WorldWideScience

Sample records for thermoelectric thin film

  1. Heat shrink formation of a corrugated thin film thermoelectric generator

    International Nuclear Information System (INIS)

    Sun, Tianlei; Peavey, Jennifer L.; David Shelby, M.; Ferguson, Scott; O’Connor, Brendan T.

    2015-01-01

    Highlights: • Demonstrate and characterize a thermoelectric generator with a corrugated geometry. • Employ a novel heat shrink fabrication approach compatible with low-cost processing. • Use thermal impedance modeling to explore design potential. • Corrugated design shown to be advantageous for low heat-flux density applications. - Abstract: A thin film thermoelectric (TE) generator with a corrugated architecture is demonstrated formed using a heat-shrink fabrication approach. Fabrication of the corrugated TE structure consists of depositing thin film thermoelectric elements onto a planar non-shrink polyimide substrate that is then sandwiched between two uniaxial stretch-oriented co-polyester (PET) films. The heat shrink PET films are adhered to the polyimide in select locations, such that when the structure is placed in a high temperature environment, the outer films shrink resulting in a corrugated core film and thermoelectric elements spanning between the outer PET films. The module has a cross-plane heat transfer architecture similar to a conventional bulk TE module, but with heat transfer in the plane of the thin film thermoelectric elements, which assists in maintaining a significant temperature difference across the thermoelectric junctions. In this demonstration, Ag and Ni films are used as the thermoelectric elements and a Seebeck coefficient of 14 μV K −1 is measured with a maximum power output of 0.22 nW per couple at a temperature difference of 7.0 K. We then theoretically consider the performance of this device architecture with high performance thermoelectric materials in the heat sink limited regime. The results show that the heat-shrink approach is a simple fabrication method that may be advantageous in large-area, low power density applications. The fabrication method is also compatible with simple geometric modification to achieve various form factors and power densities to customize the TE generator for a range of applications

  2. Variations in thermoelectric power of thin monocrystalline films with conductivity

    Science.gov (United States)

    Tellier, C. R.; Tosser, A. J.; Hafid, L.

    1980-12-01

    Starting from the bi-dimensional model for grain boundaries in monocrystalline thin films, the difference in thermoelectric power is expressed in terms of conductivity and energy dependence of the bulk electronic mean free path U. A new procedure is suggested for measuring U.

  3. Thermoelectric effects of amorphous Ga-Sn-O thin film

    Science.gov (United States)

    Matsuda, Tokiyoshi; Uenuma, Mutsunori; Kimura, Mutsumi

    2017-07-01

    The thermoelectric effects of an amorphous Ga-Sn-O (a-GTO) thin film have been evaluated as a physical parameter of a novel oxide semiconductor. Currently, a-GTO thin films are greatly desired not only because they do not contain rare metals and are therefore free from problems on the exhaustion of resources and the increase in cost but also because their initial characteristics and performance stabilities are excellent when they are used in thin-film transistors. In this study, an a-GTO thin film was deposited on a quartz substrate by RF magnetron sputtering and postannealing was performed in air at 350 °C for 1 h using an annealing furnace. The Seebeck coefficient and electrical conductivity of the a-GTO thin film were -137 µV/K and 31.8 S/cm at room temperature, and -183 µV/K and 43.8 S/cm at 397 K, respectively, and as a result, the power factor was 1.47 µW/(cm·K2) at 397 K; these values were roughly as high as those of amorphous In-Ga-Zn-O (a-IGZO) thin films. Therefore, a-GTO thin films will be a candidate material for thermoelectric devices fabricated in a large area at a low cost by controlling the carrier mobility, carrier density, device structures, and so forth.

  4. Fabrication of a Micro Cooler using Thermoelectric Thin Film

    International Nuclear Information System (INIS)

    Han, S. W.; Choi, H. J.; Kim, D. H.; Kim, W. J.; Kim, B. I.; Kim, K. M.

    2007-01-01

    In general a ThermoElectric Cooler (TEC) consists of a series of P type and N type thermoelectric materials sandwiched between two wafers. When a DC current passes through these materials, three different effects take place; Peltier effect, Joule heating effect and heat transfer by conduction due to temperature difference between hot and cold plates. In this study we have developed a micro TEC using Bi2Te3 (N type) and Bi0.5Sb1.5Te3 (P type) thin films. In order to improve that performance of a micro TEC, we made 10 um height TE legs using special PR only for lift-off. We measured COP (coefficient of performance) and temperature difference between hot and cold connectors with current

  5. Impact of the substrate on the efficiency of thin film thermoelectric technology

    International Nuclear Information System (INIS)

    Alvarez-Quintana, J.

    2015-01-01

    Thermoelectricity is one of the simplest technologies for thermal energy conversion. Moreover, because of their relatively low efficiency, bulk thermoelectric materials are generally used in environments where their solid state nature outweighs their poor efficiency. Nevertheless, low dimensional thermoelectric materials shed a light in order to achieve higher thermoelectric performance than their bulk counterparts via quantum and spatial confinement of energy carriers. The Thermoelectric figure of merit ZT is the basic criterion for estimating the performance of thermoelectric materials. In this work, by way of an extension of the Harman method to thin films onto substrate to evaluate ZT it is shown that the solely presence of a substrate affects significantly the intrinsic value of the ZT independently of the electrical and thermal nature of the substrate. Furthermore, the model unveils that as the thickness ratio between substrate and thin film increases, the parameter ZT sharply tends to zero; this effect opens a serious problem to overcome by the thin film thermoelectric technology, especially at nanoscale. In this sense, challenges in order to engineering planar thermoelectric devices at micro/nanoscale are properly identified. - Highlights: • Extended Harman method to evaluate ZT of thin films onto substrate is presented. • ZT of thermoelectric thin films is strongly affected by substrate's nature. • Thin dielectric substrates are desirable to hold ZT in in-plane configuration. • Film/substrate thickness ratio play important role on the device performance. • Challenges to engineering planar thermoelectric devices are properly identified

  6. Effect of Thermal Cycling on Zinc Antimonide Thin Film Thermoelectric Characteristics

    DEFF Research Database (Denmark)

    Mirhosseini, M.; Rezania, A.; Rosendahl, L.

    2017-01-01

    In this study, performance and stability of zinc antimonide thin film thermoelectric sample is analyzed under transient thermal conditions. The thermoelectric materials are deposited on glass based substrate where the heat flow is parallel with the thermoelectric element length. The specimen...

  7. Crystal orientation dependent thermoelectric properties of highly oriented aluminum-doped zinc oxide thin films

    KAUST Repository

    Abutaha, Anas I.; Sarath Kumar, S. R.; Alshareef, Husam N.

    2013-01-01

    We demonstrate that the thermoelectric properties of highly oriented Al-doped zinc oxide (AZO) thin films can be improved by controlling their crystal orientation. The crystal orientation of the AZO films was changed by changing the temperature

  8. Magneto-thermoelectric effects in NiFe thin films

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Maximilian

    2015-11-01

    In this thesis magneto-thermoelectric effects are investigated in a systematic way to separate the transverse spin Seebeck effect from other parasitic effects like the anomalous Nernst effect. In contrast to the first studies found in the literature, in NiFe thin films a contribution of the transverse spin Seebeck effect can be excluded. This surprising outcome was crosschecked in a variety of different sample layouts and collaborations with other universities to ensure the validity of these results. In general, this thesis solves a long time discussion about the existence of the transverse spin Seebeck effect in NiFe films and supports the importance of control measurements for the scientific community. Even if such ''negative'' results may not be the award winning ones, new discoveries should be treated with constructive criticism and be checked carefully by the scientific community.

  9. The effect of Cr buffer layer thickness on voltage generation of thin-film thermoelectric modules

    International Nuclear Information System (INIS)

    Mizoshiri, Mizue; Mikami, Masashi; Ozaki, Kimihiro

    2013-01-01

    The effect of Cr buffer layer thickness on the open-circuit voltage generated by thin-film thermoelectric modules of Bi 0.5 Sb 1.5 Te 3 (p-type) and Bi 2 Te 2.7 Se 0.3 (n-type) materials was investigated. A Cr buffer layer, whose thickness generally needs to be optimized to improve adhesion depending on the substrate surface condition, such as roughness, was deposited between thermoelectric thin films and glass substrates. When the Cr buffer layer was 1 nm thick, the Seebeck coefficients and electrical conductivity of 1 µm thermoelectric thin films with the buffer layers were approximately equal to those of the thermoelectric films without the buffer layers. When the thickness of the Cr buffer layer was 1 µm, the same as the thermoelectric films, the Seebeck coefficients of the bilayer films were reduced by an electrical current flowing inside the Cr buffer layer and the generation of Cr 2 Te 3 . The open-circuit voltage of the thin-film thermoelectric modules decreased with an increase in the thickness of the Cr buffer layer, which was primarily induced by the electrical current flow. The reduction caused by the Cr 2 Te 3 generation was less than 10% of the total voltage generation of the modules without the Cr buffer layers. The voltage generation of thin-film thermoelectric modules could be controlled by the Cr buffer layer thickness. (paper)

  10. Temperature dependent thermoelectric properties of chemically derived gallium zinc oxide thin films

    KAUST Repository

    Barasheed, Abeer Z.; Sarath Kumar, S. R.; Alshareef, Husam N.

    2013-01-01

    In this study, the temperature dependent thermoelectric properties of sol-gel prepared ZnO and 3% Ga-doped ZnO (GZO) thin films have been explored. The power factor of GZO films, as compared to ZnO, is improved by nearly 17% at high temperature. A stabilization anneal, prior to thermoelectric measurements, in a strongly reducing Ar/H2 (95/5) atmosphere at 500°C was found to effectively stabilize the chemically derived films, practically eliminating hysteresis during thermoelectric measurements. Subtle changes in the thermoelectric properties of stabilized films have been correlated to oxygen vacancies and excitonic levels that are known to exist in ZnO-based thin films. The role of Ga dopants and defects, formed upon annealing, in driving the observed complex temperature dependence of the thermoelectric properties is discussed. © The Royal Society of Chemistry 2013.

  11. Laser deposition and direct-writing of thermoelectric misfit cobaltite thin films

    Science.gov (United States)

    Chen, Jikun; Palla-Papavlu, Alexandra; Li, Yulong; Chen, Lidong; Shi, Xun; Döbeli, Max; Stender, Dieter; Populoh, Sascha; Xie, Wenjie; Weidenkaff, Anke; Schneider, Christof W.; Wokaun, Alexander; Lippert, Thomas

    2014-06-01

    A two-step process combining pulsed laser deposition of calcium cobaltite thin films and a subsequent laser induced forward transfer as micro-pixel is demonstrated as a direct writing approach of micro-scale thin film structures for potential applications in thermoelectric micro-devices. To achieve the desired thermo-electric properties of the cobaltite thin film, the laser induced plasma properties have been characterized utilizing plasma mass spectrometry establishing a direct correlation to the corresponding film composition and structure. The introduction of a platinum sacrificial layer when growing the oxide thin film enables a damage-free laser transfer of calcium cobaltite thereby preserving the film composition and crystallinity as well as the shape integrity of the as-transferred pixels. The demonstrated direct writing approach simplifies the fabrication of micro-devices and provides a large degree of flexibility in designing and fabricating fully functional thermoelectric micro-devices.

  12. Experimental Investigation of Zinc Antimonide Thin Film Thermoelectric Element over Wide Range of Operating Conditions

    DEFF Research Database (Denmark)

    Mirhosseini, Mojtaba; Rezania, Alireza; Blichfeld, Anders B.

    2017-01-01

    flows in plane with the thin film. At first, the effect of applying different temperatures at the hot side of the specimen is investigated to reach steady state in an open circuit analysis. Then, the study focuses on performance and stability analysis of the thermoelectric element operating under......Zinc antimonide compounds are among the most efficient thermoelectric (TE) materials with exceptional low thermal conductivity at moderate temperatures up to 350 °C. This study aims to evaluate the performance of a zinc antimonide thin film TE deposited on an insulating substrate, while the heat...

  13. Frequency-domain Harman technique for rapid characterization of bulk and thin film thermoelectric materials

    Science.gov (United States)

    Moran, Samuel

    Nanostructured thermoelectrics, often in the form of thin films, may potentially improve the generally poor efficiency of bulk thermoelectric power generators and coolers. In order to characterize the efficiency of these new materials it is necessary to measure their thermoelectric figure of merit, ZT. The only direct measurement of ZT is based on the Harman technique and relies on measuring the voltage drop across a sample subjected to a passing continuous current. Application of this technique to thin films is currently carried out as a time-domain measurement of the voltage as the thermal component decays after switching off an applied voltage. This work develops a technique for direct simultaneous measurement of figure of merit and Seebeck coefficient from the harmonic response of a thermoelectric material under alternating current excitation. A thermocouple mounted on the top surface measures voltage across the device as the frequency of the applied voltage is varied. A thermal model allows the sample thermal conductivity to also be determined and shows good agreement with measurements. This technique provides improved signal-to-noise ratio and accuracy compared to time-domain ZT measurements for comparable conditions while simultaneously measuring Seebeck coefficient. The technique is applied to both bulk and thin film thermoelectric samples.

  14. Using high thermal stability flexible thin film thermoelectric generator at moderate temperature

    Science.gov (United States)

    Zheng, Zhuang-Hao; Luo, Jing-Ting; Chen, Tian-Bao; Zhang, Xiang-Hua; Liang, Guang-Xing; Fan, Ping

    2018-04-01

    Flexible thin film thermoelectric devices are extensively used in the microscale industry for powering wearable electronics. In this study, comprehensive optimization was conducted in materials and connection design for fabricating a high thermal stability flexible thin film thermoelectric generator. First, the thin films in the generator, including the electrodes, were prepared by magnetron sputtering deposition. The "NiCu-Cu-NiCu" multilayer electrode structure was applied to ensure the thermal stability of the device used at moderate temperature in an air atmosphere. A design with metal layer bonding and series accordant connection was then employed. The maximum efficiency of a single PN thermocouple generator is >11%, and the output power loss of the generator is <10% after integration.

  15. Crystal orientation dependent thermoelectric properties of highly oriented aluminum-doped zinc oxide thin films

    KAUST Repository

    Abutaha, Anas I.

    2013-02-06

    We demonstrate that the thermoelectric properties of highly oriented Al-doped zinc oxide (AZO) thin films can be improved by controlling their crystal orientation. The crystal orientation of the AZO films was changed by changing the temperature of the laser deposition process on LaAlO3 (100) substrates. The change in surface termination of the LaAlO3 substrate with temperature induces a change in AZO film orientation. The anisotropic nature of electrical conductivity and Seebeck coefficient of the AZO films showed a favored thermoelectric performance in c-axis oriented films. These films gave the highest power factor of 0.26 W m−1 K−1 at 740 K.

  16. Modeling the transport properties of epitaxially grown thermoelectric oxide thin films using spectroscopic ellipsometry

    KAUST Repository

    Sarath Kumar, S. R.

    2012-02-01

    The influence of oxygen vacancies on the transport properties of epitaxial thermoelectric (Sr,La)TiO3 thin films is determined using electrical and spectroscopic ellipsometry (SE) measurements. Oxygen vacancy concentration was varied by ex-situ annealing in Ar and Ar/H2. All films exhibited degenerate semiconducting behavior, and electrical conductivity decreased (258–133 S cm−1) with increasing oxygen content. Similar decrease in the Seebeck coefficient is observed and attributed to a decrease in effective mass (7.8–3.2 me ), as determined by SE. Excellent agreement between transport properties deduced from SE and direct electrical measurements suggests that SE is an effective tool for studying oxide thin film thermoelectrics.

  17. Modeling the transport properties of epitaxially grown thermoelectric oxide thin films using spectroscopic ellipsometry

    KAUST Repository

    Sarath Kumar, S. R.; Abutaha, Anas I.; Hedhili, Mohamed N.; Alshareef, Husam N.

    2012-01-01

    The influence of oxygen vacancies on the transport properties of epitaxial thermoelectric (Sr,La)TiO3 thin films is determined using electrical and spectroscopic ellipsometry (SE) measurements. Oxygen vacancy concentration was varied by ex-situ annealing in Ar and Ar/H2. All films exhibited degenerate semiconducting behavior, and electrical conductivity decreased (258–133 S cm−1) with increasing oxygen content. Similar decrease in the Seebeck coefficient is observed and attributed to a decrease in effective mass (7.8–3.2 me ), as determined by SE. Excellent agreement between transport properties deduced from SE and direct electrical measurements suggests that SE is an effective tool for studying oxide thin film thermoelectrics.

  18. Laser-induced thermoelectric voltage in normal state MgB2 thin films

    International Nuclear Information System (INIS)

    Zhao Songqing; Zhou Yueliang; Zhao Kun; Wang Shufang; Chen Zhenghao; Jin Kuijuan; Lue Huibin; Cheng Bolin; Yang Guozhen

    2006-01-01

    Laser-induced voltage has been observed in c-axis oriented MgB 2 thin film at room temperature. The amplitude of the signal is approximately proportional to the film thickness. For the film with the thickness of 150 nm, a very fast response has been detected when the film was irradiated by a 308 nm pulsed laser of 20 ns duration. The rise time and full width at half-maximum of the signal are about 3 and 25 ns, respectively. The physical origin of the laser-induced voltage can be attributed to a transverse thermoelectricity due to the anisotropic thermopower in MgB 2

  19. 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.

  20. Thermoelectric properties of bismuth antimony tellurium thin films through bilayer annealing prepared by ion beam sputtering deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Zhuang-hao [College of Physics Science and Technology, Shenzhen University, 518060 (China); Shenzhen Key Laboratory of Sensor Technology, Shenzhen 518060 (China); Fan, Ping, E-mail: fanping308@126.com [College of Physics Science and Technology, Shenzhen University, 518060 (China); Shenzhen Key Laboratory of Sensor Technology, Shenzhen 518060 (China); Luo, Jing-ting [College of Physics Science and Technology, Shenzhen University, 518060 (China); Shenzhen Key Laboratory of Sensor Technology, Shenzhen 518060 (China); Cai, Xing-min; Liang, Guang-xing; Zhang, Dong-ping [College of Physics Science and Technology, Shenzhen University, 518060 (China); Ye, Fan [Shenzhen Key Laboratory of Sensor Technology, Shenzhen 518060 (China)

    2014-07-01

    Bismuth antimony tellurium is one of the most important tellurium-based materials for high-efficient thermoelectric application. In this paper, ion beam sputtering was used to deposit Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3} bilayer thin films on borosilicate substrates at room-temperature. Then the bismuth antimony tellurium thin films were synthesized via post thermal treatment of the Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3} bilayer thin films. The effect of annealing temperature and compositions on the thermoelectric properties of the thin films was investigated. After the thin films were annealed from 150 °C to 350 °C for 1 h in the high vacuum condition, the Seebeck coefficient changed from a negative sign to a positive sign. The X-ray diffraction results showed that the synthesized tellurium-based thermoelectric thin film exhibited various alloys phases, which contributed different thermoelectricity conductivity to the synthesized thin film. The overall Seebeck coefficient of the synthesized thin film changed from negative sign to positive sign, which was due to the change of the primary phase of the tellurium-based materials at different annealing conditions. Similarly, the thermoelectric properties of the films were also associated with the grown phase. High-quality thin film with the Seebeck coefficient of 240 μV K{sup −1} and the power factor of 2.67 × 10{sup −3} Wm{sup −1} K{sup −2} showed a single Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} phase when the Sb/Te thin film sputtering time was 40 min. - Highlights: • Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} thermoelectric thin films synthesized via bilayer annealing • The film has single Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} phase with best thermoelectric performance. • The film has high thermoelectric properties comparable with other best results.

  1. Thermoelectric characterization of Sb{sub 2}Te{sub 3} thin films deposited by ALD

    Energy Technology Data Exchange (ETDEWEB)

    Zastrow, Sebastian; Schumacher, Christian; Nielsch, Kornelius [University of Hamburg (Germany); Regus, Matthias [University of Kiel (Germany); Schulz, Stephan [University of Duisburg-Essen (Germany)

    2012-07-01

    Thermoelectric materials can be used as temperature sensors or peltier cooling devices as well as to recover a part of the massive losses of energy due to the waste heat generated in fossil-fuel driven power plants and vehicles. Antimony Telluride (Sb{sub 2}Te{sub 3}) is a p-doped semiconductor and in the focus of interest for room temperature applications because of its thermoelectric peak performance at around 350 K. However, thermoelectric properties of Sb{sub 2}Te{sub 3} ALD thin films have not been reported yet. Based on the work of Pore et al., Sb{sub 2}Te{sub 3} is deposited with a home-made reactor on SiO{sub 2} by using (Et{sub 3}Si){sub 2}Te and SbCl{sub 3}. The surface roughness as well as the growth rate depend strongly on the deposition temperature as reported by Cu et al. To check the preferential growth directions and the composition, XRD and EDX measurements are carried out. The thermoelectric properties are influenced by the deposition parameters. Therefore, spatial scans of the Seebeck coefficient are performed and the electrical resistivity is measured. In order to enhance the thermoelectric performance, a first optimization by short annealing processes is done under helium atmosphere up to 570 K. The authors would like to thank the ''Karl-Vossloh-Stiftung''.

  2. Optoelectronic and low temperature thermoelectric studies on nanostructured thin films of silver gallium selenide

    International Nuclear Information System (INIS)

    Jacob, Rajani; Philip, Rachel Reena; Nazer, Sheeba; Abraham, Anitha; Nair, Sinitha B.; Pradeep, B.; Urmila, K. S.; Okram, G. S.

    2014-01-01

    Polycrystalline thin films of silver gallium selenide were deposited on ultrasonically cleaned soda lime glass substrates by multi-source vacuum co-evaporation technique. The structural analysis done by X-ray diffraction ascertained the formation of nano structured tetragonal chalcopyrite thin films. The compound formation was confirmed by X-ray photo-electron spectroscopy. Atomic force microscopic technique has been used for surface morphological analysis. Direct allowed band gap ∼1.78eV with high absorption coefficient ∼10 6 /m was estimated from absorbance spectra. Low temperature thermoelectric effects has been investigated in the temperature range 80–330K which manifested an unusual increase in Seebeck coefficient with negligible phonon drag toward the very low and room temperature regime. The electrical resistivity of these n-type films was assessed to be ∼2.6Ωm and the films showed good photo response

  3. Optoelectronic and low temperature thermoelectric studies on nanostructured thin films of silver gallium selenide

    Science.gov (United States)

    Jacob, Rajani; Philip, Rachel Reena; Nazer, Sheeba; Abraham, Anitha; Nair, Sinitha B.; Pradeep, B.; Urmila, K. S.; Okram, G. S.

    2014-01-01

    Polycrystalline thin films of silver gallium selenide were deposited on ultrasonically cleaned soda lime glass substrates by multi-source vacuum co-evaporation technique. The structural analysis done by X-ray diffraction ascertained the formation of nano structured tetragonal chalcopyrite thin films. The compound formation was confirmed by X-ray photo-electron spectroscopy. Atomic force microscopic technique has been used for surface morphological analysis. Direct allowed band gap ˜1.78eV with high absorption coefficient ˜106/m was estimated from absorbance spectra. Low temperature thermoelectric effects has been investigated in the temperature range 80-330K which manifested an unusual increase in Seebeck coefficient with negligible phonon drag toward the very low and room temperature regime. The electrical resistivity of these n-type films was assessed to be ˜2.6Ωm and the films showed good photo response.

  4. Doping site dependent thermoelectric properties of epitaxial strontium titanate thin films

    KAUST Repository

    Abutaha, Anas I.; Sarath Kumar, S. R.; Mehdizadeh Dehkordi, Arash; Tritt, Terry M.; Alshareef, Husam N.

    2014-01-01

    We demonstrate that the thermoelectric properties of epitaxial strontium titanate (STO) thin films can be improved by additional B-site doping of A-site doped ABO3 type perovskite STO. The additional B-site doping of A-site doped STO results in increased electrical conductivity, but at the expense of Seebeck coefficient. However, doping on both sites of the STO lattice significantly reduces the lattice thermal conductivity of STO by adding more densely and strategically distributed phononic scattering centers that attack wider phonon spectra. The additional B-site doping limits the trade-off relationship between the electrical conductivity and total thermal conductivity of A-site doped STO, leading to an improvement in the room-temperature thermoelectric figure of merit, ZT. The 5% Pr3+ and 20% Nb5+ double-doped STO film exhibits the best ZT of 0.016 at room temperature. This journal is

  5. Electrical and thermoelectric properties of different compositions of Ge–Se–In thin films

    Energy Technology Data Exchange (ETDEWEB)

    Aly, K.A., E-mail: kamalaly2001@gmail.com [Physics Department, Faculty of Science and Arts Khulais, University of Jeddah (Saudi Arabia); Physics Department, Faculty of Science, Al-Azhar University, Assiut Branch, Assiut (Egypt); Dahshan, A., E-mail: adahshan73@gmail.com [Department of Physics, Faculty of Science, Port Said University, Port Said (Egypt); Department of Physics, Faculty of Science for Girls, King Khalid University, Abha (Saudi Arabia); Abbady, Gh. [Department of Physics, Faculty of Science, Assuit University, Assuit (Egypt); Saddeek, Y. [Physics Department, Faculty of Science, Al-Azhar University, Assiut Branch, Assiut (Egypt)

    2016-09-15

    The effect of temperature in the range of 300–450 K and the indium content on the electrical and thermoelectric properties of Ge{sub 20}Se{sub 80−x}In{sub x} (0.0≤x≤24 at%) chalcogenide glassy thin films have been studied. From dc electrical and thermoelectric measurements, it was observed that the activation energies for electrical conductivity (ΔE) and for thermoelectric (ΔE{sub s}) decrease while the conductivity (σ) and Seebeck coefficient (S) increase upon introducing In into the Ge–Se glasses. In contrast to the behavior obtained with Bi or Pb doping, In incorporated in Ge–Se does not lead to a p-to n-type conduction inversion. The power factor (P) which is strongly depends on both of the Seebeck coefficient and the electrical conductivity. According to the obtained results, the Ge{sub 20}Se{sub 80−x}In{sub x} films can be considered potential candidates for incurring high action thermoelectric materials.

  6. Enhancement in figure-of-merit with superlattices structures for thin-film thermoelectric devices

    Energy Technology Data Exchange (ETDEWEB)

    Venkatasubramanian, R; Colpitts, T

    1997-07-01

    Thin-film superlattice (SL) structures in thermoelectric materials are shown to be a promising approach to obtaining an enhanced figure-of-merit, ZT, compared to conventional, state-of-the-art bulk alloyed materials. In this paper the authors describe experimental results on Bi{sub 2}Te{sub 3}/Sb{sub 2}Te{sub 3} and Si/Ge SL structures, relevant to thermoelectric cooling and power conversion, respectively. The short-period Bi{sub 2}Te{sub 3} and Si/Ge SL structures appear to indicate reduced thermal conductivities compared to alloys of these materials. From the observed behavior of thermal conductivity values in the Bi{sub 2}Te{sub 3}/Sb{sub 2}Te{sub 3} SL structures, a distinction is made where certain types of periodic structures may correspond to an ordered alloy rather than an SL, and therefore, do not offer a significant reduction in thermal conductivity values. The study also indicates that SL structures, with little or weak quantum-confinement, also offer an improvement in thermoelectric power factor over conventional alloys. They present power factor and electrical transport data in the plane of the SL interfaces to provide preliminary support for the arguments on reduced alloy scattering and impurity scattering in Bi{sub 2}Te{sub 3}/Sb{sub 2}Te{sub 3} and Si/Ge SL structures. These results, though tentative due to the possible role of the substrate and the developmental nature of the 3-{omega} method used to determine thermal conductivity values, suggest that the short-period SL structures potentially offer factorial improvements in the three-dimensional figure-of-merit (ZT3D) compared to current state-of-the-art bulk alloys. An approach to a thin-film thermoelectric device called a Bipolarity-Assembled, Series-Inter-Connected Thin-Film Thermoelectric Device (BASIC-TFTD) is introduced to take advantage of these thin-film SL structures.

  7. Thermoelectric prospects of chemically deposited PbSe and SnSe thin films

    Science.gov (United States)

    Nair, P. K.; Martínez, Ana Karen; Rosa García Angelmo, Ana; Barrios Salgado, Enue; Nair, M. T. S.

    2018-03-01

    Thin films of PbSe of 400-600 nm in thickness, were obtained via chemical deposition from a solution containing lead nitrate, thiourea and selenosufate. SnSe thin films of 90-180 nm in thickness, were also obtained by chemical deposition from a solution containing selenosulfate. Optical and electrical properties of these thin films were significantly altered by heating them in selenium vapor at 300 °C. Thin film PbSe has a bandgap (Eg) of 1.17 eV (direct gap, forbidden transitions), which decreases to 0.77 eV when it has been heated. Its electrical conductivity (σ) is p-type: 0.18 Ω-1 cm-1 (as-prepared), and 6.4 Ω-1 cm-1 when heated. Thin film SnSe is of orthorhombic crystalline structure which remains stable when heated at 300 °C, but its Eg increases from 1.12 eV (indirect) in as-prepared film to 1.5 eV (direct, forbidden transitions) upon heating. Its electrical conductivity is p-type, which increases from 0.3 Ω-1 cm-1 (as-prepared) to 1 Ω-1 cm-1 when heated (without Se-vapor). When SnSe film is heated at 300 °C in the presence of Se-vapor, they transform to SnSe2, with Eg of 1.5 eV (direct, forbidden) with n-type electrical conductivity, 11 Ω-1 cm-1. The Seebeck coefficient for the PbSe films is: +0.55 mV K-1 (as prepared) and +0.275 mV K-1 (heated); for SnSe films it is: +0.3 mV K-1 (as prepared) and +0.20 mV K-1 (heated); and for SnSe2 film, - 0.35 mV K-1. A five-element PbSe-SnSe2-PbSe-SnSe2-PbSe thermoelectric device demonstrated 50 mV for a temperature difference ΔT = 20 °C (2.5 mV K-1). For SnSe-SnSe2-SnSe-SnSe2-SnSe device, the value is 15 mV for ΔT = 20 °C (0.75 mV K-1). Prospect of these thin films in thermoelectric devices of hybrid materials, in which the coatings may be applied on distinct substrate and geometries is attractive.

  8. High temperature thermoelectric properties of strontium titanate thin films with oxygen vacancy and niobium doping

    KAUST Repository

    Sarath Kumar, S. R.

    2013-08-14

    We report the evolution of high temperature thermoelectric properties of SrTiO3 thin films doped with Nb and oxygen vacancies. Structure-property relations in this important thermoelectric oxide are elucidated and the variation of transport properties with dopant concentrations is discussed. Oxygen vacancies are incorporated during growth or annealing in Ar/H2 above 800 K. An increase in lattice constant due to the inclusion of Nb and oxygen vacancies is found to result in an increase in carrier density and electrical conductivity with simultaneous decrease in carrier effective mass and Seebeck coefficient. The lattice thermal conductivity at 300 K is found to be 2.22 W m-1 K-1, and the estimated figure of merit is 0.29 at 1000 K. © 2013 American Chemical Society.

  9. High temperature thermoelectric properties of strontium titanate thin films with oxygen vacancy and niobium doping

    KAUST Repository

    Sarath Kumar, S. R.; Barasheed, Abeer Z.; Alshareef, Husam N.

    2013-01-01

    We report the evolution of high temperature thermoelectric properties of SrTiO3 thin films doped with Nb and oxygen vacancies. Structure-property relations in this important thermoelectric oxide are elucidated and the variation of transport properties with dopant concentrations is discussed. Oxygen vacancies are incorporated during growth or annealing in Ar/H2 above 800 K. An increase in lattice constant due to the inclusion of Nb and oxygen vacancies is found to result in an increase in carrier density and electrical conductivity with simultaneous decrease in carrier effective mass and Seebeck coefficient. The lattice thermal conductivity at 300 K is found to be 2.22 W m-1 K-1, and the estimated figure of merit is 0.29 at 1000 K. © 2013 American Chemical Society.

  10. Nanoscale Thermoelectrics: A Study of the Absolute Seebeck Coefficient of Thin Films

    Science.gov (United States)

    Mason, Sarah J.

    The worlds demand for energy is ever increasing. Likewise, the environmental impact of climate change due generating that energy through combustion of fossil fuels is increasingly alarming. Due to these factors new sources of renewable energies are constantly being sought out. Thermoelectric devices have the ability to generate clean, renewable, energy out of waste heat. However promising that is, their inefficiency severely inhibits applicability and practical use. The usefulness of a thermoelectric material increases with the dimensionless quantity, ZT, which depends on the Seebeck coefficient and electrical and thermal conductivity. These characteristic material parameters have interdependent energy transport contributions that classically prohibit the optimization of one with out the detriment of another. Encouraging advancements of ZT have occurred in the past ten years due to the decoupling of the thermal and electrical conductivity. Further advancements are necessary in order to produce applicable devices. One auspicious way of decoupling or tuning energy transport properties, is through size reduction to the nanoscale. However, with reduced dimensions come complications in measuring material properties. Measurements of properties such as the Seebeck coefficient, S, are primarily contingent upon the measurement apparatus. The Seebeck coefficient is defined as the amount of voltage generated by a thermal gradient. Measuring a thermally generated voltage by traditional methods gives, the voltage measured as a linear function of the Seebeck coefficient of the leads and of the material being tested divided by the applied thermal gradient. If accurate values of the Seebeck coefficients of the leads are available, simple subtraction provides the answer. This is rarely the case in nanoscale measurement devices with leads exclusively made from thin film materials that do not have well known bulk-like thermopower values. We have developed a technique to directly

  11. Preparation and thermoelectric properties of RF co-sputtered CoSb{sub 3} skutteruddite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Aziz [University of Science and Technology, Daejeon (Korea, Republic of); Han, Seungwoo [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of); University of Science and Technology, Daejeon (Korea, Republic of)

    2014-11-15

    Various skutterudites have been under investigation because of their potential application in thermoelectric materials and devices. These studies indicate that bulk materials with a skutterudite type structure show reasonable thermoelectric behaviors at elevated temperatures, which make them suitable for high-temperature thermoelectric applications. The results of thermoelectric-property measurements on skutterudite-phase CoSb{sub 3} thin films are presented in this study in order to extend the bulk material concept to micro-device applications by using thin film deposition technology. Thin films are deposited on oxidized silicon substrates by using the RF co-sputtering method. The film's composition is found to depend strongly on the deposition conditions. The temperature at which the deposited films transition from an amorphous state to a crystalline state has been reported to be about 153 .deg. C. Therefore, some experiments are performed with the substrate temperature kept at 200 .deg. C to obtain polycrystalline films. The crystal structure of the film is evaluated by using x-ray diffraction (XRD) measurements. Energy dispersive spectroscopy (EDS) is used to determine the film's composition whereas the surface morphology and the thickness are investigated and measured by using scanning electron microscopy (SEM). Finally, the thermoelectric properties, namely, the electrical resistivity and the Seebeck coefficient, are used to calculate the power factor of the deposited thin films and, their variations with temperature are measured. We report a maximum power factor of 0.41 mW/mK{sup 2} for the film deposited at a 200 .deg. C substrate temperature.

  12. Preparation of InSe Thin Films by Thermal Evaporation Method and Their Characterization: Structural, Optical, and Thermoelectrical Properties

    Directory of Open Access Journals (Sweden)

    Sarita Boolchandani

    2018-01-01

    Full Text Available The indium selenium (InSe bilayer thin films of various thickness ratios, InxSe(1-x (x = 0.25, 0.50, 0.75, were deposited on a glass substrate keeping overall the same thickness of 2500 Ǻ using thermal evaporation method under high vacuum atmosphere. Electrical, optical, and structural properties of these bilayer thin films have been compared before and after thermal annealing at different temperatures. The structural and morphological characterization was done using XRD and SEM, respectively. The optical bandgap of these thin films has been calculated by Tauc’s relation that varies within the range of 1.99 to 2.05 eV. A simple low-cost thermoelectrical power measurement setup is designed which can measure the Seebeck coefficient “S” in the vacuum with temperature variation. The setup temperature variation is up to 70°C. This setup contains a Peltier device TEC1-12715 which is kept between two copper plates that act as a reference metal. Also, in the present work, the thermoelectric power of indium selenide (InSe and aluminum selenide (AlSe bilayer thin films prepared and annealed in the same way is calculated. The thermoelectric power has been measured by estimating the Seebeck coefficient for InSe and AlSe bilayer thin films. It was observed that the Seebeck coefficient is negative for InSe and AlSe thin films.

  13. High Thermoelectric Power Factor Organic Thin Films through Combination of Nanotube Multilayer Assembly and Electrochemical Polymerization.

    Science.gov (United States)

    Culebras, Mario; Cho, Chungyeon; Krecker, Michelle; Smith, Ryan; Song, Yixuan; Gómez, Clara M; Cantarero, Andrés; Grunlan, Jaime C

    2017-02-22

    In an effort to produce effective thermoelectric nanocomposites with multiwalled carbon nanotubes (MWCNT), layer-by-layer assembly was combined with electrochemical polymerization to create synergy that would produce a high power factor. Nanolayers of MWCNT stabilized with poly(diallyldimethylammonium chloride) or sodium deoxycholate were alternately deposited from water. Poly(3,4-ethylene dioxythiophene) [PEDOT] was then synthesized electrochemically by using this MWCNT-based multilayer thin film as the working electrode. Microscopic images show a homogeneous distribution of PEDOT around the MWCNT. The electrical resistance, conductivity (σ) and Seebeck coefficient (S) were measured before and after the PEDOT polymerization. A 30 bilayer MWCNT film (<1 μm thick) infused with PEDOT is shown to achieve a power factor (PF = S 2 σ) of 155 μW/m K 2 , which is the highest value ever reported for a completely organic MWCNT-based material and competitive with lead telluride at room temperature. The ability of this MWCNT-PEDOT film to generate power was demonstrated with a cylindrical thermoelectric generator that produced 5.5 μW with a 30 K temperature differential. This unique nanocomposite, prepared from water with relatively inexpensive ingredients, should open up new opportunities to recycle waste heat in portable/wearable electronics and other applications where low weight and mechanical flexibility are needed.

  14. Controlling compositional homogeneity and crystalline orientation in Bi0.8Sb0.2 thermoelectric thin films

    Science.gov (United States)

    Rochford, C.; Medlin, D. L.; Erickson, K. J.; Siegal, M. P.

    2015-12-01

    Compositional-homogeneity and crystalline-orientation are necessary attributes to achieve high thermoelectric performance in Bi1-xSbx thin films. Following deposition in vacuum, and upon air exposure, we find that 50%-95% of the Sb in 100-nm thick films segregates to form a nanocrystalline Sb2O3 surface layer, leaving the film bulk as Bi-metal. However, we demonstrate that a thin SiN capping layer deposited prior to air exposure prevents Sb-segregation, preserving a uniform film composition. Furthermore, the capping layer enables annealing in forming gas to improve crystalline orientations along the preferred trigonal axis, beneficially reducing electrical resistivity.

  15. Band alignment measurements at heterojunction interfaces in layered thin film solar cells & thermoelectrics

    Science.gov (United States)

    Fang, Fang

    2011-12-01

    Public awareness of the increasing energy crisis and the related serious environmental concerns has led to a significantly growing demand for alternative clean and renewable energy resources. Thin film are widely applied in multiple renewable energy devices owing to the reduced amount of raw materials and increase flexibility of choosing from low-cost candidates, which translates directly into reduced capital cost. This is a key driving force to make renewable technology competitive in the energy market. This thesis is focused on the measurement of energy level alignments at interfaces of thin film structures for renewable energy applications. There are two primary foci: II -VI semiconductor ZnSe/ZnTe thin film solar cells and Bi2Te3/Sb2Te3 thin film structures for thermoelectric applications. In both cases, the electronic structure and energy band alignment at interfaces usually controls the carrier transport behavior and determines the quality of the device. High-resolution photoemission spectroscopy (lab-based XPS & synchrotron-based UPS) was used to investigate the chemical and electronic properties of epitaxial Bi2Te3 and Sb2Te3 thin films, in order to validate the anticipated band alignment at interfaces in Bi 2Te3/Sb2Te3 superlattices as one favoring electron-transmission. A simple, thorough two-step treatment of a chemical etching in dilute hydrochloric acid solution and a subsequent annealing at ˜150°C under ultra-high vacuum environment is established to remove the surface oxides completely. It is an essential step to ensure the measurements on electronic states are acquired on stoichimetric, oxide-free clean surface of Bi 2Te3 and Sb2Te3 films. The direct measurement of valence band offsets (VBO) at a real Sb 2Te3/Bi2Te3 interface is designed based on the Kraut model; a special stacking film structure is prepared intentionally: sufficiently thin Sb2Te3 film on top of Bi2Te 3 that photoelectrons from both of them are collected simultaneously. From a

  16. Thermoelectric Mixed Thick-/Thin Film Microgenerators Based on Constantan/Silver

    Directory of Open Access Journals (Sweden)

    Mirosław Gierczak

    2018-01-01

    Full Text Available This paper describes the design, manufacturing and characterization of newly developed mixed thick-/thin film thermoelectric microgenerators based on magnetron sputtered constantan (copper-nickel alloy and screen-printed silver layers. The thermoelectric microgenerator consists of sixteen thermocouples made on a 34.2 × 27.5 × 0.25 mm3 alumina substrate. One of thermocouple arms was made of magnetron-sputtered constantan (Cu-Ni alloy, the second was a Ag-based screen-printed film. The length of each thermocouple arm was equal to 27 mm, and their width 0.3 mm. The distance between the arms was equal to 0.3 mm. In the first step, a pattern mask with thermocouples was designed and fabricated. Then, a constantan layer was magnetron sputtered over the whole substrate, and a photolithography process was used to prepare the first thermocouple arms. The second arms were screen-printed onto the substrate using a low-temperature silver paste (Heraeus C8829A or ElectroScience Laboratories ESL 599-E. To avoid oxidation of constantan, they were fired in a belt furnace in a nitrogen atmosphere at 550/450 °C peak firing temperature. Thermoelectric and electrical measurements were performed using the self-made measuring system. Two pyrometers included into the system were used for temperature measurement of hot and cold junctions. The estimated Seebeck coefficient, α was from the range 35 − 41 µV/K, whereas the total internal resistances R were between 250 and 3200 ohms, depending on magnetron sputtering time and kind of silver ink (the resistance of a single thermocouple was between 15.5 and 200 ohms.

  17. X-ray photoelectron spectroscopy study and thermoelectric properties of Al-doped ZnO thin films

    International Nuclear Information System (INIS)

    Li Li; Fang Liang; Zhou Xianju; Liu Ziyi; Zhao Liang; Jiang Sha

    2009-01-01

    In this paper, high quality Al-doped ZnO (AZO) thin films were prepared by direct current (DC) reactive magnetron sputtering using a Zn target (99.99%) containing Al of 1.5 wt.%. The films obtained were characterized by X-ray photoelectron spectroscopy (XPS) and thermoelectric measurements. The XPS results reveal that Zn and Al exist only in oxidized state, while there are dominant crystal lattice and rare adsorbed oxygen for O in the annealed AZO thin films. The studies of thermoelectric property show a striking thermoelectric effect in the AZO thin films. On the one hand, the thermoelectromotive and magnetothermoelectromotive forces increase linearly with increasing temperature difference (ΔT). On the other hand, the thermoelectric power (TEP) decreases with the electrical resistance of the sample. But the TEP increases with the increase of temperature below 300 K, and it nearly does not change around room temperature. The experimental results also demonstrate that the annealing treatment increases TEP, while the external magnetic field degrades TEP.

  18. Gigantic transverse voltage induced via off-diagonal thermoelectric effect in CaxCoO2 thin films

    Science.gov (United States)

    Takahashi, Kouhei; Kanno, Tsutomu; Sakai, Akihiro; Adachi, Hideaki; Yamada, Yuka

    2010-07-01

    Gigantic transverse voltages exceeding several tens volt have been observed in CaxCoO2 thin films with tilted c-axis orientation upon illumination of nanosecond laser pulses. The voltage signals were highly anisotropic within the film surface showing close relation with the c-axis tilt direction. The magnitude and the decay time of the voltage strongly depended on the film thickness. These results confirm that the large laser-induced voltage originates from a phenomenon termed the off-diagonal thermoelectric effect, by which a film out-of-plane temperature gradient leads to generation of a film in-plane voltage.

  19. P-type Al-doped Cr-deficient CrN thin films for thermoelectrics

    DEFF Research Database (Denmark)

    Febvrier, Arnaud le; Van Nong, Ngo; Abadias, Gregory

    2018-01-01

    Thermoelectric properties of chromium nitride (CrN)-based films grown on c-plane sapphire by dc reactive magnetron sputtering were investigated. In this work, aluminum doping was introduced in CrN (degenerate n-type semiconductor) by co-deposition. Under the present deposition conditions, over......-type/n-type thermoelectric materials based on chromium nitride films, which are cheap and routinely grown on the industrial scale....

  20. Thermoelectric Transport by Surface States in Bi2Se3-Based Topological Insulator Thin Films

    International Nuclear Information System (INIS)

    Li Long-Long; Xu Wen

    2015-01-01

    We develop a tractable theoretical model to investigate the thermoelectric (TE) transport properties of surface states in topological insulator thin films (TITFs) of Bi 2 Se 3 at room temperature. The hybridization between top and bottom surface states in the TITF plays a significant role. With the increasing hybridization-induced surface gap, the electrical conductivity and electron thermal conductivity decrease while the Seebeck coefficient increases. This is due to the metal-semiconductor transition induced by the surface-state hybridization. Based on these TE transport coefficients, the TE figure-of-merit ZT is evaluated. It is shown that ZT can be greatly improved by the surface-state hybridization. Our theoretical results are pertinent to the exploration of the TE transport properties of surface states in TITFs and to the potential application of Bi 2 Se 3 -based TITFs as high-performance TE materials and devices. (paper)

  1. Fabrication of Thermoelectric Sensor and Cooling Devices Based on Elaborated Bismuth-Telluride Alloy Thin Films

    Directory of Open Access Journals (Sweden)

    Abdellah Boulouz

    2014-01-01

    Full Text Available The principal motivation of this work is the development and realization of smart cooling and sensors devices based on the elaborated and characterized semiconducting thermoelectric thin film materials. For the first time, the details design of our sensor and the principal results are published. Fabrication and characterization of Bi/Sb/Te (BST semiconducting thin films have been successfully investigated. The best values of Seebeck coefficient (α(T at room temperature for Bi2Te3, and (Bi1−xSbx2Te3 with x = 0.77 are found to be −220 µV/K and +240 µV/K, respectively. Fabrication and evaluation of performance devices are reported. 2.60°C of cooling of only one Peltier module device for an optimal current of Iopt=2.50 mA is obtained. The values of temperature measured by infrared camera, by simulation, and those measured by the integrated and external thermocouple are reported. A sensitivity of the sensors of 5 mV Torr−1 mW−1 for the pressure sensor has been found with a response time of about 600 ms.

  2. Fabrication of thin-film thermoelectric generators with ball lenses for conversion of near-infrared solar light

    OpenAIRE

    Ito, Yoshitaka; Mizoshiri, Mizue; Mikami, Masashi; Kondo, Tasuku; Sakurai, Junpei; Hata, Seiichi

    2017-01-01

    We designed and fabricated thin-film thermoelectric generators (TEGs) with ball lenses, which separated visible light and near-infrared (NIR) solar light using a chromatic aberration. The transmitted visible light was used as daylight and the NIR light was used for thermoelectric generation. Solar light was estimated to be separated into the visible light and NIR light by a ray tracing method. 92.7% of the visible light was used as daylight and 9.9% of the NIR light was used for thermoelectri...

  3. Thermoelectric properties of V{sub 2}O{sub 5} thin films deposited by thermal evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Santos, R.; Loureiro, J., E-mail: joa.loureiro@gmail.com; Nogueira, A.; Elangovan, E.; Pinto, J.V.; Veiga, J.P.; Busani, T.; Fortunato, E.; Martins, R.; Ferreira, I., E-mail: imf@fct.unl.pt

    2013-10-01

    This work reports the structural, optical, electrical and thermoelectric properties of vanadium pentoxide (V{sub 2}O{sub 5}) thin films deposited at room temperature by thermal evaporation on Corning glass substrates. A post-deposition thermal treatment up to 973 K under atmospheric conditions induces the crystallization of the as-deposited amorphous films with an orthorhombic V{sub 2}O{sub 5} phase with grain sizes around 26 nm. As the annealing temperature rises up to 773 K the electrical conductivity increases. The films exhibit thermoelectric properties with a maximum Seebeck coefficient of −218 μV/K and electrical conductivity of 5.5 (Ω m){sup −1}. All the films show NIR-Vis optical transmittance above 60% and optical band gap of 2.8 eV.

  4. Formation of nanodots and enhancement of thermoelectric power induced by ion irradiation in PbTe:Ag composite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Bala, Manju, E-mail: manjubala474@gmail.com [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Meena, Ramcharan; Gupta, Srashti; Pannu, Compesh [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Tripathi, Tripurari S. [Aalto University, Värmemansgränden 2, 02150 Espoo (Finland); Varma, Shikha [Institute of Physics, Bhubaneshwar, Odisha 751005 (India); Tripathi, Surya K. [Department of Physics, Panjab University, Chandigarh 160 014 (India); Asokan, K., E-mail: asokaniuac@gmail.com [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Avasthi, Devesh K. [Amity University, Noida 201313, Uttar Pradesh (India)

    2016-07-15

    Present study demonstrates an enhancement in thermoelectric power of 10% Ag doped PbTe (PbTe:Ag) thin films when irradiated with 200 keV Ar ion. X-ray diffraction showed an increase in crystallinity for both PbTe and PbTe:10Ag nano-composite films after Ar ion irradiation due to annealing of defects in the grain boundaries. The preferential sputtering of Pb and Te ions in comparison to Ag ions resulted in the formation of nano-dots. This was further confirmed by X-ray photoelectron spectroscopy (XPS). Such an enhancement in thermoelectric power of irradiated PbTe:10Ag films in comparison to pristine PbTe:10Ag film is attributed to the decrease in charge carrier concentration that takes part in the transport process via restricting the tunneling of carriers through the wider potential barrier formed at the interface of nano-dots.

  5. Thin films of thermoelectric compound Mg2Sn deposited by co-sputtering assisted by multi-dipolar microwave plasma

    International Nuclear Information System (INIS)

    Le-Quoc, H.; Lacoste, A.; Hlil, E.K.; Bes, A.; Vinh, T. Tan; Fruchart, D.; Skryabina, N.

    2011-01-01

    Highlights: → Mg 2 Sn thin films deposited by plasma co-sputtering, on silicon and glass substrates. → Formation of nano-grained polycrystalline films on substrates at room temperature. → Structural properties vary with target biasing and target-substrate distance. → Formation of the hexagonal phase of Mg 2 Sn in certain deposition conditions. → Power factor ∼5.0 x 10 -3 W K -2 m -1 for stoichiometric Mg 2 Sn films doped with ∼1 at.% Ag. - Abstract: Magnesium stannide (Mg 2 Sn) thin films doped with Ag intended for thermoelectric applications are deposited on both silicon and glass substrates at room temperature by plasma assisted co-sputtering. Characterization by scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction confirms the formation of fine-grained polycrystalline thin films with thickness of 1-3 μm. Stoichiometry, microstructure and crystal structure of thin films are found to vary with target biasing and the distance from targets to substrate. Measurements of electrical resistivity and Seebeck coefficient at room temperature show the maximum power factor of ∼5.0 x 10 -3 W K -2 m -1 for stoichiometric Mg 2 Sn thin films doped with ∼1 at.% Ag.

  6. Enhanced high temperature thermoelectric response of sulphuric acid treated conducting polymer thin films

    KAUST Repository

    Sarath Kumar, S. R.; Kurra, Narendra; Alshareef, Husam N.

    2015-01-01

    We report the high temperature thermoelectric properties of solution processed pristine and sulphuric acid treated poly(3, 4-ethylenedioxythiophene):poly(4-styrenesulfonate) (or PEDOT:PSS) films. The acid treatment is shown to simultaneously enhance the electrical conductivity and Seebeck coefficient of the metal-like films, resulting in a five-fold increase in thermoelectric power factor (0.052 W/m. K ) at 460 K, compared to the pristine film. By using atomic force micrographs, Raman and impedance spectra and using a series heterogeneous model for electrical conductivity, we demonstrate that acid treatment results in the removal of PSS from the films, leading to the quenching of accumulated charge-induced energy barriers that prevent hopping conduction. The continuous removal of PSS with duration of acid treatment also alters the local band structure of PEDOT:PSS, resulting in simultaneous enhancement in Seebeck coefficient.

  7. Enhanced high temperature thermoelectric response of sulphuric acid treated conducting polymer thin films

    KAUST Repository

    Sarath Kumar, S. R.

    2015-11-24

    We report the high temperature thermoelectric properties of solution processed pristine and sulphuric acid treated poly(3, 4-ethylenedioxythiophene):poly(4-styrenesulfonate) (or PEDOT:PSS) films. The acid treatment is shown to simultaneously enhance the electrical conductivity and Seebeck coefficient of the metal-like films, resulting in a five-fold increase in thermoelectric power factor (0.052 W/m. K ) at 460 K, compared to the pristine film. By using atomic force micrographs, Raman and impedance spectra and using a series heterogeneous model for electrical conductivity, we demonstrate that acid treatment results in the removal of PSS from the films, leading to the quenching of accumulated charge-induced energy barriers that prevent hopping conduction. The continuous removal of PSS with duration of acid treatment also alters the local band structure of PEDOT:PSS, resulting in simultaneous enhancement in Seebeck coefficient.

  8. Controlling compositional homogeneity and crystalline orientation in Bi0.8Sb0.2 thermoelectric thin films

    Directory of Open Access Journals (Sweden)

    C. Rochford

    2015-12-01

    Full Text Available Compositional-homogeneity and crystalline-orientation are necessary attributes to achieve high thermoelectric performance in Bi1−xSbx thin films. Following deposition in vacuum, and upon air exposure, we find that 50%–95% of the Sb in 100-nm thick films segregates to form a nanocrystalline Sb2O3 surface layer, leaving the film bulk as Bi-metal. However, we demonstrate that a thin SiN capping layer deposited prior to air exposure prevents Sb-segregation, preserving a uniform film composition. Furthermore, the capping layer enables annealing in forming gas to improve crystalline orientations along the preferred trigonal axis, beneficially reducing electrical resistivity.

  9. Analysis of thermoelectric properties of amorphous InGaZnO thin film by controlling carrier concentration

    Directory of Open Access Journals (Sweden)

    Yuta Fujimoto

    2015-09-01

    Full Text Available We have investigated the thermoelectric properties of amorphous InGaZnO (a-IGZO thin films optimized by adjusting the carrier concentration. The a-IGZO films were produced under various oxygen flow ratios. The Seebeck coefficient and the electrical conductivity were measured from 100 to 400 K. We found that the power factor (PF at 300 K had a maximum value of 82 × 10−6 W/mK2, where the carrier density was 7.7 × 1019 cm−3. Moreover, the obtained data was analyzed by fitting the percolation model. Theoretical analysis revealed that the Fermi level was located approximately above the potential barrier when the PF became maximal. The thermoelectric properties were controlled by the relationship between the position of Fermi level and the height of potential energy barriers.

  10. Thermoelectric properties of Nd0.75Sr1.25CoO4 thin films

    International Nuclear Information System (INIS)

    Huang, S.L.; Ruan, K.Q.; Jiao, X.L.; Wu, H.Y.; Lv, Z.M.; Pang, Z.Q.; Liu, J.; Yang, H.S.; Wu, W.B.; Cao, L.Z.; Li, X.G.

    2007-01-01

    Temperature dependence of the electrical resistivity (ρ) and thermopower (S) in the ab-plane of Nd 0.75 Sr 1.25 CoO 4 thin films have been investigated systematically in the temperature range 70 K< T<310 K. The specimen presents a p-type semiconducting transport property. The S nearly keeps constant at high temperatures and decreases at low ones with an additional step-like decrease, which was argued to be intimately related with the magnetic properties of the specimen. The resistivity follows the Arrhenius law. And the large value of the power factor suggests the films may be a good candidate for the thermoelectric material

  11. Fabrication of flexible thermoelectric microcoolers using planar thin-film technologies

    OpenAIRE

    Gonçalves, L. M.; Rocha, J. G.; Couto, Carlos; Alpuim, P.; Min, Gao; Rowe, D. M.; Correia, J. H.

    2007-01-01

    The present work reports on the fabrication and characterization of a planar Peltier cooler on a flexible substrate. The device was fabricated on a 12 νm thick Kapton(c) polyimide substrate using Bi2Te3 and Sb2Te3 thermoelectric elements deposited by thermal co-evaporation. The cold area of the device is cooled with four thermoelectric junctions, connected in series using metal contacts. Plastic substrates add uncommon mechanical properties to the composite film-substrate and enable integrati...

  12. Effect of Sb content on the thermoelectric properties of annealed CoSb{sub 3} thin films deposited via RF co-sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Aziz, E-mail: aziz_ahmed@ust.ac.kr [Department of Nano-Mechatronics, Korea University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon, 305-350 (Korea, Republic of); Department of Nano-Mechanics, Korea Institute of Machinery and Materials (KIMM), 156 Gajeongbuk-ro, Yuseong-gu, Daejeon, 305-343 (Korea, Republic of); Han, Seungwoo, E-mail: swhan@kimm.re.kr [Department of Nano-Mechatronics, Korea University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon, 305-350 (Korea, Republic of); Department of Nano-Mechanics, Korea Institute of Machinery and Materials (KIMM), 156 Gajeongbuk-ro, Yuseong-gu, Daejeon, 305-343 (Korea, Republic of)

    2017-06-30

    Graphical abstract: The X-ray diffraction patterns and temperature dependence of the Seebeck coefficient of the annealed Co–Sb thin films. - Highlights: • CoSb{sub 3} phase thin films were prepared using RF co sputtering method. • Thin film thermoelectric properties were hugely dependent on Sb content. • All thin films shows n-type conduction behavior at high temperatures. • The thin films with excess Sb possess the largest Seebeck coefficient. • The thin films with CoSb{sub 2} phase possess the largest power factor. - Abstract: A series of CoSb{sub 3} thin films with Sb contents in the range 70–79 at.% were deposited at room temperature via RF co-sputtering. The thin films were amorphous in the as-deposited state and annealed at 300 °C for 3 h to obtain crystalline samples. The annealed thin films were characterized using scanning electron microscopy and X-ray diffraction (XRD), and these data indicate that the films exhibited good crystallinity. The XRD patterns indicate single-phase CoSb{sub 3} thin films in the Sb-rich samples. For the Sb-deficient samples, however, mixed-phase thin films consisting of CoSb{sub 2} and CoSb{sub 3} components were obtained. The electrical and thermoelectric properties were measured at temperatures up to 760 K and found to be highly sensitive to the phases that were present. We observed a change in the thermoelectric properties of the films from p-type at low temperatures to n-type at high temperatures, which indicates potential applications as n-type thermoelectric thin films. A large Seebeck coefficient and power factor was obtained for the single-phase CoSb{sub 3} thin films. The CoSb{sub 2} phase thin films were also found to possess a significant Seebeck coefficient, which coupled with the much smaller electrical resistivity, provided a larger power factor than the single-phase CoSb{sub 3} thin films. We report maximum power factor of 7.92 mW/m K{sup 2} for the CoSb{sub 2}-containing mixed phase thin film and 1

  13. Effect of Sb content on the thermoelectric properties of annealed CoSb_3 thin films deposited via RF co-sputtering

    International Nuclear Information System (INIS)

    Ahmed, Aziz; Han, Seungwoo

    2017-01-01

    Graphical abstract: The X-ray diffraction patterns and temperature dependence of the Seebeck coefficient of the annealed Co–Sb thin films. - Highlights: • CoSb_3 phase thin films were prepared using RF co sputtering method. • Thin film thermoelectric properties were hugely dependent on Sb content. • All thin films shows n-type conduction behavior at high temperatures. • The thin films with excess Sb possess the largest Seebeck coefficient. • The thin films with CoSb_2 phase possess the largest power factor. - Abstract: A series of CoSb_3 thin films with Sb contents in the range 70–79 at.% were deposited at room temperature via RF co-sputtering. The thin films were amorphous in the as-deposited state and annealed at 300 °C for 3 h to obtain crystalline samples. The annealed thin films were characterized using scanning electron microscopy and X-ray diffraction (XRD), and these data indicate that the films exhibited good crystallinity. The XRD patterns indicate single-phase CoSb_3 thin films in the Sb-rich samples. For the Sb-deficient samples, however, mixed-phase thin films consisting of CoSb_2 and CoSb_3 components were obtained. The electrical and thermoelectric properties were measured at temperatures up to 760 K and found to be highly sensitive to the phases that were present. We observed a change in the thermoelectric properties of the films from p-type at low temperatures to n-type at high temperatures, which indicates potential applications as n-type thermoelectric thin films. A large Seebeck coefficient and power factor was obtained for the single-phase CoSb_3 thin films. The CoSb_2 phase thin films were also found to possess a significant Seebeck coefficient, which coupled with the much smaller electrical resistivity, provided a larger power factor than the single-phase CoSb_3 thin films. We report maximum power factor of 7.92 mW/m K"2 for the CoSb_2-containing mixed phase thin film and 1.26 mW/m K"2 for the stoichiometric CoSb_3 thin film.

