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Sample records for prepared thin films

  1. PREPARATION AND CHARACTERIZATION OF POLY-CRYSTALLINE SILICON THIN FILM

    Institute of Scientific and Technical Information of China (English)

    Y.F. Hu; H. Shen; Z.Y. Liu; L.S. Wen

    2003-01-01

    Poly-crystalline silicon thin film has big potential of reducing the cost of solar cells.In this paper the preparation of thin film is introduced, and then the morphology of poly-crystalline thin film is discussed. On the film we developed poly-crystalline silicon thin film solar cells with efficiency up to 6. 05% without anti-reflection coating.

  2. Preparation and properties of antimony thin film anode materials

    Institute of Scientific and Technical Information of China (English)

    SU Shufa; CAO Gaoshao; ZHAO Xinbing

    2004-01-01

    Metallic antimony thin films were deposited by magnetron sputtering and electrodeposition. Electrochemical properties of the thin film as anode materials for lithium-ion batteries were investigated and compared with those of antimony powder. It was found that both magnetron sputtering and electrodeposition are easily controllable processes to deposit antimony films with fiat charge/discharge potential plateaus. The electrochemical performances of antimony thin films, especially those prepared with magnetron sputtering, are better than those of antimony powder. The reversible capacities of the magnetron sputtered antimony thin film are above 400 mA h g-1 in the first 15 cycles.

  3. ZnO thin films prepared by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Tsoutsouva, M.G. [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780 Athens (Greece); Panagopoulos, C.N., E-mail: chpanag@metal.ntua.gr [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780 Athens (Greece); Papadimitriou, D. [National Technical University of Athens, Department of Physics, GR-15780 Athens (Greece); Fasaki, I.; Kompitsas, M. [Theor. and Phys./Chem. Institute, National Hellenic Research Foundation, 48 Vas. Konstantinou Ave., 11635 Athens (Greece)

    2011-04-15

    Zinc oxide (ZnO) thin films were deposited on soda lime glass substrates by pulsed laser deposition (PLD) in an oxygen-reactive atmosphere. The structural, optical, and electrical properties of the as-prepared thin films were studied in dependence of substrate temperature and oxygen pressure. High quality polycrystalline ZnO films with hexagonal wurtzite structure were deposited at substrate temperatures of 100 and 300 deg. C. The RMS roughness of the deposited oxide films was found to be in the range 2-9 nm and was only slightly dependent on substrate temperature and oxygen pressure. Electrical measurements indicated a decrease of film resistivity with the increase of substrate temperature and the decrease of oxygen pressure. The ZnO films exhibited high transmittance of 90% and their energy band gap and thickness were in the range 3.26-3.30 eV and 256-627 nm, respectively.

  4. Sol-gel preparation of silica and titania thin films

    Science.gov (United States)

    Thoř, Tomáš; Václavík, Jan

    2016-11-01

    Thin films of silicon dioxide (SiO2) and titanium dioxide (TiO2) for application in precision optics prepared via the solgel route are being investigated in this paper. The sol-gel process presents a low cost approach, which is capable of tailoring thin films of various materials in optical grade quality. Both SiO2 and TiO2 are materials well known for their application in the field of anti-reflective and also highly reflective optical coatings. For precision optics purposes, thickness control and high quality of such coatings are of utmost importance. In this work, thin films were deposited on microscope glass slides substrates using the dip-coating technique from a solution based on alkoxide precursors of tetraethyl orthosilicate (TEOS) and titanium isopropoxide (TIP) for SiO2 and TiO2, respectively. As-deposited films were studied using spectroscopic ellipsometry to determine their thickness and refractive index. Using a semi-empirical equation, a relationship between the coating speed and the heat-treated film thickness was described for both SiO2 and TiO2 thin films. This allows us to control the final heat-treated thin film thickness by simply adjusting the coating speed. Furthermore, films' surface was studied using the white-light interferometry. As-prepared films exhibited low surface roughness with the area roughness parameter Sq being on average of 0.799 nm and 0.33 nm for SiO2 and TiO2, respectively.

  5. Preparation and characterization of Zn Se thin films

    CERN Document Server

    Ganchev, M; Stratieva, N; Gremenok, V; Zaretskaya, E; Goncharova, O

    2003-01-01

    Chemical bath deposition technique for preparation of ZnSe thin films is presented. The influence of bath temperature and duration of deposition on film growth and quality has been studied. The effect of post-deposition annealing in different ambient is also discussed. It has been determined that heat treatment removes the oxygen-containing phase from the as-deposited films and improves crystallinity. The optical and electric properties of the deposits show their potential for an alternative buffer layer in chalcopyrite-based solar cells.

  6. Preparation and magnetic properties of Co-P thin films

    Institute of Scientific and Technical Information of China (English)

    Haicheng Wang; Zhongmei Du; Lijin Wang; Guanghua Yu; Fengwu Zhu

    2008-01-01

    Magnetic Co-P thin films were prepared by eleetroless deposition. The experiment results show that the film thickness has a significant influence on the coercivity. While the film thickness varied from 300 nm to 5 μm, the coercivity dropped sharply from 45.36 to 22.28 kA/m. As the film thickness increased further, the coercivity varied slowly. When the thickness of the film was 300 nm, the deposited film could realize the coercivity as high as 45.36 kA/m, and the remanent magnetization as high as 800 kA/m .The Co-P films were deposited on the surface of magnetic drums of encoders, whose diameter was 40 mm, and then 512 magnetic poles were recorded, meaning that the magnetizing pitch was 0.245 mm. The testing results indicate that the output signals are perfect, the output waveforms are steady and the pulses account is integral. Compared with the γ-Fe2O3 coating, the Co-P thin film is suitable to be the magnetic recording media for the high resolution magnetic rotary encoder.

  7. Preparation and properties of thin films treatise on materials science and technology

    CERN Document Server

    Tu, K N

    1982-01-01

    Treatise on Materials Science and Technology, Volume 24: Preparation and Properties of Thin Films covers the progress made in the preparation of thin films and the corresponding study of their properties. The book discusses the preparation and property correlations in thin film; the variation of microstructure of thin films; and the molecular beam epitaxy of superlattices in thin film. The text also describes the epitaxial growth of silicon structures (thermal-, laser-, and electron-beam-induced); the characterization of grain boundaries in bicrystalline thin films; and the mechanical properti

  8. Preparation and magnetization reversal of exchange bias structured thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hamann, Christine; McCord, Jeffrey; Moench, Ingolf; Kaltofen, Rainer; Gemming, Thomas; Schaefer, Rudolf; Schultz, Ludwig [Leibniz Institute for Solid State and Materials Research, Dresden (Germany)

    2008-07-01

    Magnetically patterned thin films of NiFe/IrMn/Ta-NiFe/IrMnO{sub x} with laterally modulated unidirectional anisotropy were prepared by local oxidation of the antiferromagnetic IrMn layer. Varying the lateral dimensions and orientation with respect to the anisotropy modulation, the films exhibit different magnetization reversal behaviors. While stripes aligned parallel to the unidirectional anisotropy direction display a spin valve-like two step hysteresis loop, perpendicular orientation lead to a single step shifted hysteresis loop. Magnetic domain observation reveals separate switching of the stripes for the parallel alignment and simultaneous reversal for the perpendicular orientation. By decreasing the lateral dimensions, quasi-domain states have been observed. The presented magnetic data of the exchange biased-patterned films show that we did succeed in creating an alternative method for the preparation of materials with new hybrid properties.

  9. Preparation of biaxially oriented TlCu-1234 thin films

    CERN Document Server

    Khan, N A; Tateai, F; Kojima, T; Ishida, K; Terada, N; Ihara, H

    1999-01-01

    The single phase of TlCu-1234 superconductor thin films is prepared for the first time by the amorphous phase epitaxy (APE) method, which is thallium treatment of sputtered amorphous phase at 900 degrees C for 1 h. The amorphous $9 phase is prepared by sputtering from the stoichiometric target composition CuBa/sub 2/Ca/sub 3/Cu/sub 4/O/sub 12-y/. The films on the SrTiO/sub 3/ substrate are aligned biaxially after the thallium treatment. Highly reproducible $9 TlCu-1234 films are prepared by this method. The XRD reflected a predominant single phase with the c-axis lattice constant of 18.74 AA. This lattice constant value is in between that of Cu-1234 (17.99 AA) and Tl-1234 (19.11 AA) . The $9 pole figure measurements of (103) reflection of the films showed a-axis-oriented crystals with Delta phi =0.8 degrees . The composition of the films after energy dispersive X-ray (EDX) measurements is Tl/sub 0.8/Cu/sub 0.2/Ba/sub $9 2/Ca/sub 3/Cu/sub 4/O /sub 12-y/. From the resistivity measurements, the T/sub c/ is 113 K...

  10. Preparation of organic thin-film field effect transistor

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The organic thin-film field effect transistor was prepared through vacuum deposition by using teflon as di-electric material. Indium-tin-oxide acted as the source and drain electrodes. Copper phthalocyanine and teflon were used as the semiconductor layer and dielectric layer, respectively. The gate electrode was made of Ag. The channel length between the source and drain was 50 μm. After preparing the source and drain electrodes by lithography, the copper phthalocyanine layer, teflon layer and Ag layerwere prepared by vacuum deposition sequentially. The field effect electron mobility of the device reached 1.1×10ˉ6 cm2/(V@s), and the on/off current ratio reached 500.

  11. Optical properties of rubrene thin film prepared by thermal evaporation

    Institute of Scientific and Technical Information of China (English)

    陈亮; 邓金祥; 孔乐; 崔敏; 陈仁刚; 张紫佳

    2015-01-01

    Rubrene thin films are deposited on quartz substrates and silver nanoparticles (Ag NPs) films by the thermal evapo-ration technique. The optical properties of rubrene thin film are investigated in a spectral range of 190 nm–1600 nm. The analysis of the absorption coefficient (α) reveals direct allowed transition with a corresponding energy of 2.24 eV. The photoluminescence (PL) peak of the rubrene thin film is observed to be at 563 nm (2.21 eV). With the use of Ag NPs which are fabricated by radio-frequency (RF) magnetron sputtering on the quartz, the PL intensity is 8.5 times that of as-deposited rubrene thin film. It is attributed to the fact that the surface plasmon enhances the photoluminescence.

  12. Preparation of mesoporous silica thin films by photocalcination method and their adsorption abilities for various proteins.

    Science.gov (United States)

    Kato, Katsuya; Nakamura, Hitomi; Yamauchi, Yoshihiro; Nakanishi, Kazuma; Tomita, Masahiro

    2014-07-01

    Mesoporous silica (MPS) thin film biosensor platforms were established. MPS thin films were prepared from tetraethoxysilane (TEOS) via using sol-gel and spin-coating methods using a poly-(ethylene oxide)-block-poly-(propylene oxide)-block-poly-(ethylene oxide) triblock polymer, such as P123 ((EO)20(PO)70(EO)20) or F127 ((EO)106(PO)70(EO)106), as the structure-directing agent. The MPS thin film prepared using P123 as the mesoporous template and treated via vacuum ultraviolet (VUV) irradiation to remove the triblock copolymer had a more uniform pore array than that of the corresponding film prepared via thermal treatment. Protein adsorption and enzyme-linked immunosorbent assay (ELISA) on the synthesized MPS thin films were also investigated. VUV-irradiated MPS thin films adsorbed a smaller quantity of protein A than the thermally treated films; however, the human immunoglobulin G (IgG) binding efficiency was higher on the former. In addition, protein A-IgG specific binding on MPS thin films was achieved without using a blocking reagent; i.e., nonspecific adsorption was inhibited by the uniform pore arrays of the films. Furthermore, VUV-irradiated MPS thin films exhibited high sensitivity for ELISA testing, and cytochrome c adsorbed on the MPS thin films exhibited high catalytic activity and recyclability. These results suggest that MPS thin films are attractive platforms for the development of novel biosensors.

  13. Methods for preparing colloidal nanocrystal-based thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kagan, Cherie R.; Fafarman, Aaron T.; Choi, Ji-Hyuk; Koh, Weon-kyu; Kim, David K.; Oh, Soong Ju; Lai, Yuming; Hong, Sung-Hoon; Saudari, Sangameshwar Rao; Murray, Christopher B.

    2016-05-10

    Methods of exchanging ligands to form colloidal nanocrystals (NCs) with chalcogenocyanate (xCN)-based ligands and apparatuses using the same are disclosed. The ligands may be exchanged by assembling NCs into a thin film and immersing the thin film in a solution containing xCN-based ligands. The ligands may also be exchanged by mixing a xCN-based solution with a dispersion of NCs, flocculating the mixture, centrifuging the mixture, discarding the supernatant, adding a solvent to the pellet, and dispersing the solvent and pellet to form dispersed NCs with exchanged xCN-ligands. The NCs with xCN-based ligands may be used to form thin film devices and/or other electronic, optoelectronic, and photonic devices. Devices comprising nanocrystal-based thin films and methods for forming such devices are also disclosed. These devices may be constructed by depositing NCs on to a substrate to form an NC thin film and then doping the thin film by evaporation and thermal diffusion.

  14. Preparation of iron cobaltite thin films by RF magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Le Trong, H. [Université de Toulouse, UPS, INPT, Institut Carnot CIRIMAT, 118, Route de Narbonne, F-31062 Toulouse cedex 9 (France); CNRS, Institut Carnot Cirimat, F-31062 Toulouse (France); Ho Chi Minh City University of Science, Vietnam National University Ho Chi Minh City, 227 Nguyen Van Cu Q 5, 750000 Ho Chi Minh City (Viet Nam); Bui, T.M.A. [Université de Toulouse, UPS, INPT, Institut Carnot CIRIMAT, 118, Route de Narbonne, F-31062 Toulouse cedex 9 (France); CNRS, Institut Carnot Cirimat, F-31062 Toulouse (France); University of Transport and Communications, Lang Thuong, Dong Da, Hanoi (Viet Nam); Presmanes, L., E-mail: presmane@chimie.ups-tlse.fr [Université de Toulouse, UPS, INPT, Institut Carnot CIRIMAT, 118, Route de Narbonne, F-31062 Toulouse cedex 9 (France); CNRS, Institut Carnot Cirimat, F-31062 Toulouse (France); Barnabé, A.; Pasquet, I.; Bonningue, C.; Tailhades, Ph. [Université de Toulouse, UPS, INPT, Institut Carnot CIRIMAT, 118, Route de Narbonne, F-31062 Toulouse cedex 9 (France); CNRS, Institut Carnot Cirimat, F-31062 Toulouse (France)

    2015-08-31

    Iron cobaltite thin films with spinel structure have been elaborated by radio-frequency (RF) magnetron sputtering from a Co{sub 1.75}Fe{sub 1.25}O{sub 4} target. Influence of argon pressure on structure, microstructure and physical properties of films has been examined. Iron–cobalt oxide thin films essentially consist of one spinel phase when deposited at low pressure (0.5 and 1.0 Pa). At high pressure (2.0 Pa), the global stoichiometry of the film is changed which results in the precipitation of a mixed monoxide of cobalt and iron beside the spinel phase. This in-situ reduction due to an oxygen loss occurring mainly at high deposition pressure has been revealed by X-ray diffraction and Raman spectroscopy. Microstructural evolution of thin film with argon pressure has been shown by microscopic observations (AFM and SEM). The evolution of magnetic and electrical properties, versus argon pressure, has been also studied by SQUID and 4 point probe measurements. - Highlights: • Co{sub 1.75}Fe{sub 1.25}O{sub 4} phase is obtained at room temperature without any annealing. • This phase is a ferrimagnetic semiconductor with a coercive field of 32 kOe at 5 K. • Oxygen content of the thin film is related to the argon pressure during sputtering. • Monoxide phase grows into the film at high argon pressure. • Magnetic coupling effect reveals nanoscale impurities at low argon pressure.

  15. Reactively sputtered titanium carbide thin films: Preparation and properties

    Science.gov (United States)

    Eizenberg, M.; Murarka, S. P.

    1983-06-01

    The low resistivity and refractory nature of titanium carbide makes it potentially useful as a diffusion barrier in thin film metallization schemes. In the present investigation, deposition and properties of thin titanium carbide films have been investigated. The films were deposited by reactive radio frequency sputtering in methane-argon mixtures on a variety of substrates. The effects of methane to argon ratio, total sputtering pressure, and power on the film deposition rate, composition and properties were determined. There were interactive effects of these parameters on the composition and properties of these films. Resistivity increased with carbon content; for Ti/C≥1 it was ˜200 μΩ cm. Stress that was compressive was maximum in the nearly stoichiometric TiC film. Grain size was small in all films, especially so in carbon rich films. All stoichiometric titanium carbide films were resistant to HF solutions. Films with TiC/≥1 dissolved easily in ethylene dinitrilo tetra acetric acid (EDTA) solution.

  16. Epitaxial ternary nitride thin films prepared by a chemical solution method

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Hongmei [Los Alamos National Laboratory; Feldmann, David M [Los Alamos National Laboratory; Wang, Haiyan [TEXAS A& M; Bi, Zhenxing [TEXAS A& M

    2008-01-01

    It is indispensable to use thin films for many technological applications. This is the first report of epitaxial growth of ternary nitride AMN2 films. Epitaxial tetragonal SrTiN2 films have been successfully prepared by a chemical solution approach, polymer-assisted deposition. The structural, electrical, and optical properties of the films are also investigated.

  17. Preparation of mesoporous silica thin films by photocalcination method and their adsorption abilities for various proteins

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Katsuya, E-mail: katsuya-kato@aist.go.jp [National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Anagahora, Shimoshidami, Moriyama-ku, Nagoya 463-8560 (Japan); Nakamura, Hitomi [National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Anagahora, Shimoshidami, Moriyama-ku, Nagoya 463-8560 (Japan); Yamauchi, Yoshihiro; Nakanishi, Kazuma; Tomita, Masahiro [Department of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho, Tsu, Mie 514-8570 (Japan)

    2014-07-01

    Mesoporous silica (MPS) thin film biosensor platforms were established. MPS thin films were prepared from tetraethoxysilane (TEOS) via using sol–gel and spin-coating methods using a poly-(ethylene oxide)-block-poly-(propylene oxide)-block-poly-(ethylene oxide) triblock polymer, such as P123 ((EO){sub 20}(PO){sub 70}(EO){sub 20}) or F127 ((EO){sub 106}(PO){sub 70}(EO){sub 106}), as the structure-directing agent. The MPS thin film prepared using P123 as the mesoporous template and treated via vacuum ultraviolet (VUV) irradiation to remove the triblock copolymer had a more uniform pore array than that of the corresponding film prepared via thermal treatment. Protein adsorption and enzyme-linked immunosorbent assay (ELISA) on the synthesized MPS thin films were also investigated. VUV-irradiated MPS thin films adsorbed a smaller quantity of protein A than the thermally treated films; however, the human immunoglobulin G (IgG) binding efficiency was higher on the former. In addition, protein A–IgG specific binding on MPS thin films was achieved without using a blocking reagent; i.e., nonspecific adsorption was inhibited by the uniform pore arrays of the films. Furthermore, VUV-irradiated MPS thin films exhibited high sensitivity for ELISA testing, and cytochrome c adsorbed on the MPS thin films exhibited high catalytic activity and recyclability. These results suggest that MPS thin films are attractive platforms for the development of novel biosensors. - Highlights: • VUV-treated MPS thin films with removed polymer had uniform pore. • VUV-treated MPS thin films exhibited high sensitivity by ELISA. • Cytochrome c showed the catalytic activity and recyclability on synthesized films.

  18. Surface textured molybdenum doped zinc oxide thin films prepared for thin film solar cells using pulsed direct current magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y.C., E-mail: ielinyc@cc.ncue.edu.tw; Wang, B.L.; Yen, W.T.; Shen, C.H.

    2011-06-01

    In this study, we examined the effect of etching on the electrical properties, transmittance, and scattering of visible light in molybdenum doped zinc oxide, ZnO:Mo (MZO) thin films prepared by pulsed direct current magnetron sputtering. We used two different etching solutions - KOH and HCl - to alter the surface texture of the MZO thin film so that it could trap light. The experimental results showed that an MZO film with a minimum resistivity of about 8.9 x 10{sup -4} {Omega} cm and visible light transitivity of greater than 80% can be obtained without heating at a Mo content of 1.77 wt.%, sputtering power of 100 W, working pressure of 0.4 Pa, pulsed frequency of 10 kHz, and film thickness of 500 nm. To consider the effect of resistivity and optical diffuse transmittance, we performed etching of an 800 nm thick MZO thin film with 0.5 wt.% HCl for 3-6 s at 300 K. Consequently, we obtained a resistivity of 1.74-2.75 x 10{sup -3} {Omega} cm, total transmittance at visible light of 67%-73%, diffuse transmittance at visible light of 25.1%-28.4%, haze value of 0.34-0.42, and thin film surface crater diameters of 220-350 nm.

  19. Preparation and Characterization of Self-Assembled Manganese Dioxide Thin Films

    Directory of Open Access Journals (Sweden)

    Suh Cem Pang

    2011-01-01

    Full Text Available Thin films of manganese dioxide (MnO2 were prepared by self-assembly of MnO2 nanoparticles directly unto nickel-coated poly(ethylene terephthalate flexible films using the newly developed horizontal submersion process. The thickness of deposited thin films was controllable by the deposition duration. This horizontal submersion deposition process for thin-film deposition is relatively easy, simple, and cost effective. Effects of deposition duration and calcination temperatures on the microstructure and electrochemical properties of self-assembled MnO2 thin films were investigated. Optimized MnO2 thin films exhibited high charge capacity, good cycling reversibility, and stability in a mild aqueous electrolyte and are thus promising electrode materials for the fabrication of thin-film electrochemical capacitors.

  20. Characterisation of Pb thin films prepared by the nanosecond pulsed laser deposition technique for photocathode application

    OpenAIRE

    Lorusso, Antonella; Gontad, F.; Broitman, Esteban; Chiadroni, E.; Perrone, Walter

    2015-01-01

    Pb thin films were prepared by the nanosecond pulsed laser deposition technique on Si (100) and polycrystalline Nb substrates for photocathode application. As the photoemission performances of a cathode are strongly affected by its surface characteristics, the Pb films were grown at different substrate temperatures with the aim of modifying the morphology and structure of thin films. An evident morphological modification in the deposited films with the formation of spherical grains at higher ...

  1. Preparation and Characterization of Nano-Structured SiO2 Thin Films on Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    Rong Chun XIONG; Dong Zhou YAN; Gang WEI

    2003-01-01

    Nano-structured SiO2 thin films were prepared on the surface of carbon steel for the first time by LPD. The compositions of the films were analyzed by XPS, and the surface morphology of the thin films were observed by AFM. The thin films were constituted by compact particles of SiO2, and there was no Fe in the films. In the process of film forming, the SiO2 colloid particles were deposited or absorbed directly onto the surface of carbon steel substrates that were activated by acid solution containing inhibitor, and corrosion of the substrates was avoided. The nano-structured SiO2 thin films that were prepared had excellent protective efficiency to the carbon steel.

  2. Low-temperature preparation of anatase thin films on tantalum.

    Science.gov (United States)

    Johnson, Scott E; Burgoon, Matthew W P; Wang, Qi; White, J M

    2006-07-18

    Titanium dioxide thin films were grown on oxidized Ta surfaces using a cyclic layer-by-layer wet chemistry method: successive-ionic-layer-adsorption-and-reaction (SILAR). Film thicknesses varied monotonically and approximately linearly with the number of cycles. As-grown (AG) films were amorphous and rougher (16.2 nm root-mean-square (rms)) than the Ta substrate (10.2 nm rms). After hydrothermal annealing (AN) at a remarkably low temperature of 393 K, the films exhibited anatase crystallites (10 nm dimensions) and reduced roughness (11.8 nm rms). The atomic composition of both AG and AN films was consistent with that of TiO2 containing no more than 4 atom % carbon. A small Si impurity (<1 atom %) was eliminated by using polypropylene beakers and sample holders in the SILAR steps.

  3. Preparation and structural properties of thin carbon films by very-high-frequency magnetron sputtering

    Institute of Scientific and Technical Information of China (English)

    高明伟; 叶超; 王响英; 何一松; 郭佳敏; 杨培芳

    2016-01-01

    Growth and structural properties of thin a-C films prepared by the 60 MHz very-high-frequency (VHF) magnetron sputtering were investigated. The energy and flux of ions impinging the substrate were also analyzed. It is found that the thin a-C films prepared by the 60 MHz sputtering have a lower growth rate, a smooth surface, and more sp3 contents. These features are related to the higher ion energy and the lower ions flux onto the substrate. Therefore, the 60 MHz VHF sputtering is more suitable for the preparation of thin a-C film with more sp3 contents.

  4. Effect of Soft-annealing on the Properties of CIGSe Thin Films Prepared from Solution Precursors

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Shijoon; Park, Misun; Kim, Daehwan; Kang, Jinkyu [Daegu Gyeongbuk Institute of Science and Technology, Daegu (Korea, Republic of)

    2013-05-15

    Solution-based deposition of CuIn{sub x}Ga{sub 1-x}Se{sub 2} (CIGSe) thin films is well known non-vacuum process for the fabrication of CIGSe solar cells. However, due to the usage of organic chemicals in the preparation of CIG precursor solutions, the crystallization of the polycrystalline CIGSe and the performance of CIGSe thin film solar cells were significantly affected by the carbon residues from the organic chemicals. In this work, we have tried to eliminate the carbon residues in the CIG precursor thin films efficiently by using soft-annealing process. By adjusting soft-annealing temperature, it is possible to control the amount of carbon residues in CIG precursor thin films. The reduction of the carbon residues in CIG precursors by high temperature soft-annealing improves the grain size and morphology of polycrystalline CIGSe thin films, which are also closely related with the electrical properties of CIGSe thin film solar cells.

  5. Thin-film preparation by back-surface irradiation pulsed laser deposition using metal powder targets

    Science.gov (United States)

    Kawasaki, Hiroharu; Ohshima, Tamiko; Yagyu, Yoshihito; Ihara, Takeshi; Yamauchi, Makiko; Suda, Yoshiaki

    2017-01-01

    Several kinds of functional thin films were deposited using a new thin-film preparation method named the back-surface irradiation pulsed laser deposition (BIPLD) method. In this BIPLD method, powder targets were used as the film source placed on a transparent target holder, and then a visible-wavelength pulsed laser was irradiated from the holder side to the substrate. Using this new method, titanium oxide and boron nitride thin films were deposited on the silicon substrate. Surface scanning electron microscopy (SEM) images suggest that all of the thin films were deposited on the substrate with some large droplets irrespective of the kind of target used. The deposition rate of the films prepared by using this method was calculated from film thickness and deposition time to be much lower than that of the films prepared by conventional PLD. X-ray diffraction (XRD) measurement results suggest that rutile and anatase TiO2 crystal peaks were formed for the films prepared using the TiO2 rutile powder target. Crystal peaks of hexagonal boron nitride were observed for the films prepared using the boron nitride powder target. The crystallinity of the prepared films was changed by annealing after deposition.

  6. Structure-stress-resistivity relationship in WTi alloy ultra-thin and thin films prepared by magnetron sputtering

    Science.gov (United States)

    Le Priol, A.; Le Bourhis, E.; Renault, P.-O.; Muller, P.; Sik, H.

    2013-06-01

    WTi thin films were prepared from an alloyed target (W:Ti ˜ 70:30 at. %) by magnetron sputtering. Body-centered cubic WxTi1-x solid solutions with a {110} fiber texture and columnar grains have been produced with 0.75WTi thin films is about 60-200 μΩ cm, depending on the film thickness and microstructure (sputtering conditions). For both ultra-thin (9.5 nm) and thin (180 nm) films, a stress transition from compressive to tensile is observed as the working pressure increases. The process-structure-property relations of the WTi ultra-thin and thin films are discussed in relation with the state of the art.

  7. Preparation of BiFeO3 thin films by pulsed laser deposition method

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guan-jun; CHENG Jin-rong; CHEN Rui; YU Sheng-wen; MENG Zhong-yan

    2006-01-01

    BiFeO3 (BFO) thin films were prepared on Pt(111)/TiO2/SiO2/Si(100) substrates by the pulsed-laser deposition (PLD) technique at a low temperature of 450℃. The XRD results indicate that the BFO thin films are of perovskite structure with the presence of small amount of second phases. The oxygen pressures have great effect on the crystalline structures and dielectric properties of BFO thin films. The dielectric constant of the BFO thin films decreases with increasing oxygen pressures,achieving 186,171 and 160 at the frequency of 104 Hz for the oxygen pressures of 0.666,1.333 and 13.332 Pa,respectively. The BFO thin films prepared at the oxygen pressure of 0.666 Pa reveal a saturated hysteresis loop with the remanent polarization of 7.5 μC/cm2 and the coercive field of 176 kV/cm.

  8. CdS thin films prepared by laser assisted chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, L.V.; Mendivil, M.I.; Garcia Guillen, G.; Aguilar Martinez, J.A. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Krishnan, B. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); CIIDIT – Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); Avellaneda, D.; Castillo, G.A.; Das Roy, T.K. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); CIIDIT – Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

    2015-05-01

    Highlights: • CdS thin films by conventional CBD and laser assisted CBD. • Characterized these films using XRD, XPS, AFM, optical and electrical measurements. • Accelerated growth was observed in the laser assisted CBD process. • Improved dark conductivity and good photocurrent response for the LACBD CdS. - Abstract: In this work, we report the preparation and characterization of CdS thin films by laser assisted chemical bath deposition (LACBD). CdS thin films were prepared from a chemical bath containing cadmium chloride, triethanolamine, ammonium hydroxide and thiourea under various deposition conditions. The thin films were deposited by in situ irradiation of the bath using a continuous laser of wavelength 532 nm, varying the power density. The thin films obtained during deposition of 10, 20 and 30 min were analyzed. The changes in morphology, structure, composition, optical and electrical properties of the CdS thin films due to in situ irradiation of the bath were analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV–vis spectroscopy. The thin films obtained by LACBD were nanocrystalline, photoconductive and presented interesting morphologies. The results showed that LACBD is an effective synthesis technique to obtain nanocrystalline CdS thin films having good optoelectronic properties.

  9. Preparation and characterization of DC sputtered molybdenum thin films

    Directory of Open Access Journals (Sweden)

    Abd El-Hady B. Kashyout

    2011-03-01

    Full Text Available Molybdenum (Mo thin films have been deposited on soda-lime glass substrates using a DC magnetron sputtering system. Their electrical resistivity, and their morphological, structural and adhesive properties have been examined with respect to the deposition power, deposition time and substrate temperature. The electrical resistivity of the Mo films could be reduced by increasing any of the above parameters. Within the range of the investigated deposition parameters, the films showed a mono-crystalline nature with a preferred orientation along the (1 1 0 plane. The Mo films adhesion to the soda-lime glass could be improved by increasing the substrate temperature. At a deposition power of 200 W, deposition time of 20 min and substrate temperature of 450 °C, Mo thin film exhibiting mono-crystalline structure with thickness equal to 450 nm and electrical resistivity equal to 1.85 × 10−4 Ω cm was obtained.

  10. Raman spectroscopy of chalcogenide thin films prepared by PLD

    Energy Technology Data Exchange (ETDEWEB)

    Erazu, M.; Rocca, J. [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, Universidad de Buenos Aires - CONICET, Paseo Colon 850, 1063 Buenos Aires (Argentina); Fontana, M., E-mail: merazu@fi.uba.a [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, Universidad de Buenos Aires - CONICET, Paseo Colon 850, 1063 Buenos Aires (Argentina); Urena, A.; Arcondo, B. [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, Universidad de Buenos Aires - CONICET, Paseo Colon 850, 1063 Buenos Aires (Argentina); Pradel, A. [ICG, UMR 5253 CNRS UM 2 ENSCM UM1 equipe PMDP CC3, Universite Montpellier 2, 34095 Montpellier Cedex 5 (France)

    2010-04-16

    Chalcogenide glasses have many technological applications as a result of their particular optical and electrical properties. Ge-Se and Ag-Ge-Se systems were recently studied and tested as new materials for building non-volatile memories. Following these ideas, thin films of Ge-Se and Ag-Ge-Se were deposited using pulsed laser deposition (PLD). Ag was sputtered over binary films (for a composition between 0.05 and 0.25 Ag atomic fraction) and photo-diffused afterwards. Thus, three kinds of samples were analyzed by means of Raman spectroscopy, in order to provide information on the short- and medium-range order: PLD binary films before Ag doping, after Ag doping and PLD ternary films. Before Ag doping, binary films exhibited Ge-Se corner-sharing tetrahedra modes at 190 cm{sup -1}, low scattering from edge-sharing tetrahedra at 210 cm{sup -1}, and Se chains at 260 cm{sup -1} (stretching mode). However, after the diffusion process was complete, we observed an intensity reduction of bands centered at 210 cm{sup -1} and 260 cm{sup -1}. The spectra of the photo-diffused films were similar to those of films deposited using a ternary target. Relaxation effects in binary glasses were also analyzed. Results were compared with those of other authors.

  11. Preparation and Properties of Ag-TiO2 Thin Films on Glass Substrates

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Ag-TiO2 thin films were prepared on glasses.The morphology and structure of Ag-TiO2 films were investigated by XRD, SEM and FT-IR.The photocatalytic and hydrophilic properties of Ag-TiO2 thin films were also evaluated by examining photocatalytic degradation dichlorophos under sunlight illumination and the change of contact angle respectively.The research results show that the Ag-TiO2 thin film is mainly composed of 20-100nm Ag and TiO2 particles.The Ag-TiO2 thin films possess a super-hydrophilic ability and higher photocatalytic activity than that of pure TiO2 thin film.

  12. Thin Films with Low Zn Content Prepared by Chemical Bath Deposition

    Directory of Open Access Journals (Sweden)

    Caijuan Tian

    2012-01-01

    Full Text Available Chemical bath deposition (CBD was used for the growth of thin films with low Zn content. The influence of preparation conditions, such as pH, temperature, and concentration, on film properties was investigated. The chemical growth mechanism of thin films was analyzed, and optimized growth conditions for the thin films were established. The fill factor and short-circuit current were improved while was used to replace CdS as the window layer in CdTe solar cells.

  13. Preparation and evaluation of thin-film sodium tungsten bronzes

    Science.gov (United States)

    Kautz, H. E.; Fielder, W. L.; Singer, J.; Fordyce, J. S.

    1974-01-01

    Thin films of sodium tungsten bronze (NaxWO3) were investigated as reversible sodium ion electrodes for solid electrolytes. The films were made by electron beam evaporation of the three phases, W metal, Na2WO4, and WO3, followed by sintering. The substrates were sodium beta alumina disks and glass slides. X-ray diffraction analyses of the films showed that sintering in dry nitrogen with prior exposure to air lead to mixed phases. Sintering in vacuum with no air exposure produced tetragonal I bronze with a nominal composition of Na0.31WO3, single phase within the limits of X-ray diffraction detectability. The films were uniform and adherent on sodium beta alumina substrates. The ac and dc conductivities of the beta alumina were measured with the sodium tungsten bronze films as electrodes. These experiments indicated that the tetragonal I bronze electrodes were not completely reversible. This may have resulted from sodium ion blocking within the bronze film or at the bronze beta alumina interface. Methods for attempting to make more completely reversible electrodes are suggested.

  14. [Preparation and spectral characterization of CdS(y)Te(1-y) thin films].

    Science.gov (United States)

    Li, Wei; Feng, Liang-Huan; Wu, Li-Li; Zhang, Jing-Quan; Li, Bing; Lei, Zhi; Cai, Ya-Ping; Zheng, Jia-Gui; Cai, Wei; Zhang, Dong-Min

    2008-03-01

    CdS(y)Te(1-y) (0 thin films were prepared on glass substrates by co-evaporation of powders of CdTe and CdS. For the characterization of the structure and composition of the CdS(y)Te(1-y) thin films the X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) were used. The results indicate that the values of sulfur content y detected and controlled by the quartz wafer detector show good agreement with the EDS results. The films were found to be cubic for x or = 0.3. The 20-50 nm of grain sizes for CdS(y)Te(1-y) thin films were calculated using a method of XRD analysis. Finally, the optical properties of CdS(y)Te(1-y) thin films were characterized by UV-Vis-NIR spectroscopy alone. According to a method from Swanepoel, together with the first-order Sellmeier model, the thickness, of d-535 nm, energy gap of E(g)-1.41 eV, absorption coefficient, alpha(lambda) and refractive index, n(lambda) of CdS(0.22) Te(0.78) thin films were determined from the transmittance at normal incidence of light in the wavelength range 300-2 500 nm. The results also indicate that the CdS(y)Te(1-y) thin films with any composition (0 thin films can be implemented for other semiconductor thin films.

  15. Preparation and properties of CuInS{sub 2} thin film prepared from electroplated precursor

    Energy Technology Data Exchange (ETDEWEB)

    Onuma, Yoshio; Takeuchi, Kenji; Ichikawa, Sumihiro; Suzuki, Yasunari; Fukasawa, Ryo; Matono, Daisuke; Nakamura, Kenji; Nakazawa, Masao; Takei, Koji [Core Technology Research Laboratory, Shinko Electric Industries Co., Ltd., 80 Oshimada, Nagano 381-2287 (Japan)

    2006-01-15

    Thin CuInS{sub 2} films were prepared by sulfurization of Cu/In bi-layers. First, the precursor layer was electroplated onto the treated surface of Mo-coated glass. Observation of the cross-section prepared by focused ion beam (FIB) etching revealed that the void-free film was initially formed on the top surface of the precursor layer and continued to grow until the advancing front of the film reached the Mo layer. The nucleation of voids near the bottom of the CuInS{sub 2} film followed. To determine whether the condition of the Cu/In alloy influences the CuInS{sub 2} quality we investigated the Cu/In alloy state using FIB. We found that the annealed precursor of low Cu/In ratio (1.2) has several voids in the mid position in the layer compared with Cu-rich precursor (1.6). The cross-sectional view of the Cu-rich absorber layer is uniform compared with the low copper absorber layer. Thin film solar cells were fabricated using the CuInS{sub 2} film (Cu/In ratio: 1.2) as an optical absorber layer. It was found that the optimization of a sulfurization period is important in order to improve the cell efficiency. We have not yet obtained good results with high Cu-rich absorber because of a blister problem. This blister was found before sulfurization. So, we are going to solve this blister problem before sulfurization.

  16. Ferroelectric-Like Properties of Amorphous Metal Oxide Thin Films Prepared by Sol-Gel Technique.

    Science.gov (United States)

    Xu, Yuhuan

    1995-01-01

    Advances in the field of both optical and electrical integrated circuit devices require new thin film materials. Ferroelectric materials have attractive properties such as hysteresis behavior, pyroelectricity, piezoelectricity and nonlinear optical properties. Many ferroelectric thin films have been successfully prepared from metal organic compounds via sol-gel processing. Thus far, research has concentrated upon polycrystalline or epitaxial ferroelectric films. For amorphous ferroelectric thin films, preliminary experimental results in our laboratory indicated that these amorphous films possessed good ferroelectric -like properties. The purpose of this research is (1) to fabricate amorphous metal oxide thin films by the sol-gel technique, (2) to determine whether these amorphous metal oxide thin films have ferroelectric-like properties and (3) to propose a theoretical model ("ferrons model") to explain the ferroelectric-like properties of amorphous thin films, which deals with a structure of permanent dipoles of "partially ordered clusters" (ferrons) in the amorphous films. The theoretical model is based on our experimental results of thin films of two amorphous materials (barium titanite and lead zirconate titanate). This research may provide a new functional material which could be useful for producing integrated electronic and electrooptic devices.

  17. The preparation, processing and properties of thin and thick films for microelectric applications

    Science.gov (United States)

    Bagley, B. G.; Greene, L. H.; Barboux, P.; Tarascon, J. M.; Venkatesan, T.

    High-Tc thin and thick films of YBa2Cu2O(7-y) and thick films based on the Bi-Sr-Ca-Cu and Tl-Ba-Ca-Cu systems were prepared and their properties investigated. It was found that YB2Cu3O(7-y) thin films prepared at temperatures up to 400 C, have amorphous structures, and those prepared in the 400-650 C region exhibit polyphase microstructure, due to the rapid crystallization kinetics of the competing phases. Methods for bipassing the 'forbidden' temperature region are described. Preparation of YBa2Cu2O(7-y) thick films was achieved via an aqueous sol-gel technique. Bi-Sr-Ca-Cu- and Tl-Ba-Ca-Cu-based thick films were prepared via the decomposition of glycerol-based solutions containing nitrates of the elements.

  18. Preparation of Ag-doped TiO2 Thin Film by Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Ag-TiO2 thin film has been prepared on glass substrate by sol-gel process. The structure and properties of the materials were studied by DTA, XRD, and EPR.The photocatalytic activity was examined by the photocatalytic degradation of dichlorophos. The analysis results indicate that the photocatalytic activity of the Ag-TiO2 thin film is higher than that of pure TiO2 thin film. It is also influenced by the content of anatase and heating temperature. The ESR result shows that the Ag-TiO2 thin film has more hydroxide radicals than pure TiO2 thin film after illuminated by UV light.

  19. Disinfection studies on TiO2 thin films prepared by a sol-gel method.

    Science.gov (United States)

    Kambala, Venkata Subba Rao; Naidu, Ravi

    2009-02-01

    Transparent anatase TiO2 nanometer thin films were prepared by dip-coating on soda-lime glass plates via the sol-gel method. The un-calcined and the calcined films were characterized by X-ray diffraction (XRD), AFM, Nano-indentation (hardness and Young's modulus), UV-vis spectrometry, thickness and hydrophilicity (contact angle measurements). The photocatalytic activity of the thin films was evaluated by performing disinfection studies on the Gram-negative microorganisms like Escherichia coli, and Staphylococcus Aureus, a Gram-positive organism. The photocatalytic activity for both groups of organisms was studied in saline and nutrient broth. The leakage of potassium from the bacteria was observed parallel to cell viability. The activity of the sol-gel prepared TiO2 thin films were compared under UV lamps and natural day light (ND) lamps with Degussa P-25 TiO2 thin films prepared on soda-lime glass using a polymer support and the commercial self-cleaning glass (SC). The sol-gel prepared thin films which were annealed at 450 degrees C, show highest photocatalytic activity, the slowest conversion rate from hydrophilic to a hydrophobic state, light-induced hydrophilicity, and also higher disinfection activities compared to P-25 films and commercial self-cleaning glass. The films also show excellent activities when continuously reused for more than a month.

  20. Electrochromic NiO thin films prepared by spin coating

    Science.gov (United States)

    Özütok, F.; Demiri, S.; Özbek, E.

    2017-02-01

    Recently, smart windows are very important because they are often being used in smart buildings and car glasses (windows). At this point, producing effective electrochromic materials is so necessary. In this study, we produced NiO thin films by using spin coating technique on In-doped SnO2 (ITO) substrate. Nickel proportions of these nickel oxide (NiO) films are 3, 5 and 7 %. Nickel acetate tetrahydrate is the initial solution and solvents are ethylene gl ycol and n-hexzane. Structural properties and surface images are investigated by using x-ray diffactometer (XRD) and scanning electron microscope (SEM) device, respectively. In addition, electrochemical behavior is investigated by cyclic voltammetry. A correlation between surface morphology and electrochromic performance was observed as well.

  1. Preparation and characterization of tungsten diselenide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Pouzet, J.; Bernede, J.C. (Lab. de Physique des Materiaux pour l' Electronique, Faculte des Sciences et des Techniques, 44 - Nantes (France)); Khellil, A. (Lab. de Micro-Optoelectronique, Univ. d' Oran-Es-Senia (Algeria)); Essaidi, H.; Benhida, S. (Lab. de Physique des Materiaux pour l' Electronique, Faculte des Sciences et des Techniques, 44 - Nantes (France))

    1992-02-28

    WSe{sub 2} layers synthesized by annealing tungsten foils and r.f.-sputtered tungsten thin films under selenium pressure have been investigated by scanning electron microscopy, X-ray analysis, X-ray photoelectron spectroscopy (XPS), optical absorption and electrical resistance measurements. It has been found that stoichiometric layers are obtained after appropriate processing at a temperature lower than the glass melting temperature. The films crystallize in the hexagonal structure. The crystallites develop preferentially along the c axis. The binding energies deduced from the XPS lines were found to be in good agreement with those of the reference powder. The electrical resistance is governed by hopping conduction in the low temperature range (80-250 K) and by grain-boundary-scattering mechanisms at higher temperature. (orig.).

  2. Preparation of Cu{sub 2}ZnSnS{sub 4} thin films by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction method

    Energy Technology Data Exchange (ETDEWEB)

    Su Zhenghua; Yan Chang; Sun Kaiwen; Han Zili [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Liu Fangyang, E-mail: liufangyang@csu.edu.cn [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Liu Jin [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Lai Yanqing, E-mail: laiyanqingcsu@163.com [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Li Jie; Liu Yexiang [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China)

    2012-07-15

    Earth-abundant Cu{sub 2}ZnSnS{sub 4} is a promising alternative photovoltaic material which has been examined as absorber layer of thin film solar cells. In this study, Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films have been successfully fabricated by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction (SILAR) method. The prepared CZTS thin films have been characterized by X-ray diffraction, energy dispersive spectrometer, Raman spectroscopy, UV-vis spectroscopy, Hall effect measurements and photoelectrochemical tests. Results reveal that the thin films have kesterite structured Cu{sub 2}ZnSnS{sub 4} and the p-type conductivity with a carrier concentration in the order of 10{sup 18} cm{sup -3} and an optical band gap of 1.5 eV, which are suitable for applications in thin film solar cells.

  3. Preparation of Cu2ZnSnS4 thin films by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction method

    Science.gov (United States)

    Su, Zhenghua; Yan, Chang; Sun, Kaiwen; Han, Zili; Liu, Fangyang; Liu, Jin; Lai, Yanqing; Li, Jie; Liu, Yexiang

    2012-07-01

    Earth-abundant Cu2ZnSnS4 is a promising alternative photovoltaic material which has been examined as absorber layer of thin film solar cells. In this study, Cu2ZnSnS4 (CZTS) thin films have been successfully fabricated by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction (SILAR) method. The prepared CZTS thin films have been characterized by X-ray diffraction, energy dispersive spectrometer, Raman spectroscopy, UV-vis spectroscopy, Hall effect measurements and photoelectrochemical tests. Results reveal that the thin films have kesterite structured Cu2ZnSnS4 and the p-type conductivity with a carrier concentration in the order of 1018 cm-3 and an optical band gap of 1.5 eV, which are suitable for applications in thin film solar cells.

  4. Properties of TiO2 Thin Films Prepared by Magnetron Sputtering

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With rapid progressive application of TiO2 thin films, magnetron sputtering becomes a very interesting method to prepare such multi-functional thin films. This paper focuses on influences of various deposition processes and deposition rate on the structures and properties of TiO2 thin films. Anatase, rutile or amorphous TiO2 films with various crystalline structures and different photocatalytic, optical and electrical properties can be produced by varying sputtering gases, substrate temperature, annealing process, deposition rate and the characteristics of magnetron sputtering. This may in turn affect the functions of TiO2 films in many applications. Furthermore, TiO2-based composites films can overcome many limitations and improve the properties of TiO2 films.

  5. Thin Films

    Directory of Open Access Journals (Sweden)

    M. Benmouss

    2003-01-01

    the optical absorption are consistent with the film color changes. Finally, the optical and electrochromic properties of the films prepared by this method are compared with those of our sputtered films already studied and with other works.

  6. Characterisation of Pb thin films prepared by the nanosecond pulsed laser deposition technique for photocathode application

    Energy Technology Data Exchange (ETDEWEB)

    Lorusso, A., E-mail: antonella.lorusso@le.infn.it [Dipartimento di Matematica e Fisica “E. De Giorgi” and Istituto Nazionale di Fisica Nucleare, Università del Salento, Lecce 73100 (Italy); Gontad, F. [Dipartimento di Matematica e Fisica “E. De Giorgi” and Istituto Nazionale di Fisica Nucleare, Università del Salento, Lecce 73100 (Italy); Broitman, E. [Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping SE-581 83 (Sweden); Chiadroni, E. [Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare, Frascati 00044 (Italy); Perrone, A. [Dipartimento di Matematica e Fisica “E. De Giorgi” and Istituto Nazionale di Fisica Nucleare, Università del Salento, Lecce 73100 (Italy)

    2015-03-31

    Pb thin films were prepared by the nanosecond pulsed laser deposition technique on Si (100) and polycrystalline Nb substrates for photocathode application. As the photoemission performances of a cathode are strongly affected by its surface characteristics, the Pb films were grown at different substrate temperatures with the aim of modifying the morphology and structure of thin films. An evident morphological modification in the deposited films with the formation of spherical grains at higher temperatures has been observed. X-ray diffraction measurements showed that a preferred orientation of Pb (111) normal to the substrate was achieved at 30 °C while the Pb (200) plane became strongly pronounced with the increase in the substrate temperature. Finally, a Pb thin film deposited on Nb substrate at 30 °C and tested as the photocathode showed interesting results for the application of such a device in superconducting radio frequency guns. - Highlights: • Pb thin films obtained by the nanosecond pulsed laser deposition technique at different substrate temperature. • The substrate temperature modifies the morphology and structure of Pb films. • Pb thin film was deposited at room temperature for photocathode application. • The Pb thin film photocathode was tested and the quantum efficiency of the device improved after laser cleaning treatment of the film surface.

  7. Antimicrobial activity of thin solid films of silver doped hydroxyapatite prepared by sol-gel method.

    Science.gov (United States)

    Iconaru, Simona Liliana; Chapon, Patrick; Le Coustumer, Philippe; Predoi, Daniela

    2014-01-01

    In this work, the preparation and characterization of silver doped hydroxyapatite thin films were reported and their antimicrobial activity was characterized. Silver doped hydroxyapatite (Ag:HAp) thin films coatings substrate was prepared on commercially pure Si disks by sol-gel method. The silver doped hydroxyapatite thin films were characterized by various techniques such as Scanning electron microscopy (SEM) with energy Dispersive X-ray attachment (X-EDS), Fourier transform infrared spectroscopy (FT-IR), and glow discharge optical emission spectroscopy (GDOES). These techniques have permitted the structural and chemical characterisation of the silver doped hydroxyapatite thin films. The antimicrobial effect of the Ag:HAp thin films on Escherichia coli and Staphylococcus aureus bacteria was then investigated. This is the first study on the antimicrobial effect of Ag:HAp thin films obtained by sol-gel method. The results of this study have shown that the Ag:HAp thin films with x(Ag) = 0.5 are effective against E. coli and S. aureus after 24 h.

  8. Antimicrobial Activity of Thin Solid Films of Silver Doped Hydroxyapatite Prepared by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Simona Liliana Iconaru

    2014-01-01

    Full Text Available In this work, the preparation and characterization of silver doped hydroxyapatite thin films were reported and their antimicrobial activity was characterized. Silver doped hydroxyapatite (Ag:HAp thin films coatings substrate was prepared on commercially pure Si disks by sol-gel method. The silver doped hydroxyapatite thin films were characterized by various techniques such as Scanning electron microscopy (SEM with energy Dispersive X-ray attachment (X-EDS, Fourier transform infrared spectroscopy (FT-IR, and glow discharge optical emission spectroscopy (GDOES. These techniques have permitted the structural and chemical characterisation of the silver doped hydroxyapatite thin films. The antimicrobial effect of the Ag:HAp thin films on Escherichia coli and Staphylococcus aureus bacteria was then investigated. This is the first study on the antimicrobial effect of Ag:HAp thin films obtained by sol-gel method. The results of this study have shown that the Ag:HAp thin films with xAg=0.5 are effective against E. coli and S. aureus after 24 h.

  9. Structural and Optoelectrical Properties of ZnTe Thin Films Prepared by E-Beam Evaporation

    Science.gov (United States)

    Zia, Rehana; Saleemi, Farhat; Riaz, Madeeha; Nassem, Shahzad

    2016-10-01

    ZnTe thin films have been prepared by an electron-beam evaporation technique on glass substrates, changing the accelerating voltage and the substrate temperature at accelerating voltage of 2 kV. Structural analysis showed that all the films had cubic structure with preferential orientation along (111) direction, though (220) and (311) orientations were also present. The (111) peak intensity increased with increasing film thickness. The crystallite size increased with increasing film thickness. Conductivity measurements showed that the films were p-type. Films prepared at accelerating voltage of 2 kV exhibited minimum resistivity. Optical characterization indicated that both absorbing and transparent thin films can be achieved by using different deposition conditions. The optical bandgap value was found to vary with substrate temperature.

  10. Structural characterization of supported nanocrystalline ZnO thin films prepared by dip-coating

    Energy Technology Data Exchange (ETDEWEB)

    Casanova, J.R. [CITEDEF-CINSO-CONICET Centro de Investigaciones en Solidos, Juan B. de La Salle 4397, B1603ALO, Villa Martelli, Buenos Aires (Argentina); Heredia, E.A., E-mail: eheredia@citedef.gob.ar [CITEDEF-CINSO-CONICET Centro de Investigaciones en Solidos, Juan B. de La Salle 4397, B1603ALO, Villa Martelli, Buenos Aires (Argentina); Bojorge, C.D.; Canepa, H.R. [CITEDEF-CINSO-CONICET Centro de Investigaciones en Solidos, Juan B. de La Salle 4397, B1603ALO, Villa Martelli, Buenos Aires (Argentina); Kellermann, G. [Departamento de Fisica, Universidade Federal do Parana, Curitiba, PR (Brazil); Craievich, A.F. [Instituto de Fisica, Universidade de Sao Paulo, Cidade Universitaria, Sao Paulo, SP (Brazil)

    2011-09-15

    Nanocrystalline ZnO thin films prepared by the sol-gel dip-coating technique were characterized by grazing incidence X-ray diffraction (GIXD), atomic force microscopy (AFM), X-ray reflectivity (XR) and grazing incidence small-angle X-ray scattering (GISAXS). The structures of several thin films subjected to (i) isochronous annealing at 350, 450 and 550 deg. C, and (ii) isothermal annealing at 450 deg. C during different time periods, were characterized. The studied thin films are composed of ZnO nanocrystals as revealed by analysing several GIXD patterns, from which their average sizes were determined. Thin film thickness and roughness were determined from quantitative analyses of AFM images and XR patterns. The analysis of XR patterns also yielded the average density of the studied films. Our GISAXS study indicates that the studied ZnO thin films contain nanopores with an ellipsoidal shape, and flattened along the direction normal to the substrate surface. The thin film annealed at the highest temperature, T = 550 deg. C, exhibits higher density and lower thickness and nanoporosity volume fraction, than those annealed at 350 and 450 deg. C. These results indicate that thermal annealing at the highest temperature (550 deg. C) induces a noticeable compaction effect on the structure of the studied thin films.

  11. Preparation and characterization of ZnTe thin films by SILAR method

    Energy Technology Data Exchange (ETDEWEB)

    Kale, S.S. [Inorganic Nano-Materials Laboratory, Department of Chemistry, Hanyang University, Sungdong-Ku, Seoul 133-791 (Korea, Republic of); Mane, R.S. [Inorganic Nano-Materials Laboratory, Department of Chemistry, Hanyang University, Sungdong-Ku, Seoul 133-791 (Korea, Republic of); Pathan, H.M. [Eco-Nano Research Centre, Korea Institute of Science and Technology, P.O. Box 131, Chongryang, Seoul 130-650 (Korea, Republic of); Shaikh, A.V. [AKI' s Poona College of Arts, Science and Commerce, Pune (India); Joo, Oh-Shim [Eco-Nano Research Centre, Korea Institute of Science and Technology, P.O. Box 131, Chongryang, Seoul 130-650 (Korea, Republic of); Han, Sung-Hwan [Inorganic Nano-Materials Laboratory, Department of Chemistry, Hanyang University, Sungdong-Ku, Seoul 133-791 (Korea, Republic of)]. E-mail: shhan@hanyang.ac.kr

    2007-02-28

    Nanocrystalline zinc telluride (ZnTe) thin films were prepared by using successive ionic layer adsorption and reaction (SILAR) method from aqueous solutions of zinc sulfate and sodium telluride. The films were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis and optical absorption measurement techniques. The synthesized ZnTe thin films were nanocrystalline with densely aggregated particles in nanometer scale and were free from the voids or cracks. The optical band gap energy of the film was found to be thickness dependent. The elemental chemical compositional stoichiometric analysis revealed good Zn:Te elemental ratio of 53:47.

  12. Preparation and characterization of ZnTe thin films by SILAR method

    Science.gov (United States)

    Kale, S. S.; Mane, R. S.; Pathan, H. M.; Shaikh, A. V.; Joo, Oh-Shim; Han, Sung-Hwan

    2007-02-01

    Nanocrystalline zinc telluride (ZnTe) thin films were prepared by using successive ionic layer adsorption and reaction (SILAR) method from aqueous solutions of zinc sulfate and sodium telluride. The films were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis and optical absorption measurement techniques. The synthesized ZnTe thin films were nanocrystalline with densely aggregated particles in nanometer scale and were free from the voids or cracks. The optical band gap energy of the film was found to be thickness dependent. The elemental chemical compositional stoichiometric analysis revealed good Zn:Te elemental ratio of 53:47.

  13. Preparation of silica thin films by novel wet process and study of their optical properties.

    Science.gov (United States)

    Im, Sang-Hyeok; Kim, Nam-Jin; Kim, Dong-Hwan; Hwang, Cha-Won; Yoon, Duck-Ki; Ryu, Bong-Ki

    2012-02-01

    Silicon dioxide (SiO2) thin films have gained considerable attention because of their various industrial applications. For example, SiO2 thin films are used in superhydrophilic self-cleaning surface glass, UV protection films, anti-reflection coatings, and insulating materials. Recently, many processes such as vacuum evaporation, sputtering, chemical vapor deposition, and spin coating have been widely applied to prepare thin films of functionally graded materials. However, these processes suffer from several engineering problems. For example, a special apparatus is required for the deposition of films, and conventional wet processes are not suitable for coating the surfaces of substrates with a large surface area and complex morphology. In this study, we investigated the film morphology and optical properties of SiO2 films prepared by a novel technique, namely, liquid phase deposition (LPD). Images of the SiO2 films were obtained by scanning electron microscopy (SEM) and atomic force microscopy (AFM) in order to study the surface morphology of these films: these images indicate that films deposited with different reaction times were uniform and dense and were composed of pure silica. Optical properties such as refractive index and transmittance were estimated by UV-vis spectroscopy and ellipsometry. SiO2 films with porous structures at the nanometer scale (100-250 nm) were successfully produced by LPD. The deposited film had excellent transmittance in the visible wavelength region.

  14. Faraday effect of bismuth iron garnet thin film prepared by mist CVD method

    Science.gov (United States)

    Yao, Situ; Sato, Takafumi; Kaneko, Kentaro; Murai, Shunsuke; Fujita, Koji; Tanaka, Katsuhisa

    2015-06-01

    Metastable bismuth iron garnet (BIG, an abbreviation of Bi3Fe5O12), one kind of garnet-type ferrites, is known to manifest very large Faraday rotation as well as low optical absorption in the visible to infrared region. We report on successful synthesis of thin film composed of single-phase BIG epitaxially grown on single-crystalline gadolinium gallium garnet (Gd3Ga5O12, GGG) substrate by using mist chemical vapor deposition (CVD) method, which is an emerging technique for preparation of thin films. The crystal structure, surface morphology, and magnetic, optical and magneto-optical properties of the resultant thin films have been explored. The BIG thin film has a relatively flat surface free from roughness compared to those prepared by other vapor deposition methods. Saturation magnetization is about 1620 G at room temperature, which is close to that expected from the ideal magnetic structure of BIG. The maximum value of Faraday rotation angle reaches 54.3 deg/µm at a wavelength of 424 nm. This value is rather large when compared with those reported for BIG thin films prepared by other techniques. The wavelength dependence of Faraday rotation angle is analyzed well in terms of the crystal electric field (CEF) level schema. Our result suggests that the mist CVD method is a simple and effective technique to synthesize BIG thin film with excellent magneto-optical properties.

  15. Preparation of TiO2 Thin Film and Its Antibacterial Activity

    Institute of Scientific and Technical Information of China (English)

    XU Wei-guo; CHEN An-min; ZHANG Qiang

    2004-01-01

    TiO2 nanometer thin films with photocatalytic antibacterial activity were prepared by the sol-gelmethod on fused quartz and soda lime glass precoated with a SiO2 layer. The thin films were characterized by X-ray photoelectron spectroscopy ( XPS ), scanning electron microscopy (SEM), and X- ray diffraction ( XRD ). Theresults show that sodium and calcium diffusion into nascent TiO2 film is effectively retarded by the SiO2 layer pre-coated on the soda lime glass. The antibacterial activity of the films was determined. The crystalline of TiO2 nano-meter thin film has important effects on the antibacterial activity of the film.

  16. Preparation and characterization of nanostructured CuO thin films for photoelectrochemical splitting of water

    Indian Academy of Sciences (India)

    Diwakar Chauhan; V R Satsangi; Sahab Dass; Rohit Shrivastav

    2006-12-01

    Nanostructured copper oxide thin films (CuO) were prepared on conducting glass support (SnO2: F overlayer) via sol–gel starting from colloidal solution of copper (II) acetate in ethanol. Films were obtained by dip coating under room conditions (temperature, 25–32°C) and were subsequently sintered in air at different temperatures (400–650°C). The evolution of oxide coatings under thermal treatment was studied by glancing incidence X-ray diffraction and scanning electron microscopy. Average particle size, resistivity and band gap energy were also determined. Photoelectrochemical properties of thin films and their suitability for splitting of water were investigated. Study suggests that thin films of CuO sintered at lower temperatures (≈ 400°C) are better for photoconversion than thick films or the films sintered at much higher temperatures. Plausible explanations have been provided.

  17. Preparation and characterization of nanostructured Pt/TiO2 thin films treated using electron beam.

    Science.gov (United States)

    Shin, Joong-Hyeok; Woo, Hee-Gweon; Kim, Bo-Hye; Lee, Byung Cheol; Jun, Jin

    2010-05-01

    Pt nanoparticle-doped titanium dioxide (Pt/TiO2) thin films were prepared on a silicon wafer substrate by sol-gel spin coating process. The prepared thin films were treated with electron beam (EB at 1.1 MeV, 100, 200, 300 kGy) at air atmosphere. The effect of EB-irradiation on the composition of the treated thin films, optical properties and morphology of thin films were investigated by various analytical techniques such as X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry (SE), X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The crystal structure of the TiO2 layer was found to be an anatase phase and the size of TiO2 particles was determined to be about 13 nm. Pt nanoparticles with diameter of 5 nm were observed on surface of the films. A new layer (presumed to be Pt-Ti complex and/or PtO2 compound) was created in the Pt/TiO2 thin film treated with EB (300 kGy). The transmittance of thin film decreased with EB treatment whereas the refractive index increased.

  18. Preparation and investigation of bulk and thin film samples of strontium ferrite

    Directory of Open Access Journals (Sweden)

    A Poorbafrani

    2008-07-01

    Full Text Available   In this article, bulk and thin film samples of strontium ferrite have been studied. Due to the high electrical resistivity in strontium ferrite, energy loss due to eddy currents reduces and because of this, it can be used in high frequency magnetic circuits. On the other hand, strontium ferrite has attracted much attention as a permanent magnet. At first, we study the preparation process of bulk samples of strontium ferrite by a solid state reaction technique. In preparation of samples, to optimize the magnetic properties, we have used the stoichiometry factor (n = Fe2O3 / SrO of 5.25. In addition, we have used additives such as CaO and SiO2 to control grain growth. The samples have been prepared in two series: Isotropic and Anisotropic. For preparation of anisotropic samples, the magnetic field of 1T has been used for orientation of the grains during the press. Then, X-ray diffraction, Scanning Electron Microscopy (SEM, EDAX analysis and Magnetometer, was used for analyzing and comparing of structural and magnetic properties of isotropic and anisotropic samples. The results indicate that, due to the applied magnetic field, the structural and Magnetic properties of anisotropic samples improved efficiently because of the orientation of the grains during the press. In the next stage, we used bulk samples to prepare strontium ferrite thin films by Pulsed Laser Deposition technique (PLD. The Si (111 substrate has been used to prepare the thin films. Then we have studied the microstructure of thin films by X-ray diffraction, SEM and EDAX analysis. These studies on different samples show that for the preparation of crystalline phase of strontium ferrite thin films, the substrate temperature must be higher than 800˚C. The optimum conditions for preparation of strontium, ferrite thin films have been achieved on the substrate temperature of 840˚C and oxygen pressure of 75 mtorr.

  19. Preparation of LiMn{sub 2}O{sub 4} cathode thin films for thin film lithium secondary batteries by a mist CVD process

    Energy Technology Data Exchange (ETDEWEB)

    Tadanaga, Kiyoharu, E-mail: tadanaga@chem.osakafu-u.ac.jp [Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, Sakai, Osaka, 599-8531 (Japan); Yamaguchi, Akihiro; Sakuda, Atsushi; Hayashi, Akitoshi; Tatsumisago, Masahiro [Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, Sakai, Osaka, 599-8531 (Japan); Duran, Alicia; Aparacio, Mario [Instituto de Cerámica y Vidrio, Consejo Superior de Investigaciones Científicas, Kelsen 5 (Campus de Cantoblanco), Madrid, 28049 (Spain)

    2014-05-01

    Highlights: • LiMn{sub 2}O{sub 4} thin films were prepared by using the mist CVD process. • An aqueous solution of lithium and manganese acetates is used for the precursor solution. • The cell with the LiMn{sub 2}O{sub 4} thin films exhibited a capacity of about 80 mAh/g. • The cell showed good cycling performance during 10 cycles. - Abstract: LiMn{sub 2}O{sub 4} cathode thin films for thin film lithium secondary batteries were prepared by using so-called the “mist CVD process”, employing an aqueous solution of lithium acetate and manganese acetate, as the source of Li and Mn, respectively. The aqueous solution of starting materials was ultrasonically atomized to form mist particles, and mists were transferred by nitrogen gas to silica glass substrate to form thin films. FE-SEM observation revealed that thin films obtained by this process were dense and smooth, and thin films with a thickness of about 750 nm were obtained. The electrochemical cell with the thin films obtained by sintering at 700 °C exhibited a capacity of about 80 mAh/g, and the cell showed good cycling performance during 10 cycles.

  20. Amorphous Indium Selenide Thin Films Prepared by RF Sputtering: Thickness-Induced Characteristics.

    Science.gov (United States)

    Han, Myoung Yoo; Park, Yong Seob; Kim, Nam-Hoon

    2016-05-01

    The influence of indium composition, controlled by changing the film thickness, on the optical and electrical properties of amorphous indium selenide thin films was studied for the application of these materials as Cd-free buffer layers in CI(G)S solar cells. Indium selenide thin films were prepared using RF magnetron sputtering method. The indium composition of the amorphous indium selenide thin films was varied from 94.56 to 49.72 at% by increasing the film thickness from 30 to 70 nm. With a decrease in film thickness, the optical transmittance increased from 87.63% to 96.03% and Eg decreased from 3.048 to 2.875 eV. Carrier concentration and resistivity showed excellent values of ≥1015 cm(-3) and ≤ 10(4) Ω x cm, respectively. The conductivity type of the amorphous indium selenide thin films could be controlled by changing the film-thickness-induced amount of In. These results indicate the possibility of tuning the properties of amorphous indium selenide thin films by changing their composition for use as an alternate buffer layer material in CI(G)S solar cells.

  1. Preparation of Cu2ZnSnS4 thin films by hybrid sputtering

    Science.gov (United States)

    Tanaka, Tooru; Nagatomo, Takeshi; Kawasaki, Daisuke; Nishio, Mitsuhiro; Guo, Qixin; Wakahara, Akihiro; Yoshida, Akira; Ogawa, Hiroshi

    2005-11-01

    In order to fabricate Cu2ZnSnS4 thin films, hybrid sputtering system with two sputter sources and two effusion cells is used. The Cu2ZnSnS4 films are fabricated by the sequential deposition of metal elements and annealing in S flux, varying the substrate temperature. The Cu2ZnSnS4 films with stoichiometric composition are obtained at the substrate temperature up to 400 °C, whereas the film composition becomes quite Zn-pool at the substrate temperature above 450 °C. The Cu2ZnSnS4 film shows p-type conductivity, and the optical absorption coefficient and the band gap of the Cu2ZnSnS4 film prepared in this experiment are suitable for fabricating a thin film solar cell.

  2. Cell proliferation on modified DLC thin films prepared by plasma enhanced chemical vapor deposition.

    Science.gov (United States)

    Stoica, Adrian; Manakhov, Anton; Polčák, Josef; Ondračka, Pavel; Buršíková, Vilma; Zajíčková, Renata; Medalová, Jiřina; Zajíčková, Lenka

    2015-06-12

    Recently, diamondlike carbon (DLC) thin films have gained interest for biological applications, such as hip and dental prostheses or heart valves and coronary stents, thanks to their high strength and stability. However, the biocompatibility of the DLC is still questionable due to its low wettability and possible mechanical failure (delamination). In this work, DLC:N:O and DLC: SiOx thin films were comparatively investigated with respect to cell proliferation. Thin DLC films with an addition of N, O, and Si were prepared by plasma enhanced CVD from mixtures of methane, hydrogen, and hexamethyldisiloxane. The films were optically characterized by infrared spectroscopy and ellipsometry in UV-visible spectrum. The thickness and the optical properties were obtained from the ellipsometric measurements. Atomic composition of the films was determined by Rutherford backscattering spectroscopy combined with elastic recoil detection analysis and by x-ray photoelectron spectroscopy. The mechanical properties of the films were studied by depth sensing indentation technique. The number of cells that proliferate on the surface of the prepared DLC films and on control culture dishes were compared and correlated with the properties of as-deposited and aged films. The authors found that the level of cell proliferation on the coated dishes was high, comparable to the untreated (control) samples. The prepared DLC films were stable and no decrease of the biocompatibility was observed for the samples aged at ambient conditions.

