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Sample records for thin semi-metal films

  1. Persistent semi-metal-like nature of epitaxial perovskite CaIrO3 thin films

    International Nuclear Information System (INIS)

    Biswas, Abhijit; Jeong, Yoon Hee

    2015-01-01

    Strong spin-orbit coupled 5d transition metal based ABO 3 oxides, especially iridates, allow tuning parameters in the phase diagram and may demonstrate important functionalities, for example, by means of strain effects and symmetry-breaking, because of the interplay between the Coulomb interactions and strong spin-orbit coupling. Here, we have epitaxially stabilized high quality thin films of perovskite (Pv) CaIrO 3 . Film on the best lattice-matched substrate shows semi-metal-like characteristics. Intriguingly, imposing tensile or compressive strain on the film by altering the underlying lattice-mismatched substrates still maintains semi-metallicity with minute modification of the effective correlation as tensile (compressive) strain results in tiny increases (decreases) of the electronic bandwidth. In addition, magnetoresistance remains positive with a quadratic field dependence. This persistent semi-metal-like nature of Pv-CaIrO 3 thin films with minute changes in the effective correlation by strain may provide new wisdom into strong spin-orbit coupled 5d based oxide physics

  2. Persistent semi-metal-like nature of epitaxial perovskite CaIrO{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Abhijit; Jeong, Yoon Hee, E-mail: yhj@postech.ac.kr [Department of Physics, POSTECH, Pohang 790-784 (Korea, Republic of)

    2015-05-21

    Strong spin-orbit coupled 5d transition metal based ABO{sub 3} oxides, especially iridates, allow tuning parameters in the phase diagram and may demonstrate important functionalities, for example, by means of strain effects and symmetry-breaking, because of the interplay between the Coulomb interactions and strong spin-orbit coupling. Here, we have epitaxially stabilized high quality thin films of perovskite (Pv) CaIrO{sub 3}. Film on the best lattice-matched substrate shows semi-metal-like characteristics. Intriguingly, imposing tensile or compressive strain on the film by altering the underlying lattice-mismatched substrates still maintains semi-metallicity with minute modification of the effective correlation as tensile (compressive) strain results in tiny increases (decreases) of the electronic bandwidth. In addition, magnetoresistance remains positive with a quadratic field dependence. This persistent semi-metal-like nature of Pv-CaIrO{sub 3} thin films with minute changes in the effective correlation by strain may provide new wisdom into strong spin-orbit coupled 5d based oxide physics.

  3. 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 ...

  4. 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.

  5. Polymer thin film as coating layer to prevent corrosion of metal/metal oxide film

    Science.gov (United States)

    Sarkar, Suman; Kundu, Sarathi

    2018-04-01

    Thin film of polymer is used as coating layer and the corrosion of metal/metal oxide layer is studied with the variation of the thickness of the coating layer. The thin layer of polystyrene is fabricated using spin coating method on copper oxide (CuO) film which is deposited on glass substrate using DC magnetron sputtering technique. Thickness of the polystyrene and the CuO layers are determined using X-ray reflectivity (XRR) technique. CuO thin films coated with the polystyrene layer are exposed to acetic acid (2.5 v/v% aqueous CH3COOH solution) environments and are subsequently analyzed using UV-Vis spectroscopy and atomic force microscopy (AFM). Surface morphology of the film before and after interaction with the acidic environment is determined using AFM. Results obtained from the XRR and UV-Vis spectroscopy confirm that the thin film of polystyrene acts as an anticorrosion coating layer and the strength of the coating depends upon the polymer layer thickness at a constant acid concentration.

  6. 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 ...

  7. Transition metal carbide nanocomposite and amorphous thin films

    OpenAIRE

    Tengstrand, Olof

    2014-01-01

    This thesis explores thin films of binary and ternary transition metal carbides, in the Nb-C, Ti-Si-C, Nb-Si-C, Zr-Si-C, and Nb-Ge-C systems. The electrical and mechanical properties of these systems are affected by their structure and here both nanocomposite and amorphous thin films are thus investigated. By appropriate choice of transition metal and composition the films can be designed to be multifunctional with a combination of properties, such as low electric resistivity, low contact res...

  8. 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

  9. 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.

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

    Indian Academy of Sciences (India)

    Optical limiting capability of the nanoparticle-embedded polymer film is demonstrated. Keywords. Polar crystal; uniaxial orientational order; thin film; second harmonic gen- eration; silver ... able content of metal nanoparticles would be of considerable value from an appli- ... polar chain and perpendicular to it [10].

  11. Amorphous semiconducting and conducting transparent metal oxide thin films and production thereof

    Science.gov (United States)

    Perkins, John; Van Hest, Marinus Franciscus Antonius Maria; Ginley, David; Taylor, Matthew; Neuman, George A.; Luten, Henry A.; Forgette, Jeffrey A.; Anderson, John S.