  14. P-type Al-doped Cr-deficient CrN thin films for thermoelectrics

    Science.gov (United States)

    le Febvrier, Arnaud; Van Nong, Ngo; Abadias, Gregory; Eklund, Per

    2018-05-01

    Thermoelectric properties of chromium nitride (CrN)-based films grown on c-plane sapphire by dc reactive magnetron sputtering were investigated. In this work, aluminum doping was introduced in CrN (degenerate n-type semiconductor) by co-deposition. Under the present deposition conditions, over-stoichiometry in nitrogen (CrN1+δ) rock-salt structure is obtained. A p-type conduction is observed with nitrogen-rich CrN combined with aluminum doping. The Cr0.96Al0.04N1.17 film exhibited a high Seebeck coefficient and a sufficient power factor at 300 °C. These results are a starting point for designing p-type/n-type thermoelectric materials based on chromium nitride films, which are cheap and routinely grown on the industrial scale.

  15. Fabrication of thin-film thermoelectric generators with ball lenses for conversion of near-infrared solar light

    Science.gov (United States)

    Ito, Yoshitaka; Mizoshiri, Mizue; Mikami, Masashi; Kondo, Tasuku; Sakurai, Junpei; Hata, Seiichi

    2017-06-01

    We designed and fabricated thin-film thermoelectric generators (TEGs) with ball lenses, which separated visible light and near-infrared (NIR) solar light using a chromatic aberration. The transmitted visible light was used as daylight and the NIR light was used for thermoelectric generation. Solar light was estimated to be separated into the visible light and NIR light by a ray tracing method. 92.7% of the visible light was used as daylight and 9.9% of the NIR light was used for thermoelectric generation. Then, the temperature difference of the pn junctions of the TEG surface was 0.71 K, determined by heat conduction analysis using a finite element method. The thin-film TEGs were fabricated using lithography and deposition processes. When the solar light (A.M. 1.5) was irradiated to the TEGs, the open-circuit voltage and maximum power were 4.5 V/m2 and 51 µW/m2, respectively. These TEGs are expected to be used as an energy supply for Internet of Things sensors.

  16. Effect of bath temperature on structure, morphology and thermoelectric properties of CoSb{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Suchitra, E-mail: suchitrayadav87@gmail.com; Pandya, Dinesh K.; Chaudhary, Sujeet [Thin Film Laboratory, Physics Department, Indian Institute of Technology Delhi, New Delhi-110016 (India)

    2016-05-23

    CoSb{sub 3} thin films are deposited on conducting glass substrates (FTO) by electrodeposition at different bath temperatures (60°C, 70°C and 80°C) and the resulting influence of the bath temperature on the structure, morphology and electrical properties of films is investigated. X-ray diffraction confirms the formation of CoSb{sub 3} phase in the films. Scanning electron microscopy reveals that different morphologies ranging from branched nano-flakes to nano-needles evolve as bath temperature increases. It is concluded that a growth temperature of 80°C is suitable for producing CoSb{sub 3} films with such properties that show potential feasibility for thermoelectric applications.

  17. Post-CMOS FinFET integration of bismuth telluride and antimony telluride thin-film-based thermoelectric devices on SoI substrate

    KAUST Repository

    Aktakka, Ethem Erkan; Ghafouri, Niloufar; Smith, Casey; Peterson, Rebecca Lorenz; Hussain, Muhammad Mustafa; Najafi, Khalil

    2013-01-01

    This letter reports, for the first time, heterogeneous integration of bismuth telluride (Bi2Te3) and antimony telluride (Sb 2Te3) thin-film-based thermoelectric ffect transistors) via a characterized TE-film coevaporationand shadow-mask patterning

  18. Annealing effects on room temperature thermoelectric performance of p-type thermally evaporated Bi-Sb-Te thin films

    Science.gov (United States)

    Singh, Sukhdeep; Singh, Janpreet; Tripathi, S. K.

    2018-05-01

    Bismuth antimony telluride (Bi-Sb-Te) compounds have been investigated for the past many decades for thermoelectric (TE) power generation and cooling purpose. We synthesized this compound with a stoichiometry Bi1.2Sb0.8Te3 through melt cool technique and thin films of as synthesized material were deposited by thermal evaporation. The prime focus of the present work is to study the influence of annealing temperature on the room temperature (RT) power factor of thin films. Electrical conductivity and Seebeck coefficient were studied and power factors were calculated which showed a peak value at 323 K. The compounds performance is comparable to some very efficient Bi-Sb-Te reported stoichiometries at RT scale. The values observed show that material has an enormous potential for energy production at ambient temperature scales.

  19. Hydrogenated Nano-/Micro-Crystalline Silicon Thin-Films for Thermoelectrics

    Science.gov (United States)

    Acosta, E.; Wight, N. M.; Smirnov, V.; Buckman, J.; Bennett, N. S.

    2018-06-01

    Thermoelectric technology has not yet been able to reach full-scale market penetration partly because most commercial materials employed are scarce/costly, environmentally unfriendly and in addition provide low conversion efficiency. The necessity to tackle some of these hurdles leads us to investigate the suitability of n-type hydrogenated microcrystalline silicon (μc-Si: H) in the fabrication of thermoelectric devices, produced by plasma enhanced chemical vapour deposition (PECVD), which is a mature process of proven scalability. This study reports an approach to optimise the thermoelectric power factor (PF) by varying the dopant concentration by means of post-annealing without impacting film morphology, at least for temperatures below 550°C. Results show an improvement in PF of more than 80%, which is driven by a noticeable increase of carrier mobility and Seebeck coefficient in spite of a reduction in carrier concentration. A PF of 2.08 × 10-4 W/mK2 at room temperature is reported for n-type films of 1 μm thickness, which is in line with the best values reported in recent literature for similar structures.

  20. Hydrogenated Nano-/Micro-Crystalline Silicon Thin-Films for Thermoelectrics

    Science.gov (United States)

    Acosta, E.; Wight, N. M.; Smirnov, V.; Buckman, J.; Bennett, N. S.

    2017-11-01

    Thermoelectric technology has not yet been able to reach full-scale market penetration partly because most commercial materials employed are scarce/costly, environmentally unfriendly and in addition provide low conversion efficiency. The necessity to tackle some of these hurdles leads us to investigate the suitability of n-type hydrogenated microcrystalline silicon (μc-Si: H) in the fabrication of thermoelectric devices, produced by plasma enhanced chemical vapour deposition (PECVD), which is a mature process of proven scalability. This study reports an approach to optimise the thermoelectric power factor (PF) by varying the dopant concentration by means of post-annealing without impacting film morphology, at least for temperatures below 550°C. Results show an improvement in PF of more than 80%, which is driven by a noticeable increase of carrier mobility and Seebeck coefficient in spite of a reduction in carrier concentration. A PF of 2.08 × 10-4 W/mK2 at room temperature is reported for n-type films of 1 μm thickness, which is in line with the best values reported in recent literature for similar structures.

  1. Correlating thermoelectric properties with microstructure in Bi0.8Sb0.2 thin films

    Science.gov (United States)

    Siegal, M. P.; Lima-Sharma, A. L.; Sharma, P. A.; Rochford, C.

    2017-04-01

    The room temperature electronic transport properties of 100 nm-thick thermoelectric Bi0.8Sb0.2 films, sputter-deposited onto quartz substrates and post-annealed in an ex-situ furnace, systematically correlate with the overall microstructural quality, improving with increasing annealing temperature until close to the melting point for the alloy composition. The optimized films have high crystalline quality with ˜99% of the grains oriented with the trigonal axis perpendicular to the substrate surface. Film resistivities and Seebeck coefficients are accurately measured by preventing deleterious surface oxide formation via a SiN capping layer and using Nd-doped Al for contacts. The resulting values are similar to single crystals and significantly better than previous reports from films and polycrystalline bulk alloys.

  2. Augmentation of thermoelectric performance of VO2 thin films irradiated by 200 MeV Ag9+-ions

    International Nuclear Information System (INIS)

    Khan, G.R.; Kandasami, A.; Bhat, B.A.

    2016-01-01

    Swift Heavy Ion (SHI) irradiation with 200 MeV Ag 9+ -ion beam at ion fluences of 1E11, 5E11, 1E12, and 5E12 for tuning of electrical transport properties of VO 2 thin films fabricated by so–gel technique on alumina substrates has been demonstrated in the present paper. The point defects created by SHI irradiation modulate metal to insulator phase transition temperature, carrier concentration, carrier mobility, electrical conductivity, and Seebeck coefficient of VO 2 thin films. The structural properties of the films were characterized by XRD and Raman spectroscopy and crystallite size was found to decrease upon irradiation. The atomic force microscopy revealed that the surface roughness of specimens first decreased and then increased with increasing fluence. Both resistance as well as Seebeck coefficient measurements demonstrated that all the samples exhibit metal–insulator phase transition and the transition temperatures decreases with increasing fluence. Hall effect measurements exhibited that carrier concentration increased continuously with increasing fluence which resulted in an increase of electrical conductivity by several orders of magnitude in the insulating phase. Seebeck coefficient in insulating phase remained almost constant in spite of an increase in the electrical conductivity by several orders of magnitude making SHI irradiation an alternative stratagem for augmentation of thermoelectric performance of the materials. The carrier mobility at room temperature decreased up to the beam fluence of 5E11 and then started increasing whereas Seebeck coefficient in metallic state first increased with increasing ion beam fluence up to 5E11 and thereafter decreased. Variation of these electrical transport parameters has been explained in detail. - Highlights: • Thermoelectric properties of VO 2 thin films enhance upon SHI irradiation. • Structural properties show that crystallite size decrease upon SHI irradiation. • Metal–insulator phase

  3. High-temperature stability of thermoelectric Ca3Co4O9 thin films

    DEFF Research Database (Denmark)

    Brinks, P.; Van Nong, Ngo; Pryds, Nini

    2015-01-01

    An enhanced thermal stability in thermoelectric Ca3Co4O9 thin films up to 550 °C in an oxygen rich environment was demonstrated by high-temperature electrical and X-ray diffraction measurements. In contrast to generally performed heating in helium gas, it is shown that an oxygen/helium mixture...... provides sufficient thermal contact, while preventing the previously disregarded formation of oxygen vacancies. Combining thermal cycling with electrical measurements proves to be a powerful tool to study the real intrinsic thermoelectric behaviour of oxide thin films at elevated temperatures. © 2015 AIP...

  4. Magneto-transport and thermoelectric properties of epitaxial FeSb{sub 2} thin film on MgO substrate

    Energy Technology Data Exchange (ETDEWEB)

    Duong, Anh Tuan; Rhim, S. H., E-mail: sonny@ulsan.ac.kr; Shin, Yooleemi; Nguyen, Van Quang; Cho, Sunglae, E-mail: slcho@ulsan.ac.kr [Department of Physics and Energy Harvest-Storage Research Center, University of Ulsan, Ulsan 680-749 (Korea, Republic of)

    2015-01-19

    We report magneto-transport and thermoelectric properties of FeSb{sub 2} thin film epitaxially grown on the MgO substrate using molecular beam epitaxy. The film exhibits compressive strain of 1.74% owing to large lattice mismatch, whose physical consequences are nontrivial. Magnetic phase has been changed from diamagnetic in bulk, as evidenced by anomalous Hall effect (AHE) and negative magneto-resistance (MR). The FeSb{sub 2} film is semiconducting without any metallic transition unlike the bulk counterpart. In particular, hysteresis in MR with distinct feature of AHE is evident with coercive field of 500 and 110 Oe for T = 20 and 50 K, respectively. Furthermore, from the Seebeck coefficients and temperature dependence of the resistivity, it is evident that the film is semiconducting with small band gap: 3.76 meV for T < 40 K and 13.48 meV for T > 40 K, respectively, where maximum thermoelectric power factor of 12 μV/cm·K at T = 50 K.

  5. Nano-crystalline Ag–PbTe thermoelectric thin films by a multi-target PLD system

    Energy Technology Data Exchange (ETDEWEB)

    Cappelli, E., E-mail: emilia.cappelli@ism.cnr.it [CNR-ISM, Montelibretti, Via Salaria Km 29.3, P.O.B. 10, 00016 Rome (Italy); Bellucci, A. [CNR-ISM, Montelibretti, Via Salaria Km 29.3, P.O.B. 10, 00016 Rome (Italy); Dip. Fisica, Un. Roma Sapienza, Piazzale Aldo Moro 2, 00185 Rome (Italy); Medici, L. [CNR-IMAA, Tito Scalo, 85050 Potenza (Italy); Mezzi, A.; Kaciulis, S. [CNR-ISMN, Montelibretti, Via Salaria Km 29.3, P.O.B. 10, 00016 Rome (Italy); Fumagalli, F.; Di Fonzo, F. [Center Nano Science Technology @Polimi, I.I.T., Via Pascoli 70/3, 20133 Milano (Italy); Trucchi, D.M. [CNR-ISM, Montelibretti, Via Salaria Km 29.3, P.O.B. 10, 00016 Rome (Italy)

    2015-05-01

    Highlights: • Thermoelectric PbTe thin films, with increasing Ag percentage, were deposited by PLD. • Almost stoichiometric PbTe (Ag doped) films were grown, as verified by XPS analysis. • GI-XRD established the formation of cubic PbTe, with nano-metric structure (∼35 nm). • Surface resistivity shows an increase in conductivity, with increasing Ag doping. • From Seebeck values and XPS depth analysis, 10% Ag seems to be the solubility limit. - Abstract: It has been evaluated the ability of ArF pulsed laser ablation to grow nano-crystalline thin films of high temperature PbTe thermoelectric material, and to obtain a uniform and controlled Ag blending, through the entire thickness of the film, using a multi-target system in vacuum. The substrate used was a mirror polished technical alumina slab. The increasing atomic percentage of Ag effect on physical–chemical and electronic properties was evaluated in the range 300–575 K. The stoichiometry and the distribution of the Ag component, over the whole thickness of the samples deposited, have been studied by XPS (X-ray photoelectron spectroscopy) and corresponding depth profiles. The crystallographic structure of the film was analyzed by grazing incidence X-ray diffraction (GI-XRD) system. Scherrer analysis for crystallite size shows the presence of nano-structures, of the order of 30–35 nm. Electrical resistivity of the samples, studied by the four point probe method, as a function of increasing Ag content, shows a typical semi-conductor behavior. From conductivity values, carrier concentration and Seebeck parameter determination, the power factor of deposited films was calculated. Both XPS, Hall mobility and Seebeck analysis seem to indicate a limit value to the Ag solubility of the order of 5%, for thin films of ∼200 nm thickness, deposited at 350 °C. These data resulted to be comparable to theoretical evaluation for thin films but order of magnitude lower than the corresponding bulk materials.

  6. Thermoelectric Properties of Nanograined Si-Ge-Au Thin Films Grown by Molecular Beam Deposition

    Science.gov (United States)

    Nishino, Shunsuke; Ekino, Satoshi; Inukai, Manabu; Omprakash, Muthusamy; Adachi, Masahiro; Kiyama, Makoto; Yamamoto, Yoshiyuki; Takeuchi, Tsunehiro

    2018-06-01

    Conditions to achieve extremely large Seebeck coefficient and extremely small thermal conductivity in Si-Ge-Au thin films formed of nanosized grains precipitated in amorphous matrix have been investigated. We employed molecular beam deposition to prepare Si1- x Ge x Au y thin films on sapphire substrate. The deposited films were annealed under nitrogen gas atmosphere at 300°C to 500°C for 15 min to 30 min. Nanocrystals dispersed in amorphous matrix were clearly observed by transmission electron microscopy. We did not observe anomalously large Seebeck coefficient, but very low thermal conductivity of nearly 1.0 W K-1 m-1 was found at around 0.2 Si-Ge bulk material for which dimensionless figure of merit of ZT ≈ 1 was reported at high temperature.

  7. Post-CMOS FinFET integration of bismuth telluride and antimony telluride thin-film-based thermoelectric devices on SoI substrate

    KAUST Repository

    Aktakka, Ethem Erkan

    2013-10-01

    This letter reports, for the first time, heterogeneous integration of bismuth telluride (Bi2Te3) and antimony telluride (Sb 2Te3) thin-film-based thermoelectric ffect transistors) via a characterized TE-film coevaporationand shadow-mask patterning process using predeposition surface treatment methods for reduced TE-metal contact resistance. As a demonstration vehicle, a 2 × 2 mm2-sized integrated planar thermoelectric generator (TEG) is shown to harvest 0.7 μ W from 21-K temperature gradient. Transistor performance showed no significant change upon post-CMOS TEG integration, indicating, for the first time, the CMOS compatibility of the Bi2Te3 and Sb2Te3 thin films, which could be leveraged for realization of high-performance integrated micro-TE harvesters and coolers. © 2013 IEEE.

  8. Comparison of four-probe thermal and thermoelectric transport measurements of thin films and nanostructures with microfabricated electro-thermal transducers

    Science.gov (United States)

    Kim, Jaehyun; Fleming, Evan; Zhou, Yuanyuan; Shi, Li

    2018-03-01

    Two different four-probe thermal and thermoelectric measurement methods have been reported for measuring the thermal conductivity, Seebeck coefficient, and electrical conductivity of suspended thin films and nanostructures with microfabricated electro-thermal transducers. The thermal contact resistance was extracted from the measured thermoelectric voltage drop at the contacts in the earlier four-probe method based on the assumption of constant thermal and thermoelectric properties along the sample. In comparison, the latter four-probe method can directly obtain the contact thermal resistance together with the intrinsic sample thermal resistance without making this assumption. Here, the measurement theory and data reduction processes of the latter four-probe measurement method are re-examined and improved. The measured thermal conductivity result of this improved method on representative thin film samples are found to agree with those obtained from the earlier four-probe method, which has obtained similar Seebeck coefficient and electrical conductivity as those measured with a different method for a supported thin film. The agreement provides further validation of the latest four-probe thermal transport measurement method of thin films and nanostructures.

  9. Optoelectronic and thermoelectric properties in Ga doped {beta}- PbS{sub 2} nanostructured thin films

    Energy Technology Data Exchange (ETDEWEB)

    Geethu, R.; Jacob, Rajani [Thin Film Research Lab, U.C. College, Aluva, Cochin, Kerala (India); Shripathi, T.; Okram, G.S.; Ganesan, V.; Tripathi, Shilpa; Fatima, Anees [UGC-DAE CSR, Khandwa Road, Indore-452 001, Madhya Pradesh (India); Sreenivasan, P.V. [Department of Chemistry, U.C. College, Aluva, Cochin, Kerala (India); Urmila, K.S.; Pradeep, B. [Solid State Physics Laboratory, Cochin University of Science and Technology, Cochin, Kerala (India); Philip, Rachel Reena, E-mail: reenatara@rediffmail.com [Thin Film Research Lab, U.C. College, Aluva, Cochin, Kerala (India)

    2012-06-15

    Lead sulphide nanostructured thin films were grown on soda lime glass substrates by chemical bath deposition. The films were then doped with gallium using vacuum evaporation technique. X-ray diffraction (XRD) established the structural type of the host films to be tetragonal {beta}-PbS{sub 2} with average grain size of the order of 15 nm. The nanostructure of films was further confirmed from scanning electron and atomic force micrographs. The shift in the binding energies of the 4f and 4d states of lead, 2p state of sulphur and the 2p states of Ga from their elemental binding energy values, determined from X-ray photoelectron spectroscopy (XPS), indicated intact chemical bonding in the compound. Compositional analysis showed about 0.01% doping of Ga into PbS{sub 2}. Low temperature thermopower measurements indicated p-type conductivity for the films with Fermi level positioned at about 0.017 eV above the maxima of valence band. Optical absorption studies in conjunction with photo sensitivity measurements established its pertinence in junction formation in photovoltaic applications due to the blue shift in the band gap to 2.37 eV and the increased photoconductivity of the films.

  10. Control of p-type and n-type thermoelectric properties of bismuth telluride thin films by combinatorial sputter coating technology

    International Nuclear Information System (INIS)

    Goto, Masahiro; Sasaki, Michiko; Xu, Yibin; Zhan, Tianzhuo; Isoda, Yukihiro; Shinohara, Yoshikazu

    2017-01-01

    Highlights: • p- and n-type bismuth telluride thin films have been synthesized using a combinatorial sputter coating system (COSCOS) while changing only one of the experimental conditions, the RF power. • The dimensionless figure of merit (ZT) was optimized by the technique. • The fabrication of a Π-structured TE device was demonstrated. - Abstract: p- and n-type bismuth telluride thin films have been synthesized by using a combinatorial sputter coating system (COSCOS). The crystal structure and crystal preferred orientation of the thin films were changed by controlling the coating condition of the radio frequency (RF) power during the sputter coating. As a result, the p- and n-type films and their dimensionless figure of merit (ZT) were optimized by the technique. The properties of the thin films such as the crystal structure, crystal preferred orientation, material composition and surface morphology were analyzed by X-ray diffraction, energy-dispersive X-ray spectroscopy and atomic force microscopy. Also, the thermoelectric properties of the Seebeck coefficient, electrical conductivity and thermal conductivity were measured. ZT for n- and p-type bismuth telluride thin films was found to be 0.27 and 0.40 at RF powers of 90 and 120 W, respectively. The proposed technology can be used to fabricate thermoelectric p–n modules of bismuth telluride without any doping process.

  11. Control of p-type and n-type thermoelectric properties of bismuth telluride thin films by combinatorial sputter coating technology

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Masahiro, E-mail: goto.masahiro@nims.go.jp [Thermoelectric Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Sasaki, Michiko [Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Xu, Yibin [Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Materials Database Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Zhan, Tianzhuo [Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Isoda, Yukihiro [Thermoelectric Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Shinohara, Yoshikazu [Thermoelectric Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

    2017-06-15

    Highlights: • p- and n-type bismuth telluride thin films have been synthesized using a combinatorial sputter coating system (COSCOS) while changing only one of the experimental conditions, the RF power. • The dimensionless figure of merit (ZT) was optimized by the technique. • The fabrication of a Π-structured TE device was demonstrated. - Abstract: p- and n-type bismuth telluride thin films have been synthesized by using a combinatorial sputter coating system (COSCOS). The crystal structure and crystal preferred orientation of the thin films were changed by controlling the coating condition of the radio frequency (RF) power during the sputter coating. As a result, the p- and n-type films and their dimensionless figure of merit (ZT) were optimized by the technique. The properties of the thin films such as the crystal structure, crystal preferred orientation, material composition and surface morphology were analyzed by X-ray diffraction, energy-dispersive X-ray spectroscopy and atomic force microscopy. Also, the thermoelectric properties of the Seebeck coefficient, electrical conductivity and thermal conductivity were measured. ZT for n- and p-type bismuth telluride thin films was found to be 0.27 and 0.40 at RF powers of 90 and 120 W, respectively. The proposed technology can be used to fabricate thermoelectric p–n modules of bismuth telluride without any doping process.

  12. Acido-basic control of the thermoelectric properties of poly(3,4-ethylenedioxythiophene)tosylate (PEDOT-Tos) thin films

    DEFF Research Database (Denmark)

    Khan, Zia Ullah; Bubnova, Olga; Jafari, Mohammad Javad

    2015-01-01

    study the variation in the thermoelectric properties by a simple acido-basic treatment. The emphasis of this study is to elucidate the chemical changes induced by acid (HCl) or base (NaOH) treatment in PEDOT-Tos thin films using various spectroscopic and structural techniques. We could identify changes...... in the nanoscale morphology due to anion exchange between tosylate and Cl- or OH-. But, we identified that changing the pH leads to a tuning of the oxidation level of the polymer, which can explain the changes in thermoelectric properties. Hence, a simple acid-base treatment allows finding the optimum...

  13. Preparation and Thermoelectric Characteristics of ITO/PtRh:PtRh Thin Film Thermocouple.

    Science.gov (United States)

    Zhao, Xiaohui; Wang, Hongmin; Zhao, Zixiang; Zhang, Wanli; Jiang, Hongchuan

    2017-12-15

    Thin film thermocouples (TFTCs) can provide more precise in situ temperature measurement for aerospace propulsion systems without disturbance of gas flow and surface temperature distribution of the hot components. ITO/PtRh:PtRh TFTC with multilayer structure was deposited on alumina ceramic substrate by magnetron sputtering. After annealing, the TFTC was statically calibrated for multiple cycles with temperature up to 1000 °C. The TFTC with excellent stability and repeatability was realized for the negligible variation of EMF in different calibration cycles. It is believed that owing to oxygen diffusion barriers by the oxidation of top PtRh layer and Schottky barriers formed at the grain boundaries of ITO, the variation of the carrier concentration of ITO film is minimized. Meanwhile, the life time of TFTC is more than 30 h in harsh environment. This makes ITO/PtRh:PtRh TFTC a promising candidate for precise surface temperature measurement of hot components of aeroengines.

  14. Theoretical analysis of thermoelectric power of nanocrystalline ReSi2 thin film

    International Nuclear Information System (INIS)

    Kchoudhary, K; Kaurav; Gupta, N; Varshney, D

    2007-01-01

    The formulation is developed for the predictive modeling of thermoelectric power (S) of nano-crystalline ReSi 2 . We have evaluated the phonon thermoelectric power by incorporating the scattering of phonons with impurities, grain boundaries, charge careers and phonons. It is noticed that at low temperatures (T < 400 K), S increases and show power temperature dependence because of the larger mean free path of phonon, S shows a broad peak at about 550 K, which is artefact of the competition among umklapp scattering and grain boundaries scattering. Further, by increasing temperature S decreases with change in slope. The anomalies are well accounted in terms of interaction among the phonons-impurity, phonon grain boundaries and the umklapp scattering. Under certain conditions grain boundary scattering is expected to be more effective on heat carrying phonons than on Umklapp scattering, causing an increased thermoelectric power. Numerical analysis of thermoelectric power from the present model shows similar results as those revealed from experiments

  15. Solid Liquid Interdiffusion Bonding of (Pb, Sn)Te Thermoelectric Modules with Cu Electrodes Using a Thin-Film Sn Interlayer

    Science.gov (United States)

    Chuang, T. H.; Lin, H. J.; Chuang, C. H.; Yeh, W. T.; Hwang, J. D.; Chu, H. S.

    2014-12-01

    A (Pb, Sn)Te thermoelectric element plated with a Ni barrier layer and a Ag reaction layer has been joined with a Cu electrode coated with Ag and Sn thin films using a solid-liquid interdiffusion bonding method. This method allows the interfacial reaction between Ag and Sn such that Ag3Sn intermetallic compounds form at low temperature and are stable at high temperature. In this study, the bonding strength was about 6.6 MPa, and the specimens fractured along the interface between the (Pb, Sn)Te thermoelectric element and the Ni barrier layer. Pre-electroplating a film of Sn with a thickness of about 1 μm on the thermoelectric element and pre-heating at 250°C for 3 min ensures the adhesion between the thermoelectric material and the Ni barrier layer. The bonding strength is thus increased to a maximal value of 12.2 MPa, and most of the fractures occur inside the thermoelectric material. During the bonding process, not only the Ag3Sn intermetallics but also Cu6Sn5 forms at the Ag3Sn/Cu interface, which transforms into Cu3Sn with increases in the bonding temperature or bonding time.

  16. Structural, chemical, and thermoelectric properties of Bi2Te3 Peltier materials. Bulk, thin films, and superlattices

    International Nuclear Information System (INIS)

    Peranio, Nicola

    2008-01-01

    In this work, the nature of the natural nanostructure (nns) was analysed and the correlations to the transport coefficients, particularly the lattice thermal conductivity, is discussed. Experimental methods are presented for the first time, yielding an accurate quantitative analysis of the chemical composition and of stress fields in Bi 2 Te 3 and in compounds with similar structural and chemical microstructures. This work can be subdivided as follows: (I) N-type Bi 2 (Te 0.91 Se 0.09 ) 3 and p-type (Bi 0.26 Sb 0.74 ) 1.98 (Te 0.99 Se 0.01 ) 3.02 bulk materials synthesised by the Bridgman technique. (II) Bi 2 Te 3 thin films and Bi 2 Te 3 /Bi 2 (Te 0.88 Se 0.12 ) 3 superlattices epitaxially grown by molecular beam epitaxy (MBE) on BaF 2 substrates with periods of δ-12 nm at the Fraunhofer-Institut fuer Physikalische Messtechnik (IPM). (III) Experimental methods, i.e., TEM specimen preparation, high-accuracy quantitative chemical analysis by EDX in the TEM, and image simulations of dislocations and the nns according to the two-beam dynamical diffraction theory. The nns was analysed in detail by stereomicroscopy and by image simulation and was found to be a pure sinusoidal displacement field with (i) a displacement vector parallel to and an amplitude of about 10 pm and (ii) a wave vector parallel to {1,0,10} and a wavelength of 10 nm. The results obtained here showed a significant amount of stress in the samples, induced by the nns which was still not noticed and identified. Both kinds of nanostructures, artificial (ans) and natural (nns) nanostructures, yielded in thermoelectric materials a low lattice thermal conductivity which was beneficial for the thermoelectric figure of merit ZT. (orig.)

  17. Impact of the Topological Surface State on the Thermoelectric Transport in Sb2Te3 Thin Films.

    Science.gov (United States)

    Hinsche, Nicki F; Zastrow, Sebastian; Gooth, Johannes; Pudewill, Laurens; Zierold, Robert; Rittweger, Florian; Rauch, Tomáš; Henk, Jürgen; Nielsch, Kornelius; Mertig, Ingrid

    2015-04-28

    Ab initio electronic structure calculations based on density functional theory and tight-binding methods for the thermoelectric properties of p-type Sb2Te3 films are presented. The thickness-dependent electrical conductivity and the thermopower are computed in the diffusive limit of transport based on the Boltzmann equation. Contributions of the bulk and the surface to the transport coefficients are separated, which enables to identify a clear impact of the topological surface state on the thermoelectric properties. When the charge carrier concentration is tuned, a crossover between a surface-state-dominant and a Fuchs-Sondheimer transport regime is achieved. The calculations are corroborated by thermoelectric transport measurements on Sb2Te3 films grown by atomic layer deposition.

  18. Thermoelectric power of Bi and Bi{sub 1{minus}x}Sb{sub x} alloy thin films and superlattices grown by MBE

    Energy Technology Data Exchange (ETDEWEB)

    Cho, S; DiVenere, A; Wong, G K; Ketterson, J B; Meyer, J R; Hoffman, C A

    1997-07-01

    The authors have measured the thermoelectric power (TEP) of MBE-grown epitaxial Bi and Bi{sub 1{minus}x} alloy thin films and superlattices as a function of temperature in the range 20--300 K. They have observed that the TEP of a Bi thin film of 1 {micro}m thickness is in good agreement with the bulk single crystal value and that the TEPs for superlattices with 400 {angstrom} and 800 {angstrom} Bi well thicknesses are enhanced over the bulk values. For x = 0.072 and 0.088 in Bi{sub 1{minus}x}Sb{sub x} thin films showing semiconducting behavior, TEP enhancement was observed by a factor of two. However as Bi or Bi{sub 1{minus}x}Sb{sub x} well thickness decreases in superlattice geometry, the TEP decreases, which may be due to unintentional p-type doping.

  19. Effects of Mev Si Ions and Thermal Annealing on Thermoelectric and Optical Properties of SiO2/SiO2+Ge Multi-nanolayer thin Films

    Science.gov (United States)

    Budak, S.; Alim, M. A.; Bhattacharjee, S.; Muntele, C.

    Thermoelectric generator devices have been prepared from 200 alternating layers of SiO2/SiO2+Ge superlattice films using DC/RF magnetron sputtering. The 5 MeV Si ionsbombardmenthasbeen performed using the AAMU Pelletron ion beam accelerator to formquantum dots and / or quantum clusters in the multi-layer superlattice thin films to decrease the cross-plane thermal conductivity, increase the cross-plane Seebeck coefficient and increase the cross-plane electrical conductivity to increase the figure of merit, ZT. The fabricated devices have been annealed at the different temperatures to tailor the thermoelectric and optical properties of the superlattice thin film systems. While the temperature increased, the Seebeck coefficient continued to increase and reached the maximum value of -25 μV/K at the fluenceof 5x1013 ions/cm2. The decrease in resistivity has been seen between the fluence of 1x1013 ions/cm2 and 5x1013 ions/cm2. Transport properties like Hall coefficient, density and mobility did not change at all fluences. Impedance spectroscopy has been used to characterize the multi-junction thermoelectric devices. The loci obtained in the C*-plane for these data indicate non-Debye type relaxation displaying the presence of the depression parameter.

  20. Thermoelectric PbTe thin film for superresolution optical data storage

    International Nuclear Information System (INIS)

    Lee, Hyun Seok; Cheong, Byung-ki; Lee, Taek Sung; Lee, Kyeong Seok; Kim, Won Mok; Lee, Jae Won; Cho, Sung Ho; Youl Huh, Joo

    2004-01-01

    To find its practical use in ultrahigh density optical data storage, superresolution (SR) technique needs a material that can render a high SR capability at no cost of durability against repeated readout and write. Thermoelectric materials appear to be promising candidates due to their capability of yielding phase-change-free thermo-optic changes. A feasibility study was carried out with PbTe for its large thermoelectric coefficient and high stability over a wide temperature range as a crystalline single phase. Under exposure to pulsed red light, the material was found to display positive, yet completely reversible changes of optical transmittance regardless of laser power, fulfilling basic requirements for SR readout and write. The material was also shown to have a high endurance against repeated static laser heating of up to 10 6 -10 7 cycles tested. A read only memory disk with a PbTe SR layer led to the carrier to noise ratio value of 47 dB at 3.5 mW for 0.25 μm pit; below the optical resolution limit (∼0.27 μm) of the tester

  1. Strain-Induced Rolled Thin Films for Lightweight Tubular Thermoelectric Generators

    KAUST Repository

    Singh, Devendra

    2017-11-24

    Thermoelectric generators (TEGs) are interesting energy harvesters of otherwise wasted heat. Here, a polymer-assisted generic process and its mechanics to obtain sputtered thermoelectric (TE) telluride material-based 3D tubular structures with unprecedented length (up to seamless 4 cm and further expandable) are shown. This length allows for large temperature differences between the hot and the cold ends, a critical but untapped enabler for high power generation. Compared with a flat slab, better area efficiency is observed for a rolled tube and compared with a solid rod architecture, a rolled tube uses less material (thus making it lightweight and cost effective) and has competitive performance advantage due to a smaller contact area. It is also shown that a tubular architecture thermopile-based TEG is able to generate up to 5 μW of power (eight pairs of p- and n-type thermopiles) through a temperature difference of 60 °C. The demonstrated process can play an important role in transforming 2D atomic crystal structure TE materials into 3D tubular thermopiles for effective TEG application, which can maintain higher temperature differences by longer distances between hot and cold ends.

  2. thin films

    Indian Academy of Sciences (India)

    microscopy (SEM) studies, respectively. The Fourier transform ... Thin films; chemical synthesis; hydrous tin oxide; FTIR; electrical properties. 1. Introduction ... dehydrogenation of organic compounds (Hattori et al 1987). .... SEM images of (a) bare stainless steel and (b) SnO2:H2O thin film on stainless steel substrate at a ...

  3. Printing and Folding: A Solution for High-Throughput Processing of Organic Thin-Film Thermoelectric Devices

    DEFF Research Database (Denmark)

    Mortazavinatanzi, Seyedmohammad; Rezaniakolaei, Alireza; Rosendahl, Lasse Aistrup

    2018-01-01

    implantable sensors. Introducing new semiconductor materials like organic thermoelectric materials and advancing manufacturing techniques are paving the way to overcome the barriers associated with the bulky and inflexible nature of the common TEGs and are making it possible to fabricate flexible...... and biocompatible modules. Yet, the lower efficiency of these materials in comparison with bulk-inorganic counterparts as well as applying them mostly in the form of thin layers on flexible substrates limits their applications. This research aims to improve the functionality of thin and flexible organic...

  4. On-Chip Sensing of Thermoelectric Thin Film’s Merit

    OpenAIRE

    Xiao, Zhigang; Zhu, Xiaoshan

    2015-01-01

    Thermoelectric thin films have been widely explored for thermal-to-electrical energy conversion or solid-state cooling, because they can remove heat from integrated circuit (IC) chips or micro-electromechanical systems (MEMS) devices without involving any moving mechanical parts. In this paper, we report using silicon diode-based temperature sensors and specific thermoelectric devices to characterize the merit of thermoelectric thin films. The silicon diode temperature sensors and thermoelect...

  5. Improving the thermoelectric performance of metastable rock-salt GeTe-rich Ge-Sb-Te thin films through tuning of grain orientation and vacancies

    Energy Technology Data Exchange (ETDEWEB)

    Chen, I. Nan [Department of Physics, National Taiwan University, Taipei (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei (China); Chong, Cheong-Wei [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei (China); Center for Condensed Matter Sciences, National Taiwan University, Taipei (China); Wong, Deniz P.; Lyu, Liang-Ming; Chien, Wei-Lun; Anbalagan, Ramakrishnan; Aminzare, Masoud; Chen, Kuei-Hsien [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei (China); Chen, Yang-Fang [Department of Physics, National Taiwan University, Taipei (China); Chen, Li-Chyong [Center for Condensed Matter Sciences, National Taiwan University, Taipei (China)

    2016-12-15

    Phase-change memory materials such as the pseudobinary GeTe-Sb{sub 2}Te{sub 3} compounds have recently gained attention for their good thermoelectric properties, which can be used for power-generation/cooling applications. In this work, GeTe-rich Ge-Sb-Te thin films deposited using a radio-frequency magnetron sputtering method readily exhibit the metastable face-centered cubic (FCC) phase at room temperature. This is in stark contrast to its bulk form, which only transforms to its FCC phase after a transition temperature of around 350 C. Based on previous works, the FCC phase contributes to the superior thermoelectric properties of this material system. In this study, by decreasing the working deposition pressure, the preferred orientation of (200) plane is observed that translates to improved carrier mobility. Moreover, increasing the annealing temperature has been shown to decrease the carrier concentration due to Te deficiency, leading to a significant improvement in the Seebeck coefficient of the film. By combining these effects, an optimized thermoelectric power factor (21 μW/cm K{sup 2}) was obtained at an operating temperature of 350 C. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Influence of temperature on thermoelectric properties of Fe{sub x}Co{sub 1−x}S{sub 2} thin films: A semiconductor to semimetal conversion

    Energy Technology Data Exchange (ETDEWEB)

    Clamagirand, J.M.; Ares, J.R., E-mail: joser.ares@uam.es; Flores, E.; Diaz-Chao, P.; Leardini, F.; Ferrer, I.J.; Sánchez, C.

    2016-02-01

    In this work, we investigate the thermoelectric properties of p and n-type thin films obtained by cobalt doping of FeS{sub 2}. Films were synthesized by direct sulfuration of Co–Fe thin bilayers at 300 °C. It is found that at room temperature (RT), the Seebeck coefficient is reduced from 80 μV/K to − 70 μV/K when Co concentration is increased and the electrical resistivity of the films is decreased two orders of magnitude. X-ray diffraction and Raman measurements point out that Co is replacing Fe into the pyrite lattice and, subsequently is promoting a semiconductor to semimetal conversion. The influence of temperature on transport properties of different Fe{sub x}Co{sub 1−x}S{sub 2} films has been investigated. Whereas the Seebeck coefficient is hardly modified, the film resistivity is drastically decreased when temperature increases what has been attributed to the thermal activation of electrical carriers. The influence of Co doping on the band scheme of FeS{sub 2} is shown. To this aim, donor and acceptor states are included into its forbidden gap. Whereas the band scheme of FeS{sub 2} exhibits an acceptor level with an E = 0.11 ± 0.03 eV above the top of the valence band due to iron vacancies, a wide donor level close to the bottom of the conduction band (E = 0.08 ± 0.05 eV) is created by the progressive replacement of iron by cobalt into the FeS{sub 2} lattice. - Highlights: • Thermoelectric properties of pyrite and Co-doped pyrite thin films were measured. • Whereas ρ decreases, S remains practically unaltered on increasing temperature (RT-300 °C). • On increasing Co-concentration, films exhibit a p semiconductor to n type semimetal conversion. • Donor states close to the botton of the conduction band are created by Co doping. • Energy of the donor level decreases and gets wider due to Co-concentration.

  7. On the crystal structure and thermoelectric properties of thin Si{sub 1–x}Mn{sub x} films

    Energy Technology Data Exchange (ETDEWEB)

    Erofeeva, I. V., E-mail: irfeya@mail.ru; Dorokhin, M. V.; Lesnikov, V. P.; Zdoroveishchev, A. V.; Kudrin, A. V.; Pavlov, D. A.; Usov, U. V. [Lobachevsky State University of Nizhny Novgorod, Research Institute for Physics and Technology (Russian Federation)

    2016-11-15

    Thin (25 nm) Si{sub 1–x}Mn{sub x}/Si(100) films are fabricated by pulsed laser deposition. According to high-resolution transmission electron microscopy data, the films have a nanotextured crystalline structure and are chemically homogeneous. The temperature dependences of the resistivity and thermopower are measured in the range of 300–500 K, and the temperature dependences of the Seebeck coefficient and power factor are calculated.

  8. Low-Temperature Bonding of Bi0.5Sb1.5Te3 Thermoelectric Material with Cu Electrodes Using a Thin-Film In Interlayer

    Science.gov (United States)

    Lin, Yan-Cheng; Yang, Chung-Lin; Huang, Jing-Yi; Jain, Chao-Chi; Hwang, Jen-Dong; Chu, Hsu-Shen; Chen, Sheng-Chi; Chuang, Tung-Han

    2016-09-01

    A Bi0.5Sb1.5Te3 thermoelectric material electroplated with a Ni barrier layer and a Ag reaction layer was bonded with a Ag-coated Cu electrode at low temperatures of 448 K (175 °C) to 523 K (250 °C) using a 4- μm-thick In interlayer under an external pressure of 3 MPa. During the bonding process, the In thin film reacted with the Ag layer to form a double layer of Ag3In and Ag2In intermetallic compounds. No reaction occurred at the Bi0.5Sb1.5Te3/Ni interface, which resulted in low bonding strengths of about 3.2 MPa. The adhesion of the Bi0.5Sb1.5Te3/Ni interface was improved by precoating a 1- μm Sn film on the surface of the thermoelectric element and preheating it at 523 K (250 °C) for 3 minutes. In this case, the bonding strengths increased to a range of 9.1 to 11.5 MPa after bonding at 473 K (200 °C) for 5 to 60 minutes, and the shear-tested specimens fractured with cleavage characteristics in the interior of the thermoelectric material. The bonding at 448 K (175 °C) led to shear strengths ranging from 7.1 to 8.5 MPa for various bonding times between 5 and 60 minutes, which were further increased to the values of 10.4 to 11.7 MPa by increasing the bonding pressure to 9.8 MPa. The shear strengths of Bi0.5Sb1.5Te3/Cu joints bonded with the optimized conditions of the modified solid-liquid interdiffusion bonding process changed only slightly after long-term exposure at 473 K (200 °C) for 1000 hours.

  9. Pulsed laser deposition and thermoelectric properties of In-and Yb-doped CoSb3 skutterudite thin films

    KAUST Repository

    Sarath Kumar, S. R.

    2011-07-29

    In-and Yb-doped CoSb3 thin films were prepared by pulsed laser deposition. Process optimization studies revealed that a very narrow process window exists for the growth of single-phase skutterudite films. The electrical conductivity and Seebeck coefficient measured in the temperature range 300-700 K revealed an irreversible change on the first heating cycle in argon ambient, which is attributed to the enhanced surface roughness of the films or trace secondary phases. A power factor of 0.68 W m-1 K-1 was obtained at ∼700 K, which is nearly six times lower than that of bulk samples. This difference is attributed to grain boundary scattering that causes a drop in film conductivity. Copyright © Materials Research Society 2011.

  10. Electrochemical Deposition of Lanthanum Telluride Thin Films and Nanowires

    Science.gov (United States)

    Chi, Su (Ike); Farias, Stephen; Cammarata, Robert

    2013-03-01

    Tellurium alloys are characterized by their high performance thermoelectric properties and recent research has shown nanostructured tellurium alloys display even greater performance than bulk equivalents. Increased thermoelectric efficiency of nanostructured materials have led to significant interests in developing thin film and nanowire structures. Here, we report on the first successful electrodeposition of lanthanum telluride thin films and nanowires. The electrodeposition of lanthanum telluride thin films is performed in ionic liquids at room temperature. The synthesis of nanowires involves electrodepositing lanthanum telluride arrays into anodic aluminum oxide (AAO) nanoporous membranes. These novel procedures can serve as an alternative means of simple, inexpensive and laboratory-environment friendly methods to synthesize nanostructured thermoelectric materials. The thermoelectric properties of thin films and nanowires will be presented to compare to current state-of-the-art thermoelectric materials. The morphologies and chemical compositions of the deposited films and nanowires are characterized using SEM and EDAX analysis.

  11. Thermoelectric performance of spin Seebeck effect in Fe3O4/Pt-based thin film heterostructures

    Directory of Open Access Journals (Sweden)

    R. Ramos

    2016-10-01

    Full Text Available We report a systematic study on the thermoelectric performance of spin Seebeck devices based on Fe3O4/Pt junction systems. We explore two types of device geometries: a spin Hall thermopile and spin Seebeck multilayer structures. The spin Hall thermopile increases the sensitivity of the spin Seebeck effect, while the increase in the sample internal resistance has a detrimental effect on the output power. We found that the spin Seebeck multilayers can overcome this limitation since the multilayers exhibit the enhancement of the thermoelectric voltage and the reduction of the internal resistance simultaneously, therefore resulting in significant power enhancement. This result demonstrates that the multilayer structures are useful for improving the thermoelectric performance of the spin Seebeck effect.

  12. Nanocluster metal films as thermoelectric material for radioisotope mini battery unit

    International Nuclear Information System (INIS)

    Borisyuk, P.V.; Krasavin, A.V.; Tkalya, E.V.; Lebedinskii, Yu.Yu.; Vasiliev, O.S.; Yakovlev, V.P.; Kozlova, T.I.; Fetisov, V.V.

    2016-01-01

    The paper is devoted to studying the thermoelectric and structural properties of films based on metal nanoclusters (Au, Pd, Pt). The experimental results of the study of single nanoclusters’ tunneling conductance obtained with scanning tunneling spectroscopy are presented. The obtained data allowed us to evaluate the thermoelectric power of thin film consisting of densely packed individual nanoclusters. It is shown that such thin films can operate as highly efficient thermoelectric materials. A scheme of miniature thermoelectric radioisotope power source based on the thorium-228 isotope is proposed. The efficiency of the radioisotope battery using thermoelectric converters based on nanocluster metal films is shown to reach values up to 1.3%. The estimated characteristics of the device are comparable with the parameters of up-to-date radioisotope batteries based on nickel-63.

  13. Thermoelectric properties of c-GeSb{sub 0.75}Te{sub 0.5} to h-GeSbTe{sub 0.5} thin films through annealing treatment effects

    Energy Technology Data Exchange (ETDEWEB)

    Vora-ud, Athorn, E-mail: athornvora-ud@snru.ac.th [Program of Physics, Faculty of Science and Technology, Sakon Nakhon Rajabhat University, Mueang District, Sakon Nakhon 47000 (Thailand); Thermoelectrics Research Center, Research and Development Institution, Sakon Nakhon Rajabhat University, Mueang District, Sakon Nakhon 47000 (Thailand); Horprathum, Mati, E-mail: mati.horprathum@nectec.or.th [National Electronics and Computer Technology Center, National Science and Technology Development Agency, Pathumthani 12120 (Thailand); Eiamchai, Pitak [National Electronics and Computer Technology Center, National Science and Technology Development Agency, Pathumthani 12120 (Thailand); Muthitamongkol, Pennapa; Chayasombat, Bralee; Thanachayanont, Chanchana [National Metal and Materials Technology Center, National Science and Technology Development Agency, Pathumthani 12120 (Thailand); Pankiew, Apirak [National Electronics and Computer Technology Center, National Science and Technology Development Agency, Pathumthani 12120 (Thailand); Klamchuen, Annop [National Nanotechnology Center, National Science and Technology Development Agency, Pathumthani 12120 (Thailand); Naenkieng, Daengdech; Plirdpring, Theerayuth; Harnwunggmoung, Adul [Thermoelectric and Nanotechnology Research Center, Faculty of Science and Technology, Rajamangala University of Technology Suvarnabhumi, Huntra Phranakhon, Si Ayutthaya 13000 (Thailand); Charoenphakdee, Anek [NANO-Thermoelectrics Research Center, Division of Applied Physics, Faculty of Sciences and Liberal Arts, Rajamangala University of Technology Isan, Mueng Nakorn Ratchasima 30000 Thailand (Thailand); Somkhunthot, Weerasak [Program of Physics, Faculty of Science and Technology, Loei Rajabhat University, Muang District, Loei 42000 (Thailand); and others

    2015-11-15

    Germanium–Antimony–Tellurium (Ge–Sb–Te) thin films were deposited on silicon wafers with 1-μm silicon dioxide (SiO{sub 2}/Si) by pulsed dc magnetron sputtering from a 99.99% GeSbTe target of 1:1:1 ratio at ambient temperature. The samples were annealed at 573, 623, 673, and 723 K for 3600 s in a vacuum state. The effects of the annealing treatment on phase identification, atomic composition, morphology and film thickness, carrier concentration, mobility, and Seebeck coefficient of the Ge–Sb–Te samples have been investigated by grazing-incidence X-ray diffraction, auger electron spectroscopy, field-emission scanning electron microscopy, Hall-effect measurements, and steady state method, respectively. The results demonstrated that the as-deposited Ge–Sb–Te sample was amorphous. Atomic composition of as-deposited and annealed films at 573 K and 623 K were GeSb{sub 0.75}Te{sub 0.5} while annealed films at 673 K and 723 K were GeSbTe{sub 0.5} due to Sb-rich GeSb{sub 0.75}Te{sub 0.5}. The samples annealed at 573 K and 623 K showed the crystal phases of cubic structure (c-GeSb{sub 0.75}Te{sub 0.5}) into hexagonal structure (h-GeSbTe{sub 0.5}) after annealing at 673 K and 723 K. The study demonstrated the insulating condition from the as-deposited GeSbTe film, and the changes towards the thermoelectric properties from the annealing treatments. The GeSbTe films annealed at 673 K yielded excellent thermoelectric properties with the electrical resistivity, Seebeck coefficient, and power factor at approximately 1.45 × 10{sup −5} Ωm, 71.07 μV K{sup −1}, and 3.48 × 10{sup −4} W m{sup −1} K{sup −2}, respectively. - Highlights: • GeSbTe thin films were successfully sputtered for thermoelectric properties. • GeSbTe films were examined among physical, electrical and thermoelectric properties. • Thermoelectric properties were discussed based on composition of the films.

  14. In-Situ Survey System of Resistive and Thermoelectric Properties of Either Pure or Mixed Materials in Thin Films Evaporated Under Ultra High Vacuum

    Science.gov (United States)

    Lechevallier, L.; Le Huerou, J.-Y.; Richon, G.; Sarrau, J.-M.; Gouault, J.

    1995-04-01

    The study of thermoelectric and resistive in situ behaviours depending on temperature for thin films of either pure or composite materials obtained under ultra-high vacuum, is very interesting, since they can be used as strain gauges or superficial resistances. However, studies become particularly difficult when the measurements generate very low-level electrical signals. Indeed, these turn out to be hardly detectable because of the perturbations brought by the experimental environment. The apparatus described below allows for the measurement of resistance with a relative uncertainty of 2×10^{-4}, resistance variation with an absolute uncertainty of 2 mΩ and thermoelectric e.m.f. of about 2 μV. Films studied in the laboratory generally exhibit resistances lower than 100 Ω and resistance variations due to temperature variations of about a few ohms. So this device has sufficient technical characteristics for our studies. It can be connected to a PC, which allows for easy data collection and treatment. L'étude des comportements résistif et thermoélectrique in situ en fonction de la température de couches minces de matériaux simples ou composites obtenus en milieu raréfié s'avére intéressante en vue d'applications comme jauge de contrainte ou résistance superficielle mais particulièrement délicate lorsque les mesures donnent naissance à des signaux électriques de très faible amplitude. Ces derniers deviennent en effet difficilement décelables en raison des perturbations apportées par l'environnement expérimental. Le système qui est décrit ici permet de mesurer des résistances avec une certitude relative de 2×10^{-4} et d'apprécier des variations de résistance de 2 mΩ et des f.e.m. thermoélectriques de l'ordre de 2 μV. Les couches étudiées au laboratoire présentent généralement des résistances inférieures à 100 Ω et des variations de résistance dues aux variations de température de l'ordre de quelques Ω. Le dispositif de mesure

  15. Thermoelectric properties of thin film and superlattice structure of IV-VI and V-VI compound semiconductors

    International Nuclear Information System (INIS)

    Blumers, Mathias

    2012-01-01

    The basic material property governing the efficiency of thermoelectric applications is the thermoelectric figure of merit Z=S 2 .σ/k, where S is the Seebeck-coefficient, σ is the electrical conductivity and k the thermal conductivity. A promising concept of increasing Z by one and two dimensional quantum well superlattices (QW-SL) was introduced in the early 1990s in terms of theoretical predictions. The realization of such low dimensional systems is done by use of semiconductor compounds with different energy gaps. The ambition of the Nitherma project was to investigate the thermoelectric properties of superlattices and Multi-Quantum-Well-structures (MQW) made of Pb 1-x Sr x Te and Bi 2 (Se x Te 1-x ) 3 , respectively. Therefore SL- and MQW-structures of this materials were grown and Z was determined by measuring of S, σ and κ parallel to the layer planes. Aim of this thesis is the interpretation of the transport measurements (S,σ,κ) of low dimensional structures and the improvement of preparation and measurement techniques. The influence of low dimensionality on the thermal conductivity in SL- and MQW-structures was investigated by measurements on structures with different layer thicknesses. In addition, measurements of the Seebeck-coefficient were performed, also to verify the results of the participating groups.

  16. Thin films

    International Nuclear Information System (INIS)

    Strongin, M.; Miller, D.L.

    1976-01-01

    This article reviews the phenomena that occur in films from the point of view of a solid state physicist. Films form the basis for many established and developing technologies. Metal layers have always been important for optical coatings and as protective coatings. In the most sophisticated cases, films and their interaction on silicon surfaces form the basis of modern electronic technology. Films of silicon, GaAs and composites of these materials promise to lead to practical photovoltaic devices

  17. Structural, chemical, and thermoelectric properties of Bi{sub 2}Te{sub 3} Peltier materials. Bulk, thin films, and superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Peranio, Nicola

    2008-07-01

    In this work, the nature of the natural nanostructure (nns) was analysed and the correlations to the transport coefficients, particularly the lattice thermal conductivity, is discussed. Experimental methods are presented for the first time, yielding an accurate quantitative analysis of the chemical composition and of stress fields in Bi{sub 2}Te{sub 3} and in compounds with similar structural and chemical microstructures. This work can be subdivided as follows: (I) N-type Bi{sub 2}(Te{sub 0.91}Se{sub 0.09}){sub 3} and p-type (Bi{sub 0.26}Sb{sub 0.74}){sub 1.98}(Te{sub 0.99}Se{sub 0.01}){sub 3.02} bulk materials synthesised by the Bridgman technique. (II) Bi{sub 2}Te{sub 3} thin films and Bi{sub 2}Te{sub 3}/Bi{sub 2}(Te{sub 0.88}Se{sub 0.12}){sub 3} superlattices epitaxially grown by molecular beam epitaxy (MBE) on BaF{sub 2} substrates with periods of {delta}-12 nm at the Fraunhofer-Institut fuer Physikalische Messtechnik (IPM). (III) Experimental methods, i.e., TEM specimen preparation, high-accuracy quantitative chemical analysis by EDX in the TEM, and image simulations of dislocations and the nns according to the two-beam dynamical diffraction theory. The nns was analysed in detail by stereomicroscopy and by image simulation and was found to be a pure sinusoidal displacement field with (i) a displacement vector parallel to <5,-5,1> and an amplitude of about 10 pm and (ii) a wave vector parallel to {l_brace}1,0,10{r_brace} and a wavelength of 10 nm. The results obtained here showed a significant amount of stress in the samples, induced by the nns which was still not noticed and identified. Both kinds of nanostructures, artificial (ans) and natural (nns) nanostructures, yielded in thermoelectric materials a low lattice thermal conductivity which was beneficial for the thermoelectric figure of merit ZT. (orig.)

  18. Pulsed laser deposition and thermoelectric properties of In-and Yb-doped CoSb3 skutterudite thin films

    KAUST Repository

    Sarath Kumar, S. R.; Alyamani, Ahmed Y.; Graff, Jennifer W.; Tritt, Terry M.; Alshareef, Husam N.

    2011-01-01

    was obtained at ∼700 K, which is nearly six times lower than that of bulk samples. This difference is attributed to grain boundary scattering that causes a drop in film conductivity. Copyright © Materials Research Society 2011.

  19. Manufacturing Te/PEDOT Films for Thermoelectric Applications.

    Science.gov (United States)

    Culebras, Mario; Igual-Muñoz, Ana María; Rodríguez-Fernández, Carlos; Gómez-Gómez, María Isabel; Gómez, Clara; Cantarero, Andrés

    2017-06-21

    In this work, flexible Te films have been synthesized by electrochemical deposition using PEDOT [poly(3,4-ethylenedioxythiophene)] nanofilms as working electrodes. The Te electrodeposition time was varied to find the best thermoelectric properties of the Te/PEDOT double layers. To show the high quality of the Te films grown on PEDOT, the samples were analyzed by Raman spectroscopy, showing the three Raman active modes of Te: E 1 , A 1 , and E 2 . The X-ray diffraction spectra also confirmed the presence of crystalline Te on top of the PEDOT films. The morphology of the Te/PEDOT films was studied using scanning electron microscopy, showing a homogeneous distribution of Te along the film. Also an atomic force microscope was used to analyze the quality of the Te surface. Finally, the electrical conductivity and the Seebeck coefficient of the Te/PEDOT films were measured as a function of the Te deposition time. The films showed an excellent thermoelectric behavior, giving a maximum power factor of about 320 ± 16 μW m -1 K -2 after 2.5 h of Te electrochemical deposition, a value larger than that reported for thin films of Te. Qualitative arguments to explain this behavior are given in the discussion.

  20. 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

  1. 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.

  2. Thermoelectric properties of TiNiSn and Zr0.5Hf0.5NiSn thin films and superlattices with reduced thermal conductivities

    International Nuclear Information System (INIS)

    Jaeger, Tino

    2013-01-01

    Rising energy costs and enhanced CO 2 emission have moved research about thermoelectric (TE) materials into focus. The suitability of a material for usage in TE devices depends on the figure of merit ZT and is equal to α 2 σTκ -1 including Seebeck coefficient α, conductivity σ, temperature T and thermal conductivity κ. Without affecting the power factor α 2 σ, using nanostructuring, ZT should here be increased by a depressed thermal conductivity. As half-Heusler (HH) bulk materials, the TE properties of TiNiSn and Zr 0.5 Hf 0.5 NiSn have been extensively studied. Here, semiconducting TiNiSn and Zr 0.5 Hf 0.5 NiSn thin films were fabricated for the first time by dc magnetron sputtering. On MgO (100) substrates, strongly textured polycrystalline films were obtained at substrate temperatures of about 450 C. The film consisted of grains with an elongation perpendicular to the surface of 55 nm. These generated rocking curves with FWHMs of less than 1 . Structural analyses were performed by X ray diffraction (XRD). Having deposition rates of about 1 nms -1 within shortest time also films in the order of microns were fabricated. For TiNiSn the highest in-plane power factor of about 0.4 mWK -2 m -1 was measured at about 550 K. In addition, at room temperature a cross-plane thermal conductivity of 2.8 Wm -1 K -1 was observed by the differential 3ω method. Because the reduction of thermal conductivity by mass fluctuation is well-known and interface scattering of phonons is expected, superlattices (SL) were fabricated. Therefore, TiNiSn and Zr 0.5 Hf 0.5 NiSn were successively deposited. While the sputter cathodes were continuously running, for fabrication of SLs the substrates were moved from one to another. The high crystal quality of the SLs and the sharp interfaces were proven by satellite peaks (XRD) and Scanning Transmission Electron Microscopy (STEM). For a SL with a periodicity of 21 nm (TiNiSn and Zr 0.5 Hf 0.5 NiSn each 15 nm) at a temperature of 550 K an

  3. High Performance Thermoelectric Materials Using Solution Phase Synthesis of Narrow Bandgap Core/Shell Quantum Dots Deposited Into Colloidal Crystal Thin Films

    National Research Council Canada - National Science Library

    2005-01-01

    Thermoelectrics is the science and technology associated with thermoelectric converters, that is, the generation of electrical power based on the Seebeck effect and refrigeration by the Peltier effect...