  3. Electrochemical preparation of Er-Co-Bi thin film in organic bath by cyclic electrodeposition method

    Institute of Scientific and Technical Information of China (English)

    李高仁; 童叶翔; 刘冠昆

    2004-01-01

    Cyclic electrodeposition was used to investigate the preparation of Er-Co-Bi alloy thin film in DMSO system. Experimental results indicate that Er-Co-Bi alloy thin film containing 14.83 %- 32.65 % Er is prepared from 0. 1 mol/L ErCl3 +0. 1 mol/L CoCl2 + 0.1 mol/L Bi(NO3 )3 + 0.1 mol/L LiCl+DMSO system by cyclic electrodeposition on Cu substrate. The optimum cyclic potential of electrodeposition is that upper potential is within a potential range from -0.50 V to -1.00 V and lower potential is within a potential range from -2.00 V to -2.60 V.The surface of alloy thin film observed by scanning electron microscope is black, adhesive and has metallic luster.The film is amorphous proved by the X-ray diffractometry.

  4. Preparation and properties of SrBi2.2Ta2O9 thin film

    Institute of Scientific and Technical Information of China (English)

    WANG Wen; JIA De-chang; ZHOU Yu

    2005-01-01

    SrBi2.2Ta2O9(SBT) thin film with thickness of 2 μm was successfully prepared by sol-gel method, using strontium acetate semihydrate [Sr(CH3COO)2·1/2H2O] and bismth subnitrate [BiO(NO3)], and tantalum ethoxide [Ta(OCH2CH3)5] as source materials, glacial acetic and ethylene glycol as solvents. The X-ray diffraction(XRD) and transmission electron microscope(TEM) results indicate that SBT layer-perovskite phase obtained has to be single phase, SBT thin film is formed after being annealed at 800 ℃ for 1 min. The typical hysteresis loop of SBT thin film on Pt/Ti/SiO2/Si is obtained, and the measured polarization value of the SBT thin film is 4.2 μC/cm2.

  5. Antimony sulfide thin films prepared by laser assisted chemical bath deposition

    Science.gov (United States)

    Shaji, S.; Garcia, L. V.; Loredo, S. L.; Krishnan, B.; Aguilar Martinez, J. A.; Das Roy, T. K.; Avellaneda, D. A.

    2017-01-01

    Antimony sulfide (Sb2S3) thin films were prepared by laser assisted chemical bath deposition (LACBD) technique. These thin films were deposited on glass substrates from a chemical bath containing antimony chloride, acetone and sodium thiosulfate under various conditions of normal chemical bath deposition (CBD) as well as in-situ irradiation of the chemical bath using a continuous laser of 532 nm wavelength. Structure, composition, morphology, optical and electrical properties of the Sb2S3 thin films produced by normal CBD and LACBD were analyzed by X-Ray diffraction (XRD), Raman Spectroscopy, Atomic force microscopy (AFM), X-Ray photoelectron spectroscopy (XPS), UV-vis spectroscopy and Photoconductivity. The results showed that LACBD is an effective synthesis technique to obtain Sb2S3 thin films for optoelectronic applications.

  6. The preparation of two inch double-sided YBCO thin films

    CERN Document Server

    Liu, X Z; Deng, X W; Zhang, Y; Li, Y R

    2002-01-01

    The preparation of two inch double-sided YBCO thin films by simultaneous sputtering from a single target is reported. The lateral homogeneity of microwave surface resistance of the YBCO thin films, on both sides of the two inch wafer, is characterized by using a Fabry-Perot resonator at 145 GHz and 75 K. Values of microwave surface resistance R sub s (75 K, 145 GHz, 0 T) below 55 m OMEGA were reached over the whole area of YBCO thin films on two inch LaAlO sub 3 wafers. The majority of the wafer area has R sub s (75 K, 145 GHz, 0 T) values in the range of 15 m OMEGA to 40 m OMEGA. The uniformity of R sub s values in the whole two inch wafer is excellent and the properties of YBCO thin films were found to be very similar on both sides of the wafer.

  7. Preparation and characterization of nanostructured ZnO thin films for photoelectrochemical splitting of water

    Indian Academy of Sciences (India)

    Monika Gupta; Vidhika Sharma; Jaya Shrivastava; Anjana Solanki; A P Singh; V R Satsangi; S Dass; Rohit Shrivastav

    2009-02-01

    Nanostructured zinc oxide thin films (ZnO) were prepared on conducting glass support (SnO2: F overlayer) via sol–gel starting from colloidal solution of zinc acetate 2-hydrate in ethanol and 2-methoxy ethanol. Films were obtained by spin coating at 1500 rpm under room conditions (temperature, 28–35°C) and were subsequently sintered in air at three different temperatures (400, 500 and 600°C). The evolution of oxide coatings under thermal treatment was studied by glancing incidence X-ray diffraction and scanning electron microscopy. Average particle size, resistivity and bandgap energy were also determined. Photoelectrochemical properties of thin films and their suitability for splitting of water were investigated. Study suggests that thin films of ZnO, sintered at 600°C are better for photoconversion than the films sintered at 400 or 500°C. Plausible explanations have been provided.

  8. The Preparation and Characterization of Amorphous SiCN Thin Films

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Radio Frequency plasma enhanced Chemical Vapor Deposition (RF CVD) using N2, SiH4 and C2H4 as the reaction sources was used to prepare amorphous ternary SixCyNz thin films. The chemical states of the C, Si and N atoms in the films were characterized by X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR). The refractive index n, extinction coefficient k and optical band gap Eopt of the thin films were investigated by UV-visible spectrophotometer and spectroscopic ellipsometer.The results show that a complex chemical bonding network rather than a simple mixture of Si3N4,SiC,CNx and a-C etc. , may exist in the ternary thin films. The n's of the films are within the range of 1.90-2. 45, and Eopt's of all samples are within the range of 2.71 -2. 86 eV.

  9. Ultrasonically assisted intercalation of Ni in Al2O3 thin film prepared by SILAR technique

    Science.gov (United States)

    Dhanayat, Swapnali; Digraskar, Renuka; Gattu, Ketan; Upadhye, Deepak; Mahajan, Sandeep; Sharma, Ramphal; Ghule, Anil

    2013-06-01

    The Al2O3 thin film were prepared by successive ionic layer adsorption and reaction (SILAR) technique and annealed at 250 °C. Thereafter, Ni was ultrasonically intercalated in Al2O3 thin films for different sonication time period of 5 and 10s, and subsequently annealed at 250 °C to form NiO-Al2O3. The films were further characterized using scanning electron microscopy, energy dispersive X-ray analysis, UV-Vis spectrophotometer and I-V system, to study morphological, compositional, optical and electrical properties.

  10. Preparation of polycrystalline CdS thin films by chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E.A.; Kim, B.S.; Shin, S.H.; Park, J.I.; Park, K.J. [National Industrial Technology Inst., Kwacheon (Korea, Republic of). Div. of Inorganic Chemistry

    1996-12-31

    CdS has been recognized as a promising n-type window material for CdTe/CdS and CuInSe{sub 2}/CdS heterojunction thin film solar cells. The authors prepared CdS thin films from a solution containing cadmium acetate, thiourea, ammonia, and ammonium acetate. They varied fabrication conditions such as the concentrations of reactants, reaction temperature, and heat treatment, to investigate the changes in structural and optical properties of the film. Effects of substrate on the properties were also investigated.

  11. STUDY ON Ni-Cr SYSTEM SOLAR SELECTIVE THIN FILMS PREPARED BY MAGNETRON REACTIVE SPUTTERING PROCESS

    Institute of Scientific and Technical Information of China (English)

    B.W. Wang; H. Shen

    2002-01-01

    Ni-Cr System solar selective thin solid films were prepared by d.c. magnetron reactivesputtering under the atmosphere of O2 and N2. Ni-Cr alloy was chosen as targetmaterial and copper sheets as substrate. Using SEM, Spectrophotometer and Talystepto analyze the relations between the selective characteristic and the structure, theformation and the thickness of the thin films. The aim is to obtain good solar selectivethin films with high absorptance and low emittance, which is applied to flat plate solarheat collectors.

  12. Crednerite-CuMnO{sub 2} thin films prepared using atmospheric pressure plasma annealing

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hong-Ying, E-mail: hychen@cc.kuas.edu.tw [Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, 415 Chiken Kuang Road, Kaohsiung 807, Taiwan, ROC (China); Lin, Yu-Chang [Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, 415 Chiken Kuang Road, Kaohsiung 807, Taiwan, ROC (China); Lee, Jiann-Shing [Department of Applied Physics, National Pingtung University, 4-18 Minsheng Road, Pingtung City 900, Taiwan, ROC (China)

    2015-05-30

    Highlights: • Crednerite-CuMnO{sub 2} thin films were formed at atmospheric pressure plasma with N{sub 2}–(5–10)%O{sub 2}. • The binding energy of Cu-2p spectrum of the crednerite-CuMnO{sub 2} thin films was 932.3 eV (Cu{sup +}). • The binding energies of Mn-3p spectrum were 48.1 ± 0.2 eV (Mn{sup 3+}) and 50.0 ± 0.2 eV (Mn{sup 4+}). • The cation distribution in the crednerite-CuMnO{sub 2} thin films was Cu{sub 1.0}{sup +}(Mn{sub 0.6}{sup 3+}Mn{sub 0.4}{sup 4+})O{sub 2}. • The electrical conductivity of CuMnO{sub 2} thin films was (2.61–2.65) × 10{sup 4} Ω cm. - Abstract: This study reports the preparation of crednerite-CuMnO{sub 2} thin films using atmospheric pressure plasma annealing. The pristine thin films were deposited onto a quartz substrate using the sol–gel process. The specimens were then annealed using atmospheric pressure plasma at N{sub 2}–(0–20%)O{sub 2} for 20 min. Crednerite-CuMnO{sub 2} thin films were obtained using atmospheric pressure plasma annealing at N{sub 2}–5%O{sub 2} and N{sub 2}–10%O{sub 2}. The lattice parameters of the thin films were a = 0.5574–0.5580 nm, b = 0.2874–0.2879 nm, c = 0.5878–0.5881 nm, and β = 104.15–104.25°, which agree well with previous reports. The Raman shifts of the crednerite-CuMnO{sub 2} thin films were 688 ± 2 cm{sup −1}, 381 ± 2 cm{sup −1}, and 314 ± 2 cm{sup −1}. The binding energy of Cu-2p spectrum of the crednerite-CuMnO{sub 2} thin films was 932.3 ± 0.2 eV representing the Cu{sup +} in the thin films. The binding energies of Mn-3p spectrum were 48.1 ± 0.2 eV (Mn{sup 3+}) and 50.0 ± 0.2 eV (Mn{sup 4+}). Furthermore, the cation distribution in the thin films was Cu{sup +}{sub 1.0}(Mn{sup 3+}{sub 0.6}Mn{sup 4+}{sub 0.4})O{sub 2} from the X-ray photoelectron spectroscopy measurement. When the crednerite-CuMnO{sub 2} phase was formed, the surface morphology exhibited a compact/dense granular morphology. The optical bandgap of the crednerite-CuMnO{sub 2} thin

  13. Preparation of nickel oxide thin films at different annealing temperature by sol-gel spin coating method

    Science.gov (United States)

    Abdullah, M. A. R.; Mamat, M. H.; Ismail, A. S.; Malek, M. F.; Alrokayan, Salman A. H.; Khan, Haseeb A.; Rusop, M.

    2016-07-01

    Preparation of NiO thin films at different annealing temperature by sol-gel method was conducted to synthesize the quality of the surface thin films. The effects of annealing temperature on the surface topology were systematically investigated. Our studies confirmed that the surface roughness of the thin films was increased whenever annealing temperature was increase. NiO thin films morphology structure analysis was confirmed by field emission scanning electron microscope. Surface roughness of the thin films was investigated by atomic force microscopy.

  14. Manifestation of unusual size effects in granular thin films prepared by pulsed laser deposition

    Science.gov (United States)

    Sergeenkov, S.; Cichetto, L.; Diaz, J. C. C. A.; Bastos, W. B.; Longo, E.; Araújo-Moreira, F. M.

    2016-11-01

    We demonstrate manifestation of some rather unusual size effects in granular thin films prepared by a pulsed laser deposition technique. We observed that the temperature dependence of resistivity ρ(T) notably depends on the relation between the grain size Rg and the film thickness d. Namely, more granular LaNiO3 thin films (with small values of Rg) grown on LaAlO3 substrate are found to follow a universal ρ(T) ∝T 3 / 2 law for all the measured temperatures. While less granular thin films (with larger values of Rg), exhibit a more complicated behavior accompanied by a clear-cut crossover (around Tcr = 200 K), from ρ(T) ∝T 3 / 2 (for 20 K temperature size effects (when an average grain size Rg becomes comparable with the thermal de Broglie wavelength Λ) leading to the crossover temperature Tcr ∝(d /Rg) 2 .

  15. Study of photoconductivity in Ni doped CdS thin films prepared by spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Patidar, Manju Mishra, E-mail: manjumishra.iuc@gmail.com; Gangrade, Mohan; Nath, R.; Ganesan, V. [UGC-DAE Consortium for Scientific Research, Khandawa Road, Indore 452001 (India); Ajay, Akhil [Physics Department, University of Delhi, Delhi-110007 (India); Wala, Arwa Dewas [Holkar Science College, Indore - 452001 (India); N, Kiran [Physics Department, University of Mysore, Mysore-570005 (India); Panda, Richa [AITR, Bhopal-462044 (India)

    2014-04-24

    Ni-doped cadmium sulphide [Cd{sub 1−x}Ni{sub x}S, (x=0, 0.03, 0.05 and 0.20)] thin films were investigated for photoconductive properties. The films were prepared by spray Pyrolysis technique (SPT). AFM and two probe resistivity measurements were carried out to analyze the morphological and electrical properties of the films. AFM shows the note worthy changes in the morphology where the nanorod structures in CdS is changed into nano particles with the Ni doping. The presence of persistence photo current is demonstrated and extensive photoconductivity analysis has been studied on these films.

  16. Influence of Deposition Temperature on the Structure Of Si3N4 Thin Film Prepared By MWECR-PECVD

    Institute of Scientific and Technical Information of China (English)

    肖化; 陈俊芳; 张镇西

    2004-01-01

    The Si3N4 thin film is prepared by MWECR-PECVD at different deposition temperature and the structure of the Si3N4 thin film is investigated. The results indicate that the structure of the Si3N4 thin film prepared at low deposition temperature is in the amorphous phase. However, when the deposition temperature increases to 280℃, the Si3N4 thin film changes to crystalline -Si3N4 . With a further increase of the deposition temperature, the grain of the Si3N4 thin film becomes more fine, uniform and flat. XRD analysis shows that the structure of the Si3N4 thin film prepared at 280℃ is of a crystalline structure.

  17. Nanostructured ZnO thin films prepared by sol–gel spin-coating

    Energy Technology Data Exchange (ETDEWEB)

    Heredia, E., E-mail: heredia.edu@gmail.com [UNIDEF (CONICET-MINDEF), J.B. de La Salle 4397, 1603 Villa Martelli, Pcia. de Buenos Aires (Argentina); Bojorge, C.; Casanova, J.; Cánepa, H. [UNIDEF (CONICET-MINDEF), J.B. de La Salle 4397, 1603 Villa Martelli, Pcia. de Buenos Aires (Argentina); Craievich, A. [Instituto de Física, Universidade de São Paulo, Cidade Universitária, 66318 São Paulo, SP (Brazil); Kellermann, G. [Universidade Federal do Paraná, 19044 Paraná (Brazil)

    2014-10-30

    Highlights: • ZnO films synthesized by sol–gel were deposited by spin-coating on flat substrates. • Structural features of ZnO films with several thicknesses were characterized by means of different techniques. • The thicknesses of different ZnO thin films were determined by means of FESEM and AFM. • The nanoporous structures of ZnO thin films were characterized by GISAXS using IsGISAXS software. • The average densities of ZnO thin films were derived from (i) the critical angle in 1D XR patterns, (ii) the angle of Yoneda peak in 2D GISAXS images, (iii) minimization of chi2 using IsGISAXS best fitting procedure. - Abstract: ZnO thin films deposited on silica flat plates were prepared by spin-coating and studied by applying several techniques for structural characterization. The films were prepared by depositing different numbers of layers, each deposition being followed by a thermal treatment at 200 °C to dry and consolidate the successive layers. After depositing all layers, a final thermal treatment at 450 °C during 3 h was also applied in order to eliminate organic components and to promote the crystallization of the thin films. The total thickness of the multilayered films – ranging from 40 nm up to 150 nm – was determined by AFM and FESEM. The analysis by GIXD showed that the thin films are composed of ZnO crystallites with an average diameter of 25 nm circa. XR results demonstrated that the thin films also exhibit a large volume fraction of nanoporosity, typically 30–40 vol.% in thin films having thicknesses larger than ∼70 nm. GISAXS measurements showed that the experimental scattering intensity is well described by a structural model composed of nanopores with shape of oblate spheroids, height/diameter aspect ratio within the 0.8–0.9 range and average diameter along the sample surface plane in the 5–7 nm range.

  18. Preparation and study of thickness dependent electrical characteristics of zinc sulfide thin films

    Indian Academy of Sciences (India)

    A U Ubale; D K Kulkarni

    2005-02-01

    Zinc sulfide thin films have been deposited onto glass substrates by chemical bath deposition. The various deposition parameters such as volume of sulfide ion source, pH of bath, deposition time, temperature etc are optimized. Thin films of ZnS with different thicknesses of 76–332 nm were prepared by changing the deposition time from 6–20 h at 30°C temperature. The effect of film thickness on structural and electrical properties was studied. The electrical resistivity was decreased from 1.83 × 105 -cm to 0.363 × 105 -cm as film thickness decreased from 332 nm to 76 nm. The structural and activation energy studies support this decrease in the resistivity due to improvement in crystallinity of the films which would increase the charge carrier mobility and decrease in defect levels with increase in the thickness.

  19. Surface and Electrical Properties of NiCr Thin Films Prepared by DC Magnetron Sputtering

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jicheng; TIAN Li; YAN Jianwu

    2008-01-01

    Several batches of NiCr alloy thin films with different thickness were prepared in a multi-targets magnetron sputtering apparatus by changing sputtering time while keeping sputtering target power of Ni and Cr fixed. Then the as-deposited films were characterized by energy-dispersive X-Ray spectrometer (EDX),Atomic Force Microscope (AFM) and four-point probe (FPP) to measure surface grain size, roughness and sheet resistance. The film thickness was measured by Alpha-Step IQ Profilers. The thickness dependence of surface roughness, lateral grain size and resistivity was also studied. The experimental results show that the grain size increases with film thickness and the surface roughness reaches the order of nanometer at all film thickness. The as-deposited film resistivity decreases with film thickness.

  20. Preparation and antimicrobial assay of ceramic brackets coated with TiO2 thin films

    Science.gov (United States)

    Cao, Shuai; Wang, Ye; Cao, Lin; Wang, Yu; Lin, Bingpeng; Lan, Wei

    2016-01-01

    Objective Different methods have been utilized to prevent enamel demineralization and other complications during orthodontic treatment. However, none of these methods can offer long-lasting and effective prevention of orthodontic complications or interventions after complications occur. Considering the photocatalytic effect of TiO2 on organic compounds, we hoped to synthesize a novel bracket with a TiO2 thin film to develop a photocatalytic antimicrobial effect. Methods The sol-gel dip coating method was used to prepare TiO2 thin films on ceramic bracket surfaces. Twenty groups of samples were composed according to the experimental parameters. Crystalline structure and surface morphology were characterized by X-ray diffraction and scanning electron microscopy, respectively; film thickness was examined with a surface ellipsometer. The photocatalytic properties under ultraviolet (UV) light irradiation were analyzed by evaluating the degradation ratio of methylene blue (MB) at a certain time. Antibacterial activities of selected thin films were also tested against Lactobacillus acidophilus and Candida albicans. Results Films with 5 coating layers annealed at 700℃ showed the greatest photocatalytic activity in terms of MB decomposition under UV light irradiation. TiO2 thin films with 5 coating layers annealed at 700℃ exhibited the greatest antimicrobial activity under UV-A light irradiation. Conclusions These results provide promising guidance in prevention of demineralization by increasing antimicrobial activities of film coated brackets. PMID:27226960

  1. PLD prepared nanostructured Pt-CeO2 thin films containing ionic platinum

    Science.gov (United States)

    Vorokhta, M.; Khalakhan, I.; Matolínová, I.; Nováková, J.; Haviar, S.; Lančok, J.; Novotný, M.; Yoshikawa, H.; Matolín, V.

    2017-02-01

    The composition of nanostructured Pt-CeO2 films on graphite substrates prepared by pulsed laser deposition has been investigated by means of hard X-ray photoelectron spectroscopy, scanning electron microscopy, high resolution transmission electron microscopy, and atomic force microscopy. The influence of morphology of the graphite substrates was investigated with respect to the relative concentrations of ionic and metallic Pt species in the films. It was found that the degree of Pt2+ enrichment is directly related to the surface morphology of graphite substrates. In particular, the deposition of Pt-CeO2 films on rough graphite substrate etched in oxygen plasma yielded nanostructured Pt-CeO2 catalyst films with high surface area and high Pt2+/Pt0 ratio. The presented results demonstrate that PLD is a suitable method for the preparation of thin Pt-CeO2 catalyst films for fuel cell applications.

  2. Characterization of sol-gel-prepared Ti02 thin film for O2 sensing

    Science.gov (United States)

    Atashbar, Massood Z.; Ghantasala, Muralihar K.; Wlodarski, Wojtek

    1997-11-01

    This paper presents the results of our investigation on deposition and characterization of sol-gel prepared TiO2 thin films for oxygen sensing applications. The properties of pure TiO2 thin films are compared with those doped with niobium oxide and 1%pt. These films are characterized using Rutherford backscattering spectroscopy (RBS), x-ray diffraction (XRD) and scanning electron microscopy (SEM) to study their chemical composition, structure and surface morphology respectively. Both kinds of the films are stoichiometric. Pure TiO2 as well as doped films were amorphous as deposited. Pure TiO2 films after annealing to 450 degrees Celsius and above showed the formation of anatase phase, while the doped films still predominantly amorphous, barely showing the onset of crystallinity. Pure films after annealing to 600 degrees Celsius appear to have become granular and porous. Doping with niobium oxide and Pt resulted in modification of film microstructure also. As a result of doping, the gas sensitivity of the films is increased from 8 to 24 and operating temperature decreased from 320 degrees Celsius to 190 degrees Celsius.

  3. Study on AlSb Polycrystalline Thin Films Prepared by Vacuum Co-Evaporation

    Science.gov (United States)

    Song, Huijin; Wu, Lili; Zheng, Jiagui; Feng, Lianghuan; Lei, Zhi; Zhang, Jingquan

    In this paper, the AlSb polycrystalline thin films were prepared by vacuum co-evaporation technology and their structural, optical and electrical properties have been studied. XRD results showed that the as-deposited AlSb amorphous thin films transformed to polycrystalline state after annealed in vacuum at temperatures higher than 540°C. The process of phase change was observed to depend on the annealing temperature and the film composition. Some irreversible changes took place in the annealed films during the measurement of the temperature dependence of the film conductance. The conductance activation energy of the film was 0.132 and 0.32 eV during the heating and cooling process, respectively, which suggests the decrease of Sb vacancies in the AlSb film after the heating. Hall effect and optical absorption measurement showed that the AlSb polycrystalline thin films were p-type, indirect bandgap semiconductors with absorption coefficient higher than 8 × 104 cm-1. TCO/CdS/AlSb photovoltaic devices with the local open circuit voltage of over 200 mV have been fabricated.

  4. Characterization of cobalt oxide thin films prepared by a facile spray pyrolysis technique using perfume atomizer

    Energy Technology Data Exchange (ETDEWEB)

    Louardi, A.; Rmili, A.; Ouachtari, F.; Bouaoud, A. [Laboratoire des Hautes Energies, Sciences de l' Ingenierie et Reacteurs (LHESIR), Equipe Ingenierie et Materiaux (INMA), Departement de Physique, Faculte des Sciences, Kenitra (Morocco); Elidrissi, B., E-mail: e.bachir@mailcity.com [Laboratoire des Hautes Energies, Sciences de l' Ingenierie et Reacteurs (LHESIR), Equipe Ingenierie et Materiaux (INMA), Departement de Physique, Faculte des Sciences, Kenitra (Morocco); Erguig, H. [Laboratoire des Hautes Energies, Sciences de l' Ingenierie et Reacteurs (LHESIR), Equipe Ingenierie et Materiaux (INMA), Departement de Physique, Faculte des Sciences, Kenitra (Morocco)

    2011-09-15

    Highlights: > Co{sub 3}O{sub 4} thin films show a micro porous structure. > Co{sub 3}O{sub 4} thin films are formed with spherical grains less than 50 nm in diameter. > The porous structure of Co{sub 3}O{sub 4} films is expected to have promising application in electrochromism. - Abstract: Cobalt oxide (Co{sub 3}O{sub 4}) thin films were prepared by a facile spray pyrolysis technique using perfume atomizer from aqueous solution of hydrated cobalt chloride salt (CoCl{sub 2}.6H{sub 2}O) as source of cobalt. The films were deposited onto the amorphous glass substrates kept at different temperatures (300-500 deg. C). The influences of molar concentration of the starting solution and substrate temperature on the structural, morphological and optical properties of (Co{sub 3}O{sub 4}) thin films were studied. It was found from X-ray diffraction (XRD) analysis that the films prepared with molar concentration greater than 0.025 M/L were polycrystalline spinel type cubic structure. The preferred orientation of the crystallites of these films changes gradually from (6 2 2) to (1 1 1) when the substrate temperature increases. By Raman spectroscopy, five Raman active modes characteristic of Co{sub 3}O{sub 4} spinel type cubic structure were found and identified at 194, 484, 522, 620 and 691 cm{sup -1}. The scanning electron microscopy (SEM) images showed micro porous structure with very fine grains less than 50 nm in diameter. These films exhibited also a transmittance value of about 70% in the visible and infra red range.

  5. Sputtering Preparation and Magneto-optical Properties of GdTbFeCo Thin Films

    Institute of Scientific and Technical Information of China (English)

    HUANG Zhixin; YU Weijun

    2012-01-01

    Amorphous GdTbFeCo magnetic thin films were successfully prepared on glass substrates by RF magnetron sputtering system from a mosaic target.The influences of sputtering parameters on the magnetooptical properties GdTbFeCo thin film were investigated by the variable control method.And the influence mechanism was analyzed in detail.After the sputtering parameters were optimized,it was found that when the distance between target and substrate was 72 mm,the thin film thickness was 120 nm,and the sputtering power,sputtering pressure and sputtering time was 75 W,0.5 Pa and 613 s,respectively,the coercivity with perpendicular anisotropy could be as high as 6735 Oe,and the squareness ratio of the hysteresis loop was almost equal to 1.

  6. Faraday effect of polycrystalline bismuth iron garnet thin film prepared by mist chemical vapor deposition method

    Science.gov (United States)

    Yao, Situ; Kamakura, Ryosuke; Murai, Shunsuke; Fujita, Koji; Tanaka, Katsuhisa

    2017-01-01

    We have synthesized polycrystalline thin film composed of a single phase of metastable bismuth iron garnet, Bi3Fe5O12, on a fused silica substrate, one of the most widely utilized substrates in the solid-state electronics, by using mist chemical vapor deposition (mist CVD) method. The phase purity and stoichiometry are confirmed by X-ray diffraction and Rutherford backscattering spectrometry. The resultant thin film shows a small surface roughness of 3.251 nm. The saturation magnetization at room temperature is 1200 G, and the Faraday rotation angle at 633 nm reaches -5.2 deg/μm. Both the magnetization and the Faraday rotation angles are somewhat higher than those of polycrystalline BIG thin films prepared by other methods.

  7. Preparation and Characterization of Silver Liquid Thin Films for Magnetic Fluid Deformable Mirror

    Directory of Open Access Journals (Sweden)

    Lianchao Zhang

    2015-01-01

    Full Text Available Silver liquid thin film, formed by silver nanoparticles stacking and spreading on the surface of the liquid, is one of the important parts of magnetic fluid deformable mirror. First, silver nanoparticles were prepared by liquid phase chemical reduction method using sodium citrate as reducing agent and stabilizer and silver nitrate as precursor. Characterization of silver nanoparticles was studied using X-ray diffractometer, UV-vis spectrophotometer, and transmission electron microscope (TEM. The results showed that silver nanoparticles are spherical and have a good monodispersity. Additionally, the effect of the reaction conditions on the particle size of silver is obvious. And then silver liquid thin films were prepared by oil-water two-phase interface technology using as-synthesized silver nanoparticles. Properties of the film were investigated using different technology. The results showed that the film has good reflectivity and the particle size has a great influence on the reflectivity of the films. SEM photos showed that the liquid film is composed of multilayer silver nanoparticles. In addition, stability of the film was studied. The results showed that after being stored for 8 days under natural conditions, the gloss and reflectivity of the film start to decrease.

  8. Nanostructured CuO Thin Films Prepared through Sputtering for Solar Selective Absorbers

    Directory of Open Access Journals (Sweden)

    Senthuran Karthick Kumar

    2013-01-01

    Full Text Available Nanostructured cupric oxide (CuO thin films have been deposited on copper (Cu substrates at different substrate temperatures and oxygen to argon gas ratios through direct current (DC reactive magnetron sputtering. The deposited CuO thin films are characterized by using X-ray diffraction (XRD, scanning electron microscopy (SEM, energy dispersive spectroscopy (EDS, profilometry, and spectrophotometry techniques. The crystalline phases, morphology, optical properties, and photothermal conversion efficiency of the CuO thin films are found to be significantly influenced by the change in substrate temperature and oxygen to argon gas ratio. The variations in the substrate temperature and oxygen to argon gas ratio have induced changes in Cu+ and Cu2+ concentrations of the CuO thin films that result in corresponding changes in their optical properties. The CuO thin film prepared at a substrate temperature of 30°C and O2 to Ar gas ratio of 1 : 1 has exhibited high absorptance and low emittance; thus, it could be used as a solar selective absorber in solar thermal gadgets.

  9. Biocompatible Nb2O5 thin films prepared by means of the sol-gel process.

    Science.gov (United States)

    Velten, D; Eisenbarth, E; Schanne, N; Breme, J

    2004-04-01

    Thin biocompatible oxide films with an optimised composition and structure on the surface of titanium and its alloys can improve the implant integration. The preparation of these thin oxide layers with the intended improvement of the surface properties can be realised by means of the sol-gel process. Nb2O5 is a promising coating material for this application because of its extremely high corrosion resistance and thermodynamic stability. In this study, thin Nb2O5 layers ( TiO2 sol-gel coated cp-titanium concerning the spreading of cells, collagen I synthesis and wettability.

  10. Biodegradable Polylactide-co-glycolide (PLGA) Thin Films Prepared by Electrospray and Pressurized Spray Deposition

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    PLGA thin films were prepared onto irnplantable devices by the electrospray and pressurized spray method. Thin films with structural gradients were obtained by controlling four parameters consisting of solution concentration, applied voltage, air pressure, and deposition time. The surface morphologies of the deposited films were observed using scanning electron microscopy (SEM). The image analysis revealed the control factors on the preparation of PLGA thin films. The beaded structure is easily formed with a decrease in polymer concentration while the fibrous structure is easily formed with an increase in polymer concentration. With the increase in applied voltage, the surface morphologies changed continuously from a small amount of fibrous shape to a large fibrous one: a small amount of fibrous shape at 10 kV, more fibers with non-uniform diameter at 20 kV, and most fibers with uniform diameter at 30 kV. Low air pressure (0.1 MPa ) corresponded to round particles while high air pressure (0.3 MPa) corresponded to flat particles. The change in thickness from 5.34 to 10.1 μm was a result of deposition time increasing from 5 to 10 s . From our above work, films of the bead or fiber structures can be obtained by changing electrical parameters to improve the biocompatibility of the film.

  11. Dielectric dilatometry on thin Teflon-PTFE films prepared by pulsed-laser deposition

    Science.gov (United States)

    Schwoediauer, Reinhard; Bauer-Gogonea, Simona; Bauer, Stefan; Heitz, J.; Arenholz, Enno; Baeuerle, Dieter

    1999-12-01

    Polytetrafluoroethylene (Teflon PTFE) films were grown by pulsed-laser deposition (PLD). Films prepared by ablation from press-sintered targets are found to be highly crystalline, with spherulite sizes adjustable over more than one order in magnitude by suitable thermal annealing. As revealed by dielectric dilatometry, PLD-PTFE films show characteristics remarkably similar to those of conventional PTFE, i.e. the same structural first-order phase transitions. Dielectric losses are low and indicate no tendency to film oxidation. PLD-PTFE films additionally show an excellent charge-stability, comparable and even superior to commercially available Teflon-PTFE foils. PLD-PTFE enlarges the family of Teflon materials and may thus become interesting for potential miniaturized electret devices. Furthermore, dielectric dilatometry provides an elegant means for the determination of the coefficient of thermal expansion in thin nonpolar films.

  12. Chalcogenide-based thin film sensors prepared by pulsed laser deposition technique

    Science.gov (United States)

    Schubert, J.; Schöning, M. J.; Schmidt, C.; Siegert, M.; Mesters, St.; Zander, W.; Kordos, P.; Lüth, H.; Legin, A.; Mourzina, Yu. G.; Seleznev, B.; Vlasov, Yu. G.

    One advantage of the pulsed laser deposition (PLD) method is the stoichiometric transfer of multi-component target material to a given substrate. This advantage of the PLD determined the choice to prepare chalco-genide-based thin films with an off-axis geometry PLD. Ag-As-S and Cu-Ag-As-Se-Tetargets were used to deposit thin films on Si substrates for an application as a heavy metal sensing device. The films were characterized by means of Rutherford backscattering spectrometry (RBS), transmission electron microscopy (TEM), and electrochemical measurements. The same stoichiometry of the films and the targets was confirmed by RBS measurements. We observed a good long-term stability of more than 60 days and a nearly Nernstian sensitivity towards Pb and Cu, which is comparable to bulk sensors.

  13. Structural and optical characteristics of SnS thin film prepared by SILAR

    Directory of Open Access Journals (Sweden)

    Mukherjee A.

    2015-12-01

    Full Text Available SnS thin films were grown on glass substrates by a simple route named successive ion layer adsorption and reaction (SILAR method. The films were prepared using tin chloride as tin (Sn source and ammonium sulfide as sulphur (S source. The structural, optical and morphological study was done using XRD, FESEM, FT-IR and UV-Vis spectrophotometer. XRD measurement confirmed the presence of orthorhombic phase. Particle size estimated from XRD was about 45 nm which fitted well with the FESEM measurement. The value of band gap was about 1.63 eV indicating that SnS can be used as an important material for thin film solar cells. The surface morphology showed a smooth, homogenous film over the substrate. Characteristic stretching vibration mode of SnS was observed in the absorption band of FT-IR spectrum. The electrical activation energy was about 0.306 eV.

  14. Spectroscopic ellipsometry studies of as-prepared and annealed CdS:O thin films

    Energy Technology Data Exchange (ETDEWEB)

    Khalilova, Khuraman; Hasanov, Ilham; Mamedov, Nazim [Institute of Physics, Azerbaijan National Academy of Sciences, 1143 Baku (Azerbaijan); Shim, YongGu [Department of Physics and Electronics, Graduate School of Engineering, Osaka Prefecture University, Sakai 599-8531 (Japan); Asaba, Ryo; Wakita, Kazuki [Department of Electronics and Computer Engineering, Chiba Institute of Technology, Chiba 275-0016 (Japan)

    2015-06-15

    Cadmium sulfide thin films on soda lime substrates were obtained by rf-magnetron sputtering in argon-oxygen atmosphere. As-prepared and vacuum annealed films were then studied by spectroscopic ellipsometry at room temperature over photon energy range from 0.5 to 6 eV. The obtained ellipsometric data were treated using optical dispersion models based on Gaussian type oscillators. Dielectric function of oxygen-free films, as well as those obtained under 3% of O/Ar partial pressure was reliably restored. At the same time, dielectric function obtained for 5% CdS:O can be regarded only as an average over several materials since our XPS examination disclosed presence of several compounds in thin films deposited at O/Ar ratios higher than 3%. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Phase Structural Characteristics of ZrV2 Thin Film Prepared by Magnetron Sputtering

    Institute of Scientific and Technical Information of China (English)

    XU Shi-Lin; SHI Li-Qun

    2005-01-01

    @@ The thin film metal hydride has become an emerging field of research in metal hydride batteries for its good mechanical and hydrogenation properties. ZrV2 thin films have been prepared using a dc magnetron sputtering method, and the phase structure is investigated. Only amorphous or crystalline Zr and V mixture phases are achieved when substrates are heated during either to 400℃ or to 550 ℃. The annealing causes segregation of Zr and V in the film induced by strain-driven diffusion and interdiffusion between substrate Mo and film elements at high temperature, which results in the formation of mixture phases of C14, C15, Zr and V, but the content of C15 phase is not higher compared with that in the bulk material.

  16. Ruthenium disulfide thin films prepared by the successive ionic layer adsorption and reaction (SILAR) method

    Institute of Scientific and Technical Information of China (English)

    LIU Xiaoxin; JIN Zhengguo; ZHAO Juan; BU Shaojing

    2004-01-01

    RuS2 thin films were prepared by the cost-effective chemical method-successive ionic layer adsorption and reaction (SILAR). The structural, optical, and electrical properties were investigated using X-ray diffraction, scanning electron microscopy, optical transmittance, and electrical resistivity methods. The results indicate that the films are homogeneous and dense; the structure of the as-deposited fdms is amorphous and they crystallize after annealed at 500°C for 30 min. The band gap of the as-deposited films is found to be 1.85 eV, and the electrical resistivity of them is in the order of 105 Ω.cm.

  17. Electrochemical preparation and abnormal infrared effects of nanostructured Ni thin film

    Institute of Scientific and Technical Information of China (English)

    WANG Hanchun; ZHOU Zhiyou; TANG Wei; YAN Jiawei; SUN Shigang

    2004-01-01

    Nanometer-scale thin film of Ni supported on glassy carbon (nm-Ni/GC) was prepared by electrochemical deposition through cyclic voltammetry (CV). The properties of nm-Ni/GC were studied by electrochemical in situ FTIR reflection spectroscopy using CO adsorption as probe reaction. It has revealed that the nm-Ni/GC exhibits abnormal infrared effects (AIREs). The study has extended the investigation of the AIREs that we have discovered initially on nanostruetured film materials of platinum group metals and alloys to nanostructured film materials of iron group metals.

  18. Electrical and optical properties of CZTS thin films prepared by SILAR method

    OpenAIRE

    2016-01-01

    In the present work, Cu2ZnSnS4 (CZTS) thin film was deposited onto the glass substrate by simple and economic SILAR method and its structural, morphological, optical and electrical properties were analyzed. X-ray diffraction (XRD) analysis confirms the formation of CZTS with kesterite structure and the average crystallite size is found to be 142 nm. Scanning electron microscope (SEM) image shows that the film has homogeneous, agglomerated surface without any cracks. The prepared CZTS film sho...

  19. Electrical properties of silver selenide thin films prepared by reactive evaporation

    Indian Academy of Sciences (India)

    M C Santhosh Kumar; B Pradeep

    2002-10-01

    The electrical properties of silver selenide thin films prepared by reactive evaporation have been studied. Samples show a polymorphic phase transition at a temperature of 403 ± 2 K. Hall effect study shows that it has a mobility of 2000 cm2V–1s–1 and carrier concentration of 1018 cm–3 at room temperature. The carriers are of -type. X-ray diffraction study indicates that the as-prepared films are polycrystalline in nature. The lattice parameters were found to be = 4.353 Å, = 6.929 Å and = 7.805 Å.

  20. High T(sub c) thin film superconductors: Preparation, patterning and characterization

    Science.gov (United States)

    Azoulay, J.

    A conventional oil-pumped vacuum system equipped with resistively heated tungsten boat sources was used for evaporation of bismuth- or yttrium-based cuprates for high T(sub c) thin film superconductors. A well-ground mixture with atomic proportions of bismuth, SrF2, CaF2 and copper for bismuth-based material, and of YF3, BaF2 and copper for yttrium-based material, was inserted into the boat and then resistively evaporated onto different substrates such as MgO, ZrO2 and SrTiO3 kept at room temperature. Yttrium-based thin films were found to have a better quality upon reduction of fluorine in the constituents. Thus, films prepared with an yttrium BaF2 and copper mixture show a metallic-like behavior, sharper transition and higher zero-resistance temperature as compared with that of films obtained by using a YF2 constiuent instead of yttrium. Bismuth-based thin films were found to lose bismuth during heat treatment unless the copper constiuent ended the evaporation process and was subsequently fully oxidized at 400 C. Bismuth-based patterned films were easily obtained by using a lift-off photolithographic method. Typical thickness of the films was measured to be about 0.5 micron after heat treatment.

  1. Construction of sputtering system and preparation of high temperature superconducting thin films

    CERN Document Server

    Kaynak, E

    2000-01-01

    The preparation of high T sub c superconducting thin film is important both for the understanding of fundamental behaviours of these materials and for the investigations on the usefulness of technological applications. High quality thin films can be prepared by various kinds of techniques being used today. Among these, sputtering is the most preferred one. The primary aim of this work is the construction of a r. f. and c. magnetron sputtering system. For this goal, a magnetron sputtering system was designed and constructed having powers up to 500W (r.f.) and 1KW (d.c.) that enables to deposit thin films of various kinds of materials: metals, ceramics and magnetic materials. The temperature dependence of the electrical resistance of the films was investigated by using four-point probe method. The zero resistance and the transition with of the films were measured as 80-85 K, and 2-9 K, respectively. The A.C. susceptibility experiments were done by utilising the system that was designed and constructed. The appl...

  2. Electrical properties of chemically prepared nonstoichiometric CuIn(S,Se)2 thin films

    Indian Academy of Sciences (India)

    R H Bari; L A Patil; A Soni; G S Okram

    2007-04-01

    Polycrystalline thin films of copper indium sulphoselenide [CuIn(S,Se)2] were deposited on glass substrate by chemical bath deposition technique. The deposition parameters such as pH, temperature and time were optimized. A set of films having different elemental compositions was prepared by varying Cu/In ratio from 1.87–12.15. The films were characterized by X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDAX). The chemical composition of the CuIn(S,Se)2 was found to be nonstoichiometric. The d.c. conductivities of the films were studied below and near room temperature. The thermo-electric power of the films was also measured and type of semiconductivity was ascertained.

  3. Nanostructured TiO2 thin films for DSSCs prepared by sol gel technique

    Science.gov (United States)

    Bakar, Siti Noraini Abu; Abdullah, Huda; Mahbor, Kamisah Mohamad

    2017-07-01

    In this research, nanostructured TiO2 thin films were prepared by sol-gel technique for dye-sensitized solar cells (DSSCs) were investigated. The nanostructured thin films were prepared using commercial Titania powder (Degussa P25) and titanium (IV) ethoxide (TEOT). The resulting solution were spin-coated on pieces of indium-doped tin oxide (InO2:Sn, ITO) transparent glass (8 Ω/sq, TEC GlassTM) with an area of 10 × 10 mm2 at a rate of 2000 rpm for 30 seconds. The films were annealed in furnace at 450 °C for 60 min. The working electrode was then immersed in the solution of N-719 (Ruthenium) dye at room temperature for 24 h. A thin film of platinum (Pt) was deposited on the ITO-glass substrate as the counter electrode using print-screen technique. The structures, morphological and optical properties of the films, were examined using X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and UV-VIS spectrometer respectively. The XRD results showed that the crystalline phase of the film was anatase. The micrograph obtained using FESEM demonstrated that the prepared TiO2 film has a nanosructured characteristic. The photovoltaic properties of DSSC was studied under an incident irradiation of 100 mW/cm2. The energy conversion efficiency (η) of the DSSC with nanostuctured TiO2 (P25) and TiO2 was 0.3% and 0.2 % respectively.

  4. [Preparation of large area Al-ZnO thin film by DC magnetron sputtering].

    Science.gov (United States)

    Jiao, Fei; Liao, Cheng; Han, Jun-Feng; Zhou, Zhen

    2009-03-01

    Solar cells of p-CIS/n-buffer/ZnO type, where CIS is (CuInS2, CuInSe2 or intermediates, are thin-film-based devices for the future high-efficiency and low-cost photovoltaic devices. As important thin film, the properties of Al-doped ZnO (AZO) directly affect the parameter of the cell, especially for large volume. In the present paper, AZO semiconductor transparent thin film on soda-lime glass was fabricated using cylindrical zinc-aluminum target, which can not only lower the cost of the target but also make the preparation of large area AZO thin film more easily. Using the DC magnet sputtering techniques and rolling target, high utilization efficiency of target was achieved and large area uniform and directional film was realized. An introduction to DC magnet sputtering techniques for large area film fabrication is given. With different measurement methods, such as X-ray diffraction (XRD) and scan electron microscope (SEM), we analyzed large size film's structure, appearance, and electrical and optical characteristics. The XRD spectrum indicated that the AZO film shows well zinc-blende structure with a preferred (002) growth and the c-axis is oriented normal to the substrate plane. The lattice constant is 5.603 9 nm and the mismatch with CdS thin film is only 2 percent. It absolutely satisfied the demand of the GIGS solar cell. The cross-section of the AZO thin film indicates the columnar structure and the surface morphology shows that the crystal size is about 50 nm that is consistent with the result of XRD spectrum. By the optical transmission curve, not only the high transmission rate over 85 percent in the visible spectrum between 400 nm and 700 nm was showed but also the band gap 3.1 eV was estimated. And all these parameters can meet the demand of the large area module of GIGS solar cell. The result is that using alloy target and Ar gas, and controlling the appropriate pressure of oxygen, we can get directional, condensed, uniform, high transmitting rate, low

  5. High quality antireflective ZnS thin films prepared by chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Tec-Yam, S.; Rojas, J.; Rejon, V. [Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Merida, Departamento de Fisica Aplicada, Km. 6 Antigua Carretera a Progreso, AP 73-Cordemex, 97310 Merida Yucatan (Mexico); Oliva, A.I., E-mail: oliva@mda.cinvestav.mx [Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Merida, Departamento de Fisica Aplicada, Km. 6 Antigua Carretera a Progreso, AP 73-Cordemex, 97310 Merida Yucatan (Mexico)

    2012-10-15

    Zinc sulfide (ZnS) thin films for antireflective applications were deposited on glass substrates by chemical bath deposition (CBD). Chemical analysis of the soluble species permits to predict the optimal pH conditions to obtain high quality ZnS films. For the CBD, the ZnCl{sub 2}, NH{sub 4}NO{sub 3}, and CS(NH{sub 2}){sub 2} were fixed components, whereas the KOH concentration was varied from 0.8 to 1.4 M. Groups of samples with deposition times from 60 to 120 min were prepared in a bath with magnetic agitation and heated at 90 Degree-Sign C. ZnS films obtained from optimal KOH concentrations of 0.9 M and 1.0 M exhibited high transparency, homogeneity, adherence, and crystalline. The ZnS films presented a band gap energy of 3.84 eV, an atomic Zn:S stoichiometry ratio of 49:51, a transmittance above 85% in the 300-800 nm wavelength range, and a reflectance below 25% in the UV-Vis range. X-ray diffraction analysis revealed a cubic structure in the (111) orientation for the films. The thickness of the films was tuned between 60 nm and 135 nm by controlling the deposition time and KOH concentration. The incorporation of the CBD-ZnS films into ITO/ZnS/CdS/CdTe and glass/Mo/ZnS heterostructures as antireflective layer confirms their high optical quality. -- Highlights: Black-Right-Pointing-Pointer High quality ZnS thin films were prepared by chemical bath deposition (CBD). Black-Right-Pointing-Pointer Better CBD-ZnS films were achieved by using 0.9 M-KOH concentration. Black-Right-Pointing-Pointer Reduction in the reflectance was obtained for ZnS films used as buffer layers.

  6. Investigation on Silicon Thin Film Solar Cells

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The preparation, current status and trends are investigated for silicon thin film solar cells. The advantages and disadvantages of amorphous silicon thin film, polycrystalline silicon thin film and mono-crystalline silicon thin film solar cells are compared. The future development trends are pointed out. It is found that polycrystalline silicon thin film solar cells will be more promising for application with great potential.

  7. Structural study of ZnS thin films prepared by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Afifi, H.H. [Minai Univ. (Egypt). Dept. of Phys.; Mahmoud, S.A. [Minai Univ. (Egypt). Dept. of Phys.; Ashour, A. [Minai Univ. (Egypt). Dept. of Phys.

    1995-06-15

    Thin films of ZnS were prepared by spray pyrolysis. The effect of substrate temperature as well as deposition time and annealing in air and in a nitrogen atmosphere on some structural features was investigated by X-ray diffraction. At a substrate temperature of 300 C, ZnS appears almost in amorphous form. With rising substrate temperature, the crystallinity was improved. At 550 C, a well-crystallized cubic phase of ZnS was obtained. The films were preferably oriented with the left angle 111 right angle direction perpendicular to the surface. Annealing in air created ZnO, no evidence for oxides was found when annealing was carried out in a nitrogen atmosphere. Therefore, using a spray pyrolysis technique with a substrate temperature of 500 C and annealing in a non-oxidizing atmosphere for about 120 min, one can obtain well-crystallized single-phase cubic ZnS thin films. ((orig.))

  8. Alcohol sensing of tin oxide thin film prepared by sol–gel process

    Indian Academy of Sciences (India)

    Sunita Mishra; C Ghanshyam; Nathai Ram; Satinder Singh; R P Bajpai; R K Bedi

    2002-06-01

    The present paper describes the alcohol sensing characteristics of spin coated SnO2 thin film deposited by using sol–gel process. The sensitivity of the film was measured at different temperatures and different concentrations of alcohol at ppm level. Alcohol detection result shows peak sensitivity at 623 K. The variation of sensitivity and ethanol concentration has shown a linear relationship up to 1150 ppm and after that it saturates. The response time measurement of the sensor was also observed and it was found that the response time is 30 sec. The results obtained favour the sol–gel process as a low cost method for the preparation of thin films with a high sensing characteristic.

  9. Preparation of Nanometer-structured TiO2 Thin Films by Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    HE Feng; LI Qian-tao; HU Wang-kai; DENG Tao

    2002-01-01

    The transparent anatase TiO2 nanometer thin films were prepared by the sol-gel method on soda-lime glass. X-ray diffraction, thermal analysis and UV-visible spectrophotometer were used to analyze the formation of the phases. Only increasing the heat-treatment time, the average grain size has no obvious change. The mechanism of grain growth in TiO2 thin film is probably as follows: the grain of coating will become grain core later; TiO2 sol constantly deposited on the surface of TiO2 grain and formed membrane with increasing of coating cycle times; TiO2 grain in the film grow steadily.

  10. Preparation of iron oxides using ammonium iron citrate precursor: Thin films and nanoparticles

    Science.gov (United States)

    Park, Sangmoon

    2009-09-01

    Ammonium iron citrate (C 6H 8O 7·nFe ·nH 3N) was used as a precursor for preparing both iron-oxide thin films and nanoparticles. Thin films of iron oxides were fabricated on silicon (111) substrate using a successive-ionic-layer-adsorption-and-reaction (SILAR) method and subsequent hydrothermal or furnace annealing. Atomic force microscopy (AFM) images of the iron-oxide films obtained under various annealing conditions show the changes of the micro-scale surface structures and the magnetic properties. Homogenous Fe 3O 4 nanoparticles around 4 nm in diameter were synthesized by hydrothermal reduction method at low temperature and investigated using transmission electron microscopy (TEM).

  11. Study of optical characteristics of tin oxide thin film prepared by sol–gel method

    Indian Academy of Sciences (India)

    Sumanta Kumar Tripathy; Bhabani Prasad Hota; P V Rajeswari

    2013-12-01

    In this paper, we present details of preparation of tin oxide (SnO2) thin film by sol–gel process. The film was synthesized on a glass (Corning 7059) plate by dip coating method. Here, we used tin (II) chloride as precursor and methanol as solvent. Optical characteristics and physical properties like refractive index, absorption coefficient and thickness of thin film were calculated from the study of transmission spectrum (wavelength vs transmission curve) data given by UV/VIS Spectrophotometer. Effect of number of coatings on transmittance and refractive index was also examined. It was observed that refractive index decreases with the number of coating and transmission value was more than 80% at wavelength greater than 450 nm in all cases. Structural analysis was studied by XRD measurement by using diffractometer which confirms tetragonal rutile structure of SnO2. Surface morphology was analysed from SEM micrograph and change in morphology on number of coat was discussed.

  12. Luminescence properties of p-type thin CdS films prepared by laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Ullrich, B. [Tokyo Univ. (Japan). Dept. of Physics; Ezumi, H. [Department of Electrical Engineering, Hiroshima-Denki Institute of Technology, Hiroshima 739-03 (Japan); Keitoku, S. [Hiroshima Women`s University, Hiroshima 734 (Japan); Kobayashi, T. [Tokyo Univ. (Japan). Dept. of Physics

    1995-12-01

    Investigations of the luminescence of p-type CdS:Cu thin (less than or equal to 2 {mu}m) films on glass substrate prepared by laser ablation were performed for the first time. The dependences of the luminescence on the Cu content in the thin films were studied at 300 K with argon laser lines at 457.9 nm, 488.0 nm and 514.5 nm. It is demonstrated that the luminescence excited with the 514.5 nm line corresponds to the donor-acceptor transition. Furthermore, it is shown that the intensity of the red emission of CdS:Cu films can be efficiently bleached by Cu doping. (orig.)

  13. High quality thin films of thermoelectric misfit cobalt oxides prepared by a chemical solution method

    Science.gov (United States)

    Rivas-Murias, Beatriz; Manuel Vila-Fungueiriño, José; Rivadulla, Francisco

    2015-01-01

    Misfit cobaltates ([Bi/Ba/Sr/Ca/CoO]nRS[CoO2]q) constitute the most promising family of thermoelectric oxides for high temperature energy harvesting. However, their complex structure and chemical composition makes extremely challenging their deposition by high-vacuum physical techniques. Therefore, many of them have not been prepared as thin films until now. Here we report the synthesis of high-quality epitaxial thin films of the most representative members of this family of compounds by a water-based chemical solution deposition method. The films show an exceptional crystalline quality, with an electrical conductivity and thermopower comparable to single crystals. These properties are linked to the epitaxial matching of the rock-salt layers of the structure to the substrate, producing clean interfaces free of amorphous phases. This is an important step forward for the integration of these materials with complementary n-type thermoelectric oxides in multilayer nanostructures. PMID:26153533

  14. High quality thin films of thermoelectric misfit cobalt oxides prepared by a chemical solution method.

    Science.gov (United States)

    Rivas-Murias, Beatriz; Manuel Vila-Fungueiriño, José; Rivadulla, Francisco

    2015-07-08

    Misfit cobaltates ([Bi/Ba/Sr/Ca/CoO]n(RS)[CoO2]q) constitute the most promising family of thermoelectric oxides for high temperature energy harvesting. However, their complex structure and chemical composition makes extremely challenging their deposition by high-vacuum physical techniques. Therefore, many of them have not been prepared as thin films until now. Here we report the synthesis of high-quality epitaxial thin films of the most representative members of this family of compounds by a water-based chemical solution deposition method. The films show an exceptional crystalline quality, with an electrical conductivity and thermopower comparable to single crystals. These properties are linked to the epitaxial matching of the rock-salt layers of the structure to the substrate, producing clean interfaces free of amorphous phases. This is an important step forward for the integration of these materials with complementary n-type thermoelectric oxides in multilayer nanostructures.

  15. (0 0 2-oriented growth and morphologies of ZnO thin films prepared by sol-gel method

    Directory of Open Access Journals (Sweden)

    Guo Dongyun

    2016-09-01

    Full Text Available Zinc acetate was used as a starting material to prepare Zn-solutions from solvents and ligands with different boiling temperature. The ZnO thin films were prepared on Si(1 0 0 substrates by spin-coating method. The effect of baking temperature and boiling temperature of the solvents and ligands on their morphologies and orientation was investigated. The solvents and ligands with high boiling temperature were favorable for relaxation of mechanical stress to form the smooth ZnO thin films. As the solvents and ligands with low boiling temperature were used to prepare Zn-solutions, the prepared ZnO thin films showed (0 0 2 preferred orientation. As n-propanol, 2-methoxyethanol, 2-(methylaminoethanol and monoethanolamine were used to prepare Zn-solutions, highly (0 0 2-oriented ZnO thin films were formed by adjusting the baking temperature.

  16. Preparation and characterization of thin films of the superconductor FeSe

    Energy Technology Data Exchange (ETDEWEB)

    Venzmer, Eike; Kronenberg, Alexander; Haaf, Sebastian ten; Jourdan, Martin [Institut fuer Physik, Johannes Gutenberg-Universitaet, Staudingerweg 7, 55128 Mainz (Germany); Maletz, Janek [IFW-Dresden, Institute for Solid State Research, PO Box 270116, D-01171 Dresden (Germany)

    2013-07-01

    The recently discovered class of iron pnictide compounds features a presumably unconventional mechanism of superconductivity. We investigate the iron chalcogenide FeSe, which is the structurally simplest representative of this class of materials. Epitaxial thin films are prepared by rf-sputtering from a stoichiometric FeSe target and alternatively by co-sputtering from separate Fe and Se targets. Both methods yield superconducting epitaxial thin films on MgO(100) as well as on YAlO{sub 3}(010) substrates. The influence of deposition rates and substrate temperature on phase formation, sample homogeneity, morphology and electronic transport properties are discussed. A comparison with the properties of previously prepared by MBE is presented. The main advantage of the sputter deposited samples is an improved morphology which is promising for the future integration in planar tunneling junctions for spectroscopic investigations.

  17. Comparative study of ZnO thin films prepared by different sol-gel route

    Directory of Open Access Journals (Sweden)

    F Esmaieli Ghodsi

    2012-03-01

    Full Text Available   Retraction Notice    The paper "Comparative study of ZnO thin films prepared by different sol-gel route" by H. Absalan and F. E. Ghodsi, which appeared in Iranian Journal of Physics Research, Vol. 11, No. 4, 423-428 (in Farsi is translation of the paper "Comparative Study of ZnO Thin Films Prepared by Different Sol-Gel Route" by F. E. Ghodsi and H. Absalan, which appeared in ACTA PHYSICA POLONICA A, Vol 118 (2010 (in English and for this reason is retracted from this journal.The corresponding author  (and also the first author is the only responsible person for this action.   

  18. Preparation of Thin Melanin-Type Films by Surface-Controlled Oxidation.

    Science.gov (United States)

    Salomäki, Mikko; Tupala, Matti; Parviainen, Timo; Leiro, Jarkko; Karonen, Maarit; Lukkari, Jukka

    2016-04-26

    The preparation of thin melanin films suitable for applications is challenging. In this work, we present a new alternative approach to thin melanin-type films using oxidative multilayers prepared by the sequential layer-by-layer deposition of cerium(IV) and inorganic polyphosphate. The interfacial reaction between cerium(IV) in the multilayer and 5,6-dihydroxyindole (DHI) in the adjacent aqueous solution leads to the formation of a thin uniform film. The oxidation of DHI by cerium(IV) proceeds via known melanin intermediates. We have characterized the formed DHI-melanin films using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), UV-vis spectroscopy, and spectroelectrochemistry. When a five-bilayer oxidative multilayer is used, the film is uniform with a thickness of ca. 10 nm. Its chemical composition, as determined using XPS, is typical for melanin. It is also redox active, and its oxidation occurs in two steps, which can be assigned to semiquinone and quinone formation within the indole structural motif. Oxidative multilayers can also oxidize dopamine, but the reaction stops at the dopamine quinone stage because of the limited amount of the multilayer-based oxidizing agent. However, dopamine oxidation by Ce(IV) was studied also in solution by UV-vis spectroscopy and mass spectrometry in order to verify the reaction mechanism and the final product. In solution, the oxidation of dopamine by cerium shows that the indole ring formation takes place already at low pH and that the mass spectrum of the final product is practically identical with that of commercial melanin. Therefore, layer-by-layer formed oxidative multilayers can be used to deposit functional melanin-type thin films on arbitrary substrates by a surface-controlled reaction.

  19. Structural and optical properties of phenylalanine and tyrosine thin films prepared by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Perez, M A [Laboratoire de Physico-Chimie des Materiaux Luminescents, CNRS-Universite Lyon I, 10 rue Andre-Marie Ampere, 69622 Villeurbanne (France); Garapon, C [Laboratoire de Physico-Chimie des Materiaux Luminescents, CNRS-Universite Lyon I, 10 rue Andre-Marie Ampere, 69622 Villeurbanne (France); Champeaux, C [Science des Procedes Ceramiques et Traitement de Surface, CNRS-Universite de Limoges, 123, avenue Albert Thomas, 87060 Limoges (France); Orlianges, J C [Science des Procedes Ceramiques et Traitement de Surface, CNRS-Universite de Limoges, 123, avenue Albert Thomas, 87060 Limoges (France)

    2007-04-15

    Thin films of the amino-acids phenylalanine (Phe) and tyrosine (Tyr) were prepared by PLD with a KrF laser at fluences of some hundreds mJ/cm{sup 2}. Conservation of the chemical structure and a metastable modification of the molecular interactions are evidenced by IR spectroscopy. The evolution of the refractive indices with fluence was correlated with the structure determined by X ray diffraction. The plume expansion imaging was achieved.

  20. Structural and optical properties of phenylalanine and tyrosine thin films prepared by pulsed laser deposition

    Science.gov (United States)

    Hernandez-Perez, M. A.; Garapon, C.; Champeaux, C.; Orlianges, J. C.

    2007-04-01

    Thin films of the amino-acids phenylalanine (Phe) and tyrosine (Tyr) were prepared by PLD with a KrF laser at fluences of some hundreds mJ/cm2. Conservation of the chemical structure and a metastable modification of the molecular interactions are evidenced by IR spectroscopy. The evolution of the refractive indices with fluence was correlated with the structure determined by X ray diffraction. Phe plume expansion imaging was achieved.

  1. Preparation of CulnSe2 thin films by paste coating

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Precursor pastes were obtained by milling Cu-In alloys and Se powders.CuInSe2 thin films were successfully prepared by precursor layers,which were coated using these pastes,and were annealed in a H2 atmosphere.The pastes were tested by laser particle diameter analyzer,simultaneous thermogravimetric and differential thermal analysis instruments (TG-DTA),and X-ray diffractometry (XRD).Selenized films were characterized by XRD,scanning electron microscopy (SEM),and energy dispersive spectroscopy (EDS).The results indicate that chalcopyrite CuInSe2 is formed at 180℃ and the crystallinity of this phase is improved as the temperature rises.All the CuInSe2 thin films,which were annealed at various temperatures,exhibit the preferred orientation along the (112) plane.The compression of precursor layers before selenization step is one oftbe most essential factors for the preparation of perfect CulnSe2 thin films.

  2. Appropriate materials and preparation techniques for polycrystalline-thin-film thermophotovoltaic cells

    Science.gov (United States)

    Dhere, Neelkanth G.

    1997-03-01

    Polycrystalline-thin-film thermophotovoltaic (TPV) cells have excellent potential for reducing the cost of TPV generators so as to address the hitherto inaccessible and highly competitive markets such as self-powered gas-fired residential warm air furnaces and energy-efficient electric cars, etc. Recent progress in polycrystalline-thin-film solar cells have made it possible to satisfy the diffusion length and intrinsic junction rectification criteria for TPV cells operating at high fluences. Continuous ranges of direct bandgaps of the ternary and pseudoternary compounds such as Hg1-xCdxTe, Pb1-xCdxTe, Hg1-xZnxTe, and Pb1-xZnxS cover the region of interest of 0.50-0.75 eV for efficient TPV conversion. Other ternary and pseudoternary compounds which show direct bandgaps in most of or all of the 0.50-0.75 eV range are Pb1-xZnxTe, Sn1-xCd2xTe2, Pb1-xCdxSe, Pb1-xZnxSe, and Pb1-xCdxS. Hg1-xCdxTe (with x~0.21) has been studied extensively for infrared detectors. PbTe and Pb1-xSnxTe have also been studied for infrared detectors. Not much work has been carried out on Hg1-xZnxTe thin films. Hg1-xCdxTe and Pb1-xCdxTe alloys cover a wide range of cut-off wavelengths from the far infrared to the near visible. Acceptors and donors are introduced in these materials by excess non-metal (Te) and excess metal (Hg and Pb) respectively. Extrinsic acceptor impurities are Cu, Au, and As while and In and Al are donor impurities. Hg1-xCdxTe thin films have been deposited by isothermal vapor-phase epitaxy (VPE), liquid phase epitaxy (LPE), hot-wall metalorganic chemical vapor deposition (MOCVD), electrodeposition, sputtering, molecular beam epitaxy (MBE), laser-assisted evaporation, and vacuum evaporation with or without hot-wall enclosure. The challenge in the preparation of Hg1-xCdxTe is to provide excess mercury incidence rate, to optimize the deposition parameters for enhanced mercury incorporation, and to achieve the requisite stoichiometry, grain size, and doping. MBE and MOCVD

  3. Preparation and characterization of superconductor thin films for application in printed circuit boards

    Energy Technology Data Exchange (ETDEWEB)

    Souza, G.A.; Carvalho, C.L.; Torsoni, G.B.; Rodrigues, V.D.; Souza, E.J.; Zadorosny, R. [UNESP, Ilha Solteira, SP (Brazil). Fac. de Engenharia. Grupo de Desenvolvimento e Aplicacoes de Materiais (GDAM)

    2011-07-01

    Full text: Since the discovery of high temperature superconductors (HTS) many studies have been performed, in terms to discover new materials with higher critical temperature and its potential applications. Technological advances have induced to use superconductor materials in the development of new devices that have higher processing speed, storage capacity and are miniaturized, what may imply in great evolution in the electronic area. Thinking about that advances and looking to supply some requirements, this work proposed to prepare a printed circuit board (PCB) with a superconductor thin film using an inexpensive and conventional photographic method. This work was divided in two steps: synthesis of the precursor solution and film preparation for superconductor printed circuit. In the preparation of superconductor thin film was considered to use the 2223 phase of the BSCCO system, which has been doped with Pb (BPSCCO) for stabilizing the same, and it presents a critical temperature around 110 K. This film was prepared from a precursor solution based on similar method developed by M. P. Pechini. The printed circuit was created by the photographic method of heat transfer which consisted of creation a circuit layout, with different dimensions and printed on photo paper (Epson S041140). The layout was transferred to the FR4 printed copper clad laminate was made with the household clothes iron. The precursor solution was deposited on Si substrate by spin-coating. The control of film thickness was performed by the deposition number that in this case was done five subsequent depositions to obtain an ideal thickness. Between each deposition the film was submitted to calcinations in order to eliminate organic matter. After that the film was submitted a heat treatment around 820 deg C / 5 minutes to obtain the expected superconducting phase and coupling and the grain growth. Film characterizations were made using optical microscopy, XRD and EDX, to check the dimensions and

  4. Preparation of AZO Nanoparticles, Ceramic Targets and Thin Films by a Co-precipitaition Method

    Institute of Scientific and Technical Information of China (English)

    XIU Sanmu; WEI Tiefeng; YANG Ye; ZHANG Ting; LI Jia; SONG Weijie

    2015-01-01

    We comprehensively study the co-precipitation preparation of aluminum doped zinc oxide (AZO) nanoparticles, ceramic target and thin iflm deposition. The nanoparticles calcined below 700℃possessed pure wurtzite structure of ZnO. When the calcination temperature exceeded 700℃, ZnAl2O4 phase appeared. The resistivity and relative density of the AZO target pressed from nanoparticles were 3×10-3Ω∙cm and 99.1%, respectively. The minimum resistivity of AZO thin films prepared by DC sputtering of the ceramic target reached 4.1×10–4Ω∙cm with the mobility of 33 cm2/v∙s and the carrier concentration of 4.5 ×1020 cm-3. The average optical transmittance of the AZO thin iflms in the visible wavelength range (400-800 nm) was more than 80%.

  5. Preparation, structural and optical characterization of nanocrystalline CdS thin film

    Science.gov (United States)

    Abdel-Galil, A.; Balboul, M. R.; Atta, A.; Yahia, I. S.; Sharaf, A.

    2014-08-01

    Nano-structured CdS thin film was deposited onto a glass substrate by an electron beam evaporation technique at room temperature from a powder prepared by a hydrothermal method. The morphology and structural properties of the as-deposited film were characterized using atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques. The AFM morphology study confirms that the CdS thin film has nano-sized grains and a dense morphology. The mean particle size that resulted from XRD analyses was 8.4 nm. Also, the XRD patterns show that CdS powder and thin film have hexagonal wurtzite type structure with a preferred c-axis orientation along (002) plane. The refractive index and the film thickness were obtained using the Swanepoel method from transmission spectrum. The optical band gap was calculated from the absorption spectrum, and was found to be 2.41 eV corresponding to direct optical transition. The dispersion of the refractive index was explained using a single oscillator model. The dielectric relaxation time and the optical conductivity were determined and studied with photon energy.

  6. Structure and morphology of thin films of linear aliphatic polyesters prepared by spin-coating.

    Science.gov (United States)

    Hernández, J J; Rueda, D R; García-Gutiérrez, M C; Nogales, A; Ezquerra, T A; Soccio, M; Lotti, N; Munari, A

    2010-07-06

    Thin films, with thicknesses from 10 to 400 nm of linear aliphatic polyesters (X, Y), based on propylenediol (X = 3) and on dicarboxylic acid of different chain length (Y = 2, 3, and 4 CH(2) units) were prepared by spin coating of CHCl(3) polymer solutions with different polymer concentrations. Morphology and structure of the spin coated thin films were investigated by atomic force microscopy (AFM) and by grazing incidence X-ray scattering techniques at small, (GISAXS) and wide angles (GIWAXS). AFM revealed a strong dewetting for all three polymers for coatings thinner than 100 nm. The polymer films are clearly semicrystalline for thicknesses higher than 50 nm. GIWAXS of the thicker films revealed their oriented crystalline nature. An edge-on-lamellae morphology is clearly shown by the AFM-phase images even for relatively thin films. SAXS with the beam parallel to the sample plane also support the presence of lamellae perpendicular to the substrate. The use of a mu-beam helped to interpret the GIWAXS patterns and allowed to obtain oriented WAXS patterns from melt solidified filaments. Thus, a crystal chain packing is proposed for the three polymers and consequently the indexing of the observed reflections. Accordingly, the polymer chains lie parallel to the substrate being the bc plane of the monoclinic crystal unit cell parallel to the substrate.

