that form the surface layer of porous silicon has a positive effect on the process of the filling of porous silicon with metals and semiconductors. This is demonstrated by the example of nickel and zinc oxide. The effect can be used for the formation of nanocomposite materials on the basis of porous silicon and nanostructures with a high aspect ratio.

  16. Aqueous starch as a stabilizer in zinc oxide nanoparticle synthesis via laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Zamiri, Reza; Zakaria, Azmi [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor (Malaysia); Ahangar, Hossein Abbastabar [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor (Malaysia); Darroudi, Majid [Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor (Malaysia); Zak, Ali Khorsand [Low Dimensional Material Research Center, Department of Physics, University of Malaya, Kuala Lumpur 50603 (Malaysia); Drummen, Gregor P.C., E-mail: gpcdrummen@bionano-solutions.de [Bionanoscience and Bio-Imaging Program, Cellular Stress and Ageing Program, Bio and Nano-Solutions, D-40472 Duesseldorf (Germany)

    2012-03-05

    Highlights: Black-Right-Pointing-Pointer Zinc oxide nanoparticles were synthesized via LASiS in aqueous starch solution. Black-Right-Pointing-Pointer Nanoparticles of {+-}15 nm are produced with a narrow size distribution. Black-Right-Pointing-Pointer Starch can be used as a template to control nanoparticle size. Black-Right-Pointing-Pointer Starch stabilizes zinc oxide nanoparticles in solution through steric hindrance. - Abstract: Zinc oxide is a semiconductor with exceptional thermal, luminescent and electrical properties, even compared with other semiconducting nanoparticles. Its potential for advanced applications in lasers and light emitting diodes, as bio-imaging agent, in biosensors and as drug delivery vehicles, in ointments, coatings and pigments has pulled zinc oxide into the focus of various scientific and engineering research fields. Recently we started investigating if nanoparticle synthesis via laser ablation in the presence of natural stabilizers allows control over size and shape and constitutes a useful, uncomplicated alternative over conventional synthesis methods. In the current paper, we determined the ability of natural starch to act as a size controller and stabilizer in the preparation of zinc oxide nanoparticles via ablation of a ZnO plate in a starch solution with a nanosecond Q-Switched Nd:YAG pulsed laser at its original wavelength ({lambda} = 1064 nm). Our results show that the particle diameter decreases with increasing laser irradiation time to a mean nanoparticle size of approximately 15 nm with a narrow size distribution. Furthermore, the obtained particle size in starch solution is considerably smaller compared with analogous ZnO nanoparticle synthesis in distilled water. The synthesized and capped nanoparticles retained their photoluminescent properties, but showed blue emission rather than the often reported green luminescence. Evaluation of old preparations compared with freshly made samples showed no agglomeration or

  17. Aqueous starch as a stabilizer in zinc oxide nanoparticle synthesis via laser ablation

    International Nuclear Information System (INIS)

    Zamiri, Reza; Zakaria, Azmi; Ahangar, Hossein Abbastabar; Darroudi, Majid; Zak, Ali Khorsand; Drummen, Gregor P.C.

    2012-01-01

    Highlights: ► Zinc oxide nanoparticles were synthesized via LASiS in aqueous starch solution. ► Nanoparticles of ±15 nm are produced with a narrow size distribution. ► Starch can be used as a template to control nanoparticle size. ► Starch stabilizes zinc oxide nanoparticles in solution through steric hindrance. - Abstract: Zinc oxide is a semiconductor with exceptional thermal, luminescent and electrical properties, even compared with other semiconducting nanoparticles. Its potential for advanced applications in lasers and light emitting diodes, as bio-imaging agent, in biosensors and as drug delivery vehicles, in ointments, coatings and pigments has pulled zinc oxide into the focus of various scientific and engineering research fields. Recently we started investigating if nanoparticle synthesis via laser ablation in the presence of natural stabilizers allows control over size and shape and constitutes a useful, uncomplicated alternative over conventional synthesis methods. In the current paper, we determined the ability of natural starch to act as a size controller and stabilizer in the preparation of zinc oxide nanoparticles via ablation of a ZnO plate in a starch solution with a nanosecond Q-Switched Nd:YAG pulsed laser at its original wavelength (λ = 1064 nm). Our results show that the particle diameter decreases with increasing laser irradiation time to a mean nanoparticle size of approximately 15 nm with a narrow size distribution. Furthermore, the obtained particle size in starch solution is considerably smaller compared with analogous ZnO nanoparticle synthesis in distilled water. The synthesized and capped nanoparticles retained their photoluminescent properties, but showed blue emission rather than the often reported green luminescence. Evaluation of old preparations compared with freshly made samples showed no agglomeration or flocculation, which was reflected in no significant change in the ZnO nanoparticle size and size distribution. Overall

  18. Transformation of Leaf-like Zinc Dendrite in Oxidation and Reduction Cycle

    International Nuclear Information System (INIS)

    Nakata, Akiyoshi; Murayama, Haruno; Fukuda, Katsutoshi; Yamane, Tomokazu; Arai, Hajime; Hirai, Toshiro; Uchimoto, Yoshiharu; Yamaki, Jun-ichi; Ogumi, Zempachi

    2015-01-01

    Highlights: • Leaf-like zinc dendrites change to leaf-like residual oxides at high oxidation current density (10 mA cm −2 ) whereas it completely dissolves at low oxidation current density (1 mA cm −2 ). • Leaf-like residual oxide products is transformed to zinc deposits with particulate morphology, resulting in good rechargeability. • The residual zinc oxide provides sufficient zincate on its reduction, preventing the diffusion-limited condition that causes leaf-like dendrite formation. - Abstract: Zinc is a promising negative electrode material for aqueous battery systems whereas it shows insufficient rechargeability for use in secondary batteries. It has been reported that leaf-like dendrite deposits are often the origin of cell-failure, however, their nature and behavior on discharge (oxidation) - charge (reduction) cycling have been only poorly understood. Here we investigate the transformation of the leaf-like zinc dendrites using ex-situ scanning electron microscopy, X-ray computational tomography and in-situ X-ray diffraction. It is shown that the leaf-like zinc dendrites obtained under diffusion-limited conditions are nearly completely dissolved at a low oxidation current density of 1 mA cm −2 and cause re-evolution of the zinc dendrites. Oxidation at a high current density of 10 mA cm −2 leads to the formation of leaf-like zinc oxide residual products that result in particulate zinc deposits in the following reduction process, enabling good rechargeability. The reaction behavior of this oxide residue is detailed and discussed for the development of long-life zinc electrodes

  19. Novel texturing method for sputtered zinc oxide films prepared at high deposition rate from ceramic tube targets

    Directory of Open Access Journals (Sweden)

    Hüpkes J.

    2011-10-01

    Full Text Available Sputtered and wet-chemically texture etched zinc oxide (ZnO films on glass substrates are regularly applied as transparent front contact in silicon based thin film solar cells. In this study, chemical wet etching in diluted hydrofluoric acid (HF and subsequently in diluted hydrochloric acid (HCl on aluminum doped zinc oxide (ZnO:Al films deposited by magnetron sputtering from ceramic tube targets at high discharge power (~10 kW/m target length is investigated. Films with thickness of around 800 nm were etched in diluted HCl acid and HF acid to achieve rough surface textures. It is found that the etching of the films in both etchants leads to different surface textures. A two steps etching process, which is especially favorable for films prepared at high deposition rate, was systematically studied. By etching first in diluted hydrofluoric acid (HF and subsequently in diluted hydrochloric acid (HCl these films are furnished with a surface texture which is characterized by craters with typical diameter of around 500 − 1000 nm. The resulting surface structure is comparable to etched films sputtered at low deposition rate, which had been demonstrated to be able to achieve high efficiencies in silicon thin film solar cells.

  20. Recent Advances of Solution-Processed Metal Oxide Thin-Film Transistors.

    Science.gov (United States)

    Xu, Wangying; Li, Hao; Xu, Jian-Bin; Wang, Lei

    2018-03-06

    Solution-processed metal oxide thin-film transistors (TFTs) are considered as one of the most promising transistor technologies for future large-area flexible electronics. This review surveys the recent advances in solution-based oxide TFTs, including n-type oxide semiconductors, oxide dielectrics and p-type oxide semiconductors. Firstly, we provide an introduction on oxide TFTs and the TFT configurations and operating principles. Secondly, we present the recent progress in solution-processed n-type transistors, with a special focus on low-temperature and large-area solution processed approaches as well as novel non-display applications. Thirdly, we give a detailed analysis of the state-of-the-art solution-processed oxide dielectrics for low-voltage electronics. Fourthly, we discuss the recent progress in solution-based p-type oxide semiconductors, which will enable the highly desirable future low-cost large-area complementary circuits. Finally, we draw the conclusions and outline the perspectives over the research field.

  1. investigation of the effect of zinc oxide-modified gum arabic on polar ...

    African Journals Online (AJOL)

    BARTH EKWUEME

    Gum Arabic solution, a water-based adhesive, was modified with zinc oxide filler and the formulation was applied on wood, ceramic, glass and textile substrates. A strip of paper was used as a common adherent to all the substrates. Zinc oxide increased the viscosity of 30wt% gum Arabic solution and increased bond ...

  2. Investigation of the effect of zinc oxide-modified gum Arabic on polar ...

    African Journals Online (AJOL)

    Gum Arabic solution, a water-based adhesive, was modified with zinc oxide filler and the formulation was applied on wood, ceramic, glass and textile substrates. A strip of paper was used as a common adherent to all the substrates. Zinc oxide increased the viscosity of 30wt% gum Arabic solution and increased bond ...

  3. Deposition of nanostructured photocatalytic zinc ferrite films using solution precursor plasma spraying

    International Nuclear Information System (INIS)

    Dom, Rekha; Sivakumar, G.; Hebalkar, Neha Y.; Joshi, Shrikant V.; Borse, Pramod H.

    2012-01-01

    Highlights: ► Highly economic solution precursor route capable of producing films/coating even for mass scale production. ► Pure spinel phase ZnFe 2 O 4 porous, immobilized films deposited in single step. ► Parameter optimization yields access to nanostructuring in SPPS method. ► The ecofriendly immobilized ferrite films were active under solar radiation. ► Such magnetic system display advantage w.r.t. recyclability after photocatalyst extraction. -- Abstract: Deposition of pure spinel phase, photocatalytic zinc ferrite films on SS-304 substrates by solution precursor plasma spraying (SPPS) has been demonstrated for the first time. Deposition parameters such as precursor solution pH, concentration, film thickness, plasma power and gun-substrate distance were found to control physico-chemical properties of the film, with respect to their crystallinity, phase purity, and morphology. Alkaline precursor conditions (7 2 O 4 film. Very high/low precursor concentrations yielded mixed phase, less adherent, and highly inhomogeneous thin films. Desired spinel phase was achieved in as-deposited condition under appropriately controlled spray conditions and exhibited a band gap of ∼1.9 eV. The highly porous nature of the films favored its photocatalytic performance as indicated by methylene blue de-coloration under solar radiation. These immobilized films display good potential for visible light photocatalytic applications.

  4. Controlled deposition of functionalized silica coated zinc oxide nano-assemblies at the air/water interface for blood cancer detection

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Chandra Mouli [Biomedical Instrumentation Section, CSIR-National Physical Laboratory, New Delhi 110012 (India); Nanobioelectronics Laboratory, Department of Biotechnology, Delhi Technological University, Delhi 110042 (India); Dewan, Srishti [Biomedical Instrumentation Section, CSIR-National Physical Laboratory, New Delhi 110012 (India); Biomedical Engineering Department, Deenbandhu Chhotu Ram University of Science & Technology, Haryana 131039 (India); Chawla, Seema [Biomedical Engineering Department, Deenbandhu Chhotu Ram University of Science & Technology, Haryana 131039 (India); Yadav, Birendra Kumar [Rajiv Gandhi Cancer Institute and Research Centre, Rohini, Delhi 110085 (India); Sumana, Gajjala, E-mail: sumanagajjala@gmail.com [Biomedical Instrumentation Section, CSIR-National Physical Laboratory, New Delhi 110012 (India); Malhotra, Bansi Dhar, E-mail: bansi.malhotra@gmail.com [Biomedical Instrumentation Section, CSIR-National Physical Laboratory, New Delhi 110012 (India); Nanobioelectronics Laboratory, Department of Biotechnology, Delhi Technological University, Delhi 110042 (India)

    2016-09-21

    We report results of the studies relating to controlled deposition of the amino-functionalized silica-coated zinc oxide (Am-Si@ZnO) nano-assemblies onto an indium tin oxide (ITO) coated glass substrate using Langmuir-Blodgett (LB) technique. The monolayers have been deposited by transferring the spread solution of Am-Si@ZnO stearic acid prepared in chloroform at the air-water interface, at optimized pressure (16 mN/m), concentration (10 mg/ml) and temperature (23 °C). The high-resolution transmission electron microscopic studies of the Am-Si@ZnO nanocomposite reveal that the nanoparticles have a microscopic structure comprising of hexagonal assemblies of ZnO with typical dimensions of 30 nm. The surface morphology of the LB multilayer observed by scanning electron microscopy shows uniform surface of the Am-Si@ZnO film in the nanometer range (<80 nm). These electrodes have been utilized for chronic myelogenous leukemia (CML) detection by covalently immobilizing the amino-terminated oligonucleotide probe sequence via glutaraldehyde as a crosslinker. The response studies of these fabricated electrodes carried out using electrochemical impedance spectroscopy show that this Am-Si@ZnO LB film based nucleic acid sensor exhibits a linear response to complementary DNA (10{sup −6}–10{sup −16} M) with a detection limit of 1 × 10{sup −16} M. This fabricated platform is validated with clinical samples of CML positive patients and the results demonstrate its immense potential for clinical diagnosis. - Graphical abstract: Controlled deposition of functionalized silica coated zinc oxide nano-assemblies at the air/water interface for label free electrochemical detection of chronic myelogenous leukemia. - Highlights: • Stable and controlled deposition of Am-Si@ZnO nano-assemblies using LB technique. • Uniform monolayer deposition of the Am-Si@ZnO LB film within the nanometer range. • Am-Si@ZnO LB film shows enhanced electrochemical properties. • Fabricated

  5. Zinc-oxide-based sorbents and processes for preparing and using same

    Science.gov (United States)

    Gangwal, Santosh Kumar; Turk, Brian Scott; Gupta, Raghubir Prasael

    2010-03-23

    Zinc oxide-based sorbents, and processes for preparing and using them are provided. The sorbents are preferably used to remove one or more reduced sulfur species from gas streams. The sorbents comprise an active zinc component, optionally in combination with one or more promoter components and/or one or more substantially inert components. The active zinc component is a two phase material, consisting essentially of a zinc oxide (ZnO) phase and a zinc aluminate (ZnAl.sub.2O.sub.4) phase. Each of the two phases is characterized by a relatively small crystallite size of typically less than about 500 Angstroms. Preferably the sorbents are prepared by converting a precursor mixture, comprising a precipitated zinc oxide precursor and a precipitated aluminum oxide precursor, to the two-phase, active zinc oxide containing component.

  6. Chemical solution deposition of functional oxide thin films

    CERN Document Server

    Schneller, Theodor; Kosec, Marija

    2014-01-01

    Chemical Solution Deposition (CSD) is a highly-flexible and inexpensive technique for the fabrication of functional oxide thin films. Featuring nearly 400 illustrations, this text covers all aspects of the technique.

  7. Interfacial electron transfer dynamics of photosensitized zinc oxide nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Murakoshi, Kei; Yanagida, Shozo [Osaka Univ. (Japan). Graduate School of Engineering; Capel, M. [Brookhaven National Lab., Upton, NY (United States)] [and others

    1997-06-01

    The authors have prepared and characterized photosensitized zinc oxide (ZnO) nanoclusters, dispersed in methanol, using carboxylated coumarin dyes for surface adsorption. Femtosecond time-resolved emission spectroscopy allows the authors to measure the photo-induced charge carrier injection rate constant from the adsorbed photosensitizer to the n-type semiconductor nanocluster. These results are compared with other photosensitized semiconductors.

  8. Directed spatial organization of zinc oxide nanostructures

    Science.gov (United States)

    Hsu, Julia [Albuquerque, NM; Liu, Jun [Richland, WA

    2009-02-17

    A method for controllably forming zinc oxide nanostructures on a surface via an organic template, which is formed using a stamp prepared from pre-defined relief structures, inking the stamp with a solution comprising self-assembled monolayer (SAM) molecules, contacting the stamp to the surface, such as Ag sputtered on Si, and immersing the surface with the patterned SAM molecules with a zinc-containing solution with pH control to form zinc oxide nanostructures on the bare Ag surface.

  9. Cu2O-based solar cells using oxide semiconductors

    International Nuclear Information System (INIS)

    Minami, Tadatsugu; Nishi, Yuki; Miyata, Toshihiro

    2016-01-01

    We describe significant improvements of the photovoltaic properties that were achieved in Al-doped ZnO (AZO)/n-type oxide semiconductor/p-type Cu 2 O heterojunction solar cells fabricated using p-type Cu 2 O sheets prepared by thermally oxidizing Cu sheets. The multicomponent oxide thin film used as the n-type semiconductor layer was prepared with various chemical compositions on non-intentionally heated Cu 2 O sheets under various deposition conditions using a pulsed laser deposition method. In Cu 2 O-based heterojunction solar cells fabricated using various ternary compounds as the n-type oxide thin-film layer, the best photovoltaic performance was obtained with an n-ZnGa 2 O 4 thin-film layer. In most of the Cu 2 O-based heterojunction solar cells using multicomponent oxides composed of combinations of various binary compounds, the obtained photovoltaic properties changed gradually as the chemical composition was varied. However, with the ZnO-MgO and Ga 2 O 3 -Al 2 O 3 systems, higher conversion efficiencies (η) as well as a high open circuit voltage (V oc ) were obtained by using a relatively small amount of MgO or Al 2 O 3 , e.g., (ZnO) 0.91 –(MgO) 0.09 and (Ga 2 O 3 ) 0.975 –(Al 2 O 3 ) 0.025 , respectively. When Cu 2 O-based heterojunction solar cells were fabricated using Al 2 O 3 –Ga 2 O 3 –MgO–ZnO (AGMZO) multicomponent oxide thin films deposited with metal atomic ratios of 10, 60, 10 and 20 at.% for the Al, Ga, Mg and Zn, respectively, a high V oc of 0.98 V and an η of 4.82% were obtained. In addition, an enhanced η and an improved fill factor could be achieved in AZO/n-type multicomponent oxide/p-type Cu 2 O heterojunction solar cells fabricated using Na-doped Cu 2 O (Cu 2 O:Na) sheets that featured a resistivity controlled by optimizing the post-annealing temperature and duration. Consequently, an η of 6.25% and a V oc of 0.84 V were obtained in a MgF 2 /AZO/n-(Ga 2 O 3 –Al 2 O 3 )/p-Cu 2 O:Na heterojunction solar cell fabricated using

  10. Cu2O-based solar cells using oxide semiconductors

    Science.gov (United States)

    Minami, Tadatsugu; Nishi, Yuki; Miyata, Toshihiro

    2016-01-01

    We describe significant improvements of the photovoltaic properties that were achieved in Al-doped ZnO (AZO)/n-type oxide semiconductor/p-type Cu2O heterojunction solar cells fabricated using p-type Cu2O sheets prepared by thermally oxidizing Cu sheets. The multicomponent oxide thin film used as the n-type semiconductor layer was prepared with various chemical compositions on non-intentionally heated Cu2O sheets under various deposition conditions using a pulsed laser deposition method. In Cu2O-based heterojunction solar cells fabricated using various ternary compounds as the n-type oxide thin-film layer, the best photovoltaic performance was obtained with an n-ZnGa2O4 thin-film layer. In most of the Cu2O-based heterojunction solar cells using multicomponent oxides composed of combinations of various binary compounds, the obtained photovoltaic properties changed gradually as the chemical composition was varied. However, with the ZnO-MgO and Ga2O3-Al2O3 systems, higher conversion efficiencies (η) as well as a high open circuit voltage (Voc) were obtained by using a relatively small amount of MgO or Al2O3, e.g., (ZnO)0.91-(MgO)0.09 and (Ga2O3)0.975-(Al2O3)0.025, respectively. When Cu2O-based heterojunction solar cells were fabricated using Al2O3-Ga2O3-MgO-ZnO (AGMZO) multicomponent oxide thin films deposited with metal atomic ratios of 10, 60, 10 and 20 at.% for the Al, Ga, Mg and Zn, respectively, a high Voc of 0.98 V and an η of 4.82% were obtained. In addition, an enhanced η and an improved fill factor could be achieved in AZO/n-type multicomponent oxide/p-type Cu2O heterojunction solar cells fabricated using Na-doped Cu2O (Cu2O:Na) sheets that featured a resistivity controlled by optimizing the post-annealing temperature and duration. Consequently, an η of 6.25% and a Voc of 0.84 V were obtained in a MgF2/AZO/n-(Ga2O3-Al2O3)/p-Cu2O:Na heterojunction solar cell fabricated using a Cu2O:Na sheet with a resistivity of approximately 10 Ω·cm and a (Ga0.975Al0

  11. Deposit heterogeneity and the dynamics of the organic semiconductors P3HT and PCBM solution under evaporation

    Science.gov (United States)

    Yu, H. P.; Luo, H.; Liu, T. T.; Jing, G. Y.

    2015-04-01

    The formation of organic semiconductor layer is the key procedure in the manufacture of organic photovoltaic solar cell, in which the natural evaporation of the solvent from the polymer solution plays the essential role for the conversion efficiency. Here, poly(3-hexylthiophene) (P3HT) and fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), as two types of semiconductor polymers, were selected as the active layer to form the deposit by drying the blend solution drops on the substrate. We explored the influences of droplet size and solute concentration on the homogeneity of the deposit. Additionally, the spatial distribution of molecular chains and grains and the instability of the droplet morphology during the drying were investigated. The results showed that the "coffee-ring" phenomenon occurred forming an annular deposit at the outermost edge and the width of the annular ring increased linearly with the concentration of the P3HT solution, until a saturation plateau is approached. On the other hand, the PCBM deposition presented a circular disk at low concentration, but displayed a sudden instability for an irregular perimeter at a critical concentration and there existed a second critical concentration above which the deposit exhibited the return of the stable circular shape. The results have an instructive impact on the performance of the device and the formation of fine structures during the process of printing, film preparation and painting.

  12. Thin film complementary metal oxide semiconductor (CMOS) device using a single-step deposition of the channel layer

    KAUST Repository

    Nayak, Pradipta K.; Caraveo-Frescas, J. A.; Wang, Zhenwei; Hedhili, Mohamed N.; Wang, Q. X.; Alshareef, Husam N.

    2014-01-01

    We report, for the first time, the use of a single step deposition of semiconductor channel layer to simultaneously achieve both n-and p-type transport in transparent oxide thin film transistors (TFTs). This effect is achieved by controlling

  13. Metal oxide semiconductor thin-film transistors for flexible electronics

    Energy Technology Data Exchange (ETDEWEB)

    Petti, Luisa; Vogt, Christian; Büthe, Lars; Cantarella, Giuseppe; Tröster, Gerhard [Electronics Laboratory, Swiss Federal Institute of Technology, Zürich (Switzerland); Münzenrieder, Niko [Electronics Laboratory, Swiss Federal Institute of Technology, Zürich (Switzerland); Sensor Technology Research Centre, University of Sussex, Falmer (United Kingdom); Faber, Hendrik; Bottacchi, Francesca; Anthopoulos, Thomas D. [Department of Physics and Centre for Plastic Electronics, Imperial College London, London (United Kingdom)

    2016-06-15

    The field of flexible electronics has rapidly expanded over the last decades, pioneering novel applications, such as wearable and textile integrated devices, seamless and embedded patch-like systems, soft electronic skins, as well as imperceptible and transient implants. The possibility to revolutionize our daily life with such disruptive appliances has fueled the quest for electronic devices which yield good electrical and mechanical performance and are at the same time light-weight, transparent, conformable, stretchable, and even biodegradable. Flexible metal oxide semiconductor thin-film transistors (TFTs) can fulfill all these requirements and are therefore considered the most promising technology for tomorrow's electronics. This review reflects the establishment of flexible metal oxide semiconductor TFTs, from the development of single devices, large-area circuits, up to entirely integrated systems. First, an introduction on metal oxide semiconductor TFTs is given, where the history of the field is revisited, the TFT configurations and operating principles are presented, and the main issues and technological challenges faced in the area are analyzed. Then, the recent advances achieved for flexible n-type metal oxide semiconductor TFTs manufactured by physical vapor deposition methods and solution-processing techniques are summarized. In particular, the ability of flexible metal oxide semiconductor TFTs to combine low temperature fabrication, high carrier mobility, large frequency operation, extreme mechanical bendability, together with transparency, conformability, stretchability, and water dissolubility is shown. Afterward, a detailed analysis of the most promising metal oxide semiconducting materials developed to realize the state-of-the-art flexible p-type TFTs is given. Next, the recent progresses obtained for flexible metal oxide semiconductor-based electronic circuits, realized with both unipolar and complementary technology, are reported. In

  14. Short-Term Synaptic Plasticity Regulation in Solution-Gated Indium-Gallium-Zinc-Oxide Electric-Double-Layer Transistors.

    Science.gov (United States)

    Wan, Chang Jin; Liu, Yang Hui; Zhu, Li Qiang; Feng, Ping; Shi, Yi; Wan, Qing

    2016-04-20

    In the biological nervous system, synaptic plasticity regulation is based on the modulation of ionic fluxes, and such regulation was regarded as the fundamental mechanism underlying memory and learning. Inspired by such biological strategies, indium-gallium-zinc-oxide (IGZO) electric-double-layer (EDL) transistors gated by aqueous solutions were proposed for synaptic behavior emulations. Short-term synaptic plasticity, such as paired-pulse facilitation, high-pass filtering, and orientation tuning, was experimentally emulated in these EDL transistors. Most importantly, we found that such short-term synaptic plasticity can be effectively regulated by alcohol (ethyl alcohol) and salt (potassium chloride) additives. Our results suggest that solution gated oxide-based EDL transistors could act as the platforms for short-term synaptic plasticity emulation.

  15. High Mobility Thin Film Transistors Based on Amorphous Indium Zinc Tin Oxide

    Directory of Open Access Journals (Sweden)

    Imas Noviyana

    2017-06-01

    Full Text Available Top-contact bottom-gate thin film transistors (TFTs with zinc-rich indium zinc tin oxide (IZTO active layer were prepared at room temperature by radio frequency magnetron sputtering. Sintered ceramic target was prepared and used for deposition from oxide powder mixture having the molar ratio of In2O3:ZnO:SnO2 = 2:5:1. Annealing treatment was carried out for as-deposited films at various temperatures to investigate its effect on TFT performances. It was found that annealing treatment at 350 °C for 30 min in air atmosphere yielded the best result, with the high field effect mobility value of 34 cm2/Vs and the minimum subthreshold swing value of 0.12 V/dec. All IZTO thin films were amorphous, even after annealing treatment of up to 350 °C.

  16. UV protective zinc oxide coating for biaxially oriented polypropylene packaging film by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lahtinen, Kimmo, E-mail: kimmo.lahtinen@lut.fi [ASTRaL, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland); Kääriäinen, Tommi, E-mail: tommi.kaariainen@colorado.edu [ASTRaL, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland); Johansson, Petri, E-mail: petri.johansson@tut.fi [Paper Converting and Packaging Technology, Tampere University of Technology, P.O.Box 589, FI-33101 Tampere (Finland); Kotkamo, Sami, E-mail: sami.kotkamo@tut.fi [Paper Converting and Packaging Technology, Tampere University of Technology, P.O.Box 589, FI-33101 Tampere (Finland); Maydannik, Philipp, E-mail: philipp.maydannik@lut.fi [ASTRaL, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland); Seppänen, Tarja, E-mail: tarja.seppanen@lut.fi [ASTRaL, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland); Kuusipalo, Jurkka, E-mail: jurkka.kuusipalo@tut.fi [Paper Converting and Packaging Technology, Tampere University of Technology, P.O.Box 589, FI-33101 Tampere (Finland); Cameron, David C., E-mail: david.cameron@miktech.fi [ASTRaL, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland)

    2014-11-03

    Biaxially oriented polypropylene (BOPP) packaging film was coated with zinc oxide (ZnO) coatings by atomic layer deposition (ALD) in order to protect the film from UV degradation. The coatings were made at a process temperature of 100 °C using diethylzinc and water as zinc and oxygen precursors, respectively. The UV protective properties of the coatings were tested by using UV–VIS and infrared spectrometry, differential scanning calorimetry (DSC) and a mechanical strength tester, which characterised the tensile and elastic properties of the film. The results obtained with 36 and 67 nm ZnO coatings showed that the ZnO UV protective layer is able to provide a significant decrease in photodegradation of the BOPP film under UV exposure. While the uncoated BOPP film suffered a complete degradation after a 4-week UV exposure, the 67 nm ZnO coated BOPP film was able to preserve half of its original tensile strength and 1/3 of its elongation at break after a 6-week exposure period. The infrared analysis and DSC measurements further proved the UV protection of the ZnO coatings. The results show that a nanometre scale ZnO coating deposited by ALD is a promising option when a transparent UV protection layer is sought for polymer substrates. - Highlights: • Atomic layer deposited zinc oxide coatings were used as UV protection layers. • Biaxially oriented polypropylene (BOPP) film was well protected against UV light. • Formation of UV degradation products in BOPP was significantly reduced. • Mechanical properties of the UV exposed BOPP film were significantly improved.

  17. Plasma-assisted atomic layer deposition of TiN/Al2O3 stacks for metal-oxide-semiconductor capacitor applications

    NARCIS (Netherlands)

    Hoogeland, D.; Jinesh, K.B.; Roozeboom, F.; Besling, W.F.A.; Sanden, van de M.C.M.; Kessels, W.M.M.

    2009-01-01

    By employing plasma-assisted atomic layer deposition, thin films of Al2O3 and TiN are subsequently deposited in a single reactor at a single substrate temperature with the objective of fabricating high-quality TiN/Al2O3 / p-Si metal-oxide-semiconductor capacitors. Transmission electron microscopy

  18. Large-Area Chemical Vapor Deposited MoS2 with Transparent Conducting Oxide Contacts toward Fully Transparent 2D Electronics

    KAUST Repository

    Dai, Zhenyu

    2017-09-08

    2D semiconductors are poised to revolutionize the future of electronics and photonics, much like transparent oxide conductors and semiconductors have revolutionized the display industry. Herein, these two types of materials are combined to realize fully transparent 2D electronic devices and circuits. Specifically, a large-area chemical vapor deposition process is developed to grow monolayer MoS2 continuous films, which are, for the first time, combined with transparent conducting oxide (TCO) contacts. Transparent conducting aluminum doped zinc oxide contacts are deposited by atomic layer deposition, with composition tuning to achieve optimal conductivity and band-offsets with MoS2. The optimized process gives fully transparent TCO/MoS2 2D electronics with average visible-range transmittance of 85%. The transistors show high mobility (4.2 cm2 V−1 s−1), fast switching speed (0.114 V dec−1), very low threshold voltage (0.69 V), and large switching ratio (4 × 108). To our knowledge, these are the lowest threshold voltage and subthreshold swing values reported for monolayer chemical vapor deposition MoS2 transistors. The transparent inverters show fast switching properties with a gain of 155 at a supply voltage of 10 V. The results demonstrate that transparent conducting oxides can be used as contact materials for 2D semiconductors, which opens new possibilities in 2D electronic and photonic applications.

  19. Solvothermal synthesis of gallium-indium-zinc-oxide nanoparticles for electrolyte-gated transistors.

    Science.gov (United States)

    Santos, Lídia; Nunes, Daniela; Calmeiro, Tomás; Branquinho, Rita; Salgueiro, Daniela; Barquinha, Pedro; Pereira, Luís; Martins, Rodrigo; Fortunato, Elvira

    2015-01-14

    Solution-processed field-effect transistors are strategic building blocks when considering low-cost sustainable flexible electronics. Nevertheless, some challenges (e.g., processing temperature, reliability, reproducibility in large areas, and cost effectiveness) are requirements that must be surpassed in order to achieve high-performance transistors. The present work reports electrolyte-gated transistors using as channel layer gallium-indium-zinc-oxide nanoparticles produced by solvothermal synthesis combined with a solid-state electrolyte based on aqueous dispersions of vinyl acetate stabilized with cellulose derivatives, acrylic acid ester in styrene and lithium perchlorate. The devices fabricated using this approach display a ION/IOFF up to 1 × 10(6), threshold voltage (VTh) of 0.3-1.9 V, and mobility up to 1 cm(2)/(V s), as a function of gallium-indium-zinc-oxide ink formulation and two different annealing temperatures. These results validates the usage of electrolyte-gated transistors as a viable and promising alternative for nanoparticle based semiconductor devices as the electrolyte improves the interface and promotes a more efficient step coverage of the channel layer, reducing the operating voltage when compared with conventional dielectrics gating. Moreover, it is shown that by controlling the applied gate potential, the operation mechanism of the electrolyte-gated transistors can be modified from electric double layer to electrochemical doping.

  20. Thin film complementary metal oxide semiconductor (CMOS) device using a single-step deposition of the channel layer

    KAUST Repository

    Nayak, Pradipta K.

    2014-04-14

    We report, for the first time, the use of a single step deposition of semiconductor channel layer to simultaneously achieve both n-and p-type transport in transparent oxide thin film transistors (TFTs). This effect is achieved by controlling the concentration of hydroxyl groups (OH-groups) in the underlying gate dielectrics. The semiconducting tin oxide layer was deposited at room temperature, and the maximum device fabrication temperature was 350C. Both n and p-type TFTs showed fairly comparable performance. A functional CMOS inverter was fabricated using this novel scheme, indicating the potential use of our approach for various practical applications.

  1. Layer-by-layer deposition of zirconium oxide films from aqueous solutions for friction reduction in silicon-based microelectromechanical system devices

    International Nuclear Information System (INIS)

    Liu Junfu; Nistorica, Corina; Gory, Igor; Skidmore, George; Mantiziba, Fadziso M.; Gnade, Bruce E.

    2005-01-01

    This work reports layer-by-layer deposition of zirconium oxide on a Si surface from aqueous solutions using the successive ionic layer adsorption and reaction technique. The process consists of repeated cycles of adsorption of zirconium precursors, water rinse, and hydrolysis. The film composition was determined by X-ray photoelectron spectroscopy. The film thickness was determined by Rutherford backscattering spectrometry, by measuring the Zr atom concentration. The average deposition rate from a 0.1 M Zr(SO 4 ) 2 solution on a SiO 2 /Si surface is 0.62 nm per cycle. Increasing the acidity of the zirconium precursor solution inhibits the deposition of the zirconium oxide film. Atomic force microscopy shows that the zirconium oxide film consists of nanoparticles of 10-50 nm in the lateral dimension. The surface roughness increased with increasing number of deposition cycles. Friction measurements made with a microelectromechanical system device reveal a reduction of 45% in the friction coefficient of zirconium oxide-coated surfaces vs. uncoated surfaces in air

  2. Thickness dependent growth of low temperature atomic layer deposited zinc oxide films

    International Nuclear Information System (INIS)

    Montiel-González, Z.; Castelo-González, O.A.; Aguilar-Gama, M.T.; Ramírez-Morales, E.; Hu, H.

    2017-01-01

    Highlights: • Polycrystalline columnar ZnO thin films deposited by ALD at low temperatures. • Higher deposition temperature leads to a greater surface roughness in the ALD ZnO films. • Higher temperature originates larger refractive index values of the ALD ZnO films. • ZnO thin films were denser as the numbers of ALD deposition cycles were larger. • XPS analysis revels mayor extent of the DEZ reaction during the ALD process. - Abstract: Zinc oxide films are promising to improve the performance of electronic devices, including those based on organic materials. However, the dependence of the ZnO properties on the preparation conditions represents a challenge to obtain homogeneous thin films that satisfy specific applications. Here, we prepared ZnO films of a wide range of thicknesses by atomic layer deposition (ALD) at relatively low temperatures, 150 and 175 °C. From the results of X-ray photoelectron spectroscopy, X-ray diffraction and Spectroscopic Ellipsometry it is concluded that the polycrystalline structure of the wurtzite is the main phase of the ALD samples, with OH groups on their surface. Ellipsometry revealed that the temperature and the deposition cycles have a strong effect on the films roughness. Scanning electron micrographs evidenced such effect, through the large pyramids developed at the surface of the films. It is concluded that crystalline ZnO thin films within a broad range of thickness and roughness can be obtained for optic or optoelectronic applications.

  3. Transparent Oxide Semiconductors for Emerging Electronics

    KAUST Repository

    Caraveo-Frescas, Jesus Alfonso

    2013-11-01

    Transparent oxide electronics have emerged as promising materials to shape the future of electronics. While several n-type oxides have been already studied and demonstrated feasibility to be used as active materials in thin film transistors, high performance p-type oxides have remained elusive. This dissertation is devoted to the study of transparent p-type oxide semiconductor tin monoxide and its use in the fabrication of field effect devices. A complete study on the deposition of tin monoxide thin films by direct current reactive magnetron sputtering is performed. Carrier density, carrier mobility and conductivity are studied over a set of deposition conditions where p-type conduction is observed. Density functional theory simulations are performed in order to elucidate the effect of native defects on carrier mobility. The findings on the electrical properties of SnO thin films are then translated to the fabrication of thin films transistors. The low processing temperature of tin monoxide thin films below 200 oC is shown advantageous for the fabrication of fully transparent and flexible thin film transistors. After careful device engineering, including post deposition annealing temperature, gate dielectric material, semiconductor thickness and source and drain electrodes material, thin film transistors with record device performance are demonstrated, achieving a field effect mobility >6.7 cm2V-1s-1. Device performance is further improved to reach a field effect mobility of 10.8 cm2V-1s-1 in SnO nanowire field effect transistors fabricated from the sputtered SnO thin films and patterned by electron beam lithography. Downscaling device dimension to nano scale is shown beneficial for SnO field effect devices not only by achieving a higher hole mobility but enhancing the overall device performance including better threshold voltage, subthreshold swing and lower number of interfacial defects. Use of p-type semiconductors in nonvolatile memory applications is then

  4. Atomic layer deposition: an enabling technology for the growth of functional nanoscale semiconductors

    Science.gov (United States)

    Biyikli, Necmi; Haider, Ali

    2017-09-01

    In this paper, we present the progress in the growth of nanoscale semiconductors grown via atomic layer deposition (ALD). After the adoption by semiconductor chip industry, ALD became a widespread tool to grow functional films and conformal ultra-thin coatings for various applications. Based on self-limiting and ligand-exchange-based surface reactions, ALD enabled the low-temperature growth of nanoscale dielectric, metal, and semiconductor materials. Being able to deposit wafer-scale uniform semiconductor films at relatively low-temperatures, with sub-monolayer thickness control and ultimate conformality, makes ALD attractive for semiconductor device applications. Towards this end, precursors and low-temperature growth recipes are developed to deposit crystalline thin films for compound and elemental semiconductors. Conventional thermal ALD as well as plasma-assisted and radical-enhanced techniques have been exploited to achieve device-compatible film quality. Metal-oxides, III-nitrides, sulfides, and selenides are among the most popular semiconductor material families studied via ALD technology. Besides thin films, ALD can grow nanostructured semiconductors as well using either template-assisted growth methods or bottom-up controlled nucleation mechanisms. Among the demonstrated semiconductor nanostructures are nanoparticles, nano/quantum-dots, nanowires, nanotubes, nanofibers, nanopillars, hollow and core-shell versions of the afore-mentioned nanostructures, and 2D materials including transition metal dichalcogenides and graphene. ALD-grown nanoscale semiconductor materials find applications in a vast amount of applications including functional coatings, catalysis and photocatalysis, renewable energy conversion and storage, chemical sensing, opto-electronics, and flexible electronics. In this review, we give an overview of the current state-of-the-art in ALD-based nanoscale semiconductor research including the already demonstrated and future applications.

  5. Electrochemical and hydrothermal deposition of ZnO on silicon: from continuous films to nanocrystals

    International Nuclear Information System (INIS)

    Balucani, M.; Nenzi, P.; Chubenko, E.; Klyshko, A.; Bondarenko, V.

    2011-01-01

    This article presents the study of the electrochemical deposition of zinc oxide from the non-aqueous solution based on dimethyl sulfoxide and zinc chloride into the porous silicon matrix. The features of the deposition process depending on the thickness of the porous silicon layer are presented. It is shown that after deposition process the porous silicon matrix is filled with zinc oxide nanocrystals with a diameter of 10–50 nm. The electrochemically deposited zinc oxide layers on top of porous silicon are shown to have a crystalline structure. It is also shown that zinc oxide crystals formed by hydrothermal method on the surface of electrochemically deposited zinc oxide film demonstrate ultra-violet luminescence. The effect of the porous silicon layer thickness on the morphology of the zinc oxide is shown. The structures obtained demonstrated two luminescence bands peaking at the 375 and 600 nm wavelengths. Possible applications of ZnO nanostructures, porous and continuous polycrystalline ZnO films such as gas sensors, light-emitting diodes, photovoltaic devices, and nanopiezo energy generators are considered. Aspects of integration with conventional silicon technology are also discussed.

  6. The properties of samarium-doped zinc oxide/phthalocyanine structure for optoelectronics prepared by pulsed laser deposition and organic molecular evaporation

    Czech Academy of Sciences Publication Activity Database

    Novotný, Michal; Marešová, Eva; Fitl, Přemysl; Vlček, Jan; Bergmann, M.; Vondráček, Martin; Yatskiv, Roman; Bulíř, Jiří; Hubík, Pavel; Hruška, Petr; Drahokoupil, Jan; Abdellaoui, N.; Vrňata, M.; Lančok, Ján

    2016-01-01

    Roč. 122, č. 3 (2016), 1-8, č. článku 225. ISSN 0947-8396 R&D Projects: GA MŠk(CZ) LG15050; GA ČR(CZ) GAP108/11/0958; GA MŠk(CZ) LM2011029; GA ČR(CZ) GA14-10279S; GA MŠk(CZ) 7AMB14FR010 Institutional support: RVO:68378271 ; RVO:67985882 Keywords : samarium-doped zinc oxide zinc/phthalocyanine deposition * evaporation * pulsed laser deposition * thin films Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.455, year: 2016

  7. P-type thin films transistors with solution-deposited lead sulfide films as semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Carrillo-Castillo, A.; Salas-Villasenor, A.; Mejia, I. [Department of Materials Science and Engineering, The University of Texas at Dallas. 800 West Campbell Rd, Richardson, TX 75083 (United States); Aguirre-Tostado, S. [Centro de Investigacion en Materiales Avanzados, S. C. Alianza Norte 202, Parque de Investigacion e Innovacion Tecnologica, Apodaca, Nuevo Leon, C.P. 666000 (Mexico); Gnade, B.E. [Department of Materials Science and Engineering, University of Texas at Dallas. 800 West Campbell Rd, Richardson, TX 75083 (United States); Quevedo-Lopez, M.A., E-mail: mxq071000@utdallas.edu [Department of Materials Science and Engineering, University of Texas at Dallas. 800 West Campbell Rd, Richardson, TX 75083 (United States)

    2012-01-31

    In this paper we demonstrate p-type thin film transistors fabricated with lead sulfide (PbS) as semiconductor deposited by chemical bath deposition methods. Crystallinity and morphology of the resulting PbS films were characterized using X-ray diffraction, atomic force microscopy and scanning electron microscopy. Devices were fabricated using photolithographic processes in a bottom gate configuration with Au as source and drain top contacts. Field effect mobility for as-fabricated devices was {approx} 0.09 cm{sup 2} V{sup -1} s{sup -1} whereas the mobility for devices annealed at 150 Degree-Sign C/h in forming gas increased up to {approx} 0.14 cm{sup 2} V{sup -1} s{sup -1}. Besides the thermal annealing, the entire fabrications process was maintained below 100 Degree-Sign C. The electrical performance of the PbS-thin film transistors was studied before and after the 150 Degree-Sign C anneal as well as a function of the PbS active layer thicknesses. - Highlights: Black-Right-Pointing-Pointer Thin film transistors with PbS as semiconductor deposited by chemical bath deposition. Black-Right-Pointing-Pointer Photolithography-based thin film transistors with PbS films at low temperatures. Black-Right-Pointing-Pointer Electron mobility for anneal-PbS devices of {approx} 0.14 cm{sup 2} V{sup -1} s{sup -1}. Black-Right-Pointing-Pointer Highest mobility reported in thin film transistors with PbS as the semiconductor.

  8. Low-Concentration Indium Doping in Solution-Processed Zinc Oxide Films for Thin-Film Transistors

    Directory of Open Access Journals (Sweden)

    Xue Zhang

    2017-07-01

    Full Text Available We investigated the influence of low-concentration indium (In doping on the chemical and structural properties of solution-processed zinc oxide (ZnO films and the electrical characteristics of bottom-gate/top-contact In-doped ZnO thin-film transistors (TFTs. The thermogravimetry and differential scanning calorimetry analysis results showed that thermal annealing at 400 °C for 40 min produces In-doped ZnO films. As the In content of ZnO films was increased from 1% to 9%, the metal-oxygen bonding increased from 5.56% to 71.33%, while the metal-hydroxyl bonding decreased from 72.03% to 9.63%. The X-ray diffraction peaks and field-emission scanning microscope images of the ZnO films with different In concentrations revealed a better crystalline quality and reduced grain size of the solution-processed ZnO thin films. The thickness of the In-doped ZnO films also increased when the In content was increased up to 5%; however, the thickness decreased on further increasing the In content. The field-effect mobility and on/off current ratio of In-doped ZnO TFTs were notably affected by any change in the In concentration. Considering the overall TFT performance, the optimal In doping concentration in the solution-processed ZnO semiconductor was determined to be 5% in this study. These results suggest that low-concentration In incorporation is crucial for modulating the morphological characteristics of solution-processed ZnO thin films and the TFT performance.

  9. Review of recent progresses on flexible oxide semiconductor thin film transistors based on atomic layer deposition processes

    Science.gov (United States)

    Sheng, Jiazhen; Han, Ki-Lim; Hong, TaeHyun; Choi, Wan-Ho; Park, Jin-Seong

    2018-01-01

    The current article is a review of recent progress and major trends in the field of flexible oxide thin film transistors (TFTs), fabricating with atomic layer deposition (ALD) processes. The ALD process offers accurate controlling of film thickness and composition as well as ability of achieving excellent uniformity over large areas at relatively low temperatures. First, an introduction is provided on what is the definition of ALD, the difference among other vacuum deposition techniques, and the brief key factors of ALD on flexible devices. Second, considering functional layers in flexible oxide TFT, the ALD process on polymer substrates may improve device performances such as mobility and stability, adopting as buffer layers over the polymer substrate, gate insulators, and active layers. Third, this review consists of the evaluation methods of flexible oxide TFTs under various mechanical stress conditions. The bending radius and repetition cycles are mostly considering for conventional flexible devices. It summarizes how the device has been degraded/changed under various stress types (directions). The last part of this review suggests a potential of each ALD film, including the releasing stress, the optimization of TFT structure, and the enhancement of device performance. Thus, the functional ALD layers in flexible oxide TFTs offer great possibilities regarding anti-mechanical stress films, along with flexible display and information storage application fields. Project supported by the National Research Foundation of Korea (NRF) (No. NRF-2017R1D1A1B03034035), the Ministry of Trade, Industry & Energy (No. #10051403), and the Korea Semiconductor Research Consortium.

  10. A comparative study of semiconductor-based plasmonic metamaterials

    DEFF Research Database (Denmark)

    Naik, Gururaj V.; Boltasseva, Alexandra

    2011-01-01

    and very large negative real permittivity values, and in addition, their optical properties cannot be tuned. These issues that put severe constraints on the device applications of MMs could be overcome if semiconductors are used as plasmonic materials instead of metals. Heavily doped, wide bandgap oxide...... semiconductors could exhibit both a small negative real permittivity and relatively small losses in the NIR. Heavily doped oxides of zinc and indium were already reported to be good, low loss alternatives to metals in the NIR range. Here, we consider these transparent conducting oxides (TCOs) as alternative...

  11. Preparation and characterization of zinc and cobalt (II, III) oxides ...

    Indian Academy of Sciences (India)

    1Laboratório de Processos de Oxidação Avançados, Departamento de Química, Caixa Postal 10011, ... gated through the heterogeneous photocatalysis mediated by zinc oxide, n-type semiconductor .... 3.2 Band gap energy determination.

  12. Synthesis and characterization of single-crystalline zinc tin oxide nanowires

    Science.gov (United States)

    Shi, Jen-Bin; Wu, Po-Feng; Lin, Hsien-Sheng; Lin, Ya-Ting; Lee, Hsuan-Wei; Kao, Chia-Tze; Liao, Wei-Hsiang; Young, San-Lin

    2014-05-01

    Crystalline zinc tin oxide (ZTO; zinc oxide with heavy tin doping of 33 at.%) nanowires were first synthesized using the electrodeposition and heat treatment method based on an anodic aluminum oxide (AAO) membrane, which has an average diameter of about 60 nm. According to the field emission scanning electron microscopy (FE-SEM) results, the synthesized ZTO nanowires are highly ordered and have high wire packing densities. The length of ZTO nanowires is about 4 μm, and the aspect ratio is around 67. ZTO nanowires with a Zn/(Zn + Sn) atomic ratio of 0.67 (approximately 2/3) were observed from an energy dispersive spectrometer (EDS). X-ray diffraction (XRD) and corresponding selected area electron diffraction (SAED) patterns demonstrated that the ZTO nanowire is hexagonal single-crystalline. The study of ultraviolet/visible/near-infrared (UV/Vis/NIR) absorption showed that the ZTO nanowire is a wide-band semiconductor with a band gap energy of 3.7 eV.

  13. Low temperature-pyrosol-deposition of aluminum-doped zinc oxide thin films for transparent conducting contacts

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, M.J. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, Coyoacán, 04510 México, D.F. (Mexico); Ramírez, E.B. [Universidad Autónoma de la Ciudad de México, Calle Prolongación San Isidro Núm. 151, Col. San Lorenzo Tezonco, Iztapalapa, 09790 México, D.F. (Mexico); Juárez, B.; González, J.; García-León, J.M. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, Coyoacán, 04510 México, D.F. (Mexico); Escobar-Alarcón, L. [Departamento de Física, Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, México, D.F. 11801 (Mexico); Alonso, J.C., E-mail: alonso@unam.mx [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, Coyoacán, 04510 México, D.F. (Mexico)

    2016-04-30

    Aluminum doped-zinc oxide (ZnO:Al) thin films with thickness ~ 1000 nm have been deposited by the ultrasonic spray pyrolysis technique using low substrate temperatures in the range from 285 to 360 °C. The electrical and optical properties of the ZnO:Al (AZO) films were investigated by Uv–vis spectroscopy and Hall effect measurements. The crystallinity and morphology of the films were analyzed using X-ray diffraction (XRD), atomic force microscopy (AFM), and high resolution scanning electron microcopy (SEM). XRD results reveal that all the films are nanocrystalline with a hexagonal wurtzite structure with a preferential orientation in the (002) plane. The size of the grains calculated from Scherrer's formula was in the range from 28 to 35 nm. AFM and SEM analysis reveals that the grains form round and hexagonal shaped aggregates at high deposition temperatures and larger rice shaped aggregates at low temperatures. All the films have a high optical transparency (~ 82%). According to the Hall measurements the AZO films deposited at 360 and 340 °C had resistivities of 2.2 × 10{sup −3}–4.3 × 10{sup −3} Ω cm, respectively. These films were n-type and had carrier concentrations and mobilities of 3.71–2.54 × 10{sup 20} cm{sup −3} and 7.4–5.7 cm{sup 2}/V s, respectively. The figure of merit of these films as transparent conductors was in the range of 2.6 × 10{sup −2} Ω{sup −1}–4.1 × 10{sup −2} Ω{sup −1}. Films deposited at 300 °C and 285 °C, had much higher resistivities. Based on the thermogravimetric analysis of the individual precursors used for film deposition, we speculate on possible film growing mechanisms that can explain the composition and electrical properties of films deposited under the two different ranges of temperatures. - Highlights: • Aluminum doped zinc oxide thin films were deposited at low temperatures by pyrosol. • Low resistivity was achieved from 340 °C substrate temperature. • All films deposited

  14. Electrocontact material based on silver dispersion-strengthened by nickel, titanium, and zinc oxides

    Science.gov (United States)

    Zeer, G. M.; Zelenkova, E. G.; Belousov, O. V.; Beletskii, V. V.; Nikolaev, S. V.; Ledyaeva, O. N.

    2017-09-01

    Samples of a composite electrocontact material based on silver strengthened by the dispersed phases of zinc and titanium oxides have been investigated by the electron microscopy and energy dispersive X-ray spectroscopy. A uniform distribution of the oxide phases containing 2 wt % zinc oxide in the initial charge has been revealed. The increase in the amount of zinc oxide leads to an increase of the size of the oxide phases. It has been shown that at the zinc oxide content of 2 wt %, the minimum wear is observed in the process of electroerosion tests; at 3 wt %, an overheating and welding of the contacts are observed.

  15. Nanoparticles of nickel oxide: growth and organization on zinc-substituted anionic clay matrix by one-pot route at room temperature

    International Nuclear Information System (INIS)

    Carja, Gabriela; Nakajima, Akira; Dranca, Cristian; Okada, Kiyoshi

    2010-01-01

    A room temperature nanocarving strategy is developed for the fabrication of nanoparticles of nickel oxide on zinc-substituted anionic clay matrix (Ni/ZnLDH). It is based on the growth and organization of nanoparticles of nickel oxide which occur during the structural reconstruction of the layered structure of the anionic clay in NiSO 4 aqueous solution. No organic compounds are used during the fabrication. The described material was characterized by X-ray diffraction (XRD), IR spectroscopy (FTIR), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Results show that the nickel-clay nanoarchitecture consists of small nanoparticles of nickel oxide (average size 7 nm) deposited on the larger nanoparticles (average size 90 nm) of zinc-substituted clay. The optical properties of the new nickel-zinc formulation are studied by UV-Vis.

  16. Nanoparticles of nickel oxide: growth and organization on zinc-substituted anionic clay matrix by one-pot route at room temperature

    Science.gov (United States)

    Carja, Gabriela; Nakajima, Akira; Dranca, Cristian; Okada, Kiyoshi

    2010-10-01

    A room temperature nanocarving strategy is developed for the fabrication of nanoparticles of nickel oxide on zinc-substituted anionic clay matrix (Ni/ZnLDH). It is based on the growth and organization of nanoparticles of nickel oxide which occur during the structural reconstruction of the layered structure of the anionic clay in NiSO4 aqueous solution. No organic compounds are used during the fabrication. The described material was characterized by X-ray diffraction (XRD), IR spectroscopy (FTIR), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Results show that the nickel-clay nanoarchitecture consists of small nanoparticles of nickel oxide (average size 7 nm) deposited on the larger nanoparticles (average size 90 nm) of zinc-substituted clay. The optical properties of the new nickel-zinc formulation are studied by UV-Vis.

  17. Impact of soft annealing on the performance of solution-processed amorphous zinc tin oxide thin-film transistors

    KAUST Repository

    Nayak, Pradipta K.

    2013-05-08

    It is demonstrated that soft annealing duration strongly affects the performance of solution-processed amorphous zinc tin oxide thin-film transistors. Prolonged soft annealing times are found to induce two important changes in the device: (i) a decrease in zinc tin oxide film thickness, and (ii) an increase in oxygen vacancy concentration. The devices prepared without soft annealing exhibited inferior transistor performances, in comparison to devices in which the active channel layer (zinc tin oxide) was subjected to soft annealing. The highest saturation field-effect mobility - 5.6 cm2 V-1 s-1 with a drain-to-source on-off current ratio (Ion/Ioff) of 2 × 108 - was achieved in the case of devices with 10-min soft-annealed zinc tin oxide thin films as the channel layer. The findings of this work identify soft annealing as a critical parameter for the processing of chemically derived thin-film transistors, and it correlates device performance to the changes in material structure induced by soft annealing. © 2013 American Chemical Society.

  18. Understanding the defect structure of solution grown zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Liew, Laura-Lynn [Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A-STAR), 3 Research Link, Singapore 117602 (Singapore); School of Materials Science and Engineering, Nanyang Technological University, Block N4.1 Nanyang Avenue, Singapore 639798 (Singapore); Sankar, Gopinathan, E-mail: g.sankar@ucl.ac.uk [Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom); Handoko, Albertus D. [Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A-STAR), 3 Research Link, Singapore 117602 (Singapore); Goh, Gregory K.L., E-mail: g-goh@imre.a-star.edu.sg [Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A-STAR), 3 Research Link, Singapore 117602 (Singapore); School of Materials Science and Engineering, Nanyang Technological University, Block N4.1 Nanyang Avenue, Singapore 639798 (Singapore); Kohara, Shinji [Japan Synchrotron Radiation Research Institute (JASRI), Mikazuki, Sayo, Hyogo 679-5198 (Japan)

    2012-05-15

    Zinc oxide (ZnO) is a wide bandgap semiconducting oxide with many potential applications in various optoelectronic devices such as light emitting diodes (LEDs) and field effect transistors (FETs). Much effort has been made to understand the ZnO structure and its defects. However, one major issue in determining whether it is Zn or O deficiency that provides ZnO its unique properties remains. X-ray absorption spectroscopy (XAS) is an ideal, atom specific characterization technique that is able to probe defect structure in many materials, including ZnO. In this paper, comparative studies of bulk and aqueous solution grown ({<=}90 Degree-Sign C) ZnO powders using XAS and x-ray pair distribution function (XPDF) techniques are described. The XAS Zn-Zn correlation and XPDF results undoubtedly point out that the solution grown ZnO contains Zn deficiency, rather than the O deficiency that were commonly reported. This understanding of ZnO short range order and structure will be invaluable for further development of solid state lighting and other optoelectronic device applications. - Graphical abstract: Highlights: Black-Right-Pointing-Pointer ZnO powders have been synthesized through an aqueous solution method. Black-Right-Pointing-Pointer Defect structure studied using XAS and XPDF. Black-Right-Pointing-Pointer Zn-Zn correlations are less in the ZnO powders synthesized in solution than bulk. Black-Right-Pointing-Pointer Zn vacancies are present in the powders synthesized. Black-Right-Pointing-Pointer EXAFS and XPDF, when used complementary, are useful characterization techniques.

  19. Electrochemical synthesis and characterization of zinc carbonate and zinc oxide nanoparticles

    Science.gov (United States)

    Pourmortazavi, Seied Mahdi; Marashianpour, Zahra; Karimi, Meisam Sadeghpour; Mohammad-Zadeh, Mohammad

    2015-11-01

    Zinc oxide and its precursor i.e., zinc carbonate is widely utilized in various fields of industry, especially in solar energy conversion, optical, and inorganic pigments. In this work, a facile and clean electrodeposition method was utilized for the synthesis of zinc carbonate nanoparticles. Also, zinc oxide nanoparticles were produced by calcination of the prepared zinc carbonate powder. Zinc carbonate nanoparticles with different sizes were electrodeposited by electrolysis of a zinc plate as anode in the solution of sodium carbonate. It was found that the particle size of zinc carbonate might be tuned by process parameters, i.e., electrolysis voltage, carbonate ion concentration, solvent composition and stirring rate of the electrolyte solution. An orthogonal array design was utilized to identify the optimum experimental conditions. The experimental results showed that the minimum size of the electrodeposited ZnCO3 particles is about 24 nm whereas the maximum particle size is around 40 nm. The TG-DSC studies of the nanoparticles indicated that the main thermal degradation of ZnCO3 occurs in two steps over the temperature ranges of 150-250 and 350-400 °C. The electrosynthesized ZnCO3 nanoparticles were calcined at the temperature of 600 °C to prepare ZnO nanoparticles. The prepared ZnCO3 and ZnO nanoparticles were characterized by SEM, X-ray diffraction (XRD), and FT-IR techniques.

  20. Zinc oxide's hierarchical nanostructure and its photocatalytic properties

    DEFF Research Database (Denmark)

    Kanjwal, Muzafar Ahmed; Sheikh, Faheem A.; Barakat, Nasser A. M.

    2012-01-01

    In this study, a new hierarchical nanostructure that consists of zinc oxide (ZnO) was produced by the electrospinning process followed by a hydrothermal technique. First, electrospinning of a colloidal solution that consisted of zinc nanoparticles, zinc acetate dihydrate and poly(vinyl alcohol...

  1. Photocatalysis application of zinc oxide fibers obtained by electrospinning

    International Nuclear Information System (INIS)

    Gerchman, D.; Alves, A.K.; Berutti, F.A.; Bergmann, C.P.

    2010-01-01

    Using the electrospinning technique, composite fibers of polyvinylbutyral and zinc nitrate were obtained. After a heat treatment at 600 deg C, nanostructured zinc oxide fibers were obtained. The fibers were characterized using X ray diffraction. The photocatalytic activity of the nanostructured fibers was determined using the photodegradation of a methyl orange solution. The increase in the heat treatment temperature decreases the photoactivity of the zinc oxide. The heat treatment, the phases and the surface area, affect the physical, chemical and photocatalytic activity of the zinc oxide. (author)

  2. Valorization of GaN based metal-organic chemical vapor deposition dust a semiconductor power device industry waste through mechanochemical oxidation and leaching: A sustainable green process.

    Science.gov (United States)

    Swain, Basudev; Mishra, Chinmayee; Lee, Chan Gi; Park, Kyung-Soo; Lee, Kun-Jae

    2015-07-01

    Dust generated during metal organic vapor deposition (MOCVD) process of GaN based semiconductor power device industry contains significant amounts of gallium and indium. These semiconductor power device industry wastes contain gallium as GaN and Ga0.97N0.9O0.09 is a concern for the environment which can add value through recycling. In the present study, this waste is recycled through mechanochemical oxidation and leaching. For quantitative recovery of gallium, two different mechanochemical oxidation leaching process flow sheets are proposed. In one process, first the Ga0.97N0.9O0.09 of the MOCVD dust is leached at the optimum condition. Subsequently, the leach residue is mechanochemically treated, followed by oxidative annealing and finally re-leached. In the second process, the MOCVD waste dust is mechanochemically treated, followed by oxidative annealing and finally leached. Both of these treatment processes are competitive with each other, appropriate for gallium leaching and treatment of the waste MOCVD dust. Without mechanochemical oxidation, 40.11 and 1.86 w/w% of gallium and Indium are leached using 4M HCl, 100°C and pulp density of 100 kg/m(3,) respectively. After mechanochemical oxidation, both these processes achieved 90 w/w% of gallium and 1.86 w/w% of indium leaching at their optimum condition. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Synthesis and characterization of nanohybrid of montmorillonite and zinc oxide

    International Nuclear Information System (INIS)

    Chagas, Beatriz S.; Mendes, Luis C.; Brito, Alice S.

    2009-01-01

    Zinc oxide-aluminosilicate nanohybrids through a hydrothermal reaction of a colloidal suspension of exfoliated montmorillonite nanosheets and zinc oxide in acid solution, performed in three different routes, were synthesized. The products were characterized by wide angle X-ray diffraction (WAXD). In all routes, it was found that the intercalation of zinc oxide into the host montmorillonite gallery was successfully performed so that the crystalline peaks of the montmorillonite and zinc oxide were suppressed from the X-ray patterns. The use of ultrasound decreased the reaction time.(author)

  4. High Concentration of Zinc in Sub-retinal Pigment Epithelial Deposits

    Energy Technology Data Exchange (ETDEWEB)

    Lengyel,I.; Flinn, J.; Peto, T.; Linkous, D.; Cano, K.; Bird, A.; Lanzirotti, A.; Frederickson, C.; van Kuijk, F.

    2007-01-01

    One of the hallmarks of age-related macular degeneration (AMD), the leading cause of blindness in the elderly in Western societies, is the accumulation of sub-retinal pigment epithelial deposits (sub-RPE deposits), including drusen and basal laminar deposits, in Bruch's membrane (BM). The nature and the underlying mechanisms of this deposit formation are not fully understood. Because we know that zinc contributes to deposit formation in neurodegenerative diseases, we tested the hypothesis that zinc might be involved in deposit formation in AMD. Using zinc specific fluorescent probes and microprobe synchrotron X-ray fluorescence we showed that sub-RPE deposits in post-mortem human tissues contain unexpectedly high concentrations of zinc, including abundant bio-available (ionic and/or loosely protein bound) ions. Zinc accumulation was especially high in the maculae of eyes with AMD. Internal deposit structures are especially enriched in bio-available zinc. Based on the evidence provided here we suggest that zinc plays a role in sub-RPE deposit formation in the aging human eye and possibly also in the development and/or progression of AMD.

  5. High Concentration of Zinc in Sub-retinal Pigment Epithelial Deposits

    International Nuclear Information System (INIS)

    Lengyel, I.; Flinn, J.; Peto, T.; Linkous, D.; Cano, K.; Bird, A.; Lanzirotti, A.; Frederickson, C.; van Kuijk, F.

    2007-01-01

    One of the hallmarks of age-related macular degeneration (AMD), the leading cause of blindness in the elderly in Western societies, is the accumulation of sub-retinal pigment epithelial deposits (sub-RPE deposits), including drusen and basal laminar deposits, in Bruch's membrane (BM). The nature and the underlying mechanisms of this deposit formation are not fully understood. Because we know that zinc contributes to deposit formation in neurodegenerative diseases, we tested the hypothesis that zinc might be involved in deposit formation in AMD. Using zinc specific fluorescent probes and microprobe synchrotron X-ray fluorescence we showed that sub-RPE deposits in post-mortem human tissues contain unexpectedly high concentrations of zinc, including abundant bio-available (ionic and/or loosely protein bound) ions. Zinc accumulation was especially high in the maculae of eyes with AMD. Internal deposit structures are especially enriched in bio-available zinc. Based on the evidence provided here we suggest that zinc plays a role in sub-RPE deposit formation in the aging human eye and possibly also in the development and/or progression of AMD

  6. Morphological Influence of Solution-Processed Zinc Oxide Films on Electrical Characteristics of Thin-Film Transistors

    Directory of Open Access Journals (Sweden)

    Hyeonju Lee

    2016-10-01

    Full Text Available We report on the morphological influence of solution-processed zinc oxide (ZnO semiconductor films on the electrical characteristics of ZnO thin-film transistors (TFTs. Different film morphologies were produced by controlling the spin-coating condition of a precursor solution, and the ZnO films were analyzed using atomic force microscopy, X-ray diffraction, X-ray photoemission spectroscopy, and Hall measurement. It is shown that ZnO TFTs have a superior performance in terms of the threshold voltage and field-effect mobility, when ZnO crystallites are more densely packed in the film. This is attributed to lower electrical resistivity and higher Hall mobility in a densely packed ZnO film. In the results of consecutive TFT operations, a positive shift in the threshold voltage occurred irrespective of the film morphology, but the morphological influence on the variation in the field-effect mobility was evident. The field-effect mobility in TFTs having a densely packed ZnO film increased continuously during consecutive TFT operations, which is in contrast to the mobility decrease observed in the less packed case. An analysis of the field-effect conductivities ascribes these results to the difference in energetic traps, which originate from structural defects in the ZnO films. Consequently, the morphological influence of solution-processed ZnO films on the TFT performance can be understood through the packing property of ZnO crystallites.