  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. 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...

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

    KAUST Repository

    Kim, Hyunho

    2017-02-27

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

  7. 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.

  8. Thermal conductivity model for nanoporous thin films

    Science.gov (United States)

    Huang, Congliang; Zhao, Xinpeng; Regner, Keith; Yang, Ronggui

    2018-03-01

    Nanoporous thin films have attracted great interest because of their extremely low thermal conductivity and potential applications in thin thermal insulators and thermoelectrics. Although there are some numerical and experimental studies about the thermal conductivity of nanoporous thin films, a simplified model is still needed to provide a straightforward prediction. In this paper, by including the phonon scattering lifetimes due to film thickness boundary scattering, nanopore scattering and the frequency-dependent intrinsic phonon-phonon scattering, a fitting-parameter-free model based on the kinetic theory of phonon transport is developed to predict both the in-plane and the cross-plane thermal conductivities of nanoporous thin films. With input parameters such as the lattice constants, thermal conductivity, and the group velocity of acoustic phonons of bulk silicon, our model shows a good agreement with available experimental and numerical results of nanoporous silicon thin films. It illustrates that the size effect of film thickness boundary scattering not only depends on the film thickness but also on the size of nanopores, and a larger nanopore leads to a stronger size effect of the film thickness. Our model also reveals that there are different optimal structures for getting the lowest in-plane and cross-plane thermal conductivities.

  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. Thin film tritium dosimetry

    Science.gov (United States)

    Moran, Paul R.

    1976-01-01

    The present invention provides a method for tritium dosimetry. A dosimeter comprising a thin film of a material having relatively sensitive RITAC-RITAP dosimetry properties is exposed to radiation from tritium, and after the dosimeter has been removed from the source of the radiation, the low energy electron dose deposited in the thin film is determined by radiation-induced, thermally-activated polarization dosimetry techniques.

  11. Significant enhancement of the thermoelectric figure of merit of polycrystalline Si films by reducing grain size

    International Nuclear Information System (INIS)

    Valalaki, K; Nassiopoulou, A G; Vouroutzis, N

    2016-01-01

    The thermoelectric properties of p-type polycrystalline silicon thin films deposited by low pressure chemical vapour deposition (LPCVD) were accurately determined at room temperature and the thermoelectric figure of merit was deduced as a function of film thickness, ranging from 100 to 500 nm. The effect of film thickness on their thermoelectric performance is discussed. More than threefold increase in the thermoelectric figure of merit of the 100 nm thick polysilicon film was observed compared to the 500 nm thick film, reaching a value as high as 0.033. This enhancement is mainly the result of the smaller grain size in the thinner films. With the decrease in grain size the resistivity of the films is increased twofold and electrical conductivity decreased, however the Seebeck coefficient is increased by 30% and the thermal conductivity is decreased eightfold, being mainly at the origin of the increased figure of merit of the 100 nm film. Our experimental results were compared to known theoretical models and the possible mechanisms involved are presented and discussed. (paper)

  12. Enhanced thermoelectric properties of bismuth telluride-organic hybrid films via graphene doping

    International Nuclear Information System (INIS)

    Rahman, Airul Azha Abd; Umar, Akrajas Ali; Salleh, Muhamad Mat; Chen, Xiaomei; Oyama, Munetaka

    2016-01-01

    The thermoelectric properties of graphene-doped bismuth telluride-PEDOT:PSS-glycerol (hybrid) films were investigated. Prior to the study, p-type and n-type hybrid films were prepared by doping the PEDOT:PSS-glycerol with the p- and n-type bismuth telluride. Graphene-doped hybrid films were prepared by adding graphene particles of concentration ranging from 0.02 to 0.1 wt% into the hybrid films. Films of graphene-doped hybrid system were then prepared on a glass substrate using a spin-coating technique. It was found that the electrical conductivity of the hybrid films increases with the increasing of the graphene-dopant concentration and optimum at 0.08 wt% for both p- and n-type films, namely 400 and 195 S/cm, respectively. Further increasing in the concentration caused a decreasing in the electrical conductivity. Analysis of the thermoelectric properties of the films obtained that the p-type film exhibited significant improvement in its thermoelectric properties, where the thermoelectric properties increased with the increasing of the doping concentration. Meanwhile, for the case of n-type film, graphene doping showed a negative effect to the thermoelectrical properties, where the thermoelectric properties decreased with the increasing of doping concentration. Seebeck coefficient (and power factor) for optimum p-type and n-type hybrid thin films, i.e., doped with 0.08 wt% of graphene, is 20 μV/K (and 160 μW m -1 K -2 ) and 10 μV/K (and 19.5 μW m -1 K -2 ), respectively. The obtained electrical conductivity and thermoelectric properties of graphene-doped hybrid film are interestingly several orders higher than the pristine hybrid films. A thermocouple device fabricated utilizing the p- and n-type graphene-doped hybrid films can generate an electric voltage as high as 2.2 mV under a temperature difference between the hot-side and the cold-side terminal as only low as 55 K. This is equivalent to the output power as high as 24.2 nW (for output load as high as 50

  13. Control of phonon transport by the formation of the Al2O3 interlayer in Al2O3-ZnO superlattice thin films and their in-plane thermoelectric energy generator performance.

    Science.gov (United States)

    Park, No-Won; Ahn, Jay-Young; Park, Tae-Hyun; Lee, Jung-Hun; Lee, Won-Yong; Cho, Kwanghee; Yoon, Young-Gui; Choi, Chel-Jong; Park, Jin-Seong; Lee, Sang-Kwon

    2017-06-01

    Recently, significant progress has been made in increasing the figure-of-merit (ZT) of various nanostructured materials, including thin-film and quantum dot superlattice structures. Studies have focused on the size reduction and control of the surface or interface of nanostructured materials since these approaches enhance the thermopower and phonon scattering in quantum and superlattice structures. Currently, bismuth-tellurium-based semiconductor materials are widely employed for thermoelectric (TE) devices such as TE energy generators and coolers, in addition to other sensors, for use at temperatures under 400 K. However, new and promising TE materials with enhanced TE performance, including doped zinc oxide (ZnO) multilayer or superlattice thin films, are also required for designing solid-state TE power generating devices with the maximum output power density and for investigating the physics of in-plane TE generators. Herein, we report the growth of Al 2 O 3 /ZnO (AO/ZnO) superlattice thin films, which were prepared by atomic layer deposition (ALD), and the evaluation of their electrical and TE properties. All the in-plane TE properties, including the Seebeck coefficient (S), electrical conductivity (σ), and thermal conductivity (κ), of the AO/ZnO superlattice (with a 0.82 nm-thick AO layer) and AO/ZnO films (with a 0.13 nm-thick AO layer) were evaluated in the temperature range 40-300 K, and the measured S, σ, and κ were -62.4 and -17.5 μV K -1 , 113 and 847 (Ω cm) -1 , and 0.96 and 1.04 W m -1 K -1 , respectively, at 300 K. Consequently, the in-plane TE ZT factor of AO/ZnO superlattice films was found to be ∼0.014, which is approximately two times more than that of AO/ZnO films (ZT of ∼0.007) at 300 K. Furthermore, the electrical power generation efficiency of the TE energy generator consisting of four couples of n-AO/ZnO superlattice films and p-Bi 0.5 Sb 1.5 Te 3 (p-BST) thin-film legs on the substrate was demonstrated. Surprisingly, the output

  14. Seebeck effect of some thin film carbides

    International Nuclear Information System (INIS)

    Beensh-Marchwicka, G.; Prociow, E.

    2002-01-01

    Several materials have been investigated for high-temperature thin film thermocouple applications. These include silicon carbide with boron (Si-C-B), ternary composition based on Si-C-Mn, fourfold composition based on Si-C-Zr-B and tantalum carbide (TaC). All materials were deposited on quartz or glass substrates using the pulse sputter deposition technique. Electrical conduction and thermoelectric power were measured for various compositions at 300-550 K. It has been found, that the efficiency of thermoelectric power of films containing Si-C base composition was varied from 0.0015-0.034 μW/cmK 2 . However for TaC the value about 0.093 μW/cmK 2 was obtained. (author)

  15. Thin films and nanomaterials

    International Nuclear Information System (INIS)

    Jayakumar, S.; Kannan, M.D.; Prasanna, S.

    2012-01-01

    The objective of this book is to disseminate the most recent research in Thin Films, Nanomaterials, Corrosion and Metallurgy presented at the International Conference on Advanced Materials (ICAM 2011) held in PSG College of Technology, Coimbatore, India during 12-16 December 2011. The book is a compilation of 113 chapters written by active researchers providing information and critical insights into the recent advancements that have taken place. Important new applications are possible today in the fields of microelectronics, opto-electronics, metallurgy and energy by the application of thin films on solid surfaces. Recent progress in high vacuum technology and new materials has a remarkable effect in thin film quality and cost. This has led to the development of new single or multi-layered thin film devices with diverse applications in a multitude of production areas, such as optics, thermal barrier coatings and wear protections, enhancing service life of tools and to protect materials against thermal and atmospheric influence. On the other hand, thin film process techniques and research are strongly related to the basic research activities in nano technology, an increasingly important field with countless opportunities for applications due to the emergence of new properties at the nanoscale level. Materials and structures that are designed and fabricated at the nano scale level, offer the potential to produce new devices and processes that may enhance efficiencies and reduce costs in many areas, as photovoltaic systems, hydrogen storage, fuel cells and solar thermal systems. In the book, the contributed papers are classified under two sections i) thin films and ii) nanomaterials. The thin film section includes single or multi layer conducting, insulating or semiconducting films synthesized by a wide variety of physical or chemical techniques and characterized or analyzed for different applications. The nanomaterials section deals with novel or exciting materials

  16. Effect of oxygen vacancy distribution on the thermoelectric properties of La-doped SrTiO3 epitaxial thin films

    KAUST Repository

    Sarath Kumar, S. R.; Abutaha, Anas I.; Hedhili, Mohamed N.; Alshareef, Husam N.

    2012-01-01

    A detailed study of the role of oxygen vacancies in determining the effective mass and high temperature (300–1000 K) thermoelectricproperties of La-doped epitaxial SrTiO3 thin films is presented. It is observed that at intermediate temperatures, a transition from degenerate to non-degenerate behavior is observed in the Seebeck coefficient, but not electrical conductivity, which is attributed to heterogeneous oxygen non-stoichiometry. Heikes formula is found to be invalid for the films with oxygen vacancies. By fitting the spectroscopic ellipsometry (SE) data, obtained in the range 300–2100 nm, using a Drude-Lorentz dispersion relation with two Lorentz oscillators, the electrical and optical properties of the films are extracted. Using the excellent agreement between the transport properties extracted from SE modeling and direct electrical measurements, we demonstrate that an increase in concentration of oxygen vacancies results in a simultaneous increase of both carrier concentration and electron effective mass, resulting in a higher power factor.

  17. Effect of oxygen vacancy distribution on the thermoelectric properties of La-doped SrTiO3 epitaxial thin films

    KAUST Repository

    Sarath Kumar, S. R.

    2012-12-03

    A detailed study of the role of oxygen vacancies in determining the effective mass and high temperature (300–1000 K) thermoelectricproperties of La-doped epitaxial SrTiO3 thin films is presented. It is observed that at intermediate temperatures, a transition from degenerate to non-degenerate behavior is observed in the Seebeck coefficient, but not electrical conductivity, which is attributed to heterogeneous oxygen non-stoichiometry. Heikes formula is found to be invalid for the films with oxygen vacancies. By fitting the spectroscopic ellipsometry (SE) data, obtained in the range 300–2100 nm, using a Drude-Lorentz dispersion relation with two Lorentz oscillators, the electrical and optical properties of the films are extracted. Using the excellent agreement between the transport properties extracted from SE modeling and direct electrical measurements, we demonstrate that an increase in concentration of oxygen vacancies results in a simultaneous increase of both carrier concentration and electron effective mass, resulting in a higher power factor.

  18. Thin Film Microbatteries

    International Nuclear Information System (INIS)

    Dudney, Nancy J.

    2008-01-01

    Thin film batteries are built layer by layer by vapor deposition. The resulting battery is formed of parallel plates, much as an ordinary battery construction, just much thinner. The figure (Fig. 1) shows an example of a thin film battery layout where films are deposited symmetrically onto both sides of a supporting substrate. The full stack of films is only 10 to 15 (micro)m thick, but including the support at least doubles the overall battery thickness. When the support is thin, the entire battery can be flexible. At least six companies have commercialized or are very close to commercializing such all-solid-state thin film batteries and market research predicts a growing market and a variety of applications including sensors, RFID tags, and smarter cards. In principle with a large deposition system, a thin film battery might cover a square meter, but in practice, most development is targeting individual cells with active areas less than 25 cm 2 . For very small battery areas, 2 , microfabrication processes have been developed. Typically the assembled batteries have capacities from 0.1 to 5 mAh. The operation of a thin film battery is depicted in the schematic diagram (Fig. 2). Very simply, when the battery is allowed to discharge, a Li + ion migrates from the anode to the cathode film by diffusing through the solid electrolyte. When the anode and cathode reactions are reversible, as for an intercalation compound or alloy, the battery can be recharged by reversing the current. The difference in the electrochemical potential of the lithium determines the cell voltage. Most of the thin films used in current commercial variations of this thin film battery are deposited in vacuum chambers by RF and DC magnetron sputtering and by thermal evaporation onto unheated substrates. In addition, many publications report exploring a variety of other physical and chemical vapor deposition processes, such as pulsed laser deposition, electron cyclotron resonance sputtering, and

  19. Optical thin film deposition

    International Nuclear Information System (INIS)

    Macleod, H.A.

    1979-01-01

    The potential usefulness in the production of optical thin-film coatings of some of the processes for thin film deposition which can be classified under the heading of ion-assisted techniques is examined. Thermal evaporation is the process which is virtually universally used for this purpose and which has been developed to a stage where performance is in almost all respects high. Areas where further improvements would be of value, and the possibility that ion-assisted deposition might lead to such improvements, are discussed. (author)

  20. Thin Film Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Zweibel, K.

    1998-11-19

    The motivation to develop thin film technologies dates back to the inception of photovoltaics. It is an idea based on achieving truly low-cost photovoltaics appropriate for mass production and energy significant markets. The key to the idea is the use of pennies worth of active materials. Since sunlight carries relatively little energy in comparison with combustion-based energy sources, photovoltaic (PV) modules must be cheap to produce energy that can be competitive. Thin films are presumed to be the answer to that low-cost requirement. But how cheap do they have to be? The following is an oversimplified analysis that allows some insight into this question.

  1. 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.

  2. Thin film metal-oxides

    CERN Document Server

    Ramanathan, Shriram

    2009-01-01

    Presents an account of the fundamental structure-property relations in oxide thin films. This title discusses the functional properties of thin film oxides in the context of applications in the electronics and renewable energy technologies.

  3. NMR characterization of thin films

    Science.gov (United States)

    Gerald II, Rex E.; Klingler, Robert J.; Rathke, Jerome W.; Diaz, Rocio; Vukovic, Lela

    2010-06-15

    A method, apparatus, and system for characterizing thin film materials. The method, apparatus, and system includes a container for receiving a starting material, applying a gravitational force, a magnetic force, and an electric force or combinations thereof to at least the starting material, forming a thin film material, sensing an NMR signal from the thin film material and analyzing the NMR signal to characterize the thin film of material.

  4. NMR characterization of thin films

    Science.gov (United States)

    Gerald, II, Rex E.; Klingler, Robert J.; Rathke, Jerome W.; Diaz, Rocio; Vukovic, Lela

    2008-11-25

    A method, apparatus, and system for characterizing thin film materials. The method, apparatus, and system includes a container for receiving a starting material, applying a gravitational force, a magnetic force, and an electric force or combinations thereof to at least the starting material, forming a thin film material, sensing an NMR signal from the thin film material and analyzing the NMR signal to characterize the thin film of material.

  5. Rare Earth Oxide Thin Films

    CERN Document Server

    Fanciulli, Marco

    2007-01-01

    Thin rare earth (RE) oxide films are emerging materials for microelectronic, nanoelectronic, and spintronic applications. The state-of-the-art of thin film deposition techniques as well as the structural, physical, chemical, and electrical properties of thin RE oxide films and of their interface with semiconducting substrates are discussed. The aim is to identify proper methodologies for the development of RE oxides thin films and to evaluate their effectiveness as innovative materials in different applications.

  6. Selective inorganic thin films

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, M.L.F.; Weisenbach, L.A.; Anderson, M.T. [Sandia National Laboratories, Albuquerque, NM (United States)] [and others

    1995-05-01

    This project is developing inorganic thin films as membranes for gas separation applications, and as discriminating coatings for liquid-phase chemical sensors. Our goal is to synthesize these coatings with tailored porosity and surface chemistry on porous substrates and on acoustic and optical sensors. Molecular sieve films offer the possibility of performing separations involving hydrogen, air, and natural gas constituents at elevated temperatures with very high separation factors. We are focusing on improving permeability and molecular sieve properties of crystalline zeolitic membranes made by hydrothermally reacting layered multicomponent sol-gel films deposited on mesoporous substrates. We also used acoustic plate mode (APM) oscillator and surface plasmon resonance (SPR) sensor elements as substrates for sol-gel films, and have both used these modified sensors to determine physical properties of the films and have determined the sensitivity and selectivity of these sensors to aqueous chemical species.

  7. Superconducting oxypnictide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Reisner, Andreas; Kidszun, Martin; Reich, Elke; Holzapfel, Bernhard; Schultz, Ludwig; Haindl, Silvia [IFW Dresden, Institute of Metallic Materials (Germany); Thersleff, Thomas [Uppsala University, Angstrom Laboratory (Sweden)

    2012-07-01

    We present an overview on the oxypnictide thin film preparation. So far, only LaAlO{sub 3} (001) single crystalline substrates provided a successful growth using pulsed laser deposition in combination with a post annealing process. Further experiments on the in-situ deposition will be reported. The structure of the films was investigated by X-ray diffractometry and transmission electron microscopy. Transport properties were measured with different applied fields to obtain a magnetic phase diagram for this new type of superconductor.

  8. Mechanics of Thin Films

    Science.gov (United States)

    1992-02-06

    and the second geometry was that of squat cylinders (diameter 6.4 mm, height 6.4 mm). These two geometries were tested in thermal shock tests, and a...milder [13]. More recently, Lau, Rahman and stressa nce ntrati, tha n films of lmalla rat ve spc Delale calculated the free edge singularity for stress...thickness of 3 mm); the second geometry was that As an example of the shielding effect of thin films, we of squat cylinders (diameter 6.4 mm, height 6.4

  9. Thin film with oriented cracks on a flexible substrate

    Science.gov (United States)

    Feng, Bao; McGilvray, Andrew; Shi, Bo

    2010-07-27

    A thermoelectric film is disclosed. The thermoelectric film includes a substrate that is substantially electrically non-conductive and flexible and a thermoelectric material that is deposited on at least one surface of the substrate. The thermoelectric film also includes multiple cracks oriented in a predetermined direction.

  10. Thin film processes

    CERN Document Server

    Vossen, John L

    1978-01-01

    Remarkable advances have been made in recent years in the science and technology of thin film processes for deposition and etching. It is the purpose of this book to bring together tutorial reviews of selected filmdeposition and etching processes from a process viewpoint. Emphasis is placed on the practical use of the processes to provide working guidelines for their implementation, a guide to the literature, and an overview of each process.

  11. 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.

  12. Discussion on the electrical and thermoelectrical properties of amorphous In-Sb-Te Films

    Energy Technology Data Exchange (ETDEWEB)

    Aly, K.A. [University of Jeddah, Physics Department, Faculty of Science and Arts, Khulais, Jeddah (Saudi Arabia); Al-Azhar University, Assiut Branch, Physics Department, Faculty of Science, Asyut (Egypt); Saddeek, Y. [Al-Azhar University, Assiut Branch, Physics Department, Faculty of Science, Asyut (Egypt); Dahshan, A. [Port Said University, Department of Physics, Faculty of Science, Port Said (Egypt); King Khalid University, Department of Physics, Faculty of Science for Girls, Abha (Saudi Arabia)

    2016-03-15

    Different compositions of (In{sub 0.5}Sb{sub 0.5}){sub 1-x}Te{sub x} (0.50 ≤ x ≤ 0.65) thin films were prepared by thermal evaporated technique, onto pre-cleaned glass substrates at ∝298 K. Both dark electrical resistivity (ρ) and thermoelectric power (S) were measured in the temperature range 300-420 K. The concentration of the free carriers is obtained from DC conductivity and thermoelectric power measurements. Seebeck coefficient was found to be positive over entire temperature range, indicating that (In{sub 0.5}Sb{sub 0.5}){sub 1-x}Te{sub x} films are p-type semiconducting materials. Also, the variation of the mobility with temperature has been estimated. Increasing tellurium concentration is found to affect the DC conductivity and thermoelectric power of the studied films. The activation energies obtained from the DC conductivity and thermoelectric power increase with increasing tellurium content. The obtained results were interpreted according to the chemical bond approach. (orig.)

  13. Properties of Nanostructure Bismuth Telluride Thin Films Using Thermal Evaporation

    Directory of Open Access Journals (Sweden)

    Swati Arora

    2017-01-01

    Full Text Available Bismuth telluride has high thermoelectric performance at room temperature; in present work, various nanostructure thin films of bismuth telluride were fabricated on silicon substrates at room temperature using thermal evaporation method. Tellurium (Te and bismuth (Bi were deposited on silicon substrate in different ratio of thickness. These films were annealed at 50°C and 100°C. After heat treatment, the thin films attained the semiconductor nature. Samples were studied by X-ray diffraction (XRD and scanning electron microscopy (SEM to show granular growth.

  14. Thin films for precision optics

    International Nuclear Information System (INIS)

    Araujo, J.F.; Maurici, N.; Castro, J.C. de

    1983-01-01

    The technology of producing dielectric and/or metallic thin films for high precision optical components is discussed. Computer programs were developed in order to calculate and register, graphically, reflectance and transmittance spectra of multi-layer films. The technology of vacuum evaporation of several materials was implemented in our thin-films laboratory; various films for optics were then developed. The possibility of first calculate film characteristics and then produce the film is of great advantage since it reduces the time required to produce a new type of film and also reduces the cost of the project. (C.L.B.) [pt

  15. Microstructure of Thin Films

    Science.gov (United States)

    1990-02-07

    Proceedings, Thin film Technologies II, 652, 256-263, (1986) B. Schmitt, J.P. Borgogno, G. Albrand and E. Pelletier, "In situ and air index measurements...34 SPIE Proceedings, "Optical Components and Systems", 805, 128 (1987) 11 B. Schmitt, J.P. Borgogno, G. Albrand and E. Pelletier. "In situ and air index...aT , m..a, lot,, o ,,f,02,d I4 k -1-1..... autocovariance lengths, less than 0.5 um, indicate that , 514n, ob0 o p’,Ofclllc....,,o,,oy0,1- agua sblrt

  16. Radioisotope thermoelectric generator/thin fragment impact test

    International Nuclear Information System (INIS)

    Reimus, M.A.H.; Hinckley, J.E.

    1998-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of 238 Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system (PMS). The results of this test indicated that impact of the RTG by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the convertor housing, failure of one fueled clad, and release of a small quantity of fuel

  17. Host thin films incorporating nanoparticles

    Science.gov (United States)

    Qureshi, Uzma

    The focus of this research project was the investigation of the functional properties of thin films that incorporate a secondary nanoparticulate phase. In particular to assess if the secondary nanoparticulate material enhanced a functional property of the coating on glass. In order to achieve this, new thin film deposition methods were developed, namely use of nanopowder precursors, an aerosol assisted transport technique and an aerosol into atmospheric pressure chemical vapour deposition system. Aerosol assisted chemical vapour deposition (AACVD) was used to deposit 8 series of thin films on glass. Five different nanoparticles silver, gold, ceria, tungsten oxide and zinc oxide were tested and shown to successfully deposit thin films incorporating nanoparticles within a host matrix. Silver nanoparticles were synthesised and doped within a titania film by AACVD. This improved solar control properties. A unique aerosol assisted chemical vapour deposition (AACVD) into atmospheric pressure chemical vapour deposition (APCVD) system was used to deposit films of Au nanoparticles and thin films of gold nanoparticles incorporated within a host titania matrix. Incorporation of high refractive index contrast metal oxide particles within a host film altered the film colour. The key goal was to test the potential of nanopowder forms and transfer the suspended nanopowder via an aerosol to a substrate in order to deposit a thin film. Discrete tungsten oxide nanoparticles or ceria nanoparticles within a titanium dioxide thin film enhanced the self-cleaning and photo-induced super-hydrophilicity. The nanopowder precursor study was extended by deposition of zinc oxide thin films incorporating Au nanoparticles and also ZnO films deposited from a ZnO nanopowder precursor. Incorporation of Au nanoparticles within a VO: host matrix improved the thermochromic response, optical and colour properties. Composite VC/TiC and Au nanoparticle/V02/Ti02 thin films displayed three useful

  18. Thermoelectric properties of ZnSb films grown by MOCVD

    Energy Technology Data Exchange (ETDEWEB)

    Venkatasubramanian, R; Watko, E; Colpitts, T

    1997-07-01

    The thermoelectric properties of ZnSb films grown by metallorganic chemical vapor deposition (MOCVD) are reported. The growth conditions necessary to obtain stoichiometric ZnSb films and the effects of various growth parameters on the electrical conductivity and Seebeck coefficients of the films are described. The as-grown ZnSb films are p-type. It was observed that the thicker ZnSb films offer improved carrier mobilities and lower free-carrier concentration levels. The Seebeck coefficient of ZnSb films was found to rise rapidly at approximately 160 C. The thicker films, due to the lower doping levels, indicate higher Seebeck coefficients between 25 to 200 C. A short annealing of the ZnSb film at temperatures of {approximately}200 C results in reduced free-carrier level. Thermal conductivity measurements of ZnSb films using the 3-{omega} method are also presented.

  19. Thin-film photovoltaic technology

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, R.N. [National Renewable Energy Laboratory, Golden, CO (United States)

    2010-07-01

    The high material and processing costs associated with single-crystal and polycrystalline silicon wafers that are commonly used in photovoltaic cells render these modules expensive. This presentation described thin-film solar cell technology as a promising alternative to silicon solar cell technology. Cadmium telluride (CdTe) thin films along with copper, indium, gallium, and selenium (CIGS) thin films have become the leaders in this field. Their large optical absorption coefficient can be attributed to a direct energy gap that allows the use of thin layers (1-2 {mu}m) of active material. The efficiency of thin-film solar cell devices based on CIGS is 20 per cent, compared to 16.7 per cent for thin-film solar cell devices based on CdTe. IBM recently reported an efficiency of 9.7 per cent for a new type of inorganic thin-film solar cell based on a Cu{sub 2}ZnSn(S, Se){sub 4} compound. The efficiency of an organic thin-film solar cell is 7.9 per cent. This presentation included a graph of PV device efficiencies and discussed technological advances in non-vacuum deposited, CIGS-based thin-film solar cells. 1 fig.

  20. Polymer Thin Film Stabilization.

    Science.gov (United States)

    Costa, A. C.; Oslanec, R.; Composto, R. J.; Vlcek, P.

    1998-03-01

    We study the dewetting dynamics of thin polystyrene (PS) films deposited on silicon oxide surfaces using optical (OM) and atomic force (AFM) microscopes. Quantitative analysis of the hole diameter as a function of annealing time at 175^oC shows that blending poly(styrene-block-methyl-methacrylate) (PS-b-PMMA) with PS acts to dramatically slow down the dewetting rate and even stops holes growth before they impinge. AFM studies show that the hole floor is smooth for a pure PS film but contains residual polymer for the blend. At 5% vol., a PS-b-PMMA with high molar mass and low PMMA is a more effective stabilizing agent than a low molar mass/high PMMA additive. The optimum copolymer concentration is 3% vol. beyond which film stability doesn't improve. Although dewetting is slowed down relative to pure PS, PS/PS-b-PMMA bilayers dewet at a faster rate than blends having the same overall additive concentration.

  1. Lattice dynamics and substrate-dependent transport properties of (In, Yb)-doped CoSb3 skutterudite thin films

    KAUST Repository

    Sarath Kumar, S. R.; Cha, Dong Kyu; Alshareef, Husam N.

    2011-01-01

    Lattice dynamics, low-temperature electrical transport, and high-temperature thermoelectric properties of (In, Yb)-doped CoSb3thin films on different substrates are reported. Pulsed laser deposition under optimized conditions yielded single

  2. Thin films: Past, present, future

    Energy Technology Data Exchange (ETDEWEB)

    Zweibel, K

    1995-04-01

    This report describes the characteristics of the thin film photovoltaic modules necessary for an acceptable rate of return for rural areas and underdeveloped countries. The topics of the paper include a development of goals of cost and performance for an acceptable PV system, a review of current technologies for meeting these goals, issues and opportunities in thin film technologies.

  3. Thin-film solar cell

    NARCIS (Netherlands)

    Metselaar, J.W.; Kuznetsov, V.I.

    1998-01-01

    The invention relates to a thin-film solar cell provided with at least one p-i-n junction comprising at least one p-i junction which is at an angle alpha with that surface of the thin-film solar cell which collects light during operation and at least one i-n junction which is at an angle beta with

  4. High thermoelectric power factor from multilayer solution-processed organic films

    Science.gov (United States)

    Zuo, Guangzheng; Andersson, Olof; Abdalla, Hassan; Kemerink, Martijn

    2018-02-01

    We investigate the suitability of the "sequential doping" method of organic semiconductors for thermoelectric applications. The method consists of depositing a dopant (F4TCNQ) containing solution on a previously cast semiconductor (P3HT) thin film to achieve high conductivity, while preserving the morphology. For very thin films (˜25 nm), we achieve a high power factor around 8 μW/mK-2 with a conductivity over 500 S/m. For the increasing film thickness, conductivity and power factor show a decreasing trend, which we attribute to the inability to dope the deeper parts of the film. Since thick films are required to extract significant power from thermoelectric generators, we developed a simple additive technique that allows the deposition of an arbitrary number of layers without significant loss in conductivity or power factor that, for 5 subsequent layers, remain at ˜300 S/m and ˜5 μW/mK-2, respectively, whereas the power output increases almost one order of magnitude as compared to a single layer. The efficient doping in multilayers is further confirmed by an increased intensity of (bi)polaronic features in the UV-Vis spectra.

  5. Thin-film solar cells

    International Nuclear Information System (INIS)

    Aberle, Armin G.

    2009-01-01

    The rapid progress that is being made with inorganic thin-film photovoltaic (PV) technologies, both in the laboratory and in industry, is reviewed. While amorphous silicon based PV modules have been around for more than 20 years, recent industrial developments include the first polycrystalline silicon thin-film solar cells on glass and the first tandem solar cells based on stacks of amorphous and microcrystalline silicon films ('micromorph cells'). Significant thin-film PV production levels are also being set up for cadmium telluride and copper indium diselenide.

  6. Buckling of Thin Films in Nano-Scale

    Directory of Open Access Journals (Sweden)

    Li L.A.

    2010-06-01

    Full Text Available Investigation of thin film buckling is important for life prediction of MEMS device which are damaged mainly by the delamination and buckling of thin films. In this paper the mechanical and thermal properties of compressed thin film titanium films with 150 nm thickness deposited on an organic glass substrate under mechanical and thermal loads were measured and characterized. In order to simulate the thin films which subjected to compound loads and the buckle modes the external uniaxial compression and thermal loading were subjected to the specimen by the symmetric loading device and the electrical film in this experiment. The temperature of the thin film deposited on substrate was measured using thermoelectric couple. The range of temperature accords with the temperature range of the MEMS. It is found that the size and number of the delamination and buckling of the film are depended upon the pre-fixed mechanical loading and thermal temperature. The thermal transient conduction and thermal stability of the film and substrate was studied with finite element method.

  7. Characterization of organic thin films

    CERN Document Server

    Ulman, Abraham; Evans, Charles A

    2009-01-01

    Thin films based upon organic materials are at the heart of much of the revolution in modern technology, from advanced electronics, to optics to sensors to biomedical engineering. This volume in the Materials Characterization series introduces the major common types of analysis used in characterizing of thin films and the various appropriate characterization technologies for each. Materials such as Langmuir-Blodgett films and self-assembled monolayers are first introduced, followed by analysis of surface properties and the various characterization technologies used for such. Readers will find detailed information on: -Various spectroscopic approaches to characterization of organic thin films, including infrared spectroscopy and Raman spectroscopy -X-Ray diffraction techniques, High Resolution EELS studies, and X-Ray Photoelectron Spectroscopy -Concise Summaries of major characterization technologies for organic thin films, including Auger Electron Spectroscopy, Dynamic Secondary Ion Mass Spectrometry, and Tra...

  8. Interfaces and thin films physics

    International Nuclear Information System (INIS)

    Equer, B.

    1988-01-01

    The 1988 progress report of the Interfaces and Thin Film Physics laboratory (Polytechnic School France) is presented. The research program is focused on the thin films and on the interfaces of the amorphous semiconductor materials: silicon and silicon germanium, silicon-carbon and silicon-nitrogen alloys. In particular, the following topics are discussed: the basic processes and the kinetics of the reactive gas deposition, the amorphous materials manufacturing, the physico-chemical characterization of thin films and interfaces and the electron transport in amorphous semiconductors. The construction and optimization of experimental devices, as well as the activities concerning instrumentation, are also described [fr

  9. Nanocrystalline magnetite thin films grown by dual ion-beam sputtering

    International Nuclear Information System (INIS)

    Prieto, Pilar; Ruiz, Patricia; Ferrer, Isabel J.; Figuera, Juan de la; Marco, José F.

    2015-01-01

    Highlights: • We have grown tensile and compressive strained nanocrystalline magnetite thin films by dual ion beam sputtering. • The magnetic and thermoelectric properties can be controlled by the deposition conditions. • The magnetic anisotropy depends on the crystalline grain size. • The thermoelectric properties depend on the type of strain induced in the films. • In plane uniaxial magnetic anisotropy develops in magnetite thin films with grain sizes ⩽20 nm. - Abstract: We have explored the influence of an ion-assisted beam in the thermoelectric and magnetic properties of nanocrystalline magnetite thin films grown by ion-beam sputtering. The microstructure has been investigated by XRD. Tensile and compressive strained thin films have been obtained as a function of the parameters of the ion-assisted beam. The evolution of the in-plane magnetic anisotropy was attributed to crystalline grain size. In some films, magneto-optical Kerr effect measurements reveal the existence of uniaxial magnetic anisotropy induced by the deposition process related with a small grain size (⩽20 nm). Isotropic magnetic properties have observed in nanocrystalline magnetite thin film having larger grain sizes. The largest power factor of all the films prepared (0.47 μW/K 2 cm), obtained from a Seebeck coefficient of −80 μV/K and an electrical resistivity of 13 mΩ cm, is obtained in a nanocrystalline magnetite thin film with an expanded out-of-plane lattice and with a grain size ≈30 nm

  10. Thin-Film Power Transformers

    Science.gov (United States)

    Katti, Romney R.

    1995-01-01

    Transformer core made of thin layers of insulating material interspersed with thin layers of ferromagnetic material. Flux-linking conductors made of thinner nonferromagnetic-conductor/insulator multilayers wrapped around core. Transformers have geometric features finer than those of transformers made in customary way by machining and mechanical pressing. In addition, some thin-film materials exhibit magnetic-flux-carrying capabilities superior to those of customary bulk transformer materials. Suitable for low-cost, high-yield mass production.

  11. Size effects in thin films

    CERN Document Server

    Tellier, CR; Siddall, G

    1982-01-01

    A complete and comprehensive study of transport phenomena in thin continuous metal films, this book reviews work carried out on external-surface and grain-boundary electron scattering and proposes new theoretical equations for transport properties of these films. It presents a complete theoretical view of the field, and considers imperfection and impurity effects.

  12. Superconducting thin films

    International Nuclear Information System (INIS)

    Hebard, A.F.; Vandenberg, J.M.

    1982-01-01

    This invention relates to granular metal and metal oxide superconducting films formed by ion beam sputter deposition. Illustratively, the films comprise irregularly shaped, randomly oriented, small lead grains interspersed in an insulating lead oxide matrix. The films are hillock-resistant when subjected to thermal cycling and exhibit unusual josephson-type switching characteristics. Depending on the oxygen content, a film may behave in a manner similar to that of a plurality of series connected josephson junctions, or the film may have a voltage difference in a direction parallel to a major surface of the film that is capable of being switched from zero voltage difference to a finite voltage difference in response to a current larger than the critical current

  13. Beryllium thin films for resistor applications

    Science.gov (United States)

    Fiet, O.

    1972-01-01

    Beryllium thin films have a protective oxidation resistant property at high temperature and high recrystallization temperature. However, the experimental film has very low temperature coefficient of resistance.

  14. Thermoelectric properties of ZnSb films grown by MOCVD

    International Nuclear Information System (INIS)

    Venkatasubramanian, R.; Watko, E.; Colpitts, T.

    1997-04-01

    The thermoelectric properties of metallorganic chemical vapor deposited (MOCVD) ZnSb films are reported. The growth conditions necessary to obtain stoichiometric ZnSb films and the effects of various growth parameters on the electrical conductivity and Seebeck coefficients of the films are described. The as-grown ZnSb films are p-type. It was observed that the growth of thicker ZnSb films lead to improved carrier mobilities and lower free-carrier concentrations. The Seebeck coefficient of ZnSb films was found to rise rapidly at approximately 160 to 170 C, with peak Seebeck coefficients as high as 470 microV/K at 220 C. The various growth conditions, including the use of intentional dopants, to improve the Seebeck coefficients at room temperature and above, are discussed. A short annealing of the ZnSb films at temperatures of ∼ 200 C resulted in reduced free-carrier levels and higher Seebeck coefficients at 300 K. Finally, ZT values based on preliminary thermal conductivity measurements using the 3-ω method are reported

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

    Science.gov (United States)

    Noori, Amirreza; Masoumi, Saeed; Hashemi, Najmeh

    2017-12-01

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

  16. Semiconductor-nanocrystal/conjugated polymer thin films

    Science.gov (United States)

    Alivisatos, A. Paul; Dittmer, Janke J.; Huynh, Wendy U.; Milliron, Delia

    2014-06-17

    The invention described herein provides for thin films and methods of making comprising inorganic semiconductor-nanocrystals dispersed in semiconducting-polymers in high loading amounts. The invention also describes photovoltaic devices incorporating the thin films.

  17. Preparation of thin vyns films

    International Nuclear Information System (INIS)

    Blanc, R.; Chedin, P.; Gizon, A.

    1965-01-01

    The fabrication of thin films of VYNS resin (copolymer of chloride and vinyl acetate) of superficial density from 3 to 50 μg/cm 2 with solutions in cyclohexanone is presented. Study and discussion of some properties compared with formvar film (polyvinyl formals). It appears that both can be used as source supports but formvar films are prepared more easily and more quickly, in addition they withstand higher temperatures. The main quality of VYNS is that they can be easily separated even several days after their preparation [fr

  18. Nanocrystal thin film fabrication methods and apparatus

    Science.gov (United States)

    Kagan, Cherie R.; Kim, David K.; Choi, Ji-Hyuk; Lai, Yuming

    2018-01-09

    Nanocrystal thin film devices and methods for fabricating nanocrystal thin film devices are disclosed. The nanocrystal thin films are diffused with a dopant such as Indium, Potassium, Tin, etc. to reduce surface states. The thin film devices may be exposed to air during a portion of the fabrication. This enables fabrication of nanocrystal-based devices using a wider range of techniques such as photolithography and photolithographic patterning in an air environment.

  19. Peltier cooling and onsager reciprocity in ferromagnetic thin films.

    Science.gov (United States)

    Avery, A D; Zink, B L

    2013-09-20

    We present direct measurements of the Peltier effect as a function of temperature from 77 to 325 K in Ni, Ni(80)Fe(20), and Fe thin films made using a suspended Si-N membrane structure. Measurement of the Seebeck effect in the same films allows us to directly test predictions of Onsager reciprocity between the Peltier and Seebeck effects. The Peltier coefficient Π is negative for both Ni and Ni(80)Fe(20) films and positive for the Fe film. The Fe film also exhibits a peak associated with the magnon drag Peltier effect. The observation of magnon drag in the Fe film verifies that the coupling between the phonon, magnon, and electron systems in the film is the same whether driven by heat current or charge current. The excellent agreement between Π values predicted using the experimentally determined Seebeck coefficient for these films and measured values offers direct experimental confirmation of the Onsager reciprocity between these thermoelectric effects in ferromagnetic thin films near room temperature.

  20. High-performance and flexible thermoelectric films by screen printing solution-processed nanoplate crystals.

    Science.gov (United States)

    Varghese, Tony; Hollar, Courtney; Richardson, Joseph; Kempf, Nicholas; Han, Chao; Gamarachchi, Pasindu; Estrada, David; Mehta, Rutvik J; Zhang, Yanliang

    2016-09-12

    Screen printing allows for direct conversion of thermoelectric nanocrystals into flexible energy harvesters and coolers. However, obtaining flexible thermoelectric materials with high figure of merit ZT through printing is an exacting challenge due to the difficulties to synthesize high-performance thermoelectric inks and the poor density and electrical conductivity of the printed films. Here, we demonstrate high-performance flexible films and devices by screen printing bismuth telluride based nanocrystal inks synthesized using a microwave-stimulated wet-chemical method. Thermoelectric films of several tens of microns thickness were screen printed onto a flexible polyimide substrate followed by cold compaction and sintering. The n-type films demonstrate a peak ZT of 0.43 along with superior flexibility, which is among the highest reported ZT values in flexible thermoelectric materials. A flexible thermoelectric device fabricated using the printed films produces a high power density of 4.1 mW/cm(2) with 60 °C temperature difference between the hot side and cold side. The highly scalable and low cost process to fabricate flexible thermoelectric materials and devices demonstrated here opens up many opportunities to transform thermoelectric energy harvesting and cooling applications.

  1. Laser energy tuning of carrier effective mass and thermopower in epitaxial oxide thin films

    KAUST Repository

    Abutaha, Anas I.; Sarath Kumar, S. R.; Alshareef, Husam N.

    2012-01-01

    The effect of the laser fluence on high temperature thermoelectric properties of the La doped SrTiO3 (SLTO) thin films epitaxially grown on LaAlO3 〈100〉 substrates by pulsed laser deposition is clarified. It is shown that oxygen vacancies

  2. Chemical Welding on Semimetallic TiS2 Nanosheets for High-Performance Flexible n-Type Thermoelectric Films.

    Science.gov (United States)

    Zhou, Yuan; Wan, Juanyong; Li, Qi; Chen, Lei; Zhou, Jiyang; Wang, Heao; He, Dunren; Li, Xiaorui; Yang, Yaocheng; Huang, Huihui

    2017-12-13

    Solution-based processing of two-dimensional (2D) materials provides the possibility of allowing these materials to be incorporated into large-area thin films, which can translate the interesting fundamental properties of 2D materials into available devices. Here, we report for the first time a novel chemical-welding method to achieve high-performance flexible n-type thermoelectric films using 2D semimetallic TiS 2 nanosheets. We employ chemically exfoliated TiS 2 nanosheets bridged with multivalent cationic metal Al 3+ to cross-link the nearby sheets during the film deposition process. We find that such a treatment can greatly enhance the stability of the film and can improve the power factor by simultaneously increasing the Seebeck coefficient and electrical conductivity. The resulting TiS 2 nanosheet-based flexible film shows a room temperature power factor of ∼216.7 μW m -1 K -2 , which is among the highest chemically exfoliated 2D transition-metal dichalcogenide nanosheet-based films and comparable to the best flexible n-type thermoelectric films, to our knowledge, indicating its potential applications in wearable electronics.

  3. Thin films of soft matter

    CERN Document Server

    Kalliadasis, Serafim

    2007-01-01

    A detailed overview and comprehensive analysis of the main theoretical and experimental advances on free surface thin film and jet flows of soft matter is given. At the theoretical front the book outlines the basic equations and boundary conditions and the derivation of low-dimensional models for the evolution of the free surface. Such models include long-wave expansions and equations of the boundary layer type and are analyzed via linear stability analysis, weakly nonlinear theories and strongly nonlinear analysis including construction of stationary periodic and solitary wave and similarity solutions. At the experimental front a variety of very recent experimental developments is outlined and the link between theory and experiments is illustrated. Such experiments include spreading drops and bubbles, imbibitions, singularity formation at interfaces and experimental characterization of thin films using atomic force microscopy, ellipsometry and contact angle measurements and analysis of patterns using Minkows...

  4. Review of thin film superconductivity

    International Nuclear Information System (INIS)

    Kihlstrom, K.E.

    1989-01-01

    Advances in thin film superconductivity are critical to the success of many proposed applications. The authors review several of the prominent techniques currently used to produce thin films of the high temperature superconductors including electron beam co-deposition, sputtering (both multiple and composite source configurations) and laser ablation. The authors look at the relevant parameters for each and evaluate the advantages and disadvantages of each technique. In addition, promising work on in situ oxidation is discussed. Also addressed are efforts to find optimum substrate materials and substrate buffer layers for various applications. The current state of the art for T c , J c and H c2 is presented for the yttrium, bismuth, and thallium compounds

  5. Polycrystalline thin films : A review

    Energy Technology Data Exchange (ETDEWEB)

    Valvoda, V [Charles Univ., Prague (Czech Republic). Faculty of Mathematics and Physics

    1996-09-01

    Polycrystalline thin films can be described in terms of grain morphology and in terms of their packing by the Thornton`s zone model as a function of temperature of deposition and as a function of energy of deposited atoms. Grain size and preferred grain orientation (texture) can be determined by X-ray diffraction (XRD) methods. A review of XRD analytical methods of texture analysis is given with main attention paid to simple empirical functions used for texture description and for structure analysis by joint texture refinement. To illustrate the methods of detailed structure analysis of thin polycrystalline films, examples of multilayers are used with the aim to show experiments and data evaluation to determine layer thickness, periodicity, interface roughness, lattice spacing, strain and the size of diffraction coherent volumes. The methods of low angle and high angle XRD are described and discussed with respect to their complementary information content.

  6. Magnetization in permalloy thin films

    Indian Academy of Sciences (India)

    Thin films of permalloy (Ni80Fe20) were prepared using an Ar+N2 mixture with magnetron ... alloys of Ni and Fe) take an important place. NiFe alloy with a ... room temperature (∼298 K, without intentional heating) on Si(100) substrates. A base pressure of 1×10−6 mbar was achieved prior to the deposition. Three different ...

  7. Thin-Film Material Science and Processing | Materials Science | NREL

    Science.gov (United States)

    Thin-Film Material Science and Processing Thin-Film Material Science and Processing Photo of a , a prime example of this research is thin-film photovoltaics (PV). Thin films are important because cadmium telluride thin film, showing from top to bottom: glass, transparent conducting oxide (thin layer

  8. Photoconductivity of thin organic films

    International Nuclear Information System (INIS)

    Tkachenko, Nikolai V.; Chukharev, Vladimir; Kaplas, Petra; Tolkki, Antti; Efimov, Alexander; Haring, Kimmo; Viheriaelae, Jukka; Niemi, Tapio; Lemmetyinen, Helge

    2010-01-01

    Thin organic films were deposited on silicon oxide surfaces with golden interdigitated electrodes (interelectrode gap was 2 μm), and the film resistivities were measured in dark and under white light illumination. The compounds selected for the measurements include molecules widely used in solar cell applications, such as polythiophene (PHT), fullerene (C 60 ), pyrelene tetracarboxylic diimide (PTCDI) and copper phthalocyanine (CuPc), as well as molecules potentially interesting for photovoltaic applications, e.g. porphyrin-fullerene dyads. The films were deposited using thermal evaporation (e.g. for C 60 and CuPc films), spin coating for PHT, and Langmuir-Schaeffer for the layer-by-layer deposition of porphyrin-fullerene dyads. The most conducting materials in the series are films of PHT and CuPc with resistivities 1.2 x 10 3 Ω m and 3 x 10 4 Ω m, respectively. Under light illumination resistivity of all films decreases, with the strongest light effect observed for PTCDI, for which resistivity decreases by 100 times, from 3.2 x 10 8 Ω m in dark to 3.1 x 10 6 Ω m under the light.

  9. Flexible thin film magnetoimpedance sensors

    International Nuclear Information System (INIS)

    Kurlyandskaya, G.V.; Fernández, E.; Svalov, A.; Burgoa Beitia, A.; García-Arribas, A.; Larrañaga, A.

    2016-01-01

    Magnetically soft thin film deposited onto polymer substrates is an attractive option for flexible electronics including magnetoimpedance (MI) applications. MI FeNi/Ti based thin film sensitive elements were designed and prepared using the sputtering technique by deposition onto rigid and flexible substrates at different deposition rates. Their structure, magnetic properties and MI were comparatively analyzed. The main structural features were sufficiently accurately reproduced in the case of deposition onto cyclo olefine polymer substrates compared to glass substrates for the same conditions. Although for the best condition (28 nm/min rate) of the deposition onto polymer a significant reduction of the MI field sensitivity was found satisfactory for sensor applications sensitivity: 45%/Oe was obtained for a frequency of 60 MHz. - Highlights: • [FeNi/Ti] 3 /Cu/[FeNi/Ti] 3 films were prepared by sputtering at different deposition rates. • Polymer substrates insure sufficiently accurate reproducibility of the film structure. • High deposition rate of 28 nm/min insures the highest values of the magnetoimpedance sensitivity. • Deposition onto polymer results in the satisfactory magnetoimpedance sensitivity of 45%/Oe.

  10. Flexible thin film magnetoimpedance sensors

    Energy Technology Data Exchange (ETDEWEB)

    Kurlyandskaya, G.V., E-mail: galina@we.lc.ehu.es [Universidad del País Vasco, UPV/EHU, Departamento de Electricidad y Electrónica, P.O. Box 644, Bilbao 48080 (Spain); Ural Federal University, Laboratory of Magnetic sensoric, Lenin Ave. 51, 620083 Ekaterinburg (Russian Federation); Fernández, E. [BCMaterials UPV-EHU, Vizcaya Science and Technology Park, 48160 Derio (Spain); Svalov, A. [Universidad del País Vasco, UPV/EHU, Departamento de Electricidad y Electrónica, P.O. Box 644, Bilbao 48080 (Spain); Ural Federal University, Laboratory of Magnetic sensoric, Lenin Ave. 51, 620083 Ekaterinburg (Russian Federation); Burgoa Beitia, A. [Universidad del País Vasco, UPV/EHU, Departamento de Electricidad y Electrónica, P.O. Box 644, Bilbao 48080 (Spain); García-Arribas, A. [Universidad del País Vasco, UPV/EHU, Departamento de Electricidad y Electrónica, P.O. Box 644, Bilbao 48080 (Spain); BCMaterials UPV-EHU, Vizcaya Science and Technology Park, 48160 Derio (Spain); Larrañaga, A. [SGIker, Servicios Generales de Investigación, Universidad del País Vasco (UPV/EHU), 48080 Bilbao (Spain)

    2016-10-01

    Magnetically soft thin film deposited onto polymer substrates is an attractive option for flexible electronics including magnetoimpedance (MI) applications. MI FeNi/Ti based thin film sensitive elements were designed and prepared using the sputtering technique by deposition onto rigid and flexible substrates at different deposition rates. Their structure, magnetic properties and MI were comparatively analyzed. The main structural features were sufficiently accurately reproduced in the case of deposition onto cyclo olefine polymer substrates compared to glass substrates for the same conditions. Although for the best condition (28 nm/min rate) of the deposition onto polymer a significant reduction of the MI field sensitivity was found satisfactory for sensor applications sensitivity: 45%/Oe was obtained for a frequency of 60 MHz. - Highlights: • [FeNi/Ti]{sub 3}/Cu/[FeNi/Ti]{sub 3} films were prepared by sputtering at different deposition rates. • Polymer substrates insure sufficiently accurate reproducibility of the film structure. • High deposition rate of 28 nm/min insures the highest values of the magnetoimpedance sensitivity. • Deposition onto polymer results in the satisfactory magnetoimpedance sensitivity of 45%/Oe.

  11. Thermoelectric properties and performance of flexible reduced graphene oxide films up to 3,000 K

    Science.gov (United States)

    Li, Tian; Pickel, Andrea D.; Yao, Yonggang; Chen, Yanan; Zeng, Yuqiang; Lacey, Steven D.; Li, Yiju; Wang, Yilin; Dai, Jiaqi; Wang, Yanbin; Yang, Bao; Fuhrer, Michael S.; Marconnet, Amy; Dames, Chris; Drew, Dennis H.; Hu, Liangbing

    2018-02-01

    The development of ultrahigh-temperature thermoelectric materials could enable thermoelectric topping of combustion power cycles as well as extending the range of direct thermoelectric power generation in concentrated solar power. However, thermoelectric operation temperatures have been restricted to under 1,500 K due to the lack of suitable materials. Here, we demonstrate a thermoelectric conversion material based on high-temperature reduced graphene oxide nanosheets that can perform reliably up to 3,000 K. After a reduction treatment at 3,300 K, the nanosheet film exhibits an increased conductivity to 4,000 S cm-1 at 3,000 K and a high power factor S2σ = 54.5 µW cm-1 K-2. We report measurements characterizing the film's thermoelectric properties up to 3,000 K. The reduced graphene oxide film also exhibits a high broadband radiation absorbance and can act as both a radiative receiver and a thermoelectric generator. The printable, lightweight and flexible film is attractive for system integration and scalable manufacturing.

  12. Characterization of nanocrystalline cadmium telluride thin films ...

    Indian Academy of Sciences (India)

    Unknown

    tion method, successive ionic layer adsorption and reaction (SILAR), are described. For deposition of CdTe thin films ... By conducting several trials optimization of the adsorption, reaction and rinsing time duration for CdTe thin film .... The electrical resistivity of CdTe films was studied in air. Figure 3 shows the variation of log ...

  13. Seebeck coefficient of synthesized Titanium Dioxide thin film on FTO glass substrate

    Science.gov (United States)

    Usop, R.; Hamed, N. K. A.; Megat Hasnan, M. M. I.; Ikeda, H.; Sabri, M. F. M.; Ahmad, M. K.; Said, S. M.; Salleh, F.

    2018-04-01

    In order to fabricate a thermoelectric device on glass substrate for harvesting waste heat energy through house appliances, the Seebeck coefficient of translucent TiO2 thin film was investigated. The TiO2 thin film was synthesized by using hydrothermal method with F-SnO2 coated glass as substrate. From scanning electron microscopy analysis, the synthesized TiO2 thin film was found to be in nanometer-scale rod structure with a thickness of 4 µm. The Seebeck coefficient was measured in the temperature range of 300 – 400 K. The Seebeck coefficient is found to be in negative value which shows that synthesized film is an n-type semiconductor material, and is lower than the value of bulk-size material. This reduction in Seebeck coefficient of TiO2 thin film is likely due to the low dimensional effect and the difference of carrier concentration.

  14. Thin films for emerging applications v.16

    CERN Document Server

    Francombe, Maurice H

    1992-01-01

    Following in the long-standing tradition of excellence established by this serial, this volume provides a focused look at contemporary applications. High Tc superconducting thin films are discussed in terms of ion beam and sputtering deposition, vacuum evaporation, laser ablation, MOCVD, and other deposition processes in addition to their ultimate applications. Detailed treatment is also given to permanent magnet thin films, lateral diffusion and electromigration in metallic thin films, and fracture and cracking phenomena in thin films adhering to high-elongation substrates.

  15. Analysis of Hard Thin Film Coating

    Science.gov (United States)

    Shen, Dashen

    1998-01-01

    MSFC is interested in developing hard thin film coating for bearings. The wearing of the bearing is an important problem for space flight engine. Hard thin film coating can drastically improve the surface of the bearing and improve the wear-endurance of the bearing. However, many fundamental problems in surface physics, plasma deposition, etc, need further research. The approach is using electron cyclotron resonance chemical vapor deposition (ECRCVD) to deposit hard thin film an stainless steel bearing. The thin films in consideration include SiC, SiN and other materials. An ECRCVD deposition system is being assembled at MSFC.

  16. Progress in thin film techniques

    International Nuclear Information System (INIS)

    Weingarten, W.

    1996-01-01

    Progress since the last Workshop is reported on superconducting accelerating RF cavities coated with thin films. The materials investigated are Nb, Nb 3 Sn, NbN and NbTiN, the techniques applied are diffusion from the vapour phase (Nb 3 Sn, NbN), the bronze process (Nb 3 Sn), and sputter deposition on a copper substrate (Nb, NbTiN). Specially designed cavities for sample evaluation by RF methods have been developed (triaxial cavity). New experimental techniques to assess the RF amplitude dependence of the surface resistance are presented (with emphasis on niobium films sputter deposited on copper). Evidence is increasing that they are caused by magnetic flux penetration into the surface layer. (R.P.)

  17. High temperature superconductor thin films

    International Nuclear Information System (INIS)

    Correra, L.

    1992-01-01

    Interdisciplinary research on superconducting oxides is the main focus of the contributors in this volume. Several aspects of the thin film field from fundamental properties to applications are examined. Interesting results for the Bi system are also reviewed. The 132 papers, including 8 invited, report mainly on the 1-2-3 system, indicating that the Y-Ba-Cu-O and related compounds are still the most intensively studied materials in this field. The volume attests to the significant progress that has been made in this field, as well as reporting on the challenging problems that still remain to be solved. The papers are presented in five chapters, subsequently on properties, film growth and processing, substrates and multilayers, structural characterization, and applications

  18. Minerals deposited as thin films

    International Nuclear Information System (INIS)

    Vazquez, Cristina; Leyt, D.V. de; Custo, Graciela

    1987-01-01

    Free matrix effects are due to thin film deposits. Thus, it was decided to investigate this technique as a possibility to use pure oxide of the desired element, extrapolating its concentration from analytical curves made with avoiding, at the same time, mathematical corrections. The proposed method was employed to determine iron and titanium concentrations in geological samples. The range studied was 0.1-5%m/m for titanium and 5-20%m/m for iron. For both elements the reproducibility was about 7% and differences between this method and other chemical determinations were 15% for titanium and 7% for iron. (Author) [es

  19. Thin Film Photovoltaic Partnership Project | Photovoltaic Research | NREL

    Science.gov (United States)

    Thin Film Photovoltaic Partnership Project Thin Film Photovoltaic Partnership Project NREL's Thin Film Photovoltaic (PV) Partnership Project led R&D on emerging thin-film solar technologies in the United States from 1994 to 2009. The project made many advances in thin-film PV technologies that allowed

  20. Thin liquid films dewetting and polymer flow

    CERN Document Server

    Blossey, Ralf

    2012-01-01

    This book is a treatise on the thermodynamic and dynamic properties of thin liquid films at solid surfaces and, in particular, their rupture instabilities. For the quantitative study of these phenomena, polymer thin films haven proven to be an invaluable experimental model system.   What is it that makes thin film instabilities special and interesting, warranting a whole book? There are several answers to this. Firstly, thin polymeric films have an important range of applications, and with the increase in the number of technologies available to produce and to study them, this range is likely to expand. An understanding of their instabilities is therefore of practical relevance for the design of such films.   Secondly, thin liquid films are an interdisciplinary research topic. Interdisciplinary research is surely not an end to itself, but in this case it leads to a fairly heterogeneous community of theoretical and experimental physicists, engineers, physical chemists, mathematicians and others working on the...

  1. Intrinsically conductive polymer thin film piezoresistors

    DEFF Research Database (Denmark)

    Lillemose, Michael; Spieser, Martin; Christiansen, N.O.

    2008-01-01

    We report on the piezoresistive effect in the intrinsically conductive polymer, polyaniline. A process recipe for indirect patterning of thin film polyaniline has been developed. Using a specially designed chip, the polyaniline thin films have been characterised with respect to resistivity...

  2. Excimer Laser Deposition of PLZT Thin Films

    National Research Council Canada - National Science Library

    Petersen, GAry

    1991-01-01

    .... In order to integrate these devices into optical systems, the production of high quality thin films with high transparency and perovskite crystal structure is desired. This requires development of deposition technologies to overcome the challenges of depositing and processing PLZT thin films.

  3. Thin films of mixed metal compounds

    Science.gov (United States)

    Mickelsen, Reid A.; Chen, Wen S.

    1985-01-01

    A compositionally uniform thin film of a mixed metal compound is formed by simultaneously evaporating a first metal compound and a second metal compound from independent sources. The mean free path between the vapor particles is reduced by a gas and the mixed vapors are deposited uniformly. The invention finds particular utility in forming thin film heterojunction solar cells.

  4. Field ion microscope studies on thin films

    International Nuclear Information System (INIS)

    Cavaleru, A.; Scortaru, A.