    2010-07-13

    Metal oxide thin films and production thereof are disclosed. An exemplary method of producing a metal oxide thin film may comprise introducing at least two metallic elements and oxygen into a process chamber to form a metal oxide. The method may also comprise depositing the metal oxide on a substrate in the process chamber. The method may also comprise simultaneously controlling a ratio of the at least two metallic elements and a stoichiometry of the oxygen during deposition. Exemplary amorphous metal oxide thin films produced according to the methods herein may exhibit highly transparent properties, highly conductive properties, and/or other opto-electronic properties.

  12. Metal-insulator transition induced in CaVO3 thin films

    International Nuclear Information System (INIS)

    Gu Man; Laverock, Jude; Chen, Bo; Smith, Kevin E.; Wolf, Stuart A.; Lu Jiwei

    2013-01-01

    Stoichiometric CaVO 3 (CVO) thin films of various thicknesses were grown on single crystal SrTiO 3 (STO) (001) substrates using a pulsed electron-beam deposition technique. The CVO films were capped with a 2.5 nm STO layer. We observed a temperature driven metal-insulator transition (MIT) in CVO films with thicknesses below 4 nm that was not observed in either thick CVO films or STO films. The emergence of this MIT can be attributed to the reduction in effective bandwidth due to a crossover from a three-dimensional metal to a two-dimensional insulator. The insulating phase was only induced with a drive current below 0.1 μA. X-ray absorption measurements indicated different electronic structures for thick and very thin films of CVO. Compared with the thick film (∼60 nm), thin films of CVO (2–4 nm) were more two-dimensional with the V charge state closer to V 4+ .

  13. Transparent and conductive electrodes by large-scale nano-structuring of noble metal thin-films

    DEFF Research Database (Denmark)

    Linnet, Jes; Runge Walther, Anders; Wolff, Christian

    2018-01-01

    grid, and nano-wire thin-films. The indium and carbon films do not match the chemical stability nor the electrical performance of the noble metals, and many metal films are not uniform in material distribution leading to significant surface roughness and randomized transmission haze. We demonstrate...... solution-processed masks for physical vapor-deposited metal electrodes consisting of hexagonally ordered aperture arrays with scalable aperture-size and spacing in an otherwise homogeneous noble metal thin-film that may exhibit better electrical performance than carbon nanotube-based thin-films...... for equivalent optical transparency. The fabricated electrodes are characterized optically and electrically by measuring transmittance and sheet resistance. The presented methods yield large-scale reproducible results. Experimentally realized thin-films with very low sheet resistance, Rsh = 2.01 ± 0.14 Ω...

  14. Evaluation of space environmental effects on metals and optical thin films on EOIM-3

    Energy Technology Data Exchange (ETDEWEB)

    Vaughn, J.A.; Linton, R.C.; Finckenor, M.M.; Kamenetzky, R.R.

    1995-02-01

    Metals and optical thin films exposed to the space environment on the Third Flight of the Evaluation of Oxygen Interactions with Materials (EOIM-3) payload, onboard Space Shuttle mission STS-46 were evaluated. The materials effects described in this paper include the effects of space exposure on various pure metals, optical thin films, and optical thin film metals. The changes induced by exposure to the space environment in the material properties were evaluated using bidirectional reflectance distribution function (BRDF), specular reflectance (250 nm to 2500 nm), ESCA, VUV reflectance (120 nm to 200 nm), ellipsometry, FTIR and optical properties. Using these analysis techniques gold optically thin film metal mirrors with nickel undercoats were observed to darken due to nickel diffusion through the gold to the surface. Also, thin film nickel mirrors formed nickel oxide due to exposure to both the atmosphere and space.

  15. Evaluation of space environmental effects on metals and optical thin films on EOIM-3

    Science.gov (United States)

    Vaughn, Jason A.; Linton, Roger C.; Finckenor, Miria M.; Kamenetzky, Rachel R.

    1995-01-01

    Metals and optical thin films exposed to the space environment on the Third Flight of the Evaluation of Oxygen Interactions with Materials (EOIM-3) payload, onboard Space Shuttle mission STS-46 were evaluated. The materials effects described in this paper include the effects of space exposure on various pure metals, optical thin films, and optical thin film metals. The changes induced by exposure to the space environment in the material properties were evaluated using bidirectional reflectance distribution function (BRDF), specular reflectance (250 nm to 2500 nm), ESCA, VUV reflectance (120 nm to 200 nm), ellipsometry, FTIR and optical properties. Using these analysis techniques gold optically thin film metal mirrors with nickel undercoats were observed to darken due to nickel diffusion through the gold to the surface. Also, thin film nickel mirrors formed nickel oxide due to exposure to both the atmosphere and space.