  7. Structural and optical characteristics of SnS thin film prepared by SILAR

    OpenAIRE

    2015-01-01

    SnS thin films were grown on glass substrates by a simple route named successive ion layer adsorption and reaction (SILAR) method. The films were prepared using tin chloride as tin (Sn) source and ammonium sulfide as sulphur (S) source. The structural, optical and morphological study was done using XRD, FESEM, FT-IR and UV-Vis spectrophotometer. XRD measurement confirmed the presence of orthorhombic phase. Particle size estimated from XRD was about 45 nm which fitted well with the FESEM measu...

  8. Photocatalytic activity of nanostructured TiO2 thin films prepared by pulsed spray pyrolysis

    OpenAIRE

    López, Alcides; Acosta, Dwight; Martínez, Arturo

    2006-01-01

    Nano-structured TiO2 thin films were deposited onto soda lime glass by the pneumatic spray pyrolysis method from a peroxo-titanium complex solution. Samples were prepared spraying 10 s the complex solution followed by an interruption of 20 s in order to avoid inadequate substrate cooling, the substrate temperature was varied from 230 to 430 °C in 50 °C steps. Amorphous as-deposited films crystallized to the anatase phase after an annealing process at 500 °C for 3 h. The photocatalytic activit...

  9. Preparation and characterization of nanostructured copper bismuth diselenide thin films from a chemical route

    Indian Academy of Sciences (India)

    R H Bari; L A Patil

    2010-12-01

    Thin films of copper bismuth diselenide were prepared by chemical bath deposition technique onto glass substrate below 60°C. The deposition parameters such as time, temperature of deposition and pH of the solution, were optimized. The set of films having different elemental compositions was prepared by varying Cu/Bi ratio from 0.13–1.74. Studies on structure, composition, morphology, optical absorption and electrical conductivity of the films were carried out and discussed. Characterization includes X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray analysis (EDAX), absorption spectroscopy, and electrical conductivity. The results are discussed and interpreted.

  10. ZnO THIN FILMS PREPARED BY SPRAY-PYROLYSIS TECHNIQUE FROM ORGANO-METALLIC PRECURSOR

    Directory of Open Access Journals (Sweden)

    Martin Mikulics

    2012-07-01

    Full Text Available Presented experiments utilize methanolic solution of zinc acetyl-acetonate as a precursor and sapphire (001 as a substrate for deposition of thin films of ZnO. The X-ray diffraction analysis revealed polycrystalline character of prepared films with preferential growth orientation along c-axis. The roughness of prepared films was assessed by AFM microscopy and represented by roughness root mean square (RMS value in range of 1.8 - 433 nm. The surface morphology was mapped by scanning electron microscopy showing periodical structure with several local defects. The optical transmittance spectrum of ZnO films was measured in wavelength range of 200-1000 nm. Prepared films are transparent in visible range with sharp ultra-violet cut-off at approximately 370 nm. Raman spectroscopy confirmed wurtzite structure and the presence of compressive stress within its structure as well as the occurrence of oxygen vacancies. The four-point Van der Pauw method was used to study the transport prosperities. The resistivity of presented ZnO films was found 8 × 10–2 Ω cm with carrier density of 1.3 × 1018 cm–3 and electron mobility of 40 cm2 V–1 s–1.

  11. Preparation of nanostructured PbS thin films as sensing element for NO2 gas

    Science.gov (United States)

    Kaci, S.; Keffous, A.; Hakoum, S.; Trari, M.; Mansri, O.; Menari, H.

    2014-06-01

    In this work, we demonstrate that semiconducting films of AIVBVI compounds, in particular, of nanostructured lead sulfide (PbS) which prepared by chemical bath deposition (CBD), can be used as a sensing element for nitrogen dioxide (NO2) gas. The CBD method is versatile, simple in implementation and gives homogeneous semiconductor structures. We have prepared PbS nanocrystalline thin film at different reaction baths and temperatures. In the course of deposition, variable amounts of additives, such as organic substances among them, were introduced into the baths. The energy dispersive analysis (EDX) confirms the chemical composition of PbS films. A current-voltage (I-V) characterization of Pd/nc-PbS/a-SiC:H pSi(100)/Al Schottky diode structures were studied in the presence of NO2 gas. The gas sensing behavior showed that the synthesized PbS nanocrystalline thin films were influenced by NO2 gas at room temperature. The results can be used for developing an experimental sensing element based on chemically deposited nanostructured PbS films which can be applicable in gas sensors.

  12. KTN thin films prepared by pulsed laser deposition on transparent single crystal quartz (100)

    Institute of Scientific and Technical Information of China (English)

    WANG; Xiaodong; PENG; Xiaofeng; ZHANG; Duanming

    2005-01-01

    Using the Sol-Gel method to produce the KTN ultrafine powder and the sintering technique with K2O atmosphere to prepare KTN ceramics as the targets instead of the KTN single crystal, highly oriented KTN thin films were produced on the transparent single crystal quartz (100) by the pulsed laser deposition (PLD). Since the thermal stress sustained by the quartz is relatively small, the limit temperature of the quartz substrates(300℃) is much lower than that of the P-Si substrates (560℃); the prepared thin film is at amorphous state. Increasing the pulsed laser energy density in the process incorporated with annealing the film after deposition at different temperatures converts the amorphous films into crystal. The optimal pulsed laser energy density and annealing temperature were 2.0 J/cm2 and 600℃, respectively. A discussion was made to understand the mechanism of film production at relatively low substrate temperature by PLD and effects of the annealing temperatures on the forming of the perovskite phase, and optimal conditions for the orientation of the crystal grain.

  13. Preparation and Characterization of Thermally Evaporated Octa Substituted Zinc Phthalocyanine Thin Films

    Directory of Open Access Journals (Sweden)

    Vinu T. Vadakel

    2012-12-01

    Full Text Available Thin films of Zinc Octakis Octyloxy Phthalocyanine (ZnPcOC8 are prepared at a base pressure of 10 – 5 Torr using Hind Hi-Vac-12A4 thermal evaporation plant. The films are deposited onto precleaned glass substrates kept at room temperature. Absorption spectra of the films are recorded using the Shimadzu 160A UV-Visible spectrophotometer. The effect of post deposition annealing on the optical constants are studied. The nature of optical transition is found to be direct type. The optical band gap energy of the annealed samples remains almost the same. The invariance of the optical band gap shows the thermal stability of the material for optical applications. The X-ray diffraction analysis of vacuum evaporated films reveals that the crystallinity increases with increase in annealing temperature. The variation of the surface morphology with annealing is also studied using Scanning Electron Micrograph (SEM.

  14. TiO{sub 2} thin films prepared by sol - gel method

    Energy Technology Data Exchange (ETDEWEB)

    Suciu, R C; Indrea, E; Silipas, T D; Dreve, S; Rosu, M C [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Popescu, V; Popescu, G; Nascu, H I, E-mail: ramona.suciu@itim-cj.r [Technical University of Cluj-Napoca, Physics Department, 15 C Daicoviciu, 400020 Cluj-Napoca (Romania)

    2009-08-01

    There is a growing awareness that titania (TiO{sub 2}) and TiO{sub 2}-based oxide systems are the most promising candidates for the development of photoelectrodes for photoelectrochemical cell (PEC) for solar-hydrogen production. The PEC is equipped with a single photoelectrode (photoanode) and cathode, both of which are immersed in an aqueous electrolyte. In this work we present a sol-gel method to prepare TiO{sub 2} thin films on ITO using tetraisopropoxides of titanium, acetylacetone, 1-butanol and Tween 80 as surfactant. The films were deposited on ITO coated glass slides by spray pyrolysis. UV-VIS spectra and fluorescence measurements were made for the solutions and films. X-ray diffraction was used for structural investigations and the morphology of the film was studied by Scanning Electron Microscopy.

  15. TiO2 thin films prepared by sol - gel method

    Science.gov (United States)

    Suciu, R. C.; Indrea, E.; Silipas, T. D.; Dreve, S.; Rosu, M. C.; Popescu, V.; Popescu, G.; Nascu, H. I.

    2009-08-01

    There is a growing awareness that titania (TiO2) and TiO2-based oxide systems are the most promising candidates for the development of photoelectrodes for photoelectrochemical cell (PEC) for solar-hydrogen production [1]. The PEC is equipped with a single photoelectrode (photoanode) and cathode, both of which are immersed in an aqueous electrolyte. In this work we present a sol-gel method to prepare TiO2 thin films on ITO using tetraisopropoxides of titanium, acetylacetone, 1-butanol and Tween 80 as surfactant. The films were deposited on ITO coated glass slides by spray pyrolysis. UV-VIS spectra and fluorescence measurements were made for the solutions and films. X-ray diffraction was used for structural investigations and the morphology of the film was studied by Scanning Electron Microscopy.

  16. Magnetic properties of ZnO:Cu thin films prepared by RF magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Zhuo Shiyi; Xiong Yuying; Gu Min, E-mail: xiongyy@scnu.edu.c [Laboratory of Quantum Information Technology, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China)

    2009-05-01

    ZnO films and ZnO:Cu diluted magnetic semiconductor films were prepared by radio frequency magnetron sputtering on Si (111) substrates, with targets of ZnO and Zn{sub 0.99}Cu{sub 0.01}O, respectively. The plasma emission spectra were analyzed by using a grating monochromator during sputtering. The X-ray photoelectron spectroscopy measurements indicate the existence of Zni defect in the films, and the valence state of Cu is 1+. The X-ray diffraction measurements indicate that the thin films have a hexagonal wurtzite structure and have a preferred orientation along the c-axis. The vibrating sample magnetometer measurements indicate that the sample is ferromagnetic at room temperature, and the origin of the magnetic behavior of the samples is discussed.

  17. Magnetic properties of ZnO:Cu thin films prepared by RF magnetron sputtering

    Institute of Scientific and Technical Information of China (English)

    Zhuo Shiyi; Xiong Yuying; Gu Min

    2009-01-01

    ZnO films and ZnO:Cu diluted magnetic semiconductor films were prepared by radio frequency magnetron sputtering on Si (111) substrates, with targets of ZnO and Zn0.99Cu0.01 O, respectively. The plasma emission spectra were analyzed by using a grating monochromator during sputtering. The X-ray photoelectron spectroscopy measurements indicate the existence of Zni defect in the films, and the valence state of Cu is 1. The X-ray diffraction measurements indicate that the thin films have a hexagonal wurtzite structure and have a preferred orientation along the c-axis. The vibrating sample magnetometer measurements indicate that the sample is ferromagnetic at room temperature, and the origin of the magnetic behavior of the samples is discussed.

  18. Fabrication and properties of nanocrystalline zinc oxide thin film prepared by sol-gel method

    Directory of Open Access Journals (Sweden)

    Sumetha Suwanboon

    2008-01-01

    Full Text Available Zinc oxide (ZnO thin films were prepared on glass substrate by sol-gel dip-coating method. The structural properties were investigated by x-ray diffraction (XRD method and atomic force microscope (AFM. The optical properties were measured by UV-Vis spectrophotometer. The XRD patterns showed that the films formed preferred orientation along c-axis which increased as a function of polyvinyl pyrrolidone (PVP concentration. The films gave the crystallite size of 15-18 nm calculated by Scherrer’s formula and grain size of 48-70 nm measured by AFM at different PVP concentrations. The direct optical band gap of the films was in the range of 3.80-4.08 eV.

  19. Preparation of hard magnetic materials in thin film form

    Energy Technology Data Exchange (ETDEWEB)

    Pigazo, F.; Palomares, F.J. [Instituto de Ciencia de Materiales de Madrid-CSIC, c/ Sor Juana Ines de la Cruz 3, 28049 Madrid (Spain); Cebollada, F. [EUITT-UPM, Carretera de Valencia km 7, 28031 Madrid (Spain); Gonzalez, J.M. [Unidad Asociada ICMM-IMA, c/ Sor Juana Ines de la Cruz 3, 28049 Madrid (Spain)], E-mail: jesus.m.gonzalez@icmm.csic.es

    2008-07-15

    We report on the preparation, by means of pulsed laser ablation deposition, of trilayers of nominal composition Cr/SmCo{sub 5}/Cr//Si with thicknesses in the order of 250/240/125 nm, respectively. According to the results of the structural, chemical and magnetic characterizations performed in our as-deposited samples, the Sm-Co layer was structurally amorphous, exhibited abrupt compositional interfaces with the capping and buffering layers, and coercivities of a few hundreds of Oe. Magnetic hardness was developed upon submitting the samples to current anneals under vacuum at temperatures in the range of 540-670 deg. C. The hardening process was followed in detail by correlating the phase distribution, the nature of the interlayer atomic diffusion processes, the occurrence of textures and the temperature dependence of the coercive force. From our results we conclude about (i) the occurrence of a large degree of Co diffusion/segregation, which results in the detection, from the diffraction and magnetometric results, of the presence of CoCr alloys in the treated samples, and (ii) the close correlation, evidenced from the fits of the temperature dependence of the coercive force to the micromagnetic model, between the coercivity optimization and the crystallinity enhancement of the SmCo{sub 5} grains.

  20. Multifunctional thin film surface

    Energy Technology Data Exchange (ETDEWEB)

    Brozik, Susan M.; Harper, Jason C.; Polsky, Ronen; Wheeler, David R.; Arango, Dulce C.; Dirk, Shawn M.

    2015-10-13

    A thin film with multiple binding functionality can be prepared on an electrode surface via consecutive electroreduction of two or more aryl-onium salts with different functional groups. This versatile and simple method for forming multifunctional surfaces provides an effective means for immobilization of diverse molecules at close proximities. The multifunctional thin film has applications in bioelectronics, molecular electronics, clinical diagnostics, and chemical and biological sensing.

  1. Electrical transport properties of MoO{sub 3} thin films prepared by laser assisted evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Carreno, L.D.; Pardo, A.; Zuluaga, M.; Torres, J.; Alfonso, J.E. [Group of Materials with Technological Applications, GMAT, Physics Department, Universidad Nacional de Colombia, Bogota (Colombia); Cortes-Bracho, O.L. [Group of Materials with Technological Applications, GMAT, Physics Department, Universidad Nacional de Colombia, Bogota (Colombia); Electronic Engineering Department, Universidad Nacional de Colombia, Bogota (Colombia)

    2007-07-01

    In the present paper the growth of MoO{sub 3} thin films on common glass substrates are described. The films were prepared by evaporation of a MoO{sub 3} target with a CO{sub 2} laser (10.6 {mu}m), operating in the continuous wave mode. The effect of substrate temperature on the crystallographic structure and electrical properties of MoO{sub 3} thin films was studied. The chemical composition of the different species formed on the films surface was obtained by X-ray photoelectron spectroscopy (XPS) and the crystalline structure was studied with X-ray diffraction (XRD). The electrical conductivity of the films was determined using the standard four-points method. Conductivity of the films varied from de 10{sup -9} to 10{sup -5} ({omega}cm){sup -1} in the 300-600 K temperature range. Arrhenius-type plots for the electrical conductivity indicate the presence of at least two different conduction mechanisms. The I-V characteristic curve shows an ohmic behavior only in the 4.5-60 V range. Outside this interval the I-V curve has a behavior described by a power law. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Characterizations of maghemite thin films prepared by a sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Lau, L. N., E-mail: lau7798@gmail.com; Ibrahim, N. B., E-mail: baayah@ukm.edu.my [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor. Malaysia (Malaysia)

    2015-09-25

    Iron is one of the abundant elements of Mother Nature and its compound, iron oxide is an interesting material to study since its discovery in the form of magnetite. It can exist in many phases such as hematite and maghemite, this unique nature has put it as a potential candidate in various applications. The aim of this work is to study the influence of different precursor concentrations on the microstructural and magnetic properties of iron oxide thin film. All samples were prepared via the sol-gel method followed by a spin coating technique on quartz substrates. Iron oxide films were confirmed as maghemite phase from X-ray diffraction patterns. The film morphology was examined by a field emission scanning electron microscope and it showed non-systematic value of average grain size and film thickness throughout the study. Hysteresis loop further confirmed that maghemite is a magnetic material when it was characterized by a vibrating sample magnetometer. The coercivity did not show any correlation with molarity. Nevertheless, it increased as the precursor concentration of the film increased due to the domain behaviour. In conclusion, maghemite thin films were successfully synthesized by the sol-gel method with different precursor concentrations in this work.

  3. Grain Size and Photocatalytic Activity of Nanometer TiO2 Thin Films Prepared by the Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Transparent anatase TiO2 nanometer thin films with photocatalytic activity were prepared via the sol-gel method on soda-lime glass. The thickness, crystalline phase, grain size, surface hydroxyl amount and so on were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-visible spectrophotometer (UV-VIS). The photocatalytic activity of TiO2 thin films was evaluated for the photocatalytic decolorization of aqueous methyl orange. The effects of film thickness on the crystalline phase, grain size, transmittance and photocatalytic activity of nanometer TiO2 thin films were discussed.

  4. Experimental Studies on Doped and Co-Doped ZnO Thin Films Prepared by RF Diode Sputtering

    OpenAIRE

    2009-01-01

    Our research on the growing and characterizing of p-type ZnO thin films, prepared by radio frequency (RF) diode sputtering, mono-doped with nitrogen, and co-doped with aluminium and nitrogen, is a response of the need from p-type ZnO thin films for device applications. The dopants determine the conductivity type of the film and its physical properties. We obtained p-type ZnO thin films by RF diode sputtering and using a nitrogen dopant source. The novelty in our approach is in the use of a pl...

  5. Preparation of ion-exchange thin film using plasma processes. Plasma process wo mochiita ion kokansei usumaku no sakusei

    Energy Technology Data Exchange (ETDEWEB)

    Ogumi, Z.; Uchimoto, Y. (Kyoto University, Kyoto (Japan). Faculty of Engineering)

    1992-10-31

    The present report describes a study which aims at preparation of a new functional film by plasma polymerization. For this purpose, 4-vinylpyridine monomer is plasma-polymerized to obtain a thin film, which is quaternarized with 1-bromopropane to produce an anion exchange thin film, which is laminated on the surface of a cation-exchange film to make a mono-valent cation perm-selective film. In plasma-polymerization, the relations of polymerizing pressure, as parameter, to the deposition rate of the polymerizerd film and the characteristics of compound were clarified. In preparing the anion-exchange thin film, the preparation of uniform ultrathin films with no pinhole was attempted. For this purpose, the transference number of Cl[sup -] was measured so as to confirm that Cl[sup -] is uniformly distributed and fixed cation groups are distributed uniformly in the film. The perm-selective film exhibited a high mono-valent cation perm-selectivity while its film resistance was increased. This increase is found to be broken down to the resistance of the plasma-polymerization film layer and the resistance of the film interface. The latter arises from the implantation of nitrogen-cointaining species in the plasma onto the surface of the cation exchange film. 26 refs., 10 figs., 2 tabs.

  6. Electrical and Optical Properties of Fluorine Doped Tin Oxide Thin Films Prepared by Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    Ziad Y. Banyamin

    2014-10-01

    Full Text Available Fluorine doped tin oxide (FTO coatings have been prepared using the mid-frequency pulsed DC closed field unbalanced magnetron sputtering technique in an Ar/O2 atmosphere using blends of tin oxide and tin fluoride powder formed into targets. FTO coatings were deposited with a thickness of 400 nm on glass substrates. No post-deposition annealing treatments were carried out. The effects of the chemical composition on the structural (phase, grain size, optical (transmission, optical band-gap and electrical (resistivity, charge carrier, mobility properties of the thin films were investigated. Depositing FTO by magnetron sputtering is an environmentally friendly technique and the use of loosely packed blended powder targets gives an efficient means of screening candidate compositions, which also provides a low cost operation. The best film characteristics were achieved using a mass ratio of 12% SnF2 to 88% SnO2 in the target. The thin film produced was polycrystalline with a tetragonal crystal structure. The optimized conditions resulted in a thin film with average visible transmittance of 83% and optical band-gap of 3.80 eV, resistivity of 6.71 × 10−3 Ω·cm, a carrier concentration (Nd of 1.46 × 1020 cm−3 and a mobility of 15 cm2/Vs.

  7. Optical Characteristics of La-Doped ZnS Thin Films Prepared by Chemical Bath Deposition

    Institute of Scientific and Technical Information of China (English)

    XIE Hai-Qing; CHEN Yuan; HUANG Wei-Qing; HUANG Gui-Fang; PENG Ping; PENG Li; WANG Tai-Hang; ZENG Yun

    2011-01-01

    Undoped and La-doped ZnS thin films are prepared by chemical bath deposition (CBD) process through the co-precipitation reaction of inorganic precursors zinc sulfate, thiosulfate ammonia and La2O3. Composition of the films is analyzed using an energy-dispersive x-ray spectroscopy (EDS). Absorption spectra and spectral transmittances of the films are measured using a double beam UV-VIS spectrophotometer (TU-1901). It is found that significant red shifts in absorption spectra and decrease in absorptivity are obtained with increasing lanthanum. Moreover, optical transmittance is increased as La is doped, with a transmittance of more than 80% for wavelength above 360 nm in La-doped ZnS thin films. Compared to pure ZnS, the band gap decreases and flat-band potential positively shifts to quasi-metal for the La-doped ZnS. These results indicate that La-doped ZnS thin films could be valuably adopted as transparent electrodes.%@@ Undoped and La-doped ZnS thin films are prepared by chemical bath deposition (CBD) process through the co-precipitation reaction of inorganic precursors zinc sulfate, thiosulfate ammonia and La2O2.Composition of the 61ms is analyzed using an energy-dispersive x-ray spectroscopy (EDS).Absorption spectra and spectral tra.nsmitta.nces of the 61ms are measured using a double beam UV-VIS spectrophotometer (TU-1901).It is found that significant red shifts in absorption spectra and decrease in absorptivity are obtained with increasing lanthanum.Moreover, optical transmittance is increased as La is doped, with a transmittance of more than 80% for wavelength above 360 nm in La-doped ZnS thin 61ms.Compared to pure ZnS, the band gap decreases and flat-band potential positively shifts to quasi-metal for the La-doped ZnS.These results indicate that La-doped ZnS thin 6hns could be valuably adopted as transparent electrodes.

  8. Optical properties of amorphous and polycrystalline Sb2Se3 thin films prepared by thermal evaporation

    Science.gov (United States)

    Chen, Chao; Li, Weiqi; Zhou, Ying; Chen, Cheng; Luo, Miao; Liu, Xinsheng; Zeng, Kai; Yang, Bo; Zhang, Chuanwei; Han, Junbo; Tang, Jiang

    2015-07-01

    Sb2Se3 is a very promising photovoltaic material because of its attractive material, optical and electrical properties. Very recently, we reported a superstrate CdS/Sb2Se3 solar cell with 5.6% certified efficiency. In this letter, we focused on the optical properties of amorphous and polycrystalline Sb2Se3 thin films prepared by thermal evaporation. Using temperature dependent transmission spectrum and temperature dependent photoluminescence, the indirect optical transition nature and bandgap values as functions of temperature were acquired. Using ellipsometry measurements and Swanepoel's envelope method, the refractive indices as well as the dielectric constant in a wide wavelength range of 193-2615 nm were obtained. These works would lay the foundation for the further development of Sb2Se3 thin film solar cells.

  9. A Simple Substrate Heater Device With Temperature Controller for Thin Film Preparation

    Directory of Open Access Journals (Sweden)

    G. Rendón

    2012-08-01

    Full Text Available A simple substrate heater and its temperature controller were designed and built in order to prepare thin films in a highvacuum deposition system. The substrate heater was elaborated with a glass-ceramic body and a molybdenum foilheater. The applied power and the temperature are regulated by a power controller board using a microcontrollerprogrammed with a proportional-integrative-derivative algorithm. The heater/controller system was tested in a highvacuum deposition system and the results of its characterization at 100, 200, 300 and 400 °C are presented. Avariation in temperature better than ± 0.5 °C was obtained for all the tested temperatures. An application of thesubstrate heater is demonstrated by evaporating gold thin films on heated glass substrates.

  10. Organic-inorganic Hybrids Towards the Preparation of Nanoporous Composite Thin Films for Microelectronic Application

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Silicon containing materials have traditionally been used in microelectronic fabrication. Semiconductor devices often have one or more arrays of patterned interconnect levels that serve to electrically couple the individual circuit elements forming an integrated circuit. These interconnect levels are typically separated by an insulating or dielectric film. Previously, a silicon oxide film was the most commonly used material for such dielectric films having dielectric constants(k) near 4. 0. However, as the feature size is continuously scaling down, the relatively high k of such silicon oxide films became inadequate to provide efficient electrical insulation. As such, there has been an increasing market demand for materials with even lower dielectric constant for Interlayer Dielectric (ILD) applications, yet retaining thermal and mechanical integrity. We wish to report here our investigations on the preparation of ultra-low k ILD materials using a sacrificial approach whereby organic groups are burnt out to generate low k porous ORMOSIL films. We have been able to prepare a variety of organically modified silicone resins leading to highly microporous thin films, exhibiting ultra-low k from 1.80 to 2.87, and good to high modulus, 1.5 to 5.5 Gpa. Structure property influences on porosity, dielectric constant and modulus will be discussed.

  11. Study on Preparation of High-k Organic-Inorganic Thin Film for Organic-Inorganic Thin Film Transistor Gate Dielectric Application

    Science.gov (United States)

    Lee, Wen-Hsi; Liu, Chao-Te; Lee, Ying-Chieh

    2012-06-01

    A simple solution-based deposition technique combined with spin-coating is a plausible way to prepare ultra-thin organic-inorganic nanocomposite films. In this study, we describe the spin-coating deposition of a colloidal nanoparticle suspension to obtain an ultra-thin organic-inorganic composite film as a gate insulator for organic thin film transistor (O-TFT) application. To obtain a homogenous organic-inorganic composite film, well-dispersed TiO2 nanoparticles in γ-butyrolactone and polyimide are important; therefore, several dispersants were assessed on the basis of the measurement of the rheological behavior of slurries. The thickness of the organic-inorganic composite film is mainly determined by the speed of spin-coating and viscosity of slurries. An approximately 4000-Å-thick nanocomposite film with homogeneous distribution of TiO2 nanoparticles in polyimide and low roughness was obtained after curing at 200 °C, resulting in a low leakage current density of the nano-composite film, when less than 2 vol % TiO2 nanoparticles were well dispersed in polyimide slurry. The dielectric constant of the organic-inorganic nanocomposite increases with increasing TiO2 content in polyimide, being situated in the range between 4 and 5.

  12. Cu2ZnSnS4 thin films prepared by sulfurizing different multilayer metal precursors

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun; SHAO LeXi

    2009-01-01

    Cu2ZnSnS4 (OZTS) thin films were successfully fabricated on glass substrates by sulfurizing Ou-Sn-Zn multilayer precursors, which were deposited by ion beam sputtering and RF magnetron sputtering, respectively. The structural, electrical and optical properties of the prepared films under various proc-essing conditions were investigated in detail. Results showed that the as-deposited OZTS thin films with the precursors by both ion beam sputtering and RF magnetron sputtering have a composition near stoichiometric. The crystallization of the samples, however, has a strong dependence on the atomic percent of constituents of the prepared CZTS films. A single phase stannite-type structure OZTS with a large absorption coefficient of 104/cm in the visible range could be obtained after sulfurization at 520℃for 2 h. The samples relative to the RF magnetron sputtering showed a low resistivity of 0.073 Ωcm and band gap energy of about 1.53 eV. The samples relative to the ion beam sputtering exhibited a resistiv-ity of 0.36 Ωcm and the band gap energy is about 1.51 eV.

  13. Cu2ZnSnS4 thin films prepared by sulfurizing different multilayer metal precursors

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Cu2ZnSnS4 (CZTS) thin films were successfully fabricated on glass substrates by sulfurizing Cu-Sn-Zn multilayer precursors, which were deposited by ion beam sputtering and RF magnetron sputtering, respectively. The structural, electrical and optical properties of the prepared films under various processing conditions were investigated in detail. Results showed that the as-deposited CZTS thin films with the precursors by both ion beam sputtering and RF magnetron sputtering have a composition near stoichiometric. The crystallization of the samples, however, has a strong dependence on the atomic percent of constituents of the prepared CZTS films. A single phase stannite-type structure CZTS with a large absorption coefficient of 104/cm in the visible range could be obtained after sulfurization at 520℃ for 2 h. The samples relative to the RF magnetron sputtering showed a low resistivity of 0.073 ?cm and band gap energy of about 1.53 eV. The samples relative to the ion beam sputtering exhibited a resistivity of 0.36 Ωcm and the band gap energy is about 1.51 eV.

  14. Preparation and optical properties of composite thin films with embedded InP nanoparticles

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    InP nanoparticles embedded in SiO2 thin films were prepared by radio-frequency magnetron co-sputtering. We analyzed the structure and growth behavior of the composite films under different preparation conditions. X-ray diffraction and Raman spectroscopy analyses indicate that InP nanoparticles have a polycrystalline structure. The aver-age size of InP nanoparticles is in the range of 3-10 nm. The broadening and red shift of the Raman peaks were observed,which can be interpreted by the phonon confinement model. Optical transmission spectra indicate that the optical absorp-tion edges of the films can be modulated in the visible light range. The marked blue shift of the absorption edge with respect to that of bulk InP is explained by the quantum con-finement effect. The theoretical values of the blue shift pre-dicted by the effective mass approximation model are differ-ent from the experimental results for the InP-SiO2 system. Analyses indicate that the exciton effective mass of the InP nanoparticles is not constant and is inverse relative to the particles radius,which may be the main reason that results in the discrepancy between the theoretical and the experi-mental result. We discussed the possible transition of the direct band gap to the indirect band gap for InP nanoparti-cles embedded in SiO2 thin films.

  15. Preparation of LaMnO3/graphene thin films and their photocatalytic activity

    Institute of Scientific and Technical Information of China (English)

    胡婕; 门杰; 马嘉华; 黄浩

    2014-01-01

    A novel photocatalyst of LaMnO3/graphene thin films with the perovskite-type was synthesized by sol-gel process assisted with spin-coating methods on glass substrates. The prepared samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Brumauer-Emmett-Teller (BET) surface area analyzer, X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectroscopy. Results showed that after the introduction of gra-phene, the perovskite structure was unchanged and the size of LaMnO3 particles was about 22 nm, which uniformed growth in gra-phene sheet. Determination of contact angle indicated that the contact angle of glass substrate decreased and the hydrophilicity im-proved after treating with H2SO4 and APTES. The UV-Vis photocatalytic activity of the photocatalysts was evaluated by the degrada-tion of diamine green B. LaMnO3/graphene thin films had better photocatalytic ability than LaMnO3 and TiO2 films. The obtained k was 0.5627 and 0.3441 h–1 corresponding to LaMnO3/graphene films and TiO2 films, respectively.

  16. Influence of deposition rate on the properties of ZrO2 thin films prepared in electron beam evaporation method

    Institute of Scientific and Technical Information of China (English)

    Dongping Zhang(张东平); Meiqiong Zhan(占美琼); Ming Fang(方明); Hongbo He(贺洪波); Jianda Shao(邵建达); Zhengxiu Fan(范正修)

    2004-01-01

    ZrO2 thin films were prepared in electron beam thermal evaporation method. And the deposition rate changed from 1.3 to 6.3 nm/s in our study. X-ray diffractometer and spectrophotometer were employed to characterize the films. X-ray diffraction (XRD) spectra pattern shows that films structure changed from amorphous to polycrystalline with deposition rate increasing. The results indicate that internal stresses of the films are compressive in most case. Thin films deposited in our study are inhomogeneous, and the inhomogeneity is enhanced with the deposition rate increasing.

  17. Preparation of n-type semiconductor SnO2 thin films

    Institute of Scientific and Technical Information of China (English)

    Achour Rahal; Said Benramache; Boubaker Benhaoua

    2013-01-01

    We studied fluorine-doped tin oxide on a glass substrate at 350 ℃ using an ultrasonic spray technique.Tin (Ⅱ) chloride dehydrate,ammonium fluoride dehydrate,ethanol and NaOH were used as the starting material,dopant source,solvent and stabilizer,respectively.The SnO2:F thin films were deposited at 350 ℃ and a pending time of 60 and 90 s.The as-grown films exhibit a hexagonal wurtzite structure and have (101) orientation.The G =31.82 nm value of the grain size is attained from SnO2:F film grown at 90 s,and the transmittance is greater than 80% in the visible region.The optical gap energy is found to measure 4.05 eV for the film prepared at 90 s,and the increase in the electrical conductivity of the film with the temperature of the sample is up to a maximum value of 265.58 (Ω·cm)-1,with the maximum activation energy value of the films being found to measure 22.85 meV,indicating that the films exhibit an n-type semiconducting nature.

  18. Bactericidal and Photocatalytic Activity of Fe3+- TiO2 Thin Films Prepared by the Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    WANG Xun; GONG Wenqi

    2008-01-01

    Pure TiO2 thin films and iron doped TiO2 thin films on glass substrate were prepared by sol-gel method, and characterized by X-ray diffractometer (XRD), thermo-gravimetric analysis (TG-DSC), high resolution transmission electron microscope (HRTEM), scanning electron microscope (SEM) and UV-Vis spectroscopy, respectively. The experimental results show that the pure TiO2 thin films and iron doped TiO2 thinfilms can destroy most of the eseheriehia coli and bacillus subtillis under the irradiation of 365 nm UV-light.However, the iron doped TiO2 thin film is a better photocatalyst than pure TiO2 thin film. The ultrastructural studies provide direct evidences for understanding the bactericidal mechanism of the TiO2 photocatalyst.

  19. Method for Aluminum Oxide Thin Films Prepared through Low Temperature Atomic Layer Deposition for Encapsulating Organic Electroluminescent Devices

    Directory of Open Access Journals (Sweden)

    Hui-Ying Li

    2015-02-01

    Full Text Available Preparation of dense alumina (Al2O3 thin film through atomic layer deposition (ALD provides a pathway to achieve the encapsulation of organic light emitting devices (OLED. Unlike traditional ALD which is usually executed at higher reaction n temperatures that may affect the performance of OLED, this application discusses the development on preparation of ALD thin film at a low temperature. One concern of ALD is the suppressing effect of ambient temperature on uniformity of thin film. To mitigate this issue, the pumping time in each reaction cycle was increased during the preparation process, which removed reaction byproducts and inhibited the formation of vacancies. As a result, the obtained thin film had both high uniformity and density properties, which provided an excellent encapsulation performance. The results from microstructure morphology analysis, water vapor transmission rate, and lifetime test showed that the difference in uniformity between thin films prepared at low temperatures, with increased pumping time, and high temperatures was small and there was no obvious influence of increased pumping time on light emitting performance. Meanwhile, the permeability for water vapor of the thin film prepared at a low temperature was found to reach as low as 1.5 × 10−4 g/(m2·day under ambient conditions of 25 °C and 60% relative humidity, indicating a potential extension in the lifetime for the OLED.

  20. Synthesis and characterization of SnO2 thin films prepared by dip-coating method

    Science.gov (United States)

    Carvalho, D. H. Q.; Schiavon, M. A.; Raposo, M. T.; de Paiva, R.; Alves, J. L. A.; Paniago, Roberto. M.; Speziali, N. L.; Ferlauto, A. S.; Ardisson, J. D.

    The optical, electrical and structural properties of SnOare responsible for a large number of technological 2 applications such as gas sensors, optical-electonic devices, varistors and displays. In this paper, we report the preparation of SnO thin films deposited on glass, quartz and silicon substrates by the technique of sol-gel dip-2coating. The films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ellipsometry and Mössbauer spectroscopy. We combine the experimental results with ab initio all-electrons calculations, using the density functional theory within the framework of the full-potential linear augmented plane waves method, in order to extract hyperfine parameters. The results show that the synthesis method is able to produce good quality films and that the theory can be helpful to determine quantities difficult to be measured experimentally.

  1. Study on UV Shielding TiO2 Thin Film Prepared by Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    Shihai Zhao; Xiaohui Wang; Shaobo Xin; Qiang Jiang; Xiaoping Liang

    2006-01-01

    Titanium dioxide (TiO2) thin films were prepared on microscopes slides by sol-gel and dip-coating processes from specially formulated sols. The results show that there exists anatase and rutile structure of TiO2 when heat treatment temperature is 450℃, and at 800℃, TiO2 particle size is of below 100 nm and rutile structure is presented. In the range of 360 nm~400 nm the transmittance of TiO2 sol increases with the increasing of the concentration of Ti(OC4H9)4 in ethanol solution.The transmittance of TiO2 films with various number of the layer is measured to be 0% below 320 nm, and the three-layer TiO2 film is of the best UV resistance in the range of 320 nm~400 nm.

  2. HT-LiCoO2 Thin Film Positive Electrodes Prepared by RF Magnetron Sputtering

    Science.gov (United States)

    Kumar, P. Jeevan; Babu, K. Jayanth; Hussain, O. M.

    2011-07-01

    Thin films of LiCoO2 prepared by RF magnetron sputtering on Si/SiO2/Ti/Au substrates are investigated microstructural and electrochemical properties. The as deposited film shown layered with (003) preferred orientation. After annealing at 923 K in presence of O2 ambient (5×10-2 mbar), HT hexagonal phase LiCoO2 is obtained for the films deposited at O2 to Ar ratio 1:9 and at substrate temperature 523 K. LiCoO2 deposit is unambiguously shown two Raman bands at 465 and 545 cm-1 confirming layered hexagonal structure. Also, studied the performance of the LiCoO2 as positive electrode in aqueous (Pt// LiCoO2) and non-aqueous (Li// LiCoO2) Li-ion rechargeable batteries.

  3. Magnetic properties of FeCoC thin films prepared by various sputtering methods

    Energy Technology Data Exchange (ETDEWEB)

    Edon, V; Dubourg, S [CEA, DAM, LE RIPAULT, F-37260 Monts (France); Vernieres, J; Bobo, J-F, E-mail: sebastien.dubourg@cea.fr [LNMH-CEMES-CNRS-ONERA, F-31055 Toulouse (France)

    2011-07-06

    In order to grow nanocrystallized soft magnetic thin films, FeCoC alloys were first deposited by reactive sputtering in Ar/C{sub 2}H{sub 2} plasma. This deposition process rendered it possible to incorporate a carbon content between 0 and 30 at.% into the FeCo samples. The films were then compared to FeCoC samples obtained from a Fe{sub 65}Co{sub 35}/C composite target, with an adjustable amount of C slots. Layers with soft magnetic properties were achieved when increasing the C{sub 2}H{sub 2} rate during the reactive deposition, whereas films deposited by sputtering of FeCo and C on the same target demonstrated a very high coercivity. Permeability spectra measurements (and published elsewhere) demonstrated that FeCoC prepared with acetylene is a very promising material for high-frequency magnetic devices.

  4. Influence of Annealing on Physical Properties of CdO Thin Films Prepared by SILAR Method

    Institute of Scientific and Technical Information of China (English)

    B. Gokul; P. Matheswaran; R. Sathyamoorthy

    2013-01-01

    Cadmium oxide (CdO) thin films were prepared by successive ionic layer adsorption and reaction (SILAR) method and annealed at 250-450 ℃ for 2 h.The prepared films were characterized by X-ray diffraction (XRD),optical spectroscopy,scanning electron microscopy (SEM) and Hall effect measurement.The XRD analysis reveals that the films were polycrystalline with cubic structure.Both crystallinity and the grain size were found to increase with increasing annealing temperature.SEM analysis shows the porous nature of the surface with spherical nanoclusters.Energy dispersive spectroscopic analysis (EDS) confirmed the presence of Cd and O elements without any additional impurities.The films exhibited maximum transmittance (82%-86%) in infra-red (IR) region.Transmittance was found to decrease with increasing annealing temperature and the estimated band gap energy (Eg) was in the range of 2.24-2.44 eV.Hall effect measurement shows an increase in carrier concentration and a decrease in resistivity with increasing annealing temperature.The carrier concentration (N) and resistivity (ρ) of about 1.26 × 1022 cm 3 and 8.71 × 10 3 Ω cm are achieved for the film annealed at 450 ℃ for 2 h.

  5. Electrical and optical properties of CZTS thin films prepared by SILAR method

    Directory of Open Access Journals (Sweden)

    J. Henry

    2016-03-01

    Full Text Available In the present work, Cu2ZnSnS4 (CZTS thin film was deposited onto the glass substrate by simple and economic SILAR method and its structural, morphological, optical and electrical properties were analyzed. X-ray diffraction (XRD analysis confirms the formation of CZTS with kesterite structure and the average crystallite size is found to be 142 nm. Scanning electron microscope (SEM image shows that the film has homogeneous, agglomerated surface without any cracks. The prepared CZTS film shows good optical absorption (104 cm−1 in the visible region and the optical band gap energy is found to be quite close to the optimum value of about 1.54 eV for solar cell application. The refractive index of the prepared film is found to be 2.85. The electrical resistivity of the film is found to be ∼10−2 Ω cm at room temperature.

  6. Preparation and characterization of CdTeO{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    El Azhari, M.Y.; Azizan, M.; Bennouna, A.; Outzourhit, A.; Ameziane, E.L. [Dept. de Phys. Marrakech (Morocco). Lab. de Physique des Solides et des Couches Minces; Brunel, M. [Laboratoire de Cristallographie, CNRS, 166X, 38042, Grenoble (France)

    2000-05-01

    Cadmium telluride oxide CdTeO{sub 3} thin films were prepared by r.f.-sputtering from a polycrystalline CdTe target in an atmosphere of nitrogen and oxygen. X-ray diffraction (XRD) analysis showed that the as-deposited samples were amorphous. X-ray photoelectron spectroscopy (XPS) measurements revealed that the films were nearly stoichiometric. The resistivity and the static dielectric constant of the as-deposited layers were found to be 3 x 10{sup 6} {omega}m and 16, respectively. Optical transmission measurements in the ultraviolet-visible-near-IR (UV-VIS-NIR) region allowed the determination of the optical constants of the prepared films. Post-deposition annealing of the layers at 420 C for 2 h favored their crystallization. Finally, we show that polycrystalline CdTO{sub 3} films can be grown on CdTe films, deposited on C7059 glass by an appropriate heat-treatment of the CdTeO{sub 3}/CdTe/C7059 structure. (orig.)

  7. Photovoltaic properties of undoped ZnO thin films prepared by the spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Ikhmayies, S.J. [Applied Science Private Univ., Amman (Jordan). Dept. of Physics; Abu El-Haija, N.M.; Ahmad-Bitar, R.N. [Jordan Univ., Amman (Jordan). Dept. of Physics

    2009-07-01

    Zinc oxide (ZnO) can be used as a window material, transparent electrode and active layer in different types of solar cells, UV emitters, and UV sensors. In addition to being low cost, ZnO is more abundant than indium tin oxide. ZnO is non toxic and has a high chemical stability in reduction environments. When ZnO films are made without any intentional doping, they exhibit n-type conductivity. ZnO thin films can be prepared by reactive sputtering, laser ablation, chemical-vapour deposition, laser molecular-beam epitaxy, thermal evaporation, sol-gel, atomic layer deposition and spray pyrolysis, with the latter being simple, inexpensive and adaptable to large area depositions. In this work ZnCl{sub 2} was used as a source of Zn where it was dissolved in distilled water. The structural, electrical and optical properties of the films were investigated due to their important characteristic for solar cell applications. Polycrystalline ZnO thin films were deposited on glass substrate by spray pyrolysis using a home-made spraying system at substrate temperature of 450 degrees C. The films were characterized by recording and analyzing their I-V plots, their transmittance, X-ray diffraction and SEM micrographs. There resistivity was found to be about 200 ohms per cm and their bandgap energy about 3.27 eV. X-ray diffraction patterns revealed that the films have a hexagonal wurtzite structure and are highly ordered with a preferential orientation (002). SEM images revealed that the substrates are continuously covered and the surface of the film is uniform. 16 refs., 4 figs.

  8. Thin film ceramic thermocouples

    Science.gov (United States)

    Gregory, Otto (Inventor); Fralick, Gustave (Inventor); Wrbanek, John (Inventor); You, Tao (Inventor)

    2011-01-01

    A thin film ceramic thermocouple (10) having two ceramic thermocouple (12, 14) that are in contact with each other in at least on point to form a junction, and wherein each element was prepared in a different oxygen/nitrogen/argon plasma. Since each element is prepared under different plasma conditions, they have different electrical conductivity and different charge carrier concentration. The thin film thermocouple (10) can be transparent. A versatile ceramic sensor system having an RTD heat flux sensor can be combined with a thermocouple and a strain sensor to yield a multifunctional ceramic sensor array. The transparent ceramic temperature sensor that could ultimately be used for calibration of optical sensors.

  9. Metal Organic Chemical Vapour Deposited Thin Films of Cobalt Oxide Prepared via Cobalt Acetylacetonate

    Institute of Scientific and Technical Information of China (English)

    C.U. Mordi; M.A. Eleruja; B.A. Taleatu; G.O. Egharevba; A.V. Adedeji; 0.0. Akinwunmi; B. Olofinjana; C. Jeynes; E.O.B. Ajayi

    2009-01-01

    The single solid source precursor, cobalt (Ⅱ) acetylacetonate was prepared and characterized by infrared spec-troscopy. Thin films of cobalt oxide were deposited on soda lime glass substrates through the pyrolysis (metal organic chemical vapour deposition (MOCVD)) of single solid source precursor, cobalt acetylaceto-nate, Co[C5H7O2]2 at a temperature of 420℃. The compositional characterization carried out by rutherford backscattering spectroscopy and X-ray diffraction (XRD), showed that the films have a stoichiometry of Co2O3 and an average thickness of 227±0.2 nm. A direct energy gap of 2.15±0.01 eV was calculated by the data obtained by optical absorption spectroscopy. The morphology of the films obtained by scanning electron mi-croscopy, showed that the grains were continuous and uniformly distributed at various magnifications, while the average grain size was less than 1 micron for the deposited thin films of cobalt oxide.

  10. Preparation and characterization of BiFeO3 thin films by the LPD on OH-functionalized organic SAMs

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    BiFeO3 (BFO) thin films were grown on OH-functionalized organic self-assembled monolayers (SAMs) via liquid-phase deposition (LPD) method at a temperature below 100°C. The BiFeO3 thin films were induced to synthesize on the OH-functionalized organic OTS monolayers prepared on hydroxylated glass substrate by self-assembling technique. The hydrophilic characteristic of the as-prepared OTS-SAMs was measured by contact angle tester. The crystal phase composition, microstructure and topography of the as-synthesized BFO thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy disperse spectroscopy (EDS) and atomic force microscope (AFM), respectively. Results show that compact and homogeneous BFO thin films can be formed on the OH-functionalized SAMs at low temperature.

  11. Enhanced photocatalytic activity of silver nanoparticles modified TiO{sub 2} thin films prepared by RF magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Meng Fanming, E-mail: mrmeng@ahu.edu.cn [School of Physics and Materials Science, Anhui University, Hefei 230039 (China); State Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Dalian 116024 (China); Anhui Key Laboratory of Information Materials and Devices, Anhui University, Hefei 230039 (China); Sun Zhaoqi [School of Physics and Materials Science, Anhui University, Hefei 230039 (China); Anhui Key Laboratory of Information Materials and Devices, Anhui University, Hefei 230039 (China)

    2009-12-15

    Ag-TiO{sub 2} nanostructured thin films with silver volume fraction of 0-40% were prepared by RF magnetron sputtering. The microstructure, surface topography, and optical properties of the films were characterized by X-ray diffractometer, transmission electron microscope, and ultraviolet-visible spectrophotometer. Photocatalytic activity of the films was evaluated by light-induced degradation of methyl orange (C{sub 14}H{sub 14}N{sub 3}NaO{sub 3}S) solution using a high pressure mercury lamp as lamp-house. The relation of photocatalytic activity and silver content was studied in detail. It is found that silver content influences microstructure of TiO{sub 2} thin films, and silver in the films is metallic Ag (Ag{sup 0}). Photocatalytic activity of the films increases with increasing silver content up to 5 vol.% Ag and then decreases to values significantly still bigger than that of pure TiO{sub 2} thin films. Silver nanoparticles significantly enhance the photocatalytic activity of TiO{sub 2} films. The better separation between electrons and holes on silver modified TiO{sub 2} thin films surface allowed more efficiency for the oxidation and reduction reactions. The enhanced photocatalytic activity was mainly attributed to the decrease of energy gap of the films and the increase of oxygen anion radicals O{sub 2}{sup -} and reactive center of surface Ti{sup 3+} on silver modified TiO{sub 2} thin films surface.

  12. Preparation and Photoemission Spectra of Rb3C60 Single-Crystal Thin Films

    Institute of Scientific and Technical Information of China (English)

    李宏年; 吴太权; 陈晓; 李海洋; 鲍世宁; 徐亚伯; 钱海杰; 易卜拉欣奎热西; 刘风琴

    2002-01-01

    Rb3 C60 single-crystal thin films were prepared on the cleaved (111) surface of C60 single crystal. The photoemission spectrum line shapes of the lowest unoccupied molecular orbital (LUMO) derived band at room temperature and 150K were established by synchrotron radiation photoemission spectrum measurements. The density of states near the Fermi level was distinctly affected by temperature. No less than six sub-peaks of the LUMOband were observed even at room temperature. The existence of so many sub-peaks offered the opportunities to analyse in more detail the orientational structure and the electron-Boson interactions of the narrow-band metallic Rb3 C60 .

  13. Crystallographic dependence of photocatalytic activity of WO3 thin films prepared by molecular beam epitaxy.

    Science.gov (United States)

    Li, Guoqiang; Varga, Tamas; Yan, Pengfei; Wang, Zhiguo; Wang, Chongmin; Chambers, Scott A; Du, Yingge

    2015-06-21

    We investigated the impact of crystallographic orientation on the photocatalytic activity of single crystalline WO3 thin films prepared by molecular beam epitaxy on the photodegradation of rhodamine B (RhB). A clear effect is observed, with (111) being the most reactive surface, followed by (110) and (001). Photoreactivity is directly correlated with the surface free energy determined by density functional theory calculations. The RhB photodegradation mechanism is found to involve hydroxyl radicals in solution formed from photo-generated holes and differs from previous studies performed on nanoparticles and composites.

  14. High-purity cobalt thin films with perpendicular magnetic anisotropy prepared by chemical vapor deposition

    Science.gov (United States)

    Ootera, Yasuaki; Shimada, Takuya; Kado, Masaki; Quinsat, Michael; Morise, Hirofumi; Nakamura, Shiho; Kondo, Tsuyoshi

    2015-11-01

    A study of the chemical vapor deposition (CVD) of high-purity cobalt thin films is described. The Co layer prepared by a thermal CVD technique with a Pt/Ta underlayer and a Pt cap layer shows a saturation magnetization (Ms) of ∼1.8 T and perpendicular magnetic anisotropy (PMA) with an anisotropy energy (Ku) of ∼105 J/m3. The cobalt thickness dependence of Ku reveals that the interfacial anisotropy at the Pt/Co interface is most likely the origin of the obtained PMA.

  15. The effect of thermal annealing on the properties of thin alumina films prepared by low pressure MOCVD

    NARCIS (Netherlands)

    Haanappel, V.A.C.; Vendel, van de D.; Corbach, van H.D.; Fransen, T.; Gellings, P.J.

    1995-01-01

    Thin amorphous alumina films were prepared on stainless steel, type AISI 304, by low pressure metal-organic chemical vapour deposition. The effect of thermal annealing in nitrogen (for 2, 4 and 17 h at 600, 700 and 800 °C) on the film properties, including the protection of the underlying substrate

  16. The effect of thermal annealing on the properties of thin alumina films prepared by low pressure MOCVD

    NARCIS (Netherlands)

    Haanappel, V.A.C.; Haanappel, V.A.C.; van de Vendel, D.; van Corbach, H.D.; Fransen, T.; Gellings, P.J.

    1995-01-01

    Thin amorphous alumina films were prepared on stainless steel, type AISI 304, by low pressure metal-organic chemical vapour deposition. The effect of thermal annealing in nitrogen (for 2, 4 and 17 h at 600, 700 and 800 °C) on the film properties, including the protection of the underlying substrate

  17. Preparation of Magneto-Optic Ce:YIG Thin Films for Integrated Optical Isolator

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This paper presents the growth of cerium substituted YIG (Ce1 YIG) thin films on silica substrate.The large Faraday rotation coefficient and strong in-plane anisotropy were observed. The film is desirable for waveguide configuration isolator application.

  18. Preparation of TiO2 nanometer thin films with high photocatalytic activity by reverse micellar method

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Two kinds of TiO2 nanometer thin films were prepared on stainless steel by the reverse micellar and sol-gelmethods, respectively. The calcined TiO2 thin films were characterized by X-ray diffraction (XRD), atomic force micros-copy (AFM), BET surface area and X-ray photoelectron spectroscopy (XPS). Photocatalytic activity was evaluated byphotocatalytic decoloration of methyl orange aqueous solution. The results showed that the TiO2 thin films prepared by re-verse micellar method (designated as RM-TiO2 films) showed higher photocatalytic activity than those by sol-gel method(designated as SG-TiO2 films). This is attributed to the fact that the former is composed of smaller monodispersed sphericalparticles with a size of about 15 nm and possesses higher surface areas.

  19. Preparation and characterization of LiFePO4 thin films as cathode materials for lithium ion battery

    Institute of Scientific and Technical Information of China (English)

    XIAO Zhuo-bing; MA Ming-you

    2006-01-01

    LiFePO4 thin films were prepared by sol-gel technique. The phase and surface morphology were characterized by X-ray diffraction and scanning electron microscopy. The electrochemical properties of the thin films were measured by cyclic voltammetry, galvanostatic charge-discharge experiments and electrochemical impedance spectroscopy in 1 mol/L LiPF6/EC-DMC solution using lithium metal as both counter and reference electrodes. The films prepared by this method are of pure LiFePO4 phase. The capacity of the film annealed at 700 ℃ for 30 min is 145 Ma·h/g, and the capacity loss per cycle is 0.06% after being cycled 50 times. The electrochemical impedance spectroscopy shows that the diffusion rate of lithium ion in LiFePO4 thin film is 5.1×10-14cm2/s.

  20. Infrared Thermochromic Properties of VO2 Thin Films Prepared through Aqueous Sol-gel Process

    Institute of Scientific and Technical Information of China (English)

    LIU Dongqing; CHENG Haifeng; ZHENG Wenwei; ZHANG Chaoyang

    2012-01-01

    The stoichiometric vanadium(Ⅳ) oxide thin films were obtained by controlling the temperature,time and pressure of annealing.The thermochromic phase transition and the IR thermochromic property of 400 nm and 900 nm VO2 thin films in the 7.5 μm-14 μm region were discussed.The derived VO2 thin film samples were characterized by Raman,XRD,XPS,AFM,SEM,and DSC.The resistance and infrared emissivity of VO2 thin films under different temperature were measured,and the thermal images of films were obtained using infrared imager.The results show that the VO2 thin film annealed at 550 ℃ for 10 hours through aqueous sol-gel process is pure and uniform.The 900 nm VO2 thin film exhibits better IR thermochromic property than the 400 nm VO2 thin film.The resistance of 900 nm VO2 film can change by 4orders of magnitude and the emissivity can change by 0.6 during the phase transition,suggesting the outstanding IR thermochromic property.The derived VO2 thin film can control its infrared radiation intensity and lower its apparent temperature actively when the real temperature increases,which may be applied in the field of energy saving,thermal control and camouflage.

  1. Preparation of Nano-Particles (Pb,La)TiO3 Thin Films by Liquid Source Misted Chemical Deposition

    Institute of Scientific and Technical Information of China (English)

    张之圣; 曾建平; 李小图

    2004-01-01

    Nano-particles lanthanum-modified lead titanate (PLT) thin films are grown on Pt/Ti/SiO2/Si substrate by liquid source misted chemical deposition (LSMCD). PLT films are deposited for 4-8 times, and then annealed at various temperature. XRD and SEM show that the prepared films have good crystallization behavior and perovskite structure. The crystallite is about 60 nm. The deposition speed is 3 nm/min. This deposition method can exactly control stoichiometry ratios, doping concentration ratio and thickness of PLT thin films. The best annealing process is to bake at 300 ℃ for 10 min and anneal at 600 ℃ for 1 h.

  2. Ion beam analysis of copper selenide thin films prepared by chemical bath deposition

    Science.gov (United States)

    Andrade, E.; García, V. M.; Nair, P. K.; Nair, M. T. S.; Zavala, E. P.; Huerta, L.; Rocha, M. F.

    2000-03-01

    Analyses of Rutherford back scattered (RBS) 4He+-particle spectra of copper selenide thin films deposited on glass slides by chemical bath were carried out to determine the changes brought about in the thin film by annealing processes. The atomic density per unit area and composition of the films were obtained from these measurements. This analysis shows that annealing in a nitrogen atmosphere at 400°C leads to the conversion of Cu xSe thin film to Cu 2Se. Results of X-ray diffraction, optical, and electrical characteristics on the films are presented to supplement the RBS results.

  3. Combined sonochemical/CVD method for preparation of nanostructured carbon-doped TiO2 thin film

    Science.gov (United States)

    Rasoulnezhad, Hossein; Kavei, Ghassem; Ahmadi, Kamran; Rahimipour, Mohammad Reza

    2017-06-01

    The present work reports the successful synthesis of the nanostructured carbon-doped TiO2 thin films on glass substrate by combination of chemical vapor deposition (CVD) and ultrasonic methods, for the first time. In this method the ultrasound waves act as nebulizer for converting of sonochemically prepared TiO2 sol to the mist particles. These mist particles were thermally decomposed in subsequent CVD chamber at 320 °C to produce the carbon-doped TiO2 thin films. The obtained thin films were characterized by means of X-ray Diffraction (XRD), Raman spectroscopy, diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques. The results show that the prepared thin films have anatase crystal structure and nanorod morphology, which calcination of them at 800 °C results in the conversion of nanorods to nanoparticles. In addition, the prepared samples have high transparency, monodispersity and homogeneity. The presence of the carbon element in the structure of the thin films causes the narrowing of the band-gap energy of TiO2 to about 2.8 eV, which results in the improvement of visible light absorption capabilities of the thin film.

  4. Silica-Copper Oxide Composite Thin Films as Solar Selective Coatings Prepared by Dipping Sol Gel

    Directory of Open Access Journals (Sweden)

    E. Barrera-Calva

    2008-01-01

    Full Text Available Silica-copper oxide (silica-CuO composite thin films were prepared by a dipping sol-gel route using ethanolic solutions comprised TEOS and a copper-propionate complex. Sols with different TEOS/Cu-propionate (Si/Cu molar ratios were prepared and applied on stainless steel substrates using dipping process. During the annealing process, copper-propionate complexes developed into particulate polycrystalline CuO dispersed in a partially crystallized silica matrix, as indicated by the X-ray diffraction (XRD and X-ray photoelectron spectroscopy (XPS analyses. The gel thermal analysis revealed that the prepared material might be stable up to 400°C. The silica-CuO/stainless steel system was characterized as a selective absorber surface and its solar selectivity parameters, absorptance (α, and emittance (ε were evaluated from UV-NIR reflectance data. The solar parameters of such a system were mostly affected by the thickness and phase composition of the SiO2-CuO film. Interestingly, the best solar parameters (α = 0.92 and ε = 0.2 were associated to the thinnest films, which comprised a CuO-Cu2O mixture immersed in the silica matrix, as indicated by XPS.

  5. Temperature dependence growth of CdO thin film prepared by spray pyrolysis

    Directory of Open Access Journals (Sweden)

    Hassan H. Afify

    2014-09-01

    Full Text Available CdO thin films prepared by spray pyrolysis technique show temperature dependence growth when the spray time is constant. In contrast, the growth is film thickness dependent when the substrate temperature is constant. The films are polycrystalline in the covered spray time and substrate temperature ranges. The crystallite size and microstrain are calculated and analyzed. The Atomic Force Microscopy (AFM micrographs prove that the grains are uniformly distributed within the scanning areas (5 μm × 5 μm and (50 μm × 50 μm. The roughness shows a considerable decrease with substrate temperature. All samples show an abrupt change in transmission which indicates a direct transition and good crystallinity. The transmission of films is increased up to 80% with increasing substrate temperature in wavelength ranged from 450 nm to 1000 nm. Also, a broad absorption band is observed in the range 1500–2000 nm. This band could be attributed to the increase in free carrier concentration which confirmed by a reasonable decrease in the film sheet resistance. The band gap Eg is determined and found to be in the range 2.45–2.55 eV. The sheet resistance is reduced with increasing deposition temperature due to the increase in free carrier concentration and found to be 66 Ω/□ at 450 °C.

  6. Properties Study of ZnS Thin Films Prepared by Spray Pyrolysis Method

    Directory of Open Access Journals (Sweden)

    A. Djelloul

    2015-12-01

    Full Text Available Zinc sulfide (ZnS is important II-VI semiconductors material for the development of various modern technologies and photovoltaic applications. ZnS thin film was prepared by using chemical spray pyrolysis technique. The starting solution is a mixture of 0.1 M zinc chloride as source of Zn and 0.05 M thiourea as source of S. The glass substrate temperature was varied in the range of 300 °C-400 °C to investigate the influence of substrate temperature on the structure, chemical composition, morphological and optical properties of ZnS films. The DRX analyses indicated that ZnS films have polycrystalline cubic structure with (111 preferential orientation and grain size varied from 25 to 60 nm, increasing with substrate temperature. The optical properties of these films have been studied in the wavelength range 300-2500 nm using UV-VIS spectro-photometer. The ZnS films has a band gap of 3.89 eV-3.96 eV.

  7. Study of CuInSe{sub 2} thin films prepared by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, S.N.; Li, L.; Qiu, C.X.; Shih, I.; Champness, C.H. [Electrical Engineering Dept., McGill University, University Street, Montreal, QU (Canada)

    1995-07-30

    Thin films of p-type CuInSe{sub 2} prepared by a one-step electrodeposition method have been studied by constructing CdS/CuInSe{sub 2} junctions. After the electrodeposition, the CuInSe{sub 2} films were treated either in vacuum or in Ar. Cells of the form CdS (high {sigma})/CdS (low {sigma})/CuInSe{sub 2} were then fabricated for studying the electrodeposited films. Measurements were specifically carried out to determine the diffusion length of minority carriers in the p-type CuInSe{sub 2}. It was found that the minority carrier diffusion length in CuInSe{sub 2} films treated in Ar was generally greater than that for films treated in vacuum under similar conditions. A small area cell (active area 0.11 cm{sup 2}) with a conversion efficiency of about 7% (under 125 mW/cm{sup 2} illumination) has been fabricated

  8. Surface enhanced Raman scattering activity of TiN thin film prepared via nitridation of sol-gel derived TiO2 film

    Science.gov (United States)

    Dong, Zhanliang; Wei, Hengyong; Chen, Ying; Wang, Ruisheng; Zhao, Junhong; Lin, Jian; Bu, Jinglong; Wei, Yingna; Cui, Yi; Yu, Yun

    2015-10-01

    Surface-enhanced Raman scattering (SERS) is a powerful and non-destructive analytical technique tool for chemical and biological sensing applications. Metal-free SERS substrates have recently been developed by using semiconductor nanostructures. The optical property of TiN film is similar to that of gold. Besides that, its good chemical inertness and thermodynamic stability make TiN thin film an excellent candidate for SERS. In order to investigate its SERS activity, the TiN thin film was successfully prepared via direct nitridation of the sol-gel derived TiO2 thin film on the quartz substrate using ammonia gas as reducing agent. The crystallite structures and morphology of TiN thin film were determined by XRD, RAMAN and FE-SEM. The results show that the thin film obtained is cubic titanium nitride with a lattice parameter of 4.2349 Å. The surface of TiN thin film is rough and with the particles of 50 nm in average sizes. The thickness of TiN thin film is about 130 nm. The TiN thin film displays a surface Plasmon resonance absorption peak at around 476 nm, which can lead to a strong enhancement of the EM field on the interface. The Raman signal of the probe molecule R6G was greatly enhanced through TiN thin film substrates. The enhancement factor is about 4.1×103 and the detection limit achieves 10-6 M for R6G. The TiN thin film substrate also shows a good reproducibility of SERS performance. The results indicate that TiN thin film is an attractive material with potential application in SERS substrates.

  9. Optical Properties of Nitrogen-Substituted Strontium Titanate Thin Films Prepared by Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Alexander Wokaun

    2009-09-01

    Full Text Available Perovskite-type N-substituted SrTiO3 thin films with a preferential (001 orientation were grown by pulsed laser deposition on (001-oriented MgO and LaAlO3 substrates. Application of N2 or ammonia using a synchronized reactive gas pulse produces SrTiO3-x:Nx films with a nitrogen content of up to 4.1 at.% if prepared with the NH3 gas pulse at a substrate temperature of 720 °C. Incorporating nitrogen in SrTiO3 results in an optical absorption at 370-460 nm associated with localized N(2p orbitals. The estimated energy of these levels is ≈2.7 eV below the conduction band. In addition, the optical absorption increases gradually with increasing nitrogen content.

  10. Crystallization study of SrTiO3 thin films prepared by dip coating

    Directory of Open Access Journals (Sweden)

    Edson R. Leite

    1999-04-01

    Full Text Available In this study, the crystallization process of SrTiO3 thin films, prepared by a chemical method, was characterized by Fourier Transformed Infra Red (FT-IR, Grazing Incident X-ray Diffraction (GIXRD, Thermal Analysis (TG and X-ray Absorption Near Edge Structure (XANES. The results showed that an amorphous inorganic phase is formed, consisting of clusters of oxygen five-coordinate titanium. The amorphous phase begins crystallizing at temperatures above 450 °C. No intermediate crystalline phase and no preferential orientation was observed for films deposited on MgO (100. FT-IR results suggest the presence of the carbonate group. However, the low thermal stability of this group and the low crystallization temperature of the observed SrTiO3 phase indicate that this carbonate is adsorbed.

  11. Preparation of donor doped ZnO{sub x}S{sub 1-x} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kronenberger, Achim; Schurig, Philipp; Laufer, Andreas; Metelmann, Hauke; Stehr, Jan E.; Philipps, Jan; Kramm, Benedikt; Polity, Angelika; Hofmann, Detlev M.; Meyer, Bruno K. [I. Physikalisches Institut, Justus-Liebig-Universitaet Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany)

    2011-07-01

    It is well known that ZnO can easily be doped n-type which is commonly realized by incorporating group-III elements on a Zn lattice place. In contrast to that there are rather few publications reporting successful n-type doping of ZnS. The ternary material system ZnO{sub x}S{sub 1-x} can be prepared without any miscibility gap by radio frequency sputtering. This offers the possibility to study the electrical activity of the shallow donor dopants over the complete composition range. In our work ZnO{sub x}S{sub 1-x} thin films were deposited from a ceramic ZnS target by radio frequency sputtering on glass, sapphire and semiconductor substrates. Through reactive sputtering with oxygen gas the film composition can be adjusted to the wanted oxygen/sulphur ratio. As dopants Al, F and H were incorporated by using additional target material or reactive gas, respectively.

  12. Dynamic simulation on the preparation process of thin films by pulsed laser

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Duanming(

    2001-01-01

    [1]Agostinelli, J. A. , Braunstein, G. H. , Blanton, T. N., Epitaxial LiTaO3 film by pulsed laser ablation, Appl. Phys.Lett., 1993, 63(2): 123-132.[2]Liu, J. M., Zhang, F., Liu, Z. G. et al., Epitaxial growth of optical Ba2NaNb5015 waveguide film by pulsed laser deposition, Appl. Phys. Lett., 1994, 65(16): 1995-2011.[3]Venkatesan, T., Observation of two distinct components during pulsed laser deposition of high Tc superconducting films, Appl. Phys. Lett., 1988, 52(14): 1193-1198.[4]Foltyn, S. R., Tiwari, P., Dye, R. C. et al., Pulsed laser deposition of thick YBa2Cu3O7-x films with Jc> 1MA/cm2, Appl. Phys. Lett., 1993, 63: 1848-1852.[5]Singh, R. K., Narayan, J., Pulsed-laser evaporation technique for deposition of thin films: Physics and theoretical model,Phys. Rev. B., 1990, 41(13): 8843-8859.[6]De Groot, J. S., Estabrook, K. G., Kruer, W. L. et al., Distributed absorption model for moderate to high laser powers,Phys. Fluids B, 1992, 4(3): 701-707.[7]Lu Jian, Ni Xiaown, The Interaction Physics of Laser and Materials (in Chinese), Beijing: Machinery Industry Press, 1996.[8]Fabbro, R., Max, C., Fubre, E., Planar laser-driven ablation: Effect of inhibited electron thermal conduction, Phys. Fluids, 1995, 28(5): 1463-1479.[9]Ozisik, M. N. , Heat Conduction (in Chinese), translated by Yu Changming, Beijing: Higher Education Press, 1984.[10]Eckert, E. R. G. , Drake, R. M. , Jr. , Analysis of Heat and Mass Transfer (in Chinese), translated by Hang Qing, Beijing: Science Press, 1983.[11]Chen Junguo (ed.), High-grade Heat Conduction (in Chinese), Chongqing: Chongqing University Press, 1991.[12]Yu Gang, An Yongqiang, Hu Youjuan et al., The enthalpy-solution method on phase-transfer problem in pulse pure, Chinese Laser Journal (in Chinese), 2000, 27(10): 931-936.[13]Wang Shimin, Zhang Duanming, Dielectric ferroelectric properties of KTN thin films prepared by sol-gel process, Journal of Sol-Gel Science and

  13. Effects of discharge power on the structural and optical properties of TGZO thin films prepared by RF magnetron sputtering technique

    Science.gov (United States)

    Gu, Jin-hua; Lu, Zhou; Zhong, Zhi-you; Long, Lu; Long, Hao

    2016-05-01

    The transparent semiconductors of Ti and Ga-incorporated ZnO (TGZO) thin films were prepared by radio frequency (RF) magnetron sputtering onto glass substrates. The effects of discharge power on the physical properties of thin films are studied. Experimental results show that all nanocrystalline TGZO thin films possess preferential orientation along the (002) plane. The discharge power significantly affects the crystal structure and optical properties of thin films. When the discharge power is 200 W, the TGZO thin film has the optimal crystalline quality and optical properties, with the narrowest full width at half-maximum ( FWHM) of 1.76×10-3 rad, the largest average grain size of 82.4 nm and the highest average transmittance of 84.3% in the visible range. The optical gaps of thin films are estimated by the Tauc's relation and observed to increase firstly and then decrease with the increase of the discharge power. In addition, the optical parameters, including refractive index, extinction coefficient, dielectric function and dissipation factor of the thin films, are determined by optical characterization methods. The dispersion behavior of the refractive index is also analyzed using the Sellmeier's dispersion model.