  7. Bimodal gate-dielectric deposition for improved performance of AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors

    International Nuclear Information System (INIS)

    Pang Liang; Kim, Kyekyoon

    2012-01-01

    A bimodal deposition scheme combining radiofrequency magnetron sputtering and plasma enhanced chemical vapour deposition (PECVD) is proposed as a means for improving the performance of GaN-based metal-oxide-semiconductor high-electron-mobility transistors (MOSHEMTs). High-density sputtered-SiO 2 is utilized to reduce the gate leakage current and enhance the breakdown voltage while low-density PECVD-SiO 2 is employed to buffer the sputtering damage and further increase the drain current by engineering the stress-induced-polarization. Thus-fabricated MOSHEMT exhibited a low leakage current of 4.21 × 10 -9 A mm -1 and high breakdown voltage of 634 V for a gate-drain distance of 6 µm, demonstrating the promise of bimodal-SiO 2 deposition scheme for the development of GaN-based MOSHEMTs for high-power application. (paper)

  8. Signatures of Quantized Energy States in Solution-Processed Ultrathin Layers of Metal-Oxide Semiconductors and Their Devices

    KAUST Repository

    Labram, John G.; Lin, Yenhung; Zhao, Kui; Li, Ruipeng; Thomas, Stuart R.; Semple, James; Androulidaki, Maria; Sygellou, Lamprini; McLachlan, Martyn A.; Stratakis, Emmanuel; Amassian, Aram; Anthopoulos, Thomas D.

    2015-01-01

    reports of the growth of uniform, ultrathin (<5 nm) metal-oxide semiconductors from solution, however, have potentially opened the door to such phenomena manifesting themselves. Here, a theoretical framework is developed for energy quantization

  9. Homo-junction ferroelectric field-effect-transistor memory device using solution-processed lithium-doped zinc oxide thin films

    KAUST Repository

    Nayak, Pradipta K.; Caraveo-Frescas, J. A.; Bhansali, Unnat. S.; Alshareef, Husam N.

    2012-01-01

    High performance homo-junction field-effect transistor memory devices were prepared using solution processed transparent lithium-doped zinc oxide thin films for both the ferroelectric and semiconducting active layers. A highest field-effect mobility

  10. Water resistant surfaces using zinc oxide structured nanorod arrays with switchable wetting property

    OpenAIRE

    Ennaceri, H.; Wang, L.; Erfurt, D.; Riedel, W.; Mangalgiri, G.; Khaldoun, A.; El Kenz, A.; Benyoussef, A.; Ennaoui, A

    2016-01-01

    This study presents an experimental approach for fabricating super hydrophobic coatings based on a dual roughness structure composed of zinc oxide nanorod arrays coated with a sputtered zinc oxide nano layer. The ZnO nanorod arrays were grown by means of a low temperature electrochemical deposition technique 75 C on FTO substrates. The ZnO nanorods show a 002 orientation along the c axis, and have a hexagonal structure, with an average length of 710 nm, and average width of 156 nm. On th...

  11. Thermoluminescence properties of zinc oxide obtained by solution combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Orante B, V. R.; Escobar O, F. M.; Cruz V, C. [Universidad de Sonora, Departamento de Investigacion en Polimeros y Materiales, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Bernal, R., E-mail: victor.orante@polimeros.uson.mx [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83190 Hermosillo, Sonora (Mexico)

    2014-08-15

    High-dose thermoluminescence dosimetry properties of novel zinc oxide obtained by solution combustion synthesis in a glycine-nitrate process, with a non-stoichiometric value of the elemental stoichiometric coefficient (Φ{sub c}) are presented in this work. Zn O powder samples obtained were annealed afterwards at 900 grades C during 2 h in air. Sintered particles of sizes between ∼ 0.5 and ∼ 2 μm were obtained, according to scanning electron microscopy results. X-ray diffraction indicates the presence of the hexagonal phase of Zn O for the powder samples obtained, before and after thermal annealing, without any remaining nitrate peaks observed. Thermoluminescence glow curves of Zn O obtained after being exposed to beta radiation consists of two maxima; one located at ∼ 149 grades C and another at ∼ 308 grades C, being the latter the dosimetric component of the curve. Dosimetric characterization of non-stoichiometric zinc oxide provided experimental evidence like asymptotic behavior of the Tl signal fading for times greater than 16 h between irradiation and the corresponding Tl readout, as well as the linear behaviour of the dose response without saturation in the dose interval studied (from 12.5 up to 400 Gy). Such characteristics place Zn O phosphors obtained in this work as a promising material for high-dose radiation dosimetry applications (e.g., radiotherapy and food industry). (author)

  12. Thermoluminescence properties of zinc oxide obtained by solution combustion synthesis

    International Nuclear Information System (INIS)

    Orante B, V. R.; Escobar O, F. M.; Cruz V, C.; Bernal, R.

    2014-08-01

    High-dose thermoluminescence dosimetry properties of novel zinc oxide obtained by solution combustion synthesis in a glycine-nitrate process, with a non-stoichiometric value of the elemental stoichiometric coefficient (Φ c ) are presented in this work. Zn O powder samples obtained were annealed afterwards at 900 grades C during 2 h in air. Sintered particles of sizes between ∼ 0.5 and ∼ 2 μm were obtained, according to scanning electron microscopy results. X-ray diffraction indicates the presence of the hexagonal phase of Zn O for the powder samples obtained, before and after thermal annealing, without any remaining nitrate peaks observed. Thermoluminescence glow curves of Zn O obtained after being exposed to beta radiation consists of two maxima; one located at ∼ 149 grades C and another at ∼ 308 grades C, being the latter the dosimetric component of the curve. Dosimetric characterization of non-stoichiometric zinc oxide provided experimental evidence like asymptotic behavior of the Tl signal fading for times greater than 16 h between irradiation and the corresponding Tl readout, as well as the linear behaviour of the dose response without saturation in the dose interval studied (from 12.5 up to 400 Gy). Such characteristics place Zn O phosphors obtained in this work as a promising material for high-dose radiation dosimetry applications (e.g., radiotherapy and food industry). (author)

  13. Effect of Al2O3 insulator thickness on the structural integrity of amorphous indium-gallium-zinc-oxide based thin film transistors.

    Science.gov (United States)

    Kim, Hak-Jun; Hwang, In-Ju; Kim, Youn-Jea

    2014-12-01

    The current transparent oxide semiconductors (TOSs) technology provides flexibility and high performance. In this study, multi-stack nano-layers of TOSs were designed for three-dimensional analysis of amorphous indium-gallium-zinc-oxide (a-IGZO) based thin film transistors (TFTs). In particular, the effects of torsional and compressive stresses on the nano-sized active layers such as the a-IGZO layer were investigated. Numerical simulations were carried out to investigate the structural integrity of a-IGZO based TFTs with three different thicknesses of the aluminum oxide (Al2O3) insulator (δ = 10, 20, and 30 nm), respectively, using a commercial code, COMSOL Multiphysics. The results are graphically depicted for operating conditions.

  14. Dye-sensitized solar cells based on nanostructured zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Conradt, Jonas; Maier-Flaig, Florian; Sartor, Janos; Fallert, Johannes [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Szmytkowski, Jedrzej; Kalt, Heinz [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Reinhard, Manuel; Colsmann, Alexander [Karlsruhe Institute of Technology (KIT), Lichttechnisches Institut, Karlsruhe (Germany); Lemmer, Uli [Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Lichttechnisches Institut, Karlsruhe (Germany); Balaban, Teodor Silviu [Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Institute for Nanotechnology, Karlsruhe (Germany)

    2009-07-01

    Hybrid solar cells represent a promising (cost-efficient) alternative to pure inorganic solar cells. We present dye-sensitized solar cells (DSSC) which are based on a zinc oxide (ZnO) electrode covered with a ruthenium dye. Our work focuses on the morphology of the ZnO electrode and its impact on the photovoltaic performance of the solar cell. Nanocrystalline ZnO powder layers and arrays of nanorods are incorporated into the DSSCs. The ZnO nanorods are grown by vapor transport deposition. The morphology and doping concentration of the rods can be controlled by the choice of substrate material, growth condition and catalytic metal layers. The nanorod arrays are expected to fasten the electron transport towards the anode and thereby improve the solar cell efficiency. In addition, novel self-assembling (porphyrin) dyes are tested as sensitizer within a DSSC.

  15. Impact of soft annealing on the performance of solution-processed amorphous zinc tin oxide thin-film transistors

    KAUST Repository

    Nayak, Pradipta K.; Hedhili, Mohamed N.; Cha, Dong Kyu; Alshareef, Husam N.

    2013-01-01

    It is demonstrated that soft annealing duration strongly affects the performance of solution-processed amorphous zinc tin oxide thin-film transistors. Prolonged soft annealing times are found to induce two important changes in the device: (i) a

  16. Photoelectrocatalytic degradation of oxalic acid by spray deposited nanocrystalline zinc oxide thin films

    International Nuclear Information System (INIS)

    Shinde, S.S.; Shinde, P.S.; Sapkal, R.T.; Oh, Y.W.; Haranath, D.; Bhosale, C.H.; Rajpure, K.Y.

    2012-01-01

    Highlights: ► Influence of substrate temperature onto the physico-chemical properties. ► Photochemical, structural, luminescent, optoelectrical and thermal properties. ► The kinetics of oxalic acid degradation with reaction mechanism. ► Extent of mineralization by COD and TOC. - Abstract: The high quality nano-crystalline zinc oxide thin films are deposited onto corning glasses by spray pyrolysis technique. The influence of reaction temperature onto their photoelectrochemical, structural, morphological, optoelectronic, luminescence and thermal properties has been investigated. The structural characteristics studied by X-ray diffractometry has complemented by resistivity measurements and UV–Vis spectroscopy. The photoelectrochemical activity shows enhancement in short circuit current (I sc = 0.357 mA) and open circuit voltage (V oc = 0.48 V). Direct band gap calculated by considering R and T values of ZnO thin films increases from 3.14–3.21 eV exhibiting a slight blue shift in band edge. Three characteristic luminescence peaks having near band-edge, blue and green emission are observed in the photoluminescence spectra. The specific heat and thermal conductivity study shows the phonon conduction behavior is dominant in films. Photocatalytic degradation of oxalic acid followed with reaction mechanism by using zinc oxide photoelectrode under solar illumination has been investigated.

  17. Optimizing the deposition of hydrogen evolution sites on suspended semiconductor particles using on-line photocatalytic reforming of aqueous methanol solutions.

    Science.gov (United States)

    Busser, G Wilma; Mei, Bastian; Muhler, Martin

    2012-11-01

    The deposition of hydrogen evolution sites on photocatalysts is a crucial step in the multistep process of synthesizing a catalyst that is active for overall photocatalytic water splitting. An alternative approach to conventional photodeposition was developed, applying the photocatalytic reforming of aqueous methanol solutions to deposit metal particles on semiconductor materials such as Ga₂O₃ and (Ga₀.₆ Zn₀.₄)(N₀.₆O₀.₄). The method allows optimizing the loading of the co-catalysts based on the stepwise addition of their precursors and the continuous online monitoring of the evolved hydrogen. Moreover, a synergetic effect between different co-catalysts can be directly established. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Zinc deposition and dissolution in methanesulfonic acid onto a carbon composite electrode as the negative electrode reactions in a hybrid redox flow battery

    International Nuclear Information System (INIS)

    Leung, P.K.; Ponce-de-Leon, C.; Low, C.T.J.; Walsh, F.C.

    2011-01-01

    Highlights: → Use methanesulfonic acid to avoid dendrite formation during a long (>4 h) zinc electrodeposition. → Electrochemical characterization of Zn(II) deposition and its morphology using methanesulfonic acid solutions. → Use of additives to improve the efficiency of zinc deposition and dissolution as the half cell reaction of a redox flow battery. - Abstract: Electrodeposition and dissolution of zinc in methanesulfonic acid were studied as the negative electrode reactions in a hybrid redox flow battery. Cyclic voltammetry at a rotating disk electrode was used to characterize the electrochemistry and the effect of process conditions on the deposition and dissolution rate of zinc in aqueous methanesulfonic acid. At a sufficiently high current density, the deposition process became a mass transport controlled reaction. The diffusion coefficient of Zn 2+ ions was 7.5 x 10 -6 cm 2 s -1 . The performance of the zinc negative electrode in a parallel plate flow cell was also studied as a function of Zn 2+ ion concentration, methanesulfonic acid concentration, current density, electrolyte flow rate, operating temperature and the addition of electrolytic additives, including potassium sodium tartarate, tetrabutylammonium hydroxide, and indium oxide. The current-, voltage- and energy efficiencies of the zinc-half cell reaction and the morphologies of the zinc deposits are also discussed. The energy efficiency improved from 62% in the absence of additives to 73% upon the addition of 2 x 10 -3 mol dm -3 of indium oxide as a hydrogen suppressant. In aqueous methanesulfonic acid with or without additives, there was no significant dendrite formation after zinc electrodeposition for 4 h at 50 mA cm -2 .

  19. The effect of zinc addition on PWR corrosion product deposition on zircaloy-4

    International Nuclear Information System (INIS)

    Walters, W.S.; Page, J.D.; Gaffka, A.P.; Kingsbury, A.F.; Foster, J.; Anderson, A.; Wickenden, D.; Henshaw, J.; Zmitko, M.; Masarik, V.; Svarc, V.

    2002-01-01

    During the period 1995 to 2001 a programme of loop irradiation tests have been performed to confirm the effectiveness of zinc additions on PWR circuit chemistry and corrosion. The programme included two loop irradiation experiments, and subsequent PIE; the experiments were a baseline test (no added zinc) and a test with added zinc (10 ppb). This paper addresses the findings regarding corrosion product deposition and activation on irradiated Zircaloy-4 surfaces. The findings are relevant to overall corrosion of the reactor primary circuit, the use of zinc as a corrosion inhibitor, and activation and transport of corrosion products. The irradiation experience provides information on the equilibration of the loop chemistry, with deliberate injection of zinc. The PIE used novel and innovative techniques (described below) to obtain samples of the oxide from the irradiated Zircaloy. The results of the PIE, under normal chemistry and zinc chemistry, indicate the effect of zinc on the deposition and activation of corrosion products on Zircaloy. It was found that corrosion product deposition on Zircaloy is enhanced by the addition of zinc (but corrosion product deposition on other materials was reduced in the presence of zinc). Chemical analysis and radioisotope gamma counting results are presented, to interpret the findings. A computer model has also been used to simulate the corrosion product deposition and activation, to assist in the interpretation of the results. (authors)

  20. Tungsten trioxide as high-{kappa} gate dielectric for highly transparent and temperature-stable zinc-oxide-based thin-film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Michael; Wenckstern, Holger von; Grundmann, Marius [Universitaet Leipzig, Fakultaet fuer Physik und Geowissenschaften, Institut fuer Experimentelle Physik II, Linnestr. 5, 04103 Leipzig (Germany)

    2012-07-01

    We demonstrate metal-insulator-semiconductor field-effect transistors with high-{kappa}, room-temperature deposited, highly transparent tungsten trioxide (WO{sub 3}) as gate dielectric. The channel material consists of a zinc oxide (ZnO) thin-film. The transmittance and resistivity of WO{sub 3} films was tuned in order to obtain a highly transparent and insulating WO{sub 3} dielectric. The devices were processed by standard photolithography using lift-off technique. On top of the WO{sub 3} dielectric a highly transparent and conductive oxide consisting of ZnO: Al 3% wt. was deposited. The gate structure of the devices exhibits an average transmittance in the visible spectral range of 86%. The on/off-current ratio is larger than 10{sup 8} with off- and gate leakage-currents below 3 x 10{sup -8} A/cm{sup 2}. Due to the high relative permittivity of {epsilon}{sub r} {approx} 70, a gate voltage sweep of only 2 V is necessary to turn the transistor on and off with a minimum subthreshold swing of 80 mV/decade. The channel mobility of the transistors equals the Hall-effect mobility with a value of 5 cm{sup 2}/Vs. It is furthermore shown, that the devices are stable up to operating temperatures of at least 150 C.

  1. Zinc oxide nano-rods based glucose biosensor devices fabrication

    Science.gov (United States)

    Wahab, H. A.; Salama, A. A.; El Saeid, A. A.; Willander, M.; Nur, O.; Battisha, I. K.

    2018-06-01

    ZnO is distinguished multifunctional material that has wide applications in biochemical sensor devices. For extracellular measurements, Zinc oxide nano-rods will be deposited on conducting plastic substrate with annealing temperature 150 °C (ZNRP150) and silver wire with annealing temperature 250 °C (ZNRW250), for the extracellular glucose concentration determination with functionalized ZNR-coated biosensors. It was performed in phosphate buffer saline (PBS) over the range from 1 μM to 10 mM and on human blood plasma. The prepared samples crystal structure and surface morphologies were characterized by XRD and field emission scanning electron microscope FESEM respectively.

  2. High-performance photoresponse from single-walled carbon nanotube-zinc oxide heterojunctions

    International Nuclear Information System (INIS)

    Chang, Jingbo; Najeeb, Choolakadavil Khalid; Lee, Jae-Hyeok; Lee, Minsu; Kim, Jae-Ho

    2011-01-01

    Photoactive materials consisting of single-walled carbon nanotube (SWNT)-zinc oxide (ZnO) heterojunctions targeted for optoelectronic applications are investigated in terms of photoresponse and photovoltaic effects. The devices based on SWNT-ZnO heterojunction films are fabricated by two step processes: first, a well aligned SWNT monolayer is deposited on an oxide substrate by the Langmuir-Blodgett (LB) technique; then a ZnO film prepared by filtration of ZnO nanowire solution is transferred onto the SWNT film to form SWNT-ZnO junctions. The SWNT-ZnO heterojunction demonstrates faster photoresponse time (2.75 s) up to 18 times and photovoltaic efficiency (1.33 nA) up to 4 times higher than that of only a ZnO device. Furthermore, the mechanisms of UV sensitivity enhancement and photovoltaic effects are explained according to the high electron mobility in the SWNT-ZnO heterojunctions.

  3. Topographic, optical and chemical properties of zinc particle coatings deposited by means of atmospheric pressure plasma

    International Nuclear Information System (INIS)

    Wallenhorst, L.M.; Loewenthal, L.; Avramidis, G.; Gerhard, C.; Militz, H.; Ohms, G.; Viöl, W.

    2017-01-01

    Highlights: • Zn/ZnO mixed systems were deposited from elemental zinc by a cold plasma-spray process. • Oxidation was confirmed by XPS. • The coatings exhibited a strong absorption in the UV spectral range, thus being suitable as protective layers, e.g. on thermosensitive materials. - Abstract: In this research, topographic, optical and chemical properties of zinc oxide layers deposited by a cold plasma-spray process were measured. Here, zinc micro particles were fed to the afterglow of a plasma spark discharge whereas the substrates were placed in a quite cold zone of the effluent plasma jet. In this vein, almost closed layers were realised on different samples. As ascertained by laser scanning and atomic force microscopic measurements the particle size of the basic layer is in the nanometre scale. Additionally, larger particles and agglomerates were found on its top. The results indicate a partial plasma-induced diminishment of the initial particles, most probably due to melting or vaporisation. It is further shown that the plasma gives rise to an increased oxidation of such particles as confirmed by X-ray photoelectron spectroscopy. Quantitative analysis of the resulting mixed layer was performed. It is shown that the deposited layers consist of zinc oxide and elemental zinc in approximately equal shares. In addition, the layer's band gap energy was determined by spectroscopic analysis. Here, considerable UV blocking properties of the deposited layers were observed. Possible underlying effects as well as potential applications are presented.

  4. Topographic, optical and chemical properties of zinc particle coatings deposited by means of atmospheric pressure plasma

    Energy Technology Data Exchange (ETDEWEB)

    Wallenhorst, L.M., E-mail: lena.wallenhorst@hawk-hhg.de [University of Applied Sciences and Arts, Laboratory of Laser and Plasma Technologies, Von-Ossietzky-Str. 99, 37085 Göttingen (Germany); Loewenthal, L.; Avramidis, G. [University of Applied Sciences and Arts, Laboratory of Laser and Plasma Technologies, Von-Ossietzky-Str. 99, 37085 Göttingen (Germany); Gerhard, C. [University of Applied Sciences and Arts, Laboratory of Laser and Plasma Technologies, Von-Ossietzky-Str. 99, 37085 Göttingen (Germany); Fraunhofer Institute for Surface Engineering and Thin Films, Application Center for Plasma and Photonics, Von-Ossietzky-Str. 100, 37085 Göttingen (Germany); Militz, H. [Wood Biology and Wood Products, Burckhardt Institute, Georg-August-University Göttingen, Büsgenweg 4, 37077 Göttingen (Germany); Ohms, G. [University of Applied Sciences and Arts, Laboratory of Laser and Plasma Technologies, Von-Ossietzky-Str. 99, 37085 Göttingen (Germany); Viöl, W. [University of Applied Sciences and Arts, Laboratory of Laser and Plasma Technologies, Von-Ossietzky-Str. 99, 37085 Göttingen (Germany); Fraunhofer Institute for Surface Engineering and Thin Films, Application Center for Plasma and Photonics, Von-Ossietzky-Str. 100, 37085 Göttingen (Germany)

    2017-07-15

    Highlights: • Zn/ZnO mixed systems were deposited from elemental zinc by a cold plasma-spray process. • Oxidation was confirmed by XPS. • The coatings exhibited a strong absorption in the UV spectral range, thus being suitable as protective layers, e.g. on thermosensitive materials. - Abstract: In this research, topographic, optical and chemical properties of zinc oxide layers deposited by a cold plasma-spray process were measured. Here, zinc micro particles were fed to the afterglow of a plasma spark discharge whereas the substrates were placed in a quite cold zone of the effluent plasma jet. In this vein, almost closed layers were realised on different samples. As ascertained by laser scanning and atomic force microscopic measurements the particle size of the basic layer is in the nanometre scale. Additionally, larger particles and agglomerates were found on its top. The results indicate a partial plasma-induced diminishment of the initial particles, most probably due to melting or vaporisation. It is further shown that the plasma gives rise to an increased oxidation of such particles as confirmed by X-ray photoelectron spectroscopy. Quantitative analysis of the resulting mixed layer was performed. It is shown that the deposited layers consist of zinc oxide and elemental zinc in approximately equal shares. In addition, the layer's band gap energy was determined by spectroscopic analysis. Here, considerable UV blocking properties of the deposited layers were observed. Possible underlying effects as well as potential applications are presented.

  5. Chemical solution deposition techniques for epitaxial growth of complex oxides

    NARCIS (Netherlands)

    ten Elshof, Johan E.; Koster, G.; Huijben, Mark; Rijnders, G.

    2015-01-01

    The chemical solution deposition (CSD) process is a wet-chemical process that is employed to fabricate a wide variety of amorphous and crystalline oxide thin films. This chapter describes the typical steps in a CSD process and their influence on the final microstructure and properties of films, and

  6. Zinc-Nickel Codeposition in Sulfate Solution Combined Effect of Cadmium and Boric Acid

    Directory of Open Access Journals (Sweden)

    Y. Addi

    2011-01-01

    Full Text Available The combined effect of cadmium and boric acid on the electrodeposition of zinc-nickel from a sulfate has been investigated. The presence of cadmium ion decreases zinc in the deposit. In solution, cadmium inhibits the zinc ion deposition and suppresses it when deposition potential value is more negative than −1.2 V. Low concentration of CdSO4 reduces the anomalous nature of Zn-Ni deposit. Boric acid decreases current density and shifts potential discharge of nickel and hydrogen to more negative potential. The combination of boric acid and cadmium increases the percentage of nickel in the deposit. Boric acid and cadmium.

  7. Fabrication of visible light-triggered photocatalytic materials from the coupling of n-type zinc oxide and p-type copper oxide

    Science.gov (United States)

    Gorospe, A. B.; Herrera, M. U.

    2017-04-01

    Coupling of copper oxide (CuO) and zinc oxide (ZnO) was done by chemical precipitation method. In this method, copper sulfate pentahydrate and zinc sulfate heptahydrate salt precursors were separately dissolved in distilled water; then were mixed together. The copper sulfate-zinc sulfate solution was then combined with a sodium hydroxide solution. The precipitates were collected and washed in distilled water and ethanol several times, then filtered and dried. The dried sample was grounded, and then undergone heat treatment. After heating, the sample was grounded again. Zinc oxide powder and copper oxide powder were also fabricated using chemical precipitation method. X-Ray Diffraction measurements of the coupled CuO/ZnO powder showed the presence of CuO and ZnO in the fabricated sample. Furthermore, other peaks shown by XRD were also identified corresponding to copper, copper (II) oxide, copper sulfate and zinc sulfate. Results of the photocatalytic activity investigation show that the sample exhibited superior photocatalytic degradation of methyl orange under visible light illumination compared to copper oxide powder and zinc oxide powder. This may be attributed to the lower energy gap at the copper oxide-zinc oxide interface, compared to zinc oxide, allowing visible light to trigger its photocatalytic activity.

  8. Monodispersed Zinc Oxide Nanoparticle-Dye Dyads and Triads

    Energy Technology Data Exchange (ETDEWEB)

    Gladfelter, Wayne L. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemistry; Blank, David A. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemistry; Mann, Kent R. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemistry

    2017-06-22

    The overall energy conversion efficiency of photovoltaic cells depends on the combined efficiencies of light absorption, charge separation and charge transport. Dye-sensitized solar cells are photovoltaic devices in which a molecular dye absorbs light and uses this energy to initiate charge separation. The most efficient dye-sensitized solar cells (DSSCs) use nanocrystal titanium dioxide films to which are attached ruthenium complexes. Numerous studies have provided valuable insight into the dynamics of these and analogous photosystems, but the lack of site homogeneity in binding dye molecules to metal oxide films and nanocrystals (NCs) is a significant impediment to extracting fundamental details about the electron transfer across the interface. Although zinc oxide is emerging as a potential semiconducting component in DSSCs, there is less known about the factors controlling charge separation across the dye/ZnO interface. Zinc oxide crystallizes in the wurtzite lattice and has a band gap of 3.37 eV. One of the features that makes ZnO especially attractive is the remarkable ability to control the morphology of the films. Using solution deposition processes, one can prepare NCs, nanorods and nanowires having a variety of shapes and dimensions. This project solved problems associated with film heterogeneity through the use of dispersible sensitizer/ZnO NC ensembles. The overarching goal of this research was to study the relationship between structure, energetics and dynamics in a set of synthetically controlled donor-acceptor dyads and triads. These studies provided access to unprecedented understanding of the light absorption and charge transfer steps that lie at the heart of DSSCs, thus enabling significant future advances in cell efficiencies. The approach began with the construction of well-defined dye-NC dyads that were sufficiently dispersible to allow the use of state of the art pulsed laser spectroscopic and kinetic methods to understand the charge transfer

  9. Thin film transistor performance of amorphous indium–zinc oxide semiconductor thin film prepared by ultraviolet photoassisted sol–gel processing

    Science.gov (United States)

    Kodzasa, Takehito; Nobeshima, Taiki; Kuribara, Kazunori; Yoshida, Manabu

    2018-05-01

    We have fabricated an amorphous indium–zinc oxide (IZO, In/Zn = 3/1) semiconductor thin-film transistor (AOS-TFT) by the sol–gel technique using ultraviolet (UV) photoirradiation and post-treatment in high-pressure O2 at 200 °C. The obtained TFT showed a hole carrier mobility of 0.02 cm2 V‑1 s‑1 and an on/off current ratio of 106. UV photoirradiation leads to the decomposition of the organic agents and hydroxide group in the IZO gel film. Furthermore, the post-treatment annealing at a high O2 pressure of more than 0.6 MPa leads to the filling of the oxygen vacancies in a poor metal–oxygen network in the IZO film.

  10. Review of flexible and transparent thin-film transistors based on zinc oxide and related materials

    International Nuclear Information System (INIS)

    Zhang Yong-Hui; Mei Zeng-Xia; Liang Hui-Li; Du Xiao-Long

    2017-01-01

    Flexible and transparent electronics enters into a new era of electronic technologies. Ubiquitous applications involve wearable electronics, biosensors, flexible transparent displays, radio-frequency identifications (RFIDs), etc. Zinc oxide (ZnO) and relevant materials are the most commonly used inorganic semiconductors in flexible and transparent devices, owing to their high electrical performances, together with low processing temperatures and good optical transparencies. In this paper, we review recent advances in flexible and transparent thin-film transistors (TFTs) based on ZnO and relevant materials. After a brief introduction, the main progress of the preparation of each component (substrate, electrodes, channel and dielectrics) is summarized and discussed. Then, the effect of mechanical bending on electrical performance is highlighted. Finally, we suggest the challenges and opportunities in future investigations. (paper)

  11. Textured indium tin oxide thin films by chemical solution deposition and rapid thermal processing

    International Nuclear Information System (INIS)

    Mottern, Matthew L.; Tyholdt, Frode; Ulyashin, Alexander; Helvoort, Antonius T.J. van; Verweij, Henk; Bredesen, Rune

    2007-01-01

    The microstructure of state-of-the-art chemical solution deposited indium tin oxide thin films typically consists of small randomly oriented grains, high porosity and poor homogeneity. The present study demonstrates how the thin film microstructure can be improved significantly by tailoring the precursor solutions and deposition conditions to be kinetically and thermodynamically favorable for generation of homogeneous textured thin films. This is explained by the occurrence of a single heterogeneous nucleation mechanism. The as-deposited thin films, crystallized at 800 deg. C, have a high apparent density, based on a refractive index of ∼ 1.98 determined by single wavelength ellipsometry at 633 nm. The microstructure of the films consists of columnar grains with preferred orientation as determined by X-ray diffraction and transmission electron microscopy. The resistivity, measured by the four point probe method, is ∼ 2 x 10 -3 Ω cm prior to post-deposition treatments

  12. Deposition of Zinc Oxide on Different Polymer Textiles and Their Antibacterial Properties

    Directory of Open Access Journals (Sweden)

    Marta Fiedot-Toboła

    2018-04-01

    Full Text Available A surface modification of polyamide 6 (PA, polyethylene terephthalate (PET and polypropylene (PP textiles was performed using zinc oxide to obtain antibacterial layer. ZnO microrods were synthesized on ZnO nanoparticles (NPs as a nucleus centers by chemical bath deposition (CBD process. Scanning Electron Microscopy (SEM and X-ray diffraction (XRD indicated that wurzite ZnO microrods were obtained on every sample. Differential Scanning Calorimetry (DSC, Fourier Transform Infrared Spectroscopy (FTIR, Atomic Force Microscopy (AFM and Liquid Absorption Capacity (LAC analysis indicate that the amount and structure of antibacterial layer is dependent on roughness and wettability of textile surface. The rougher and more hydrophilic is the material, the more ZnO were deposited. All studied textiles show significant bactericidal activity against Escherichia coli (E. coli and Staphylococcus aureus (S. aureus. A possible mechanism and difference in sensitivity between Gram-negative and Gram-positive bacteria to ZnO is discussed. Considering that antibacterial activity of ZnO is caused by Reactive Oxygen Species (ROS generation, an influence of surface to volume ratio and crystalline parameters is also discussed.

  13. Transparent conductive zinc oxide basics and applications in thin film solar cells

    CERN Document Server

    Klein, Andreas; Rech, Bernd

    2008-01-01

    Zinc oxide (ZnO) belongs to the class of transparent conducting oxides which can be used as transparent electrodes in electronic devices or heated windows. In this book the material properties of, the deposition technologies for, and applications of zinc oxide in thin film solar cells are described in a comprehensive manner. Structural, morphological, optical and electronic properties of ZnO are treated in this review. The editors and authors of this book are specialists in deposition, analysis and fabrication of thin-film solar cells and especially of ZnO. This book is intended as an overview and a data collection for students, engineers and scientist.

  14. Deposition and characterization of noble metal onto surfaces of 304l stainless steel

    International Nuclear Information System (INIS)

    Contreras R, A.; Arganis J, C. R.; Aguilar T, J. A.; Medina A, A. L.

    2010-10-01

    Noble metal chemical addition (NMCA) plus hydrogen water chemistry is an industry-wide accepted approach for potential intergranular stress corrosion cracking mitigation of BWR internals components. NMCA is a method of applying noble metal onto BWR internals surfaces using reactor water as the transport medium that causes the deposition of noble metal from the liquid onto surfaces. In this work different platinum concentration solutions were deposited onto pre-oxidized surfaces of 304l steel at 180 C during 48 hr in an autoclave. In order to simulate the zinc water conditions, deposits of Zn and Pt-Zn were also carried out. The solutions used to obtain the deposits were: sodium hexahydroxyplatinate (IV), zinc nitrate hydrate and zinc oxide. The deposits obtained were characterized by scanning electron microscopy and X-ray diffraction. Finally, the electrochemical corrosion potential of pre-oxidized samples with Pt deposit were obtained and compared with the electrochemical corrosion potential of only pre-oxidized samples. (Author)

  15. Solution deposited and modified iron oxide for enhanced solar water splitting

    Science.gov (United States)

    Abel, Anthony J.

    Growing worldwide energy demand coupled with an increasing awareness of anthropogenic climate change has driven research into carbon-neutral and solar-derived energy sources. One attractive strategy is the storage of solar energy in the bonds of H2 formed by photoelectrochemical (PEC) water splitting. Hematite, an iron oxide, has been widely investigated as a candidate material for PEC water splitting due to its stability, non-toxicity, earth abundance and consequent low cost, and a theoretical 15% solar-to-hydrogen conversion efficiency. However, poor electrical properties and slow rates of the water oxidation reaction have limited its potential as an economical water splitting catalyst. Additionally, the most efficient hematite-based devices are fabricated via expensive, vacuum-phase techniques, limiting scalability to broad integration into the energy supply. In this thesis, I develop a new, solution-based deposition method for high quality, planar hematite thin films using successive ionic layer adsorption and reaction (SILAR). The constant geometry and tight control over layer thickness possible with SILAR makes these films ideal model systems to understand the two key steps of PEC water oxidation: charge separation and interfacial hole transfer. In Chapter 3, I report on facile annealing treatments to dope hematite with Ti and Sn, and I show that these impurity atoms at the hematite/electrolyte interface increase hole transfer efficiency from nearly 0 to above 60%. However, charge separation remains below 15% with these dopants incorporated via solid state diffusion, mainly due to low hole mobility. To overcome this associated small transport length, extremely thin hematite coatings were deposited on Sb:SnO2 monolayer inverse opal scaffolds. With this modified substrate, photocurrent increased proportionately to the surface area of the scaffold. While Chapter 3 discusses incorporation of dopants via solid state diffusion, Chapter 4 examines methods to

  16. Spray-combustion synthesis: efficient solution route to high-performance oxide transistors.

    Science.gov (United States)

    Yu, Xinge; Smith, Jeremy; Zhou, Nanjia; Zeng, Li; Guo, Peijun; Xia, Yu; Alvarez, Ana; Aghion, Stefano; Lin, Hui; Yu, Junsheng; Chang, Robert P H; Bedzyk, Michael J; Ferragut, Rafael; Marks, Tobin J; Facchetti, Antonio

    2015-03-17

    Metal-oxide (MO) semiconductors have emerged as enabling materials for next generation thin-film electronics owing to their high carrier mobilities, even in the amorphous state, large-area uniformity, low cost, and optical transparency, which are applicable to flat-panel displays, flexible circuitry, and photovoltaic cells. Impressive progress in solution-processed MO electronics has been achieved using methodologies such as sol gel, deep-UV irradiation, preformed nanostructures, and combustion synthesis. Nevertheless, because of incomplete lattice condensation and film densification, high-quality solution-processed MO films having technologically relevant thicknesses achievable in a single step have yet to be shown. Here, we report a low-temperature, thickness-controlled coating process to create high-performance, solution-processed MO electronics: spray-combustion synthesis (SCS). We also report for the first time, to our knowledge, indium-gallium-zinc-oxide (IGZO) transistors having densification, nanoporosity, electron mobility, trap densities, bias stability, and film transport approaching those of sputtered films and compatible with conventional fabrication (FAB) operations.

  17. All solution processed tandem polymer solar cells based on thermocleavable materials

    DEFF Research Database (Denmark)

    Hagemann, Ole; Bjerring, Morten; Nielsen, Niels Chr.

    2008-01-01

    efficiently solved. Devices comprised a transparent front cathode based on solution processed zinc oxide nanoparticles, a large band gap active layer based on a bulk heterojunction between zinc oxide and poly(3-carboxydithiophene) (P3CT) followed by a layer of PEDOT:PSS processed from water. The second cell...... in the stack employed a zinc oxide front cathode processed on top of the PEDOT:PSS layer from an organic solvent, a low band gap active layer based on a bulk heterojunction between zinc oxide and the novel poly(carboxyterthiophene-co-diphenylthienopyrazine) (P3CTTP) followed by a layer of PEDOT:PSS again...

  18. Solution processing of polymer semiconductor: Insulator blends-Tailored optical properties through liquid-liquid phase separation control

    KAUST Repository

    Hellmann, Christoph; Treat, Neil D.; Scaccabarozzi, Alberto D.; Razzell Hollis, Joseph; Fleischli, Franziska D.; Bannock, James H.; de Mello, John; Michels, Jasper J.; Kim, Ji-Seon; Stingelin, Natalie

    2014-01-01

    © 2014 Wiley Periodicals, Inc. It has been demonstrated that the 0-0 absorption transition of poly(3-hexylthiophene) (P3HT) in blends with poly(ethylene oxide) (PEO) could be rationally tuned through the control of the liquid-liquid phase separation process during solution deposition. Pronounced J-like aggregation behavior, characteristic for systems of a low exciton band width, was found for blends where the most pronounced liquid-liquid phase separation occurred in solution, leading to domains of P3HT and PEO of high phase purity. Since liquid-liquid phase separation could be readily manipulated either by the solution temperature, solute concentration, or deposition temperature, to name a few parameters, our findings promise the design from the out-set of semiconductor:insulator architectures of pre-defined properties by manipulation of the interaction parameter between the solutes as well as the respective solute:solvent system using classical polymer science principles.

  19. Solution processing of polymer semiconductor: Insulator blends-Tailored optical properties through liquid-liquid phase separation control

    KAUST Repository

    Hellmann, Christoph

    2014-12-17

    © 2014 Wiley Periodicals, Inc. It has been demonstrated that the 0-0 absorption transition of poly(3-hexylthiophene) (P3HT) in blends with poly(ethylene oxide) (PEO) could be rationally tuned through the control of the liquid-liquid phase separation process during solution deposition. Pronounced J-like aggregation behavior, characteristic for systems of a low exciton band width, was found for blends where the most pronounced liquid-liquid phase separation occurred in solution, leading to domains of P3HT and PEO of high phase purity. Since liquid-liquid phase separation could be readily manipulated either by the solution temperature, solute concentration, or deposition temperature, to name a few parameters, our findings promise the design from the out-set of semiconductor:insulator architectures of pre-defined properties by manipulation of the interaction parameter between the solutes as well as the respective solute:solvent system using classical polymer science principles.

  20. Zinc oxide overdose

    Science.gov (United States)

    Zinc oxide is an ingredient in many products. Some of these are certain creams and ointments used ... prevent or treat minor skin burns and irritation. Zinc oxide overdose occurs when someone eats one of ...

  1. Determination of Insulator-to-Semiconductor Transition in Sol-Gel Oxide Semiconductors Using Derivative Spectroscopy.

    Science.gov (United States)

    Lee, Woobin; Choi, Seungbeom; Kim, Kyung Tae; Kang, Jingu; Park, Sung Kyu; Kim, Yong-Hoon

    2015-12-23

    We report a derivative spectroscopic method for determining insulator-to-semiconductor transition during sol-gel metal-oxide semiconductor formation. When an as-spun sol-gel precursor film is photochemically activated and changes to semiconducting state, the light absorption characteristics of the metal-oxide film is considerable changed particularly in the ultraviolet region. As a result, a peak is generated in the first-order derivatives of light absorption ( A' ) vs. wavelength (λ) plots, and by tracing the peak center shift and peak intensity, transition from insulating-to-semiconducting state of the film can be monitored. The peak generation and peak center shift are described based on photon-energy-dependent absorption coefficient of metal-oxide films. We discuss detailed analysis method for metal-oxide semiconductor films and its application in thin-film transistor fabrication. We believe this derivative spectroscopy based determination can be beneficial for a non-destructive and a rapid monitoring of the insulator-to-semiconductor transition in sol-gel oxide semiconductor formation.

  2. Electrodeposition of compact zinc from the hydrophobic Brønsted acidic ionic liquid-based electrolytes and the study of zinc stability along with the acidity manipulation

    International Nuclear Information System (INIS)

    Chen, Yi-Han; Yeh, Hsin-Wen; Lo, Nai-Chang; Chiu, Chen-Wei; Sun, I-Wen; Chen, Po-Yu

    2017-01-01

    Highlights: • Compact Zn with no crack is deposited from protic ionic liquid-based electrolytes. • The ionic liquid is composed of the protonated betaine ion. • This ionic liquid is hydrophobic and zinc oxide is soluble in it. • The effects of co-solvents, propylene carbonate and water, are studied. • The Zn stripping/deposition efficiency can be manipulated via acidity adjustment. - Abstract: Compact crystalline zinc was electrodeposited on stainless-steel electrode (SS) via potentiostatic/galvanostatic electrolysis from the hydrophobic Brønsted acidic ionic liquid, protonated betaine bis((trifluoromethyl)sulfonyl)imide (IL [Hbet][TFSI]), −based electrolytes containing ZnCl 2 or ZnO under argon or ambient air atmosphere. Approximate 10 wt% of propylene carbonate and water, respectively, were used as the co-solvents for [Hbet][TFSI] to form the IL-based electrolytes. The efficiency of zinc deposition/stripping, which is significantly affected by the Brønsted acidity of the IL-based electrolytes, was studied at glassy carbon electrode (GC) to evaluate the stability of the zinc electrodeposits along with the electrolyte acidity. The stability is very poor for the zinc electrodeposits obtained from ZnCl 2 solution. However, it increases with increasing the quantity of ZnO or urea in the electrolytes; the former neutralize the dissociable protons in [Hbet] cations to form water, and the latter may form H-bonding with [Hbet] or be protonated to form the weakly acidic cations [HUrea]. Both suppress the reaction between the Zn electrodeposits and protons. The stability of the Zn electrodeposits, therefore, can be improved via the manipulation of the IL acidity.

  3. Properties of zinc oxide at low and moderate temperatures

    International Nuclear Information System (INIS)

    Lashkarev, G.V.; Karpina, V.A.; Lazorenko, V.I.; Evtushenko, A.I.; Shteplyuk, I.I.; Khranovskij, V.D.

    2011-01-01

    The properties of zinc oxide as an analogue of gallium nitride are considered in a wide temperature range and the field of its potential applications. The economic and ecologic benefits as well as radiation resistivity of ZnO in comparison with Group III nitrides are indicated. Methods of growth of films and nanostructures of high crystal perfection are proposed. In particular, a magnetron method for layer growth of films is implemented which permits to realize their high structural perfection and considerable thickness inappropriate to some other methods. It is shown that monochromatic UV light may be obtained on excitation of films by short-wave radiation and electrons. This makes it possible to use them in the sources of short-wave radiation. The effectiveness of field emission for ZnO nanostructures and films is demonstrated which opens the prospect for their use in vacuum microelectronics devices. In particular, a phototransistor based on ZnO films doped with nitrogen was fabricated the photosensitivity of which was two orders of magnitude higher than that of conventional detectors. The physical basis of creating blue, green LEDs based on zinc oxide film and its solid solutions with CdO are outlined. The importance of active research in physics, and production procedures of zinc oxide-based devices is underlined.

  4. PRISM -- A tool for modelling proton energy deposition in semiconductor materials

    International Nuclear Information System (INIS)

    Oldfield, M.K.; Underwood, C.I.

    1996-01-01

    This paper presents a description of, and test results from, a new PC based software simulation tool PRISM (Protons in Semiconductor Materials). The model describes proton energy deposition in complex 3D sensitive volumes of semiconductor materials. PRISM is suitable for simulating energy deposition in surface-barrier detectors and semiconductor memory devices, the latter being susceptible to Single-Event Upset (SEU) and Multiple-Bit Upset (MBU). The design methodology on which PRISM is based, together with the techniques used to simulate ion transport and energy deposition, are described. Preliminary test results used to analyze the PRISM model are presented

  5. Combinatorial study of zinc tin oxide thin-film transistors

    Science.gov (United States)

    McDowell, M. G.; Sanderson, R. J.; Hill, I. G.

    2008-01-01

    Groups of thin-film transistors using a zinc tin oxide semiconductor layer have been fabricated via a combinatorial rf sputtering technique. The ZnO :SnO2 ratio of the film varies as a function of position on the sample, from pure ZnO to SnO2, allowing for a study of zinc tin oxide transistor performance as a function of channel stoichiometry. The devices were found to have mobilities ranging from 2to12cm2/Vs, with two peaks in mobility in devices at ZnO fractions of 0.80±0.03 and 0.25±0.05, and on/off ratios as high as 107. Transistors composed predominantly of SnO2 were found to exhibit light sensitivity which affected both the on/off ratios and threshold voltages of these devices.

  6. Solution processed zinc oxide nanopyramid/silver nanowire transparent network films with highly tunable light scattering properties

    KAUST Repository

    Mehra, Saahil

    2013-01-01

    Metal nanowire transparent networks are promising replacements to indium tin oxide (ITO) transparent electrodes for optoelectronic devices. While the transparency and sheet resistance are key metrics for transparent electrode performance, independent control of the film light scattering properties is important to developing multifunctional electrodes for improved photovoltaic absorption. Here we show that controlled incorporation of ZnO nanopyramids into a metal nanowire network film affords independent, highly tunable control of the scattering properties (haze) with minimal effects on the transparency and sheet resistance. Varying the zinc oxide/silver nanostructure ratios prior to spray deposition results in sheet resistances, transmission (600 nm), and haze (600 nm) of 6-30 Ω □-1, 68-86%, and 34-66%, respectively. Incorporation of zinc oxide nanopyramid scattering agents into the conducting nanowire mesh has a negligible effect on mesh connectivity, providing a straightforward method of controlling electrode scattering properties. The decoupling of the film scattering power and electrical characteristics makes these films promising candidates for highly scattering transparent electrodes in optoelectronic devices and can be generalized to other metal nanowire films as well as carbon nanotube transparent electrodes. © 2013 The Royal Society of Chemistry.

  7. Study of the Morphological, Structural, Optical and Photoelectrochemical Properties of Zinc Oxide Nanorods Grown Using a Microwave Chemical Bath Deposition Method

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Sungjin; Ryu, Hyukhyun [Inje University, Gimhae (Korea, Republic of); Lee, Won-Jae [Dong-Eui University, Busan (Korea, Republic of)

    2017-04-15

    In this study, zinc oxide (ZnO) nanostructures were grown on a ZnO-buffered fluorine-doped tin oxide (FTO) substrate using a microwave chemical bath deposition method with different zinc oxide precursor concentrations from 0.01 to 0.5 M. We investigated the effects of the zinc oxide precursor concentration on the morphological, structural, optical and photoelectrochemical properties of the ZnO nanostructures. From this work, we found that ZnO one-dimensional structures mainly grew along the (002) plane, and the nanorod length, diameter, surface area and photoelectrochemical properties were largely dependent on the precursor concentration. That is, the photoelectrochemical properties were affected by the morphological and structural properties of the ZnO. The morphological, structural, optical and photoelectrochemical properties of the ZnO nanostructure were investigated by field emission scanning electron microscopy (FE-SEM) and atomic force microscope (AFM), X-ray diffraction (XRD), UV-visible spectroscopy and 3-electrode potentiostat. We obtained the highest photocurrent density of 0.37 mA/cm{sup 2} (at 1.1 V vs. SCE) from the precursor concentration of 0.07 M, which resulted in ZnO nanostructures with proper length and diameter, large surface area and good structural properties.

  8. Key Topics in Producing New Ultraviolet Led and Laser Devices Based on Transparent Semiconductor Zinc Oxide

    International Nuclear Information System (INIS)

    Tuezemen, S.

    2004-01-01

    Recently, it has been introduced that ZnO as II-VI semiconductor is promising various technological applications, especially for optoelectronic short wavelength light emitting devices due to its wide and direct band gap profile. The most important advantage of ZnO over the other currently used wide band gap semiconductors such as GaN is that its nearly 3 times higher exciton binding energy (60 meV), which permits efficient excitonic emission at room temperature and above. As-grown ZnO is normally n-type because of the Zn-rich defects such as zinc interstitials (Zn i ) oxygen vacancies (Vo), natively acting as shallow donors and main source of n-type conductivity in as-grown material. Therefore, making p-type ZnO has been more difficult due to unintentional compensation of possible acceptors by these residual donors. In order to develop electro luminescent and laser devices based on the ultraviolet (UV) exciton emission of ZnO, it will be important to fabricate good p-n junctions. Attempts to observe p-type conductivity in ours and our collaborators' laboratories in USA, either by co-doping with N or tuning O pressure have been first successful achievements, resulting in hole concentrations up to 10 1 9 cm - 3 in reactively sputtered thin layers of ZnO. Moreover, in order to produce ZnO based quantum well lasers similar to the previously introduced n-AlGaAs/GaAs/p-AlGaAs structures; we have attempted to grow Zn 1 -xSn x O thin films to enlarge the band gap energy. An increase up to 170 meV has been observed in Zn 1 -xSn x O thin films and this is enough barrier to be able to trap electron-hole pairs in quantum well structures. As a result, two important key issues; p-type conductivity and enhancement of the band gap energy in order to step forward towards the production of electro luminescent UV LEDs and quantum well lasers have been investigated and will be presented in this study

  9. Electroplated zinc-cobalt alloy

    International Nuclear Information System (INIS)

    Carpenter, D.E.O.S.; Farr, J.P.G.

    2005-01-01

    Recent work on the deposition and use of ectrodeposited zinc-cobalt alloys is surveyed. Alloys containing lower of Nuclear quantities of cobalt are potentially more useful. The structures of the deposits is related to their chemical and mechanical properties. The inclusion of oxide and its role in the deposition mechanism may be significant. Chemical and engineering properties relate to the metallurgical structure of the alloys, which derives from the mechanism of deposition. The inclusion of oxides and hydroxides in the electroplate may provide evidence for this mechanism. Electrochemical impedance measurements have been made at significant deposition potentials, in alkaline electrolytes. These reveal a complex electrode behaviour which depends not only on the electrode potential but on the Co content of the electrolyte. For the relevant range of cathodic potential zinc-cobalt alloy electrodeposition occurs through a stratified interface. The formation of an absorbed layer ZnOH/sup +/ is the initial step, this inhibits the deposition of cobalt at low cathodic potentials, so explaining its 'anomalous deposition'. A porous layer of zinc forms on the adsorbed ZnOH/sup +/ at underpotential. As the potential becomes more cathodic, cobalt co- deposits from its electrolytic complex forming a metallic solid solution of Co in Zn. In electrolytes containing a high concentration of cobalt a mixed entity (ZnCo)/sub +/ is assumed to adsorb at the cathode from which a CoZn intermetallic deposits. (author)

  10. Influence of sputtering deposition parameters on electrical and optical properties of aluminium-doped zinc oxide thin films for photovoltaic applications

    Science.gov (United States)

    Krawczak, Ewelina; Agata, Zdyb; Gulkowski, Slawomir; Fave, Alain; Fourmond, Erwann

    2017-11-01

    Transparent Conductive Oxides (TCOs) characterized by high visible transmittance and low electrical resistivity play an important role in photovoltaic technology. Aluminum doped zinc oxide (AZO) is one of the TCOs that can find its application in thin film solar cells (CIGS or CdTe PV technology) as well as in other microelectronic applications. In this paper some optical and electrical properties of ZnO:Al thin films deposited by RF magnetron sputtering method have been investigated. AZO layers have been deposited on the soda lime glass substrates with use of variable technological parameters such as pressure in the deposition chamber, power applied and temperature during the process. The composition of AZO films has been investigated by EDS method. Thickness and refraction index of the deposited layers in dependence on certain technological parameters of sputtering process have been determined by spectroscopic ellipsometry. The measurements of transmittance and sheet resistance were also performed.

  11. Topographic, optical and chemical properties of zinc particle coatings deposited by means of atmospheric pressure plasma

    Science.gov (United States)

    Wallenhorst, L. M.; Loewenthal, L.; Avramidis, G.; Gerhard, C.; Militz, H.; Ohms, G.; Viöl, W.

    2017-07-01

    In this research, topographic, optical and chemical properties of zinc oxide layers deposited by a cold plasma-spray process were measured. Here, zinc micro particles were fed to the afterglow of a plasma spark discharge whereas the substrates were placed in a quite cold zone of the effluent plasma jet. In this vein, almost closed layers were realised on different samples. As ascertained by laser scanning and atomic force microscopic measurements the particle size of the basic layer is in the nanometre scale. Additionally, larger particles and agglomerates were found on its top. The results indicate a partial plasma-induced diminishment of the initial particles, most probably due to melting or vaporisation. It is further shown that the plasma gives rise to an increased oxidation of such particles as confirmed by X-ray photoelectron spectroscopy. Quantitative analysis of the resulting mixed layer was performed. It is shown that the deposited layers consist of zinc oxide and elemental zinc in approximately equal shares. In addition, the layer's band gap energy was determined by spectroscopic analysis. Here, considerable UV blocking properties of the deposited layers were observed. Possible underlying effects as well as potential applications are presented.

  12. Aerosol - assisted Chemical Vapor Deposition of Metal Oxide Structures: Zinc Oxide Rods

    Czech Academy of Sciences Publication Activity Database

    Vallejos, S.; Pizúrová, Naděžda; Čechal, J.; Grácia, I.; Cané, C.

    2017-01-01

    Roč. 2017, Č. 127 (2017), č. článku e56127. ISSN 1940-087X Institutional support: RVO:68081723 Keywords : Zinc oxide * columnar structures * rods * AACVD * non-catalyzed growth * vapor-solid mechanism Subject RIV: CA - Inorganic Chemistry OBOR OECD: Polymer science Impact factor: 1.232, year: 2016 https://www.jove.com/video/56127

  13. Development of zinc oxide nanoparticle by sonochemical method and study of their physical and optical properties

    International Nuclear Information System (INIS)

    Khan, Samreen Heena; Suriyaprabha, R.; Pathak, Bhawana; Fulekar, M. H.

    2016-01-01

    With the miniaturization of crystal size, the fraction of under-coordinated surface atoms becomes dominant, and hence, materials in the nano-regime behave very differently from the similar material in a bulk. Zinc oxide (ZnO), particularly, exhibits extraordinary properties such as a wide direct band gap (3.37 eV), large excitation binding energy (60 meV), low refractive index (1.9), stability to intense ultraviolet (UV) illumination, resistance to high-energy irradiation, and lower toxicity as compared to other semiconductors. This very property makes Zinc Oxide a potential candidate in many application fields, particularly as a prominent semiconductor. Zinc Oxide plays a significant role in many technological advances with its application in semiconductor mediated photocatalytic processes and sensor, solar cells and others. In present study, Zinc Oxide (ZnO) has been synthesized using three different precursors by sonochemical method. Zinc Acetate Dihydrate, Zinc Nitrate Hexahydrate and Zinc Sulphate Heptahydrate used as a precursor for the synthesis process. The synthesized ZnO nanoparticle has been found under the range of ∼50 nm. Zinc oxide nanoparticles were characterized using different characterizing tools. The as-synthesized ZnO was characterized by Fourier Transform-Infrared Spectroscopy (FT-IR) for the determination of functional group; Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy (SEM-EDS) for Morphology and elemental detection respectively, Transmission Electron Microscopy for Particle size distribution and morphology and X-Ray Diffraction (XRD) for the confirmation of crystal structure of the nanomaterial. The optical properties of the ZnO were examined by UV-VIS spectroscopy equipped with Diffuse Reflectance spectroscopy (DRS) confirmed the optical band gap of ZnO-3 around 3.23 eV resembles with the band gap of bulk ZnO (3.37eV). The TEM micrograph of the as-synthesized material showed perfectly spherical shaped

  14. Development of zinc oxide nanoparticle by sonochemical method and study of their physical and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Samreen Heena, E-mail: samreen.heena.khan@gmail.com; Suriyaprabha, R. [Centre for Nanosciences, Central University of Gujarat, Gandhinagar, India- 382030 (India); Pathak, Bhawana, E-mail: bhawana.pathak@cug.ac.in; Fulekar, M. H., E-mail: mhfulekar@yahoo.com [School of Environment and Sustainable Development, Central University of Gujarat, Gandhinagar, India- 382030 (India)

    2016-04-13

    With the miniaturization of crystal size, the fraction of under-coordinated surface atoms becomes dominant, and hence, materials in the nano-regime behave very differently from the similar material in a bulk. Zinc oxide (ZnO), particularly, exhibits extraordinary properties such as a wide direct band gap (3.37 eV), large excitation binding energy (60 meV), low refractive index (1.9), stability to intense ultraviolet (UV) illumination, resistance to high-energy irradiation, and lower toxicity as compared to other semiconductors. This very property makes Zinc Oxide a potential candidate in many application fields, particularly as a prominent semiconductor. Zinc Oxide plays a significant role in many technological advances with its application in semiconductor mediated photocatalytic processes and sensor, solar cells and others. In present study, Zinc Oxide (ZnO) has been synthesized using three different precursors by sonochemical method. Zinc Acetate Dihydrate, Zinc Nitrate Hexahydrate and Zinc Sulphate Heptahydrate used as a precursor for the synthesis process. The synthesized ZnO nanoparticle has been found under the range of ∼50 nm. Zinc oxide nanoparticles were characterized using different characterizing tools. The as-synthesized ZnO was characterized by Fourier Transform-Infrared Spectroscopy (FT-IR) for the determination of functional group; Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy (SEM-EDS) for Morphology and elemental detection respectively, Transmission Electron Microscopy for Particle size distribution and morphology and X-Ray Diffraction (XRD) for the confirmation of crystal structure of the nanomaterial. The optical properties of the ZnO were examined by UV-VIS spectroscopy equipped with Diffuse Reflectance spectroscopy (DRS) confirmed the optical band gap of ZnO-3 around 3.23 eV resembles with the band gap of bulk ZnO (3.37eV). The TEM micrograph of the as-synthesized material showed perfectly spherical shaped

  15. Zinc electrodeposition from alkaline zincate solution by pulsating overpotentials

    Directory of Open Access Journals (Sweden)

    MILOS V. SIMICIC

    2000-09-01

    Full Text Available It is well known that smooth zinc deposits cannot be obtained from alkaline zincate using constant overpotential and current rate. During prolonged metal deposition, spongy and dendritic deposits are formed. It has been shown that the deposits are less agglomerated in the case of square-wave pulsating overpotentials regime than the ones obtained in case of constant overpotential regime. This is explained in a semiquantitative way by two phenomena: selective anodic dissolution during overpotentials “off” period and decreasing diffusion control. These effects is more pronounced at higher pause-to-pulse ratio. Increasing the pause-to-pulse ratio causes a reduction of the ratio between diffusion and activation overpotential, resulting in a more compact deposit. Confirmation of the proposed semiquantitative mathematical model was obtained by zinc electrodeposition onto a copper wire from a 0.1 M zincate solution in 1.0 M KOH at room temperature.

  16. Preparation, characterization and electrocatalytic behavior of zinc oxide/zinchexacyanoferrate and ruthenium oxide hexacyanoferrate hybrid film-modified electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Chu, H.-W.; Thangamuthu, R. [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan (China); Chen, S.-M. [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan (China)], E-mail: smchen78@ms15.hinet.net

    2008-02-15

    Polynuclear mixed-valent hybrid films of zinc oxide/zinchexacyanoferrate and ruthenium oxide hexacyanoferrate (ZnO/ZnHCF-RuOHCF) have been deposited on electrode surfaces from H{sub 2}SO{sub 4} solution containing Zn(NO{sub 3}){sub 2}, RuCl{sub 3} and K{sub 3}[Fe(CN){sub 6}] by potentiodynamic cycling method. Simultaneous cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM) measurements demonstrate the steady growth of hybrid film. Surface morphology of hybrid film was investigated using scanning electron microscopy (SEM). Energy dispersive spectrometer (EDS) data confirm existence of zinc oxide and ruthenium oxide hexacyanoferrate (RuOHCF) in the hybrid film. The effect of type of monovalent cations on the redox behavior of hybrid film was investigated. In pure supporting electrolyte, electrochemical responses of Ru{sup II/III} redox transition occurring at negative potential region resemble with that of a surface immobilized redox couple. The electrocatalytic activity of ZnO/ZnHCF-RuOHCF hybrid film was investigated towards oxidation of epinephrine, dopamine and L-cysteine, and reduction of S{sub 2}O{sub 8}{sup 2-} and SO{sub 5}{sup 2-} as well as IO{sub 3}{sup -} using cyclic voltammetry and rotating ring disc electrode (RRDE) techniques.

  17. Effect of thermal processing on silver thin films of varying thickness deposited on zinc oxide and indium tin oxide

    International Nuclear Information System (INIS)

    Sivaramakrishnan, K.; Ngo, A. T.; Alford, T. L.; Iyer, S.

    2009-01-01

    Silver films of varying thicknesses (25, 45, and 60 nm) were deposited on indium tin oxide (ITO) on silicon and zinc oxide (ZnO) on silicon. The films were annealed in vacuum for 1 h at different temperatures (300-650 deg. C). Four-point-probe measurements were used to determine the resistivity of the films. All films showed an abrupt change in resistivity beyond an onset temperature that varied with thickness. Rutherford backscattering spectrometry measurements revealed agglomeration of the Ag films upon annealing as being responsible for the resistivity change. X-ray pole figure analysis determined that the annealed films took on a preferential texturing; however, the degree of texturing was significantly higher in Ag/ZnO/Si than in Ag/ITO/Si samples. This observation was accounted for by interface energy minimization. Atomic force microscopy (AFM) measurements revealed an increasing surface roughness of the annealed films with temperature. The resistivity behavior was explained by the counterbalancing effects of increasing crystallinity and surface roughness. Average surface roughness obtained from the AFM measurements were also used to model the agglomeration of Ag based on Ostwald ripening theory

  18. Group one impurities in single crystalline Zinc Oxide

    OpenAIRE

    Johansen, Klaus Magnus Håland

    2011-01-01

    Zinc Oxide (ZnO) has been used as a material in many different technologies from pharmaceuticals to electronics. This exciting material can also be utilized as a wide band gap semiconductor for application in optoelectronic devices. The availability of Zn, the possibility to grow single crystal bulk material and the exitonic binding energy of 60 meV makes this material especially interesting. Even though the material has been studied already since the late 1920s there are still some fundament...

  19. Bi-component semiconductor oxide photoanodes for the photoelectrocatalytic oxidation of organic solutes and vapours: a short review with emphasis to TiO2-WO3 photoanodes.

    Science.gov (United States)

    Georgieva, J; Valova, E; Armyanov, S; Philippidis, N; Poulios, I; Sotiropoulos, S

    2012-04-15

    The use of binary semiconductor oxide anodes for the photoelectrocatalytic oxidation of organic species (both in solution and gas phase) is reviewed. In the first part of the review, the principle of electrically assisted photocatalysis is presented, the preparation methods for the most common semiconductor oxide catalysts are briefly mentioned, while the advantages of appropriately chosen semiconductor combinations for efficient UV and visible (vis) light utilization are highlighted. The second part of the review focuses on the discussion of TiO(2)-WO(3) photoanodes (among the most studied bi-component semiconductor oxide systems) and in particular on coatings prepared by electrodeposition/electrosynthesis or powder mixtures (the focus of the authors' research during recent years). Studies concerning the microscopic, spectroscopic and photoelectrochemical characterization of the catalysts are presented and examples of photoanode activity towards typical dissolved organic contaminants as well as organic vapours are given. Particular emphasis is paid to: (a) The dependence of photoactivity on catalyst morphology and composition and (b) the possibility of carrying out photoelectrochemistry in all-solid cells, thus opening up the opportunity for photoelectrocatalytic air treatment. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Effect of hydroxylamine hydrochloride on the floral decoration of zinc oxide synthesized by solution method

    International Nuclear Information System (INIS)

    Wahab, Rizwan; Ansari, S.G.; Kim, Young Soon; Khang, Gilson; Shin, Hyung-Shik

    2008-01-01

    Effect of the structure-directing agent on the floral (depicting flower) morphological variation of ZnO is systematically studied and presented here. Flowery decorated (resembling flower) zinc oxide structure composed of hexagonal nanorods (sharp tips and wider bases) was synthesized at 90 deg. C using zinc acetate dihydrate and sodium hydroxide at various concentrations of hydroxylamine hydrochloride for 12 h by solution method. Single crystalline nature with the wurtzite hexagonal phase remained unaltered with increasing concentration of hydroxylamine hydrochloride while the morphology changes from nanorod to plate like structure. Photoelectron spectroscopic measurement presented spectra close to the standard bulk ZnO, with an O 1s peak composed of surface adsorbed O-H group, O 2- in the oxygen vacancies on ZnO structure and ZnO. At higher concentration (0.8 M), surface adsorbed O-H group increases while other component decreases because of the changes in the nucleation and surface energy. Results clearly indicate that hydroxylamine hydrochloride works as a structure-directing agent without affecting other properties

  1. Transparent conducting oxide films of group V doped titania prepared by aqueous chemical solution deposition

    International Nuclear Information System (INIS)

    Elen, Ken; Capon, Boris; De Dobbelaere, Christopher; Dewulf, Daan; Peys, Nick; Detavernier, Christophe; Hardy, An; Van Bael, Marlies K.