    1976-01-01

    A review of the progress made in the last years in FIM application to thin film structure studies and adatom properties important in the nucleation stage of thin film growth: substrate binding and mobility of individual adatoms, behaviour of adatoms clusters is presented. (author)

  5. MeV Si ion modifications on the thermoelectric generators from Si/Si + Ge superlattice nano-layered films

    Science.gov (United States)

    Budak, S.; Heidary, K.; Johnson, R. B.; Colon, T.; Muntele, C.; Ila, D.

    2014-08-01

    The performance of thermoelectric materials and devices is characterized by a dimensionless figure of merit, ZT = S2σT/K, where, S and σ denote, respectively, the Seebeck coefficient and electrical conductivity, T is the absolute temperature in Kelvin and K represents the thermal conductivity. The figure of merit may be improved by means of raising either S or σ or by lowering K. In our laboratory, we have fabricated and characterized the performance of a large variety of thermoelectric generators (TEG). Two TEG groups comprised of 50 and 100 alternating layers of Si/Si + Ge multi-nanolayered superlattice films have been fabricated and thoroughly characterized. Ion beam assisted deposition (IBAD) was utilized to assemble the alternating sandwiched layers, resulting in total thickness of 300 nm and 317 nm for 50 and 100 layer devices, respectively. Rutherford Backscattering Spectroscopy (RBS) was employed in order to monitor the precise quantity of Si and Ge utilized in the construction of specific multilayer thin films. The material layers were subsequently impregnated with quantum dots and/or quantum clusters, in order to concurrently reduce the cross plane thermal conductivity, increase the cross plane Seebeck coefficient and raise the cross plane electrical conductivity. The quantum dots/clusters were implanted via the 5 MeV Si ion bombardment which was performed using a Pelletron high energy ion beam accelerator. We have achieved remarkable results for the thermoelectric and optical properties of the Si/Si + Ge multilayer thin film TEG systems. We have demonstrated that with optimal setting of the 5 MeV Si ion beam bombardment fluences, one can fabricate TEG systems with figures of merits substantially higher than the values previously reported.

  6. MeV Si ion modifications on the thermoelectric generators from Si/Si + Ge superlattice nano-layered films

    Energy Technology Data Exchange (ETDEWEB)

    Budak, S., E-mail: satilmis.budak@aamu.edu [Department of Electrical Engineering and Computer Science, Alabama A and M University, Huntsville, AL (United States); Heidary, K. [Department of Electrical Engineering and Computer Science, Alabama A and M University, Huntsville, AL (United States); Johnson, R.B.; Colon, T. [Department of Physics, Alabama A and M University, Huntsville, AL (United States); Muntele, C. [Cygnus Scientific Services, Huntsville, AL (United States); Ila, D. [Department of Physics, Fayetteville St. University, Fayetteville, NC (United States)

    2014-08-15

    The performance of thermoelectric materials and devices is characterized by a dimensionless figure of merit, ZT = S{sup 2}σT/K, where, S and σ denote, respectively, the Seebeck coefficient and electrical conductivity, T is the absolute temperature in Kelvin and K represents the thermal conductivity. The figure of merit may be improved by means of raising either S or σ or by lowering K. In our laboratory, we have fabricated and characterized the performance of a large variety of thermoelectric generators (TEG). Two TEG groups comprised of 50 and 100 alternating layers of Si/Si + Ge multi-nanolayered superlattice films have been fabricated and thoroughly characterized. Ion beam assisted deposition (IBAD) was utilized to assemble the alternating sandwiched layers, resulting in total thickness of 300 nm and 317 nm for 50 and 100 layer devices, respectively. Rutherford Backscattering Spectroscopy (RBS) was employed in order to monitor the precise quantity of Si and Ge utilized in the construction of specific multilayer thin films. The material layers were subsequently impregnated with quantum dots and/or quantum clusters, in order to concurrently reduce the cross plane thermal conductivity, increase the cross plane Seebeck coefficient and raise the cross plane electrical conductivity. The quantum dots/clusters were implanted via the 5 MeV Si ion bombardment which was performed using a Pelletron high energy ion beam accelerator. We have achieved remarkable results for the thermoelectric and optical properties of the Si/Si + Ge multilayer thin film TEG systems. We have demonstrated that with optimal setting of the 5 MeV Si ion beam bombardment fluences, one can fabricate TEG systems with figures of merits substantially higher than the values previously reported.

  7. Cellulose triacetate, thin film dielectric capacitor

    Science.gov (United States)

    Yen, Shiao-Ping S. (Inventor); Jow, T. Richard (Inventor)

    1995-01-01

    Very thin films of cellulose triacetate are cast from a solution containing a small amount of high boiling temperature, non-solvent which evaporates last and lifts the film from the casting surface. Stretched, oriented, crystallized films have high electrical breakdown properties. Metallized films less than about 2 microns in thickness form self-healing electrodes for high energy density, pulsed power capacitors. Thicker films can be utilized as a dielectric for a capacitor.

  8. Nanostructured thin films and coatings functional properties

    CERN Document Server

    Zhang, Sam

    2010-01-01

    The second volume in ""The Handbook of Nanostructured Thin Films and Coatings"" set, this book focuses on functional properties, including optical, electronic, and electrical properties, as well as related devices and applications. It explores the large-scale fabrication of functional thin films with nanoarchitecture via chemical routes, the fabrication and characterization of SiC nanostructured/nanocomposite films, and low-dimensional nanocomposite fabrication and applications. The book also presents the properties of sol-gel-derived nanostructured thin films as well as silicon nanocrystals e

  9. Experimental Investigation of Zinc Antimonide Thin Films under Different Thermal Boundary Conditions

    DEFF Research Database (Denmark)

    Mir Hosseini, Seyed Mojtaba; Rosendahl, Lasse Aistrup; Rezaniakolaei, Alireza

    for all cases, showing that the electrical potential difference is increasing by temperature for all cases with the same slope. Also the value of Seebeck coefficient (α) is almost constant for all cases. The obtained value of α can compete with developed bulk TEG materials in literature. The thin film...... is able to operate in relatively high range of temperature with long working period without failure. Furthermore, effects of implementing thermal cycling on stability analysis of a TEG sample are considered. By testing the thermoelectric thin film specimen during a thermal cycling, behavior of the TEG...

  10. BDS thin film damage competition

    Science.gov (United States)

    Stolz, Christopher J.; Thomas, Michael D.; Griffin, Andrew J.

    2008-10-01

    A laser damage competition was held at the 2008 Boulder Damage Symposium in order to determine the current status of thin film laser resistance within the private, academic, and government sectors. This damage competition allows a direct comparison of the current state-of-the-art of high laser resistance coatings since they are all tested using the same damage test setup and the same protocol. A normal incidence high reflector multilayer coating was selected at a wavelength of 1064 nm. The substrates were provided by the submitters. A double blind test assured sample and submitter anonymity so only a summary of the results are presented here. In addition to the laser resistance results, details of deposition processes, coating materials, and layer count will also be shared.

  11. Comparative evaluation of corrosion behaviour of type K thin film thermocouple and its bulk counterpart

    International Nuclear Information System (INIS)

    Mukherjee, S.K.; Barhai, P.K.; Srikanth, S.

    2011-01-01

    Highlights: → Anodic vacuum arc deposited chromel and alumel films are more 'noble' in 5% NaCl solution than their respective wires. → Chromel undergoes localised corrosion while alumel shows uniform corrosion. → Virgin samples of chromel-alumel TFTCs exhibit good thermoelectric response. → Their thermoelectric outputs remain largely unaffected when shelved under normal atmospheric conditions. → After 288 h of exposure in salt spray environment, their thermoelectric outputs show noticeable change due to size effects. - Abstract: This paper investigates the corrosion behaviour of type K thermoelements and their thin films, and compares the performance of chromel-alumel thin film thermocouple with its wire counterpart before and after exposure to 5% NaCl medium. Potentiodynamic polarisation tests reveal that chromel and alumel films are more 'noble' than their respective wires. Alumel corrodes faster when coupled with chromel in films than as wires. Secondary electron micrographs and electrochemical impedance spectroscopy measurements suggest that chromel shows localised corrosion while alumel undergoes uniform corrosion. Corrosion adversely affects the thermocouple output and introduces an uncertainty in the measurement.

  12. Method of producing thin cellulose nitrate film

    International Nuclear Information System (INIS)

    Lupica, S.B.

    1975-01-01

    An improved method for forming a thin nitrocellulose film of reproducible thickness is described. The film is a cellulose nitrate film, 10 to 20 microns in thickness, cast from a solution of cellulose nitrate in tetrahydrofuran, said solution containing from 7 to 15 percent, by weight, of dioctyl phthalate, said cellulose nitrate having a nitrogen content of from 10 to 13 percent

  13. Thermoelectric properties of thin film and superlattice structure of IV-VI and V-VI compound semiconductors; Thermoelektrische Eigenschaften duenner Schichten und Uebergitterstrukturen von IV-VI- und V-VI-Verbundhalbleitern

    Energy Technology Data Exchange (ETDEWEB)

    Blumers, Mathias

    2012-02-29

    The basic material property governing the efficiency of thermoelectric applications is the thermoelectric figure of merit Z=S{sup 2}.{sigma}/k, where S is the Seebeck-coefficient, {sigma} is the electrical conductivity and k the thermal conductivity. A promising concept of increasing Z by one and two dimensional quantum well superlattices (QW-SL) was introduced in the early 1990s in terms of theoretical predictions. The realization of such low dimensional systems is done by use of semiconductor compounds with different energy gaps. The ambition of the Nitherma project was to investigate the thermoelectric properties of superlattices and Multi-Quantum-Well-structures (MQW) made of Pb{sub 1-x}Sr{sub x}Te and Bi{sub 2}(Se{sub x}Te{sub 1-x}){sub 3}, respectively. Therefore SL- and MQW-structures of this materials were grown and Z was determined by measuring of S, {sigma} and {kappa} parallel to the layer planes. Aim of this thesis is the interpretation of the transport measurements (S,{sigma},{kappa}) of low dimensional structures and the improvement of preparation and measurement techniques. The influence of low dimensionality on the thermal conductivity in SL- and MQW-structures was investigated by measurements on structures with different layer thicknesses. In addition, measurements of the Seebeck-coefficient were performed, also to verify the results of the participating groups.

  14. Thermoelectric properties of atomically thin silicene and germanene nanostructures

    Science.gov (United States)

    Yang, K.; Cahangirov, S.; Cantarero, A.; Rubio, A.; D'Agosta, R.

    2014-03-01

    The thermoelectric properties in one- and two-dimensional silicon and germanium structures have been investigated using first-principles density functional techniques and linear response for the thermal and electrical transport. We have considered here the two-dimensional silicene and germanene, together with nanoribbons of different widths. For the nano ribbons, we have also investigated the possibility of nano structuring these systems by mixing silicon and germanium. We found that the figure of merit at room temperature of these systems is remarkably high, up to 2.5.

  15. Macro stress mapping on thin film buckling

    Energy Technology Data Exchange (ETDEWEB)

    Goudeau, P.; Villain, P.; Renault, P.-O.; Tamura, N.; Celestre, R.S.; Padmore, H.A.

    2002-11-06

    Thin films deposited by Physical Vapour Deposition techniques on substrates generally exhibit large residual stresses which may be responsible of thin film buckling in the case of compressive stresses. Since the 80's, a lot of theoretical work has been done to develop mechanical models but only a few experimental work has been done on this subject to support these theoretical approaches and nothing concerning local stress measurement mainly because of the small dimension of the buckling (few 10th mm). This paper deals with the application of micro beam X-ray diffraction available on synchrotron radiation sources for stress mapping analysis of gold thin film buckling.

  16. Optoelectronic properties of cadmium sulfide thin films deposited by thermal evaporation technique

    International Nuclear Information System (INIS)

    Ali, N.; Iqbal, M.A.; Hussain, S.T.; Waris, M.; Munair, S.A.

    2011-01-01

    The substrate temperature in depositions of thin films plays a vital role in the characteristics of deposited films. We studied few characteristics of cadmium sulphide thin film deposited at different temperature (150 deg. C- 300 deg. C) on corning 7059 glass substrate. We measured transmittance, absorbance, band gap and reflectance via UV spectroscopy. It was found that the transmittance for 300 nm to 1100 nm was greater than 80%. The resistivity and mobility was calculated by Vander Pauw method which were 10-80 cm and 2-60 cm/sup 2/V/sup -1/S/sup -1/ respectively. The thermoelectric properties of the film were measured by hot and cold probe method which shows the N-type nature of the film. (author)

  17. Solid thin film materials for use in thin film charge-coupled devices

    International Nuclear Information System (INIS)

    Lynch, S.J.

    1983-01-01

    Solid thin films deposited by vacuum deposition were evaluated to ascertain their effectiveness for use in the manufacturing of charge-coupled devices (CCDs). Optical and electrical characteristics of tellurium and Bi 2 Te 3 solid thin films were obtained in order to design and to simulate successfully the operation of thin film (TF) CCDs. In this article some of the material differences between single-crystal material and the island-structured thin film used in TFCCDs are discussed. The electrical parameters were obtained and tabulated, e.g. the mobility, conductivity, dielectric constants, permittivity, lifetime of holes and electrons in the thin films and drift diffusion constants. The optical parameters were also measured and analyzed. After the design was complete, experimental TFCCDs were manufactured and were successfully operated utilizing the aforementioned solid thin films. (Auth.)

  18. Passivation Effects in Copper Thin Films

    International Nuclear Information System (INIS)

    Wiederhirn, G.; Nucci, J.; Richter, G.; Arzt, E.; Balk, T. J.; Dehm, G.

    2006-01-01

    We studied the influence of a 10 nm AlxOy passivation on the stress-temperature behavior of 100 nm and 1 μm thick Cu films. At low temperatures, the passivation induces a large tensile stress increase in the 100 nm film; however, its effect on the 1 μm film is negligible. At high temperatures, the opposite behavior is observed; while the passivation does not change the 100 nm film behavior, it strengthens the 1 μm film by driving it deeper into compression. These observations are explained in light of a combination of constrained diffusional creep and dislocation dynamics unique to ultra-thin films

  19. Thermoelectric properties of epitaxial ScN films deposited by reactive magnetron sputtering onto MgO(001) substrates

    Science.gov (United States)

    Burmistrova, Polina V.; Maassen, Jesse; Favaloro, Tela; Saha, Bivas; Salamat, Shuaib; Rui Koh, Yee; Lundstrom, Mark S.; Shakouri, Ali; Sands, Timothy D.

    2013-04-01

    Epitaxial ScN(001) thin films were grown on MgO(001) substrates by dc reactive magnetron sputtering. The deposition was performed in an Ar/N2 atmosphere at 2 × 10-3 Torr at a substrate temperature of 850 °C in a high vacuum chamber with a base pressure of 10-8 Torr. In spite of oxygen contamination of 1.6 ± 1 at. %, the electrical resistivity, electron mobility, and carrier concentration obtained from a typical film grown under these conditions by room temperature Hall measurements are 0.22 mΩ cm, 106 cm2 V-1 s-1, and 2.5 × 1020 cm-3, respectively. These films exhibit remarkable thermoelectric power factors of 3.3-3.5 × 10-3 W/mK2 in the temperature range of 600 K to 840 K. The cross-plane thermal conductivity is 8.3 W/mK at 800 K yielding an estimated ZT of 0.3. Theoretical modeling of the thermoelectric properties of ScN calculated using a mean-free-path of 23 nm at 300 K is in very good agreement with the experiment. These results also demonstrate that further optimization of the power factor of ScN is possible. First-principles density functional theory combined with the site occupancy disorder technique was used to investigate the effect of oxygen contamination on the electronic structure and thermoelectric properties of ScN. The computational results suggest that oxygen atoms in ScN mix uniformly on the N site forming a homogeneous solid solution alloy. Behaving as an n-type donor, oxygen causes a shift of the Fermi level in ScN into the conduction band without altering the band structure and the density of states.

  20. Epitaxy, thin films and superlattices

    International Nuclear Information System (INIS)

    Jagd Christensen, Morten

    1997-05-01

    This report is the result of structural investigations of 3d transition metal superlattices consisting of Fe/V, Cr/Mn, V/Mn and Fe/Mn, and a structural and magnetic study of a series of Ho/Pr alloys. The work includes preparation and characterization of substrates as well as growth of thin films and Fe/V superlattices by molecular beam epitaxy, including in-situ characterization by reflection high energy electron diffraction and Auger electron spectroscopy. Structural characterization has been done by x-ray diffraction and neutron diffraction. The x-ray diffraction experiments have been performed on the rotating copper anode at Risoe, and at synchrotron facilities in Hamburg and Brookhaven, and the neutron scattering was done at the Danish research reactor DR3 at Risoe. In addition to longitudinal scans, giving information about the structural parameters in the modulation direction, non-specular scans were also performed. This type of scans gives information about in-plane orientation and lattice parameters. From the analysis, structural information is obtained about lattice parameters, epitaxial strain, coherence lengths and crystallographic orientation for the superlattice systems, except Fe/Mn superlattices, which could not be modelled. For the Ho/Pr alloys, x-ray magnetic scattering was performed, and the crystal and magnetic structure was investigated. (au)

  1. Epitaxy, thin films and superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Jagd Christensen, Morten

    1997-05-01

    This report is the result of structural investigations of 3d transition metal superlattices consisting of Fe/V, Cr/Mn, V/Mn and Fe/Mn, and a structural and magnetic study of a series of Ho/Pr alloys. The work includes preparation and characterization of substrates as well as growth of thin films and Fe/V superlattices by molecular beam epitaxy, including in-situ characterization by reflection high energy electron diffraction and Auger electron spectroscopy. Structural characterization has been done by x-ray diffraction and neutron diffraction. The x-ray diffraction experiments have been performed on the rotating copper anode at Risoe, and at synchrotron facilities in Hamburg and Brookhaven, and the neutron scattering was done at the Danish research reactor DR3 at Risoe. In addition to longitudinal scans, giving information about the structural parameters in the modulation direction, non-specular scans were also performed. This type of scans gives information about in-plane orientation and lattice parameters. From the analysis, structural information is obtained about lattice parameters, epitaxial strain, coherence lengths and crystallographic orientation for the superlattice systems, except Fe/Mn superlattices, which could not be modelled. For the Ho/Pr alloys, x-ray magnetic scattering was performed, and the crystal and magnetic structure was investigated. (au) 14 tabs.; 58 ills., 96 refs.

  2. Flush Mounting Of Thin-Film Sensors

    Science.gov (United States)

    Moore, Thomas C., Sr.

    1992-01-01

    Technique developed for mounting thin-film sensors flush with surfaces like aerodynamic surfaces of aircraft, which often have compound curvatures. Sensor mounted in recess by use of vacuum pad and materials selected for specific application. Technique involves use of materials tailored to thermal properties of substrate in which sensor mounted. Together with customized materials, enables flush mounting of thin-film sensors in most situations in which recesses for sensors provided. Useful in both aircraft and automotive industries.

  3. Thin film description by wavelet coefficients statistics

    Czech Academy of Sciences Publication Activity Database

    Boldyš, Jiří; Hrach, R.

    2005-01-01

    Roč. 55, č. 1 (2005), s. 55-64 ISSN 0011-4626 Grant - others:GA UK(CZ) 173/2003 Institutional research plan: CEZ:AV0Z10750506 Keywords : thin films * wavelet transform * descriptors * histogram model Subject RIV: BD - Theory of Information Impact factor: 0.360, year: 2005 http://library.utia.cas.cz/separaty/2009/ZOI/boldys-thin film description by wavelet coefficients statistics .pdf

  4. Photoluminescence properties of perovskite multilayer thin films

    Energy Technology Data Exchange (ETDEWEB)

    Macario, Leilane Roberta; Longo, Elson, E-mail: leilanemacario@gmail.com [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil); Mazzo, Tatiana Martelli [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil); Bouquet, Valerie; Deputier, Stephanie; Ollivier, Sophie; Guilloux-Viry, Maryline [Universite de Rennes (France)

    2016-07-01

    Full text: The knowledge of the optical properties of thin films is important in many scientific, technological and industrial applications of thin films such as photoconductivity, solar energy, photography, and numerous other applications [1]. In this study, perovskite type oxides were grown by pulsed laser deposition [2] in order to obtain thin films with applicable optical properties. The LaNiO{sub 3} (LN), BaTiO{sub 3} (BT) and KNbO{sub 3} (KNb) targets were prepared by solid-state reaction. The X-ray Diffraction revealed the presence of the desired phases, containing the elements of interest in the targets and in the thin films that were produced. The LN, BT and KNb thin films were polycrystalline and the corresponding diffraction peaks were indexed in the with JCPDS cards n. 00-033-0711, n. 00-005-0626, and n. 00-009-0156, respectively. The multilayers films were polycrystalline. The majority of the micrographs obtained by scanning electron microscopy presented films with a thickness from 100 to 400 nm. The photoluminescent (PL) emission spectra of thin films show different broad bands that occupies large region of the visible spectrum, ranging from about 300-350 to 600-650 nm of the electromagnetic spectrum. The PL emission is associated with the order-disorder structural, even small structural changes can modify the interactions between electronic states. The structural disorder results in formation of new energy levels in the forbidden region. The proximity or distance of these new energy levels formed in relation to valence band and to the conduction band results in PL spectra located at higher or lower energies. These interactions change the electronic states which can be influenced by defects, particularly the interface defects between the layers of the thin films. The presence of defects results in changes in the broad band matrix intensity and in displacement of the PL emission maximum. (author)

  5. Nanosphere lithography applied to magnetic thin films

    Science.gov (United States)

    Gleason, Russell

    Magnetic nanostructures have widespread applications in many areas of physics and engineering, and nanosphere lithography has recently emerged as promising tool for the fabrication of such nanostructures. The goal of this research is to explore the magnetic properties of a thin film of ferromagnetic material deposited onto a hexagonally close-packed monolayer array of polystyrene nanospheres, and how they differ from the magnetic properties of a typical flat thin film. The first portion of this research focuses on determining the optimum conditions for depositing a monolayer of nanospheres onto chemically pretreated silicon substrates (via drop-coating) and the subsequent characterization of the deposited nanosphere layer with scanning electron microscopy. Single layers of permalloy (Ni80Fe20) are then deposited on top of the nanosphere array via DC magnetron sputtering, resulting in a thin film array of magnetic nanocaps. The coercivities of the thin films are measured using a home-built magneto-optical Kerr effect (MOKE) system in longitudinal arrangement. MOKE measurements show that for a single layer of permalloy (Py), the coercivity of a thin film deposited onto an array of nanospheres increases compared to that of a flat thin film. In addition, the coercivity increases as the nanosphere size decreases for the same deposited layer. It is postulated that magnetic exchange decoupling between neighboring nanocaps suppresses the propagation of magnetic domain walls, and this pinning of the domain walls is thought to be the primary source of the increase in coercivity.

  6. Electrical transport properties of thermally evaporated phthalocyanine (H 2Pc) thin films

    Science.gov (United States)

    El-Nahass, M. M.; Farid, A. M.; Attia, A. A.; Ali, H. A. M.

    2006-08-01

    Thin films of H 2Pc of various thicknesses have been deposited onto glass substrates using thermal evaporation technique at room temperature. The dark electrical resistivity measurements were carried out at different temperatures in the range 298-473 K. An estimation of mean free path ( lo) of charge carriers in H 2Pc thin films was attempted. Measurements of thermoelectric power confirm that H 2Pc thin films behave as a p-type semiconductor. The current density-voltage characteristics of Au/H 2Pc/Au at room temperature showed ohmic conduction mechanism at low voltages. At higher voltages the space-charge-limited conduction (SCLC) accompanied by an exponential trap distribution was dominant. The temperature dependence of current density allows the determination of some essential parameters such as the hole mobility ( μh), the total trap concentration ( Nt), the characteristic temperature ( Tt) and the trap density P( E).

  7. Orientation control and thermoelectric properties of FeSb2 films

    DEFF Research Database (Denmark)

    Sun, Ye; Zhang, Eryun; Johnsen, Simon

    2010-01-01

    FeSb2 has a high potential for technological applications due to its colossal thermoelectric power, giant carrier mobility and large magnetoresistance. Earlier, growth of lang1 0 1rang-textured FeSb2 films on quartz (0 0 0 1) substrates has been reported. Here magnetron sputtering is used to obtain...

  8. Characterization of chemically deposited Ag/sub 2/S thin films

    International Nuclear Information System (INIS)

    Choudhury, M.G.M.; Rahman, M.M; Shahjahan, M.; Hossain, M.S.; Muhibbullah, M.; Uddin, M.A.; Banu, D.A.

    2001-01-01

    Silver Sulphide (Ag/sub 2/S) thin films were prepared by the chemical deposition method on glass substrates. Films of different thickness were deposited at room temperature. The films obtained were found to the uniform, pin-hole free and strongly adherent to the substrates. Films were characterized by X-$D, Hall effect, dc conductivity, thermoelectric power and optical measurements. X-RD revealed that as deposited films are amorphous with some microcrystalline structure. Hall effect measurement shows that the material deposited is n-type semiconductor with carrier concentration of the order of 10/sup 14/ cm/sup -3/. The dc dark conductivity shows two distinct conduction regions. The conductivity increases quite sharply above a transition temperature. Tt and below Tt the conductivity is weakly activated process with hopping via localized states. Above Tt the activation energy is quite high and the conduction may be due to impurity states to extended states. From the nature of variation of thermoelectric power with temperature it was found that in this material the position of Fermi level lie above the conduction band for thicker films and below the conduction band for relatively thinner films. The optical band gap of the films has been calculated from the transmittance spectra. The evaluated optical band gap E/sup opt/ was found to be about 1.1 eV and the value do not change much with film thickness. The refractive index, extinction coefficient and dielectric constants have also been evaluated from the transmission measurements. (author)

  9. Tailoring electronic structure of polyazomethines thin films

    OpenAIRE

    J. Weszka; B. Hajduk; M. Domański; M. Chwastek; J. Jurusik; B. Jarząbek; H. Bednarski; P. Jarka

    2010-01-01

    Purpose: The aim of this work is to show how electronic properties of polyazomethine thin films deposited by chemical vapor deposition method (CVD) can be tailored by manipulating technological parameters of pristine films preparation as well as modifying them while the as-prepared films put into iodine atmosphere.Design/methodology/approach: The recent achievements in the field of designing and preparation methods to be used while preparing polymer photovoltaic solar cells or optoelectronic ...

  10. Electrochemical fabrication of nanoporous polypyrrole thin films

    International Nuclear Information System (INIS)

    Li Mei; Yuan Jinying; Shi Gaoquan

    2008-01-01

    Polypyrrole thin films with pores in nanometer scale were synthesized by direct electrochemical oxidation of pyrrole in a mixed electrolyte of isopropyl alcohol, boron trifluoride diethyl etherate, sodium dodecylsulfonate and poly(ethylene glycol) using well-aligned ZnO nanowires arrays as templates. The thin films exhibit high conductivity of ca. σ rt ∼ 20.5 s/cm and can be driven to bend during redox processes in 1.0 M lithium perchlorate aqueous solution. The movement rate of an actuator based on this nanoporous film was measured to be over 90 o /s at a driving potential of 0.8 V (vs. Ag/AgCl)

  11. Polymer surfaces, interfaces and thin films

    Energy Technology Data Exchange (ETDEWEB)

    Stamm, M [Max-Planck-Institut fuer Polymerforschung, Mainz (Germany)

    1996-11-01

    Neutron reflectometry can be used in various ways to investigate surfaces, interfaces and thin films of polymers. Its potential comes mostly from the possibilities offered by selective deuteration, where a particular component can be made visible with respect to its activity at the interface. In addition the depth resolution is much better than with most other direct techniques, and details of the profiles may be resolved. Several examples will be discussed including the segment diffusion at the interface between two polymer films, the determination of the narrow interfaces between incompatible polymer blends and the development of order in thin diblock copolymer films. (author) 10 figs., 2 tabs., 38 refs.

  12. Polymer surfaces, interfaces and thin films

    International Nuclear Information System (INIS)

    Stamm, M.

    1996-01-01

    Neutron reflectometry can be used in various ways to investigate surfaces, interfaces and thin films of polymers. Its potential comes mostly from the possibilities offered by selective deuteration, where a particular component can be made visible with respect to its activity at the interface. In addition the depth resolution is much better than with most other direct techniques, and details of the profiles may be resolved. Several examples will be discussed including the segment diffusion at the interface between two polymer films, the determination of the narrow interfaces between incompatible polymer blends and the development of order in thin diblock copolymer films. (author) 10 figs., 2 tabs., 38 refs

  13. Simulated Thin-Film Growth and Imaging

    Science.gov (United States)

    Schillaci, Michael

    2001-06-01

    Thin-films have become the cornerstone of the electronics, telecommunications, and broadband markets. A list of potential products includes: computer boards and chips, satellites, cell phones, fuel cells, superconductors, flat panel displays, optical waveguides, building and automotive windows, food and beverage plastic containers, metal foils, pipe plating, vision ware, manufacturing equipment and turbine engines. For all of these reasons a basic understanding of the physical processes involved in both growing and imaging thin-films can provide a wonderful research project for advanced undergraduate and first-year graduate students. After producing rudimentary two- and three-dimensional thin-film models incorporating ballsitic deposition and nearest neighbor Coulomb-type interactions, the QM tunneling equations are used to produce simulated scanning tunneling microscope (SSTM) images of the films. A discussion of computational platforms, languages, and software packages that may be used to accomplish similar results is also given.

  14. Restructuring in block copolymer thin films

    DEFF Research Database (Denmark)

    Posselt, Dorthe; Zhang, Jianqi; Smilgies, Detlef-M.

    2017-01-01

    Block copolymer (BCP) thin films have been proposed for a number of nanotechnology applications, such as nanolithography and as nanotemplates, nanoporous membranes and sensors. Solvent vapor annealing (SVA) has emerged as a powerful technique for manipulating and controlling the structure of BCP...... thin films, e.g., by healing defects, by altering the orientation of the microdomains and by changing the morphology. Due to high time resolution and compatibility with SVA environments, grazing-incidence small-angle X-ray scattering (GISAXS) is an indispensable technique for studying the SVA process......, providing information of the BCP thin film structure both laterally and along the film normal. Especially, state-of-the-art combined GISAXS/SVA setups at synchrotron sources have facilitated in situ and real-time studies of the SVA process with a time resolution of a few seconds, giving important insight...

  15. Nanostructured thin films as functional coatings

    Energy Technology Data Exchange (ETDEWEB)

    Lazar, Manoj A; Tadvani, Jalil K; Tung, Wing Sze; Lopez, Lorena; Daoud, Walid A, E-mail: Walid.Daoud@sci.monash.edu.au [School of Applied Sciences and Engineering, Monash University, Churchill, VIC 3842 (Australia)

    2010-06-15

    Nanostructured thin films is one of the highly exploiting research areas particularly in applications such as photovoltaics, photocatalysis and sensor technologies. Highly tuned thin films, in terms of thickness, crystallinity, porosity and optical properties, can be fabricated on different substrates using the sol-gel method, chemical solution deposition (CSD), electrochemical etching, along with other conventional methods such as chemical vapour deposition (CVD) and physical vapour deposition (PVD). The above mentioned properties of these films are usually characterised using surface analysis techniques such as XRD, SEM, TEM, AFM, ellipsometry, electrochemistry, SAXS, reflectance spectroscopy, STM, XPS, SIMS, ESCA, X-ray topography and DOSY-NMR. This article presents a short review of the preparation and characterisation of thin films of nanocrystalline titanium dioxide and modified silicon as well as their application in solar cells, water treatment, water splitting, self cleaning fabrics, sensors, optoelectronic devices and lab on chip systems.

  16. Fundamental Mechanisms of Roughening and Smoothing During Thin Film Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Headrick, Randall [Univ. of Vermont, Burlington, VT (United States)

    2016-03-18

    pulsed nature of the deposition where particles arrive at the growth surface in an interval of a few microseconds. We have observed effects such as transient formation of two dimensional islands on elemental crystalline surfaces. Pulsed deposition may also lead to non-equilibrium phases in some cases, such as the observation anomalously high tetragonality for ferroelectric thin films. All of the results described above feature in-situ synchrotron X-ray scattering as the main experimental method, which has become an indispensable technique for observing the kinetics of structures forming in real-time. We have also investigated in-situ coherent X-ray scattering and have developed methods to characterize temporal correlations that are not possible to observe with low-coherence X-rays. A high profile result of this work is a new technique to monitor defect propagation velocities in thin films. This has practical significance since defects limit the properties of thin films and it is desirable to understand their properties and origin in order to control them for practical applications. More broadly, amorphous thin films and multilayers have applications in optical devices, including mirrors and filters. Epitaxial thin films and multilayers have applications in electronic devices such as ferroelectric multilayers for non-volatile data storage, and thermoelectric nanostructures for energy conversion. Our progress in this project points the way for improved deposition methods and for improved simulation and modeling of thin film deposition processes for nanoscale control of materials with novel applications in these areas.

  17. Laser energy tuning of carrier effective mass and thermopower in epitaxial oxide thin films

    KAUST Repository

    Abutaha, Anas I.

    2012-04-18

    The effect of the laser fluence on high temperature thermoelectric properties of the La doped SrTiO3 (SLTO) thin films epitaxially grown on LaAlO3 〈100〉 substrates by pulsed laser deposition is clarified. It is shown that oxygen vacancies that influence the effective mass of carriers in SLTO films can be tuned by varying the laser energy. The highest power factor of 0.433 W K−1 m−1 has been achieved at 636 K for a filmdeposited using the highest laser fluence of 7 J cm−2 pulse−1.

  18. DC magnetron sputtering prepared Ag-C thin film anode for thin film lithium ion microbatteries

    International Nuclear Information System (INIS)

    Li, Y.; Tu, J.P.; Shi, D.Q.; Huang, X.H.; Wu, H.M.; Yuan, Y.F.; Zhao, X.B.

    2007-01-01

    An Ag-C thin film was prepared by DC magnetron co-sputtering, using pure silver and graphite as the targets. The microstructure and morphology of the deposited thin film were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Electrochemical performances of the Ag-C thin film anode were investigated by means of discharge/charge and cyclic voltammogram (CV) tests in model cells. The electrochemical impedance spectrum (EIS) characteristics and the chemical diffusion coefficient, D Li of the Ag-C thin film electrode at different discharging states were discussed. It was believed that the excellent cycling performance of the Ag-C electrode was ascribed to the good conductivity of silver and the volume stability of the thin film

  19. Microscopic local fatigue in PZT thin films

    International Nuclear Information System (INIS)

    Li, B S; Wu, A; Vilarinho, P M

    2007-01-01

    The reduction in switchable polarization during fatigue largely limits the application of PZT thin films in ferroelectric nonvolatile memories. So, it is very important to understand the fatigue mechanism in PZT films, especially at a nanoscale level. In this paper, nanoscale fatigue properties in PZT thin films have been studied by piezoresponse force microscopy and local piezoloops. It has been found that a piezoloop obtained on a fatigued point exhibits a much more pinched shape and a local imprint phenomenon is observed after severe fatigue. Furthermore, the domain structure evolves from a simple single-peak profile to a complex fluctuant one. However, there is only some shift of the piezoloop when a unipolar field with the same amplitude is applied on the film. The available experimental data show that there exist obvious domain wall pinning and injection of electrons into the film during fatigue. Finally, a schematic illustration is suggested to explain the possible fatigue mechanism

  20. Optical constant of thin gold films

    DEFF Research Database (Denmark)

    Yakubovsky, D. I.; Fedyanin, D. Yu; Arsenin, A. V.

    2017-01-01

    The performance of metal-based devices is limited by ohmic losses in the metal, which are determined by electron scattering. The structural properties of gold thin films also play an important role in the film quality, which may affect its' optical properties and the overall capability...... and spectroscopic ellipsometry, the structural morphology and optical properties of polycrystalline gold thin films (fabricated by e-beam deposition at a low sputtering rate smooth gold) in the thickness range of 20 - 200 nm. By extracting the real and imaginary dielectric function and the Drude parameter...... of the device. At the same time, metal films of different thicknesses are needed for different applications and, since these films are polycrystalline, their internal properties and surface roughness can greatly vary from one thickness to another. In this work, we study, using atomic force microscopy...

  1. Thermal conductivity of nanoscale thin nickel films

    Institute of Scientific and Technical Information of China (English)

    YUAN Shiping; JIANG Peixue

    2005-01-01

    The inhomogeneous non-equilibrium molecular dynamics (NEMD) scheme is applied to model phonon heat conduction in thin nickel films. The electronic contribution to the thermal conductivity of the film is deduced from the electrical conductivity through the use of the Wiedemann-Franz law. At the average temperature of T = 300 K, which is lower than the Debye temperature ()D = 450 K,the results show that in a film thickness range of about 1-11 nm, the calculated cross-plane thermal conductivity decreases almost linearly with the decreasing film thickness, exhibiting a remarkable reduction compared with the bulk value. The electrical and thermal conductivities are anisotropic in thin nickel films for the thickness under about 10 nm. The phonon mean free path is estimated and the size effect on the thermal conductivity is attributed to the reduction of the phonon mean free path according to the kinetic theory.

  2. Magnetostrictive thin films prepared by RF sputtering

    International Nuclear Information System (INIS)

    Carabias, I.; Martinez, A.; Garcia, M.A.; Pina, E.; Gonzalez, J.M.; Hernando, A.; Crespo, P.

    2005-01-01

    Fe 80 B 20 thin films have been prepared by ion beam sputtering magnetron on room temperature. The films were fabricated on different substrates to compare the different magnetic and structural properties. In particular the growth of films on flexible substrates (PDMS, Kapton) has been studied to allow a simple integration of the system in miniaturized magnetostrictive devices. X-ray diffraction patterns indicate that films are mainly amorphous although the presence of some Fe nanoparticles cannot be ruled out. The coercive field of thin films ranges between 15 and 35 Oe, depending on substrate. Magnetostriction measurements indicate the strong dependence of the saturation magnetostriction with the substrate. Samples on flexible substrates exhibit a better performance than samples deposited onto glass substrates

  3. Critical behavior of ferromagnetic Ising thin films

    International Nuclear Information System (INIS)

    Cossio, P.; Mazo-Zuluaga, J.; Restrepo, J.

    2006-01-01

    In the present work, we study the magnetic properties and critical behavior of simple cubic ferromagnetic thin films. We simulate LxLxd films with semifree boundary conditions on the basis of the Monte Carlo method and the Ising model with nearest neighbor interactions. A Metropolis dynamics was implemented to carry out the energy minimization process. For different film thickness, in the nanometer range, we compute the temperature dependence of the magnetization, the magnetic susceptibility and the fourth order Binder's cumulant. Bulk and surface contributions of these quantities are computed in a differentiated fashion. Additionally, according to finite size scaling theory, we estimate the critical exponents for the correlation length, magnetic susceptibility, and magnetization. Results reveal a strong dependence of critical temperature and critical exponents on the film thickness. The obtained critical exponents are finally compared to those reported in literature for thin films

  4. Radiance intensity enhanced by thin inhomogeneous lossy films

    International Nuclear Information System (INIS)

    Ben-Abdallah, Philippe; Ni Bo

    2004-01-01

    Basically, the classical radiative transfer theory assumes that the coherent component of the radiation field is equal to zero and heuristic considerations about energy conservation are used in the phenomenological derivation of the RTE. Here a self-consistent theory is presented to investigate radiative transport in the presence of diffraction processes within thin inhomogeneous films. The problem of linear optics about the transport of scalar radiation within film is solved, a new definition of the radiance is introduced in agreement with earlier definitions and a corresponding radiative transfer equation is derived. The influence of spatial variations of the bulk properties on the propagating mode is described in detail. It is analytically predicted that, unlike homogeneous media, an inhomogeneous film can enhance the radiance intensity in spite of the diffraction and the local extinction. From a practical point of view, the results of this work should be useful to perform the optimal design for many thermoelectric devices such as the new generations of photovoltaiec cells

  5. Thin Films in the Photovoltaic Industry

    International Nuclear Information System (INIS)

    Jaeger-Waldau, A.

    2008-03-01

    In the past years, the yearly world market growth rate for Photovoltaics was an average of more than 40%, which makes it one of the fastest growing industries at present. Business analysts predict the market volume to increase to 40 billion euros in 2010 and expect rising profit margins and lower prices for consumers at the same time. Today PV is still dominated by wafer based Crystalline Silicon Technology as the 'working horse' in the global market, but thin films are gaining market shares. For 2007 around 12% are expected. The current silicon shortage and high demand has kept prices higher than anticipated from the learning curve experience and has widened the windows of opportunities for thin film solar modules. Current production capacity estimates for thin films vary between 3 and 6 GW in 2010, representing a 20% market share for these technologies. Despite the higher growth rates for thin film technologies compared with the industry average, Thin Film Photovoltaic Technologies are still facing a number of challenges to maintain this growth and increase market shares. The four main topics which were discussed during the workshop were: Potential for cost reduction; Standardization; Recycling; Performance over the lifetime.

  6. Polycrystalline Mg2Si thin films: A theoretical investigation of their electronic transport properties

    International Nuclear Information System (INIS)

    Balout, H.; Boulet, P.; Record, M.-C.

    2015-01-01

    The electronic structures and thermoelectric properties of a polycrystalline Mg 2 Si thin film have been investigated by first-principle density-functional theory (DFT) and Boltzmann transport theory calculations within the constant-relaxation time approximation. The polycrystalline thin film has been simulated by assembling three types of slabs each having the orientation (001), (110) or (111) with a thickness of about 18 Å. The effect of applying the relaxation procedure to the thin film induces disorder in the structure that has been ascertained by calculating radial distribution functions. For the calculations of the thermoelectric properties, the energy gap has been fixed at the experimental value of 0.74 eV. The thermoelectric properties, namely the Seebeck coefficient, the electrical conductivity and the power factor, have been determined at three temperatures of 350 K, 600 K and 900 K with respect to both the energy levels and the p-type and n-type doping levels. The best Seebeck coefficient is obtained at 350 K: the S yy component of the tensor amounts to about ±1000 μV K −1 , depending on the type of charge carriers. However, the electrical conductivity is much too small which results in low values of the figure of merit ZT. Structure–property relationship correlations based on directional radial distribution functions allow us to tentatively draw some explanations regarding the anisotropy of the electrical conductivity. Finally, the low ZT values obtained for the polycrystalline Mg 2 Si thin film are paralleled with those recently reported in the literature for bulk chalcogenide glasses. - Graphical abstract: Structure of the polycrystalline thin film of Mg 2 Si. - Author-Highlights: • Polycrystalline Mg 2 Si film has been modelled by DFT approach. • Thermoelectric properties have been evaluated by semi-classical Boltzmann theory. • The structure was found to be slightly disordered after relaxation. • The highest value of Seebeck

  7. Lithium ion intercalation into thin film anatase

    International Nuclear Information System (INIS)

    Kundrata, I.; Froehlich, K.; Ballo, P.

    2015-01-01

    The aim of this work is to find the optimal parameters for thin film TiO 2 anatase grown by Atomic layer deposition (ALD) for use as electrode in lithium ion batteries. Two parameters, the optimal film thickness and growth conditions are aimed for. Optimal film thickness for achieving optimum between capacity gained from volume and capacity gained by changing of the intercalation constant and optimal growth conditions for film conformity on structured substrates with high aspect ratio. Here we presents first results from this ongoing research and discuss future outlooks. (authors)

  8. Ion beam-based characterization of multicomponent oxide thin films and thin film layered structures

    International Nuclear Information System (INIS)

    Krauss, A.R.; Rangaswamy, M.; Lin, Yuping; Gruen, D.M.; Schultz, J.A.; Schmidt, H.K.; Chang, R.P.H.

    1992-01-01

    Fabrication of thin film layered structures of multi-component materials such as high temperature superconductors, ferroelectric and electro-optic materials, and alloy semiconductors, and the development of hybrid materials requires understanding of film growth and interface properties. For High Temperature Superconductors, the superconducting coherence length is extremely short (5--15 Angstrom), and fabrication of reliable devices will require control of film properties at extremely sharp interfaces; it will be necessary to verify the integrity of thin layers and layered structure devices over thicknesses comparable to the atomic layer spacing. Analytical techniques which probe the first 1--2 atomic layers are therefore necessary for in-situ characterization of relevant thin film growth processes. However, most surface-analytical techniques are sensitive to a region within 10--40 Angstrom of the surface and are physically incompatible with thin film deposition and are typically restricted to ultra high vacuum conditions. A review of ion beam-based analytical methods for the characterization of thin film and multi-layered thin film structures incorporating layers of multicomponent oxides is presented. Particular attention will be paid to the use of time-of-flight techniques based on the use of 1- 15 key ion beams which show potential for use as nondestructive, real-time, in-situ surface diagnostics for the growth of multicomponent metal and metal oxide thin films

  9. Organic thin films and surfaces directions for the nineties

    CERN Document Server

    Ulman, Abraham

    1995-01-01

    Physics of Thin Films has been one of the longest running continuing series in thin film science consisting of 20 volumes since 1963. The series contains some of the highest quality studies of the properties ofvarious thin films materials and systems.In order to be able to reflect the development of todays science and to cover all modern aspects of thin films, the series, beginning with Volume 20, will move beyond the basic physics of thin films. It will address the most important aspects of both inorganic and organic thin films, in both their theoretical as well as technological aspects. Ther

  10. Microstructure of thermoelectric (Bi0.15Sb0.85)2Te3 film

    International Nuclear Information System (INIS)

    Yildiz, Koksal; Akgul, Unal; Atici, Yusuf; Leipner, Hartmut S.

    2014-01-01

    The film of thermoelectric ternary p-type (Bi 0.15 Sb 0.85 ) 2 Te 3 was deposited on polyimide foil substrate at 168 C using direct-current magnetron sputtering. Microstructural investigations of the film were performed by electron microscopy techniques. SEM observations showed that the film surface consisted of large-sized particulates with small-sized particles and also mound-like crystal agglomerates in some areas. Chemical composition of the film was analyzed using energy-dispersive X-ray spectrometer (EDS). It has been observed that the EDS results were in an agreement with nominal composition for the film. Detailed microstructural investigations were carried out using transmission electron microscopy (TEM). TEM images and selected area electron diffraction patterns showed that the film has randomly oriented polycrystalline grain structure. High-resolution TEM images indicated that the microstructure of film also contained nano-crystal structure, smaller than 10 nm. (orig.)

  11. Magnetic characterisation of longitudinal thin film media

    International Nuclear Information System (INIS)

    Dova, P.

    1998-09-01

    Magnetic characterisation techniques, as applied to longitudinal thin film media, have been investigated. These included the study of the differentials of the remanence curves, the delta-M plot and the examination of the critical volumes. Several thin film structures, which are currently used or are being considered for future media applications, have been examined using these techniques. Most of the films were Co-alloys with the exception of a set of Barium ferrite films. Both monolayer and multilayer structures were studied. It was found that the study of activation volumes provides a better insight into the reversal mechanisms of magnetic media, especially in the case of complex structures such as multilayer films and films with bicrystal microstructure. Furthermore, an evaluation study of different methods of determining critical volumes showed that the method using time dependence measurements and the micromagnetic approach is the most appropriate. The magnetic characteristics of the thin film media under investigation were correlated with their microstructure and, where possible, with their noise performance. Magnetic force microscopy was also used for acquiring quasi-domain images in the ac-demagnetised state. It was found that in all Co-alloy films the dominant intergranular coupling is magnetising in nature, the level of which is governed by the Cr content in the magnetic layer. In the case of laminated media it was found that when non-magnetic spacers are used, the nature of the interlayer coupling depends on the spacer thickness. In double layer structures with no spacer, the top layer replicates the crystallographic texture of the bottom layer, and the overall film properties are a combination of the two layers. In bicrystal films the coupling is determined by the Cr segregation in the grain boundaries. Furthermore, the presence of stacking faults in bicrystal films deteriorates their thermal stability, but can be prevented by improving the epitaxial

  12. Vibration welding system with thin film sensor

    Science.gov (United States)

    Cai, Wayne W; Abell, Jeffrey A; Li, Xiaochun; Choi, Hongseok; Zhao, Jingzhou

    2014-03-18

    A vibration welding system includes an anvil, a welding horn, a thin film sensor, and a process controller. The anvil and horn include working surfaces that contact a work piece during the welding process. The sensor measures a control value at the working surface. The measured control value is transmitted to the controller, which controls the system in part using the measured control value. The thin film sensor may include a plurality of thermopiles and thermocouples which collectively measure temperature and heat flux at the working surface. A method includes providing a welder device with a slot adjacent to a working surface of the welder device, inserting the thin film sensor into the slot, and using the sensor to measure a control value at the working surface. A process controller then controls the vibration welding system in part using the measured control value.

  13. Solid surfaces, interfaces and thin films

    CERN Document Server

    Lüth, Hans

    2015-01-01

    This book emphasises both experimental and theoretical aspects of surface, interface and thin-film physics. As in previous editions the preparation of surfaces and thin films, their atomic and morphological structure, their vibronic and electronic properties as well as fundamentals of adsorption are treated. Because of their importance in modern information technology and nanostructure research, particular emphasis is paid to electronic surface and interface states, semiconductor space charge layers and heterostructures. A special chapter of the book is devoted to collective phenomena at interfaces and in thin films such as superconductivity and magnetism. The latter topic includes the meanwhile important issues giant magnetoresistance and spin-transfer torque mechanism, both effects being of high interest in information technology. In this new edition, for the first time, the effect of spin-orbit coupling on surface states is treated. In this context the class of the recently detected topological insulators,...

  14. Thin films for the manipulation of light

    International Nuclear Information System (INIS)

    Piegari, Angela; Sytchkova, Anna

    2015-01-01

    The manipulation of light is typically accomplished by a series of optical surfaces on which the incident beam is reflected, or through which the beam is transmitted. Thin film coatings help to modify the behavior of such surfaces for obtaining the desired result: antireflection coatings to reduce reflection losses, high-reflectance mirrors, filters to divide or combine beams of different wavelengths, and many other types. The amount of light that is transmitted or reflected depends on the optical parameters of the materials and on interference phenomena in thin-film structures. Dedicated software is available to design the proper coating for each requirement. There are several applications of optical thin films, many of them are useful in the everyday life, many others are dedicated to scientific purposes, as will be described in this paper [it

  15. Thin Film Photovoltaic/Thermal Solar Panels

    Institute of Scientific and Technical Information of China (English)

    David JOHNSTON

    2008-01-01

    A solar panel is described.in which thin films of semiconductor are deposited onto a metal substrate.The semiconductor-metal combination forms a thin film photovoltaic cell,and also acts as a reflector,absorber tandem, which acts as a solar selective surface,thus enhancing the solar thermal performance of the collector plate.The use of thin films reduces the distance heat is required to flow from the absorbing surface to the metal plate and heat exchange conduits.Computer modelling demonstrated that,by suitable choice of materials,photovohaic efficiency call be maintained,with thermal performance slishtly reduced,compared to that for thermal-only panels.By grading the absorber layer-to reduce the band gap in the lower region-the thermal performance can be improved,approaching that for a thermal-only solar panel.

  16. Nanostructured thin films and coatings mechanical properties

    CERN Document Server

    2010-01-01

    The first volume in "The Handbook of Nanostructured Thin Films and Coatings" set, this book concentrates on the mechanical properties, such as hardness, toughness, and adhesion, of thin films and coatings. It discusses processing, properties, and performance and provides a detailed analysis of theories and size effects. The book presents the fundamentals of hard and superhard nanocomposites and heterostructures, assesses fracture toughness and interfacial adhesion strength of thin films and hard nanocomposite coatings, and covers the processing and mechanical properties of hybrid sol-gel-derived nanocomposite coatings. It also uses nanomechanics to optimize coatings for cutting tools and explores various other coatings, such as diamond, metal-containing amorphous carbon nanostructured, and transition metal nitride-based nanolayered multilayer coatings.

  17. Solid Surfaces, Interfaces and Thin Films

    CERN Document Server

    Lüth, Hans

    2010-01-01

    This book emphasises both experimental and theoretical aspects of surface, interface and thin film physics. As in previous editions the preparation of surfaces and thin films, their atomic and morphological, their vibronic and electronic properties as well as fundamentals of adsorption are treated. Because of their importance in modern information technology and nanostructure physics particular emphasis is paid to electronic surface and interface states, semiconductor space charge layers and heterostructures as well as to superconductor/semiconductor interfaces and magnetic thin films. The latter topic was significantly extended in this new edition by more details about the giant magnetoresistance and a section about the spin-transfer torque mechanism including one new problem as exercise. Two new panels about Kerr-effect and spin-polarized scanning tunnelling microscopy were added, too. Furthermore, the meanwhile important group III-nitride surfaces and high-k oxide/semiconductor interfaces are shortly discu...

  18. Domains in Ferroic Crystals and Thin Films

    CERN Document Server

    Tagantsev, Alexander K; Fousek, Jan

    2010-01-01

    Domains in Ferroic Crystals and Thin Films presents experimental findings and theoretical understanding of ferroic (non-magnetic) domains developed during the past 60 years. It addresses the situation by looking specifically at bulk crystals and thin films, with a particular focus on recently-developed microelectronic applications and methods for observation of domains with techniques such as scanning force microscopy, polarized light microscopy, scanning optical microscopy, electron microscopy, and surface decorating techniques. Domains in Ferroic Crystals and Thin Films covers a large area of material properties and effects connected with static and dynamic properties of domains, which are extremely relevant to materials referred to as ferroics. In most solid state physics books, one large group of ferroics is customarily covered: those in which magnetic properties play a dominant role. Numerous books are specifically devoted to magnetic ferroics and cover a wide spectrum of magnetic domain phenomena. In co...

  19. Synthesis and characterization of Fe doped cadmium selenide thin films by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Abhijit A., E-mail: aay_physics@yahoo.co.in [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur 413 512, Maharashtra (India)

    2012-12-05

    Highlights: Black-Right-Pointing-Pointer Simple and inexpensive method to dope trivalent Fe in CdSe thin films. Black-Right-Pointing-Pointer Fe doped CdSe thin films are highly photosensitive. Black-Right-Pointing-Pointer AFM analysis shows uniform deposition of film over the entire substrate surface. Black-Right-Pointing-Pointer The band gap energy decreases from 1.74 to 1.65 eV with Fe doping. Black-Right-Pointing-Pointer Film resistivity decreases to 6.76 Multiplication-Sign 10{sup 4} {Omega}-cm with Fe doping in CdSe thin films. - Abstract: Undoped and Fe doped CdSe thin films have been deposited onto the amorphous and fluorine doped tin oxide coated glass substrates by spray pyrolysis. The Fe doping concentration has been optimized by photoelectrochemical (PEC) characterization technique. The structural, surface morphological, compositional, optical and electrical properties of undoped and Fe doped CdSe thin films have been studied. X-ray diffraction study reveals that the as deposited CdSe films possess hexagonal crystal structure with preferential orientation along (1 0 0) plane. AFM analysis shows uniform deposition of the film over the entire substrate surface with minimum surface roughness of 7.90 nm. Direct allowed type of transition with band gap decreasing from 1.74 to 1.65 eV with Fe doping has been observed. The activation energy of the films has been found to be in the range of 0.14-0.19 eV at low temperature and 0.27-0.44 eV at high temperature. Semi-conducting behavior has been observed from resistivity measurements. The thermoelectric power measurements reveal that the films are of n type.

  20. Thin film oxygen partial pressure sensor

    Science.gov (United States)

    Wortman, J. J.; Harrison, J. W.; Honbarrier, H. L.; Yen, J.

    1972-01-01

    The development is described of a laboratory model oxygen partial pressure sensor using a sputtered zinc oxide thin film. The film is operated at about 400 C through the use of a miniature silicon bar. Because of the unique resistance versus temperature relation of the silicon bar, control of the operational temperature is achieved by controlling the resistance. A circuit for accomplishing this is described. The response of sputtered zinc oxide films of various thicknesses to oxygen, nitrogen, argon, carbon dioxide, and water vapor caused a change in the film resistance. Over a large range, film conductance varied approximately as the square root of the oxygen partial pressure. The presence of water vapor in the gas stream caused a shift in the film conductance at a given oxygen partial pressure. A theoretical model is presented to explain the characteristic features of the zinc oxide response to oxygen.

  1. Magnetite thin films: A simulational approach

    International Nuclear Information System (INIS)

    Mazo-Zuluaga, J.; Restrepo, J.

    2006-01-01

    In the present work the study of the magnetic properties of magnetite thin films is addressed by means of the Monte Carlo method and the Ising model. We simulate LxLxd magnetite thin films (d being the film thickness and L the transversal linear dimension) with periodic boundary conditions along transversal directions and free boundary conditions along d direction. In our model, both the three-dimensional inverse spinel structure and the interactions scheme involving tetrahedral and octahedral sites have been considered in a realistic way. Results reveal a power-law dependence of the critical temperature with the film thickness accordingly by an exponent ν=0.81 and ruled out by finite-size scaling theory. Estimates for the critical exponents of the magnetization and the specific heat are finally presented and discussed

  2. Feasibility Study of Thin Film Thermocouple Piles

    Science.gov (United States)

    Sisk, R. C.

    2001-01-01

    Historically, thermopile detectors, generators, and refrigerators based on bulk materials have been used to measure temperature, generate power for spacecraft, and cool sensors for scientific investigations. New potential uses of small, low-power, thin film thermopiles are in the area of microelectromechanical systems since power requirements decrease as electrical and mechanical machines shrink in size. In this research activity, thin film thermopile devices are fabricated utilizing radio frequency sputter coating and photoresist lift-off techniques. Electrical characterizations are performed on two designs in order to investigate the feasibility of generating small amounts of power, utilizing any available waste heat as the energy source.

  3. Novel chemical analysis for thin films

    International Nuclear Information System (INIS)

    Usui, Toshio; Kamei, Masayuki; Aoki, Yuji; Morishita, Tadataka; Tanaka, Shoji

    1991-01-01

    Scanning electron microscopy and total-reflection-angle X-ray spectroscopy (SEM-TRAXS) was applied for fluorescence X-ray analysis of 50A- and 125A-thick Au thin films on Si(100). The intensity of the AuM line (2.15 keV) emitted from the Au thin films varied as a function of the take-off angle (θ t ) with respect to the film surface; the intensity of AuM line from the 125A-thick Au thin film was 1.5 times as large as that of SiK α line (1.74 keV) emitted from the Si substrate when θ t = 0deg-3deg, in the vicinity of a critical angle for total external reflection of the AuM line at Si (0.81deg). In addition, the intensity of the AuM line emitted from the 50A-thick Au thin film was also sufficiently strong for chemical analysis. (author)

  4. Perovskite Thin Films via Atomic Layer Deposition

    KAUST Repository

    Sutherland, Brandon R.; Hoogland, Sjoerd; Adachi, Michael M.; Kanjanaboos, Pongsakorn; Wong, Chris T. O.; McDowell, Jeffrey J.; Xu, Jixian; Voznyy, Oleksandr; Ning, Zhijun; Houtepen, Arjan J.; Sargent, Edward H.

    2014-01-01

    © 2014 Wiley-VCH Verlag GmbH & Co. KGaA. (Graph Presented) A new method to deposit perovskite thin films that benefit from the thickness control and conformality of atomic layer deposition (ALD) is detailed. A seed layer of ALD PbS is place-exchanged with PbI2 and subsequently CH3NH3PbI3 perovskite. These films show promising optical properties, with gain coefficients of 3200 ± 830 cm-1.

  5. Perovskite Thin Films via Atomic Layer Deposition

    KAUST Repository

    Sutherland, Brandon R.

    2014-10-30

    © 2014 Wiley-VCH Verlag GmbH & Co. KGaA. (Graph Presented) A new method to deposit perovskite thin films that benefit from the thickness control and conformality of atomic layer deposition (ALD) is detailed. A seed layer of ALD PbS is place-exchanged with PbI2 and subsequently CH3NH3PbI3 perovskite. These films show promising optical properties, with gain coefficients of 3200 ± 830 cm-1.

  6. NREL Research Yields Significant Thermoelectric Performance | News | NREL

    Science.gov (United States)

    Chemical and Materials Science and Technology center, said the introduction of SWCNT into fabrics could from an exemplary SWNCT thin film improved thermoelectric properties. The newest paper revealed that that the same SWCNT thin film achieved identical performance when doped with either positive or

  7. Mechanical integrity of thin films

    International Nuclear Information System (INIS)

    Hoffman, R.W.

    1979-01-01

    Mechanical considerations starting with the initial film deposition including questions of adhesion and grading the interface are reviewed. Growth stresses, limiting thickness, stress relief, control aging, and creep are described

  8. Mesoscale simulations of confined Nafion thin films

    Science.gov (United States)

    Vanya, P.; Sharman, J.; Elliott, J. A.