  14. Handbook of thin film technology

    CERN Document Server

    Frey, Hartmut

    2015-01-01

    “Handbook of Thin Film Technology” covers all aspects of coatings preparation, characterization and applications. Different deposition techniques based on vacuum and plasma processes are presented. Methods of surface and thin film analysis including coating thickness, structural, optical, electrical, mechanical and magnetic properties of films are detailed described. The several applications of thin coatings and a special chapter focusing on nanoparticle-based films can be found in this handbook. A complete reference for students and professionals interested in the science and technology of thin films.

  15. Photoluminescence properties of ZnSe/SiO2 composite thin films prepared by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    JIANG Hai-qing; CHE Jun; YAO Xi

    2006-01-01

    ZnSe/SiO2 composite thin films was prepared by sol-gel method. XRD results indicate the phase structure of ZnSe particles embedded in ZnSe/SiO2 composite thin films is sphalerite (cubic ZnS). Spectroscopic ellipsometers were used to investigated the dependences of ellipsometric angle with wavelength of ZnSe/SiO2 composite thin films. The optical constant,thickness,porosity and the concentration of ZnSe of ZnSe/SiO2 thin composite films were fitted according to Maxwell-Garnett effective medium theory. The thickness of ZnSe/SiO2 composite thin thin films was also measured through surface profile. The photoluminescence properties of ZnSe/SiO2 thin composite thin films was investigated through fluorescence spectrometer. The photoluminescence results show that the emission peak at 487 nm (2.5 eV) is excited at 395 nm corresponds to the band-to-band emission of sphalerite ZnSe crystal(2.58 eV). The strength free exciton emission and other emission peaks correlating to ZnSe lattice defect were also observed.

  16. Organic thin film devices with stabilized threshold voltage and mobility, and method for preparing the devices

    Science.gov (United States)

    Nastasi, Michael Anthony; Wang, Yongqiang; Fraboni, Beatrice; Cosseddu, Piero; Bonfiglio, Annalisa

    2013-06-11

    Organic thin film devices that included an organic thin film subjected to a selected dose of a selected energy of ions exhibited a stabilized mobility (.mu.) and threshold voltage (VT), a decrease in contact resistance R.sub.C, and an extended operational lifetime that did not degrade after 2000 hours of operation in the air.

  17. Optical properties of PMN-PT thin films prepared using pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Tong, X.L., E-mail: tongxinglin@yahoo.com.cn [Key Laboratory of Fiber Optic Sensing Technology and Information Processing, Wuhan University of Technology, Ministry of Education, 122 Luoshi Road, Wuhan 430070 (China); Lin, K.; Lv, D.J.; Yang, M.H.; Liu, Z.X.; Zhang, D.S. [Key Laboratory of Fiber Optic Sensing Technology and Information Processing, Wuhan University of Technology, Ministry of Education, 122 Luoshi Road, Wuhan 430070 (China)

    2009-06-30

    (1 - x)Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-xPbTiO{sub 3} (PMN-PT) thin films have been deposited on quartz substrates using pulsed laser deposition (PLD). Crystalline microstructure of the deposited PMN-PT thin films has been investigated with X-ray diffraction (XRD). Optical transmission spectroscopy and Raman spectroscopy are used to characterize optical properties of the deposited PMN-PT thin films. The results show that the PMN-PT thin films of perovskite structure have been formed, and the crystalline and optical properties of the PMN-PT thin films can be improved as increasing the annealing temperature to 750 deg. C, but further increasing the annealing temperature to 950 deg. C may lead to a degradation of the crystallinity and the optical properties of the PMN-PT thin films. In addition, a weak second harmonic intensity (SHG) has been observed for the PMN-PT thin film formed at the optimum annealing temperature of 750 deg. C according to Maker fringe method. All these suggest that the annealing temperature has significant effect on the structural and optical properties of the PMN-PT thin films.

  18. Cu2SixSn1-xS3 Thin Films Prepared by Reactive Magnetron Sputtering For Low-Cost Thin Film Solar Cells

    Institute of Scientific and Technical Information of China (English)

    YAN Chang; LIU Fang-Yang; LAI Yan-Qing; LI Jie; LIU Ye-Xiang

    2011-01-01

    We report the preparation of Cu2SixSn1-xS3 thin films for thin film solar cell absorbers using the reactive magnetron co-sputtering technique.Energy dispersive spectrometer and x-ray diffraction analyses indicate that Cu2Si1-xSnxS3 thin films can be synthesized successfully by partly substituting Si atoms for Sn atoms in the Cu2SnS3 lattice,leading to a shrinkage of the lattice,and,accordingly,by 2θ shifting to larger values.The blue shift of the Raman peak further confirms the formation of Cu2SixSn1-xS3.Environmental scanning electron microscope analyses reveal a polycrystalline and homogeneous morphology with a grain size of about 200-300 nm.Optical measurements indicate an optical absorption coefficient of higher than 104 cm-1 and an optical bandgap of 1.17±0.01 eV.Solar cells based on Cu(In,Ga)Se2 (CIGS) absorbers have achieved conversion efficiencies as high as 20.3%,holding the record for thin film photovoltaics.[1] However,using the rare and expensive elements In and Ga limits the scalability to GWp/yr power production levels.Fortunately,Cu2SixSn1-xS3 (CSTS) is one of the potential earthabundant alternatives to Cu(In,Ga)Se2,and can replace In and Ga with inexpensive and benign elements due to its similar electronic and crystal structure.[2- 5]%We report the preparation of Cu2SixSn1-xS3 thin 61ms for thin 61m solar cell absorbers using the reactive magnetron co-sputtering technique. Energy dispersive spectrometer and x-ray diffraction analyses indicate that Cu2Si1-xSnxS3 thin films can be synthesized successfully by partly substituting Si atoms for Sn atoms in the CuzSnS3 lattice, leading to a shrinkage of the lattice, and, accordingly, by 20 shifting to larger values. The blue shift of the Raman peak further con6rms the formation of Cu2SixSn1-xS3. Environmental scanning electron microscope anaiyses reveal a polycrystalline and homogeneous morphology with a grain size of about 200-300 nm. Optical measurements indicate an optical absorption coefficient of

  19. Preparation of Large Area Double Sided YBCO Thin Films by DC Magneton Sputtering

    Institute of Scientific and Technical Information of China (English)

    Li Tao; Gu Hongwei; Wang Peiwen; Wang Xiaoping; Xie Bowei

    2004-01-01

    Tc, Jc and Rs properties of large area double sided YBCO thin films deposited on LaAlO3 substrates by direct current sputtering were reported.Film thickness of the obtained thin films is over 300 nm, Tc > 90 K; Rs can be as low as less than 1.0 mΩ(77 K, 10 GHz).Homogenousity of the properties around the plane was studied.Under the measnous distributions.Influences of substrate temperature and Ar and O2 pressures on properties of the double-sided thin films were discussed.

  20. Preparation of Li4Ti5O12 electrode thin films by a mist CVD process with aqueous precursor solution

    Directory of Open Access Journals (Sweden)

    Kiyoharu Tadanaga

    2015-03-01

    Full Text Available Spinel Li4Ti5O12 thin films were prepared by a mist CVD process, using an aqueous solution of lithium nitrate and a water-soluble titanium lactate complex as the source of Li and Ti, respectively. In this process, mist particles ultrasonically atomized from a source aqueous solution were transferred by nitrogen gas to a heating substrate to prepare thin films. Scanning electron microscopy observation showed that thin films obtained by this process were dense and smooth, and thin films with a thickness of about 500 nm were obtained. In the X-ray diffraction analysis, formation of Li4Ti5O12 spinel phase was confirmed in the obtained thin film sintered at 700 °C for 4 h. The cell with the thin films as an electrode exhibited a capacity of about 110 mAh g−1, and the cell showed good cycling performance during 10 cycles.

  1. Sensing CO gas with SnO{sub 2} thin films wetted with Cu prepared by sol-gel technique

    Energy Technology Data Exchange (ETDEWEB)

    Tirado G, S.; Cazares R, J. M. [Escuela Superior de Fisica y Matematicas, IPN, A. P. 75-544, 07300 Mexico D. F. (Mexico); Maldonado, A. [Departamento de Ingenieria Electrica, Centro de Investigacion y de Estudios Avanzados, IPN, A. P. 14-740, 07000 Mexico D. F. (Mexico)

    2009-10-15

    Pure and Cu surface deposited SnO{sub 2} thin films have been prepared on soda-lime substrate using the sol-gel technique. The sensing CO gas properties were investigated in 230 nm in thickness thin films. Pure thin films were wetted with several layers of Cu. The sensors were fabricated and proved at 0, 1, 5, 50, 100 and 200 ppm concentration CO gas and at 23, 100, 200 and 300 C working temperatures. The structural, morphology, electrical and optical properties of such thin films are reported. The route of 2-methoxyethanol and monoethanolamine was used. The resistance was high for all the samples. As was proposed, all the samples resulted enough amorphous and so the X-ray diffraction spectra show such structural state. the surface morphology for the samples was characterized by SEM and also by AFM techniques. (Author)

  2. Preparation of nano-polycrystalline WO3 thin films and their solid-state electrochromic display devices.

    Science.gov (United States)

    Luo, Jianyi; Zeng, Qingguang; Long, Yongbing; Wang, Yi

    2013-02-01

    In this paper, nano-polycrystalline WO3 thin films with the thickness in the range of 100-200 nm have been uniformly prepared on the designed regions of ITO (indium tin oxide) glass substrates by thermal evaporation deposition. Their crystal structures, surface morphologies and uniformities are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM), respectively. The solid-state electrochromic display (ECD) devices based on these nano-polycrystalline WO3 thin films have been also fabricated and have demonstrated to have better performance than normal thin films, including shorter response time, higher contrast, and furthermore, higher stability to keep the colored state without power consumption. These results demonstrate nano-polycrystalline WO3 thin films can be applied to improve the performance of ECD devices, especially suitable to static display.

  3. SBA-15 mesoporous silica free-standing thin films containing copper ions bounded via propyl phosphonate units - preparation and characterization

    Science.gov (United States)

    Laskowski, Lukasz; Laskowska, Magdalena; Jelonkiewicz, Jerzy; Dulski, Mateusz; Wojtyniak, Marcin; Fitta, Magdalena; Balanda, Maria

    2016-09-01

    The SBA-15 silica thin films containing copper ions anchored inside channels via propyl phosphonate groups are investigated. Such materials were prepared in the form of thin films, with hexagonally arranged pores, laying rectilinear to the substrate surface. However, in the case of our thin films, their free standing form allowed for additional research possibilities, that are not obtainable for typical thin films on a substrate. The structural properties of the samples were investigated by X-ray reflectometry, atomic force microscopy (AFM) and transmission electron microscopy (TEM). The molecular structure was examined by Raman spectroscopy supported by numerical simulations. Magnetic measurements (SQUID magnetometry and EPR spectroscopy) showed weak antiferromagnetic interactions between active units inside silica channels. Consequently, the pores arrangement was determined and the process of copper ions anchoring by propyl phosphonate groups was verified in unambiguous way. Moreover, the type of interactions between magnetic atoms was determined.

  4. Preparation of nano-Ag/TiO2 thin-film

    Institute of Scientific and Technical Information of China (English)

    PENG Bing; WANG Jia; CHAI Li-yuan; MAO Ai-li; WANG Yun-yan

    2008-01-01

    Steady TiO2 water-sol was prepared by peptization and the effects of pH value, temperature, concentration of colloid and peptizator on sol were investigated. Laser grain analyzer was used to verify nano-particles in the sol. The photocatalytic degradation ratio and antibacterial property of nano-Ag/TiO2 thin-film on ceramics were used as the main index in addition to XRD analysis. The effect of film layers, embedding Ag+, annealing temperature and time on the degradation ratio and antibacterial property was studied. The temperature 30-80 ℃, pH 1.2-2.0, concentrations of 0.05-0.3 mol/L sol and 5% HNO3 would be the optimal parameters for the TiO2 water-sol preparation. The nano-Ag/TiO2 film of three layers with 3% AgNO3 embedded and treated at 350 ℃ for 2 h exhibits good performance. The elementary research on the kinetics of degradation shows that the reactions are on the first order kinetics equation.

  5. Chemical bath deposition of indium sulphide thin films: preparation and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Lokhande, C.D.; Ennaoui, A.; Patil, P.S.; Giersig, M.; Diesner, K.; Muller, M.; Tributsch, H. [Hahn-Meitner-Institut Berlin GmbH (Germany). Bereich Physikalische Chemie

    1999-02-26

    Indium sulphide (In{sub 2}S{sub 3}) thin films have been successfully deposited on different substrates under varying deposition conditions using chemical bath deposition technique. The deposition mechanism of In{sub 2}S{sub 3} thin films from thioacetamide deposition bath has been proposed. Films have been characterized with respect to their crystalline structure, composition, optical and electrical properties by means of X-ray diffraction, TEM, EDAX, optical absorption, TRMC (time resolved microwave conductivity) and RBS. Films on glass substrates were amorphous and on FTO (flourine doped tin oxide coated) glass substrates were polycrystalline (element of phase). The optical band gap of In{sub 2}S{sub 3} thin film was estimated to be 2.75 eV. The as-deposited films were photoactive as evidenced by TRMC studies. The presence of oxygen in the film was detected by RBS analysis. (orig.) 27 refs.

  6. Preparation and properties of CdS thin films grown by ILGAR method

    Institute of Scientific and Technical Information of China (English)

    QIU Jijun; JIN Zhengguo; WU Weibing; LIU Xiaoxin; CHENG Zhijie

    2004-01-01

    CdS thin films were deposited by the ion layer gas reaction (ILGAR) method. Structural, chemical, topographical development as well as optical and electrical properties of as-deposited and annealed thin films were investigated by XRD,SEM, XPS, AFM and UV-VIS. The results showed that the thin films are uniform, compact and good in adhesion to the substrates, and the growth of the films is 2.8 nm/cycle. The evolution of structure undergoes from the cubic structure to the hexagonal one with a preferred orientation along the (002) plane after annealing at 673 K. An amount of C, O and Cl impuriries can be reduced by increasing the drying temperature or by annealing in N2 atmosphere. It was found that the band gap of the CdS films shifts to higher wavelength after annealing or increasing film thickness. The electrical resistivity decreases with increasing annealing temperature and film thickness.

  7. Suppression of Cross Contamination in Multi-Layer Thin Film Prepared by Using Rotating Hexagonal Sputtering Cathode.

    Science.gov (United States)

    Park, Se Yeon; Choi, Bum Ho; Lee, Jong Ho

    2015-01-01

    In this study, single- and multi-layered thin films were prepared on a glass substrate using a newly developed rotating hexagonal sputtering cathode in a single chamber. The rotatinghexagonal sputtering cathode can install up to six different sputtering targets or six single targets in a cathode. Using the rotating hexagonal cathode, we prepared a single-layered AZO film and a multi-layer film to evaluate the performance of hexagonal gun. Cross-contamination, which is often observed in multi-layer thin film preparation, was suppressed to nearly zero by controlling process parameters and revising hardware. Energy-saving effects of five-layered glass were also verified by measuring the temperature.

  8. Effect of deposition conditions on the physical properties of SnxSy thin films prepared by the spray pyrolysis technique

    Institute of Scientific and Technical Information of China (English)

    M. R. Fadavieslam; N. Shahtahmasebi; M. Rezaee-Roknabadi; M. M. Bagheri-Mohagheghi

    2011-01-01

    Tin sulfide thin films (SnxSy ) with an atomic ratio of y / x =0.5 have been deposited on a glass substrate by spray pyrolysis.The effects of deposition parameters,such as spray solution rate (R),substrate temperature (Ts) and film thickness (t),on the structural,optical,thermo-electrical and photoconductivity related properties of the films have been studied.The precursor solution was prepared by dissolving tin chloride (SnCl4,5H2O)and thiourea in propanol,and SnxSy thin film was prepared with a mole ratio of y/x =0.5.The prepared films were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM) and UV-vis spectroscopy.It is indicated that the XRD patterns of SnxSy films have amorphous and polycrystalline structures and the size of the grains has been changed from 7 to 16 nm.The optical gap of SnxSy thin films is determined to be about 2.41 to 3.08 eV by a plot of the variation of (ohv)2 versus hv related to the change of deposition conditions.The thermoelectric and photo-conductivity measurement results for the films show that these properties are depend considerably on the deposition parameters.

  9. Preparation and characterization of Co epitaxial thin films on Al2O3(0001) single-crystal substrates

    Science.gov (United States)

    Yabuhara, Osamu; Ohtake, Mitsuru; Nukaga, Yuri; Futamoto, Masaaki

    2011-01-01

    Co epitaxial thin films were prepared on Al2O3(0001) single-crystal substrates in a substrate temperature range between 50 and 500 °C by ultra high vacuum molecular beam epitaxy. Effects of substrate temperature on the structure and the magnetic properties of the films were investigated. The films grown at temperatures lower than 150 °C consist of fcc- Co(111) crystal. With increasing the substrate temperature, hcp-Co(0001) crystal coexists with the fcc crystal and the volume ratio of hcp to fcc crystal increases. The films prepared at temperatures higher than 250 °C consist primarily of hcp crystal. The film growth seems to follow island-growth mode. The films consisting primarily of hcp crystal show perpendicular magnetic anisotropy. The domain structure and the magnetization properties are influenced by the magnetocrystalline anisotropy and the shape anisotropy caused by the film surface roughness.

  10. Thin copper oxide films prepared by ion beam sputtering with subsequent thermal oxidation: Application in chemiresistors

    Science.gov (United States)

    Horak, P.; Bejsovec, V.; Vacik, J.; Lavrentiev, V.; Vrnata, M.; Kormunda, M.; Danis, S.

    2016-12-01

    Copper oxide films were prepared by thermal oxidation of thin Cu films deposited on substrates by ion beam sputtering. The subsequent oxidation was achieved in the temperature range of 200 °C-600 °C with time of treatment from 1 to 7 h (with a 1-h step) in a furnace open to air. At temperatures 250 °C-600 °C, the dominant phase formed was CuO, while at 200 °C mainly the Cu2O phase was identified. However, the oxidation at 200 °C led to a more complicated composition - in the depth Cu2O phase was observed, though in the near-surface layer the CuO dominant phase was found with a significant presence of Cu(OH)2. A limited amount of Cu2O was also found in samples annealed at 600 °C. The sheet resistance RS of the as-deposited Cu sample was 2.22 Ω/□, after gradual annealing RS was measured in the range 2.64 MΩ/□-2.45 GΩ/□. The highest RS values were obtained after annealing at 300 °C and 350 °C, respectively. Oxygen depth distribution was studied using the 16O(α,α) nuclear reaction with the resonance at energy 3032 keV. It was confirmed that the higher oxidation degree of copper is located in the near-surface region. Preliminary tests of the copper oxide films as an active layer of a chemiresistor were also performed. Hydrogen and methanol vapours, with a concentration of 1000 ppm, were detected by the sensor at an operating temperature of 300 °C and 350 °C, respectively. The response of the sensors, pointed at the p-type conductivity, was improved by the addition of thin Pd or Au catalytic films to the oxidic film surface. Pd-covered films showed an increased response to hydrogen at 300 °C, while Au-covered films were more sensitive to methanol vapours at 350 °C.

  11. Preparation and characteristics of chemical bath deposited ZnS thin films: Effects of different complexing agents

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Seung Wook [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of); Agawane, G.L.; Gang, Myeng Gil [Photonics Technology Research Institute, Department of Materials Science Engineering, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Moholkar, A.V. [Department of Physics, Shivaji University, Kolhapur 416-004 (India); Moon, Jong-Ha [Photonics Technology Research Institute, Department of Materials Science Engineering, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Kim, Jin Hyeok, E-mail: jinhyeok@chonnam.ac.kr [Photonics Technology Research Institute, Department of Materials Science Engineering, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Lee, Jeong Yong, E-mail: j.y.lee@kaist.ac.kr [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Thick ZnS thin films were successfully prepared by chemical bath deposition in a basic medium using less toxic complexing agents. Black-Right-Pointing-Pointer Effect of different complexing agents such as no complexing agent, Na{sub 3}-citrate and a mixture of Na{sub 3}-citrate and EDTA on the properties of ZnS thin films was investigated. Black-Right-Pointing-Pointer ZnS thin film deposited using two complexing agent showed the outstanding characteristics as compared to those using no and one complexing agent. - Abstract: Zinc sulfide (ZnS) thin films were prepared on glass substrates by a chemical bath deposition technique using aqueous zinc acetate and thiourea solutions in a basic medium (pH {approx} 10) at 80 Degree-Sign C. The effects of different complexing agents, such as a non-complexing agent, Na{sub 3}-citrate, and a mixture of Na{sub 3}-citrate and ethylenediamine tetra-acetate (EDTA), on the structural, chemical, morphological, optical, and electrical properties of ZnS thin films were investigated. X-ray diffraction pattern showed that the ZnS thin film deposited without any complexing agent was grown on an amorphous phase. However, the ZnS thin films deposited with one or two complexing agents showed a polycrystalline hexagonal structure. No secondary phase (ZnO) was observed. X-ray photoelectron spectroscopy showed that all ZnS thin films exhibited both Zn-S and Zn-OH bindings. Field emission scanning electron microscopy (FE-SEM) images showed that ZnS thin films deposited with complexing agents had thicker thicknesses than that deposited without a complexing agent. The electrical resistivity of ZnS thin films was over 10{sup 5} {Omega} cm regardless of complexing agents. The average transmittance of the ZnS thin films deposited without a complexing agent, those with Na{sub 3}-citrate, and those with a mixture of Na{sub 3}-citrate and EDTA was approximately 85%, 65%, and 70%, respectively, while the band gap

  12. Fabrication and characterization of NiO thin films prepared by SILAR method

    Energy Technology Data Exchange (ETDEWEB)

    Akaltun, Yunus [Department of Electrical and Electronic Engineering, Erzincan University, 24100 Erzincan (Turkey); Çayır, Tuba [Department of Biomedical Engineering, Erzincan University, 24100 Erzincan (Turkey)

    2015-03-15

    Highlights: • NiO thin films have been deposited on glass substrates using SILAR method for the first time. • The electron effective mass, refractive index were calculated by using the energy bandgap values. • The effect of film thickness on the structural, optical and electrical properties were studied. • The bandgap values of the films decreased from 3.71 to 3.67 eV. - Abstract: NiO thin films were synthesised on glass substrates at room temperature using the Successive Ionic Layer Adsorption and Reaction (SILAR) method. The effect of film thickness on the structural, morphological, optical and electrical properties of NiO thin films was investigated. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies showed that all the films exhibit polycrystalline structure are covered well with glass substrates. The crystalline and surface properties of the films improved with increasing film thickness. The energy band gap values were decreased from 3.71 to 3.67 eV depending on the film thickness. The refractive index (n), optical static (ε{sub o}) and high frequency dielectric constant (ε{sub ∞}) values were calculated by using the energy band gap values as a function of the film thickness. The resistivity of the films varied between 4.1 and 802.1 Ω cm with increasing film thickness at room temperature.

  13. Influence of preparation conditions on superconducting properties of Bi-2223 thin films

    Indian Academy of Sciences (India)

    N T Mua; A Sundaresan; N K Man; D D Dung

    2014-02-01

    We report electrical transport properties of Bi2Sr2Ca2Cu3O10+ (Bi-2223) superconducting thin films fabricated by pulsed-laser deposition on SrTiO3 substrate. The aim of the study was to investigate the influence of preparation conditions such as deposition temperature (S), annealing time (A) and deposition rate (). A critical temperature (c) as high as 110 K and critical current density (c) of 6.2 × 106 A/cm2 at 20 K were obtained for S = 760° C, A = 4h and = 1.5 Å/s. We also investigated the effect of Li doping on Bi-2223 thin films. Li intercalation results in high resistive onset transition temperature and the resistivity shows broadening in magnetic field that increases with field. The large broadening of resistivity curve in magnetic field suggests that this phenomenon is directly related to the intrinsic superconducting properties of the copper oxide superconductors. The sudden drop in c at relatively low magnetic field ( < 0.5 tesla) is due to the effect of Josephson weak-links at the grain boundaries.

  14. Photoluminescence properties of ZnO thin films prepared by DC magnetron sputtering

    Institute of Scientific and Technical Information of China (English)

    YANG Bing-chu; LIU Xiao-yan; GAO Fei; MA Xue-long

    2008-01-01

    ZnO thin films were prepared by direct current(DC) reactive magnetron sputtering under different oxygen partial pressures.And then the samples were annealed in vacuum at 450 ℃. The effects of the oxygen partial pressures and the treatment of annealing in vacuum on the photoluminescence and the concentration of six intrinsic defects in ZnO thin films such as oxygen vacancy(Vo),zinc vacancy(VZn), antisite oxygen(OZn), antisite zinc(ZnO), interstitial oxygen(Oi) and interstitial zinc(Zni) were studied. The results show that a green photoluminescence peak at 520 nm can be observed in all the samples, whose intensity increases with increasing oxygen partial pressure; for the sample annealed in vacuum, the intensity of the green peak increases as well. The green photoluminescence peak observed in ZnO may be attributed to zinc vacancy, which probably originates from transitions between electrons in the conduction band and zinc vacancy levels, or from transitions between electrons in zinc vacancy levels and up valence band.

  15. Preparation of Cu2Sn3S7 Thin-Film Using a Three-Step Bake-Sulfurization-Sintering Process and Film Characterization

    Directory of Open Access Journals (Sweden)

    Tai-Hsiang Lui

    2015-01-01

    Full Text Available Cu2Sn3S7 (CTS can be used as the light absorbing layer for thin-film solar cells due to its good optical properties. In this research, the powder, baking, sulfur, and sintering (PBSS process was used instead of vacuum sputtering or electrochemical preparation to form CTS. During sintering, Cu and Sn powders mixed in stoichiometric ratio were coated to form the thin-film precursor. It was sulfurized in a sulfur atmosphere to form CTS. The CTS film metallurgy mechanism was investigated. After sintering at 500°C, the thin film formed the Cu2Sn3S7 phase and no impurity phase, improving its energy band gap. The interface of CTS film is continuous and the formation of intermetallic compound layer can increase the carrier concentration and mobility. Therefore, PBSS process prepared CTS can potentially be used as a solar cell absorption layer.

  16. Structural and morphological properties of HfxZr 1-xO2 thin films prepared by Pechini route

    KAUST Repository

    García-Cerda, L. A.

    2010-03-01

    In this study, HfxZr1-xO2 (0 < x < 1) thin films were deposited on silicon wafers using a dip-coating technique and by using a precursor solution prepared by the Pechini route. The effects of annealing temperature on the structure and morphological properties of the proposed films were investigated. HfxZr1-xO2 thin films with 1, 3 and 5 layers were annealed in air for 2 h at 600 and 800 °C and the structural and morphological properties studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results show that the films have monoclinic and tetragonal structure depending of the Hf and Zr concentration. SEM photographs show that all films consist of nanocrystalline grains with sizes in the range of 6 - 13 nm. The total film thickness is about 90 nm. © (2010) Trans Tech Publications.

  17. Kinetic Effects on Self-Assembly and Function of Protein-Polymer Bioconjugates in Thin Films Prepared by Flow Coating

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Dongsook [Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave Cambridge MA 02142 USA; Huang, Aaron [Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave Cambridge MA 02142 USA; Olsen, Bradley D. [Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave Cambridge MA 02142 USA

    2016-11-04

    The self-assembly of nanostructured globular protein arrays in thin films is demonstrated using protein–polymer block copolymers based on a model protein mCherry and the polymer poly(oligoethylene glycol acrylate) (POEGA). Conjugates are flow coated into thin films on a poly(ethylene oxide) grafted Si surface, forming self-assembled cylindrical nanostructures with POEGA domains selectively segregating to the air–film interface. Long-range order and preferential arrangement of parallel cylinders templated by selective surfaces are demonstrated by controlling relative humidity. Long-range order increases with coating speed when the film thicknesses are kept constant, due to reduced nucleation per unit area of drying film. Fluorescence emission spectra of mCherry in films prepared at <25% relative humidity shows a small shift suggesting that proteins are more perturbed at low humidity than high humidity or the solution state.

  18. TiO 2 Thin Films Prepared via Adsorptive Self-Assembly for Self-Cleaning Applications

    KAUST Repository

    Xi, Baojuan

    2012-02-22

    Low-cost controllable solution-based processes for preparation of titanium oxide (TiO 2) thin films are highly desirable, because of many important applications of this oxide in catalytic decomposition of volatile organic compounds, advanced oxidation processes for wastewater and bactericidal treatments, self-cleaning window glass for green intelligent buildings, dye-sensitized solar cells, solid-state semiconductor metal-oxide solar cells, self-cleaning glass for photovoltaic devices, and general heterogeneous photocatalysis for fine chemicals etc. In this work, we develop a solution-based adsorptive self-assembly approach to fabricate anatase TiO 2 thin films on different glass substrates such as simple plane glass and patterned glass at variable compositions (normal soda lime glass or solar-grade borofloat glass). By tuning the number of process cycles (i.e., adsorption-then-heating) of TiO 2 colloidal suspension, we could facilely prepare large-area TiO 2 films at a desired thickness and with uniform crystallite morphology. Moreover, our as-prepared nanostructured TiO 2 thin films on glass substrates do not cause deterioration in optical transmission of glass; instead, they improve optical performance of commercial solar cells over a wide range of incident angles of light. Our as-prepared anatase TiO 2 thin films also display superhydrophilicity and excellent photocatalytic activity for self-cleaning application. For example, our investigation of photocatalytic degradation of methyl orange indicates that these thin films are indeed highly effective, in comparison to other commercial TiO 2 thin films under identical testing conditions. © 2012 American Chemical Society.

  19. TiO2 thin films prepared via adsorptive self-assembly for self-cleaning applications.

    Science.gov (United States)

    Xi, Baojuan; Verma, Lalit Kumar; Li, Jing; Bhatia, Charanjit Singh; Danner, Aaron James; Yang, Hyunsoo; Zeng, Hua Chun

    2012-02-01

    Low-cost controllable solution-based processes for preparation of titanium oxide (TiO(2)) thin films are highly desirable, because of many important applications of this oxide in catalytic decomposition of volatile organic compounds, advanced oxidation processes for wastewater and bactericidal treatments, self-cleaning window glass for green intelligent buildings, dye-sensitized solar cells, solid-state semiconductor metal-oxide solar cells, self-cleaning glass for photovoltaic devices, and general heterogeneous photocatalysis for fine chemicals etc. In this work, we develop a solution-based adsorptive self-assembly approach to fabricate anatase TiO(2) thin films on different glass substrates such as simple plane glass and patterned glass at variable compositions (normal soda lime glass or solar-grade borofloat glass). By tuning the number of process cycles (i.e., adsorption-then-heating) of TiO(2) colloidal suspension, we could facilely prepare large-area TiO(2) films at a desired thickness and with uniform crystallite morphology. Moreover, our as-prepared nanostructured TiO(2) thin films on glass substrates do not cause deterioration in optical transmission of glass; instead, they improve optical performance of commercial solar cells over a wide range of incident angles of light. Our as-prepared anatase TiO(2) thin films also display superhydrophilicity and excellent photocatalytic activity for self-cleaning application. For example, our investigation of photocatalytic degradation of methyl orange indicates that these thin films are indeed highly effective, in comparison to other commercial TiO(2) thin films under identical testing conditions.

  20. Studies on Hall Effect and DC Conductivity Measurements of Semiconductor Thin films Prepared by Chemical Bath Deposition (CBD method

    Directory of Open Access Journals (Sweden)

    S. Thirumavalavana

    2015-12-01

    Full Text Available Semiconductors have various useful properties that can be exploited for the realization of a large number of high performance devices in fields such as electronics and optoelectronics. Many novel semiconductors, especially in the form of thin films, are continually being developed. Thin films have drawn the attention of many researchers because of their numerous applications. As the film becomes thinner, the properties acquire greater importance in the miniaturization of elements such as resistors, transistors, capacitors, and solar cells. In the present work, copper selenide (CuSe, cadmium selenide (CdSe, zinc selenide (ZnSe, lead sulphide (PbS, zinc sulphide (ZnS, and cadmium sulphide (CdS thin films were prepared by chemical bath deposition (CBD method. The prepared thin films were analyzed by using Hall measurements in Van Der Pauw configuration (ECOPIA HMS-3000 at room temperature. The Hall parameters such as Hall mobility of the material, resistivity, carrier concentration, Hall coefficient and conductivity were determined. The DC electrical conductivity measurements were also carried out for the thin films using the conventional two – probe technique. The activation energies were also calculated from DC conductivity studies.

  1. Thin Film Inorganic Electrochemical Systems.

    Science.gov (United States)

    1995-07-01

    determined that thin film cathodes of LiCoO2 can be readily performed by either spray pyrolysis or spin coating . These cathodes are electrochemically...active. We have also determined that thin film anodes of Li4Ti5O12 can be prepared by spray pyrolysis or spin coating . These anodes are also

  2. Effects of Ni doping on photocatalytic activity of TiO2 thin films prepared by liquid phase deposition technique

    Indian Academy of Sciences (India)

    Noor Shahina Begum; H M Farveez Ahmed; K R Gunashekar

    2008-10-01

    The TiO2 thin films doped by Ni uniformly and non-uniformly were prepared on glass substrate from an aqueous solution of ammonium hexa-fluoro titanate and NiF2 by liquid phase deposition technique. The addition of boric acid as an – scavenger will shift the equilibrium to one side and thereby deposition of the film is progressed. The rate of the reaction and the nature of deposition depend on growing time and temperature. The resultant films were characterized by XRD, EDAX, UV and SEM. The result shows that the deposited films have amorphous background, which becomes crystalline at 500°C. The EDAX data confirms the existence of Ni atoms in TiO2 matrix. XRD analysis reveals the peaks corresponding to Ni but no peak of crystalline NiO was found. The transmittance spectra of Ni uniformly and non-uniformly doped TiO2 thin films show `blue shift and red shift’, respectively. Ni-doped TiO2 thin films can be used as photocatalyst for the photodegradation of methyl orange dye. It was found that, organic dye undergoes degradation efficiently in presence of non-uniformly Ni-doped TiO2 thin films when compared to uniformly doped films and pure TiO2 films under visible light. The photocatalytic activity increases with increase in the concentration of Ni in case of nonuniformly doped thin films but decreases with the concentration when uniformly doped thin films were used.

  3. Advanced fabrication method for the preparation of MOF thin films: Liquid-phase epitaxy approach meets spin coating method.

    KAUST Repository

    Chernikova, Valeriya

    2016-07-14

    Here we report a new and advanced method for the fabrication of highly oriented/polycrystalline metal-organic framework (MOF) thin films. Building on the attractive features of the liquid-phase epitaxy (LPE) approach, a facile spin coating method was implemented to generate MOF thin films in a high-throughput fashion. Advantageously, this approach offers a great prospective to cost-effectively construct thin-films with a significantly shortened preparation time and a lessened chemicals and solvents consumption, as compared to the conventional LPE-process. Certainly, this new spin-coating approach has been implemented successfully to construct various MOF thin films, ranging in thickness from a few micrometers down to the nanometer scale, spanning 2-D and 3-D benchmark MOF materials including Cu2(bdc)2•xH2O, Zn2(bdc)2•xH2O, HKUST-1 and ZIF-8. This method was appraised and proved effective on a variety of substrates comprising functionalized gold, silicon, glass, porous stainless steel and aluminum oxide. The facile, high-throughput and cost-effective nature of this approach, coupled with the successful thin film growth and substrate versatility, represents the next generation of methods for MOF thin film fabrication. Thereby paving the way for these unique MOF materials to address a wide range of challenges in the areas of sensing devices and membrane technology.

  4. Advanced Fabrication Method for the Preparation of MOF Thin Films: Liquid-Phase Epitaxy Approach Meets Spin Coating Method.

    Science.gov (United States)

    Chernikova, Valeriya; Shekhah, Osama; Eddaoudi, Mohamed

    2016-08-10

    Here, we report a new and advanced method for the fabrication of highly oriented/polycrystalline metal-organic framework (MOF) thin films. Building on the attractive features of the liquid-phase epitaxy (LPE) approach, a facile spin coating method was implemented to generate MOF thin films in a high-throughput fashion. Advantageously, this approach offers a great prospective to cost-effectively construct thin-films with a significantly shortened preparation time and a lessened chemicals and solvents consumption, as compared to the conventional LPE-process. Certainly, this new spin-coating approach has been implemented successfully to construct various MOF thin films, ranging in thickness from a few micrometers down to the nanometer scale, spanning 2-D and 3-D benchmark MOF materials including Cu2(bdc)2·xH2O, Zn2(bdc)2·xH2O, HKUST-1, and ZIF-8. This method was appraised and proved effective on a variety of substrates comprising functionalized gold, silicon, glass, porous stainless steel, and aluminum oxide. The facile, high-throughput and cost-effective nature of this approach, coupled with the successful thin film growth and substrate versatility, represents the next generation of methods for MOF thin film fabrication. Therefore, paving the way for these unique MOF materials to address a wide range of challenges in the areas of sensing devices and membrane technology.

  5. Influence of preparation conditions on the dispersion parameters of sprayed iron oxide thin films

    Science.gov (United States)

    Akl, Alaa A.

    2010-10-01

    Iron oxide thin films were prepared by spray pyrolysis technique (SPT) at various substrate temperatures ( Tsub) and different deposition time. X-ray diffraction (XRD) analysis showed that, at Tsub ≥ 350 °C, a single phase of α-Fe 2O 3 film is formed which has the rhombohedral structure. Moreover, the crystallinity was improved by increasing Tsub. The effect of Tsub as well as deposition time on the optical dispersion of these films has been investigated. The optical transmittance and reflectance measurements were performed by using spectrophotometer in the wavelength range from 300 to 2500 nm. The refractive index was determined by using Murmann's exact equation. It was observed that, the refractive index increased with increasing in both the Tsub and film thickness. The optical dispersion parameters have been evaluated and analyzed by using Wemple-Didomenico equation. The obtained results showed that, the dielectric properties have weak dependencies of growth temperature and film thickness. At Tsub ≥ 350 °C, the average values of oscillator energy, Eo and dispersion energy, Ed were found to be 5.96 and 34.08 eV. While at different thickness, the average values of dispersion energies were found to be 3.93 and 17.08 eV. Also, the average values of oscillator strength So and single resonant frequency ωo were estimated 10.78 × 10 13 m -2 and 5.99 × 10 15 Hz, while at different thickness were evaluating 4.81 × 10 13 m -2 and 6.11 × 10 15 Hz. Furthermore, the optical parameters such as wavelength of single oscillator λo, plasma frequency ωp, and dielectric constant ɛ have been evaluated. The carrier concentration Nopt by using Drud's theory was obtained the range of 5.07 × 10 25 m -3 to 1.04 × 10 26 m -3.

  6. Multilayer systems of alternating chalcogenide As Se and polymer thin films prepared using thermal evaporation and spin-coating techniques

    Science.gov (United States)

    Kohoutek, T.; Wagner, T.; Orava, J.; Krbal, M.; Ilavsky, J.; Vesely, D.; Frumar, M.

    2007-05-01

    We describe preparation and characterization of multilayer planar systems based on alternating chalcogenide As Se and polymer polyamide-imide (PAI) or polyvinyl-butyral (PVB) thin films. We deposited films of thermally evaporated As33Se67 chalcogenide glass periodically alternating with PAI or PVB films. Fifteen layers of As Se+PAI system and 17 layers of As Se+PVB system were deposited. The film thicknesses were approximately 100 nm for all of the film types. Polymer film thicknesses were calculated from profilometric measurements performed by an atomic force microscopy. Optical properties of prepared multilayers and also As Se, PAI and PVB single layers were established using UV vis NIR and ellipsometric spectroscopies. Both, As Se+PAI and As Se+PVB multilayer systems, exhibited the reflection (stop) bands centered near 830 nm. The bandwidth of reflection band of As Se+PAI multilayer was 90 nm while bandwidth of As Se+PVB system increased to 150 nm because PVB films had about 0.2 lower refractive index. A new possibility for the application of chalcogenide thin films appeared as high refractive index materials suitable for fabrication of optical elements (reflectors) for near-infrared region. Changing the films composition and thickness, multilayer systems with tailored position of stop band could be designed and prepared.

  7. Heavy lithium-doped ZnO thin films prepared by spray pyrolysis method

    Indian Academy of Sciences (India)

    M Ardyanian; N Sedigh

    2014-10-01

    Lithium-doped ZnO thin films (ZnO : Li) were prepared by spray pyrolysis method on the glass substrates for ( = [Li]/[Zn]) value varied between 5 and 70%. Structural, electrical and optical properties of the samples were studied by X-ray diffraction (XRD), UV–Vis–NIR spectroscopy, scanning electron microscopy (SEM), Hall effect and sheet resistance measurements. XRD results show that for ≤ 50%, the structure of the films tends to be polycrystals of wurtzite structure with preferred direction along (0 0 2). The best crystalline order is found at = 20% and the crystal structure is stable until = 60%. The Hall effect results describe that Li doping leads to change in the conduction type from - to -type, again it changes to -type at = 70% and is attributed to self-compensation effect. Moreover, the carrier density was calculated in the order of 1013 cm-3. The resistivity of Li-doped films decreases until 22 cm at = 50%. Optical bandgap was reduced slightly, from 3.27 to 3.24 eV as a function of the grain size. Optical transmittance in the visible range reaches = 97%, by increasing of Li content until = 20%. Electrical and optical properties are coherent with structural results.

  8. PREPARATION OF NANO-CRYSTALLINE Fe-Cu THIN FILMS AND THEIR MAGNETIC PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    X.F.Bi; S.K.Gong; H.B.Xu; K.I.Arai

    2002-01-01

    Fe-Cu thin films of 0.2μm in thickness with different Cu contents were prepared byusing r.f. magnetron sputtering onto glass substrate. The effect of sputtering param-eters, including Ar gas pressure and input rf power, on the structure and magneticproperties was investigated. It was found that when the power is lower than 70W,the structure of the films remained single bcc-Fe phase with Cu solubility of up to50at.%. TEM observations for the bcc-Fe phase showed that the grain size was inthe nanometer range of less than 20nm. The coercivity of Fe-Cu films was largelyaffected by not only Ar gas pressure but also rf power, and reached about 2.5Oe in thepressure of 0.67-6.67Pa and in the power of less than 100W. In addition, saturationmagnetization, with Cu content less than 60at.%, was about proportional to the con-tent of bcc-Fe. When Cu content was at 60at.%, however, saturation magnetizationwas much smaller than its calculation value.

  9. Magnetic and electric properties of C-Co thin films prepared by vaccum arc technique

    Energy Technology Data Exchange (ETDEWEB)

    Tembre, A.; Clin, M.; Picot, J.-C. [Laboratoire de Physique de la Matiere Condensee, Universite de Picardie Jules Verne, 33 rue Saint Leu, 80039 Amiens (France); Dellis, J.-L., E-mail: jean-luc.dellis@u-picardie.fr [Laboratoire de Physique de la Matiere Condensee, Universite de Picardie Jules Verne, 33 rue Saint Leu, 80039 Amiens (France); Henocque, J. [Laboratoire de Physique de la Matiere Condensee, Universite de Picardie Jules Verne, 33 rue Saint Leu, 80039 Amiens (France); Bouzerar, R. [Laboratoire de Physique des Systemes Complexes, Universite de Picardie Jules Verne, 33 rue Saint leu, 80039 Amiens (France); Djellab, K. [Plate-forme de Microscopie Electronique, Universite de Picardie Jules Verne, 33 rue Saint Leu, 80039 Amiens (France)

    2011-09-15

    Highlights: > Cobalt doped carbon thin films have been deposited by pulsed anodic electric arc technique. > The films are composed of well-crystallized cobalt layers and complex graphitic microstructure. > An insulating to a metallic state transition at 60 K is observed. > The magnetic susceptibility measurements show anomalous behaviour around 60 K. - Abstract: Cobalt doped carbon thin films have been deposited by a pulsed anodic electric arc technique. The films were characterized by high resolution transmission electron microscopy, electric measurements under dc magnetic fields, and ac magnetic susceptibility measurements within a temperature range 15-300 K. An insulating to a metallic state transition at a critical temperature around 60 K was observed.

  10. Sol-gel preparation of lead magnesium niobate (PMN) powders and thin films

    Science.gov (United States)

    Boyle, T.J.

    1999-01-12

    A method of preparing a lead magnesium niobium oxide (PMN), Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}, precursor solution by a solvent method wherein a liquid solution of a lead-complex PMN precursor is combined with a liquid solution of a niobium-complex PMN precursor, the combined lead- and niobium-complex liquid solutions are reacted with a magnesium-alkyl solution, forming a PMN precursor solution and a lead-based precipitate, and the precipitate is separated from the reacted liquid PMN precursor solution to form a precipitate-free PMN precursor solution. This precursor solution can be processed to form both ferroelectric powders and thin films. 3 figs.

  11. Physical Properties Investigation of Reduced Graphene Oxide Thin Films Prepared by Material Inkjet Printing

    Directory of Open Access Journals (Sweden)

    Veronika Schmiedova

    2017-01-01

    Full Text Available The article is focused on the study of the optical properties of inkjet-printed graphene oxide (GO layers by spectroscopic ellipsometry. Due to its unique optical and electrical properties, GO can be used as, for example, a transparent and flexible electrode material in organic and printed electronics. Spectroscopic ellipsometry was used to characterize the optical response of the GO layer and its reduced form (rGO, obtainable, for example, by reduction of prepared layers by either annealing, UV radiation, or chemical reduction in the visible range. The thicknesses of the layers were determined by a mechanical profilometer and used as an input parameter for optical modeling. Ellipsometric spectra were analyzed according to the dispersion model and the influence of the reduction of GO on optical constants is discussed. Thus, detailed analysis of the ellipsometric data provides a unique tool for qualitative and also quantitative description of the optical properties of GO thin films for electronic applications.

  12. Preparation and characteristics of flexible all-organic thin-film field-effect transistor

    Institute of Scientific and Technical Information of China (English)

    QIU Yong; HU Yuanchuan; Dong Guifang; WANG Liduo; Xie Junfeng; MA Yaning

    2003-01-01

    All-organic thin-film field-effect transistor was prepared on flexible poly(ethylene-terephthalate) (PET) substrate. Poly(methyl-methacrylate) (PMMA) and pentacene are used as a dielectric layer and a semiconductor layer, respectively. The hole mobility of the transistor can reach 2.10×10-2 cm2/Vs, and the on/off current ratio was larger than 105. The performances of the transistor, when the substrate is cured under different radius, were also measured. It was found that the device performance did not change when the curly direction was vertical to the channel length direction and when the curly direction was parallel to the channel length direction with 3.67 cm curvature radius, the mobility of the device increased by more than 20% and the on/off ratio decreased more than one order.

  13. Structural, optical, and electrical properties of Mo-doped ZnO thin films prepared by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Muying, E-mail: wumy@dgut.edu.cn [School of Electronic Engineering, Dongguan University of Technology, Guangdong Dongguan 523808 (China); Yu, Shihui [School of Electronic and Information Engineering, Tianjin University, Tianjin 300072 (China); Chen, Guihua; He, Lin; Yang, Lei [School of Electronic Engineering, Dongguan University of Technology, Guangdong Dongguan 523808 (China); Zhang, Weifeng [Key Laboratory of Photovoltaic Materials of Henan Province and School of Physics and Electronics, Henan University, Kaifeng 475004 (China)

    2015-01-01

    Highlights: • Mo-doped ZnO thin films were prepared successfully by magnetron sputtering. • The lowest electrical resistivity of the MZO thin film is about 9.2 × 10{sup −4} Ω cm. • The mechanism of the changes of carrier mobility was studied. • The mechanism of the changes of band-gap was discussed and explained possibly. - Abstract: Molybdenum doped zinc oxide thin films have been prepared by RF magnetron sputtering. The influence of the film thickness (120–500 nm) on the structural, electrical, and optical properties of the films is investigated respectively. X-ray diffraction (XRD) studies reveal that with an increase in the film thickness, the crystallinity of the film improves. The obtained film with thickness of 500 nm exhibits the best electrical properties with the lowest resistivity of around 9.6 × 10{sup −4} Ω cm. The mobility varied from 7.8 to 14.7 cm{sup 2} V{sup −1} s{sup −1} without reducing the achieved high carrier concentration of ∼4.5 × 10{sup 20} cm{sup −3}. Optical band gaps extracted from transmission spectra shows irregular changes due to the Burstein–Moss shift modulated by many-body effects.

  14. Properties of Li-Doped NiO Thin Films Prepared by RF-Magnetron Sputtering.

    Science.gov (United States)

    Kwon, Ho-Beom; Han, Joo-Hwan; Lee, Hee Young; Lee, Jai-Yeoul

    2016-02-01

    Li-doped NiO thin films were deposited on glass and c-axis (0001) sapphire single crystal substrates by radio frequency (RF)-niagnetron sputtering. The effects of the type of substrate, substrate temperature and atmosphere on the structural, electrical and optical properties of the NiO thin films were examined. The electrical conductivity of the NiO thin films depends on the type of substrate, substrate temperature and oxygen atmosphere. The electrical conductivity of the thin films on the glass and sapphire substrates was improved by the introduction of oxygen and decreased with increasing substrate temperature. The optical transmittance decreased with the introduction of oxygen and increased with increasing substrate temperature.

  15. Preparation and Characterization of Sb2Te3 Thin Films by Coevaporation

    Directory of Open Access Journals (Sweden)

    Bin Lv

    2010-01-01

    Full Text Available Deposition of Sb2Te3 thin films on soda-lime glass substrates by coevaporation of Sb and Te is described in this paper. Sb2Te3 thin films were characterized by x-ray diffraction (XRD, x-ray fluorescence (XRF, atomic force microscopy (AFM, x-ray photoelectron spectroscopy (XPS, electrical conductivity measurements, and Hall measurements. The abnormal electrical transport behavior occurred from in situ electrical conductivity measurements. The results indicate that as-grown Sb2Te3 thin films are amorphous and undergo an amorphous-crystalline transition after annealing, and the posttreatment can effectively promote the formation of Sb-Te bond and prevent oxidation of thin film surface.

  16. Characteristics and properties of metal aluminum thin films prepared by electron cyclotron resonance plasma-assisted atomic layer deposition technology

    Institute of Scientific and Technical Information of China (English)

    Xiong Yu-Qing; Li Xing-Cun; Chen Qiang; Lei Wen-Wen; Zhao Qiao; Sang Li-Jun; Liu Zhong-Wei; Wang Zheng-Duo; Yang Li-Zhen

    2012-01-01

    Metal aluminum (Al) thin films are prepared by 2450 MHz electron cyclotron resonance plasma-assisted atomic layer deposition on glass and p-Si substrates using trimethylaluminum as the precursor and hydrogen as the reductive gas.We focus our attention on the plasma source for the thin-film preparation and annealing of the as-deposited films relative to the surface square resistivity.The square resistivity of as-deposited Al films is greatly reduced after annealing and almost reaches the value of bulk metal.Through chemical and structural analysis,we conclude that the square resistivity is determined by neither the contaminant concentration nor the surface morphology,but by both the crystallinity and crystal size in this process.

  17. Characterization and Electrochemical Properties of LiMn2O4 Thin Films Prepared by Solution Deposition

    Institute of Scientific and Technical Information of China (English)

    WU Xianming; HE Zeqiang; XU Mingfei; LI Xinhai; XIAO Zhuobing

    2006-01-01

    LiMn2O4 thin films were prepared by solution deposition using lithium acetate and manganese acetate as raw materials. The phase constitution and surface morphology were observed by X-ray diffraction and scanning electron microscopy. The electrochemical properties of the thin films were studied by cyclic voltammetry, charge-discharge experiments and impedance spectroscopy in 1 mol·L-1 LiPF6/EC-DMC solution using lithium metal as both the counter and reference electrodes. The films prepared by this method are of spinel phase. The lattice parameter increases with the annealing temperature and annealing time. The film annealed at 750 ℃ for 30 minutes has the highest capacity of 34.5 μAh·cm-2·μm-1, and its capacity loss per cycle is 0.05% after being cycled 100 times.

  18. Perpendicularly oriented barium ferrite thin films with low microwave loss, prepared by pulsed laser deposition

    Science.gov (United States)

    Da-Ming, Chen; Yuan-Xun, Li; Li-Kun, Han; Chao, Long; Huai-Wu, Zhang

    2016-06-01

    Barium ferrite (BaM) thin films are deposited on platinum coated silicon wafers by pulsed laser deposition (PLD). The effects of deposition substrate temperature on the microstructure, magnetic and microwave properties of BaM thin films are investigated in detail. It is found that microstructure, magnetic and microwave properties of BaM thin film are very sensitive to deposition substrate temperature, and excellent BaM thin film is obtained when deposition temperature is 910 °C and oxygen pressure is 300 mTorr (1 Torr = 1.3332 × 102 Pa). X-ray diffraction patterns and atomic force microscopy images show that the best thin film has perpendicular orientation and hexagonal morphology, and the crystallographic alignment degree can be calculated to be 0.94. Hysteresis loops reveal that the squareness ratio (M r/M s) is as high as 0.93, the saturated magnetization is 4004 Gs (1 Gs = 104 T), and the anisotropy field is 16.5 kOe (1 Oe = 79.5775 A·m-1). Ferromagnetic resonance measurements reveal that the gyromagnetic ratio is 2.8 GHz/kOe, and the ferromagnetic resonance linewith is 108 Oe at 50 GHz, which means that this thin film has low microwave loss. These properties make the BaM thin films have potential applications in microwave devices. Project supported by the Open Foundation of State Key Laboratory of Electronic Thin Films and Integrated Devices (Grant No. KFJJ201506), the Scientific Research Starting Foundation of Hainan University (Grant No. kyqd1539), and the Natural Science Foundation of Hainan Province (Grant No. 20165187).

  19. Ethanol Sensing Properties of Nanosheets ZnO Thin Films Prepared by Chemical Bath Deposition

    Science.gov (United States)

    Julia, Sri; Nururddin, Ahmad; Nugraha, Suyatman; Yuliarto, Brian

    2011-12-01

    Nanosheets ZnO thin films were successfully fabricated on alumina substrate by chemical bath deposition method using Zinc Nitrate Tetra hydrate as precursor. Films were annealed at 300 °C for 30 minutes and observed by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDS) to know crystal phase and structure, surface morphology, and elemental composition respectively. The gas sensing performance of ZnO thin films was studied on exposure to ethanol gas sensing in various concentration (300 and 600 ppm). The films showed higher response towards ethanol gas sensing at optimized temperature of 250 °C and exhibited excellent sensitivity of 62.45% upon exposure 300 ppm and 69% upon exposure of 600 ppm ethanol gas sensing. Further, the response and recovery times of ZnO thin films to ethanol become shorter at higher operating temperatures. A possible mechanism of ethanol sensing has been explained.

  20. A Humidity Sensor Based on Silver Nanoparticles Thin Film Prepared by Electrostatic Spray Deposition Process

    Directory of Open Access Journals (Sweden)

    Thutiyaporn Thiwawong

    2013-01-01

    Full Text Available In this work, thin film of silver nanoparticles for humidity sensor application was deposited by electrostatic spray deposition technique. The influence of the deposition times on properties of films was studied. The crystal structures of sample films, their surface morphology, and optical properties have been investigated by X-ray diffraction (XRD, field emission scanning electron microscopy (FE-SEM, and UV-VIS spectrophotometer, respectively. The crystalline structure of silver nanoparticles thin film was found in the orientation of (100 and (200 planes of cubic structure at diffraction angles 2θ  =  38.2° and 44.3°, respectively. Moreover, the silver nanoparticles thin films humidity sensor was fabricated onto the interdigitated electrodes. The sensor exhibited the humidity adsorption and desorption properties. The sensing mechanisms of the device were also elucidated by complex impedance analysis.

  1. Method for preparing microstructure arrays on the surface of thin film material

    KAUST Repository

    Wang, Peng

    2017-02-09

    Methods are provided for growing a thin film of a nanoscale material. Thin films of nanoscale materials are also provided. The films can be grown with microscale patterning. The method can include vacuum filtration of a solution containing the nanostructured material through a porous substrate. The porous substrate can have a pore size that is comparable to the size of the nanoscale material. By patterning the pores on the surface of the substrate, a film can be grown having the pattern on a surface of the thin film, including on the top surface opposite the substrate. The nanoscale material can be graphene, graphene oxide, reduced graphene oxide, molybdenum disulfide, hexagonal boron nitride, tungsten diselenide, molybdenum trioxide, or clays such as montmorillonite or lapnotie. The porous substrate can be a porous organic or inorganic membrane, a silicon stencil membrane, or similar membrane having pore sizes on the order of microns.

  2. Preparation and characterization of ALD deposited ZnO thin films studied for gas sensors

    Energy Technology Data Exchange (ETDEWEB)

    Boyadjiev, S.I., E-mail: boiajiev@gmail.com [MTA-BME Technical Analytical Chemistry Research Group, Szent Gellért tér 4, Budapest, H-1111 (Hungary); Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria); Georgieva, V. [Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria); Yordanov, R. [Department of Microelectronics, Technical University of Sofia, 8 Kliment Ohridski Blvd., 1756 Sofia (Bulgaria); Raicheva, Z. [Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria); Szilágyi, I.M. [MTA-BME Technical Analytical Chemistry Research Group, Szent Gellért tér 4, Budapest, H-1111 (Hungary); Budapest University of Technology and Economics, Department of Inorganic and Analytical Chemistry, Szent Gellért tér 4, Budapest, H-1111 (Hungary)

    2016-11-30

    Highlights: • For the first time the gas sensing towards NO{sub 2} of very thin ALD ZnO films is studied. • The very thin ALD ZnO films showed excellent sensitivity to NO{sub 2} at room temperature. • These very thin film ZnO-based QCM sensors very well register even low concentrations. • The sensors have fully reversible sorption and are able to be recovered in short time. • Described fast and cost-effective ALD deposition of ZnO thin films for QCM gas sensor. - Abstract: Applying atomic layer deposition (ALD), very thin zinc oxide (ZnO) films were deposited on quartz resonators, and their gas sensing properties were studied using the quartz crystal microbalance (QCM) method. The gas sensing of the ZnO films to NO{sub 2} was tested in the concentration interval between 10 and 5000 ppm. On the basis of registered frequency change of the QCM, for each concentration the sorbed mass was calculated. Further characterization of the films was carried out by various techniques, i.e. by SEM-EDS, XRD, ellipsometry, and FTIR spectroscopy. Although being very thin, the films were gas sensitive to NO{sub 2} already at room temperature and could register very well as low concentrations as 100 ppm, while the sorption was fully reversible. Our results for very thin ALD ZnO films show that the described fast, simple and cost-effective technology could be implemented for producing gas sensors working at room temperature and being capable to detect in real time low concentrations of NO{sub 2}.

  3. Low-temperature preparation of rutile-type TiO2 thin films for optical coatings by aluminum doping

    Science.gov (United States)

    Ishii, Akihiro; Kobayashi, Kosei; Oikawa, Itaru; Kamegawa, Atsunori; Imura, Masaaki; Kanai, Toshimasa; Takamura, Hitoshi

    2017-08-01

    A rutile-type TiO2 thin film with a high refractive index (n), a low extinction coefficient (k) and small surface roughness (Ra) is required for use in a variety of optical coatings to improve the controllability of the reflection spectrum. In this study, Al-doped TiO2 thin films were prepared by pulsed laser deposition, and the effects of Al doping on their phases, optical properties, surface roughness and nanoscale microstructure, including Al distribution, were investigated. By doping 5 and 10 mol%Al, rutile-type TiO2 was successfully prepared under a PO2 of 0.5 Pa at 350-600 °C. The nanoscale phase separation in the Al-doped TiO2 thin films plays an important role in the formation of the rutile phase. The 10 mol%Al-doped rutile-type TiO2 thin film deposited at 350 °C showed excellent optical properties of n ≈ 3.05, k ≈ 0.01 (at λ = 400 nm) and negligible surface roughness, at Ra ≈ 0.8 nm. The advantages of the superior optical properties and small surface roughness of the 10 mol%Al-doped TiO2 thin film were confirmed by fabricating a ten-layered dielectric mirror.

  4. Preparation and photochromism of Keggin-type molybdphosphoric acid/silica mesoporous composite thin films

    Institute of Scientific and Technical Information of China (English)

    ZHANG XueAo; WU WenJian; MAN YaHui; TIAN Tian; TIAN XiaoZhou; WANG JianFang

    2007-01-01

    Using tetraethoxysilane and 3-aminopropyltriethoxysilane as the silica sources, amino-functionalized organic/inorganic hybrid mesoporous silica thin films with 2-dimensional hexagonal structure have been synthesized by evaporation induced self-assembly process in the presence of cetyltrimethyl ammonium bromide templates under acid conditions. The Keggin-type molybdphosphoric acid (PMo) is incorporated into the mesoporous silica thin films with amino-groups by wetness impregnation, and the PMo/silica mesoporous composite thin films are obtained. The results of X-ray diffraction (XRD),high resolution transmission electron microscopy (HRTEM), and Fourier transform infrared (FTIR)spectra indicate the PMo molecules maintain Keggin structure and are homogeneously distributed inside mesopores. The composite thin films possess excellent reversible photochromic properties, and change from colorless to blue under ultraviolet irradiation. The photochromic mechanism of the composite thin films is studied by ultraviolet-visible (UV-vis), electron spin resonance (ESR) and X-ray photoelectron spectroscopy (XPS) spectra. It is shown that intervalence charge transfer (IVCT) and ligand-to-metal charge transfer (LMCT) are the main reasons of photochromism. PMo anions interact strongly with amino-groups of the mesoporous suface via hydrogen bond and electrostatic force. After ultraviolet irradiation, the charge transfer occurs by reduction of heteropolyanions accompanying the formation of heteropolyblues with multivalence Mo(Ⅵ, Ⅴ), and the bleaching process of composite thin films is closely related to the presence of oxygen.

  5. Preparation and photochromism of Keggin-type molybdphosphoric acid/silica mesoporous composite thin films

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Using tetraethoxysilane and 3-aminopropyltriethoxysilane as the silica sources, amino-functionalized organic/inorganic hybrid mesoporous silica thin films with 2-dimensional hexagonal structure have been synthesized by evaporation induced self-assembly process in the presence of cetyltrimethyl ammonium bromide templates under acid conditions. The Keggin-type molybdphosphoric acid (PMo) is incorporated into the mesoporous silica thin films with amino-groups by wetness impregnation, and the PMo/silica mesoporous composite thin films are obtained. The results of X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), and Fourier transform infrared (FTIR) spectra indicate the PMo molecules maintain Keggin structure and are homogeneously distributed inside mesopores. The composite thin films possess excellent reversible photochromic properties, and change from colorless to blue under ultraviolet irradiation. The photochromic mechanism of the composite thin films is studied by ultraviolet-visible (UV-vis), electron spin resonance (ESR) and X-ray photoelectron spectroscopy (XPS) spectra. It is shown that intervalence charge transfer (IVCT) and ligand-to-metal charge transfer (LMCT) are the main reasons of photochromism. PMo anions interact strongly with amino-groups of the mesoporous suface via hydrogen bond and electrostatic force. After ultraviolet irradiation, the charge transfer occurs by reduction of heteropolyanions accompanying the formation of heteropolyblues with multivalence Mo(VI, V), and the bleaching process of composite thin films is closely related to the presence of oxygen.

  6. Low power optical limiting studies on nanocrystalline benzimidazole thin films prepared by modified liquid phase growth technique

    Indian Academy of Sciences (India)

    P A Praveen; S P Prabhakaran; R Ramesh Babu; K Sethuraman; K Ramamurthi

    2015-06-01

    In the present work, benzimidazole (BMZ), a well known nonlinear optical material, thin films were deposited using the modified liquid phase growth technique at different solution temperatures. The prepared samples were subjected to spectral, structural and surface analyses. Linear optical properties and third-order optical nonlinearity of the deposited BMZ thin films were analysed using UV–visible–NIR spectrum and -scan technique, respectively. The experimental results show that the BMZ films exhibit reverse saturable absorption and positive nonlinearity at 650 nm CW laser of power 5 mW. The measured third-order nonlinear susceptibility of the films is about 10−10 esu. Optical limiting studies were performed using the same laser source and the potentiality of the BMZ films is reported.

  7. Method of preparing water purification membranes. [polymerization of allyl amine as thin films in plasma discharge

    Science.gov (United States)

    Hollahan, J. R.; Wydeven, T. J., Jr. (Inventor)

    1974-01-01

    Allyl amine and chemically related compounds are polymerized as thin films in the presence of a plasma discharge. The monomer compound can be polymerized by itself or in the presence of an additive gas to promote polymerization and act as a carrier. The polymerized films thus produced show outstanding advantages when used as reverse osmosis membranes.

  8. Metal-insulator transition of valence-controlled VO2 thin film prepared by RF magnetron sputtering using oxygen radical

    Science.gov (United States)

    Suetsugu, Takaaki; Shimazu, Yuichi; Tsuchiya, Takashi; Kobayashi, Masaki; Minohara, Makoto; Sakai, Enju; Horiba, Koji; Kumigashira, Hiroshi; Higuchi, Tohru

    2016-06-01

    We have prepared b-axis-oriented VO2 thin films by RF magnetron sputtering using oxygen radicals as the reactive gas. The VO2 thin films consist of a mixed-valence V3+/V4+ state formed by oxygen vacancies. The V3+ ratio strongly depends on the film thickness and the oxygen partial pressure of the radical gun during deposition. The lattice constant of the b-axis increases and the metal-insulator transition (MIT) temperature decreases with decreasing V3+ ratio, although the VO2 thin films with a high V3+ ratio of 42% do not exhibit MIT. The bandwidths and spectral weights of V 3d a1g and \\text{e}\\text{g}σ bands at around the Fermi level, which correspond to the insulating phase at 300 K, are smaller in the VO2 thin films with a low V3+ ratio. These results indicate that the control of the mixed-valence V3+/V4+ state is important for the MIT of b-axis-oriented VO2 thin films.

  9. Inorganic Thin-film Sensor Membranes with PLD-prepared Chalcogenide Glasses: Challenges and Implementation

    Directory of Open Access Journals (Sweden)

    Michael J. Schöning

    2004-10-01

    Full Text Available Abstract: Chalcogenide glasses offer an excellent “challenge” for their use and implementation in sensor arrays due to their good sensor-specific advantages in comparison to their crystalline counterparts. This paper will give an introduction on the preparation of chalcogenide glasses in the thin-film state. First, single microsensors have been prepared with the methods of semiconductor technology. In a next step, three microsensors are implemented onto one single silicon substrate to an “one chip” sensor array. Different ionselective chalcogenide glass membranes (PbSAgIAs2S3, CdSAgIAs2S3, CuAgAsSeTe and TlAgAsIS were prepared by means of the pulsed laser deposition (PLD process. The different sensor membranes and structures have been physically characterized by means of Rutherford backscattering spectrometry, scanning electron microscopy and video microscopy. The electrochemical behavior has been investigated by potentiometric measurements.

  10. The preparation and chemical reaction kinetics of tungsten bronze thin films and nitrobenzene with and without a catalyst

    Science.gov (United States)

    Materer, Nicholas F.; Apblett, Allen; Kadossov, Evgueni B.; Khan, Kashif Rashid; Casper, Walter; Hays, Kevin; Shams, Eman F.

    2016-06-01

    Microcrystalline tungsten bronze thin films were prepared using wet chemical techniques to reduce a tungsten oxide thin film that was prepared by thermal oxidation of a sputter deposited tungsten metal film on a quartz substrate. The crystallinity of these films was determined by X-ray diffraction and the surface was characterized by X-ray and Ultra-Violet Photoelectron spectroscopy. The total amount of hydrogen incorporated in the film was monitored using absorbance spectroscopy at 900 nm. The oxidation kinetics of the film and the hydrogenation of nitrobenzene in hexane were measured as a function of film thickness. A satisfactory fit of the resulting kinetics was obtained using a model that involves two simultaneous processes. The first one is the proton diffusion from the bulk of the film to the surface, and the second is a reaction of the surface protons with the oxidants. Finally, the dependence of the reaction rates on the presence of catalytic amounts of first row transition metals on the surface of the film was explored.