    2014-01-01

    Transparent conducting oxide (TCO) films of titania doped with vanadium (V), niobium (Nb) and tantalum (Ta) are obtained by aqueous Chemical Solution Deposition (CSD). The effect of the dopant on the crystallization and microstructure of the resulting films is examined by means of X-ray diffraction and electron microscopy. During annealing of the thin films, in-situ characterization of the crystal structure and sheet resistance is carried out. Niobium doped anatase films, obtained after annealing in forming gas, show a resistivity of 0,28 Ohm cm, which is the lowest resistivity reported for a solution deposited anatase-based TCO so far. Here, we demonstrate that aqueous CSD may provide a strategy for scalable TCO production in the future. - Highlights: • Aqueous chemical solution deposition of doped titanium dioxide • Doping delays the phase transition from anatase to rutile • Lowest resistivity after doping with niobium and annealing in Forming Gas • Transparency higher than 80% in the visible range of optical spectrum

  2. Transparent conducting oxide films of group V doped titania prepared by aqueous chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Elen, Ken [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Strategisch Initiatief Materialen (SIM), SoPPoM Program (Belgium); Capon, Boris [Strategisch Initiatief Materialen (SIM), SoPPoM Programm (Belgium); Coating and Contacting of Nanostructures, Ghent University, Krijgslaan 281 S1, B-9000 Ghent (Belgium); De Dobbelaere, Christopher [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Dewulf, Daan [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Peys, Nick [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw, Kapeldreef 75, B-3001 Heverlee (Belgium); Detavernier, Christophe [Coating and Contacting of Nanostructures, Ghent University, Krijgslaan 281 S1, B-9000 Ghent (Belgium); Hardy, An [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Van Bael, Marlies K., E-mail: marlies.vanbael@uhasselt.be [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium)

    2014-03-31

    Transparent conducting oxide (TCO) films of titania doped with vanadium (V), niobium (Nb) and tantalum (Ta) are obtained by aqueous Chemical Solution Deposition (CSD). The effect of the dopant on the crystallization and microstructure of the resulting films is examined by means of X-ray diffraction and electron microscopy. During annealing of the thin films, in-situ characterization of the crystal structure and sheet resistance is carried out. Niobium doped anatase films, obtained after annealing in forming gas, show a resistivity of 0,28 Ohm cm, which is the lowest resistivity reported for a solution deposited anatase-based TCO so far. Here, we demonstrate that aqueous CSD may provide a strategy for scalable TCO production in the future. - Highlights: • Aqueous chemical solution deposition of doped titanium dioxide • Doping delays the phase transition from anatase to rutile • Lowest resistivity after doping with niobium and annealing in Forming Gas • Transparency higher than 80% in the visible range of optical spectrum.

  3. Structural properties of perovskite films on zinc oxide nanoparticles-reduced graphene oxide (ZnO-NPs/rGO) prepared by electrophoretic deposition technique

    Science.gov (United States)

    Bahtiar, Ayi; Nurazizah, Euis Siti; Latiffah, Efa; Risdiana, Furukawa, Yukio

    2018-02-01

    Perovskite solar cells highly believed as next generation solar cells to replace currently available inorganic silicon solar cells due to their high power conversion efficiency and easy processing to thin films using solution processing techniques. Performance and stability, however still need to be improved for mass production and widely used for public electricity generation. Perovskite solar cells are commonly deposited on Titanium Dioxide (TiO2) film as an effective electron transport layer (ETL). We used Zinc Oxide nanoparticles (ZnO-NPs) as ETL in perovskite solar cells due to the low temperature required for crystallization and can be formed into different shapes of nanostructures. However, perovskite film can easily degrade into insulating lead iodide due to deprotonation of the methylammoniumcation at the surface of ZnO-NPs, in particular when it stored in ambient air with high relative humidity. The degradation of perovskite layer is therefore needed to be overcome. Here, we capped ZnO-NPs with reduced graphene oxide (rGO) to overcome the degradation of perovskite film where ZnO-NPs is synthesized by sol-gel method. The average nanoparticle size of ZnO is 15 nm. ZnO-NPs and ZnO-NPs-rGO films are prepared using electrophoretic deposition technique, which can produce large area with good homogeneity and high reproducibility. The stability of perovskite layer can significantly be improved by capping ZnO with rGO, which is indicated by absence of color change of perovskite after storage for 5 (five) days in ambient air with relative humidity above 95%. Moreover, the X-Ray Diffaction peaks of perovskite film are more preserved when deposited on ZnO/rGO film than using only ZnO film. We strongly believe, by capping ZnO film with rGO, both the performance and stability of perovskite solar cells can be improved significantly.

  4. Structure evolution of zinc oxide thin films deposited by unbalance DC magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Aryanto, Didik, E-mail: didi027@lipi.go.id [Research Center for Physics, Indonesian Institute of Sciences, Serpong 15314, Tangerang Selatan (Indonesia); Materials Research Group, Physics Department, Universitas Negeri Semarang, Gunungpati, Semarang 50229 Jawa Tengah (Indonesia); Marwoto, Putut; Sugianto [Physics Department, Faculty of Mathematics and Science, Universitas Negeri Semarang, Gunungpati, Semarang 50229 Jawa Tengah (Indonesia); Materials Research Group, Physics Department, Universitas Negeri Semarang, Gunungpati, Semarang 50229 Jawa Tengah (Indonesia); Sudiro, Toto [Research Center for Physics, Indonesian Institute of Sciences, Serpong 15314, Tangerang Selatan (Indonesia); Birowosuto, Muhammad D. [Research Center for Physics, Indonesian Institute of Sciences, Serpong 15314, Tangerang Selatan (Indonesia); CINTRA UMI CNRS/NTU/THALES 3288 Research Techno Plaza, 50 Nanyang Drive, Border X Block, level 6, 637553 (Singapore); Sulhadi [Physics Department, Faculty of Mathematics and Science, Universitas Negeri Semarang, Gunungpati, Semarang 50229 Jawa Tengah (Indonesia)

    2016-04-19

    Zinc oxide (ZnO) thin films are deposited on corning glass substrates using unbalanced DC magnetron sputtering. The effect of growth temperature on surface morphology and crystallographic orientation of ZnO thin film is studied using atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques. The surface morphology and crystallographic orientation of ZnO thin film are transformed against the increasing of growth temperature. The mean grain size of film and the surface roughness are inversely and directly proportional towards the growth temperature from room temperature to 300 °C, respectively. The smaller grain size and finer roughness of ZnO thin film are obtained at growth temperature of 400 °C. The result of AFM analysis is in good agreement with the result of XRD analysis. ZnO thin films deposited in a series of growth temperatures have hexagonal wurtzite polycrystalline structures and they exhibit transformations in the crystallographic orientation. The results in this study reveal that the growth temperature strongly influences the surface morphology and crystallographic orientation of ZnO thin film.

  5. Room temperature synthesis of indium tin oxide nanotubes with high precision wall thickness by electroless deposition

    Directory of Open Access Journals (Sweden)

    Mario Boehme

    2011-02-01

    Full Text Available Conductive nanotubes consisting of indium tin oxide (ITO were fabricated by electroless deposition using ion track etched polycarbonate templates. To produce nanotubes (NTs with thin walls and small surface roughness, the tubes were generated by a multi-step procedure under aqueous conditions. The approach reported below yields open end nanotubes with well defined outer diameter and wall thickness. In the past, zinc oxide films were mostly preferred and were synthesized using electroless deposition based on aqueous solutions. All these methods previously developed, are not adaptable in the case of ITO nanotubes, even with modifications. In the present work, therefore, we investigated the necessary conditions for the growth of ITO-NTs to achieve a wall thickness of around 10 nm. In addition, the effects of pH and reductive concentrations for the formation of ITO-NTs are also discussed.

  6. Synthesis of zinc sulfide by chemical vapor deposition using an organometallic precursor: Di-tertiary-butyl-disulfide

    International Nuclear Information System (INIS)

    Vasekar, Parag; Dhakal, Tara; Ganta, Lakshmikanth; Vanhart, Daniel; Desu, Seshu

    2012-01-01

    Zinc sulfide has gained popularity in the last few years as a cadmium-free heterojunction partner for thin film solar cells and is seen as a good replacement for cadmium sulfide due to better blue photon response and non-toxicity. In this work, zinc sulfide films are prepared using an organic sulfur source. We report a simple and repeatable process for development of zinc sulfide using a cost-effective and less hazardous organic sulfur source. The development of zinc sulfide has been studied on zinc oxide-coated glass where the zinc oxide is converted into zinc sulfide. Zinc oxide grown by atomic layer deposition as well as commercially available zinc oxide-coated glass was used. The zinc sulfide synthesis has been studied and the films are characterized using scanning electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and a UV–VIS spectrophotometer. XRD, XPS and optical characterization confirm the zinc sulfide phase formation. - Highlights: ► Synthesis of ZnS using a less-hazardous precursor, di-tertiary-butyl-disulfide. ► ZnS process optimized for two types of ZnO films. ► Preliminary results for a solar cell show an efficiency of 1.09%.

  7. Synthesis and characterization of zinc oxide thin films prepared by ...

    African Journals Online (AJOL)

    Zinc oxide thin films were prepared with ammonia/ammonium chloride buffer as the reaction moderating agent in the chemical bath deposition technique. An observable color change during the reaction due to variations in the reactants concentration indicated the existence of the cupric (CuO) and cuprous (Cu2O) oxides ...

  8. High-performance all-printed amorphous oxide FETs and logics with electronically compatible electrode/ channel interface.

    Science.gov (United States)

    Sharma, Bhupendra Kumar; Stoesser, Anna; Mondal, Sandeep Kumar; Garlapati, Suresh K; Fawey, Mohammed H; Chakravadhanula, Venkata Sai Kiran; Kruk, Robert; Hahn, Horst; Dasgupta, Subho

    2018-06-12

    Oxide semiconductors typically show superior device performance compared to amorphous silicon or organic counterparts, especially, when they are physical vapor deposited. However, it is not easy to reproduce identical device characteristics when the oxide field-effect transistors (FETs) are solution-processed/ printed; the level of complexity further intensifies with the need to print the passive elements as well. Here, we developed a protocol for designing the most electronically compatible electrode/ channel interface based on the judicious material selection. Exploiting this newly developed fabrication schemes, we are now able to demonstrate high-performance all-printed FETs and logic circuits using amorphous indium-gallium-zinc oxide (a-IGZO) semiconductor, indium tin oxide (ITO) as electrodes and composite solid polymer electrolyte as the gate insulator. Interestingly, all-printed FETs demonstrate an optimal electrical performance in terms of threshold voltages and device mobility and may very well be compared with devices fabricated using sputtered ITO electrodes. This observation originates from the selection of electrode/ channel materials from the same transparent semiconductor oxide family, resulting in the formation of In-Sn-Zn-O (ITZO) based diffused a-IGZO/ ITO interface that controls doping density while ensuring high electrical performance. Compressive spectroscopic studies reveal that Sn doping mediated excellent band alignment of IGZO with ITO electrodes is responsible for the excellent device performance observed. All-printed n-MOS based logic circuits have also been demonstrated towards new-generation portable electronics.

  9. Amorphous indium-tin-zinc oxide films deposited by magnetron sputtering with various reactive gases: Spatial distribution of thin film transistor performance

    International Nuclear Information System (INIS)

    Jia, Junjun; Torigoshi, Yoshifumi; Shigesato, Yuzo; Kawashima, Emi; Utsuno, Futoshi; Yano, Koki

    2015-01-01

    This work presents the spatial distribution of electrical characteristics of amorphous indium-tin-zinc oxide film (a-ITZO), and how they depend on the magnetron sputtering conditions using O 2 , H 2 O, and N 2 O as the reactive gases. Experimental results show that the electrical properties of the N 2 O incorporated a-ITZO film has a weak dependence on the deposition location, which cannot be explained by the bombardment effect of high energy particles, and may be attributed to the difference in the spatial distribution of both the amount and the activity of the reactive gas reaching the substrate surface. The measurement for the performance of a-ITZO thin film transistor (TFT) also suggests that the electrical performance and device uniformity of a-ITZO TFTs can be improved significantly by the N 2 O introduction into the deposition process, where the field mobility reach to 30.8 cm 2 V –1 s –1 , which is approximately two times higher than that of the amorphous indium-gallium-zinc oxide TFT

  10. Influence of sputtering deposition parameters on electrical and optical properties of aluminium-doped zinc oxide thin films for photovoltaic applications

    Directory of Open Access Journals (Sweden)

    Krawczak Ewelina

    2017-01-01

    Full Text Available Transparent Conductive Oxides (TCOs characterized by high visible transmittance and low electrical resistivity play an important role in photovoltaic technology. Aluminum doped zinc oxide (AZO is one of the TCOs that can find its application in thin film solar cells (CIGS or CdTe PV technology as well as in other microelectronic applications. In this paper some optical and electrical properties of ZnO:Al thin films deposited by RF magnetron sputtering method have been investigated. AZO layers have been deposited on the soda lime glass substrates with use of variable technological parameters such as pressure in the deposition chamber, power applied and temperature during the process. The composition of AZO films has been investigated by EDS method. Thickness and refraction index of the deposited layers in dependence on certain technological parameters of sputtering process have been determined by spectroscopic ellipsometry. The measurements of transmittance and sheet resistance were also performed.

  11. Valorization of GaN based metal-organic chemical vapor deposition dust a semiconductor power device industry waste through mechanochemical oxidation and leaching: A sustainable green process

    Energy Technology Data Exchange (ETDEWEB)

    Swain, Basudev, E-mail: Swain@iae.re.kr [Institute for Advanced Engineering (IAE), Advanced Materials & Processing Center, Yongin-Si 449-863 (Korea, Republic of); Mishra, Chinmayee; Lee, Chan Gi; Park, Kyung-Soo [Institute for Advanced Engineering (IAE), Advanced Materials & Processing Center, Yongin-Si 449-863 (Korea, Republic of); Lee, Kun-Jae [Department of Energy Engineering, Dankook University, Cheonan 330-714 (Korea, Republic of)

    2015-07-15

    Dust generated during metal organic vapor deposition (MOCVD) process of GaN based semiconductor power device industry contains significant amounts of gallium and indium. These semiconductor power device industry wastes contain gallium as GaN and Ga{sub 0.97}N{sub 0.9}O{sub 0.09} is a concern for the environment which can add value through recycling. In the present study, this waste is recycled through mechanochemical oxidation and leaching. For quantitative recovery of gallium, two different mechanochemical oxidation leaching process flow sheets are proposed. In one process, first the Ga{sub 0.97}N{sub 0.9}O{sub 0.09} of the MOCVD dust is leached at the optimum condition. Subsequently, the leach residue is mechanochemically treated, followed by oxidative annealing and finally re-leached. In the second process, the MOCVD waste dust is mechanochemically treated, followed by oxidative annealing and finally leached. Both of these treatment processes are competitive with each other, appropriate for gallium leaching and treatment of the waste MOCVD dust. Without mechanochemical oxidation, 40.11 and 1.86 w/w% of gallium and Indium are leached using 4 M HCl, 100 °C and pulp density of 100 kg/m{sup 3,} respectively. After mechanochemical oxidation, both these processes achieved 90 w/w% of gallium and 1.86 w/w% of indium leaching at their optimum condition. - Highlights: • Waste MOCVD dust is treated through mechanochemical leaching. • GaN is hardly leached, and converted to NaGaO{sub 2} through ball milling and annealing. • Process for gallium recovery from waste MOCVD dust has been developed. • Thermal analysis and phase properties of GaN to Ga{sub 2}O{sub 3} and GaN to NaGaO{sub 2} is revealed. • Solid-state chemistry involved in this process is reported.

  12. Precipitation of Zinc Oxide Nanoparticles in Bicontinuous Microemulsions

    Directory of Open Access Journals (Sweden)

    Liliana E. Romo

    2011-01-01

    Full Text Available Zinc oxide nanoparticles were obtained directly, avoiding the calcination step, by precipitation at 70°C in bicontinuous microemulsions stabilized with a mixture of surfactants sodium bis (2-ethylhexyl sulfosuccinate/sodium dodecyl sulfate (2/1, wt./wt. containing 0.7 M zinc nitrate aqueous solution. Two concentrations of aqueous solution of precipitating agent sodium hydroxide were used under different dosing times on microemulsion. Characterization by X-ray diffraction and electron microscopy allowed us to identify particles with an acicular rod-like morphology and a hexagonal wurtzite crystal structure as small as 8.5 and 30 nm in average diameter and length, respectively. Productivities much higher than those typical in the preparation of zinc oxide nanoparticles via reverse microemulsions were obtained. Particle size was the same at the two studied sodium hydroxide concentrations, while it increases as dosing time of the precipitant agent increases. It is believed that the surfactant film on the microemulsion channels restricts the particle diameter growth.

  13. Supergene Nonsulfide Zinc-Lead Deposits: The Examples of Jabali (Yemen) and Yanque (Peru)

    OpenAIRE

    Mondillo, Nicola

    2013-01-01

    “Nonsulfide zinc” is a very general term, referred to a group of ore deposits consisting of Zn-oxidized minerals, mainly represented by smithsonite, hydrozincite, hemimorphite, sauconite and willemite, which are markedly different from sphalerite ores, typically exploited for zinc. Locally, Ag minerals can occur too. The supergene nonsulfide deposits form from low-temperature oxidation of sulfide-bearing concentrations. Objective of this study is to increase the knowledge on the geology, mine...

  14. Zinc Oxide Nano crystals Synthesized by Quenching Technique

    International Nuclear Information System (INIS)

    Norhayati Abu Bakar; Akrajas Ali Umar; Muhamad Mat Salleh; Muhammad Yahya

    2011-01-01

    This paper reports an attempt to synthesize non toxic zinc oxide (ZnO) nano crystals using a simple quenching technique. The hot zinc oxide powder was quenched in hexane solution to obtain ZnO nano crystals. As the result, diameter size of the synthesized ZnO is 200 nm. It was also exhibited a good crystalline with wurtzite phase. The nano crystals properties of ZnO were revealed from good absorbance and green luminescence under UV exposure. This may be related with oxygen vacancy ionization during the annealing process. (author)

  15. Two-Dimensional Electron Gas at SrTiO3-Based Oxide Heterostructures via Atomic Layer Deposition

    Directory of Open Access Journals (Sweden)

    Sang Woon Lee

    2016-01-01

    Full Text Available Two-dimensional electron gas (2DEG at an oxide interface has been attracting considerable attention for physics research and nanoelectronic applications. Early studies reported the formation of 2DEG at semiconductor interfaces (e.g., AlGaAs/GaAs heterostructures with interesting electrical properties such as high electron mobility. Besides 2DEG formation at semiconductor junctions, 2DEG was realized at the interface of an oxide heterostructure such as the LaAlO3/SrTiO3 (LAO/STO heterojunction. The origin of 2DEG was attributed to the well-known “polar catastrophe” mechanism in oxide heterostructures, which consist of an epitaxial LAO layer on a single crystalline STO substrate among proposed mechanisms. Recently, it was reported that the creation of 2DEG was achieved using the atomic layer deposition (ALD technique, which opens new functionality of ALD in emerging nanoelectronics. This review is focused on the origin of 2DEG at oxide heterostructures using the ALD process. In particular, it addresses the origin of 2DEG at oxide interfaces based on an alternative mechanism (i.e., oxygen vacancies.

  16. Residual stress and texture in Aluminum doped Zinc Oxide layers deposited by reactive radio frequency magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Azanza Ricardo, C.L., E-mail: Cristy.Azanza@ing.unitn.it [Department of Civil, Environmental and Mechanical Engineering, University of Trento, 38123 via Mesiano 77, Trento (Italy); Pastorelli, M.; D' Incau, M. [Department of Civil, Environmental and Mechanical Engineering, University of Trento, 38123 via Mesiano 77, Trento (Italy); Aswath, P. [College of Engineering, University of Texas at Arlington, TX (United States); Scardi, P. [Department of Civil, Environmental and Mechanical Engineering, University of Trento, 38123 via Mesiano 77, Trento (Italy)

    2016-04-30

    Aluminum doped Zinc Oxide thin films were deposited on standard soda-lime substrates by reactive radio frequency magnetron sputtering. Residual stress and texture were studied by X-ray diffraction, while X-ray Absorption Near Edge Spectroscopy provided information on the Al environment in the best performing thin films. The influence of deposition parameters on structural and microstructural properties is discussed. A correlation between microstructure and residual stress state with electrical and optical properties is proposed. - Highlights: • Al doped ZnO thin films were obtained by reactive radio frequency magnetron sputtering. • Correlation of stresses and texture with electrical and optical properties is shown. • Homogeneous and stress-free thin-films are the best performing ones. • XANES confirmed the doping mechanism and excluded some spurious phases.

  17. Method to induce a conductivity type in a semiconductor

    International Nuclear Information System (INIS)

    Aboaf, J.A.; Sedgwick, T.O.

    1977-01-01

    The invention deals with a method in which one can produce a region of a desired type of conductivity in a semiconductor as is required for, e.g., field effect transistors. A metal oxide layer combination consisting of several metal oxides is thus deposited on the semiconductor. This is carried out according to the invention in a non-oxidizing atmosphere at temperatures at which the metal oxides do not diffuse into the semiconductor. The sign and degree of the induced conductivity type is adjusted by dosed depositing of the individual metal oxides related to one another. The gaseous metal oxides due to heating, mixed with a non-oxidizing gas are added in compounds to the semiconductor heated to depositing temperature. These compounds decompose at the depositing temperature into the metal oxide and a gaseous residual component. The semiconductor consists of silicon, and nitrogen is used as carrier gas; when depositing aluminium oxide, gaseous aluminium isopropoxide is added; when depositing silicon dioxide, gaseous tetra-ethyl orthosilicate. (ORU) [de

  18. COMPOSITE MATERIALS BASED ON ZINC SULFIDE AND ZINC OXIDE: STRUCTURAL AND BIOCIDAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Sukhodub L.B

    2016-12-01

    Full Text Available Introduction. The widespread use of drugs with antimicrobial action has led to the formation of microorganism resistance against wide range of antibiotics. One of the approaches to dissolving this problem is the substances modification by inorganic bioactive ions in oder to initiate a controlled reaction in the bone tissues and provision of antimicrobial activity. It is known that ZnO-based materials have a pronounced biocompatibility, they are characterized by high limit strength, absolute mechanical hardness, as well as the ability to withstand the harsh operating conditions. The aim of this work is the study of structural and biocidal properties of composite material based on zinc oxide and zinc sulfide (ZnS-ZnO and its complex with an organic substance - sodium alginate (ZnS-ZnO-Alg for use in biomedical purpose. Materials and methods. For the synthesis of ZnS-ZnO composite 50 ml 0.2M solution zinc nitrate was added to the 50 ml 0.2M thiourea CS (NH ₂ ₂ solution and stirred in a shaker for 60 minutes. The formation of the compound took place when added to a mixture of 25 mas.% solution of ammonia with the subsequent heating at 80 oC for 30 minutes. Synthesis of the metalorganic complex of ZnS-ZnO-Alg was performed by above mentioned procedure, but to the thiourea solution was previously added 1 ml of 3 mas.% solution of sodium alginate under ultrasonic mixing.. For the next research composites were dried or lyophilized. Study of antibacterial activity of the ZnS-ZnO and ZnS-ZnO-Alg particles was carried out with the use of nutrient mediums: Muller Hinton, meat-pepton nutrient (MPN. As the reference cultures were used E. coli ATCC 25922, S. aureus ATCC 25923, S. aureus ATSS 29213, S. aureus ATSS-6538, C albicans ATCC 885-653. Determination of the minimum bactericidal concentration (MBC was carried out by a modified serial diluted method in liquid nutrient broth followed plating on solid Muller Hinton nutrient medium. In addition, the

  19. Printed indium gallium zinc oxide transistors. Self-assembled nanodielectric effects on low-temperature combustion growth and carrier mobility.

    Science.gov (United States)

    Everaerts, Ken; Zeng, Li; Hennek, Jonathan W; Camacho, Diana I; Jariwala, Deep; Bedzyk, Michael J; Hersam, Mark C; Marks, Tobin J

    2013-11-27

    Solution-processed amorphous oxide semiconductors (AOSs) are emerging as important electronic materials for displays and transparent electronics. We report here on the fabrication, microstructure, and performance characteristics of inkjet-printed, low-temperature combustion-processed, amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) grown on solution-processed hafnia self-assembled nanodielectrics (Hf-SANDs). TFT performance for devices processed below 300 °C includes >4× enhancement in electron mobility (μFE) on Hf-SAND versus SiO2 or ALD-HfO2 gate dielectrics, while other metrics such as subthreshold swing (SS), current on:off ratio (ION:IOFF), threshold voltage (Vth), and gate leakage current (Ig) are unchanged or enhanced. Thus, low voltage IGZO/SAND TFT operation (IGZO combustion processing leaves the underlying Hf-SAND microstructure and capacitance intact. This work establishes the compatibility and advantages of all-solution, low-temperature fabrication of inkjet-printed, combustion-derived high-mobility IGZO TFTs integrated with self-assembled hybrid organic-inorganic nanodielectrics.

  20. Study of transport properties of copper/zinc-oxide-nanorods-based Schottky diode fabricated on textile fabric

    International Nuclear Information System (INIS)

    Khan, Azam; Hussain, Mushtaque; Abbasi, Mazhar Ali; Ibupoto, Zafar Hussain; Nur, Omer; Willander, Magnus

    2013-01-01

    In this work, a copper/zinc-oxide (ZnO)-nanorods-based Schottky diode was fabricated on the textile fabric substrate. ZnO nanorods were grown on a silver-coated textile fabric substrate by using the hydrothermal route. Scanning electron microscopy and x-ray diffraction techniques were used for the structural study. The electrical characterization of copper/ZnO-nanorods-based Schottky diodes was investigated by using a semiconductor parameter analyzer and an impedance spectrometer. The current density–voltage (J–V) and capacitance–voltage (C–V) measurements were used to estimate the electrical parameters. The threshold voltage (V th ), ideality factor (η), barrier height (ϕ b ), reverse saturation current density (J s ), carrier concentration (N D ) and built-in potential (V bi ) were determined by using experimental data and (simulated) curve fitting. This study describes the possible fabrication of electronic and optoelectronic devices on textile fabric substrate with an acceptable performance. (paper)

  1. Thermoluminescence of novel zinc oxide nano phosphors obtained by glycine-based solution combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Orante B, V. R.; Escobar O, F. M.; Cruz V, C. [Universidad de Sonora, Departamento de Investigacion en Polimeros y Materiales, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Bernal, R., E-mail: victor.orante@polimeros.uson.mx [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83190 Hermosillo, Sonora (Mexico)

    2015-10-15

    Full text: High-dose thermoluminescence dosimetry properties of novel zinc oxide nano phosphors synthesized by a solution combustion method in a glycine-nitrate process are presented for the very first time in this work. Sintered particles with sizes ranging between ∼500 nm and ∼2 μm were obtained by annealing the synthesized Zn O at 900 degrees C during 2 h in air. X-ray diffraction patterns indicate the presence of the Zn O hexagonal phase, without any remaining nitrate peaks observed. Thermoluminescence glow curves of Zn O obtained after being exposed to beta radiation consists of two maxima: one located at ∼ 149 degrees C and another at ∼ 308 degrees C, the latter being the dosimetric component of the curve. The integrated Tl fading displays an asymptotic behaviour for times longer than 16 h between irradiation and the corresponding Tl readout, as well as a linear behaviour of the dose response without saturation in the studied dose interval (from 12.5 up to 400 Gy). Such features place synthesized Zn O as a promising material for high-dose radiation dosimetry applications. (Author)

  2. Thermoluminescence of novel zinc oxide nano phosphors obtained by glycine-based solution combustion synthesis

    International Nuclear Information System (INIS)

    Orante B, V. R.; Escobar O, F. M.; Cruz V, C.; Bernal, R.

    2015-10-01

    Full text: High-dose thermoluminescence dosimetry properties of novel zinc oxide nano phosphors synthesized by a solution combustion method in a glycine-nitrate process are presented for the very first time in this work. Sintered particles with sizes ranging between ∼500 nm and ∼2 μm were obtained by annealing the synthesized Zn O at 900 degrees C during 2 h in air. X-ray diffraction patterns indicate the presence of the Zn O hexagonal phase, without any remaining nitrate peaks observed. Thermoluminescence glow curves of Zn O obtained after being exposed to beta radiation consists of two maxima: one located at ∼ 149 degrees C and another at ∼ 308 degrees C, the latter being the dosimetric component of the curve. The integrated Tl fading displays an asymptotic behaviour for times longer than 16 h between irradiation and the corresponding Tl readout, as well as a linear behaviour of the dose response without saturation in the studied dose interval (from 12.5 up to 400 Gy). Such features place synthesized Zn O as a promising material for high-dose radiation dosimetry applications. (Author)

  3. Method for depositing high-quality microcrystalline semiconductor materials

    Science.gov (United States)

    Guha, Subhendu [Bloomfield Hills, MI; Yang, Chi C [Troy, MI; Yan, Baojie [Rochester Hills, MI

    2011-03-08

    A process for the plasma deposition of a layer of a microcrystalline semiconductor material is carried out by energizing a process gas which includes a precursor of the semiconductor material and a diluent with electromagnetic energy so as to create a plasma therefrom. The plasma deposits a layer of the microcrystalline semiconductor material onto the substrate. The concentration of the diluent in the process gas is varied as a function of the thickness of the layer of microcrystalline semiconductor material which has been deposited. Also disclosed is the use of the process for the preparation of an N-I-P type photovoltaic device.

  4. Properties of Co-deposited indium tin oxide and zinc oxide films using a bipolar pulse power supply and a dual magnetron sputter source

    International Nuclear Information System (INIS)

    Hwang, Man-Soo; Seob Jeong, Heui; Kim, Won Mok; Seo, Yong Woon

    2003-01-01

    Multilayer coatings consisting of metal layers sandwiched between transparent conducting oxide layers are widely used for flat panel display electrodes and electromagnetic shield coatings for plasma displays, due to their high electrical conductivity and light transmittance. The electrical and optical properties of these multilayer films depend largely on the surface characteristics of the transparent conducting oxide thin films. A smoother surface on the transparent conducting oxide thin films makes it easier for the metal layer to form a continuous film, thus resulting in a higher conductivity and visible light transmittance. Indium tin oxide (ITO) and zinc oxide (ZnO) films were co-deposited using a dual magnetron sputter and a bipolar pulse power supply to decrease the surface roughness of the transparent conducting oxide films. The symmetric pulse mode of the power supply was used to simultaneously sputter an In 2 O 3 (90 wt %) : SnO 2 (10 wt %) target and a ZnO target. We varied the duty of the pulses to control the ratio of ITO : ZnO in the thin films. The electrical and optical properties of the films were studied, and special attention was paid to the surface roughness and the crystallinity of the films. By co-depositing ITO and ZnO at a pulse duty ratio of ITO:ZnO=45:45 using a dual magnetron sputter and a bipolar pulse power supply, we were able to obtain amorphous transparent conducting oxide films with a very smooth surface which had a Zn-rich buffer layer under a In-rich surface layer. All of the films exhibited typical electrical and optical properties of transparent conducting oxide films deposited at room temperature

  5. DC sputter deposition of amorphous indium-gallium-zinc-oxide (a-IGZO) films with H2O introduction

    International Nuclear Information System (INIS)

    Aoi, Takafumi; Oka, Nobuto; Sato, Yasushi; Hayashi, Ryo; Kumomi, Hideya; Shigesato, Yuzo

    2010-01-01

    Amorphous indium-gallium-zinc-oxide (a-IGZO) films were deposited by dc magnetron sputtering with H 2 O introduction and how the H 2 O partial pressure (P H 2 O ) during the deposition affects the electrical properties of the films was investigated in detail. Resistivity of the a-IGZO films increased dramatically to over 2 x 10 5 Ωcm with increasing P H 2 O to 2.7 x 10 -2 Pa while the hydrogen concentration in the films increased to 2.0 x 10 21 cm -3 . TFTs using a-IGZO channels deposited under P H 2 O at 1.6-8.6 x 10 -2 Pa exhibited a field-effect mobility of 1.4-3.0 cm 2 /Vs, subthreshold swing of 1.0-1.6 V/decade and on-off current ratio of 3.9 x 10 7 -1.0 x 10 8 .

  6. Activation of sputter-processed indium-gallium-zinc oxide films by simultaneous ultraviolet and thermal treatments.

    Science.gov (United States)

    Tak, Young Jun; Ahn, Byung Du; Park, Sung Pyo; Kim, Si Joon; Song, Ae Ran; Chung, Kwun-Bum; Kim, Hyun Jae

    2016-02-23

    Indium-gallium-zinc oxide (IGZO) films, deposited by sputtering at room temperature, still require activation to achieve satisfactory semiconductor characteristics. Thermal treatment is typically carried out at temperatures above 300 °C. Here, we propose activating sputter- processed IGZO films using simultaneous ultraviolet and thermal (SUT) treatments to decrease the required temperature and enhance their electrical characteristics and stability. SUT treatment effectively decreased the amount of carbon residues and the number of defect sites related to oxygen vacancies and increased the number of metal oxide (M-O) bonds through the decomposition-rearrangement of M-O bonds and oxygen radicals. Activation of IGZO TFTs using the SUT treatment reduced the processing temperature to 150 °C and improved various electrical performance metrics including mobility, on-off ratio, and threshold voltage shift (positive bias stress for 10,000 s) from 3.23 to 15.81 cm(2)/Vs, 3.96 × 10(7) to 1.03 × 10(8), and 11.2 to 7.2 V, respectively.

  7. Enhanced photoluminescence in transparent thin films of polyaniline–zinc oxide nanocomposite prepared from oleic acid modified zinc oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sajimol Augustine, M., E-mail: sajimollazar@gmail.com [Department of Physics, St. Teresa' s College, Kochi-11, Kerala (India); Jeeju, P.P.; Varma, S.J.; Francis Xavier, P.A. [Division for Research in Advanced Materials, Department of Physics, Cochin University of Science and Technology, Kochi-22, Kerala (India); Jayalekshmi, S., E-mail: lakshminathcusat@gmail.com [Division for Research in Advanced Materials, Department of Physics, Cochin University of Science and Technology, Kochi-22, Kerala (India)

    2014-07-01

    Oleic acid capped zinc oxide (ZnO) nanoparticles have been synthesized by a wet chemical route. The chemical oxidative method is employed to synthesize polyaniline (PANI) and PANI/ZnO nanocomposites doped with four different dopants such as orthophosphoric acid (H{sub 3}PO{sub 4}), hydrochloric acid (HCl), naphthalene-2-sulphonic acid and camphor sulphonic acid (CSA). The samples have been structurally characterized by X-ray diffraction (XRD), field emission scanning electron microscopy and Fourier transform infrared (FT-IR) spectroscopic techniques. A comparison of the photoluminescence (PL) emission intensity of PANI and PANI/ZnO nanocomposites is attempted. The enhanced PL intensity in PANI/ZnO nanocomposites is caused by the presence of nanostructured and highly fluorescent ZnO in the composites. It has been observed that, among the composites, the H{sub 3}PO{sub 4} doped PANI/ZnO nanocomposite is found to exhibit the highest PL intensity because of the higher extent of (pi) conjugation and the more orderly arrangement of the benzenoid and quinonoid units. In the present work, transparent thin films of PANI and PANI/ZnO nanocomposite for which PL intensity is found to be maximum, have been prepared after re-doping with CSA by the spin-coating technique. The XRD pattern of the PANI/ZnO film shows exceptionally good crystallanity compared to that of pure PANI, which suggests that the addition of ZnO nanocrystals helps in enhancing the crystallanity of the PANI/ZnO nanocomposite. There is a significant increase in the PL emission intensity of the PANI/ZnO nanocomposite film making it suitable for the fabrication of optoelectronic devices. - Highlights: • Oleic acid capped zinc oxide nanoparticles are synthesized by wet chemical method. • Polyaniline/zinc oxide nanocomposites are prepared by in-situ polymerization. • Polyaniline and polyaniline/zinc oxide thin films are deposited using spin-coating. • Enhanced photoluminescence is observed in polyaniline/zinc

  8. Charge transport in dye-sensibilized porous zinc oxide films; Ladungstransport in farbstoffsensibilisierten poroesen Zinkoxidfilmen

    Energy Technology Data Exchange (ETDEWEB)

    Reemts, J.

    2006-05-18

    During the last decades, zinc oxide has attracted a lot of attention as an important material in various electrical, chemical, and optical applications. In the present work results are discussed gained from investigations of highly porous electrochemically deposited zinc oxide, which is a promising electrode material both in the area of solar energy conversion and sensor technology. The films were prepared by adding detergents during the electrodeposition process. The detergents have a structure-directing influence during the film deposition and, therefore, on the morphology of the films. The obtained electrodes can easily be sensitized for light or different chemicals by a simple adsorption of different molecules. In the present work I discuss the fundamental charge transport properties of electrochemically deposited zinc oxide films. Temperature-dependent measurements of the current-voltage characteristics are carried out and the spectral response of the photoconductivity is investigated. In order to understand the charge transport properties of this highly porous material, it is necessary to get a deeper insight in the electrode morphology. Therefore, different optical and scanning probe microscopy methods are used to characterize the inner structure of the electrodes. The electrical conductivity of the zinc oxide films can be seen as a thermally activated process, which can be explained by electronic transitions from the valence band of the zinc oxide to two shallow impurity levels. The current-voltage characteristic unveils a nonlinear behavior which can be explained by a space-charge-limited current model with traps distributed in energy. Upon excitation with different wavelengths, the conductivity of the zinc oxide increases already under sub-band gap illumination due to widely distributed trap states within the band gap. The transients of the photoconductivity follow a stretched exponential law with time scales in the range of several hours, either if the

  9. Solid solutions of gadolinium doped zinc oxide nanorods by combined microwave-ultrasonic irradiation assisted crystallization

    Science.gov (United States)

    Kiani, Armin; Dastafkan, Kamran; Obeydavi, Ali; Rahimi, Mohammad

    2017-12-01

    Nanocrystalline solid solutions consisting of un-doped and gadolinium doped zinc oxide nanorods were fabricated by a modified sol-gel process utilizing combined ultrasonic-microwave irradiations. Polyvinylpyrrolidone, diethylene glycol, and triethylenetetramine respectively as capping, structure directing, and complexing agents were used under ultrasound dynamic aging and microwave heating to obtain crystalline nanorods. Crystalline phase monitoring, lattice parameters and variation, morphology and shape, elemental analysis, functional groups, reducibility, and the oxidation state of emerged species were examined by PXRD, FESEM, TEM, EDX, FTIR, micro Raman, H2-TPR, and EPR techniques. Results have verified that irradiation mechanism of gelation and crystallization reduces the reaction time, augments the crystal quality, and formation of hexagonal close pack structure of Wurtzite morphology. Besides, dissolution of gadolinium within host lattice involves lattice deformation, unit cell distortion, and angular position variation. Structure related shape and growth along with compositional purity were observed through microscopic and spectroscopic surveys. Furthermore, TPR and EPR studies elucidated more detailed behavior upon exposure to the exerted irradiations and subsequent air-annealing including the formed oxidation states and electron trapping centers, presence of gadolinium, zinc, and oxygen disarrays and defects, as well as alteration in the host unit cell via gadolinium addition.

  10. Zinc electrode - its behaviour in the nickel oxide-zinc accumulator

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    Certain aspects of zinc electrode reaction and behavior are investigated in view of their application to batteries. The properties of the zinc electrode in a battery system are discussed, emphasizing porous structure. Shape change is emphasized as the most important factor leading to limited battery cycle life. It is shown that two existing models of shape change based on electroosmosis and current distribution are unable to consistently describe observed phenomena. The first stages of electrocrystallization are studied and the surface reactions between the silver substrate and the deposited zinc layer are investigated. The reaction mechanism of zinc and amalgamated zinc in an alkaline electrolyte is addressed, and the batter system is studied to obtain information on cycling behavior and on the shape change phenomenon. The effect on cycle behavior of diferent amalgamation techniques of the zinc electrode and several additives is addressed. Impedance measurements on zinc electrodes are considered, and battery behavior is correlated with changes in the zinc electrode during cycling. 193 references.

  11. Monocrystalline zinc oxide films grown by atomic layer deposition

    International Nuclear Information System (INIS)

    Wachnicki, L.; Krajewski, T.; Luka, G.; Witkowski, B.; Kowalski, B.; Kopalko, K.; Domagala, J.Z.; Guziewicz, M.; Godlewski, M.; Guziewicz, E.

    2010-01-01

    In the present work we report on the monocrystalline growth of (00.1) ZnO films on GaN template by the Atomic Layer Deposition technique. The ZnO films were obtained at temperature of 300 o C using dietylzinc (DEZn) as a zinc precursor and deionized water as an oxygen precursor. High resolution X-ray diffraction analysis proves that ZnO layers are monocrystalline with rocking curve FWHM of the 00.2 peak equals to 0.07 o . Low temperature photoluminescence shows a sharp and bright excitonic line with FWHM of 13 meV.

  12. Effects of Zinc Injection on the Cladding Oxide Thickness in the Domestic Nuclear Power Plant

    International Nuclear Information System (INIS)

    Yoon, Hak Kyu; Kim, Hong Jin; Shin, Jung Cheol

    2013-01-01

    The first commercial plant for zinc injection demonstration was Farley-2 in 1994, and the effect of zinc injection was successfully demonstrated. Since then the PWR with zinc injection has been increased, there are about 80 PWR with zinc injection in the world in 2012. Zinc injection at the high duty plant has potential risk of increasing the cladding oxide thickness. Zinc injection doesn't affect the cladding corrosion directly but it may negatively affect crud deposit in the subcooled boiling region of the fuel. So the effect of zinc injection on fuel integrity has been evaluated. For low duty plant it is confirmed that zinc injection doesn't affect the fuel integrity. For high duty plant Callaway in U. S. and Vandellos II in Spain were successfully demonstrated but the experience with zinc injection of high duty plant was still lacking. Thus EPRI recommend the fuel surveillance programs for the high duty plant to apply zinc. The High Duty Core Index (HDCI) of most domestic nuclear power plant is above 150 Btu/ft 2 -gal- .deg. F. Those plants with a HDCI of 150 Btu/ft 2 -gal- .deg. F or greater may be considered as 'high duty'. As aforementioned, the experience with zinc injection of high duty plant was lacking. Thus to apply zinc injection in domestic plant with high duty, prudent approach is needed. In this study the effect of zinc injection in Hanul unit 1 with a HDCI of around 150 Btu/ft 2 -gal- .deg. F was evaluated. And in the next study the effect of zinc injection in the plant of HDCI of around 200 Btu/ft 2 -gal- .deg. F will be evaluated. Zinc injection had not caused any increase in oxide thickness in Hanul unit 1. Most of the oxide thickness measurement data with zinc injection are well within the non-zinc injection database. And the computer code which was developed based on non-zinc injection database well predicts oxide thickness for fuel rod with zinc injection. Thus, it can be concluded that zinc injection doesn't accelerate clad corrosion. Based

  13. Semiconductor

    International Nuclear Information System (INIS)

    2000-01-01

    This book deals with process and measurement of semiconductor. It contains 20 chapters, which goes as follows; semiconductor industry, introduction of semiconductor manufacturing, yield of semiconductor process, materials, crystal growth and a wafer forming, PN, control pollution, oxidation, photomasking photoresist chemistry, photomasking technologies, diffusion and ion injection, chemical vapor deposition, metallization, wafer test and way of evaluation, semiconductor elements, integrated circuit and semiconductor circuit technology.

  14. Tantalum-based semiconductors for solar water splitting.

    Science.gov (United States)

    Zhang, Peng; Zhang, Jijie; Gong, Jinlong

    2014-07-07

    Solar energy utilization is one of the most promising solutions for the energy crises. Among all the possible means to make use of solar energy, solar water splitting is remarkable since it can accomplish the conversion of solar energy into chemical energy. The produced hydrogen is clean and sustainable which could be used in various areas. For the past decades, numerous efforts have been put into this research area with many important achievements. Improving the overall efficiency and stability of semiconductor photocatalysts are the research focuses for the solar water splitting. Tantalum-based semiconductors, including tantalum oxide, tantalate and tantalum (oxy)nitride, are among the most important photocatalysts. Tantalum oxide has the band gap energy that is suitable for the overall solar water splitting. The more negative conduction band minimum of tantalum oxide provides photogenerated electrons with higher potential for the hydrogen generation reaction. Tantalates, with tunable compositions, show high activities owning to their layered perovskite structure. (Oxy)nitrides, especially TaON and Ta3N5, have small band gaps to respond to visible-light, whereas they can still realize overall solar water splitting with the proper positions of conduction band minimum and valence band maximum. This review describes recent progress regarding the improvement of photocatalytic activities of tantalum-based semiconductors. Basic concepts and principles of solar water splitting will be discussed in the introduction section, followed by the three main categories regarding to the different types of tantalum-based semiconductors. In each category, synthetic methodologies, influencing factors on the photocatalytic activities, strategies to enhance the efficiencies of photocatalysts and morphology control of tantalum-based materials will be discussed in detail. Future directions to further explore the research area of tantalum-based semiconductors for solar water splitting

  15. The bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens

    OpenAIRE

    Veldkamp, T.; Diepen, van, J.T.M.; Bikker, P.

    2014-01-01

    Zinc is an essential trace element for all farm animal species. It is commonly included in animal diets as zinc oxide, zinc sulphate or organically bound zinc. Umicore Zinc Chemicals developed zinc oxide products with different mean particle sizes. Umicore Zinc Chemicals requested Wageningen UR Livestock Research to determine the bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens. A precise estimate of the bioavailability of zinc sources is required both for fulf...

  16. Pulsed laser deposition of transparent conductive oxide thin films on flexible substrates

    Science.gov (United States)

    Socol, G.; Socol, M.; Stefan, N.; Axente, E.; Popescu-Pelin, G.; Craciun, D.; Duta, L.; Mihailescu, C. N.; Mihailescu, I. N.; Stanculescu, A.; Visan, D.; Sava, V.; Galca, A. C.; Luculescu, C. R.; Craciun, V.

    2012-11-01

    The influence of target-substrate distance during pulsed laser deposition of indium zinc oxide (IZO), indium tin oxide (ITO) and aluminium-doped zinc oxide (AZO) thin films grown on polyethylene terephthalate (PET) substrates was investigated. It was found that the properties of such flexible transparent conductive oxide (TCO)/PET electrodes critically depend on this parameter. The TCO films that were deposited at distances of 6 and 8 cm exhibited an optical transmittance higher than 90% in the visible range and electrical resistivities around 5 × 10-4 Ω cm. In addition to these excellent electrical and optical characteristics the films grown at 8 cm distance were homogenous, smooth, adherent, and without cracks or any other extended defects, being suitable for opto-electronic device applications.

  17. Solution precursor plasma deposition of nanostructured ZnO coatings

    International Nuclear Information System (INIS)

    Tummala, Raghavender; Guduru, Ramesh K.; Mohanty, Pravansu S.

    2011-01-01

    Highlights: → The solution precursor route employed is an inexpensive process with capability to produce large scale coatings at fast rates on mass scale production. → It is highly capable of developing tailorable nanostructures. → This technique can be employed to spray the coatings on any kind of substrates including polymers. → The ZnO coatings developed via solution precursor plasma spray process have good electrical conductivity and reflectivity properties in spite of possessing large amount of particulate boundaries, porosity and nanostructured grains. -- Abstract: Zinc oxide (ZnO) is a wide band gap semiconducting material that has various applications including optical, electronic, biomedical and corrosion protection. It is usually synthesized via processing routes, such as vapor deposition techniques, sol-gel, spray pyrolysis and thermal spray of pre-synthesized ZnO powders. Cheaper and faster synthesis techniques are of technological importance due to increased demand in alternative energy applications. Here, we report synthesis of nanostructured ZnO coatings directly from a solution precursor in a single step using plasma spray technique. Nanostructured ZnO coatings were deposited from the solution precursor prepared using zinc acetate and water/isopropanol. An axial liquid atomizer was employed in a DC plasma spray torch to create fine droplets of precursor for faster thermal treatment in the plasma plume to form ZnO. Microstructures of coatings revealed ultrafine particulate agglomerates. X-ray diffraction confirmed polycrystalline nature and hexagonal Wurtzite crystal structure of the coatings. Transmission electron microscopy studies showed fine grains in the range of 10-40 nm. Observed optical transmittance (∼65-80%) and reflectivity (∼65-70%) in the visible spectrum, and electrical resistivity (48.5-50.1 mΩ cm) of ZnO coatings are attributed to ultrafine particulate morphology of the coatings.

  18. Solution precursor plasma deposition of nanostructured ZnO coatings

    Energy Technology Data Exchange (ETDEWEB)

    Tummala, Raghavender [Department of Mechanical Engineering, University of Michigan - Dearborn, MI 48128 (United States); Guduru, Ramesh K., E-mail: rkguduru@umich.edu [Department of Mechanical Engineering, University of Michigan - Dearborn, MI 48128 (United States); Mohanty, Pravansu S. [Department of Mechanical Engineering, University of Michigan - Dearborn, MI 48128 (United States)

    2011-08-15

    Highlights: {yields} The solution precursor route employed is an inexpensive process with capability to produce large scale coatings at fast rates on mass scale production. {yields} It is highly capable of developing tailorable nanostructures. {yields} This technique can be employed to spray the coatings on any kind of substrates including polymers. {yields} The ZnO coatings developed via solution precursor plasma spray process have good electrical conductivity and reflectivity properties in spite of possessing large amount of particulate boundaries, porosity and nanostructured grains. -- Abstract: Zinc oxide (ZnO) is a wide band gap semiconducting material that has various applications including optical, electronic, biomedical and corrosion protection. It is usually synthesized via processing routes, such as vapor deposition techniques, sol-gel, spray pyrolysis and thermal spray of pre-synthesized ZnO powders. Cheaper and faster synthesis techniques are of technological importance due to increased demand in alternative energy applications. Here, we report synthesis of nanostructured ZnO coatings directly from a solution precursor in a single step using plasma spray technique. Nanostructured ZnO coatings were deposited from the solution precursor prepared using zinc acetate and water/isopropanol. An axial liquid atomizer was employed in a DC plasma spray torch to create fine droplets of precursor for faster thermal treatment in the plasma plume to form ZnO. Microstructures of coatings revealed ultrafine particulate agglomerates. X-ray diffraction confirmed polycrystalline nature and hexagonal Wurtzite crystal structure of the coatings. Transmission electron microscopy studies showed fine grains in the range of 10-40 nm. Observed optical transmittance ({approx}65-80%) and reflectivity ({approx}65-70%) in the visible spectrum, and electrical resistivity (48.5-50.1 m{Omega} cm) of ZnO coatings are attributed to ultrafine particulate morphology of the coatings.

  19. Separation of cadmium from solutions containing high concentration of zinc ions

    International Nuclear Information System (INIS)

    Sharma, K.D.; Bhutani, A.K.; Parvathisem, P.

    1984-01-01

    In hydrometallurgical process of extracting cadmium as a byproduct, zinc dust is added for separation of cadmium as cadimum sponge. High amounts of zinc are quite often noticed in the cadmium electrolyte subjected for electrowinning of the metal. This leads to poor quality of cadmium deposit and lower current efficiencies. Study of cadmium sponge cementation process revealed that zinc dust may be added to an acidic cadmium solution for precipitation of cadmium sponge without neutralization of the free acidity present in the system. This fact is utilized for obtaining a high cadmium sponge with 75-80 per cent cadmium and 5-10 per cent zinc with 98 per cent recovery of cadmium from the solution as sponge. The suggested process is confirmed in a cadmium production plant producing 11.0 MT of cadmium per month. (author)

  20. Second order nonlinear optical properties of zinc oxide films deposited by low temperature dual ion beam sputtering

    International Nuclear Information System (INIS)

    Larciprete, M.C.; Passeri, D.; Michelotti, F.; Paoloni, S.; Sibilia, C.; Bertolotti, M.; Belardini, A.; Sarto, F.; Somma, F.; Lo Mastro, S.

    2005-01-01

    We investigated second order optical nonlinearity of zinc oxide thin films, grown on glass substrates by the dual ion beam sputtering technique under different deposition conditions. Linear optical characterization of the films was carried out by spectrophotometric optical transmittance and reflectance measurements, giving the complex refractive index dispersion. Resistivity of the films was determined using the four-point probe sheet resistance method. Second harmonic generation measurements were performed by means of the Maker fringes technique where the fundamental beam was originated by nanosecond laser at λ=1064 nm. We found a relatively high nonlinear optical response, and evidence of a dependence of the nonlinear coefficient on the deposition parameters for each sample. Moreover, the crystalline properties of the films were investigated by x-ray diffraction measurements and correlation with second order nonlinearity were analyzed. Finally, we investigated the influence of the oxygen flow rate during the deposition process on both the second order nonlinearity and the structural properties of the samples

  1. Laser vapor phase deposition of semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Karlov, N.V.; Luk' ianchuk, B.S.; Sisakian, E.V.; Shafeev, G.A.

    1987-06-01

    The pyrolytic effect of IR laser radiation is investigated with reference to the initiation and control of the vapor phase deposition of semiconductor films. By selecting the gas mixture composition and laser emission parameters, it is possible to control the deposition and crystal formation processes on the surface of semiconductors, with the main control action achieved due to the nonadiabatic kinetics of reactions in the gas phase and high temperatures in the laser heating zone. This control mechanism is demonstrated experimentally during the laser vapor deposition of germanium and silicon films from tetrachlorides on single-crystal Si and Ge substrates. 5 references.

  2. Highly sensitive methanol chemical sensor based on undoped silver oxide nanoparticles prepared by a solution method

    International Nuclear Information System (INIS)

    Rahman, M.M.; Khan, S.B.; Asiri, A.M.; Jamal, A.; Faisal, M.

    2012-01-01

    We have prepared silver oxide nanoparticles (NPs) by a simple solution method using reducing agents in alkaline medium. The resulting NPs were characterized by UV-vis and FT-IR spectroscopy, X-ray powder diffraction, and field-emission scanning electron microscopy. They were deposited on a glassy carbon electrode to give a sensor with a fast response towards methanol in liquid phase. The sensor also displays good sensitivity and long-term stability, and enhanced electrochemical response. The calibration plot is linear (r 2 = 0.8294) over the 0.12 mM to 0.12 M methanol concentration range. The sensitivity is ∼ 2.65 μAcm -2 mM -1 , and the detection limit is 36.0 μM (at a SNR of 3). We also discuss possible future prospective uses of this metal oxide semiconductor nanomaterial in terms of chemical sensing. (author)

  3. Properties of Semiconductors: Synthesis of Oriented ZnO for Photoelectrochemistry and Photoremediation

    Science.gov (United States)

    Koenig, Emma; Jacobs, Ari; Lisensky, George

    2017-01-01

    Semiconductors are an important class of materials; preparing ZnO nanorods allows semiconducting properties to be easily observed. The week before lab, groups of four students take 15 min to setup two fluorine-doped tin oxide glass (FTO) slides in a zinc nitrate and hexamethylenetetramine solution stored at 90°C until the next lab. Hexagonal ZnO…

  4. Memory characteristics of Au nanocrystals embedded in metal-oxide-semiconductor structure by using atomic-layer-deposited Al2O3 as control oxide

    International Nuclear Information System (INIS)

    Wang, C.-C.; Chiou, Y.-K.; Chang, C.-H.; Tseng, J.-Y.; Wu, L.-J.; Chen, C.-Y.; Wu, T.-B.

    2007-01-01

    The nonvolatile memory characteristics of metal-oxide-semiconductor (MOS) structures containing Au nanocrystals in the Al 2 O 3 /SiO 2 matrix were studied. In this work, we have demonstrated that the use of Al 2 O 3 as control oxide prepared by atomic-layer-deposition enhances the erase speed of the MOS capacitors. A giant capacitance-voltage hysteresis loop and a very short erase time which is lower than 1 ms can be obtained. Compared with the conventional floating-gate electrically erasable programmable read-only memories, the erase speed was promoted drastically. In addition, very low leakage current and large turn-around voltage resulting from electrons or holes stored in the Au nanocrystals were found in the current-voltage relation of the MOS capacitors

  5. A Zinc Oxide Nanorod Ammonia Microsensor Integrated with a Readout Circuit on-a-Chip

    Directory of Open Access Journals (Sweden)

    Chyan-Chyi Wu

    2011-11-01

    Full Text Available A zinc oxide nanorod ammonia microsensor integrated with a readout circuit on-a-chip fabricated using the commercial 0.35 mm complementary metal oxide semiconductor (CMOS process was investigated. The structure of the ammonia sensor is composed of a sensitive film and polysilicon electrodes. The ammonia sensor requires a post-process to etch the sacrificial layer, and to coat the sensitive film on the polysilicon electrodes. The sensitive film that is prepared by a hydrothermal method is made of zinc oxide. The sensor resistance changes when the sensitive film adsorbs or desorbs ammonia gas. The readout circuit is used to convert the sensor resistance into the voltage output. Experiments show that the ammonia sensor has a sensitivity of about 1.5 mV/ppm at room temperature.

  6. Enhancement in sensitivity of graphene-based zinc oxide assisted bimetallic surface plasmon resonance (SPR) biosensor

    Science.gov (United States)

    Kumar, Rajeev; Kushwaha, Angad S.; Srivastava, Monika; Mishra, H.; Srivastava, S. K.

    2018-03-01

    In the present communication, a highly sensitive surface plasmon resonance (SPR) biosensor with Kretschmann configuration having alternate layers, prism/zinc oxide/silver/gold/graphene/biomolecules (ss-DNA) is presented. The optimization of the proposed configuration has been accomplished by keeping the constant thickness of zinc oxide (32 nm), silver (32 nm), graphene (0.34 nm) layer and biomolecules (100 nm) for different values of gold layer thickness (1, 3 and 5 nm). The sensitivity of the proposed SPR biosensor has been demonstrated for a number of design parameters such as gold layer thickness, number of graphene layer, refractive index of biomolecules and the thickness of biomolecules layer. SPR biosensor with optimized geometry has greater sensitivity (66 deg/RIU) than the conventional (52 deg/RIU) as well as other graphene-based (53.2 deg/RIU) SPR biosensor. The effect of zinc oxide layer thickness on the sensitivity of SPR biosensor has also been analysed. From the analysis, it is found that the sensitivity increases significantly by increasing the thickness of zinc oxide layer. It means zinc oxide intermediate layer plays an important role to improve the sensitivity of the biosensor. The sensitivity of SPR biosensor also increases by increasing the number of graphene layer (upto nine layer).

  7. Fabrication and RF characterization of zinc oxide based Film Bulk Acoustic Resonator

    Science.gov (United States)

    Patel, Raju; Bansal, Deepak; Agrawal, Vimal Kumar; Rangra, Kamaljit; Boolchandani, Dharmendar

    2018-06-01

    This work reports fabrication and characterization of Film Bulk Acoustic Resonator (FBAR) to improve the performance characteristics for RF filter and sensing application. Zinc oxide as a piezoelectric (PZE) material was deposited on an aluminum bottom electrode using an RF magnetron sputtering, at room temperature, and gold as top electrode for the resonator. Tetramethyl ammonium hydroxide (TMAH) setup was used for bulk silicon etching to make back side cavity to confine the acoustic signals. The transmission characteristics show that the FBARs have a central frequency at 1.77 GHz with a return loss of -10.7 dB.

  8. The bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens

    NARCIS (Netherlands)

    Veldkamp, T.; Diepen, van J.T.M.; Bikker, P.

    2014-01-01

    Zinc is an essential trace element for all farm animal species. It is commonly included in animal diets as zinc oxide, zinc sulphate or organically bound zinc. Umicore Zinc Chemicals developed zinc oxide products with different mean particle sizes. Umicore Zinc Chemicals requested Wageningen UR

  9. High permittivity materials for oxide gate stack in Ge-based metal oxide semiconductor capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Molle, Alessandro, E-mail: alessandro.molle@mdm.infm.i [Laboratorio Nazionale MDM, CNR-INFM, via C. Olivetti 2, 20041 Agrate Brianza, Milano (Italy); Baldovino, Silvia [Laboratorio Nazionale MDM, CNR-INFM, via C. Olivetti 2, 20041 Agrate Brianza, Milano (Italy); Dipartimento di Scienza dei Materiali, Universita degli Studi di Milano Bicocca, Milano (Italy); Spiga, Sabina [Laboratorio Nazionale MDM, CNR-INFM, via C. Olivetti 2, 20041 Agrate Brianza, Milano (Italy); Fanciulli, Marco [Laboratorio Nazionale MDM, CNR-INFM, via C. Olivetti 2, 20041 Agrate Brianza, Milano (Italy); Dipartimento di Scienza dei Materiali, Universita degli Studi di Milano Bicocca, Milano (Italy)

    2010-01-01

    In the effort to ultimately shrink the size of logic devices towards a post-Si era, the integration of Ge as alternative channel material for high-speed p-MOSFET devices and the concomitant coupling with high permittivity dielectrics (high-k) as gate oxides is currently a key-challenge in microelectronics. However, the Ge option still suffers from a number of unresolved drawbacks and open issues mainly related to the thermodynamic and electrical compatibility of Ge substrates with high-k gate stack. Strictly speaking, two main concerns can be emphasized. On one side is the dilemma on which chemical/physical passivation is more suitable to minimize the unavoidable presence of electrically active defects at the oxide/semiconductor interface. On the other side, overcoming the SiO{sub 2} gate stack opens the route to a number of potentially outperforming high-k oxides. Two deposition approaches were here separately adopted to investigate the high-k oxide growth on Ge substrates, the molecular beam deposition (MBD) of Gd{sub 2}O{sub 3} and the atomic layer deposition (ALD) of HfO{sub 2}. In the MBD framework epitaxial and amorphous Gd{sub 2}O{sub 3} films were grown onto GeO{sub 2}-passivated Ge substrates. In this case, Ge passivation was achieved by exploiting the Ge{sup 4+} bonding state in GeO{sub 2} ultra-thin interface layers intentionally deposited in between Ge and the high-k oxide by means of atomic oxygen exposure to Ge. The composition of the interface layer has been characterized as a function of the oxidation temperature and evidence of Ge dangling bonds at the GeO{sub 2}/Ge interface has been reported. Finally, the electrical response of MOS capacitors incorporating Gd{sub 2}O{sub 3} and GeO{sub 2}-passivated Ge substrates has been checked by capacitance-voltage measurements. On the other hand, the structural and electrical properties of HfO{sub 2} films grown by ALD on Ge by using different oxygen precursors, i.e. H{sub 2}O, Hf(O{sup t}Bu){sub 2}(mmp

  10. Daya antibakteri penambahan Propolis pada zinc oxide eugenol dan zinc oxide terhadap kuman campur gigi molar sulung non vital (The antibacterial effect of propolis additional to zinc oxide eugenol and zinc oxide on polybacteria of necrotic primary molar

    Directory of Open Access Journals (Sweden)

    Yemy Ameliana

    2014-12-01

    Full Text Available Background: Materials commonly used for root canal filling of primary teeth is zinc oxide eugenol. Eugenol has some disadvantages that can irritate the periapical tissues, has the risk of disturbing the growth and development of permanent tooth buds, and has a narrow antibacterial spectrum. Studies showed that propolis at concentration of 20 % has antibacterial activity against Staphylococcus aureus. Purpose: The purpose of this study was to examine the antimicrobial activity of root canal pastes with the additional of propolis additional to zinc oxide eugenol (ZOEP and to zinc oxide (ZOP. Methods: Polybacteria cultures collected from root canals of necrotic primary molar from 5 children patients who received root canal treatment. The bacteria were grown in BHI Broth, and inoculated into Muller Hinton Agar media. The agar plates was divided into 3 areas, and one well was made at each area. The first well filled with ZOE as a control, second well filled with ZOEP and the third well filled with ZOP, then incubated for 24 hour at 370 C. Antimicrobial activity was determined by measuring the diameters of inhibition zones of polybacteria growth. The data were statistically analyzed by independent T-test. Results: The pasta mixture of zinc oxide propolis had the strongest antibacterial activity against polybacteria of necrotic primary molar, followed by zinc oxide eugenol propolis paste, and zinc oxide eugenol paste. There were significant differences of inhibition zones between ZOE, ZOEP and ZOP (p<0,05. Conclusion: The study suggested that the additional of propolis to zinc oxide paste could increase the antimicrobial effect against root canal polybacteria of necrotic primary molar.Latar belakang: Bahan yang sering digunakan untuk pengisian saluran akar gigi sulung adalah zinc oxide eugenol. Eugenol memiliki beberapa kekurangan yaitu dapat mengiritasi jaringan periapikal, beresiko mengganggu pertumbuhan dan perkembangan benih gigi permanen pengganti

  11. Oxidant-Dependent Thermoelectric Properties of Undoped ZnO Films by Atomic Layer Deposition

    KAUST Repository

    Kim, Hyunho

    2017-02-27

    Extraordinary oxidant-dependent changes in the thermoelectric properties of undoped ZnO thin films deposited by atomic layer deposition (ALD) have been observed. Specifically, deionized water and ozone oxidants are used in the growth of ZnO by ALD using diethylzinc as a zinc precursor. No substitutional atoms have been added to the ZnO films. By using ozone as an oxidant instead of water, a thermoelectric power factor (σS) of 5.76 × 10 W m K is obtained at 705 K for undoped ZnO films. In contrast, the maximum power factor for the water-based ZnO film is only 2.89 × 10 W m K at 746 K. Materials analysis results indicate that the oxygen vacancy levels in the water- and ozone-grown ZnO films are essentially the same, but the difference comes from Zn-related defects present in the ZnO films. The data suggest that the strong oxidant effect on thermoelectric performance can be explained by a mechanism involving point defect-induced differences in carrier concentration between these two oxides and a self-compensation effect in water-based ZnO due to the competitive formations of both oxygen and zinc vacancies. This strong oxidant effect on the thermoelectric properties of undoped ZnO films provides a pathway to improve the thermoelectric performance of this important material.

  12. Effect of aluminum oxide doping on the structural, electrical, and optical properties of zinc oxide (AOZO) nanofibers synthesized by electrospinning

    International Nuclear Information System (INIS)

    Lotus, A.F.; Kang, Y.C.; Walker, J.I.; Ramsier, R.D.; Chase, G.G.