    2017-12-01

    The morphology and transport properties of thin films of the ionomer Nafion, with thicknesses on the order of the bulk cluster size, have been investigated as a model system to explain the anomalous behaviour of catalyst/electrode-polymer interfaces in membrane electrode assemblies. We have employed dissipative particle dynamics (DPD) to investigate the interaction of water and fluorocarbon chains, with carbon and quartz as confining materials, for a wide range of operational water contents and film thicknesses. We found confinement-induced clustering of water perpendicular to the thin film. Hydrophobic carbon forms a water depletion zone near the film interface, whereas hydrophilic quartz results in a zone with excess water. There are, on average, oscillating water-rich and fluorocarbon-rich regions, in agreement with experimental results from neutron reflectometry. Water diffusivity shows increasing directional anisotropy of up to 30% with decreasing film thickness, depending on the hydrophilicity of the confining material. A percolation analysis revealed significant differences in water clustering and connectivity with the confining material. These findings indicate the fundamentally different nature of ionomer thin films, compared to membranes, and suggest explanations for increased ionic resistances observed in the catalyst layer.

  9. Processing of thin SU-8 films

    International Nuclear Information System (INIS)

    Keller, Stephan; Blagoi, Gabriela; Lillemose, Michael; Haefliger, Daniel; Boisen, Anja

    2008-01-01

    This paper summarizes the results of the process optimization for SU-8 films with thicknesses ≤5 µm. The influence of soft-bake conditions, exposure dose and post-exposure-bake parameters on residual film stress, structural stability and lithographic resolution was investigated. Conventionally, the SU-8 is soft-baked after spin coating to remove the solvent. After the exposure, a post-exposure bake at a high temperature T PEB ≥ 90 °C is required to cross-link the resist. However, for thin SU-8 films this often results in cracking or delamination due to residual film stress. The approach of the process optimization is to keep a considerable amount of the solvent in the SU-8 before exposure to facilitate photo-acid diffusion and to increase the mobility of the monomers. The experiments demonstrate that a replacement of the soft-bake by a short solvent evaporation time at ambient temperature allows cross-linking of the thin SU-8 films even at a low T PEB = 50 °C. Fourier-transform infrared spectroscopy is used to confirm the increased cross-linking density. The low thermal stress due to the reduced T PEB and the improved structural stability result in crack-free structures and solve the issue of delamination. The knowledge of the influence of different processing parameters on the responses allows the design of optimized processes for thin SU-8 films depending on the specific application

  10. Thin films prepared from tungstate glass matrix

    Energy Technology Data Exchange (ETDEWEB)

    Montanari, B.; Ribeiro, S.J.L.; Messaddeq, Y. [Departamento de Quimica Geral e Inorganica, Instituto de Quimica, Sao Paulo State University-UNESP, CP 355, CEP 14800-900, Araraquara, SP (Brazil); Li, M.S. [Instituto de Fisica, USP, CP 369, CEP 13560-970, Sao Carlos, SP (Brazil); Poirier, G. [Departamento de Ciencias Exatas, UNIFAL-MG, CEP 37130-000, Alfenas-MG (Brazil)], E-mail: gael@unifal-mg.edu.br

    2008-01-30

    Vitreous samples containing high concentrations of WO{sub 3} (above 40% M) have been used as a target to prepare thin films. Such films were deposited using the electron beam evaporation method onto soda-lime glass substrates. These films were characterized by X-ray diffraction (XRD), perfilometry, X-ray energy dispersion spectroscopy (EDS), M-Lines and UV-vis absorption spectroscopy. In this work, experimental parameters were established to obtain stable thin films showing a chemical composition close to the glass precursor composition and with a high concentration of WO{sub 3}. These amorphous thin films of about 4 {mu}m in thickness exhibit a deep blue coloration but they can be bleached by thermal treatment near the glass transition temperature. Such bleached films show several guided modes in the visible region and have a high refractive index. Controlled crystallization was realized and thus it was possible to obtain WO{sub 3} microcrystals in the amorphous phase.

  11. Atomic Structure Control of Silica Thin Films on Pt(111)

    KAUST Repository

    Crampton, Andrew S; Ridge, Claron J.; Rö tzer, Marian David; Zwaschka, Gregor; Braun, Thomas; D'Elia, Valerio; Basset, Jean-Marie; Schweinberger, Florian Frank; Gü nther, Sebastian; Heiz, Ueli

    2015-01-01

    Metal oxide thin films grown on metal single crystals are commonly used to model heterogeneous catalyst supports. The structure and properties of thin silicon dioxide films grown on metal single crystals have only recently been thoroughly

  12. Optical characterization of niobium pentoxide thin films

    International Nuclear Information System (INIS)

    Pawlicka, A.

    1996-01-01

    Thin films of Nb 2 O 5 were obtained by sol-gel method using ultrasonic irradiation and deposited by dip-coating technique. After calcination at temperatures superior than 500 deg C these films (300 nm thick) were characterized by cyclic voltametry and cronoamperometry. The memory measurements, color efficiency, optical density as a function of wave number and applied potential were effectuated to determine their electrochromic properties. The study of electrochromic properties of these films shows that the insertion process of lithium is reversible and changes their coloration from transparent (T=80%) to dark blue (T=20%). (author)

  13. Electrical resistivity of ferrimagnetic magnetite thin film

    International Nuclear Information System (INIS)

    Varshney, Dinesh; Yogi, A.; Kaurav, N.; Gupta, R.P.; Phase, D.M.

    2006-01-01

    We have grown Fe 3 O 4 (III) epitaxial film on Al 2 O 3 (0001) substrate by pulsed laser deposition, with thickness of 130 nm. X-ray diffraction studies of magnetite show the spinel cubic structure of film with preferential (III) orientation. The electrical resistivity measurement demonstrates that the properties of thin film of magnetite are basically similar to those of bulk magnetite and clearly shows semiconductor-insulator transition at Verwey transition temperature (≅140 K). We have found higher Verwey transition temperature when compared with earlier reports on similar type of system. Possible causes for increase in transition temperature are discussed. (author)

  14. Investigation of the Full Spectrum Phonon Lifetime in Thin Silicon Films from the Bulk Spectral Phonon Mean-Free-Path Distribution by Using Kinetic Theory

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Jae Sik [Chosun College of Science and Technology, Gwangju (Korea, Republic of)

    2017-03-15

    Phonon dynamics in nanostructure is critically important to thermoelectric and optoelectronic devices because it determines the transport and other crucial properties. However, accurately evaluating the phonon lifetimes is extremely difficult. This study reports on the development of a new semi-empirical method to estimate the full-spectrum phonon lifetimes in thin silicon films at room temperature based on the experimental data on the phonon mean-free-path spectrum in bulk silicon and a phenomenological consideration of phonon transport in thin films. The bulk of this work describes the theory and the validation; then, we discuss the trend of the phonon lifetimes in thin silicon films when their thicknesses decrease.

  15. Surface Plasmon Waves on Thin Metal Films.

    Science.gov (United States)

    Craig, Alan Ellsworth

    Surface-plasmon polaritons propagating on thin metal films bounded by dielectrics of nearly equal refractive indexes comprise two bound modes. Calculations indicate that, while the modes are degenerate on thick films, both the real and the imaginary components of the propagation constants for the modes split into two branches on successively thinner films. Considering these non-degenerate modes, the mode exhibiting a symmetric (antisymmetric) transverse profile of the longitudinally polarized electric field component, has propagation constant components both of which increase (decrease) with decreasing film thickness. Theoretical propagation constant eigenvalue (PCE) curves have been plotted which delineate this dependence of both propagation constant components on film thickness. By means of a retroreflecting, hemispherical glass coupler in an attenuated total reflection (ATR) configuration, light of wavelength 632.8 nm coupled to the modes of thin silver films deposited on polished glass substrates. Lorentzian lineshape dips in the plots of reflectance vs. angle of incidence indicate the presence of the plasmon modes. The real and imaginary components of the propagation constraints (i.e., the propagation constant and loss coefficient) were calculated from the angular positions and widths of the ATR resonances recorded. Films of several thicknesses were probed. Results which support the theoretically predicted curves were reported.

  16. New techniques for producing thin boron films

    International Nuclear Information System (INIS)

    Thomas, G.E.

    1988-01-01

    A review will be presented of methods for producing thin boron films using an electron gun. Previous papers have had the problem of spattering of the boron source during the evaporation. Methods for reducing this problem will also be presented. 12 refs., 4 figs

  17. Intelligent Processing of Ferroelectric Thin Films

    Science.gov (United States)

    1994-05-31

    unsatisfactory. To detect the electroopic effects of thin films deposited on opaque substrates a waveguide refractometry of category 3 was reported. An advantage...of the waveguide refractometry is its capability of resolving the change in ordinary index from the change in the extraordinary index. Some successes

  18. Tailored piezoelectric thin films for energy harvester

    NARCIS (Netherlands)

    Wan, X.

    2013-01-01

    Piezoelectric materials are excellent materials to transfer mechanical energy into electrical energy, which can be stored and used to power other devices. PiezoMEMS is a good way to combine silicon wafer processing and piezoelectric thin film technology and lead to a variety of miniaturized and

  19. Amperometric Noise at Thin Film Band Electrodes

    DEFF Research Database (Denmark)

    Larsen, Simon T.; Heien, Michael L.; Taboryski, Rafael

    2012-01-01

    Background current noise is often a significant limitation when using constant-potential amperometry for biosensor application such as amperometric recordings of transmitter release from single cells through exocytosis. In this paper, we fabricated thin-film electrodes of gold and conductive...

  20. Stabilized thin film heterostructure for electrochemical applications

    DEFF Research Database (Denmark)

    2015-01-01

    The invention provides a method for the formation of a thin film multi-layered heterostructure upon a substrate, said method comprising the steps of: a. providing a substrate; b. depositing a buffer layer upon said substrate, said buffer layer being a layer of stable ionic conductor (B); c. depos...

  1. Reliability growth of thin film resistors contact

    Directory of Open Access Journals (Sweden)

    Lugin A. N.

    2010-10-01

    Full Text Available Necessity of resistive layer growth under the contact and in the contact zone of resistive element is shown in order to reduce peak values of current flow and power dissipation in the contact of thin film resistor, thereby to increase the resistor stability to parametric and catastrophic failures.

  2. Bilaterally Microstructured Thin Polydimethylsiloxane Film Production

    DEFF Research Database (Denmark)

    Vudayagiri, Sindhu; Yu, Liyun; Hassouneh, Suzan Sager

    2015-01-01

    Thin PDMS films with complex microstructures are used in the manufacturing of dielectric electro active polymer (DEAP) actuators, sensors and generators, to protect the metal electrode from large strains and to assure controlled actuation. The current manufacturing process at Danfoss Polypower A/...

  3. Flexible thin-film NFC tags

    NARCIS (Netherlands)

    Myny, K.; Tripathi, A.K.; Steen, J.L. van der; Cobb, B.

    2015-01-01

    Thin-film transistor technologies have great potential to become the key technology for leafnode Internet of Things by utilizing the NFC protocol as a communication medium. The main requirements are manufacturability on flexible substrates at a low cost while maintaining good device performance

  4. Magnetic surfaces, thin films, and multilayers

    International Nuclear Information System (INIS)

    Parkin, S.S.P.; Renard, J.P.; Shinjo, T.; Zinn, W.

    1992-01-01

    This paper details recent developments in the magnetism of surfaces, thin films and multilayers. More than 20 invited contributions and more than 60 contributed papers attest to the great interest and vitality of this subject. In recent years the study of magnetic surfaces, thin films and multilayers has undergone a renaissance, partly motivated by the development of new growth and characterization techniques, but perhaps more so by the discovery of many exciting new properties, some quite unanticipated. These include, most recently, the discovery of enormous values of magnetoresistance in magnetic multilayers far exceeding those found in magnetic single layer films and the discovery of oscillatory interlayer coupling in transition metal multilayers. These experimental studies have motivated much theoretical work. However these developments are to a large extent powered by materials engineering and our ability to control and understand the growth of thin layers just a few atoms thick. The preparation of single crystal thin film layers and multilayers remains important for many studies, in particular, for properties dependent. These studies obviously require engineering not just a layer thicknesses but of lateral dimensions as well. The properties of such structures are already proving to be a great interest

  5. Electrical characterization of thin film ferroelectric capacitors

    NARCIS (Netherlands)

    Tiggelman, M.P.J.; Reimann, K.; Klee, M.; Beelen, D.; Keur, W.; Schmitz, Jurriaan; Hueting, Raymond Josephus Engelbart

    2006-01-01

    Tunable capacitors can be used to facilitate the reduction of components in wireless technologies. The tunability of the capacitors is caused by the sensitivity of the relative dielectric constant to a change in polarization with electric field. Thin film ferroelectric MIM capacitors on silicon

  6. Flexo-green Polypyrrole – Silver nanocomposite films for thermoelectric power generation

    International Nuclear Information System (INIS)

    Bharti, Meetu; Singh, Ajay; Samanta, Soumen; Debnath, A.K.; Aswal, D.K.; Muthe, K.P.; Gadkari, S.C.

    2017-01-01

    Graphical abstract: Flexible PPy-Ag films prepared via environment friendly photo-polymerization in aqueous medium exhibited a record figure-of-merit of ∼7.4 × 10 −3 at 335 K among reported PPy based composites due to unique combination of high electrical and low thermal conductivity with increasing content of Ag nanoparticles. A proto-type thermoelectric power generator exhibiting output voltage of 6 mV has been demonstrated using these flexible PPy-Ag films. - Highlights: • Polypyrrole-silver (PPy-Ag) nanocomposites films were prepared on flexible BOPET sheet. • Ag particles anchored between PPy chains improve electrical transport but suppress thermal transport. • This work demonstrates highest figure-of-merit (∼7.4 × 10 −3 at 335 K) among PPy based materials. • A prototype thermoelectric power generator exhibiting output voltage of 6 mV has been fabricated using PPy-Ag films. - Abstract: Conducting polymers offer various advantages over inorganic thermoelectric materials such as eco-friendliness, a reduced manufacturing cost, flexibility, low thermal conductivity and amenability to tuning of electrical properties through doping; have recently drawn much attention for conversion of low temperature waste heat (≤150 °C) into electricity. In this study, we investigated the thermoelectric properties of hybrid films of polypyrrole and silver (PPy-Ag). These films were prepared on biaxially oriented polyethylene terephthalate (BOPET) flexible substrates by eco-friendly one pot photo-polymerization method using aqueous solution of silver nitrate (AgNO 3 ) as photo initiator. Detailed characterization of the samples revealed that morphology of composite films reorganized with the change in AgNO 3 concentration during synthesis. Increasing AgNO 3 concentrations resulted in PPy films containing Ag nanoparticles, nanoclusters as well as macroclusters. With alteration in concentration and size of Ag particles in PPy matrix, it has been observed that the

  7. Internal stress control of boron thin film

    International Nuclear Information System (INIS)

    Satomi, N.; Kitamura, M.; Sasaki, T.; Nishikawa, M.

    1998-01-01

    The occurrence of stress in thin films has led to serious stability problems in practical use. We have investigated the stress in the boron films to find the deposition condition of the boron films with less stress. It was found that the stress in the boron film varies sufficiently from compressive to tensile stress, that is from -1.0 to 1.4 GPa, depending on the evaporation conditions, such as deposition rate and the substrate temperature. Hydrogen ion bombardment resulted in the enhancement of the compressive stress, possibly due to ion peening effect, while under helium ion bombardment, stress relief was observed. The boron film with nearly zero stress was obtained by the evaporation at a deposition rate of 0.5 nm s -1 and substrate temperature of 300 C. (orig.)

  8. Correlated dewetting patterns in thin polystyrene films

    CERN Document Server

    Neto, C; Seemann, R; Blossey, R; Becker, J; Grün, G

    2003-01-01

    We describe preliminary results of experiments and simulations concerned with the dewetting of thin polystyrene films (thickness < 7 nm) on top of silicon oxide wafers. In the experiments we scratched an initially flat film with an atomic force microscopy (AFM) tip, producing dry channels in the film. Dewetting of the films was imaged in situ using AFM and a correlated pattern of holes ('satellite holes') was observed along the rims bordering the channels. The development of this complex film rupture process was simulated and the results of experiments and simulations are in good agreement. On the basis of these results, we attempt to explain the appearance of satellite holes and their positions relative to pre-existing holes.

  9. Correlated dewetting patterns in thin polystyrene films

    International Nuclear Information System (INIS)

    Neto, Chiara; Jacobs, Karin; Seemann, Ralf; Blossey, Ralf; Becker, Juergen; Gruen, Guenther

    2003-01-01

    We describe preliminary results of experiments and simulations concerned with the dewetting of thin polystyrene films (thickness < 7 nm) on top of silicon oxide wafers. In the experiments we scratched an initially flat film with an atomic force microscopy (AFM) tip, producing dry channels in the film. Dewetting of the films was imaged in situ using AFM and a correlated pattern of holes ('satellite holes') was observed along the rims bordering the channels. The development of this complex film rupture process was simulated and the results of experiments and simulations are in good agreement. On the basis of these results, we attempt to explain the appearance of satellite holes and their positions relative to pre-existing holes

  10. Rim instability of bursting thin smectic films

    Science.gov (United States)

    Trittel, Torsten; John, Thomas; Tsuji, Kinko; Stannarius, Ralf

    2013-05-01

    The rupture of thin smectic bubbles is studied by means of high speed video imaging. Bubbles of centimeter diameter and film thicknesses in the nanometer range are pierced, and the instabilities of the moving rim around the opening hole are described. Scaling laws describe the relation between film thickness and features of the filamentation process of the rim. A flapping motion of the retracting smectic film is assumed as the origin of the observed filamentation instability. A comparison with similar phenomena in soap bubbles is made. The present experiments extend studies on soap films [H. Lhuissier and E. Villermaux, Phys. Rev. Lett. 103, 054501 (2009), 10.1103/PhysRevLett.103.054501] to much thinner, uniform films of thermotropic liquid crystals.

  11. Internal stress control of boron thin film

    Energy Technology Data Exchange (ETDEWEB)

    Satomi, N.; Kitamura, M.; Sasaki, T.; Nishikawa, M. [Osaka Univ., Suita (Japan). Graduate Sch. of Eng.

    1998-09-01

    The occurrence of stress in thin films has led to serious stability problems in practical use. We have investigated the stress in the boron films to find the deposition condition of the boron films with less stress. It was found that the stress in the boron film varies sufficiently from compressive to tensile stress, that is from -1.0 to 1.4 GPa, depending on the evaporation conditions, such as deposition rate and the substrate temperature. Hydrogen ion bombardment resulted in the enhancement of the compressive stress, possibly due to ion peening effect, while under helium ion bombardment, stress relief was observed. The boron film with nearly zero stress was obtained by the evaporation at a deposition rate of 0.5 nm s{sup -1} and substrate temperature of 300 C. (orig.) 12 refs.

  12. Enhanced thermoelectric properties of metal film on bismuth telluride-based materials

    International Nuclear Information System (INIS)

    Chao, Wen Hsuan; Chen, Yi Ray; Tseng, Shih Chun; Yang, Ping Hsing; Wu, Ren Jye; Hwang, Jenn Yeu

    2014-01-01

    Diffusion barriers have a significant influence on the reliability and life time of thermoelectric modules. Although nickel is commonly used as a diffusion barrier in commercial thermoelectric modules, several studies have verified that Ni migrates to bismuth telluride-based material during high temperature cycles and causes a loss in efficacy. In this paper, the influence of metal layers coated to p-type and n-type Bi 2 Te 3 on the interface characterization and thermoelectric property is studied using a RF magnetron sputtering. The findings from this study demonstrate the structural and thermoelectric properties of p-type and n-type Bi 2 Te 3 coated with different metal layers. The crystalline phase and compositional change of the interface between the Bi 2 Te 3 materials and the metal layers were determined using an X-ray diffractometer and scanning electron microscopy with energy dispersive spectroscopy. Formation of NiTe was observed in the sample of Ni/p-type Bi 2 Te 3 based films post-annealed in an N 2 atmosphere at 200 °C. In contrast, no Co x Te y was formed in the sample of Co/p-type Bi 2 Te 3 based films post-annealed at 200 °C. For as-deposited Ni/p-type and n-type Bi 2 Te 3 based legs, the Ni slightly diffused into the Bi 2 Te 3 based legs. A similar phenomenon also occurred in the as-deposited Co/p-type and n-type Bi 2 Te 3 based legs. The Seebeck coefficients of the Co contacts on the Bi 2 Te 3 based material displayed better behavior than those of the Ni contacts on the Bi 2 Te 3 based legs. Thus Co could be a suitable diffusion barrier for bulk Bi 2 Te 3 based material. The observed effects on the thermoelectric and structural properties of metal/Bi 2 Te 3 based material are crucial for understanding the interface between the diffusion barrier and thermoelectric materials. - Highlights: • Interface characterization of metal coated to p-type and n-type Bi 2 Te 3 is studied. • We examined the phase transformation of metal/Bi 2 Te 3 based films

  13. Dielectric loss of strontium titanate thin films

    Science.gov (United States)

    Dalberth, Mark Joseph

    1999-12-01

    Interest in strontium titanate (STO) thin films for microwave device applications continues to grow, fueled by the telecommunications industry's interest in phase shifters and tunable filters. The optimization of these devices depends upon increasing the phase or frequency tuning and decreasing the losses in the films. Currently, the dielectric response of thin film STO is poorly understood through lack of data and a theory to describe it. We have studied the growth of STO using pulsed laser deposition and single crystal substrates like lanthanum aluminate and neodymium gallate. We have researched ways to use ring resonators to accurately measure the dielectric response as a function of temperature, electric field, and frequency from low radio frequencies to a few gigahertz. Our films grown on lanthanum aluminate show marked frequency dispersion in the real part of the dielectric constant and hints of thermally activated loss behavior. We also found that films grown with conditions that optimized the dielectric constant showed increased losses. In an attempt to simplify the system, we developed a technique called epitaxial lift off, which has allowed us to study films removed from their growth substrates. These free standing films have low losses and show obvious thermally activated behavior. The "amount of tuning," as measured by a figure of merit, KE, is greater in these films than in the films still attached to their growth substrates. We have developed a theory that describes the real and imaginary parts of the dielectric constant. The theory models the real part using a mean field description of the ionic motion in the crystal and includes the loss by incorporating the motion of charged defects in the films.

  14. Thin film preparation of semiconducting iron pyrite

    Science.gov (United States)

    Smestad, Greg P.; Ennaoui, Ahmed; Fiechter, Sebastian; Hofmann, Wolfgang; Tributsch, Helmut; Kautek, Wolfgang

    1990-08-01

    Pyrite (Fe52) has been investigated as a promising new absorber material for thin film solar cell applications because of its high optical absorption coefficient of 1OL cm1, and its bandgap of 0.9 to 1.0 eV. Thin layers have been prepared by Metal Organic Chemical Vapor Deposition, MOCVD, Chemical Spray Pyrolysis, CSP, Chemical Vapor Transport, CVT, and Sulfurization of Iron Oxide films, 510. It is postulated that for the material FeS2, if x is not zero, a high point defect concentration results from replacing 2 dipoles by single S atoms. This causes the observed photovoltages and solar conversion efficiencies to be lower than expected. Using the Fe-O-S ternary phase diagram and the related activity plots, a thermodynamic understanding is formulated for the resulting composition of each of these types of films. It is found that by operating in the oxide portion of the phase diagram, the resulting oxidation state favors pyrite formation over FeS. By proper orientation of the grains relative to the film surface, and by control of pinholes and stoichiometry, an efficient thin film photovolatic solar cell material could be achieved.

  15. Electrochemical fabrication of nanoporous polypyrrole thin films

    Energy Technology Data Exchange (ETDEWEB)

    Li Mei [Key Laboratory of Organic Optoelectronics and Molecular Engineering (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084 (China); Yuan Jinying [Key Laboratory of Organic Optoelectronics and Molecular Engineering (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084 (China)], E-mail: yuanjy@mail.tsinghua.edu.cn; Shi Gaoquan [Key Laboratory of Organic Optoelectronics and Molecular Engineering (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084 (China)], E-mail: gshi@mail.tsinghua.edu.cn

    2008-04-30

    Polypyrrole thin films with pores in nanometer scale were synthesized by direct electrochemical oxidation of pyrrole in a mixed electrolyte of isopropyl alcohol, boron trifluoride diethyl etherate, sodium dodecylsulfonate and poly(ethylene glycol) using well-aligned ZnO nanowires arrays as templates. The thin films exhibit high conductivity of ca. {sigma}{sub rt} {approx} 20.5 s/cm and can be driven to bend during redox processes in 1.0 M lithium perchlorate aqueous solution. The movement rate of an actuator based on this nanoporous film was measured to be over 90{sup o}/s at a driving potential of 0.8 V (vs. Ag/AgCl)

  16. Dynamics in thin folded polymer films

    Science.gov (United States)

    Croll, Andrew; Rozairo, Damith

    Origami and Kirigami inspired structures depend on a complex interplay between geometry and material properties. While clearly important to the overall function, very little attention has focused on how extreme curvatures and singularities in real materials influence the overall dynamic behaviour of folded structures. In this work we use a set of three polymer thin films in order to closely examine the interaction of material and geometry. Specifically, we use polydimethylsiloxane (PDMS), polystyrene (PS) and polycarbonate (PC) thin films which we subject to loading in several model geometries of varying complexity. Depending on the material, vastly different responses are noted in our experiments; D-cones can annihilate, cut or lead to a crumpling cascade when pushed through a film. Remarkably, order can be generated with additional perturbation. Finally, the role of adhesion in complex folded structures can be addressed. AFOSR under the Young Investigator Program (FA9550-15-1-0168).

  17. Characterization of CuS nanocrystalline thin films synthesized by chemical bath deposition and dip coating techniques

    International Nuclear Information System (INIS)

    Chaki, Sunil H.; Deshpande, M.P.; Tailor, Jiten P.

    2014-01-01

    CuS thin films were synthesized by chemical bath deposition and dip coating techniques at ambient temperature. The energy dispersive analysis of X-rays of the thin films confirmed that both the as synthesized thin films are stoichiometric. The X-ray diffraction of the chemical bath deposited and dip coating deposited thin films showed that the films possess hexagonal structure having lattice parameters, a = b = 3.79 A and c = 16.34 A. The crystallite sizes determined from the X-ray diffraction data using Scherrer's formula for the chemical bath deposition and dip coating deposition thin films came out to be nearly 11 nm and 13 nm, respectively. The optical microscopy of the as deposited thin films surfaces showed that the substrates are well covered in both the deposited films. The scanning electron microscopy of the thin films clearly showed that in chemical bath deposited thin films the grain size varies from few μm to nm, while in dip coating deposited films the grain size ranges in nm. The optical bandgap determined from the optical absorbance spectrum analysis showed, chemical bath deposited thin films possess direct bandgap of 2.2 eV and indirect bandgap of 1.8 eV. In the case of dip coating deposited thin films, the direct bandgap is 2.5 eV and indirect bandgap is 1.9 eV. The d.c. electrical resistivity variation with temperature for both the deposited films showed that the resistivity decreases with temperature thus confirming the semiconducting nature. The thermoelectric power variations with temperature and the room temperature Hall Effect study of both the synthesized CuS thin films showed them to be of p-type conductivity. The obtained results are discussed in details. - Highlights: • CuS thin films were synthesized by chemical bath deposition and dip coating techniques. • The films possessed hexagonal structure. • The optical absorption showed that the films had direct and indirect bandgap. • Study of electrical transport properties

  18. Magnon dispersion in thin magnetic films

    International Nuclear Information System (INIS)

    Balashov, T; Wulfhekel, W; Buczek, P; Sandratskii, L; Ernst, A

    2014-01-01

    Although the dispersion of magnons has been measured in many bulk materials, few studies deal with the changes in the dispersion when the material is in the form of a thin film, a system that is of interest for applications. Here we review inelastic tunneling spectroscopy studies of magnon dispersion in Mn/Cu 3 Au(1 0 0) and present new studies on Co and Ni thin films on Cu(1 0 0). The dispersion in Mn and Co films closely follows the dispersion of bulk samples with negligible dependence on thickness. The lifetime of magnons depends slightly on film thickness, and decreases considerably as the magnon energy increases. In Ni/Cu(1 0 0) films the thickness dependence of dispersion is much more pronounced. The measurements indicate a considerable mode softening for thinner films. Magnon lifetimes decrease dramatically near the edge of the Brillouin zone due to a close proximity of the Stoner continuum. The experimental study is supported by first-principles calculations. (paper)

  19. Magnon dispersion in thin magnetic films.

    Science.gov (United States)

    Balashov, T; Buczek, P; Sandratskii, L; Ernst, A; Wulfhekel, W

    2014-10-01

    Although the dispersion of magnons has been measured in many bulk materials, few studies deal with the changes in the dispersion when the material is in the form of a thin film, a system that is of interest for applications. Here we review inelastic tunneling spectroscopy studies of magnon dispersion in Mn/Cu3Au(1 0 0) and present new studies on Co and Ni thin films on Cu(1 0 0). The dispersion in Mn and Co films closely follows the dispersion of bulk samples with negligible dependence on thickness. The lifetime of magnons depends slightly on film thickness, and decreases considerably as the magnon energy increases. In Ni/Cu(1 0 0) films the thickness dependence of dispersion is much more pronounced. The measurements indicate a considerable mode softening for thinner films. Magnon lifetimes decrease dramatically near the edge of the Brillouin zone due to a close proximity of the Stoner continuum. The experimental study is supported by first-principles calculations.

  20. Function and application of ultra thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sasabe, Hiroyuki

    1988-02-01

    A film 10-100mm thick which is strong dynamically to some extent and has possibility to manifest fuctions of high degree different from the nature extrapolated from the normal thin film is called an ultra thin film. As an example of its concrete application, there is an electro-luminescence element which is made by laminating 5 layers of LB films of poly-L-phenylalanine on a n-GaP and has vapor-deposited gold electrodes. When voltage of 5V is imposed to it, light emission of 565nm can be observed and the emission efficiency of 2% is obtained. Besides, it has an excellent stability through the lapse of time. There is also a junction element and the ion concentration injected into macromolecule films of this element has a Gaussian distribution from the surface towards the direction of depth. Accordingly, the most active domain in terms of semiconductor as the result of doping is the location in the neighborhood of the peak. Furthermore, a photo memory is also proposed. It is applied to the artificial hemoglobine which is made of LB films, suggesting the feasibility of creating the artificial protein capable of functioning in the conditions in which the natural protein is unable to function. (5 figs, 1 tab, 7 refs)

  1. Thin film platinum–palladium thermocouples for gas turbine engine applications

    Energy Technology Data Exchange (ETDEWEB)

    Tougas, Ian M.; Gregory, Otto J., E-mail: gregory@egr.uri.edu

    2013-07-31

    Thin film platinum:palladium thermocouples were fabricated on alumina and mullite surfaces using radio frequency sputtering and characterized after high temperature exposure to oxidizing environments. The thermoelectric output, hysteresis, and drift of these sensors were measured at temperatures up to 1100 °C. Auger electron spectroscopy was used to follow the extent of oxidation in each thermocouple leg and interdiffusion at the metallurgical junction. Minimal oxidation of the platinum and palladium thermoelements was observed after high temperature exposure, but considerable dewetting and faceting of the films were observed in scanning electron microscopy. An Arrhenius temperature dependence on the drift rate was observed and later attributed to microstructural changes during thermal cycling. The thin film thermocouples, however, did exhibit excellent stability at 1000 °C with drift rates comparable to commercial type-K wire thermocouples. Based on these results, platinum:palladium thin film thermocouples have considerable potential for use in the hot sections of gas turbine engines. - Highlights: • Stable thin film platinum:palladium thermocouples for gas turbine engines • Little oxidation but significant microstructural changes from thermal cycling • Minimal hysteresis during repeated thermal cycling • Drift comparable to commercial wire thermocouples.

  2. Phonon Drag in Thin Films, Cases of Bi2Te3 and ZnTe

    Science.gov (United States)

    Chi, Hang; Uher, Ctirad

    2014-03-01

    At low temperatures, in (semi-)conductors subjected to a thermal gradient, charge carriers (electrons and holes) are swept (dragged) by out-of-equilibrium phonons due to strong electron-phonon interaction, giving rise to a large contribution to the Seebeck coefficient called the phonon-drag effect. Such phenomenon was surprisingly observed in our recent transport study of highly mismatched alloys as potential thermoelectric materials: a significant phonon-drag thermopower reaching 1.5-2.5 mV/K was recorded for the first time in nitrogen-doped ZnTe epitaxial layers on GaAs (100). In thin films of Bi2Te3, we demonstrate a spectacular influence of substrate phonons on charge carriers. We show that one can control and tune the position and magnitude of the phonon-drag peak over a wide range of temperatures by depositing thin films on substrates with vastly different Debye temperatures. Our experiments also provide a way to study the nature of the phonon spectrum in thin films, which is rarely probed but clearly important for a complete understanding of thin film properties and the interplay of the substrate and films. This work is supported by the Center for Solar and Thermal Energy Conversion, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0000957.

  3. Thin film diamond microstructure applications

    Science.gov (United States)

    Roppel, T.; Ellis, C.; Ramesham, R.; Jaworske, D.; Baginski, M. E.; Lee, S. Y.

    1991-01-01

    Selective deposition and abrasion, as well as etching in atomic oxygen or reduced-pressure air, have been used to prepare patterned polycrystalline diamond films which, on further processing by anisotropic Si etching, yield the microstructures of such devices as flow sensors and accelerometers. Both types of sensor have been experimentally tested in the respective functions of hot-wire anemometer and both single- and double-hinged accelerometer.

  4. Improvement of thermoelectric properties of Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3} films grown on graphene substrate

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Wan [Thin Film Materials Research Group, Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of); School of Electrical and Electronic Engineering, Yonsei University, Seoul (Korea, Republic of); Kim, Gun Hwan; Choi, Ji Woon; An, Ki-Seok; Lee, Young Kuk [Thin Film Materials Research Group, Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of); Kim, Jin-Sang [Center for Electronic Materials, Korea Institute of Science and Technology, Seoul (Korea, Republic of); Kim, Hyungjun [School of Electrical and Electronic Engineering, Yonsei University, Seoul (Korea, Republic of)

    2017-06-15

    A study of substrate effect on the thermoelectric (TE) properties of Bi{sub 2}Te{sub 3} (BT) and Sb{sub 2}Te{sub 3} (ST) thin films grown by plasma-enhanced chemical vapor deposition (PECVD) was performed. Graphene substrates which have small lattice mismatch with BT and ST were used for the preparation of highly oriented BT and ST thin films. Carrier mobility of the epitaxial BT and ST films grown on the graphene substrates increased as the deposition temperature increased, which was not observed in that of SiO{sub 2}/Si substrates. Seebeck coefficients of the as-grown BT and ST films were observed to be maintained even though carrier concentration increased in the epitaxial BT and ST films on graphene substrate. Although Seebeck coefficient was not improved, power factor of the as-grown BT and ST films was considerably enhanced due to the increase of electrical conductivity resulting from the high carrier mobility and moderate carrier concentration in the epitaxial BT and ST films. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Thin film bismuth iron oxides useful for piezoelectric devices

    Science.gov (United States)

    Zeches, Robert J.; Martin, Lane W.; Ramesh, Ramamoorthy

    2016-05-31

    The present invention provides for a composition comprising a thin film of BiFeO.sub.3 having a thickness ranging from 20 nm to 300 nm, a first electrode in contact with the BiFeO.sub.3 thin film, and a second electrode in contact with the BiFeO.sub.3 thin film; wherein the first and second electrodes are in electrical communication. The composition is free or essentially free of lead (Pb). The BFO thin film is has the piezoelectric property of changing its volume and/or shape when an electric field is applied to the BFO thin film.

  6. Nanostructured thin film coatings with different strengthening effects

    Directory of Open Access Journals (Sweden)

    Panfilov Yury

    2017-01-01

    Full Text Available A number of articles on strengthening thin film coatings were analyzed and a lot of unusual strengthening effects, such as super high hardness and plasticity simultaneously, ultra low friction coefficient, high wear-resistance, curve rigidity increasing of drills with small diameter, associated with process formation of nanostructured coatings by the different thin film deposition methods were detected. Vacuum coater with RF magnetron sputtering system and ion-beam source and arc evaporator for nanostructured thin film coating manufacture are represented. Diamond Like Carbon and MoS2 thin film coatings, Ti, Al, Nb, Cr, nitride, carbide, and carbo-nitride thin film materials are described as strengthening coatings.

  7. Physical Vapor Deposition of Thin Films

    Science.gov (United States)

    Mahan, John E.

    2000-01-01

    A unified treatment of the theories, data, and technologies underlying physical vapor deposition methods With electronic, optical, and magnetic coating technologies increasingly dominating manufacturing in the high-tech industries, there is a growing need for expertise in physical vapor deposition of thin films. This important new work provides researchers and engineers in this field with the information they need to tackle thin film processes in the real world. Presenting a cohesive, thoroughly developed treatment of both fundamental and applied topics, Physical Vapor Deposition of Thin Films incorporates many critical results from across the literature as it imparts a working knowledge of a variety of present-day techniques. Numerous worked examples, extensive references, and more than 100 illustrations and photographs accompany coverage of: * Thermal evaporation, sputtering, and pulsed laser deposition techniques * Key theories and phenomena, including the kinetic theory of gases, adsorption and condensation, high-vacuum pumping dynamics, and sputtering discharges * Trends in sputter yield data and a new simplified collisional model of sputter yield for pure element targets * Quantitative models for film deposition rate, thickness profiles, and thermalization of the sputtered beam

  8. Flexible magnetic thin films and devices

    Science.gov (United States)

    Sheng, Ping; Wang, Baomin; Li, Runwei

    2018-01-01

    Flexible electronic devices are highly attractive for a variety of applications such as flexible circuit boards, solar cells, paper-like displays, and sensitive skin, due to their stretchable, biocompatible, light-weight, portable, and low cost properties. Due to magnetic devices being important parts of electronic devices, it is essential to study the magnetic properties of magnetic thin films and devices fabricated on flexible substrates. In this review, we mainly introduce the recent progress in flexible magnetic thin films and devices, including the study on the stress-dependent magnetic properties of magnetic thin films and devices, and controlling the properties of flexible magnetic films by stress-related multi-fields, and the design and fabrication of flexible magnetic devices. Project supported by the National Key R&D Program of China (No. 2016YFA0201102), the National Natural Science Foundation of China (Nos. 51571208, 51301191, 51525103, 11274321, 11474295, 51401230), the Youth Innovation Promotion Association of the Chinese Academy of Sciences (No. 2016270), the Key Research Program of the Chinese Academy of Sciences (No. KJZD-EW-M05), the Ningbo Major Project for Science and Technology (No. 2014B11011), the Ningbo Science and Technology Innovation Team (No. 2015B11001), and the Ningbo Natural Science Foundation (No. 2015A610110).

  9. Nanocomposite thin films for triggerable drug delivery.

    Science.gov (United States)

    Vannozzi, Lorenzo; Iacovacci, Veronica; Menciassi, Arianna; Ricotti, Leonardo

    2018-05-01

    Traditional drug release systems normally rely on a passive delivery of therapeutic compounds, which can be partially programmed, prior to injection or implantation, through variations in the material composition. With this strategy, the drug release kinetics cannot be remotely modified and thus adapted to changing therapeutic needs. To overcome this issue, drug delivery systems able to respond to external stimuli are highly desirable, as they allow a high level of temporal and spatial control over drug release kinetics, in an operator-dependent fashion. Areas covered: On-demand drug delivery systems actually represent a frontier in this field and are attracting an increasing interest at both research and industrial level. Stimuli-responsive thin films, enabled by nanofillers, hold a tremendous potential in the field of triggerable drug delivery systems. The inclusion of responsive elements in homogeneous or heterogeneous thin film-shaped polymeric matrices strengthens and/or adds intriguing properties to conventional (bare) materials in film shape. Expert opinion: This Expert Opinion review aims to discuss the approaches currently pursued to achieve an effective on-demand drug delivery, through nanocomposite thin films. Different triggering mechanisms allowing a fine control on drug delivery are described, together with current challenges and possible future applications in therapy and surgery.

  10. Thermoelectric properties of electrodeposited tellurium films and the sodium lignosulfonate effect

    International Nuclear Information System (INIS)

    Abad, Begoña; Rull-Bravo, Marta; Hodson, Stephen L.; Xu, Xianfan; Martin-Gonzalez, Marisol

    2015-01-01

    The effect of the addition of a surfactant, sodium lignosulfonate (SLS), on the thermoelectric properties of tellurium films prepared by electrochemical deposition is studied. The growth mechanism is found to have an important role in the thermoelectric properties since the grain size of the films is sharply reduced when the surfactant is added to the solution. For this reason, the electrical resistivity of the tellurium films when the surfactant is not added is 229 μΩ·m, which is lower than 798 μΩ·m with SLS. The Seebeck coefficient values are not influenced, with values in the vicinity of 285 μV/K for both solutions. The power factor resulted higher values than previous works, reaching values of 280 μW/m·K 2 (without SLS) and 82 μW/m·K 2 (with SLS) at room temperature. Finally, the thermal conductivity was measured by means of the Photoacoustic technique, which showed values of the order of 1 W/m·K for both solutions, which is a factor of 3 less than the bulk value of tellurium. A notable observation is that the power factor and the thermal conductivity of electrodeposited tellurium films have the same order of magnitude of bismuth telluride films grown by electrodeposition. The figure of merit is estimated to be approximately one order of magnitude higher than the bulk value, 0.09 without SLS and 0.03 with SLS, both at room temperature

  11. Doping dependence of electrical and thermal conductivity of nanoscale polyaniline thin films

    Energy Technology Data Exchange (ETDEWEB)

    Jin Jiezhu; Wang Qing [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Haque, M A [Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA 16802 (United States)

    2010-05-26

    We performed simultaneous characterization of electrical and thermal conductivity of 55 nm thick polyaniline (PANI) thin films doped with different levels of camphor sulfonic acids (CSAs). The effect of the doping level is more pronounced on electrical conductivity than on thermal conductivity of PANIs, thereby greatly affecting their ratio that determines the thermoelectric efficiency. At the 60% (the molar ratio of CSA to phenyl-N repeat unit of PANI) doping level, PANI exhibited the maximum electrical and thermal conductivity due to the formation of mostly delocalized structures. Whereas polarons are the charge carriers responsible for the electrical conduction, phonons are believed to play a dominant role in the heat conduction in nanoscale doped PANI thin films.

  12. Optical thin films and coatings from materials to applications

    CERN Document Server

    Flory, Francois

    2013-01-01

    Optical coatings, including mirrors, anti-reflection coatings, beam splitters, and filters, are an integral part of most modern optical systems. This book provides an overview of thin film materials, the properties, design and manufacture of optical coatings and their use across a variety of application areas.$bOptical coatings, including mirrors, anti-reflection coatings, beam splitters, and filters, are an integral part of most modern optical systems. Optical thin films and coatings provides an overview of thin film materials, the properties, design and manufacture of optical coatings and their use across a variety of application areas. Part one explores the design and manufacture of optical coatings. Part two highlights unconventional features of optical thin films including scattering properties of random structures in thin films, optical properties of thin film materials at short wavelengths, thermal properties and colour effects. Part three focusses on novel materials for optical thin films and coatings...

  13. Temperature dependence of LRE-HRE-TM thin films

    Science.gov (United States)

    Li, Zuoyi; Cheng, Xiaomin; Lin, Gengqi; Li, Zhen; Huang, Zhixin; Jin, Fang; Wang, Xianran; Yang, Xiaofei

    2003-04-01

    Temperature dependence of the properties of RE-TM thin films is very important for MO recording. In this paper, we studied the temperature dependence of the magnetic and magneto-optical properties of the amorphous LRE-HRE-TM single layer thin films and LRE-HRE-TM/HRE-TM couple-bilayered thin films. For LRE-HRE-TM single layer thin films, the temperature dependence of the magnetization was investigated by using the mean field theory. The experimental and theoretical results matched very well. With the LRE substitution in HRE-TM thin film, the compensation temperature Tcomp decreased and the curie temperature Tc remained unchanged. Kerr rotation angle became larger and the saturation magnetization Ms at room temperature increased. For LRE-HRE-TM/HRE-TM couple-bilayered thin films, comparisons of the temperature dependences of the coercivities and Kerr rotation angles were made between isolated sublayers and couple-bilayered thin film.

  14. Application-related properties of giant magnetostrictive thin films

    International Nuclear Information System (INIS)

    Lim, S.H.; Kim, H.J.; Na, S.M.; Suh, S.J.

    2002-01-01

    In an effort to facilitate the utilization of giant magnetostrictive thin films in microdevices, application-related properties of these thin films, which include induced anisotropy, residual stress and corrosion properties, are investigated. A large induced anisotropy with an energy of 6x10 4 J/m 3 is formed in field-sputtered amorphous Sm-Fe-B thin films, resulting in a large magnetostriction anisotropy. Two components of residual stress, intrinsic compressive stress and tensile stress due to the difference of the thermal expansion coefficients between the substrate and thin film, are identified. The variation of residual stress with fabrication parameter and annealing temperature, and its influence on mechanical bending and magnetic properties are examined. Better corrosion properties are observed in Sm-Fe thin films than in Tb-Fe. Corrosion properties of Tb-Fe thin films, however, are much improved with the introduction of nitrogen to the thin films without deteriorating magnetostrictive properties

  15. Laser assisted hybrid additive manufacturing of thermoelectric modules

    Science.gov (United States)

    Zhang, Tao; Tewolde, Mahder; Longtin, Jon P.; Hwang, David J.

    2017-02-01

    Thermoelectric generators (TEGs) are an attractive means to produce electricity, particular from waste heat applications. However, TEGs are almost exclusively manufactured as flat, rigid modules of limited size and shape, and therefore an appropriate mounting for intimate contact of TEGs modules onto arbitrary surfaces represents a significant challenge. In this study, we introduce laser assisted additive manufacturing method to produce multi-layered thermoelectric generator device directly on flat and non-flat surfaces for waste heat recovery. The laser assisted processing spans from laser scribing of thermal sprayed thin films, curing of dispensed thermoelectric inks and selective laser sintering to functionalize thermoelectric materials.

  16. In situ annealing of hydroxyapatite thin films

    International Nuclear Information System (INIS)

    Johnson, Shevon; Haluska, Michael; Narayan, Roger J.; Snyder, Robert L.

    2006-01-01

    Hydroxyapatite is a bioactive ceramic that mimics the mineral composition of natural bone. Unfortunately, problems with adhesion, poor mechanical integrity, and incomplete bone ingrowth limit the use of many conventional hydroxyapatite surfaces. In this work, we have developed a novel technique to produce crystalline hydroxyapatite thin films involving pulsed laser deposition and postdeposition annealing. Hydroxyapatite films were deposited on Ti-6Al-4V alloy and Si (100) using pulsed laser deposition, and annealed within a high temperature X-ray diffraction system. The transformation from amorphous to crystalline hydroxyapatite was observed at 340 deg. C. Mechanical and adhesive properties were examined using nanoindentation and scratch adhesion testing, respectively. Nanohardness and Young's modulus values of 3.48 and 91.24 GPa were realized in unannealed hydroxyapatite films. Unannealed and 350 deg. C annealed hydroxyapatite films exhibited excellent adhesion to Ti-6Al-4V alloy substrates. We anticipate that the adhesion and biological properties of crystalline hydroxyapatite thin films may be enhanced by further consideration of deposition and annealing parameters

  17. Thermal conductivities of thin, sputtered optical films

    International Nuclear Information System (INIS)

    Henager, C.H. Jr.; Pawlewicz, W.T.

    1991-05-01

    The normal component of the thin film thermal conductivity has been measured for the first time for several advanced sputtered optical materials. Included are data for single layers of boron nitride (BN), aluminum nitride (AIN), silicon aluminum nitride (Si-Al-N), silicon aluminum oxynitride (Si-Al-O-N), silicon carbide (SiC), and for dielectric-enhanced metal reflectors of the form Al(SiO 2 /Si 3 N 4 ) n and Al(Al 2 O 3 /AIN) n . Sputtered films of more conventional materials like SiO 2 , Al 2 O 3 , Ta 2 O 5 , Ti, and Si have also been measured. The data show that thin film thermal conductivities are typically 10 to 100 times lower than conductivities for the same materials in bulk form. Structural disorder in the amorphous or very fine-grained films appears to account for most of the conductivity difference. Conclusive evidence for a film/substrate interface contribution is presented

  18. Electromagnetic properties of thin film lead superconductors

    International Nuclear Information System (INIS)

    Moriyama, K.

    1978-01-01

    The dependence of critical film magnetic field H/sub cf/ on temperature, thickness, and surface texture of lead superconducting films was investigated, as well as the relationship between the applied magnetic field and the applied current at the critical field. Temperature and thickness dependence data were consistent with the predictions of London, of Ginzburg, and of Bardeen, Cooper, and Schreiffer. The values of H/sub cf/ of lead films deposited on a rough surface were consistently lower than for those on a smooth surface and so were not in agreement with any currently accepted theory. The degree of lowering of H/sub cf/ by a rough surface was greater in thin films than in thick films. The expected dependence of penetration depth lambda on thickness d was not observed, and the range of lambda was somewhat greater than expected. The range of coherence length was greater than predicted. The prediction for temperature dependence of critical current by Glover and Coffey was found to involve some oversimplification, and a suggested correction is supported by the data. For applied magnetic fields perpendicular to the applied current and parallel to the film surface, the relationship between the critical values of the magnetic field and the current was as predicted for lead films by Alphonse and Bergstein

  19. Flexible screen printed thick film thermoelectric generator with reduced material resistivity

    International Nuclear Information System (INIS)

    Cao, Z; Koukharenko, E; Torah, R N; Tudor, J; Beeby, S P

    2014-01-01

    This work presents a flexible thick-film Bismuth Tellurium/Antimony Tellurium (BiTe/SbTe) thermoelectric generator (TEG) with reduced material resistivity fabricated by screen printing technology. Cold isostatic pressing (CIP) was introduced to lower the resistivity of the printed thermoelectric materials. The Seebeck coefficient (α) and the resistivity (ρ) of printed materials were measured as a function of applied pressure. A prototype TEG with 8 thermocouples was fabricated on flexible polyimide substrate. The dimension of a single printed element was 20 mm × 2 mm × 78.4 pm. The coiled-up prototype produced a voltage of 36.4 mV and a maximum power of 40.3 nW from a temperature gradient of 20 °C

  20. Multiferroic oxide thin films and heterostructures

    KAUST Repository

    Lu, Chengliang

    2015-05-26

    Multiferroic materials promise a tantalizing perspective of novel applications in next-generation electronic, memory, and energy harvesting technologies, and at the same time they also represent a grand scientific challenge on understanding complex solid state systems with strong correlations between multiple degrees of freedom. In this review, we highlight the opportunities and obstacles in growing multiferroic thin films with chemical and structural integrity and integrating them in functional devices. Besides the magnetoelectric effect, multiferroics exhibit excellent resistant switching and photovoltaic properties, and there are plenty opportunities for them to integrate with other ferromagnetic and superconducting materials. The challenges include, but not limited, defect-related leakage in thin films, weak magnetism, and poor control on interface coupling. Although our focuses are Bi-based perovskites and rare earth manganites, the insights are also applicable to other multiferroic materials. We will also review some examples of multiferroic applications in spintronics, memory, and photovoltaic devices.

  1. Domain switching of fatigued ferroelectric thin films

    Science.gov (United States)

    Tak Lim, Yun; Yeog Son, Jong; Shin, Young-Han

    2014-05-01

    We investigate the domain wall speed of a ferroelectric PbZr0.48Ti0.52O3 (PZT) thin film using an atomic force microscope incorporated with a mercury-probe system to control the degree of electrical fatigue. The depolarization field in the PZT thin film decreases with increasing the degree of electrical fatigue. We find that the wide-range activation field previously reported in ferroelectric domains result from the change of the depolarization field caused by the electrical fatigue. Domain wall speed exhibits universal behavior to the effective electric field (defined by an applied electric field minus the depolarization field), regardless of the degree of the electrical fatigue.

  2. Domain switching of fatigued ferroelectric thin films

    International Nuclear Information System (INIS)

    Tak Lim, Yun; Yeog Son, Jong; Shin, Young-Han

    2014-01-01

    We investigate the domain wall speed of a ferroelectric PbZr 0.48 Ti 0.52 O 3 (PZT) thin film using an atomic force microscope incorporated with a mercury-probe system to control the degree of electrical fatigue. The depolarization field in the PZT thin film decreases with increasing the degree of electrical fatigue. We find that the wide-range activation field previously reported in ferroelectric domains result from the change of the depolarization field caused by the electrical fatigue. Domain wall speed exhibits universal behavior to the effective electric field (defined by an applied electric field minus the depolarization field), regardless of the degree of the electrical fatigue

  3. Highly coercive thin-film nanostructures

    International Nuclear Information System (INIS)

    Zhou, J.; Skomski, R.; Kashyap, A.; Sorge, K.D.; Sui, Y.; Daniil, M.; Gao, L.; Yan, M.L.; Liou, S.-H.; Kirby, R.D.; Sellmyer, D.J.

    2005-01-01

    The processing, structure, and magnetism of highly coercive Sm-Co and FePt thin-film nanostructures are investigated. The structures include 1:5 based Sm-Co-Cu-Ti magnets, particulate FePt:C thin films, and FePt nanotubes. As in other systems, the coercivity depends on texture and imperfections, but there are some additional features. A specific coercivity mechanism in particulate media is a discrete pinning mode intermediate between Stoner-Wohlfarth rotation and ordinary domain-wall pinning. This mechanism yields a coercivity maximum for intermediate intergranular exchange and explains the occurrence of coercivities of 5 T in particulate Sm-Co-Cu-Ti magnets

  4. High efficiency thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Hans-Werner [Helmholtz Zentrum Berlin (Germany). Solar Energy

    2012-11-01

    Production of photovoltaics is growing worldwide on a gigawatt scale. Among the thin film technologies, Cu(In,Ga)S,Se{sub 2} (CIS or CIGS) based solar cells have been the focus of more and more attention. This paper aims to analyze the success of CIGS based solar cells and the potential of this technology for future photovoltaics large-scale production. Specific material properties make CIS unique and allow the preparation of the material with a wide range of processing options. The huge potential lies in the possibility to take advantage of modern thin film processing equipment and combine it with very high efficiencies beyond 20% already achieved on the laboratory scale. A sustainable development of this technology could be realized by modifying the materials and replacing indium by abundant elements. (orig.)

  5. Quantifying clustering in disordered carbon thin films

    International Nuclear Information System (INIS)

    Carey, J.D.

    2006-01-01

    The quantification of disorder and the effects of clustering in the sp 2 phase of amorphous carbon thin films are discussed. The sp 2 phase is described in terms of disordered nanometer-sized conductive sp 2 clusters embedded in a less conductive sp 3 matrix. Quantification of the clustering of the sp 2 phase is estimated from optical as well as from electron and nuclear magnetic resonance methods. Unlike in other disordered group IV thin film semiconductors, we show that care must be exercised in attributing a meaning to the Urbach energy extracted from absorption measurements in the disordered carbon system. The influence of structural disorder, associated with sp 2 clusters of similar size, and topological disorder due to undistorted clusters of different sizes is also discussed. Extensions of this description to other systems are also presented

  6. Thin film photovoltaic panel and method

    Science.gov (United States)

    Ackerman, Bruce; Albright, Scot P.; Jordan, John F.

    1991-06-11

    A thin film photovoltaic panel includes a backcap for protecting the active components of the photovoltaic cells from adverse environmental elements. A spacing between the backcap and a top electrode layer is preferably filled with a desiccant to further reduce water vapor contamination of the environment surrounding the photovoltaic cells. The contamination of the spacing between the backcap and the cells may be further reduced by passing a selected gas through the spacing subsequent to sealing the backcap to the base of the photovoltaic panels, and once purged this spacing may be filled with an inert gas. The techniques of the present invention are preferably applied to thin film photovoltaic panels each formed from a plurality of photovoltaic cells arranged on a vitreous substrate. The stability of photovoltaic conversion efficiency remains relatively high during the life of the photovoltaic panel, and the cost of manufacturing highly efficient panels with such improved stability is significantly reduced.

  7. Strain quantification in epitaxial thin films

    International Nuclear Information System (INIS)

    Cushley, M

    2008-01-01

    Strain arising in epitaxial thin films can be beneficial in some cases but devastating in others. By altering the lattice parameters, strain may give a thin film properties hitherto unseen in the bulk material. On the other hand, heavily strained systems are prone to develop lattice defects in order to relieve the strain, which can cause device failure or, at least, a decrease in functionality. Using convergent beam electron diffraction (CBED) and high-resolution transmission electron microscopy (HRTEM), it is possible to determine local strains within a material. By comparing the results from CBED and HRTEM experiments, it is possible to gain a complete view of a material, including the strain and any lattice defects present. As well as looking at how the two experimental techniques differ from each other, I will also look at how results from different image analysis algorithms compare. Strain in Si/SiGe samples and BST/SRO/MgO capacitor structures will be discussed.

  8. Method of formation of thin film component

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Chikara; Kato, Kinya

    1988-04-16

    In the production process of component which is carrying thin film device, such as thin film transistor, acid treatment is applied for etching or for preventing contamination. In case of barium borsilicate glass base, the base is affected by the acid treatment resulting the decrease of transparency. To avoid the effect, deposition of SiO/sub 2/ layer on the surface of the base is usually applied. This invention relates to the protective method of barium borosilicate surface by harnessing the effect of coexisting ion in the acid treatment bath. The method is to add 0.03-5 mol/l of phosphoric acid or its salt in the bath. By the effect of coexisting ion, barium borsilicate glass surface was protected from the damage. (2 figs)

  9. Nanostructured Thermoelectric Oxides for Energy Harvesting Applications

    KAUST Repository

    Abutaha, Anas I.

    2015-11-24

    As the world strives to adapt to the increasing demand for electrical power, sustainable energy sources are attracting significant interest. Around 60% of energy utilized in the world is wasted as heat. Different industrial processes, home heating, and exhausts in cars, all generate a huge amount of unused waste heat. With such a huge potential, there is also significant interest in discovering inexpensive technologies for power generation from waste heat. As a result, thermoelectric materials have become important for many renewable energy research programs. While significant advancements have been done in improving the thermoelectric properties of the conventional heavy-element based materials (such as Bi2Te3 and PbTe), high-temperature applications of thermoelectrics are still limited to one materials system, namely SiGe, since the traditional thermoelectric materials degrade and oxidize at high temperature. Therefore, oxide thermoelectrics emerge as a promising class of materials since they can operate athigher temperatures and in harsher environments compared to non-oxide thermoelectrics. Furthermore, oxides are abundant and friendly to the environment. Among oxides, crystalline SrTiO3 and ZnO are promising thermoelectric materials. The main objective of this work is therefore to pursue focused investigations of SrTiO3 and ZnO thin films and superlattices grown by pulsed laser deposition (PLD), with the goal of optimizing their thermoelectric properties by following different strategies. First, the effect of laser fluence on the thermoelectric properties of La doped epitaxial SrTiO3 films is discussed. Films grown at higher laser fluences exhibit better thermoelectric performance. Second, the role of crystal orientation in determining the thermoelectric properties of epitaxial Al doped ZnO (AZO) films is explained. Vertically aligned (c-axis) AZO films have superior thermoelectric properties compared to other films with different crystal orientations. Third

  10. Thin film solar cell technology in Germany

    International Nuclear Information System (INIS)

    Diehl, W.; Sittinger, V.; Szyszka, B.

    2005-01-01

    Within the scope of limited nonrenewable energy resources and the limited capacity of the ecosystem for greenhouse gases and nuclear waste, sustainability is one important target in the future. Different energy scenarios showed the huge potential for photovoltaics (PV) to solve this energy problem. Nevertheless, in the last decade, PV had an average growth rate of over 20% per year. In 2002, the solar industry delivered more than 500 MWp/year of photovoltaic generators [A. Jaeger-Waldau, A European Roadmap for PV R and D, E-MRS Spring Meeting, (2003)]. More than 85% of the current production involves crystalline silicon technologies. These technologies still have a high cost reduction potential, but this will be limited by the silicon feedstock. On the other hand the so-called second generation thin film solar cells based on a-Si, Cu(In,Ga)(Se,S 2 (CIGS) or CdTe have material thicknesses of a few microns as a result of their direct band gap. Also, the possibility of circuit integration offers an additional cost reduction potential. Especially in Germany, there are a few companies who focus on thin film solar cells. Today, there are two manufacturers with production lines: the Phototronics (PST) division of RWE-Schott Solar with a-Si thin film technology and the former Antec Solar GmbH (now Antec Solar Energy GmbH) featuring the CdTe technology. A pilot line based on CIGS technology is run by Wuerth Solar GmbH. There is also a variety of research activity at other companies, namely, at Shell Solar, Sulfurcell Solartechnik GmbH, Solarion GmbH and the CIS-Solartechnik GmbH. We will give an overview on research activity on various thin film technologies, as well as different manufacturing and production processes in the companies mentioned above. (Author)

  11. Optical characterization of thin solid films

    CERN Document Server

    Ohlídal, Miloslav

    2018-01-01

    This book is an up-to-date survey of the major optical characterization techniques for thin solid films. Emphasis is placed on practicability of the various approaches. Relevant fundamentals are briefly reviewed before demonstrating the application of these techniques to practically relevant research and development topics. The book is written by international top experts, all of whom are involved in industrial research and development projects.