  11. Bismuth(III) dialkyldithiophosphates: Facile single source precursors for the preparation of bismuth sulfide nanorods and bismuth phosphate thin films

    Energy Technology Data Exchange (ETDEWEB)

    Biswal, Jasmine B. [Department of Chemistry, University of Mumbai, Vidyanagari, Santacruz (East), Mumbai 400098 (India); Garje, Shivram S., E-mail: ssgarje@chem.mu.ac.in [Department of Chemistry, University of Mumbai, Vidyanagari, Santacruz (East), Mumbai 400098 (India); Nuwad, Jitendra; Pillai, C.G.S. [Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2013-08-15

    Two different phase pure materials (Bi{sub 2}S{sub 3} and Bi{sub 2}P{sub 4}O{sub 13}) have been prepared under different conditions using the same single source precursors. Solvothermal decomposition of the complexes, Bi(S{sub 2}P(OR){sub 2}){sub 3} [where, R=Methyl (Me) (1), Ethyl (Et) (2), n-Propyl (Pr{sup n}) (3) and iso-Propyl (Pr{sup i}) (4)] in ethylene glycol gave orthorhombic bismuth sulfide nanorods, whereas aerosol assisted chemical vapor deposition (AACVD) of the same precursors deposited monoclinic bismuth tetraphosphate (Bi{sub 2}P{sub 4}O{sub 13}) thin films on glass substrates. Surface study of the thin films using SEM illustrated the formation of variety of nanoscale morphologies (spherical-, wire-, pendent-, doughnut- and flower-like) at different temperatures. AFM studies were carried out to evaluate quality of the films in terms of uniformity and roughness. Thin films of average roughness as low as 1.4 nm were deposited using these precursors. Photoluminescence studies of Bi{sub 2}P{sub 4}O{sub 13} thin films were also carried out. - Graphical abstract: Solvothermal decomposition of bismuth(III) dialkyldithiophosphates in ethylene glycol gave Bi{sub 2}S{sub 3} nanoparticles, whereas aerosol assisted chemical vapor deposition of these single source precursors deposited Bi{sub 2}P{sub 4}O{sub 13} thin films. Display Omitted - Highlights: • Preparation of phase pure orthorhombic Bi{sub 2}S{sub 3} nanorods and monoclinic Bi{sub 2}P{sub 4}O{sub 13} thin films. • Use of single source precursors for deposition of bismuth phosphate thin films. • Use of solvothermal decomposition and AACVD methods. • Morphology controlled synthesis of Bi{sub 2}P{sub 4}O{sub 13} thin films. • Bi{sub 2}S{sub 3} nanorods and Bi{sub 2}P{sub 4}O{sub 13} thin films using same single source precursors.

  12. Thermoelectric properties of cobalt–antimonide thin films prepared by radio frequency co-sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Aziz; Han, Seungwoo, E-mail: swhan@kimm.re.kr

    2015-07-31

    Co–Sb thin films with an Sb content in the range 65–76 at.%, were deposited on a thermally oxidized Si (100) substrate preheated at 200 °C using radio-frequency co-sputtering. Evaluation using scanning electron microscopy images and X-ray diffraction reveals that the films were polycrystalline, with a grain size in the range 100–250 nm. Energy-dispersive spectroscopy analysis indicates single-phase CoSb{sub 2} and CoSb{sub 3} films, as well as multiphase thin films with either CoSb{sub 2} or CoSb{sub 3} as the dominant phase. The electrical and thermoelectric properties were measured and found to be strongly dependent on the observed phases and the defect concentrations. The CoSb{sub 2} thin films were found to exhibit a significant n-type thermoelectric effect, which, coupled with the very low electrical resistivity, resulted in a larger power factor than that of the CoSb{sub 3} thin films. We find power factors of 0.73 mWm{sup −1} K{sup −2} and 0.67 mWm{sup −1} K{sup −2} for the CoSb{sub 2} and CoSb{sub 3} thin films, respectively. - Highlights: • Polycrystalline Co–Sb thin films were obtained by present deposition strategy. • CoSb{sub 2} and CoSb{sub 3} have semimetal and semiconductor characteristics respectively. • The Seebeck coefficient depends heavily on defect concentration and impurity phases. • Film properties in the second heating cycle were different from the first. • CoSb{sub 2} is found to possess significant n-type thermopower.

  13. Optical Properties and Characterization of Prepared Sn-Doped PbSe Thin Film

    Directory of Open Access Journals (Sweden)

    M. R. Khanlary

    2012-01-01

    Full Text Available Physical vapor deposition of tin-doped lead selenide (Sn/PbSe thin films on SiO2 glass is described. Interaction of high-energy Ar+ ions bombardment on the doped PbSe films is discussed by XRD analysis. The improvement of optical band gap of Sn/PbSe films irradiated by different doses of irradiation was studied using transmission spectroscopy.

  14. Preparation of nanostructured tungsten trioxide thin films by high pressure sublimation and condensation

    Energy Technology Data Exchange (ETDEWEB)

    Abdel Samad, B., E-mail: bassel.abdel.samad@umoncton.ca; Thibodeau, J.; Ashrit, P.V.

    2015-09-30

    Highlights: • A new technique combines the high pressure sublimation and condensation with the variation of source–substrate distance to control the thin film nanostructure. • The nanostructure of WO{sub 3} thin films is systematically controlled in terms of the grain size and porosity. • The dependence of nanostructure, roughness, grain size, porosity and index of refraction to the source–substrate distance is studied. • The potential tailoring of the film properties for solar energy applications through the precise control of film nanostructure is suggested. - Abstract: Thin films of tungsten trioxide (WO{sub 3}) have gained increasing importance due to their interesting chromogenic properties and for their high application potential in electrochromic devices. It is very well known that their electrochromic switching properties depend very sensitively on their nanostructure. Hence, a vast majority of the research work carried out in this domain at present is dedicated to the various techniques of controlled inducing of a nanostructure in these WO{sub 3} thin films in order to enhance their electrochromic performance. In the present work we have carried out a systematic study of the nanostructured WO{sub 3} thin films by using a novel technique of varying the source–substrate distance in a high pressure sublimation and condensation method. This technique has been found to be very efficient in controlling the grain size and thus the nanostructure of the deposited films. A correlation is established between the optical and electrochromic properties of the WO{sub 3} films and the induced nanostructure. The electrochromic properties are studied by a dry lithiation process developed in our laboratory. The results indicate a strong dependence of the film nanostructure on the source–substrate distance which influences quite sensitively the electrochromic properties. These results are expected to help design electrochromic devices suitable for different

  15. Preparation and characterization of TiO{sub 2} thin films grown by RF magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Selmi, M.; Chaabouni, F.; Abaab, M.; Rezig, B. [Photovoltaic and Semiconductor Materials Laboratory, Enit (Tunisia)

    2008-07-01

    Titanium dioxide (TiO{sub 2}) thin films were obtained by RF sputtering technique. The samples were deposited on glass and p- silicon substrates at an argon flow rate of 4.9 sccm and at room temperature during 4 h. In this work, the influences of RF power density and annealing temperature on properties of obtained thin films were investigated. The morphological, structural and optical properties were studied by Atomic Force Microscope (AFM), X-ray Diffractometer and UV-VIS-NIR spectrophotometer respectively. A high transmission (about 80%) in the visible region, crystalline structure and a direct band gap (between 3.4 and 3.5 eV) were ob- served by the measurements. Thin films were annealed at different temperatures (from 300 to 500 C) during 30 minutes in order to investigate the annealing effect on properties of TiO{sub 2} thin films. The refractive index and the roughness increase with increasing annealing temperature. The results of this work suggest that the properties of TiO{sub 2} thin films are sensitive to sputtering parameters. It is possible to obtain sputter-deposited TiO{sub 2} films at room temperature, without using reactive oxygen, with a good predominance of anatase (101) structure after the annealing at 400 C. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Preparation and Properties of Amorphous NiFe/Cu/NiFe Thin Films

    Institute of Scientific and Technical Information of China (English)

    YE Yun; JIANG Ya-dong; HU Wen-cheng; ZENG Hong-juan

    2004-01-01

    The amorphous of Permalloy on the copper subtract was studied using composite electroplating method. A portion of hydrogen brings the counteraction on the surface of cathode leading nickel-iron alloys to be anomalous in the process of co-depositing. The results of X-ray diffraction (XRD) show that the Ni-Fe alloys layer is amorphous. The Giant Magneto -Impedance (GMI) effect of Ni-Fe alloys was obtained under the optimal conditions, dependence on the soft magnetic property of Ni-Fe amorphous thin film. As a result, the ratios△ Z/Z of NiFe/Cu/NiFe amorphous thin film are 30% at 40 kHz which is in low frequency. Furthermore, the GMI value of NiFe/Cu/NiFe amorphous thin film with a sandwich structure is higher than that of single-layer ferromagnetic films of the same thickness.

  17. Architectured morphologies of chemically prepared NiO/MWCNTs nanohybrid thin films for high performance supercapacitors.

    Science.gov (United States)

    Gund, Girish S; Dubal, Deepak P; Shinde, Sujata S; Lokhande, Chandrakant D

    2014-03-12

    The preparation of nanostructured metal oxide decorated on multiwalled carbon nanotubes (MWCNTs) nanohybrid films through simple, scalable, additive-free, binderless, and cost-effective route has fascinated significant attention not only in fundamental research areas but also its commercial applications, in order to reduce the growing environmental pollution and the cost of electrode fabrication. Here, we report the fabrication of highly flexible electrode with NiO/MWCNTs nanohybrid thin films directly on stainless steel substrate using successive ionic layer adsorption and reaction (SILAR) method. The impact of ratio of adsorption and reaction cycles on structural, surface areas and electrochemical properties of NiO/MWCNTs nanohybrids was investigated. X-ray diffraction measurements confirm the hybridization and face centered cubic (FCC) crystal structure of NiO in NiO/MWCNTs nanohybrids. In addition, these nanohybrids exhibit excellent surface properties such as uniform surface morphology, good surface area, pore volume, and uniform pore size distribution. The electrochemical tests demonstrate the highest specific capacitance of 1727 F g(-1) at 5 mA cm(-2) of current density with 91% capacitance retention after 2000 cycles. In addition, the Ragone plot confirms the better power and energy densities for all NiO/MWCNTs nanohybrids. The attractive electrochemical capacitive activity revealed by NiO/MWCNTs nanohybrid electrode proposes that it is an auspicious respondent for future energy storage application.

  18. Effect of nickel doping on physical properties of zinc oxide thin films prepared by the spray pyrolysis method

    Energy Technology Data Exchange (ETDEWEB)

    Jlassi, M., E-mail: mohamedjlassilpv@yahoo.fr [Laboratoire de Photovoltaïque, Centre de Recherche et des Technologies de l’Energie, Technopole de Borj-Cédria, BP 95, 2050 Hammam-Lif (Tunisia); Sta, I. [Laboratoire de Photovoltaïque, Centre de Recherche et des Technologies de l’Energie, Technopole de Borj-Cédria, BP 95, 2050 Hammam-Lif (Tunisia); Hajji, M. [Laboratoire de Photovoltaïque, Centre de Recherche et des Technologies de l’Energie, Technopole de Borj-Cédria, BP 95, 2050 Hammam-Lif (Tunisia); Ecole Nationale d’Electronique et des Télécommunications de Sfax, Université de Sfax, BP 1163, CP 3021 Sfax (Tunisia); Ezzaouia, H. [Laboratoire de Photovoltaïque, Centre de Recherche et des Technologies de l’Energie, Technopole de Borj-Cédria, BP 95, 2050 Hammam-Lif (Tunisia)

    2014-05-01

    Highlights: • ZnO and ZnO:Ni thin films are prepared by spray pyrolysis technique. • We have studied the effects of the pulverization time on the physical properties. • We optimize the most suitable duration of pulverization of ZnO thin films. • Amelioration on optical and electrical properties of ZnO:Ni films was noticed. - Abstract: In this study, undoped and nickel-doped zinc oxide thin films (ZnO:Ni) were deposited on glass substrates using a spray pyrolysis technique. The effects of the Zn concentration in the initial solution and the substrate temperature on the physical properties of the thin films are studied. The results show that the optimum Zn concentration and substrate temperature for preparation of basic undoped ZnO films with n-type conductivity and high optical transparency are 0.02 M and 350 °C, respectively. Then, by using these optimized deposition parameters, nickel-doped zinc oxide films are prepared. Surface morphology and crystalline structure of the films are investigated by atomic force microscopy (AFM) and X-ray diffractometer. X-ray diffraction (XRD) patterns show that the films are polycrystalline. The structural analysis shows that all the samples have a hexagonal structure. The crystallite size and the preferred orientation were calculated from the XRD data. From AFM investigations, the surface morphology of the nanostructured films is found to depend on the concentration of Ni. Optical measurements have shown that an increase in the Ni doping results in a reduction in the optical transmission of the layer, but it remains higher than 80% for Ni doping greater than 8 wt%. At the same time, the optical gap increases from 3.4 to 4 eV when the Ni ratio increases. The electrical measurements show that the resistance of the films varies with the duration of pulverization and the nickel content of the film. Low values for the electrical resistivity (around 10{sup 3} Ω cm) were obtained for Ni-doped ZnO thin films.

  19. Preparation and electrical properties of BaPbO3 thin film

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BaPbO3 thin films were deposited on Al2O3 substrates by sol-gel spin-coating and rapid thermal annealing. The microstructure and phase of BaPbO3 thin films were determined by X-ray diffractometry, scanning electrons microscopy and energy dispersive X-ray spectrometry. The influence of annealing temperature and annealing time on sheet resistance of the thin films was investigated. The results show that heat treatment, including annealing temperature and time, causes notable change in molar ratio of Pb to Ba, resulting in the variations of sheet resistance. The variation of electrical properties demonstrates that the surface state of the film changes from two-dimensional behavior to three-dimensional behavior with the increase of film thickness. Crack-free BaPbO3thin films with grain size of 90 nm can be obtained by a rapid thermal annealing at 700 ℃ for 10 min. And the BaPbO3 films with a thickness of 2.5 μm has a sheet resistance of 35 Ω.□-1.

  20. Development of spray technique for the preparation of thin films and characterization of tin oxide transparent conductors

    Energy Technology Data Exchange (ETDEWEB)

    Amanullah, F.M.; Saleh Al Mobarak, M.; Al-Dhafiri, A.M.; Al-Shibani, K.M. [King Saud Univ., Riyadh (Saudi Arabia). Dept. of Physics

    1999-06-15

    Tin oxide (TO) thin films of different thickness have been prepared by a specially designed, fabricated and developed spray technique using a stock solution of alcoholic stannous chloride (0.5 M concentration). The films have been characterized by X-ray diffraction, optical transmission and electrical studies. The XRD patterns show that the films are polycrystalline in nature and the results are in good agreement with ASTM data. From the XRD data `d` values and grain size of the crystallites have been calculated. The grain size of TO films lie in the range 300-514 A. Refractive index (n) and thickness of the films have been determined using optical transmission data. The effect of film thickness on different parameters (figure of merit, conductivity, transmission and refractive index) is presented and discussed. Variation of sheet resistance as a function of film thickness has been discussed. It is observed that the optical and electrical properties of TO films strongly depend on the thickness of the film. Optimum conditions are established based on the maximum figure of merit value. The film prepared at 450 C with the maximum thickness of 5262 A showed the maximum figure of merit 0.7 x 10{sup -3} {Omega}{sup -1}. The corresponding film properties are R = 30 {Omega} per square, T{sub f} = 0.70 (orig.) 23 refs.

  1. Structure, optical and electrical properties of indium tin oxide ultra thin films prepared by jet nebulizer spray pyrolysis technique

    Directory of Open Access Journals (Sweden)

    M. Thirumoorthi

    2016-03-01

    Full Text Available Indium tin oxide (ITO thin films have been prepared by jet nebulizer spray pyrolysis technique for different Sn concentrations on glass substrates. X-ray diffraction patterns reveal that all the films are polycrystalline of cubic structure with preferentially oriented along (222 plane. SEM images show that films exhibit uniform surface morphology with well-defined spherical particles. The EDX spectrum confirms the presence of In, Sn and O elements in prepared films. AFM result indicates that the surface roughness of the films is reduced as Sn doping. The optical transmittance of ITO thin films is improved from 77% to 87% in visible region and optical band gap is increased from 3.59 to 4.07 eV. Photoluminescence spectra show mainly three emissions peaks (UV, blue and green and a shift observed in UV emission peak. The presence of functional groups and chemical bonding was analyzed by FTIR. Hall effect measurements show prepared films having n-type conductivity with low resistivity (3.9 × 10−4 Ω-cm and high carrier concentrations (6.1 × 1020 cm−3.

  2. Multifractal spectra of scanning electron microscope images of SnO2 thin films prepared by pulsed laser deposition

    Science.gov (United States)

    Chen, Z. W.; Lai, J. K. L.; Shek, C. H.

    2005-09-01

    The concept of fractal geometry has proved useful in describing structures and processes in experimental systems. In this Letter, the surface topographies of SnO2 thin films prepared by pulsed laser deposition for various substrate temperatures were measured by scanning electron microscope (SEM). Multifractal spectra f(α) show that the higher the substrate temperature, the wider the spectrum, and the larger the Δf(Δf=f(α)-f(α)). It is apparent that the nonuniformity of the height distribution increases with the increasing substrate temperature, and the liquid droplets of SnO2 thin films are formed on previous thin films. These results show that the SEM images can be characterized by the multifractal spectra.

  3. Multifractal spectra of scanning electron microscope images of SnO{sub 2} thin films prepared by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z.W. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China)]. E-mail: cnzwchen@yahoo.com.cn; Lai, J.K.L. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China); Shek, C.H. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China)

    2005-09-26

    The concept of fractal geometry has proved useful in describing structures and processes in experimental systems. In this Letter, the surface topographies of SnO{sub 2} thin films prepared by pulsed laser deposition for various substrate temperatures were measured by scanning electron microscope (SEM). Multifractal spectra f({alpha}) show that the higher the substrate temperature, the wider the spectrum, and the larger the {delta}f({delta}f=f({alpha}{sub min})-f({alpha}{sub max})). It is apparent that the nonuniformity of the height distribution increases with the increasing substrate temperature, and the liquid droplets of SnO{sub 2} thin films are formed on previous thin films. These results show that the SEM images can be characterized by the multifractal spectra.

  4. Spectroscopic studies of UV irradiated erythrosine B thin films prepared by spin coating technique.

    Science.gov (United States)

    Zeyada, H M; El-Mallah, H M; Atwee, T; El-Damhogi, D G

    2017-05-15

    The spectroscopic studies of erythrosine B thin films manufactured by the spin coating technique have been presented. The spectra of infrared absorption allow characterization of vibrational modes for erythrosine B in powder form, pristine and UV irradiated thin films. The absorption spectra recorded in UV-vis-NIR for pristine films of erythrosine B display two main bands. UV irradiation on erythrosine B films decreased absorbance over the spectra. Indirect allowed transition with optical energy gap of 2.57eV is observed in pristine films. UV irradiation introduced structural defects and decreased optical band gap. Some of the optical absorption parameters and their relation to UV irradiation times, namely molar extinction coefficient (ε), electronic dipole strength (q(2)), and oscillator strength (f), of the principal optical transitions have also been evaluated.

  5. Laser Induced Nonlinear Optical Properties of Zinc Oxide Thin Film Prepared by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Vinay Kumari

    2011-01-01

    Full Text Available Optical nonlinearities of spin coated ZnO thin film have been investigated by using single beam Z-Scan technique in the visible region. X- ray diffraction shows that all films are oriented along the c-axis direction of the hexagonal crystal structure. The average optical transmittance of all films is higher than 80 %. The nonlinear optical parameters viz. nonlinear absorption coefficient (β, nonlinear index of refraction (η2, nonlinear susceptibility (χ3, have been estimated using nanosecond laser pulses of second harmonic of Nd:YAG Laser. The value of nonlinear absorption coefficient β is estimated to be greater than the already reported value. The films clearly exhibit a-ve value of nonlinear refraction at 532 nm which is attributed to the two photon absorption and free carrier absorption. The presence of RSA in ZnO thin films inferes that ZnO is a potential material for the development of optical limiter.

  6. Preparation of c-axis-oriented zinc-oxide thin films and the study of their microstructure and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Aslan, M.H.; Gul, A.; Basaran, E. [Department of Physics, Gebze Institute of Technology, P.K. 141, Kocaeli 41400 (Turkey); Oral, A.Y. [Department of Material Science and Engineering, Gebze Institute of Technology, Kocaeli (Turkey); Mensur, E. [Department of Physics, University of Kocaeli, Kocaeli (Turkey)

    2004-05-30

    c-axis-oriented zinc-oxide (ZnO) thin films were prepared on microscope glass substrates by sol-gel deposition. A homogeneous and stable solution was prepared by dissolving zinc-acetate 2-hydrate (ZnAc) in 2-propanol and diethanolamine. Crystalline ZnO thin films were obtained following an annealing process at temperatures between 450C and 550C for 1h. Increasing annealing temperature increased the grain size and the c-axis orientation. The X-ray diffraction analysis revealed single-phase ZnO with hexagonal zincite structure. The absorption edge analysis revealed that the optical band-gap energy for the films were between 3.26 and 3.28eV and electronic transition was direct transition type.

  7. Application of Response Surface Methodology in Development of Sirolimus Liposomes Prepared by Thin Film Hydration Technique

    Directory of Open Access Journals (Sweden)

    Saeed Ghanbarzadeh

    2013-04-01

    Full Text Available Introduction: The present investigation was aimed to optimize the formulating process of sirolimus liposomes by thin film hydration method. Methods: In this study, a 32 factorial design method was used to investigate the influence of two independent variables in the preparation of sirolimus liposomes. The dipalmitoylphosphatidylcholine (DPPC /Cholesterol (Chol and dioleoyl phosphoethanolamine(DOPE /DPPC molar ratios were selected as the independent variables. Particle size (PS and Encapsulation Efficiency (EE % were selected as the dependent variables. To separate the un-encapsulated drug, dialysis method was used. Drug analysis was performed with a validated RP-HPLC method. Results: Using response surface methodology and based on the coefficient values obtained for independent variables in the regression equations, it was clear that the DPPC/Chol molar ratio was the major contributing variable in particle size and EE %. The use of a statistical approach allowed us to see individual and/or interaction effects of influencing parameters in order to obtain liposomes with desired properties and to determine the optimum experimental conditions that lead to the enhancement of characteristics. In the prediction of PS and EE % values, the average percent errors are found to be as 3.59 and 4.09%. This value is sufficiently low to confirm the high predictive power of model. Conclusion: Experimental results show that the observed responses were in close agreement with the predicted values and this demonstrates the reliability of the optimization procedure in prediction of PS and EE % in sirolimus liposomes preparation.

  8. Formulation and delivery of improved amorphous fenofibrate solid dispersions prepared by thin film freezing.

    Science.gov (United States)

    Zhang, Meimei; Li, Houli; Lang, Bo; O'Donnell, Kevin; Zhang, Haohao; Wang, Zhouhua; Dong, Yixuan; Wu, Chuanbin; Williams, Robert O

    2012-11-01

    The objective of this study was to prepare amorphous fenofibrate (FB) solid dispersions using thin film freezing (TFF) and to incorporate the solid dispersions into pharmaceutically acceptable dosage forms. FB solid dispersions prepared with optimized drug/polymer ratios were characterized by modulated differential scanning calorimetry (MDSC), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) specific surface area measurements, Fourier-transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR), and supersaturation dissolution testing. Furthermore, a dry granulation technique was used to encapsulate the TFF compositions for in vitro dissolution and in vivo animal pharmacokinetic studies. The results showed that the TFF process produced amorphous, porous, microstructured, and stable solid dispersions with high surface areas. Development of solid oral dosage forms revealed that the performance of the FB containing solid dispersions was not affected by the formulation process, which was confirmed by DSC and XRD. Moreover, an in vivo pharmacokinetic study in rats revealed a significant increase in FB absorption compared to bulk FB. We confirmed that amorphous solid dispersions with large surface areas produced by the TFF process displayed superior dissolution rates and corresponding enhanced bioavailability of the poorly water-soluble drug, FB. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Femtosecond Transient Absorption Studies in Cadmium Selenide Nanocrystal Thin Films Prepared by Chemical Bath Deposition Method

    Directory of Open Access Journals (Sweden)

    M. C. Rath

    2007-01-01

    Full Text Available Dynamics of photo-excited carrier relaxation processes in cadmium selenide nanocrystal thin films prepared by chemical bath deposition method have been studied by nondegenerate femtosecond transient pump-probe spectroscopy. The carriers were generated by exciting at 400 nm laser light and monitored by several other wavelengths. The induced absorption followed by a fast bleach recovery observed near and above the bandgap indicates that the photo-excited carriers (electrons are first trapped by the available traps and then the trapped electrons absorb the probe light to show a delayed absorption process. The transient decay kinetics was found to be multiexponential in nature. The short time constant, <1 picosecond, was attributed to the trapping of electrons by the surface and/or deep traps and the long time constant, ≥20 picoseconds, was due to the recombination of the trapped carriers. A very little difference in the relaxation processes was observed in the samples prepared at bath temperatures from 25∘C to 60∘C.

  10. Preparation of TiO2 thin film by the LPD method on functionalized organic self-assembled monolayers

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper, uniform titania (TiO2) films have been formed at 50℃ on silanol SAMs by the liquid-phase deposition (LPD) method at a temperature below 100℃. OTS (Octadecyltrichloro-Silane) selfassembled monolayers (SAMs) on glass wafers were used as substrates for the deposition of titanium dioxide thin films. This functionalized organic surface has shown to be effective for promoting the growth of films from titanic aqueous solutions by the LPD method at a low temperature below 100℃. The crystal phase composition, microstructure and topography of the as-prepared films were characterized by various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The results indicate that the as-prepared thin films are purely crystallized anatase TiO2 constituted by nanorods after being annealed at 500℃. The pH values, concentration of reactants, and deposition temperatures play important roles in the growth of TiO2 thin films.

  11. Preparation of dye-adsorbing ZnO thin films by electroless deposition and their photoelectrochemical properties.

    Science.gov (United States)

    Nagaya, Satoshi; Nishikiori, Hiromasa

    2013-09-25

    Dye-adsorbing ZnO thin films were prepared on ITO films by electroless deposition. The films were formed in an aqueous solution containing zinc nitrate, dimethylamine-borane, and eosin Y at 328 K. The film thickness was 1.2-2.0 μm. Thinner and larger-plane hexagonal columns were produced from the solution containing a higher concentration of eosin Y. A photocurrent was observed in the electrodes containing such ZnO films during light irradiation. The photoelectrochemical performance of the film was improved by increasing the concentration of eosin Y because of increases in the amount of absorbed photons and the electronic conductivity of ZnO.

  12. Structural, optical, and electrical properties of Mo-doped ZnO thin films prepared by magnetron sputtering

    Science.gov (United States)

    Wu, Muying; Yu, Shihui; Chen, Guihua; He, Lin; Yang, Lei; Zhang, Weifeng

    2015-01-01

    Molybdenum doped zinc oxide thin films have been prepared by RF magnetron sputtering. The influence of the film thickness (120-500 nm) on the structural, electrical, and optical properties of the films is investigated respectively. X-ray diffraction (XRD) studies reveal that with an increase in the film thickness, the crystallinity of the film improves. The obtained film with thickness of 500 nm exhibits the best electrical properties with the lowest resistivity of around 9.6 × 10-4 Ω cm. The mobility varied from 7.8 to 14.7 cm2 V-1 s-1 without reducing the achieved high carrier concentration of ∼4.5 × 1020 cm-3. Optical band gaps extracted from transmission spectra shows irregular changes due to the Burstein-Moss shift modulated by many-body effects.

  13. Double-layer indium doped zinc oxide for silicon thin-film solar cell prepared by ultrasonic spray pyrolysis

    Institute of Scientific and Technical Information of China (English)

    Jiao Bao-Chen; Zhang Xiao-Dan; Wei Chang-Chun; Sun Jian; Ni Jian; Zhao Ying

    2011-01-01

    Indium doped zinc oxide (ZnO:In) thin films were prepared by ultrasonic spray pyrolysis on corning eagle 2000 glass substrate. 1 and 2 at.% indium doped single-layer ZnO:In thin films with different amounts of acetic acid added in the initial solution were fabricated. The 1 at.% indium doped single-layers have triangle grains. The 2 at.% indium doped single-layer with 0.18 acetic acid adding has the resistivity of 6.82 × 10-3 Ω· cm and particle grains. The double-layers structure is designed to fabricate the ZnO:In thin film with low resistivity (2.58×10-3 Ω· cm) and good surface morphology. It is found that the surface morphology of the double-layer ZnO:In film strongly depends on the substrate-layer, and the second-layer plays a large part in the resistivity of the double-layer ZnO:In thin film. Both total and direct transmittances of the double-layer ZnO:In film are above 80% in the visible light region. Single junction a-Si:H solar cell based on the double-layer ZnO:In as front electrode is also investigated.

  14. Synthesis, Structural and Optoelectronic Properties of Nanocrystalline CdSe Thin Films Prepared By Chemical Bath Deposition Route

    Directory of Open Access Journals (Sweden)

    C. P. Nikam

    2015-12-01

    Full Text Available Cadmium Selenide (CdSe thin films were deposited onto glass substrates by simple and low cost chemical bath deposition (CBD technique. Aqueous ammonia was used as a complexing agent for the synthesis of these films. Deposition parameters were optimised and the crystal structure and morphology of the films were characterized by x-ray diffraction (XRD and field emission scanning electron microscopy (FE-SEM, respectively. XRD pattern revealed that the as-prepared CdSe thin films are polycrystalline with hexagonal structure. The average crystallite size of CdSe thin film was found to be in the range of 12-16 nm. FE-SEM image revealed that deposited thin films were consisting of nanocrystalline grains, which were coalesced to form bigger grains that are in cluster form distributed over the substrate surface. Transmission spectra showed high transmittance in the visible region and direct optical band gap energy was found to be a function of deposition time.

  15. Structural, Optical and Electrochromic Properties of Nanocrystalline TiO2 Thin Films Prepared by Spin Coating

    OpenAIRE

    2004-01-01

    Nanocrystalline TiO2 thin filmswere prepared by spin coating on covered glass substrates with an indium tin oxide (ITO) layer. The structural, electrochromic and optical properties of the films were investigated. The films are crystallized predominantly in the anatase phase with lattice parameters a = b = 0.378 nm and c = 0.958 nm . The crystallite size was found to be of the order of 14 nm. The films showed reversible coloration/bleaching cycles as demonstrated by cyclic voltametry and curre...

  16. Influence of preparation conditions on the dispersion parameters of sprayed iron oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Akl, Alaa A., E-mail: alaaakl@link.net [Physics Department, Faculty of Science, El-Minia University, El-Minia 111955 (Egypt)

    2010-10-01

    Iron oxide thin films were prepared by spray pyrolysis technique (SPT) at various substrate temperatures (T{sub sub}) and different deposition time. X-ray diffraction (XRD) analysis showed that, at T{sub sub} {>=} 350 deg. C, a single phase of {alpha}-Fe{sub 2}O{sub 3} film is formed which has the rhombohedral structure. Moreover, the crystallinity was improved by increasing T{sub sub}. The effect of T{sub sub} as well as deposition time on the optical dispersion of these films has been investigated. The optical transmittance and reflectance measurements were performed by using spectrophotometer in the wavelength range from 300 to 2500 nm. The refractive index was determined by using Murmann's exact equation. It was observed that, the refractive index increased with increasing in both the T{sub sub} and film thickness. The optical dispersion parameters have been evaluated and analyzed by using Wemple-Didomenico equation. The obtained results showed that, the dielectric properties have weak dependencies of growth temperature and film thickness. At T{sub sub} {>=} 350 deg. C, the average values of oscillator energy, E{sub o} and dispersion energy, E{sub d} were found to be 5.96 and 34.08 eV. While at different thickness, the average values of dispersion energies were found to be 3.93 and 17.08 eV. Also, the average values of oscillator strength S{sub o} and single resonant frequency {omega}{sub o} were estimated 10.78 x 10{sup 13} m{sup -2} and 5.99 x 10{sup 15} Hz, while at different thickness were evaluating 4.81 x 10{sup 13} m{sup -2} and 6.11 x 10{sup 15} Hz. Furthermore, the optical parameters such as wavelength of single oscillator {lambda}{sub o}, plasma frequency {omega}{sub p}, and dielectric constant {epsilon} have been evaluated. The carrier concentration N{sub opt} by using Drud's theory was obtained the range of 5.07 x 10{sup 25} m{sup -3} to 1.04 x 10{sup 26} m{sup -3}.

  17. Preparation, structure and optical properties of transparent conducting gallium-doped zinc oxide thin films

    Directory of Open Access Journals (Sweden)

    Gu J. H.

    2015-09-01

    Full Text Available Highly conductive gallium-doped zinc oxide (GZO transparent thin films were deposited on glass substrates by RF mag­netron sputtering. The deposited films were characterized by X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, four-point probe and UV-Vis spectrophotometer, respectively. The effect of growth temperature on the structure and optoelectrical properties of the films was investigated. The results demonstrate that high quality GZO films oriented with their crystal­lographic c-axis perpendicular to the substrates are obtained. The structure and optoelectrical properties of the films are highly dependent on the growth temperature. It is found that with increasing growth temperature, the average visible transmittance of the deposited films is enhanced and the residual stress in the thin films is obviously relaxed. The GZO films deposited at the growth temperature of 400°C, which have the largest grain size (74.3 nm, the lowest electrical resistivity (1.31×10-3 Ω·cm and the maximum figure of merit (1.46×1O-2Ω-1, exhibit the best optoelectrical properties. Furthermore, the optical proper­ties of the deposited films were determined by the optical characterization methods and the optical energy-gaps were evaluated by extrapolation method. A blue shift of the optical energy gap is observed with an increase in the growth temperature.

  18. Temperature dependent grain-size and microstrain of CdO thin films prepared by spray pyrolysis method

    Indian Academy of Sciences (India)

    B G Jeyaprakash; K Kesavan; R Ashok Kumar; S Mohan; A Amalarani

    2011-07-01

    CdO thin films on glass substrate were prepared by home built spray pyrolysis unit from aqueous solution of Cd(CH3COO)2.2H2O at different substrate temperatures. X-ray diffraction (XRD) studies indicate the formation of polycrystalline cubic CdO phase with preferential orientation along (111) plane. X-ray line broadening technique is adopted to study the effect of substrate temperature on microstructural parameters such as grain size and microstrain. Scanning electron microscopy (SEM) shows that the film prepared at 250°C consists of spherical shape grains with size in nanometer range and is comparable with the XRD studies.

  19. Electrical and Optical Properties of GeSi−:H Thin Films Prepared by Thermal Evaporation Method

    Directory of Open Access Journals (Sweden)

    A. A. J. Al-Douri

    2010-01-01

    Full Text Available Thin a-GeSi1−:H films were grown successfully by fabrication of designated ingot followed by evaporation onto glass slides. A range of growth conditions, Ge contents, dopant concentration (Al and As, and substrate temperature, were employed. Stoichiometry of the thin films composition was confirmed using standard surface techniques. The structure of all films was amorphous. Film composition and deposition parameters were investigated for their bearing on film electrical and optical properties. More than one transport mechanism is indicated. It was observed that increasing substrate temperature, Ge contents, and dopant concentration lead to a decrease in the optical energy gap of those films. The role of the deposition conditions on values of the optical constants was determined. Accordingly, models of the density of states for the Ge0.5Si0.5:H thin films as pure, doped with 3.5% of Al (p-type and that doped with 3.5% As (n-type, were proposed.

  20. Preparation, characterization and electrochromic properties of composite thin films incorporation of polyaniline

    Science.gov (United States)

    Farasat, Mahshid; Golzan, M. Maqsood; Farhadi, Khalil; Shojaei, S. H. Reza; Gheisvandi, Sorayya

    2016-05-01

    Two different electrochromic composite films consisting of aniline/sodium molybdate (S1) and aniline/ferric nitrate (S2) were obtained by electrochemical polymerization method on indium tin oxide (ITO) coated glass substrates in oxalic acid (H2C2O4ṡ2H2O) aqueous solution. The electrochromic properties of the resulting thin films were investigated by spectroelectrochemical measurement and cyclic voltammetry (CV). Under a square electrical potential, they show capacitive current characteristic and represent electrochromic performance, with maximum optical attenuations (ΔT%) of 30.8% at 355nm and 28.3% at 400nm for aniline/ferric nitrate and aniline/sodium molybdate thin films, respectively. Optical behavior of thin films was examined by UV-Vis spectrophotometry technique. The doped films indicated multiple color changes (yellow; green; and bluish green). The spectra also showed that produced layers have high absorption of UV radiation with respect to pure polyaniline (PANI) films. The optical band gap energy of PANI film decreased by dopant injection. Due to their decent transparency and electrochromic behavior, they are promising materials for electrochromic devices.

  1. Gallium doping in transparent conductive ZnO thin films prepared by chemical spray pyrolysis

    Science.gov (United States)

    Babar, A. R.; Deshamukh, P. R.; Deokate, R. J.; Haranath, D.; Bhosale, C. H.; Rajpure, K. Y.

    2008-07-01

    Zinc oxide (ZnO) and ZnO : Ga films have been deposited by the spray pyrolysis method onto preheated glass substrates using zinc acetate and gallium nitrate as precursors for Zn and Ga ions, respectively. The effect of Ga doping on the structural, morphological, optical and electrical properties of sprayed ZnO thin films were investigated using x-ray diffraction (XRD), scanning electron microscopy, optical absorption, photoluminescence (PL) and Hall effect techniques. XRD studies reveal that films are polycrystalline with hexagonal (wurtzite) crystal structure. The thin films were oriented along the (0 0 2) plane. Room temperature PL measurements indicate that the deposited films exhibit proper doping of Ga in ZnO lattice. The average transparency in the visible range was around ~85-95% for typical thin film deposited using 2 at% gallium doping. The optical band gap increased from 3.31 to 3.34 eV with Ga doping of 2 at%. The addition of gallium induces a decrease in electrical resistivity of the ZnO : Ga films up to 2 at% gallium doping. The highest figure of merit observed in this present study was 3.09 × 10-3 cm2 Ω-1.

  2. Gallium doping in transparent conductive ZnO thin films prepared by chemical spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Babar, A R; Deshamukh, P R; Deokate, R J; Bhosale, C H; Rajpure, K Y [Electrochemical Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004 (India); Haranath, D [National Physical Laboratory, Dr K S Krishnan Road, New Delhi 110 012 (India)], E-mail: rajpure@yahoo.com

    2008-07-07

    Zinc oxide (ZnO) and ZnO : Ga films have been deposited by the spray pyrolysis method onto preheated glass substrates using zinc acetate and gallium nitrate as precursors for Zn and Ga ions, respectively. The effect of Ga doping on the structural, morphological, optical and electrical properties of sprayed ZnO thin films were investigated using x-ray diffraction (XRD), scanning electron microscopy, optical absorption, photoluminescence (PL) and Hall effect techniques. XRD studies reveal that films are polycrystalline with hexagonal (wurtzite) crystal structure. The thin films were oriented along the (0 0 2) plane. Room temperature PL measurements indicate that the deposited films exhibit proper doping of Ga in ZnO lattice. The average transparency in the visible range was around {approx}85-95% for typical thin film deposited using 2 at% gallium doping. The optical band gap increased from 3.31 to 3.34 eV with Ga doping of 2 at%. The addition of gallium induces a decrease in electrical resistivity of the ZnO : Ga films up to 2 at% gallium doping. The highest figure of merit observed in this present study was 3.09 x 10{sup -3} cm{sup 2} {omega}{sup -1}.

  3. High Tc thin film superconductors: preparation, patterning and characterization. [Y-Ba-Cu-O; Bi-Sr-Ca-Cu-O

    Energy Technology Data Exchange (ETDEWEB)

    Azoulay, J. (Center for Tech. Education, Holon (Israel) Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics and Astronomy, Tel-Aviv Univ. (Israel))

    1991-12-10

    A conventional oil-pumped vacuum system equipped with resistively heated tungsten boat sources was used for evaporation of bismuth- or yttrium-based cuprates for high Tc thin films superconductors. A well-ground mixture with atomic proportions of bismuth, SrF{sub 2}, CaF{sub 2} and copper for bismuth-based material, and of YF{sub 3}, BaF{sub 2} and copper for yttrium-based material, was inserted into the boat and then resistively evaporated onto different substrates such as MgO, ZrO{sub 2} and SrTiO{sub 3} kept at room temperature. Yttrium-based thin films were found to have a better quality upon reduction of fluorine in the constituents. Thus, films prepared with an yttrium BaF{sub 2} and copper mixture show a metallic-like behaviour, sharper transition and higher zero-resistance temperature as compared with that of films obtained by using a YF{sub 2} constituent instead of yttrium. Bismuth-based thin films were found to lose bismuth during heat treatment unless the copper constituent ended the evaporation process and was subsequently fully oxidized at 400degC. Bismuth-based patterned films were easily obtained by using a lift-off photolithographic method. Typical thickness of the films was measured to be about 0.5 {mu}m after heat treatment. (orig.).

  4. Thin film processes II

    CERN Document Server

    Kern, Werner

    1991-01-01

    This sequel to the 1978 classic, Thin Film Processes, gives a clear, practical exposition of important thin film deposition and etching processes that have not yet been adequately reviewed. It discusses selected processes in tutorial overviews with implementation guide lines and an introduction to the literature. Though edited to stand alone, when taken together, Thin Film Processes II and its predecessor present a thorough grounding in modern thin film techniques.Key Features* Provides an all-new sequel to the 1978 classic, Thin Film Processes* Introduces new topics, and sever

  5. Pyrolyzed thin film carbon

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Liger, Matthieu (Inventor); Harder, Theodore (Inventor); Konishi, Satoshi (Inventor); Miserendino, Scott (Inventor)

    2010-01-01

    A method of making carbon thin films comprises depositing a catalyst on a substrate, depositing a hydrocarbon in contact with the catalyst and pyrolyzing the hydrocarbon. A method of controlling a carbon thin film density comprises etching a cavity into a substrate, depositing a hydrocarbon into the cavity, and pyrolyzing the hydrocarbon while in the cavity to form a carbon thin film. Controlling a carbon thin film density is achieved by changing the volume of the cavity. Methods of making carbon containing patterned structures are also provided. Carbon thin films and carbon containing patterned structures can be used in NEMS, MEMS, liquid chromatography, and sensor devices.

  6. Colored and transparent oxide thin films prepared by magnetron sputtering: the glass blower approach.

    Science.gov (United States)

    Gil-Rostra, Jorge; Chaboy, Jesús; Yubero, Francisco; Vilajoana, Antoni; González-Elipe, Agustín R

    2013-03-01

    This work describes the reactive magnetron sputtering processing at room temperature of several mixed oxide MxSiyOz thin films (M: Fe, Ni, Co, Mo, W, Cu) intended for optical, coloring, and aesthetic applications. Specific colors can be selected by adjusting the plasma gas composition and the Si-M ratio in the magnetron target. The microstructure and chemistry of the films are characterized by a large variety of techniques including X-ray photoemission spectroscopy, X-ray absorption spectroscopy (XAS), and infrared spectroscopy, while their optical properties are characterized by UV-vis transmission and reflection analysis. Particularly, XAS analysis of the M cations in the amorphous thin films has provided valuable information about their chemical state and local structure. It is concluded that the M cations are randomly distributed within the SiO2 matrix and that both the M concentration and its chemical state are the key parameters to control the final color of the films.

  7. Preparation and atomic force microscopy of CTAB stabilized polythiophene nanoparticles thin film

    Science.gov (United States)

    Graak, Pinki; Devi, Ranjna; Kumar, Dinesh; Singh, Vishal; Kumar, Sacheen

    2016-05-01

    Polythiophene nanoparticles were synthesized by iron catalyzed oxidative polymerization method. Polythiophene formation was detected by UV-Visible spectroscopy with λmax 375nm. Thin films of CTAB stabilized polythiophene nanoparticles was deposited on n-type silicon wafer by spin coating technique at 3000rpm in three cycles. Thickness of the thin films was computed as 300-350nm by ellipsometry. Atomic force micrscopyrevealws the particle size of polymeric nanoparticles in the range of 30nm to 100nm. Roughness of thinfilm was also analyzed from the atomic force microscopy data by Picoimage software. The observed RMS value lies in the range of 6 nm to 12 nm.

  8. Recent trends in preparation and application of carbon nanotube-graphene hybrid thin films

    Science.gov (United States)

    Thanh Dang, Van; Dung Nguyen, Duc; Thanh Cao, Thi; Le, Phuoc Huu; Tran, Dai Lam; Phan, Ngoc Minh; Chuc Nguyen, Van

    2016-09-01

    The combination of one-dimensional (1D) carbon nanotubes (CNTs) and two-dimensional (2D) graphene materials to generate three-dimensional (3D) carbon nanotube-graphene hybrid thin films (CNGHTFs) has attracted great attention owing to their intriguing properties via the synergistic effects of these two materials on their electrical, optical, and electrochemical properties in comparison with their individual components. This review aims to provide a brief introduction of recent trends in preparation methodologies and some outstanding applications of CNGHTFs. It contains two main scientific subjects. The first of these is the research on preparation techniques of CNGHTFs, including reduction agent-assisted mechanical blending of reduced graphene oxide (rGO) and CNTs, hybridization methods for layer-by-layer (LBL) assembly of CNTs and rGO sheets, multi-step methods using combinations of a solution and chemical vapor deposition (CVD) processing, one-step growth of CNGHTFs by the CVD method, and modified CVD methods via thermal deposition of carbon source on catalyst surfaces. The advantages and disadvantages of the preparation methods of CNGHTFs are presented and discussed in detail. The second scientific subject of the review is the research on some outstanding applications of CNGHTFs in various research fields, including transparent conductors, electron field emitters, field-effect transistors, biosensors and supercapacitors. In most cases, the CNGHTFs showed superior performances than those of the pristine GO/graphene or CNT materials. Therefore, the CNGHTFs exhibit as high-potential materials for various practical applications. Opportunites and challenges in the fields are also presented.

  9. Microstructural and Electrical Properties of ZrO2 Thin Films Prepared on silicon on Insulator with Thin Top silicon

    Institute of Scientific and Technical Information of China (English)

    章宁琳; 宋志棠; 沈勤我; 林成鲁

    2003-01-01

    Amorphous zirconia thin films were deposited directly on silicon-on-insulator (SOI) substrates with thin top silicon by ultra-high vacuum electron beam evaporation. Spreading resistance profile and scanning transmission-electron microscopy (TEM) were used to detect the interface quality and microstructure, revealing that the interface between the zirconium oxide films and top silicon was abrupt and clear. The films kept to be amorphous up to the rapid thermal temperature of 700°C for 300s, but arriving at 700°C an unknown interfacial product appeared,which was probably ZrSixOy. High frequency capacitance-voltage (C- V) characteristics at 1 MHz performed on metal-oxide-SOI structure revealed that this interfacial product exhibited good electrical properties of zirconia thin films. When the annealing temperature increased from 600°C to 700°C, flat voltage VFB changed from -2.451 to -1.741 eV, showing the improvement in the quality of the films. The cumulative region capacitance decreased from 3.058 × 10-11F to 3.012 × 10-11F, indicating increasing equivalent oxide thickness, which is in agreement with the result of high-resolution cross-sectional TEM.

  10. Structural, optical and electrical properties of ZnO thin films prepared by spray pyrolysis: Effect of precursor concentration

    Indian Academy of Sciences (India)

    F Zahedi; R S Dariani; S M Rozati

    2014-05-01

    ZnO thin films have been prepared using zinc acetate precursor by spray pyrolytic decomposition of zinc acetate on glass substrates at 450 °C. Effect of precursor concentration on structural and optical properties has been investigated. ZnO films are polycrystalline with (002) plane as preferential orientation. The optical transmission spectrum shows that transmission increases with decrease in the concentration and the maximum transmission in visible region is about 95% for ZnO films prepared with 0.1 M. The direct band-gap value decreases from 3.37 to 3.19 eV, when the precursor concentration increases from 0.1 to 0.4 M. Photoluminescence spectra at room temperature show an ultraviolet (UV) emission at 3.26 eV and two visible emissions at 2.82 and 2.38 eV. Lowest resistivity is obtained at 2.09 cm for 0.3 M. The current–voltage characteristic of the ZnO thin films were measured in dark and under UV illumination. The values of photocurrent and photoresponsivity at 5 V are increased with increase in precursor concentration and reaches to maximum value of 1148 A and 0.287 A/W, respectively which is correlated to structural properties of ZnO thin films.

  11. Influence of pH on ZnO nanocrystalline thin films prepared by sol–gel dip coating method

    Indian Academy of Sciences (India)

    K Sivakumar; V Senthil Kumar; N Muthukumarasamy; M Thambidurai; T S Senthil

    2012-06-01

    ZnO nanocrystalline thin films have been prepared on glass substrates by sol–gel dip coating method. ZnO thin films have been coated at room temperature and at four different pH values of 4, 6, 8 and 10. The X-ray diffraction pattern showed that ZnO nanocrystalline thin films are of hexagonal structure and the grain size was found to be in the range of 25–45 nm. Scanning electron microscopic images show that the surface morphology improves with increase of pH values. TEM analysis reveals formation of ZnO nanocrystalline with an average grain size of 44 nm. The compositional analysis results show that Zn and O are present in the sample. Optical band studies show that the films are highly transparent and exhibit a direct bandgap. The bandgap has been found to lie in the range of 3.14–3.32 eV depending on pH suggesting the formation of ZnO nanocrystalline thin films.

  12. Characteristics of SnO2 thin films prepared by SILAR

    Science.gov (United States)

    Yıldırım, M. Ali; Akaltun, Yunus; Ateş, Aytunç

    2012-09-01

    SnO2 thin films were deposited on glass substrates by using Successive Ionic Layer Adsorption and Reaction (SILAR) method at room temperature. The film thickness effect on characteristic parameters such as structural, morphological, optical and electrical properties of the films was studied. Also, the films were annealed in oxygen atmosphere (400 °C, 30 min) and characteristic parameters of the films were investigated. The X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) studies showed that all the films exhibited polycrystalline nature with tetragonal structure and were covered well on glass substrates. After the investigation of the crystalline and surface properties of the films, it was found that they were improving with increasing film thickness. Optical band gap decreased from 3.90 eV to 3.54 eV and electrical conductivity changed between 0.015-0.815 (Ω-cm)-1as the film thickness increased from 215 to 490 nm. The refractive index (n), optical static and high frequency dielectric constants (ɛo, ɛ∞) values were calculated by using the optical band gap values as a function of the film thickness.

  13. Nanocrystalline Pt-doped TiO2 thin films prepared by spray pyrolysis for hydrogen gas detection

    Indian Academy of Sciences (India)

    Lalchand A Patil; Dinesh N Suryawanshi; Idris G Pathan; Dhanashri G Patil

    2014-05-01

    Nanostructured pure and Pt-doped TiO2 thin films were prepared by chemical spray pyrolysis technique. Aqueous solution of TiCl3.6H2O (0.01 M) was chosen as the starting solution for the preparation of pure TiO2 thin film. Aqueous solutions of PtCl6.6H2O (0.01 M) and TiCl3.6H2O (0.01 M) were mixed in volume % of 1 : 99, 2.5 : 97.5 and 5 : 95 respectively to obtain Pt-doped TiO2 thin films. The solutions were sprayed onto quartz substrate heated at 350 °C temperature to obtain the films. These thin films were fired for one hour at 550 °C. The sensing performance of these films was tested for various gases such as LPG, H2, CO2, ethanol, NH3 and Cl2 (1000 ppm). The Pt-doped TiO2 (1 : 99) was observed to be most sensitive (572) to H2 at 400 °C with high selectivity against other gases. Its response time was short (10 s) and recovery was also fast (14 s). To understand the reasons behind the gas-sensing performance of the films, their structural and micro-structral properties were studied using X-ray diffraction and electron microscopy (FE–SEM and TEM), respectively. Thicknesses of all these samples were determined using Surface Profiler. The results are interpreted.

  14. Preparation of high dielectric constant thin films of CaCu3Ti4O12 by sol–gel

    Indian Academy of Sciences (India)

    Deepam Maurya; Devendra P Singh; D C Agrawal; Y N Mohapatra

    2008-02-01

    Preparation of sol–gel derived CaCu3Ti4O12 (CCTO) thin films using two different sols and their characterization including their dielectric response are reported. The properties of CCTO films depend heavily on solvents used to prepare the sols. Dielectric constant as high as ∼900 at 100 kHz could be obtained when acetic acid was used to prepare the sol; in contrast, use of hexanoic acid in the sol yielded films with a much lower dielectric constant. The variation in grain and grain boundary conductivities with temperature has been measured. Activation energies of 0.08 eV and 0.68 eV have been found for grain and grain boundary conduction, respectively.

  15. Transparent conducting zinc oxide thin film prepared by off-axis rf magnetron sputtering

    Indian Academy of Sciences (India)

    M K Jayaraj; Aldrin Antony; Manoj Ramachandran

    2002-06-01

    Highly conducting and transparent ZnO : Al thin films were grown by off-axis rf magnetron sputtering on amorphous silica substrates without any post-deposition annealing. The electrical and optical properties of the films deposited at various substrate temperatures and target to substrate distances were investigated in detail. Optimized ZnO : Al films have conductivity of 2200 S cm–1 and average transmission in the visible range is higher than 85%. The conductivity and mobility show very little temperature dependence.

  16. Dielectric properties of BiFeO3-PbTiO3 thin films prepared by PLD

    Institute of Scientific and Technical Information of China (English)

    CHEN Rui; YU Sheng-wen; ZHANG Guan-jun; CHENG Jin-rong; MENG Zhong-yan

    2006-01-01

    BiFeO3-PbTiO3 (BFO-PT) thin films were prepared on Pt/TiO2/SiO2/Si substrates by pulsed-laser deposition (PLD) technique under different oxygen pressures. The structures of the films were characterized by means of XRD. The current densities were performed to check the conductivity of the films. The dielectric constant and loss factor (tanδ) of the films were measured. The results show that the BFO-PT layers are mainly perovskite structured:the film deposited under 6.665 Pa exhibits low leakage current,low dielectric loss (0.017-0.041) and saturated hysteresis loop with polarization (Pr) value and coercive field (Ec) of 3 μC/cm2 and 109 kV/cm.

  17. PZT/P(VDF-HFP) 0-3 composites as solvent-cast thin films: preparation, structure and piezoelectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Wegener, Michael; Arlt, Kristin [Functional Polymer Systems, Fraunhofer Institute for Applied Polymer Research (IAP), Geiselbergstrasse 69, 14476 Potsdam-Golm (Germany)], E-mail: michael.wegener@iap.fraunhofer.de

    2008-08-21

    Composite films of lead zirconate titanate (PZT) and poly(vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)) were prepared as 100 {mu}m thin films by solvent casting. Within the 0-3 composites, the ceramic-volume fraction was varied between 0.19 and 0.65, which yielded films with different structural and dielectric properties. These influenced the piezoelectric properties of the composite films found after electric poling, which was performed here at room temperature. The piezoelectric activity, with a maximum piezoelectric coefficient of 11 pC N{sup -1} in the film-thickness direction, originates from the polarization of the embedded ceramic particles as proved by poling experiments in corona discharges as well as in direct contact.

  18. Preparation of grain size controlled boron-doped diamond thin films and their applications in selective detection of glucose in basic solutions

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Boron-doped diamond (BDD) thin films with different crystal grain sizes were prepared by controlling the reacting gas pressure using hot filament chemical vapor deposition (HFCVD).The morphologies and structures of the prepared diamond thin films were characterized by scanning electron microscopy (SEM) and Raman spectroscopy.The electrochemical responses of K4Fe(CN)6 on different BDD electrodes were investigated.The results suggested that electron transfer was faster at the boron-doped nanocrystalline diamond (BDND) thin film electrodes in comparison with that at other BDD thin film electrodes.The prepared BDD thin film electrodes without any modification were used to directly detect glucose in the basic solution.The results showed that the as-prepared BDD thin film electrodes exhibited good selectivity for detecting glucose in the presence of ascorbic acid (AA) and uric acid (UA).The higher sensitivity was observed on the BDND thin film grown on the boron-doped microcrystalline diamond (BDMD) thin film surface,and the linear response range,sensitivity and the low detection limit were 0.25–10 mM,189.1 μA mmol-1 cm-2 and 25 μM (S/N=3) for glucose in the presence of AA and UA,respectively.

  19. Controllable preparation of nanosized TiO2 thin film and relationship between structure of film and its photocatalytic activity

    Institute of Scientific and Technical Information of China (English)

    WEI; Gang; (魏刚); ZHANG; Yuanjing; (张元晶); XIONG; Rongchun; (熊蓉春)

    2003-01-01

    TiO2 nano-crystalline film and fixed bed photocatalytic reactor were prepared by the sol-gel process using tetrabutylorthotitanate as a precursor and glass tube as the substrate. XRD, AFM, SEM and thickness analysis results indicate that the preparation of nano-crystalline film can be controlled by optimizing experiment process. Under the optimized process, the phase of TiO2 in film is anatase, and the grain size is 3-4 nm. The size of particles, which is about 20-80 nm, can be controlled. The thickness of monolayer film is in nanometer grade. The thickness and particles size in films growing on nanometer film can also be controlled in nanometer grade. As a result, the crack of film can be effectively avoided. Rhodamine B degradation results using UV-Vis spectrophotometer show that the activity of nano-crystalline film in the photocatalytic reactor has a good relation with the diameter of TiO2 particles, that is, the film shows high activity when the size is 20-30 nm and greatly reduced when the size is above 60 nm. The activity of film does not decrease with the increase of film thickness, and this result indicates that nano-crystalline film has no ill influence on the transmissivity of ultraviolet light.

  20. Preparation of high T(c) Tl-Ba-Ca-Cu-O thin films by pulsed laser evaporation and Tl2O3 vapor processing

    Science.gov (United States)

    Johs, B.; Thompson, D.; Ianno, N. J.; Woollam, John A.; Liou, S. H.

    1989-01-01

    Tl-Ba-Ca-Cu-O superconducting thin films with zero-resistance temperatures up to 115 K have been prepared using a Tl2O3 vapor process on Ba-Ca-Cu-O precursor thin films. The Ba-Ca-Cu-O thin films were made by laser deposition on Y-stabilized ZrO2 substrates. This technique minimizes problems caused by the toxicity of Tl2O3, and its subsequent decomposition to the volatile and toxic Tl2O upon heating. Therefore, it may have practical application in the fabrication of high T(c) Tl-Ba-Ca-Cu-O superconducting thin-film devices.

  1. Preparation and study of nanostructured TiAlSiN thin films

    Directory of Open Access Journals (Sweden)

    Jakab-Farkas L.

    2011-12-01

    Full Text Available TiAlSiN thin film coatings were deposited by DC reactive magnetron sputtering of TiAlSi target with 40 at.% Ti, 40 at.% Al and 20 at.% Si, performed in N2-Ar gas mixture. The sputtering power used in these experiments was controlled for 400 W. The bias voltage of the substrates was kept at -20 V DC and the temperature at 500 0C. All the samples were prepared with a constant flow rate of Ar and different nitrogen flow rates, which were selected from 1.25 sccm to 4.0 sccm. Nanostructured TiAlSiN coatings were developed on Si(100 and HSS substrates. Microstructure investigation of the coatings was performed by transmission electron microscopy investigation, structure investigation was performed by XRD analysis, and the mechanical properties of the coatings have been tested by ball-on-disk tribological investigation and micro-Vickers hardness measurements. In this paper will be shown that for optimized nitrogen concentration the microstructure of TiAlSiN coating evolve from a competitive columnar growth to a dendritic growth one with very fine nano-lamellae like morphology. The developed nanostructured TiAlSiN coatingshave hardness HV exceeding 40 GPa and show an increased abrasive wear resistance

  2. Electrochemical Evaluation of Thin-Film Li-Si Anodes Prepared by Plasma Spraying

    Energy Technology Data Exchange (ETDEWEB)

    GUIDOTTI,RONALD A.; REINHARDT,FREDERICK W.; SCHARRER,GREGORY L.

    1999-09-08

    Thin-film electrodes of a plasma-sprayed Li-Si alloy were evaluated for use as anodes in high-temperature thermally activated (thermal) batteries. These anodes were prepared using 44% Li/56% Si (w/w) material as feed material in a special plasma-spray apparatus under helium or hydrogen, to protect this air- and moisture-sensitive material during deposition. Anodes were tested in single cells using conventional pressed-powder separators and lithiated pyrite cathodes at temperatures of 400 to 550 C at several different current densities. A limited number of 5-cell battery tests were also conducted. The data for the plasma-sprayed anodes was compared to that for conventional pressed-powder anodes. The performance of the plasma-sprayed anodes was inferior to that of conventional pressed-powder anodes, in that the cell emfs were lower (due to the lack of formation of the desired alloy phases) and the small porosity of these materials severely limited their rate capability. Consequently, plasma-sprayed Li-Si anodes would not be practical for use in thermal batteries.

  3. Electron-Induced Secondary Electron Emission Properties of MgO/Au Composite Thin Film Prepared by Magnetron Sputtering

    Science.gov (United States)

    Li, Jie; Hu, Wenbo; Wei, Qiang; Wu, Shengli; Hua, Xing; Zhang, Jintao

    2016-12-01

    As a type of electron-induced secondary electron emitter, MgO/Au composite thin film was prepared by reactive magnetron sputtering of individual Mg target and Au target, and the effects of key process parameters on its surface morphology and secondary electron emission (SEE) properties were investigated. It is found that to deposit a NiO buffer layer on the substrate is conducive to the subsequent growth of MgO grains owing to the lattice matching. The gold addition can raise the electrical conductivity of MgO film and further suppress the surface charging. However, the gold deposition would interfere with the MgO crystallization and increase the surface roughness of MgO/Au film. Therefore, MgO/Au composite thin film with a NiO buffer layer and proper deposition times of MgO and Au can achieve superior SEE properties due to good MgO crystallization, low surface roughness and reasonable electrical conductivity. The optimized MgO/Au composite thin film has a higher SEE coefficient and a lower 1-h SEE degradation rate under electron beam bombardment in comparison with MgO film.

  4. Effect of Annealing on the Properties of Nanocrystalline CdS Thin Films Prepared by CBD Method

    Directory of Open Access Journals (Sweden)

    A. Djelloul

    2016-06-01

    Full Text Available The CdS thin films were deposited on glass substrate by chemical bath deposition (CBD. The effect of annealing temperature on the morphological, structural, optical and electrical properties of the crystalline CdS films were investigated for different annealing temperature (as deposited, 300, 400 and 500 °C.The annealing time is 1 h. The materials have been prepared using simple aqueous solutions containing cadmium sulfate, as source of cadmium, and thiourea as source of sulfur and ammonium hydroxide as the complexing agent. The temperature of the bath was maintained at low temperature of 80 °C. The surface morphological properties studied by SEM and AFM respectively. The structural properties of CdS thin film was studied by X-ray diffraction. The optical parameter such as transmittance and energy band gap of the films with thermal annealing temperature was investigated by UV-Visible spectrophotometer. The variation of band gap values of CdS thin film samples were found to be in the range of 2.37 to 2.5 eV. Electrical resistivity measurements were carried out in four-probe Van Der Pauw geometry at room temperature by the Hall measurement. SEM image confirmed that film of smooth surface morphology.

  5. Effects of Thermal Annealing on the Optical Properties of Titanium Oxide Thin Films Prepared by Chemical Bath Deposition Technique

    Directory of Open Access Journals (Sweden)

    H.U. Igwe

    2010-08-01

    Full Text Available A titanium oxide thin film was prepared by chemical bath deposition technique, deposited on glass substrates using TiO2 and NaOH solution with triethanolamine (TEA as the complexing agent. The films w ere subjected to post deposition annealing under various temperatures, 100, 150, 200, 300 and 399ºC. The thermal treatment streamlined the properties of the oxide films. The films are transparent in the entire regions of the electromagnetic spectrum, firmly adhered to the substrate and resistant to chemicals. The transmittance is between 20 and 95% while the reflectance is between 0.95 and 1%. The band gaps obtained under various thermal treatments are between 2.50 and 3.0 ev. The refractive index is between 1.52 and 2.55. The thickness achieved is in the range of 0.12-0.14 :m.These properties of the oxide film make it suitable for application in solar cells: Liquid and solid dye-sensitized photoelectrochemical solar cells, photo induced water splitting, dye synthesized solar cells, environmental purifications, gas sensors, display devices, batteries, as well as, solar cells with an organic or inorganic extremely thin absorber. These thin films are also of interest for the photooxidation of water, photocatalysis, electro chromic devices and other uses.

  6. Comparison of barium titanate thin films prepared by inkjet printing and spin coating

    Directory of Open Access Journals (Sweden)

    Jelena Vukmirović

    2015-09-01

    Full Text Available In this paper, barium titanate films were prepared by different deposition techniques (spin coating, office Epson inkjet printer and commercial Dimatix inkjet printer. As inkjet technique requires special rheological properties of inks the first part of the study deals with the preparation of inks, whereas the second part examines and compares structural characteristics of the deposited films. Inks were synthesized by sol-gel method and parameters such as viscosity, particle size and surface tension were measured. Deposited films were examined by optical and scanning electron microscopy, XRD analysis and Raman spectroscopy. The findings consider advantages and disadvantages of the particular deposition techniques.

  7. Luminescence evolution of porous GaN thin films prepared via UV-assisted electrochemical etching

    Energy Technology Data Exchange (ETDEWEB)

    Cheah, S.F., E-mail: sookfongcheah@yahoo.com [Nano-Optoelectronic Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Lee, S.C. [Nano-Optoelectronic Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Ng, S.S.; Yam, F.K.; Abu Hassan, H.; Hassan, Z. [Nano-Optoelectronic Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia)

    2015-03-15

    Porous gallium nitride (GaN) thin films with different surface morphologies and free carriers properties were fabricated from Si-doped GaN thin films using ultra-violet assisted electrochemical etching approach under various etching voltages. Fluctuation of luminescence signals was observed in the photoluminescence spectra of porous GaN thin films. Taking advantage of the spectral sensitivity of infrared attenuated total reflection spectroscopy on semiconductor materials, roles of free carriers and porous structure in controlling luminescence properties of GaN were investigated thoroughly. The results revealed that enhancement in luminescence signal is not always attained upon porosification. Although porosification is correlated to the luminescence enhancement, however, free carrier is the primary factor to enhance luminescence intensity. Due to unavoidable significant reduction of free carriers from Si-doped GaN in the porosification process, control of etching depth (i.e., thickness of porous layer formed from the Si-doped layer) is critical in fabricating porous GaN thin film with enhanced luminescence response. - Highlights: • Various pore morphologies with free carrier properties are produced by Si-doped GaN. • Free carriers are important to control the luminescence signal of porous GaN. • Enhancement of luminescence signal relies on the pore depth of Si-doped layer.

  8. Polyelectrolyte-assisted preparation and characterization of nanostructured ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Shijun

    2005-05-15

    The present work focuses on the synthesis and characterization of nanostructured ZnO thin films onto silicon wafers modified by self-assembled-monolayers via chemical bath deposition. Two precursor solutions were designed and used for the film deposition, in which two different polymers were introduced respectively to control the growth of the ZnO colloidal particles in solution. ZnO films were deposited from an aqueous solution containing zinc salt and hexamethylenetetramine (HMTA) in the presence of a graft-copolymer (P (MAA{sub 0.50}-co(MAA-EO{sub 20}){sub 0.50}){sub 70}). A film-formation-diagram was established based on the results obtained by scanning electron microscopy (SEM) and atomic force microscopy (AFM), which describes the influence of the concentration of HMTA and copolymer on the ZnO film formation. According to the film morphology, film formation can be classified into three categories: (a) island-like films, (b) uniform films and (c) canyon-like films. The ZnO films annealed at temperatures of 450 C, 500 C, 600 C and 700 C were examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). After annealing, the films are polycrystalline ZnO with wurtzite structure. XRD measurements indicate that with increasing annealing temperature, the average grain size increases accordingly and the crystallinity of the films is improved. Upon heating to 600 C, the ZnO films exhibit preferred orientation with c-axis normal to substrate, whereas the films annealed at 700 C even show a more explicit texture. By annealing at temperatures above 600 C the ZnO film reacts with the substrate to form an interfacial layer of Zn{sub 2}SiO{sub 4}, which grows thicker at elevated annealing temperatures. The ZnO films annealed at 600 C and 700 C show strong UV emission. Another non-aqueous solution system for ZnO thin film deposition was established, in which 2- propanol was used as a solvent and Zn(CH3COO){sub 2}.2H{sub 2}O as well as NaOH as reactants

  9. Synthesis and Properties of ZnO/Al Thin Films Prepared by Dip-Coating Process

    OpenAIRE

    Juhņeviča, I; Mašonkina, M; Mežinskis, G; Gabrene, A

    2015-01-01

    In this work sol–gel dip-coating technique was used to synthesize ZnO and ZnO/Al films. The influence of annealing regime and dopant concentration on the structural properties of ZnO and aluminum doped ZnO (ZnO/Al) films was investigated. The surface morphology and crystallinity of ZnO films were determined using atomic force microscopy and Xray diffraction, respectively. The experimental results show that ZnO and ZnO/Al films prepared using “shock” conditions have smo...

  10. Preparation and properties of ZnO thin films deposited by sol-gel technique

    Institute of Scientific and Technical Information of China (English)

    LAN Wei; PENG Xingping; LIU Xueqin; HE Zhiwei; WANG Yinyue

    2007-01-01

    Zinc oxide (ZnO) thin films were deposited on (100) Si substrates by sol-gel technique.Zinc acetate was used as the precursor material.The effect of different anneal-ing atmospheres and annealing temperatures on composition, structural and optical properties of ZnO thin films was inves-tigated by using Fourier transform infrared spectroscopy, X-ray diffraction,atomic force microscopy and photolumi-nescence (PL),respectively.At an annealing temperature of 400℃ in N2 for 2 h,dried gel films were propitious to undergo structural relaxation and grow ZnO grains.ZnO thin film annealed at 400℃ in N2 for 2 h exhibited the optimal structure and PL property,and the grain size and the lattice constants of the film were calculated (41.6 nm,a = 3.253 A and c=5.210A).Moreover,a green emission around 495 nm was observed in the PL spectra owing to the oxygen vacancies located at the surface of ZnO grains.With increas- ing annealing temperature,both the amount of the grown ZnO and the specific surface area of the grains decrease,which jointly weaken the green emission.