    2010-01-01

    Zinc oxide nanofibers doped with aluminum oxide were prepared by sol-gel processing and electrospinning techniques using polyvinylpyrrolidone (PVP), zinc acetate and aluminum acetate as precursors. The resulting nanofibers were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis spectroscopy, and current-voltage (I-V) properties. The nanofibers had diameters in the range of 60-150 nm. The incorporation of aluminum oxide resulted in a decrease in the crystallite sizes of the zinc oxide nanofibers. Aluminum oxide doped zinc oxide (AOZO) nanofibers exhibited lower bandgap energies compared to undoped zinc oxide nanofibers. However, as the aluminum content (Al/(Al + Zn) x 100%) was increased from 1.70 at.% to 3.20 at.% in the electrospinning solution, the bandgap energy increased resulting in lower conductivity. The electrical conductivity of the AOZO samples was found to depend on the amount of aluminum dopant in the matrix as reflected in the changes in oxidation state elucidated from XPS data. Electrospinning was found to be a productive, simple, and easy method for tuning the bandgap energy and conductivity of zinc oxide semiconducting nanofibers.

  13. Indium Doped Zinc Oxide Thin Films Deposited by Ultrasonic Chemical Spray Technique, Starting from Zinc Acetylacetonate and Indium Chloride

    Directory of Open Access Journals (Sweden)

    Rajesh Biswal

    2014-07-01

    Full Text Available The physical characteristics of ultrasonically sprayed indium-doped zinc oxide (ZnO:In thin films, with electrical resistivity as low as 3.42 × 10−3 Ω·cm and high optical transmittance, in the visible range, of 50%–70% is presented. Zinc acetylacetonate and indium chloride were used as the organometallic zinc precursor and the doping source, respectively, achieving ZnO:In thin films with growth rate in the order of 100 nm/min. The effects of both indium concentration and the substrate temperature on the structural, morphological, optical, and electrical characteristics were measured. All the films were polycrystalline, fitting well with hexagonal wurtzite type ZnO. A switching in preferential growth, from (002 to (101 planes for indium doped samples were observed. The surface morphology of the films showed a change from hexagonal slices to triangle shaped grains as the indium concentration increases. Potential applications as transparent conductive electrodes based on the resulting low electrical resistance and high optical transparency of the studied samples are considered.

  14. The anodic dissolution of zinc and zinc alloys in alkaline solution. II. Al and Zn partial dissolution from 5% Al–Zn coatings

    International Nuclear Information System (INIS)

    Vu, T.N.; Mokaddem, M.; Volovitch, P.; Ogle, K.

    2012-01-01

    Graphical abstract: - Abstract: The polarization behavior of a 5 wt% Al–Zn steel coating (Galfan™) has been investigated in alkaline solution using atomic emission spectroelectrochemistry (AESEC). The instantaneous Zn and Al dissolution rates were measured as a function of time during a linear scan and potential step transients. The formation rate of insoluble oxides was determined from the difference between the convoluted total current and the sum of the elemental dissolution currents. It was found that, over a wide potential range, the zinc and aluminum partial currents behaved in a similar way to pure zinc and pure aluminum independently. However, during the period in which zinc was active, aluminum dissolution was inhibited. This is attributed to the inhibitive effect of the first and/or the second states of zinc oxide that are formed during the active potential domain. The third form of zinc oxide, observed at higher potential and responsible for the passivation of zinc dissolution, does not have a measurable effect on the Al dissolution rate.

  15. Activity incorporation into zinc doped PWR oxides

    International Nuclear Information System (INIS)

    Maekelae, Kari

    1998-01-01

    Activity incorporation into the oxide layers of PWR primary circuit constructional materials has been studied in Halden since 1993. The first zinc injection tests showed that zinc addition resulted in thinner oxide layers on new metal surfaces and reduced further incorporation of activity into already existing oxides. These tests were continued to find out the effects of previous zinc additions on the pickup of activity onto the surface oxides which were subsequently exposed to zinc-free coolant. The results showed that previous zinc addition will continue to reduce the rate of Co-60 build-up on out-of-core surfaces in subsequent exposure to zinc-free coolants. However, the previous Zn free test was performed for a relatively short period of time and the water chemistry programme was continued to find out the long term effects for extended periods without zinc. The activity incorporation into the stainless steel oxides started to increase as soon as zinc dosing to the coolant was stopped. The Co-60 concentration was lowest on all of the coupons which were first oxidised in Zn containing primary coolant. After the zinc injection period the thickness of the oxides increased, but activity in the oxide films did not increase at the same rate. This could indicate that zinc in the oxide blocks the adsorption sites for Co-60 incorporation. The Co-60 incorporation rate into the oxides on Inconel 600 seemed to be linear whether the oxide was pre-oxidised with or without Zn. The results indicate that zinc can either replace or prevent cobalt transport in the oxides. The results show that for zinc injection to be effective it should be carried out continuously. Furthermore the actual mechanism by which Zn inhibits the activity incorporation into the oxides is still not clear. Therefore, additional work has to follow with specified materials to verify the conclusions drawn in this work. (author)

  16. Ciprofloxacin conjugated zinc oxide nanoparticle: A camouflage ...

    Indian Academy of Sciences (India)

    ZNP were small in size with particle size distribution 18–20 nm as obtained ... of zinc oxide and ciprofloxacin is effective against bacterial system. However, no reports are still available on antibacte- ... 20% aqueous TRIS solution was added drop wise to 25 ml .... Phillips CM 200 (Netherlands) at an operational voltage of.

  17. Geochemistry of the furnace magnetite bed, Franklin, New Jersey, and the relationship between stratiform iron oxide ores and stratiform zinc oxide-silicate ores in the New Jersey highlands

    Science.gov (United States)

    Johnson, C.A.; Skinner, B.J.

    2003-01-01

    The New Jersey Highlands terrace, which is an exposure of the Middle Proterozoic Grenville orogenic belt located in northeastern United States, contains stratiform zinc oxide-silicate deposits at Franklin and Sterling Hill and numerous massive magnetite deposits. The origins of the zinc and magnetite deposits have rarely been considered together, but a genetic link is suggested by the occurrence of the Furnace magnetite bed and small magnetite lenses immediately beneath the Franklin zinc deposit. The Furnace bed was metamorphosed and deformed along with its enclosing rocks during the Grenvillian orogeny, obscuring the original mineralogy and obliterating the original rock fabrics. The present mineralogy is manganiferous magnetite plus calcite. Trace hydrous silicates, some coexisting with fluorite, have fluorine contents that are among the highest ever observed in natural assemblages. Furnace bed calcite has ??13C values of -5 ?? 1 per mil relative to Peedee belemnite (PDB) and ??18O values of 11 to 20 per mil relative to Vienna-standard mean ocean water (VSMOW). The isotopic compositions do not vary as expected for an original siderite layer that decarbonated during metamorphism, but they are consistent with nearly isochemical metamorphism of an iron oxide + calcite protolith that is chemically and minerlogically similar to iron-rich sediments found near the Red Sea brine pools and isotopically similar to Superior-type banded iron formations. Other magniferous magnite + calcite bodies occur at approximately the same stratigraphic position as far 50 km from the zinc deposits. A model is presented in which the iron and zinc deposits formed along the western edge of a Middle Proterozoic marine basin. Zinc was transported by sulfate-stable brines and was precipitated under sulfate-stable conditions as zincian carbonates and Fe-Mn-Zn oxides and silicates. Whether the zincian assemblages settled from the water column or formed by replacement reactions in shallowly

  18. Effects of Zinc Injection on the Cladding Oxide Thickness in the Domestic Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hak Kyu; Kim, Hong Jin; Shin, Jung Cheol [KEPCO Nuclear Fuel Co. Ltd., Daejeon (Korea, Republic of)

    2013-10-15

    The first commercial plant for zinc injection demonstration was Farley-2 in 1994, and the effect of zinc injection was successfully demonstrated. Since then the PWR with zinc injection has been increased, there are about 80 PWR with zinc injection in the world in 2012. Zinc injection at the high duty plant has potential risk of increasing the cladding oxide thickness. Zinc injection doesn't affect the cladding corrosion directly but it may negatively affect crud deposit in the subcooled boiling region of the fuel. So the effect of zinc injection on fuel integrity has been evaluated. For low duty plant it is confirmed that zinc injection doesn't affect the fuel integrity. For high duty plant Callaway in U. S. and Vandellos II in Spain were successfully demonstrated but the experience with zinc injection of high duty plant was still lacking. Thus EPRI recommend the fuel surveillance programs for the high duty plant to apply zinc. The High Duty Core Index (HDCI) of most domestic nuclear power plant is above 150 Btu/ft{sup 2}-gal- .deg. F. Those plants with a HDCI of 150 Btu/ft{sup 2}-gal- .deg. F or greater may be considered as 'high duty'. As aforementioned, the experience with zinc injection of high duty plant was lacking. Thus to apply zinc injection in domestic plant with high duty, prudent approach is needed. In this study the effect of zinc injection in Hanul unit 1 with a HDCI of around 150 Btu/ft{sup 2}-gal- .deg. F was evaluated. And in the next study the effect of zinc injection in the plant of HDCI of around 200 Btu/ft{sup 2}-gal- .deg. F will be evaluated. Zinc injection had not caused any increase in oxide thickness in Hanul unit 1. Most of the oxide thickness measurement data with zinc injection are well within the non-zinc injection database. And the computer code which was developed based on non-zinc injection database well predicts oxide thickness for fuel rod with zinc injection. Thus, it can be concluded that zinc injection doesn

  19. High Quality Zinc Oxide Thin films and Nanostructures Prepared by Pulsed Laser Deposition for Photodetectors

    KAUST Repository

    Flemban, Tahani H.

    2017-12-11

    Zinc oxide (ZnO) semiconductors have been utilized by many researchers, due to its unique properties beneficial for functional devices. In particular, gadolinium (Gd)–doped ZnO exhibits high ferromagnetic and electrical properties, which is attributed to defect/impurity bands mediated by Gd dopants. In this dissertation, I study the effects of Gd concentration, oxygen pressure using pulsed laser deposition (PLD), and thermal annealing on the optical and structural properties of undoped and Gd-doped ZnO films and nanostructures. Moreover, as the growth of practical ZnO nanostructures-based devices without catalyst, while presently challenging, is highly important for many applications. Thus, for the first time, a novel method is developed for growing well aligned ZnO nanorods (NRs) by optimizing PLD conditions using Gd-doped ZnO target without any catalyst in a single step. This study shows that, both the lattice orientation of the substrate and the Gd characteristics are significant in enhancing the NR growth. Our findings reveal that precise control of the NR density can be achieved by changing the oxygen partial pressure. Furthermore, due to the Gd incorporation, these NRs possess favorable electrical properties with a significant mobility of 177 cm2 (V.s)-1 compared to that reported in literature. Nonetheless significant challenges need to be overcome to achieve reproducible and stable p-type ZnO for commercial applications. Hence, several attempts based on n-type ZnO grown on foreign p-type substrates were made to achieve high-performance devices and overcome the issues arising when p-type doped ZnO is employed. Moreover, Growth of ZnO nanostructures on a foreign p-type substrates does not require a lattice-matched p-type substrate. Thus, for the first time, PLD conditions are improved to grow high quality ZnO nanotubes (NTs) with high optical, structural and electrical properties on a p-type Si (100) substrate without catalyst for high-performance devices. A

  20. Boron-doped zinc oxide thin films grown by metal organic chemical vapor deposition for bifacial a-Si:H/c-Si heterojunction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Xiangbin, E-mail: eexbzeng@mail.hust.edu.cn; Wen, Xixing; Sun, Xiaohu; Liao, Wugang; Wen, Yangyang

    2016-04-30

    Boron-doped zinc oxide (BZO) films were grown by metal organic chemical vapor deposition. The influence of B{sub 2}H{sub 6} flow rate and substrate temperature on the microstructure, optical, and electrical properties of BZO films was investigated by X-ray diffraction spectrum, scanning electron microscope, optical transmittance spectrum, and Hall measurements. The BZO films with optical transmittance above 85% in the visible and infrared light range, resistivity of 0.9–1.0 × 10{sup −3} Ω cm, mobility of 16.5–25.5 cm{sup 2}/Vs, and carrier concentration of 2.2–2.7 × 10{sup 20} cm{sup −3} were deposited under optimized conditions. The optimum BZO films were applied on the bifacial BZO/p-type a-Si:H/i-type a-Si:H/n-type c-Si/i-type a-Si:H/n{sup +}-type a-Si:H/BZO heterojunction solar cell as both front and back transparent electrodes. Meanwhile, the bifacial heterojunction solar cell with indium tin oxide (ITO) as both front and back transparent electrodes was fabricated. The efficiencies of 17.788% (open-circuit voltage: 0.628 V, short-circuit current density: 41.756 mA/cm{sup 2} and fill factor: 0.678) and 16.443% (open-circuit voltage: 0.590 V, short-circuit current density: 36.515 mA/cm{sup 2} and fill factor: 0.762) were obtained on the a-Si/c-Si heterojunction solar cell with BZO and ITO transparent electrodes, respectively. - Highlights: • Boron-doped zinc oxide films with low resistivity were fabricated. • The boron-doped zinc oxide films have the high transmittance. • B-doped ZnO film was applied in a-Si:H/c-Si solar cell as transparent electrodes. • The a-Si:H/c-Si solar cell with efficiency of 17.788% was obtained.

  1. Boron-doped zinc oxide thin films grown by metal organic chemical vapor deposition for bifacial a-Si:H/c-Si heterojunction solar cells

    International Nuclear Information System (INIS)

    Zeng, Xiangbin; Wen, Xixing; Sun, Xiaohu; Liao, Wugang; Wen, Yangyang

    2016-01-01

    Boron-doped zinc oxide (BZO) films were grown by metal organic chemical vapor deposition. The influence of B_2H_6 flow rate and substrate temperature on the microstructure, optical, and electrical properties of BZO films was investigated by X-ray diffraction spectrum, scanning electron microscope, optical transmittance spectrum, and Hall measurements. The BZO films with optical transmittance above 85% in the visible and infrared light range, resistivity of 0.9–1.0 × 10"−"3 Ω cm, mobility of 16.5–25.5 cm"2/Vs, and carrier concentration of 2.2–2.7 × 10"2"0 cm"−"3 were deposited under optimized conditions. The optimum BZO films were applied on the bifacial BZO/p-type a-Si:H/i-type a-Si:H/n-type c-Si/i-type a-Si:H/n"+-type a-Si:H/BZO heterojunction solar cell as both front and back transparent electrodes. Meanwhile, the bifacial heterojunction solar cell with indium tin oxide (ITO) as both front and back transparent electrodes was fabricated. The efficiencies of 17.788% (open-circuit voltage: 0.628 V, short-circuit current density: 41.756 mA/cm"2 and fill factor: 0.678) and 16.443% (open-circuit voltage: 0.590 V, short-circuit current density: 36.515 mA/cm"2 and fill factor: 0.762) were obtained on the a-Si/c-Si heterojunction solar cell with BZO and ITO transparent electrodes, respectively. - Highlights: • Boron-doped zinc oxide films with low resistivity were fabricated. • The boron-doped zinc oxide films have the high transmittance. • B-doped ZnO film was applied in a-Si:H/c-Si solar cell as transparent electrodes. • The a-Si:H/c-Si solar cell with efficiency of 17.788% was obtained.

  2. Reactions of organic zinc- and cadmium elementoxides with ethylene oxide

    International Nuclear Information System (INIS)

    Dodonov, V.A.; Krasnov, Yu.N.

    1980-01-01

    Studied are reactions of triphenylmethoxy, -triphenylsiloxyethylzinc and -cadmium with ethylene oxide in ratio of 1:1. Reactions have been carried out in tolyene solutions in ampules sealed in argon atmosphere. It is found that interaction of triphenylsiloxy-, triphenylmethoxyethylcadmium and triphenylsiloxyethylzinc with ethylene oxide occurs at the metal-carbon bond with formation of implantation products. Triphenylmethoxyethylzinc reacts with ethylene oxide both at the metal-carbon and metal-oxygen bonds. Alkoxytriphenylsiloxyderivatives of zinc and cadmium are thermally instable and decompose under the conditions of reaction (130 deg C) with migration of phenyl group from silicon to zinc or cadmium, giving alkoxyphenylderivative and with bensene splitting out

  3. Electrophoretic deposition of zinc-substituted hydroxyapatite coatings.

    Science.gov (United States)

    Sun, Guangfei; Ma, Jun; Zhang, Shengmin

    2014-06-01

    Zinc-substituted hydroxyapatite nanoparticles synthesized by the co-precipitation method were used to coat stainless steel plates by electrophoretic deposition in n-butanol with triethanolamine as a dispersant. The effect of zinc concentration in the synthesis on the morphology and microstructure of coatings was investigated. It is found that the deposition current densities significantly increase with the increasing zinc concentration. The zinc-substituted hydroxyapatite coatings were analyzed by X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. It is inferred that hydroxyapatite and triethanolamine predominate in the chemical composition of coatings. With the increasing Zn/Ca ratios, the contents of triethanolamine decrease in the final products. The triethanolamine can be burnt out by heat treatment. The tests of adhesive strength have confirmed good adhesion between the coatings and substrates. The formation of new apatite layer on the coatings has been observed after 7days of immersion in a simulated body fluid. In summary, the results show that dense, uniform zinc-substituted hydroxyapatite coatings are obtained by electrophoretic deposition when the Zn/Ca ratio reaches 5%. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. High performance Schottky diodes based on indium-gallium-zinc-oxide

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiawei; Song, Aimin, E-mail: A.Song@manchester.ac.uk [School of Electrical and Electronic Engineering, University of Manchester, Manchester M13 9PL (United Kingdom); Xin, Qian [School of Physics, Shandong University, Jinan 250100 (China)

    2016-07-15

    Indium-gallium-zinc-oxide (IGZO) Schottky diodes exhibit excellent performance in comparison with conventional devices used in future flexible high frequency electronics. In this work, a high performance Pt IGZO Schottky diode was presented by using a new fabrication process. An argon/oxygen mixture gas was introduced during the deposition of the Pt layer to reduce the oxygen deficiency at the Schottky interface. The diode showed a high barrier height of 0.92 eV and a low ideality factor of 1.36 from the current–voltage characteristics. Even the radius of the active area was 0.1 mm, and the diode showed a cut-off frequency of 6 MHz in the rectifier circuit. Using the diode as a demodulator, a potential application was also demonstrated in this work.

  5. Zinc oxide nanotubes decorated with silver nanoparticles as an ultrasensitive substrate for surface-enhanced Raman scattering

    International Nuclear Information System (INIS)

    Gao, M.; Feng, B.; Sun, Y.; Xing, G.; Li, S.; Yang, J.; Yang, L.; Zhang, Y.; Liu, H.; Fan, H.; Sui, Y.; Zhang, Z.; Liu, S.; Song, H.

    2012-01-01

    We report on the fabrication of a highly aligned silver-decorated array of zinc oxide nanotubes for use in surface-enhanced Raman spectroscopy (SERS). The ZnO nanotube array was first prepared by chemical etching, and the silver nanoparticles (AgNPs) were then deposited on their surface by magnetron sputtering. Such ZnO/Ag hybrid structures are shown to act as SERS-active substrates with remarkable sensitivity. The enhancement factor can be as high as 10 5 when using 4-mercaptopyridine in solution as a SERS probe. The synergistic combination between SERS 'hot spots' and the formation of an interfacial electric field between the zinc oxide nanotubes and the AgNPs in our opinion contribute to the high sensitivity. The relative standard deviations of signal intensities for the major SERS peaks are <7 %. This demonstrates that the optimized ZnO/Ag hybrid represents an excellent SERS substrate that may be used in trace analysis and ultrasensitive molecular sensing. (author)

  6. Binary copper oxide semiconductors: From materials towards devices

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, B.K.; Polity, A.; Reppin, D.; Becker, M.; Hering, P.; Klar, P.J.; Sander, T.; Reindl, C.; Benz, J.; Eickhoff, M.; Heiliger, C.; Heinemann, M. [1. Physics Institute, Justus-Liebig University of Giessen (Germany); Blaesing, J.; Krost, A. [Institute of Experimental Physics (IEP), Otto-von-Guericke University Magdeburg (Germany); Shokovets, S. [Institute of Physics, Ilmenau University of Technology (Germany); Mueller, C.; Ronning, C. [Institute of Solid State Physics, Friedrich Schiller University Jena (Germany)

    2012-08-15

    Copper-oxide compound semiconductors provide a unique possibility to tune the optical and electronic properties from insulating to metallic conduction, from bandgap energies of 2.1 eV to the infrared at 1.40 eV, i.e., right into the middle of the efficiency maximum for solar-cell applications. Three distinctly different phases, Cu{sub 2}O, Cu{sub 4}O{sub 3}, and CuO, of this binary semiconductor can be prepared by thin-film deposition techniques, which differ in the oxidation state of copper. Their material properties as far as they are known by experiment or predicted by theory are reviewed. They are supplemented by new experimental results from thin-film growth and characterization, both will be critically discussed and summarized. With respect to devices the focus is on solar-cell performances based on Cu{sub 2}O. It is demonstrated by photoelectron spectroscopy (XPS) that the heterojunction system p-Cu{sub 2}O/n-AlGaN is much more promising for the application as efficient solar cells than that of p-Cu{sub 2}O/n-ZnO heterojunction devices that have been favored up to now. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Amorphous Hafnium-Indium-Zinc Oxide Semiconductor Thin Film Transistors

    Directory of Open Access Journals (Sweden)

    Sheng-Po Chang

    2012-01-01

    Full Text Available We reported on the performance and electrical properties of co-sputtering-processed amorphous hafnium-indium-zinc oxide (α-HfIZO thin film transistors (TFTs. Co-sputtering-processed α-HfIZO thin films have shown an amorphous phase in nature. We could modulate the In, Hf, and Zn components by changing the co-sputtering power. Additionally, the chemical composition of α-HfIZO had a significant effect on reliability, hysteresis, field-effect mobility (μFE, carrier concentration, and subthreshold swing (S of the device. Our results indicated that we could successfully and easily fabricate α-HfIZO TFTs with excellent performance by the co-sputtering process. Co-sputtering-processed α-HfIZO TFTs were fabricated with an on/off current ratio of ~106, higher mobility, and a subthreshold slope as steep as 0.55 V/dec.

  8. Activation of sputter-processed indium–gallium–zinc oxide films by simultaneous ultraviolet and thermal treatments

    Science.gov (United States)

    Tak, Young Jun; Du Ahn, Byung; Park, Sung Pyo; Kim, Si Joon; Song, Ae Ran; Chung, Kwun-Bum; Kim, Hyun Jae

    2016-01-01

    Indium–gallium–zinc oxide (IGZO) films, deposited by sputtering at room temperature, still require activation to achieve satisfactory semiconductor characteristics. Thermal treatment is typically carried out at temperatures above 300 °C. Here, we propose activating sputter- processed IGZO films using simultaneous ultraviolet and thermal (SUT) treatments to decrease the required temperature and enhance their electrical characteristics and stability. SUT treatment effectively decreased the amount of carbon residues and the number of defect sites related to oxygen vacancies and increased the number of metal oxide (M–O) bonds through the decomposition-rearrangement of M–O bonds and oxygen radicals. Activation of IGZO TFTs using the SUT treatment reduced the processing temperature to 150 °C and improved various electrical performance metrics including mobility, on-off ratio, and threshold voltage shift (positive bias stress for 10,000 s) from 3.23 to 15.81 cm2/Vs, 3.96 × 107 to 1.03 × 108, and 11.2 to 7.2 V, respectively. PMID:26902863

  9. Wrinkle-free graphene electrodes in zinc tin oxide thin-film transistors for large area applications

    Science.gov (United States)

    Lee, Se-Hee; Kim, Jae-Hee; Park, Byeong-Ju; Park, Jozeph; Kim, Hyun-Suk; Yoon, Soon-Gil

    2017-02-01

    Wrinkle-free graphene was used to form the source-drain electrodes in thin film transistors based on a zinc tin oxide (ZTO) semiconductor. A 10 nm thick titanium adhesion layer was applied prior to transferring a conductive graphene film on top of it by chemical detachment. The formation of an interlayer oxide between titanium and graphene allows the achievement of uniform surface roughness over the entire substrate area. The resulting devices were thermally treated in ambient air, and a substantial decrease in field effect mobility is observed with increasing annealing temperature. The increase in electrical resistivity of the graphene film at higher annealing temperatures may have some influence, however the growth of the oxide interlayer at the ZTO/Ti boundary is suggested to be most influential, thereby inducing relatively high contact resistance.

  10. Impact of residual elements on zinc quality in the production of zinc oxide

    Czech Academy of Sciences Publication Activity Database

    Luptáková, Natália; Dymáček, Petr; Pešlová, F.; Jurkovič, Z.; Barborák, O.; Stodola, J.

    2016-01-01

    Roč. 55, č. 3 (2016), s. 407-410 ISSN 0543-5846 Institutional support: RVO:68081723 Keywords : zinc * metallography * microstructure of zinc * zinc oxide * production of zinc oxide Subject RIV: JG - Metallurgy Impact factor: 0.959, year: 2014

  11. Recent Developments in p-Type Oxide Semiconductor Materials and Devices

    KAUST Repository

    Wang, Zhenwei

    2016-02-16

    The development of transparent p-type oxide semiconductors with good performance may be a true enabler for a variety of applications where transparency, power efficiency, and greater circuit complexity are needed. Such applications include transparent electronics, displays, sensors, photovoltaics, memristors, and electrochromics. Hence, here, recent developments in materials and devices based on p-type oxide semiconductors are reviewed, including ternary Cu-bearing oxides, binary copper oxides, tin monoxide, spinel oxides, and nickel oxides. The crystal and electronic structures of these materials are discussed, along with approaches to enhance valence-band dispersion to reduce effective mass and increase mobility. Strategies to reduce interfacial defects, off-state current, and material instability are suggested. Furthermore, it is shown that promising progress has been made in the performance of various types of devices based on p-type oxides. Several innovative approaches exist to fabricate transparent complementary metal oxide semiconductor (CMOS) devices, including novel device fabrication schemes and utilization of surface chemistry effects, resulting in good inverter gains. However, despite recent developments, p-type oxides still lag in performance behind their n-type counterparts, which have entered volume production in the display market. Recent successes along with the hurdles that stand in the way of commercial success of p-type oxide semiconductors are presented.

  12. Recent Developments in p-Type Oxide Semiconductor Materials and Devices

    KAUST Repository

    Wang, Zhenwei; Nayak, Pradipta K.; Caraveo-Frescas, Jesus Alfonso; Alshareef, Husam N.

    2016-01-01

    The development of transparent p-type oxide semiconductors with good performance may be a true enabler for a variety of applications where transparency, power efficiency, and greater circuit complexity are needed. Such applications include transparent electronics, displays, sensors, photovoltaics, memristors, and electrochromics. Hence, here, recent developments in materials and devices based on p-type oxide semiconductors are reviewed, including ternary Cu-bearing oxides, binary copper oxides, tin monoxide, spinel oxides, and nickel oxides. The crystal and electronic structures of these materials are discussed, along with approaches to enhance valence-band dispersion to reduce effective mass and increase mobility. Strategies to reduce interfacial defects, off-state current, and material instability are suggested. Furthermore, it is shown that promising progress has been made in the performance of various types of devices based on p-type oxides. Several innovative approaches exist to fabricate transparent complementary metal oxide semiconductor (CMOS) devices, including novel device fabrication schemes and utilization of surface chemistry effects, resulting in good inverter gains. However, despite recent developments, p-type oxides still lag in performance behind their n-type counterparts, which have entered volume production in the display market. Recent successes along with the hurdles that stand in the way of commercial success of p-type oxide semiconductors are presented.

  13. Deep electron traps in HfO_2-based metal-oxide-semiconductor capacitors

    International Nuclear Information System (INIS)

    Salomone, L. Sambuco; Lipovetzky, J.; Carbonetto, S.H.; García Inza, M.A.; Redin, E.G.; Campabadal, F.

    2016-01-01

    Hafnium oxide (HfO_2) is currently considered to be a good candidate to take part as a component in charge-trapping nonvolatile memories. In this work, the electric field and time dependences of the electron trapping/detrapping processes are studied through a constant capacitance voltage transient technique on metal-oxide-semiconductor capacitors with atomic layer deposited HfO_2 as insulating layer. A tunneling-based model is proposed to reproduce the experimental results, obtaining fair agreement between experiments and simulations. From the fitting procedure, a band of defects is identified, located in the first 1.7 nm from the Si/HfO_2 interface at an energy level E_t = 1.59 eV below the HfO_2 conduction band edge with density N_t = 1.36 × 10"1"9 cm"−"3. A simplified analytical version of the model is proposed in order to ease the fitting procedure for the low applied voltage case considered in this work. - Highlights: • We characterized deep electron trapping/detrapping in HfO_2 structures. • We modeled the experimental results through a tunneling-based model. • We obtained an electron trap energy level of 1.59 eV below conduction band edge. • We obtained a spatial trap distribution extending 1.7 nm within the insulator. • A simplified tunneling front model is able to reproduce the experimental results.

  14. Zinc electrodeposition from flowing alkaline zincate solutions: Role of hydrogen evolution reaction

    Science.gov (United States)

    Dundálek, Jan; Šnajdr, Ivo; Libánský, Ondřej; Vrána, Jiří; Pocedič, Jaromír; Mazúr, Petr; Kosek, Juraj

    2017-12-01

    The hydrogen evolution reaction is known as a parasitic reaction during the zinc electrodeposition from alkaline zincate solutions and is thus responsible for current efficiency losses during the electrolysis. Besides that, the rising hydrogen bubbles may cause an extra convection within a diffusion layer, which leads to an enhanced mass transport of zincate ions to an electrode surface. In this work, the mentioned phenomena were studied experimentally in a flow through electrolyzer and the obtained data were subsequently evaluated by mathematical models. The results prove the indisputable influence of the rising hydrogen bubbles on the additional mixing of the diffusion layer, which partially compensates the drop of the current efficiency of the zinc deposition at higher current flows. Moreover, the results show that the current density ratio (i.e., the ratio of an overall current density to a zinc limiting current density) is not suitable for the description of the zinc deposition, because the hydrogen evolution current density is always involved in the overall current density.

  15. The protective nature of passivation films on zinc: surface charge

    International Nuclear Information System (INIS)

    Muster, Tim H.; Cole, Ivan S.

    2004-01-01

    The influence of oxide surface charge on the corrosion performance of zinc metals was investigated. Oxidised zinc species (zinc oxide, zinc hydroxychloride, zinc hydroxysulfate and zinc hydroxycarbonate) with chemical compositions similar to those produced on zinc during atmospheric corrosion were formed as particles from aqueous solution, and as passive films deposited onto zinc powder, and rolled zinc, surfaces. Synthesized oxides were characterised by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and electron probe X-ray microanalysis. The zeta potentials of various oxide particles, as determined by microelectrophoresis, are reported as a function of pH. Particulates containing a majority of zinc hydroxycarbonate and zinc hydroxysulfate crystallites were found to possess a negative surface charge below pH 6, whilst zinc oxide-hydroxide and zinc hydroxychloride crystallites possessed isoelectric points (IEP's) higher than pH 8. The ability of chloride species to pass through a bed of 3 μm diameter zinc powder was found to increase for surfaces possessing carboxy and sulfate surface species, suggesting that negatively charged surfaces can aid in the repulsion of chloride ions. Electrochemical analysis of the open-circuit potential as a function of time at a fixed pH of 6.5 showed that the chemical composition of passive films on zinc plates influenced the ability of chloride ions to access anodic sites for periods of approximately 1 h

  16. Thermal stability of atomic layer deposited WCxNy electrodes for metal oxide semiconductor devices

    Science.gov (United States)

    Zonensain, Oren; Fadida, Sivan; Fisher, Ilanit; Gao, Juwen; Danek, Michal; Eizenberg, Moshe

    2018-01-01

    This study is a thorough investigation of the chemical, structural, and electrical stability of W based organo-metallic films, grown by atomic layer deposition, for future use as gate electrodes in advanced metal oxide semiconductor structures. In an earlier work, we have shown that high effective work-function (4.7 eV) was produced by nitrogen enriched films (WCxNy) dominated by W-N chemical bonding, and low effective work-function (4.2 eV) was produced by hydrogen plasma resulting in WCx films dominated by W-C chemical bonding. In the current work, we observe, using x-ray diffraction analysis, phase transformation of the tungsten carbide and tungsten nitride phases after 900 °C annealing to the cubic tungsten phase. Nitrogen diffusion is also observed and is analyzed with time-of-flight secondary ion mass spectroscopy. After this 900 °C anneal, WCxNy effective work function tunability is lost and effective work-function values of 4.7-4.8 eV are measured, similar to stable effective work function values measured for PVD TiN up to 900 °C anneal. All the observed changes after annealing are discussed and correlated to the observed change in the effective work function.

  17. Diagnostic study of the roughness surface effect of zirconium on the third-order nonlinear-optical properties of thin films based on zinc oxide nanomaterials

    International Nuclear Information System (INIS)

    Bahedi, K.; Addou, M.; El Jouad, M.; Sofiani, Z.; Alaoui Lamrani, M.; El Habbani, T.; Fellahi, N.; Bayoud, S.; Dghoughi, L.; Sahraoui, B.; Essaidi, Z.

    2009-01-01

    Zinc oxide (ZnO) and zirconium doped zinc oxide (ZnO:Zr) thin films were deposited by reactive chemical pulverization spray pyrolysis technique on heated glass substrates at 500 deg. C using zinc and zirconium chlorides as precursors. Effects of zirconium doping agent and surface roughness on the nonlinear optical properties were investigated in detail using atomic force microscopy (AFM) and third harmonic generation (THG) technique. The best value of nonlinear optical susceptibility χ (3) was obtained from the doped films with less roughness. A strong third order nonlinear optical susceptibility χ (3) = 20.12 x 10 -12 (esu) of the studied films was found for the 3% doped sample.

  18. Sol-gel zinc oxide humidity sensors integrated with a ring oscillator circuit on-a-chip.

    Science.gov (United States)

    Yang, Ming-Zhi; Dai, Ching-Liang; Wu, Chyan-Chyi

    2014-10-28

    The study develops an integrated humidity microsensor fabricated using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process. The integrated humidity sensor consists of a humidity sensor and a ring oscillator circuit on-a-chip. The humidity sensor is composed of a sensitive film and branch interdigitated electrodes. The sensitive film is zinc oxide prepared by sol-gel method. After completion of the CMOS process, the sensor requires a post-process to remove the sacrificial oxide layer and to coat the zinc oxide film on the interdigitated electrodes. The capacitance of the sensor changes when the sensitive film adsorbs water vapor. The circuit is used to convert the capacitance of the humidity sensor into the oscillation frequency output. Experimental results show that the output frequency of the sensor changes from 84.3 to 73.4 MHz at 30 °C as the humidity increases 40 to 90%RH.

  19. Electro-chemical deposition of nano hydroxyapatite-zinc coating on titanium metal substrate.

    Science.gov (United States)

    El-Wassefy, N A; Reicha, F M; Aref, N S

    2017-08-13

    Titanium is an inert metal that does not induce osteogenesis and has no antibacterial properties; it is proposed that hydroxyapatite coating can enhance its bioactivity, while zinc can contribute to antibacterial properties and improve osseointegration. A nano-sized hydroxyapatite-zinc coating was deposited on commercially pure titanium using an electro-chemical process, in order to increase its surface roughness and enhance adhesion properties. The hydroxyapatite-zinc coating was attained using an electro-chemical deposition in a solution composed of a naturally derived calcium carbonate, di-ammonium hydrogen phosphate, with a pure zinc metal as the anode and titanium as the cathode. The applied voltage was -2.5 for 2 h at a temperature of 85 °C. The resultant coating was characterized for its surface morphology and chemical composition using a scanning electron microscope (SEM), energy dispersive x-ray spectroscope (EDS), and Fourier transform infrared (FT-IR) spectrometer. The coated specimens were also evaluated for their surface roughness and adhesion quality. Hydroxyapatite-zinc coating had shown rosette-shaped, homogenous structure with nano-size distribution, as confirmed by SEM analysis. FT-IR and EDS proved that coatings are composed of hydroxyapatite (HA) and zinc. The surface roughness assessment revealed that the coating procedure had significantly increased average roughness (Ra) than the control, while the adhesive tape test demonstrated a high-quality adhesive coat with no laceration on tape removal. The developed in vitro electro-chemical method can be employed for the deposition of an even thickness of nano HA-Zn adhered coatings on titanium substrate and increases its surface roughness significantly.

  20. Zinc (hydr)oxide/graphite oxide/AuNPs composites: role of surface features in H₂S reactive adsorption.

    Science.gov (United States)

    Giannakoudakis, Dimitrios A; Bandosz, Teresa J

    2014-12-15

    Zinc hydroxide/graphite oxide/AuNPs composites with various levels of complexity were synthesized using an in situ precipitation method. Then they were used as H2S adsorbents in visible light. The materials' surfaces were characterized before and after H2S adsorption by various physical and chemical methods (XRD, FTIR, thermal analysis, potentiometric titration, adsorption of nitrogen and SEM/EDX). Significant differences in surface features and synergistic effects were found depending on the materials' composition. Addition of graphite oxide and the deposition of gold nanoparticles resulted in a marked increase in the adsorption capacity in comparison with that on the zinc hydroxide and zinc hydroxide/AuNP. Addition of AuNPs to zinc hydroxide led to a crystalline ZnO/AuNP composite while the zinc hydroxide/graphite oxide/AuNP composite was amorphous. The ZnOH/GO/AuNPs composite exhibited the greatest H2S adsorption capacity due to the increased number of OH terminal groups and the conductive properties of GO that facilitated the electron transfer and consequently the formation of superoxide ions promoting oxidation of hydrogen sulfide. AuNPs present in the composite increased the conductivity, helped with electron transfer to oxygen, and prevented the fast recombination of the electrons and holes. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Semiconductors for plasmonics and metamaterials

    DEFF Research Database (Denmark)

    Naik, G.V.; Boltasseva, Alexandra

    2010-01-01

    Plasmonics has conventionally been in the realm of metal-optics. However, conventional metals as plasmonic elements in the near-infrared (NIR) and visible spectral ranges suffer from problems such as large losses and incompatibility with semiconductor technology. Replacing metals with semiconduct......Plasmonics has conventionally been in the realm of metal-optics. However, conventional metals as plasmonic elements in the near-infrared (NIR) and visible spectral ranges suffer from problems such as large losses and incompatibility with semiconductor technology. Replacing metals...... with semiconductors can alleviate these problems if only semiconductors could exhibit negative real permittivity. Aluminum doped zinc oxide (AZO) is a low loss semiconductor that can show negative real permittivity in the NIR. A comparative assessment of AZO-based plasmonic devices such as superlens and hyperlens...... with their metal-based counterparts shows that AZO-based devices significantly outperform at a wavelength of 1.55 µm. This provides a strong stimulus in turning to semiconductor plasmonics at the telecommunication wavelengths. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)....

  2. Oxidation and Condensation of Zinc Fume From Zn-CO2-CO-H2O Streams Relevant to Steelmaking Off-Gas Systems

    International Nuclear Information System (INIS)

    Bronson, Tyler Mark; Ma, Naiyang; Zhu, Liang Zhu; Sohn, Hong Yong

    2017-01-01

    Here the objective of this research was to study the condensation of zinc vapor to metallic zinc and zinc oxide solid under varying environments to investigate the feasibility of in-process separation of zinc from steelmaking off-gas dusts. Water vapor content, temperature, degree of cooling, gas composition, and initial zinc partial pressure were varied to simulate the possible conditions that can occur within steelmaking off-gas systems, limited to Zn-CO 2 -CO-H 2 O gas compositions. The temperature of deposition and the effect of rapidly quenching the gas were specifically studied. A homogeneous nucleation model for applicable experiments was applied to the analysis of the experimental data. It was determined that under the experimental conditions, oxidation of zinc vapor by H 2 O or CO 2 does not occur above 1108 K (835 °C) even for highly oxidizing streams (CO 2 /CO = 40/7). Rate expressions that correlate CO 2 and H 2 O oxidation rates to gas composition, partial pressure of water vapor, temperature, and zinc partial pressure were determined to be as follows: Rate ((mol)/(m 2 s)) = 406 exp ((−50.2kJ/mol)/(RT)) (pZnpCO 2 − PCO/K eq CO 2 ) ((mol)/(m 2 xs)) Rate (((mol)/(m 2 s))) = 32.9 exp (((−13.7kJ/mol)/(RT))) (pZnPH 2 O − PH 2 /K eq H 2 O) ((mol)/(m 2 xs)). It was proven that a rapid cooling rate (500 K/s) significantly increases the ratio of metallic zinc to zinc oxide as opposed to a slow cooling rate (250 K/s). SEM analysis found evidence of heterogeneous growth of ZnO as well as of homogeneous formation of metallic zinc. The homogeneous nucleation model fit well with experiments where only metallic zinc deposited. An expanded model with rates of oxidation by CO 2 and H 2 O as shown was combined with the homogenous nucleation model and then compared with experimental data. The calculated results based on the model gave a reasonable fit to the measured data. For the conditions used in this study, the rate equations for the oxidation of zinc by

  3. Defects in semiconductors

    CERN Document Server

    Romano, Lucia; Jagadish, Chennupati

    2015-01-01

    This volume, number 91 in the Semiconductor and Semimetals series, focuses on defects in semiconductors. Defects in semiconductors help to explain several phenomena, from diffusion to getter, and to draw theories on materials' behavior in response to electrical or mechanical fields. The volume includes chapters focusing specifically on electron and proton irradiation of silicon, point defects in zinc oxide and gallium nitride, ion implantation defects and shallow junctions in silicon and germanium, and much more. It will help support students and scientists in their experimental and theoret

  4. Electrical properties of undoped zinc oxide nanostructures at different annealing temperature

    Energy Technology Data Exchange (ETDEWEB)

    Nasir, M. F., E-mail: babaibaik2002@yahoo.com; Zainol, M. N., E-mail: nizarzainol@yahoo.com; Hannas, M., E-mail: mhannas@gmail.com [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Mamat, M. H., E-mail: mhmamat@salam.uitm.edu.my; Rusop, Mohamad, E-mail: rusop@salam.uitm.edu.my [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); NANO-SciTech Centre (NST), Institute of Science (IOS), Universiti Teknologi MARA - UiTM, 40450 Shah Alam, Selangor (Malaysia); Rahman, S. A., E-mail: saadah@um.edu.my [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Low Dimensional Materials Research Centre, Physics Department, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2016-07-06

    This project has been focused on the electrical and optical properties respectively on the effect of Undoped zinc oxide (ZnO) thin films at different annealing temperature which is varied 400 °C, 450 °C, 500 °C, and 550 °C.Undoped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thin films were characterized using Current Voltage (I-V) measurement and UV-vis-NIR spectrophotometer for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 500 °C which its resistivity is 5.36 × 10{sup 4} Ωcm{sup −1}. The absorption coefficient spectrum obtained from UV-Vis-NIR spectrophotometer measurement shows all films exhibit very low absorption in the visible (400-800 nm) and near infrared (NIR) (>800 nm) range but exhibit high absorption in the UV range.

  5. Direct observation of both contact and remote oxygen scavenging of GeO2 in a metal-oxide-semiconductor stack

    International Nuclear Information System (INIS)

    Fadida, S.; Shekhter, P.; Eizenberg, M.; Cvetko, D.; Floreano, L.; Verdini, A.; Nyns, L.; Van Elshocht, S.; Kymissis, I.

    2014-01-01

    In the path to incorporating Ge based metal-oxide-semiconductor into modern nano-electronics, one of the main issues is the oxide-semiconductor interface quality. Here, the reactivity of Ti on Ge stacks and the scavenging effect of Ti were studied using synchrotron X-ray photoelectron spectroscopy measurements, with an in-situ metal deposition and high resolution transmission electron microscopy imaging. Oxygen removal from the Ge surface was observed both in direct contact as well as remotely through an Al 2 O 3 layer. The scavenging effect was studied in situ at room temperature and after annealing. We find that the reactivity of Ti can be utilized for improved scaling of Ge based devices.

  6. Effect of Solution Molarity, Substrate Temperature and Spray Time on The Structural and Optical Properties Of ZnO Thin Films Deposited By Spray Pyrolysis

    International Nuclear Information System (INIS)

    Ramadan, A.A.; Hashem, H. M.; El-Sayed, S. M.; Ashour, A.H.; Abdel-Haleem, S.M.

    2013-01-01

    Zinc oxide thin films were deposited on a glass substrate by spray pyrolysis technique using solution of zinc acetate and air as the carrier gas. Effects of solution molarity, substrate temperature and spray time on films properties were investigated. All films deposited were characterized using X-ray diffraction for structural characterization and UV-VIS transmission spectrophotometry for optical properties. According to the analytical method, the type of crystal lattice was found to be hexagonal and X-ray diffraction (XRD) patterns showed that the films deposited were polycrystalline with (002) plane as preferential orientation. The values of lattice constant, grain size, micro strain and dislocation density of all samples were calculated. In addition, Optical behaviors of film samples were analyzed by obtaining transmission spectra, in the wavelength range of 350-800 nm. The UV-VIS spectroscopy shows the high transparency of ZnO films in the UV region. An optimization of the films has been carried out to determine the best preparation conditions.

  7. Optical and structural characterization of nickel oxide-based thin films obtained by chemical bath deposition

    International Nuclear Information System (INIS)

    Vidales-Hurtado, M.A.; Mendoza-Galvan, A.

    2008-01-01

    Nickel oxide-based thin films were obtained using the chemical bath deposition method on glass and silicon substrates. The precursor solution used was a mixture of nickel nitrate, urea, and deionized water. Molar concentration of nickel (0.3-1.0 M), deposition time, and immersing cycles were considered as deposition variables. Infrared spectroscopy and X-ray diffraction data reveal that all as-deposited films correspond to the transparent turbostratic phase α(II)-Ni(OH) 2 . However, the rate of deposition depends on nickel content in the solution. After annealing in air at temperatures above of 300 deg. C, the films are transformed to the NiO phase and show a grey/black color. In these films, scanning electron microscopy images show aggregates of thin stacked sheets on their surface, such aggregates can be easily removed leaving only a thin NiO layer of about 30 nm adhered firmly to the substrate, regardless of nickel concentration in the solution and deposition time. In order to obtain thicker NiO films with good optical properties a procedure is developed performing several immersing-annealing cycles

  8. Characterizing and simulation the scintillation properties of zinc oxide nanowires in AAO membrane for medical imaging applications

    International Nuclear Information System (INIS)

    Esfandi, F.; Saramad, S.; Shahmirzadi, M. Rezaei

    2017-01-01

    In this work, a new method is proposed for extracting some X-ray detection properties of ZnO nanowires electrodeposited on Anodized Aluminum Oxide (AAO) nanoporous template. The results show that the detection efficiency for 12μm thickness of zinc oxide nano scintillator at an energy of 9.8 keV, near the K-edge of ZnO (9.65 keV), is 24%. The X-rays that interact with AAO can also generate electrons that reach the nano scintillator. The scintillation events of these electrons are seen as a low energy tail in the spectrum. In addition, it is found that all the X-rays that are absorbed in 300 nm thickness of the gold layer on the top of the zinc oxide nanowires can participate in the scintillation process with an efficiency of 6%. Hence, the scintillation detection efficiency of the whole detector for 9.8 keV X-ray energy is 30%. The simulation results from Geant4 and the experimental detected photons per MeV energy deposition are also used to extract the light yield of the zinc oxide nano scintillator. The results show that the light yield of the zinc oxide nanowires deposited by the electrochemical method is approximately the same as for single crystal zinc oxide scintillator (9000). Much better spatial resolution of this nano scintillator in comparison to the bulk ones is an advantage which candidates this nano scintillator for medical imaging applications.

  9. Extracellular synthesis of zinc oxide nanoparticle using seaweeds of gulf of Mannar, India

    Science.gov (United States)

    2013-01-01

    Background The biosynthesis of metal nanoparticles by marine resources is thought to be clean, nontoxic, and environmentally acceptable “green procedures”. Marine ecosystems are very important for the overall health of both marine and terrestrial environments. The use of natural sources like Marine biological resources essential for nanotechnology. Seaweeds constitute one of the commercially important marine living renewable resources. Seaweeds such as green Caulerpa peltata, red Hypnea Valencia and brown Sargassum myriocystum were used for synthesis of Zinc oxide nanoparticles. Result The preliminary screening of physico-chemical parameters such as concentration of metals, concentration of seaweed extract, temperature, pH and reaction time revealed that one seaweed S. myriocystum were able to synthesize zinc oxide nanoparticles. It was confirmed through the, initial colour change of the reaction mixture and UV visible spectrophotometer. The extracellular biosynthesized clear zinc oxide nanoparticles size 36 nm through characterization technique such as DLS, AFM, SEM –EDX, TEM, XRD and FTIR. The biosynthesized ZnO nanoparticles are effective antibacterial agents against Gram-positive than the Gram-negative bacteria. Conclusion Based on the FTIR results, fucoidan water soluble pigments present in S. myriocystum leaf extract is responsible for reduction and stabilization of zinc oxide nanoparticles. by this approach are quite stable and no visible changes were observed even after 6 months. These soluble elements could have acted as both reduction and stabilizing agents preventing the aggregation of nanoparticles in solution, extracellular biological synthesis of zinc oxide nanoparticles of size 36 nm. PMID:24298944

  10. Review of recent developments in amorphous oxide semiconductor thin-film transistor devices

    International Nuclear Information System (INIS)

    Park, Joon Seok; Maeng, Wan-Joo; Kim, Hyun-Suk; Park, Jin-Seong

    2012-01-01

    The present article is a review of the recent progress and major trends in the field of thin-film transistor (TFT) research involving the use of amorphous oxide semiconductors (AOS). First, an overview is provided on how electrical performance may be enhanced by the adoption of specific device structures and process schemes, the combination of various oxide semiconductor materials, and the appropriate selection of gate dielectrics and electrode metals in contact with the semiconductor. As metal oxide TFT devices are excellent candidates for switching or driving transistors in next generation active matrix liquid crystal displays (AMLCD) or active matrix organic light emitting diode (AMOLED) displays, the major parameters of interest in the electrical characteristics involve the field effect mobility (μ FE ), threshold voltage (V th ), and subthreshold swing (SS). A study of the stability of amorphous oxide TFT devices is presented next. Switching or driving transistors in AMLCD or AMOLED displays inevitably involves voltage bias or constant current stress upon prolonged operation, and in this regard many research groups have examined and proposed device degradation mechanisms under various stress conditions. The most recent studies involve stress experiments in the presence of visible light irradiating the semiconductor, and different degradation mechanisms have been proposed with respect to photon radiation. The last part of this review consists of a description of methods other than conventional vacuum deposition techniques regarding the formation of oxide semiconductor films, along with some potential application fields including flexible displays and information storage.

  11. Transparent megahertz circuits from solution-processed composite thin films.

    Science.gov (United States)

    Liu, Xingqiang; Wan, Da; Wu, Yun; Xiao, Xiangheng; Guo, Shishang; Jiang, Changzhong; Li, Jinchai; Chen, Tangsheng; Duan, Xiangfeng; Fan, Zhiyong; Liao, Lei

    2016-04-21

    Solution-processed amorphous oxide semiconductors have attracted considerable interest in large-area transparent electronics. However, due to its relative low carrier mobility (∼10 cm(2) V(-1) s(-1)), the demonstrated circuit performance has been limited to 800 kHz or less. Herein, we report solution-processed high-speed thin-film transistors (TFTs) and integrated circuits with an operation frequency beyond the megahertz region on 4 inch glass. The TFTs can be fabricated from an amorphous indium gallium zinc oxide/single-walled carbon nanotube (a-IGZO/SWNT) composite thin film with high yield and high carrier mobility of >70 cm(2) V(-1) s(-1). On-chip microwave measurements demonstrate that these TFTs can deliver an unprecedented operation frequency in solution-processed semiconductors, including an extrinsic cut-off frequency (f(T) = 102 MHz) and a maximum oscillation frequency (f(max) = 122 MHz). Ring oscillators further demonstrated an oscillation frequency of 4.13 MHz, for the first time, realizing megahertz circuit operation from solution-processed semiconductors. Our studies represent an important step toward high-speed solution-processed thin film electronics.

  12. Epitaxial solution deposition of YBa2Cu3O7-6 coated conductors.

    Energy Technology Data Exchange (ETDEWEB)

    Overmyer, Donald L.; Clem, Paul Gilbert; Siegal, Michael P.; Holesinger, Terry A. (Los Alamos National Laboratory, Los Alamos, NM); Voigt, James A.; Richardson, Jacob J.; Dawley, Jeffrey Todd

    2004-11-01

    A variety of solution deposition routes have been reported for processing complex perovskite-based materials such as ferroelectric oxides and conductive electrode oxides, due to ease of incorporating multiple elements, control of chemical stoichiometry, and feasibility for large area deposition. Here, we report an extension of these methods toward long length, epitaxial film solution deposition routes to enable biaxially oriented YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO)-coated conductors for superconducting transmission wires. Recent results are presented detailing an all-solution deposition approach to YBCO-coated conductors with critical current densities J{sub c} (77 K) > 1 MA/cm{sup 2} on rolling-assisted, biaxially textured, (200)-oriented Ni-W alloy tapes. Solution-deposition methods such as this approach and those of other research groups appear to have promise to compete with vapor phase methods for superconductor electrical properties, with potential advantages for large area deposition and low cost/kA {center_dot} m of wire.

  13. Synthesis of cadmium oxide doped ZnO nanostructures using electrochemical deposition

    International Nuclear Information System (INIS)

    Singh, Trilok; Pandya, D.K.; Singh, R.

    2011-01-01

    Research highlights: → Ternary ZnCdO alloy semiconductor nanostructures were grown using electrochemical deposition. → X-ray diffraction measurements showed that the nanostructures were of wurtzite structure and possessed a compressive stress along the c-axis direction. → The cut-off wavelength shifted from blue to red on account of the Cd incorporation in the ZnO and the average transmittance decreased by ∼31%. → The bandgap tuning for 4-16 at% Cd in the initial solution was achieved in the range of 3.08-3.32 eV (up to 0.24 eV). - Abstract: Ternary ZnCdO alloy semiconductor nanostructures were grown using electrochemical deposition. Crystalline nanostructures/nanorods with cadmium concentration ranging from 4 to 16 at% in the initial solution were electrodeposited on tin doped indium oxide (ITO) conducting glass substrates at a constant cathodic potential -0.9 V and subsequently annealed in air at 300 deg. C. X-ray diffraction measurements showed that the nanostructures were of wurtzite structure and possessed a compressive stress along the c-axis direction. The elemental composition of nanostructures was confirmed by energy dispersive spectroscopy (EDS). ZnO nanostructures were found to be highly transparent and had an average transmittance of 85% in the visible range of the spectrum. After the incorporation of Cd content into ZnO the average transmittance decreased and the bandgap tuning was also achieved.

  14. Chemical solution route to self-assembled epitaxial oxide nanostructures.

    Science.gov (United States)

    Obradors, X; Puig, T; Gibert, M; Queraltó, A; Zabaleta, J; Mestres, N

    2014-04-07

    Self-assembly of oxides as a bottom-up approach to functional nanostructures goes beyond the conventional nanostructure formation based on lithographic techniques. Particularly, chemical solution deposition (CSD) is an ex situ growth approach very promising for high throughput nanofabrication at low cost. Whereas strain engineering as a strategy to define nanostructures with tight control of size, shape and orientation has been widely used in metals and semiconductors, it has been rarely explored in the emergent field of functional complex oxides. Here we will show that thermodynamic modeling can be very useful to understand the principles controlling the growth of oxide nanostructures by CSD, and some attractive kinetic features will also be presented. The methodology of strain engineering is applied in a high degree of detail to form different sorts of nanostructures (nanodots, nanowires) of the oxide CeO2 with fluorite structure which then is used as a model system to identify the principles controlling self-assembly and self-organization in CSD grown oxides. We also present, more briefly, the application of these ideas to other oxides such as manganites or BaZrO3. We will show that the nucleation and growth steps are essentially understood and manipulated while the kinetic phenomena underlying the evolution of the self-organized networks are still less widely explored, even if very appealing effects have been already observed. Overall, our investigation based on a CSD approach has opened a new strategy towards a general use of self-assembly and self-organization which can now be widely spread to many functional oxide materials.

  15. Fabrication of Vertically Aligned Carbon Nanotube or Zinc Oxide Nanorod Arrays for Optical Diffraction Gratings.

    Science.gov (United States)

    Kim, Jeong; Kim, Sun Il; Cho, Seong-Ho; Hwang, Sungwoo; Lee, Young Hee; Hur, Jaehyun

    2015-11-01

    We report on new fabrication methods for a transparent, hierarchical, and patterned electrode comprised of either carbon nanotubes or zinc oxide nanorods. Vertically aligned carbon nanotubes or zinc oxide nanorod arrays were fabricated by either chemical vapor deposition or hydrothermal growth, in combination with photolithography. A transparent conductive graphene layer or zinc oxide seed layer was employed as the transparent electrode. On the patterned surface defined using photoresist, the vertically grown carbon nanotubes or zinc oxides could produce a concentrated electric field under applied DC voltage. This periodic electric field was used to align liquid crystal molecules in localized areas within the optical cell, effectively modulating the refractive index. Depending on the material and morphology of these patterned electrodes, the diffraction efficiency presented different behavior. From this study, we established the relationship between the hierarchical structure of the different electrodes and their efficiency for modulating the refractive index. We believe that this study will pave a new path for future optoelectronic applications.

  16. Cathodic deposition of CdSe films from dimethyl formamide solution at optimized temperature

    Energy Technology Data Exchange (ETDEWEB)

    Datta, J. [Department of Chemistry, Bengal Engineering and Science University, Shibpur, Howrah 711 103, West Bengal (India)]. E-mail: jayati_datta@rediffmail.com; Bhattacharya, C. [Department of Chemistry, Bengal Engineering and Science University, Shibpur, Howrah 711 103, West Bengal (India); Visiting Research Associate, School of Materials Science and Engineering, UNSW (Australia); Bandyopadhyay, S. [School of Materials Science and Engineering, UNSW, Sydney 2052 (Australia)

    2006-12-15

    In the present paper, thin film CdSe compound semiconductors have been electroplated on transparent conducting oxide coated glass substrates from nonaqueous dimethyl formamide bath containing CdCl{sub 2}, KI and Se under controlled temperature ranging from 100 to 140 deg. C. Thickness of the deposited films as obtained through focussed ion beam technique as well as their microstructural and photoelectrochemical properties have been found to depend on temperature. The film growth was therefore optimized at a bath temperature {approx}125 deg. C. The formation of crystallites in the range of 100-150 nm size has been ascertained through atomic force microscopy and scanning electron microscopy. Energy dispersive analysis of X-rays for the as deposited film confirmed the 1:1 composition of CdSe compound in the matrix exhibiting band-gap energy of 1.74 eV. Microstructural properties of the deposited films have been determined through X-ray diffraction studies, high-resolution transmission electron microscopy and electron diffraction pattern analysis. Electrochemical impedance spectroscopy and current-potential measurements have been performed to characterize the electrochemical behavior of the semiconductor-electrolyte interface. The photo-activity of the films have been recorded in polysulphide solution under illumination and solar conversion efficiency {>=}1% was achieved.

  17. The behavior of thiourea and flotation reagents in zinc electrowinning circuits

    Science.gov (United States)

    MacKinnon, D. J.; Dutrizac, J. E.; Brannen, J. M.; Hardy, D. J.

    1988-04-01

    The effect of thiourea and flotation reagents on the electrowinning of zinc from industrial electrolytes was studied, and all the compounds were found to reduce the zinc deposition current efficiency and to change the properties of the zinc deposits. The effectiveness of activated carbon, two-stage cementation, and hot acid leaching on the destruction/removal of the organic compounds also was addressed. Activated carbon pretreatment of thiourea-containing electrolytes restored the current efficiency for 1-hour zinc deposits to values comparable to those obtained for thiourea-free electrolytes. The activated carbon pretreatment, however, altered the deposit morphology and orientation, but produced a cyclic voltammogram similar to that of the thiourea-free solution. Two-stage cementation did not counteract the harmful effects of thiourea. Hot acid leaching destroyed the thiourea but generated large concentrations of ferrous ion that reduced the current efficiency. The ferrous concentrations, however, were readily controlled by KMnO4 or MnO2 oxidation. None of the treatment options (activated carbon, two-stage cementation, or hot acid leaching) was effective in controlling the flotation reagents, and their moderately harmful effect on zinc electrowinning persisted. Even low concentrations of these reagents polarized zinc deposition, and this resulted in a “glue-type” zinc deposit.

  18. Transparent field-effect transistors based on AlN-gate dielectric and IGZO-channel semiconductor

    International Nuclear Information System (INIS)

    Besleaga, C.; Stan, G.E.; Pintilie, I.; Barquinha, P.; Fortunato, E.; Martins, R.

    2016-01-01

    Highlights: • TFTs based on IGZO channel semiconductor and AlN gate dielectric were fabricated. • AlN films – a viable and cheap gate dielectric alternative for transparent TFTs. • Influence of gate dielectric layer thickness on TFTs electrical characteristics. • No degradation of AlN gate dielectric was observed during devices stress testing. - Abstract: The degradation of thin-film transistors (TFTs) caused by the self-heating effect constitutes a problem to be solved for the next generation of displays. Aluminum nitride (AlN) is a viable alternative for gate dielectric of TFTs due to its good thermal conductivity, matching coefficient of thermal expansion to indium–gallium–zinc-oxide, and excellent stability at high temperatures. Here, AlN thin films of different thicknesses were fabricated by a low temperature reactive radio-frequency magnetron sputtering process, using a low cost, metallic Al target. Their electrical properties have been thoroughly assessed. Furthermore, the 200 nm and 500 nm thick AlN layers have been integrated as gate-dielectric in transparent TFTs with indium–gallium–zinc-oxide as channel semiconductor. Our study emphasizes the potential of AlN thin films for transparent electronics, whilst the functionality of the fabricated field-effect transistors is explored and discussed.

  19. Transparent field-effect transistors based on AlN-gate dielectric and IGZO-channel semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Besleaga, C.; Stan, G.E.; Pintilie, I. [National Institute of Materials Physics, 405A Atomistilor, 077125 Magurele-Ilfov (Romania); Barquinha, P.; Fortunato, E. [CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, and CEMOP-UNINOVA, 2829-516 Caparica (Portugal); Martins, R., E-mail: rm@uninova.pt [CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, and CEMOP-UNINOVA, 2829-516 Caparica (Portugal)

    2016-08-30

    Highlights: • TFTs based on IGZO channel semiconductor and AlN gate dielectric were fabricated. • AlN films – a viable and cheap gate dielectric alternative for transparent TFTs. • Influence of gate dielectric layer thickness on TFTs electrical characteristics. • No degradation of AlN gate dielectric was observed during devices stress testing. - Abstract: The degradation of thin-film transistors (TFTs) caused by the self-heating effect constitutes a problem to be solved for the next generation of displays. Aluminum nitride (AlN) is a viable alternative for gate dielectric of TFTs due to its good thermal conductivity, matching coefficient of thermal expansion to indium–gallium–zinc-oxide, and excellent stability at high temperatures. Here, AlN thin films of different thicknesses were fabricated by a low temperature reactive radio-frequency magnetron sputtering process, using a low cost, metallic Al target. Their electrical properties have been thoroughly assessed. Furthermore, the 200 nm and 500 nm thick AlN layers have been integrated as gate-dielectric in transparent TFTs with indium–gallium–zinc-oxide as channel semiconductor. Our study emphasizes the potential of AlN thin films for transparent electronics, whilst the functionality of the fabricated field-effect transistors is explored and discussed.

  20. Rapid growth of zinc oxide nanobars in presence of electric field by physical vapor deposition

    Science.gov (United States)

    Jouya, Mehraban; Taromian, Fahime; Siami, Simin

    2017-12-01

    In this contribution, electric field has some effects to increase growth for specific time duration on zinc oxide (ZnO) nanobars. First, the zinc (Zn) thin film has been prepared by 235,000 V/m electric field assisted physical vapor deposition (PVD) at vacuum of 1.33 × 10-5 mbar. Second, strong electric field of 134,000 V/m has been used in ambient for growing ZnO nanobars in term of the time include 2.5 and 10 h. The performances of the ZnO nanostructure in absence and presence of electric field have been determined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results of XRD analysis showed that ZnO has a hexagonal bars structure and a strongly preferred (101) orientation which is strongest than without applying electric field. SEM analysis revealed that physical vapored ZnO thin film in presence of electric field are densely packed with uniform morphological, thinner and denser in distribution. Electric field effect for ZnO growth in 2.5 h is better than it in the 2.5 h without electric field but by passing the time the media influence has good power almost as same as electric field. Through this electric field in PVD, the compact and uniform Zn film has been achieved which is less diameter than ordinary PVD method. Finally, we carry out a series of experiments to grow different-orientation ZnO nanobars with less than 100 nm in diameter, which are the time saving process in base of PVD ever reported. Therefore, the significant conclusion in usage electric field is reducing time of growth.

  1. Dye-Sensitized Solar Cells Based on High Surface Area Nanocrystalline Zinc Oxide Spheres

    Directory of Open Access Journals (Sweden)

    Pavuluri Srinivasu

    2011-01-01

    Full Text Available High surface area nanocrystalline zinc oxide material is fabricated using mesoporous nanostructured carbon as a sacrificial template through combustion process. The resulting material is characterized by XRD, N2 adsorption, HR-SEM, and HR-TEM. The nitrogen adsorption measurement indicates that the materials possess BET specific surface area ca. 30 m2/g. Electron microscopy images prove that the zinc oxide spheres possess particle size in the range of 0.12 μm–0.17 μm. The nanocrystalline zinc oxide spheres show 1.0% of energy conversion efficiency for dye-sensitized solar cells.