  12. Thin-film silicon solar cell technology

    Czech Academy of Sciences Publication Activity Database

    Shah, A. V.; Schade, H.; Vaněček, Milan; Meier, J.; Vallat-Sauvain, E.; Wyrsch, N.; Kroll, U.; Droz, C.; Bailat, J.

    2004-01-01

    Roč. 12, - (2004), s. 113-142 ISSN 1062-7995 R&D Projects: GA MŽP SN/320/11/03 Institutional research plan: CEZ:AV0Z1010914 Keywords : thin-film silicon modules * hydrogenerated amorphous silicon(a-Si:H) * hydrogenerated microcrystalline (ćc-Si:H) * transparent conductive oxydes(TCOs) * building-integrated photovoltaics(BIPV) Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.196, year: 2004

  13. The carbonization of thin polyaniline films

    Czech Academy of Sciences Publication Activity Database

    Morávková, Zuzana; Trchová, Miroslava; Exnerová, Milena; Stejskal, Jaroslav

    2012-01-01

    Roč. 520, č. 19 (2012), s. 6088-6094 ISSN 0040-6090 R&D Projects: GA AV ČR IAA400500905; GA AV ČR IAA100500902; GA ČR GAP205/12/0911 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : polyaniline * thin films * infrared spectroscopy Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.604, year: 2012

  14. High-Performance Screen-Printed Thermoelectric Films on Fabrics.

    Science.gov (United States)

    Shin, Sunmi; Kumar, Rajan; Roh, Jong Wook; Ko, Dong-Su; Kim, Hyun-Sik; Kim, Sang Il; Yin, Lu; Schlossberg, Sarah M; Cui, Shuang; You, Jung-Min; Kwon, Soonshin; Zheng, Jianlin; Wang, Joseph; Chen, Renkun

    2017-08-04

    Printing techniques could offer a scalable approach to fabricate thermoelectric (TE) devices on flexible substrates for power generation used in wearable devices and personalized thermo-regulation. However, typical printing processes need a large concentration of binder additives, which often render a detrimental effect on electrical transport of the printed TE layers. Here, we report scalable screen-printing of TE layers on flexible fiber glass fabrics, by rationally optimizing the printing inks consisting of TE particles (p-type Bi 0.5 Sb 1.5 Te 3 or n-type Bi 2 Te 2.7 Se 0.3 ), binders, and organic solvents. We identified a suitable binder additive, methyl cellulose, which offers suitable viscosity for printability at a very small concentration (0.45-0.60 wt.%), thus minimizing its negative impact on electrical transport. Following printing, the binders were subsequently burnt off via sintering and hot pressing. We found that the nanoscale defects left behind after the binder burnt off became effective phonon scattering centers, leading to low lattice thermal conductivity in the printed n-type material. With the high electrical conductivity and low thermal conductivity, the screen-printed TE layers showed high room-temperature ZT values of 0.65 and 0.81 for p-type and n-type, respectively.

  15. Microstructure evolution in pulsed laser deposited epitaxial Ge-Sb-Te chalcogenide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Ulrich; Lotnyk, Andriy, E-mail: andriy.lotnyk@iom-leipzig.de; Thelander, Erik; Rauschenbach, Bernd

    2016-08-15

    The thin film deposition and structure of highly oriented telluride compounds is of particular interest for phase-change applications in next-generation non-volatile memory such as heterostructure designs, as well as for the investigation of novel optical, thermoelectric and ferroelectric properties in layered telluride compounds. In this work, epitaxial Ge-Sb-Te thin films were successfully produced by pulsed laser deposition on silicon with and without amorphous SiO{sub x} interlayer at elevated process temperatures from a Ge{sub 2}Sb{sub 2}Te{sub 5} target. Aberration-corrected high-resolution scanning transmission electron microscopy (STEM) imaging reveals a distinct interface configuration of the trigonal phase connected by a quasi van der Waals gap (vacancy) to the Sb/Te-passivated single crystalline Si substrate, yet also an intermediate textured growth regime in which the substrate symmetry is only weakly coupled to the thin film orientation, as well as strong deviation of composition at high deposition temperatures. Textured growth of Ge-Sb-Te thin film was also observed on SiO{sub x}/Si substrate with no evidence of an intermediate Sb/Te surface layer on top of an SiO{sub x} layer. In addition, particular defect structures formed by local reorganization of the stacking sequence across the vacancy gap are observed and appear to be intrinsic to these van der Waals-layered compounds. Theoretical image simulations of preferred stacking sequences can be matched to individual building blocks in the Ge-Sb-Te grain. - Highlights: • Atomic-resolution Cs-corrected STEM imaging of PLD deposited Ge-Sb-Te thin films. • Changing of overall composition with increasing deposition temperature. • Direct imaging of surface passivation Sb/Te layer at the Ge-Sb-Te/Si(111) interface. • The Sb/Te passivation layer is not a prerequisite for highly oriented growth of Ge-Sb-Te thin films.

  16. Study of obliquely deposited thin cobalt films

    International Nuclear Information System (INIS)

    Szmaja, W.; Kozlowski, W.; Balcerski, J.; Kowalczyk, P.J.; Grobelny, J.; Cichomski, M.

    2010-01-01

    Research highlights: → The paper reports simultaneously on the magnetic domain structure of obliquely deposited thin cobalt films (40 nm and 100 nm thick) and their morphological structure. Such studies are in fact rare (Refs. cited in the paper). → Moreover, to our knowledge, observations of the morphological structure of these films have not yet been carried out simultaneously by transmission electron microscopy (TEM) and atomic force microscopy (AFM). → The films of both thicknesses were found to have uniaxial in-plane magnetic anisotropy. → The magnetic microstructure of the films 40 nm thick was composed of domains running and magnetized predominantly in the direction perpendicular to the incidence plane of the vapor beam. → As the film thickness was changed from 40 nm to 100 nm, the magnetic anisotropy was observed to change from the direction perpendicular to parallel with respect to the incidence plane. → Thanks to the application of TEM and AFM, complementary information on the morphological structure of the films could be obtained. → In comparison with TEM images, AFM images revealed grains larger in size and slightly elongated in the direction perpendicular rather than parallel to the incidence plane. → These experimental findings clearly show that surface diffusion plays an important role in the process of film growth. → For the films 40 nm thick, the alignment of columnar grains in the direction perpendicular to the incidence plane was observed. → This correlates well with the magnetic domain structure of these films. → For the films 100 nm thick, the perpendicular alignment of columnar grains could also be found, although in fact with larger difficulty. → TEM studies showed that the films consisted mainly of the hexagonal close-packed (HCP) crystalline structure, but no preferred crystallographic orientation of the grains could be detected for the films of both thicknesses. → For the films 100 nm thick, the alignment of

  17. P-type CuxS thin films: Integration in a thin film transistor structure

    International Nuclear Information System (INIS)

    Nunes de Carvalho, C.; Parreira, P.; Lavareda, G.; Brogueira, P.; Amaral, A.

    2013-01-01

    Cu x S thin films, 80 nm thick, are deposited by vacuum thermal evaporation of sulfur-rich powder mixture, Cu 2 S:S (50:50 wt.%) with no intentional heating of the substrate. The process of deposition occurs at very low deposition rates (0.1–0.3 nm/s) to avoid the formation of Cu or S-rich films. The evolution of Cu x S films surface properties (morphology/roughness) under post deposition mild annealing in air at 270 °C and their integration in a thin film transistor (TFT) are the main objectives of this study. Accordingly, Scanning Electron Microscopy studies show Cu x S films with different surface morphologies, depending on the post deposition annealing conditions. For the shortest annealing time, the Cu x S films look to be constructed of grains with large dimension at the surface (approximately 100 nm) and consequently, irregular shape. For the longest annealing time, films with a fine-grained surface are found, with some randomly distributed large particles bound to this fine-grained surface. Atomic Force Microscopy results indicate an increase of the root-mean-square roughness of Cu x S surface with annealing time, from 13.6 up to 37.4 nm, for 255 and 345 s, respectively. The preliminary integration of Cu x S films in a TFT bottom-gate type structure allowed the study of the feasibility and compatibility of this material with the remaining stages of a TFT fabrication as well as the determination of the p-type characteristic of the Cu x S material. - Highlights: • Surface properties of annealed Cu x S films. • Variation of conductivity with annealing temperatures of Cu x S films. • Application of evaporated Cu x S films in a thin film transistor (TFT) structure. • Determination of Cu x S p-type characteristic from TFT behaviour

  18. Neutron reflectivity of electrodeposited thin magnetic films

    International Nuclear Information System (INIS)

    Cooper, Joshaniel F.K.; Vyas, Kunal N.; Steinke, Nina-J.; Love, David M.; Kinane, Christian J.; Barnes, Crispin H.W.

    2014-01-01

    Highlights: • Electrodeposited magnetic bi-layers were measured by polarised neutron reflectivity. • When growing a CoNiCu alloy from a single bath a Cu rich region is initially formed. • This Cu rich region is formed in the first layer but not subsequent ones. • Ni deposition is inhibited in thin film growth and Co deposits anomalously. • Alloy magnetism and neutron scattering length give a self-consistent model. - Abstract: We present a polarised neutron reflectivity (PNR) study of magnetic/non-magnetic (CoNiCu/Cu) thin films grown by single bath electrodeposition. We find that the composition is neither homogeneous with time, nor consistent with bulk values. Instead an initial, non-magnetic copper rich layer is formed, around 2 nm thick. This layer is formed by the deposition of the dilute, but rapidly diffusing, Cu 2+ ions near the electrode surface at the start of growth, before the region is depleted and the deposition becomes mass transport limited. After the region has been depleted, by growth etc., this layer does not form and thus may be prevented by growing a copper buffer layer immediately preceding the magnetic layer growth. As has been previously found, cobalt deposits anomalously compared to nickel, and even inhibits Ni deposition in thin films. The layer magnetisation and average neutron scattering length are fitted independently but both depend upon the alloy composition. Thus these parameters can be used to check for model self-consistency, increasing confidence in the derived composition

  19. Preventing Thin Film Dewetting via Graphene Capping.

    Science.gov (United States)

    Cao, Peigen; Bai, Peter; Omrani, Arash A; Xiao, Yihan; Meaker, Kacey L; Tsai, Hsin-Zon; Yan, Aiming; Jung, Han Sae; Khajeh, Ramin; Rodgers, Griffin F; Kim, Youngkyou; Aikawa, Andrew S; Kolaczkowski, Mattew A; Liu, Yi; Zettl, Alex; Xu, Ke; Crommie, Michael F; Xu, Ting

    2017-09-01

    A monolayer 2D capping layer with high Young's modulus is shown to be able to effectively suppress the dewetting of underlying thin films of small organic semiconductor molecule, polymer, and polycrystalline metal, respectively. To verify the universality of this capping layer approach, the dewetting experiments are performed for single-layer graphene transferred onto polystyrene (PS), semiconducting thienoazacoronene (EH-TAC), gold, and also MoS 2 on PS. Thermodynamic modeling indicates that the exceptionally high Young's modulus and surface conformity of 2D capping layers such as graphene and MoS 2 substantially suppress surface fluctuations and thus dewetting. As long as the uncovered area is smaller than the fluctuation wavelength of the thin film in a dewetting process via spinodal decomposition, the dewetting should be suppressed. The 2D monolayer-capping approach opens up exciting new possibilities to enhance the thermal stability and expands the processing parameters for thin film materials without significantly altering their physical properties. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Aluminum nitride and nanodiamond thin film microstructures

    Energy Technology Data Exchange (ETDEWEB)

    Knoebber, Fabian; Bludau, Oliver; Roehlig, Claus-Christian; Williams, Oliver; Sah, Ram Ekwal; Kirste, Lutz; Cimalla, Volker; Lebedev, Vadim; Nebel, Christoph; Ambacher, Oliver [Fraunhofer-Institute for Applied Solid State Physics, Freiburg (Germany)

    2010-07-01

    In this work, aluminum nitride (AlN) and nanocrystalline diamond (NCD) thin film microstructures have been developed. Freestanding NCD membranes were coated with a piezoelectrical AlN layer in order to build tunable micro-lens arrays. For the evaluation of the single material quality, AlN and NCD thin films on silicon substrates were fabricated using RF magnetron sputtering and microwave chemical vapor deposition techniques, respectively. The crystal quality of AlN was investigated by X-ray diffraction. The piezoelectric constant d{sub 33} was determined by scanning laser vibrometry. The NCD thin films were optimized with respect to surface roughness, mechanical stability, intrinsic stress and transparency. To determine the mechanical properties of the materials, both, micromechanical resonator and membrane structures were fabricated and measured by magnetomotive resonant frequency spectroscopy and bulging experiments, respectively. Finally, the behavior of AlN/NCD heterostructures was modeled using the finite element method and the first structures were characterized by piezoelectrical measurements.

  1. Process for forming thin film, heat treatment process of thin film sheet, and heat treatment apparatus therefor

    International Nuclear Information System (INIS)

    Watanabe, S.

    1984-01-01

    The invention provides a process for forming a magnetic thin film on a base film, a heat treatment process of a thin film sheet consisting of the base film and the magnetic thin film, and an apparatus for performing heat treatment of the thin film sheet. Tension applied to the thin film sheet is substantially equal to that applied to the base film when the magnetic thin film is formed thereon. Then, the thin film sheet is treated with heat. The thin film sheet is heated with a given temperature gradient to a reactive temperature at which heat shrinkage occurs, while the tension is being applied thereto. Thereafter, the thin film sheet to which the tension is still applied is cooled with substantially the same temperature gradient as applied in heating. The heat treatment apparatus has a film driving unit including a supply reel, a take-up reel, a drive source and guide rollers; a heating unit including heating plates, heater blocks and a temperature controller for heating the sheet to the reactive temperature; and a heat insulating unit including a thermostat and another temperature controller for maintaining the sheet at the nonreactive temperature which is slightly lower than the reactive temperature

  2. Collective Behavior of Amoebae in Thin Films

    Science.gov (United States)

    Bae, Albert

    2005-03-01

    We have discovered new aspects of social behavior in Dictyostelium discoideum by culturing high density colonies in liquid media depleted of nutrients in confined geometries by using three different preparations: I. thin (15-40um thick) and II. ultrathin (behavior of cells despite flattening that increased their areas by over an order of magnitude. We also observed that the earliest synchronized response of cells following the onset of starvation, a precursor to aggregation, was hastened by reducing the thickness of the aqueous culture layer. We were surprised to find that the threshold concentration for aggregation was raised by thin film confinement when compared to bulk behavior. Finally, both the ultra thin and microfluidic preparations reveal, with new clarity, vortex states of aggregation.

  3. Ion beam deposited epitaxial thin silicon films

    International Nuclear Information System (INIS)

    Orrman-Rossiter, K.G.; Al-Bayati, A.H.; Armour, D.G.; Donnelly, S.E.; Berg, J.A. van den

    1991-01-01

    Deposition of thin films using low energy, mass-separated ion beams is a potentially important low temperature method of producing epitaxial layers. In these experiments silicon films were grown on Si (001) substrates using 10-200 eV 28 Si + and 30 Si + ions at substrate temperatures in the range 273-1073 K, under ultrahigh-vacuum conditions (deposition pressure -7 Pa). The film crystallinity was assessed in situ using medium energy ion scattering (MEIS). Films of crystallinity comparable to bulk samples were grown using 10-40 eV 28 Si + and 30 Si + ions at deposition temperatures in the range 623-823 K. These experiments confirmed the role of key experimental parameters such as ion energy, substrate temperature during deposition, and the surface treatment prior to deposition. It was found that a high temperature in situ anneal (1350-1450 K) gave the best results for epitaxial nucleation, whereas low energy (20-40 eV) Cl + ion bombardment resulted in amorphous film growth. The deposition energy for good epitaxial growth indicates that it is necessary to provide enough energy to induce local mobility but not to cause atomic displacements leading to the buildup of stable defects, e.g. divacancies, below the surface layer of the growing film. (orig.)

  4. Infrared characterization of strontium titanate thin films

    International Nuclear Information System (INIS)

    Almeida, B.G.; Pietka, A.; Mendes, J.A.

    2004-01-01

    Strontium titanate thin films have been prepared at different oxygen pressures with various post-deposition annealing treatments. The films were deposited by pulsed laser ablation at room temperature on Si(0 0 1) substrates with a silica buffer layer. Infrared reflectance measurements were performed in order to determine relevant film parameters such as layer thicknesses and chemical composition. The infrared reflectance spectra were fitted by using adequate dielectric function forms for each layer. The fitting procedure provided the extraction of the dielectric functions of the strontium titanate film, the silica layer and the substrate. The as-deposited films are found to be amorphous, and their infrared spectra present peaks corresponding to modes with high damping constants. As the annealing time and temperature increases the strontium titanate layer becomes more ordered so that it can be described by its SrTiO 3 bulk mode parameters. Also, the silica layer grows along with the ordering of the strontium titanate film, due to oxidation during annealing

  5. Superconducting properties of iron chalcogenide thin films

    Directory of Open Access Journals (Sweden)

    Paolo Mele

    2012-01-01

    Full Text Available Iron chalcogenides, binary FeSe, FeTe and ternary FeTexSe1−x, FeTexS1−x and FeTe:Ox, are the simplest compounds amongst the recently discovered iron-based superconductors. Thin films of iron chalcogenides present many attractive features that are covered in this review, such as: (i easy fabrication and epitaxial growth on common single-crystal substrates; (ii strong enhancement of superconducting transition temperature with respect to the bulk parent compounds (in FeTe0.5Se0.5, zero-resistance transition temperature Tc0bulk = 13.5 K, but Tc0film = 19 K on LaAlO3 substrate; (iii high critical current density (Jc ~ 0.5 ×106 A cm2 at 4.2 K and 0 T for FeTe0.5Se0.5 film deposited on CaF2, and similar values on flexible metallic substrates (Hastelloy tapes buffered by ion-beam assisted deposition with a weak dependence on magnetic field; (iv high upper critical field (~50 T for FeTe0.5Se0.5, Bc2(0, with a low anisotropy, γ ~ 2. These highlights explain why thin films of iron chalcogenides have been widely studied in recent years and are considered as promising materials for applications requiring high magnetic fields (20–50 T and low temperatures (2–10 K.

  6. Thermal decomposition of titanium deuteride thin films

    International Nuclear Information System (INIS)

    Malinowski, M.E.

    1983-01-01

    The thermal desorption spectra of deuterium from essentially clean titanium deuteride thin films were measured by ramp heating the films in vacuum; the film thicknesses ranged from 20 to 220 nm and the ramp rates varied from 0.5 to about 3 0 C s - 1 . Each desorption spectrum consisted of a low nearly constant rate at low temperatures followed by a highly peaked rate at higher temperatures. The cleanliness and thinness of the films permitted a description of desorption rates in terms of a simple phenomenological model based on detailed balancing in which the low temperature pressure-composition characteristics of the two-phase (α-(α+#betta#)-#betta#) region of the Ti-D system were used as input data. At temperatures below 340 0 C the model predictions were in excellent agreement with the experimentally measured desorption spectra. Interpretations of the spectra in terms of 'decomposition trajectories'' are possible using this model, and this approach is also used to explain deviations of the spectra from the model at temperatures of 340 0 C and above. (Auth.)

  7. Electrical resistivity of thin metal films

    CERN Document Server

    Wissmann, Peter

    2007-01-01

    The aim of the book is to give an actual survey on the resistivity of thin metal and semiconductor films interacting with gases. We discuss the influence of the substrate material and the annealing treatment of the films, presenting our experimental data as well as theoretical models to calculate the scattering cross section of the conduction electrons in the frame-work of the scattering hypothesis. Main emphasis is laid on the comparison of gold and silver films which exhibit nearly the same lattice structure but differ in their chemical activity. In conclusion, the most important quantity for the interpretation is the surface charging z while the correlation with the optical data or the frustrated IR vibrations seems the show a more material-specific character. Z can be calculated on the basis of the density functional formalism or the self-consistent field approximation using Mulliken’s population analysis.

  8. Sulfated cellulose thin films with antithrombin affinity

    Directory of Open Access Journals (Sweden)

    2009-11-01

    Full Text Available Cellulose thin films were chemically modified by in situ sulfation to produce surfaces with anticoagulant characteristics. Two celluloses differing in their degree of polymerization (DP: CEL I (DP 215–240 and CEL II (DP 1300–1400 were tethered to maleic anhydride copolymer (MA layers and subsequently exposed to SO3•NMe3 solutions at elevated temperature. The impact of the resulting sulfation on the physicochemical properties of the cellulose films was investigated with respect to film thickness, atomic composition, wettability and roughness. The sulfation was optimized to gain a maximal surface concentration of sulfate groups. The scavenging of antithrombin (AT by the surfaces was determined to conclude on their potential anticoagulant properties.

  9. 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.

  10. Structural characterization of vacuum evaporated ZnSe thin films

    Indian Academy of Sciences (India)

    The lattice parameter, grain size, average internal stress, microstrain, dislocation density and degree of pre- ferred orientation in the film are calculated and correlated with Ts. Keywords. ZnSe thin films; X-ray diffraction; average internal stress; microstrain; dislocation density. 1. Introduction. Thin films of ZnSe has attracted ...

  11. Scanning tunneling spectroscopy of Pb thin films

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Michael

    2010-12-13

    The present thesis deals with the electronic structure, work function and single-atom contact conductance of Pb thin films, investigated with a low-temperature scanning tunneling microscope. The electronic structure of Pb(111) thin films on Ag(111) surfaces is investigated using scanning tunneling spectroscopy (STS). Quantum size effects, in particular, quantum well states (QWSs), play a crucial role in the electronic and physical properties of these films. Quantitative analysis of the spectra yields the QWS energies as a function of film thickness, the Pb bulk-band dispersion in {gamma}-L direction, scattering phase shifts at the Pb/Ag interface and vacuum barrier as well as the lifetime broadening at anti {gamma}. The work function {phi} is an important property of surfaces, which influences catalytic reactivity and charge injection at interfaces. It controls the availability of charge carriers in front of a surface. Modifying {phi} has been achieved by deposition of metals and molecules. For investigating {phi} at the atomic scale, scanning tunneling microscopy (STM) has become a widely used technique. STM measures an apparent barrier height {phi}{sub a}, which is commonly related to the sample work function {phi}{sub s} by: {phi}{sub a}=({phi}{sub s}+{phi}{sub t}- vertical stroke eV vertical stroke)/2, with {phi}{sub t} the work function of the tunneling tip, V the applied tunneling bias voltage, and -e the electron charge. Hence, the effect of the finite voltage in STM on {phi}{sub a} is assumed to be linear and the comparison of {phi}{sub a} measured at different surface sites is assumed to yield quantitative information about work function differences. Here, the dependence of {phi}{sub a} on the Pb film thickness and applied bias voltage V is investigated. {phi}{sub a} is found to vary significantly with V. This bias dependence leads to drastic changes and even inversion of contrast in spatial maps of {phi}{sub a}, which are related to the QWSs in the Pb

  12. Preparation and characterization of vanadium oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Monfort, O.; Plesch, G. [Comenius University of Bratislava, Faculty of Natural Sciences, Department of Inorganic Chemistry, 84215 Bratislava (Slovakia); Roch, T. [Comenius University of Bratislava, Faculty of Mathematics Physics and Informatics, Department of Experimental Physics, 84248 Bratislava (Slovakia)

    2013-04-16

    The thermotropic VO{sub 2} films have many applications, since they exhibit semiconductor-conductor switching properties at temperature around 70 grad C. Vanadium oxide thin films were prepared via sol-gel method. Spin coater was used to depose these films on Si/SiO{sub 2} and lime glass substrates. Thin films of V{sub 2}O{sub 5} can be reduced to metastable VO{sub 2} thin films at the temperature of 450 grad C under the pressure of 10{sup -2} Pa. These films are then converted to thermotropic VO{sub 2} at 700 grad C in argon under normal pressure. (authors)

  13. Thin film structures and phase stability

    International Nuclear Information System (INIS)

    Clemens, B.M.; Johnson, W.L.

    1990-01-01

    This was a two day symposium, with invited and contributed papers as well as an evening poster session. The first day concentrated on solid state reactions with invited talks by Lindsay Greer from the University of Cambridge, King Tu from IBM Yorktown Heights, and Carl Thompson from MIT. Professor Greer observed that the diffusion of Zr is 10 6 times slower than that of Ni in amorphous NiZr, confirming that Ni is the mobile species in solid state amorphization. King Tu explained the formation of metastable phases in this film diffusion couples by the concept of maximum rate of free energy change. Carl Thompson discussed the formation of amorphous phases in metal silicon systems, and discussed a two stage nucleation and growth process. The contributed papers also generated discussion on topics such as phase segregation, amorphous silicide formation, room temperature oxidation of silicon, and nucleation during ion beam irradiation. There was a lively poster session on Monday evening with papers on a wide variety of topics covering the general area of thin film science. The second day had sessions Epitaxy and Multilayer Structure I and II, with the morning focussing on epitaxial and heteroepitaxial growth of thin films. Robin Farrow of IBM Almaden led off with an invited talk where he reported on some remarkable success he and his co-workers have had in growing single crystal epitaxial thin films and superlattices of silver, iron, cobalt and platinum on GaAs. This was followed by several talks on epitaxial growth and characterization. The afternoon focused on interfaces and structure of multilayered materials. A session on possible stress origins of the supermodulus effect was highlighted by lively interaction from the audience. Most of the papers presented at the symposium are presented in this book

  14. Chemical bath deposition of Hg doped CdSe thin films and their characterization

    International Nuclear Information System (INIS)

    Bhuse, V.M.

    2005-01-01

    The deliberate addition of Hg in CdSe thin film have been carried out using a simple, modified, chemical bath deposition technique with the objective to study the effect of Hg doping on properties of CdSe thin films. Synthesis was initiated at 278 K temperature using complexed cadmium sulphate, mercuric nitrate and sodium selenosulphate in an aqueous ammonical medium at pH 10. Films were characterized by XRD, SEM, optical absorption, electrical and thermoelectric techniques. The 'as deposited' films were uniform, well adherent, nearly stoichiometric and polycrystalline in a single cubic phase (zinc blende). Crystallite size determined from XRD and SEM was found to increase slightly with addition of Hg. The optical band gap of CdSe remains constant upto 0.05 mol% Hg doping, while it decreases monotonically with further increase in mercury content. Dark dc electrical resistivity and conduction activation energy of CdSe were found to decrease initially upto 0.05 mol% of Hg, thereafter increased for higher values of Hg but remains less than those of CdSe. All the films showed n-type of conductivity. A CdSe film containing 0.05 mol% of Hg showed higher absorption coefficient, and conductivity

  15. Self-Limited Growth in Pentacene Thin Films.

    Science.gov (United States)

    Pachmajer, Stefan; Jones, Andrew O F; Truger, Magdalena; Röthel, Christian; Salzmann, Ingo; Werzer, Oliver; Resel, Roland

    2017-04-05

    Pentacene is one of the most studied organic semiconducting materials. While many aspects of the film formation have already been identified in very thin films, this study provides new insight into the transition from the metastable thin-film phase to bulk phase polymorphs. This study focuses on the growth behavior of pentacene within thin films as a function of film thickness ranging from 20 to 300 nm. By employing various X-ray diffraction methods, combined with supporting atomic force microscopy investigations, one crystalline orientation for the thin-film phase is observed, while three differently tilted bulk phase orientations are found. First, bulk phase crystallites grow with their 00L planes parallel to the substrate surface; second, however, crystallites tilted by 0.75° with respect to the substrate are found, which clearly dominate the former in ratio; third, a different bulk phase polymorph with crystallites tilted by 21° is found. The transition from the thin-film phase to the bulk phase is rationalized by the nucleation of the latter at crystal facets of the thin-film-phase crystallites. This leads to a self-limiting growth of the thin-film phase and explains the thickness-dependent phase behavior observed in pentacene thin films, showing that a large amount of material is present in the bulk phase much earlier during the film growth than previously thought.

  16. Theoretical investigation of the thermodynamic properties of metallic thin films

    International Nuclear Information System (INIS)

    Hung, Vu Van; Phuong, Duong Dai; Hoa, Nguyen Thi; Hieu, Ho Khac

    2015-01-01

    The thermodynamic properties of metallic thin films with face-centered cubic structure at ambient conditions were investigated using the statistical moment method including the anharmonicity effects of thermal lattice vibrations. The analytical expressions of Helmholtz free energy, lattice parameter, linear thermal expansion coefficient, specific heats at the constant volume and constant pressure were derived in terms of the power moments of the atomic displacements. Numerical calculations of thermodynamic properties have been performed for Au and Al thin films and compared with those of bulk metals. This research proposes that thermodynamic quantities of thin films approach the values of bulk when the thickness of thin film is about 70 nm. - Highlights: • Thermodynamic properties of thin films were investigated using the moment method. • Expressions of Helmholtz energy, expansion coefficient, specific heats were derived. • Calculations for Au, Al thin films were performed and compared with those of bulks

  17. Theoretical investigation of the thermodynamic properties of metallic thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Vu Van [Vietnam Education Publishing House, 81 Tran Hung Dao, Hanoi (Viet Nam); Phuong, Duong Dai [Hanoi National University of Education, 136 Xuan Thuy, Hanoi (Viet Nam); Hoa, Nguyen Thi [University of Transport and Communications, Lang Thuong, Dong Da, Hanoi (Viet Nam); Hieu, Ho Khac, E-mail: hieuhk@duytan.edu.vn [Institute of Research and Development, Duy Tan University, K7/25 Quang Trung, Danang (Viet Nam)

    2015-05-29

    The thermodynamic properties of metallic thin films with face-centered cubic structure at ambient conditions were investigated using the statistical moment method including the anharmonicity effects of thermal lattice vibrations. The analytical expressions of Helmholtz free energy, lattice parameter, linear thermal expansion coefficient, specific heats at the constant volume and constant pressure were derived in terms of the power moments of the atomic displacements. Numerical calculations of thermodynamic properties have been performed for Au and Al thin films and compared with those of bulk metals. This research proposes that thermodynamic quantities of thin films approach the values of bulk when the thickness of thin film is about 70 nm. - Highlights: • Thermodynamic properties of thin films were investigated using the moment method. • Expressions of Helmholtz energy, expansion coefficient, specific heats were derived. • Calculations for Au, Al thin films were performed and compared with those of bulks.

  18. PZT Thin Film Piezoelectric Traveling Wave Motor

    Science.gov (United States)

    Shen, Dexin; Zhang, Baoan; Yang, Genqing; Jiao, Jiwei; Lu, Jianguo; Wang, Weiyuan

    1995-01-01

    With the development of micro-electro-mechanical systems (MEMS), its various applications are attracting more and more attention. Among MEMS, micro motors, electrostatic and electromagnetic, are the typical and important ones. As an alternative approach, the piezoelectric traveling wave micro motor, based on thin film material and integrated circuit technologies, circumvents many of the drawbacks of the above mentioned two types of motors and displays distinct advantages. In this paper we report on a lead-zirconate-titanate (PZT) piezoelectric thin film traveling wave motor. The PZT film with a thickness of 150 micrometers and a diameter of 8 mm was first deposited onto a metal substrate as the stator material. Then, eight sections were patterned to form the stator electrodes. The rotor had an 8 kHz frequency power supply. The rotation speed of the motor is 100 rpm. The relationship of the friction between the stator and the rotor and the structure of the rotor on rotation were also studied.

  19. Solution processed pentacene thin films and their structural properties

    International Nuclear Information System (INIS)

    Tao Chunlan; Zhang Xuhui; Zhang Fujia; Liu Yiyang; Zhang Haoli

    2007-01-01

    The paper reported the solution process of pentacene thin films from organic solvent O-dichlorobenzene. The pentacene thin films obtained from different conditions were characterized by X-ray diffraction (XRD), optical microscopy, scanning electron microscopy (SEM), and UV-vis spectroscopy. The result shows that the pentacene solution was successfully obtained at a minimum temperature of 40 deg. C. The optimum temperature of forming pentacene thin films was 100 deg. C

  20. Polarized Neutron Reflectivity Simulation of Ferromagnet/ Antiferromagnet Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Yeon; Lee, Jeong Soo

    2008-02-15

    This report investigates the current simulating and fitting programs capable of calculating the polarized neutron reflectivity of the exchange-biased ferromagnet/antiferromagnet magnetic thin films. The adequate programs are selected depending on whether nonspin flip and spin flip reflectivities of magnetic thin films and good user interface are available or not. The exchange-biased systems such as Fe/Cr, Co/CoO, CoFe/IrMn/Py thin films have been simulated successfully with selected programs.

  1. Thermoelectric devices and applications for the same

    Science.gov (United States)

    Olsen, Larry C.; DeSteese, John G.; Martin, Peter M.; Johnston, John W.; Peters, Timothy J.

    2016-03-08

    High performance thin film thermoelectric couples and methods of making the same are disclosed. Such couples allow fabrication of at least microwatt to watt-level power supply devices operating at voltages greater than one volt even when activated by only small temperature differences.

  2. Tin oxide transparent thin-film transistors

    International Nuclear Information System (INIS)

    Presley, R E; Munsee, C L; Park, C-H; Hong, D; Wager, J F; Keszler, D A

    2004-01-01

    A SnO 2 transparent thin-film transistor (TTFT) is demonstrated. The SnO 2 channel layer is deposited by RF magnetron sputtering and then rapid thermal annealed in O 2 at 600 deg. C. The TTFT is highly transparent, and enhancement-mode behaviour is achieved by employing a very thin channel layer (10-20 nm). Maximum field-effect mobilities of 0.8 cm 2 V -1 s -1 and 2.0 cm 2 V -1 s -1 are obtained for enhancement- and depletion-mode devices, respectively. The transparent nature and the large drain current on-to-off ratio of 10 5 associated with the enhancement-mode behaviour of these devices may prove useful for novel gas-sensor applications

  3. Fabrications of Polyaniline Films by Pulse Electrodeposition in Acidic Solutions with Different Anions and Their Thermoelectric Performances

    Science.gov (United States)

    Yang, Weifang; Xu, Han; Li, Yuanyuan; Wang, Wei

    2017-08-01

    Polymerization of aniline was prepared by the pulse potentiostatic method in H3PO4, HClO4 and H2SO4 acidic solutions. The morphologies and thermoelectric performances were analyzed by scanning electron microscopy, Seebeck coefficient ( S) and resistivity ( R) measurements. The results show that flake polyaniline (PANI) films can be obtained in H3PO4 and HClO4 acidic solutions, and porous PANI films with nanofiber-overlapped structures can be prepared in H2SO4 solution under the same pulse parameters. PANI films prepared in the three solutions are all p-type thermoelectric materials. PANI films polymerized in H2SO4 solution possess the highest S (30.2 μV K-1) and lowest R (1.6 × 10-3 Ω m) compared with those prepared in H3PO4 and HClO4 solutions, indicating that nanofiber-overlapped structures formed in H2SO4 solution contribute better thermoelectric performance. In addition, the effects of pulse parameters (anodic potential φ a, anodic pulse duration t a and cathodic pulse duration t c) on the surface morphologies and thermoelectric performances of PANI films were systematically investigated.

  4. Deposition and characterisation of epitaxial oxide thin films for SOFCs

    KAUST Repository

    Santiso, José ; Burriel, Mó nica

    2010-01-01

    This paper reviews the recent advances in the use of thin films, mostly epitaxial, for fundamental studies of materials for solid oxide fuel cell (SOFC) applications. These studies include the influence of film microstructure, crystal orientation

  5. Switching, storage, and erasure effects in a superconducting thin film

    International Nuclear Information System (INIS)

    Testardi, L.R.

    1976-01-01

    Thin niobium films can be switched from a superconducting to a resistive state permanently by application of a short electrical pulse. Application of a short pulse of opposite polarity returns the film to the superconducting state

  6. CO2 gas sensitivity of sputtered zinc oxide thin films

    Indian Academy of Sciences (India)

    TECS

    Gas sensitivity; ZnO; sputtering; XRD patterns; structure; thin films. 1. Introduction. Because zinc ... voltage and absorption properties of those fabricated films have been ... tations are useful in many physical applications. The in- plane (Hegde ...

  7. Physics of thin films advances in research and development

    CERN Document Server

    Hass, Georg; Vossen, John L

    2013-01-01

    Physics of Thin Films: Advances in Research and Development, Volume 12 reviews advances that have been made in research and development concerning the physics of thin films. This volume covers a wide range of preparative approaches, physics phenomena, and applications related to thin films. This book is comprised of four chapters and begins with a discussion on metal coatings and protective layers for front surface mirrors used at various angles of incidence from the ultraviolet to the far infrared. Thin-film materials and deposition conditions suitable for minimizing reflectance changes with

  8. Sputtering materials for VLSI and thin film devices

    CERN Document Server

    Sarkar, Jaydeep

    2010-01-01

    An important resource for students, engineers and researchers working in the area of thin film deposition using physical vapor deposition (e.g. sputtering) for semiconductor, liquid crystal displays, high density recording media and photovoltaic device (e.g. thin film solar cell) manufacturing. This book also reviews microelectronics industry topics such as history of inventions and technology trends, recent developments in sputtering technologies, manufacturing steps that require sputtering of thin films, the properties of thin films and the role of sputtering target performance on overall p

  9. Thin-Film Materials Synthesis and Processing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides a wide capability for deposition and processing of thin films, including sputter and ion-beam deposition, thermal evaporation, electro-deposition,...

  10. Characterizations of photoconductivity of graphene oxide thin films

    Directory of Open Access Journals (Sweden)

    Shiang-Kuo Chang-Jian

    2012-06-01

    Full Text Available Characterizations of photoresponse of a graphene oxide (GO thin film to a near infrared laser light were studied. Results showed the photocurrent in the GO thin film was cathodic, always flowing in an opposite direction to the initial current generated by the preset bias voltage that shows a fundamental discrepancy from the photocurrent in the reduced graphene oxide thin film. Light illumination on the GO thin film thus results in more free electrons that offset the initial current. By examining GO thin films reduced at different temperatures, the critical temperature for reversing the photocurrent from cathodic to anodic was found around 187°C. The dynamic photoresponse for the GO thin film was further characterized through the response time constants within the laser on and off durations, denoted as τon and τoff, respectively. τon for the GO thin film was comparable to the other carbon-based thin films such as carbon nanotubes and graphenes. τoff was, however, much larger than that of the other's. This discrepancy was attributable to the retardation of exciton recombination rate thanks to the existing oxygen functional groups and defects in the GO thin films.

  11. Atomic Structure Control of Silica Thin Films on Pt(111)

    KAUST Repository

    Crampton, Andrew S

    2015-05-27

    Metal oxide thin films grown on metal single crystals are commonly used to model heterogeneous catalyst supports. The structure and properties of thin silicon dioxide films grown on metal single crystals have only recently been thoroughly characterized and their spectral properties well established. We report the successful growth of a three- dimensional, vitreous silicon dioxide thin film on the Pt(111) surface and reproduce the closed bilayer structure previously reported. The confirmation of the three dimensional nature of the film is unequivocally shown by the infrared absorption band at 1252 cm−1. Temperature programmed desorption was used to show that this three-dimensional thin film covers the Pt(111) surface to such an extent that its application as a catalyst support for clusters/nanoparticles is possible. The growth of a three-dimensional film was seen to be directly correlated with the amount of oxygen present on the surface after the silicon evaporation process. This excess of oxygen is tentatively attributed to atomic oxygen being generated in the evaporator. The identification of atomic oxygen as a necessary building block for the formation of a three-dimensional thin film opens up new possibilities for thin film growth on metal supports, whereby simply changing the type of oxygen enables thin films with different atomic structures to be synthesized. This is a novel approach to tune the synthesis parameters of thin films to grow a specific structure and expands the options for modeling common amorphous silica supports under ultra high vacuum conditions.

  12. Tension Tests of Copper Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kyung Jo; Kim, Chung Youb [Chonnam Nat’l Univ., Gwangju (Korea, Republic of)

    2017-08-15

    Tension tests for copper thin films with thickness of 12 μm were performed by using a digital image correlation method based on consecutive digital images. When calculating deformation using digital image correlation, a large deformation causes errors in the calculated result. In this study, the calculation procedure was improved to reduce the error, so that the full field deformation and the strain of the specimen could be accurately and directly measured on its surface. From the calculated result, it can be seen that the strain distribution is not uniform and its variation is severe, unlike the distribution in a common bulk specimen. This might result from the surface roughness introduced in the films during the fabrication process by electro-deposition.

  13. TEM characterization of nanodiamond thin films.

    Energy Technology Data Exchange (ETDEWEB)

    Qin, L.-C.; Zhou, D.; Krauss, A. R.; Gruen, D. M.; Chemistry

    1998-05-01

    The microstructure of thin films grown by microwave plasma-enhanced chemical vapor deposition (MPCVD) from fullerene C{sub 60} precursors has been characterized by scanning electron microscopy (SEM), selected-area electron diffraction (SAED), bright-field electron microscopy, high-resolution electron microscopy (HREM), and parallel electron energy loss spectroscopy (PEELS). The films are composed of nanosize crystallites of diamond, and no graphitic or amorphous phases were observed. The diamond crystallite size measured from lattice images shows that most grains range between 3-5 nm, reflecting a gamma distribution. SAED gave no evidence of either sp2-bonded glassy carbon or sp3-bonded diamondlike amorphous carbon. The sp2-bonded configuration found in PEELS was attributed to grain boundary carbon atoms, which constitute 5-10% of the total. Occasionally observed larger diamond grains tend to be highly faulted.

  14. Studies of tantalum nitride thin film resistors

    International Nuclear Information System (INIS)

    Langley, R.A.

    1975-01-01

    Backscattering of 2-MeV He ions was used to correlate the electrical properties of sputtered TaN/sub x/ thin-film resistors with their N content. The properties measured were sheet resistance, differential Seebeck potential (DSP), thermal coefficient of resistance (TCR), and stability. Resistivity and DSP are linearly dependent on N content for N/Ta ratios of 0.25 to 0.55. TCR decreases sharply below N/Ta = 0.35 and is relatively constant from 0.35 to 0.55. Stability is independent of N content. (DLC)

  15. Methods for producing thin film charge selective transport layers

    Science.gov (United States)

    Hammond, Scott Ryan; Olson, Dana C.; van Hest, Marinus Franciscus Antonius Maria

    2018-01-02

    Methods for producing thin film charge selective transport layers are provided. In one embodiment, a method for forming a thin film charge selective transport layer comprises: providing a precursor solution comprising a metal containing reactive precursor material dissolved into a complexing solvent; depositing the precursor solution onto a surface of a substrate to form a film; and forming a charge selective transport layer on the substrate by annealing the film.

  16. Chemical vapour deposition of thin-film dielectrics

    International Nuclear Information System (INIS)

    Vasilev, Vladislav Yu; Repinsky, Sergei M

    2005-01-01

    Data on the chemical vapour deposition of thin-film dielectrics based on silicon nitride, silicon oxynitride and silicon dioxide and on phosphorus- and boron-containing silicate glasses are generalised. The equipment and layer deposition procedures are described. Attention is focussed on the analysis and discussion of the deposition kinetics and on the kinetic models for film growth. The film growth processes are characterised and data on the key physicochemical properties of thin-film covalent dielectric materials are given.

  17. Characterization of ultrasonic spray pyrolysed ruthenium oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-11-21

    The ultrasonic spray pyrolysis (USP) technique was employed to deposit ruthenium oxide thin films. The films were prepared at 190 C substrate temperature and further annealed at 350 C for 30 min in air. The films were 0.22 {mu} thick and black grey in color. The structural, compositional and optical properties of ruthenium oxide thin films are reported. Contactless transient photoconductivity measurement was carried out to calculate the decay time of excess charge carriers in ruthenium oxide thin films. (orig.) 28 refs.

  18. Nitrogen incorporation in sputter deposited molybdenum nitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Stöber, Laura, E-mail: laura.stoeber@tuwien.ac.at; Patocka, Florian, E-mail: florian.patocka@tuwien.ac.at; Schneider, Michael, E-mail: michael.schneider@tuwien.ac.at; Schmid, Ulrich, E-mail: ulrich.e366.schmid@tuwien.ac.at [Institute of Sensor and Actuator Systems, TU Wien, Gußhausstraße 27-29, A-1040 Vienna (Austria); Konrath, Jens Peter, E-mail: jenspeter.konrath@infineon.com; Haberl, Verena, E-mail: verena.haberl@infineon.com [Infineon Technologies Austria AG, Siemensstraße 2, 9500 Villach (Austria)

    2016-03-15

    In this paper, the authors report on the high temperature performance of sputter deposited molybdenum (Mo) and molybdenum nitride (Mo{sub 2}N) thin films. Various argon and nitrogen gas compositions are applied for thin film synthetization, and the amount of nitrogen incorporation is determined by Auger measurements. Furthermore, effusion measurements identifying the binding conditions of the nitrogen in the thin film are performed up to 1000 °C. These results are in excellent agreement with film stress and scanning electron microscope analyses, both indicating stable film properties up to annealing temperatures of 500 °C.

  19. Dimensional scaling of perovskite ferroelectric thin films

    Science.gov (United States)

    Keech, Ryan R.

    Dimensional size reduction has been the cornerstone of the exponential improvement in silicon based logic devices for decades. However, fundamental limits in the device physics were reached ˜2003, halting further reductions in clock speed without significant penalties in power consumption. This has motivated the research into next generation transistors and switching devices to reinstate the scaling laws for clock speed. This dissertation aims to support the scaling of devices that are based on ferroelectricity and piezoelectricity and to provide a roadmap for the corresponding materials performance. First, a scalable growth process to obtain highly {001}-oriented lead magnesium niobate - lead titanate (PMN-PT) thin films was developed, motivated by the high piezoelectric responses observed in bulk single crystals. It was found that deposition of a 2-3 nm thick PbO buffer layer on {111} Pt thin film bottom electrodes, prior to chemical solution deposition of PMN-PT reduces the driving force for Pb diffusion from the PMN-PT to the bottom electrode, and facilitates nucleation of {001}-oriented perovskite grains. Energy dispersive spectroscopy demonstrated that up to 10% of the Pb from a PMN-PT precursor solution may diffuse into the bottom electrode. PMN-PT grains with a mixed {101}/{111} orientation in a matrix of Pb-deficient pyrochlore phase were then promoted near the interface. When this is prevented, phase pure films with {001} orientation with Lotgering factors of 0.98-1.0, can be achieved. The resulting films of only 300 nm in thickness exhibit longitudinal effective d33,f coefficients of ˜90 pm/V and strain values of ˜1% prior to breakdown. 300 nm thick epitaxial and polycrystalline lead magnesium niobate - lead titanate (70PMN-30PT) blanket thin films were studied for the relative contributions to property thickness dependence from interfacial and grain boundary low permittivity layers. Epitaxial PMN-PT films were grown on SrRuO 3 /(001)SrTiO3, while

  20. Thermoelectric properties of P-type Sb2Te3 thick film processed by a screen-printing technique and a subsequent annealing process

    International Nuclear Information System (INIS)

    Kim, Sun Jin; We, Ju Hyung; Kim, Jin Sang; Kim, Gyung Soo; Cho, Byung Jin

    2014-01-01

    Highlights: • We report on thermoelectric properties of screen-printed Sb 2 Te 3 thick film. • Subsequent annealing process determines thermoelectric properties of Sb 2 Te 3 film. • Annealing in tellurium powder ambient contributes to tellurium-rich Sb 2 Te 3 film. • Annealing in tellurium powder ambient enhances carrier mobility of Sb 2 Te 3 film. -- Abstract: We herein report the thermoelectric properties of Sb 2 Te 3 thick film fabricated by a screen-printing technique and a subsequent annealing process. Each step of the screen-printing fabrication process of Sb 2 Te 3 thick film is described in detail. It was found that the subsequent annealing process must be carefully designed to achieve good thermoelectric properties of the screen-printed film. The results show that the annealing of the screen-printed Sb 2 Te 3 thick film together with tellurium powder in the same process chamber significantly improves the carrier mobility by increasing the average scattering time of the carrier in the film, resulting in a large improvement of the power factor. By optimizing the annealing process, we achieved a maximum thermoelectric figure-of-merit, ZT, of 0.32 at room temperature, which is slightly higher than that of bulk Sb 2 Te 3 . Because screen-printing is a simple and low-cost process and given that it is easy to scale up to large sizes, this result will be useful for the realization of large, film-type thermoelectric devices

  1. Scanning thermal microscopy of Bi2Te3 and Yb0.19Co4Sb12 thermoelectric films

    Czech Academy of Sciences Publication Activity Database

    Zeipl, R.; Jelínek, M.; Vaniš, Jan; Remsa, J.; Kocourek, T.; Navrátil, J.

    2016-01-01

    Roč. 122, č. 4 (2016), č. článku 478. ISSN 0947-8396 Institutional support: RVO:67985882 Keywords : thermoelectric properties * thin nanolayers * pulsed laser deposition * scanning thermal microscope Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.455, year: 2016

  2. Perfect absorption in nanotextured thin films via Anderson-localized photon modes

    Science.gov (United States)

    Aeschlimann, Martin; Brixner, Tobias; Differt, Dominik; Heinzmann, Ulrich; Hensen, Matthias; Kramer, Christian; Lükermann, Florian; Melchior, Pascal; Pfeiffer, Walter; Piecuch, Martin; Schneider, Christian; Stiebig, Helmut; Strüber, Christian; Thielen, Philip

    2015-10-01

    The enhancement of light absorption in absorber layers is crucial in a number of applications, including photovoltaics and thermoelectrics. The efficient use of natural resources and physical constraints such as limited charge extraction in photovoltaic devices require thin but efficient absorbers. Among the many different strategies used, light diffraction and light localization at randomly nanotextured interfaces have been proposed to improve absorption. Although already exploited in commercial devices, the enhancement mechanism for devices with nanotextured interfaces is still subject to debate. Using coherent two-dimensional nanoscopy and coherent light scattering, we demonstrate the existence of localized photonic states in nanotextured amorphous silicon layers as used in commercial thin-film solar cells. Resonant absorption in these states accounts for the enhanced absorption in the long-wavelength cutoff region. Our observations establish that Anderson localization—that is, strong localization—is a highly efficient resonant absorption enhancement mechanism offering interesting opportunities for the design of efficient future absorber layers.

  3. Recent progress of obliquely deposited thin films for industrial applications

    Science.gov (United States)

    Suzuki, Motofumi; Itoh, Tadayoshi; Taga, Yasunori

    1999-06-01

    More than 10 years ago, birefringent films of metal oxides were formed by oblique vapor deposition and investigated with a view of their application to optical retardation plates. The retardation function of the films was explained in terms of the birefringence caused by the characteristic anisotropic nanostructure inside the films. These films are now classified in the genre of the so-called sculptured thin films. However, the birefringent films thus prepared are not yet industrialized even now due to the crucial lack of the durability and the yield of products. In this review paper, we describe the present status of application process of the retardation films to the information systems such as compact disc and digital versatile disc devices with a special emphasis on the uniformity of retardation properties in a large area and the stability of the optical properties of the obliquely deposited thin films. Finally, further challenges for wide application of the obliquely deposited thin films are also discussed.

  4. Effects of MeV Si ions bombardment on the thermoelectric generator from SiO{sub 2}/SiO{sub 2} + Cu and SiO{sub 2}/SiO{sub 2} + Au nanolayered multilayer films

    Energy Technology Data Exchange (ETDEWEB)

    Budak, S., E-mail: satilmis.budak@aamu.edu [Department of Electrical Engineering, Alabama A and M University, Normal, AL (United States); Chacha, J., E-mail: chacha_john79@hotmail.com [Department of Electrical Engineering, Alabama A and M University, Normal, AL (United States); Smith, C., E-mail: cydale@cim.aamu.edu [Center for Irradiation of Materials, Alabama A and M University, Normal, AL (United States); Department of Physics, Alabama A and M University, Normal, AL (United States); Pugh, M., E-mail: marcuspughp@yahoo.com [Department of Electrical Engineering, Alabama A and M University, Normal, AL (United States); Colon, T. [Department of Mechanical Engineering, Alabama A and M University, Normal, AL (United States); Heidary, K., E-mail: kaveh.heidary@aamu.edu [Department of Electrical Engineering, Alabama A and M University, Normal, AL (United States); Johnson, R.B., E-mail: barry@w4wb.com [Department of Physics, Alabama A and M University, Normal, AL (United States); Ila, D., E-mail: ila@cim.aamu.edu [Center for Irradiation of Materials, Alabama A and M University, Normal, AL (United States); Department of Physics, Alabama A and M University, Normal, AL (United States)

    2011-12-15

    The defects and disorder in the thin films caused by MeV ions bombardment and the grain boundaries of these nanoscale clusters increase phonon scattering and increase the chance of an inelastic interaction and phonon annihilation. We prepared the thermoelectric generator devices from 100 alternating layers of SiO{sub 2}/SiO{sub 2} + Cu multi-nano layered superlattice films at the total thickness of 382 nm and 50 alternating layers of SiO{sub 2}/SiO{sub 2} + Au multi-nano layered superlattice films at the total thickness of 147 nm using the physical vapor deposition (PVD). Rutherford Backscattering Spectrometry (RBS) and RUMP simulation have been used to determine the stoichiometry of the elements of SiO{sub 2}, Cu and Au in the multilayer films and the thickness of the grown multi-layer films. The 5 MeV Si ions bombardments have been performed using the AAMU-Center for Irradiation of Materials (CIM) Pelletron ion beam accelerator to make quantum (nano) dots and/or quantum (quantum) clusters in the multilayered superlattice thin films to decrease the cross plane thermal conductivity, increase the cross plane Seebeck coefficient and cross plane electrical conductivity. To characterize the thermoelectric generator devices before and after Si ion bombardments we have measured Seebeck coefficient, cross-plane electrical conductivity, and thermal conductivity in the cross-plane geometry for different fluences.

  5. Operating method of amorphous thin film semiconductor element

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Koshiro; Ono, Masaharu; Hanabusa, Akira; Osawa, Michio; Arita, Takashi

    1988-05-31

    The existing technologies concerning amorphous thin film semiconductor elements are the technologies concerning the formation of either a thin film transistor or an amorphous Si solar cell on a substrate. In order to drive a thin film transistor for electronic equipment control by the output power of an amorphous Si solar cell, it has been obliged to drive the transistor weth an amorphous solar cell which was formed on a substrate different from that for the transistor. Accordingly, the space for the amorphous solar cell, which was formed on the different substrate, was additionally needed on the substrate for the thin film transistor. In order to solve the above problem, this invention proposes an operating method of an amorphous thin film semiconductor element that after forming an amorphous Si solar cell through lamination on the insulation coating film which covers the thin film transistor formed on the substrate, the thin film transistor is driven by the output power of this solar cell. The invention eliminates the above superfluous space and reduces the size of the amorphous thin film semiconductor element including the electric source. (3 figs)

  6. Stable organic thin-film transistors

    Science.gov (United States)

    Jia, Xiaojia; Fuentes-Hernandez, Canek; Wang, Cheng-Yin; Park, Youngrak; Kippelen, Bernard

    2018-01-01

    Organic thin-film transistors (OTFTs) can be fabricated at moderate temperatures and through cost-effective solution-based processes on a wide range of low-cost flexible and deformable substrates. Although the charge mobility of state-of-the-art OTFTs is superior to that of amorphous silicon and approaches that of amorphous oxide thin-film transistors (TFTs), their operational stability generally remains inferior and a point of concern for their commercial deployment. We report on an exhaustive characterization of OTFTs with an ultrathin bilayer gate dielectric comprising the amorphous fluoropolymer CYTOP and an Al2O3:HfO2 nanolaminate. Threshold voltage shifts measured at room temperature over time periods up to 5.9 × 105 s do not vary monotonically and remain below 0.2 V in microcrystalline OTFTs (μc-OTFTs) with field-effect carrier mobility values up to 1.6 cm2 V−1 s−1. Modeling of these shifts as a function of time with a double stretched-exponential (DSE) function suggests that two compensating aging mechanisms are at play and responsible for this high stability. The measured threshold voltage shifts at temperatures up to 75°C represent at least a one-order-of-magnitude improvement in the operational stability over previous reports, bringing OTFT technologies to a performance level comparable to that reported in the scientific literature for other commercial TFTs technologies. PMID:29340301

  7. Properties of superconducting thin-film microbridges

    International Nuclear Information System (INIS)

    Pei, S.S.

    1978-01-01

    This work reports investigations upon the dependences of critical current and current phase relation on the dimensions of a superconducting thin-film microbridge. A model has been developed upon the Volkov's hyperbolic bridges and the Zaitsev's boundary conditions to calculate the spatial variation of the order parameter for given bridge dimensions. The results indicate that the rigid boundary conditions are good approximations to narrow bridges (W much less than L) only. The critical current density of the bridge has been calculated also as a function of the bridge dimensions. It is found that the critical current density of small bridges is enhanced above its mean field critical value due to the proximity effects of the banks. Very good agreement is found between the calculated enhancement of the critical current density and the experimental results. Direct measurements have been made on the current phase relation of indium bridges with width smaller than 0.6 μm. The difficulties due to the extra phase shifts from the series thin film electrodes are overcome by a specially designed double loop configuration which has an extra low effective inductance. It is found that the current phase relation of small bridges (W,L, xi, the results agree with the predictions of rigid boundary calculations as expected by our model

  8. Optical characteristics of the thin-film scintillator detector

    International Nuclear Information System (INIS)

    Muga, L.; Burnsed, D.

    1976-01-01

    A study of the thin-film detector (TFD) was made in which various light guide and scintillator film support configurations were tested for efficiency of light coupling. Masking of selected portions of the photomultiplier (PM) tube face revealed the extent to which emitted light was received at the exposed PM surfaces. By blocking off selected areas of the scintillator film surface from direct view of the PM tube faces, a measure of the light-guiding efficiency of the film and its support could be estimated. The picture that emerges is that, as the light which is initially trapped in the thin film spreads radially outward from the ion entrance/exit point, it is scattered out of the film by minute imperfections. Optimum signals were obtained by a configuration in which the thin scintillator film was supported on a thin rectangular Celluloid frame inserted within a highly polished metal cylindrical sleeve

  9. Polycystalline silicon thin films for electronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, Christian Claus

    2012-01-15

    For the thin polycrystalline Si films fabricated with the aluminium-induced-layer-exchange (ALILE) process a good structural quality up to a layer-thickness value of 10 nm was determined. For 5 nm thick layers however after the layer exchange no closes poly-silicon film was present. In this case the substrate was covered with spherically arranged semiconductor material. Furthermore amorphous contributions in the layer could be determined. The electrical characterization of the samples at room temperature proved a high hole concentration in the range 10{sup 18} cm{sup -3} up to 9.10{sup 19} cm{sup -3}, which is influenced by the process temperature and the layer thickness. Hereby higher hole concentrations at higher process temperatures and thinner films were observed. Furthermore above 150-200 K a thermically activated behaviour of the electrical conductivity was observed. At lower temperatures a deviation of the measured characteristic from the exponential Arrhenius behaviour was determined. For low temperatures (below 20 K) the conductivity follows the behaviour {sigma}{proportional_to}[-(T{sub 0}/T){sup 1/4}]. The hole mobility in the layers was lowered by a passivation step, which can be explained by defect states at the grain boundaries. The for these very thin layers present situation was simulated in the framework of the model of Seto, whereby both the defect states at the grain boundaries (with an area density Q{sub t}) and the defect states at the interfaces (with an area density Q{sub it}) were regarded. By this the values Q{sub t}{approx}(3-4).10{sup 12} cm{sup -2} and Q{sub it}{approx}(2-5).10{sup 12} cm{sup -2} could be determined for these thin ALILE layers on quartz substrates. Additionally th R-ALILE process was studied, which uses the reverse precursor-layer sequence substrate/amorphous silicon/oxide/aluminium. Hereby two steps in the crystallization process of the R-ALILE process were found. First a substrate/Al-Si mixture/poly-Si layer structure

  10. Optical constants and structural properties of thin gold films

    DEFF Research Database (Denmark)

    Yakubovsky, Dmitry I.; Arsenin, Aleksey V.; Stebunov, Yury V.

    2017-01-01

    We report a comprehensive experimental study of optical and electrical properties of thin polycrystalline gold films in a wide range of film thicknesses (from 20 to 200 nm). Our experimental results are supported by theoretical calculations based on the measured morphology of the fabricated gold...... rules for thin-film plasmonic and nanophotonic devices....... films. We demonstrate that the dielectric function of the metal is determined by its structural morphology. Although the fabrication process can be absolutely the same for different films, the dielectric function can strongly depend on the film thickness. Our studies show that the imaginary part...