  11. Ti-doped ZnO Thin Films Prepared at Different Ambient Conditions: Electronic Structures and Magnetic Properties

    Directory of Open Access Journals (Sweden)

    Zhihua Yong

    2010-06-01

    Full Text Available We present a comprehensive study on Ti-doped ZnO thin films using X-ray Absorption Fine Structure (XAFS spectroscopy. Ti K edge XAFS spectra were measured to study the electronic and chemical properties of Ti ions in the thin films grown under different ambient atmospheres. A strong dependence of Ti speciation, composition, and local structures upon the ambient conditions was observed. The XAFS results suggest a major tetrahedral coordination and a 4+ valence state. The sample grown in a mixture of 80% Ar and 20% O2 shows a portion of precipitates with higher coordination. A large distortion was observed by the Ti substitution in the ZnO lattice. Interestingly, the film prepared in 80% Ar, 20% O2 shows the largest saturation magnetic moment of 0.827 ± 0.013 µB/Ti.

  12. Preparation and characterization of double layer thin films ZnO/ZnO:Ag for methylene blue photodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Wibowo, Singgih, E-mail: singgih@st.fisika.undip.ac.id; Sutanto, Heri, E-mail: herisutanto@undip.ac.id [Department of Physics, Faculty of Science and Mathematics, Diponegoro University (Indonesia)

    2016-02-08

    Double layer (DL) thin films of zinc oxide and silver-doped zinc oxide (ZnO/ZnO:Ag) were deposited on glass substrate by sol-gel spray coating technique. The prepared thin films were subjected for optical and photocatalytic studies. UV-visible transmission spectra shows that the subtitution of Ag in ZnO leads to band gap reduction. The influence of Ag doping on the photocatalytic activity of ZnO for the degradation of methylene blue dye was studied under solar radiation. The light absorption over an extended visible region by Ag ion doping in ZnO film contributed equally to improve the photocatalytic activity up to 98.29%.

  13. Preparation and characterization of double layer thin films ZnO/ZnO:Ag for methylene blue photodegradation

    Science.gov (United States)

    Wibowo, Singgih; Sutanto, Heri

    2016-02-01

    Double layer (DL) thin films of zinc oxide and silver-doped zinc oxide (ZnO/ZnO:Ag) were deposited on glass substrate by sol-gel spray coating technique. The prepared thin films were subjected for optical and photocatalytic studies. UV-visible transmission spectra shows that the subtitution of Ag in ZnO leads to band gap reduction. The influence of Ag doping on the photocatalytic activity of ZnO for the degradation of methylene blue dye was studied under solar radiation. The light absorption over an extended visible region by Ag ion doping in ZnO film contributed equally to improve the photocatalytic activity up to 98.29%.

  14. A novel sol-gel method for preparing favorable TiO2 thin film

    Science.gov (United States)

    Wang, Xiaoyi; Zhang, Dainan; Li, Jie; Zhong, Zhiyong; Jia, Lijun; Wen, Tianlong; Zhang, Huaiwu; Liao, Yulong

    2016-01-01

    Nanocrystalline TiO2 thin films were synthesized by the sol-gel spin-coating method with different variables. Tetrabutyl titanate (TBOT) proportion and C5H8O2: TBOT molar ratio were confirmed to be influential on the gelation time. X-ray diffraction analysis indicated that the samples presented rutile TiO2 phases, which is a basis for subsequent experiments. Scanning electron microscope results revealed that TiO2 thin films with homogeneous and compact surfaces were synthesized successfully when adding moderate TBOT. It was found the thickness of films could reach about 60 nm when sintered at 750 °C, and the influence of sintering temperature was also investigated.

  15. Spinodal dewetting of thin films

    Science.gov (United States)

    Jaiswal, Prabhat K.; Puri, S.

    2009-01-01

    Stable thin liquid films are of various scientific and technological applications, e.g., in optical coating, painting technologies, coating thin wires and fibers, lubricants, adhesives, etc. However, the instabilities in a thin film may lead to rupture, hole formation, and other morphological changes which amplify the nonuniformity in the thin film [1]. This morphological evolution in an unstable thin film is generally known as `dewetting' [2]. There have recently been a number of theoretical and experimental studies on dewetting in thin films [3-6]. The process of `spinodal dewetting' comes into the category of a general class of phenomena, spinodal decomposition [7]. The pattern formation taking place during dewetting can also be of great importance in nanotechnology, e.g., for preparing quantum dots [8], nanorings [9], etc. We numerically solve the nonlinear two-dimensional thin film equation [2] for a thin liquid film subjected to the long range van der Waals attraction and short range Born repulsion. The simulation results for the temporal evolution of domains and height profile along diagonal direction of the lattice show the `hills and valleys' short of structures which is the typical morphology obtained during the spinodal dewetting [10]. We obtain the dynamical correlation function and structure factor showing the existence of a characteristic length scale in the system at late time. We give the scaling arguments for the length scale of the drops to be proportional to t1/3 which is in agreement with our numerical results for the domain growth.

  16. Low pressure hand made PVD system for high crystalline metal thin film preparation in micro-nanometer scale

    Energy Technology Data Exchange (ETDEWEB)

    Rosikhin, Ahmad, E-mail: a.rosikhin86@yahoo.co.id; Hidayat, Aulia Fikri; Marimpul, Rinaldo; Syuhada, Ibnu; Winata, Toto, E-mail: toto@fi.itb.ac.id [Department of physics, physics of electronic materials research division Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung Jl. Ganesha 10, Bandung 40132, Jawa Barat – Indonesia (Indonesia)

    2016-02-08

    High crystalline metal thin film preparation in application both for catalyst substrate or electrode in any electronic devices always to be considered in material functional material research and development. As a substrate catalyst, this metal take a role as guidance for material growth in order to resulted in proper surface structure although at the end it will be removed via etching process. Meanwhile as electrodes, it will dragging charges to be collected inside. This brief discussion will elaborate general fundamental principle of physical vapor deposition (PVD) system for metal thin film preparation in micro-nanometer scale. The influence of thermodynamic parameters and metal characteristic such as melting point and particle size will be elucidated. Physical description of deposition process in the chamber can be simplified by schematic evaporation phenomena which is supported by experimental measurement such as SEM and XRD.

  17. Ethanol sensing of V2O5 thin film prepared by spray pyrolysis technique: Effect of substrate to nozzle distance

    Science.gov (United States)

    Immanuel, P.; Prakash, A. Arockia; Mohan, C. Raja

    2017-05-01

    In the present investigation V2O5 thin films were prepared by spray pyrolysis by varying substrate to nozzle distance (SND) from 20 to 35 cm in steps of 5 cm. The structural studies by XRD results indicates that the crystallinity increases with increase in SND along (101), (201) orientation and for the film prepared at 30 cm gives a good crystallinity. The SEM image shows that the change in morphology, which strongly depends on the SND. Above 30 cm it slightly affects the surface morphology of the V2O5 thinfilm due to agglomeration. The presence of elemental constituents is confirmed from EDAX analysis. The band gap of the film prepared at 30 cm has a lowest value of 2.1 eV. The electrical studies like I-V, Hall Effect measurement and the conductivity is maximum for the film prepared at 30 cm. The ethanol sensing of the prepared film has been studied using Keithley source meter and the detailed results are presented and discussed.

  18. Preparation of manganese-doped ZnO thin films and their characterization

    Indian Academy of Sciences (India)

    S Mondal; S R Bhattacharyya; P Mitra

    2013-04-01

    In this study, pure and manganese-doped zinc oxide (Mn:ZnO) thin films were deposited on quartz substrate following successive ion layer adsorption and reaction (SILAR) technique. The film growth rate was found to increase linearly with number of dipping cycle. Characterization techniques of XRD, SEM with EDX and UV–visible spectra measurement were done to investigate the effect of Mn doping on the structural and optical properties of Mn:ZnO thin films. Structural characterization by X-ray diffraction reveals that polycrystalline nature of the films increases with increasing manganese incorporation. Particle size evaluated using X-ray line broadening analysis shows decreasing trend with increasing manganese impurification. The average particle size for pure ZnO is 29.71nm and it reduces to 23.76nm for 5%Mn-doped ZnO. The strong preferred c-axis orientation is lost due to manganese (Mn) doping. The degree of polycrystallinity increases and the average microstrain in the films decreases with increasing Mn incorporation. Incorporation of Mn was confirmed from elemental analysis using EDX. As the Mn doping concentration increases the optical bandgap of the films decreases for the range of Mn doping reported here. The value of fundamental absorption edge is 3.22 eV for pure ZnO and it decreases to 3.06 eV for 5%Mn:ZnO.

  19. Optical parameters of In Se and In Se Te thin amorphous films prepared by pulsed laser deposition

    Science.gov (United States)

    Hrdlicka, M.; Prikryl, J.; Pavlista, M.; Benes, L.; Vlcek, M.; Frumar, M.

    2007-05-01

    The thin films of materials based on In Se are under study for their applicability in photovoltaic devices, solid-state batteries and phase-change memories. The amorphous thin films of In2Se3-xTex (x=0 1.5) and InSe were prepared by pulsed laser deposition method (PLD) using a KrF excimer laser beam (λ=248 nm, 0.5 J cm-2) from polycrystalline bulk targets. The compositions of films verified by energy-dispersive X-ray analysis (EDX) were close to the compositions of targets. The surfaces of PLD films containing small amount of droplets were viewed by optical and scanning electron microscopy (SEM). The optical properties (transmittance and reflectance spectra, spectral dependence of index of refraction, optical gap, single-oscillator energy, dispersion energy, dielectric constant) of the films were determined. The values of index of refraction increased with increasing substitution of Te for Se in In2Se3 films, the values of the optical gap decreased with increasing substitution of Te for Se in In2Se3 films.

  20. The optical properties and applications of AlN thin films prepared by a helicon sputtering system

    CERN Document Server

    Chiu, W Y; Kao, H L; Jeng, E S; Chen, J S; Jaing, C C

    2002-01-01

    AlN thin films were grown on SiO sub 2 /Si and quartz substrates using a helicon sputtering system. The dependence of film quality on growth parameters, such as total sputtering pressure, substrate temperature, and nitrogen concentration has been studied. There is a good correlation of thin film crystallinity addressed by x-ray diffraction (XRD) and spectroscopic ellipsometer. The optimized films exhibit highly oriented, with only (002) peak shown in a theta-2 theta scan XRD pattern, and extremely smooth surface with rms roughness of 2 Aa. The extinction coefficient of the film was 4x10 sup - sup 4 , which is lower than that of AlN films grown by conventional sputtering. Double-layer antireflection (DLAR) coating using AlN and Al sub 3 O sub 3 grown on quartz has been demonstrated. The transmittance of DLAR was high as 96% compared to 93% of bare substrates with the measurement error less than 0.2%. AlN films prepared by Helicon sputtering thus are potential for optical application.

  1. Gas sensing properties of nanostructured MoO{sub 3} thin films prepared by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, H.M.; Torres, J. [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica, Universidad Nacional de Colombia, Bogota (Colombia); Rodriguez-Garcia, M.E. [Departamento de Nanotecnologia, Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, Campus Juriquilla, Queretaro, Qro. (Mexico); Lopez Carreno, L.D., E-mail: ldlopezca@unal.edu.co [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica, Universidad Nacional de Colombia, Bogota (Colombia)

    2012-08-15

    Thin films of molybdenum trioxide (MoO{sub 3}) were deposited on common glass using the chemical spray pyrolysis technique. A (NH{sub 4}){sub 6}Mo{sub 7}O{sub 24}4H{sub 2}0 solution 0.1 M was used as the precursor one. The influence of substrate temperature on the crystallographic structure, surface morphology and electrical behavior of MoO{sub 3} thin films was studied. MoO{sub 3} can exist in two crystalline forms, the thermodynamically stable orthorhombic {alpha}-MoO{sub 3} and the metastable monoclinic {beta}-MoO{sub 3} phase. XRD-spectra showed a growth of {alpha}-MoO{sub 3} phase percentage as substrate temperature increases from 420 K up to 670 K. Films deposited in the 500-600 K range have a clearly porous surface structure of nanometer order as can be seen in SEM images. Changes up to six magnitude orders were observed in MoO{sub 3} thin films electrical resistance when films temperature varied from 100 K up to 500 K. The sensing property of these MoO{sub 3} films was also studied. The sensitivity was investigated in the temperature range 160 and 360 K for H{sub 2}O and CO gases, respectively. Both of them are of reducing nature. In all studied cases sensitivity decreases slowly as film temperature is raised. At room temperature the sensitivity changes from 12 up to 75% depending on substrate temperature. The sensitivity for CO gas was found to be lower than that of H{sub 2}O.

  2. Preparation of Copper Iodide (CuI) Thin Film by In-Situ Spraying and Its Properties

    Science.gov (United States)

    Rahmi, G. H.; Pratiwi, P.; Nuryadi, B. W.; Aimon, A. H.; Winata, T.; Iskandar, F.

    2016-08-01

    Perovskite based solar cells have attracted interest as low-cost and high-efficiency solar cells due to their great performance, with efficiency up to 20.1%. One type of hole transport material (HTM) used in perovskite based solar cells is copper iodide (CuI) thin film. CuI is inexpensive and has high mobility compared to other HTMs commonly used in perovskite based solar cells. However, diisopropylsulfide solvent, which is used to dissolve CuI in the preparation process, is a malodorous and toxic compound. Therefore, the objective of this research was to develop a synthesis method for CuI thin film with in-situ spraying, a low- cost, safe and easy fabrication method. As precursor solution, CuSO45H2O was dissolved in ammonia and KI aqueous solution. The precursor solution was then sprayed directly onto a glass substrate with appropriate temperature to form CuI film. The prepared thin films were characterized by X-ray diffractometer, UV-Vis spectrophotometer, scanning electron microscope and four-point probes to study their properties.

  3. Preparation and characterization of highly photosensitive ZnO thin films

    Science.gov (United States)

    Jiménez González, Antonio E.; Nair, P. K.

    1996-07-01

    Highly photosensitive ZnO films were prepared by the chemical technique Successive Ion Layer Adsorption and Reaction (SILAR). The films posses high optical transmittance (>90%) in the VIS and IR ranges. The cristallinity, orientation of the crystallites and surface morphology undergo changes with annealing. The optical transmittance and reflectance measurements indicated changes in the position of the optical absorption edge: shifting from 353 nm to 366 nm when annealed at 450 °C for 2 hours. The films are highly photosensitive, offering photocurrent to dark current ratio of 105, in as prepared films under 900 Wm-2 illumination from a solar simulator. Annealing in oxygen, hydrogen and vacuum improved the dark conductivity and the photoconductivity of the films. This effect is related to the modification of the defect statistics of the films and involves cation interstitials and anion vacancies. The studies indicate that the ZnO films prepared by the SILAR process may be used, with appropriated postdeposition treatments, for specific applications.

  4. Preparation of conductive PDDA/(PEDOT:PSS) multilayer thin film: influence of polyelectrolyte solution composition.

    Science.gov (United States)

    Jurin, F E; Buron, C C; Martin, N; Filiâtre, C

    2014-10-01

    Self-assembled multilayer films made of PEDOT:PSS poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) and PDDA poly(diallyldimethylammonium chloride) were prepared using layer-by-layer method. In order to modify the growth regime of the multilayer, to fabricate an electrical conductive film and to control its thickness, the effects of pH, type of electrolyte, ionic strength and polyelectrolyte concentration were investigated. Optical reflectometry measurements show that the pH of the solutions has no effect on the film growth while the adsorbed amount increases more rapidly when BaCl2 is used instead of NaCl as electrolyte. An increase in the ionic strength (with NaCl) induces a change in the growth regime from a linear to an exponential one at low polyelectrolyte concentration. As UV-vis measurements indicate, no decomplexation of PEDOT was recorded after film preparation. With polyelectrolyte concentration below 1 g L(-1), no conductive films were obtained even if 50 bilayers were deposited. A conductive film was prepared with a polyelectrolyte concentration of 1 g L(-1) and the measured conductivity was 0.3 S m(-1). A slight increase in conductivity was recorded when BaCl2 was used probably due to a modification of the film structure. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. [Research on the polycrystalline CdS thin films prepared by close-spaced sublimation].

    Science.gov (United States)

    Yang, Ding-Yu; Xia, Geng-Pei; Zheng, Jia-Gui; Feng, Liang-Huan; Cai, Ya-Ping

    2009-01-01

    In the present paper, the factors of influence on the deposition rate of CdS films prepared by close-spaced sublimation (CSS) were first studied systematically, and it was found from the experiments that the deposition rate increased with the raised temperature of sublimation source, while decreased with the raised substrate temperature and the deposition pressure. The structure, morphology and light transmittance of the prepared samples were tested subsequently, and the results show: (1) The CdS films deposited under different oxygen partial pressure all present predominating growth lattice orientation (103), and further more the films will be strengthened after annealed under CdCl2 atmosphere. (2) The AFM images of CdS show that the films are compact and uniform in grain diameter, and the grain size becomes larger with the increased substrate temperature. Along with it, the film roughness was also augmented. (3) The transmittance in the shortwave region of visible light through the CdS films would be enhanced when its thickness is reduced, and that will help improve the shortwave spectral response of CdTe solar cells. Finally, the prepared CdS films were employed to fabricate CdTe solar cells, which have achieved a conversion efficiency of 10.29%, and thus the feasibility of CSS process in the manufacture of CdTe solar cells was validated primarily.

  6. PREPARATION AND SURFACE CHARACTERIZATION OF TiO2 THIN FILMS ON GLASS BY MAGNETRON SPUTTERING METHOD

    Institute of Scientific and Technical Information of China (English)

    L.S. Yin; H. Shen; J.X. Zhang

    2002-01-01

    Ti thin films were firstly deposited on glass substrates by magnetron sputtering method,then sintered the Ti thin films in air atmosphere and finally TiO2 transparence thinfilms on glass substrates were obtained. The structure and surface morphologies ofthe thin films were characterized by X-ray diffraction and SEM. The growth processof the thin filns has been observed. The annealing time and annealing temperatureshave an affect on the growth of the films.

  7. Nanostructured Mesoporous Titanium Dioxide Thin Film Prepared by Sol-Gel Method for Dye-Sensitized Solar Cell

    Directory of Open Access Journals (Sweden)

    Yu-Chang Liu

    2011-01-01

    Full Text Available Titanium dioxide (TiO2 paste was prepared by sol-gel and hydrothermal method with various precursors. Nanostructured mesoporous TiO2 thin-film back electrode was fabricated from the nanoparticle colloidal paste, and its performance was compared with that made of commercial P25 TiO2. The best performance was demonstrated by the DSSC having a 16 μm-thick TTIP-TiO2 back electrode, which gave a solar energy conversion efficiency of 6.03%. The ability of stong adhesion on ITO conducting glass substrate and the high surface area are considered important characteristics of TiO2 thin film. The results show that a thin film with good adhesion can be made from the prepared colloidal paste as a result of alleviating the possibility of electron transfer loss. One can control the colloidal particle size from sol-gel method. Therefore, by optimizing the preparation conditions, TiO2 paste with nanoparticle and narrow diameter distribution was obtained.

  8. Investigation of the preparation and properties of organic dye/metal oxide composite thin films

    Science.gov (United States)

    Jaeger, Steffen; Neumann, F.; Klages, Claus-Peter

    1994-11-01

    In this study the growth, structure and physical, particularly optical properties of composite thin films (copper-phthalocyanine-SiO2) with different dye contents are investigated by means of optical spectroscopy (UV-IR), electron probe micro analysis, atomic force microscopy and scanning electron microscopy measurements and compared with the properties of pure dye thin films of different thicknesses and dye/metal oxide multilayer structures, respectively. The composite thin films show spectral shifts and changes in the extension and the intensity of the typical absorption bands in the visible spectral range depending on the dye concentration in the composites. This behavior is accompanied by pronounced color changes, e.g. from blue-green to green in the CuPc-SiO2 system. The results show, that the CuPc- SiO2 composite properties are mainly influenced by the size and kind of dye aggregates in the films (monomer, dimer) and not by interaction of dye molecules with the metal oxide matrix.

  9. Characterization of CuInS2 thin films prepared by sulfurization of Cu-In precursor

    Institute of Scientific and Technical Information of China (English)

    YAN You-hua; LIU Ying-chun; FANG Ling; ZHU Jing-sen; ZHAO Hai-hua; LI De-ren; LU Zhi-chao; ZHOU Shao-xiong

    2008-01-01

    CuInS2 thin films were prepared by sulfurization of Cu-In precursors. The influences of the deposition sequence of Cu and In layers, such as Cu/In, Cu/In/In, and In/Cu/In, on structure, topography, and optical properties of CuInS2 thin films were investigated. X-ray diffraction results show that the deposition sequence of Cu and In layers affects the crystalline quality of CuInS2 films. Atomic force microstructure images reveal that the grain size and surface roughness are related to the deposition sequence used. When the deposition sequence of precursor is In/Cu/In, the CuInS2 thin films show a single-phase chalcopyrite structure with (112) preferred orientation. The surface morphology of CIS films is uniform and compacted. The absorption coefficient is larger than 104cm-1 with optical band gap Eg close to 1.4 eV.

  10. Preparation and dielectric properties of compositionally graded (Ba,Sr)TiO3 thin film by sol-gel technique

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tian-jin; WANG Jun; ZHANG Bai-shun; WANG Jin-zhao; WAN Neng; HU Lan

    2006-01-01

    Compositional graded BaxSr1-xTiO3 (x=0.6,0.7,0.8,0.9,1.0) (BST) thin films (less than 400 nm) were fabricated on Si and Pt/Ti/SiO2/Si substrates by sol-gel technique. A special heating treatment was employed to form the uniform composition gradients at 700 ℃. The microstructures of the films were studied by means of X-ray diffraction,atomic force microscope and field emission scanning electron microscopy. The results show that the films have uniform and crack-free surface morphology with perovskite structure phase. The small signal dielectric constant (εr) and dielectric loss (tanδ) are found to be 335 and 0.045 at room temperature and 200 kHz. The dielectric properties change significantly with applied dc bias,and the graded thin film show high tunability of 42.3% at an applied field of 250 kV/cm. All the results indicate that the graded BST thin films prepared by sol-gel technique have a promising candidate for microelectronic device.

  11. Preparation and characterization of polymeric thin films containing gold nanoshells via electrostatic layer-by-layer self-assembly

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Ho; Jamison, Andrew C.; Hoffman, David M., E-mail: hoffman@uh.edu; Jacobson, Allan J., E-mail: ajjacob@uh.edu; Lee, T. Randall, E-mail: trlee@uh.edu

    2014-05-02

    As an initial step in the development of surfaces for collecting thermal energy, gold shell/silica core particles (∼ 200 nm in diameter with shells ∼ 25 nm thick) were synthesized and incorporated into organic polymeric thin films. The morphologies of these nanoshells were characterized with scanning and transmission electron microscopy. Powder X-ray diffraction demonstrated that the gold layers were highly crystalline. Thin films containing the gold nanoshells and polyethyleneimine were generated using dip-coating techniques based on electrostatic layer-by-layer self-assembly methods. Scanning electron microscopy was used to image the resultant composite films, which contained uniformly distributed gold nanoshells with limited aggregation. The optical properties were analyzed by absorption spectroscopy, revealing broad extinctions ranging from the visible to the near-IR spectral regions. X-ray photoelectron spectroscopy spectra were also obtained to determine the elements present and the oxidation states of these elements. - Highlights: • Prepared gold nanoshells with broad light absorption from visible to near IR. • Added the gold nanoshells to polyethyleneimine films via layer-by-layer assembly. • The resulting layered thin films exhibited minimal gold nanoshell aggregation.

  12. Microstructural characterization of Ti-C-N thin films prepared by reactive crossed beam pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Escobar-Alarcon, L., E-mail: luis.escobar@inin.gob.mx [Departamento de Fisica, Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, Mexico DF 11801 (Mexico); Medina, V.; Camps, Enrique; Romero, S. [Departamento de Fisica, Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, Mexico DF 11801 (Mexico); Fernandez, M. [Departamento de Aceleradores, Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, Mexico DF 11801 (Mexico); Solis-Casados, D. [Centro Conjunto de Investigacion en Quimica Sustentable, Facultad de Quimica UAEMex, km. 14.5 carr. Toluca-Atlacomulco (Mexico)

    2011-08-15

    In this work, Raman spectroscopy has been used to characterize Ti-C-N thin films in order to obtain information about the microstructure of the deposited materials, and in particular to study the effects due to the carbon incorporation into the TiN lattice. Ti-C-N thin films were prepared using a crossed plasma configuration in which the ablation of two different targets, titanium and carbon, in a reactive atmosphere was performed. With this configuration, the carbon content in the films was varied in an easy way from 5.0 at% to 40.0 at%. Thin film composition was determined from Non-Rutherford Backscattering Spectroscopy (NRBS) measurements. X-ray photoelectron spectroscopy and X-Ray diffraction measurements were also carried out in order to characterize the films in more detail, with this being used to give support to the interpretation of the Raman spectra. The Raman results revealed that at lower carbon concentrations a solid solution Ti(C, N) is formed, whilst at higher carbon concentrations a nanocomposite, consisting of nanocrystalline TiCN and TiC immersed in an amorphous carbon matrix is obtained.

  13. Ferromagnetism in doped TiO{sub 2} thin films prepared by PLD

    Energy Technology Data Exchange (ETDEWEB)

    Duhalde, S [Laboratorio de Ablacion Laser, Facultad de IngenierIa, Universidad de Buenos Aires, Paseo Colon 850, 1063 Buenos Aires (Argentina); Torres, C E RodrIguez [Dpto de Fisica-IFLP, Fac. Cs. Exactas, Universidad Nacional de La Plata, CC 67, 1900 La Plata (Argentina); Vignolo, M F [Laboratorio de Ablacion Laser, Facultad de IngenierIa, Universidad de Buenos Aires, Paseo Colon 850, 1063 Buenos Aires (Argentina); Golmar, F [Laboratorio de Ablacion Laser, Facultad de IngenierIa, Universidad de Buenos Aires, Paseo Colon 850, 1063 Buenos Aires (Argentina); Chillote, C [Laboratorio de Bajas Temperaturas, Fac. de Ciencias Exactas, Universidad de Buenos Aires, Av. Int. Gueiraldes 2160, 1428 Buenos Aires (Argentina); Cabrera, A F [Dpto de Fisica-IFLP, Fac. Cs. Exactas, Universidad Nacional de La Plata, CC 67, 1900 La Plata (Argentina); Sanchez, F H [Dpto de Fisica-IFLP, Fac. Cs. Exactas, Universidad Nacional de La Plata, CC 67, 1900 La Plata (Argentina)

    2007-04-15

    Transition-Metal-doped TiO{sub 2} thin films, with nominal composition Ti{sub 0.9}TM{sub 0.1}O{sub 2-{delta}} (TM = Mn, Fe, Co, Ni, Cu), were grown by pulsed laser deposition (PLD), in order to study the role of dopants in the origin and significance of room temperature ferromagnetism in these systems. The crystallographic structures and their magnetic properties were characterized and the experimental results are compared to ab-initio calculations previously reported. The films are ferromagnetic at room temperature in the cases of Fe, Co, Ni and even Cu impurities, but not in the case of Mn doping. Our results support the hypothesis that oxygen vacancies play a key role in the origin of magnetism in doped TiO{sub 2} films, and can explain the diversity of magnetic moments observed experimentally for films grown under different conditions.

  14. Characterization of Si sub 1 sub - sub x Ge sub x thin films prepared by sputtering

    CERN Document Server

    Noguchi, T

    2000-01-01

    By bombarding solid targets, we deposited Si sub 1 sub - sub x Ge sub x thin films by sputtering without using inflammable CVD (chemical vapor deposition) gases. After the B sup + -implanted Si sub 1 sub - sub x Ge sub x films were thermally annealed, they were characterized. As the content of Ge increased, the refractive index increased and the band edge narrowed. The higher the annealing temperature, the lower the resistivity. For Si sub 1 sub - sub x Ge sub x films with a high Ge content (X approx 0.5), the flat-band voltage of the gate deduced from C-V curve was adjusted to the middle point between p sup + and n sup + polySi gates. Boron-doped SiGe films are promising gate materials for MOS (metal oxide semiconductor) and SOI (silicon on insulator) transistors driven at low driving voltage.

  15. Thermal Oxidation Preparation of Doped Hematite Thin Films for Photoelectrochemical Water Splitting

    Directory of Open Access Journals (Sweden)

    Song Li

    2014-01-01

    Full Text Available Sn- or Ge-doped hematite thin films were fabricated by annealing alloyed films for the purpose of photoelectrochemical (PEC water splitting. The alloyed films were deposited on FTO glass by magnetron sputtering and their compositions were controlled by the target. The morphology, crystalline structure, optical properties, and photocatalytic activities have been investigated. The SEM observation showed that uniform, large area arrays of nanoflakes formed after thermal oxidation. The incorporation of doping elements into the hematite structure was confirmed by XRD. The photocurrent density-voltage characterization illustrated that the nanoflake films of Sn-doped hematite exhibited high PEC performance and the Sn concentration was optimized about 5%. The doped Ge4+ ions were proposed to occupy the empty octahedral holes and their effect on PEC performance of hematite is smaller than that of tin ions.

  16. Effect of Annealing on the Properties of Nanocrystalline CdS Thin Films Prepared by CBD Method

    OpenAIRE

    2016-01-01

    The CdS thin films were deposited on glass substrate by chemical bath deposition (CBD). The effect of annealing temperature on the morphological, structural, optical and electrical properties of the crystalline CdS films were investigated for different annealing temperature (as deposited, 300, 400 and 500 °C).The annealing time is 1 h. The materials have been prepared using simple aqueous solutions containing cadmium sulfate, as source of cadmium, and thiourea as source of sulfur and ammoniu...

  17. Investigation of MgF2 optical thin films with ultralow refractive indices prepared from autoclaved sols.

    Science.gov (United States)

    Murata, Tsuyoshi; Ishizawa, Hitoshi; Tanaka, Akira

    2008-05-01

    We have successfully developed a process to form high quality MgF(2) thin films with ultralow refractive indices from autoclaved sols prepared from magnesium acetate and hydrofluoric acid. And we have confirmed that our porous MgF(2) coatings have not only high transmittance in the UV region but also high uniformity of film thickness. They can be uniformly formed on phiv 300 mm substrates as a single coating and as a hybrid coating with sublayers formed by physical vapor deposition. They are expected to be applied to various optics that need high transmittance in the UV region.

  18. Structural, optical and magnetic properties of Mn doped ZnO thin films prepared by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Aravind, Arun, E-mail: aruncusat@gmail.com [Nanophotonic and Optoelectronic Devices Laboratory, Department of Physics, Cochin University of Science and Technology, Kochi 682 022, Kerala (India); Jayaraj, M.K., E-mail: mkj@cusat.ac.in [Nanophotonic and Optoelectronic Devices Laboratory, Department of Physics, Cochin University of Science and Technology, Kochi 682 022, Kerala (India); Kumar, Mukesh; Chandra, Ramesh [Nano Science Laboratory, Institute Instrumentation Centre, IIT Roorkee, Roorkee 247 667, Uttarakhand (India)

    2012-08-01

    Highlights: Black-Right-Pointing-Pointer Defect induced Raman active modes in Mn doped ZnO thin films. Black-Right-Pointing-Pointer Room temperature ferromagnetism. Black-Right-Pointing-Pointer Morphological variations of ZnO thin films with Mn doping. Black-Right-Pointing-Pointer Variation of refractive index of ZnO thin films with Mn doping. - Abstract: Zn{sub 1-x}Mn{sub x}O thin films were grown by pulsed laser deposition. The phase purity and the structure were confirmed by X-ray diffraction studies. The films have a transmittance more than 80% in the visible region. The refractive index of Zn{sub 0.90}Mn{sub 0.10}O films is found to be 1.77 at 550 nm. The presence of non-polar E{sub 2}{sup high} and E{sub 2}{sup low} Raman modes in thin films indicates that 'Mn' doping does not change the wurtzite structure of ZnO. Apart from the normal modes of ZnO the Zn{sub 1-x}Mn{sub x}O ceramic targets show two additional modes at 332 cm{sup -1} (I{sub 1}) and 524 cm{sup -1} (I{sub 2}). The broad Raman peaks (340-600 cm{sup -1}) observed Zn{sub 0.90}Mn{sub 0.10}O thin films can be deconvoluted into five peaks, denoted as P{sub 1}-P{sub 5}. The possible origins of Raman peaks in Zn{sub 1-x}Mn{sub x}O films are the structural disorder and morphological change caused by the Mn dopant. The B{sub 1}{sup low}, {sup 2}B{sub 1}{sup low}, B{sub 1}{sup high} and A{sub 1}{sup LO} modes as well as the surface phonon mode have been observed in heavily Mn-doped ZnO films. Zn{sub 0.98}Mn{sub 0.02}O thin film shows room temperature ferromagnetism. The saturation magnetic moment of the Zn{sub 0.98}Mn{sub 0.02}O thin film is 0.42{mu}{sub B}/Mn atom. The undoped ZnO film prepared under the same condition shows diamagnetic nature. At higher doping concentrations the formation of Mn clusters suppress the room temperature ferromagnetism in Zn{sub 1-x}Mn{sub x}O thin films and shows paramagnetism. XPS confirms the incorporation of Mn{sup 2+} into the ZnO lattice.

  19. Preparation of nanostructured PbS thin films as sensing element for NO{sub 2} gas

    Energy Technology Data Exchange (ETDEWEB)

    Kaci, S., E-mail: k_samira05@yahoo.fr [Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE) Division Couches Minces et Interfaces, 02 Bd Frantz Fanon, B.P. 140, 7 Merveilles, 16038 Algiers (Algeria); Keffous, A.; Hakoum, S. [Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE) Division Couches Minces et Interfaces, 02 Bd Frantz Fanon, B.P. 140, 7 Merveilles, 16038 Algiers (Algeria); Trari, M. [Université des Sciences et Technologies Houari Boumediene (USTHB), Laboratoire de Stockage et de Valorisation des Eneriges Renouvelables, Faculté de Chimie, BP 32, EL Alia, 16111 Bab Ezzouar, Algiers (Algeria); Mansri, O.; Menari, H. [Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE) Division Couches Minces et Interfaces, 02 Bd Frantz Fanon, B.P. 140, 7 Merveilles, 16038 Algiers (Algeria)

    2014-06-01

    In this work, we demonstrate that semiconducting films of A{sub IV}B{sub VI} compounds, in particular, of nanostructured lead sulfide (PbS) which prepared by chemical bath deposition (CBD), can be used as a sensing element for nitrogen dioxide (NO{sub 2}) gas. The CBD method is versatile, simple in implementation and gives homogeneous semiconductor structures. We have prepared PbS nanocrystalline thin film at different reaction baths and temperatures. In the course of deposition, variable amounts of additives, such as organic substances among them, were introduced into the baths. The energy dispersive analysis (EDX) confirms the chemical composition of PbS films. A current–voltage (I–V) characterization of Pd/nc-PbS/a-SiC:H pSi(100)/Al Schottky diode structures were studied in the presence of NO{sub 2} gas. The gas sensing behavior showed that the synthesized PbS nanocrystalline thin films were influenced by NO{sub 2} gas at room temperature. The results can be used for developing an experimental sensing element based on chemically deposited nanostructured PbS films which can be applicable in gas sensors.

  20. [Study on preparation of lanthanum-doped TiO2 nanometer thin film materials and its photocatalytic activity].

    Science.gov (United States)

    Zheng, Huai-li; Tang, Ming-fang; Gong, Ying-kun; Deng, Xiao-jun; Wu, Bang-hua

    2003-04-01

    In this paper, lanthanum-doped TiO2 nanometer film materials coated on glass were prepared in Ti(OBu)4 precursor solutions by sol-gel processing. Transmittance and photocatalytic activity were respectively investigated and tested for these nanometer thin films prepared with different amount of lanthanum (La), different amount of polyethylene glycol (PEG), and different coating layer times. Some reactive mechanisms were also discussed. For one layer La-addition had little effect on the film transmissivity; but the photocatalytic activity was significantly improved due to La-addition. With increasing PEG, the transmittance of the film decreased for one layer film; but its photocatalytic activity did not rise. Increasing layer number did not affect the transmissivity of multilayer film. After coating two times, increasing layer number did not significantly improve the photocatalytic activity. The highest photocatalytic activity and best transmissivity were obtained for two layer TiO2 film when the dosage of lanthanum was 0.5 g and the dosage of polyethylene was 0.2 g in the precursor solutions. These materials will probably be used in the protection of environment, waste water treatment, and air purification.

  1. Effects of annealing temperature on the physicochemical, optical and photoelectrochemical properties of nanostructured hematite thin films prepared via electrodeposition method

    Energy Technology Data Exchange (ETDEWEB)

    Phuan, Yi Wen [School of Engineering, Chemical Engineering Discipline, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 46150 Selangor DE (Malaysia); Chong, Meng Nan, E-mail: Chong.Meng.Nan@monash.edu [School of Engineering, Chemical Engineering Discipline, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 46150 Selangor DE (Malaysia); Sustainable Water Alliance, Advanced Engineering Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 46150 Selangor DE (Malaysia); Zhu, Tao; Yong, Siek-Ting [School of Engineering, Chemical Engineering Discipline, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 46150 Selangor DE (Malaysia); Chan, Eng Seng [School of Engineering, Chemical Engineering Discipline, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 46150 Selangor DE (Malaysia); Sustainable Water Alliance, Advanced Engineering Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 46150 Selangor DE (Malaysia)

    2015-09-15

    Highlights: • Nanostructured hematite thin films were synthesized via electrodeposition method. • Effects of annealing on size, grain boundary and PEC properties were examined. • Photocurrents generation was enhanced when the thin films were annealed at 600 °C. • The highest photocurrent density of 1.6 mA/cm{sup 2} at 0.6 V vs Ag/AgCl was achieved. - Abstract: Hematite (α-Fe{sub 2}O{sub 3}) is a promising photoanode material for hydrogen production from photoelectrochemical (PEC) water splitting due to its wide abundance, narrow band-gap energy, efficient light absorption and high chemical stability under aqueous environment. The key challenge to the wider utilisation of nanostructured hematite-based photoanode in PEC water splitting, however, is limited by its low photo-assisted water oxidation caused by large overpotential in the nominal range of 0.5–0.6 V. The main aim of this study was to enhance the performance of hematite for photo-assisted water oxidation by optimising the annealing temperature used during the synthesis of nanostructured hematite thin films on fluorine-doped tin oxide (FTO)-based photoanodes prepared via the cathodic electrodeposition method. The resultant nanostructured hematite thin films were characterised using field emission-scanning electron microscopy (FE-SEM) coupled with energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), UV-visible spectroscopy and Fourier transform infrared spectroscopy (FTIR) for their elemental composition, average nanocrystallites size and morphology; phase and crystallinity; UV-absorptivity and band gap energy; and the functional groups, respectively. Results showed that the nanostructured hematite thin films possess good ordered nanocrystallites array and high crystallinity after annealing treatment at 400–600 °C. FE-SEM images illustrated an increase in the average hematite nanocrystallites size from 65 nm to 95 nm when the annealing temperature was varied from 400 °C to 600

  2. Sol-gel preparation of ion-conducting ceramics for use in thin films

    Energy Technology Data Exchange (ETDEWEB)

    Steinhauser, M.I.

    1992-12-01

    A metal alkoxide sol-gel solution suitable for depositing a thin film of La{sub 0.6}Sr{sub 0.4}CoO{sub 3} on a porous substrate has been developed; such films should be useful in fuel cell electrode and oxygen separation membrane manufacture. Crack-free films have been deposited on both dense and porous substrates by dip-coating and spin-coating techniques followed by a heat treatment in air. Fourier transform infrared spectroscopy was used to determine the chemical structure of metal alkoxide solution system. X-ray diffraction was used to determine crystalline phases formed at various temperatures, while scanning electron microscopy was used to determine physical characteristics of the films. Surface coatings have been successfully applied to porous substrates through the control of the substrate pore size, deposition parameters, and firing parameters. Conditions have been defined for which films can be deposited, and for which the physical and chemical characteristics of the film can be improved. A theoretical discussion of the chemical reactions taking place before and after hydrolysis in the mixed alkoxide solutions is presented, and the conditions necessary for successful synthesis are defined. Applicability of these films as ionic and electronic conductors is discussed.

  3. Investigation of structural properties of chromium thin films prepared by a plasma focus device

    Science.gov (United States)

    Javadi, S.; Habibi, M.; Ghoranneviss, M.; Lee, S.; Saw, S. H.; Behbahani, R. A.

    2012-08-01

    We report the synthesis of chromium thin films on Si(400) substrates by utilizing a low-energy (1.6 kJ) plasma focus device. The films of chromium are deposited with different numbers of focus shots (15, 25 and 35) at a distance of 8 cm and at 0° angular position with respect to the anode axis. The films are investigated structurally by x-ray diffraction analysis and morphologically by atomic force microscopy and scanning electron microscopy. The elemental composition is characterized by energy dispersive x-ray analysis. Furthermore, Vicker's micro hardness is used to study the mechanical properties of the deposited films. The degree of crystallinity of chromium films, the size of the particles and the hardness values of the films increase when the number of focus shots is raised from 15 to 25 and then decrease when the substrate is treated with 35 shots. We discuss the dynamic processes involved in the formation of the chromium films.

  4. Fabrication and properties of zinc oxide thin film prepared by sol-gel dip coating method

    Directory of Open Access Journals (Sweden)

    Kayani Zohra Nazir

    2015-09-01

    Full Text Available ZnO thin films were deposited on a glass substrate by dip coating technique using a solution of zinc acetate, ethanol and distilled water. Optical constants, such as refractive index n and extinction coefficient k. were determined from transmittance spectrum in the ultraviolet-visible-near infrared (UV-Vis-NIR regions using envelope methods. The films were found to exhibit high transmittance, low absorbance and low reflectance in the visible regions. Absorption coefficient α and the thickness of the film t were calculated from interference of transmittance spectra. The direct optical band gap of the films was in the range of 3.98 to 3.54 eV and the thickness of the films was evaluated in the range of 173 to 323 nm, while the refractive index slightly varied in the range of 1.515 to 1.622 with an increase in withdrawal speed from 100 to 250 mm/s. The crystallographic structure of the films was analyzed with X-ray diffractometer. The films were amorphous in nature.

  5. Thin Film CuInS2 Prepared by Spray Pyrolysis with Single-Source Precursors

    Science.gov (United States)

    Jin, Michael H.; Banger, Kulinder K.; Harris, Jerry D.; Cowen, Jonathan E.; Hepp, Aloysius F.; Lyons, Valerie (Technical Monitor)

    2002-01-01

    Both horizontal hot-wall and vertical cold-wall atmospheric chemical spray pyrolysis processes deposited near single-phase stoichiometric CuInS2 thin films. Single-source precursors developed for ternary chalcopyrite materials were used for this study, and a new liquid phase single-source precursor was tested with a vertical cold-wall reactor. The depositions were carried out under an argon atmosphere, and the substrate temperature was kept at 400 C. Columnar grain structure was obtained with vapor deposition, and the granular structure was obtained with (liquid) droplet deposition. Conductive films were deposited with planar electrical resistivities ranging from 1 to 30 Omega x cm.

  6. Preparation of Mn{sub 3-x}Ga Heusler thin films with perpendicular magnetic anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Glas, Manuel; Ebke, Daniel; Thomas, Patrick; Reiss, Guenter [Thin Films and Physics of Nanostructures, Physics Department, Bielefeld University (Germany)

    2011-07-01

    Recently, the integration of materials with perpendicular magnetic anisotropy into magnetic tunnel junctions (MTJs) has found a lot of attraction due to the predicted lowered current densities for spin transfer switching and a higher thermal stability. Because of the predicted high spin polarization and the low magnetic moment Mn{sub 3}Ga is a promising material for future spin torque transfer (STT) magnetic switching devices. For this work, we have fabricated Mn{sub 3-x}Ga Heusler thin films with varying stoichiometries into half magnetic tunnel junctions. The effect of Heusler film composition will be discussed with respect to the magnetic and crystal properties.

  7. Preparation and Photochromic Properties of Hybrid Thin Films Based on Heteropolyoxometallate and Polyacrylamide

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    series of photochromic hybrid films were prepared through entrapping Dawson type tungsten heteropolyoxometallates (P2W18O626-) and molybdenum heteropolyoxometallate (P2Mo18O626-) into polyacrylamide matrix. FTIR results showed that the Dawson geometry of heteropolyoxometallates is still preserved inside the composites and strong coulombic interaction is built between heteropolyoxometallates and polyacrylamide via hydrogen bonding. Irradiated with ultraviolet light, the transparent films change from colorless to blue and show reversible photochromism.The bleaching process occurs when the films are in contact with air or O2 in the dark. The molybdenum heteropolyoxometallate hybrid film has higher photochromic efficiency and slower bleaching reaction than tungsten heteropolyoxometallate hybrid film. ESR results indicated that polyacrylamide is a hydrogen donor and the photoreduced process is in accordance with the radical mechanism.

  8. Thin Film Deposition Techniques (PVD)

    Science.gov (United States)

    Steinbeiss, E.

    The most interesting materials for spin electronic devices are thin films of magnetic transition metals and magnetic perovskites, mainly the doped La-manganites [1] as well as several oxides and metals for passivating and contacting the magnetic films. The most suitable methods for the preparation of such films are the physical vapor deposition methods (PVD). Therefore this report will be restricted to these deposition methods.

  9. Hybrid functional IrO2-TiO2 thin film resistor prepared by atomic layer deposition for thermal inkjet printheads

    Institute of Scientific and Technical Information of China (English)

    Won-Sub KWACK; Hyoung-Seok MOON; Seong-Jun JEONG; Qi-min WANG; Se-Hun KWON

    2011-01-01

    IrO2-TiO2 thin films were prepared by atomic layer deposition using Ir(EtCp)(COD) and titanium isopropoxide (TTIP).in the IrO2-TiO2 thin films. The low temperature coefficient of resistance(TCR) values can be obtained by adopting IrO2-TiO2 composite thin films. Moreover, the change in the resistivity of lrO2-TiO2 thin films was below 10% even after O2 annealing process at 600 ℃. The step stress test results show that IrO2-TiO2 films have better characteristics than conventional TaN08 heater resistor.Therefore, IrO2-TiO2 composite thin films can be used as a heater resistor material in thermal inkjet printhead.

  10. Optical refractive index and static permittivity of mixed Zr-Si oxide thin films prepared by ion beam induced CVD

    Energy Technology Data Exchange (ETDEWEB)

    Ferrer, F.J. [Centro Nacional de Aceleradores, Av. Thomas A. Edison, 7, 41092 Sevilla (Spain)], E-mail: fjferrer@us.es; Frutos, F. [E.T.S. de Ingenieria Informatica, Avda. Reina Mercedes, s/n, 41012 Sevilla (Spain); Garcia-Lopez, J. [Centro Nacional de Aceleradores, Av. Thomas A. Edison, 7, 41092 Sevilla (Spain); Gonzalez-Elipe, A.R.; Yubero, F. [Insituto de Ciencia de Materiales de Sevilla, c/ Americo vespucio, no. 49, 41092 Sevilla (Spain)

    2007-12-03

    Mixed oxides Zr{sub x}Si{sub 1-x}O{sub 2} (0 < x < 1) thin films have been prepared at room temperature by decomposition of (CH{sub 3}CH{sub 2}O){sub 3}SiH and Zr[OC(CH{sub 3}){sub 3}]{sub 4} volatile precursors induced by mixtures of O{sub 2}{sup +} and Ar{sup +} ions. The films were flat and amorphous independently of the Si/Zr ratio and did not present phase segregation of the pure single oxides (SiO{sub 2} and ZrO{sub 2}). A 10-23 at.% of H and 1-5 at.% of C atoms remained incorporated in the films depending on the mixture ratio of the Si and Zr precursors and the composition of the bombarding gas used during the deposition process. These impurities are mainly forming hydroxyl and carboxylic groups. Optical refractive index and static permittivity of the films were determined by reflection NIR-Vis spectroscopy and C-V electrical characterization, respectively. It is found that the refractive index increases non-linearly from 1.45 to 2.10 as the Zr content in the thin films increases. The static permittivity also increases non-linearly from {approx} 4 for pure SiO{sub 2} to {approx} 15 for pure ZrO{sub 2}. Optical and electrical characteristics of the films are justified by their impurity content and the available theories.

  11. Vanadium dioxide thin films prepared on silicon by low temperature MBE growth and ex-situ annealing

    Science.gov (United States)

    Homm, Pia; van Bilzen, Bart; Menghini, Mariela; Locquet, Jean-Pierre; Ivanova, Todora; Sanchez, Luis; Sanchis, Pablo

    Vanadium dioxide (VO2) is a material that shows an insulator to metal transition (IMT) near room temperature. This property can be exploited for applications in field effect devices, electro-optical switches and nonlinear circuit components. We have prepared VO2 thin films on silicon wafers by combining a low temperature MBE growth with an ex-situ annealing at high temperature. We investigated the structural, electrical and optical characteristics of films with thicknesses ranging from 10 to 100 nm. We have also studied the influence of the substrate cleaning. The films grown with our method are polycrystalline with a preferred orientation in the (011) direction of the monoclinic phase. For the films produced on silicon with a native oxide, an IMT at around 75 °C is observed. The magnitude of the resistance change across the IMT decreases with thickness while the refractive index at room temperature corresponds with values reported in the literature for thin films. The successful growth of VO2 films on silicon with good electrical and optical properties is an important step towards the integration of VO2 in novel devices. The authors acknowledge financial support from the FWO project G052010N10 and EU-FP7 SITOGA project. PH acknowledges support from Becas Chile - CONICYT.

  12. Preparation and investigation of optical, structural, and morphological properties of nanostructured ZnO:Mn thin films

    Indian Academy of Sciences (India)

    E Amoupour; F E Ghodsi; H Andarva; A Abdolahzadeh Ziabari

    2013-08-01

    Nanostructured ZnO:Mn thin films have been prepared by sol–gel dip coating method. The content of Mn in the sol was varied from 0 to 12 wt%. The effect of Mn concentration on the optical, structural, and morphological properties of ZnO thin films were studied by using Fourier transform infrared (FTIR), UV–visible and photoluminescence (PL) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results showed that the films have hexagonal wurtzite structure at lower content of Mn. The diffraction peaks corresponding to ZnO disappeared and two diffraction peaks of MnO2 and Mn3O4 appeared at the highest value of doping concentration (viz., 12 wt\\%). SEM results revealed that the surface smoothness of the films improved at higher content of Mn. The optical band gap of the films decreased from 3.89 to 3.15 eV when the Mn concentration increased from 0 to 12 wt\\%. The PL spectra of the films showed the characteristic peaks linked to band-to-band, green and yellow emissions. Besides, the PL intensity of the samples decreased with increase in Mn concentration.

  13. Preparation of room temperature terahertz detector with lithium tantalate crystal and thin film

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jun, E-mail: ueoewj@gmail.com; Gou, Jun; Li, Weizhi [State Key Lab of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2014-02-15

    Research on room temperature terahertz (THz) detector is essential for promoting the application of THz science and technology. Both lithium tantalate crystal (LiTaO{sub 3}) and lithium tantalate thin film were used to fabricate the THz detector in this paper. Polishing process were used to reduce the thickness of LiTaO{sub 3} crystal slice by chemical mechanical polishing techniques and an improved sol-gel process was used to obtain high concentration LiTaO{sub 3} precursor solution to fabricate LiTaO{sub 3} thin film. Three dimension models of two THz detectors were set up and the temperature increasing map of two devices were simulated using finite element method. The lowest noise equivalent power value for terahertz detector using pyroelectric material reaches 6.8 × 10{sup −9} W at 30 Hz operating frequency, which is suitable for THz imaging application.

  14. Preparation of room temperature terahertz detector with lithium tantalate crystal and thin film

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2014-02-01

    Full Text Available Research on room temperature terahertz (THz detector is essential for promoting the application of THz science and technology. Both lithium tantalate crystal (LiTaO3 and lithium tantalate thin film were used to fabricate the THz detector in this paper. Polishing process were used to reduce the thickness of LiTaO3 crystal slice by chemical mechanical polishing techniques and an improved sol-gel process was used to obtain high concentration LiTaO3 precursor solution to fabricate LiTaO3 thin film. Three dimension models of two THz detectors were set up and the temperature increasing map of two devices were simulated using finite element method. The lowest noise equivalent power value for terahertz detector using pyroelectric material reaches 6.8 × 10−9 W at 30 Hz operating frequency, which is suitable for THz imaging application.

  15. Preparation of Copper Oxide Nanostructure Thin Film For Carbon Monoxide Gas Sensor

    Directory of Open Access Journals (Sweden)

    Brian Yuliarto

    2016-11-01

    Full Text Available This work reports the synthesis of nanostructure of CuO thin film using dip coating and chemical bath deposition method. Seed layer was deposited by dip coating method using zinc nitrate as a precursor. The CuO nanostructure has successfully grown on CBD process at 95oC for 6 hours. The X Ray Diffraction characterization result shows that the CuO has monoclinic crystallization and good crystallinity. Moreover, the Scanning Electron Microscope characterization results  shows that CuO has nanospike-like shape. The CuO thin film as a gas sensor shows relatively high response on CO gas at the temperature working above 200oC. The highest response is obtained at 350oC of working temperature toward 30 ppm CO gas at 186% of sensor response.

  16. Composition and crystalline properties of TiNi thin films prepared by pulsed laser deposition under vacuum and in ambient Ar gas.

    Science.gov (United States)

    Cha, Jeong Ok; Nam, Tae Hyun; Alghusun, Mohammad; Ahn, Jeung Sun

    2012-01-05

    TiNi shape memory alloy thin films were deposited using the pulsed laser deposition under vacuum and in an ambient Ar gas. Our main purpose is to investigate the influences of ambient Ar gas on the composition and the crystallization temperature of TiNi thin films. The deposited films were characterized by energy-dispersive X-ray spectrometry, a surface profiler, and X-ray diffraction at room temperature. In the case of TiNi thin films deposited in an ambient Ar gas, the compositions of the films were found to be very close to the composition of target when the substrate was placed at the shock front. The in-situ crystallization temperature (ca. 400°C) of the TiNi film prepared at the shock front in an ambient Ar gas was found to be lowered by ca. 100°C in comparison with that of a TiNi film prepared under vacuum.

  17. Thickness dependence of dispersion parameters of the MoO{sub x} thin films prepared using the vacuum evaporation technique

    Energy Technology Data Exchange (ETDEWEB)

    Akın, Ümmühan, E-mail: uakin@selcuk.edu.tr; Şafak, Haluk

    2015-10-25

    The optical behaviors of molybdenum oxide thin films are highly important due to their widespread applications. In the present paper, the effect of thickness on the structure, morphology and optical properties of molybdenum oxide (MoO{sub x}) thin films prepared on Corning glass substrates using thermal evaporation technique was studied. The structure and morphology of films were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively, while their optical properties were investigated by UV-VIS-NIR spectrophotometry in the spectral range from 300 to 2500 nm. It was observed that whole films have amorphous structure and also they showed rather high transmittance values reached nearly up to 90%. Absorption analysis showed two types of electronic transitions; both direct and indirect interband transition energy values of films decrease from 4.47 to 3.45 eV and from 3.00 to 2.75 eV, respectively, with increasing the film thickness, while the width of the localized states tail increases with thickness. This decrease in the band gap value can be attributed to the rising oxygen-ion vacancy densities with the thickness. The refractive indices of films were calculated from Sellmeier coefficients determined by nonlinear curve fitting method based on the measured transmittance spectral data. The dispersion of the refractive index was discussed in terms of the Wemple-DiDomenico single-oscillator model. The dispersion parameters such as average oscillator energy, E{sub o}, the dispersion energy, E{sub d}, and static refractive index n{sub o} were evaluated and they found to vary significantly with the film thickness. - Highlights: • MoO{sub x} thin films with different thickness were prepared using the vacuum evaporation technique. • The variation of fundamental absorption edge with the film thickness was determined. • A detailed dispersion analysis based on the Wemple-DiDomenico model was performed. • The dependence of all

  18. Dynamic simulation on the preparation process of thin films by pulsed laser

    Institute of Scientific and Technical Information of China (English)

    张端明; 李智华; 郁伯铭; 黄明涛; 关丽; 钟志成; 李国栋

    2001-01-01

    An ablation model of targets irradiated by pulsed laser is established. By using the simple energy balance conditions, the relationship between ablation surface location and time is derived. By an adiabatic approximation, the continuous-temperature condition, energy conservation and all boundany conditions can be established. By applying the analytical method and integral-approximation method, the solid and liquid phase temperature distributions are obtained and found to be a function of time and location. The interface of solid and liquid phase is also derived. The results are compared with the other published data. In addition, the dynamics process of pulsed laser deposition of KTN (Kta0.65Nb0.35O3) thin film is simulated in detail by using fluid dynamics theory. By combining the expression of the target ablation ratio and the dynamic equation and by using the experimental data, the effects of laser action parameters on the thickness distribution of thin film and on the thin film component characteristics are discussed. The results are in good agreement with the experimental data.

  19. CrN thin films prepared by reactive DC magnetron sputtering for symmetric supercapacitors

    KAUST Repository

    Wei, Binbin

    2016-12-29

    Supercapacitors have been becoming indispensable energy storage devices in micro-electromechanical systems and have been widely studied over the past few decades. Transition metal nitrides with excellent electrical conductivity and superior cycling stability are promising candidates as supercapacitor electrode materials. In this work, we report the fabrication of CrN thin films using reactive DC magnetron sputtering and further their applications for symmetric supercapacitors for the first time. The CrN thin film electrodes fabricated under the deposition pressure of 3.5 Pa show an areal specific capacitance of 12.8 mF cm at 1.0 mA cm and high cycling stability with 92.1% capacitance retention after 20 000 cycles in a 0.5 M HSO electrolyte. Furthermore, our developed CrN//CrN symmetric supercapacitor can deliver a high energy density of 8.2 mW h cm at the power density of 0.7 W cm along with outstanding cycling stability. Thus, the CrN thin films have great potential for application in supercapacitors and other energy storage systems.

  20. Preparation of metal-organic decomposition-derived strontium zirconate dielectric thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chen Changhong; Zhu Weiguang; Yu Ting; Chen Xiaofeng; Yao Xi

    2003-04-30

    Metal-organic decomposition-derived SrZrO{sub 3} dielectric thin films were investigated using differential thermal analysis, thermogravimetric analysis, X-ray diffraction, Fourier transform infrared reflectivity spectroscopy and atomic force microscopy to study the mechanism of phase transformation and crystallinity, and were characterized by electric and dielectric properties as well. The phase transformation and crystallinity results show that the film has amorphous structure with carbonate existing when annealed at 550 deg. C; while when annealed at 600 deg. C and above, the carbonate is decomposed and those films crystallize into perovskite phase without preferred orientation. In addition, the electric properties show these films exhibit very low leakage current density and high breakdown strength. Typically, the film annealed at 600 deg. C has the lowest leakage current density of 4.2x10{sup -10} A cm{sup -2} at the field strength of 580 kV cm{sup -1} and the breakdown strength is close to 1.3 MV cm{sup -1}. Moreover, the dielectric properties show that, at room temperature, these films have their dielectric constants higher than 22.0 with very little dispersion in a frequency range from 100 Hz to 1 MHz and are nearly independent of applied dc bias.

  1. Preparation and characterization of electrodeposited SnS:In thin films: Effect of In dopant

    Science.gov (United States)

    Kafashan, Hosein; Balak, Zohre

    2017-09-01

    SnS:In thin films were grown on fluorine doped tin oxide (FTO) substrate by cathodic electrodeposition technique. The solution was containing 2 mM SnCl2 and 16 mM Na2S2O3 and different amounts of 1 mM InCl3 as In-dopant. The pH, bath temperature, deposition time, and deposition potential (E) were fixed at 2.1, 60 °C, 30 min, and - 1 V, respectively. The XRD results showed that the synthesized films were polycrystalline orthorhombic SnS. The XPS results demonstrated that the films were composed of Sn, S and In. According to the FESEM images, an increase in In-dopant concentration leads to a change in morphology from grain-like to sheet-like having a nanoscale thickness of 20-80 nm and fiber-like. The PL spectra of undoped SnS exhibited four emission peaks including a UV peak, two blue emission peaks, and an IR emission peak. According to the UV-Vis spectra, the direct band gap of SnS:In thin films was estimated to be 1.40-1.66 eV.

  2. Preparation and Properties of a-Si :H Thin Films Deposited on Different Substrates

    Institute of Scientific and Technical Information of China (English)

    RAO Rui

    2007-01-01

    The effects of different substrates on the structure and hydrogen evolution from a-Si:H thin films deposited by plasma enhanced chemical vapour deposition were studied, as well as the similar films exposed to an hydrogen plasma. Spectroscopic ellipsometry and hydrogen evolution measurements were used to analyse the effects of the substrate and hydrogen plasma on the films microstructure,thickness, hydrogen content. hydrogen bonding and hydrogen evolution. The hydrogen evolution spectra show a strong substrate dependence. In particular on crystalline silicon substrate, the formation of bubbles was observed. For different substrates, hydrogen plasma treatments lightly affected the hydrogen evolution spectra. These results indicate that the action of hydrogen in a-Si:H was modified by the nature of the substrate.

  3. Optical properties and surface morphology of ZnTe thin films prepared by multiple potential steps

    Energy Technology Data Exchange (ETDEWEB)

    Gromboni, Murilo F.; Lucas, Francisco W. S.; Mascaro, Lucia H., E-mail: lmascaro@ufscar.br [Universidade de Federal de Sao Carlos (LIEC/UFSCar), SP (Brazil). Departamento de Quimica. Lab. de Eletroquimica e Ceramica

    2014-03-15

    In this work, the ZnTe thin films were electrodeposited using potentiostatic steps, on Pt substrate. The effect of steps number, the deposition time for each element (Zn or Te) and layer order (Zn/Te or Te/Zn) in the morphology, composition, band gap energy and photocurrent was evaluated. Microanalysis data showed that the ratio Zn/Te ranged from 0.12 and 0.30 and the film was not stoichiometric. However, the band-gap value obtained from in all experimental conditions used in this work was 2.28 eV, indicating film growth of ZnTe. The samples with higher Zn showed higher photocurrent, which was of the order of 2.64 μA cm{sup -2} and dendritic morphology (author)

  4. Ceramic Composite Thin Films

    Science.gov (United States)

    Ruoff, Rodney S. (Inventor); Stankovich, Sasha (Inventor); Dikin, Dmitriy A. (Inventor); Nguyen, SonBinh T. (Inventor)

    2013-01-01

    A ceramic composite thin film or layer includes individual graphene oxide and/or electrically conductive graphene sheets dispersed in a ceramic (e.g. silica) matrix. The thin film or layer can be electrically conductive film or layer depending the amount of graphene sheets present. The composite films or layers are transparent, chemically inert and compatible with both glass and hydrophilic SiOx/silicon substrates. The composite film or layer can be produced by making a suspension of graphene oxide sheet fragments, introducing a silica-precursor or silica to the suspension to form a sol, depositing the sol on a substrate as thin film or layer, at least partially reducing the graphene oxide sheets to conductive graphene sheets, and thermally consolidating the thin film or layer to form a silica matrix in which the graphene oxide and/or graphene sheets are dispersed.

  5. [Preparation of Fe(3+) -doped TiO2 nanometer thin film and study on its photocatalytic performances].

    Science.gov (United States)

    Zheng, Huai-Li; Zhang, Jun-Hua; Li, Hong; Li, Zhi-Liang

    2005-12-01

    In the present paper, Fe(3+) -doped TiO2 nanometer thin films were prepared on the surface of glass by sol-gel processing. Effects of ferro-dopant, PEG addition levels, and the number of layers on transmittance and photocatalytic degradability were then respectively investigated. Meanwhile some relative mechanisms of the effects were discussed. It was shown that the photocatalytic activity of the films could be promoted by ferro-dopant, and the rate of degradation was 1.38 times that without ferro-dopant. Moreover, the optimal photocatalytic activity and transmittance were obtained by adding 0.1 g (0.13 wt%) PEG to the sol precursor. In addition, the TiO2 nanometer thin films with 2 to 5 layers all had better transmittance, and the best one for practical application had two layers. The glass coated with TiO2 nanometer thin film shows potential and wide application value in construction industry, lamps manufacture, urban lighting engineering, etc. because of its remarkable abilities of self-purification, economy in energy, and environmental protection.

  6. Structural and electrical properties of Ta2O5 thin films prepared by photo-induced CVD

    Indian Academy of Sciences (India)

    Jun Liu; Aixiang Wei; Xianghui Zhao; Haiyan Zhang

    2011-06-01

    Tantalum oxide (Ta2O5) films and Al/Ta2O5/Si MOS capacitors were prepared at various powers by ultraviolet photo-inducing hot filament chemical vapour deposition (HFCVD). Effects of ultraviolet light powers on the structure and electrical properties of Ta2O5 thin films were studied using X-ray diffraction (XRD) and atomic forcemicroscopy (AFM). The dielectric constant, leakage current density and breakdown electric field of the samples were studied by the capacitance–voltage (C–V) and current–voltage (–) measurements of the Al/Ta2O5/Si MOS capacitors. Results show that the Ta2O5 thin films grown without inducement of UV light belong to amorphous phase, whereas the samples grown with inducement of UV-light belong to -Ta2O5 phase. The dielectric constant and leakage current density of the Ta2O5 thin films increase with increasing powers of the UV- lamps. Effects of UVlamp powers on the structural and electrical properties were discussed.

  7. Humidity sensing properties of Ce-doped nanoporous ZnO thin film prepared by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    Mansoor Anbia; Seyyed Ebrahim Moosavi Fard

    2012-01-01

    The humidity sensitive characteristics of the sensor fabricated from Ce-doped nanoporous ZnO by screen-printing on the alumina substrate with Ag-Pd interdigital electrodes were investigated at different sintering temperatures.The nanoporous thin films were prepared by sol-gel technique.It was found that the impedance of the sensor sintered at 600 ℃ changed more than four order of magnitude in the relative humidity (RH) range of 11%-95% at 25 ℃.The response and recovery time of the sensor were about 13 and 17 s,respectively.The sensor showed high humidity sensitivity,rapid response and recovery,prominent stability,good repeatability and narrow hysteresis loop.These results indicated that Ce-doped nanoporous ZnO thin films can be used in fabricating high-performance humidity sensors.

  8. In situ preparation of YH2 thin films by PLD for switchable devices

    NARCIS (Netherlands)

    Dam, B; Lokhorst, AC; Remhof, A; Heijna, MCR; Rector, JH; Borsa, D; Kerssemakers, JWJ

    2003-01-01

    We prepared epitaxial YH2 films on (111) CaF2 by pulsed laser deposition (PLD) from a metallic yttrium target. Without adding any reactive hydrogen, the dihydride is formed in situ due to the hydrogen evolving from the metallic target which contains similar to7 at% H. Upon pulsed laser irradiation,

  9. Oxidant-assisted preparation of CaMoO{sub 4} thin film using an irreversible galvanic cell method

    Energy Technology Data Exchange (ETDEWEB)

    Gao Daojiang, E-mail: daojianggao@126.co [College of Chemistry and Materials Science, Sichuan Normal University, No.5 Jing' an Road, Jinjiang District, Chengdu, 610066 (China); Lai Xin, E-mail: laixin1972@126.co [College of Chemistry and Materials Science, Sichuan Normal University, No.5 Jing' an Road, Jinjiang District, Chengdu, 610066 (China); Cui Chunhua; Cheng Ping; Bi Jian; Lin Dunmin [College of Chemistry and Materials Science, Sichuan Normal University, No.5 Jing' an Road, Jinjiang District, Chengdu, 610066 (China)

    2010-04-02

    CaMoO{sub 4} thin films were prepared by an irreversible galvanic cell method at room temperature; the crystalline phase structure, surface morphology, chemical composition and room temperature photoluminescence property were characterized by X-ray diffraction, Raman spectroscopy, scanning electronic microscopy, X-ray photoelectron spectroscopy as well as photoluminescence spectroscopy. Our results reveal that it is very difficult to directly deposit dense and uniform CaMoO{sub 4} thin films in saturated Ca(OH){sub 2} solution at room temperature by the irreversible galvanic cell method. After adding some oxidant (NaClO solution or H{sub 2}O{sub 2} solution), the growth of CaMoO{sub 4} grains has been promoted, and well-crystallized, dense, and uniform CaMoO{sub 4} films were obtained. The as-prepared CaMoO{sub 4} films exhibit a good green photoluminescence, with the excitation of various wavelengths (220 nm, 230 nm, 240 nm, 250 nm and 270 nm) of ultraviolet irradiation.

  10. Microstructure Control of Nanoporous Silica Thin Film Prepared by Sol-gel Process

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Nanoporous silica films were prepared by sol-gel process with base, acid and base/acid two-step catalysis.Transmission electron microscope (TEM) and particle size analyzer were used to characterize the microstructure and the particle size distribution of the sols. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and spectroscopic ellipsometer were used to characterize the surface microstructure and the optical properties of the silica films. Stability of the sols during long-term storage was investigated. Moreover,the dispersion relation of the optical constants of the silica films, and the control of the microstructure and properties of the films by changing the catalysis conditions during sol-gel process were also discussed.

  11. Preparation and Microstructure of Highly - Oriented LaNiO3 Thin Films by RF Sputtering Method

    Institute of Scientific and Technical Information of China (English)

    CHENG Xing-hua; QIAO Liang; BI Xiao-fang

    2006-01-01

    In an attempt of being used as buffer layers and electrodes for the textured BaTiO3 (BTO) ferroelectric thin films, highly (100)-oriented LaNiO3 (LNO) thin films of different thicknesses were deposited directly on Si (100) substrate with radio-frequency (RF) magnetron sputtering method. It is observed that the substrate temperatures and the film thicknesses bring main influences on the microstructures and orientation of the thin film. The effects of the thicknesses and substrate temperatures on the orientation of the films were studied on the LNO films of different thicknesses. The highly (100)-oriented LNO thin films were obtained at the substrate temperature of 600 ℃. The existence of epitaxially grown BTO films indicates that the oriented LNO thin films obtained in this work could be used as a buffer layer for epitaxial growth.