  2. Band Engineering Small Bandgap p-Type Semiconductors: Investigations of their Optical and Photoelectrochemical Properties

    Science.gov (United States)

    Zoellner, Brandon

    Mixed-metal oxides containing Mn(II), Cu(I), Ta(V), Nb(V), and V(V) were investigated for their structures and properties as new p-type semiconductors and in the potential applications involving the photocatalytic conversion of water into hydrogen and oxygen. Engineering of the bandgaps was achieved by combining metal cations that have halffilled (Mn 3d5) or filled (Cu 3d10) d-orbitals together with metal cations that have empty (V/Nb/Ta 3/4/5 d0) d-orbitals. The research described herein focuses on the synthesis, optical, electronic, and photocatalytic properties of the metal-oxide semiconductors MnV2O6, Cu3VO 4, CuNb1-xTaxO3, and Cu5(Ta1-xNbx)11O30. Powder X-ray diffraction was used to probe their phase purity as well as atomic-level crystallographic details, i.e. shifts of lattice parameters, chemical compositions, and changes in local bonding environments. Optical measurements revealed visible-light bandgap sizes of ˜1.17 eV (Cu3VO4), ˜1.45 eV (MnV2O6), ˜1.89-1.97 eV (CuNb1-xTa xO3), and ˜1.97-2.50 eV (Cu5(Ta1-xNb x)11O30). The latter two were found to systematically vary as a function of composition. Electrochemical impedance spectroscopy measurements of MnV2O6 and Cu3VO 4 provided the first experimental characterization of the energetic positions of the valence and conduction bands with respect to the water oxidation and reduction potentials, as well as confirmed the p-type nature of each semiconductor. The valence and conduction band energies were found to be suitable for driving either one or both of the water-splitting half reaction (i.e. 2H+ → H2 and 2H2O → O2 + 4H+). Photoelectrochemical measurements on polycrystalline films of the Cu(I)-based semiconductors under visible-light irradiation produced cathodic currents indicative of p-type semiconductor character and chemical reduction at their surfaces in the electrolyte solution. The stability of the photocurrents was increased by the addition of CuO oxide particles either externally deposited or

  3. Atomic layer deposition for semiconductors

    CERN Document Server

    Hwang, Cheol Seong

    2014-01-01

    This edited volume discusses atomic layer deposition (ALD) for all modern semiconductor devices, moving from the basic chemistry of ALD and modeling of ALD processes to sections on ALD for memories, logic devices, and machines.

  4. Diagnostic study of the roughness surface effect of zirconium on the third-order nonlinear-optical properties of thin films based on zinc oxide nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Bahedi, K., E-mail: bahedikhadija@yahoo.com [Laboratoire Optoelectronique et Physico-chimie des Materiaux Universite Ibn Tofail, Faculte des Sciences BP 133 Kenitra 14000, Maroc (Morocco); Addou, M.; El Jouad, M.; Sofiani, Z.; Alaoui Lamrani, M.; El Habbani, T.; Fellahi, N.; Bayoud, S.; Dghoughi, L. [Laboratoire Optoelectronique et Physico-chimie des Materiaux Universite Ibn Tofail, Faculte des Sciences BP 133 Kenitra 14000, Maroc (Morocco); Sahraoui, B.; Essaidi, Z. [Laboratoire POMA, UMR CNRS 6136, Universite d' Angers 2, Bd Lavoisier, 49045 France (France)

    2009-02-01

    Zinc oxide (ZnO) and zirconium doped zinc oxide (ZnO:Zr) thin films were deposited by reactive chemical pulverization spray pyrolysis technique on heated glass substrates at 500 deg. C using zinc and zirconium chlorides as precursors. Effects of zirconium doping agent and surface roughness on the nonlinear optical properties were investigated in detail using atomic force microscopy (AFM) and third harmonic generation (THG) technique. The best value of nonlinear optical susceptibility {chi}{sup (3)} was obtained from the doped films with less roughness. A strong third order nonlinear optical susceptibility {chi}{sup (3)} = 20.12 x 10{sup -12} (esu) of the studied films was found for the 3% doped sample.

  5. Sol-Gel Zinc Oxide Humidity Sensors Integrated with a Ring Oscillator Circuit On-a-Chip

    Directory of Open Access Journals (Sweden)

    Ming-Zhi Yang

    2014-10-01

    Full Text Available The study develops an integrated humidity microsensor fabricated using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS process. The integrated humidity sensor consists of a humidity sensor and a ring oscillator circuit on-a-chip. The humidity sensor is composed of a sensitive film and branch interdigitated electrodes. The sensitive film is zinc oxide prepared by sol-gel method. After completion of the CMOS process, the sensor requires a post-process to remove the sacrificial oxide layer and to coat the zinc oxide film on the interdigitated electrodes. The capacitance of the sensor changes when the sensitive film adsorbs water vapor. The circuit is used to convert the capacitance of the humidity sensor into the oscillation frequency output. Experimental results show that the output frequency of the sensor changes from 84.3 to 73.4 MHz at 30 °C as the humidity increases 40 to 90%RH.

  6. Semiconductor nanocrystals dispersed in imidazolium-based ionic liquids: a spectroscopic and morphological investigation

    International Nuclear Information System (INIS)

    Panniello, Annamaria; Binetti, Enrico; Ingrosso, Chiara; Curri, M. Lucia; Agostiano, Angela; Tommasi, Raffaele; Striccoli, Marinella

    2013-01-01

    A growing interest is devoted to the study of imidazolium-based ionic liquids as innovative materials to combine with functional elements for advanced technological applications. Materials based on semiconductor and oxide nanocrystals in ionic liquids can be promising for their integration in lithium batteries, as well as in innovative solar cells. Although the physical chemical properties and the solvation dynamics of bare ionic liquids have been extensively studied, their combination with colloidal nanocrystals still remains almost unexplored. Here, the optical properties of organic-capped luminescent cadmium selenide nanocrystals coated by a shell of zinc sulfide (CdSe(ZnS)) dispersed in 1,3-dialkyl imidazolium ionic liquids have been investigated, also in dependence of the alkyl chain length on the imidazolium ring and of the anion nature, by using both time-integrated and time-resolved optical spectroscopy. The observed variations in decay profiles of the ionic liquid in presence of colloidal nanocrystals suggest that the dispersion of the nanostructures induces modifications in the ionic liquid structural order. Finally, atomic force microscopy analysis has provided insight into the topography of the investigated dispersions deposited as film, confirming the organization of the ionic liquids in super-structures, also upon nanocrystal incorporation.

  7. Aluminum-doped zinc oxide films as transparent conductive electrode for organic light-emitting devices

    International Nuclear Information System (INIS)

    Jiang, X.; Wong, F.L.; Fung, M.K.; Lee, S.T.

    2003-01-01

    Highly transparent conductive, aluminum-doped zinc oxide (ZnO:Al) films were deposited on glass substrates by midfrequency magnetron sputtering of metallic aluminum-doped zinc target. ZnO:Al films with surface work functions between 3.7 and 4.4 eV were obtained by varying the sputtering conditions. Organic light-emitting diodes (OLEDs) were fabricated on these ZnO:Al films. A current efficiency of higher than 3.7 cd/A, was achieved. For comparison, 3.9 cd/A was achieved by the reference OLEDs fabricated on commercial indium-tin-oxide substrates

  8. Compositional influence on the electrical performance of zinc indium tin oxide transparent thin-film transistors

    International Nuclear Information System (INIS)

    Marsal, A.; Carreras, P.; Puigdollers, J.; Voz, C.; Galindo, S.; Alcubilla, R.; Bertomeu, J.; Antony, A.

    2014-01-01

    In this work, zinc indium tin oxide layers with different compositions are used as the active layer of thin film transistors. This multicomponent transparent conductive oxide is gaining great interest due to its reduced content of the scarce indium element. Experimental data indicate that the incorporation of zinc promotes the creation of oxygen vacancies, which results in a higher free carrier density. In thin-film transistors this effect leads to a higher off current and threshold voltage values. The field-effect mobility is also strongly degraded, probably due to coulomb scattering by ionized defects. A post deposition annealing in air reduces the density of oxygen vacancies and improves the field-effect mobility by orders of magnitude. Finally, the electrical characteristics of the fabricated thin-film transistors have been analyzed to estimate the density of states in the gap of the active layers. These measurements reveal a clear peak located at 0.3 eV from the conduction band edge that could be attributed to oxygen vacancies. - Highlights: • Zinc promotes the creation of oxygen vacancies in zinc indium tin oxide transistors. • Post deposition annealing in air reduces the density of oxygen. • Density of states reveals a clear peak located at 0.3 eV from the conduction band

  9. Mechanical properties of bioplastics cassava starch film with Zinc Oxide nanofiller as reinforcement

    Science.gov (United States)

    Harunsyah; Yunus, M.; Fauzan, Reza

    2017-06-01

    This study focuses on investigating the influence of zinc oxide nanofiller on the mechanical properties of bioplastic cassava starch films. Bioplastic cassava starch film-based zinc oxide reinforced composite biopolymeric films were prepared by casting technique. The content of zinc oxide in the bioplastic films was varied from 0.2%, 0.4%, 0.6%, 0.8% and 1.0% (w/w) by weight of starch. Surface morphologies of the composites bioplastic films were examined by scanning electron microscope (SEM).The result showed that the Tensile strength (TS) was improved significantly with the additional of zinc oxide but the elongation at break (EB %) of the composites was decreased. The maximum tensile strength obtained was 22.30 kgf / mm on the additional of zinc oxide by 0.6% and plastilizer by 25%. Based on data of FTIR, the produced film plastic did not change the group function and it can be concluded that theinteraction in film plastic produced was only a physical interaction. Biodegradable plastic film based on cassava starch-zinc oxide and plasticizer glycerol showed that interesting mechanical properties being transparent, clear, homogeneous, flexible, and easily handled.

  10. Fully patterned and low temperature transparent ZnO-based inverters

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez-Heredia, G. [Centro de Investigación en Materiales Avanzados, Unidad Monterrey, México (Mexico); Department of Materials Science and Engineering, University of Texas at Dallas (United States); Mejia, I.; Rivas-Aguilar, M.E.; Hernandez-Como, N. [Department of Materials Science and Engineering, University of Texas at Dallas (United States); Martinez-Landeros, V.H. [Centro de Investigación en Materiales Avanzados, Unidad Monterrey, México (Mexico); Department of Materials Science and Engineering, University of Texas at Dallas (United States); Aguirre-Tostado, F.S. [Centro de Investigación en Materiales Avanzados, Unidad Monterrey, México (Mexico); Quevedo-Lopez, M.A., E-mail: mquevedo@utdallas.edu [Department of Materials Science and Engineering, University of Texas at Dallas (United States)

    2013-10-31

    The fabrication and characterization of transparent logic inverters based on zinc oxide (ZnO) thin film transistors (TFTs) is reported. The inverters are fabricated using standard photolithographic techniques on glass substrates, and the entire fabrication process temperature is maintained < 100 °C, which render the devices suitable for flexible and transparent electronics applications. Pulsed laser deposition is used to deposit aluminum-doped zinc oxide and ZnO as electrode and active semiconductor materials, respectively. Electrical characterization for individual TFTs demonstrate mobilities of ∼ 10 cm{sup 2}/V-s, threshold voltages of 6 V, sub-threshold slopes of 630 mV/decade and I{sub ON}/I{sub OFF} ratios of 5 × 10{sup 6}. Films characterized by UV-Vis showed optical transmission > 80% in the visible spectrum. The inverters are analyzed with AC input signals at frequencies of 100 and 500 Hz. The AC response shows an average rise and fall time transitions of 0.65 and 0.44 ms, respectively. Measured inverters delay is in the order of 0.21 ms. - Highlights: • Logic inverters based on zinc oxide thin film transistors. • Inverters fabricated using temperatures below 100 °C and standard photolithography. • Transparent aluminum-doped zinc oxide as gate, drain and source electrodes. • Devices with total transmittance in the visible range above 80%. • AC inverter response up to 500 Hz.

  11. Fully patterned and low temperature transparent ZnO-based inverters

    International Nuclear Information System (INIS)

    Gutierrez-Heredia, G.; Mejia, I.; Rivas-Aguilar, M.E.; Hernandez-Como, N.; Martinez-Landeros, V.H.; Aguirre-Tostado, F.S.; Quevedo-Lopez, M.A.

    2013-01-01

    The fabrication and characterization of transparent logic inverters based on zinc oxide (ZnO) thin film transistors (TFTs) is reported. The inverters are fabricated using standard photolithographic techniques on glass substrates, and the entire fabrication process temperature is maintained < 100 °C, which render the devices suitable for flexible and transparent electronics applications. Pulsed laser deposition is used to deposit aluminum-doped zinc oxide and ZnO as electrode and active semiconductor materials, respectively. Electrical characterization for individual TFTs demonstrate mobilities of ∼ 10 cm 2 /V-s, threshold voltages of 6 V, sub-threshold slopes of 630 mV/decade and I ON /I OFF ratios of 5 × 10 6 . Films characterized by UV-Vis showed optical transmission > 80% in the visible spectrum. The inverters are analyzed with AC input signals at frequencies of 100 and 500 Hz. The AC response shows an average rise and fall time transitions of 0.65 and 0.44 ms, respectively. Measured inverters delay is in the order of 0.21 ms. - Highlights: • Logic inverters based on zinc oxide thin film transistors. • Inverters fabricated using temperatures below 100 °C and standard photolithography. • Transparent aluminum-doped zinc oxide as gate, drain and source electrodes. • Devices with total transmittance in the visible range above 80%. • AC inverter response up to 500 Hz

  12. III-V semiconductors for photoelectrochemical applications: surface preparation and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Fertig, Dominic; Schaechner, Birgit; Calvet, Wofram; Kaiser, Bernhard; Jaegermann, Wolfram [TU Darmstadt, Fachbereich Materialwissenschaft, Fachgebiet Oberflaechenforschung (Germany)

    2011-07-01

    III-V semiconductors are promising reference systems for photoelectrochemical energy conversion. Therefore we have studied the influence of different acids and acidic solutions on the etching of p-doped gallium-arsenide and gallium-phosphide single crystal surfaces. From our experiments we conclude, that etching with HCl and subsequent annealing up to 450 C gives the best results for the removal of the carbonates and the oxides without affecting the quality of the sample. By treating the surfaces with ''piranha''-solution (H{sub 2}SO{sub 4}:H{sub 2}O{sub 2}:H{sub 2}O/7:2:1), the creation of an oxide layer with well defined thickness can be achieved. For the creation of an efficient photoelectrochemical cell, Pt nanoparticles have been deposited from solution. These surfaces are then characterized by photoelectron spectroscopy and AFM. Further electrochemical measurements try to correlate the effect of the surface cleaning and the Pt deposition on the photoactivity of the GaAs- and GaP-semiconductors.

  13. Antibacterial properties of composite resins incorporating silver and zinc oxide nanoparticles on Streptococcus mutans and Lactobacillus

    Directory of Open Access Journals (Sweden)

    Shahin Kasraei

    2014-05-01

    Full Text Available Objectives Recurrent caries was partly ascribed to lack of antibacterial properties in composite resin. Silver and zinc nanoparticles are considered to be broad-spectrum antibacterial agents. The aim of the present study was to evaluate the antibacterial properties of composite resins containing 1% silver and zinc-oxide nanoparticles on Streptococcus mutans and Lactobacillus. Materials and Methods Ninety discoid tablets containing 0%, 1% nano-silver and 1% nano zinc-oxide particles were prepared from flowable composite resin (n = 30. The antibacterial properties of composite resin discs were evaluated by direct contact test. Diluted solutions of Streptococcus mutans (PTCC 1683 and Lactobacillus (PTCC 1643 were prepared. 0.01 mL of each bacterial species was separately placed on the discs. The discs were transferred to liquid culture media and were incubated at 37℃ for 8 hr. 0.01 mL of each solution was cultured on blood agar and the colonies were counted. Data was analyzed with Kruskall-Wallis and Mann-Whitney U tests. Results Composites containing nano zinc-oxide particles or silver nanoparticles exhibited higher antibacterial activity against Streptococcus mutans and Lactobacillus compared to the control group (p < 0.05. The effect of zinc-oxide on Streptococcus mutans was significantly higher than that of silver (p < 0.05. There were no significant differences in the antibacterial activity against Lactobacillus between composites containing silver nanoparticles and those containing zinc-oxide nanoparticles. Conclusions Composite resins containing silver or zinc-oxide nanoparticles exhibited antibacterial activity against Streptococcus mutans and Lactobacillus.

  14. The role of pH variation on the growth of zinc oxide nanostructures

    International Nuclear Information System (INIS)

    Wahab, Rizwan; Ansari, S.G.; Kim, Young Soon; Song, Minwu; Shin, Hyung-Shik

    2009-01-01

    In this paper we present a systematic study on the morphological variation of ZnO nanostructure by varying the pH of precursor solution via solution method. Zinc acetate dihydrate and sodium hydroxide were used as a precursor, which was refluxed at 90 deg. C for an hour. The pH of the precursor solution (zinc acetate di hydrate) was increased from 6 to 12 by the controlled addition of sodium hydroxide (NaOH). Morphology of ZnO nanorods markedly varies from sheet-like (at pH 6) to rod-like structure of zinc oxide (pH 10-12). Diffraction patterns match well with standard ZnO at all pH values. Crystallinity and nanostructures were confirmed by high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) pattern, which indicates structure grew along [0 0 0 1] direction with an ideal lattice fringes distance 0.52 nm. FTIR spectroscopic measurement showed a standard peak of zinc oxide at 464 cm -1 . Amount of H + and OH - ions are found key to the structure control of studied material, as discussed in the growth mechanism.

  15. Properties of RF sputtered zinc oxide based thin films made from different targets

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, M A; Herrero, J; Gutierrez, M T [Instituto de Energias Renovables, Madrid (Spain)

    1994-01-01

    The effect of deposition parameters on optoelectronic and structural properties of ZnO based thin films prepared by RF magnetron sputtering have been studied. Different targets (pure Zn, ZnO, Zn-Al (98/2 at%), ZnO-Al (98/2 at%), and ZnO-Al{sub 2}O{sub 3} (98/2 wt%)) have been investigated to compare resulting samples and establish the best target composition. From reactive sputtering, using a Zn-Al target, transparent conductive zinc oxide has been obtained at 380{sup o}C with E{sub g}=3.25-3.35 eV and {rho}=4.8x10{sup -4} {Omega}cm. Reduction of substrate temperature at 200{sup o}C has been possible by nonreactive sputtering from ZnO-Al and ZnO-Al{sub 2}O{sub 3} targets. The values of the energy gap and resistivity under these conditions are 3.30-3.35 eV and 1x10{sup -3} {Omega}cm respectively

  16. Pulsed laser deposition of transparent conductive oxide thin films on flexible substrates

    International Nuclear Information System (INIS)

    Socol, G.; Socol, M.; Stefan, N.; Axente, E.; Popescu-Pelin, G.; Craciun, D.; Duta, L.; Mihailescu, C.N.; Mihailescu, I.N.; Stanculescu, A.; Visan, D.; Sava, V.; Galca, A.C.; Luculescu, C.R.; Craciun, V.

    2012-01-01

    Highlights: ► TCO thin films were grown by PLD on PET substrate at low temperature. ► We found that the quality of TCO on PET substrate depends on the target–substrate distance. ► TCO with high transparency (>95%) and reduced electrical resistivity (∼5 × 10 −4 Ω cm) were obtained. ► Optimized TCO films deposited on PET were free of any cracks. - Abstract: The influence of target–substrate distance during pulsed laser deposition of indium zinc oxide (IZO), indium tin oxide (ITO) and aluminium-doped zinc oxide (AZO) thin films grown on polyethylene terephthalate (PET) substrates was investigated. It was found that the properties of such flexible transparent conductive oxide (TCO)/PET electrodes critically depend on this parameter. The TCO films that were deposited at distances of 6 and 8 cm exhibited an optical transmittance higher than 90% in the visible range and electrical resistivities around 5 × 10 −4 Ω cm. In addition to these excellent electrical and optical characteristics the films grown at 8 cm distance were homogenous, smooth, adherent, and without cracks or any other extended defects, being suitable for opto-electronic device applications.

  17. Study on the photoresponse of amorphous In-Ga-Zn-O and zinc oxynitride semiconductor devices by the extraction of sub-gap-state distribution and device simulation.

    Science.gov (United States)

    Jang, Jun Tae; Park, Jozeph; Ahn, Byung Du; Kim, Dong Myong; Choi, Sung-Jin; Kim, Hyun-Suk; Kim, Dae Hwan

    2015-07-22

    Persistent photoconduction (PPC) is a phenomenon that limits the application of oxide semiconductor thin-film transistors (TFTs) in optical sensor-embedded displays. In the present work, a study on zinc oxynitride (ZnON) semiconductor TFTs based on the combination of experimental results and device simulation is presented. Devices incorporating ZnON semiconductors exhibit negligible PPC effects compared with amorphous In-Ga-Zn-O (a-IGZO) TFTs, and the difference between the two types of materials are examined by monochromatic photonic C-V spectroscopy (MPCVS). The latter method allows the estimation of the density of subgap states in the semiconductor, which may account for the different behavior of ZnON and IGZO materials with respect to illumination and the associated PPC. In the case of a-IGZO TFTs, the oxygen flow rate during the sputter deposition of a-IGZO is found to influence the amount of PPC. Small oxygen flow rates result in pronounced PPC, and large densities of valence band tail (VBT) states are observed in the corresponding devices. This implies a dependence of PPC on the amount of oxygen vacancies (VO). On the other hand, ZnON has a smaller bandgap than a-IGZO and contains a smaller density of VBT states over the entire range of its bandgap energy. Here, the concept of activation energy window (AEW) is introduced to explain the occurrence of PPC effects by photoinduced electron doping, which is likely to be associated with the formation of peroxides in the semiconductor. The analytical methodology presented in this report accounts well for the reduction of PPC in ZnON TFTs, and provides a quantitative tool for the systematic development of phototransistors for optical sensor-embedded interactive displays.

  18. Microwave Synthesis of Zinc Hydroxy Sulfate Nanoplates and Zinc Oxide Nanorods in the Classroom

    Science.gov (United States)

    Dziedzic, Rafal M.; Gillian-Daniel, Anne Lynn; Peterson, Greta M.; Martínez-Herna´ndez, Kermin J.

    2014-01-01

    In this hands-on, inquiry-based lab, high school and undergraduate students learn about nanotechnology by synthesizing their own nanoparticles in a single class period. This simple synthesis of zinc oxide nanorods and zinc hydroxy sulfate nanoplates can be done in 15 min using a household microwave oven. Reagent concentration, reaction…

  19. Semiconductor properties and protective role of passive films of iron base alloys

    International Nuclear Information System (INIS)

    Fujimoto, Shinji; Tsuchiya, Hiroaki

    2007-01-01

    Semiconductor properties of passive films formed on the Fe-18Cr alloy in a borate buffer solution (pH = 8.4) and 0.1 M H 2 SO 4 solution were examined using a photoelectrochemical spectroscopy and an electrochemical impedance spectroscopy. Photo current reveals two photo action spectra that derived from outer hydroxide and inner oxide layers. A typical n-type semiconductor behaviour is observed by both photo current and impedance for the passive films formed in the borate buffer solution. On the other hand, a negative photo current generated, the absolute value of which decreased as applied potential increased in the sulfuric acid solution. This indicates that the passive film behaves as a p-type semiconductor. However, Mott-Schottky plot revealed the typical n-type semiconductor property. It is concluded that the passive film on the Fe-18Cr alloy formed in the borate buffer solution is composed of both n-type outer hydroxide and inner oxide layers. On the other hand, the passive film of the Fe-18Cr alloy in the sulphuric acid consists of p-type oxide and n-type hydroxide layers. The behaviour of passive film growth and corrosion was discussed in terms of the electronic structure in the passive film

  20. An anode with aluminum doped on zinc oxide thin films for organic light emitting devices

    International Nuclear Information System (INIS)

    Xu Denghui; Deng Zhenbo; Xu Ying; Xiao Jing; Liang Chunjun; Pei Zhiliang; Sun Chao

    2005-01-01

    Doped zinc oxides are attractive alternative materials as transparent conducting electrode because they are nontoxic and inexpensive compared with indium tin oxide (ITO). Transparent conducting aluminum-doped zinc oxide (AZO) thin films have been deposited on glass substrates by DC reactive magnetron sputtering method. Films were deposited at a substrate temperature of 150-bar o C in 0.03 Pa of oxygen pressure. The electrical and optical properties of the film with the Al-doping amount of 2 wt% in the target were investigated. For the 300-nm thick AZO film deposited using a ZnO target with an Al content of 2 wt%, the lowest electrical resistivity was 4x10 -4 Ωcm and the average transmission in the visible range 400-700 nm was more than 90%. The AZO film was used as an anode contact to fabricate organic light-emitting diodes. The device performance was measured and the current efficiency of 2.9 cd/A was measured at a current density of 100 mA/cm 2

  1. Zinc oxide tetrapod: a morphology with multifunctional applications

    International Nuclear Information System (INIS)

    Modi, Gaurav

    2015-01-01

    Zinc oxide has emerged as a material of great interest due to its unique optical, electrical and magnetic properties. This review comprehensively covers the various aspects of zinc oxide tetrapods. Tetrapod is a one dimensional zinc oxide nano-microstructure and has been found to have very promising applications in diverse fields. The growth model, properties, synthesis methods and variations in the tetrapod morphology by varying the synthesis conditions have been discussed. The promising applications of zinc oxide tetrapod morphology have been also discussed in detail. (review)

  2. Evaluations of Effective Factors on Efficiency Zinc Oxides Nanoparticles in Cadmium Removal from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    MH Ehrampoush

    2014-09-01

    Results: The results indicated that the adsorption process is affected by different parameters such as initial pollutant concentrations, adsorbent dose, pH, and contact time and Cadmiumremoval efficiency increases with increasing adsorbent dose and reaction time and decreases with increasing initial concentration of Cadmium. Therefore, it is observed that by raising the initial Cadmium concentration, the adsorption rate increases. The maximum efficiency of adsorptionin pH=7amounted to 89.6%. Conclusion: It is concluded that Zinc Oxide nanoparticles have proper efficiency in removal of Cadmium from aqueous solutions and can be used in the treatment of wastewater that contains ion Cadmium. However, its efficiency is deeply dependent on ion strength and the interaction of other metals in wastewater.

  3. Self-limiting growth of ZnO films on (0 0 0 1) sapphire substrates by atomic layer deposition at low temperatures using diethyl-zinc and nitrous oxide

    International Nuclear Information System (INIS)

    Lin, Yen-Ting; Chung, Ping-Han; Lai, Hung-Wei; Su, Hsin-Lun; Lyu, Dong-Yuan; Yen, Kuo-Yi; Lin, Tai-Yuan; Kung, Chung-Yuan; Gong, Jyh-Rong

    2009-01-01

    Atomic layer deposition (ALD) of zinc oxide (ZnO) films on (0 0 0 1) sapphire substrates was conducted at low temperatures by using diethyl-zinc (DEZn) and nitrous oxide (N 2 O) as precursors. It was found that a monolayer-by-monolayer growth regime occurred at 300 deg. C in a range of DEZn flow rates from 5.7 to 8.7 μmol/min. Furthermore, the temperature self-limiting process window for the ALD-grown ZnO films was also observed ranging from 290 to 310 deg. C. A deposition mechanism is proposed to explain how saturated growth of ZnO is achieved by using DEZn and N 2 O. Transmission spectroscopic studies of the ZnO films prepared in the self-limiting regime show that the transmittances of ZnO films are as high as 80% in visible and near infrared spectra. Experimental results indicate that ZnO films with high optical quality can be achieved by ALD at low temperatures using DEZn and N 2 O precursors.

  4. The study and microstructure analysis of zinc and zinc oxide

    Czech Academy of Sciences Publication Activity Database

    Luptáková, Natália; Pešlová, F.; Kliber, J.

    2015-01-01

    Roč. 54, č. 1 (2015), s. 43-46 ISSN 0543-5846 Grant - others:KEGA(SK) KEGA 007 TnUAD-4/2013 Institutional support: RVO:68081723 Keywords : zinc * production of zinc oxide * microstructure * chemical composition * zinc slag Subject RIV: JG - Metal lurgy Impact factor: 0.959, year: 2014

  5. Formulation of Synthesized Zinc Oxide Nanopowder into Hybrid Beads for Dye Separation

    Directory of Open Access Journals (Sweden)

    H. Shokry Hassan

    2014-01-01

    Full Text Available The sol-gel prepared zinc oxide nanopowder was immobilized onto alginate-polyvinyl alcohol polymer blend to fabricate novel biocomposite beads. Various physicochemical characterization techniques have been utilized to identify the crystalline, morphological, and chemical structures of both the fabricated zinc oxide hybrid beads and their corresponding zinc oxide nanopowder. The thermal stability investigations demonstrate that ZnO nanopowder stability dramatically decreased with its immobilization into the polymeric alginate and PVA matrix. The formulated beads had very strong mechanical strength and they are difficult to be broken up to 1500 rpm. Moreover, these hybrid beads are chemically stable at the acidic media (pH < 7 especially within the pH range of 2–7. Finally, the applicability of the formulated ZnO hybrid beads for C.I. basic blue 41 (BB41 decolorization from aqueous solution was examined.

  6. Comparison of the Effects of Pre-training Administration of Zinc Oxide and ‎Zinc Oxide Nanoparticles on Long-term Memory of Adult Male Mice

    Directory of Open Access Journals (Sweden)

    N Issapare

    2016-01-01

    Full Text Available BACKGROUND AND OBJECTIVE: Zinc oxide nanoparticles are one of the most widely used nanoparticles in fields of industry, medicine, pharmaceutical sciences, cosmetics, and nutrition. Multiple studies have demonstrated the negative effects of zinc oxide nanoparticles on the nervous system, while others have revealed their enhancing effects on the activity of nerve cells, involved in memory processes. The aim of this study was to compare the effects of zinc oxide nanoparticles and zinc oxide on long-term memory of mice. METHODS: In this experimental study, 49 NMRI adult male mice, with the mean weight of 25±5 g, were randomly divided into seven groups, each consisting of seven mice: control group, three treatment groups receiving zinc oxide nanoparticles (1, 2.5, and 5 mg/kg of  zinc oxide nanoparticles, respectively, and three treatment groups receiving zinc oxide (1, 2.5, and 5 mg/kg of zinc oxide, respectively. Intraperitoneal injections were performed before training (electric shock. Passive avoidance memory of mice was evaluated, using the Step-Down device. The latency time to descend the platform was regarded as an indicator of memory on days 1, 3, and 7 following training. FINDINGS: Pre-training administration of zinc oxide nanoparticles and zinc oxide at a dose of 2.5 mg/kg yielded no effects on the motor activity of mice. However, a significant decline was reported in the latency time to descend the platform on days 1, 3, and 7 following training (58±17, 45±13, and 39±14 in the zinc oxide group and 93±18, 62±12, and 14±3 in the nano zinc oxide group, respectively (p<0.01 however, the dosage of 5 mg/kg had less significant short-term effects (130±38, 49±14, and 68±10 in the zinc oxide group and 132±46, 41±13, and 58±24 in the nano zinc oxide group, respectively. Also, the dosage of 1 mg/kg was almost ineffective. CONCLUSION: The results showed that weakened long-term memory, caused by zinc oxide administration, is not

  7. Templated growth of cadmium zinc telluride (CZT) nanowires using pulsed-potentials in hot non-aqueous solution

    International Nuclear Information System (INIS)

    Gandhi, T.; Raja, K.S.; Misra, M.

    2006-01-01

    A single step non-aqueous electrodeposition of cadmium zinc telluride (CZT) nanowires on nanoporous TiO 2 substrate was investigated under pulsed-potential conditions. Propylene carbonate was used as the non-aqueous medium. Cyclic voltammogram studies were carried out to understand the growth mechanism of CZT. EDAX and XRD measurements indicated formation of a compound semiconductor with a stoichiometry of Cd 1-x Zn x Te, where x varied between 0.04 and 0.2. Variation of the pulsed-cathodic potentials could modulate the composition of the CZT. More negative cathodic potentials resulted in increased Zn content. The nanowires showed an electronic band gap of about 1.6 eV. Mott-Schottky analyses indicated p-type semiconductor properties of both as-deposited and annealed CZT materials. Increase in Zn content increased the charge carrier density. Annealing of the deposits resulted in lower charge carrier densities, in the order of 10 15 cm -3

  8. The Silver Oxide-Zinc Alkaline Primary Cell. Part 2. Effects of Various Types of Negative Electrodes on Cell Characteristics

    National Research Council Canada - National Science Library

    Shepherd, C. M

    1951-01-01

    ... (generally a potassium hydroxide solution). During discharge, the silver peroxide in the positive electrode is reduced to metallic silver and the metallic zinc in the negative electrode is oxidized either to zinc oxide or to a complex zincate ion...

  9. Improvement of transistor characteristics and stability for solution-processed ultra-thin high-valence niobium doped zinc-tin oxide thin film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Jeng, Jiann-Shing, E-mail: jsjeng@mail.nutn.edu.tw

    2016-08-15

    Nb-doped Zinc tin oxide (NZTO) channel materials have been prepared by solution process in combination with the spin-coating method. All NZTO thin film transistors (TFTs) are n-type enhancement-mode devices, either without or with Nb additives. High-valence niobium ion (ionic charge = +5) has a larger ionic potential and similar ionic radius to Zn{sup 2+} and Sn{sup 4+} ions. As compared with the pure ZTO device, introducing Nb{sup 5+} ions into the ZTO channel layers can improve the electrical properties and bias stability of TFTs because of the reduction of the oxygen vacancies. This study discusses the connection among the material properties of the NZTO films and the electrical performance and bias stability of NZTO TFTs and how they are influenced by the Nb/(Nb + Sn) molar ratios of NZTO films. - Highlights: • Ultra-thin high-valence niobium doped zinc-tin oxide (NZTO) thin films are prepared using a solution process. • Nb dopants in ZTO films reduce the oxygen vacancy and subgap adsorption of the ZTO films. • The Nb-doping concentration of the NZTO channel layer has a strong influence on the TFT performance.

  10. David Adler Lectureship Award in the Field of Materials Physics Talk: Novel Nitride and Oxide Electronics

    Science.gov (United States)

    Pearton, Stephen

    2011-03-01

    Recent progress in development of GaN-based transistors for gas and bio-sensing applications and amorphous IGZO layers for use thin film transistors (TFTs)on flexible substrates, including paper,will be presented. For the detection of gases such as hydrogen, the gateless GaN transistors are typically coated with a catalyst metal such as Pd or Pt to increase the detection sensitivity at room temperature. Functionalizing the surface with oxides, polymers and nitrides is also useful in enhancing the detection sensitivity for gases and ionic solutions.The use of enzymes or adsorbed antibody layers on the semiconductor surface leads to highly specific detection of a broad range of antigens of interest in the medical and security fields. We give examples of recent work showing sensitive detection of glucose, lactic acid, prostate cancer and breast cancer markers and the integration of the sensors with wireless data transmission systems to achieve robust, portable sensors. The amorphous transparent conducting oxide InZnGaO4 (IGZO) is attracting attention because of its high electron mobility (10-50 cm2.V-1.sec-1), high transparency in the visible region of the spectrum and its ability to be deposited with a wide range of conductivities.This raises the possibility of making low-cost electronics on a very wide range of arbitrary surfaces, including paper and plastics. N-type oxides such as zinc oxide, zinc tin oxide, indium gallium oxide, and indium gallium zinc tin oxide (IGZO) exhibit surprisingly high carrier mobilities even for amorphous films deposited at 300K. This has been explained by the fact that the conduction in these materials is predominantly through non-directional s orbitals which are less affected by disorder than the directional sp3 orbitals which control electron transport in Si. Examples of progress and discussion of remaining obstacles to use of IGZO TFTs will be presented Work performed in collaboration with Fan Ren.

  11. Zinc oxide nanoparticles for water disinfection

    Directory of Open Access Journals (Sweden)

    Emelita Asuncion S. Dimapilis

    2018-03-01

    Full Text Available The world faces a growing challenge for adequate clean water due to threats coming from increasing demand and decreasing supply. Although there are existing technologies for water disinfection, their limitations, particularly the formation of disinfection-by-products, have led to researches on alternative methods. Zinc oxide, an essential chemical in the rubber and pharmaceutical industries, has attracted interest as antimicrobial agent. In nanoscale, zinc oxide has shown antimicrobial properties which make its potential great for various applications. This review discusses the synthesis of zinc oxide with focus on precipitation method, its antimicrobial property and the factors affecting it, disinfection mechanisms, and the potential application to water disinfection.

  12. Homo-junction ferroelectric field-effect-transistor memory device using solution-processed lithium-doped zinc oxide thin films

    Science.gov (United States)

    Nayak, Pradipta K.; Caraveo-Frescas, J. A.; Bhansali, Unnat. S.; Alshareef, H. N.

    2012-06-01

    High performance homo-junction field-effect transistor memory devices were prepared using solution processed transparent lithium-doped zinc oxide thin films for both the ferroelectric and semiconducting active layers. A highest field-effect mobility of 8.7 cm2/Vs was obtained along with an Ion/Ioff ratio of 106. The ferroelectric thin film transistors showed a low sub-threshold swing value of 0.19 V/dec and a significantly reduced device operating voltage (±4 V) compared to the reported hetero-junction ferroelectric transistors, which is very promising for low-power non-volatile memory applications.

  13. Homo-junction ferroelectric field-effect-transistor memory device using solution-processed lithium-doped zinc oxide thin films

    KAUST Repository

    Nayak, Pradipta K.

    2012-06-22

    High performance homo-junction field-effect transistor memory devices were prepared using solution processed transparent lithium-doped zinc oxide thin films for both the ferroelectric and semiconducting active layers. A highest field-effect mobility of 8.7 cm2/Vs was obtained along with an Ion/Ioff ratio of 106. The ferroelectric thin filmtransistors showed a low sub-threshold swing value of 0.19 V/dec and a significantly reduced device operating voltage (±4 V) compared to the reported hetero-junction ferroelectrictransistors, which is very promising for low-power non-volatile memory applications.

  14. Efficient n-type doping of zinc-blende III-V semiconductor nanowires

    Science.gov (United States)

    Besteiro, Lucas V.; Tortajada, Luis; Souto, J.; Gallego, L. J.; Chelikowsky, James R.; Alemany, M. M. G.

    2014-03-01

    We demonstrate that it is preferable to dope III-V semiconductor nanowires by n-type anion substitution as opposed to cation substitution. Specifically, we show the dopability of zinc-blende nanowires is more efficient when the dopants are placed at the anion site as quantified by formation energies and the stabilization of DX-like defect centers. The comparison with previous work on n - type III-V semiconductor nanocrystals also allows to determine the role of dimensionality and quantum confinement on doping characteristics of materials. Our results are based on first-principles calculations of InP nanowires by using the PARSEC code. Work supported by the Spanish MICINN (FIS2012-33126) and Xunta de Galicia (GPC2013-043) in conjunction with FEDER. JRC acknowledges support from DoE (DE-FG02-06ER46286 and DESC0008877). Computational support was provided in part by CESGA.

  15. Surface plasmon resonance based fiber optic detection of chlorine utilizing polyvinylpyrolidone supported zinc oxide thin films.

    Science.gov (United States)

    Tabassum, Rana; Gupta, Banshi D

    2015-03-21

    A highly sensitive chlorine sensor for an aqueous medium is fabricated using an optical fiber surface plasmon resonance (OFSPR) system. An OFSPR-based chlorine sensor is designed with a multilayer-type platform by zinc oxide (ZnO) and polyvinylpyrollidone (PVP) film morphology manipulations. Among all the methodologies of transduction reported in the field of solid state chemical and biochemical sensing, our attention is focused on the Kretschmann configuration optical fiber sensing technique using the mechanism of surface plasmon resonance. The optical fiber surface plasmon resonance (SPR) chlorine sensor is developed using a multimode optical fiber with the PVP-supported ZnO film deposited over a silver-coated unclad core of the fiber. A spectral interrogation mode of operation is used to characterize the sensor. In an Ag/ZnO/PVP multilayer system, the absorption of chlorine in the vicinity of the sensing region is performed by the PVP layer and the zinc oxide layer enhances the shift in resonance wavelength. It is, experimentally, demonstrated that the SPR wavelength shifts nonlinearly towards the red side of the visible region with an increase in the chlorine concentration in an aqueous medium while the sensitivity of the sensor decreases linearly with an increase in the chlorine concentration. As the proposed sensor utilizes an optical fiber, it possesses the additional advantages of fiber such as less signal degradation, less susceptibility to electromagnetic interference, possibility of remote sensing, probe miniaturization, probe re-usability, online monitoring, small size, light weight and low cost.

  16. Inert gas annealing effect in solution-processed amorphous indium-gallium-zinc-oxide thin-film transistors

    Science.gov (United States)

    Lee, Seungwoon; Jeong, Jaewook

    2017-08-01

    In this paper, the annealing effect of solution-processed amorphous indium-gallium-zinc-oxide thin-film transistors (a-IGZO TFTs), under ambient He (He-device), is systematically analyzed by comparison with those under ambient O2 (O2-device) and N2 (N2-device), respectively. The He-device shows high field-effect mobility and low subthreshold slope owing to the minimization of the ambient effect. The degradation of the O2- and N2-device performances originate from their respective deep acceptor-like and shallow donor-like characteristics, which can be verified by comparison with the He-device. However, the three devices show similar threshold voltage instability under prolonged positive bias stress due to the effect of excess oxygen. Therefore, annealing in ambient He is the most suitable method for the fabrication of reference TFTs to study the various effects of the ambient during the annealing process in solution-processed a-IGZO TFTs.

  17. A comparative study of ultraviolet photoconductivity relaxation in zinc oxide (ZnO) thin films deposited by different techniques

    International Nuclear Information System (INIS)

    Yadav, Harish Kumar; Gupta, Vinay

    2012-01-01

    Photoresponse characteristics of ZnO thin films deposited by three different techniques namely rf diode sputtering, rf magnetron sputtering, and electrophoretic deposition has been investigated in the metal-semiconductor-metal (MSM) configuration. A significant variation in the crystallinity, surface morphology, and photoresponse characteristics of ZnO thin film with change in growth kinetics suggest that the presence of defect centers and their density govern the photodetector relaxation properties. A relatively low density of traps compared to the true quantum yield is found very crucial for the realization of practical ZnO thin film based ultraviolet (UV) photodetector.

  18. A comparative study of ultraviolet photoconductivity relaxation in zinc oxide (ZnO) thin films deposited by different techniques

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Harish Kumar; Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi, Delhi 110 007 (India)

    2012-05-15

    Photoresponse characteristics of ZnO thin films deposited by three different techniques namely rf diode sputtering, rf magnetron sputtering, and electrophoretic deposition has been investigated in the metal-semiconductor-metal (MSM) configuration. A significant variation in the crystallinity, surface morphology, and photoresponse characteristics of ZnO thin film with change in growth kinetics suggest that the presence of defect centers and their density govern the photodetector relaxation properties. A relatively low density of traps compared to the true quantum yield is found very crucial for the realization of practical ZnO thin film based ultraviolet (UV) photodetector.

  19. Chemical solution deposition of LaMnO3-based films for coated conductors

    International Nuclear Information System (INIS)

    Shi, D Q; Zhu, X B; Kim, J H; Wang, L; Zeng, R; Dou, S X; Lei, H C; Sun, Y P

    2008-01-01

    LaMnO 3 -based films were prepared using the chemical solution deposition method. It was found that the films on perovskite oxide single crystal substrates are highly (h00)-oriented when the annealing atmosphere is oxygen or air; however, when the substrate is yttrium-stabilized ZrO 2 , only the La 1-x Na x MnO 3 films are highly (h00)-oriented, and other LaMnO 3 -based films are (110)-oriented. Under a reducing annealing atmosphere, the atmosphere must be wet in order to create a suitable oxygen partial pressure to crystallize the LaMnO 3 -based films. After annealing under a wet reducing atmosphere the LaMnO 3 -based films are (110)-oriented when the films are directly deposited on Ni tapes; however, when SrTiO 3 -buffered Ni tapes are used, the LaMnO 3 films are (h00)-oriented, which is suitable for subsequent growth of YBCO. The results suggest that it is possible to tune the orientation of buffer layers using suitable templates, which can widen the selection of buffer layers for coated conductors in the all metallorganic deposition approach

  20. Electrical and optical properties of zinc oxide: thin films

    International Nuclear Information System (INIS)

    Zuhairusnizam Md Darus; Abdul Jalil Yeop Majlis; Anis Faridah Md Nor; Burhanuddin Kamaluddin

    1992-01-01

    Zinc oxide films have been prepared by high temperature oxidation of thermally evaporated zinc films on glass substrates. The resulting films are characterized using X-ray diffraction, optical absorption and electrical conductivity measurements. These zinc oxide films are very transparent and photoconductive

  1. Metal-oxide-semiconductor devices based on epitaxial germanium-carbon layers grown directly on silicon substrates by ultra-high-vacuum chemical vapor deposition

    Science.gov (United States)

    Kelly, David Quest

    After the integrated circuit was invented in 1959, complementary metal-oxide-semiconductor (CMOS) technology soon became the mainstay of the semiconductor industry. Silicon-based CMOS has dominated logic technologies for decades. During this time, chip performance has grown at an exponential rate at the cost of higher power consumption and increased process complexity. The performance gains have been made possible through scaling down circuit dimensions by improvements in lithography capabilities. Since scaling cannot continue forever, researchers have vigorously pursued new ways of improving the performance of metal-oxide-semiconductor field-effect transistors (MOSFETs) without having to shrink gate lengths and reduce the gate insulator thickness. Strained silicon, with its ability to boost transistor current by improving the channel mobility, is one of the methods that has already found its way into production. Although not yet in production, high-kappa dielectrics have also drawn wide interest in industry since they allow for the reduction of the electrical oxide thickness of the gate stack without having to reduce the physical thickness of the dielectric. Further out on the horizon is the incorporation of high-mobility materials such as germanium (Ge), silicon-germanium (Si1-xGe x), and the III-V semiconductors. Among the high-mobility materials, Ge has drawn the most attention because it has been shown to be compatible with high-kappa dielectrics and to produce high drive currents compared to Si. Among the most difficult challenges for integrating Ge on Si is finding a suitable method for reducing the number of crystal defects. The use of strain-relaxed Si1- xGex buffers has proven successful for reducing the threading dislocation density in Ge epitaxial layers, but questions remain as to the viability of this method in terms of cost and process complexity. This dissertation presents research on thin germanium-carbon (Ge 1-yCy layers on Si for the fabrication

  2. Performance improvement for solution-processed high-mobility ZnO thin-film transistors

    International Nuclear Information System (INIS)

    Li Chensha; Loutfy, Rafik O; Li Yuning; Wu Yiliang; Ong, Beng S

    2008-01-01

    The fabrication technology of stable, non-toxic, transparent, high performance zinc oxide (ZnO) thin-film semiconductors via the solution process was investigated. Two methods, which were, respectively, annealing a spin-coated precursor solution and annealing a drop-coated precursor solution, were compared. The prepared ZnO thin-film semiconductor transistors have well-controlled, preferential crystal orientation and exhibit superior field-effect performance characteristics. But the ZnO thin-film transistor (TFT) fabricated by annealing a drop-coated precursor solution has a distinctly elevated linear mobility, which further approaches the saturated mobility, compared with that fabricated by annealing a spin-coated precursor solution. The performance of the solution-processed ZnO TFT was further improved when substituting the spin-coating process by the drop-coating process

  3. Performance improvement for solution-processed high-mobility ZnO thin-film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Li Chensha; Loutfy, Rafik O [Department of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L7 (Canada); Li Yuning; Wu Yiliang; Ong, Beng S [Materials Design and Integration Laboratory, Xerox Research Centre of Canada, 2660 Speakman Drive, Mississauga, Ontario L5K 2L1 (Canada)], E-mail: lichnsa@163.com

    2008-06-21

    The fabrication technology of stable, non-toxic, transparent, high performance zinc oxide (ZnO) thin-film semiconductors via the solution process was investigated. Two methods, which were, respectively, annealing a spin-coated precursor solution and annealing a drop-coated precursor solution, were compared. The prepared ZnO thin-film semiconductor transistors have well-controlled, preferential crystal orientation and exhibit superior field-effect performance characteristics. But the ZnO thin-film transistor (TFT) fabricated by annealing a drop-coated precursor solution has a distinctly elevated linear mobility, which further approaches the saturated mobility, compared with that fabricated by annealing a spin-coated precursor solution. The performance of the solution-processed ZnO TFT was further improved when substituting the spin-coating process by the drop-coating process.

  4. Effects of deposition time in chemically deposited ZnS films in acidic solution

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, H.; Chelouche, A., E-mail: azeddinechelouche@gmail.com; Talantikite, D.; Merzouk, H.; Boudjouan, F.; Djouadi, D.

    2015-08-31

    We report an experimental study on the synthesis and characterization of zinc sulfide (ZnS) single layer thin films deposited on glass substrates by chemical bath deposition technique in acidic solution. The effect of deposition time on the microstructure, surface morphology, optical absorption, transmittance, and photoluminescence (PL) was investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), UV-Vis–NIR spectrophotometry and photoluminescence (PL) spectroscopy. The results showed that the samples exhibit wurtzite structure and their crystal quality is improved by increasing deposition time. The latter, was found to affect the morphology of the thin films as showed by SEM micrographs. The optical measurements revealed a high transparency in the visible range and a dependence of absorption edge and band gap on deposition time. The room temperature PL spectra indicated that all ZnS grown thin films emit a UV and blue light, while the band intensities are found to be dependent on deposition times. - Highlights: • Single layer ZnS thin films were deposited by CBD in acidic solution at 95 °C. • The effect of deposition time was investigated. • Coexistence of ZnS and ZnO hexagonal structures for time deposition below 2 h • Thicker ZnS films were achieved after monolayer deposition for 5 h. • The highest UV-blue emission observed in thin film deposited at 5 h.

  5. Survey Efficiency of Ultraviolet and Zinc Oxide Process (UV/ZnO for Removal of Diazinon Pesticide from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Mohammad Hadi Dehghani

    2015-03-01

    Full Text Available The presence of persistent organic pollutants and toxics (e.g., pesticides in ground, surface, and drinking water resources combined with the inability of conventional treatment methods to remove these pollutants have led to the development of advanced oxidation processes. Nowadays, nanophotocatalyst processes are considered as clean and environmentally-friendly treatment methods that can be extensively used for removing contaminants. The objective of the present study was to determine the efficiency of the ultraviolet and zinc oxide (UV/ZnO process in the removal of diazinon pesticide from aqueous solutions. For the purposes of this study, samples were adjusted in a batch reactor at five different detention times. The pH levels used were 3, 7, and 9. Irradiation was performed using a 125 W medium-pressure mercury lamp. The diazinon concentrations of the samples were 100 and 500 µg/L and the concentrations of zinc oxide nanoparticles were 50, 100, and 150 mg/L. The highest degradation efficiency was observed at pH 7 (mean = 80.92 30.3, while the lowest was observed for pH 3 (mean 67.11 24.49. Results showed that the optimal concentration of nanoparticles (6-12 nm was 100 mg L-1.

  6. EXAMINATION OF THE OXIDATION PROTECTION OF ZINC COATINGS FORMED ON COPPER ALLOYS AND STEEL SUBSTRATES

    International Nuclear Information System (INIS)

    Papazoglou, M.; Chaliampalias, D.; Vourlias, G.; Pavlidou, E.; Stergioudis, G.; Skolianos, S.

    2010-01-01

    The exposure of metallic components at aggressive high temperature environments, usually limit their usage at similar application because they suffer from severe oxidation attack. Copper alloys are used in a wide range of high-quality indoor and outdoor applications, statue parts, art hardware, high strength and high thermal conductivity applications. On the other hand, steel is commonly used as mechanical part of industrial set outs or in the construction sector due to its high mechanical properties. The aim of the present work is the examination of the oxidation resistance of pack cementation zinc coatings deposited on copper, leaded brass and steel substrates at elevated temperature conditions. Furthermore, an effort made to make a long-term evaluation of the coated samples durability. The oxidation results showed that bare substrates appear to have undergone severe damage comparing with the coated ones. Furthermore, the mass gain of the uncoated samples was higher than this of the zinc covered ones. Particularly zinc coated brass was found to be more resistant to oxidation conditions in which it was exposed as it has the lower mass gain as compared to the bare substrates and zinc coated copper. Zinc coated steel was also proved to be more resistive than the uncoated steel.

  7. Photocatalysis application of zinc oxide fibers obtained by electrospinning; Fribras de oxido de zinco obtidas por electrospinning aplicadas a fotocatalise

    Energy Technology Data Exchange (ETDEWEB)

    Gerchman, D.; Alves, A.K.; Berutti, F.A.; Bergmann, C.P. [Universidade Federal do Rio Grande do Sul (DEM/UFRGS), Porto Alegre, RS (Brazil). Dept. de Materiais

    2010-07-01

    Using the electrospinning technique, composite fibers of polyvinylbutyral and zinc nitrate were obtained. After a heat treatment at 600 deg C, nanostructured zinc oxide fibers were obtained. The fibers were characterized using X ray diffraction. The photocatalytic activity of the nanostructured fibers was determined using the photodegradation of a methyl orange solution. The increase in the heat treatment temperature decreases the photoactivity of the zinc oxide. The heat treatment, the phases and the surface area, affect the physical, chemical and photocatalytic activity of the zinc oxide. (author)

  8. Optical and electrical properties of zinc oxide thin films with low resistivity via Li-N dual-acceptor doping

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Daoli, E-mail: zhang_daoli@mail.hust.edu.cn [Department of Electronic Science and Technology, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China); Wuhan National Laboratory for Optoelectronics, 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China); Zhang Jianbing [Department of Electronic Science and Technology, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China); Wuhan National Laboratory for Optoelectronics, 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China); Guo Zhe [Department of Electronic Science and Technology, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China); Miao Xiangshui [Department of Electronic Science and Technology, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China); Wuhan National Laboratory for Optoelectronics, 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China)

    2011-05-19

    Highlights: > Zinc oxide films have been deposited on glass substrates by Li-N dual-acceptor doping method via a modified SILAR method. > The resistivity of ZnO film was found to be 1.04 {Omega} cm with a Hall mobility of 0.749 cm{sup 2} V{sup -1} s{sup -1}, carrier concentration of 8.02 x 1018 cm{sup -3}, and transmittance of about 80% in visible range showing good crystallinity with prior c-axis orientation. > A shallow acceptor level of 91 meV is identified from free-to-neutral-acceptor transitions. > Another deep level of 255 meV was ascribed to Li{sub Zn}-Li{sub i} complex. - Abstract: Zinc oxide thin films with low resistivity have been deposited on glass substrates by Li-N dual-acceptor doping method via a modified successive ionic layer adsorption and reaction process. The thin films were systematically characterized via scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction, ultraviolet-visible spectrophotometry and fluorescence spectrophotometry. The resistivity of zinc oxide film was found to be 1.04 {Omega} cm with a Hall mobility of 0.749 cm{sup 2} V{sup -1} s{sup -1} and carrier concentration of 8.02 x 10{sup 18} cm{sup -3}. The Li-N dual-acceptor doped zinc oxide films showed good crystallinity with prior c-axis orientation, and high transmittance of about 80% in visible range. Moreover, the effects of Li doping level and other parameters on crystallinity, electrical and ultraviolet emission of zinc oxide films were investigated.

  9. Influence of thickness and coatings morphology in the antimicrobial performance of zinc oxide coatings

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, P. [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal); Sampaio, P. [CBMA, University of Minho, Campus de Gualtar, 4700 Braga (Portugal); Azevedo, S. [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal); Vaz, C. [CBMA, University of Minho, Campus de Gualtar, 4700 Braga (Portugal); Espinós, J.P. [Instituto de Ciencia de Materiales de Sevilla, CSIC-University of Sevilla, Avda. Américo Vespucio 49, 41092 Sevilla (Spain); Teixeira, V., E-mail: vasco@fisica.uminho.pt [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal); Carneiro, J.O., E-mail: carneiro@fisica.uminho.pt [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal)

    2014-07-01

    In this research work, the production of undoped and silver (Ag) doped zinc oxide (ZnO) thin films for food-packaging applications were developed. The main goal was to determine the influence of coatings morphology and thickness on the antimicrobial performance of the produced samples. The ZnO based thin films were deposited on PET (Polyethylene terephthalate) substrates by means of DC reactive magnetron sputtering. The thin films were characterized by optical spectroscopy, X-Ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Scanning Electron Microscopy (SEM). The antimicrobial performance of the undoped and Ag-doped ZnO thin films was also evaluated. The results attained have shown that all the deposited zinc oxide and Ag-doped ZnO coatings present columnar morphology with V-shaped columns. The increase of ZnO coatings thickness until 200 nm increases the active surface area of the columns. The thinner samples (50 and 100 nm) present a less pronounced antibacterial activity than the thickest ones (200–600 nm). Regarding Ag-doped ZnO thin films, it was verified that increasing the silver content decreases the growth rate of Escherichia coli and decreases the amount of bacteria cells present at the end of the experiment.

  10. High Stability Performance of Quinary Indium Gallium Zinc Aluminum Oxide Films and Thin-Film Transistors Deposited Using Vapor Cooling Condensation Method

    Science.gov (United States)

    Lin, Yung-Hao; Lee, Ching-Ting

    2017-08-01

    High-quality indium gallium zinc aluminum oxide (IGZAO) thin films with various Al contents have been deposited using the vapor cooling condensation method. The electron mobility of the IGZAO films was improved by 89.4% on adding Al cation to IGZO film. The change in the electron concentration and mobility of the IGZAO films was 7.3% and 7.0%, respectively, when the temperature was changed from 300 K to 225 K. These experimental results confirm the high performance and stability of the IGZAO films. The performance stability mechanisms of IGZAO thin-film transistors (TFTs) were investigated in comparison with IGZO TFTs.

  11. Optimisation of chemical solution deposition of indium tin oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sunde, Tor Olav Løveng; Einarsrud, Mari-Ann; Grande, Tor, E-mail: grande@ntnu.no

    2014-12-31

    An environmentally friendly aqueous sol–gel process has been optimised to deposit indium tin oxide (ITO) thin films, aiming to improve the film properties and reduce the deposition costs. It was demonstrated how parameters such as cation concentration and viscosity could be applied to modify the physical properties of the sol and thereby reduce the need for multiple coatings to yield films with sufficient conductivity. The conductivity of the thin films was enhanced by adjusting the heat treatment temperature and atmosphere. Both increasing the heat treatment temperature of the films from 530 to 800 °C and annealing in reducing atmosphere significantly improved the electrical conductivity, and conductivities close to the state of the art sputtered ITO films were obtained. A pronounced decreased conductivity was observed after exposing the thin films to air and the thermal reduction and ageing of the film was studied by in situ conductivity measurements. - Highlights: • Spin coating of indium tin oxide using an aqueous solution was optimised. • The conductivity was enhanced by thermal annealing in reducing atmosphere. • The conductivity of is comparable to the conductivity of sputtered films. • A relaxation process in the reduced thin film was observed after exposure in air.

  12. Light-emitting diodes based on solution-processed nontoxic quantum dots: oxides as carrier-transport layers and introducing molybdenum oxide nanoparticles as a hole-inject layer.

    Science.gov (United States)

    Bhaumik, Saikat; Pal, Amlan J

    2014-07-23

    We report fabrication and characterization of solution-processed quantum dot light-emitting diodes (QDLEDs) based on a layer of nontoxic and Earth-abundant zinc-diffused silver indium disulfide (AIZS) nanoparticles as an emitting material. In the QDLEDs fabricated on indium tin oxide (ITO)-coated glass substrates, we use layers of oxides, such as graphene oxide (GO) and zinc oxide (ZnO) nanoparticles as a hole- and electron-transport layer, respectively. In addition, we introduce a layer of MoO3 nanoparticles as a hole-inject one. We report a comparison of the characteristics of different device architectures. We show that an inverted device architecture, ITO/ZnO/AIZS/GO/MoO3/Al, yields a higher electroluminescence (EL) emission, compared to direct ones, for three reasons: (1) the GO/MoO3 layers introduce barriers for electrons to reach the Al electrode, and, similarly, the ZnO layers acts as a barrier for holes to travel to the ITO electrode; (2) the introduction of a layer of MoO3 nanoparticles as a hole-inject layer reduces the barrier height for holes and thereby balances charge injection in the inverted structure; and (3) the wide-bandgap zinc oxide next to the ITO electrode does not absorb the EL emission during its exit from the device. In the QDLEDs with oxides as carrier inject and transport layers, the EL spectrum resembles the photoluminescence emission of the emitting material (AIZS), implying that excitons are formed in the quaternary nanocrystals and decay radiatively.

  13. Electrical and optical properties of amorphous indium zinc oxide films

    International Nuclear Information System (INIS)

    Ito, N.; Sato, Y.; Song, P.K.; Kaijio, A.; Inoue, K.; Shigesato, Y.

    2006-01-01

    Valence electron control and electron transport mechanisms on the amorphous indium zinc oxide (IZO) films were investigated. The amorphous IZO films were deposited by dc magnetron sputtering using an oxide ceramic IZO target (89.3 wt.% In 2 O 3 and 10.7 wt.% ZnO). N-type impurity dopings, such as Sn, Al or F, could not lead to the increase in carrier density in the IZO. Whereas, H 2 introduction into the IZO deposition process was confirmed to be effective to increase carrier density. By 30% H 2 introduction into the deposition process, carrier density increased from 3.08 x 10 2 to 7.65 x 10 2 cm -3 , which must be originated in generations of oxygen vacancies or interstitial Zn 2+ ions. Decrease in the transmittance in the near infrared region and increase in the optical band gap were observed with the H 2 introduction, which corresponded to the increase in carrier density. The lowest resistivity of 3.39 x 10 -4 Ω cm was obtained by 10% H 2 introduction without substrate heating during the deposition

  14. Study on a corrosion products behavior with zinc injection in PWR primary circuit based on the crud investigation in actual plant

    International Nuclear Information System (INIS)

    Hisamune Kenji; Nambu Tohru; Akutagawa Daisuke; Nagata Nobuaki; Shimizu, Yuichi; Nagamine, Kunitaka; Kogawa Noritaka

    2012-09-01

    Zinc injection into the reactor coolant of Pressurized Water Reactor (PWR) is one of the most effective techniques for removing radioactive cobalt from the chromite type spinel oxides in the inner layer of reactor coolant component surfaces. Many documents have reported that zinc injection applied plants have generally achieved positive dose rate reduction effects for the reactor coolant components and piping. Tsuruga Nuclear Power Plant unit 2 (hereafter Tsuruga unit 2) which applied zinc injection in 2005 has also achieved good dose reduction effects in most primary coolant piping. However, some piping without dose-rate reduction effects exist, it has come to an issue to plan radiation exposure reduction measures for the works around relevant piping. To plan a reasonable dose-rate reduction measures for respective components and piping in primary systems, it is considered necessary to understand the dose-rate reduction effects of zinc injection mechanically. Therefore, the surface oxides/deposits on piping and fuel cladding tubes with operational histories under zinc injection were investigated. As a result of the investigation, the changes in specific aspects of oxide layers and CRUDs are found as follow: - Owing to long-term zinc injection, deposits and oxides on the primary coolant piping are extremely reduced, the boundary between the outer oxide layer and the inner oxide layer become unclear with the thinning of the outer oxide layers. - At a Pressurizer Spray Piping, the dose-rate increases than before zinc injection. The oxide layers have the same 3-layer construction as before zinc injection, and the surface concentration of the radioactive cobalt is high. - At the fuel cladding tube surfaces, what is observed is the amount of metal nickel decrease and the chromium composition increase in the spinel type oxide From these results, it is suggested that, the oxide layers composed principally of zinc chromite spinel grow up on the pipe surface with zinc

  15. Characterization of Zinc Oxide (ZnO) piezoelectric properties for Surface Acoustic Wave (SAW) device

    Science.gov (United States)

    Rosydi Zakaria, Mohd; Johari, Shazlina; Hafiz Ismail, Mohd; Hashim, Uda

    2017-11-01

    In fabricating Surface Acoustic Wave (SAW) biosensors device, the substrate is one of important factors that affected to performance device. there are many types of piezoelectric substrate in the markets and the cheapest is zinc Oxide substrate. Zinc Oxide (ZnO) with its unique properties can be used as piezoelectric substrate along with SAW devices for detection of DNA in this research. In this project, ZnO thin film is deposited onto silicon oxide substrate using electron beam evaporation (E-beam) and Sol-Gel technique. Different material structure is used to compare the roughness and best piezoelectric substrate of ZnO thin film. Two different structures of ZnO target which are pellet and granular are used for e-beam deposition and one sol-gel liquid were synthesize and compared. Parameter for thickness of ZnO e-beam deposition is fixed to a 0.1kÅ for both materials structure and sol-gel was coat using spin coat technique. After the process is done, samples are annealed at temperature of 500°C for 2 hours. The structural properties of effect of post annealing using different material structure of ZnO are studied using Atomic Force Microscopic (AFM) for surface morphology and X-ray Diffraction (XRD) for phase structure.

  16. Preparation of surface modified zinc oxide nanoparticle with high capacity dye removal ability

    International Nuclear Information System (INIS)

    Mahmoodi, Niyaz Mohammad; Najafi, Farhood

    2012-01-01

    Highlights: ► Amine-functionalized zinc oxide nanoparticle (AFZON) was synthesized. ► Isotherm and kinetics data followed Langmuir isotherm and pseudo-second order kinetic model, respectively. ► Q 0 of ZON for AB25, DR23 and DR31 was 20, 12 and 15 mg/g, respectively. ► Q 0 of AFZON for AB25, DR23 and DR31 was 1250, 1000 and 1429 mg/g, respectively. ► AFZON was regenerated at pH 12. -- Abstract: In this paper, the surface modification of zinc oxide nanoparticle (ZON) by amine functionalization was studied to prepare high capacity adsorbent. Dye removal ability of amine-functionalized zinc oxide nanoparticle (AFZON) and zinc oxide nanoparticle (ZON) was also investigated. The physical characteristics of AFZON were studied using Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Acid Blue 25 (AB25), Direct Red 23 (DR23) and Direct Red 31 (DR31) were used as model compounds. The effect of operational parameters such as dye concentration, adsorbent dosage, pH and salt on dye removal was evaluated. The isotherm and kinetic of dye adsorption were studied. The maximum dye adsorption capacity (Q 0 ) was 20 mg/g AB25, 12 mg/g DR23 and 15 mg/g DR31 for ZON and 1250 mg/g AB25, 1000 mg/g DR23 and 1429 mg/g DR31 for AFZON. It was found that dye adsorption followed Langmuir isotherm. Adsorption kinetic of dyes was found to conform to pseudo-second order kinetics. Dye desorption tests (adsorbent regeneration) showed that the maximum dye release of 90% AB25, 86% for DR23 and 90% for DR31 were achieved in aqueous solution at pH 12. Based on the data of the present investigation, it can be concluded that the AFZON being an adsorbent with high dye adsorption capacity might be a suitable alternative to remove dyes from colored aqueous solutions.