  11. Enhanced thermoelectric properties of PEDOT/PSS/Te composite films treated with H2SO4

    International Nuclear Information System (INIS)

    Song, Haijun; Cai, Kefeng; Shen, Shirley

    2016-01-01

    Firstly, tellurium (Te) nanorods with a high Seebeck coefficient have been integrated into a conducting polymer PEDOT/PSS to form PEDOT/PSS/Te composite films. The Seebeck coefficient of the PEDOT/PSS/Te (90 wt.%) composite films is ~191 μV/K, which is about 13 times greater than that of pristine PEDOT/PSS. Then, H 2 SO 4 treatment has been used to further tune the thermoelectric properties of the composite films by adjusting the doping level and increasing the carrier concentration. After the acid treatment, the electrical conductivity of the composite films has increased from 0.22 to 1613 S/cm due to the removal of insulating PSS and the structural rearrangement of PEDOT. An optimized power factor of 42.1 μW/mK 2 has been obtained at room temperature for a PEDOT/PSS/Te (80 wt.%) sample, which is about ten times larger than that of the untreated PEDOT/PSS/Te composite film.

  12. Electrodeposition and Thermoelectric Properties of Cu-Se Binary Compound Films

    Science.gov (United States)

    Yang, Mengqian; Shen, Zhengwu; Liu, Xiaoqing; Wang, Wei

    2016-03-01

    Cu-Se binary compound films have been prepared by electrodeposition from solutions containing CuSO4, H2SeO3, and H2SO4 and their composition, structure, and thermoelectric performance analyzed. Moving the depositing potential negatively increased the Cu content in the film, remarkably so for relatively low Cu2+ concentration in the solution. X-ray diffraction analysis showed that the phase composition of the films varied with their Cu content. Cu-Se binary compound films electrodeposited from solutions with different concentration ratios of CuSO4 to H2SeO3 showed two different phases: α-Cu2- x Se (monoclinic) with Se content in the range of 33.3 at.% to 33.8 at.%, and β-Cu2Se (cubic) with Se content in the range of 35.3 at.% to 36.0 at.%. The highest power factor for electrodeposited Cu2- x Se film was 0.13 mW/(K2 m) with Seebeck coefficient of 56.0 μV/K.

  13. Thinning and rupture of a thin liquid film on a heated surface

    Energy Technology Data Exchange (ETDEWEB)

    Bankoff, S.G.; Davis, S.H.

    1992-08-05

    Results on the dynamics and stability of thin films are summarized on the following topics: forced dryout, film instabilities on a horizontal plane and on inclined planes, instrumentation, coating flows, and droplet spreading. (DLC)

  14. Microbridge tests on gallium nitride thin films

    International Nuclear Information System (INIS)

    Huang, Hai-You; Li, Zhi-Ying; Lu, Jun-Yong; Wang, Zhi-Jia; Zhang, Tong-Yi; Wang, Chong-Shun; Lau, Kei-May; Chen, Kevin Jing

    2009-01-01

    In this work, we develop further the microbridge testing method by deriving a closed formula of deflection versus load, which is applied at an arbitrary position on the microbridge beam. Testing a single beam at various positions allows us to characterize simultaneouslyYoung's modulus and residual stress of the beam. The developed method was then used to characterize the mechanical properties of GaN thin films on patterned-Si (1 1 1) substrates grown by metal organic chemical vapor deposition (MOCVD). The microbridge samples were fabricated by using the microelectromechanical fabrication technique and tested with a nanoindentation system. Young's modulus and residual stress of the GaN films were determined to be 287 ± 190 GPa and 851 ± 155 MPa, respectively. In addition, alternative measurements of the residual stress, Young's modulus and hardness of the GaN films, were conducted with micro-Raman spectroscopy and the nanoindentation test, yielding the corresponding values of 847 ± 46 MPa, 269.0 ± 7.0 GPa and 17.8 ± 1.1 GPa

  15. Surface microtopography of thin silver films

    Science.gov (United States)

    Costa, Manuel F. M.; Almeida, Jose B.

    1991-01-01

    The authors present ne applications for the recently developed nori-contact optical inicrotopographer emphasizing the results of topographic inspections of thin silver films edges. These films were produced by sputtering of silver through different masks, using a planar magnetron source. The results show the influence ot the thickness and position of the masks on the topography of the film near its edge. Topographic information is obtained from the horizontal shift incurred by the bright spot on an horizontal surface, which is displaced vertically, when this is illuminated by an oblique collimated laser beam. The laser beam is focused onto the surface into a diffraction limited spot and is made to sweep the surface to be examined.. The horizontal position of the bright spot is continuously imaged onto a light detector array and the information about individual detectors that are activated is used to compute the corresponding horizontal shift on the reference plane. Simple trignometric calculations are used to relate the horizontal shift to the distance between the surface and a reference plane at each sampling point and thus a map of the surface topography can be built.

  16. Controlled nanostructuration of polycrystalline tungsten thin films

    Energy Technology Data Exchange (ETDEWEB)

    Girault, B. [Institut P' (UPR 3346 CNRS), Universite de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France); Institut de Recherche en Genie Civil et Mecanique (UMR CNRS 6183), LUNAM Universite, Universite de Nantes, Centrale Nantes, CRTT, 37 Bd de l' Universite, BP 406, 44602 Saint-Nazaire Cedex (France); Eyidi, D.; Goudeau, P.; Guerin, P.; Bourhis, E. Le; Renault, P.-O. [Institut P' (UPR 3346 CNRS), Universite de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France); Sauvage, T. [CEMHTI/CNRS (UPR 3079 CNRS), Universite d' Orleans, 3A rue de la Ferollerie, 45071 Orleans Cedex 2 (France)

    2013-05-07

    Nanostructured tungsten thin films have been obtained by ion beam sputtering technique stopping periodically the growing. The total thickness was maintained constant while nanostructure control was obtained using different stopping periods in order to induce film stratification. The effect of tungsten sublayers' thicknesses on film composition, residual stresses, and crystalline texture evolution has been established. Our study reveals that tungsten crystallizes in both stable {alpha}- and metastable {beta}-phases and that volume proportions evolve with deposited sublayers' thicknesses. {alpha}-W phase shows original fiber texture development with two major preferential crystallographic orientations, namely, {alpha}-W<110> and unexpectedly {alpha}-W<111> texture components. The partial pressure of oxygen and presence of carbon have been identified as critical parameters for the growth of metastable {beta}-W phase. Moreover, the texture development of {alpha}-W phase with two texture components is shown to be the result of a competition between crystallographic planes energy minimization and crystallographic orientation channeling effect maximization. Controlled grain size can be achieved for the {alpha}-W phase structure over 3 nm stratification step. Below, the {beta}-W phase structure becomes predominant.

  17. Surfactant induced flows in thin liquid films : an experimental study

    NARCIS (Netherlands)

    Sinz, D.K.N.

    2012-01-01

    The topic of the experimental work summarized in my thesis is the flow in thin liquid films induced by non-uniformly distributed surfactants. The flow dynamics as a consequence of the deposition of a droplet of an insoluble surfactant onto a thin liquid film covering a solid substrate where

  18. Optimized grid design for thin film solar panels

    NARCIS (Netherlands)

    Deelen, J. van; Klerk, L.; Barink, M.

    2014-01-01

    There is a gap in efficiency between record thin film cells and mass produced thin film solar panels. In this paper we quantify the effect of monolithic integration on power output for various configurations by modeling and present metallization as a way to improve efficiency of solar panels. Grid

  19. Dynamics of a spreading thin film with gravitational counterflow ...

    Indian Academy of Sciences (India)

    film climbing up on a vertical substrate against gravity shows interesting dynamics ... For the spreading of a thin film several theoretical studies have shown quantitative agree- ..... The two critical values of this param- ... Davis J M, Fischer B J and Troian S M 2003 A general approach to the linear stability of thin spreading.

  20. Plastic response of thin films due to thermal cycling

    NARCIS (Netherlands)

    Nicola, L.; van der Giessen, E.; Needleman, A.; Ahzi, S; Cherkaoui, M; Khaleel, MA; Zbib, HM; Zikry, MA; Lamatina, B

    2004-01-01

    Discrete dislocation simulations of thin films on semi-infinite substrates under cyclic thermal loading are presented. The thin film is modelled as a two-dimensional single crystal under plane strain conditions. Dislocations of edge character can be generated from initially present sources and glide

  1. Cadmium sulphide thin film for application in gamma radiation ...

    African Journals Online (AJOL)

    Cadmium Sulphide (CdS) thin film was prepared using pyrolytic spraying technique and then irradiated at varied gamma dosage. The CdS thin film absorption before gamma irradiation was 0.6497. Absorbed doses were computed using standard equation established for an integrating dosimeter. The plot of absorbed dose ...

  2. Electrical properties of epitaxially grown VOx thin films

    NARCIS (Netherlands)

    Rata, A.D.; Chezan, A.R; Presura, C.N.; Hibma, T

    2003-01-01

    High quality VOx thin films on MgO(100) substrates were prepared and studied from the structural and electronic point of view. Epitaxial growth was confirmed by RHEED and XRD techniques. The oxygen content of VOx thin films as a function of oxygen flux was determined using RBS. The upper and lower

  3. Determination of oxygen diffusion kinetics during thin film ruthenium oxidation

    NARCIS (Netherlands)

    Coloma Ribera, R.; van de Kruijs, Robbert Wilhelmus Elisabeth; Yakshin, Andrey; Bijkerk, Frederik

    2015-01-01

    In situ X-ray reflectivity was used to reveal oxygen diffusion kinetics for thermal oxidation of polycrystalline ruthenium thin films and accurate determination of activation energies for this process. Diffusion rates in nanometer thin RuO2 films were found to show Arrhenius behaviour. However, a

  4. Thin films of metal-organic compounds and metal nanoparticle

    Indian Academy of Sciences (India)

    Thin films of metal-organic compounds and metal nanoparticle-embedded polymers for nonlinear optical applications. S Philip Anthony Shatabdi Porel D ... Thin films based on two very different metal-organic systems are developed and some nonlinear optical applications are explored. A family of zinc complexes which ...

  5. Fabrication and Performance Study of Uniform Thin Film Integrated ...

    African Journals Online (AJOL)

    The transmission line model of a uniform rectangular thin film R-C-KR structure consisting of a dielectric layer of constant per unit shunt capacitance C sandwiched between two resistive thin films of constant per unit length resistances R and KR has been analysed using the concept of matrix parameter functions. The above ...

  6. Thermal stability of gold-PS nanocomposites thin films

    Indian Academy of Sciences (India)

    Low-temperature transmission electron microscopy (TEM) studies were performed on polystyrene (PS, w = 234 K) – Au nanoparticle composite thin films that were annealed up to 350°C under reduced pressure conditions. The composite thin films were prepared by wet chemical approach and the samples were then ...

  7. Thermal properties and stabilities of polymer thin films

    International Nuclear Information System (INIS)

    Kanaya, Toshiji; Kawashima, Kazuko; Inoue, Rintaro; Miyazaki, Tsukasa

    2009-01-01

    Recent extensive studies have revealed that polymer thin films showed very interesting but unusual thermal properties and stabilities. In the article we show that X-ray reflectivity and neutron reflectivity are very powerful tools to study the anomalous properties of polymer thin films. (author)

  8. Piezoelectric MEMS: Ferroelectric thin films for MEMS applications

    Science.gov (United States)

    Kanno, Isaku

    2018-04-01

    In recent years, piezoelectric microelectromechanical systems (MEMS) have attracted attention as next-generation functional microdevices. Typical applications of piezoelectric MEMS are micropumps for inkjet heads or micro-gyrosensors, which are composed of piezoelectric Pb(Zr,Ti)O3 (PZT) thin films and have already been commercialized. In addition, piezoelectric vibration energy harvesters (PVEHs), which are regarded as one of the key devices for Internet of Things (IoT)-related technologies, are promising future applications of piezoelectric MEMS. Significant features of piezoelectric MEMS are their simple structure and high energy conversion efficiency between mechanical and electrical domains even on the microscale. The device performance strongly depends on the function of the piezoelectric thin films, especially on their transverse piezoelectric properties, indicating that the deposition of high-quality piezoelectric thin films is a crucial technology for piezoelectric MEMS. On the other hand, although the difficulty in measuring the precise piezoelectric coefficients of thin films is a serious obstacle in the research and development of piezoelectric thin films, a simple unimorph cantilever measurement method has been proposed to obtain precise values of the direct or converse transverse piezoelectric coefficient of thin films, and recently this method has become to be the standardized testing method. In this article, I will introduce fundamental technologies of piezoelectric thin films and related microdevices, especially focusing on the deposition of PZT thin films and evaluation methods for their transverse piezoelectric properties.

  9. Density functional study of ferromagnetism in alkali metal thin films

    Indian Academy of Sciences (India)

    thickness uniform jellium model (UJM), and it is argued that within LSDA or GGA, alkali metal thin films cannot be claimed to have an FM ground state. Relevance of these results to the experiments on transition metal-doped alkali metal thin films ...

  10. NbN thin films for superconducting radio frequency cavities

    Science.gov (United States)

    Roach, W. M.; Skuza, J. R.; Beringer, D. B.; Li, Z.; Clavero, C.; Lukaszew, R. A.

    2012-12-01

    NbN thin films have the potential to be incorporated into radio frequency cavities in a multilayer coating to overcome the fundamental field gradient limit of 50 MV m-1 for the bulk niobium based technology that is currently implemented in particle accelerators. In addition to having a larger critical field value than bulk niobium, NbN films develop smoother surfaces which are optimal for cavity performance and lead to fewer losses. Here, we present a study on the correlation of film deposition parameters, surface morphology, microstructure, transport properties and superconducting properties of NbN thin films. We have achieved films with bulk-like lattice parameters and superconducting transition temperatures. These NbN films have a lower surface roughness than similarly grown niobium films of comparable thickness. The potential application of NbN thin films in accelerator cavities is discussed.

  11. NbN thin films for superconducting radio frequency cavities

    International Nuclear Information System (INIS)

    Roach, W M; Clavero, C; Lukaszew, R A; Skuza, J R; Beringer, D B; Li, Z

    2012-01-01

    NbN thin films have the potential to be incorporated into radio frequency cavities in a multilayer coating to overcome the fundamental field gradient limit of 50 MV m −1 for the bulk niobium based technology that is currently implemented in particle accelerators. In addition to having a larger critical field value than bulk niobium, NbN films develop smoother surfaces which are optimal for cavity performance and lead to fewer losses. Here, we present a study on the correlation of film deposition parameters, surface morphology, microstructure, transport properties and superconducting properties of NbN thin films. We have achieved films with bulk-like lattice parameters and superconducting transition temperatures. These NbN films have a lower surface roughness than similarly grown niobium films of comparable thickness. The potential application of NbN thin films in accelerator cavities is discussed. (paper)

  12. Advanced platform for the in-plane ZT measurement of thin films

    Science.gov (United States)

    Linseis, V.; Völklein, F.; Reith, H.; Nielsch, K.; Woias, P.

    2018-01-01

    The characterization of nanostructured samples with at least one restricted dimension like thin films or nanowires is challenging, but important to understand their structure and transport mechanism, and to improve current industrial products and production processes. We report on the 2nd generation of a measurement chip, which allows for a simplified sample preparation process, and the measurement of samples deposited from the liquid phase using techniques like spin coating and drop casting. The new design enables us to apply much higher temperature gradients for the Seebeck coefficient measurement in a shorter time, without influencing the sample holder's temperature distribution. Furthermore, a two membrane correction method for the 3ω thermal conductivity measurement will be presented, which takes the heat loss due to radiation into account and increases the accuracy of the measurement results significantly. Errors caused by different sample compositions, varying sample geometries, and different heat profiles are avoided with the presented measurement method. As a showcase study displaying the validity and accuracy of our platform, we present temperature-dependent measurements of the thermoelectric properties of an 84 nm Bi87Sb13 thin film and a 15 μm PEDOT:PSS thin film.

  13. Magnetic damping phenomena in ferromagnetic thin-films and multilayers

    Science.gov (United States)

    Azzawi, S.; Hindmarch, A. T.; Atkinson, D.

    2017-11-01

    Damped ferromagnetic precession is an important mechanism underpinning the magnetisation processes in ferromagnetic materials. In thin-film ferromagnets and ferromagnetic/non-magnetic multilayers, the role of precession and damping can be critical for spintronic device functionality and as a consequence there has been significant research activity. This paper presents a review of damping in ferromagnetic thin-films and multilayers and collates the results of many experimental studies to present a coherent synthesis of the field. The terms that are used to define damping are discussed with the aim of providing consistent definitions for damping phenomena. A description of the theoretical basis of damping is presented from early developments to the latest discussions of damping in ferromagnetic thin-films and multilayers. An overview of the time and frequency domain methods used to study precessional magnetisation behaviour and damping in thin-films and multilayers is also presented. Finally, a review of the experimental observations of magnetic damping in ferromagnetic thin-films and multilayers is presented with the most recent explanations. This brings together the results from many studies and includes the effects of ferromagnetic film thickness, the effects of composition on damping in thin-film ferromagnetic alloys, the influence of non-magnetic dopants in ferromagnetic films and the effects of combining thin-film ferromagnets with various non-magnetic layers in multilayered configurations.

  14. Nanocoatings and ultra-thin films technologies and applications

    CERN Document Server

    Tiginyanu, Ion

    2011-01-01

    Gives a comprehensive account of the developments of nanocoatings and ultra-thin films. This book covers the fundamentals, processes of deposition and characterisation of nanocoatings, as well as the applications. It is suitable for the glass and glazing, automotive, electronics, aerospace, construction and biomedical industries in particular.$bCoatings are used for a wide range of applications, from anti-fogging coatings for glass through to corrosion control in the aerospace and automotive industries. Nanocoatings and ultra-thin films provides an up-to-date review of the fundamentals, processes of deposition, characterisation and applications of nanocoatings. Part one covers technologies used in the creation and analysis of thin films, including chapters on current and advanced coating technologies in industry, nanostructured thin films from amphiphilic molecules, chemical and physical vapour deposition methods and methods for analysing nanocoatings and ultra-thin films. Part two focuses on the applications...

  15. Infrared analysis of thin films amorphous, hydrogenated carbon on silicon

    CERN Document Server

    Jacob, W; Schwarz-Selinger, T

    2000-01-01

    The infrared analysis of thin films on a thick substrate is discussed using the example of plasma-deposited, amorphous, hydrogenated carbon layers (a-C:H) on silicon substrates. The framework for the optical analysis of thin films is presented. The main characteristic of thin film optics is the occurrence of interference effects due to the coherent superposition of light multiply reflected at the various internal and external interfaces of the optical system. These interference effects lead to a sinusoidal variation of the transmitted and reflected intensity. As a consequence, the Lambert-Beer law is not applicable for the determination of the absorption coefficient of thin films. Furthermore, observable changes of the transmission and reflection spectra occur in the vicinity of strong absorption bands due to the Kramers-Kronig relation. For a sound data evaluation these effects have to be included in the analysis. To be able to extract the full information contained in a measured optical thin film spectrum, ...

  16. Room temperature ferroelectricity in continuous croconic acid thin films

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xuanyuan; Lu, Haidong; Yin, Yuewei; Ahmadi, Zahra; Costa, Paulo S. [Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588 (United States); Zhang, Xiaozhe [Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588 (United States); Department of Physics, Xi' an Jiaotong University, Xi' an 710049 (China); Wang, Xiao; Yu, Le; Cheng, Xuemei [Department of Physics, Bryn Mawr College, Bryn Mawr, Pennsylvania 19010 (United States); DiChiara, Anthony D. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Gruverman, Alexei, E-mail: alexei-gruverman@unl.edu, E-mail: a.enders@me.com, E-mail: xiaoshan.xu@unl.edu; Enders, Axel, E-mail: alexei-gruverman@unl.edu, E-mail: a.enders@me.com, E-mail: xiaoshan.xu@unl.edu; Xu, Xiaoshan, E-mail: alexei-gruverman@unl.edu, E-mail: a.enders@me.com, E-mail: xiaoshan.xu@unl.edu [Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588 (United States); Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, Nebraska 68588 (United States)

    2016-09-05

    Ferroelectricity at room temperature has been demonstrated in nanometer-thin quasi 2D croconic acid thin films, by the polarization hysteresis loop measurements in macroscopic capacitor geometry, along with observation and manipulation of the nanoscale domain structure by piezoresponse force microscopy. The fabrication of continuous thin films of the hydrogen-bonded croconic acid was achieved by the suppression of the thermal decomposition using low evaporation temperatures in high vacuum, combined with growth conditions far from thermal equilibrium. For nominal coverages ≥20 nm, quasi 2D and polycrystalline films, with an average grain size of 50–100 nm and 3.5 nm roughness, can be obtained. Spontaneous ferroelectric domain structures of the thin films have been observed and appear to correlate with the grain patterns. The application of this solvent-free growth protocol may be a key to the development of flexible organic ferroelectric thin films for electronic applications.

  17. Room temperature deposition of magnetite thin films on organic substrate

    International Nuclear Information System (INIS)

    Arisi, E.; Bergenti, I.; Cavallini, M.; Murgia, M.; Riminucci, A.; Ruani, G.; Dediu, V.

    2007-01-01

    We report on the growth of magnetite films directly on thin layers of organic semiconductors by means of an electron beam ablation method. The deposition was performed at room temperature in a reactive plasma atmosphere. Thin films show ferromagnetic (FM) hysteresis loops and coercive fields of hundreds of Oersted. Micro Raman analysis indicates no presence of spurious phases. The morphology of the magnetite film is strongly influenced by the morphology of the underlayer of the organic semiconductor. These results open the way for the application of magnetite thin films in the field of organic spintronics

  18. Thin Films for Advanced Glazing Applications

    Directory of Open Access Journals (Sweden)

    Ann-Louise Anderson

    2016-09-01

    Full Text Available Functional thin films provide many opportunities for advanced glazing systems. This can be achieved by adding additional functionalities such as self-cleaning or power generation, or alternately by providing energy demand reduction through the management or modulation of solar heat gain or blackbody radiation using spectrally selective films or chromogenic materials. Self-cleaning materials have been generating increasing interest for the past two decades. They may be based on hydrophobic or hydrophilic systems and are often inspired by nature, for example hydrophobic systems based on mimicking the lotus leaf. These materials help to maintain the aesthetic properties of the building, help to maintain a comfortable working environment and in the case of photocatalytic materials, may provide external pollutant remediation. Power generation through window coatings is a relatively new idea and is based around the use of semi-transparent solar cells as windows. In this fashion, energy can be generated whilst also absorbing some solar heat. There is also the possibility, in the case of dye sensitized solar cells, to tune the coloration of the window that provides unheralded external aesthetic possibilities. Materials and coatings for energy demand reduction is highly desirable in an increasingly energy intensive world. We discuss new developments with low emissivity coatings as the need to replace scarce indium becomes more apparent. We go on to discuss thermochromic systems based on vanadium dioxide films. Such systems are dynamic in nature and present a more sophisticated and potentially more beneficial approach to reducing energy demand than static systems such as low emissivity and solar control coatings. The ability to be able to tune some of the material parameters in order to optimize the film performance for a given climate provides exciting opportunities for future technologies. In this article, we review recent progress and challenges in

  19. Modifying thin film diamond for electronic applications

    International Nuclear Information System (INIS)

    Baral, B.

    1999-01-01

    The unique combination of properties that diamond possesses are being exploited in both electronic and mechanical applications. An important step forward in the field has been the ability to grow thin film diamond by chemical vapour deposition (CVD) methods and to control parameters such as crystal orientation, dopant level and surface roughness. An extensive understanding of the surface of any potential electronic material is vital to fully comprehend its behaviour within device structures. The surface itself ultimately controls key aspects of device performance when interfaced with other materials. This study has provided insight into important chemical reactions on polycrystalline CVD diamond surfaces, addressing how certain surface modifications will ultimately affect the properties of the material. A review of the structure, bonding, properties and potential of diamond along with an account of the current state of diamond technology and CVD diamond growth is provided. The experimental chapter reviews bulk material and surface analytical techniques employed in this work and is followed by an investigation of cleaning treatments for polycrystalline CVD diamond aimed at removing non-diamond carbon from the surface. Selective acid etch treatments are compared and contrasted for efficacy with excimer laser irradiation and hydrogen plasma etching. The adsorption/desorption kinetics of potential dopant-containing precursors on polycrystalline CVD diamond surfaces have been investigated to compare their effectiveness at introducing dopants into the diamond during the growth stage. Both boron and sulphur-containing precursor compounds have been investigated. Treating polycrystalline CVD diamond in various atmospheres / combination of atmospheres has been performed to enhance electron field emission from the films. Films which do not emit electrons under low field conditions can be modified such that they emit at fields as low as 10 V/μm. The origin of this enhancement

  20. Evaluation of residual stress in sputtered tantalum thin-film

    Energy Technology Data Exchange (ETDEWEB)

    Al-masha’al, Asa’ad, E-mail: asaad.al@ed.ac.uk; Bunting, Andrew; Cheung, Rebecca

    2016-05-15

    Highlights: • Tantalum thin-films have been deposited by DC magnetron sputtering system. • Thin-film stress is observed to be strongly influenced by sputtering pressure. • Transition towards the compressive stress is ascribed to the annealing at 300 °C. • Expose thin-film to air ambient or ion bombardment lead to a noticeable change in the residual stress. - Abstract: The influence of deposition conditions on the residual stress of sputtered tantalum thin-film has been evaluated in the present study. Films have been deposited by DC magnetron sputtering and curvature measurement method has been employed to calculate the residual stress of the films. Transitions of tantalum film stress from compressive to tensile state have been observed as the sputtering pressure increases. Also, the effect of annealing process at temperature range of 90–300 °C in oxygen ambient on the residual stress of the films has been studied. The results demonstrate that the residual stress of the films that have been deposited at lower sputtering pressure has become more compressive when annealed at 300 °C. Furthermore, the impact of exposure to atmospheric ambient on the tantalum film stress has been investigated by monitoring the variation of the residual stress of both annealed and unannealed films over time. The as-deposited films have been exposed to pure Argon energy bombardment and as result, a high compressive stress has been developed in the films.

  1. Electrical and optical properties of Cu–Cr–O thin films fabricated by chemical vapour deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lunca Popa, P., E-mail: petru.luncapopa@list.lu; Crêpellière, J.; Leturcq, R.; Lenoble, D.

    2016-08-01

    We present electrical and optical properties of CuCrO{sub 2} thin films deposited by chemical vapour deposition, as well as the influence of depositions' parameters on these properties. Oxygen partial pressure and precursor's concentrations have the greatest influence on optical and electrical properties of the films. Values of conductivities ranging from 10{sup −4} to 10 S/cm were obtained using different deposition conditions. The conductivity is thermally activated with an activation energy ranging from 57 to 283 meV. Thermoelectric measurements confirm the p-type conduction, and demonstrate high carrier concentration typical for a degenerate semiconductor. The as-deposited films show a medium degree of crystallinity, a maximum optical transmission up to 80% in the visible range with a corresponding band gap around 3.2 eV. - Highlights: • CuCrO{sub 2} thin films deposited via a new innovative method - DLICVD. • Band gap and electrical conductivity can be tuned by controlling deposition parameters • Key process parameter is the metallic/oxygen atomic ratio involved in the process • Electrical conductivities values spanning 5 orders of magnitudes were obtained using different deposition parameters.

  2. The Structure and Stability of Molybdenum Ditelluride Thin Films

    Directory of Open Access Journals (Sweden)

    Zhouling Wang

    2014-01-01

    Full Text Available Molybdenum-tellurium alloy thin films were fabricated by electron beam evaporation and the films were annealed in different conditions in N2 ambient. The hexagonal molybdenum ditelluride thin films with well crystallization annealed at 470°C or higher were obtained by solid state reactions. Thermal stability measurements indicate the formation of MoTe2 took place at about 350°C, and a subtle weight-loss was in the range between 30°C and 500°C. The evolution of the chemistry for Mo-Te thin films was performed to investigate the growth of the MoTe2 thin films free of any secondary phase. And the effect of other postdeposition treatments on the film characteristics was also investigated.

  3. Investigation of ferromagnetism in oxygen deficient hafnium oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt, Erwin; Kurian, Jose; Krockenberger, Yoshiharu; Alff, Lambert [Institut fuer Materialwissenschaft, TU Darmstadt (Germany); Suter, Andreas [PSI, Villingen (Switzerland); Wilhelm, Fabrice; Rogalev, Andrei [ESRF, Grenoble (France)

    2008-07-01

    Oxygen deficient thin films of hafnium oxide were grown on single crystal r-cut and c-cut sapphire by reactive molecular beam epitaxy. RF-activated oxygen was used for the in situ oxidation of hafnium oxide thin films. Oxidation conditions were varied substantially in order to create oxygen deficiency in hafnium oxide films intentionally. The films were characterized by X-ray and magnetic measurements. X-ray diffraction studies show an increase in lattice parameter with increasing oxygen deficiency. Oxygen deficient hafnium oxide thin films also showed a decreasing bandgap with increase in oxygen deficiency. The magnetisation studies carried out with SQUID did not show any sign of ferromagnetism in the whole oxygen deficiency range. X-ray magnetic circular dichroism measurements also confirmed the absence of ferromagnetism in oxygen deficient hafnium oxide thin films.

  4. In vitro behaviour of nanocrystalline silver-sputtered thin films

    International Nuclear Information System (INIS)

    Piedade, A P; Vieira, M T; Martins, A; Silva, F

    2007-01-01

    Silver thin films were deposited with different preferential orientations and special attention was paid to the bioreactivity of the surfaces. The study was essentially focused on the evaluation of the films by x-ray diffraction (XRD), atomic force microscopy (AFM), high-resolution transmission electron microscopy (HRTEM), electron probe microanalysis (EPMA) and contact angle measurements. The deposited thin films were characterized before and after immersion in S-enriched simulated human plasma in order to estimate the influence of the preferential crystallographic orientation on the in vitro behaviour. Silver thin films with and without (111) preferential crystallographic orientation were deposited by r.f. magnetron sputtering to yield nanocrystalline coatings, high compact structures, very hydrophobic surfaces and low roughness. These properties reduce the chemisorption of reactive species onto the film surface. The in vitro tests indicate that silver thin films can be used as coatings for biomaterials applications

  5. Novel photon management for thin-film photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Menon, Rajesh [Univ. of Utah, Salt Lake City, UT (United States)

    2016-11-11

    The objective of this project is to enable commercially viable thin-film photovoltaics whose efficiencies are increased by over 10% using a novel optical spectral-separation technique. A thin planar diffractive optic is proposed that efficiently separates the solar spectrum and assigns these bands to optimal thin-film sub-cells. An integrated device that is comprised of the optical element, an array of sub-cells and associated packaging is proposed.

  6. Altering properties of cerium oxide thin films by Rh doping

    International Nuclear Information System (INIS)

    Ševčíková, Klára; Nehasil, Václav; Vorokhta, Mykhailo; Haviar, Stanislav; Matolín, Vladimír

    2015-01-01

    Highlights: • Thin films of ceria doped by rhodium deposited by RF magnetron sputtering. • Concentration of rhodium has great impact on properties of Rh–CeO x thin films. • Intensive oxygen migration in films with low concentration of rhodium. • Oxygen migration suppressed in films with high amount of Rh dopants. - Abstract: Ceria containing highly dispersed ions of rhodium is a promising material for catalytic applications. The Rh–CeO x thin films with different concentrations of rhodium were deposited by RF magnetron sputtering and were studied by soft and hard X-ray photoelectron spectroscopies, Temperature programmed reaction and X-ray powder diffraction techniques. The sputtered films consist of rhodium–cerium mixed oxide where cerium exhibits a mixed valency of Ce 4+ and Ce 3+ and rhodium occurs in two oxidation states, Rh 3+ and Rh n+ . We show that the concentration of rhodium has a great influence on the chemical composition, structure and reducibility of the Rh–CeO x thin films. The films with low concentrations of rhodium are polycrystalline, while the films with higher amount of Rh dopants are amorphous. The morphology of the films strongly influences the mobility of oxygen in the material. Therefore, varying the concentration of rhodium in Rh–CeO x thin films leads to preparing materials with different properties

  7. Pulsed laser deposition and characterisation of thin superconducting films

    Energy Technology Data Exchange (ETDEWEB)

    Morone, A [CNR, zona industriale di Tito Scalo, Potenza (Italy). Istituto per i Materiali Speciali

    1996-09-01

    Same concepts on pulsed laser deposition of thin films will be discussed and same examples of high transition temperature (HTc) BiSrCaCuO (BISCO) and low transition temperature NbN/MgO/NbN multilayers will be presented. X-ray and others characterizations of these films will be reported and discussed. Electrical properties of superconducting thin films will be realized as a function of structural and morphological aspect.

  8. Thin film coatings for space electrical power system applications

    Science.gov (United States)

    Gulino, Daniel A.

    1988-01-01

    This paper examines some of the ways in which thin film coatings can play a role in aerospace applications. Space systems discussed include photovoltaic and solar dynamic electric power generation systems, including applications in environmental protection, thermal energy storage, and radiator emittance enhancement. Potential applications of diamondlike films to both atmospheric and space based systems are examined. Also, potential uses of thin films of the recently discovered high-temperature superconductive materials are discussed.

  9. Preparation and optical characterization of DNA-riboflavin thin films

    Science.gov (United States)

    Paulson, Bjorn; Shin, Inchul; Kong, Byungjoo; Sauer, Gregor; Dugasani, Sreekantha Reddy; Khazaeinezhad, Reza; Jung, Woohyun; Joo, Boram; Oh, Kyunghwan

    2016-09-01

    Thin films of DNA biopolymer thin film are fabricated by a drop casting process on glass and silicon substrates, as well as freestanding. The refractive index is measured by elliposmetry and in bulk DNA film the refractive index is shown to be increased in the 600 to 900 nm DNA transparency window by doping with riboflavin. Further analysis with FT-IR, Raman, and XRD are used to determine whether binding between riboflavin and DNA occurs.

  10. Thin film adhesion by nanoindentation-induced superlayers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gerberich, William W.; Volinsky, A.A.

    2001-06-01

    This work has analyzed the key variables of indentation tip radius, contact radius, delamination radius, residual stress and superlayer/film/interlayer properties on nanoindentation measurements of adhesion. The goal to connect practical works of adhesion for very thin films to true works of adhesion has been achieved. A review of this work titled ''Interfacial toughness measurements of thin metal films,'' which has been submitted to Acta Materialia, is included.

  11. Relation of planar Hall and planar Nernst effects in thin film permalloy

    Science.gov (United States)

    Wesenberg, D.; Hojem, A.; Bennet, R. K.; Zink, B. L.

    2018-06-01

    We present measurements of the planar Nernst effect (PNE) and the planar Hall effect (PHE) of nickel-iron (Ni–Fe) alloy thin films. We suspend the thin-film samples, measurement leads, and lithographically-defined heaters and thermometers on silicon-nitride membranes to greatly simplify control and measurement of thermal gradients essential to quantitative determination of magnetothermoelectric effects. Since these thermal isolation structures allow measurements of longitudinal thermopower, or the Seebeck coefficient, and four-wire electrical resistivity of the same thin film, we can quantitatively demonstrate the link between the longitudinal and transverse effects as a function of applied in-plane field and angle. Finite element thermal analysis of this essentially 2D structure allows more confident determination of the thermal gradient, which is reduced from the simplest assumptions due to the particular geometry of the membranes, which are more than 350 μm wide in order to maximize sensitivity to transverse thermoelectric effects. The resulting maximum values of the PNE and PHE coefficients for the Ni–Fe film with 80% Ni we study here are and , respectively. All signals are exclusively symmetry with applied field, ruling out long-distance spin transport effects. We also consider a Mott-like relation between the PNE and PHE, and use both this and the standard Mott relation to determine the energy-derivative of the resistivity at the Fermi energy to be , which is very similar to values for films we previously measured using similar thermal platforms. Finally, using an estimated value for the lead contribution to the longitudinal thermopower, we show that the anisotropic magnetoresistance (AMR) ratio in this Ni–Fe film is two times larger than the magnetothermopower ratio, which is the first evidence of a deviation from strict adherence to the Mott relation between Seebeck coefficient and resistivity.

  12. Simple turbulence measurements with azopolymer thin films.

    Science.gov (United States)

    Barillé, Regis; Pérez, Darío G; Morille, Yohann; Zielińska, Sonia; Ortyl, Ewelina

    2013-04-01

    A simple method to measure the influence on the laser beam propagation by a turbid medium is proposed. This measurement is based on the inscription of a surface relief grating (SRG) on an azopolymer thin film. The grating obtained with a single laser beam after propagation into a turbulent medium is perturbed and directly analyzed by a CCD camera through its diffraction pattern. Later, by scanning the surface pattern with an atomic force microscope, the inscribed SRG is analyzed with the Radon transform. This method has the advantage of using a single beam to remotely inscribe a grating detecting perturbations during the beam path. A method to evaluate the refractive index constant structure is developed.

  13. Thin film femtosecond laser damage competition

    Science.gov (United States)

    Stolz, Christopher J.; Ristau, Detlev; Turowski, Marcus; Blaschke, Holger

    2009-10-01

    In order to determine the current status of thin film laser resistance within the private, academic, and government sectors, a damage competition was started at the 2008 Boulder Damage Symposium. This damage competition allows a direct comparison of the current state of the art of high laser resistance coatings since they are tested using the same damage test setup and the same protocol. In 2009 a high reflector coating was selected at a wavelength of 786 nm at normal incidence at a pulse length of 180 femtoseconds. A double blind test assured sample and submitter anonymity so only a summary of the results are presented here. In addition to the laser resistance results, details of deposition processes, coating materials and layer count, and spectral results will also be shared.

  14. PZT thin film actuated elastic fin micromotor.

    Science.gov (United States)

    Dubois, M A; Muralt, P

    1998-01-01

    A piezoelectric elastic fin micromotor based on a PbZr(0.53 )Ti(0.47)O(3) thin film driving a micromachined silicon membrane was fabricated and studied. The stator was characterized by interferometry, and a laser set-up was used to measure the angular velocity and acceleration of the motor. The torque, the output power, and the efficiency of the device were extracted from these measurements. Values up to 1020 rpm and 0.94 microNm were observed for the velocity and the torque, respectively, which would be sufficient for a wristwatch application. The present version exhibited an efficiency of 0.17%, which could theoretically be increased to 4.8%

  15. Quantitative MFM on superconducting thin films

    Energy Technology Data Exchange (ETDEWEB)

    Stopfel, Henry; Vock, Silvia; Shapoval, Tetyana; Neu, Volker; Wolff, Ulrike; Haindl, Silvia; Engelmann, Jan; Schaefer, Rudolf; Holzapfel, Bernhard; Schultz, Ludwig [IFW Dresden, Institute for Metallic Material (Germany); Inosov, Dmytro S. [Max Planck Institute for Solid State Research, Stuttgart (Germany)

    2012-07-01

    Quantitative interpretation of magnetic force microscopy (MFM) data is a challenge, because the measured signal is a convolution between the magnetization of the tip and the stray field emanated by the sample. It was established theoretically that the field distribution just above the surface of the superconductor can be well approximated by the stray field of a magnetic monopole. The description of the MFM tip, however, needs a second approximation. The temperature-dependent vortex-distribution images on a NbN thin film were fitted using two different tip models. Firstly, the magnetic tip was assumed to be a monopole that leads to the simple monopole-monopole model for the tip-sample interaction force. Performing a 2D fitting of the data with this model, we extracted λ, Δ and the vortex pinning force. Secondly, a geometrical model was applied to calculate the tip-transfer-function of the MFM tip using the numerical BEM method.

  16. Multiferroics and magnetoelectrics: thin films and nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Martin, L W; Crane, S P; Chu, Y-H; Holcomb, M B; Gajek, M; Huijben, M; Yang, C-H; Balke, N; Ramesh, R [Department of Materials Science and Engineering, University of California, Berkeley, CA 94720 (United States); Department of Physics, University of California, Berkeley, CA 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)], E-mail: lwmartin@lbl.gov

    2008-10-29

    Multiferroic materials, or materials that simultaneously possess two or more ferroic order parameters, have returned to the forefront of materials research. Driven by the desire to achieve new functionalities-such as electrical control of ferromagnetism at room temperature-researchers have undertaken a concerted effort to identify and understand the complexities of multiferroic materials. The ability to create high quality thin film multiferroics stands as one of the single most important landmarks in this flurry of research activity. In this review we discuss the basics of multiferroics including the important order parameters and magnetoelectric coupling in materials. We then discuss in detail the growth of single phase, horizontal multilayer, and vertical heterostructure multiferroics. The review ends with a look to the future and how multiferroics can be used to create new functionalities in materials.

  17. Multiferroics and magnetoelectrics: thin films and nanostructures

    Science.gov (United States)

    Martin, L. W.; Crane, S. P.; Chu, Y.-H.; Holcomb, M. B.; Gajek, M.; Huijben, M.; Yang, C.-H.; Balke, N.; Ramesh, R.

    2008-10-01

    Multiferroic materials, or materials that simultaneously possess two or more ferroic order parameters, have returned to the forefront of materials research. Driven by the desire to achieve new functionalities—such as electrical control of ferromagnetism at room temperature—researchers have undertaken a concerted effort to identify and understand the complexities of multiferroic materials. The ability to create high quality thin film multiferroics stands as one of the single most important landmarks in this flurry of research activity. In this review we discuss the basics of multiferroics including the important order parameters and magnetoelectric coupling in materials. We then discuss in detail the growth of single phase, horizontal multilayer, and vertical heterostructure multiferroics. The review ends with a look to the future and how multiferroics can be used to create new functionalities in materials.

  18. Multiferroics and magnetoelectrics: thin films and nanostructures

    International Nuclear Information System (INIS)

    Martin, L W; Crane, S P; Chu, Y-H; Holcomb, M B; Gajek, M; Huijben, M; Yang, C-H; Balke, N; Ramesh, R

    2008-01-01

    Multiferroic materials, or materials that simultaneously possess two or more ferroic order parameters, have returned to the forefront of materials research. Driven by the desire to achieve new functionalities-such as electrical control of ferromagnetism at room temperature-researchers have undertaken a concerted effort to identify and understand the complexities of multiferroic materials. The ability to create high quality thin film multiferroics stands as one of the single most important landmarks in this flurry of research activity. In this review we discuss the basics of multiferroics including the important order parameters and magnetoelectric coupling in materials. We then discuss in detail the growth of single phase, horizontal multilayer, and vertical heterostructure multiferroics. The review ends with a look to the future and how multiferroics can be used to create new functionalities in materials.

  19. Fluctuation conductivity of thin superconductive vanadium films

    International Nuclear Information System (INIS)

    Dmitrenko, I.M.; Sidorenko, A.S.; Fogel, N.Y.

    1982-01-01

    Resistive transitions into the superconductive state are studied in thin [d >T/sub c/ the experimental data on the excess conductivity of the films agree qualitatively and quantitively with Aslamazov--Larkin theory. There is no Maki--Thompson contribution to fluctuation conductivity. Near T/sub c/ the excess conductivity sigma' changes exponentially with temperature in accordance with the predictions of the theory of the critical fluctuations of the order parameter. The values of the effective charge carrier mass defined from data on sigma' for the low fluctuation and critical fluctuation regions differ markedly. This difference is within the spread of effective masses for various charge carrier groups already known for vanadium. Causes of the difference in resistive behavior for the regions T >T/sub c/ are considered

  20. General-purpose heat source: Research and development program, radioisotope thermoelectric generator/thin fragment impact test

    International Nuclear Information System (INIS)

    Reimus, M.A.H.; Hinckley, J.E.

    1996-11-01

    The general-purpose heat source provides power for space missions by transmitting the heat of 238 Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system. The results of this test indicated that impact by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel

  1. The Characterization of Thin Film Nickel Titanium Shape Memory Alloys

    Science.gov (United States)

    Harris Odum, Nicole Latrice

    Shape memory alloys (SMA) are able to recover their original shape through the appropriate heat or stress exposure after enduring mechanical deformation at a low temperature. Numerous alloy systems have been discovered which produce this unique feature like TiNb, AgCd, NiAl, NiTi, and CuZnAl. Since their discovery, bulk scale SMAs have undergone extensive material property investigations and are employed in real world applications. However, its thin film counterparts have been modestly investigated and applied. Researchers have introduced numerous theoretical microelectromechanical system (MEMS) devices; yet, the research community's overall unfamiliarity with the thin film properties has delayed growth in this area. In addition, it has been difficult to outline efficient thin film processing techniques. In this dissertation, NiTi thin film processing and characterization techniques will be outlined and discussed. NiTi thin films---1 mum thick---were produced using sputter deposition techniques. Substrate bound thin films were deposited to analysis the surface using Scanning Electron Microscopy; the film composition was obtained using Energy Dispersive Spectroscopy; the phases were identified using X-ray diffraction; and the transformation temperatures acquired using resistivity testing. Microfabrication processing and sputter deposition were employed to develop tensile membranes for membrane deflection experimentation to gain insight on the mechanical properties of the thin films. The incorporation of these findings will aid in the movement of SMA microactuation devices from theory to fruition and greatly benefit industries such as medicinal and aeronautical.

  2. Thin Film Approaches to the SRF Cavity Problem Fabrication and Characterization of Superconducting Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Beringer, Douglas [College of William and Mary, Williamsburg, VA (United States)

    2017-08-01

    Superconducting Radio Frequency (SRF) cavities are responsible for the acceleration of charged particles to relativistic velocities in most modern linear accelerators, such as those employed at high-energy research facilities like Thomas Jefferson National Laboratory’s CEBAF and the LHC at CERN. Recognizing SRF as primarily a surface phenomenon enables the possibility of applying thin films to the interior surface of SRF cavities, opening a formidable tool chest of opportunities by combining and designing materials that offer greater performance benefit. Thus, while improvements in radio frequency cavity design and refinements in cavity processing techniques have improved accelerator performance and efficiency – 1.5 GHz bulk niobium SRF cavities have achieved accelerating gradients in excess of 35 MV/m – there exist fundamental material bounds in bulk superconductors limiting the maximally sustained accelerating field gradient (≈ 45 MV/m for Nb) where inevitable thermodynamic breakdown occurs. With state of the art Nb based cavity design fast approaching these theoretical limits, novel material innovations must be sought in order to realize next generation SRF cavities. One proposed method to improve SRF performance is to utilize thin film superconducting-insulating-superconducting (SIS) multilayer structures to effectively magnetically screen a bulk superconducting layer such that it can operate at higher field gradients before suffering critically detrimental SRF losses. This dissertation focuses on the production and characterization of thin film superconductors for such SIS layers for radio frequency applications. Correlated studies on structure, surface morphology and superconducting properties of epitaxial Nb and MgB2 thin films are presented.

  3. Fluorine doped vanadium dioxide thin films for smart windows

    International Nuclear Information System (INIS)

    Kiri, Pragna; Warwick, Michael E.A.; Ridley, Ian; Binions, Russell

    2011-01-01

    Thermochromic fluorine doped thin films of vanadium dioxide were deposited from the aerosol assisted chemical vapour deposition reaction of vanadyl acetylacetonate, ethanol and trifluoroacetic acid on glass substrates. The films were characterised with scanning electron microscopy, variable temperature Raman spectroscopy and variable temperature UV/Vis spectroscopy. The incorporation of fluorine in the films led to an increase in the visible transmittance of the films whilst retaining the thermochromic properties. This approach shows promise for improving the aesthetic properties of vanadium dioxide thin films.

  4. Sensing of volatile organic compounds by copper phthalocyanine thin films

    Science.gov (United States)

    Ridhi, R.; Saini, G. S. S.; Tripathi, S. K.

    2017-02-01

    Thin films of copper phthalocyanine have been deposited by thermal evaporation technique. We have subsequently exposed these films to the vapours of methanol, ethanol and propanol. Optical absorption, infrared spectra and electrical conductivities of these films before and after exposure to chemical vapours have been recorded in order to study their sensing mechanisms towards organic vapours. These films exhibit maximum sensing response to methanol while low sensitivities of the films towards ethanol and propanol have been observed. The changes in sensitivities have been correlated with presence of carbon groups in the chemical vapours. The effect of different types of electrodes on response-recovery times of the thin film with organic vapours has been studied and compared. The electrodes gap distance affects the sensitivity as well as response-recovery time values of the thin films.

  5. Glass transition and thermal expansivity of polystyrene thin films

    International Nuclear Information System (INIS)

    Inoue, R.; Kanaya, T.; Miyazaki, T.; Nishida, K.; Tsukushi, I.; Shibata, K.

    2006-01-01

    We have studied glass transition temperature and thermal expansivity of polystyrene thin films supported on silicon substrate using X-ray reflectivity and inelastic neutron scattering techniques. In annealing experiments, we have found that the reported apparent negative expansivity of polymer thin films is caused by unrelaxed structure due to insufficient annealing. Using well-annealed films, we have evaluated glass transition temperature T g and thermal expansivity as a function of film thickness. The glass transition temperature decreases with film thickness and is constant below about 10 nm, suggesting the surface glass transition temperature of 355 K, which is lower than that in bulk. We have also found that the thermal expansivity in the glassy state decreases with film thickness even after annealing. The decrease has been attributed to hardening of harmonic force constant arising from chain confinement in a thin film. This idea has been confirmed in the inelastic neutron scattering measurements

  6. Glass transition and thermal expansivity of polystyrene thin films

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, R. [Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011 (Japan); Kanaya, T. [Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011 (Japan)]. E-mail: kanaya@scl.kyoto-u.ac.jp; Miyazaki, T. [Nitto Denko Corporation, 1-1-2 Shimohozumi, Ibaraki, Osaka-fu 567-8680 (Japan); Nishida, K. [Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011 (Japan); Tsukushi, I. [Chiba Institute of Technology, Narashino, Chiba-ken 275-0023 (Japan); Shibata, K. [Japan Atomic Energy Research Institute, Tokai, Ibaraki-ken 319-1195 (Japan)

    2006-12-20

    We have studied glass transition temperature and thermal expansivity of polystyrene thin films supported on silicon substrate using X-ray reflectivity and inelastic neutron scattering techniques. In annealing experiments, we have found that the reported apparent negative expansivity of polymer thin films is caused by unrelaxed structure due to insufficient annealing. Using well-annealed films, we have evaluated glass transition temperature T {sub g} and thermal expansivity as a function of film thickness. The glass transition temperature decreases with film thickness and is constant below about 10 nm, suggesting the surface glass transition temperature of 355 K, which is lower than that in bulk. We have also found that the thermal expansivity in the glassy state decreases with film thickness even after annealing. The decrease has been attributed to hardening of harmonic force constant arising from chain confinement in a thin film. This idea has been confirmed in the inelastic neutron scattering measurements.

  7. Thin film characterization by resonantly excited internal standing waves

    Energy Technology Data Exchange (ETDEWEB)

    Di Fonzio, S [SINCROTRONE TRIESTE, Trieste (Italy)

    1996-09-01

    This contribution describes how a standing wave excited in a thin film can be used for the characterization of the properties of the film. By means of grazing incidence X-ray reflectometry one can deduce the total film thickness. On the other hand in making use of a strong resonance effect in the electric field intensity distribution inside a thin film on a bulk substrate one can learn more about the internal structure of the film. The profile of the internal standing wave is proven by diffraction experiments. The most appropriate non-destructive technique for the subsequent thin film characterization is angularly dependent X-ray fluorescence analysis. The existence of the resonance makes it a powerful tool for the detection of impurities and of ultra-thin maker layers, for which the position can be determined with very high precision (about 1% of the total film thickness). This latter aspect will be discussed here on samples which had a thin Ti marker layer at different positions in a carbon film. Due to the resonance enhancement it was still possible to perform these experiments with a standard laboratory x-ray tube and with standard laboratory tool for marker or impurity detection in thin films.

  8. Thin Film Approaches to the SRF Cavity Problem: Fabrication and Characterization of Superconducting Thin Films

    Science.gov (United States)

    Beringer, Douglas B.

    Superconducting Radio Frequency (SRF) cavities are responsible for the acceleration of charged particles to relativistic velocities in most modern linear accelerators, such as those employed at high-energy research facilities like Thomas Jefferson National Laboratory's CEBAF and the LHC at CERN. Recognizing SRF as primarily a surface phenomenon enables the possibility of applying thin films to the interior surface of SRF cavities, opening a formidable tool chest of opportunities by combining and designing materials that offer greater benefit. Thus, while improvements in radio frequency cavity design and refinements in cavity processing techniques have improved accelerator performance and efficiency - 1.5 GHz bulk niobium SRF cavities have achieved accelerating gradients in excess of 35 MV/m - there exist fundamental material bounds in bulk superconductors limiting the maximally sustained accelerating field gradient (approximately 45 MV/m for Niobium) where inevitable thermodynamic breakdown occurs. With state of the art niobium based cavity design fast approaching these theoretical limits, novel material innovations must be sought in order to realize next generation SRF cavities. One proposed method to improve SRF performance is to utilize thin film superconducting-insulating-superconducting (SIS) multilayer structures to effectively magnetically screen a bulk superconducting layer such that it can operate at higher field gradients before suffering critically detrimental SRF losses. This dissertation focuses on the production and characterization of thin film superconductors for such SIS layers for radio-frequency applications.

  9. Thin-film growth and the shadow instability

    International Nuclear Information System (INIS)

    Karunasiri, R.P.U.; Bruinsma, R.; Rudnick, J.

    1989-01-01

    We propose a growth model for deposition of thin amorphous films by the sputtering technique. For small values of the diffusion constant, the film develops a self-similar mountain landscape. As the diffusion constant is increased a regime is reached where growth of compact flat films is possible up to a critical height. Further deposition leads to surface roughening

  10. Inhomogeneous strain states in sputter deposited tungsten thin films

    International Nuclear Information System (INIS)

    Noyan, I.C.; Shaw, T.M.; Goldsmith, C.C.

    1997-01-01

    The results of an x-ray diffraction study of dc-magnetron sputtered tungsten thin films are reported. It is shown that the phase transformation from the β to α W can cause multilayered single-phase films where the layers have very different stress states even if the films are in the 500 nm thickness range. copyright 1997 American Institute of Physics

  11. Strain-induced properties of epitaxial VOx thin films

    NARCIS (Netherlands)

    Rata, AD; Hibma, T

    We have grown VOx thin films on different substrates in order to investigate the influence of epitaxial strain on the transport properties. We found that the electric conductivity is much larger for films grown under compressive strain on SrTiO3 substrates, as compared to bulk material and VOx films

  12. Electrical Conductivity of CUXS Thin Film Deposited by Chemical ...

    African Journals Online (AJOL)

    Thin films of CuxS have successfully been deposited on glass substrates using the Chemical Bath Deposition (CBD) technique. The films were then investigated for their electrical properties. The results showed that the electrical conductivities of the CuxS films with different molarities (n) of thiourea (Tu), determined using ...

  13. The electrical, optical, structural and thermoelectrical characterization of n- and p-type cobalt-doped SnO 2 transparent semiconducting films prepared by spray pyrolysis technique

    Science.gov (United States)

    Bagheri-Mohagheghi, Mohammad-Mehdi; Shokooh-Saremi, Mehrdad

    2010-10-01

    The electrical, optical and structural properties of Cobalt (Co) doped SnO 2 transparent semiconducting thin films, deposited by the spray pyrolysis technique, have been studied. The SnO 2:Co films, with different Co-content, were deposited on glass substrates using an aqueous-ethanol solution consisting of tin and cobalt chlorides. X-ray diffraction studies showed that the SnO 2:Co films were polycrystalline only with tin oxide phases and preferential orientations along (1 1 0) and (2 1 1) planes and grain sizes in the range 19-82 nm. Optical transmittance spectra of the films showed high transparency ∼75-90% in the visible region, decreasing with increase in Co-doping. The optical absorption edge for undoped SnO 2 films was found to be 3.76 eV, while for higher Co-doped films shifted toward higher energies (shorter wavelengths) in the range 3.76-4.04 eV and then slowly decreased again to 4.03 eV. A change in sign of the Hall voltage and Seebeck coefficient was observed for a specific acceptor dopant level ∼11.4 at% in film and interpreted as a conversion from n-type to p-type conductivity. The thermoelectric electro-motive force (e.m.f.) of the films was measured in the temperature range 300-500 K and Seebeck coefficients were found in the range from -62 to +499 μVK -1 for various Co-doped SnO 2 films.

  14. The electrical, optical, structural and thermoelectrical characterization of n- and p-type cobalt-doped SnO2 transparent semiconducting films prepared by spray pyrolysis technique

    International Nuclear Information System (INIS)

    Bagheri-Mohagheghi, Mohammad-Mehdi; Shokooh-Saremi, Mehrdad

    2010-01-01

    The electrical, optical and structural properties of Cobalt (Co) doped SnO 2 transparent semiconducting thin films, deposited by the spray pyrolysis technique, have been studied. The SnO 2 :Co films, with different Co-content, were deposited on glass substrates using an aqueous-ethanol solution consisting of tin and cobalt chlorides. X-ray diffraction studies showed that the SnO 2 :Co films were polycrystalline only with tin oxide phases and preferential orientations along (1 1 0) and (2 1 1) planes and grain sizes in the range 19-82 nm. Optical transmittance spectra of the films showed high transparency ∼75-90% in the visible region, decreasing with increase in Co-doping. The optical absorption edge for undoped SnO 2 films was found to be 3.76 eV, while for higher Co-doped films shifted toward higher energies (shorter wavelengths) in the range 3.76-4.04 eV and then slowly decreased again to 4.03 eV. A change in sign of the Hall voltage and Seebeck coefficient was observed for a specific acceptor dopant level ∼11.4 at% in film and interpreted as a conversion from n-type to p-type conductivity. The thermoelectric electro-motive force (e.m.f.) of the films was measured in the temperature range 300-500 K and Seebeck coefficients were found in the range from -62 to +499 μVK -1 for various Co-doped SnO 2 films.

  15. Photoinduced conductivity in tin dioxide thin films

    International Nuclear Information System (INIS)

    Muraoka, Y.; Takubo, N.; Hiroi, Z.

    2009-01-01

    The effects of ultraviolet light irradiation on the conducting properties of SnO 2-x thin films grown epitaxially on TiO 2 or Al 2 O 3 single-crystal substrates are studied at room temperature. A large increase in conductivity by two to four orders of magnitude is observed with light irradiation in an inert atmosphere and remains after the light is removed. The high-conducting state reverts to the original low-conducting state by exposing it to oxygen gas. These reversible phenomena are ascribed to the desorption and adsorption of negatively charged oxygen species at the grain boundaries, which critically change the mobility of electron carriers already present inside grains by changing the potential barrier height at the grain boundary. The UV light irradiation provides us with an easy and useful route to achieve a high-conducting state even at low carrier density in transparent conducting oxides and also to draw an invisible conducting wire or a specific pattern on an insulating film.

  16. Electrodeposition of thin Pd-Ag films

    International Nuclear Information System (INIS)

    Hasler, P.; Allmendinger, T.

    1993-01-01

    Thin Pd-Ag layers were electroplated preferably on brass and on nickel substrates using a two-compartment cell separated by an anion exchange membrane. The weakly alkaline electrolyte contained glycine-glycinate as the major complexing agents. The plating experiments were usually carried out without stirring, at different potentials and temperatures and in the absence or in the presence of sodium benzaldehyde-2,4-disulphonate (BDS). The samples were characterized by scanning electron microscopy and light microscopy. Their compositions were determined analytically by the inductively coupled plasma technique. In addition, the film porosity was tested. Electrodeposition in almost limiting current conditions for both components and without simultaneous hydrogen evolution led to deposits with compositions being in good agreement with the molar metal ratio in the electrolyte (77:23). The best results were achieved between 0 and -50 mV with respect to a reversible hydrogen electrode at 0 C in the presence of BDS. These deposits were bright, had good adherence and exhibited no pores at a film thickness of 1.2 μm. At too negative potentials, the deposits became black and powdery. (orig.)

  17. Mechanics of evolving thin film structures

    Science.gov (United States)

    Liang, Jim

    In the Stranski-Krastanov system, the lattice mismatch between the film and the substrate causes the film to break into islands. During annealing, both the surface energy and the elastic energy drive the islands to coarsen. Motivated by several related studies, we suggest that stable islands should form when a stiff ceiling is placed at a small gap above the film. We show that the role of elasticity is reversed: with the ceiling, the total elastic energy stored in the system increases as the islands coarsen laterally. Consequently, the islands select an equilibrium size to minimize the combined elastic energy and surface energy. In lithographically-induced self-assembly, when a two-phase fluid confined between parallel substrates is subjected to an electric field, one phase can self-assemble into a triangular lattice of islands in another phase. We describe a theory of the stability of the island lattice. The islands select the equilibrium diameter to minimize the combined interface energy and electrostatic energy. Furthermore, we study compressed SiGe thin film islands fabricated on a glass layer, which itself lies on a silicon wafer. Upon annealing, the glass flows, and the islands relax. A small island relaxes by in-plane expansion. A large island, however, wrinkles at the center before the in-plane relaxation arrives. The wrinkles may cause significant tensile stress in the island, leading to fracture. We model the island by the von Karman plate theory and the glass layer by the Reynolds lubrication theory. Numerical simulations evolve the in-plane expansion and the wrinkles simultaneously. We determine the critical island size, below which in-plane expansion prevails over wrinkling. Finally, in devices that integrate dissimilar materials in small dimensions, crack extension in one material often accompanies inelastic deformation in another. We analyze a channel crack advancing in an elastic film under tension, while an underlayer creeps. We use a two

  18. Subtractive fabrication of ferroelectric thin films with precisely controlled thickness

    Science.gov (United States)

    Ievlev, Anton V.; Chyasnavichyus, Marius; Leonard, Donovan N.; Agar, Joshua C.; Velarde, Gabriel A.; Martin, Lane W.; Kalinin, Sergei V.; Maksymovych, Petro; Ovchinnikova, Olga S.