  12. Transparent and conductive indium doped cadmium oxide thin films prepared by pulsed filtered cathodic arc deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Yuankun, E-mail: yuan.kun.zhu@gmail.com [Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin 150080 (China); Plasma Applications Group, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Mendelsberg, Rueben J. [Plasma Applications Group, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Zhu Jiaqi, E-mail: zhujq@hit.edu.cn [Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin 150080 (China); Han Jiecai [Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin 150080 (China); Anders, Andre [Plasma Applications Group, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer High quality CdO:In films were prepared on glass by pulsed filtered cathodic arc. Black-Right-Pointing-Pointer 230 nm thick films show low resistivity of 7.23 Multiplication-Sign 10{sup -5} {Omega} cm and mobility of 142 cm{sup 2}/Vs. Black-Right-Pointing-Pointer In-doping significantly improves the conductivity and extends the transparent range. Black-Right-Pointing-Pointer Film crystalline quality is maintained with increasing In concentration. Black-Right-Pointing-Pointer The pulsed arc-grown CdO:In show excellent reproducibility of film properties. - Abstract: Indium doped cadmium oxide (CdO:In) films with different In concentrations were prepared on low-cost glass substrates by pulsed filtered cathodic arc deposition (PFCAD). It is shown that polycrystalline CdO:In films with smooth surface and dense structure are obtained. In-doping introduces extra electrons leading to remarkable improvements of electron mobility and conductivity, as well as improvement in the optical transmittance due to the Burstein-Moss effect. CdO:In films on glass substrates with thickness near 230 nm show low resistivity of 7.23 Multiplication-Sign 10{sup -5} {Omega} cm, high electron mobility of 142 cm{sup 2}/Vs, and mean transmittance over 80% from 500 to 1250 nm (including the glass substrate). These high quality pulsed arc-grown CdO:In films are potentially suitable for high efficiency multi-junction solar cells that harvest a broad range of the solar spectrum.

  13. Photoluminescence and electrochemical properties of transparent CeO2-ZnO nanocomposite thin films prepared by Pechini method

    Science.gov (United States)

    Sani, Z. Khosousi; Ghodsi, F. E.; Mazloom, J.

    2017-02-01

    Nanocomposite thin films of CeO2-ZnO with different molar ratios of Zn/Ce (=0, 0.25, 0.5, 0.75 and 1) were prepared by the Pechini sol-gel route. Various spectroscopic and electrochemical techniques were applied to investigate the films. XRD patterns of all the samples exhibited the peaks corresponding to cubic fluorite structure of ceria and the (101) and (103) peaks of ZnO with hexagonal structure was just observed in the sample with molar ratio of 1. EDS confirmed the presence of constituent of element in the samples. FESEM images of the films showed a surface composed of nanograins. AFM analysis revealed that root mean square roughness was enhanced as molar ratio of Zn/Ce increased. Moreover, fractal dimension of surfaces were calculated by cube counting approach. Optical measurements indicated that the film with molar ratio of 1 has the highest transmission and lowest reflectivity. The optical band gap values varied between 2.95 and 3.42 eV. The compositional dependence of refractive index and extinction coefficient were reported. The UV and blue emission appeared in PL spectra. The highest photoluminescence emission intensity was observed in the 1:1 molar ratio sample. The cyclic voltammetry measurements indicated the highest charge density (9.75 mC cm-2) and diffusion coefficient (3.507 × 10-17 cm2 s-1) belonged to the Ce/Zn (1:1) thin film.

  14. Thermal stability of tungsten sub-nitride thin film prepared by reactive magnetron sputtering

    Science.gov (United States)

    Zhang, X. X.; Wu, Y. Z.; Mu, B.; Qiao, L.; Li, W. X.; Li, J. J.; Wang, P.

    2017-03-01

    Tungsten sub-nitride thin films deposited on silicon samples by reactive magnetron sputtering were used as a model system to study the phase stability and microstructural evolution during thermal treatments. XRD, SEM&FIB, XPS, RBS and TDS were applied to investigate the stability of tungsten nitride films after heating up to 1473 K in vacuum. At the given experimental parameters a 920 nm thick crystalline film with a tungsten and nitrogen stoichiometry of 2:1 were achieved. The results showed that no phase and microstructure change occurred due to W2N film annealing in vacuum up to 973 K. Heating up to 1073 K led to a partial decomposition of the W2N phase and the formation of a W enrichment layer at the surface. Increasing the annealing time at the same temperature, the further decomposition of the W2N phase was negligible. The complete decomposition of W2N film happened as the temperature reached up to 1473 K.

  15. SnS Thin Films Prepared by Chemical Spray Pyrolysis at Different Substrate Temperatures for Photovoltaic Applications

    Science.gov (United States)

    Sall, Thierno; Soucase, Bernabé Marí; Mollar, Miguel; Sans, Juan Angel

    2017-03-01

    The preparation and analysis of morphological, structural, optical, vibrational and compositional properties of tin monosulfide (SnS) thin films deposited on glass substrate by chemical spray pyrolysis is reported herein. The growth conditions were evaluated to reduce the presence of residual phases different to the SnS orthorhombic phase. X-ray diffraction spectra revealed the polycrystalline nature of the SnS films with orthorhombic structure and a preferential grain orientation along the (111) direction. At high substrate temperature (450°C), a crystalline phase corresponding to the Sn2S3 phase was observed. Raman spectroscopy confirmed the dominance of the SnS phase and the presence of an additional Sn2S3 phase. Scanning electron microscopy (SEM) images reveal that the SnS film morphology depends on the substrate temperature. Between 250°C and 350°C, SnS films were shaped as rounded grains with some cracks between them, while at substrate temperatures above 400°C, films were denser and more compact. Energy-dispersive x-ray spectroscopy (EDS) analysis showed that the stoichiometry of sprayed SnS films improved with the increase of substrate temperature and atomic force microscopy micrographs showed films well covered at 350°C resulting in a rougher and bigger grain size. Optical and electrical measurements showed that the optical bandgap and the resistivity decreased when the substrate temperature increased, and smaller values, 1.46 eV and 60 Ω cm, respectively, were attained at 450°C. These SnS thin films could be used as an absorber layer for the development of tandem solar cell devices due to their high absorbability in the visible region with optimum bandgap energy.

  16. Nanostructured p-type CZTS thin films prepared by a facile solution process for 3D p-n junction solar cells.

    Science.gov (United States)

    Park, Si-Nae; Sung, Shi-Joon; Sim, Jun-Hyoung; Yang, Kee-Jeong; Hwang, Dae-Kue; Kim, JunHo; Kim, Gee Yeong; Jo, William; Kim, Dae-Hwan; Kang, Jin-Kyu

    2015-07-07

    Nanoporous p-type semiconductor thin films prepared by a simple solution-based process with appropriate thermal treatment and three-dimensional (3D) p-n junction solar cells fabricated by depositing n-type semiconductor layers onto the nanoporous p-type thin films show considerable photovoltaic performance compared with conventional thin film p-n junction solar cells. Spin-coated p-type Cu2ZnSnS4 (CZTS) thin films prepared using metal chlorides and thiourea show unique nanoporous thin film morphology, which is composed of a cluster of CZTS nanograins of 50-500 nm, and the obvious 3D p-n junction structure is fabricated by the deposition of n-type CdS on the nanoporous CZTS thin films by chemical bath deposition. The photovoltaic properties of 3D p-n junction CZTS solar cells are predominantly affected by the scale of CZTS nanograins, which is easily controlled by the sulfurization temperature of CZTS precursor films. The scale of CZTS nanograins determines the minority carrier transportation within the 3D p-n junction between CZTS and CdS, which are closely related with the photocurrent of series resistance of 3D p-n junction solar cells. 3D p-n junction CZTS solar cells with nanograins below 100 nm show power conversion efficiency of 5.02%, which is comparable with conventional CZTS thin film solar cells.

  17. Nanomorph Silicon Thin Films Prepared by Using an HW-MWECR CVD System

    Institute of Scientific and Technical Information of China (English)

    HU Yue-Hui; MA Zhan-Jie; ZHOU Huai-En; ZHU Xiu-Hong; CHEN Guang-Hua; ZHOU Jian-Er; RONG Yan-Dong; LI Ying; SONG Xue-Mei; ZHANG Wen-Li; DING Yi; GAO Zhuo

    2005-01-01

    @@ We have prepared hydrogenated nano-amorph silicon (na-Si:H) films by using a hot-wire-assisted microwave electron-cyclotron-resonance (HW-MWECR) chemical vapour deposition (CVD) system. The films are deposited in two steps: in the first 9min, a hydrogenated amorphous silicon layer is deposited by using hydrogen-diluted silane with a concentration of SiH4/(SiH4+H2) = 20%, and then a nanocrystalline silicon (nc-Si) layer is deposited by using various highly hydrogen-diluted silane. The Raman TO-like mode peak of the films was found in the range 497-508 cm-1. When the silane concentration used for preparation of the nc-Si layer is 14.3%, the film has a large crystalline volume fraction of 65.4%, a wide optical band gap of 1.89eV and a low hydrogen content of 9.5at.%. Moreover, the na-Si:H films rather than nc-Si possess high photosensitivity of about 15.

  18. Preparation and characterization of a homemade Josephson junction prepared from a thin film sintered in a domestic microwave oven

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, Gustavo Quereza; Moreto, Jeferson Aparecido [Instituto Federal de Educacao, Ciencia e Tecnologia Goiano (IFGO), Rio Verde, GO (Brazil); Zadorosny, Rafael; Silveira, Joao Borsil; Carvalho, Claudio Luiz [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Ilha Solteira, SP (Brazil); Cena, Cicero Rafael, E-mail: gustavoquereza@yahoo.com.br [Instituto Federal de Educacao, Ciencia e Tecnologia de Sao Paulo (IFSP), Birigui, SP (Brazil)

    2016-03-15

    A homemade Josephson junction was successfully obtained using a superconductor thin film of the BSCCO system. The film was deposited on a lanthanum aluminate, produced from a commercial powder with a nominal composition Bi{sub 1.8}Pb{sub 0.4}Sr{sub 2}CaCu{sub 2}O{sub x}, was thermally treated by a domestic microwave oven. The XRD analysis of the film indicated the coexistence of Bi-2212 and Bi-2223 phases and SEM images revealed that a typical superconductor plate-like morphology was formed. From the electrical characterization, performed using DC four probes technique, it was observed an onset superconducting transition temperature measured around 81K. At the current-voltage characteristics curve, a step of electric current at zero-voltage could be observed, an indicative that the tunneling Josephson occurred. (author)

  19. Preparation of Ni doped ZnO thin films by SILAR and their characterization

    Science.gov (United States)

    Mondal, S.; Mitra, P.

    2013-02-01

    Pure and nickel (Ni) doped zinc oxide (NZO) thin films were deposited on glass substrates from ammonium zincate bath using successive ion layer adsorption and reaction (SILAR). Characterization techniques such as XRD, TEM, SEM and EDX were utilized to investigate the effect of Ni doping on the microstructure of Ni:ZnO thin films. Structural characterization by X-ray diffraction reveals the polycrystalline nature of the films. Particle size shows slightly decreasing trend with increasing nickel impurification. The average particle size for pure ZnO is 22.75 nm and it reduces to 20.51 nm for 10 % Ni doped ZnO. Incorporation of Ni was confirmed from elemental analysis using EDX. The value of fundamental absorption edge is 3.23 eV for pure ZnO and it decreases to 3.19 eV for 10 % Ni:ZnO. The activation energy barrier value to electrical conduction process increases from 0.261 eV for pure ZnO to 0.293 eV for 10 % Ni doped ZnO.

  20. Photocatalytic activity of cobalt-doped zinc oxide thin film prepared using the spray coating technique

    Science.gov (United States)

    Sutanto, Heri; Wibowo, Singgih; Hadiyanto; Arifin, Mohammad; Hidayanto, Eko

    2017-07-01

    We report on the synthesis, characterization and photocatalytic activity of ZnO: Co thin films coated onto amorphous glass substrates by sol-gel spray coating technique. Structural and optical properties of the films were evaluated using x-ray diffractometer (XRD) and uv-vis spectrophotometer (UV-Vis), respectively. XRD patterns showed that the samples exhibited hexagonal wurtzite structure. The addition of cobalt reduced the (0 0 2) peak. This doping also reduces transparency and optical band gap. The band gap (E g) markedly decreased from 3.20 eV to 3.00 eV for undoped ZnO and ZnO: Co with 10 mol% of doping concentration, respectively. Our thin films exhibited good structural, optical and photo cataytic properties. In this study, ZnO with 4 mol% of Co was observed to have the highest photocatalytic activity with methylene blue (MB) degradation of about 76.31% for 2 h under UV irradiation.

  1. Optical characteristics of ZnS {sub x}Se{sub 1-x} thin films prepared by electron beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Abo-Hassan, Khedr M.M. [Department of Physics and Mathematics, School of Engineering, UCSI, Lot 18113, Off Jalan Cerdas, Taman Connaught, 56000 Cheras, Kuala Lumpur (Malaysia)]. E-mail: khedr@ucsi.edu.my; Muhamad, M.R. [Department of Physics, University of Malaya, K.L. Malaysia (Malaysia); Radhakrishna, S

    2005-11-22

    The optical transmission measurements are used to determine various optical constants and properties of ZnS {sub x}Se{sub 1-x} thin films prepared by electron beam evaporation onto glass substrates at 60 deg. C. The dispersion of the complex refractive index, the complex dielectric function and the absorption coefficient is studied in the transparent region of the spectrum and compared with the theoretical results calculated based on the model dielectric function. The fundamental optical energy gap is estimated by fitting the absorption coefficient data in the high absorption region to the direct transition expression. The variation of the energy gap with the composition in the film is investigated and compared with the results reported previously by other workers. The shift in the energy gap caused by the uniaxial stress inside the film and the grain size effect is estimated.

  2. Thin Film & Deposition Systems (Windows)

    Data.gov (United States)

    Federal Laboratory Consortium — Coating Lab: Contains chambers for growing thin film window coatings. Plasma Applications Coating Lab: Contains chambers for growing thin film window coatings. Solar...

  3. Thin Film & Deposition Systems (Windows)

    Data.gov (United States)

    Federal Laboratory Consortium — Coating Lab: Contains chambers for growing thin film window coatings. Plasma Applications Coating Lab: Contains chambers for growing thin film window coatings. Solar...

  4. [Effects of Temperature on the Preparation of Al/Zn3N2 Thin Films Using Magnetron Reactive Sputtering].

    Science.gov (United States)

    Feng, Jun-qin; Chen, Jun-fang

    2015-08-01

    The effects of substrate temperature on the plasma active species were investigated by plasma optical emission spectroscopy. With increasing substrate temperature, the characteristic spectroscopy intensity of the first positive series of N2* (B(3)Πg-->A(3)Σu(+)), the second positive N2* (C(3)Πu-->B(3)Πg), the first negative series N2(+)* (B(2)Σu(+)-->X(2)Σg(+)) and Zn* are increased. Due to the substrate temperature, each ion kinetic energy is increased and the collision ionization intensified in the chamber. That leading to plasma ion density increase. These phenomenons's show that the substrate temperature raises in a certain range was conducive to zinc nitride thin films growth. Zn3N2 thin films were prepared on Al films using ion sources-assisted magnetron sputtering deposition method. The degree of crystalline of the films was examined with X-ray diffraction (XRD). The results show that has a dominant peak located at 34.359° in room temperature, which was corresponding to the (321) plane of cubic anti-bixbyite zinc nitride structure (JCPDS Card No35-0762). When the substrate temperature was 100 °C, in addition to the (321) reflection, more diffraction peaks appeared corresponding to the (222), (400) and (600) planes, which were located at 31.756°, 36.620° and 56.612° respectively. When the substrate temperature was 200 °C, in addition to the (321), (222), (400) and (600) reflection, more new diffraction peaks also appeared corresponding to the (411), (332), (431) and (622) planes, which were located at 39.070, 43.179°, 47.004° and 62.561° respectively. These results show the film crystalline increased gradually with raise the substrate temperature. XP-1 profilometer were used to analyze the thickness of the Zn3N2 films. The Zn3N2 films deposited on Al films in mixture gas plasma had a deposition rate of 2.0, 2.2, and 2.7 nm · min(-1). These results indicate that the deposition rate was gradually enhanced as substrate temperature increased

  5. Preparation of Aluminum Nanomesh Thin Films from an Anodic Aluminum Oxide Template as Transparent Conductive Electrodes

    Science.gov (United States)

    Li, Yiwen; Chen, Yulong; Qiu, Mingxia; Yu, Hongyu; Zhang, Xinhai; Sun, Xiao Wei; Chen, Rui

    2016-02-01

    We have employed anodic aluminum oxide as a template to prepare ultrathin, transparent, and conducting Al films with a unique nanomesh structure for transparent conductive electrodes. The anodic aluminum oxide template is obtained through direct anodization of a sputtered Al layer on a glass substrate, and subsequent wet etching creates the nanomesh metallic film. The optical and conductive properties are greatly influenced by experimental conditions. By tuning the anodizing time, transparent electrodes with appropriate optical transmittance and sheet resistance have been obtained. The results demonstrate that our proposed strategy can serve as a potential method to fabricate low-cost TCEs to replace conventional indium tin oxide materials.

  6. Preparation and photochromic behavior of crosslinked polymer thin films containing polyoxometalates

    Energy Technology Data Exchange (ETDEWEB)

    Chen Jie; Liu Yan; Xiong Deqi [College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026 (China); Feng Wei [College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026 (China)], E-mail: weifeng@newmail.dlmu.edu.cn; Cai Weimin [College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026 (China)

    2008-03-31

    A series of reversible photochromic nanocomposite films were prepared by entrapping phosphotungstic acid (PWA) and molybdenumphsophoric acid (PMoA) into P(VP-BVA), which was a crosslinked polymer based on N-vinylpyrrolidone (VP) and bisvinyl-A (BVA). The microstructure, photochromic behavior and mechanism of the films were studied with transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectra (UV-vis) and electron resonance spectra (ESR). The TEM image showed that the polyoxometalates particles had regular microstructure with narrow size distribution (average diameter of 30 nm) in hybrid films. FT-IR results showed that the Keggin geometry of polyoxometalates (POM) was still preserved inside the composites and strong coulombic interaction between POM and crosslinked polymer matrix was built. Irradiated with ultraviolet light, the transparent films changed from colorless to blue and showed reversible photochromism. Oxygen plays an important role during the bleaching process. PMoA/P(VP-BVA) film had higher photochromic efficiency and slower bleaching reaction than PWA/P(VP-BVA) film. The characteristic signals of W (V) or Mo (V) in ESR spectra indicated that electron transfer occurred between the organic substrates and heteropolyanions under UV irradiation, which induced heteropolyanions to heteropolybules with simultaneous oxidation of the organic substrates.

  7. Hydrogenated Nanocrystalline Silicon Thin Films Prepared by Hot-Wire Method with Varied Process Pressure

    Directory of Open Access Journals (Sweden)

    V. S. Waman

    2011-01-01

    Full Text Available Hydrogenated nanocrystalline silicon films were prepared by hot-wire method at low substrate temperature (200∘C without hydrogen dilution of silane (SiH4. A variety of techniques, including Raman spectroscopy, low angle X-ray diffraction (XRD, Fourier transform infrared (FTIR spectroscopy, atomic force microscopy (AFM, and UV-visible (UV-Vis spectroscopy, were used to characterize these films for structural and optical properties. Films are grown at reasonably high deposition rates (>15 Å/s, which are very much appreciated for the fabrication of cost effective devices. Different crystalline fractions (from 2.5% to 63% and crystallite size (3.6–6.0 nm can be achieved by controlling the process pressure. It is observed that with increase in process pressure, the hydrogen bonding in the films shifts from Si–H to Si–H2 and (Si–H2n complexes. The band gaps of the films are found in the range 1.83–2.11 eV, whereas the hydrogen content remains <9 at.% over the entire range of process pressure studied. The ease of depositing films with tunable band gap is useful for fabrication of tandem solar cells. A correlation between structural and optical properties has been found and discussed in detail.

  8. Low-dielectric, nanoporous polyimide thin films prepared from block copolymer templating

    Directory of Open Access Journals (Sweden)

    C. Wang

    2013-08-01

    Full Text Available In this paper, a new method to the preparation of low-dielectric nanoporous polyimide (PI films was addressed, based on the self-assembly structures of PS-b-P4VP/poly(amic acid (PAA, precursor of PI blends. It is found the microphase-separation structure of PS-b-P4VP/PAA is a precondition of the formation of nanoporous structures, which could be achieved by solvent annealing. Nanoporous PI films with spherical pore size of ~11 nm were obtained by thermal imidization followed by the removal of the PS-b-P4VP block copolymer. The porosity of the nanoporous PI films could be controlled by the weight fraction of the PS-b-P4VP block copolymer. The dielectric properties of the nanoporous PI films were studied, and it was found that the introduction of nanopores could effectively reduce the dielectric constant from 3.60 of dense PI films to 2.41 of nanoporous PI films with a porosity of 26%, making it promising in microelectronic devices. The fabrication method described here could be extended to other polymer systems.

  9. Preparation of bismuth telluride thin film by electrochemical atomic layer epitaxy(ECALE)

    Institute of Scientific and Technical Information of China (English)

    ZHU Wen; YANG Junyou; GAO Xianhui; HOU Jie; BAO Siqian; FAN Xian

    2007-01-01

    Thin-layer electrochemical studies of the underpotential deposition(UPD)of Bi and Te on cold rolled silver substrate have been performed.The voltammetric analysis of underpotential shift demonstrates that the initial Te UPD on Bi-covered Ag and Bi UPD on Te-covered Ag fitted UPD dynamics mechanism.A thin film of bismuth telluride was formed by alternately depositing Te and Bi via an automated flow deposition system.X-ray diffraction indicated the deposits of Bi2Te3.Energy Dispersive X-ray Detector quantitative analysis gave a 2:3 stoichiornetric ratio of Bi to Te,which was consistent with X-ray Diffraction results.Electron probe microanalysis of the deposits showed a network structure that results from the surface defects of the cold rolled Ag substrate and the lattice mismatch between substrate and deposit.

  10. Metal-insulator transition in Mg-doped SrRuO{sub 3} thin films prepared by laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Crandles, D A; Yazdanian, Mohammad Mehdi; Razavi, F S [Department of Physics, Brock University, St Catharines, ON L2S 3A1 (Canada)

    2006-01-07

    Thin films of magnesium doped SrRuO{sub 3} (Mg-SRO) have been successfully prepared by laser ablation on SrTiO{sub 3} (100) substrates. The stoichiometry, structural, electrical and magnetic properties of the films depend on the substrate temperature (T{sub s}) and oxygen pressure (P{sub O{sub 2}}) during deposition. All Mg-SRO films are ferromagnetic, but the transport properties and remanent moments vary with T{sub s} and P{sub O{sub 2}}. Metallic films are produced for T{sub s} {>=} 700 deg. C whereas insulating films can be produced with T{sub s} = 500 deg. C with P{sub O{sub 2}}{>=}27 Pa. A correlation between lattice parameter, stoichiometry and transport properties has been discovered: the larger lattice parameter correlates with the decreased Ru content and more insulating samples. Insulating samples prepared at T{sub s} = 500 deg. C and P{sub O{sub 2}}{>=}27 Pa have stoichiometry close to the SrMg{sub 0.15}Ru{sub 0.85}O{sub 3} and are ferromagnetic Anderson insulators with transport properties consistent with variable range hopping.

  11. Role of precursors on morphology and optical properties of ZnS thin films prepared by chemical spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Fenollosa, M.A. [Departamento de Fisica Aplicada, Universidad Politecnica de Valencia, Cami de Vera s/n, 46071 - Valencia (Spain)], E-mail: mhernan@fis.upv.es; Lopez, M.C. [Laboratorio de Materiales y Superficie (Unidad Asociada al CSIC), Dptos Fisica Aplicada and Dpto. Ingenieria Quimica, Facultad de Ciencias, Unversidad de Malaga, E29071 Malaga (Spain); Donderis, V. [Departamento de Ingenieria Electrica, Universidad Politecnica de Valencia, Cami de Vera s/n, 46071 - Valencia (Spain); Gonzalez, M.; Mari, B. [Departamento de Fisica Aplicada, Universidad Politecnica de Valencia, Cami de Vera s/n, 46071 - Valencia (Spain); Ramos-Barrado, J.R. [Laboratorio de Materiales y Superficie (Unidad Asociada al CSIC), Dptos Fisica Aplicada and Dpto. Ingenieria Quimica, Facultad de Ciencias, Unversidad de Malaga, E29071 Malaga (Spain)

    2008-02-15

    This study investigates the effect of different growth parameters on the structural and optical properties of ZnS thin films, prepared using spray pyrolysis. The films were prepared using different Zn:S ratios (between 1:1 and 1:6) and in different growth solutions: (A), zinc chloride and thiourea and (B) dehydrated zinc acetate and thiourea, both in distilled water. By varying the Zn:S ratio in the films, the optical properties (absorption and photoluminescence) show that different species are created during film growth. This was deduced from the wide emission band appearing in the green region of the photoluminescence spectra, and from the change in band gap, which varies between 3.2 and 3.5 eV. Films formed from solution (A) with a Zn:S ratio of 1:3 or 1:4 show the best morphology and transmission. ZnS has a wider band gap than other conventional II-VI semiconductors utilized in various electronic and optical devices and can be expected to provide a useful window layer of solar cells which leads to an improvement in overall efficiency by decreasing absorption loss.

  12. Properties of inductively coupled N2 plasma processed AlInN thin film prepared by post annealing of rf sputtered Al/InN stack

    Science.gov (United States)

    Shanmugan, S.; Mutharasu, D.

    2016-12-01

    InN is a potential material for low cost tandem solar cells and its combination with Si could make the cell conversion efficiency over 30%. Doping into InN is a promising method which alters the properties of InN thin film. In this work, InN thin film was deposited on Si substrate and the doping was achieved by stacking Al elemental layer on InN thin film followed by annealing process. The doped InN (AlInN) thin film was characterized and confirmed the formation of (002) and (103) oriented phases. The prepared AlInN thin film was plasma processed using Inductively coupled plasma (ICP) in presence of N2 gas and the surface and structural properties was modified. The N2 plasma was influenced the preferred orientation of AlInN thin film and their structural parameters such as crystallite size, strain and dislocation density noticeably. Very smooth surface (<4 nm) with small particle size (97 nm) of AlInN thin film was achieved for 15 sccm flow rate during the plasma process. Very low value in leakage current was confirmed for AlInN thin film processed at 15 sccm N2 flow by current-voltage (IV) characteristics.

  13. Preparation of GdBCO Thin Film by Ex-situ Process using Nitrate Precursors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byeong Joo; Le, Chul Sun; Lee, Jong Beom; Lee, Hee Gyoun; Hong, Gye Won [Korea Polytechnic University, Siheung (Korea, Republic of); Lee, Jae Hun; Moon, Sung Hyun [SuNAM Co., Anseong (Korea, Republic of)

    2011-12-15

    Many research groups have been manufacturing coated conductor by various processes such as PLD, MOD, and MOCVD, but the methods with production cost suitable for wide and massive application of coated conductor did not develop yet. Spray pyrolysis method adopting ultrasonic atomization was tried as one of the possible option. GdBCO precursor films have been deposited on IBAD substrate by spray pyrolysis method at low temperature and converted to GdBCO by post heat treatment. Ultrasonic atomization was used to generate fine droplets from precursor solution of Gd, Ba, and Cu nitrate dissolved in water. Primary GdBCO films were deposited at 500 degree C and oxygen partial pressure of 1 torr. After that, the films were converted at various temperatures and low oxygen partial pressures. C-Axis oriented films were obtained IBAD substrates at conversion temperature of around 870 degree C and oxygen partial pressures of 500 mtorr - 1 torr in a vacuum. Thick c-axis epitaxial film with the thickness of 0.4 - 0.5 {mu}m was obtained on IBAD substrate. C-axis epitaxial GdBCO films were successfully prepared by ex-situ methods using nitrate precursors on IBAD metal substrate. Converted GdBCO films have very dense microstructures with good grain connectivity. EDS composition analysis of the film showed a number of Cu-rich phase in surface. The precursor solution having high copper concent with the composition of Gd : Ba : Cu = 1 : 2 : 4 showed the better grain connectivity and electrical conductivity.

  14. TiO2:(Fe, S Thin Films Prepared from Complex Precursors by CVD, Physical Chemical Properties, and Photocatalysis

    Directory of Open Access Journals (Sweden)

    V. G. Bessergenev

    2012-01-01

    Full Text Available The TiO2 thin films were prepared using Ti(dpm2(OPri2 and Ti(OPri4 (dpm = 2,2,6,6-tetramethylheptane-3,5-dione, Pri = isopropyl as the precursors. The volatile compounds Fe[(C2H52NCS2]3 and [(CH3C]2S2 were used to prepare doped TiO2 films. The synthesis was done in vacuum or in the presence of Ar and O2. The pressure in the CVD chamber was varied between 1.2×10−4 mbar and 0.1 mbar, with the system working either in the molecular beam or gas flow regime. Physical, chemical, and photocatalytic properties of the (Fe, S-doped TiO2 films were studied. Those TiO2:(Fe, S films prepared from the Ti(OPri4 precursor show increased photocatalytic activities, very close to those of Degussa P25 powder in UV region.

  15. Studies of thin films of Ti- Zr -V as non-evaporable getter films prepared by RF sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Nidhi; Jagannath,; Sharma, R. K.; Gadkari, S. C.; Muthe, K. P.; Mukundhan, R.; Gupta, S. K. [Technical Physics Division, BARC Mumbai-400085 (India)

    2013-02-05

    Non-Evaporable Getter (NEG) films of the Ti-Zr-V prepared on stainless steel substrates by Radio Frequency sputtering. To observe its getter behavior at the lowest activation temperature, the sample is heated continuously at different temperatures (100 Degree-Sign C, 150 Degree-Sign C, 200 Degree-Sign C and 250 Degree-Sign C) for 2 hours. The changes of the surface chemical composition at different temperaturesare analyzed by using XPS and SEM (Scanning Electron Microscopy) techniques. The volume elemental composition of the film has been measured by energy dispersive X-ray spectroscopy (EDX). The in-situ XPS measurements of the activated getter films show the disappearance of the superficial oxide layer through the variation in the oxygen stoichiometry during thermal activation. Results of these studies show that the deposited films of Ti-Zr-V could be used as NEG to produce extreme high vacuum.

  16. Preparation of AgInSe2 thin films grown by vacuum evaporation method

    Science.gov (United States)

    Matsuo, H.; Yoshino, K.; Ikari, T.

    2006-09-01

    Polycrystalline AgInSe2 thin films were successfully grown on glass substrates by an evaporation method. The starting materials were stoichiometrically mixed Ag2Se and In2Se3 powders. X-ray diffraction revealed that the sample annealed at 600 °C consisted of AgInSe2 single phase, with (112) orientation and a large grain size. The lattice constant (a axis) was close to JCPDS values. From optical transmittance and reflectance measurements, the bandgap energy was estimated to be 1.17 eV.

  17. Preparation of Copper (Cu)-Nickel (Ni) Alloy Thin Films for Bilayer Graphene Growth

    Science.gov (United States)

    2016-02-01

    10. SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release... morphological changes in the metal surfaces such as roughness, grain size, and crystal orientation due to the effects of annealing temperature, hydrogen...Ni thin film a) sputtered at 5 mT and 25 °C and b) sputtered at 15 mT and 400 °C 3.2 Grain Growth Characterization The morphology of the as

  18. Preparation of Cu(In,Ga)(S,Se){sub 2} thin films by sequential evaporation and annealing in sulfur atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Toshiyuki; Asai, Yasutaka; Oku, Naoyuki [Wakayama National College of Technology, 77 Noshima, Nada-cho, Gobo-shi, Wakayama 6440023 (Japan); Niiyama, Shigetoshi; Imanishi, Toshito [Industrial Technology Center of Wakayama Prefecture, 60 Ogura, Wakayama-shi 6496261 (Japan); Nakamura, Shigeyuki [Tsuyama National College of Technology, Tsuyama-shi 708-8509 (Japan)

    2011-01-15

    Cu(In,Ga)(S,Se){sub 2} thin films with high Ga/III ratio (around 0.8) were prepared by sequential evaporation from CuGaSe{sub 2}, CuInSe{sub 2}, In{sub 2}Se{sub 3} and Ga{sub 2}Se{sub 3} compounds and then annealing in H{sub 2}S gas atmosphere. The annealing temperature was varied from 400 to 500 C. These samples were characterized by means of XRF, EPMA, XRD and SEM. The S/(S+Se) mole ratio in the thin films increased with increase in the annealing temperature, keeping the Cu, In and Ga contents nearly constant. The open circuit voltage increased and the short circuit current density decreased with increase in the annealing temperature. The best solar cell using Cu(In,Ga)(S,Se){sub 2} thin film with Ga/(In+Ga)=0.79 and S/(S+Se)=0.11 annealed at 400 C demonstrated V{sub oc}=535 mV, I{sub sc}=13.3 mA/cm{sup 2}, FF=0.61 and efficiency=4.34% without AR-coating. (author)

  19. Preparation and Characterization of NiO Thin Films by DC Reactive Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    Y. Ashok Kumar Reddy

    2012-12-01

    Full Text Available Nickel oxide (NiO thin films were successfully deposited on Corning 7059 glass substrates at different oxygen partial pressures in the range of 1 × 10 – 4 to 9 × 10 – 4 mbar using dc reactive magnetron sputtering technique. Structural properties of NiO films showed polycrystalline nature with cubic structure along (220 orientation. The optical transmittance and band gap values of the films increased with increasing the oxygen partial pressure from 1 × 10 – 4 to 5 × 10 – 4 mbar and decreased on further increasing the oxygen partial pressure. Using Scanning Electron Microscopy (SEM, fine grains were observed at oxygen partial pressure of 5 × 10 – 4 mbar. The film resistivity decreases from 90.48 to 13.24 Ω cm with increase in oxygen partial pressure to 5 × 10 – 4 mbar and then increased on further increasing the oxygen partial pressure.

  20. Preparation of cadmium-doped ZnO thin films by SILAR and their characterization

    Indian Academy of Sciences (India)

    S Mondal; P Mitra

    2012-10-01

    Cadmium-doped zinc oxide (Cd : ZnO) thin films were deposited from sodium zincate bath following a chemical dipping technique called successive ion layer adsorption and reaction (SILAR). Structural characterization by X-ray diffraction reveals that polycrystalline nature of the films increases with increasing cadmium incorporation. Particle size evaluated using X-ray line broadening analysis shows decreasing trend with increasing cadmium impurification. The average particle size for pure ZnO is 36.73nm and it reduces to 29.9 nm for 10% Cd:ZnO, neglecting strain broadening. The strong preferred c-axis orientation is lost due to cadmium doping and degree of polycrystallinity of the films also increases with increasing Cd incorporation. Incorporation of cadmium was confirmed from elemental analysis using EDX. The optical bandgap of the films decreases with increasing Cd dopant. The value of fundamental absorption edge is 3.18 eV for pure ZnO and it decreases to 3.11 eV for 10% Cd:ZnO.

  1. Study of cobalt mononitride thin films prepared using DC and high power impulse magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Rachana, E-mail: dr.rachana.gupta@gmail.com [Institute of Engineering & Technology, DAVV, Khandwa Road, Indore – 452 017 (India); Pandey, Nidhi; Behera, Layanta; Gupta, Mukul [UGC-DAE Consortium for Scientific Research, Khandwa Road, University Campus, Indore-452001 (India)

    2016-05-23

    In this work we studied cobalt mononitride (CoN) thin films deposited using dc magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS). A Co target was sputtered using pure N{sub 2} gas alone as the sputtering medium. Obtained long-range structural ordering was studies using x-ray diffraction (XRD), short-range structure using Co L{sub 2,3} and N K absorption edges using soft x-ray absorption spectroscopy (XAS) and the surface morphology using atomic force microscopy (AFM). It was found that HiPIMS deposited films have better long-range ordering, better stoichiometric ratio for mononitride composition and smoother texture as compared to dcMS deposited films. In addition, the thermal stability of HiPIMS deposited CoN film seems to be better. On the basis of different type of plasma conditions generated in HiPIMS and dcMS process, obtained results are presented and discussed.

  2. Silicon template preparation for the fabrication of thin patterned gold films via template stripping

    Science.gov (United States)

    Schmidl, G.; Dellith, J.; Dellith, A.; Teller, N.; Zopf, D.; Li, G.; Dathe, A.; Mayer, G.; Hübner, U.; Zeisberger, M.; Stranik, O.; Fritzsche, W.

    2015-12-01

    Metallic nanostructures play an important role in the vast field of modern nanophotonics, which ranges from the life sciences to biomedicine and beyond. Gold is a commonly-used and attractive material for plasmonics in the visible wavelength range, most importantly due to its chemical stability. In the present work, we focused on the different methods of plasmonic nanostructure fabrication that possess the greatest potential for cost-efficient fabrication. Initially, reusable (1 0 0) silicon templates were prepared. For this purpose, three different lithography methods (i.e. e-beam, optical, and nanoparticle lithography) were used that correspond to the desired structural scales. The application of a subsequent anisotropic crystal orientation-dependent wet etching process produced well-defined pyramidal structures in a wide variety of sizes, ranging from several microns to less than 100 nm. Finally, a 200 nm-thick gold layer was deposited by means of confocal sputtering on the silicon templates and stripped in order to obtain gold films that feature a surface replica of the initial template structure. The surface roughness that was achieved on the stripped films corresponds well with the roughness of the template used. This makes it possible to prepare cost-efficient high-quality structured films in large quantities with little effort. The gold films produced were thoroughly characterized, particularly with respect to their plasmonic response.

  3. Studies of Nano-structured Se77Sb23- x Ge x Thin Films Prepared by Physical Vapor Condensation Technique

    Science.gov (United States)

    Alvi, M. A.

    2017-02-01

    Bulk Se77Sb23- x Ge x material with x = 4 and 12 was prepared by employing a melt quench technique. Its amorphous as well as glassy nature was confirmed by x-ray diffraction analysis and nonisothermal differential scanning calorimetry measurements. The physical vapor condensation technique was applied to prepare nanostructured thin films of Se77Sb23- x Ge x material. The surface morphology of the films was examined using field-emission scanning electron microscopy, revealing average particle size between 20 nm and 50 nm. Systematic investigation of optical absorption data indicated that the optical transition was indirect in nature. The dark conductivity (dc conductivity) of nano-structured Se77Sb23- x Ge x thin films was also investigated at temperatures from 313 K to 463 K, revealing that it tended to increase with increasing temperature. Analyses of our experimental data also indicate that the conduction is due to thermally supported tunneling of charge carriers in confined states close to the band edges. The calculated values of activation energy agree well with the optical bandgap.

  4. PREPARATION OF PHOTOFUNCTIONAL POLYMER THIN FILMS BY LANGMUIR-BLODGETT TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    Tokuji Miyashita; Tatsuo Taniguchi; Yoshihito Fukasawa

    1999-01-01

    Polymer LB films containing photofuntional groups were prepared by the copolymerization of N-dodecylacrylamide (DDA), which has an excellent property to form a stable monolayer and LB multilayers with photofunctional monomers. Tris(2, 2'-bipyridine) ruthenium complex, Ru(bpy)32+, one of the most wellknown redox-active sensitizer, was incorporated into the DDA copolymer. The photogalvanic effect based on the photoinduced electron transfer using the ruthenium complex in the polymer LB monolayer was discussed.

  5. A Study of Thin Film Resistors Prepared Using Ni-Cr-Si-Al-Ta High Entropy Alloy

    Directory of Open Access Journals (Sweden)

    Ruei-Cheng Lin

    2015-01-01

    Full Text Available Ni-Cr-Si-Al-Ta resistive thin films were prepared on glass and Al2O3 substrates by DC magnetron cosputtering from targets of Ni0.35-Cr0.25-Si0.2-Al0.2 casting alloy and Ta metal. Electrical properties and microstructures of Ni-Cr-Si-Al-Ta films under different sputtering powers and annealing temperatures were investigated. The phase evolution, microstructure, and composition of Ni-Cr-Si-Al-Ta films were characterized by X-ray diffraction (XRD, transmission electron microscopy (TEM, and Auger electron spectroscopy (AES. When the annealing temperature was set to 300°C, the Ni-Cr-Si-Al-Ta films with an amorphous structure were observed. When the annealing temperature was at 500°C, the Ni-Cr-Si-Al-Ta films crystallized into Al0.9Ni4.22, Cr2Ta, and Ta5Si3 phases. The Ni-Cr-Si-Al-Ta films deposited at 100 W and annealed at 300°C which exhibited the higher resistivity 2215 μΩ-cm with −10 ppm/°C of temperature coefficient of resistance (TCR.

  6. Preparation and characterization of polyaniline/indium(III) oxide (PANi/In2O3) nanocomposite thin film

    Science.gov (United States)

    Yan, Xiaolei; Xie, Guangzhong; Du, Xiaosong; Tai, Huiling; Jiang, Yadong

    2009-05-01

    In the last few decades, conductive polymers such as polyaniline, polypyrrole, and polythiophene have been widely investigated as effective sensitive materials for chemical gas sensors. Among them, polyaniline (PANI) is frequently used because of its ease and cheap of synthesis, environmental stability and intrinsic redox reaction. However, problems with these conductive polymers include their low processing ability, poor mechanical strength and chemical stability. There are tremendous approaches for the enhancement of mechanical strength and chemical stability of organic materials by combining organic materials with inorganic counterparts in nano-size to form composite materials..which would optimize the characteristics of gas sensors. In the paper, polyaniline/Indium(III) Oxide(PANi/In2O3) nanocomposite thin films was prepared on a quartz substrate by combination techniques of electrostatic self-assembly and in situ chemical oxidation polymerization at 10°C. Infrared spectrum analysis (IR) of the composite and scanning electron microscope(SEM) of nanocomposite thin films were performed. PANi/In2O3 nanocomposite thin film gas sensor was fabricated on AT-Cut quartz crystal microbalance(QCM) of Ag electrodes, and the sensitive properties of gas sensor to CH4 and CO are characterized and analyzed. The results indicate that PANi/In2O3 thin film gas sensor has good linear sensitive property to CH4 and CO, and is more sensitive to CH4, i.e., the sensitivity is 0.386Hz per ppm when the sensor is exposed to 500 ppm CH4 while only 0.16Hz per ppm to the same concentration of CO. Such sensitive properties of gas sensor in the constant concentration of CH4 at different temperature are also characterized. The result shows that temperature would affect the sensitive property of gas sensor.

  7. Correlation between structural and electrical properties of PLD prepared ZnO thin films used as a photodetector material

    Energy Technology Data Exchange (ETDEWEB)

    Triolo, C., E-mail: trioloc@unime.it [Dipartimento di Fisica e di Scienze della Terra, Università degli Studi di Messina, Viale F. Stagno d‘Alcontres 31, 98166, Messina (Italy); Fazio, E.; Neri, F.; Mezzasalma, A.M. [Dipartimento di Fisica e di Scienze della Terra, Università degli Studi di Messina, Viale F. Stagno d‘Alcontres 31, 98166, Messina (Italy); Trusso, S. [CNR-IPCF Istituto per i Processi Chimico-Fisici, Viale F. Stagno d’Alcontres 37, 98158, Messina (Italy); Patanè, S. [Dipartimento di Fisica e di Scienze della Terra, Università degli Studi di Messina, Viale F. Stagno d‘Alcontres 31, 98166, Messina (Italy)

    2015-12-30

    Highlights: • ZnO thin filmswere deposited by pulsed laser ablation from a metallic zinc target in a controlled oxygen atmosphere in shock wave regime. • The samples morphology is tuned, varying the growth temperature. • The transport properties were measured at RT and at 30 K under vacuumboth illuminating the sample by an UV laser and in dark conditions. • All samples are sensible to the UV radiations; the oxygen chemisorbed on the grain surface affects the speed of photoresponse. - Abstract: The electrical transport properties of a set of zinc oxide (ZnO) thin films, prepared by pulsed laser ablation, were investigated at the temperatures of 30 K and 300 K. Information about the structural and morphological properties of the samples were obtained by means of atomic force microscopy (AFM) and X-ray diffraction (XRD). A significant variation in the surface morphology and photoresponse characteristics of the ZnO thin films were observed as a function of the deposition temperature. Upon increasing the deposition temperature, the surface topography changes from a more fine-grained to a more coarse-grained structure, showing a tetragonal wurtzite crystalline structure. Time resolved photocurrent measurements showed significantly variations as function of the observed samples morphologies. A photocurrent value of about three order of magnitude larger is observed for samples showing a more coarse-grained structure with respect to the fine-grained ones. Such a result is interpreted as due to the contributions of both “bulk” and defect centers that affect the conduction mechanisms and influence both the photoconductivity values and the photoresponse speed. The observed decay times are very long with respect to films grown by other techniques, due to the reduction of the surface localized centers of defect available for recombination. In this context, the sample morphology appears to be a key parameter to control the photoconductivity in ZnO thin films.

  8. Low-temperature Preparation of Photocatalytic TiO2 Thin Films on Polymer Substrates by Direct Deposition from Anatase Sol

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Anatase TiO2 sol was synthesized under mild conditions (75C and ambient pressure) by hydrolysis of titaniumn-butoxide in abundant acidic aqueous solution and subsequent reflux to enhance crystallization. At room temperature and in ambient atmosphere, crystalline TiO2 thin films were deposited on polymethylmethacrylate (PMMA), SiO2-coated PMMA and SiO2-coated silicone rubber substrates from the as-prepared TiO2 sol by a dip-coating process. SiO2 layers prior to TiO2 thin films on polymer substrates could not only protect the substrates from the photocatalytic decomposition of the TiO2 thin films but also enhance the adhesion of the TiO2 thin films to the substrates. Field-emission type scanning electron microscope (FE-SEM) investigations revealed that the average particle sizes of the nanoparticles composing the TiO2 thin films were about 35~47 nm. The TiO2 thin films exhibited high photocatalytic activities in the degradation of reactive brilliant red dye X-3B in aqueous solution under aerated conditions. The preparation process of photocatalytic TiO2 thin films on the polymer substrates was quite simple and a low temperature route.

  9. Electrochemical performance of nanocrystalline LiMPO{sub 4} thin-films prepared by electrostatic spray deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Jun; Qin, Qi-Zong [Department of Chemistry, Laser Chemistry Institute, Fudan University, Shanghai 200433 (China)

    2005-09-15

    LiMPO{sub 4} (M=Mn, Fe) and LiMn{sub 0.4}Fe{sub 0.6}PO{sub 4} thin-films have been fabricated by electrostatic spray deposition (ESD) combined with sol-gel method, in which P{sub 2}O{sub 5} was used as a phosphorous resource in Li-M-P-O alcohol precursor solution. Analyses of LiMPO{sub 4} solid films using X-ray diffractometry (XRD) and scanning electron microscopy (SEM) demonstrated the formation of an olivine phase of space group Pmnb with nanocrystalline morphology. The prepared LiMPO{sub 4} films were evaluated electrochemically by cyclic-voltammetry and charge/discharge measurements. The results showed that thin-film electrode of LiMn{sub 0.4}Fe{sub 0.6}PO{sub 4} exhibited better electrochemical performance than that of pure LiFePO{sub 4} and LiMnPO{sub 4}. (author)

  10. PPHASE AND MORPHOLOGY FORMATION OF Na DOPED PMN THIN FILMS PREPARED BY MODIFIED SOL-GEL METHOD

    Directory of Open Access Journals (Sweden)

    HELENA BRUNCKOVÁ

    2013-03-01

    Full Text Available Na doped lead magnesium niobate Pb(Mg1/3Nb2/3O3 (Na-PMN thin films of 100 nm thickness were prepared by modified sol-gel route with niobium precursor. Na-PMN films were deposited from sol derived using tartaric acid modified polymerizable complex method by mixing of Nb-tartarate (Pechini complex with Na, Pb and Mg acetates at 80°C with molar ratio of Na : Pb : Mg : Nb = 1/2 : 1 :1/3 : 2/3 on Pt/Al2O3 substrates by spin-coating method. In Na doped PMN film the perovskite Pb(Mg1/3Nb2/3O3 phase (65 vol. % and a small amount of pyrochlore Na2Nb8O21 phase were revealed after sintering at 650°C. In the microstructure of 2-layered Na-PMN/Pt/Al2O3 thin film, with ~9.5 nm of roughness, the bimodal particle distribution was observed with small spherical particles of pyrochlore phase and larger sponge-like particles of the perovskite phase. The smallest visible spherical particles (~30 nm and mutually interconected particles (~125 nm were found in TEM and AFM micrographs.

  11. Structural and optical properties of Zn1−xNixTe thin films prepared by electron beam evaporation technique

    Directory of Open Access Journals (Sweden)

    Arshad Mahmood

    2015-02-01

    Full Text Available Zn1−xNixTe thin films with different composition (x=0.0, 0.05, 0.10, 0.15 and 0.20 were deposited on glass substrate by electron beam evaporation technique followed by its characterization using advanced structural and optical analysis techniques. Structural properties of the prepared thin films were studied by X-ray diffraction (XRD. The XRD patterns revealed that the binary compounds transformed into a ternary compound with cubic structure having preferred orientation along the c-direction with (111 planes. Composition analysis of the films was determined by energy dispersive analysis of X-rays (EDAX and found to be in agreement with the precursor composition. Optical properties such as extinction coefficient (k and band gap energy of these films were examined by using a spectroscopic ellipsometer. It was found that the extinction coefficient (k increased with the addition of Ni content in the alloy. In comparison, the band gap energy was also determined by using transmission spectra and found to be agreed with that of the ellipsometric results. These analyses confirm that the band gap energy decreases with the increase of Ni content in the alloy.

  12. Annealing effect of thermal spike in MgO thin film prepared by cathodic vacuum arc deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Daoyun, E-mail: zhudy@gdut.edu.cn [Experiment Teaching Department, Guangdong University of Technology, Guangzhou 510006 (China); State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Zhao, Shoubai [School of Physics and Electronic Engineering, Guangzhou University, Guangzhou 510400 (China); Zheng, Changxi; Chen, Dihu [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); He, Zhenhui, E-mail: stshzh@mail.sysu.edu.cn [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

    2013-12-16

    MgO films were prepared by using pulsed cathodic vacuum arc deposition technique. The substrate bias voltage was in the range of −150 to −750 V. Film structure was investigated by X-ray diffraction (XRD). The annealing effect of thermal spike produced by the impacting of energetic ions was analyzed. The calculated results showed that the lifetime of a thermal spike generated by an energetic ion with the energy of 150 eV was less than one picosecond and it was sufficient to allow Mg{sup 2+} or O{sup 2-} to move one bond length to satisfy the intrinsic stress relief in the affected volume. The MgO(200) lattice spacings of the films deposited at different bias voltages were all larger than the ideal value of 2.1056 Å. As the bias amplitude increased the lattice spacing decreased, which indicated that the compressive stress in the film was partially relieved with increasing impacting ion energy. The stress relief also could be reflected from the film orientation with bias voltage. The biaxial elastic modulus for MgO(100), MgO(110) and MgO(111) planes were calculated and they were M{sub (100)} = 199 GPa, M{sub (110)} = 335 GPa and M{sub (111)} = 340 GPa, respectively. The M values indicated that the preferred orientation will be MgO(200) due to the minimum energy configuration when the lattice strain was large. It was confirmed by the XRD results in our experiments. - Highlights: • MgO thin films with preferred orientation were obtained by CVAD technique. • Annealing effect of a thermal spike in MgO film was discussed. • Lattice spacing of MgO film decreased with the increase of bias voltage. • Film preferred orientation changed from (200) to (220) as the bias voltage increased.

  13. Nanoparticle Thin Films for Gas Sensors Prepared by Matrix Assisted Pulsed Laser Evaporation

    Directory of Open Access Journals (Sweden)

    Roberto Rella

    2009-04-01

    Full Text Available The matrix assisted pulsed laser evaporation (MAPLE technique has been used for the deposition of metal dioxide (TiO2, SnO2 nanoparticle thin films for gas sensor applications. For this purpose, colloidal metal dioxide nanoparticles were diluted in volatile solvents, the solution was frozen at the liquid nitrogen temperature and irradiated with a pulsed excimer laser. The dioxide nanoparticles were deposited on Si and Al2O3 substrates. A rather uniform distribution of TiO2 nanoparticles with an average size of about 10 nm and of SnO2 nanoparticles with an average size of about 3 nm was obtained, as demonstrated by high resolution scanning electron microscopy (SEM-FEG inspections. Gas-sensing devices based on the resistive transduction mechanism were fabricated by depositing the nanoparticle thin films onto suitable rough alumina substrates equipped with interdigitated electrical contacts and heating elements. Electrical characterization measurements were carried out in controlled environment. The results of the gas-sensing tests towards low concentrations of ethanol and acetone vapors are reported. Typical gas sensor parameters (gas responses, response/recovery time, sensitivity, and low detection limit towards ethanol and acetone are presented.

  14. Preparation of 3 Inch Double-Sided YBa2Cu3O7-X High Temperature Superconducting Thin Films

    Institute of Scientific and Technical Information of China (English)

    TAO Bo-wan

    2005-01-01

    @@ Owing to its excellent electrical property,YBCO thin film is much better than metal in the application for microwave devices. It makes the devices smaller, lighter, and with higher quality factor and lower insertion loss. YBCO thin film has attracted attentions for many years. Aiming at the uniformity and property of 3-inch double-sided YBCO thin film, the following aspects is considered in this dissertation:

  15. Preparation and characterization of epitaxial thin films and patterned nanostructures of Ni/Cu and Fe/Cu

    OpenAIRE

    Corredor, Edna C.

    2012-01-01

    El objetivo del trabajo realizado en esta tesis titulada: Preparation and magnetic characterization of epitaxial thin films and patterned nanostructures of Ni/Cu and Fe/Cu es establecer relaciones entre las propiedades magnéticas de sistemas nanoestructurados y sus dimensiones físicas o factores estructurales que aparecen al reducirse la dimensión espacial a dos, en el caso de películas delgadas, y a una en el caso de elementos patronados. Los sistemas objeto de estudio se caracterizan por se...

  16. Preparation and characterization of epitaxial thin films and patterned nanostructures of Ni/Cu and Fe/Cu

    OpenAIRE

    Corredor Vega, Edna Consuelo; Ciria Remacha, Miguel Ángel; Arnaudas Pontaque, José Ignacio

    2013-01-01

    El objetivo del trabajo realizado en esta tesis titulada: Preparation and magnetic characterization of epitaxial thin films and patterned nanostructures of Ni/Cu and Fe/Cu es establecer relaciones entre las propiedades magnéticas de sistemas nanoestructurados y sus dimensiones físicas o factores estructurales que aparecen al reducirse la dimensión espacial a dos, en el caso de películas delgadas, y a una en el caso de elementos patronados. Los sistemas objeto de estudio se caracterizan por se...

  17. Biomimetic thin film synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Graff, G.L.; Campbell, A.A.; Gordon, N.R.

    1995-05-01

    The purpose of this program is to develop a new process for forming thin film coatings and to demonstrate that the biomimetic thin film technology developed at PNL is useful for industrial applications. In the biomimetic process, mineral deposition from aqueous solution is controlled by organic functional groups attached to the underlying substrate surface. The coatings process is simple, benign, inexpensive, energy efficient, and particularly suited for temperature sensitive substrate materials (such as polymers). In addition, biomimetic thin films can be deposited uniformly on complex shaped and porous substrates providing a unique capability over more traditional line-of-sight methods.

  18. Effect of substrate temperature on transparent conducting Al and F co-doped ZnO thin films prepared by rf magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Fang-Hsing, E-mail: fansen@dragon.nchu.edu.tw; Chang, Chiao-Lu

    2016-05-01

    Highlights: • Al and F co-doped ZnO (AFZO) thin films were prepared by rf magnetron sputtering. • Effects of substrate temperature on properties of AFZO films were investigated. • The AFZO films show a typical hexagonal wurtzite structure and are (0 0 2) oriented. • The AFZO thin film prepared at 200 °C exhibits a low resistivity of 2.88 × 10{sup −4} Ω-cm. • The average visible transmittances of all the AFZO thin films exceed 92%. - Abstract: ZnO is a wide bandgap semiconductor that has many potential applications such as solar cells, thin film transistors, light emitting diodes, and gas/biological sensors. In this study, a composite ceramic ZnO target containing 1 wt% Al{sub 2}O{sub 3} and 1.5 wt% ZnF{sub 2} was prepared and used to deposit transparent conducting Al and F co-doped zinc oxide (AFZO) thin films on glass substrates by radio frequency magnetron sputtering. The effect of substrate temperatures ranging from room temperature (RT) to 200 °C on structural, morphological, electrical, chemical, and optical properties of the deposited thin films were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), Hall effect measurement, X-ray photoelectron spectroscopy, secondary ion mass spectrometry, and UV–vis spectrophotometer. The XRD results showed that all the AFZO thin films had a (0 0 2) diffraction peak, indicating a typical wurtzite structure with a preferential orientation of the c-axis perpendicular to the substrate. The FE-SEM and AFM analyses indicated that the crystallinity and grain size of the films were enhanced while the surface roughness decreased as the substrate temperature increased. Results of Hall effect measurement showed that Al and F co-doping decreased the resistivity more effectively than single-doping (either Al or F doping) in ZnO thin films. The resistivity of the AFZO thin films decreased from 5.48 × 10{sup −4} to 2.88 × 10{sup −4}

  19. Preparation of Nano-crystalline Tungsten Carbide Thin Film by Magnetron Sputtering and Their Electrocatalytic Property for PNP Reduction

    Institute of Scientific and Technical Information of China (English)

    Hua Jun ZHENG; Jian Guo HUANG; Chun An MA

    2005-01-01

    Nano-crystalline tungsten carbide thin films were deposited on Ni substrates by magnetron sputtering using WC as target material. The crystal structure and morphology of the thin films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).Electrochemical investigations showed that the electrode of the thin film exhibited higher electrocatalytic activity in the reaction of p-nitrophenol (PNP) reduction. FT-IR analysis indicated that p-aminophenol (PAP) was synthesized after two step reduction of PNP on nano-crystalline tungsten carbide thin film electrode.

  20. Synthesis and characterization of thin film electroluminescent devices all-prepared by ultrasonic spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Ramírez, E.B. [Universidad Autónoma de la Ciudad de México, Calle Prolongación San Isidro Núm. 151, Col. San Lorenzo Tezonco, Iztapalapa 09790, D. F., México (Mexico); Bizarro, M. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, Coyoacán 04510, Distrito Federal, México (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, Distrito Federal, México (Mexico)

    2013-12-02

    Alternating current thin film electroluminescent devices have been fabricated using aluminum-doped zinc oxide (ZnO:Al) as transparent conducting layer, aluminum oxide (Al{sub 2}O{sub 3}) as insulating layers, and manganese-doped zinc sulfide (ZnS:Mn) as electroluminescent layer. All these films were deposited by the ultrasonic spray pyrolysis technique at the same temperature (450°) on glass substrates, forming a standard MISIM (metal–insulator–semiconductor–insulator–metal) configuration. The electroluminescence of MISIM devices with a total thickness of ∼ 1330 nm was investigated by applying a sinusoidal voltage with a frequency of 10 kHz. The devices showed orange-emission spectra centered at approximately 570 nm, characteristic of {sup 4}T{sub 1} → {sup 6}A{sub 1} radiative transitions of Mn{sup 2+} ions in the ZnS host, with a sharp intensity increase upon increasing the root mean square voltage above a threshold of 25 V and a rapid saturation for voltages higher than 38 V. The electroluminescent emission of these MISIM structures can be observed with the naked eye under ambient illumination. - Highlights: • Thin film electroluminescent devices were fabricated by ultrasonic spray pyrolysis at 450 °C. • The electroluminescent devices were fabricated on glass substrates. • ZnO:Al was used as transparent conductive layer. • ZnS:Mn and Al{sub 2}O{sub 3} were used as phosphor and insulating layers, respectively. • The electroluminescent devices have a low threshold operation voltage.

  1. Thin films of arylenevinylene oligomers prepared by MAPLE for applications in non-linear optics

    Energy Technology Data Exchange (ETDEWEB)

    Stanculescu, A., E-mail: sanca@infim.ro [National Institute of Materials Physics, Optics and Spectroscopy Laboratory, 105 bis Atomistilor Street, P.O. Box MG-7, Bucharest-Magurele 077125 (Romania); Vacareanu, L.; Grigoras, M. [P. Poni' Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Socol, M. [National Institute of Materials Physics, Optics and Spectroscopy Laboratory, 105 bis Atomistilor Street, P.O. Box MG-7, Bucharest-Magurele 077125 (Romania); Socol, G. [National Institute for Laser, Plasma and Radiation Physics, Str. Atomistilor, Nr. 409, P.O. Box MG-36, Magurele, Bucharest 077125 (Romania); Stanculescu, F. [Faculty of Physics, University of Bucharest, Str. Atomistilor nr.405, P.O. Box MG-11, Bucharest-Magurele 077125 (Romania); Preda, N.; Matei, E. [National Institute of Materials Physics, Optics and Spectroscopy Laboratory, 105 bis Atomistilor Street, P.O. Box MG-7, Bucharest-Magurele 077125 (Romania); Ionita, I. [Faculty of Physics, University of Bucharest, Str. Atomistilor nr.405, P.O. Box MG-11, Bucharest-Magurele 077125 (Romania); Girtan, M. [Laboratoire de Photonique d' Angers, Universite d' Angers, 2, Bd. Lavoisier, 49045 Angers (France); Mihailescu, I.N. [National Institute for Laser, Plasma and Radiation Physics, Str. Atomistilor, Nr. 409, P.O. Box MG-36, Magurele, Bucharest 077125 (Romania)

    2011-04-01

    This paper discusses two arylenevinylene oligomers with optical nonlinear properties. Their trans molecular structure was confirmed by Fourier Transform Infrared Spectroscopy and Nuclear Magnetic Resonance. Second Harmonic Generation and two-photon fluorescence have been observed on Matrix Assisted Pulsed Laser Evaporation-deposited thin films. We have seen two local maxima in UV-Vis spectra and a red shift of the photoluminescence peak for carbazole-based oligomer, which can be correlated with a higher conformational flexibility and with strong polarization interactions in the solid state. Scanning Electron Microscopy and Atomic Force Microscopy images have revealed a grainy morphology of the film deposited on titanium and a higher roughness for carbazole-based oligomer. Second harmonic measurements have shown nearly equal values of the second-order nonlinear optical coefficient for the triphenylamine and carbazole-based oligomers for P{sub laser} < 100 mW. z-Scan and x-scan representations of the carbazole-based oligomer film have shown strong two-photon fluorescence intensity inside the sample confirming a volume process, and a strong second harmonic at the surface of the sample determined by the surface morphology.

  2. Preparation and Basic Properties of BaTiO3-BaPbO3 Multilayer Thin Films by Metal-Alkoxides Method

    Science.gov (United States)

    Azuma, Takahiro; Takahashi, Sheiji; Kuwabara, Makoto

    1993-09-01

    Preferentially oriented barium titanate (BTO)-barium metaplumbate (BPO) multilayer thin films were prepared by the metal-alkoxides method on MgO single crystals. The BPO layer is an electrode for the BTO layer. Thin films were deposited on cleaved MgO (100) substrates by spin coating. A BTO film of 0.4 μm thickness on the BPO layer shows a dielectric constant of about 400 at room temperature. No formation of reaction phases between BTO and BPO, fired at 800°C to yield a well-crystallized BTO film, was detected in X-ray diffraction analysis.

  3. Effect of post annealing on MgO thin film prepared on silicon(001) substrate in high oxygen pressure and high substrate temperature by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, Satoru; Akiyama, Kensuke; Ito, Takeshi; Yasui, Manabu; Ozawa, Takeshi; Soga, Masayasu; Motoizumi, Yu [Kanagawa Industrial Technology Center, Kanagawa Prefectural Government, 705-1 Shimo-Imaizumi, Ebina, Kanagawa 243-0435 (Japan); Yoshimoto, Mamoru, E-mail: satoru@kanagawa-iri.go.jp [Department of Innovative and Engineered Materials, Tokyo Institute of Technology, 4259 Nagatsuda, Midori-ku, Yokohama, Kanagawa 226-8503 (Japan)

    2011-03-15

    Epitaxial growth of MgO was verified with the relation of MgO(100) parallel to Si(100) (cubic on cubic growth) even with a large mismatch of lattice constants {approx} 22%, instead of 9% mismatch in 45{sup 0} rotation growth. MgO films prepared at higher deposition temperature showed (001) preferred orientation on Si(001) substrate. After post-annealing the MgO thin films, the pole figure of X-ray diffraction verified the epitaxial growth of cubic on cubic relation. Fe{sub 3}Si thin film was deposited on Si(001) substrate with the MgO film as buffer layer.

  4. Structural, Morphological, and LPG Sensing Properties of Al-Doped ZnO Thin Film Prepared by SILAR

    OpenAIRE

    Shampa Mondal; Shatabda Bhattacharya; Mitra, P.

    2013-01-01

    Undoped and aluminum doped zinc oxide (AZO) thin films were deposited on glass substrates by successive ion layer adsorption and reaction (SILAR) technique from ammonium zincate complex. The thin films are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) for their structural and morphological studies. Both undoped and Al-doped film show strong preferred c-axis orientation. The texture coefficient (TC) of the film along (002) direction increases due to Al incorpo...

  5. The effects of solvents on the properties of ultra-thin poly (methyl methacrylate) films prepared by spin coating

    Energy Technology Data Exchange (ETDEWEB)

    Tippo, T. [Faculty of Engineering, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Road, Ladkrabang, Bangkok 10520 (Thailand); Thanachayanont, C.; Muthitamongkol, P.; Junin, C. [National Metal and Materials Technology Center, Thailand Science Park, Klong 1, KlongLuang, Pathumthani 12120 (Thailand); Hietschold, M. [Chemnitz University of Technology, Institute of Physics, Solid Surface Analysis Group, D-09107 Chemnitz (Germany); Thanachayanont, A., E-mail: ktapinun@kmitl.ac.th [Faculty of Engineering, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Road, Ladkrabang, Bangkok 10520 (Thailand)

    2013-11-01

    Poly (methyl methacrylate) (PMMA) is extensively used as an insulating layer in organic electronic devices. In this study, spin coating method was used to cast thin layers of PMMA for dielectric application from solutions in three different solvents, namely dimethylformamide (DMF), n-butyl acetate and toluene. The solvent's vapor pressure causes the solvent to vaporize at different rates leading to layer's distortion and different surface roughnesses. Preparation of suitable surface morphologies, for example, pinhole-free and crack-free was studied. A step profilometer was used to measure the film thicknesses. Alternatively an equation correlating final film thickness to spin speed and solution concentration was proposed. A metal/insulator/metal parallel plate capacitor structure was fabricated and the current density dependence on the applied electric field was measured. The resulting low surface roughness, low leakage currents, high breakdown voltage, and high dielectric constant were obtained for the 100 nm-thick PMMA film prepared with DMF. - Highlights: • Solvent effect on quality of poly (methyl methacrylate) films • Thickness, surface morphology, and electrical properties were studied. • Best surface morphology and electrical properties obtained using dimethylformamide.

  6. Preparation of CuAlO2 Thin Films by Sol-Gel Method Using Nitrate Solution Dip-Coating

    Directory of Open Access Journals (Sweden)

    Ehara Takashi

    2016-01-01

    Full Text Available CuAlO2 thin films are prepared by sol-gel dip-coating followed by annealing in nitrogen atmosphere using copper nitrate and aluminum nitrate as metal source materials. X-ray diffraction (XRD patterns show (003, (006 and (009 oriented peaks of CuAlO2 at annealing temperature of 800 – 1000°C. This result indicates that the CuAlO2 films prepared in the present work are c-axis oriented. XRD peak intensity increase with annealing temperature and becomes maximum at 850°C. The CuAlO2 XRD peak decreased at annealing temperature of 900°C with appearance of a peak of CuO, and then increased again with annealing temperature until 1000 °C. The films have bandgap of 3.4 eV at annealing temperature of 850°C in which the transparency becomes the highest. At the annealing temperature of 850°C, scanning electron microscope (SEM observation reveals that the films are consist of amorphous fraction and microcrystalline CuAlO2 fraction.