  17. Semiconductor photocatalysts for water oxidation: current status and challenges.

    Science.gov (United States)

    Yang, Lingling; Zhou, Han; Fan, Tongxiang; Zhang, Di

    2014-04-21

    Artificial photosynthesis is a highly-promising strategy to convert solar energy into hydrogen energy for the relief of the global energy crisis. Water oxidation is the bottleneck for its kinetic and energetic complexity in the further enhancement of the overall efficiency of the artificial photosystem. Developing efficient and cost-effective photocatalysts for water oxidation is a growing desire, and semiconductor photocatalysts have recently attracted more attention due to their stability and simplicity. This article reviews the recent advancement of semiconductor photocatalysts with a focus on the relationship between material optimization and water oxidation efficiency. A brief introduction to artificial photosynthesis and water oxidation is given first, followed by an explanation of the basic rules and mechanisms of semiconductor particulate photocatalysts for water oxidation as theoretical references for discussions of componential, surface structure, and crystal structure modification. O2-evolving photocatalysts in Z-scheme systems are also introduced to demonstrate practical applications of water oxidation photocatalysts in artificial photosystems. The final part proposes some challenges based on the dynamics and energetics of photoholes which are fundamental to the enhancement of water oxidation efficiency, as well as on the simulation of natural water oxidation that will be a trend in future research.

  18. Defects in Amorphous Semiconductors: The Case of Amorphous Indium Gallium Zinc Oxide

    Science.gov (United States)

    de Jamblinne de Meux, A.; Pourtois, G.; Genoe, J.; Heremans, P.

    2018-05-01

    Based on a rational classification of defects in amorphous materials, we propose a simplified model to describe intrinsic defects and hydrogen impurities in amorphous indium gallium zinc oxide (a -IGZO). The proposed approach consists of organizing defects into two categories: point defects, generating structural anomalies such as metal—metal or oxygen—oxygen bonds, and defects emerging from changes in the material stoichiometry, such as vacancies and interstitial atoms. Based on first-principles simulations, it is argued that the defects originating from the second group always act as perfect donors or perfect acceptors. This classification simplifies and rationalizes the nature of defects in amorphous phases. In a -IGZO, the most important point defects are metal—metal bonds (or small metal clusters) and peroxides (O - O single bonds). Electrons are captured by metal—metal bonds and released by the formation of peroxides. The presence of hydrogen can lead to two additional types of defects: metal-hydrogen defects, acting as acceptors, and oxygen-hydrogen defects, acting as donors. The impact of these defects is linked to different instabilities observed in a -IGZO. Specifically, the diffusion of hydrogen and oxygen is connected to positive- and negative-bias stresses, while negative-bias illumination stress originates from the formation of peroxides.

  19. Degradation of zinc oxide thin films in aqueous environment. Pt. II. Coated films

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, L. de; Mitton, D.B.; Monetta, T.; Bellucci, F. [Naples Univ. (Italy). Dept. of Materials and Production Engineering; Springer, J. [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany)

    2001-12-01

    cn Part I of this research, the degradation mechanism of two different bare ZnO thin films was assessed. Degradation of the electrical properties of ZnO as well as changes in morphology were observed for both films. In the current paper, the degradation of zinc oxide thin films coated with protective acrylic paint is addressed during exposure to (i) an aqueous 3.5% NaCl solution at 85 C and (ii) a standard damp heat test at 85% R.H. and 85 C. Electrical and electrochemical techniques were employed to monitor zinc oxide degradation during exposure to the test environments. Electrochemical Impedance Spectroscopy was employed to investigate the delamination phenomena at the ZnO/coating interface and a simple equivalent circuit was developed to quantitatively measure the delamination ratio. The effect of different silane based adhesion promoters (glycidil-oxypropyl-trimethoxy-silane and aminopropyl-trimethoxy-silane) was also investigated. (orig.)

  20. Study and characterization of noble metal deposits on similar rusty surfaces to those of the reactor U-1 type BWR of nuclear power station of Laguna Verde

    International Nuclear Information System (INIS)

    Flores S, V. H.

    2011-01-01

    In the present investigation work, were determined the parameters to simulate the conditions of internal oxidation reactor circulation pipes of the nuclear power plant of Laguna Verde in Veracruz. We used 304l stainless steel cylinders with two faces prepared with abrasive paper of No. 600, with the finality to obtain similar surface to the internal circulation piping nuclear reactor. Oxides was formed within an autoclave (Autoclave MEX-02 unit B), which is a device that simulates the working conditions of the nuclear reactor, but without radiation generated by the fission reaction within the reactor. The oxidation conditions were a temperature of 280 C and pressure of 8 MPa, similar conditions to the reactor operating in nuclear power plant of Laguna Verde in Veracruz, Mexico (BWR conditions), with an average conductivity of 4.58 ms / cm and 2352 ppb oxygen to simulate normal water chemistry NWC. Were obtained deposits of noble metal oxides formed on 304l stainless steel samples, in a 250 ml autoclave at a temperature range of 180 to 200 C. The elements that were used to deposit platinum-rhodium (Pt-Rh) with aqueous Na 2 Pt (OH) 6 and Na 3 Rh (NO 2 ) 6 , Silver (Ag) with an aqueous solution of AgNO 3 , zirconium (Zr) with aqueous Zr O (NO 3 ) and ZrO 2 , and zinc (Zn) in aqueous solution of Zn (NO 3 ) 2 under conditions of normal water chemistry. Also there was the oxidation of 304l stainless steel specimens in normal water chemistry with a solution of Zinc (Zn) (NWC + Zn). Oxidation of the specimens in water chemistry with a solution of zinc (Zn + NWC) was prepared in two ways: within the MEX-02 autoclave unit A in a solution of zinc and a flask at constant temperature in zinc solution. The oxides formed and deposits were characterized by scanning electron microscopy, energy dispersive X-ray analysis, elemental field analysis and X-ray diffraction. By other hand was evaluated the electrochemical behavior of the oxides formed on the surface of 304l stainless steel

  1. Zinc oxide integrated area efficient high output low power wavy channel thin film transistor

    International Nuclear Information System (INIS)

    Hanna, A. N.; Ghoneim, M. T.; Bahabry, R. R.; Hussain, A. M.; Hussain, M. M.

    2013-01-01

    We report an atomic layer deposition based zinc oxide channel material integrated thin film transistor using wavy channel architecture allowing expansion of the transistor width in the vertical direction using the fin type features. The experimental devices show area efficiency, higher normalized output current, and relatively lower power consumption compared to the planar architecture. This performance gain is attributed to the increased device width and an enhanced applied electric field due to the architecture when compared to a back gated planar device with the same process conditions

  2. Zinc oxide integrated area efficient high output low power wavy channel thin film transistor

    KAUST Repository

    Hanna, Amir; Ghoneim, Mohamed T.; Bahabry, Rabab R.; Hussain, Aftab M.; Hussain, Muhammad Mustafa

    2013-01-01

    We report an atomic layer deposition based zinc oxide channel material integrated thin film transistor using wavy channel architecture allowing expansion of the transistor width in the vertical direction using the fin type features. The experimental devices show area efficiency, higher normalized output current, and relatively lower power consumption compared to the planar architecture. This performance gain is attributed to the increased device width and an enhanced applied electric field due to the architecture when compared to a back gated planar device with the same process conditions.

  3. Zinc oxide integrated area efficient high output low power wavy channel thin film transistor

    KAUST Repository

    Hanna, Amir

    2013-11-26

    We report an atomic layer deposition based zinc oxide channel material integrated thin film transistor using wavy channel architecture allowing expansion of the transistor width in the vertical direction using the fin type features. The experimental devices show area efficiency, higher normalized output current, and relatively lower power consumption compared to the planar architecture. This performance gain is attributed to the increased device width and an enhanced applied electric field due to the architecture when compared to a back gated planar device with the same process conditions.

  4. The electronic structure of co-sputtered zinc indium tin oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Carreras, Paz; Antony, Aldrin; Bertomeu, Joan [Departament de Fisica Aplicada i Optica, Universitat de Barcelona, 08028 Barcelona (Spain); Gutmann, Sebastian [Department of Chemistry, University of South Florida, Tampa, Florida 33620 (United States); Schlaf, Rudy [Department of Electrical Engineering, University of South Florida, Tampa, Florida 33620 (United States)

    2011-10-01

    Zinc indium tin oxide (ZITO) transparent conductive oxide layers were deposited via radio frequency (RF) magnetron co-sputtering at room temperature. A series of samples with gradually varying zinc content was investigated. The samples were characterized with x-ray and ultraviolet photoemission spectroscopy (XPS, UPS) to determine the electronic structure of the surface. Valence and conduction bands maxima (VBM, CBM), and work function were determined. The experiments indicate that increasing Zn content results in films with a higher defect rate at the surface leading to the formation of a degenerately doped surface layer if the Zn content surpasses {approx}50%. Furthermore, the experiments demonstrate that ZITO is susceptible to ultraviolet light induced work function reduction, similar to what was earlier observed on ITO and TiO{sub 2} films.

  5. Biofunctionalized Zinc Oxide Field Effect Transistors for Selective Sensing of Riboflavin with Current Modulation

    Directory of Open Access Journals (Sweden)

    Morley O. Stone

    2011-06-01

    Full Text Available Zinc oxide field effect transistors (ZnO-FET, covalently functionalized with single stranded DNA aptamers, provide a highly selective platform for label-free small molecule sensing. The nanostructured surface morphology of ZnO provides high sensitivity and room temperature deposition allows for a wide array of substrate types. Herein we demonstrate the selective detection of riboflavin down to the pM level in aqueous solution using the negative electrical current response of the ZnO-FET by covalently attaching a riboflavin binding aptamer to the surface. The response of the biofunctionalized ZnO-FET was tuned by attaching a redox tag (ferrocene to the 3’ terminus of the aptamer, resulting in positive current modulation upon exposure to riboflavin down to pM levels.

  6. Electronic Structure of the Perylene / Zinc Oxide Interface: A Computational Study of Photoinduced Electron Transfer and Impact of Surface Defects

    KAUST Repository

    Li, Jingrui

    2015-07-29

    The electronic properties of dye-sensitized semiconductor surfaces consisting of pery- lene chromophores chemisorbed on zinc oxide via different spacer-anchor groups, have been studied at the density-functional-theory level. The energy distributions of the donor states and the rates of photoinduced electron transfer from dye to surface are predicted. We evaluate in particular the impact of saturated versus unsaturated aliphatic spacer groups inserted between the perylene chromophore and the semiconductor as well as the influence of surface defects on the electron-injection rates.

  7. Electronic Structure of the Perylene / Zinc Oxide Interface: A Computational Study of Photoinduced Electron Transfer and Impact of Surface Defects

    KAUST Repository

    Li, Jingrui; Li, Hong; Winget, Paul; Bredas, Jean-Luc

    2015-01-01

    The electronic properties of dye-sensitized semiconductor surfaces consisting of pery- lene chromophores chemisorbed on zinc oxide via different spacer-anchor groups, have been studied at the density-functional-theory level. The energy distributions of the donor states and the rates of photoinduced electron transfer from dye to surface are predicted. We evaluate in particular the impact of saturated versus unsaturated aliphatic spacer groups inserted between the perylene chromophore and the semiconductor as well as the influence of surface defects on the electron-injection rates.

  8. Spectrophotometric determination of zinc in impure solutions

    International Nuclear Information System (INIS)

    Rodriguez Hernandez, B.; Reyes Tamaral, A.

    1972-01-01

    A dithizone colorimetric method is described for determining zinc concentrations of 0.001 to 5 g/l in aqueous solutions from Rio Tinto Mines, containing copper, iron and other impurities. Citrate, cyanide and bis-2hydroxyethyl)-dithiocarbamate are added to the aqueous sample of masking several metals, and zinc is extracted at pH 5 with a solution of dithizone in carbon tetrachloride. Excess of dithizone is removed with sodium sulphide, and optical density of zinc dithionate in organic solution is measured at 5.35 nm. Calibration curves obey Beer's law up to 0.5 micro Zn/ml. (Author) 5 refs

  9. Effect of electrolysis condition of zinc powder production on zinc-silver oxide battery operation

    International Nuclear Information System (INIS)

    Mojtahedi, M.; Goodarzi, M.; Sharifi, B.; Vahdati Khaki, J.

    2011-01-01

    A research conducted to produce zinc powder through electrolysis of alkaline solutions by using various concentrations of KOH and zincate in the bath. Different current densities were applied for each concentration and then, morphological changes of Zn powder batches were examined by scanning electron microscopy. Afterward, an anode electrode was produced from each pack of powder. Thirty-six Zn-AgO battery cells were prepared totally. Discharge parameters of the cells were examined and time-voltage curves were analyzed. Discharge times were investigated for various conditions of Zn deposition and the proper terms were suggested. It has been seen that increase of KOH concentration and decrease of zincate ion in the bath solution will change the zinc morphology and increase the resultant battery discharge time. The longest time of discharge, before reduction of cell voltage to 1.25 V, was 7.91 min. This result was obtained for Zn powder produced in zincate concentration of 0.5 M, KOH concentration of 11 M and current density of 2500 A/m 2 .

  10. Electrical effect of titanium diffusion on amorphous indium gallium zinc oxide

    International Nuclear Information System (INIS)

    Choi, Seung-Ha; Jung, Woo-Shik; Park, Jin-Hong

    2012-01-01

    In this work, thermal diffusion phenomenon of Ti into amorphous indium gallium zinc oxide (α-IGZO) was carefully investigated with secondary ion mass spectroscopy, I-V, and R s measurement systems and HSC chemistry simulation tool. According to the experimental and simulated results, the diffused Ti atoms were easily oxidized due to its lowest oxidation free energy. Since oxygen atoms were decomposed from the α-IGZO during the oxidation of Ti, the number of oxygen vacancies working as electron-donating sites in α-IGZO was dramatically increased, contributing to the decrease of resistivity (ρ) from 1.96 Ω cm (as-deposited α-IGZO) to 1.33 × 10 −3 Ω cm (350 °C annealed α-IGZO).

  11. Room temperature deposition of high figure of merit Al-doped zinc oxide by pulsed-direct current magnetron sputtering: Influence of energetic negative ion bombardment on film's optoelectronic properties

    Energy Technology Data Exchange (ETDEWEB)

    Fumagalli, F., E-mail: francesco.fumagalli@iit.it; Martí-Rujas, J., E-mail: javier.rujas@iit.it; Di Fonzo, F., E-mail: fabio.difonzo@iit.it

    2014-10-31

    Aluminum-doped zinc oxide is regarded as a promising indium-free transparent conductive oxide for photovoltaic and transparent electronics. In this study high transmittance (up to 90,6%) and low resistivity (down to 8,4°1{sup −4} Ω cm) AZO films were fabricated at room temperature on thermoplastic and soda-lime glass substrates by means of pulsed-DC magnetron sputtering in argon gas. Morphological, optical and electrical film properties were characterized using scanning electron microscopy, UV–vis–nIR photo-spectrometer, X-ray spectroscopy and four probes method. Optimal deposition conditions were found to be strongly related to substrate position. The dependence of functional properties on substrate off-axis position was investigated and correlated to the angular distributions of negative ions fluxes emerging from the plasma discharge. Figure of merit as high as 2,15 ± 0,14 Ω{sup −1} were obtained outside the negative oxygen ions confinement region. Combination of high quality AZO films deposited on flexible polymers substrates by means of a solid and scalable fabrication technique is of interest for application in cost-effective optoelectrical devices, organic photovoltaics and polymer based electronics. - Highlights: • High figure of merit transparent conductive oxide's deposited at room temperature. • High transmittance and low resistivity obtained on thermoplastic substrates. • Competitive optoelectrical properties compared to high temperature deposition. • Negative ion fluxes confinement influence structural and optoelectrical properties. • Easily adaptable for scaled-up low temperature AZO film deposition installations.

  12. Synthesis of vertically aligned metal oxide nanostructures

    KAUST Repository

    Roqan, Iman S.; Flemban, Tahani H.

    2016-01-01

    ablation of a target including a metal oxide and, optionally, a dopant. In some embodiments zinc oxide nanostructures are deposited onto a substrate by pulsed laser deposition of a zinc oxide target using an excimer laser emitting UV radiation. The zinc

  13. Effect of substrate temperature on the properties of pyrolytically deposited nitrogen-doped zinc oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Golshahi, S., E-mail: golshahi@iaurasht.ac.ir [Department of Physics, Rasht Branch, Islamic Azad University, Rasht (Iran, Islamic Republic of); Rozati, S.M. [Department of Physics, University of Guilan, 41335-1914 Rasht (Iran, Islamic Republic of); Botelho do Rego, A.M. [Centro de Quimica-Fisica Molecular and IN, Technical University of Lisbon, IST 1049-001 Lisboa (Portugal); Wang, J. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Elangovan, E.; Martins, R.; Fortunato, E. [CENIMAT/I3N, Departamento de Ciencia dos Materiais, Faculdade de Ciencias e Tecnologia, FCT, Universidade Nova de Lisboa (UNL), 2829-516 Caparica (Portugal)

    2013-01-01

    Highlights: Black-Right-Pointing-Pointer Hall-effect measurement introduces the optimum temperature of 450 Degree-Sign C for fabricating p-type high quality ZnO films. Black-Right-Pointing-Pointer X-ray photoelectron spectroscopy (XPS) proved the nitrogen presence at the surface of doped ZnO thin films at all substrate temperatures. Black-Right-Pointing-Pointer Films prepared at lower substrate temperature (300 Degree-Sign C and 350 Degree-Sign C) own wider band gaps. Black-Right-Pointing-Pointer Surface roughness strongly is affected by substrate temperature variations. - Abstract: The effect of substrate temperature (T{sub s}) on the properties of pyrolytically deposited nitrogen (N) doped zinc oxide (ZnO) thin films was investigated. The T{sub s} was varied from 300 Degree-Sign C to 500 Degree-Sign C, with a step of 50 Degree-Sign C. The positive sign of Hall coefficient confirmed the p-type conductivity in the films deposited at 450 Degree-Sign C and 500 Degree-Sign C. X-ray diffraction studies confirmed the ZnO structure with a dominant peak from (1 0 0) crystal plane, irrespective of the variation in T{sub s}. The presence of N in the ZnO structure was evidenced through X-ray photoelectron spectroscopy (XPS) analysis. The obtained high N concentration reveals that the 450 Degree-Sign C is the optimal T{sub s}. Atomic force microscope (AFM) analysis showed that the surface roughness was increased with the increasing T{sub s} until 400 Degree-Sign C but then decreased. It is found that the transmittance of the deposited films is increased with the increasing T{sub s}. The optical band gap calculated from the absorption edge showed that the films deposited with T{sub s} of 300 Degree-Sign C and 350 Degree-Sign C possess higher values than those deposited at higher T{sub s}.

  14. Effect of substrate temperature on the properties of pyrolytically deposited nitrogen-doped zinc oxide thin films

    International Nuclear Information System (INIS)

    Golshahi, S.; Rozati, S.M.; Botelho do Rego, A.M.; Wang, J.; Elangovan, E.; Martins, R.; Fortunato, E.

    2013-01-01

    Highlights: ► Hall-effect measurement introduces the optimum temperature of 450 °C for fabricating p-type high quality ZnO films. ► X-ray photoelectron spectroscopy (XPS) proved the nitrogen presence at the surface of doped ZnO thin films at all substrate temperatures. ► Films prepared at lower substrate temperature (300 °C and 350 °C) own wider band gaps. ► Surface roughness strongly is affected by substrate temperature variations. - Abstract: The effect of substrate temperature (T s ) on the properties of pyrolytically deposited nitrogen (N) doped zinc oxide (ZnO) thin films was investigated. The T s was varied from 300 °C to 500 °C, with a step of 50 °C. The positive sign of Hall coefficient confirmed the p-type conductivity in the films deposited at 450 °C and 500 °C. X-ray diffraction studies confirmed the ZnO structure with a dominant peak from (1 0 0) crystal plane, irrespective of the variation in T s . The presence of N in the ZnO structure was evidenced through X-ray photoelectron spectroscopy (XPS) analysis. The obtained high N concentration reveals that the 450 °C is the optimal T s . Atomic force microscope (AFM) analysis showed that the surface roughness was increased with the increasing T s until 400 °C but then decreased. It is found that the transmittance of the deposited films is increased with the increasing T s . The optical band gap calculated from the absorption edge showed that the films deposited with T s of 300 °C and 350 °C possess higher values than those deposited at higher T s .

  15. Significance of polymethylmethacrylate (PMMA) modification by zinc oxide nanoparticles for fungal biofilm formation.

    Science.gov (United States)

    Cierech, Mariusz; Kolenda, Adam; Grudniak, Anna M; Wojnarowicz, Jacek; Woźniak, Bartosz; Gołaś, Marlena; Swoboda-Kopeć, Ewa; Łojkowski, Witold; Mierzwińska-Nastalska, Elżbieta

    2016-08-20

    The objective of this study was to obtain a material composite with antifungal properties for dentures to be used as an alternative protocol in denture stomatitis treatment and prevention. Denture stomatitis is still a clinical problem in patients particularly vulnerable to this disease. Composites of PMMA and doped ZnO-NPs (weight concentrations, 2.5%, 5%, 7.5%) and PMMA with sprayed solvothermal and hydrothermal ZnO-NPs were tested. The following investigations of newly formed biomaterials were undertaken: influence on Candida albicans solution, biofilm staining, XTT analysis and a quantitative analysis of adhered C. albicans. These studies evidenced the antifungal activity of both nanocomposites PMMA-ZnO-NPs and the efficacy of sputtering of zinc oxide nanoparticles on the PMMA. The study of the biofilm deposition on the surface showed that antifungal properties increase with increasing concentration of ZnO-NPs. The XTT assay in conjunction with testing the turbidity of solutions may indicate the mechanism by which ZnO-NPs exert their effect on the increased induction of antioxidative stress in microorganism cells. The denture base made of the aforesaid materials may play a preventive role in patients susceptible to fungal infections. Based on the results obtained a modified treatment of stomatitis Type II (Newton's classification) complicated by fungal infection was proposed. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Effects of nanorod structure and conformation of fatty acid self-assembled layers on superhydrophobicity of zinc oxide surface.

    Science.gov (United States)

    Badre, Chantal; Dubot, P; Lincot, Daniel; Pauporte, Thierry; Turmine, Mireille

    2007-12-15

    Superhydrophobic surfaces have been prepared from nanostructured zinc oxide layers by a treatment with fatty acid molecules. The layers are electrochemically deposited from an oxygenated aqueous zinc chloride solution. The effects of the layer's structure, from a dense film to that of a nanorod array, as well as that of the properties of the fatty acid molecules based on C18 chains are described. A contact angle (CA) as high as 167 degrees is obtained with the nanorod structure and the linear saturated molecule (stearic acid). Lower values are found with molecules having an unsaturated bond on C9, in particular with a cis conformation (140 degrees ). These results, supplemented by infrared spectroscopy, indicate an enhancement of the sensitivity to the properties of the fatty acid molecules (conformation, flexibility, saturated or not) when moving from the flat surface to the nanostructured surface. This is attributed to a specific influence of the structure of the tops of the rods and lateral wall properties on the adsorption and organization of the molecules. CA measurements show a very good stability of the surface in time if stored in an environment protected from UV radiations.

  17. Methods of preparing deposits containing iron oxides for recycling

    Directory of Open Access Journals (Sweden)

    T. Lis

    2013-04-01

    Full Text Available The metallurgical industry is one of the largest sources of wastes. Some of them, however, owing to their content of metals such as zinc or iron, may become valuable secondary raw materials. In order to achieve that purpose, they require appropriate preparation. This article provides a discussion on the methods of preparation of scrap from steelworks, namely deposits containing iron oxides, enabling their recycling.

  18. Influence of addition of indium and of post-annealing on structural, electrical and optical properties of gallium-doped zinc oxide thin films deposited by direct-current magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Duy Phong [Laboratory of Advanced Materials, University of Science, Vietnam National University, HoChiMinh (Viet Nam); College of Information and Communication Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Nguyen, Huu Truong [Laboratory of Advanced Materials, University of Science, Vietnam National University, HoChiMinh (Viet Nam); Phan, Bach Thang [Laboratory of Advanced Materials, University of Science, Vietnam National University, HoChiMinh (Viet Nam); Faculty of Materials Science, University of Science, Vietnam National University, HoChiMinh (Viet Nam); Hoang, Van Dung [Laboratory of Advanced Materials, University of Science, Vietnam National University, HoChiMinh (Viet Nam); Maenosono, Shinya [School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292 (Japan); Tran, Cao Vinh, E-mail: tcvinh@hcmus.edu.vn [Laboratory of Advanced Materials, University of Science, Vietnam National University, HoChiMinh (Viet Nam)

    2015-05-29

    In this study, both gallium-doped zinc oxide (GZO) and indium-added gallium-doped zinc oxide (IGZO) thin films were deposited on commercial glasses by magnetron dc-sputtering in argon atmosphere. The crystal structure, electrical conductivity and optical transmission of as-deposited as well as post-annealed thin films of both GZO and IGZO were investigated for comparison. A small amount of indium introduced into GZO thin films had improved their polycrystalline structure and increased their electrical conductivity by over 29%. All obtained GZO and IGZO thin films have strong [002] crystalline direction, a characteristic orientation of ZnO thin films. Although post-annealed in air at high temperatures up to 500 °C, IGZO thin films still had very low sheet resistance of 6.6 Ω/□. Furthermore, they had very high optical transmission of over 80% in both visible and near-infrared regions. - Highlights: • Doping 0.1 at.% indium enhanced crystalline, electrical properties of GZO films. • The mobility of IGZO films was 25% higher than that of GZO films. • The IGZO films will be potential materials for transparent conducting electrodes.

  19. Influence of addition of indium and of post-annealing on structural, electrical and optical properties of gallium-doped zinc oxide thin films deposited by direct-current magnetron sputtering

    International Nuclear Information System (INIS)

    Pham, Duy Phong; Nguyen, Huu Truong; Phan, Bach Thang; Hoang, Van Dung; Maenosono, Shinya; Tran, Cao Vinh

    2015-01-01

    In this study, both gallium-doped zinc oxide (GZO) and indium-added gallium-doped zinc oxide (IGZO) thin films were deposited on commercial glasses by magnetron dc-sputtering in argon atmosphere. The crystal structure, electrical conductivity and optical transmission of as-deposited as well as post-annealed thin films of both GZO and IGZO were investigated for comparison. A small amount of indium introduced into GZO thin films had improved their polycrystalline structure and increased their electrical conductivity by over 29%. All obtained GZO and IGZO thin films have strong [002] crystalline direction, a characteristic orientation of ZnO thin films. Although post-annealed in air at high temperatures up to 500 °C, IGZO thin films still had very low sheet resistance of 6.6 Ω/□. Furthermore, they had very high optical transmission of over 80% in both visible and near-infrared regions. - Highlights: • Doping 0.1 at.% indium enhanced crystalline, electrical properties of GZO films. • The mobility of IGZO films was 25% higher than that of GZO films. • The IGZO films will be potential materials for transparent conducting electrodes

  20. Pulsed laser deposition of HfO{sub 2} thin films on indium zinc oxide: Band offsets measurements

    Energy Technology Data Exchange (ETDEWEB)

    Craciun, D.; Craciun, V., E-mail: valentin.craciun@inflpr.ro

    2017-04-01

    Highlights: • High quality amorphous IZO and HfO{sub 2} films were obtained by PLD technique. • XPS measurements were used to obtain the valence band alignment in HfO{sub 2}/IZO heterostructure. • A valence band offset (ΔE{sub V}) of 1.75 eV was obtained for the HfO{sub 2}/IZO heterostructure. • A conduction band offset (ΔE{sub C}) of 0.65 eV was estimated for the HfO{sub 2}/IZO heterostructure. - Abstract: One of the most used dielectric films for amorphous indium zinc oxide (IZO) based thin films transistor is HfO{sub 2}. The estimation of the valence band discontinuity (ΔE{sub V}) of HfO{sub 2}/IZO heterostructure grown using the pulsed laser deposition technique, with In/(In + Zn) = 0.79, was obtained from X-ray photoelectron spectroscopy (XPS) measurements. The binding energies of Hf 4d5, Zn 2p3 and In 3d5 core levels and valence band maxima were measured for thick pure films and for a very thin HfO{sub 2} film deposited on a thick IZO film. A value of ΔE{sub V} = 1.75 ± 0.05 eV was estimated for the heterostructure. Taking into account the measured HfO{sub 2} and IZO optical bandgap values of 5.50 eV and 3.10 eV, respectively, a conduction band offset ΔE{sub C} = 0.65 ± 0.05 eV in HfO{sub 2}/IZO heterostructure was then obtained.

  1. Synthesis and characterization of fly ash-zinc oxide nanocomposite

    Directory of Open Access Journals (Sweden)

    Kunal Yeole

    2014-04-01

    Full Text Available Fly ash, generated in thermal power plants, is recognized as an environmental pollutant. Thus, measures are required to be undertaken to dispose it in an environmentally friendly method. In this paper an attempt is made to coat zinc oxide nano-particles on the surface of fly ash by a simple and environmentally friendly facile chemical method, at room temperature. Zinc oxide may serve as effective corrosion inhibitor by providing sacrificial protection. Concentration of fly ash was varied as 5, 10 and 15 (w/w % of zinc oxide. It was found that crystallinity increased, whereas particle size, specific gravity and oil absorption value decreased with increased concentration of fly ash in zinc oxide, which is attributed to the uniform distribution of zinc oxide on the surface of fly ash. These nanocomposites can potentially be used in commercial applications as additive for anticorrosion coatings.

  2. Bioavailability of Zinc in Wistar Rats Fed with Rice Fortified with Zinc Oxide

    Science.gov (United States)

    Della Lucia, Ceres Mattos; Santos, Laura Luiza Menezes; Rodrigues, Kellen Cristina da Cruz; Rodrigues, Vivian Cristina da Cruz; Martino, Hércia Stampini Duarte; Pinheiro Sant’Ana, Helena Maria

    2014-01-01

    The study of zinc bioavailability in foods is important because this mineral intake does not meet the recommended doses for some population groups. Also, the presence of dietary factors that reduce zinc absorption contributes to its deficiency. Rice fortified with micronutrients (Ultra Rice®) is a viable alternative for fortification since this cereal is already inserted into the population habit. The aim of this study was to evaluate the bioavailability of zinc (Zn) in rice fortified with zinc oxide. During 42 days, rats were divided into four groups and fed with diets containing two different sources of Zn (test diet: UR® fortified with zinc oxide, or control diet: zinc carbonate (ZnCO3)), supplying 50% or 100%, respectively, of the recommendations of this mineral for animals. Weight gain, food intake, feed efficiency ratio, weight, thickness and length of femur; retention of zinc, calcium (Ca) and magnesium (Mg) in the femur and the concentrations of Zn in femur, plasma and erythrocytes were evaluated. Control diet showed higher weight gain, feed efficiency ratio, retention of Zn and Zn concentration in the femur (p 0.05) for dietary intake, length and thickness of the femur, erythrocyte and plasmatic Zn between groups. Although rice fortified with zinc oxide showed a lower bioavailability compared to ZnCO3, this food can be a viable alternative to be used as a vehicle for fortification. PMID:24932657

  3. Properties of InGaAs/GaAs metal-oxide-semiconductor heterostructure field-effect transistors modified by surface treatment

    Energy Technology Data Exchange (ETDEWEB)

    Gregušová, D., E-mail: Dagmar.Gregusova@savba.sk [Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava SK-84104 (Slovakia); Gucmann, F.; Kúdela, R. [Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava SK-84104 (Slovakia); Mičušík, M. [Polymer Institute of Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava SK-84541 (Slovakia); Stoklas, R.; Válik, L. [Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava SK-84104 (Slovakia); Greguš, J. [Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynská dolina, Bratislava SK-84248 (Slovakia); Blaho, M. [Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava SK-84104 (Slovakia); Kordoš, P. [Institute of Electronics and Photonics, Faculty of Electrical Engineering and Information Technology STU, Ilkovičova 3, Bratislava SK-81219 (Slovakia)

    2017-02-15

    Highlights: • AlGaAs/InGaAs/GaAs-based metal oxide semiconductor transistors-MOSHFET. • Thin Al-layer deposited in-situ and oxidize in air – gate insulator. • MOSHFET vs HFET transistor properties, density of traps evaluated. - Abstract: GaAs-based heterostructures exhibit excellent carrier transport properties, mainly the high carrier velocity. An AlGaAs-GaAs heterostructure field-effect transistor (HFET) with an InGaAs channel was prepared using metal-organic chemical vapor deposition (MOVPE). An AlOx layer was formed on the AlGaAs barrier layer by the air-assisted oxidation of a thin Al layer deposited in-situ in an MOVPE reactor immediately after AlGaAs/InGaAs growth. The HFETs and MOSHFETs exhibited a very low trap state density in the order of 10{sup 11} cm{sup −2} eV{sup −1}. Capacitance measurement yielded no significant difference between the HFET and MOSHFET structures. The formation of an AlOx layer modified the surface by partially eliminating surface states that arise from Ga-and As-based native oxides. The presence of an AlOx layer reflected in a reduced gate leakage current, which was evidenced by the two-terminal transistor measurement. Presented preparation procedure and device properties show great potential of AlGaAs/InGaAs-based MOSHFETs.

  4. Electrosprayed Metal Oxide Semiconductor Films for Sensitive and Selective Detection of Hydrogen Sulfide

    Directory of Open Access Journals (Sweden)

    Maryam Siadat

    2009-11-01

    Full Text Available Semiconductor metal oxide films of copper-doped tin oxide (Cu-SnO2, tungsten oxide (WO3 and indium oxide (In2O3 were deposited on a platinum coated alumina substrate employing the electrostatic spray deposition technique (ESD. The morphology studied with scanning electron microscopy (SEM and atomic force microscopy (AFM shows porous homogeneous films comprising uniformly distributed aggregates of nano particles. The X-ray diffraction technique (XRD proves the formation of crystalline phases with no impurities. Besides, the Raman cartographies provided information about the structural homogeneity. Some of the films are highly sensitive to low concentrations of H2S (10 ppm at low operating temperatures (100 and 200 °C and the best response in terms of Rair/Rgas is given by Cu-SnO2 films (2500 followed by WO3 (1200 and In2O3 (75. Moreover, all the films exhibit no cross-sensitivity to other reducing (SO2 or oxidizing (NO2 gases.

  5. Oxygen effect of transparent conducting amorphous Indium Zinc Tin Oxide films on Polyimide substrate for flexible electrode

    International Nuclear Information System (INIS)

    Ko, Yoon Duk; Lee, Chang Hun; Moon, Doo Kyung; Kim, Young Sung

    2013-01-01

    This paper discusses the effect of oxygen on the transparent conducting properties and mechanical durability of the amorphous indium zinc tin oxide (IZTO) films. IZTO films deposited on flexible clear polyimide (PI) substrate using pulsed direct current (DC) magnetron sputtering at room temperature under various oxygen partial pressures. All IZTO films deposited at room temperature exhibit an amorphous structure. The electrical and optical properties of the IZTO films were sensitively influenced by oxygen partial pressures. At optimized deposition condition of 3.0% oxygen partial pressure, the IZTO film shows the lowest resistivity of 6.4 × 10 −4 Ωcm, high transmittance of over 80% in the visible range, and figure of merit value of 3.6 × 10 −3 Ω −1 without any heat controls. In addition, high work function and good mechanical flexibility of amorphous IZTO films are beneficial to flexible applications. It is proven that the proper oxygen partial pressure is important parameter to enhance the transparent conducting properties of IZTO films on PI substrate deposited at room temperature. - Highlights: • Indium zinc tin oxide (IZTO) films were deposited on polyimide at room temperature. • Transparent conducting properties of IZTO were influenced with oxygen partial pressure. • The smooth surface and high work function of IZTO were beneficial to anode layer. • The mechanical reliability of IZTO shows better performance to indium tin oxide film

  6. Suppression of persistent photo-conductance in solution-processed amorphous oxide thin-film transistors

    Science.gov (United States)

    Lee, Minkyung; Kim, Minho; Jo, Jeong-Wan; Park, Sung Kyu; Kim, Yong-Hoon

    2018-01-01

    This study offers a combinatorial approach for suppressing the persistent photo-conductance (PPC) characteristic in solution-processed amorphous oxide semiconductor (AOS) thin-film transistors (TFTs) in order to achieve rapid photo-recovery. Various analyses were used to examine the photo-instability of indium-gallium-zinc-oxide (IGZO) TFTs including negative-bias-illumination-stress (NBIS) and transient photo-response behaviors. It was found that the indium ratio in metallic components had a significant impact on their PPC and photo-recovery characteristics. In particular, when the indium ratio was low (51.5%), the PPC characteristic was significantly suppressed and achieving rapid photo-recovery was possible without significantly affecting the electrical performance of AOSs. These results imply that the optimization of the indium composition ratio may allow achieving highly photo-stable and near PPC-free characteristics while maintaining high electrical performance of AOSs. It is considered that the negligible PPC behavior and rapid photo-recovery observed in IGZO TFTs with a lower indium composition are attributed to the less activation energy required for the neutralization of ionized oxygen vacancies.

  7. In vivo target bio-imaging of Alzheimer's disease by fluorescent zinc oxide nanoclusters.

    Science.gov (United States)

    Lai, Lanmei; Zhao, Chunqiu; Su, Meina; Li, Xiaoqi; Liu, Xiaoli; Jiang, Hui; Amatore, Christian; Wang, Xuemei

    2016-07-21

    Alzheimer's disease (AD) is an irreversible neurodegenerative disease which is difficult to cure. When Alzheimer's disease occurs, the level of zinc ions in the brain changes, and the relevant amount of zinc ions continue decreasing in the cerebrospinal fluid and plasma of Alzheimer's patients with disease exacerbation. In view of these considerations, we have explored a new strategy for the in vivo rapid fluorescence imaging of Alzheimer's disease through target bio-labeling of zinc oxide nanoclusters which were biosynthesized in vivo in the Alzheimer's brain via intravenous injection of zinc gluconate solution. By using three-month-old and six-month-old Alzheimer's model mice as models, our observations demonstrate that biocompatible zinc ions could pass through the blood-brain barrier of the Alzheimer's disease mice and generate fluorescent zinc oxide nanoclusters (ZnO NCs) through biosynthesis, and then the bio-synthesized ZnO NCs could readily accumulate in situ on the hippocampus specific region for the in vivo fluorescent labeling of the affected sites. This study provides a new way for the rapid diagnosis of Alzheimer's disease and may have promising prospects in the effective diagnosis of Alzheimer's disease.

  8. Deep subgap feature in amorphous indium gallium zinc oxide: Evidence against reduced indium

    International Nuclear Information System (INIS)

    Sallis, Shawn; Williams, Deborah S.; Quackenbush, Nicholas F.; Senger, Mikell; Woicik, Joseph C.; White, Bruce E.; Piper, Louis F.J.

    2015-01-01

    Amorphous indium gallium zinc oxide (a-IGZO) is the archetypal transparent amorphous oxide semiconductor. Despite the gains made with a-IGZO over amorphous silicon in the last decade, the presence of deep subgap states in a-IGZO active layers facilitate instabilities in thin film transistor properties under negative bias illumination stress. Several candidates could contribute to the formation of states within the band gap. Here, we present evidence against In + lone pair active electrons as the origin of the deep subgap features. No In + species are observed, only In 0 nano-crystallites under certain oxygen deficient growth conditions. Our results further support under coordinated oxygen as the source of the deep subgap states. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Ultrasound irradiation based in-situ synthesis of star-like Tragacanth gum/zinc oxide nanoparticles on cotton fabric.

    Science.gov (United States)

    Ghayempour, Soraya; Montazer, Majid

    2017-01-01

    Application of natural biopolymers for green and safe synthesis of zinc oxide nanoparticles on the textiles is a novel and interesting approach. The present study offers the use of natural biopolymer, Tragacanth gum, as the reducing, stabilizing and binding agent for in-situ synthesis of zinc oxide nanoparticles on the cotton fabric. Ultrasonic irradiation leads to clean and easy synthesis of zinc oxide nanoparticles in short-time at low-temperature. FESEM/EDX, XRD, FT-IR spectroscopy, DSC, photocatalytic activities and antimicrobial assay are used to characterize Tragacanth gum/zinc oxide nanoparticles coated cotton fabric. The analysis confirmed synthesis of star-like zinc oxide nanoparticles with hexagonal wurtzite structure on the cotton fabric with the average particle size of 62nm. The finished cotton fabric showed a good photocatalytic activity on degradation of methylene blue and 100% antimicrobial properties with inhibition zone of 3.3±0.1, 3.1±0.1 and 3.0±0.1mm against Staphylococcus aureus, Escherichia coli and Candida albicans. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Electrodeposition behavior of nickel and nickel-zinc alloys from the zinc chloride-1-ethyl-3-methylimidazolium chloride low temperature molten salt

    International Nuclear Information System (INIS)

    Gou Shiping; Sun, I.-W.

    2008-01-01

    The electrodeposition of nickel and nickel-zinc alloys was investigated at polycrystalline tungsten electrode in the zinc chloride-1-ethyl-3-methylimidazolium chloride molten salt. Although nickel(II) chloride dissolved easily into the pure chloride-rich 1-ethyl-3-methylimidazolium chloride ionic melt, metallic nickel could not be obtained by electrochemical reduction of this solution. The addition of zinc chloride to this solution shifted the reduction of nickel(II) to more positive potential making the electrodeposition of nickel possible. The electrodeposition of nickel, however, requires an overpotential driven nucleation process. Dense and compact nickel deposits with good adherence could be prepared by controlling the deposition potential. X-ray powder diffraction measurements indicated the presence of crystalline nickel deposits. Non-anomalous electrodeposition of nickel-zinc alloys was achieved through the underpotential deposition of zinc on the deposited nickel at a potential more negative than that of the deposition of nickel. X-ray powder diffraction and energy-dispersive spectrometry measurements of the electrodeposits indicated that the composition and the phase types of the nickel-zinc alloys are dependent on the deposition potential. For the Ni-Zn alloy deposits prepared by underpotential deposition of Zn on Ni, the Zn content in the Ni-Zn was always less than 50 atom%

  11. Metal/Semiconductor and Transparent Conductor/Semiconductor Heterojunctions in High Efficient Photoelectric Devices: Progress and Features

    Directory of Open Access Journals (Sweden)

    M. Melvin David Kumar

    2014-01-01

    Full Text Available Metal/semiconductor and transparent conductive oxide (TCO/semiconductor heterojunctions have emerged as an effective modality in the fabrication of photoelectric devices. This review is following a recent shift toward the engineering of TCO layers and structured Si substrates, incorporating metal nanoparticles for the development of next-generation photoelectric devices. Beneficial progress which helps to increase the efficiency and reduce the cost, has been sequenced based on efficient technologies involved in making novel substrates, TCO layers, and electrodes. The electrical and optical properties of indium tin oxide (ITO and aluminum doped zinc oxide (AZO thin films can be enhanced by structuring the surface of TCO layers. The TCO layers embedded with Ag nanoparticles are used to enhance the plasmonic light trapping effect in order to increase the energy harvesting nature of photoelectric devices. Si nanopillar structures which are fabricated by photolithography-free technique are used to increase light-active surface region. The importance of the structure and area of front electrodes and the effect of temperature at the junction are the value added discussions in this review.

  12. Electrochemical evaluation of zinc effect on the corrosion of nickel alloy in PWR solutions with increasing temperature

    International Nuclear Information System (INIS)

    Alvial M, Gaston; Neves, Celia F.C.; Schvartzman, Monica M.A.M.; Quinan, Marco Antonio D.

    2007-01-01

    The main objective for the addition of zinc acetate to the reactor coolant system of PWRs is to effect radiation dose rate reductions. However, zinc is also added as an approach to mitigate the occurrence or severity of primary water stress corrosion cracking of nickel alloy 600. The mechanism by which zinc affects the corrosion of austenitic nickel-base alloys is by incorporation of zinc into the spinel oxide corrosion films. The purpose of this work is to evaluate the influence of zinc on the corrosion behavior of the nickel alloy 600 in PWR chemical environment (1200 ppm B, 2.2 ppm Li, deoxygenated water) with increasing temperature at room pressure. Electrochemical tests (anodic potentiodynamic polarization and electrochemical impedance spectroscopy) were used to characterize the alloy 600. Two conditions were applied: 0 and 100 ppb zinc and the temperature range was 50 - 90 deg C, at ambient pressure. Potentiodynamic polarization was inefficient to present conclusive results. Impedance measurements showed single semicircle in the Nyquist plane suggesting reduction of the charge transference resistance in zinc-containing solutions. This effect is evident at 90 deg C suggesting prejudicial influence of zinc for the alloy 600 at room pressure. (author)

  13. Preparation of transparent conducting zinc oxide films by rf reactive sputtering

    International Nuclear Information System (INIS)

    Vasanelli, L.; Valentini, A.; Losacco, A.

    1986-01-01

    Transparent conducting zinc oxide films have been prepared by reactive sputtering in a Ar/H/sub 2/ mixture. The optical and electrical properties of the films are presented and discussed. The effects of some post-deposition thermal treatment have been also investigated. ZnO/CdTe heterojunctions have been prepared by sputtering ZnO films on CdTe single crystals. The photovoltaic conversion efficiencies of the obtained solar cells was 6.8%

  14. Photo-Electrochemical Effect of Zinc Addition on the Electrochemical Corrosion Potentials of Stainless Steels and Nickel Alloys in High Temperature Water

    International Nuclear Information System (INIS)

    Lee, Yi-Ching; Fong, Clinton; Fang-Chu, Charles; Chang, Ching

    2012-09-01

    Hydrogen water chemistry (HWC) is one of the main mitigating methods for stress corrosion cracking problem of reactor core stainless steel and nickel based alloy components. Zinc is added to minimize the radiation increase associated with HWC. However, the subsequently formed zinc-containing surface oxides may exhibit p-type semiconducting characteristics. Upon the irradiation of Cherenkov and Gamma ray in the reactor core, the ECP of stainless steels and nickel based alloys may shift in the anodic direction, possibly offsetting the beneficial effect of HWC. This study will evaluate the photo-electrochemical effect of Zinc Water Chemistry on SS304 stainless steel and Alloy 182 nickel based weld metal under simulated irradiated BWR water environments with UV illumination. The experimental results reveal that Alloy 182 nickel-based alloy generally possesses n-type semiconductor characteristics in both oxidizing NWC and reducing HWC conditions with zinc addition. Upon UV irradiation, the ECP of Alloy 182 will shift in the cathodic direction. In most conditions, SS304 will also exhibit n-type semiconducting properties. Only under hydrogen water chemistry, a weak p-type property may emerge. Only a slight upward shift in the anodic direction is detected when SS304 is illuminated with UV light. The potential influence of p-type semiconductor of zinc containing surface oxides is weak and the mitigation effect of HWC on the stress corrosion cracking is not adversely affected. (authors)

  15. The speciation of aqueous zinc(II) bromide solutions to 500 °C and 900 MPa determined using Raman spectroscopy

    Science.gov (United States)

    Mibe, Kenji; Chou, I-Ming; Anderson, Alan J.; Mayanovic, Robert A.; Bassett, William A.

    2009-01-01

    A Raman spectral study was carried out on 3 solutions of varying concentration and bromide/zinc ratios. Spectra were collected at 11 different temperature-pressure conditions ranging from ambient to 500????C-0.9??GPa. Raman band assignments for zinc(II) bromide species reported in previous studies were used to determine the relative concentrations of ZnBr42-, ZnBr3-, ZnBr2, and ZnBr+ species at various temperatures and pressures. Our results are in close agreement with X-ray absorption spectroscopic (XAS) data, and confirm that the tetrabromo zinc(II) complex, ZnBr42-, is the predominant species up to 500????C in solutions having high Zn concentrations (1??m) and high bromide/zinc molar ratios ([Br]/[Zn] = 8). In agreement with previous solubility and Raman spectroscopic experiments, our measurements indicate that species with a lower number of halide ligands and charge are favored with increasing temperature in dilute solutions, and solutions with low bromide/zinc ratios ([Br]/[Zn] Raman technique provides an independent experimental means of evaluating the quality of XAS analyses of data obtained from high temperature disordered systems. The combination of these two techniques provides complementary data on speciation and the structure of zinc(II) bromide complexes. The preponderance of the ZnBr42- species in highly saline brines at high temperature is consistent with the predominance of ZnCl42- in chloride-rich brines reported in previous XAS studies. Knowledge of Zn complexing in metal-rich highly saline brines is important for numerical models of ore deposition in high temperature systems such as skarns and porphyry-type deposits. ?? 2008 Elsevier B.V.

  16. Hydrogen plasma treatment for improved conductivity in amorphous aluminum doped zinc tin oxide thin films

    Directory of Open Access Journals (Sweden)

    M. Morales-Masis

    2014-09-01

    Full Text Available Improving the conductivity of earth-abundant transparent conductive oxides (TCOs remains an important challenge that will facilitate the replacement of indium-based TCOs. Here, we show that a hydrogen (H2-plasma post-deposition treatment improves the conductivity of amorphous aluminum-doped zinc tin oxide while retaining its low optical absorption. We found that the H2-plasma treatment performed at a substrate temperature of 50 °C reduces the resistivity of the films by 57% and increases the absorptance by only 2%. Additionally, the low substrate temperature delays the known formation of tin particles with the plasma and it allows the application of the process to temperature-sensitive substrates.

  17. Hydrogen plasma treatment for improved conductivity in amorphous aluminum doped zinc tin oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Masis, M., E-mail: monica.moralesmasis@epfl.ch; Ding, L.; Dauzou, F. [Photovoltaics and Thin-Film Electronics Laboratory (PVLab), Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne - EPFL, Rue de la Maladière 71b, CH-2002 Neuchatel (Switzerland); Jeangros, Q. [Interdisciplinary Centre for Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland); Hessler-Wyser, A. [Photovoltaics and Thin-Film Electronics Laboratory (PVLab), Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne - EPFL, Rue de la Maladière 71b, CH-2002 Neuchatel (Switzerland); Interdisciplinary Centre for Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland); Nicolay, S. [Centre Suisse d’Electronique et de Microtechnique (CSEM) SA, Rue Jaquet-Droz 1, CH-2002 Neuchatel (Switzerland); Ballif, C. [Photovoltaics and Thin-Film Electronics Laboratory (PVLab), Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne - EPFL, Rue de la Maladière 71b, CH-2002 Neuchatel (Switzerland); Centre Suisse d’Electronique et de Microtechnique (CSEM) SA, Rue Jaquet-Droz 1, CH-2002 Neuchatel (Switzerland)

    2014-09-01

    Improving the conductivity of earth-abundant transparent conductive oxides (TCOs) remains an important challenge that will facilitate the replacement of indium-based TCOs. Here, we show that a hydrogen (H{sub 2})-plasma post-deposition treatment improves the conductivity of amorphous aluminum-doped zinc tin oxide while retaining its low optical absorption. We found that the H{sub 2}-plasma treatment performed at a substrate temperature of 50 °C reduces the resistivity of the films by 57% and increases the absorptance by only 2%. Additionally, the low substrate temperature delays the known formation of tin particles with the plasma and it allows the application of the process to temperature-sensitive substrates.

  18. Electron Band Alignment at Interfaces of Semiconductors with Insulating Oxides: An Internal Photoemission Study

    Directory of Open Access Journals (Sweden)

    Valeri V. Afanas'ev

    2014-01-01

    Full Text Available Evolution of the electron energy band alignment at interfaces between different semiconductors and wide-gap oxide insulators is examined using the internal photoemission spectroscopy, which is based on observations of optically-induced electron (or hole transitions across the semiconductor/insulator barrier. Interfaces of various semiconductors ranging from the conventional silicon to the high-mobility Ge-based (Ge, Si1-xGex, Ge1-xSnx and AIIIBV group (GaAs, InxGa1-xAs, InAs, GaP, InP, GaSb, InSb materials were studied revealing several general trends in the evolution of band offsets. It is found that in the oxides of metals with cation radii larger than ≈0.7 Å, the oxide valence band top remains nearly at the same energy (±0.2 eV irrespective of the cation sort. Using this result, it becomes possible to predict the interface band alignment between oxides and semiconductors as well as between dissimilar insulating oxides on the basis of the oxide bandgap width which are also affected by crystallization. By contrast, oxides of light elements, for example, Be, Mg, Al, Si, and Sc exhibit significant shifts of the valence band top. General trends in band lineup variations caused by a change in the composition of semiconductor photoemission material are also revealed.

  19. Selectivity in the oxidative dehydrogenation of butene on zinc-iron oxide catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Kung, H.H.; Kundalkar, B.; Kung, M.C.; Cheng, W.H.

    1980-02-21

    Adsorption, temperature-programed desorption, and pulse reaction studies of cis-2-butene and butadiene on spinel zinc ferrite by previously described methods provided evidence that the selectivity for oxidative dehydrogenation of butenes increases when zinc is added to the iron oxide catalyst because selective oxidation and complete oxidation proceed on separate sites, as they do on pure iron; because the density of sites for selective oxidation is higher and the density of sites for complete combustion is lower than on pure iron oxide; and because the activity of the combustion sites is lower.

  20. Tungsten oxide proton conducting films for low-voltage transparent oxide-based thin-film transistors

    International Nuclear Information System (INIS)

    Zhang, Hongliang; Wan, Qing; Wan, Changjin; Wu, Guodong; Zhu, Liqiang

    2013-01-01

    Tungsten oxide (WO x ) electrolyte films deposited by reactive magnetron sputtering showed a high room temperature proton conductivity of 1.38 × 10 −4 S/cm with a relative humidity of 60%. Low-voltage transparent W-doped indium-zinc-oxide thin-film transistors gated by WO x -based electrolytes were self-assembled on glass substrates by one mask diffraction method. Enhancement mode operation with a large current on/off ratio of 4.7 × 10 6 , a low subthreshold swing of 108 mV/decade, and a high field-effect mobility 42.6 cm 2 /V s was realized. Our results demonstrated that WO x -based proton conducting films were promising gate dielectric candidates for portable low-voltage oxide-based devices.

  1. Preliminary study on zinc-air battery using zinc regeneration electrolysis with propanol oxidation as a counter electrode reaction

    Science.gov (United States)

    Wen, Yue-Hua; Cheng, Jie; Ning, Shang-Qi; Yang, Yu-Sheng

    A zinc-air battery using zinc regeneration electrolysis with propanol oxidation as a counter electrode reaction is reported in this paper. It possesses functions of both zincate reduction and electrochemical preparation, showing the potential for increasing the electronic energy utilization. Charge/discharge tests and scanning electron microscopy (SEM) micrographs reveal that when a nickel sheet plated with the high-H 2-overpotential metal, cadmium, was used as the negative substrate electrode, the dendritic formation and hydrogen evolution are suppressed effectively, and granular zinc deposits become larger but relatively dense with the increase of charge time. The performance of batteries is favorable even if the charge time is as long as 5 h at the current density of 20 mA cm -2. Better discharge performance is achieved using a 'cavity-opening' configuration for the discharge cell rather than a 'gas-introducing' configuration. The highest energy efficiency is up to 59.2%. That is, the energy consumed by organic electro-synthesis can be recovered by 59.2%. Cyclic voltammograms show that the sintered nickel electrode exhibits a good electro-catalysis activity for the propanol oxidation. The increase of propanol concentration conduces to an enhancement in the organic electro-synthesis efficiency. The organic electro-synthesis current efficiency of 82% can be obtained.

  2. Novel Dry-Type Glucose Sensor Based on a Metal-Oxide-Semiconductor Capacitor Structure with Horseradish Peroxidase + Glucose Oxidase Catalyzing Layer

    Science.gov (United States)

    Lin, Jing-Jenn; Wu, You-Lin; Hsu, Po-Yen

    2007-10-01

    In this paper, we present a novel dry-type glucose sensor based on a metal-oxide-semiconductor capacitor (MOSC) structure using SiO2 as a gate dielectric in conjunction with a horseradish peroxidase (HRP) + glucose oxidase (GOD) catalyzing layer. The tested glucose solution was dropped directly onto the window opened on the SiO2 layer, with a coating of HRP + GOD catalyzing layer on top of the gate dielectric. From the capacitance-voltage (C-V) characteristics of the sensor, we found that the glucose solution can induce an inversion layer on the silicon surface causing a gate leakage current flowing along the SiO2 surface. The gate current changes Δ I before and after the drop of glucose solution exhibits a near-linear relationship with increasing glucose concentration. The Δ I sensitivity is about 1.76 nA cm-2 M-1, and the current is quite stable 20 min after the drop of the glucose solution is tested.

  3. Sediment-Hosted Zinc-Lead Deposits of the World - Database and Grade and Tonnage Models

    Science.gov (United States)

    Singer, Donald A.; Berger, Vladimir I.; Moring, Barry C.

    2009-01-01

    This report provides information on sediment-hosted zinc-lead mineral deposits based on the geologic settings that are observed on regional geologic maps. The foundation of mineral-deposit models is information about known deposits. The purpose of this publication is to make this kind of information available in digital form for sediment-hosted zinc-lead deposits. Mineral-deposit models are important in exploration planning and quantitative resource assessments: Grades and tonnages among deposit types are significantly different, and many types occur in different geologic settings that can be identified from geologic maps. Mineral-deposit models are the keystone in combining the diverse geoscience information on geology, mineral occurrences, geophysics, and geochemistry used in resource assessments and mineral exploration. Too few thoroughly explored mineral deposits are available in most local areas for reliable identification of the important geoscience variables, or for robust estimation of undiscovered deposits - thus, we need mineral-deposit models. Globally based deposit models allow recognition of important features because the global models demonstrate how common different features are. Well-designed and -constructed deposit models allow geologists to know from observed geologic environments the possible mineral-deposit types that might exist, and allow economists to determine the possible economic viability of these resources in the region. Thus, mineral-deposit models play the central role in transforming geoscience information to a form useful to policy makers. This publication contains a computer file of information on sediment-hosted zinc-lead deposits from around the world. It also presents new grade and tonnage models for nine types of these deposits and a file allowing locations of all deposits to be plotted in Google Earth. The data are presented in FileMaker Pro, Excel and text files to make the information available to as many as possible. The

  4. Effect of the Milling Time of the Precursors on the Physical Properties of Sprayed Aluminum-Doped Zinc Oxide (ZnO:Al Thin Films

    Directory of Open Access Journals (Sweden)

    María De La Luz Olvera

    2012-08-01

    Full Text Available Aluminum doped zinc oxide (ZnO:Al thin films were deposited on soda-lime glass substrates by the chemical spray technique. The atomization of the solution was carried out by ultrasonic excitation. Six different starting solutions from both unmilled and milled Zn and Al precursors, dissolved in a mix of methanol and acetic acid, were prepared. The milling process was carried out using a planetary ball mill at a speed of 300 rpm, and different milling times, namely, 15, 25, 35, 45, and 60 min. Molar concentration, [Al]/[Zn] atomic ratio, deposition temperature and time, were kept at constant values; 0.2 M, 3 at.%, 475 °C, and 10 min, respectively. Results show that, under the same deposition conditions, electrical resistivities of ZnO:Al thin films deposited from milled precursors are lower than those obtained for films deposited from unmilled precursors. X-ray diffraction analysis revealed that all films display a polycrystalline structure, fitting well with the hexagonal wurtzite structure. Changes in surface morphology were observed by scanning electron microscopy (SEM as well, since films deposited from unmilled precursors show triangular shaped grains, in contrast to films deposited from 15 and 35 min milled precursors that display thin slices with hexagonal shapes. The use of milled precursors to prepare starting solutions for depositing ZnO:Al thin films by ultrasonic pyrolysis influences their physical properties.

  5. Low-temperature processed ZnO and CdS photodetectors deposited by pulsed laser deposition

    International Nuclear Information System (INIS)

    Hernandez-Como, N; Moreno, S; Mejia, I; Quevedo-Lopez, M A

    2014-01-01

    UV-VIS photodetectors using an interdigital configuration, with zinc oxide (ZnO) and cadmium sulfide (CdS) semiconductors deposited by pulsed laser deposition, were fabricated with a maximum processing temperature of 100 °C. Without any further post-growth annealing, the photodetectors are compatible with flexible and transparent substrates. Aluminum (Al) and indium tin oxide (ITO) were investigated as contacts. Focusing on underwater communications, the impact of metal contact (ITO versus Al) was investigated to determine the maximum responsivity using a laser with a 405 nm wavelength. As expected, the responsivity increases for reduced metal finger separation. This is a consequence of reduced carrier transit time for shorter finger separation. For ITO, the highest responsivities for both films (ZnO and CdS) were ∼3 A W −1 at 5 V. On the other hand, for Al contacts, the maximum responsivities at 5 V were ∼0.1 A W −1 and 0.7 A W −1 for CdS and ZnO, respectively. (paper)

  6. Structural and Optical Studies of Magnesium Doped Zinc Oxide Thin Films

    OpenAIRE

    Arpana Agrawal; Tanveer Ahmad Dar; Pratima Sen

    2013-01-01

    The paper describes the structural and optical properties of Magnesium doped Zinc Oxide (Mg  3.5 %, 6 %, 9 %, 12 % by weight) thin films prepared by pulsed laser deposition technique. The samples are characterized by X-ray diffraction technique, Ultra-violet visible absorption spectroscopy, X-ray photoelectron spectroscopy. X-ray diffraction results reveal the polycrystalline nature of samples with no impurity or secondary phase formation. Ultra-violet visible absorption spectroscopy studies...

  7. Highly sensitive uric acid biosensor based on individual zinc oxide micro/nanowires

    International Nuclear Information System (INIS)

    Zhao, Yanguang; Yan, Xiaoqin; Kang, Zhuo; Lin, Pei; Fang, Xiaofei; Lei, Yang; Ma, Siwei; Zhang, Yue

    2013-01-01

    We describe the use of individual zinc oxide (ZnO) micro/nanowires in an electrochemical biosensor for uric acid. The wires were synthesized by chemical vapor deposition and possess uniform morphology and high crystallinity as revealed by scanning electron microscopy, X-ray diffraction, and photoluminescence studies. The enzyme uricase was then immobilized on the surface of the ZnO micro/nanowires by physical adsorption, and this was proven by Raman spectroscopy and fluorescence microscopy. The resulting uric acid biosensor undergoes fast electron transfer between the active site of the enzyme and the surface of the electrode. It displays high sensitivity (89.74 μA cm −2 mM −1 ) and a wide linear analytical range (between 0.1 mM and 0.59 mM concentrations of uric acid). This study also demonstrates the potential of the use of individual ZnO micro/nanowires for the construction of highly sensitive nano-sized biosensors. (author)

  8. A review of zinc oxide mineral beneficiation using flotation method.

    Science.gov (United States)

    Ejtemaei, Majid; Gharabaghi, Mahdi; Irannajad, Mehdi

    2014-04-01

    In recent years, extraction of zinc from low-grade mining tailings of oxidized zinc has been a matter of discussion. This is a material which can be processed by flotation and acid-leaching methods. Owing to the similarities in the physicochemical and surface chemistry of the constituent minerals, separation of zinc oxide minerals from their gangues by flotation is an extremely complex process. It appears that selective leaching is a promising method for the beneficiation of this type of ore. However, with the high consumption of leaching acid, the treatment of low-grade oxidized zinc ores by hydrometallurgical methods is expensive and complex. Hence, it is best to pre-concentrate low-grade oxidized zinc by flotation and then to employ hydrometallurgical methods. This paper presents a critical review on the zinc oxide mineral flotation technique. In this paper, the various flotation methods of zinc oxide minerals which have been proposed in the literature have been detailed with the aim of identifying the important factors involved in the flotation process. The various aspects of recovery of zinc from these minerals are also dealt with here. The literature indicates that the collector type, sulfidizing agent, pH regulator, depressants and dispersants types, temperature, solid pulp concentration, and desliming are important parameters in the process. The range and optimum values of these parameters, as also the adsorption mechanism, together with the resultant flotation of the zinc oxide minerals reported in the literature are summarized and highlighted in the paper. This review presents a comprehensive scientific guide to the effectiveness of flotation strategy. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Light-induced hysteresis and recovery behaviors in photochemically activated solution-processed metal-oxide thin-film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Jeong-Wan; Park, Sung Kyu, E-mail: yhkim76@skku.edu, E-mail: skpark@cau.ac.kr [School of Electrical and Electronics Engineering, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Kim, Yong-Hoon, E-mail: yhkim76@skku.edu, E-mail: skpark@cau.ac.kr [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-07-28

    In this report, photo-induced hysteresis, threshold voltage (V{sub T}) shift, and recovery behaviors in photochemically activated solution-processed indium-gallium-zinc oxide (IGZO) thin-film transistors (TFTs) are investigated. It was observed that a white light illumination caused negative V{sub T} shift along with creation of clockwise hysteresis in electrical characteristics which can be attributed to photo-generated doubly ionized oxygen vacancies at the semiconductor/gate dielectric interface. More importantly, the photochemically activated IGZO TFTs showed much reduced overall V{sub T} shift compared to thermally annealed TFTs. Reduced number of donor-like interface states creation under light illumination and more facile neutralization of ionized oxygen vacancies by electron capture under positive gate potential are claimed to be the origin of the less V{sub T} shift in photochemically activated TFTs.

  10. Photocatalytic self-cleaning properties of cellulosic fibers modified by nano-sized zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Moafi, Hadi Fallah; Shojaie, Abdollah Fallah, E-mail: a.f.shojaie@guilan.ac.ir; Zanjanchi, Mohammad Ali

    2011-03-31

    Nano-sized zinc oxide was synthesized and deposited onto cellulosic fibers using the sol-gel process at ambient temperature. The prepared materials were characterized using several techniques including scanning electron microscopy, transmission electron microscopy, diffuse reflectance spectroscopy, X-ray diffraction and thermogravimetric analysis. X-ray diffraction studies of the ZnO-coated fiber indicate formation of the hexagonal crystal phase which was satisfactory crystallized on the fiber surface. The electron micrographs show formation of zinc oxide nanoparticles within 10-15 nm in size which have been homogeneously dispersed on the fiber surface. The prepared materials show significant photocatalytic self-cleaning activity, which was monitored by diffuse reflectance spectroscopy. The photoactivity was studied upon measuring the photodegradation of methylene blue and eosin yellowish under UV-Vis irradiation. The photocatalytic activity of the treated fabrics was fully maintained performing several cycles of photodegradation.