    2018-04-01

    The ability to control thin-film growth has led to advances in our understanding of fundamental physics as well as to the emergence of novel technologies. However, common thin-film growth techniques introduce a number of limitations related to the concentration of defects on film interfaces and surfaces that limit the scope of systems that can be produced and studied experimentally. Here, we developed an ion-beam based subtractive fabrication process that enables creation and modification of thin films with pre-defined thicknesses. To accomplish this we transformed a multimodal imaging platform that combines time-of-flight secondary ion mass spectrometry with atomic force microscopy to a unique fabrication tool that allows for precise sputtering of the nanometer-thin layers of material. To demonstrate fabrication of thin-films with in situ feedback and control on film thickness and functionality we systematically studied thickness dependence of ferroelectric switching of lead-zirconate-titanate, within a single epitaxial film. Our results demonstrate that through a subtractive film fabrication process we can control the piezoelectric response as a function of film thickness as well as improve on the overall piezoelectric response versus an untreated film.

  19. Relaxation in Thin Polymer Films Mapped across the Film Thickness by Astigmatic Single-Molecule Imaging

    KAUST Repository

    Oba, Tatsuya; Vacha, Martin

    2012-01-01

    We have studied relaxation processes in thin supported films of poly(methyl acrylate) at the temperature corresponding to 13 K above the glass transition by monitoring the reorientation of single perylenediimide molecules doped into the films

  20. Resistivity of thiol-modified gold thin films

    International Nuclear Information System (INIS)

    Correa-Puerta, Jonathan; Del Campo, Valeria; Henríquez, Ricardo; Häberle, Patricio

    2014-01-01

    In this work, we study the effect of thiol self assembled monolayers on the electrical resistivity of metallic thin films. The analysis is based on the Fuchs–Sondheimer–Lucas theory and on electrical transport measurements. We determined resistivity change due to dodecanethiol adsorption on gold thin films. For this purpose, we controlled the deposition and annealing temperatures of the films to change the surface topography and to diminish the effect of electron grain boundary scattering. Results show that the electrical response to the absorption of thiols strongly depends on the initial topography of the surface. - Highlights: • We study the effect of self assembled monolayers on the resistivity of thin films. • Fuchs–Sondheimer theory reproduces the resistivity increase due to thiol deposition. • We determined resistivity change due to dodecanethiol deposition on gold thin films. • The electrical response strongly depends on the substrate surface topography

  1. Effect of solution concentration on MEH-PPV thin films

    Science.gov (United States)

    Affendi, I. H. H.; Sarah, M. S. P.; Alrokayan, Salman A. H.; Khan, Haseeb A.; Rusop, M.

    2018-05-01

    MEH-PPV thin films were prepared with a mixture of THF (tetrahydrofuran) solution deposited by spin coating method. The surface topology of MEH-PPV thin film were characterize by atomic force microscopy (AFM) and optical properties of absorption spectra were characterized by using Ultraviolet-visible-near-infrared (UV-Vis-NIR). The MEH-PPV concentration variation affects the surface and optical properties of the thin film where 0.5 mg/ml MEH-PPV concentration have a good surface topology provided the same film also gives the highest absorption coefficient were then deposited to a TiO2 thin film forming composite layer. The composite layer then shows low current flow of short circuit current of Isc = -5.313E-7 A.

  2. Resistivity of thiol-modified gold thin films

    Energy Technology Data Exchange (ETDEWEB)

    Correa-Puerta, Jonathan [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Av. Universidad 330, Curauma, Valparaíso (Chile); Del Campo, Valeria [Departamento de Física, Universidad Técnica Federico Santa María, Av. España 1680, Valparaiso 2390123 (Chile); Henríquez, Ricardo, E-mail: ricardo.henriquez@usm.cl [Departamento de Física, Universidad Técnica Federico Santa María, Av. España 1680, Valparaiso 2390123 (Chile); Häberle, Patricio [Departamento de Física, Universidad Técnica Federico Santa María, Av. España 1680, Valparaiso 2390123 (Chile)

    2014-11-03

    In this work, we study the effect of thiol self assembled monolayers on the electrical resistivity of metallic thin films. The analysis is based on the Fuchs–Sondheimer–Lucas theory and on electrical transport measurements. We determined resistivity change due to dodecanethiol adsorption on gold thin films. For this purpose, we controlled the deposition and annealing temperatures of the films to change the surface topography and to diminish the effect of electron grain boundary scattering. Results show that the electrical response to the absorption of thiols strongly depends on the initial topography of the surface. - Highlights: • We study the effect of self assembled monolayers on the resistivity of thin films. • Fuchs–Sondheimer theory reproduces the resistivity increase due to thiol deposition. • We determined resistivity change due to dodecanethiol deposition on gold thin films. • The electrical response strongly depends on the substrate surface topography.

  3. Valence control of cobalt oxide thin films by annealing atmosphere

    International Nuclear Information System (INIS)

    Wang Shijing; Zhang Boping; Zhao Cuihua; Li Songjie; Zhang Meixia; Yan Liping

    2011-01-01

    The cobalt oxide (CoO and Co 3 O 4 ) thin films were successfully prepared using a spin-coating technique by a chemical solution method with CH 3 OCH 2 CH 2 OH and Co(NO 3 ) 2 .6H 2 O as starting materials. The grayish cobalt oxide films had uniform crystalline grains with less than 50 nm in diameter. The phase structure is able to tailor by controlling the annealing atmosphere and temperature, in which Co 3 O 4 thin film was obtained by annealing in air at 300-600, and N 2 at 300, and transferred to CoO thin film by raising annealing temperature in N 2 . The fitted X-ray photoelectron spectroscopy (XPS) spectra of the Co2p electrons are distinguishable from different valence states of cobalt oxide especially for their satellite structure. The valence control of cobalt oxide thin films by annealing atmosphere contributes to the tailored optical absorption property.

  4. Laser nanostructuring of ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Nedyalkov, N., E-mail: nned@ie.bas.bg [Department of Electronics and Electrical Engineering, Keio University, 3-14-1 Hiyoshi Kohoku-ku, Yokohama-shi, Kanagawa-ken 223-8522 (Japan); Institute of Electronics, Bulgarian Academy of Sciences, Tzarigradsko shousse 72, Sofia 1784 (Bulgaria); Koleva, M.; Nikov, R.; Atanasov, P. [Institute of Electronics, Bulgarian Academy of Sciences, Tzarigradsko shousse 72, Sofia 1784 (Bulgaria); Nakajima, Y.; Takami, A.; Shibata, A.; Terakawa, M. [Department of Electronics and Electrical Engineering, Keio University, 3-14-1 Hiyoshi Kohoku-ku, Yokohama-shi, Kanagawa-ken 223-8522 (Japan)

    2016-06-30

    Highlights: • Nanosecond laser pulse nanostructuring of ZnO thin films on metal substrate is demonstrated. • Two regimes of the thin film modification are observed depending on the applied laser fluence. • At high fluence regime the ZnO film is homogeneously decomposed into nanosized particles. • The characteristic size of the formed nanostructures corresponds to the domain size of the thin film. - Abstract: In this work, results on laser processing of thin zinc oxide films deposited on metal substrate are presented. ZnO films are obtained by classical nanosecond pulsed laser deposition method in oxygen atmosphere on tantalum substrate. The produced films are then processed by nanosecond laser pulses at wavelength of 355 nm. The laser processing parameters and the film thickness are varied and their influence on the fabricated structures is estimated. The film morphology after the laser treatment is found to depend strongly on the laser fluence as two regimes are defined. It is shown that at certain conditions (high fluence regime) the laser treatment of the film leads to formation of a discrete nanostructure, composed of spherical like nanoparticles with narrow size distribution. The dynamics of the melt film on the substrate and fast cooling are found to be the main mechanisms for fabrication of the observed structures. The demonstrated method is an alternative way for direct fabrication of ZnO nanostructures on metal which can be easy implemented in applications as resistive sensor devices, electroluminescent elements, solar cell technology.

  5. Oxidation of ruthenium thin films using atomic oxygen

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, A.P.; Bogan, J.; Brady, A.; Hughes, G.

    2015-12-31

    In this study, the use of atomic oxygen to oxidise ruthenium thin films is assessed. Atomic layer deposited (ALD) ruthenium thin films (~ 3 nm) were exposed to varying amounts of atomic oxygen and the results were compared to the impact of exposures to molecular oxygen. X-ray photoelectron spectroscopy studies reveal substantial oxidation of metallic ruthenium films to RuO{sub 2} at exposures as low as ~ 10{sup 2} L at 575 K when atomic oxygen was used. Higher exposures of molecular oxygen resulted in no metal oxidation highlighting the benefits of using atomic oxygen to form RuO{sub 2}. Additionally, the partial oxidation of these ruthenium films occurred at temperatures as low as 293 K (room temperature) in an atomic oxygen environment. - Highlights: • X-ray photoelectron spectroscopy study of the oxidation of Ru thin films • Oxidation of Ru thin films using atomic oxygen • Comparison between atomic oxygen and molecular oxygen treatments on Ru thin films • Fully oxidised RuO{sub 2} thin films formed with low exposures to atomic oxygen.

  6. Molecular simulation of freestanding amorphous nickel thin films

    Energy Technology Data Exchange (ETDEWEB)

    Dong, T.Q. [Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, UMR 8208 CNRS, 5 Boulevard Descartes, 77454 Marne-la-Vallée, Cedex 2 (France); Hoang, V.V., E-mail: vvhoang2002@yahoo.com [Department of Physics, Institute of Technology, National University of Ho Chi Minh City, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City (Viet Nam); Lauriat, G. [Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, UMR 8208 CNRS, 5 Boulevard Descartes, 77454 Marne-la-Vallée, Cedex 2 (France)

    2013-10-31

    Size effects on glass formation in freestanding Ni thin films have been studied via molecular dynamics simulation with the n-body Gupta interatomic potential. Atomic mechanism of glass formation in the films is determined via analysis of the spatio-temporal arrangements of solid-like atoms occurred upon cooling from the melt. Solid-like atoms are detected via the Lindemann ratio. We find that solid-like atoms initiate and grow mainly in the interior of the film and grow outward. Their number increases with decreasing temperature and at a glass transition temperature they dominate in the system to form a relatively rigid glassy state of a thin film shape. We find the existence of a mobile surface layer in both liquid and glassy states which can play an important role in various surface properties of amorphous Ni thin films. We find that glass formation is size independent for models containing 4000 to 108,000 atoms. Moreover, structure of amorphous Ni thin films has been studied in details via coordination number, Honeycutt–Andersen analysis, and density profile which reveal that amorphous thin films exhibit two different parts: interior and surface layer. The former exhibits almost the same structure like that found for the bulk while the latter behaves a more porous structure containing a large amount of undercoordinated sites which are the origin of various surface behaviors of the amorphous Ni or Ni-based thin films found in practice. - Highlights: • Glass formation is analyzed via spatio-temporal arrangements of solid-like atoms. • Amorphous Ni thin film exhibits two different parts: surface and interior. • Mobile surface layer enhances various surface properties of the amorphous Ni thin films. • Undercoordinated sites play an important role in various surface activities.

  7. Multifunctional Parylene-C Microfibrous Thin Films

    Science.gov (United States)

    Chindam, Chandraprakash

    Towards sustainable development, multifunctional products have many advantageous over single-function products: reduction in number of parts, raw material, assembly time, and cost involved in a product's life cycle. My goal for this thesis was to demonstrate the multifunctionalities of Parylene-C microfibrous thin films. To achieve this goal, I chose Parylene C, a polymer, because the fabrication of periodic mediums of Parylene C in the form of microfibrous thin films (muFTFs) was already established. A muFTFs is a parallel arrangement of identical micrometer-sized fibers of shapes cylindrical, chevronic, or helical. Furthermore, Parylene C had three existing functions: in medical-device industries as corrosion-resistive coatings, in electronic industries as electrically insulating coatings, and in biomedical research for tissue-culture substrates. As the functionalities of a material are dependent on the microstructure and physical properties, the investigation made for this thesis was two-fold: (1) Experimentally, I determined the wetting, mechanical, and dielectric properties of columnar muFTFs and examined the microstructural and molecular differences between bulk films and muFTFs. (2) Using physical properties of bulk film, I computationally determined the elastodynamic and determined the electromagnetic filtering capabilities of Parylene-C muFTFs. Several columnar muFTFs of Parylene C were fabricated by varying the monomer deposition angle. Following are the significant experimental findings: 1. Molecular and microstructural characteristics: The dependence of the microfiber inclination angle on the monomer deposition angle was classified into four regimes of two different types. X-ray diffraction experiments indicated that the columnar muFTFs contain three crystal planes not evident in bulk Parylene-C films and that the columnar muFTFs are less crystalline than bulk films. Infrared absorbance spectra revealed that the atomic bonding is the same in all

  8. Fabrication and Film Qualification of Sr Modified Pb(Ca) TiO3 Thin Films

    International Nuclear Information System (INIS)

    Naw Hla Myat San; Khin Aye Thwe; Than Than Win; Yin Maung Maung; Ko Ko Kyaw Soe

    2011-12-01

    Strontium and calcium - modified lead titanate (Pb0.7 Ca0.15 Sr0.15 ) TiO3 (PCST)thin films were prepared by using spin coating technique. Phase transition of PCST was interpreted by means of Er-T characteristics. Process temperature dependence on micro-structure of PCST film was studied. Charge conduction mechanism of PCST thin film was also investigated for film qualification.

  9. Development of neutron diffuse scattering analysis code by thin film and multilayer film

    International Nuclear Information System (INIS)

    Soyama, Kazuhiko

    2004-01-01

    To research surface structure of thin film and multilayer film by neutron, a neutron diffuse scattering analysis code using DWBA (Distorted-Wave Bron Approximation) principle was developed. Subjects using this code contain the surface and interface properties of solid/solid, solid/liquid, liquid/liquid and gas/liquid, and metal, magnetism and polymer thin film and biomembran. The roughness of surface and interface of substance shows fractal self-similarity and its analytical model is based on DWBA theory by Sinha. The surface and interface properties by diffuse scattering are investigated on the basis of the theoretical model. The calculation values are proved to be agreed with the experimental values. On neutron diffuse scattering by thin film, roughness of surface of thin film, correlation function, neutron propagation by thin film, diffuse scattering by DWBA theory, measurement model, SDIFFF (neutron diffuse scattering analysis program by thin film) and simulation results are explained. On neutron diffuse scattering by multilayer film, roughness of multilayer film, principle of diffuse scattering, measurement method and simulation examples by MDIFF (neutron diffuse scattering analysis program by multilayer film) are explained. (S.Y.)To research surface structure of thin film and multilayer film by neutron, a neutron diffuse scattering analysis code using DWBA (Distorted-Wave Bron Approximation) principle was developed. Subjects using this code contain the surface and interface properties of solid/solid, solid/liquid, liquid/liquid and gas/liquid, and metal, magnetism and polymer thin film and biomembran. The roughness of surface and interface of substance shows fractal self-similarity and its analytical model is based on DWBA theory by Sinha. The surface and interface properties by diffuse scattering are investigated on the basis of the theoretical model. The calculation values are proved to be agreed with the experimental values. On neutron diffuse scattering

  10. Stability of tetraphenyl butadiene thin films in liquid xenon

    International Nuclear Information System (INIS)

    Sanguino, P.; Balau, F.; Botelho do Rego, A.M.; Pereira, A.; Chepel, V.

    2016-01-01

    Tetraphenyl butadiene (TPB) is widely used in particle detectors as a wavelength shifter. In this work we studied the stability of TPB thin films when immersed in liquid xenon (LXe). The thin films were deposited on glass and quartz substrates by thermal evaporation. Morphological and chemical surface properties were monitored before and after immersion into LXe by scanning electron microscopy and X-ray photoelectron spectroscopy. No appreciable changes have been detected with these two methods. Grain size and surface chemical composition were found to be identical before and after submersion into LXe. However, the film thickness, measured via optical transmission in the ultraviolet–visible wavelength regions, decreased by 1.6 μg/cm 2 (24%) after immersion in LXe during 20 h. These results suggest the necessity of using a protective thin film over the Tetraphenyl butadiene when used as a wavelength shifter in LXe particle detectors. - Highlights: • Stability of tetraphenyl butadiene (TPB) thin films immersed in liquid xenon (LXe). • Thermally evaporated TPB thin films were immersed in LXe for 20 h. • Film morphology and chemical surface properties remained unchanged. • Surface density of the films decreased by 1.6 μg/cm 2 (24%) after immersion in LXe. • For using in LXe particle detectors, TPB films should be protected with a coating.

  11. Modification of thin film properties by ion bombardment during deposition

    International Nuclear Information System (INIS)

    Harper, J.M.E.; Cuomo, J.J.; Gambino, R.J.; Kaufman, H.R.

    1984-01-01

    Many thin film deposition techniques involve some form of energetic particle bombardment of the growing film. The degree of bombardment greatly influences the film composition, structure and other properties. While in some techniques the degree of bombardment is secondary to the original process design, in recent years more deposition systems are being designed with the capability for controlled ion bombardment of thin films during deposition. The highest degree of control is obtained with ion beam sources which operate independently of the vapor source providing the thin film material. Other plasma techniques offer varying degrees of control of energetic particle bombardment. Deposition methods involving ion bombardment are described, and the basic processes with which film properties are modified by ion bombardment are summarized. (Auth.)

  12. Electrochromic properties of nanocrystalline MoO3 thin films

    International Nuclear Information System (INIS)

    Hsu, C.-S.; Chan, C.-C.; Huang, H.-T.; Peng, C.-H.; Hsu, W.-C.

    2008-01-01

    Electrochromic MoO 3 thin films were prepared by a sol-gel spin-coating technique. The spin-coated films were initially amorphous; they were calcined, producing nanocrystalline MoO 3 thin films. The effects of annealing temperatures ranging from 100 o C to 500 o C were investigated. The electrochemical and electrochromic properties of the films were measured by cyclic voltammetry and by in-situ optical transmittance techniques in 1 M LiClO 4 /propylene carbonate electrolyte. Experimental results showed that the transmittance of MoO 3 thin films heat-treated at 350 o C varied from 80% to 35% at λ = 550 nm (ΔT = ∼ 45%) and from 86% to 21% at λ ≥ 700 nm (ΔT = ∼ 65%) after coloration. Films heat-treated at 350 deg. C exhibited the best electrochromic properties in the present study

  13. Residual stress in spin-cast polyurethane thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hong; Zhang, Li, E-mail: lizhang@mae.cuhk.edu.hk [Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin N.T., Hong Kong (China); Chow Yuk Ho Technology Centre for Innovative Medicine, The Chinese University of Hong Kong, Shatin N.T., Hong Kong (China)

    2015-01-19

    Residual stress is inevitable during spin-casting. Herein, we report a straightforward method to evaluate the residual stress in as-cast polyurethane thin films using area shrinkage measurement of films in floating state, which shows that the residual stress is independent of radial location on the substrate and decreased with decreasing film thickness below a critical value. We demonstrate that the residual stress is developed due to the solvent evaporation after vitrification during spin-casting and the polymer chains in thin films may undergo vitrification at an increased concentration. The buildup of residual stress in spin-cast polymer films provides an insight into the size effects on the nature of polymer thin films.

  14. Copper zinc tin sulfide-based thin film solar cells

    CERN Document Server

    Ito, Kentaro

    2014-01-01

    Beginning with an overview and historical background of Copper Zinc Tin Sulphide (CZTS) technology, subsequent chapters cover properties of CZTS thin films, different preparation methods of CZTS thin films, a comparative study of CZTS and CIGS solar cell, computational approach, and future applications of CZTS thin film solar modules to both ground-mount and rooftop installation. The semiconducting compound (CZTS) is made up earth-abundant, low-cost and non-toxic elements, which make it an ideal candidate to replace Cu(In,Ga)Se2 (CIGS) and CdTe solar cells which face material scarcity and tox

  15. Optical modeling and simulation of thin-film photovoltaic devices

    CERN Document Server

    Krc, Janez

    2013-01-01

    In wafer-based and thin-film photovoltaic (PV) devices, the management of light is a crucial aspect of optimization since trapping sunlight in active parts of PV devices is essential for efficient energy conversions. Optical modeling and simulation enable efficient analysis and optimization of the optical situation in optoelectronic and PV devices. Optical Modeling and Simulation of Thin-Film Photovoltaic Devices provides readers with a thorough guide to performing optical modeling and simulations of thin-film solar cells and PV modules. It offers insight on examples of existing optical models

  16. The state of the art of thin-film photovoltaics

    International Nuclear Information System (INIS)

    Surek, T.

    1993-10-01

    Thin-film photovoltaic technologies, based on materials such as amorphous or polycrystalline silicon, copper indium diselenide, cadmium telluride, and gallium arsenide, offer the potential for significantly reducing the cost of electricity generated by photovoltaics. The significant progress in the technologies, from the laboratory to the marketplace, is reviewed. The common concerns and questions raised about thin films are addressed. Based on the progress to date and the potential of these technologies, along with continuing investments by the private sector to commercialize the technologies, one can conclude that thin-film PV will provide a competitive alternative for large-scale power generation in the future

  17. Thin film circuits for future applications. Pt. 2. Evaporation technique

    Energy Technology Data Exchange (ETDEWEB)

    Haug, G; Houska, K H; Schmidt, H J; Sprengel, H P; Wohak, K

    1976-06-01

    Investigations of thin film diffusion processes and reactions with encapsulation materials resulted in improved long term stability of evaporated NiCr resistors, SiO capacitors and NiCr/Au conductors for thin film circuits. Stable NiCr resistor networks can be formed on ceramic substrates, and SiO capacitors of good quality can be deposited on the new very smooth ceramic substrates. The knowledge of the influence of evaporation parameters make the production of SiO capacitors with definite properties and good reproducibility possible. The range of capacitance of tantalum thin film circuits can be extended by integration with evaporated SiO capacitors.

  18. XRay Study of Transfer Printed Pentacene Thin Films

    International Nuclear Information System (INIS)

    Shao, Y.; Solin, S. A.; Hines, D. R.; Williams, E. D.

    2007-01-01

    We investigated the structural properties and transfer properties of pentacene thin films fabricated by thermal deposition and transfer printing onto SiO2 and plastic substrates, respectively. The dependence of the crystallite size on the printing time, temperature and pressure were measured. The increases of crystalline size were observed when pentacene thin films were printed under specific conditions, e.g. 120 deg. C and 600 psi and can be correlated with the improvement of the field effect mobility of pentacene thin-film transistors

  19. Optical properties of CeO 2 thin films

    Indian Academy of Sciences (India)

    Cerium oxide (CeO2) thin films have been prepared by electron beam evaporation technique onto glass substrate at a pressure of about 6 × 10-6 Torr. The thickness of CeO2 films ranges from 140–180 nm. The optical properties of cerium oxide films are studied in the wavelength range of 200–850 nm. The film is highly ...

  20. Principles of electron backscattering by solids and thin films

    International Nuclear Information System (INIS)

    Niedrig, H.

    1977-01-01

    The parameters concerning the electron backscattering from thin films and solids (atomic scattering cross-section, atomic number, single/multiple scattering, film thickness of self-supporting films and of surface films on bulk substrates, scattering angular distribution, angle of incidence, diffraction effects) are described. Their influence on some important contrast mechanisms in scanning electron microscopy (thickness contrast, Z/material contrast, tilting/topography contrast, orientation contrast) is discussed. The main backscattering electron detection systems are briefly described. (orig.) [de

  1. Dewetting of thin polymer film on rough substrate: II. Experiment

    International Nuclear Information System (INIS)

    Volodin, Pylyp; Kondyurin, Alexey

    2008-01-01

    The theory of the dewetting process developed for a model of substrate-film interaction forces was examined by an experimental investigation of the dewetting process of thin polystyrene (PS) films on chemically etched silicon substrates. In the dependence on PS films thickness and silicon roughness, various situations of dewetting were observed as follows: (i) if the wavelength of the substrate roughness is much larger than the critical spinodal wavelength of a film, then spinodal dewetting of the film is observed; (ii) if the wavelength of the substrate roughness is smaller than the critical wavelength of the film and the substrate roughness is larger in comparison with film thickness, then the dewetting due to substrate roughness is observed and the dewetted film patterns repeat the rough substrate structure; (iii) if the wavelength of the substrate roughness is smaller than the critical wavelength of the film and the substrate roughness is small in comparison with the film thickness, then spinodal dewetting proceeds

  2. Ideal glass transitions in thin films: An energy landscape perspective

    Science.gov (United States)

    Truskett, Thomas M.; Ganesan, Venkat

    2003-07-01

    We introduce a mean-field model for the potential energy landscape of a thin fluid film confined between parallel substrates. The model predicts how the number of accessible basins on the energy landscape and, consequently, the film's ideal glass transition temperature depend on bulk pressure, film thickness, and the strength of the fluid-fluid and fluid-substrate interactions. The predictions are in qualitative agreement with the experimental trends for the kinetic glass transition temperature of thin films, suggesting the utility of landscape-based approaches for studying the behavior of confined fluids.

  3. Strain Relaxation and Vacancy Creation in Thin Platinum Films

    International Nuclear Information System (INIS)

    Gruber, W.; Chakravarty, S.; Schmidt, H.; Baehtz, C.; Leitenberger, W.; Bruns, M.; Kobler, A.; Kuebel, C.

    2011-01-01

    Synchrotron based combined in situ x-ray diffractometry and reflectometry is used to investigate the role of vacancies for the relaxation of residual stress in thin metallic Pt films. From the experimentally determined relative changes of the lattice parameter a and of the film thickness L the modification of vacancy concentration and residual strain was derived as a function of annealing time at 130 deg. C. The results indicate that relaxation of strain resulting from compressive stress is accompanied by the creation of vacancies at the free film surface. This proves experimentally the postulated dominant role of vacancies for stress relaxation in thin metal films close to room temperature.

  4. Soft Magnetic Multilayered Thin Films for HF Applications

    Science.gov (United States)

    Loizos, George; Giannopoulos, George; Serletis, Christos; Maity, Tuhin; Roy, Saibal; Lupu, Nicoleta; Kijima, Hanae; Yamaguchi, Masahiro; Niarchos, Dimitris

    Multilayered thin films from various soft magnetic materials were successfully prepared by magnetron sputtering in Ar atmosphere. The magnetic properties and microstructure were investigated. It is found that the films show good soft magnetic properties: magnetic coercivity of 1-10 Oe and saturation magnetization higher than 1T. The initial permeability of the films is greater than 300 and flattens up to 600 MHz. The multilayer thin film properties in combination with their easy, fast and reproducible fabrication indicate that they are potential candidates for high frequency applications.

  5. Microwave Josephson generation in thin film superconducting bridges

    International Nuclear Information System (INIS)

    Gubankov, V.N.; Koshelets, V.P.; Ovsyannikov, G.A.

    1975-01-01

    Thin-film bridges have some advantage over other types of superconducting weak links: good definition of electromagnetic parameters and of weak region geometry. Up to now Josephson properties of bridges have been investigated by using indirect methods (the effect of magnetic field on the critical current I 0 , the bridge behavior in a microwave field, etc.). Direct experimental observation of Josephson radiation from autonomous thin film bridges is reported. Microwave radiation in tin bridges of 'variable' thickness has been investigated where the thickness of the film forming the bridge is far less than the thickness of the bank films. (Auth.)

  6. Photoinduced hydrophobic surface of graphene oxide thin films

    International Nuclear Information System (INIS)

    Zhang Xiaoyan; Song Peng; Cui Xiaoli

    2012-01-01

    Graphene oxide (GO) thin films were deposited on transparent conducting oxide substrates and glass slides by spin coating method at room temperature. The wettability of GO thin films before and after ultraviolet (UV) irradiation was characterized with water contact angles, which increased from 27.3° to 57.6° after 3 h of irradiation, indicating a photo-induced hydrophobic surface. The UV–vis absorption spectra, Raman spectroscopy, X-ray photoelectron spectroscopy, and conductivity measurements of GO films before and after UV irradiation were taken to study the mechanism of photoinduced hydrophobic surface of GO thin films. It is demonstrated that the photoinduced hydrophobic surface is ascribed to the elimination of oxygen-containing functional groups on GO molecules. This work provides a simple strategy to control the wettability properties of GO thin films by UV irradiation. - Highlights: ► Photoinduced hydrophobic surface of graphene oxide thin films has been demonstrated. ► Elimination of oxygen-containing functional groups in graphene oxide achieved by UV irradiation. ► We provide novel strategy to control surface wettability of GO thin films by UV irradiation.

  7. Tools to synthesize the learning of thin films

    International Nuclear Information System (INIS)

    Rojas, Roberto; Fuster, Gonzalo; Sluesarenko, Viktor

    2011-01-01

    After a review of textbooks written for undergraduate courses in physics, we have found that discussions on thin films are mostly incomplete. They consider the reflected and not the transmitted light for two instead of the four types of thin films. In this work, we complement the discussion in elementary textbooks, by analysing the phase differences required to match the conditions for constructive and destructive interference, in the reflected and transmitted light in four types of thin films. We consider thin films with varied sequences in the refractive index, which we identify as barriers, wells and stairs (up and down). Also, we use the conservation of energy in order to understand the complementary colour fringes observed in the reflected and transmitted light through thin films. We analyse systematically the phase changes by introducing a phase table and we synthesize the results in a circular diagram matching 16 physical situations of interference and their corresponding conditions on the film thickness. The phase table and the circular diagram are a pair of tools easily assimilated by students, and useful to organize, analyse and activate the knowledge about thin films.

  8. Thin Films for X-ray Optics

    Science.gov (United States)

    Conley, Raymond

    Focusing x-rays with refraction requires an entire array of lens instead of a single element, each contributing a minute amount of focusing to the system. In contrast to their visible light counterparts, diffractive optics require a certain depth along the optical axis in order to provide sufficient phase shift. Mirrors reflect only at very shallow angles. In order to increase the angle of incidence, contribution from constructive interference within many layers needs to be collected. This requires a multilayer coating. Thin films have become a central ingredient for many x-ray optics due to the ease of which material composition and thickness can be controlled. Chapter 1 starts with a short introduction and survey of the field of x-ray optics. This begins with an explanation of reflective multilayers. Focusing optics are presented next, including mirrors, zone plates, refractive lenses, and multilayer Laue lens (MLL). The strengths and weaknesses of each "species" of optic are briefly discussed, alongside fabrication issues and the ultimate performance for each. Practical considerations on the use of thin-films for x-ray optics fabrication span a wide array of topics including material systems selection and instrumentation design. Sputter deposition is utilized exclusively for the work included herein because this method of thin-film deposition allows a wide array of deposition parameters to be controlled. This chapter also includes a short description of two deposition systems I have designed. Chapter 2 covers a small sampling of some of my work on reflective multilayers, and outlines two of the deposition systems I have designed and built at the Advanced Photon Source. A three-stripe double multilayer monochromator is presented as a case study in order to detail specifications, fabrication, and performance of this prolific breed of x-ray optics. The APS Rotary Deposition System was the first deposition system in the world designed specifically for multilayer

  9. Large carbon cluster thin film gauges for measuring aerodynamic heat transfer rates in hypersonic shock tunnels

    International Nuclear Information System (INIS)

    Srinath, S; Reddy, K P J

    2015-01-01

    Different types of Large Carbon Cluster (LCC) layers are synthesized by a single-step pyrolysis technique at various ratios of precursor mixture. The aim is to develop a fast responsive and stable thermal gauge based on a LCC layer which has relatively good electrical conduction in order to use it in the hypersonic flow field. The thermoelectric property of the LCC layer has been studied. It is found that these carbon clusters are sensitive to temperature changes. Therefore suitable thermal gauges were developed for blunt cone bodies and were tested in hypersonic shock tunnels at a flow Mach number of 6.8 to measure aerodynamic heating. The LCC layer of this thermal gauge encounters high shear forces and a hostile environment for test duration in the range of a millisecond. The results are favorable to use large carbon clusters as a better sensor than a conventional platinum thin film gauge in view of fast responsiveness and stability. (paper)

  10. Thermionic vacuum arc (TVA) technique for magnesium thin film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Balbag, M.Z., E-mail: zbalbag@ogu.edu.t [Eskisehir Osmangazi University, Education Faculty, Primary Education, Meselik Campus, Eskisehir 26480 (Turkey); Pat, S.; Ozkan, M.; Ekem, N. [Eskisehir Osmangazi University, Art and Science Faculty, Physics Department, Eskisehir 26480 (Turkey); Musa, G. [Ovidius University, Physics Department, Constanta (Romania)

    2010-08-15

    In this study, magnesium thin films were deposited on glass substrate by the Thermionic Vacuum Arc (TVA) technique for the first time. We present a different technique for deposition of high-quality magnesium thin films. By means of this technique, the production of films is achieved by condensing the plasma of anode material generated using Thermionic Vacuum Arc (TVA) under high vacuum conditions onto the surface to be coated. The crystal orientation and morphology of the deposited films were investigated by using XRD, EDX, SEM and AFM. The aim of this study is to search the use of TVA technique to coat magnesium thin films and to determine some of the physical properties of the films generated. Furthermore, this study will contribute to the scientific studies which search the thin films of magnesium or the compounds containing magnesium. In future, this study will be preliminary work to entirely produce magnesium diboride (MgB{sub 2}) superconductor thin film with the TVA technique.

  11. ITO thin films deposited by advanced pulsed laser deposition

    International Nuclear Information System (INIS)

    Viespe, Cristian; Nicolae, Ionut; Sima, Cornelia; Grigoriu, Constantin; Medianu, Rares

    2007-01-01

    Indium tin oxide thin films were deposited by computer assisted advanced PLD method in order to obtain transparent, conductive and homogeneous films on a large area. The films were deposited on glass substrates. We studied the influence of the temperature (room temperature (RT)-180 deg. C), pressure (1-6 x 10 -2 Torr), laser fluence (1-4 J/cm 2 ) and wavelength (266-355 nm) on the film properties. The deposition rate, roughness, film structure, optical transmission, electrical conductivity measurements were done. We deposited uniform ITO thin films (thickness 100-600 nm, roughness 5-10 nm) between RT and 180 deg. C on a large area (5 x 5 cm 2 ). The films have electrical resistivity of 8 x 10 -4 Ω cm at RT, 5 x 10 -4 Ω cm at 180 deg. C and an optical transmission in the visible range, around 89%

  12. Broadband back grating design for thin film solar cells

    KAUST Repository

    Janjua, Bilal; Jabbour, Ghassan E.

    2013-01-01

    In this paper, design based on tapered circular grating structure was studied, to provide broadband enhancement in thin film amorphous silicon solar cells. In comparison to planar structure an absorption enhancement of ~ 7% was realized.

  13. Laser-Printed Organic Thin-Film Transistors

    KAUST Repository

    Diemer, Peter J.; Harper, Angela F.; Niazi, Muhammad Rizwan; Petty, Anthony J.; Anthony, John E.; Amassian, Aram; Jurchescu, Oana D.

    2017-01-01

    their incorporation in large-scale manufacturing processes. Here, the first ever organic thin-film transistor fabricated with an electrophotographic laser printing process using a standard office laser printer is reported. This completely solvent-free additive

  14. Preparation of Nb thin films with bulk transition temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Peirce, L H [Florida State Univ., Tallahassee (USA). Dept. of Physics

    1984-08-01

    Thin films (1000-2000 A) of Nb were prepared with bulk transition temperatures (9.25 K) by evaporation from an electron gun. Necessary substrate temperatures, evaporation rates and H/sub 2/O pressures were determined.

  15. A Variational approach to thin film hydrodynamics of binary mixtures

    KAUST Repository

    Xu, Xinpeng; Thiele, Uwe; Qian, Tiezheng

    2015-01-01

    In order to model the dynamics of thin films of mixtures, solutions, and suspensions, a thermodynamically consistent formulation is needed such that various coexisting dissipative processes with cross couplings can be correctly described

  16. Chemical solution deposition of functional oxide thin films

    CERN Document Server

    Schneller, Theodor; Kosec, Marija

    2014-01-01

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

  17. Mechanism of spontaneous hole formation in thin polymeric films

    DEFF Research Database (Denmark)

    Yu, Kaijia; Rasmussen, Henrik K.; Román Marín, José Manuel

    2012-01-01

    We show computationally that (molten) thin polymeric film containing nonequilibrium configurations originating from a solvent evaporation may develop holes spontaneously in the molten state, and that they appear delayed. Polymers above the glass transition temperature are liquids where the flow...

  18. Simple gun for vapor deposition of organic thin films

    International Nuclear Information System (INIS)

    Sato, N.; Seki, K.; Inokuchi, H.

    1987-01-01

    A simple evaporation gun for preparing organic thin films was fabricated using commercially available parts of an electron gun for a TV Braun tube. The device permits sample heating to be easily controlled because of the small heat capacity

  19. Multiferroic iron oxide thin films at room temperature

    Czech Academy of Sciences Publication Activity Database

    Gich, M.; Fina, I.; Morelli, Alessio; Sánchez, F.; Alexe, M.; Gazquez, J.; Fontcuberta, J.; Roig, A.

    2014-01-01

    Roč. 26, č. 27 (2014), s. 4645-4652 ISSN 0935-9648 Institutional support: RVO:68378271 Keywords : multiferroic * iron oxide * thin film Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 17.493, year: 2014

  20. Bandtail characteristics in InN thin films

    International Nuclear Information System (INIS)

    Shen, W.Z.; Jiang, L.F.; Yang, H.F.; Meng, F.Y.; Ogawa, H.; Guo, Q.X.

    2002-01-01

    The Urbach bandtail characteristics in InN thin films grown by radio-frequency magnetron sputtering on sapphire (0001) substrates have been investigated both theoretically and experimentally. The bandtail parameter in InN thin films has been obtained by temperature-dependent transmission spectra, with the aid of a detailed calculation of the transmission profile. A bandtail model based on the calculation of density of occupied states and the carrier-phonon interaction has been employed to analyze the temperature-dependent bandtail characteristics. The bandtail parameter is in the range of 90-120 meV in the InN thin film. It is found that the carrier-phonon interaction in InN is weak and the structural disorder contribution (∼90 meV) dominates over the interactive terms. The high structural disorder in InN thin films may relate to the high nonradiative recombination centers

  1. High Performance Thin-Film Composite Forward Osmosis Membrane

    KAUST Repository

    Yip, Ngai Yin; Tiraferri, Alberto; Phillip, William A.; Schiffman, Jessica D.; Elimelech, Menachem

    2010-01-01

    obstacle hindering further advancements of this technology. This work presents the development of a high performance thin-film composite membrane for forward osmosis applications. The membrane consists of a selective polyamide active layer formed

  2. A thin film hydroponic system for plant studies

    Science.gov (United States)

    Hines, Robert; Prince, Ralph; Muller, Eldon; Schuerger, Andrew

    1990-01-01

    The Land Pavillion, EPCOT Center, houses a hydroponic, thin film growing system identical to that residing in NASA's Biomass Production Chamber at Kennedy Space Center. The system is targeted for plant disease and nutrition studies. The system is described.

  3. Phonon transport across nano-scale curved thin films

    Energy Technology Data Exchange (ETDEWEB)

    Mansoor, Saad B.; Yilbas, Bekir S., E-mail: bsyilbas@kfupm.edu.sa

    2016-12-15

    Phonon transport across the curve thin silicon film due to temperature disturbance at film edges is examined. The equation for radiative transport is considered via incorporating Boltzmann transport equation for the energy transfer. The effect of the thin film curvature on phonon transport characteristics is assessed. In the analysis, the film arc length along the film centerline is considered to be constant and the film arc angle is varied to obtain various film curvatures. Equivalent equilibrium temperature is introduced to assess the phonon intensity distribution inside the curved thin film. It is found that equivalent equilibrium temperature decay along the arc length is sharper than that of in the radial direction, which is more pronounced in the region close to the film inner radius. Reducing film arc angle increases the film curvature; in which case, phonon intensity decay becomes sharp in the close region of the high temperature edge. Equivalent equilibrium temperature demonstrates non-symmetric distribution along the radial direction, which is more pronounced in the near region of the high temperature edge.

  4. Phonon transport across nano-scale curved thin films

    International Nuclear Information System (INIS)

    Mansoor, Saad B.; Yilbas, Bekir S.

    2016-01-01

    Phonon transport across the curve thin silicon film due to temperature disturbance at film edges is examined. The equation for radiative transport is considered via incorporating Boltzmann transport equation for the energy transfer. The effect of the thin film curvature on phonon transport characteristics is assessed. In the analysis, the film arc length along the film centerline is considered to be constant and the film arc angle is varied to obtain various film curvatures. Equivalent equilibrium temperature is introduced to assess the phonon intensity distribution inside the curved thin film. It is found that equivalent equilibrium temperature decay along the arc length is sharper than that of in the radial direction, which is more pronounced in the region close to the film inner radius. Reducing film arc angle increases the film curvature; in which case, phonon intensity decay becomes sharp in the close region of the high temperature edge. Equivalent equilibrium temperature demonstrates non-symmetric distribution along the radial direction, which is more pronounced in the near region of the high temperature edge.

  5. Inverse bilayer magnetoelectric thin film sensor

    Energy Technology Data Exchange (ETDEWEB)

    Yarar, E.; Piorra, A.; Quandt, E., E-mail: eq@tf.uni-kiel.de [Chair for Inorganic Functional Materials, Institute for Materials Science, Faculty of Engineering, Kiel University, Kaiserstraße 2, D-24143 Kiel (Germany); Salzer, S.; Höft, M.; Knöchel, R. [Microwave Laboratory, Institute of Electrical and Information Engineering, Faculty of Engineering, Kiel University, Kaiserstraße 2, D-24143 Kiel (Germany); Hrkac, V.; Kienle, L. [Chair for Synthesis and Real Structure, Institute for Materials Science, Faculty of Engineering, Kiel University, Kaiserstraße 2, D-24143 Kiel (Germany)

    2016-07-11

    Prior investigations on magnetoelectric (ME) thin film sensors using amorphous FeCoSiB as a magnetostrictive layer and AlN as a piezoelectric layer revealed a limit of detection (LOD) in the range of a few pT/Hz{sup 1/2} in the mechanical resonance. These sensors are comprised of a Si/SiO{sub 2}/Pt/AlN/FeCoSiB layer stack, as dictated by the temperatures required for the deposition of the layers. A low temperature deposition route of very high quality AlN allows the reversal of the deposition sequence, thus allowing the amorphous FeCoSiB to be deposited on the very smooth Si substrate. As a consequence, the LOD could be enhanced by almost an order of magnitude reaching 400 fT/Hz{sup 1/2} at the mechanical resonance of the sensor. Giant ME coefficients (α{sub ME}) as high as 5 kV/cm Oe were measured. Transmission electron microscopy investigations revealed highly c-axis oriented growth of the AlN starting from the Pt-AlN interface with local epitaxy.

  6. Degradation analysis of thin film photovoltaic modules

    International Nuclear Information System (INIS)

    Radue, C.; Dyk, E.E. van

    2009-01-01

    Five thin film photovoltaic modules were deployed outdoors under open circuit conditions after a thorough indoor evaluation. Two technology types were investigated: amorphous silicon (a-Si:H) and copper indium gallium diselenide (CIGS). Two 14 W a-Si:H modules, labelled Si-1 and Si-2, were investigated. Both exhibited degradation, initially due to the well-known light-induced degradation described by Staebler and Wronski [Applied Physics Letters 31 (4) (1977) 292], and thereafter due to other degradation modes such as cell degradation. The various degradation modes contributing to the degradation of the a-Si:H modules will be discussed. The initial maximum power output (P MAX ) of Si-1 was 9.92 W, with the initial light-induced degradation for Si-1 ∼30% and a total degradation of ∼42%. For Si-2 the initial P MAX was 7.93 W, with initial light-induced degradation of ∼10% and a total degradation of ∼17%. Three CIGS modules were investigated: two 20 W modules labelled CIGS-1 and CIGS-2, and a 40 W module labelled CIGS-3. CIGS-2 exhibited stable performance while CIGS-1 and CIGS-3 exhibited degradation. CIGS is known to be stable over long periods of time, and thus the possible reasons for the degradation of the two modules are discussed.

  7. Degradation analysis of thin film photovoltaic modules

    Energy Technology Data Exchange (ETDEWEB)

    Radue, C., E-mail: chantelle.radue@nmmu.ac.z [Department of Physics, PO Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth 6031 (South Africa); Dyk, E.E. van [Department of Physics, PO Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth 6031 (South Africa)

    2009-12-01

    Five thin film photovoltaic modules were deployed outdoors under open circuit conditions after a thorough indoor evaluation. Two technology types were investigated: amorphous silicon (a-Si:H) and copper indium gallium diselenide (CIGS). Two 14 W a-Si:H modules, labelled Si-1 and Si-2, were investigated. Both exhibited degradation, initially due to the well-known light-induced degradation described by Staebler and Wronski [Applied Physics Letters 31 (4) (1977) 292], and thereafter due to other degradation modes such as cell degradation. The various degradation modes contributing to the degradation of the a-Si:H modules will be discussed. The initial maximum power output (P{sub MAX}) of Si-1 was 9.92 W, with the initial light-induced degradation for Si-1 approx30% and a total degradation of approx42%. For Si-2 the initial P{sub MAX} was 7.93 W, with initial light-induced degradation of approx10% and a total degradation of approx17%. Three CIGS modules were investigated: two 20 W modules labelled CIGS-1 and CIGS-2, and a 40 W module labelled CIGS-3. CIGS-2 exhibited stable performance while CIGS-1 and CIGS-3 exhibited degradation. CIGS is known to be stable over long periods of time, and thus the possible reasons for the degradation of the two modules are discussed.

  8. Product reliability and thin-film photovoltaics

    Science.gov (United States)

    Gaston, Ryan; Feist, Rebekah; Yeung, Simon; Hus, Mike; Bernius, Mark; Langlois, Marc; Bury, Scott; Granata, Jennifer; Quintana, Michael; Carlson, Carl; Sarakakis, Georgios; Ogden, Douglas; Mettas, Adamantios

    2009-08-01

    Despite significant growth in photovoltaics (PV) over the last few years, only approximately 1.07 billion kWhr of electricity is estimated to have been generated from PV in the US during 2008, or 0.27% of total electrical generation. PV market penetration is set for a paradigm shift, as fluctuating hydrocarbon prices and an acknowledgement of the environmental impacts associated with their use, combined with breakthrough new PV technologies, such as thin-film and BIPV, are driving the cost of energy generated with PV to parity or cost advantage versus more traditional forms of energy generation. In addition to reaching cost parity with grid supplied power, a key to the long-term success of PV as a viable energy alternative is the reliability of systems in the field. New technologies may or may not have the same failure modes as previous technologies. Reliability testing and product lifetime issues continue to be one of the key bottlenecks in the rapid commercialization of PV technologies today. In this paper, we highlight the critical need for moving away from relying on traditional qualification and safety tests as a measure of reliability and focus instead on designing for reliability and its integration into the product development process. A drive towards quantitative predictive accelerated testing is emphasized and an industrial collaboration model addressing reliability challenges is proposed.

  9. Magnetostatic excitations in thin ferrite films

    International Nuclear Information System (INIS)

    Zil'berman, P.E.; Lugovskoi, A.V.

    1987-01-01

    The authors discuss the influence of the exchange interaction and dissipative processes in thin ferrite films on the eigenfrequency spectrum of magnetostatic standing waves and on the dispersion relation and attenuation of magnetostatic traveling waves. For the first time they obtain explicitly the dispersion relation for magnetostatic waves (MSWs) in a tangential saturating magnetic field H 0 to second order (inclusive) in the exchange interaction parameter λ. The authors obtain computer solutions for this equation in the complex frequency (ω) plane (for standing waves) or wave-number (q) plane (for traveling waves). The authors show that the dispersion relation constructed from the standing-wave spectrum is different from that of the traveling waves if λ≠0, even if dissipation is neglected. The traveling waves have auxiliary branches of the dispersion relation with weak damping near the spin-wave-resonance (SWR) frequencies. Dissipation has only a relatively weak effect on the frequency spectrum of the standing waves, shifting it upward. For the traveling waves, however, dissipation leads to qualitative changes in the structure of the dispersion relation, giving rise to new branches, forbidden bands, reentrant and anomalous-dispersion regions

  10. Thin film deposition using rarefied gas jet

    Science.gov (United States)

    Pradhan, Sahadev, , Dr.

    2017-06-01

    The rarefied gas jet of aluminium is studied at Mach number Ma = (Uj /√{ kbTj / mg }) in the range .01 PVD) process for the development of the highly oriented pure metallic aluminum thin film with uniform thickness and strong adhesion on the surface of the substrate in the form of ionic plasma, so that the substrate can be protected from corrosion and oxidation and thereby enhance the lifetime and safety, and to introduce the desired surface properties for a given application. Here, H is the characteristic dimension, U_j and T_j are the jet velocity and temperature, n_d is the number density of the jet, m and d are the molecular mass and diameter, and kbis the Boltzmann constant. An important finding is that the capture width (cross-section of the gas jet deposited on the substrate) is symmetric around the centerline of the substrate, and decreases with increased Mach number due to an increase in the momentum of the gas molecules. DSMC simulation results reveals that at low Knudsen number ((Kn=0.01); shorter mean free paths), the atoms experience more collisions, which direct them toward the substrate. However, the atoms also move with lower momentum at low Mach number, which allows scattering collisions to rapidly direct the atoms to the substrate.

  11. Nanopolar reorientation in ferroelectric thin films

    International Nuclear Information System (INIS)

    Hubert, C.; Levy, J.; Rivkin, T. V.; Carlson, C.; Parilla, P. A.; Perkins, J. D.; Ginley, D. S.

    2001-01-01

    The influence of varying oxygen pressure P(O 2 ) during the growth of Ba 0.4 Sr 0.6 TiO 3 thin films is investigated using dielectric and local optical probes. A transition from in-plane to out-of-plane ferroelectricity is observed with increasing P(O 2 ). Signatures of in-plane and out-of-plane ferroelectricity are identified using dielectric response and time-resolved confocal scanning optical microscopy (TRCSOM). At the crossover pressure between in-plane and out-of-plane polarization (P c =85 mTorr), TRCSOM measurements reveal a soft, highly dispersive out-of-plane polarization that reorients in plane under modest applied electric fields. At higher deposition pressures, the out-of-plane polarization is hardened and is less dispersive at microwave frequencies, and the dielectric tuning is suppressed. Nanopolar reorientation is believed to be responsible for the marked increase in dielectric tuning at P(O 2 )=P c

  12. Trends and new applications in thin films

    International Nuclear Information System (INIS)

    1996-01-01

    The proceedings of this symposium comprise 95 communications from which 64 were selected and fall into the scope of INIS subject categories, and 1 was selected for ETDE indexing. The selected communications deal with the techniques used for thin films preparation using chemical or physical vapor deposition techniques (plasma-arc or jet spraying, cathode sputtering, reactive DC or RF magnetron sputtering, plasma-ion deposition, ion implantation, electron or ion beam spraying, ion beam assisted plasma etching, dynamic ion mixing, distributed electron cyclotron resonance plasma sputtering, laser induced plasma sputtering etc..). The effects and interactions with the substrates (ion implantation, crystal growth, crystal-phase transformations, microstructures, penetration depth, changes in lattice parameters etc..) are analysed using various techniques such as grazing incidence X-ray diffraction, X-ray reflectometry, X-ray and angle resolved electron spectroscopy, Auger electron spectroscopy, Rutherford backscattering spectroscopy, SEM, TEM, IR absorption spectroscopy, UV or visible emission spectroscopy, conversion electron Moessbauer spectroscopy, X-ray fluorescence, mass spectroscopy, optical ellipsometry etc.. Mechanical tests such as scratch, microhardness and wear tests are also performed on the coatings to analyse their mechanical properties. (J.S.)

  13. Lasing in liquid crystal thin films

    Energy Technology Data Exchange (ETDEWEB)

    Palto, S. P. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)], E-mail: palto@online.ru

    2006-09-15

    A lasing condition is formulated in matrix form for optically anisotropic thin films. Lasing behavior of liquid-crystal slabs is analyzed. In particular, it is shown that if the spatial extent of a liquid crystal slab is much larger than its thickness, then laser emission is feasible not only along the normal to the slab, but also in the entire angular sector. The generated laser light can be observed experimentally as a spot or as concentric rings on a screen. The lowest lasing threshold corresponds to in-plane sliding modes leaking into the substrate. The feedback required for lasing is provided by reflection from the interfaces, rather than edges, of the liquid-crystal slab operating as a planar Fabry-Perot cavity. For cholesteric liquid crystals, it is shown that energy loss to the sliding modes leaking into the substrates and escaping through their edges is a key factor that limits the efficiency of band-edge emission along the normal to the slab.

  14. Silicon Thin-Film Solar Cells

    Directory of Open Access Journals (Sweden)

    Guy Beaucarne

    2007-01-01

    with plasma-enhanced chemical vapor deposition (PECVD. In spite of the fundamental limitation of this material due to its disorder and metastability, the technology is now gaining industrial momentum thanks to the entry of equipment manufacturers with experience with large-area PECVD. Microcrystalline Si (also called nanocrystalline Si is a material with crystallites in the nanometer range in an amorphous matrix, and which contains less defects than amorphous silicon. Its lower bandgap makes it particularly appropriate as active material for the bottom cell in tandem and triple junction devices. The combination of an amorphous silicon top cell and a microcrystalline bottom cell has yielded promising results, but much work is needed to implement it on large-area and to limit light-induced degradation. Finally thin-film polysilicon solar cells, with grain size in the micrometer range, has recently emerged as an alternative photovoltaic technology. The layers have a grain size ranging from 1 μm to several tens of microns, and are formed at a temperature ranging from 600 to more than 1000∘C. Solid Phase Crystallization has yielded the best results so far but there has recently been fast progress with seed layer approaches, particularly those using the aluminum-induced crystallization technique.

  15. Nanostructured refractory thin films for solar applications

    Science.gov (United States)

    Ollier, E.; Dunoyer, N.; Dellea, O.; Szambolics, H.

    2014-08-01

    Selective solar absorbers are key elements of all solar thermal systems. Solar thermal panels and Concentrated Solar Power (CSP) systems aim respectively at producing heat and electricity. In both cases, a surface receives the solar radiation and is designed to have the highest optical absorption (lowest optical reflectivity) of the solar radiation in the visible wavelength range where the solar intensity is the highest. It also has a low emissivity in the infrared (IR) range in order to avoid radiative thermal losses. Current solutions in the state of the art usually consist in deposited interferential thin films or in cermets [1]. Structured surfaces have been proposed and have been simulated because they are supposed to be more efficient when the solar radiation is not normal to the receiving surface and because they could potentially be fabricated with refractory materials able to sustain high operating temperatures. This work presents a new method to fabricate micro/nanostructured surfaces on molybdenum (refractory metal with a melting temperature of 2623°C). This method now allows obtaining a refractory selective surface with an excellent optical selectivity and a very high absorption in the visible range. This high absorption performance was obtained by achieving a double structuration at micro and nano scales thanks to an innovative process flow.

  16. Properties of Spray Pyrolysied Copper Oxide Thin Films

    Directory of Open Access Journals (Sweden)

    S. S. Roy

    2017-02-01

    Full Text Available Copper oxide (CuO thin films were deposited on well cleaned glass substrates by spray pyrolysis technique (SPT from cupric acetate (Cu(CH3COO2.H2O precursor solutions of 0.05 – 0.15 M molar concentrations (MC at a substrate temperature of 350 °C and at an air pressure of 1 bar. Effect of varying MC on the surface morphology, structural optical and electrical properties of CuO thin films were investigated. XRD patterns of the prepared films revealed the formation of CuO thin films having monoclinic structure with the main CuO (111 orientation and crystalline size ranging from 8.02 to 9.05 nm was observed. The optical transmission of the film was found to decrease with the increase of MC. The optical band gap of the thin films for 0.10 M was fond to be 1.60 eV. The room temperature electrical resistivity varies from 31 and 24 ohm.cm for the films grown with MC of 0.05 and 0.10 M respectively. The change in resistivity of the films was studied with respect to the change in temperature was shown that semiconductor nature is present. This information is expected to underlie the successful development of CuO films for solar windows and other semi-conductor applications including gas sensors.

  17. Laser-induced damage to thin film dielectric coatings

    International Nuclear Information System (INIS)

    Walker, T.W.

    1980-01-01

    The laser-induced damage thresholds of dielectric thin film coatings have been found to be more than an order of magnitude lower than the bulk material damage thresholds. Prior damage studies have been inconclusive in determining the damage mechanism which is operative in thin films. A program was conducted in which thin film damage thresholds were measured as a function of laser wavelength (1.06 μm, 0.53 μm, 0.35 μm and 0.26 μm), laser pulse length (5 and 15 nanoseconds), film materials and film thickness. The large matrix of data was compared to predictions given by avalanche ionization, multiphoton ionization and impurity theories of laser damage. When Mie absorption cross-sections and the exact thermal equations were included into the impurity theory excellent agreement with the data was found. The avalanche and multiphoton damage theories could not account for most parametric variations in the data. For example, the damage thresholds for most films increased as the film thickness decreased and only the impurity theory could account for this behavior. Other observed changes in damage threshold with changes in laser wavelength, pulse length and film material could only be adequately explained by the impurity theory. The conclusion which results from this study is that laser damage in thin film coatings results from absorbing impurities included during the deposition process

  18. Characterization of thin films with synchrotron radiation in SPring-8

    International Nuclear Information System (INIS)

    Komiya, Satoshi

    2005-01-01

    Many studies about thin films by using synchrotron radiation in SPring-8 were reviewed. Structural analyses and assessment of thin films used for electronics, and also assessment of insulating films for the gate used in LSI were carried out. Film thickness, unevenness, and density of SiO 2 films in order of nanomer thickness were determined by interference fringes of x-ray reflection curves. The interface structure of (SiO 2 /Si) films was studied by x-ray crystal truncation rod scattering, and the correlation between leakage character depending on nitrogen concentration and interface structure was clarified on SiON film. The oxygen concentration in HfO films in nanometer thickness was determined by x-ray fluorescence analysis, and the interface reaction for HfO 2 /SiO 2 was clearly observed by electron spectroscopy. The structure of amorphous thin films with large dielectric constant was analyzed by x-ray absorption fine structure (XAFS) spectrum. Devices fabricated from multi-layer films showing giant magnetic resistance were developed for hard disk with a large memory. The character of giant magnetic resistance was governed by multi-layer thin film structure piled up by magnetic and nonmagnetic polycrystalline thin metals. For the multi-layer structure, the concentration distribution of constituent elements was determined to the direction of film thickness by x-ray reflection analysis and grazing incident x-ray fluorescence analysis. In the semiconductor laser source, Ga 1-x In x N, used for DVD, the local structure around In ions was studied by XAFS since constituent instability, especially overpopulation of In element, caused the deterioration of lifetime and light emission of the laser. The lattice constant of the light emission layer in InGaAs was measured by x-ray micro-beams. (author)

  19. Application of HTSC-thin films in microwave bandpass filters

    International Nuclear Information System (INIS)

    Jha, A.R.

    1993-01-01

    This paper reveals unique performance capabilities of High-Temperature Superconducting Thin-Film (HTSCTFs) for possible applications in microwave bandpass filters (BPFs). Microwave filters fabricated with HTSCTFs have demonstrated lowest insertion loss, highest rejection, and sharpest skirt selectivity. Thin films of Yttrium Barium Copper Oxide (YBCO), Bismuth Strontium Calcium Copper Oxide (BSCCO) and Thallium Calcium Barium Copper Oxide (TCBCO) will be most attractive for filters

  20. Liquid phase epitaxial growth of heterostructured hierarchical MOF thin films

    KAUST Repository

    Chernikova, Valeriya; Shekhah, Osama; Spanopoulos, Ioannis; Trikalitis, Pantelis N.; Eddaoudi, Mohamed

    2017-01-01

    Precise control of epitaxial growth of MOF-on-MOF thin films, for ordered hierarchical tbo-type structures is demonstrated. The heterostructured MOF thin film was fabricated by successful sequential deposition of layers from two different MOFs. The 2-periodic layers, edge-transitive 4,4-square lattices regarded as supermolecular building layers, were commendably cross-linked using a combination of inorganic/organic and organic pillars.