  7. Synthesis and modification of mesoporous silica and the preparation of molecular sieve thin films via pulsed laser deposition

    Science.gov (United States)

    Coutinho, Decio Heringer

    2001-07-01

    Hexagonal mesoporous DAM-1 (Dallas Amorphous Material-1) was prepared using Vitamin E TPGS as the structure-directing agent. Depending upon the temperature and gel composition, highly ordered and hydrothermally stable DAM-1 with various morphologies could be achieved including spheres, gyroids, discoid, hexagonal plates and rods. This synthesis was modified to prepare hybrid organic-inorganic amine and thiol bifunctionalized DAM-1 by direct co-condensation under acidic conditions. Patterned DAM-1 thin films were prepared on patterned transparencies utilizing pulsed laser deposition (PLD) and line patterning techniques. DAM-1 laser ablation onto the patterned substrate followed by hydrothermal treatment resulted in a densely packed film. Removal of the patterned lines by sonication revealed patterned DAM-1 films. Thin films of zeolite type X were also prepared using the PLD technique. Laser ablation of zeolite X onto TiN-coated silicon wafers followed by a hydrothermal treatment resulted in partially oriented, crystalline membranes. Hydrothermal treatment of PLD films on stainless steel mesh produced a coated wire mesh with a 3-mum thick zeolite X film. A novel strategy for imprinting mesoporous SBA-15 that combines a triblock copolymer template and a chiral ruthenium complex is reported. A chiral PEO helix was formed by the chiral ruthenium complex interaction with the block copolymer during the synthesis of SBA-15. Upon removal of the chiral ruthenium complex, a stereospecfic cavity was created. Preliminary results indicated stereoselective absorption of Delta or Λ-Ru(phen)3 2+ isomer from a racemic mixture could be achieved depending on the chirality of the PEO chain. Practicum Two. The industrial practicum report describes the process development unit (PDU) 3-pentenenitrile (3PN) refining operation. This distillation works was operated to refine crude 3PN product, which contained 3PN, 2-methyl-3-butenenitrile (2M3BN), and other byproducts. This report also

  8. The influence of preparation conditions on structural evolution and electrochemical properties of sputtered LiNi0.5Mn1.5O4 thin film electrodes

    Science.gov (United States)

    Lv, Shasha; Li, Zhengcao; Luo, Xinyi

    2017-10-01

    LiNi0.5Mn1.5O4 (LNMO) thin films were prepared by radio frequency magnetron sputtering, followed by thermal annealing in ambient atmosphere. The growth of the films has been studied as a function of deposition temperature, atmosphere, and annealing temperature. Electrochemical properties of LNMO thin-film cathodes were investigated using galvanostatic charge/discharge and cyclic voltammetry against a lithium anode. The initial capacity and capacity retention of the films are highly dependent on the crystallinity and morphology of the films. LNMO thin film grown at 400 °C in an Ar/O2 atmosphere and annealed at 550 °C exhibits good crystallinity and well-defined grain structure. Also it exhibits larger capacity and higher cyclic stability under a high cutoff voltage of 4.9 V.

  9. Thin film device applications

    CERN Document Server

    Kaur, Inderjeet

    1983-01-01

    Two-dimensional materials created ab initio by the process of condensation of atoms, molecules, or ions, called thin films, have unique properties significantly different from the corresponding bulk materials as a result of their physical dimensions, geometry, nonequilibrium microstructure, and metallurgy. Further, these characteristic features of thin films can be drasti­ cally modified and tailored to obtain the desired and required physical characteristics. These features form the basis of development of a host of extraordinary active and passive thin film device applications in the last two decades. On the one extreme, these applications are in the submicron dimensions in such areas as very large scale integration (VLSI), Josephson junction quantum interference devices, magnetic bubbles, and integrated optics. On the other extreme, large-area thin films are being used as selective coatings for solar thermal conversion, solar cells for photovoltaic conver­ sion, and protection and passivating layers. Ind...

  10. Preparation and tribological properties of Sol-Gel TiO2-ZrO2 composite thin films

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    High oriented TiO2-ZrO2 composite thin films on Si (100) and glass sheet were suc-cessfully prepared by sol-gel process followed by dip-coating the ethanol solution of zirconiumoxychloride and titanium tetrachloride. The sol-gel process, microstructure, morphology and tri-bological properties of TiO2 -ZrO2 films were investigated using TGA, DSC, XPS, XRD, AFM anddynamic-static tribometer. The results show that the TiO2-ZrO2films are dense, homogeneous andat a complete tetragonal phase with an excellent antiwear and friction reduction performance. Un-der 0.5N applied load, the friction coefficient is 0.14-0.20 and the antiwear life is more than 5000sliding cycles for both TiO2-ZrO2/ AISI 52100 steel and TiO2-ZrO2/ Si3N4. SEM observation sug-gests that wear mechanism of TiO2 -ZrO2 composite film under low load was fatigue wear, andunder high load was adhesive wear. The TiO2 -ZrO2 films show potential applications as coatingsfor antiwear and friction reduction under the harsh condition.

  11. Synthesis and Properties of Tin Sulfide Thin Films from Nanocolloids Prepared by Pulsed Laser Ablation in Liquid.

    Science.gov (United States)

    Johny, Jacob; Sepulveda-Guzman, Selene; Krishnan, Bindu; Avellaneda, David A; Aguilar Martinez, Josue A; Shaji, Sadasivan

    2016-12-15

    Tin sulfide (SnS) nanoparticles were synthesized by pulsed laser ablation in liquid (PLAL) technique using an Nd:YAG laser operated at 532 nm. SnS thin films were deposited by spraying the colloidal suspension onto the heated substrates. The influence of different liquid media (dimethyl formamide and isopropyl alcohol) on the thin film properties were studied. Morphology, crystalline structure, and chemical composition of the nanoparticles were identified using transmission electron microscopy with energy dispersive X-ray analysis. The crystalline structure of the thin films was analyzed by using grazing incidence X-ray diffraction, and the chemical states by X-ray photoelectron spectroscopy. Scanning electron microscopy was employed for the morphological analysis of the thin films. Annealing the films at 380 °C improved the crystallinity of the films exhibiting a layered morphology, which may be useful in optoelectronic and sensing applications. Cyclic voltammetry studies showed that the films have good electrochemical properties.

  12. Preparation and Photochromic Behavior of Novel Hybrid Inorganic-Organic Thin Film

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A novel photochromic complex comprising of Keggin type tungstophosphate acid (PW12) and polyacrylamide (PAM) was prepared. FT-IR results showed that the Keggin geometry of PW12 was still preserved inside the composite, and a charge-transfer bridge was built between PW12 and PAM via hydrogen bond. AFM images indicated that surface topography of polymer matrix changed after adding PW12. Under UV irradiation, the film was reduced photochemically to yield a blue species, which was reversible in the present of oxygen in polymeric network.

  13. Dopamine/TiO{sub 2} hybrid thin films prepared by the liquid phase deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez-Tauste, David [Departament de Quimica, Universitat Autonoma de Barcelona, Campus UAB, Edifici Cn, 08290 Cerdanyola del Valles, Barcelona (Spain)], E-mail: davidg@qf.uab.es; Domenech, Xavier [Departament de Quimica, Universitat Autonoma de Barcelona, Campus UAB, Edifici Cn, 08290 Cerdanyola del Valles, Barcelona (Spain); Domingo, Concepcion [Instituto de Ciencia de Materiales (CSIC), Campus UAB, 08290 Cerdanyola del Valles, Barcelona (Spain); Ayllon, Jose A. [Departament de Quimica, Universitat Autonoma de Barcelona, Campus UAB, Edifici Cn, 08290 Cerdanyola del Valles, Barcelona (Spain)

    2008-04-30

    Liquid phase deposition method is applied to one-step production of a hybrid material composed by dopamine(DA) and TiO{sub 2} anatase. An optimized amount of the enediol derivative is added to a fluoride titania precursor aqueous solution in order to entrap this modifier within the growing TiO{sub 2}, yielding a DA/TiO{sub 2} nanocomposite material. Uniform, well-adhered and brown-colored thin films are deposited on indium tin oxide covered glass substrate. The DA/TiO{sub 2} hybrid material has been characterized by infrared spectroscopy, electronic microscopy, X-ray diffraction and UV-vis spectroscopy. The formation of the hybrid material seems to be reasonably explained by linkage of different TiO{sub 2} nanocrystallites taking advantage of both enediol and amine groups of DA.

  14. Enhanced photoelectrochemical performance of Ti-doped hematite thin films prepared by the sol-gel method

    Science.gov (United States)

    Lian, Xiaojuan; Yang, Xin; Liu, Shangjun; Xu, Ying; Jiang, Chunping; Chen, Jinwei; Wang, Ruilin

    2012-01-01

    Ti-doped α-Fe2O3 thin films were successfully prepared on FTO substrates by the sol-gel route. Hematite film was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS). The XRD data showed α-Fe2O3 had a preferred (1 1 0) orientation which belonged to the rhombohedral system. Interestingly, the grains turned into worm-like shape after annealed at high temperature. The IPCE could reach 32.6% at 400 nm without any additional potential vs. SCE. Titanium in the lattice can affect the photo electro chemical performance positively by increasing the conductivity of the thin film. So the excited electrons and holes could live longer, rather than recombining with each other rapidly as undoped hematite. And the efficient carrier density on the Ti-doped anode surface was higher than the undoped anode, which contribute to the well PEC performance.

  15. INFLUENCE OF PREPARATION CONDITIONS ON THE MICROSTRUCTURE AND OPTICAL PROPERTIES OF LiNbO3 THIN FILMS

    Directory of Open Access Journals (Sweden)

    Dana Mikolasova

    2015-06-01

    Full Text Available Thin films of Er3+/Yb3+: LiNbO3 were deposited on sapphire (0001 substrates using a spin-coating process. A deposited solution was prepared by a non-aqueous sol-gel method using 2-methoxyethanol, metallic lithium, niobium(V ethoxide and erbium and ytterbium acetates. Two starting compositions of LiNbO3 solution (1:1 or congruent were tested in order to minimize the present of secondary (Er/YbNbO4phases. The effect of different temperature (800oC or 1000oC and different used atmosphere (air or oxygen during the films crystallization was also investigated. Rapid annealing (at 1150oC with the heating rate 55oC.s-1/ was also tested and its influence on secondary phases crystallinity and luminescence of Er3+/Yb3+: LiNbO3 was established. The thin films were characterized by X-ray diffraction analysis, scanning electron microscopy and photoluminescence spectroscopy.

  16. Preparation of nanostructured Bi-modified TiO2 thin films by crossed-beam laser ablation plasmas

    Science.gov (United States)

    Escobar-Alarcon, L.; Solís-Casados, D. A.; González-Zavala, F.; Romero, S.; Fernandez, M.; Haro-Poniatowski, E.

    2017-01-01

    The preparation and characterization of titanium dioxide thin films modified with different amounts of bismuth using a two laser ablation plasmas configuration is reported. The plasmas were produced ablating simultaneously two different targets, one of bismuth and other of titanium dioxide, using a Nd:YAG laser with emission in the fundamental line. The elemental composition, together with the vibrational and optical properties of the deposited films were investigated as a function of the parameters of the bismuth plasma. The composition of the thin films was determined from measurements of X-ray photoelectron spectroscopy (XPS) as well as by Rutherford backscattering spectroscopy (RBS). The structural modification of the deposited material, due to the incorporation of Bi, was characterized by Raman spectroscopy. The optical properties were determined from UV-Vis spectroscopy measurements. It is found that bismuth incorporation has an important effect on the optical properties of TiO2 narrowing the band gap from 3.2 to 2.5 eV.

  17. Compositionally and structurally modified SrTiO{sub 3} thin films prepared by chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Spitzner, Dirk; Gutmann, Emanuel; Reibold, Marianne; Meyer, Dirk C. [Institut fuer Strukturphysik, Technische Universitaet Dresden (Germany); Mahltig, Boris [GMBU e.V., Arbeitsgruppe Funktionelle Schichten, Dresden (Germany)

    2009-07-01

    For electronic and architectural design of functional electroceramic devices, materials with a perovskite-type of structure play a major role. For high-k dielectric, sensing and thermal switching applications the introduction of Barium into SrTiO{sub 3}(STO) allows tuning the electrical properties by tuning the paraelectric-to-ferroelectric transition temperature. For thin film preparation a classic sol-gel route was modified by refluxing as well as solvothermal treatment of the as-synthesized sols. For treated sols the decomposition, phase evolution and transition behaviour differed and from X-ray diffraction (XRD) we observed a supression of foreign phases and a higher degree of compositional homogeneity. In this context also the homologous series of perovskite-related Ruddlesden-Popper (RP) phases promise an engineering of electrical properties by selecting a specific member. Exemplarily we realised the chemical solution deposition of epitaxial thin films of SrO(SrTiO{sub 3}){sub n} RP phases (n=1,2,3) on STO substrates. Structural characteristics of the films were analysed by means of XRD and HRTEM. An application as buffer layers exhibiting tuneable dielectric properties is conceivable.

  18. A chitosan based, laser activated thin film surgical adhesive, 'SurgiLux': preparation and demonstration.

    Science.gov (United States)

    Foster, L John R; Karsten, Elizabeth

    2012-10-23

    Sutures are a 4,000 year old technology that remain the 'gold-standard' for wound closure by virtue of their repair strength (~100 KPa). However, sutures can act as a nidus for infection and in many procedures are unable to effect wound repair or interfere with functional tissue regeneration.(1) Surgical glues and adhesives, such as those based on fibrin and cyanoacrylates, have been developed as alternatives to sutures for the repair of such wounds. However, current commercial adhesives also have significant disadvantages, ranging from viral and prion transfer and a lack of repair strength as with the fibrin glues, to tissue toxicity and a lack of biocompatibility for the cyanoacrylate based adhesives. Furthermore, currently available surgical adhesives tend to be gel-based and can have extended curing times which limit their application.(2) Similarly, the use of UV lasers to facilitate cross-linking mechanisms in protein-based or albumin 'solders' can lead to DNA damage while laser tissue welding (LTW) predisposes thermal damage to tissues.(3) Despite their disadvantages, adhesives and LTW have captured approximately 30% of the wound closure market reported to be in excess of US $5 billion per annum, a significant testament to the need for sutureless technology.(4) In the pursuit of sutureless technology we have utilized chitosan as a biomaterial for the development of a flexible, thin film, laser-activated surgical adhesive termed 'SurgiLux'. This novel bioadhesive uses a unique combination of biomaterials and photonics that are FDA approved and successfully used in a variety of biomedical applications and products. SurgiLux overcomes all the disadvantages associated with sutures and current surgical adhesives (see Table 1). In this presentation we report the relatively simple protocol for the fabrication of SurgiLux and demonstrate its laser activation and tissue weld strength. SurgiLux films adhere to collagenous tissue without chemical modification such as

  19. Microphase-Separated PE/PEO Thin Films Prepared by Plasma-Assisted Vapor Phase Deposition.

    Science.gov (United States)

    Choukourov, Andrei; Gordeev, Ivan; Ponti, Jessica; Uboldi, Chiara; Melnichuk, Iurii; Vaidulych, Mykhailo; Kousal, Jaroslav; Nikitin, Daniil; Hanyková, Lenka; Krakovský, Ivan; Slavínská, Danka; Biederman, Hynek

    2016-03-01

    Immiscible polymer blends tend to undergo phase separation with the formation of nanoscale architecture which can be used in a variety of applications. Different wet-chemistry techniques already exist to fix the resultant polymeric structure in predictable manner. In this work, an all-dry and plasma-based strategy is proposed to fabricate thin films of microphase-separated polyolefin/polyether blends. This is achieved by directing (-CH2-)100 and (-CH2-CH2-O-)25 oligomer fluxes produced by vacuum thermal decomposition of poly(ethylene) and poly(ethylene oxide) onto silicon substrates through the zone of the glow discharge. The strategy enables mixing of thermodynamically incompatible macromolecules at the molecular level, whereas electron-impact-initiated radicals serve as cross-linkers to arrest the subsequent phase separation at the nanoscale. The mechanism of the phase separation as well as the morphology of the films is found to depend on the ratio between the oligomeric fluxes. For polyolefin-rich mixtures, polyether molecules self-organize by nucleation and growth into spherical domains with average height of 22 nm and average diameter of 170 nm. For equinumerous fluxes and for mixtures with the prevalence of polyethers, spinodal decomposition is detected that results in the formation of bicontinuous structures with the characteristic domain size and spacing ranging between 5 × 10(1) -7 × 10(1) nm and 3 × 10(2)-4 × 10(2) nm, respectively. The method is shown to produce films with tunable wettability and biologically nonfouling properties.

  20. Silicon thin films prepared in the transition region and their use in solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S.; Raniero, L.; Fortunato, E.; Aguas, H.; Ferreira, I.; Martins, R. [Department of Materials Science/CENIMAT, Faculty of Sciences and Technology, New University of Lisbon and CEMOP-UNINOVA, 2829-516 Caparica (Portugal); Liao, X.; Xu, Y.; Kong, G. [State Key Laboratory for Surface Physics, Institute of Semiconductors & amp; Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100083 (China)

    2006-11-23

    Diphasic silicon films (nc-Si/a-Si:H) have been prepared by a new regime of plasma enhanced chemical vapour deposition in the region adjacent of phase transition from amorphous to microcrystalline state. Comparing to the conventional amorphous silicon (a-Si:H), the nc-Si/a-Si:H has higher photoconductivity ({sigma}{sub ph}), better stability, and a broader light spectral response range in the longer wavelength range. It can be found from Raman spectra that there is a notable improvement in the medium range order. The blue shift for the stretching mode and red shift for the wagging mode in the IR spectra also show the variation of the microstructure. By using this kind of film as intrinsic layer, a p-i-n junction solar cell was prepared with the initial efficiency of 8.51% and a stabilized efficiency of 8.01% (AM1.5, 100mw/cm{sup 2}) at room temperature. (author)

  1. Effect of heat treatment in aluminium oxide preparation by UV/ozone oxidation for organic thin-film transistors.

    Science.gov (United States)

    Chinnam, Krishna Chytanya; Gleskova, Helena

    2013-07-01

    Effect of heat treatment in aluminium oxide (AlO(x)) preparation employing UV/ozone exposure of thermally-evaporated aluminium is reported. AlO(x) is combined with 1-octylphosphonic acid to form a gate dielectric in low-voltage organic thin-film transistors based on pentacene. For short UV/ozone exposure times the 100 degrees C-heating step that immediately follows UV/ozone oxidation of aluminium leads to a decrease in the transistor threshold voltage of up to 8% and - fourfold reduction in the gate dielectric current density. Transistors with AlO(x) prepared by 60-minute UV/ozone oxidation do not exhibit such behaviour. These results are explained in terms of reduced density of charged oxygen vacancies in the UV/ozone oxidized AlO(x).

  2. 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

  3. Effects of NIR annealing on the characteristics of al-doped ZnO thin films prepared by RF sputtering.

    Science.gov (United States)

    Jun, Min-Chul; Koh, Jung-Hyuk

    2012-06-06

    Aluminum-doped zinc oxide (AZO) thin films have been deposited on glass substrates by employing radio frequency (RF) sputtering method for transparent conducting oxide applications. For the RF sputtering process, a ZnO:Al2O3 (2 wt.%) target was employed. In this paper, the effects of near infrared ray (NIR) annealing technique on the structural, optical, and electrical properties of the AZO thin films have been researched. Experimental results showed that NIR annealing affected the microstructure, electrical resistance, and optical transmittance of the AZO thin films. X-ray diffraction analysis revealed that all films have a hexagonal wurtzite crystal structure with the preferentially c-axis oriented normal to the substrate surface. Optical transmittance spectra of the AZO thin films exhibited transmittance higher than about 80% within the visible wavelength region, and the optical direct bandgap (Eg) of the AZO films was increased with increasing the NIR energy efficiency.

  4. 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.

  5. Optical Properties of Ca0.25Ba0.75Nb2O6 Thin Films Prepared by Spinning Coating

    Institute of Scientific and Technical Information of China (English)

    Yuehua Wang; Min Zhang; Xinyin Zhao; Na Zhao

    2011-01-01

    Ca0.25Ba0.75Nb2O6 (CBN25) thin film was prepared on quartz substrate by spinning coating and the optical properties were investigated by a Hitachi U-3410 spectrophotometer and a Metricon 2010 prism coupler. The optical band gap, thickness and refractive index at 632.8 nm of the CBN25 thin film were determined to be 3.65 eV, 529 nm and 2.2258, respectively. The dispersion of the refractive index fitted to Sellmeier relation well and optical waves could be guided into the thin film, which implied that CBN25 thin films were promising for integrated optics and optically active devices.

  6. Preparation of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} epitaxial thin films by pulsed ion-beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Sorasit, S.; Yoshida, G.; Suzuki, T.; Suematsu, H.; Jiang, W.; Yatsui, K. [Nagaoka University of Technology, Extreme Energy-Density Research Institute, Nagaoka, Niigata (Japan)

    2001-09-01

    Thin films of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (Y-123) grown epitaxially have been successfully deposited by ion-beam evaporation (IBE). The c-axis oriented YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} thin films were successfully deposited on MgO and SrTiO{sub 3} substrates. The Y-123 thin films which were prepared on the SrTiO{sub 3} substrates were confirmed to be epitaxially grown, by X-ray diffraction analysis. The instantaneous deposition rate of the Y-123 thin films was estimated as high as 4 mm/s. (author)

  7. Rapid mixing chemical oxidative polymerization: an easy route to prepare PANI coated small-diameter CNTs/PANI nanofibres composite thin film

    Indian Academy of Sciences (India)

    G Venkata Ramana; Balaji Padya; Vadali V S S Srikanth; P K Jain

    2014-05-01

    Composite thin film containing polyaniline (PANI) coated small diameter carbon nanotubes (SDCNTs)/PANI nanofibres (NFs) has been prepared using an easy in situ rapid mixing chemical oxidative polymerization method. SDCNTs thin film was obtained using thermal chemical vapour deposition method in a separate experiment, whilst PANI NFs are formed in situ during the synthesis of composite. In the composite, PANI coated SDCNTs are uniformly distributed among PANI NFs. The presence of SDCNTs during the composite synthesis does not influence the nucleation and growth of PANI NFs. Raman analysis shows a good interaction between PANI and SDCNTs. Room temperature d.c. electrical sheet resistance of SDCNTs/PANI NFs composite thin film surface is three orders lesser than that of PANI NFs thin film (PANI NFs have the same morphology as in the composite) synthesized using the same method but without the presence of SDCNTs.

  8. Carbon nanotube based transparent conductive thin films.

    Science.gov (United States)

    Yu, X; Rajamani, R; Stelson, K A; Cui, T

    2006-07-01

    Carbon nanotube (CNT) based optically transparent and electrically conductive thin films are fabricated on plastic substrates in this study. Single-walled carbon nanotubes (SWNTs) are chemically treated with a mixture of concentrated sulfuric acid and nitric acid before being dispersed in aqueous surfactant-contained solutions. SWNT thin films are prepared from the stable SWNT solutions using wet coating techniques. The 100 nm thick SWNT thin film exhibits a surface resistivity of 6 kohms/square nanometer with an average transmittance of 88% on the visible light range, which is three times better than the films prepared from the high purity as-received SWNTs.

  9. Transparent conducting properties of Ni doped zinc oxide thin films prepared by a facile spray pyrolysis technique using perfume atomizer

    Energy Technology Data Exchange (ETDEWEB)

    Bouaoud, A.; Rmili, A.; Ouachtari, F.; Louardi, A.; Chtouki, T. [Laboratoire des Hautes Energies, Sciences de l' Ingenierie et Reacteurs (LHESIR), Equipe Ingenierie et Materiaux (INMA), Departement de Physique, Faculte des Sciences, Kenitra (Morocco); Elidrissi, B., E-mail: e.bachir@mailcity.com [Laboratoire des Hautes Energies, Sciences de l' Ingenierie et Reacteurs (LHESIR), Equipe Ingenierie et Materiaux (INMA), Departement de Physique, Faculte des Sciences, Kenitra (Morocco); Erguig, H. [Laboratoire des Hautes Energies, Sciences de l' Ingenierie et Reacteurs (LHESIR), Equipe Ingenierie et Materiaux (INMA), Departement de Physique, Faculte des Sciences, Kenitra (Morocco); Ecole Nationale des Sciences Appliquees de Kenitra (ENSAK) (Morocco)

    2013-01-15

    Undoped and Ni doped zinc oxide (Ni-ZnO) thin films were prepared by a facile spray pyrolysis technique using perfume atomizer from aqueous solution of anhydrous zinc acetate (Zn(CH{sub 3}COOH){sub 2} and hexahydrated nickel chloride (NiCl{sub 2}{center_dot}6H{sub 2}O) as sources of zinc and nickel, respectively. The films were deposited onto the amorphous glass substrates kept at (450 Degree-Sign C). The effect of the [Ni]/[Zn] ratio on the structural, morphological, optical and electrical properties of Ni doped ZnO thin film was studied. It was found from X-ray diffraction (XRD) analysis that both the undoped and Ni doped ZnO films were crystallized in the hexagonal structure with a preferred orientation of the crystallites along the [002] direction perpendicular to the substrate. The scanning electron microscopy (SEM) images showed a relatively dense surface structure composed of crystallites in the spherical form whose average size decreases when the [Ni]/[Zn] ratio increases. The optical study showed that all the films were highly transparent. The optical transmittance in the visible region varied between 75 and 85%, depending on the dopant concentrations. The variation of the band gap versus the [Ni]/[Zn] ratio showed that the energy gap decreases from 2.95 to 2.72 eV as the [Ni]/[Zn] ratio increases from 0 to 0.02 and then increases to reach 3.22 eV for [Ni]/[Zn] = 0.04. The films obtained with the [Ni]/[Zn] ratio = 0.02 showed minimum resistivity of 2 Multiplication-Sign 10{sup -3} {Omega} cm at room temperature. -- Highlights: Black-Right-Pointing-Pointer The optical transmittance of Ni doped ZnO varies between 75 and 85%. Black-Right-Pointing-Pointer The energy gap of these films decreases from 2.95 to 2.72 eV as the [Ni]/[Zn] ratio increases from 0 to 0.02. Black-Right-Pointing-Pointer The energy gap increases to reach 3.22 eV for [Ni]/[Zn] = 0.04. Black-Right-Pointing-Pointer The films obtained with [Ni]/[Zn] ratio = 0.02 show minimum resistivity of 2

  10. Studies on Hall Effect and DC Conductivity Measurements of Semiconductor Thin films Prepared by Chemical Bath Deposition (CBD) method

    OpenAIRE

    S. Thirumavalavana; K. Mani; S. Suresh Sagadevan

    2015-01-01

    Semiconductors have various useful properties that can be exploited for the realization of a large number of high performance devices in fields such as electronics and optoelectronics. Many novel semiconductors, especially in the form of thin films, are continually being developed. Thin films have drawn the attention of many researchers because of their numerous applications. As the film becomes thinner, the properties acquire greater importance in the miniaturization of elements such as resi...

  11. TiO2 thin film photocatalyst

    Institute of Scientific and Technical Information of China (English)

    YU Jiaguo

    2004-01-01

    It is well known that the photocatalytic activity of TiO2 thin films strongly depends on the preparing methods and post-treatment conditions, since they have a decisive influence on the chemical and physical properties of TiO2 thin films.Therefore, it is necessary to elucidate the influence of the preparation process and post-treatment conditions on the photocatalytic activity and surface microstructures of the films. This review deals with the preparation of TiO2 thin film photocatalysts by wet-chemical methods (such as sol-gel, reverse micellar and liquid phase deposition) and the comparison of various preparation methods as well as their advantage and disadvantage. Furthermore, it is discussed that the advancement of photocatalytic activity, super-hydrophilicity and bactericidal activity of TiO2 thin film photocatalyst in recent years.

  12. Enhanced magneto-optical Kerr effect in rare earth substituted nanostructured cobalt ferrite thin film prepared by sol-gel method

    Science.gov (United States)

    Avazpour, L.; Toroghinejad, M. R.; Shokrollahi, H.

    2016-11-01

    A series of rare-earth (RE)-doped nanocrystalline Cox RE(1-x) Fe2O4 (x = 0, 0.1, 0.2 and RE: Nd, Eu) thin films were prepared on silicon substrates by a sol-gel process, and the influences of different RE3+ ions on the microstructure, magnetism and polar magneto-optical Kerr effect of the deposited films were investigated. Also this research presents the optimization process of cobalt ferrite thin films deposited via spin coating, by studying their structural and morphological properties at different thicknesses (200, 350 nm) and various heat treatment temperatures 300-850 °C. Nanoparticulate polycrystalline thin film were formed with heat treatment above 400 °C but proper magnetic properties due to well crystallization of the film were achieved at about 650 °C. AFM results indicated that the deposited thin films were crack-free exhibiting a dense nanogranular structure. The root-mean square (RMS) roughness of the thin films was in the range of 0.2-3.2 nm. The results revealed that both of the magnetism and magneto optical Kerr (MOKE) spectra of Cox RE(1-x) Fe2O4 films could be mediated by doping with various RE ions. The Curie temperature of substituted samples was lower than pristine cobalt ferrite thin films. In MOKE spectra both dominant peaks were blue shifted with addition of RE ions. For low concentration dopant the inter-valence charge transfer related rotation was enhanced and for higher concentration dopant the crystal field rotation peak was enhanced. The MOKE enhancement for Eu3+ substituted samples was more than Nd3+ doped cobalt ferrite films. The enhanced MOKEs in nanocrystalline thin films might promise their applications for magneto-optical sensors in adopted wavelengths.

  13. [Spectral Characteristics of Si Quantum Dots Embedded in SiN(x) Thin Films Prepared by Magnetron Co-Sputtering].

    Science.gov (United States)

    Chen, Xiao-bo; Yang, Wen; Duan, Liang-fei; Zhang, Li-yuan; Yang, Pei-zhi; Song, Zhao-ning

    2015-07-01

    The silicon-rich SiN(x) films were fabricated on Si(100) substrate and quartz substrate at different substrate temperatures varying from room temperature to 400 degrees C by bipolar pulse ane RF magnetron co-sputtering deposition technique. After deposition, the films were annealed in a nitrogen atmosphere by rapid photothermal annealing at 1050 degrees C for 3 minutes. This thermal step allows the formation of the silicon quantum dots. Fourier transform infrared spectroscopy, Raman spectroscopy, grazing incidence X-ray diffraction and photoluminescence spectroscopy were used to analyze the bonding configurations, microstructures and luminescence properties of the films. The experimental results showed that: silicon-rich Si-N bonds were found in Fourier transform infrared spectra, suggesting that the silicon-rich SiN, films were successfully prepared; when the substrate temperature was not lower than 200 degrees C, the Raman spectra of the films showed the transverse optical mode of Si-Si vibration, while the significant diffraction peaks of Si(111) and Si(311) were shown in grazing incidence X-ray diffraction spectra, confirming the formation of silicon quantum dots; our work indicated that there was an optimal substrate temperature (300 degrees C), which could significantly increase the amount and the crystalline volume fraction of silicon quantum dots; three visible photoluminescence bands can be obtained for both 30 degrees C sample and 400 degrees C sample, and in combination with Raman results, the emission peaks were reasonably explained by using the quantum confinement effect and radiative recombination defect state of Si nanocrystals; the average size of the silicon quantum dots is 3.5 and 3.4 nm for the 300 degrees C sample and 400 degrees C sample, respectively. These results are useful for optimizing the fabrication parameters of silicon quantum dots embedded in SiN. thin films and have valuable implications for silicon based photoelectric device

  14. Correlation between microstructure and optical properties of nano-crystalline TiO{sub 2} thin films prepared by sol-gel dip coating

    Energy Technology Data Exchange (ETDEWEB)

    Mechiakh, R., E-mail: raouf_mechiakh@yahoo.fr [Departement de Medecine, Faculte de Medecine, Universite Hadj Lakhdar, Batna (Algeria); Laboratoire de Photovoltaique de Semi-conducteurs et de Nanostructures, Centre de Recherche des Sciences et Technologies de l' Energie, BP.95, Hammam-Lif 2050 (Tunisia); Laboratoire de Ceramiques, Universite Mentouri Constantine (Algeria); Sedrine, N. Ben; Chtourou, R. [Laboratoire de Photovoltaique de Semi-conducteurs et de Nanostructures, Centre de Recherche des Sciences et Technologies de l' Energie, BP.95, Hammam-Lif 2050 (Tunisia); Bensaha, R. [Laboratoire de Ceramiques, Universite Mentouri Constantine (Algeria)

    2010-11-15

    Titanium dioxide thin films have been prepared from tetrabutyl-orthotitanate solution and methanol as a solvent by sol-gel dip coating technique. TiO{sub 2} thin films prepared using a sol-gel process have been analyzed for different annealing temperatures. Structural properties in terms of crystal structure were investigated by Raman spectroscopy. The surface morphology and composition of the films were investigated by atomic force microscopy (AFM). The optical transmittance and reflectance spectra of TiO{sub 2} thin films deposited on silicon substrate were also determined. Spectroscopic ellipsometry study was used to determine the annealing temperature effect on the optical properties and the optical gap of the TiO{sub 2} thin films. The results show that the TiO{sub 2} thin films crystallize in anatase phase between 400 and 800 deg. C, and into the anatase-rutile phase at 1000 deg. C, and further into the rutile phase at 1200 deg. C. We have found that the films consist of titanium dioxide nano-crystals. The AFM surface morphology results indicate that the particle size increases from 5 to 41 nm by increasing the annealing temperature. The TiO{sub 2} thin films have high transparency in the visible range. For annealing temperatures between 1000 and 1400 deg. C, the transmittance of the films was reduced significantly in the wavelength range of 300-800 nm due to the change of crystallite phase and composition in the films. We have demonstrated as well the decrease of the optical band gap with the increase of the annealing temperature.

  15. Effect of surface microstructure and wettability on plasma protein adsorption to ZnO thin films prepared at different RF powers

    Energy Technology Data Exchange (ETDEWEB)

    Huang Zhanyun; Chen Min; Chen Dihu [State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275 (China); Pan Shirong, E-mail: stscdh@mail.sysu.edu.c [Artificial Heart Lab, the 1st Affiliate Hospital of Sun Yat-Sen University, Guangzhou 510080 (China)

    2010-10-01

    In this paper, the adsorption behavior of plasma proteins on the surface of ZnO thin films prepared by radio frequency (RF) sputtering under different sputtering powers was studied. The microstructures and surface properties of the ZnO thin films were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible optical absorption spectroscopy and contact angle techniques. The results show that the ZnO thin films have better orientation of the (0 0 2) peak with increasing RF power, especially at around 160 W, and the optical band gap of the ZnO films varies from 3.2 to 3.4 eV. The contact angle test carried out by the sessile drop technique denoted a hydrophobic surface of the ZnO films, and the surface energy and adhesive work of the ZnO thin films decreased with increasing sputtering power. The amounts of human fibrinogen (HFG) and human serum albumin (HSA) adsorbing on the ZnO films and reference samples were determined by using enzyme-linked immunosorbent assay (ELISA). The results show that fewer plasma proteins and a smaller HFG/HSA ratio adsorb on the ZnO thin films' surface.

  16. Effect of surface microstructure and wettability on plasma protein adsorption to ZnO thin films prepared at different RF powers.

    Science.gov (United States)

    Huang, Zhan-Yun; Chen, Min; Pan, Shi-Rong; Chen, Di-Hu

    2010-10-01

    In this paper, the adsorption behavior of plasma proteins on the surface of ZnO thin films prepared by radio frequency (RF) sputtering under different sputtering powers was studied. The microstructures and surface properties of the ZnO thin films were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible optical absorption spectroscopy and contact angle techniques. The results show that the ZnO thin films have better orientation of the (0 0 2) peak with increasing RF power, especially at around 160 W, and the optical band gap of the ZnO films varies from 3.2 to 3.4 eV. The contact angle test carried out by the sessile drop technique denoted a hydrophobic surface of the ZnO films, and the surface energy and adhesive work of the ZnO thin films decreased with increasing sputtering power. The amounts of human fibrinogen (HFG) and human serum albumin (HSA) adsorbing on the ZnO films and reference samples were determined by using enzyme-linked immunosorbent assay (ELISA). The results show that fewer plasma proteins and a smaller HFG/HSA ratio adsorb on the ZnO thin films' surface.

  17. The role of cobalt doping on magnetic and optical properties of indium oxide nanostructured thin film prepared by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Baqiah, H. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Ibrahim, N.B., E-mail: baayah@ukm.my [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Halim, S.A. [Superconductors and Thin film laboratory, Department of Physics, Faculty of Science, University Putra Malaysia 43400 UPM Serdang, Selangor (Malaysia); Flaifel, Moayad Husein; Abdi, M.H. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2015-03-15

    Highlights: • Cobalt doped indium oxide thin films have been prepared by a sol–gel method. • The films have a thickness less than 100 nm and grain size less than 10 nm. • The lattice parameters and grain size of films decrease as Co content increase. • The optical band gap of films increases as the grain size decrease. • The films' magnetic behaviour is sensitive to ratio of oxygen defects per Co ions. - Abstract: The effect of Co doping concentration, (x = 0.025–0.2), in In{sub 2−x}Co{sub x}O{sub 3} thin film was investigated by X-rays diffraction (XRD), transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), Ultraviolet visible spectrophotometer (UV–vis) and vibrating sample magnetometer (VSM). All films were prepared by sol–gel technique followed by spin coating process. The XRD and XPS measurements indicate that Co{sup +2} has been successfully substituted in In{sup +3} site. The TEM measurement shows nanostructure morphology of the films. The doping of Co in indium oxide resulted in a decrease in the lattice parameters and grain size while the band gap increased with increasing Co concentration. Further, by comparing VSM and XPS results, the magnetic behaviour of the films were found to be sensitive to Co concentrations, oxygen vacancies and ratio of oxygen defects to Co concentrations. The magnetic behaviour of the prepared films was explained using bound magnetic polaron (BMP) model.

  18. Preparation and characterization of Co epitaxial thin films on Al{sub 2}O{sub 3}(0001) single-crystal substrates

    Energy Technology Data Exchange (ETDEWEB)

    Yabuhara, Osamu; Ohtake, Mitsuru; Nukaga, Yuri; Futamoto, Masaaki, E-mail: yabuhara@futamoto.elect.chuo-u.ac.jp [Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551 (Japan)

    2011-01-01

    Co epitaxial thin films were prepared on Al{sub 2}O{sub 3}(0001) single-crystal substrates in a substrate temperature range between 50 and 500 deg. C by ultra high vacuum molecular beam epitaxy. Effects of substrate temperature on the structure and the magnetic properties of the films were investigated. The films grown at temperatures lower than 150 deg. C consist of fcc- Co(111) crystal. With increasing the substrate temperature, hcp-Co(0001) crystal coexists with the fcc crystal and the volume ratio of hcp to fcc crystal increases. The films prepared at temperatures higher than 250 deg. C consist primarily of hcp crystal. The film growth seems to follow island-growth mode. The films consisting primarily of hcp crystal show perpendicular magnetic anisotropy. The domain structure and the magnetization properties are influenced by the magnetocrystalline anisotropy and the shape anisotropy caused by the film surface roughness.

  19. Preparation and characterization of thin ferromagnetic CrO{sub 2} films for applications in magnetoelectronics

    Energy Technology Data Exchange (ETDEWEB)

    Rabe, M. E-mail: rabe@physik.rwth-aachen.de; Dressen, J.; Dahmen, D.; Pommer, J.; Stahl, H.; Ruediger, U.; Guentherodt, G.; Senz, S.; Hesse, D

    2000-03-01

    The theoretically predicted high spin polarization of half-metallic ferromagnets like CrO{sub 2} and NiMnSb make them to promising materials for magnetoelectronic applications. Highly textured CrO{sub 2} films have been prepared by chemical vapor deposition and molecular beam epitaxy. The temperature-dependent magnetotransport data has been correlated with electronic properties of CrO{sub 2}. Over a wide temperature range (150-330 K) the resistivity follows a T{sup 2} behaviour, consistent with electron-electron scattering. Near the Curie temperature of CrO{sub 2} no metal-insulator transition, a magnetoresistance of -7% (B=9 T) and an enhancement of the resistance due to electron-magnon scattering are observed.

  20. Electrical properties of AlN{sub x}O{sub y} thin films prepared by reactive magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Borges, J., E-mail: joelborges@fisica.uminho.pt [Centro de Fisica, Universidade do Minho, 4710-057 Braga (Portugal); Martin, N. [Institut FEMTO-ST, Departement MN2S, UMR 6174 (CNRS, UFC, ENSMM, UTBM) 32, Avenue de l' Observatoire 25044 BESANCON Cedex (France); Barradas, N.P.; Alves, E. [Instituto Superior Tecnico, Instituto Tecnologico Nuclear, E.N. 10, 2686-953 Sacavem (Portugal); Eyidi, D.; Beaufort, M.F.; Riviere, J.P. [Institut PPRIME, UPR 3346 CNRS-Universite de Poitiers-ENSMA, Departement de Physique et Mecanique des Materiaux, BP 30179 86962 Chasseneuil-Futuroscope Cedex (France); Vaz, F.; Marques, L. [Centro de Fisica, Universidade do Minho, 4710-057 Braga (Portugal)

    2012-08-31

    Direct current magnetron sputtering was used to produce AlN{sub x}O{sub y} thin films, using an aluminum target, argon and a mixture of N{sub 2} + O{sub 2} (17:3) as reactive gases. The partial pressure of the reactive gas mixture was increased, maintaining the discharge current constant. Within the two identified regimes of the target (metallic and compound), four different tendencies for the deposition rate were found and a morphological evolution from columnar towards cauliflower-type, ending up as dense and featureless-type films. The structure was found to be Al-type (face centered cubic) and the structural characterization carried out by X-ray diffraction and transmission electron microscopy suggested the formation of an aluminum-based polycrystalline phase dispersed in an amorphous aluminum oxide/nitride (or oxynitride) matrix. This type of structure, composition, morphology and grain size, were found to be strongly correlated with the electrical response of the films, which showed a gradual transition between metallic-like responses towards semiconducting and even insulating-type behaviors. A group of films with high aluminum content revealed a sharp decrease of the temperature coefficient of resistance (TCR) as the concentration ratio of non-metallic/aluminum atomic ratio increased. Another group of samples, where the non-metallic content became more important, revealed a smooth transition between positive and negative values of TCR. In order to test whether the oxynitride films have a unique behavior or simply a transition between the typical responses of aluminum and of those of the correspondent nitride and oxide, the electrical properties of the ternary oxynitride system were compared with AlN{sub x} and AlO{sub y} systems, prepared in similar conditions. - Highlights: Black-Right-Pointing-Pointer AlN{sub x}O{sub y} thin films were produced using magnetron sputtering. Black-Right-Pointing-Pointer AlN{sub x}O{sub y} film morphology, composition and

  1. Structural and photodegradation behaviors of Fe{sup 3+}-doping TiO{sub 2} thin films prepared by a sol–gel spin coating

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Huey-Jiuan; Yang, Tien-Syh [Department of Materials Science and Engineering, National United University, 1 Lien-Da, Kung-Ching Li, Miao-Li 36003, Taiwan (China); Wang, Moo-Chin, E-mail: mcwang@kmu.edu.tw [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 80782, Taiwan (China); Hsi, Chi-Shiung, E-mail: chsi@nuu.edu.tw [Department of Materials Science and Engineering, National United University, 1 Lien-Da, Kung-Ching Li, Miao-Li 36003, Taiwan (China)

    2014-10-15

    Highlights: • Pure and various Fe{sup 3+}-doped TiO{sub 2} thin films have been successfully fabricated. • The phase of all thin films was single phase of anatase TiO{sub 2} when calcined at 823 K. • The crystallinity of TiO{sub 2} thin films decreased as Fe{sup 3+}-doping increased. • The photodegradation of each sample increased as the irradiation time increased. • The photodegradation increased as Fe{sup 3+}-doping increased at a fixed irradiation time. - Abstract: Pure and various Fe{sup 3+}-doping TiO{sub 2} thin films have been successfully fabricated on glass substrate prepared by a sol–gel spin coating route. The structural and photodegradation behavior of these films after calcined at various temperatures for 1 h were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) spectrum and degradation of 1.0 × 10{sup −5} M methylene blue solution. When all thin films after calcined at 823 K for 1 h, the crystalline phase are comprised only contained single phase of anatase TiO{sub 2}. The crystallinity of various Fe{sup 3+}-doping TiO{sub 2} thin films decreases with Fe{sup 3+}-doping concentration increased. The PL intensity of all thin films also decreases with Fe{sup 3+}-doping concentration increased. When all various Fe{sup 3+}-doping TiO{sub 2} thin films after calcined at 823 K for 1 h, the photodegradation of each sample increases with irradiation time increased. Moreover, the photodegradation also increases with Fe{sup 3+}-doping concentration increased when fixed at constant irradiation time.

  2. Memory and Electrical Properties of (100-Oriented AlN Thin Films Prepared by Radio Frequency Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    Maw-Shung Lee

    2014-01-01

    Full Text Available The (100-oriented aluminum nitride (AlN thin films were well deposited onto p-type Si substrate by radio frequency (RF magnetron sputtering method. The optimal deposition parameters were the RF power of 350 W, chamber pressure of 9 mTorr, and nitrogen concentration of 50%. Regarding the physical properties, the microstructure of as-deposited (002- and (100-oriented AlN thin films were obtained and compared by XRD patterns and TEM images. For electrical properties analysis, we found that the memory windows of (100-oriented AlN thin films are better than those of (002-oriented thin films. Besides, the interface and interaction between the silicon and (100-oriented AlN thin films was serious important problem. Finally, the current transport models of the as-deposited and annealed (100-oriented AlN thin films were also discussed. From the results, we suggested and investigated that large memory window of the annealed (100-oriented AlN thin films was induced by many dipoles and large electric field applied.

  3. Preparation of thin Si:H films in an inductively coupled plasma reactor and analysis of their surface roughness

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Wenfeng [School of Physics and Telecommunication Engineering, Laboratory of Quantum Information Technology, South China Normal University, Guangzhou 510006 (China); College of Engineering, South China Agricultural University, Guangzhou 510642 (China); Chen Junfang, E-mail: chenjf@scnu.edu.cn [School of Physics and Telecommunication Engineering, Laboratory of Quantum Information Technology, South China Normal University, Guangzhou 510006 (China); Meng Ran; Wang Yang; Wang Hui; Guo Chaofeng; Xue Yongqi [School of Physics and Telecommunication Engineering, Laboratory of Quantum Information Technology, South China Normal University, Guangzhou 510006 (China)

    2010-01-15

    An important concern in the deposition of Si:H films is to obtain smooth surfaces. Herein, we deposit the thin Si:H films using Ar-diluted SiH{sub 4} as feedstock gas in an inductively coupled plasma reactor. And we carry a real-time monitor on the deposition process by using optical emission spectrum technology in the vicinity of substrate and diagnose the Ar plasma radial distribution by Langmuir probe. Surface detecting by AFM and surface profilometry in large scale shows that the thin Si:H films have small surface roughness. Distributions of both the ion density and the electron temperature are homogeneous at h = 0.5 cm. Based on these experimental results, it can be proposed inductively coupled plasma reactor is fit to deposit the thin film in large scale. Also, Ar can affect the reaction process and improve the thin Si:H films characteristics.

  4. AES depth profile and photoconductive studies of AgInS2 thin films prepared by co-evaporation

    Directory of Open Access Journals (Sweden)

    C. A Arredondo

    2014-06-01

    Full Text Available In this study, thin films of AgInS2 with chalcopyrite-type tetragonal structure were grown by means of a procedure based on the sequential evaporation of metallic precursors in presence of elemental sulfur in a two-stage process. The effect of the growth temperature and the proportion of the evaporated Ag mass in relation to the evaporated In mass (mAg/mIn on the phase and homogeneity in the chemical composition were researched through X-ray diffraction measurements and Auger electrons spectroscopy. These measurements evidenced that the conditions for preparing thin films containing only the AgInS2 phase, grown with tetragonal chalcopyrite-type structure and good homogeneity of the chemical composition in the entire volume, are a temperature of 500 °C and a 0.89 mAg/mIn proportion. The transient photocurrent measurements indicated that the electricity transmission is affected by recombination processes via band-to-band transitions and trap-assisted transitions.

  5. Flux pinning properties of MgB{sub 2} thin films on Ti buffered substrate prepared by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Yonekura, K., E-mail: kenji@st.cs.kumamoto-u.ac.j [Department of Computer Science and Electrical Engineering, Kumamoto University, 2-39-1, Kurokami, Kumamoto 860-8555 (Japan); Kugo, A.; Fujiyoshi, T.; Sueyoshi, T. [Department of Computer Science and Electrical Engineering, Kumamoto University, 2-39-1, Kurokami, Kumamoto 860-8555 (Japan); Harada, Y. [JST Satellite Iwate, 3-35-2, Iiokashinden Morioka, Iwate 020-0852 (Japan); Yoshizawa, M.; Ikeda, T. [Department of Materials Science and Engineering, Iwate University, 4-3-5, Ueda, Morioka, Iwate 020-8551 (Japan); Awaji, S.; Watanabe, K. [Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2010-11-01

    Transport properties of the MgB{sub 2} thin films on Si, MgO and ZnO substrates with Ti buffer layer prepared by molecular beam epitaxy were investigated to clarify effects of the substrates and the Ti buffer layer on flux pinning. The critical current density J{sub c} of each sample shows different dependence on magnetic fields parallel to c-axis. However, the scaling analysis of the macroscopic pinning force for all the measured samples implies that the grain boundaries work as the dominant pinning centers for B//c. The pinning parameter for MgB{sub 2}/Ti/Si estimated from the electric field E vs. the current density J characteristics shows the highest value among all the measured samples. This result is attributed to the high density of grain boundaries caused by the effect of both the Ti buffer and Si substrate in the growth process. Therefore, the selection of substrates and buffer layer strongly affects the flux pining properties of MgB{sub 2} thin films and plays an important role in the determination of performance for superconducting devices and wires.

  6. Osmium Complexes Useful in the Preparation of Metal Thin Film and Highly Efficient Electroluminescent Devices

    Institute of Scientific and Technical Information of China (English)

    Yun Chi

    2004-01-01

    Treatment of β-diketone ligand, such as hfacH (hexafluoroacetylacetone), with Os3(CO)12 in a stainless steel autoclave at elevated temperature afforded the corresponding mononuclear osmium complex [Os(CO)3(hfac)(tfa)] (1) in good yield. This complex is highly volatile and displays moderate stability at the higher temperatures; thus, it can be utilized for depositing metal thin-film material with overall quality comparable or better than those deposited using the commercially available chemical reagents. Moreover, combination of Os3(CO)12 with another class of chelate ligand such as 3-trifluoromethyl-5-(2-pyridyl) pyrazole (ppz)H gave formation of the Os(H) dicarbonyl complex [Os(CO)2(ppz)2] (2). This osmium complex shows blue phosphorescence at room temperature, which is characteristic for the 3ππ* emission with vibronic progressions at 430,457 and 480 nm. The remarkable photophysical properties were rationalized by a combination of π electron accepting CO ligand, relative ppz orientation and heavy-atom enhanced spin-orbit coupling effects. Related chemical transformations that afforded other useful luminescent Os complexes are presented.

  7. Evaluation of thin film ceria membranes for syngas membrane reactors—Preparation, characterization and testing

    DEFF Research Database (Denmark)

    Kaiser, Andreas; Foghmoes, Søren Preben Vagn; Chatzichristodoulou, Christodoulos

    2011-01-01

    up, cooling, reduction and re-oxidation) was also investigated. Chemically induced stress in the CGO10 membrane due to harsh reduction of the CGO10 material at high temperatures and very low pO2 values can lead to mechanical failure by lattice expansion. Calculations of the oxygen non......Gadolinium doped ceria (Ce0.1Gd0.9O1.95−δ, CGO10) was investigated as oxygen separation membrane material for application in syngas production. Planar, thin film CGO10 membranes were fabricated by tape casting and lamination on porous NiO-YSZ supports and subsequent co-sintering. High oxygen fluxes......, up to 16Nmlcm−2min−1 at 900°C, were obtained when placing the membrane between air and humidified hydrogen (H2/H2O=20). Initial experiments for syngas production were performed by testing the CGO10 membrane with methane and steam feed.The mechanical integrity of CGO10 membranes during operation (heat...

  8. Characterizations of Cuprous Oxide Thin Films Prepared by Sol-Gel Spin Coating Technique with Different Additives for the Photoelectrochemical Solar Cell

    Directory of Open Access Journals (Sweden)

    D. S. C. Halin

    2014-01-01

    Full Text Available Cuprous oxide (Cu2O thin films were deposited onto indium tin oxide (ITO coated glass substrate by sol-gel spin coating technique using different additives, namely, polyethylene glycol and ethylene glycol. It was found that the organic additives added had a significant influence on the formation of Cu2O films and lead to different microstructures and optical properties. The films were characterized by X-ray diffraction (XRD, field emission scanning electron microscopy (FESEM, and ultraviolet-visible spectroscopy (UV-Vis. Based on the FESEM micrographs, the grain size of film prepared using polyethylene glycol additive has smaller grains of about 83 nm with irregular shapes. The highest optical absorbance film was obtained by the addition of polyethylene glycol. The Cu2O thin films were used as a working electrode in the application of photoelectrochemical solar cell (PESC.

  9. Enhanced magneto-optical Kerr effect in rare earth substituted nanostructured cobalt ferrite thin film prepared by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Avazpour, L.; Toroghinejad, M.R. [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Shokrollahi, H., E-mail: Shokrollahi@sutech.ac.ir [Electroceramics Group, Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz 13876-71557 (Iran, Islamic Republic of)

    2016-11-30

    Highlights: • The nanostructured rare earth doped Co-ferrite thin film was synthesized by the sol–gel method. • The coercivity of as high as 1.8 kOe is achieved for 20% substituted cobalt ferrite. • The average particle diameter of particulate film is decreasing by increasing substitute content. • Kerr spectra of films shifted to higher energies. • Kerr rotation angle increased to 1.65° for 0.1 Eu doped thin film. - Abstract: A series of rare-earth (RE)-doped nanocrystalline Co{sub x} RE{sub (1−x)} Fe{sub 2}O{sub 4} (x = 0, 0.1, 0.2 and RE: Nd, Eu) thin films were prepared on silicon substrates by a sol–gel process, and the influences of different RE{sup 3+} ions on the microstructure, magnetism and polar magneto-optical Kerr effect of the deposited films were investigated. Also this research presents the optimization process of cobalt ferrite thin films deposited via spin coating, by studying their structural and morphological properties at different thicknesses (200, 350 nm) and various heat treatment temperatures 300–850 °C. Nanoparticulate polycrystalline thin film were formed with heat treatment above 400 °C but proper magnetic properties due to well crystallization of the film were achieved at about 650 °C. AFM results indicated that the deposited thin films were crack-free exhibiting a dense nanogranular structure. The root-mean square (RMS) roughness of the thin films was in the range of 0.2–3.2 nm. The results revealed that both of the magnetism and magneto optical Kerr (MOKE) spectra of Co{sub x} RE{sub (1−x)} Fe{sub 2}O{sub 4} films could be mediated by doping with various RE ions. The Curie temperature of substituted samples was lower than pristine cobalt ferrite thin films. In MOKE spectra both dominant peaks were blue shifted with addition of RE ions. For low concentration dopant the inter-valence charge transfer related rotation was enhanced and for higher concentration dopant the crystal field rotation peak was enhanced

  10. Changes in chemical composition and nanostructure of SiC thin films prepared by PECVD during thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Kuenle, Matthias; Janz, Stefan [Fraunhofer Institute of Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg (Germany); Nickel, Klaus Georg [Applied Mineralogy, Institute for Geosciences, Eberhard-Karl-University Tuebingen, Wilhelmstr. 52, 72074 Tuebingen (Germany); Eibl, Oliver [Institute for Applied Physics, Eberhard-Karls-University Tuebingen, Auf der Morgenstelle 10, 72074 Tuebingen (Germany)

    2011-08-15

    Silicon carbide (SiC) thin films were deposited on silicon (Si) using plasma enhanced chemical vapor deposition (PECVD). Annealing was done in a rapid thermal annealing furnace at a temperature of 1300 C. As-deposited and annealed Si-rich and stoichiometric SiC thin films were investigated by analytical transmission electron microscopy (AEM). TEM-energy-dispersive X-ray spectroscopy was used to quantify the chemical composition of the SiC thin films with high accuracy. The chemical composition of the near stoichiometric SiC thin film changed during annealing from Si{sub 0.4}C{sub 0.6} to Si{sub 0.5}C{sub 0.5} due to diffusion of Si from the Si substrate into the film. The Si-rich Si{sub 1-x}C{sub x} film had the identical chemical composition of Si{sub 0.8}C{sub 0.2} before and after annealing. As-deposited films show nanoporosity within the bulk film. During annealing, v-shaped defect structures were formed at the interface of the stoichiometric SiC thin film to the Si substrate. Diffraction patterns revealed that as-deposited films were amorphous. During annealing the crystallization of 3C-SiC occurred in near-stoichiometric SiC thin films, whereas in Si-rich Si{sub 1-x}C{sub x} thin films two phases, namely Si and 3C-SiC, crystallized. Low-loss and core-loss electron energy loss spectroscopy (EELS) verified the diffraction results. In the low-loss spectra of the near stoichiometric SiC thin film, a plasmon peak located at 20.2 eV before and at 22.3 eV after annealing was detected. The low-loss spectra of the Si-rich Si{sub 1-x}C{sub x} thin film showed an asymmetric plasmon peak with two maxima located at 18.5 and 25.0 eV in the as-deposited film and 18.6 and 24.3 eV in the annealed Si-rich Si{sub 1-x}C{sub x} film. The 18.5 eV plasmon peaks is assigned to Si and the 25 eV plasmon peak is attributed to the SiC phase. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Room temperature inorganic polycondensation of oxide (Cu{sub 2}O and ZnO) nanoparticles and thin films preparation by the dip-coating technique

    Energy Technology Data Exchange (ETDEWEB)

    Salek, G.; Tenailleau, C., E-mail: tenailleau@chimie.ups-tlse.fr; Dufour, P.; Guillemet-Fritsch, S.

    2015-08-31

    Oxide thin solid films were prepared by dip-coating into colloidal dispersions of oxide nanoparticles stabilized at room temperature without the use of chelating or complex organic dispersing agents. Crystalline oxide nanoparticles were obtained by inorganic polycondensation and characterized by X-ray diffraction and field emission gun scanning electron microscopy. Water and ethanol synthesis and solution stabilization of oxide nanoparticle method was optimized to prepare two different structural and compositional materials, namely Cu{sub 2}O and ZnO. The influence of hydrodynamic parameters over the particle shape and size is discussed. Spherical and rod shape nanoparticles were formed for Cu{sub 2}O and ZnO, respectively. Isoelectric point values of 7.5 and 8.2 were determined for cuprous and zinc oxides, respectively, after zeta potential measurements. A shear thinning and thixotropic behavior was observed in both colloidal sols after peptization at pH ~ 6 with dilute nitric acid. Every colloidal dispersion stabilized in a low cost and environmentally friendly azeotrope solution composed of 96 vol.% of ethanol with water was used for the thin film preparation by the dip-coating technique. Optical properties of the light absorber cuprous oxide and transparent zinc oxide thin solid films were characterized by means of transmittance and reflectance measurements (300–1100 nm). - Highlights: • Room temperature inorganic polycondensation of crystalline oxides • Water and ethanol synthesis and solution stabilization of oxide nanoparticles • Low cost method for thin solid film preparation.

  12. Preparation and properties of thin films used in activity determinations with a 4 {pi} counter; Preparation et proprietes des films minces utilises dans les determinations d'activite au compteur 4 {pi}

    Energy Technology Data Exchange (ETDEWEB)

    Jannez, M.; Le Gallic, Y.; Thenard, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Comparative study of various methods of preparing thin films, for use as source holders in the 4 {pi} counter, and of measuring their thickness. Comparative study of various properties: mechanical resistance; heat resistance; ageing; resistance of rhodopas, polystyrene, formvar and cellulose acetate films to the action of various chemical agents. (author) [French] Etude comparee de divers procedes de preparation de films minces, destines a etre utilises comme supports de sources dans le compteur 4 {pi} et de la mesure de leur epaisseur. Etude comparee de diverses proprietes: resistance mecanique; resistance a la chaleur; vieillissement; resistance a l'action de divers agents chimiques de films de rhodopas, polystyrene, formvar et acetate de cellulose. (auteur)

  13. Electrical and structural properties of TiO2-δ thin film with oxygen vacancies prepared by RF magnetron sputtering using oxygen radical

    Science.gov (United States)

    Kawamura, Kinya; Suzuki, Naoya; Tsuchiya, Takashi; Shimazu, Yuichi; Minohara, Makoto; Kobayashi, Masaki; Horiba, Koji; Kumigashira, Hiroshi; Higuchi, Tohru

    2016-06-01

    Anatase TiO2-δ thin film was prepared by RF magnetron sputtering using oxygen radical and Ti-metal target. Degrees of the TiO2-δ crystal orientation in the thin film depends of the oxygen gas pressure (P\\text{O2}) in the radical gun. The (004)- and (112)-oriented TiO2-δ thin films crystallized without postannealing have the mixed valence Ti4+/Ti3+ state. The electrical conductivities, which corresponds to n-type oxide semiconductor, is higher in the case of (004)-oriented TiO2-δ thin film containing with high concentration of oxygen vacancy. The donor band of TiO2-δ thin film is observed at ˜1.0 eV from the Fermi level (E F). The density-of-state at E F is higher in (004)-oriented TiO2-δ thin film. The above results indicate that the oxygen vacancies can control by changing the P\\text{O2} of the oxygen radical.

  14. Structural, optical and thermal properties of {beta}-SnS{sub 2} thin films prepared by the spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Khelia, C.; Ben Nasrallah, T.; Amlouk, M.; Belgacem, S. [Faculte des Sciences, Tunis (Tunisia). Lab. de Physique de la Matiere Condensee; Maiz, F. [Equipe de Photothermique de Nabeul, Inst. Preparatoire aux Etudes d' Ingenieur de Nabeul (Tunisia); Mnari, M. [Lab. de Chimie Analytique, Campus Univ., Tunis (Tunisia)

    2000-03-01

    Tin disulfide {beta}-SnS{sub 2} thin films have been prepared on pyrex substrates by the spray pyrolysis technique using tin tetrachloride and thiourea as starting materials. The depositions were carried out in the range of substrate temperatures from 240 to 400 C. Highly c-axis oriented {beta}-SnS{sub 2} films, having a strong (001) X-ray diffraction line are obtained at temperature 280 C and using concentration ratio in solution R = [S]/[Sn] = 2.5. Films surfaces were analyzed by contact atomic force microscopy (AFM) and by scanning electron microscopy (SEM) in order to understand the effect of the deposited temperature on the surface structure. On the other hand, from transmission and reflection spectra, the band gap energy determined is about 2.71 eV. Finally using the photodeflection spectroscopy technique, the thermal conductivity K{sub c} and diffusivity D{sub c} were obtained. Their values are 10 Wm{sup -1}K{sup -1} and 10{sup -5} m{sup 2}s{sup -1} respectively. (orig.)

  15. Thin film superfluid optomechanics

    CERN Document Server

    Baker, Christopher G; McAuslan, David L; Sachkou, Yauhen; He, Xin; Bowen, Warwick P

    2016-01-01

    Excitations in superfluid helium represent attractive mechanical degrees of freedom for cavity optomechanics schemes. Here we numerically and analytically investigate the properties of optomechanical resonators formed by thin films of superfluid $^4$He covering micrometer-scale whispering gallery mode cavities. We predict that through proper optimization of the interaction between film and optical field, large optomechanical coupling rates $g_0>2\\pi \\times 100$ kHz and single photon cooperativities $C_0>10$ are achievable. Our analytical model reveals the unconventional behaviour of these thin films, such as thicker and heavier films exhibiting smaller effective mass and larger zero point motion. The optomechanical system outlined here provides access to unusual regimes such as $g_0>\\Omega_M$ and opens the prospect of laser cooling a liquid into its quantum ground state.

  16. Lattice reorientation in tetragonal PMN-PT thin film induced by focused ion beam preparation for transmission electron microscopy

    Science.gov (United States)

    Denneulin, Thibaud; Maeng, Wanjoo; Eom, Chang-Beom; Hÿtch, Martin

    2017-02-01

    Focused ion beam sample preparation for transmission electron microscopy (TEM) can induce relaxation mechanisms in epitaxial thin films. Here, we describe a relaxation mechanism that can occur in materials having a tetragonal structure. We investigated the lattice structure of a 600 nm thick 0.4 [ Pb ( Mg 1 / 3 Nb 2 / 3 ) O 3 ] - 0.6 [ PbTiO 3 ] layer grown by epitaxy on (110) GdScO3 substrate using geometrical phase analysis applied to high resolution TEM images. The lattice mismatch at the interface is expected to favor the formation of c-domains. However, it was measured that the out-of-plane lattice parameter can decrease abruptly along the growth direction and the transition depends on the thickness of the TEM lamella. Different observations indicate that the crystal flipped by 90° following the preparation of the sample, so that the c-axis is oriented in the thinning direction. Such a mechanism can easily lead to misinterpretations and might happen in other materials with a similar structure.

  17. Effect of La Doping on Microstructure and Ferroelectric Properties of Bi4Ti3O12 Thin Films Prepared by Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    FU Chengju; HUANG Zhixiong; GUO Dongyun

    2008-01-01

    The Bi4Ti3O12 and Bi3.25La0.75Ti3O12 thin films were prepared on the Pt/Ti/SiO2/Si substrate using the sol-gel method. The effect of La doping on the microstructure and ferroelectric properties of Bi4Ti3O12 films were investigated. Both the Bi4Ti3O12 and Bi3.25La0.75Ti3O12 thin films exhibited typical bismuth layered perovskite structure. The 2Pr (remanent polarization) value of Bi3.25La0.75Ti3O12 thin films is 18.6 Μc/cm2, which is much larger than that of Bi4Ti3O12 thin films. And the Bi3.25La0.75Ti3O12 films show fatigue-free behavior, while the Bi4Ti3O12 thin films exhibit the fatigue problem. The mechanism of improvement of La doping was discussed.

  18. Preparation and ferroelectric properties of Bi3.4Ce0.6Ti3O12 thin films grown by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We have investigated the preparation and properties of Bi3.4Ce0.6Ti3O12 thin films. The Bi3.4Ce0.6Ti3O12 thin films were fabricated on the Pt/Ti/SiO2/Si substrates using sol-gel method. The structure and morphology of the films were characterized us- ing X-ray diffraction and atomic force microscopy. The thin films showed a perovskite phase and dense microstructure. The dielectric constant and the dissi- pation factor of the Bi3.4Ce0.6Ti3O12 thin films were about 172 and 0.031 at 1 kHz, respectively. The 2Pr and 2Ec of the Bi3.4Ce0.6Ti3O12 thin films were 67.1 μC/cm2 and 299.7 kV/cm, respectively, under an applied field of 600 kV/cm. The Bi3.4Ce0.6Ti3O12 film did not show fatigue up to 4.46×109 switching cycles at a frequency of 1 MHz, and showed good insulating behavior according to the test of leakage current.

  19. Hydrophilic Cu{sub 2}O nanostructured thin films prepared by facile spin coating method: Investigation of surface energy and roughness

    Energy Technology Data Exchange (ETDEWEB)

    Eskandari, A.; Sangpour, P., E-mail: sangpour@merc.ac.ir; Vaezi, M.R.

    2014-10-15

    We demonstrate a facile, uniform and large scale chemical route to synthesize the cuprous oxide (Cu{sub 2}O) nanostructured thin film via spin coating technique. The samples were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), simultaneous thermal analysis (STA) and UV–visible spectra. Based on the results, the transparent Cu{sub 2}O thin films were formed at the low temperature (275 °C) due to employed N{sub 2} atmosphere in annealing processes. The average roughness is decreased by increasing the number of layers from 11 to 6.4 nm for 1 and 5 times of successive deposition of copper oxide, respectively. Afterward, by increasing the cycle of deposition, the roughness increased (∼87%) owning to the transformation of the growth mechanism of thin films from Volmer–Weber to Stranski–Krastanov mode. Moreover, the prepared films were extremely hydrophilic with water contact angle about 45° and surface energy 54.26 mJ m{sup −2} after 10-cycle coating. The smooth and low energy surface with this technique could be tailored for photoelectrochemical applications such as water splitting. - Highlights: • Hydrophilic Cu{sub 2}O nanostructured thin films synthesized by a facile method. • By increasing the cycle of deposition, finer particles obtained. • Surface energy and contact angle strongly depend on the film formation mechanism. • Transformation of the thin films growth mechanism was studied.

  20. Biomimetic thin film deposition

    Science.gov (United States)

    Rieke, P. C.; Campbell, A. A.; Tarasevich, B. J.; Fryxell, G. E.; Bentjen, S. B.

    1991-04-01

    Surfaces derivatized with organic functional groups were used to promote the deposition of thin films of inorganic minerals. These derivatized surfaces were designed to mimic the nucleation proteins that control mineral deposition during formation of bone, shell, and other hard tissues in living organisms. By the use of derivatized substrates control was obtained over the phase of mineral deposited, the orientation of the crystal lattice and the location of deposition. These features are of considerable importance in many technically important thin films, coatings, and composite materials. Methods of derivatizing surfaces are considered and examples of controlled mineral deposition are presented.

  1. The large-area CdTe thin film for CdS/CdTe solar cell prepared by physical vapor deposition in medium pressure

    Science.gov (United States)

    Luo, Run; Liu, Bo; Yang, Xiaoyan; Bao, Zheng; Li, Bing; Zhang, Jingquan; Li, Wei; Wu, Lili; Feng, Lianghuan

    2016-01-01

    The Cadmium telluride (CdTe) thin film has been prepared by physical vapor deposition (PVD), the Ar + O2 pressure is about 0.9 kPa. This method is a newer technique to deposit CdTe thin film in large area, and the size of the film is 30 × 40 cm2. This method is much different from the close-spaced sublimation (CSS), as the relevance between the source temperature and the substrate temperature is weak, and the gas phase of CdTe is transferred to the substrate by Ar + O2 flow. Through this method, the compact and uniform CdTe film (30 × 40 cm2) has been achieved, and the performances of the CdTe thin film have been determined by transmission spectrum, SEM and XRD. The film is observed to be compact with a good crystallinity, the CdTe is polycrystalline with a cubic structure and a strongly preferred (1 1 1) orientation. Using the CdTe thin film (3 × 5 cm2) which is taken from the deposited large-area film, the 14.6% efficiency CdS/CdTe thin film solar cell has been prepared successfully. The structure of the cell is glass/FTO/CdS/CdTe/graphite slurry/Au, short circuit current density (Jsc) of the cell is 26.9 mA/cm2, open circuit voltage (Voc) is 823 mV, and filling factor (FF) is 66.05%. This technique can be a quite promising method to apply in the industrial production, as it has great prospects in the fabricating of large-area CdTe film.

  2. X-ray absorption spectroscopy of Mn doped ZnO thin films prepared by rf sputtering technique

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Ashok Kumar; Jha, S. N.; Bhattacharyya, D., E-mail: dibyendu@barc.gov.in [Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai – 400 085 (India); Haque,