  11. Photocatalytic self-cleaning properties of cellulosic fibers modified by nano-sized zinc oxide

    International Nuclear Information System (INIS)

    Moafi, Hadi Fallah; Shojaie, Abdollah Fallah; Zanjanchi, Mohammad Ali

    2011-01-01

    Nano-sized zinc oxide was synthesized and deposited onto cellulosic fibers using the sol-gel process at ambient temperature. The prepared materials were characterized using several techniques including scanning electron microscopy, transmission electron microscopy, diffuse reflectance spectroscopy, X-ray diffraction and thermogravimetric analysis. X-ray diffraction studies of the ZnO-coated fiber indicate formation of the hexagonal crystal phase which was satisfactory crystallized on the fiber surface. The electron micrographs show formation of zinc oxide nanoparticles within 10-15 nm in size which have been homogeneously dispersed on the fiber surface. The prepared materials show significant photocatalytic self-cleaning activity, which was monitored by diffuse reflectance spectroscopy. The photoactivity was studied upon measuring the photodegradation of methylene blue and eosin yellowish under UV-Vis irradiation. The photocatalytic activity of the treated fabrics was fully maintained performing several cycles of photodegradation.

  12. GaAs metal-oxide-semiconductor based non-volatile flash memory devices with InAs quantum dots as charge storage nodes

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Sk Masiul, E-mail: masiulelt@gmail.com; Chowdhury, Sisir; Sarkar, Krishnendu; Nagabhushan, B.; Banerji, P. [Materials Science Centre, Indian Institute of Technology, Kharagpur 721 302 (India); Chakraborty, S. [Applied Materials Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Sector-I, Kolkata 700 064 (India); Mukherjee, Rabibrata [Department of Chemical Engineering, Indian Institute of Technology, Kharagpur 721302 (India)

    2015-06-24

    Ultra-thin InP passivated GaAs metal-oxide-semiconductor based non-volatile flash memory devices were fabricated using InAs quantum dots (QDs) as charge storing elements by metal organic chemical vapor deposition technique to study the efficacy of the QDs as charge storage elements. The grown QDs were embedded between two high-k dielectric such as HfO{sub 2} and ZrO{sub 2}, which were used for tunneling and control oxide layers, respectively. The size and density of the QDs were found to be 5 nm and 1.8×10{sup 11} cm{sup −2}, respectively. The device with a structure Metal/ZrO{sub 2}/InAs QDs/HfO{sub 2}/GaAs/Metal shows maximum memory window equivalent to 6.87 V. The device also exhibits low leakage current density of the order of 10{sup −6} A/cm{sup 2} and reasonably good charge retention characteristics. The low value of leakage current in the fabricated memory device is attributed to the Coulomb blockade effect influenced by quantum confinement as well as reduction of interface trap states by ultra-thin InP passivation on GaAs prior to HfO{sub 2} deposition.

  13. An innovative zinc oxide-coated zeolite adsorbent for removal of humic acid

    Science.gov (United States)

    Zinc oxide (ZnO)-coated zeolite adsorbents were developed by both nitric acid modification and Zn(NO3)2•6H2O functionalization of zeolite. The developed adsorbents were used for the removal of humic acid (HA) from aqueous solutions. The adsorption capacity of the adsorbents at 21...

  14. Synthesis and characterization of (zinc-layered hydroxide-hippurate) nano hybrid by direct reaction of zinc oxide under aqueous environment

    International Nuclear Information System (INIS)

    Mohd Zobir Hussein; Samer Hasan Al Ali; Zulkarnain Zainal

    2011-01-01

    A new method for synthesis of hippurate nano hybrid has been developed. In this method, zinc oxide was added directly into aqueous solution of hippurate anions (A - ). The resulting hippurate nano hybrid (HAN) is composed of the organic moieties sandwiched between zinc layered hydroxide (ZLH) inorganic interlayers. HAN synthesized using 0.2 M hippuric acid showed the best crystallinity compared to other samples synthesized in this work. X-ray powder diffraction shows the basal spacing of the HAN was 21.3 Angstrom indicating that the monolayer of A - was arranged vertically to the ZLH interlayers. (author)

  15. Deep subgap feature in amorphous indium gallium zinc oxide: Evidence against reduced indium

    Energy Technology Data Exchange (ETDEWEB)

    Sallis, Shawn; Williams, Deborah S. [Materials Science and Engineering, Binghamton University, Binghamton, New York, 13902 (United States); Quackenbush, Nicholas F.; Senger, Mikell [Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, New York, 13902 (United States); Woicik, Joseph C. [Materials Science and Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland, 20899 (United States); White, Bruce E.; Piper, Louis F.J. [Materials Science and Engineering, Binghamton University, Binghamton, New York, 13902 (United States); Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, New York, 13902 (United States)

    2015-07-15

    Amorphous indium gallium zinc oxide (a-IGZO) is the archetypal transparent amorphous oxide semiconductor. Despite the gains made with a-IGZO over amorphous silicon in the last decade, the presence of deep subgap states in a-IGZO active layers facilitate instabilities in thin film transistor properties under negative bias illumination stress. Several candidates could contribute to the formation of states within the band gap. Here, we present evidence against In{sup +} lone pair active electrons as the origin of the deep subgap features. No In{sup +} species are observed, only In{sup 0} nano-crystallites under certain oxygen deficient growth conditions. Our results further support under coordinated oxygen as the source of the deep subgap states. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Urea impedimetric biosensing using electrospun nanofibers modified with zinc oxide nanoparticles

    Science.gov (United States)

    Migliorini, Fernanda L.; Sanfelice, Rafaela C.; Mercante, Luiza A.; Andre, Rafaela S.; Mattoso, Luiz H. C.; Correa, Daniel. S.

    2018-06-01

    Reliable analytical techniques to evaluate dairy products, including milk, are of outmost importance to ensure food safety against contaminants. Among possible substances employed as adulterants in milk, urea raises deep concern due to its harmful effects to consumer's health. In the present study, a biosensing platform was developed to be applied in the electrochemical detection of urea. The sensing platform was fabricated using polymeric electrospun nanofibers of polyamide 6 (PA6) and polypyrrole (PPy) deposited onto fluorine doped tin oxide (FTO) electrodes, which were then modified with zinc oxide nanoparticles (ZnO). This material showed excellent properties for the immobilization of urease enzyme, conferring the FTO/PA6/PPy/ZnO/urease electrode high sensitivity for urea detection within the concentration range between 0.1 and 250 mg dL-1 with a limit of detection of 0.011 mg dL-1. The results achieved evidence the potential of electrospun nanofibers-based electrodes for applications in biosensors aiming at dairy products analysis.

  17. Optimization of aluminum-doped zinc oxide films deposited at low temperature by radio-frequency sputtering on flexible substrates for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, S. [Departamento de Energias Renovables, Energia Solar Fotovoltaica, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Avda. Complutense 22, 28040 Madrid (Spain); Naranjo, F.B. [Grupo de Ingenieria Fotonica (GRIFO), Departamento de Electronica, Escuela Politecnica Superior, Universidad de Alcala, Campus Universitario, 28871 Alcala de Henares, Madrid (Spain)

    2010-02-15

    Aluminum-doped zinc oxide films were deposited at 100 C on polyethylene terephthalate by radio-frequency magnetron sputtering. The sputtering parameters such as RF power and Argon working pressure were varied from 25 to 125 W and from 1.1 to 0.2 Pa, respectively. The structural properties of as-deposited films were analysed by X-ray diffraction, showing that all the deposited films were polycrystalline, with hexagonal structure and a strong preferred c-axis orientation (0 0 2). Full width at half maximum and grain sizes were around 0.27 and ranged from 24 to 32 nm, respectively. The strain state of the samples was also estimated from X-ray diffraction measurements, obtaining compressive stresses from 0.29 to 0.05 GPa. Resistivity as low as 1.1 x 10{sup -3} {omega} cm was achieved for the film deposited at 75 W and 0.2 Pa, sample that showed a low strain state of -0.06 GPa. High optical transmittance ({proportional_to}80%) was exhibited when films were deposited at RF powers below 100 W. Band gap energies ranged from 3.36 to 3.39 eV and a refractive index of 1.80{+-}0.05, constant in the visible region, was also obtained. (author)

  18. Synthesis and application of multiple rods gold-zinc oxide nano structures in the photo catalytic degradation of methyl orange

    International Nuclear Information System (INIS)

    Arab Chamjangali, M.; Bagherian, G.; Bahramian, B.; Fahimi Rad, B.

    2015-01-01

    Zinc oxide and gold-zinc oxide (Au-Zn O) nano structures with multiple rods (multi pods) morphology were successfully prepared. Au-Zn O nano structures were synthesized via a simple precipitation route method in the presence of oligo aniline-coated gold nanoparticles. The Au-Zn O catalyst obtained was applied for the degradation of methyl orange in an aqueous solution under UV irradiation Effects of the operational parameters such as the solution p H, amount of photocatalyst, and dye concentration on the photo catalytic degradation and decolorisation of methyl orange were studied. Detailed studies including kinetic study and regeneration of catalyst were carried out on the optimal conditions for the photodegradation of methyl orange by Au-Zn O multi pods in aqueous solution. Effect of foreign species on the photodegradation of methyl orange was also studied. An enhancement of the photo catalytic activities for photodegradation of methyl orange was observed when the gold nanoparticles were loaded on the zinc oxide multi pods. The proposed catalyst was applied for the degradation of methyl orange in synthetic wastewater samples with satisfactory results.

  19. Zinc and cadmium mobility in a 5-year-old dredged sediment deposit: experiments and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Lions, J. [BRGM, Orleans (France). Water Div.; Centre National de Recherche sur les Sites et Sols Pollues, Douai (France); Lee, J. van der [Ecole des Mines de Paris, Fontainebleau (France). Geosciences - Reactive Hydrodynamics Group; Guerin, V.; Bataillard, P. [BRGM, Orleans (France). Environment and Process Div.; Centre National de Recherche sur les Sites et Sols Pollues, Douai (France); Laboudigue, A. [Ecole des Mines de Douai (France). Environmental and Civil Engineering; Centre National de Recherche sur les Sites et Sols Pollues, Douai (France)

    2007-08-15

    Background. Landfill deposits of contaminated, dredged sediments are subject to chemical alteration and especially to oxidation processes. Accordingly, sulphides are gradually oxidized leading to the formation of secondary phases and associated metals could become mobile and redistributed among the sediment components, such as carbonates, clay and freshly precipitated (hydr)oxides. Once mobilised, metals could represent a hazard for the environment and especially for drinking water supply facilities. Methods. In the present study, leaching experiments have been carried out on a dredged sediment to study metal mobilisation after 5 years of field aging. First, kinetic batch tests allowed one to evaluate the impact of solid-liquid contact time and to determine the kinetic parameters. Secondly, two types of dynamic experiments have been conducted: dynamic flush reactor and column leach test to evaluate the impact of solution renewing by excluding or not excluding the transport processes, respectively. In order to evaluate the impact of calcium on the metal mobilisation, the column leaching test is conducted with pure water and Ca(NO{sub 3}){sub 2} solution, at the beginning and at the end of the injection, respectively. Geochemical and reactive transport modelling of the experiments was performed using the geochemical code CHESS and the reactive transport model HYTEC. Results and Discussion. The studied sediment is complex with numerous reactive phases such as sulphides, (hydr)oxides, organic matter, phyllosilicates. All leaching tests highlight that zinc and cadmium are mobilised in significant concentrations and lead remains insoluble. A conceptual geochemical model of the sediment has been built to allow simulations of the whole experiments, based on a single, coherent phase description and parameter set. Simulations of the batch, flush and column experiments were performed taking into account the major reaction-controlling mechanisms including, among others, p

  20. Influence of pH-control in phosphoric acid treatment of zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Onoda, H., E-mail: onoda@kpu.ac.jp [Department of Informatics and Environmental Sciences, Kyoto Prefectural University (Japan); Chemel, M. [Ecole de Biologie Industrielle, CERGY Cedex (France)

    2017-04-15

    Zinc oxide is often used as a white pigment for cosmetics; however, it shows photocatalytic activity that causes decomposition of sebum on the skin when exposed to the ultraviolet radiation in sunlight. In this work, zinc oxide was reacted with phosphoric acid at various pH values to synthesize a novel white pigment for cosmetics. The chemical composition, powder properties, photocatalytic activities, colors, and smoothness of these pigments were studied. The obtained materials exhibited X-ray diffraction peaks relating to zinc oxide and phosphate after phosphoric acid treatment. The ratio of zinc phosphate to zinc oxide was estimated from inductively coupled plasma - atomic emission spectroscopy results. Samples treated at pH 4-7 yielded small particles with sub-micrometer sizes. The photocatalytic activity of zinc oxide became lower after phosphoric acid treatment. Samples treated at pH 4-7 showed the same reflectance as zinc oxide in both the ultraviolet and visible ranges. Adjustment of the pH was found to be important in the phosphoric acid treatment of zinc oxide. (author)

  1. A 94GHz Temperature Compensated Low Noise Amplifier in 45nm Silicon-on-Insulator Complementary Metal-Oxide Semiconductor (SOI CMOS)

    Science.gov (United States)

    2014-01-01

    ring oscillator based temperature sensor will be designed to compensate for gain variations over temperature. For comparison to a competing solution...Simulated (Green) Capacitance of the GSG Pads ........................ 9 Figure 6: Die Picture and Schematic of the L-2L Coplanar Waveguides...complementary metal-oxide-semiconductor (CMOS) technology. A ring oscillator based temperature sensor was designed to compensate for gain variations

  2. Zinc oxide crystal whiskers as a novel sorbent for solid-phase extraction of flavonoids.

    Science.gov (United States)

    Wang, Licheng; Shangguan, Yangnan; Hou, Xiudan; Jia, Yong; Liu, Shujuan; Sun, Yingxin; Guo, Yong

    2017-08-15

    As a novel solid-phase extraction material, zinc oxide crystal whiskers were used to extract flavonoid compounds and showed good extraction abilities. X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy and surface area/pore volume characterized the sorbent. The zinc oxide was packed into a solid-phase extraction micro-column and its extraction ability was evaluated by four model flavonoid compounds. The sample loading and elution parameters were optimized and the zinc oxide based analytical method for flavonoids was established. It showed that the method has wide linearities from 1 to 150μg/L and low limits of detection at 0.25μg/L. The relative standard deviations of a single column repeatability and column to column reproducibility were less than 6.8% and 10.6%. Several real samples were analyzed by the established method and satisfactory results were obtained. The interactions between flavonoids and zinc oxide were calculated and proved to be from the Van der Waals' forces between the 4p and 5d orbitals from zinc atom and the neighboring π orbitals from flavonoid phenyl groups. Moreover, the zinc oxide crystal whiskers showed good stability and could be reused more than 50 times under the operation conditions. This work proves that the zinc oxide crystal whiskers are a good candidate for flavonoids enrichment. Copyright © 2017. Published by Elsevier B.V.

  3. Hydrazine-Free Solution-Deposited CuIn(S,Se)2 Solar Cells by Spray Deposition of Metal Chalcogenides.

    Science.gov (United States)

    Arnou, Panagiota; van Hest, Maikel F A M; Cooper, Carl S; Malkov, Andrei V; Walls, John M; Bowers, Jake W

    2016-05-18

    Solution processing of semiconductors, such as CuInSe2 and its alloys (CIGS), can significantly reduce the manufacturing costs of thin film solar cells. Despite the recent success of solution deposition approaches for CIGS, toxic reagents such as hydrazine are usually involved, which introduce health and safety concerns. Here, we present a simple and safer methodology for the preparation of high-quality CuIn(S, Se)2 absorbers from metal sulfide solutions in a diamine/dithiol mixture. The solutions are sprayed in air, using a chromatography atomizer, followed by a postdeposition selenization step. Two different selenization methods are explored resulting in power conversion efficiencies of up to 8%.

  4. Synthesis of vertically aligned metal oxide nanostructures

    KAUST Repository

    Roqan, Iman S.

    2016-03-03

    Metal oxide nanostructure and methods of making metal oxide nanostructures are provided. The metal oxide nanostructures can be 1 -dimensional nanostructures such as nanowires, nanofibers, or nanotubes. The metal oxide nanostructures can be doped or undoped metal oxides. The metal oxide nanostructures can be deposited onto a variety of substrates. The deposition can be performed without high pressures and without the need for seed catalysts on the substrate. The deposition can be performed by laser ablation of a target including a metal oxide and, optionally, a dopant. In some embodiments zinc oxide nanostructures are deposited onto a substrate by pulsed laser deposition of a zinc oxide target using an excimer laser emitting UV radiation. The zinc oxide nanostructure can be doped with a rare earth metal such as gadolinium. The metal oxide nanostructures can be used in many devices including light-emitting diodes and solar cells.

  5. Zinc oxide nanostructured layers for gas sensing applications

    Science.gov (United States)

    Caricato, A. P.; Cretí, A.; Luches, A.; Lomascolo, M.; Martino, M.; Rella, R.; Valerini, D.

    2011-03-01

    Various kinds of zinc oxide (ZnO) nanostructures, such as columns, pencils, hexagonal pyramids, hexagonal hierarchical structures, as well as smooth and rough films, were grown by pulsed laser deposition using KrF and ArF excimer lasers, without use of any catalyst. ZnO films were deposited at substrate temperatures from 500 to 700°C and oxygen background pressures of 1, 5, 50, and 100 Pa. Quite different morphologies of the deposited films were observed using scanning electron microscopy when different laser wavelengths (248 or 193 nm) were used to ablate the bulk ZnO target. Photoluminescence studies were performed at different temperatures (down to 7 K). The gas sensing properties of the different nanostructures were tested against low concentrations of NO2. The variation in the photoluminescence emission of the films when exposed to NO2 was used as transduction mechanism to reveal the presence of the gas. The nanostructured films with higher surface-to-volume ratio and higher total surface available for gas adsorption presented higher responses, detecting NO2 concentrations down to 3 ppm at room temperature.

  6. Zinc in the prevention of Fe2initiated lipid and protein oxidation

    Directory of Open Access Journals (Sweden)

    M. PAOLA ZAGO

    2000-01-01

    Full Text Available In the present study we characterized the capacity of zinc to protect lipids and proteins from Fe2+-initiated oxidative damage. The effects of zinc on lipid oxidation were investigated in liposomes composed of brain phosphatidylcholine (PC and phosphatidylserine (PS at a molar relationship of 60:40 (PC:PS, 60:40. Lipid oxidation was evaluated as the oxidation of cis-parinaric acid or as the formation of 2-thiobarbituric acid-reactive substances (TBARS. Zinc protected liposomes from Fe2+ (2.5-50 muM-supported lipid oxidation. However, zinc (50 muM did not prevent the oxidative inactivation of glutamine synthelase and glucose 6-phosphate dehydrogenase when rat brain superntants were oxidized in the presence of 5 muM Fe2+ and 0.5 mM H2O2 .We also studied the interactions of zinc with epicatechin in the prevention of liid oxidation in liposomes. The simulaneous addition of 0.5 muM epicatechin (EC and 50 muM zinc or EC separately. Zinc (50 muM also protecte liposomes from the stimulatory effect of aluminum on Fe2+-initiated lipid oxidation. Zinc could play an important role as an antioxidant in biological systems, replacing iron and other metals with pro-oxidant activity from binding sites and interacting with other components of the oxidant defense system.

  7. Influence of Camellia sinensis extract on Zinc Oxide nanoparticle green synthesis

    Science.gov (United States)

    Nava, O. J.; Luque, P. A.; Gómez-Gutiérrez, C. M.; Vilchis-Nestor, A. R.; Castro-Beltrán, A.; Mota-González, M. L.; Olivas, A.

    2017-04-01

    This work addresses low cost, non-toxic green synthesis of Zinc Oxide nanoparticles prepared using different amounts of Camellia sinensis extract. The Synthesized material was studied and characterized through Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), transmission electron microscopy (TEM). The Zinc Oxide nanoparticles presented the desired Znsbnd O bond at 618 cm-1, demonstrated growth in a purely hexagonal Wurtzite crystal structure, and, depending on the amount of extract used, they presented different size and shape homogeneity. The photocatalytic activity of the obtained Zinc Oxide nanoparticles was studied. The photocatalytic degradation studies were done at a 1:1 M ratio of methylene blue to Zinc Oxide nanoparticles under UV light. The obtained results presented a better degradation rate than commercially available Zinc Oxide nanoparticles.

  8. Transformation of zinc hydroxide chloride monohydrate to crystalline zinc oxide.

    Science.gov (United States)

    Moezzi, Amir; Cortie, Michael; McDonagh, Andrew

    2016-04-25

    Thermal decomposition of layered zinc hydroxide double salts provides an interesting alternative synthesis for particles of zinc oxide. Here, we examine the sequence of changes occurring as zinc hydroxide chloride monohydrate (Zn5(OH)8Cl2·H2O) is converted to crystalline ZnO by thermal decomposition. The specific surface area of the resultant ZnO measured by BET was 1.3 m(2) g(-1). A complicating and important factor in this process is that the thermal decomposition of zinc hydroxide chloride is also accompanied by the formation of volatile zinc-containing species under certain conditions. We show that this volatile compound is anhydrous ZnCl2 and its formation is moisture dependent. Therefore, control of atmospheric moisture is an important consideration that affects the overall efficiency of ZnO production by this process.

  9. Structural properties of III-V zinc-blende semiconductors under pressure

    International Nuclear Information System (INIS)

    Froyen, S.; Cohen, M.L.

    1983-01-01

    The pseudopotential method within the local-density approximation is used to investigate the static and structural properties of some III-V compound semiconductors. Comparisons of calculated total energies as a function of volume and structure yield information about solid-solid phase transformations. At high pressures the results indicate that several metallic structures are lower in energy than the zinc-blende structure. From our results the compounds (AlP, AlAs, GaP, and GaAs) can be divided into two classes. In the Ga compounds, we find a pressure-induced phase transformation to either rocksalt, β-Sn, or NiAs, whereas in the Al compounds rocksalt and NiAs are stabilized with respect to β-Sn. All structures except zinc blende are metallic. We discuss the electronic structure of each phase and show how it relates to structural stability

  10. Amorphous Zinc Oxide Integrated Wavy Channel Thin Film Transistor Based High Performance Digital Circuits

    KAUST Repository

    Hanna, Amir; Hussain, Aftab M.; Omran, Hesham; Alshareef, Sarah; Salama, Khaled N.; Hussain, Muhammad Mustafa

    2015-01-01

    High performance thin film transistor (TFT) can be a great driving force for display, sensor/actuator, integrated electronics, and distributed computation for Internet of Everything applications. While semiconducting oxides like zinc oxide (Zn

  11. Photodiodes based on fullerene semiconductor

    International Nuclear Information System (INIS)

    Voz, C.; Puigdollers, J.; Cheylan, S.; Fonrodona, M.; Stella, M.; Andreu, J.; Alcubilla, R.

    2007-01-01

    Fullerene thin films have been deposited by thermal evaporation on glass substrates at room temperature. A comprehensive optical characterization was performed, including low-level optical absorption measured by photothermal deflection spectroscopy. The optical absorption spectrum reveals a direct bandgap of 2.3 eV and absorption bands at 2.8 and 3.6 eV, which are related to the creation of charge-transfer excitons. Various photodiodes on indium-tin-oxide coated glass substrates were also fabricated, using different metallic contacts in order to compare their respective electrical characteristics. The influence of a poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) buffer layer between the indium-tin-oxide electrode and the fullerene semiconductor is also demonstrated. These results are discussed in terms of the workfunction for each electrode. Finally, the behaviour of the external quantum efficiency is analyzed for the whole wavelength spectrum

  12. Influence of indium concentration and substrate temperature on the physical characteristics of chemically sprayed ZnO:In thin films deposited from zinc pentanedionate and indium sulfate

    International Nuclear Information System (INIS)

    Castaneda, L; Morales-Saavedra, O G; Cheang-Wong, J C; Acosta, D R; Banuelos, J G; Maldonado, A; Olvera, M de la L

    2006-01-01

    Chemically sprayed indium-doped zinc oxide thin films (ZnO:In) were deposited on glass substrates starting from zinc pentanedionate and indium sulfate. The influence of both the dopant concentration in the starting solution and the substrate temperature on the transport, morphology, composition, linear and nonlinear optical (NLO) properties of the ZnO:In thin films were studied. The structure of all the ZnO:In thin films was polycrystalline, and variation in the preferential growth with the indium content in the solution was observed: from an initial (002) growth in films with low In content, switching to a predominance of (101) planes for intermediate dopant regime, and finally turning to a (100) growth for heavily doped films. The crystallite size was found to decrease with doping concentration and range from 36 to 23 nm. The film composition and the dopant concentration were determined by Rutherford backscattering spectrometry; these results showed that the films are almost stoichiometric ZnO. The optimum deposition conditions leading to conductive and transparent ZnO:In thin films were also found. In this way a resistivity of 4 x 10 -3 Ω cm and an average transmittance in the visible spectra of 85%, with a (101) preferential growth, were obtained in optimized ZnO:In thin films

  13. Epitaxial crystal growth by sputter deposition: Applications to semiconductors. Part 2

    International Nuclear Information System (INIS)

    Greene, J.E.

    1984-01-01

    The understanding of the physics of ion-surface interactions has progressed sufficiently to allow sputter depositinn to be used as a crystal growth technique for depositing a wide variety of single crystal elemental, compound, alloy, and superlattice semiconductors. In many cases, films with essentially bulk values of carrier concentrations and mobilities have been obtained. The controlled use of low energy particle bombardment of the growing film during sputter deposition has been shown to affect all stages of crystal growth ranging from adatom mobilities and nucleation kinetics to elemental incorporation probabilities. Such effects provide inherent advantages for sputter deposition over other vapor phase techniques for the low temperature growth of compound and alloy semiconductors and are essential in allowing the growth of new and unique single crystal metastable semiconductors. Part 1 of this review includes sections on experimental techniques, the physics of ion-surface interactions, and ion bombardment effects on film nucleation and growth, while Part 2 presents a discussion of recent results in the growth of elemental, III-V, II-VI, IV-VI, metastable, and other compound semiconductors

  14. New insight into the mechanism of cathodic electrodeposition of zinc oxide thin films onto vitreous carbon

    OpenAIRE

    Ait Ahmed , N.; Eyraud , M.; Hammache , H.; Vacandio , F.; Sam , S.; Gabouze , N.; Knauth , P.; Pelzer , K.; Djenizian , T.

    2014-01-01

    International audience; In this study, the mechanism of zinc oxide (ZnO) electrodeposition from aqueous zinc nitrate solution at 70°C was investigated on vitreous carbon and bulk zinc electrodes using cyclic voltammetry experiments. Mechanisms are presented for the ZnO formation: the first widely accepted route corresponds to ZnO precipitation from Zn 2+ and OH-produced by NO3-reduction; the second route, which is discussed in this article, is due to Zn 2+ reduction into metallic Zn followed ...

  15. Post-growth annealing of zinc oxide thin films pulsed laser deposited under enhanced oxygen pressure on quartz and silicon substrates

    International Nuclear Information System (INIS)

    Rusop, M.; Uma, K.; Soga, T.; Jimbo, T.

    2006-01-01

    Zinc oxide (ZnO) thin films have been prepared by pulsed laser deposition (PLD) technique at room temperature on quartz and single crystal silicon (1 0 0) substrates. The oxygen ambient gas pressure was attained at 6 Torr during the deposition. The deposited films were post-growth annealed in air at various annealing temperatures for 30 min. The X-ray diffraction (XRD), optical and electrical properties have been measured to study the properties of the films as a function of annealing temperatures. XRD has shown the strength of (0 0 2) peak increases and FWHM value decreases as the annealing temperatures increases from 200 to 600 deg. C. The post-growth annealed at 600 deg. C show dominant c-axis oriented hexagonal wurtize crystal structure and exhibit high average transmittance about 85% in the visible region and very sharp absorption edge at 376 nm with energy band gap of approximately 3.46 eV. Electrical measurement indicates the resistivity decreases with the annealing temperatures up to 600 deg. C, after which it increases with higher annealing temperatures at 800 deg. C. The complex of oxygen vacancy in the ZnO films may be the source of low conductivity in undoped ZnO films

  16. High stability mechanisms of quinary indium gallium zinc aluminum oxide multicomponent oxide films and thin film transistors

    International Nuclear Information System (INIS)

    Lee, Ching-Ting; Lin, Yung-Hao; Lin, Jhong-Ham

    2015-01-01

    Quinary indium gallium zinc aluminum oxide (IGZAO) multicomponent oxide films were deposited using indium gallium zinc oxide (IGZO) target and Al target by radio frequency magnetron cosputtering system. An extra carrier transport pathway could be provided by the 3 s orbitals of Al cations to improve the electrical properties of the IGZO films, and the oxygen instability could be stabilized by the strong Al-O bonds in the IGZAO films. The electron concentration change and the electron mobility change of the IGZAO films for aging time of 10 days under an air environment at 40 °C and 75% humidity were 20.1% and 2.4%, respectively. The experimental results verified the performance stability of the IGZAO films. Compared with the thin film transistors (TFTs) using conventional IGZO channel layer, in conducting the stability of TFTs with IGZAO channel layer, the transconductance g m change, threshold voltage V T change, and the subthreshold swing S value change under the same aging condition were improved to 7.9%, 10.5%, and 14.8%, respectively. Furthermore, the stable performances of the IGZAO TFTs were also verified by the positive gate bias stress. In this research, the quinary IGZAO multicomponent oxide films and that applied in TFTs were the first studied in the literature

  17. High stability mechanisms of quinary indium gallium zinc aluminum oxide multicomponent oxide films and thin film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ching-Ting, E-mail: ctlee@ee.ncku.edu.tw; Lin, Yung-Hao; Lin, Jhong-Ham [Institute of Microelectronics, Department of Electrical Engineering, Research Center for Energy Technology and Strategy (RCETS), National Cheng Kung University, Tainan, Taiwan (China)

    2015-01-28

    Quinary indium gallium zinc aluminum oxide (IGZAO) multicomponent oxide films were deposited using indium gallium zinc oxide (IGZO) target and Al target by radio frequency magnetron cosputtering system. An extra carrier transport pathway could be provided by the 3 s orbitals of Al cations to improve the electrical properties of the IGZO films, and the oxygen instability could be stabilized by the strong Al-O bonds in the IGZAO films. The electron concentration change and the electron mobility change of the IGZAO films for aging time of 10 days under an air environment at 40 °C and 75% humidity were 20.1% and 2.4%, respectively. The experimental results verified the performance stability of the IGZAO films. Compared with the thin film transistors (TFTs) using conventional IGZO channel layer, in conducting the stability of TFTs with IGZAO channel layer, the transconductance g{sub m} change, threshold voltage V{sub T} change, and the subthreshold swing S value change under the same aging condition were improved to 7.9%, 10.5%, and 14.8%, respectively. Furthermore, the stable performances of the IGZAO TFTs were also verified by the positive gate bias stress. In this research, the quinary IGZAO multicomponent oxide films and that applied in TFTs were the first studied in the literature.

  18. Attachment of Quantum Dots on Zinc Oxide Nanorods

    Science.gov (United States)

    Seay, Jared; Liang, Huan; Harikumar, Parameswar

    2011-03-01

    ZnO nanorods grown by hydrothermal technique are of great interest for potential applications in photovoltaic and optoelectronic devices. In this study we investigate the optimization of the optical absorption properties by a low temperature, chemical bath deposition technique. Our group fabricated nanorods on indium tin oxide (ITO) substrate with precursor solution of zinc nitrate hexahydrate and hexamethylenetramine (1:1 molar ratio) at 95C for 9 hours. In order to optimize the light absorption characteristics of ZnO nanorods, CdSe/ZnS core-shell quantum dots (QDs) of various diameters were attached to the surface of ZnO nanostructures grown on ITO and gold-coated silicon substrates. Density of quantum dots was varied by controlling the number drops on the surface of the ZnO nanorods. For a 0.1 M concentration of QDs of 10 nm diameter, the PL intensity at 385 nm increased as the density of the quantum dots on ZnO nanostructures was increased. For quantum dots at 1 M concentration, the PL intensity at 385 nm increased at the beginning and then decreased at higher density. We will discuss the observed changes in PL intensity with QD concentration with ZnO-QD band structure and recombination-diffusion processes taking place at the interface.

  19. Intrinsic defect oriented visible region absorption in zinc oxide films

    Science.gov (United States)

    Rakhesh, V.; Shankar, Balakrishnan

    2018-05-01

    Zinc Oxide films were deposited on the glass substrate using vacuum arc sputtering technology. Films were prepared in oxygen ambience for 10mA and 15 mA deposition current separately. The UV-Visible spectroscopy of the samples showed that both samples possess sharp absorption near 3.5eV which is the characteristic band gap absorption energy of ZnO films. The absorption coefficient were calculated for the samples and the (αℎϑ)2 vs energy plot is drawn. The plot suggested that in addition to the sharp band edge absorption, the sample prepared at 10mA deposition current showed sharp absorption edge near 1.51eV and that at 15 mA showed absorption edge near 1.47eV. This refers to the presence of an intrinsic defect level which is likely to be deep in the band gap.

  20. Alcohol vapor sensing by cadmium-doped zinc oxide thick films based chemical sensor

    Science.gov (United States)

    Zargar, R. A.; Arora, M.; Chackrabarti, S.; Ahmad, S.; Kumar, J.; Hafiz, A. K.

    2016-04-01

    Cadmium-doped zinc oxide nanoparticles were derived by simple chemical co-precipitation route using zinc acetate dihydrate and cadmium acetate dihydrate as precursor materials. The thick films were casted from chemical co-precipitation route prepared nanoparticles by economic facile screen printing method. The structural, morphological, optical and electrical properties of the film were characterized relevant to alcohol vapor sensing application by powder XRD, SEM, UV-VIS and DC conductivity techniques. The response and sensitivity of alcohol (ethanol) vapor sensor are obtained from the recovery curves at optimum working temperature range from 20∘C to 50∘C. The result shows that maximum sensitivity of the sensor is observed at 25∘C operating temperature. On varying alcohol vapor concentration, minor variation in resistance has been observed. The sensing mechanism of sensor has been described in terms of physical adsorption and chemical absorption of alcohol vapors on cadmium-doped zinc oxide film surface and inside film lattice network through weak hydrogen bonding, respectively.

  1. Zinc oxide films prepared by spray pyrolysis

    Directory of Open Access Journals (Sweden)

    Maciąg Andrzej

    2017-01-01

    Full Text Available In this work we developed and tested spray pyrolysis system for layers deposition. In the system we have used ultrasonic apparatus (nebulizator as a sprayer. A zinc nitrate aqueous solution has been used as a precursor solution. The idea of the method is the decomposition of nitrate on a hot substrate according to the reaction Zn(NO32 → ZnO +2 NO2 +1/2O2. The layers were grown on glass, (001Si and KCl substrates at the temperatures 300 – 500°C. The thickness of the obtained layers was in the range 50 – 500 nm, depending on the growth time and rate. The influence of substrate temperature on the morphology of the layers has been studied by SEM method. The energy gap of the layers was found to be the range of 3.26-3.3 eV from their absorption spectra.

  2. Electrical properties of tin-doped zinc oxide nanostructures doped at different dopant concentrations

    International Nuclear Information System (INIS)

    Nasir, M. F.; Zainol, M. N.; Hannas, M.; Mamat, M. H.; Rusop, Mohamad; Rahman, S. A.

    2016-01-01

    This project has been focused on the electrical and optical properties respectively on the effect of Tin doped zinc oxide (ZnO) thin films at different dopant concentrations. These thin films were doped with different Sn dopant concentrations at 1 at%, 2 at%, 3 at%, 4 at% and 5 at% was selected as the parameter to optimize the thin films quality while the annealing temperature is fixed 500 °C. Sn doped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thin films were characterized using Current Voltage (I-V) measurement and ultraviolet-visible-near-infrared (UV-vis-NIR) spectrophotometer (Perkin Elmer Lambda 750) for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 4 at% Sn doping concentration with the value 3.08 × 10"3 Ωcm"−"1. The absorption coefficient spectrum obtained shows all films exhibit very low absorption in the visible (400-800 nm) and near infrared (NIR) (>800 nm) range but exhibit high absorption in the UV range.

  3. Electrical properties of tin-doped zinc oxide nanostructures doped at different dopant concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Nasir, M. F., E-mail: babaibaik2002@yahoo.com; Zainol, M. N., E-mail: nizarzainol@yahoo.com; Hannas, M., E-mail: mhannas@gmail.com [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Mamat, M. H., E-mail: mhmamat@salam.uitm.edu.my; Rusop, Mohamad, E-mail: rusop@salam.uitm.edu.my [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); NANO-SciTech Centre (NST), Institute of Science (IOS), Universiti Teknologi MARA - UiTM, 40450 Shah Alam, Selangor (Malaysia); Rahman, S. A., E-mail: saadah@um.edu.my [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Low Dimensional Materials Research Centre, Physics Department, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2016-07-06

    This project has been focused on the electrical and optical properties respectively on the effect of Tin doped zinc oxide (ZnO) thin films at different dopant concentrations. These thin films were doped with different Sn dopant concentrations at 1 at%, 2 at%, 3 at%, 4 at% and 5 at% was selected as the parameter to optimize the thin films quality while the annealing temperature is fixed 500 °C. Sn doped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thin films were characterized using Current Voltage (I-V) measurement and ultraviolet-visible-near-infrared (UV-vis-NIR) spectrophotometer (Perkin Elmer Lambda 750) for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 4 at% Sn doping concentration with the value 3.08 × 10{sup 3} Ωcm{sup −1}. The absorption coefficient spectrum obtained shows all films exhibit very low absorption in the visible (400-800 nm) and near infrared (NIR) (>800 nm) range but exhibit high absorption in the UV range.

  4. Amphoteric oxide semiconductors for energy conversion devices: a tutorial review.

    Science.gov (United States)

    Singh, Kalpana; Nowotny, Janusz; Thangadurai, Venkataraman

    2013-03-07

    In this tutorial review, we discuss the defect chemistry of selected amphoteric oxide semiconductors in conjunction with their significant impact on the development of renewable and sustainable solid state energy conversion devices. The effect of electronic defect disorders in semiconductors appears to control the overall performance of several solid-state ionic devices that include oxide ion conducting solid oxide fuel cells (O-SOFCs), proton conducting solid oxide fuel cells (H-SOFCs), batteries, solar cells, and chemical (gas) sensors. Thus, the present study aims to assess the advances made in typical n- and p-type metal oxide semiconductors with respect to their use in ionic devices. The present paper briefly outlines the key challenges in the development of n- and p-type materials for various applications and also tries to present the state-of-the-art of defect disorders in technologically related semiconductors such as TiO(2), and perovskite-like and fluorite-type structure metal oxides.

  5. Ambipolar Small-Molecule:Polymer Blend Semiconductors for Solution-Processable Organic Field-Effect Transistors.

    Science.gov (United States)

    Kang, Minji; Hwang, Hansu; Park, Won-Tae; Khim, Dongyoon; Yeo, Jun-Seok; Kim, Yunseul; Kim, Yeon-Ju; Noh, Yong-Young; Kim, Dong-Yu

    2017-01-25

    We report on the fabrication of an organic thin-film semiconductor formed using a blend solution of soluble ambipolar small molecules and an insulating polymer binder that exhibits vertical phase separation and uniform film formation. The semiconductor thin films are produced in a single step from a mixture containing a small molecular semiconductor, namely, quinoidal biselenophene (QBS), and a binder polymer, namely, poly(2-vinylnaphthalene) (PVN). Organic field-effect transistors (OFETs) based on QBS/PVN blend semiconductor are then assembled using top-gate/bottom-contact device configuration, which achieve almost four times higher mobility than the neat QBS semiconductor. Depth profile via secondary ion mass spectrometry and atomic force microscopy images indicate that the QBS domains in the films made from the blend are evenly distributed with a smooth morphology at the bottom of the PVN layer. Bias stress test and variable-temperature measurements on QBS-based OFETs reveal that the QBS/PVN blend semiconductor remarkably reduces the number of trap sites at the gate dielectric/semiconductor interface and the activation energy in the transistor channel. This work provides a one-step solution processing technique, which makes use of soluble ambipolar small molecules to form a thin-film semiconductor for application in high-performance OFETs.

  6. Monolithic integration of a silicon nanowire field-effect transistors array on a complementary metal-oxide semiconductor chip for biochemical sensor applications.

    Science.gov (United States)

    Livi, Paolo; Kwiat, Moria; Shadmani, Amir; Pevzner, Alexander; Navarra, Giulio; Rothe, Jörg; Stettler, Alexander; Chen, Yihui; Patolsky, Fernando; Hierlemann, Andreas

    2015-10-06

    We present a monolithic complementary metal-oxide semiconductor (CMOS)-based sensor system comprising an array of silicon nanowire field-effect transistors (FETs) and the signal-conditioning circuitry on the same chip. The silicon nanowires were fabricated by chemical vapor deposition methods and then transferred to the CMOS chip, where Ti/Pd/Ti contacts had been patterned via e-beam lithography. The on-chip circuitry measures the current flowing through each nanowire FET upon applying a constant source-drain voltage. The analog signal is digitized on chip and then transmitted to a receiving unit. The system has been successfully fabricated and tested by acquiring I-V curves of the bare nanowire-based FETs. Furthermore, the sensing capabilities of the complete system have been demonstrated by recording current changes upon nanowire exposure to solutions of different pHs, as well as by detecting different concentrations of Troponin T biomarkers (cTnT) through antibody-functionalized nanowire FETs.

  7. Integration of functional complex oxide nanomaterials on silicon

    Directory of Open Access Journals (Sweden)

    Jose Manuel eVila-Fungueiriño

    2015-06-01

    Full Text Available The combination of standard wafer-scale semiconductor processing with the properties of functional oxides opens up to innovative and more efficient devices with high value applications that can be produced at large scale. This review uncovers the main strategies that are successfully used to monolithically integrate functional complex oxide thin films and nanostructures on silicon: the chemical solution deposition approach (CSD and the advanced physical vapor deposition techniques such as oxide molecular beam epitaxy (MBE. Special emphasis will be placed on complex oxide nanostructures epitaxially grown on silicon using the combination of CSD and MBE. Several examples will be exposed, with a particular stress on the control of interfaces and crystallization mechanisms on epitaxial perovskite oxide thin films, nanostructured quartz thin films, and octahedral molecular sieve nanowires. This review enlightens on the potential of complex oxide nanostructures and the combination of both chemical and physical elaboration techniques for novel oxide-based integrated devices.

  8. Improvement of bias-stability in amorphous-indium-gallium-zinc-oxide thin-film transistors by using solution-processed Y{sub 2}O{sub 3} passivation

    Energy Technology Data Exchange (ETDEWEB)

    An, Sungjin; Mativenga, Mallory; Kim, Youngoo; Jang, Jin, E-mail: jjang@khu.ac.kr [Advanced Display Research Center, Department of Information Display, Kyung Hee University, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of)

    2014-08-04

    We demonstrate back channel improvement of back-channel-etch amorphous-indium-gallium-zinc-oxide (a-IGZO) thin-film transistors by using solution-processed yttrium oxide (Y{sub 2}O{sub 3}) passivation. Two different solvents, which are acetonitrile (35%) + ethylene glycol (65%), solvent A and deionized water, solvent B are investigated for the spin-on process of the Y{sub 2}O{sub 3} passivation—performed after patterning source/drain (S/D) Mo electrodes by a conventional HNO{sub 3}-based wet-etch process. Both solvents yield devices with good performance but those passivated by using solvent B exhibit better light and bias stability. Presence of yttrium at the a-IGZO back interface, where it occupies metal vacancy sites, is confirmed by X-ray photoelectron spectroscopy. The passivation effect of yttrium is more significant when solvent A is used because of the existence of more metal vacancies, given that the alcohol (65% ethylene glycol) in solvent A may dissolve the metal oxide (a-IGZO) through the formation of alkoxides and water.

  9. Direct in situ measurement of dissolved zinc in the presence of zinc oxide nanoparticles using anodic stripping voltammetry.

    Science.gov (United States)

    Jiang, Chuanjia; Hsu-Kim, Heileen

    2014-11-01

    The wide use of metal-based nanomaterials such as zinc oxide (ZnO) nanoparticles (NPs) has generated concerns regarding their environmental and health risks. For ZnO NPs, their toxicity in aquatic systems often depends on the release of dissolved zinc species, and the rate of dissolution is influenced by water chemistry, including the presence of zinc-chelating ligands. A challenge, however, remains in quantifying the dissolution of ZnO NPs, particularly for time scales that are short enough to determine rates. This paper reports the application of anodic stripping voltammetry (ASV) with a hanging mercury drop electrode to directly measure the concentration of dissolved zinc in ZnO NP suspensions, without separation of the ZnO NPs from the aqueous phase. The effects of the deposition time and the electrochemical potential scan rate on the ASV measurement were consistent with expectations for dissolved phase measurements. The dissolved zinc concentration measured by ASV ([Zn]ASV) was compared with that measured by inductively coupled plasma mass spectrometry (ICP-MS) after ultracentrifugation ([Zn]ICP-MS), for four types of ZnO NPs with different coatings and primary particle diameters. For small ZnO NPs (4-5 nm), [Zn]ASV was 20% higher than [Zn]ICP-MS, suggesting that these small NPs contributed to the voltammetric measurement. For larger ZnO NPs (approximately 20 nm), [Zn]ASV was (79 ± 19)% of [Zn]ICP-MS, despite the high concentrations of ZnO NPs in suspension. Using ASV, the dissolution of ZnO NPs was studied, with or without Suwannee River Fulvic Acid (SRFA). Although SRFA diminished the ASV stripping current, dissolution of 20 nm ZnO NPs was significantly promoted at high fulvic acid to ZnO NP ratios. The ASV method described in this paper provides a useful tool for studying the dissolution kinetics of ZnO NPs in complex environmental matrices.

  10. Antimicrobial effects of zinc oxide nanoparticles modified with silver

    International Nuclear Information System (INIS)

    Lopes, Rayssa Souza; Arantes, Tatiane Moraes

    2016-01-01

    Full text: With the emergence of resistant microbial organisms to multiple antibiotics, different shapes of silver nanoparticles are among the most promising antimicrobial agents that have been developed from nanotechnology. Besides the silver nanoparticles oxide nanoparticles such as zinc oxide (ZnO) is gaining prominence due to its bactericidal properties. [1-3]. Thus, this study aims to develop biomaterials from zinc oxide nanoparticles modified with silver with antimicrobial properties. The ZnO nanoparticles were synthesized by hydrothermal processing by alkaline hydrolysis zinc acetate. Colloidal dispersions of silver nanoparticles were synthesized by the Turkevich method using sodium citrate to reduce silver nitrate at high pH and at 90 °C in the presence of zinc oxide nanoparticles. Both nanoparticles were characterized by X-ray diffraction (XRD), FTIR and Raman spectroscopy and scanning electron microscopy (SEM). The XRD and Raman spectra showed crystalline ZnO colloidal nanoparticles were obtained in the hexagonal phase. XRD measure showed cubic silver diffraction peaks cubic phase confirmed the presence of the silver nanoparticles decorated zinc oxide nanoparticles. SEM images showed ZnO nanoparticles presented a nanorod shapes with length around 80 nm decorated with spherical silver nanoparticles about 20 nm in diameter The results showed that crystalline zinc oxide colloidal nanoparticles with rod-like morphology and uniform decorated with silver spherical nanoparticles size were obtained by hydrothermal synthesis. Results of antibacterial tests indicate that the ZnO/Ag nanoparticles have antibacterial properties against both Staphylococcus aureus and Escherichia coli. The results demonstrated that the ZnO/Ag nanoparticles have potential use as biomaterials in medical/odontological applications. (author)

  11. Antimicrobial effects of zinc oxide nanoparticles modified with silver

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Rayssa Souza; Arantes, Tatiane Moraes, E-mail: rayssasouza.net@gmail.com [Universidade Federal de Goias (UFG), Goiania (Brazil)

    2016-07-01

    Full text: With the emergence of resistant microbial organisms to multiple antibiotics, different shapes of silver nanoparticles are among the most promising antimicrobial agents that have been developed from nanotechnology. Besides the silver nanoparticles oxide nanoparticles such as zinc oxide (ZnO) is gaining prominence due to its bactericidal properties. [1-3]. Thus, this study aims to develop biomaterials from zinc oxide nanoparticles modified with silver with antimicrobial properties. The ZnO nanoparticles were synthesized by hydrothermal processing by alkaline hydrolysis zinc acetate. Colloidal dispersions of silver nanoparticles were synthesized by the Turkevich method using sodium citrate to reduce silver nitrate at high pH and at 90 °C in the presence of zinc oxide nanoparticles. Both nanoparticles were characterized by X-ray diffraction (XRD), FTIR and Raman spectroscopy and scanning electron microscopy (SEM). The XRD and Raman spectra showed crystalline ZnO colloidal nanoparticles were obtained in the hexagonal phase. XRD measure showed cubic silver diffraction peaks cubic phase confirmed the presence of the silver nanoparticles decorated zinc oxide nanoparticles. SEM images showed ZnO nanoparticles presented a nanorod shapes with length around 80 nm decorated with spherical silver nanoparticles about 20 nm in diameter The results showed that crystalline zinc oxide colloidal nanoparticles with rod-like morphology and uniform decorated with silver spherical nanoparticles size were obtained by hydrothermal synthesis. Results of antibacterial tests indicate that the ZnO/Ag nanoparticles have antibacterial properties against both Staphylococcus aureus and Escherichia coli. The results demonstrated that the ZnO/Ag nanoparticles have potential use as biomaterials in medical/odontological applications. (author)

  12. Insight about electrical properties of low-temperature solution-processed Al-doped ZnO nanoparticle based layers for TFT applications

    Energy Technology Data Exchange (ETDEWEB)

    Diallo, Abdou Karim; Gaceur, Meriem; Fall, Sadiara; Didane, Yahia; Ben Dkhil, Sadok; Margeat, Olivier, E-mail: margeat@cinam.univ-mrs.fr; Ackermann, Jörg; Videlot-Ackermann, Christine, E-mail: videlot@cinam.univ-mrs.fr

    2016-12-15

    Highlights: • Al-doped ZnO (AZO) nanoparticles. • Impact of dispersion state and solid state on electrical properties. • Extrinsic doping with Al for high conducting AZO nanoparticle based layers. • Low-temperature operating nanoparticulate AZO TFTs. - Abstract: Aluminium-doped zinc oxide nanoparticles (NPs) with controlled Al doping contents (AZO{sub x} with x = 0–0.8 at% of Al) were explored as new oxide semiconductor materials to study the impact of doping on both solution and solid states. Polycrystalline AZO{sub x} thin films were produced by spin-coating the dispersions following by a thermal post-treatment at low-temperature (80 °C or 150 °C). The coated AZO{sub x} films were employed as active layer in thin-film transistors. Morphology and microstructure were studied by scanning electron microscopy and X-ray diffraction. The impact on the device performances (mobility, conductivity, charge carrier density) of Al-doping content together with the solution state was examined. Spin-coated films delivered an electron mobility up to 3 × 10{sup −2} cm{sup 2}/Vs for the highest Al-doping ratio AZO{sub 0.8}. Despite highly different morphologies, extrinsic doping with aluminium significantly increases the conductivity of low temperature solution-processed AZO{sub x} NPs series based layers by several orders of magnitude from AZO{sub 0} to AZO{sub 0.8}.

  13. After oxidation, zinc nanoparticles lose their ability to enhance responses to odorants.

    Science.gov (United States)

    Hagerty, Samantha; Daniels, Yasmine; Singletary, Melissa; Pustovyy, Oleg; Globa, Ludmila; MacCrehan, William A; Muramoto, Shin; Stan, Gheorghe; Lau, June W; Morrison, Edward E; Sorokulova, Iryna; Vodyanoy, Vitaly

    2016-12-01

    Electrical responses of olfactory sensory neurons to odorants were examined in the presence of zinc nanoparticles of various sizes and degrees of oxidation. The zinc nanoparticles were prepared by the underwater electrical discharge method and analyzed by atomic force microscopy and X-ray photoelectron spectroscopy. Small (1.2 ± 0.3 nm) zinc nanoparticles significantly enhanced electrical responses of olfactory neurons to odorants. After oxidation, however, these small zinc nanoparticles were no longer capable of enhancing olfactory responses. Larger zinc oxide nanoparticles (15 nm and 70 nm) also did not modulate responses to odorants. Neither zinc nor zinc oxide nanoparticles produced olfactory responses when added without odorants. The enhancement of odorant responses by small zinc nanoparticles was explained by the creation of olfactory receptor dimers initiated by small zinc nanoparticles. The results of this work will clarify the mechanisms for the initial events in olfaction, as well as to provide new ways to alleviate anosmia related to the loss of olfactory receptors.

  14. Zinc-based electrolyte compositions, and related electrochemical processes and articles

    Science.gov (United States)

    Kniajanski, Sergei; Soloveichik, Grigorii Lev

    2018-02-20

    An aqueous electrolyte composition is described, including a zinc salt based on zinc acetate or zinc glocolate. The saturation concentration of zinc in the electrolyte composition is in the range of about 2.5M to about 3.5M. The composition also contains at least one salt of a monovalent cation. The molar ratio of zinc to the monovalent cation is about 1:2. An aqueous zinc electroplating bath, containing the aqueous electrolyte composition, is also disclosed, along with a method for the electrochemical deposition of zinc onto a substrate surface, using the electroplating bath. Related flow batteries are also described, including a catholyte, as well as an anolyte based on the aqueous electrolyte composition, with a membrane between the catholyte and the anolyte.

  15. Production of high purity granular metals: cadmium, zinc, lead

    Directory of Open Access Journals (Sweden)

    Shcherban A. P.

    2017-04-01

    Full Text Available Cadmium, zinc and lead are constituent components of many semiconductor compounds. The obtained high purity distillates and ingots are large-size elements, which is not always convenient to use, and thus require additional grinding, which does not always allow maintaining the purity of the original materials. For the growth of semiconductor and scintillation single crystals it is advisable to use "friable" granular high-purity distillates, which can be processed without the risk of contamination. For example, the European low-background experiment LUCIFER required more than 20 kg of high-purity granulated zinc, which was agreed to be supplied by NSC KIPT. This task was then extended to cadmium and lead. Motivated by these tasks, the authors of this paper propose complex processes of deep refining of cadmium, zinc and lead by vacuum distillation. A device producing granules has been developed. The process of granulation of high-purity metals is explored. The purity of produced granules for cadmium and zinc is >99,9999, and >99,9995% for lead granules. To prevent oxidation of metal granules during exposition to air, chemical methods of surface passivation were used. Organic solvent based on dimethylformamide used as a coolant improves the resistance of granules to atmospheric corrosion during the granulation of high purity Cd, Zn and Pb.

  16. Electrical properties of solution-deposited ZnO thin-film transistors by low-temperature annealing.

    Science.gov (United States)

    Lim, Chul; Oh, Ji Young; Koo, Jae Bon; Park, Chan Woo; Jung, Soon-Won; Na, Bock Soon; Chu, Hye Yong

    2014-11-01

    Flexible oxide thin-film transistors (Oxide-TFTs) have emerged as next generation transistors because of their applicability in electronic device. In particular, the major driving force behind solution-processed zinc oxide film research is its prospective use in printing for electronics. A low-temperature process to improve the performance of solution-processed n-channel ZnO thin-film transistors (TFTs) fabricated via spin-coating and inkjet-printing is introduced here. ZnO nanoparticles were synthesized using a facile sonochemical method that was slightly modified based on a previously reported method. The influence of the annealing atmosphere on both nanoparticle-based TFT devices fabricated via spin-coating and those created via inkjet printing was investigated. For the inkjet-printed TFTs, the characteristics were improved significantly at an annealing temperature of 150 degrees C. The field effect mobility, V(th), and the on/off current ratios were 3.03 cm2/Vs, -3.3 V, and 10(4), respectively. These results indicate that annealing at 150 degrees C 1 h is sufficient to obtain a mobility (μ(sat)) as high as 3.03 cm2/Vs. Also, the active layer of the solution-based ZnO nanoparticles allowed the production of high-performance TFTs for low-cost, large-area electronics and flexible devices.

  17. Electrical properties of GaAs metal–oxide–semiconductor structure comprising Al2O3 gate oxide and AlN passivation layer fabricated in situ using a metal–organic vapor deposition/atomic layer deposition hybrid system

    Directory of Open Access Journals (Sweden)

    Takeshi Aoki

    2015-08-01

    Full Text Available This paper presents a compressive study on the fabrication and optimization of GaAs metal–oxide–semiconductor (MOS structures comprising a Al2O3 gate oxide, deposited via atomic layer deposition (ALD, with an AlN interfacial passivation layer prepared in situ via metal–organic chemical vapor deposition (MOCVD. The established protocol afforded self-limiting growth of Al2O3 in the atmospheric MOCVD reactor. Consequently, this enabled successive growth of MOCVD-formed AlN and ALD-formed Al2O3 layers on the GaAs substrate. The effects of AlN thickness, post-deposition anneal (PDA conditions, and crystal orientation of the GaAs substrate on the electrical properties of the resulting MOS capacitors were investigated. Thin AlN passivation layers afforded incorporation of optimum amounts of nitrogen, leading to good capacitance–voltage (C–V characteristics with reduced frequency dispersion. In contrast, excessively thick AlN passivation layers degraded the interface, thereby increasing the interfacial density of states (Dit near the midgap and reducing the conduction band offset. To further improve the interface with the thin AlN passivation layers, the PDA conditions were optimized. Using wet nitrogen at 600 °C was effective to reduce Dit to below 2 × 1012 cm−2 eV−1. Using a (111A substrate was also effective in reducing the frequency dispersion of accumulation capacitance, thus suggesting the suppression of traps in GaAs located near the dielectric/GaAs interface. The current findings suggest that using an atmosphere ALD process with in situ AlN passivation using the current MOCVD system could be an efficient solution to improving GaAs MOS interfaces.

  18. A Solution-Doped Polymer Semiconductor:Insulator Blend for Thermoelectrics

    KAUST Repository

    Kiefer, David; Yu, Liyang; Fransson, Erik; Gó mez, André s; Primetzhofer, Daniel; Amassian, Aram; Campoy-Quiles, Mariano; Mü ller, Christian

    2016-01-01

    Poly(ethylene oxide) is demonstrated to be a suitable matrix polymer for the solution-doped conjugated polymer poly(3-hexylthiophene). The polarity of the insulator combined with carefully chosen processing conditions permits the fabrication of tens of micrometer-thick films that feature a fine distribution of the F4TCNQ dopant:semiconductor complex. Changes in electrical conductivity from 0.1 to 0.3 S cm−1 and Seebeck coefficient from 100 to 60 μV K−1 upon addition of the insulator correlate with an increase in doping efficiency from 20% to 40% for heavily doped ternary blends. An invariant bulk thermal conductivity of about 0.3 W m−1 K−1 gives rise to a thermoelectric Figure of merit ZT ∼ 10−4 that remains unaltered for an insulator content of more than 60 wt%. Free-standing, mechanically robust tapes illustrate the versatility of the developed dopant:semiconductor:insulator ternary blends.

  19. A Solution-Doped Polymer Semiconductor:Insulator Blend for Thermoelectrics

    KAUST Repository

    Kiefer, David

    2016-09-01

    Poly(ethylene oxide) is demonstrated to be a suitable matrix polymer for the solution-doped conjugated polymer poly(3-hexylthiophene). The polarity of the insulator combined with carefully chosen processing conditions permits the fabrication of tens of micrometer-thick films that feature a fine distribution of the F4TCNQ dopant:semiconductor complex. Changes in electrical conductivity from 0.1 to 0.3 S cm−1 and Seebeck coefficient from 100 to 60 μV K−1 upon addition of the insulator correlate with an increase in doping efficiency from 20% to 40% for heavily doped ternary blends. An invariant bulk thermal conductivity of about 0.3 W m−1 K−1 gives rise to a thermoelectric Figure of merit ZT ∼ 10−4 that remains unaltered for an insulator content of more than 60 wt%. Free-standing, mechanically robust tapes illustrate the versatility of the developed dopant:semiconductor:insulator ternary blends.

  20. Various ways to reduce zinc oxide levels in S-SBR rubber compounds

    NARCIS (Netherlands)

    Heideman, G.; Noordermeer, Jacobus W.M.; Datta, Rabin; van Baarle, Ben

    2007-01-01

    Because of environmental concerns, the zinc content in rubber compounds has come under scrutiny. The research described in this article encompasses zinc-oxide, various zinc-complexes and alternative metal oxides as activators for sulphur vulcanisation. Regarding zinc complexes, it can be concluded

  1. Adsorption of poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) polymers on zinc, zinc oxide, iron, and iron oxide surfaces.

    Science.gov (United States)

    Seifert, Susan; Simon, Frank; Baumann, Giesela; Hietschold, Michael; Seifert, Andreas; Spange, Stefan

    2011-12-06

    The adsorption of poly(vinyl formamide) (PVFA) and the statistic copolymers poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) onto zinc and iron metal particles as well as their oxides was investigated. The adsorbates were characterized by means of XPS, DRIFT spectroscopy, wet chemical analysis, and solvatochromic probes. Dicyano-bis-(1,10-phenanthroline)-iron(II) (1), 3-(4-amino-3-methylphenyl)-7-phenyl-benzo-[1,2-b:4,5-b']difuran-2,6-dione (2), and 4-tert-butyl-2-(dicyano-methylene)-5-[4-(diethylamino)-benzylidene]-Δ(3)-thiazoline (3) as solvatochromic probes were coadsorbed onto zinc oxide to measure various effects of surface polarity. The experimental findings showed that the adsorption mechanism of PVFA and PVFA-co-PVAm strongly depends on the degree of hydrolysis of PVFA and pH values and also on the kind of metal or metal oxide surfaces that were employed as adsorbents. The adsorption mechanism of PVFA/PVFA-co-PVAm onto zinc oxide and iron oxide surfaces is mainly affected by electrostatic interactions. Particularly in the region of pH 5, the adsorption of PVFA/PVFA-co-PVAm onto zinc and iron metal particles is additionally influenced by redox processes, dissolution, and complexation reactions. © 2011 American Chemical Society

  2. Conductivity study of nitrogen-doped calcium zinc oxide prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Hsu, Yu-Ting; Lan, Wen-How; Huang, Kai-Feng; Lin, Jia-Ching; Chang, Kuo-Jen

    2016-01-01

    In this study, the spray pyrolysis method was used to prepare unintentionally doped and nitrogen-doped calcium zinc oxide films by using zinc acetate, calcium nitrate precursor, and ammonium acetate precursor. Morphological and structural analyses were conducted using scanning electron microscopy and X-ray diffraction. The results indicated that film grain size decreased as the nitrogen doping was increased. Both calcium oxide and zinc oxide structures were identified in the unintentionally doped calcium zinc oxide. When nitrogen doping was introduced, the film mainly exhibited a zinc oxide structure with preferred (002) and (101) orientations. The concentration and mobility were investigated using a Hall measurement system. P-type films with a mobility and concentration of 10.6 cm"2 V"−"1 s"−"1 and 2.8×10"1"7 cm"−"3, respectively, were obtained. Moreover, according to a temperature-dependent conductivity analysis, an acceptor state with activation energy 0.266 eV dominated the p-type conduction for the unintentionally doped calcium zinc oxide. By contrast, a grain boundary with a barrier height of 0.274–0.292 eV dominated the hole conduction for the nitrogen-doped calcium zinc oxide films.

  3. Kinetics and Photodegradation Study of Aqueous Methyl tert-Butyl Ether Using Zinc Oxide: The Effect of Particle Size

    Directory of Open Access Journals (Sweden)

    Zaki S. Seddigi

    2013-01-01

    Full Text Available Zinc oxide of different average particle sizes 25 nm, 59 nm, and 421 nm as applied in the photodegradation of MTBE. This study was carried out in a batch photoreactor having a high pressure mercury lamp. Zinc oxide of particle size of 421 nm was found to be the most effective in degrading MTBE in an aqueous solution. On using this type of ZnO in a solution of 100 ppm MTBE, the concentration of MTBE has decreased to 5.1 ppm after a period of five hours. The kinetics of the photocatalytic degradation of MTBE was found to be a first order reaction.

  4. I-III-VI.sub.2 based solar cell utilizing the structure CuInGaSe.sub.2 CdZnS/ZnO

    Science.gov (United States)

    Chen, Wen S.; Stewart, John M.

    1992-01-07

    A thin film I-III-VI.sub.2 based solar cell having a first layer of copper indium gallium selenide, a second layer of cadmium zinc sulfide, a double layer of zinc oxide, and a metallization structure comprised of a layer of nickel covered by a layer of aluminum. An optional antireflective coating may be placed on said metallization structure. The cadmium zinc sulfide layer is deposited by means of an aqueous solution growth deposition process and may actually consist of two layers: a low zinc content layer and a high zinc content layer. Photovoltaic efficiencies of 12.5% at Air Mass 1.5 illumination conditions and 10.4% under AMO illumination can be achieved.

  5. Significant deposits of gold, silver, copper, lead, and zinc in the United States

    Science.gov (United States)

    Long, K.R.; DeYoung, J.H.; Ludington, S.

    2000-01-01

    Approximately 99 percent of past production and remaining identified resources of gold, silver, copper, lead, and zinc in the United States are accounted for by deposits that originally contained at least 2 metric tonnes (t) gold, 85 t silver, 50,000 t copper, 30,000 t lead, or 50,000 t zinc. The U.S. Geological Survey, beginning with the 1996 National Mineral Resource Assessment, is systematically compiling data on these deposits, collectively known as 'significant' deposits. As of December 31, 1996, the significant deposits database contained 1,118 entries corresponding to individual deposits or mining districts. Maintaining, updating and analyzing a database of this size is much easier than managing the more than 100,000 records in the Mineral Resource Data System and Minerals Availability System/Minerals Industry Location System, yet the significant deposits database accounts for almost all past production and remaining identified resources of these metals in the United States. About 33 percent of gold, 22 percent of silver, 42 percent of copper, 39 percent of lead, and 46 percent of zinc are contained in or were produced from deposits discovered after World War II. Even within a database of significant deposits, a disproportionate share of past production and remaining resources is accounted for by a very small number of deposits. The largest 10 producers for each metal account for one third of the gold, 60 percent of the silver, 68 percent of the copper, 85 percent of the lead, and 75 percent of the zinc produced in the United States. The 10 largest deposits in terms of identified remaining resources of each of the five metals contain 43 percent of the gold, 56 percent of the silver, 48 percent of the copper, 94 percent of the lead, and 72 percent of the zinc. Identified resources in significant deposits for each metal are less than the mean estimates of resources in undiscovered deposits from the 1996 U.S. National Mineral Resource Assessment. Identified

  6. Heterojunction oxide thin-film transistors with unprecedented electron mobility grown from solution.

    Science.gov (United States)

    Faber, Hendrik; Das, Satyajit; Lin, Yen-Hung; Pliatsikas, Nikos; Zhao, Kui; Kehagias, Thomas; Dimitrakopulos, George; Amassian, Aram; Patsalas, Panos A; Anthopoulos, Thomas D

    2017-03-01

    Thin-film transistors made of solution-processed metal oxide semiconductors hold great promise for application in the emerging sector of large-area electronics. However, further advancement of the technology is hindered by limitations associated with the extrinsic electron transport properties of the often defect-prone oxides. We overcome this limitation by replacing the single-layer semiconductor channel with a low-dimensional, solution-grown In 2 O 3 /ZnO heterojunction. We find that In 2 O 3 /ZnO transistors exhibit band-like electron transport, with mobility values significantly higher than single-layer In 2 O 3 and ZnO devices by a factor of 2 to 100. This marked improvement is shown to originate from the presence of free electrons confined on the plane of the atomically sharp heterointerface induced by the large conduction band offset between In 2 O 3 and ZnO. Our finding underscores engineering of solution-grown metal oxide heterointerfaces as an alternative strategy to thin-film transistor development and has the potential for widespread technological applications.

  7. Heterojunction oxide thin-film transistors with unprecedented electron mobility grown from solution

    KAUST Repository

    Faber, Hendrik

    2017-04-28

    Thin-film transistors made of solution-processed metal oxide semiconductors hold great promise for application in the emerging sector of large-area electronics. However, further advancement of the technology is hindered by limitations associated with the extrinsic electron transport properties of the often defect-prone oxides. We overcome this limitation by replacing the single-layer semiconductor channel with a low-dimensional, solution-grown In2O3/ZnO heterojunction. We find that In2O3/ZnO transistors exhibit band-like electron transport, with mobility values significantly higher than single-layer In2O3 and ZnO devices by a factor of 2 to 100. This marked improvement is shown to originate from the presence of free electrons confined on the plane of the atomically sharp heterointerface induced by the large conduction band offset between In2O3 and ZnO. Our finding underscores engineering of solution-grown metal oxide heterointerfaces as an alternative strategy to thin-film transistor development and has the potential for widespread technological applications.

  8. Deposition of zinc on deposits on tubes in combustion systems - a thermodynamic study; Deponering av zink i belaeggningar paa panntuber - en termodynamisk studie

    Energy Technology Data Exchange (ETDEWEB)

    Nolaeng, Bengt; Sjoeblom, Rolf

    2011-02-15

    expected also for chlorides other than potassium chloride. The effect of condensation of chlorides with a low melting point may be counteracted by presence of sulphur provided that the conditions are oxidizing. In such a case sulphates are more stable than chlorides. Thus, the conclusion of this study is that presence of zinc and chlorine can contribute to the development of deposits with low melting point in boilers. This means that thermodynamical calculations now also support the general conclusions from Vaermeforsk's framework programmes on recovered wood based fuels that these elements are potentially harmful

  9. Searching Room Temperature Ferromagnetism in Wide Gap Semiconductors Fe-doped Strontium Titanate and Zinc Oxide

    CERN Document Server

    Pereira, LMC; Wahl, U

    Scientific findings in the very beginning of the millennium are taking us a step further in the new paradigm of technology: spintronics. Upgrading charge-based electronics with the additional degree of freedom of the carriers spin-state, spintronics opens a path to the birth of a new generation of devices with the potential advantages of non-volatility and higher processing speed, integration densities and power efficiency. A decisive step towards this new age lies on the attribution of magnetic properties to semiconductors, the building block of today's electronics, that is, the realization of ferromagnetic semiconductors (FS) with critical temperatures above room temperature. Unfruitful search for intrinsic RT FS lead to the concept of Dilute(d) Magnetic Semiconductors (DMS): ordinary semiconductor materials where 3 d transition metals randomly substitute a few percent of the matrix cations and, by some long-range mechanism, order ferromagnetically. The times are of intense research activity and the last fe...

  10. A deposit model for magmatic iron-titanium-oxide deposits related to Proterozoic massif anorthosite plutonic suites

    Science.gov (United States)

    Woodruff, Laurel G.; Nicholson, Suzanne W.; Fey, David L.

    2013-01-01

    This descriptive model for magmatic iron-titanium-oxide (Fe-Ti-oxide) deposits hosted by Proterozoic age massif-type anorthosite and related rock types presents their geological, mineralogical, geochemical, and geoenvironmental attributes. Although these Proterozoic rocks are found worldwide, the majority of known deposits are found within exposed rocks of the Grenville Province, stretching from southwestern United States through eastern Canada; its extension into Norway is termed the Rogaland Anorthosite Province. This type of Fe-Ti-oxide deposit dominated by ilmenite rarely contains more than 300 million tons of ore, with between 10- to 45-percent titanium dioxide (TiO2), 32- to 45-percent iron oxide (FeO), and less than 0.2-percent vanadium (V). The origin of these typically discordant ore deposits remains as enigmatic as the magmatic evolution of their host rocks. The deposits clearly have a magmatic origin, hosted by an age-constrained unique suite of rocks that likely are the consequence of a particular combination of tectonic circumstances, rather than any a priori temporal control. Principal ore minerals are ilmenite and hemo-ilmenite (ilmenite with extensive hematite exsolution lamellae); occurrences of titanomagnetite, magnetite, and apatite that are related to this deposit type are currently of less economic importance. Ore-mineral paragenesis is somewhat obscured by complicated solid solution and oxidation behavior within the Fe-Ti-oxide system. Anorthosite suites hosting these deposits require an extensive history of voluminous plagioclase crystallization to develop plagioclase-melt diapirs with entrained Fe-Ti-rich melt rising from the base of the lithosphere to mid- and upper-crustal levels. Timing and style of oxide mineralization are related to magmatic and dynamic evolution of these diapiric systems and to development and movement of oxide cumulates and related melts. Active mines have developed large open pits with extensive waste-rock piles, but

  11. Antibacterial effects of zinc oxide nanoparticles on Escherichia coli ...

    African Journals Online (AJOL)

    To study the antibacterial mechanisms, atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to observe morphological changes of E. coli K88 treated with 0.8 μg/ml zinc oxide nanoparticles. The results reveal that zinc oxide nanoparticles could damage cell membranes, lead to leakage of ...

  12. Ionic behavior of organic-inorganic metal halide perovskite based metal-oxide-semiconductor capacitors.

    Science.gov (United States)

    Wang, Yucheng; Zhang, Yuming; Pang, Tiqiang; Xu, Jie; Hu, Ziyang; Zhu, Yuejin; Tang, Xiaoyan; Luan, Suzhen; Jia, Renxu

    2017-05-24

    Organic-inorganic metal halide perovskites are promising semiconductors for optoelectronic applications. Despite the achievements in device performance, the electrical properties of perovskites have stagnated. Ion migration is speculated to be the main contributing factor for the many unusual electrical phenomena in perovskite-based devices. Here, to understand the intrinsic electrical behavior of perovskites, we constructed metal-oxide-semiconductor (MOS) capacitors based on perovskite films and performed capacitance-voltage (C-V) and current-voltage (I-V) measurements of the capacitors. The results provide direct evidence for the mixed ionic-electronic transport behavior within perovskite films. In the dark, there is electrical hysteresis in both the C-V and I-V curves because the mobile negative ions take part in charge transport despite frequency modulation. However, under illumination, the large amount of photoexcited free carriers screens the influence of the mobile ions with a low concentration, which is responsible for the normal C-V properties. Validation of ion migration for the gate-control ability of MOS capacitors is also helpful for the investigation of perovskite MOS transistors and other gate-control photovoltaic devices.

  13. Microwave Synthesis of Zinc Oxide/Reduced Graphene Oxide Hybrid for Adsorption-Photocatalysis Application

    Directory of Open Access Journals (Sweden)

    Fatin Saiha Omar

    2014-01-01

    Full Text Available This work reports on synthesis of zinc oxide/reduced graphene oxide (ZnO/rGO nanocomposites in the presence of diethylenetriamine (DETA via a facile microwave method. The X-ray diffraction (XRD patterns of the nanocomposites correspond to the ZnO hexagonal phase wurtzite structure. The high-resolution transmission electron microscopy (HRTEM images revealed that the ZnO nanorods, with an average length : diameter ratio of 10, were successfully deposited on the rGO sheets. Under the irradiation of sunlight, the nanocomposites showed enhanced adsorption-photocatalysis by more than twofold and photocurrent response by sixfold compared to the ZnO. The excellent photoactivity performance of the nanocomposites is contributed by smaller ZnO nanorod and the presence of rGO that acts as a photosensitizer by transferring electrons to the conduction band of ZnO within the nanocomposite during sunlight illumination.

  14. Comparative Study of Antidiabetic Activity and Oxidative Stress Induced by Zinc Oxide Nanoparticles and Zinc Sulfate in Diabetic Rats.

    Science.gov (United States)

    Nazarizadeh, Ali; Asri-Rezaie, Siamak

    2016-08-01

    In the current study, antidiabetic activity and toxic effects of zinc oxide nanoparticles (ZnO) were investigated in diabetic rats compared to zinc sulfate (ZnSO4) with particular emphasis on oxidative stress parameters. One hundred and twenty male Wistar rats were divided into two healthy and diabetic groups, randomly. Each major group was further subdivided into five subgroups and then orally supplemented with various doses of ZnO (1, 3, and 10 mg/kg) and ZnSO4 (30 mg/kg) for 56 consecutive days. ZnO showed greater antidiabetic activity compared to ZnSO4 evidenced by improved glucose disposal, insulin levels, and zinc status. The altered activities of erythrocyte antioxidant enzymes as well as raised levels of lipid peroxidation and a marked reduction of total antioxidant capacity were observed in rats receiving ZnO. ZnO nanoparticles acted as a potent antidiabetic agent, however, severely elicited oxidative stress particularly at higher doses.

  15. The growth and tensile deformation behavior of the silver solid solution phase with zinc

    International Nuclear Information System (INIS)

    Wu, Jiaqi; Lee, Chin C.

    2016-01-01

    The growth of homogeneous silver solid solution phase with zinc are conducted at two different compositions. X-ray diffraction (XRD) and Scanning electron microscope/Energy dispersive X-ray spectroscopy (SEM/EDX) are carried out for phase identification and chemical composition verification. The mechanical properties of silver solid solution phase with zinc are evaluated by tensile test. The engineering and true stress vs. strain curves are presented and analyzed, with those of pure silver in comparison. According to the experimental results, silver solid solution phase with zinc at both compositions show tempered yield strength, high tensile strength and large uniform strain compared to those of pure silver. Fractography further confirmed the superior ductility of silver solid solution phase with zinc at both compositions. Our preliminary but encouraging results may pave the way for the silver based alloys to be applied in industries such as electronic packaging and structure engineering.

  16. Surface functionalization of carbon nanofibers by sol-gel coating of zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Shao Dongfeng [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China); Changzhou Textile Garment Institute, Changzhou 213164 (China); Wei Qufu [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China)], E-mail: qfwei@jiangnan.edu.cn; Zhang Liwei; Cai Yibing; Jiang Shudong [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China)

    2008-08-15

    In this paper the functional carbon nanofibers were prepared by the carbonization of ZnO coated PAN nanofibers to expand the potential applications of carbon nanofibers. Polyacrylonitrile (PAN) nanofibers were obtained by electrospinning. The electrospun PAN nanofibers were then used as substrates for depositing the functional layer of zinc oxide (ZnO) on the PAN nanofiber surfaces by sol-gel technique. The effects of coating, pre-oxidation and carbonization on the surface morphology and structures of the nanofibers were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Scanning electron microscopy (SEM), respectively. The results of SEM showed a significant increase of the size of ZnO nanograins on the surface of nanofibers after the treatments of coating, pre-oxidation and carbonization. The observations by SEM also revealed that ZnO nanoclusters were firmly and clearly distributed on the surface of the carbon nanofibers. FTIR examination also confirmed the deposition of ZnO on the surface of carbon nanofibers. The XRD analysis indicated that the crystal structure of ZnO nanograins on the surface of carbon nanofibers.

  17. Pyrolytically grown indium sulfide sensitized zinc oxide nanowires for solar water splitting

    Energy Technology Data Exchange (ETDEWEB)

    Komurcu, Pelin; Can, Emre Kaan; Aydin, Erkan; Semiz, Levent [Micro and Nanotechnology Graduate Program, TOBB University of Economics and Technology, 06560 Ankara (Turkey); Gurol, Alp Eren; Alkan, Fatma Merve [Department of Materials Science and Nanotechnology Engineering, TOBB University of Economics and Technology, 06560 Ankara (Turkey); Sankir, Mehmet; Sankir, Nurdan Demirci [Micro and Nanotechnology Graduate Program, TOBB University of Economics and Technology, 06560 Ankara (Turkey); Department of Materials Science and Nanotechnology Engineering, TOBB University of Economics and Technology, 06560 Ankara (Turkey)

    2015-11-15

    Zinc oxide (ZnO) nanowires, sensitized with spray pyrolyzed indium sulfide, were obtained by chemical bath deposition. The XRD analysis indicated dominant evolution of hexagonal ZnO phase. Significant gain in photoelectrochemical current using ZnO nanowires is largely accountable to enhancement of the visible light absorption and the formation of heterostructure. The maximum photoconversion efficiency of 2.77% was calculated for the indium sulfide sensitized ZnO nanowire photoelectrodes. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Solution growth, characterization and applications of zinc sulphide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ndukwe, I C [School of Physical Sciences, Abia State University, Uturu, Abia State (Nigeria)

    1996-04-29

    Zinc sulphide (ZnS) thin films were successfully deposited on glass substrates under varying deposition conditions using the electroless or solution growth technique. The film properties investigated include their transmittance/reflectance/absorbance spectra, bandgap, optical constants, and thicknesses. Films grown under certain parametric conditions were found to exhibit high transmittance (64-98%), low absorbance, and low reflectance in the ultraviolet (uv)/visible/near infrared (nir) regions up to 1.00 {mu}m. Those obtained under other conditions exhibited high transmittance (78-98%) and low absorbance (0.01-0.1) in the uv/visible regions but low transmittance (30-37) and high absorbance (0.56) in the nir region. These characteristics revealed their suitability for various solar device applications. Bandgap range E{sub g}=3.7-3.8 eV and thickness range t=0.07 - 0.73 {mu}m were obtained.

  19. Plasma-deposited aluminum-doped zinc oxide : controlling nucleation, growth and electrical properties

    NARCIS (Netherlands)

    Ponomarev, M.

    2012-01-01

    In this work, the Expanding Thermal Plasma (ETP) deposition technique was employed to study the growth development of ZnO:Al thin film as a transparent conductive oxide layer for sustainable applications. Characteristic for ETP-grown ZnO:Al is a gradually reducing resistivity of the growing layer

  20. Status of zinc injection in PWRs

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, C.A. [Westinghouse Electric Co., Pittsburgh, PA (United States)

    1995-03-01

    Based on laboratory and other studies, it was concluded that zinc addition in a PWR primary coolant should result in reduced Alloy 600 PWSCC and general corrosion rates of the materials of construction. Because of these positive results, a Westinghouse Owner`s Subgroup, EPRI, and Westinghouse provided funds to continue the development and application of zinc in an operating plant. As part of the program, Southern Operating Nuclear Company agreed to operate the Farley 2 plant with zinc addition as a demonstration test of the effectiveness of zinc. Since zinc is incorporated in the corrosion oxide film on the primary system surfaces and Farley 2 is a mature plant, it was estimated that about 10 kgs of zinc would be needed to condition the plant before an equilibrium value in the coolant would be reached. The engineered aspects of a Zinc Addition and Monitoring System (ZAMS) considered such items as the constitutents, location, sizing and water supply of the ZAMS. Baseline data such as the PWSCC history of the Alloy 600 steam generator tubing, fuel oxide thickness, fuel crud deposits, radiation levels, and RCP seal leak-off rates were obtained before zinc addition is initiated. This presentation summarizes some of the work performed under the program, and the status of zinc injection in the Farley 2 plant.

  1. Hydrothermal synthesis of zinc oxide nanoparticles using rice as soft biotemplate.

    Science.gov (United States)

    Ramimoghadam, Donya; Bin Hussein, Mohd Zobir; Taufiq-Yap, Yun Hin

    2013-01-01

    Rice as a renewable, abundant bio-resource with unique characteristics can be used as a bio-template to synthesize various functional nanomaterials. Therefore, the effect of uncooked rice flour as bio-template on physico-chemical properties, especially the morphology of zinc oxide nanostructures was investigated in this study. The ZnO particles were synthesized through hydrothermal-biotemplate method using zinc acetate-sodium hydroxide and uncooked rice flour at various ratios as precursors at 120°C for 18 hours. The results indicate that rice as a bio-template can be used to modify the shape and size of zinc oxide particles. Different morphologies, namely flake-, flower-, rose-, star- and rod-like structures were obtained with particle size at micro- and nanometer range. Pore size and texture of the resulting zinc oxide particles were found to be template-dependent and the resulting specific surface area enhanced compared to the zinc oxide synthesized without rice under the same conditions. However, optical property particularly the band gap energy is generally quite similar. Pure zinc oxide crystals were successfully synthesized using rice flour as biotemplate at various ratios of zinc salt to rice. The size- and shape-controlled capability of rice to assemble the ZnO particles can be employed for further useful practical applications.

  2. Copper Doping of Zinc Oxide by Nuclear Transmutation

    Science.gov (United States)

    2014-03-27

    Copper Doping of Zinc Oxide by Nuclear Transmutation THESIS Matthew C. Recker, Captain, USAF AFIT-ENP-14-M-30 DEPARTMENT OF THE AIR FORCE AIR...NUCLEAR TRANSMUTATION THESIS Presented to the Faculty Department of Engineering Physics Graduate School of Engineering and Management Air Force...COPPER DOPING OF ZINC OXIDE BY NUCLEAR TRANSMUTATION Matthew C. Recker, BS Captain, USAF Approved: //signed// 27 February 2014 John W. McClory, PhD

  3. Plasma deposition of amorphous silicon-based materials

    CERN Document Server

    Bruno, Giovanni; Madan, Arun

    1995-01-01

    Semiconductors made from amorphous silicon have recently become important for their commercial applications in optical and electronic devices including FAX machines, solar cells, and liquid crystal displays. Plasma Deposition of Amorphous Silicon-Based Materials is a timely, comprehensive reference book written by leading authorities in the field. This volume links the fundamental growth kinetics involving complex plasma chemistry with the resulting semiconductor film properties and the subsequent effect on the performance of the electronic devices produced. Key Features * Focuses on the plasma chemistry of amorphous silicon-based materials * Links fundamental growth kinetics with the resulting semiconductor film properties and performance of electronic devices produced * Features an international group of contributors * Provides the first comprehensive coverage of the subject, from deposition technology to materials characterization to applications and implementation in state-of-the-art devices.

  4. Production of zinc pellets

    Science.gov (United States)

    Cooper, J.F.

    1996-11-26

    Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries. 6 figs.

  5. Structural, Optical and Electrical Properties of Transparent Conducting Oxide Based on Al Doped ZnO Prepared by Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Abdeslam DOUAYAR

    2014-05-01

    Full Text Available Aluminum doped zinc oxide (AZO thin films were deposited on glass substrates at 350 °C by spray pyrolysis technique. X-ray diffraction patterns show that the undoped and AZO films exhibit the hexagonal wűrtzite crystal structure with a preferential orientation along 2 direction. AFM images showed that AZO film with 3 % of Al has a uniform grain sizes with a surface roughness of about 24 nm. All films present a high transmittance in the visible range. Both undoped and AZO films were n-type degenerate semiconductor and the best electrical resistivity value was around 8.0 ´ 10- 2 W.cm obtained for 3 % Al content.

  6. Localized zinc distribution in shark vertebrae suggests differential deposition during ontogeny and across vertebral structures.

    Science.gov (United States)

    Raoult, Vincent; Howell, Nicholas; Zahra, David; Peddemors, Victor M; Howard, Daryl L; de Jonge, Martin D; Buchan, Benjamin L; Williamson, Jane E

    2018-01-01

    The development of shark vertebrae and the possible drivers of inter- and intra-specific differences in vertebral structure are poorly understood. Shark vertebrae are used to examine life-history traits related to trophic ecology, movement patterns, and the management of fisheries; a better understanding of their development would be beneficial to many fields of research that rely on these calcified structures. This study used Scanning X-ray Fluorescence Microscopy to observe zinc distribution within vertebrae of ten shark species from five different orders. Zinc was mostly localised within the intermedialis and was generally detected at levels an order of magnitude lower in the corpus calcareum. In most species, zinc concentrations were higher pre-birth mark, indicating a high rate of pre-natal zinc deposition. These results suggest there are inter-specific differences in elemental deposition within vertebrae. Since the deposition of zinc is physiologically-driven, these differences suggest that the processes of growth and deposition are potentially different in the intermedialis and corpus calcareum, and that caution should be taken when extrapolating information such as annual growth bands from one structure to the other. Together these results suggest that the high inter-specific variation in vertebral zinc deposition and associated physiologies may explain the varying effectiveness of ageing methodologies applied to elasmobranch vertebrae.

  7. In2Ga2ZnO7 oxide semiconductor based charge trap device for NAND flash memory

    Science.gov (United States)

    Hwang, Eun Suk; Kim, Jun Shik; Jeon, Seok Min; Lee, Seung Jun; Jang, Younjin; Cho, Deok-Yong; Hwang, Cheol Seong

    2018-04-01

    The programming characteristics of charge trap flash memory device adopting amorphous In2Ga2ZnO7 (a-IGZO) oxide semiconductors as channel layer were evaluated. Metal-organic chemical vapor deposition (MOCVD) and RF-sputtering processes were used to grow a 45 nm thick a-IGZO layer on a 20 nm thick SiO2 (blocking oxide)/p++-Si (control gate) substrate, where 3 nm thick atomic layer deposited Al2O3 (tunneling oxide) and 5 nm thick low-pressure CVD Si3N4 (charge trap) layers were intervened between the a-IGZO and substrate. Despite the identical stoichiometry and other physicochemical properties of the MOCVD and sputtered a-IGZO, a much faster programming speed of MOCVD a-IGZO was observed. A comparable amount of oxygen vacancies was found in both MOCVD and sputtered a-IGZO, confirmed by x-ray photoelectron spectroscopy and bias-illumination-instability test measurements. Ultraviolet photoelectron spectroscopy analysis revealed a higher Fermi level (E F) of the MOCVD a-IGZO (∼0.3 eV) film than that of the sputtered a-IGZO, which could be ascribed to the higher hydrogen concentration in the MOCVD a-IGZO film. Since the programming in a flash memory device is governed by the tunneling of electrons from the channel to charge trapping layer, the faster programming performance could be the result of a higher E F of MOCVD a-IGZO.

  8. Phosphonic Acids for Interfacial Engineering of Transparent Conductive Oxides

    KAUST Repository

    Paniagua, Sergio A.; Giordano, Anthony J.; Smith, O’ Neil L.; Barlow, Stephen; Li, Hong; Armstrong, Neal R.; Pemberton, Jeanne E.; Bredas, Jean-Luc; Ginger, David; Marder, Seth R.

    2016-01-01

    Transparent conducting oxides (TCOs), such as indium tin oxide and zinc oxide, play an important role as electrode materials in organic-semiconductor devices. The properties of the inorganic-organic interface - the offset between the TCO Fermi level and the relevant transport level, the extent to which the organic semiconductor can wet the oxide surface, and the influence of the surface on semiconductor morphology - significantly affect device performance. This review surveys the literature on TCO modification with phosphonic acids (PAs), which has increasingly been used to engineer these interfacial properties. The first part outlines the relevance of TCO surface modification to organic electronics, surveys methods for the synthesis of PAs, discusses the modes by which they can bind to TCO surfaces, and compares PAs to alternative organic surface modifiers. The next section discusses methods of PA monolayer deposition, the kinetics of monolayer formation, and structural evidence regarding molecular orientation on TCOs. The next sections discuss TCO work-function modification using PAs, tuning of TCO surface energy using PAs, and initiation of polymerizations from TCO-tethered PAs. Finally, studies that examine the use of PA-modified TCOs in organic light-emitting diodes and organic photovoltaics are compared. © 2016 American Chemical Society.

  9. Phosphonic Acids for Interfacial Engineering of Transparent Conductive Oxides

    KAUST Repository

    Paniagua, Sergio A.

    2016-05-26

    Transparent conducting oxides (TCOs), such as indium tin oxide and zinc oxide, play an important role as electrode materials in organic-semiconductor devices. The properties of the inorganic-organic interface - the offset between the TCO Fermi level and the relevant transport level, the extent to which the organic semiconductor can wet the oxide surface, and the influence of the surface on semiconductor morphology - significantly affect device performance. This review surveys the literature on TCO modification with phosphonic acids (PAs), which has increasingly been used to engineer these interfacial properties. The first part outlines the relevance of TCO surface modification to organic electronics, surveys methods for the synthesis of PAs, discusses the modes by which they can bind to TCO surfaces, and compares PAs to alternative organic surface modifiers. The next section discusses methods of PA monolayer deposition, the kinetics of monolayer formation, and structural evidence regarding molecular orientation on TCOs. The next sections discuss TCO work-function modification using PAs, tuning of TCO surface energy using PAs, and initiation of polymerizations from TCO-tethered PAs. Finally, studies that examine the use of PA-modified TCOs in organic light-emitting diodes and organic photovoltaics are compared. © 2016 American Chemical Society.

  10. Boron-doped zinc oxide thin films for large-area solar cells grown by metal organic chemical vapor deposition

    International Nuclear Information System (INIS)

    Chen, X.L.; Xu, B.H.; Xue, J.M.; Zhao, Y.; Wei, C.C.; Sun, J.; Wang, Y.; Zhang, X.D.; Geng, X.H.

    2007-01-01

    Boron-doped zinc oxide (ZnO:B) films were grown by metal organic chemical vapor deposition using diethylzinc (DEZn), and H 2 O as reactant gases and diborane (B 2 H 6 ) as an n-type dopant gas. The structural, electrical and optical properties of ZnO films doped at different B 2 H 6 flow rates were investigated. X-ray diffraction spectra and scanning electron microscopy images indicate that boron-doping plays an important role on the microstructure of ZnO films, which induced textured morphology. With optimized conditions, low sheet resistance (∼ 30 Ω/□), high transparency (> 85% in the visible light and infrared range) and high mobility (17.8 cm 2 V -1 s -1 ) were obtained for 700-nm ZnO:B films deposited on 20 cm x 20 cm glass substrates at the temperature of 443 K. After long-term exposure in air, the ZnO:B films also showed a better electrical stability than the un-doped samples. With the application of ZnO:B/Al back contacts, the short circuit current density was effectively enhanced by about 3 mA/cm 2 for a small area a-Si:H cell and a high efficiency of 9.1% was obtained for a large-area (20 cm x 20 cm) a-Si solar module

  11. Supported versus colloidal zinc oxide for advanced oxidation processes

    Science.gov (United States)

    Laxman, Karthik; Al Rashdi, Manal; Al Sabahi, Jamal; Al Abri, Mohammed; Dutta, Joydeep

    2017-07-01

    Photocatalysis is a green technology which typically utilizes either supported or colloidal catalysts for the mineralization of aqueous organic contaminants. Catalyst surface area and surface energy are the primary factors determining its efficiency, but correlation between the two is still unclear. This work explores their relation and hierarchy in a photocatalytic process involving both supported and colloidal catalysts. In order to do this the active surface areas of supported zinc oxide nanorods (ZnO NR's) and colloidal zinc oxide nanoparticles (having different surface energies) were equalized and their phenol oxidation mechanism and capacity was analyzed. It was observed that while surface energy had subtle effects on the oxidation rate of the catalysts, the degradation efficiency was primarily a function of the surface area; which makes it a better parameter for comparison when studying different catalyst forms of the same material. Thus we build a case for the use of supported catalysts, wherein their catalytic efficiency was tested to be unaltered over several days under both natural and artificial light, suggesting their viability for practical applications.

  12. Spin-transport-phenomena in metals, semiconductors, and insulators

    Energy Technology Data Exchange (ETDEWEB)

    Althammer, Matthias Klaus

    2012-07-19

    Assuming that one could deterministically inject, transport, manipulate, store and detect spin information in solid state devices, the well-established concepts of charge-based electronics could be transferred to the spin realm. This thesis explores the injection, transport, manipulation and storage of spin information in metallic conductors, semiconductors, as well as electrical insulators. On the one hand, we explore the spin-dependent properties of semiconducting zinc oxide thin films deposited via laser-molecular beam epitaxy (laser-MBE). After demonstrating that the zinc oxide films fabricated during this thesis have excellent structural, electrical, and optical properties, we investigate the spin-related properties by optical pump/probe, electrical injection/optical detection, and all electrical spin valve-based experiments. The two key results from these experiments are: (i) Long-lived spin states with spin dephasing times of 10 ns at 10 K related to donor bound excitons can be optically addressed. (ii) The spin dephasing times relevant for electrical transport-based experiments are {<=} 2 ns at 10 K and are correlated with structural quality. On the other hand we focus on two topics of current scientific interest: the comparison of the magnetoresistance to the magnetothermopower of conducting ferromagnets, and the investigation of pure spin currents generated in ferromagnetic insulator/normal metal hybrid structures. We investigate the magnetoresistance and magnetothermopower of gallium manganese arsenide and Heusler thin films as a function of external magnetic field orientation. Using a series expansion of the resistivity and Seebeck tensors and the inherent symmetry of the sample's crystal structure, we show that a full quantitative extraction of the transport tensors from such experiments is possible. Regarding the spin currents in ferromagnetic insulator/normal metal hybrid structures we studied the spin mixing conductance in yttrium iron garnet

  13. pn junctions based on a single transparent perovskite semiconductor BaSnO3

    Science.gov (United States)

    Kim, Hoon Min; Kim, Useong; Park, Chulkwon; Kwon, Hyukwoo; Lee, Woongjae; Kim, Tai Hoon; Kim, Kee Hoon; Char, Kookrin; Mdpl, Department Of Physics; Astronomy Team; Censcmr, Department Of Physics; Astronomy Team

    2014-03-01

    Successful p doping of transparent oxide semiconductor will further increase its potential, especially in the area of optoelectronic applications. We will report our efforts to dope the BaSnO3 (BSO) with K by pulsed laser deposition. Although the K doped BSO exhibits rather high resistivity at room temperature, its conductivity increases dramatically at higher temperatures. Furthermore, the conductivity decreases when a small amount of oxygen was removed from the film, consistent with the behavior of p type doped oxides. We have fabricated pn junctions by using K doped BSO as a p type and La doped BSO as an n type material. I_V characteristics of these devices show the typical rectifying behavior of pn junctions. We will present the analysis of the junction properties from the temperature dependent measurement of their electrical properties, which shows that the I_V characteristics are consistent with the material parameters such as the carrier concentration, the mobility, and the bandgap. Our demonstration of pn junctions based on a single transparent perovskite semiconductor further enhances the potential of BSO system with high mobility and stability.

  14. Properties of Zinc Oxide Nanoparticles and Their Activity Against Microbes

    Science.gov (United States)

    Siddiqi, Khwaja Salahuddin; ur Rahman, Aziz; Tajuddin; Husen, Azamal

    2018-05-01

    Zinc oxide is an essential ingredient of many enzymes, sun screens, and ointments for pain and itch relief. Its microcrystals are very efficient light absorbers in the UVA and UVB region of spectra due to wide bandgap. Impact of zinc oxide on biological functions depends on its morphology, particle size, exposure time, concentration, pH, and biocompatibility. They are more effective against microorganisms such as Bacillus subtilis, Bacillus megaterium, Staphylococcus aureus, Sarcina lutea, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Pseudomonas vulgaris, Candida albicans, and Aspergillus niger. Mechanism of action has been ascribed to the activation of zinc oxide nanoparticles by light, which penetrate the bacterial cell wall via diffusion. It has been confirmed from SEM and TEM images of the bacterial cells that zinc oxide nanoparticles disintegrate the cell membrane and accumulate in the cytoplasm where they interact with biomolecules causing cell apoptosis leading to cell death.

  15. Atomic Layer Deposition of Gallium Oxide Films as Gate Dielectrics in AlGaN/GaN Metal-Oxide-Semiconductor High-Electron-Mobility Transistors.

    Science.gov (United States)

    Shih, Huan-Yu; Chu, Fu-Chuan; Das, Atanu; Lee, Chia-Yu; Chen, Ming-Jang; Lin, Ray-Ming

    2016-12-01

    In this study, films of gallium oxide (Ga2O3) were prepared through remote plasma atomic layer deposition (RP-ALD) using triethylgallium and oxygen plasma. The chemical composition and optical properties of the Ga2O3 thin films were investigated; the saturation growth displayed a linear dependence with respect to the number of ALD cycles. These uniform ALD films exhibited excellent uniformity and smooth Ga2O3-GaN interfaces. An ALD Ga2O3 film was then used as the gate dielectric and surface passivation layer in a metal-oxide-semiconductor high-electron-mobility transistor (MOS-HEMT), which exhibited device performance superior to that of a corresponding conventional Schottky gate HEMT. Under similar bias conditions, the gate leakage currents of the MOS-HEMT were two orders of magnitude lower than those of the conventional HEMT, with the power-added efficiency enhanced by up to 9 %. The subthreshold swing and effective interfacial state density of the MOS-HEMT were 78 mV decade(-1) and 3.62 × 10(11) eV(-1) cm(-2), respectively. The direct-current and radio-frequency performances of the MOS-HEMT device were greater than those of the conventional HEMT. In addition, the flicker noise of the MOS-HEMT was lower than that of the conventional HEMT.

  16. Limonia acidissima L. leaf mediated synthesis of zinc oxide nanoparticles: A potent tool against Mycobacterium tuberculosis.

    Science.gov (United States)

    Taranath, Tarikere C; Patil, Bheemanagouda N

    2016-06-01

    The present investigation was undertaken to synthesize zinc oxide nanoparticles using Limonia acidissima L. and to test their efficacy against the growth of Mycobacterium tuberculosis. The formation of zinc oxide nanoparticles was confirmed with UV-visible spectrophotometry. Fourier transform infrared spectroscopy shows the presence of bio-molecules involved in the stabilization of zinc oxide nanoparticles. The shape and size was confirmed with atomic force microscope, X-ray diffraction, and high resolution transmission electron microscope. These nanoparticles were tested for their effect on the growth of M. tuberculosis through the microplate alamar blue assay technique. The UV-visible data reveal that an absorbance peak at 374nm confirms formation of zinc oxide nanoparticles and they are spherical in shape with sizes between 12nm and 53nm. These nanoparticles control the growth of M. tuberculosis at 12.5μg/mL. Phytosynthesis of zinc oxide nanoparticles is a green, eco-friendly technology because it is inexpensive and pollution free. In the present investigation, based on our results we conclude that the aqueous extract of leaves of L. acidissima can be used for the synthesis of zinc oxide nanoparticles. These nanoparticles control the growth of M. tuberculosis and this was confirmed with the microplate alamar blue method. The potential of biogenic zinc oxide nanoparticles may be harnessed as a novel medicine ingredient to combat tuberculosis disease. Copyright © 2016 Asian-African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

  17. Generic process for preparing a crystalline oxide upon a group IV semiconductor substrate

    Science.gov (United States)

    McKee, Rodney A.; Walker, Frederick J.; Chisholm, Matthew F.

    2000-01-01

    A process for growing a crystalline oxide epitaxially upon the surface of a Group IV semiconductor, as well as a structure constructed by the process, is described. The semiconductor can be germanium or silicon, and the crystalline oxide can generally be represented by the formula (AO).sub.n (A'BO.sub.3).sub.m in which "n" and "m" are non-negative integer repeats of planes of the alkaline earth oxides or the alkaline earth-containing perovskite oxides. With atomic level control of interfacial thermodynamics in a multicomponent semiconductor/oxide system, a highly perfect interface between a semiconductor and a crystalline oxide can be obtained.

  18. Chemical vapour deposition of vanadium oxide thermochromic thin films

    Science.gov (United States)

    Piccirillo, Clara

    Thermochromic materials change optical properties, such as transmittance or reflectance, with a variation in temperature. An ideal intelligent (smart) material will allow solar radiation in through a window in cold conditions, but reflect that radiation in warmer conditions. The variation in the properties is often associated with a phase change, which takes place at a definite temperature, and is normally reversible. Such materials are usually applied to window glass as thin films. This thesis presents the work on the development of thermochromic vanadium (IV) oxide (VO2) thin films - both undoped and doped with tungsten, niobium and gold nanoparticles - which could be employed as solar control coatings. The films were deposited using Chemical Vapour Deposition (CVD), using improved Atmospheric Pressure (APCVD), novel Aerosol Assisted (AACVD) and novel hybrid AP/AACVD techniques. The effects of dopants on the metalto- semiconductor transition temperature and transmittance/reflectance characteristics were also investigated. This work significantly increased the understanding of the mechanisms behind thermochromic behaviour, and resulted in thermochromic materials based on VO2 with greatly improved properties.

  19. Microbially-mediated method for synthesis of non-oxide semiconductor nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Phelps, Tommy J.; Lauf, Robert J.; Moon, Ji-Won; Rondinone, Adam Justin; Love, Lonnie J.; Duty, Chad Edward; Madden, Andrew Stephen; Li, Yiliang; Ivanov, Ilia N.; Rawn, Claudia Jeanette

    2017-09-19

    The invention is directed to a method for producing non-oxide semiconductor nanoparticles, the method comprising: (a) subjecting a combination of reaction components to conditions conducive to microbially-mediated formation of non-oxide semiconductor nanoparticles, wherein said combination of reaction components comprises i) anaerobic microbes, ii) a culture medium suitable for sustaining said anaerobic microbes, iii) a metal component comprising at least one type of metal ion, iv) a non-metal component comprising at least one non-metal selected from the group consisting of S, Se, Te, and As, and v) one or more electron donors that provide donatable electrons to said anaerobic microbes during consumption of the electron donor by said anaerobic microbes; and (b) isolating said non-oxide semiconductor nanoparticles, which contain at least one of said metal ions and at least one of said non-metals. The invention is also directed to non-oxide semiconductor nanoparticle compositions produced as above and having distinctive properties.

  20. Microbially-mediated method for synthesis of non-oxide semiconductor nanoparticles

    Science.gov (United States)

    Phelps, Tommy J.; Lauf, Robert J.; Moon, Ji Won; Rondinone, Adam J.; Love, Lonnie J.; Duty, Chad Edward; Madden, Andrew Stephen; Li, Yiliang; Ivanov, Ilia N.; Rawn, Claudia Jeanette

    2014-06-24

    The invention is directed to a method for producing non-oxide semiconductor nanoparticles, the method comprising: (a) subjecting a combination of reaction components to conditions conducive to microbially-mediated formation of non-oxide semiconductor nanoparticles, wherein said combination of reaction components comprises i) anaerobic microbes, ii) a culture medium suitable for sustaining said anaerobic microbes, iii) a metal component comprising at least one type of metal ion, iv) a non-metal component containing at least one non-metal selected from the group consisting of S, Se, Te, and As, and v) one or more electron donors that provide donatable electrons to said anaerobic microbes during consumption of the electron donor by said anaerobic microbes; and (b) isolating said non-oxide semiconductor nanoparticles, which contain at least one of said metal ions and at least one of said non-metals. The invention is also directed to non-oxide semiconductor nanoparticle compositions produced as above and having distinctive properties.

  1. Carbon deposition thresholds on nickel-based solid oxide fuel cell anodes I. Fuel utilization

    Science.gov (United States)

    Kuhn, J.; Kesler, O.

    2015-03-01

    In the first of a two part publication, the effect of fuel utilization (Uf) on carbon deposition rates in solid oxide fuel cell nickel-based anodes was studied. Representative 5-component CH4 reformate compositions (CH4, H2, CO, H2O, & CO2) were selected graphically by plotting the solutions to a system of mass-balance constraint equations. The centroid of the solution space was chosen to represent a typical anode gas mixture for each nominal Uf value. Selected 5-component and 3-component gas mixtures were then delivered to anode-supported cells for 10 h, followed by determination of the resulting deposited carbon mass. The empirical carbon deposition thresholds were affected by atomic carbon (C), hydrogen (H), and oxygen (O) fractions of the delivered gas mixtures and temperature. It was also found that CH4-rich gas mixtures caused irreversible damage, whereas atomically equivalent CO-rich compositions did not. The coking threshold predicted by thermodynamic equilibrium calculations employing graphite for the solid carbon phase agreed well with empirical thresholds at 700 °C (Uf ≈ 32%); however, at 600 °C, poor agreement was observed with the empirical threshold of ∼36%. Finally, cell operating temperatures correlated well with the difference in enthalpy between the supplied anode gas mixtures and their resulting thermodynamic equilibrium gas mixtures.

  2. Changes in inorganic matrices of dye sensitized solar cells during preparation

    Energy Technology Data Exchange (ETDEWEB)

    Graaf, Harald; Baumgaertel, Thomas; Luettich, Franziska; Kehr, Mirko [Institute of Physics, University of Technology Chemnitz (Germany); Maedler, Carsten [Institute of Physics, University of Technology Chemnitz (Germany); Department of Physics, Boston University, Boston, MA (United States); Oekermann, Thorsten [Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover (Germany)

    2010-07-01

    Dye-sensitized solar cells (DSSC) containing zinc oxide (ZnO) as the inorganic semiconductor and organic dye molecules as the sensitizer are well known devices with high efficiency. Such DSSC are prepared by electrochemical deposition of an aqueous zinc salt solution including organic molecules as templates. The template is desorbed in a second step to obtain a porous ZnO network. As a final step the sensitizing organic molecules were re-adsorped from solution. Within these different processing steps the structure of the ZnO can be influenced. We will discuss the growth mechanism during film deposition e.g. due to different template molecules. Also the crystal structure changes accompanying the desorption process, which is performed in an alkaline aqueous solution. Different techniques as X-ray investigations, optical absorption and scanning probe methods are used to identify the variations in different cells and within the production process.

  3. 21 CFR 73.1991 - Zinc oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Zinc oxide. 73.1991 Section 73.1991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR... oxide is a white or yellow-white amorphous powder manufactured by the French process (described as the...

  4. Hierarchical Assembly of Multifunctional Oxide-based Composite Nanostructures for Energy and Environmental Applications

    Directory of Open Access Journals (Sweden)

    Hui-Jan Lin

    2012-06-01

    Full Text Available Composite nanoarchitectures represent a class of nanostructured entities that integrates various dissimilar nanoscale building blocks including nanoparticles, nanowires, and nanofilms toward realizing multifunctional characteristics. A broad array of composite nanoarchitectures can be designed and fabricated, involving generic materials such as metal, ceramics, and polymers in nanoscale form. In this review, we will highlight the latest progress on composite nanostructures in our research group, particularly on various metal oxides including binary semiconductors, ABO3-type perovskites, A2BO4 spinels and quaternary dielectric hydroxyl metal oxides (AB(OH6 with diverse application potential. Through a generic template strategy in conjunction with various synthetic approaches—such as hydrothermal decomposition, colloidal deposition, physical sputtering, thermal decomposition and thermal oxidation, semiconductor oxide alloy nanowires, metal oxide/perovskite (spinel composite nanowires, stannate based nanocompostes, as well as semiconductor heterojunction—arrays and networks have been self-assembled in large scale and are being developed as promising classes of composite nanoarchitectures, which may open a new array of advanced nanotechnologies in solid state lighting, solar absorption, photocatalysis and battery, auto-emission control, and chemical sensing.

  5. Interfacial Chemistry-Induced Modulation of Schottky Barrier Heights: In Situ Measurements of the Pt-Amorphous Indium Gallium Zinc Oxide Interface Using X-ray Photoelectron Spectroscopy.

    Science.gov (United States)

    Flynn, Brendan T; Oleksak, Richard P; Thevuthasan, Suntharampillai; Herman, Gregory S

    2018-01-31

    A method to understand the role of interfacial chemistry on the modulation of Schottky barrier heights for platinum and amorphous indium gallium zinc oxide (a-IGZO) interfaces is demonstrated through thermal processing and background ambient pressure control. In situ X-ray photoelectron spectroscopy was used to characterize the interfacial chemistries that modulate barrier heights in this system. The primary changes were a significant chemical reduction of indium, from In 3+ to In 0 , that occurs during deposition of Pt on to the a-IGZO surface in ultrahigh vacuum. Postannealing and controlling the background ambient O 2 pressure allows further tuning of the reduction of indium and the corresponding Schottky barrier heights from 0.17 to 0.77 eV. Understanding the detailed interfacial chemistries at Pt/a-IGZO interfaces may allow for improved electronic device performance, including Schottky diodes, memristors, and metal-semiconductor field-effect transistors.

  6. Effects of intratesticular injection of zinc-based solution in rats in combination with anti-inflammatory and analgesic drugs during chemical sterilization

    Directory of Open Access Journals (Sweden)

    Simone Regina Barros de Macedo

    2018-05-01

    Full Text Available Aim: Chemical sterilization is a non-surgical method of contraception based on compounds injected into the testis to induce infertility. However, these injections can cause discomfort and pain able to impair the recovery of animals after this treatment. The objective of this study was to investigate if anti-inflammatories or pain relievers inhibited the sterilizing effect of zinc gluconate-based solution on the testis. Materials and Methods: Adult rats were treated in groups: G1 (control, G2 (dimethyl sulfoxide + dipyrone; G3 (dipyrone/ zinc; G4 (dipyrone + celecoxib/zinc; G5 (dipyrone + meloxicam/zinc, and G6 (dipyrone + dexamethasone/zinc in a single dose per day during 7 days. Animals were analyzed at 7, 15, and 30 days after treatments. Results: The zinc-induced a widespread testicular degeneration and decreased testosterone levels even in combination with anti-inflammatories or pain relievers. Testis, epididymis, prostate, and seminal vesicle had a weight reduction. The anti-inflammatory effect of dexamethasone interfered in the desired action of zinc gluconate in the 1st 15 days and celecoxib up to 7 days. Conclusion: Meloxicam plus dipyrone did not impair the chemical sterilization based on zinc gluconate, and it can be used to reduce nociceptive effects in animals after chemical sterilization.

  7. The development of latent fingerprints by zinc oxide and tin oxide nanoparticles prepared by precipitation technique

    Science.gov (United States)

    Luthra, Deepali; Kumar, Sacheen

    2018-05-01

    Fingerprints are the very important evidence at the crime scene which must be developed clearly with shortest duration of time to solve the case. Metal oxide nanoparticles could be the mean to develop the latent fingerprints. Zinc oxide and Tin Oxide Nanoparticles were prepared by using chemical precipitation technique which were dried and characterized by X-ray diffraction, UV-Visible spectroscopy and FTIR. The size of zinc oxide crystallite was found to be 14.75 nm with minimum reflectance at 360 nm whereas tin oxide have the size of 90 nm and reflectance at minimum level 321 nm. By using these powdered samples on glass, plastic and glossy cardboard, latent fingerprints were developed. Zinc oxide was found to be better candidate than tin oxide for the fingerprint development on all the three types of substrates.

  8. Dual passivation of intrinsic defects at the compound semiconductor/oxide interface using an oxidant and a reductant.

    Science.gov (United States)

    Kent, Tyler; Chagarov, Evgeniy; Edmonds, Mary; Droopad, Ravi; Kummel, Andrew C

    2015-05-26

    Studies have shown that metal oxide semiconductor field-effect transistors fabricated utilizing compound semiconductors as the channel are limited in their electrical performance. This is attributed to imperfections at the semiconductor/oxide interface which cause electronic trap states, resulting in inefficient modulation of the Fermi level. The physical origin of these states is still debated mainly because of the difficulty in assigning a particular electronic state to a specific physical defect. To gain insight into the exact source of the electronic trap states, density functional theory was employed to model the intrinsic physical defects on the InGaAs (2 × 4) surface and to model the effective passivation of these defects by utilizing both an oxidant and a reductant to eliminate metallic bonds and dangling-bond-induced strain at the interface. Scanning tunneling microscopy and spectroscopy were employed to experimentally determine the physical and electronic defects and to verify the effectiveness of dual passivation with an oxidant and a reductant. While subsurface chemisorption of oxidants on compound semiconductor substrates can be detrimental, it has been shown theoretically and experimentally that oxidants are critical to removing metallic defects at oxide/compound semiconductor interfaces present in nanoscale channels, oxides, and other nanostructures.

  9. High-mobility pyrene-based semiconductor for organic thin-film transistors.

    Science.gov (United States)

    Cho, Hyunduck; Lee, Sunyoung; Cho, Nam Sung; Jabbour, Ghassan E; Kwak, Jeonghun; Hwang, Do-Hoon; Lee, Changhee

    2013-05-01

    Numerous conjugated oligoacenes and polythiophenes are being heavily studied in the search for high-mobility organic semiconductors. Although many researchers have designed fused aromatic compounds as organic semiconductors for organic thin-film transistors (OTFTs), pyrene-based organic semiconductors with high mobilities and on-off current ratios have not yet been reported. Here, we introduce a new pyrene-based p-type organic semiconductor showing liquid crystal behavior. The thin film characteristics of this material are investigated by varying the substrate temperature during the deposition and the gate dielectric condition using the surface modification with a self-assembled monolayer, and systematically studied in correlation with the performances of transistor devices with this compound. OTFT fabricated under the optimum deposition conditions of this compound, namely, 1,6-bis(5'-octyl-2,2'-bithiophen-5-yl)pyrene (BOBTP) shows a high-performance transistor behavior with a field-effect mobility of 2.1 cm(2) V(-1) s(-1) and an on-off current ratio of 7.6 × 10(6) and enhanced long-term stability compared to the pentacene thin-film transistor.

  10. Localized zinc distribution in shark vertebrae suggests differential deposition during ontogeny and across vertebral structures.

    Directory of Open Access Journals (Sweden)

    Vincent Raoult

    Full Text Available The development of shark vertebrae and the possible drivers of inter- and intra-specific differences in vertebral structure are poorly understood. Shark vertebrae are used to examine life-history traits related to trophic ecology, movement patterns, and the management of fisheries; a better understanding of their development would be beneficial to many fields of research that rely on these calcified structures. This study used Scanning X-ray Fluorescence Microscopy to observe zinc distribution within vertebrae of ten shark species from five different orders. Zinc was mostly localised within the intermedialis and was generally detected at levels an order of magnitude lower in the corpus calcareum. In most species, zinc concentrations were higher pre-birth mark, indicating a high rate of pre-natal zinc deposition. These results suggest there are inter-specific differences in elemental deposition within vertebrae. Since the deposition of zinc is physiologically-driven, these differences suggest that the processes of growth and deposition are potentially different in the intermedialis and corpus calcareum, and that caution should be taken when extrapolating information such as annual growth bands from one structure to the other. Together these results suggest that the high inter-specific variation in vertebral zinc deposition and associated physiologies may explain the varying effectiveness of ageing methodologies applied to elasmobranch vertebrae.

  11. Comparison of the electronic structure of amorphous versus crystalline indium gallium zinc oxide semiconductor: structure, tail states and strain effects

    International Nuclear Information System (INIS)

    De Jamblinne de Meux, A; Genoe, J; Heremans, P; Pourtois, G

    2015-01-01

    We study the evolution of the structural and electronic properties of crystalline indium gallium zinc oxide (IGZO) upon amorphization by first-principles calculation. The bottom of the conduction band (BCB) is found to be constituted of a pseudo-band of molecular orbitals that resonate at the same energy on different atomic sites. They display a bonding character between the s orbitals of the metal sites and an anti-bonding character arising from the interaction between the oxygen and metal s orbitals. The energy level of the BCB shifts upon breaking of the crystal symmetry during the amorphization process, which may be attributed to the reduction of the coordination of the cationic centers. The top of the valence band (TVB) is constructed from anti-bonding oxygen p orbitals. In the amorphous state, they have random orientation, in contrast to the crystalline state. This results in the appearance of localized tail states in the forbidden gap above the TVB. Zinc is found to play a predominant role in the generation of these tail states, while gallium hinders their formation. Last, we study the dependence of the fundamental gap and effective mass of IGZO on mechanical strain. The variation of the gap under strain arises from the enhancement of the anti-bonding interaction in the BCB due to the modification of the length of the oxygen–metal bonds and/or to a variation of the cation coordination. This effect is less pronounced for the amorphous material compared to the crystalline material, making amorphous IGZO a semiconductor of choice for flexible electronics. Finally, the effective mass is found to increase upon strain, in contrast to regular materials. This counterintuitive variation is due to the reduction of the electrostatic shielding of the cationic centers by oxygen, leading to an increase of the overlaps between the metal orbitals at the origin of the delocalization of the BCB. For the range of strain typically met in flexible electronics, the induced

  12. Study and characterization of noble metal deposits on similar rusty surfaces to those of the reactor U-1 type BWR of nuclear power station of Laguna Verde; Estudio y caracterizacion de depositos de metales nobles sobre superficies oxidadas similares a las del reactor de la Central de Laguna Verde (CNLV) U1 del tipo BWR

    Energy Technology Data Exchange (ETDEWEB)

    Flores S, V. H.

    2011-07-01

    In the present investigation work, were determined the parameters to simulate the conditions of internal oxidation reactor circulation pipes of the nuclear power plant of Laguna Verde in Veracruz. We used 304l stainless steel cylinders with two faces prepared with abrasive paper of No. 600, with the finality to obtain similar surface to the internal circulation piping nuclear reactor. Oxides was formed within an autoclave (Autoclave MEX-02 unit B), which is a device that simulates the working conditions of the nuclear reactor, but without radiation generated by the fission reaction within the reactor. The oxidation conditions were a temperature of 280 C and pressure of 8 MPa, similar conditions to the reactor operating in nuclear power plant of Laguna Verde in Veracruz, Mexico (BWR conditions), with an average conductivity of 4.58 ms / cm and 2352 ppb oxygen to simulate normal water chemistry NWC. Were obtained deposits of noble metal oxides formed on 304l stainless steel samples, in a 250 ml autoclave at a temperature range of 180 to 200 C. The elements that were used to deposit platinum-rhodium (Pt-Rh) with aqueous Na{sub 2}Pt (OH){sub 6} and Na{sub 3}Rh (NO{sub 2}){sub 6}, Silver (Ag) with an aqueous solution of AgNO{sub 3}, zirconium (Zr) with aqueous Zr O (NO{sub 3}) and ZrO{sub 2}, and zinc (Zn) in aqueous solution of Zn (NO{sub 3}){sub 2} under conditions of normal water chemistry. Also there was the oxidation of 304l stainless steel specimens in normal water chemistry with a solution of Zinc (Zn) (NWC + Zn). Oxidation of the specimens in water chemistry with a solution of zinc (Zn + NWC) was prepared in two ways: within the MEX-02 autoclave unit A in a solution of zinc and a flask at constant temperature in zinc solution. The oxides formed and deposits were characterized by scanning electron microscopy, energy dispersive X-ray analysis, elemental field analysis and X-ray diffraction. By other hand was evaluated the electrochemical behavior of the oxides

  13. Role of atomic layer deposited aluminum oxide as oxidation barrier for silicon based materials

    Energy Technology Data Exchange (ETDEWEB)

    Fiorentino, Giuseppe, E-mail: g.fiorentino@tudelft.nl; Morana, Bruno [Department of Microelectronic, Delft University of Technology, Feldmannweg 17, 2628 CT Delft (Netherlands); Forte, Salvatore [Department of Electronic, University of Naples Federico II, Piazzale Tecchio, 80125 Napoli (Italy); Sarro, Pasqualina Maria [Department of Microelectronic, Delft University of Technology, Feldmannweg 17, 2628 CT, Delft (Netherlands)

    2015-01-15

    In this paper, the authors study the protective effect against oxidation of a thin layer of atomic layer deposited (ALD) aluminum oxide (Al{sub 2}O{sub 3}). Nitrogen doped silicon carbide (poly-SiC:N) based microheaters coated with ALD Al{sub 2}O{sub 3} are used as test structure to investigate the barrier effect of the alumina layers to oxygen and water vapor at very high temperature (up to 1000 °C). Different device sets have been fabricated changing the doping levels, to evaluate possible interaction between the dopants and the alumina layer. The as-deposited alumina layer morphology has been evaluated by means of AFM analysis and compared to an annealed sample (8 h at 1000 °C) to estimate the change in the grain structure and the film density. The coated microheaters are subjected to very long oxidation time in dry and wet environment (up to 8 h at 900 and 1000 °C). By evaluating the electrical resistance variation between uncoated reference devices and the ALD coated devices, the oxide growth on the SiC is estimated. The results show that the ALD alumina coating completely prevents the oxidation of the SiC up to 900 °C in wet environment, while an oxide thickness reduction of 50% is observed at 1000 °C compared to uncoated devices.

  14. ZnO Nanowires Synthesized by Vapor Phase Transport Deposition on Transparent Oxide Substrates

    Directory of Open Access Journals (Sweden)

    Taylor Curtis

    2010-01-01

    Full Text Available Abstract Zinc oxide nanowires have been synthesized without using metal catalyst seed layers on fluorine-doped tin oxide (FTO substrates by a modified vapor phase transport deposition process using a double-tube reactor. The unique reactor configuration creates a Zn-rich vapor environment that facilitates formation and growth of zinc oxide nanoparticles and wires (20–80 nm in diameter, up to 6 μm in length, density <40 nm apart at substrate temperatures down to 300°C. Electron microscopy and other characterization techniques show nanowires with distinct morphologies when grown under different conditions. The effect of reaction parameters including reaction time, temperature, and carrier gas flow rate on the size, morphology, crystalline structure, and density of ZnO nanowires has been investigated. The nanowires grown by this method have a diameter, length, and density appropriate for use in fabricating hybrid polymer/metal oxide nanostructure solar cells. For example, it is preferable to have nanowires no more than 40 nm apart to minimize exciton recombination in polymer solar cells.

  15. Transparent heaters based on solution-processed indium tin oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Im, Kiju [Department of Electrical Engineering and Institute for Nano Science, Korea University, 5-1, Anam-dong, Sungbuk-gu, Seoul 136-701 (Korea, Republic of); Research Institute of TNB Nanoelec Co. Ltd., Seoul 136-701 (Korea, Republic of); Cho, Kyoungah [Department of Electrical Engineering and Institute for Nano Science, Korea University, 5-1, Anam-dong, Sungbuk-gu, Seoul 136-701 (Korea, Republic of); Kim, Jonghyun [Research Institute of TNB Nanoelec Co. Ltd., Seoul 136-701 (Korea, Republic of); Kim, Sangsig, E-mail: sangsig@korea.ac.k [Department of Electrical Engineering and Institute for Nano Science, Korea University, 5-1, Anam-dong, Sungbuk-gu, Seoul 136-701 (Korea, Republic of)

    2010-05-03

    We demonstrate transparent heaters constructed on glass substrates using solution-processed indium tin oxide (ITO) nanoparticles (NPs) and their heating capability. The heat-generating characteristics of the heaters depended significantly on the sintering temperature at which the ITO NPs deposited on a glass substrate by spin-coating were transformed thermally into a solid film. The steady-state temperature of the ITO NP film sintered at 400 {sup o}C was 163 {sup o}C at a bias voltage of 20 V, and the defrosting capability of the film was confirmed by using dry-ice.

  16. Properties and electric characterizations of tetraethyl orthosilicate-based plasma enhanced chemical vapor deposition oxide film deposited at 400 °C for through silicon via application

    International Nuclear Information System (INIS)

    Su, Meiying; Yu, Daquan; Liu, Yijun; Wan, Lixi; Song, Chongshen; Dai, Fengwei; Xue, Kai; Jing, Xiangmeng; Guidotti, Daniel

    2014-01-01

    The dielectric via liner of through silicon vias was deposited at 400 °C using a tetraethyl orthosilicate (TEOS)-based plasma enhanced chemical vapor deposition process in a via-middle integration scheme. The morphology, conformality and chemical compositions of the liner film were characterized using field emission scanning electron microscopy and Fourier Transform Infrared spectroscopy. The thermal properties and electrical performance of blanket TEOS films were investigated by high temperature film stress and mercury probe Capacitance–Voltage measurements. The TEOS SiO 2 films show good conformality, excellent densification, low thermal stress, high breakdown voltage and low current leakage. - Highlights: • Tetraethyl orthosilicate-based oxide films were deposited for packaging application. • The oxide films deposited plasma-enhanced chemical vapor deposition (PECVD) at 400 °C. • The PECVD oxide films exhibit good step coverage. • The 400 °C PECVD oxide films exhibit low thermal stress and current leakage. • The 400 °C PECVD oxide films show high breakdown voltage and acceptable permittivity

  17. Properties and electric characterizations of tetraethyl orthosilicate-based plasma enhanced chemical vapor deposition oxide film deposited at 400 °C for through silicon via application

    Energy Technology Data Exchange (ETDEWEB)

    Su, Meiying, E-mail: sumeiying@ime.ac.cn [Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029 (China); National Center for Advanced Packaging, Wuxi 214135 (China); Yu, Daquan, E-mail: yudaquan@ime.ac.cn [Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029 (China); National Center for Advanced Packaging, Wuxi 214135 (China); Jiangsu R and D Center for Internet of Things, Wuxi 214135 (China); Liu, Yijun [Piotech Co. Ltd, Shenyang 110179 (China); Wan, Lixi [Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029 (China); Song, Chongshen; Dai, Fengwei [Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029 (China); National Center for Advanced Packaging, Wuxi 214135 (China); Xue, Kai [National Center for Advanced Packaging, Wuxi 214135 (China); Jing, Xiangmeng [Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029 (China); National Center for Advanced Packaging, Wuxi 214135 (China); Guidotti, Daniel [Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029 (China)

    2014-01-01

    The dielectric via liner of through silicon vias was deposited at 400 °C using a tetraethyl orthosilicate (TEOS)-based plasma enhanced chemical vapor deposition process in a via-middle integration scheme. The morphology, conformality and chemical compositions of the liner film were characterized using field emission scanning electron microscopy and Fourier Transform Infrared spectroscopy. The thermal properties and electrical performance of blanket TEOS films were investigated by high temperature film stress and mercury probe Capacitance–Voltage measurements. The TEOS SiO{sub 2} films show good conformality, excellent densification, low thermal stress, high breakdown voltage and low current leakage. - Highlights: • Tetraethyl orthosilicate-based oxide films were deposited for packaging application. • The oxide films deposited plasma-enhanced chemical vapor deposition (PECVD) at 400 °C. • The PECVD oxide films exhibit good step coverage. • The 400 °C PECVD oxide films exhibit low thermal stress and current leakage. • The 400 °C PECVD oxide films show high breakdown voltage and acceptable permittivity.

  18. Deposition of heated whey proteins on a chromium oxide surface.

    NARCIS (Netherlands)

    Jeurnink, Th.; Verheul, M.; Cohen Stuart, M.A.; Kruif, de C.G.

    1996-01-01

    Whey protein solutions were given different heat treatments after which their deposition on a chromium oxide surface (the outer layer of stainless steel) was measured by reflectometry. The deposition was studied under controlled flow conditions by using a stagnation point flow configuration. The

  19. Note: A disposable x-ray camera based on mass produced complementary metal-oxide-semiconductor sensors and single-board computers

    Energy Technology Data Exchange (ETDEWEB)

    Hoidn, Oliver R.; Seidler, Gerald T., E-mail: seidler@uw.edu [Physics Department, University of Washington, Seattle, Washington 98195 (United States)

    2015-08-15

    We have integrated mass-produced commercial complementary metal-oxide-semiconductor (CMOS) image sensors and off-the-shelf single-board computers into an x-ray camera platform optimized for acquisition of x-ray spectra and radiographs at energies of 2–6 keV. The CMOS sensor and single-board computer are complemented by custom mounting and interface hardware that can be easily acquired from rapid prototyping services. For single-pixel detection events, i.e., events where the deposited energy from one photon is substantially localized in a single pixel, we establish ∼20% quantum efficiency at 2.6 keV with ∼190 eV resolution and a 100 kHz maximum detection rate. The detector platform’s useful intrinsic energy resolution, 5-μm pixel size, ease of use, and obvious potential for parallelization make it a promising candidate for many applications at synchrotron facilities, in laser-heating plasma physics studies, and in laboratory-based x-ray spectrometry.

  20. Preparation and photovoltaic properties of CdS quantum dot-sensitized solar cell based on zinc tin mixed metal oxides.

    Science.gov (United States)

    Cao, Jiupeng; Zhao, Yifan; Zhu, Yatong; Yang, Xiaoyu; Shi, Peng; Xiao, Hongdi; Du, Na; Hou, Wanguo; Qi, Genggeng; Liu, Jianqiang

    2017-07-15

    The present study reports a new type of quantum dot sensitized solar cells (QDSSCs) using the zinc tin mixed metal oxides (MMO) as the anode materials, which were obtained from the layered double hydroxide (LDH) precursor. The successive ionic layer adsorption and reaction (SILAR) method is applied to deposit CdS quantum dots. The effects of sensitizing cycles on the performance of CdS QDSSC are studied. Scanning electron microscopy (SEM), Transmission electron microscope (TEM) and X-ray diffraction (XRD) are used to identify the surface profile and crystal structure of the mixed metal oxides anode. The photovoltaic performance of the QDSSC is studied by the electrochemical method. The new CdS QDSSC exhibits power conversion efficiency (PCE) up to 0.48% when the anode was sensitized for eight cycles. Copyright © 2017 Elsevier Inc. All rights reserved.