  16. Metal-insulator transition induced in CaVO{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Gu Man [Department of Physics, University of Virginia, 382 McCormick Rd., Charlottesville, Virginia 22904 (United States); Laverock, Jude; Chen, Bo; Smith, Kevin E. [Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215 (United States); Wolf, Stuart A. [Department of Physics, University of Virginia, 382 McCormick Rd., Charlottesville, Virginia 22904 (United States); Department of Materials Science and Engineering, University of Virginia, 395 McCormick Rd., Charlottesville, Virginia 22904 (United States); Lu Jiwei [Department of Materials Science and Engineering, University of Virginia, 395 McCormick Rd., Charlottesville, Virginia 22904 (United States)

    2013-04-07

    Stoichiometric CaVO{sub 3} (CVO) thin films of various thicknesses were grown on single crystal SrTiO{sub 3} (STO) (001) substrates using a pulsed electron-beam deposition technique. The CVO films were capped with a 2.5 nm STO layer. We observed a temperature driven metal-insulator transition (MIT) in CVO films with thicknesses below 4 nm that was not observed in either thick CVO films or STO films. The emergence of this MIT can be attributed to the reduction in effective bandwidth due to a crossover from a three-dimensional metal to a two-dimensional insulator. The insulating phase was only induced with a drive current below 0.1 {mu}A. X-ray absorption measurements indicated different electronic structures for thick and very thin films of CVO. Compared with the thick film ({approx}60 nm), thin films of CVO (2-4 nm) were more two-dimensional with the V charge state closer to V{sup 4+}.

  17. An optimized In–CuGa metallic precursors for chalcopyrite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jun-feng, E-mail: junfeng.han@cnrs-imn.fr [Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, UMR CNRS 6502, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Department of Physics, Peking University, Beijing 100871 (China); Liao, Cheng [Department of Physics, Peking University, Beijing 100871 (China); Chengdu Green Energy and Green Manufacturing Technology R and D Center, Chengdu, Sichuan Province 601207 (China); Jiang, Tao; Xie, Hua-mu; Zhao, Kui [Department of Physics, Peking University, Beijing 100871 (China); Besland, M.-P. [Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, UMR CNRS 6502, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France)

    2013-10-31

    We report a study of CuGa–In metallic precursors for chalcopyrite thin film. CuGa and In thin films were prepared by DC sputtering at room temperature. Due to low melting point of indium, the sputtering power on indium target was optimized. Then, CuGa and In multilayers were annealed at low temperature. At 120 °C, the annealing treatment could enhance diffusion and alloying of CuGa and In layers; however, at 160 °C, it caused a cohesion and crystalline of indium from the alloy which consequently formed irregular nodules on the film surface. The precursors were selenized to form copper indium gallium selenide (CIGS) thin films. The morphological and structural properties were investigated by scanning electron microscopy, X-ray diffraction and Raman spectra. The relationships between metallic precursors and CIGS films were discussed in the paper. A smooth precursor layer was the key factor to obtain a homogeneous and compact CIGS film. - Highlights: • An optimized sputtered indium film • An optimized alloying process of metallic precursor • An observation of nodules forming on the indium film and precursor surface • An observation of cauliflower structure in copper indium gallium selenide film • The relationship between precursor and CIGS film surface morphology.

  18. Synthesis of 2D Metal Chalcogenide Thin Films through the Process Involving Solution-Phase Deposition.

    Science.gov (United States)

    Giri, Anupam; Park, Gyeongbae; Yang, Heeseung; Pal, Monalisa; Kwak, Junghyeok; Jeong, Unyong

    2018-04-24

    2D metal chalcogenide thin films have recently attracted considerable attention owing to their unique physicochemical properties and great potential in a variety of applications. Synthesis of large-area 2D metal chalcogenide thin films in controllable ways remains a key challenge in this research field. Recently, the solution-based synthesis of 2D metal chalcogenide thin films has emerged as an alternative approach to vacuum-based synthesis because it is relatively simple and easy to scale up for high-throughput production. In addition, solution-based thin films open new opportunities that cannot be achieved from vacuum-based thin films. Here, a comprehensive summary regarding the basic structures and properties of different types of 2D metal chalcogenides, the mechanistic details of the chemical reactions in the synthesis of the metal chalcogenide thin films, recent successes in the synthesis by different reaction approaches, and the applications and potential uses is provided. In the last perspective section, the technical challenges to be overcome and the future research directions in the solution-based synthesis of 2D metal chalcogenides are discussed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Thermal oxidation of Zr–Cu–Al–Ni amorphous metal thin films

    International Nuclear Information System (INIS)

    Oleksak, R.P.; Hostetler, E.B.; Flynn, B.T.; McGlone, J.M.; Landau, N.P.; Wager, J.F.; Stickle, W.F.; Herman, G.S.

    2015-01-01

    The initial stages of thermal oxidation for Zr–Cu–Al–Ni amorphous metal thin films were investigated using X-ray photoelectron spectroscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy. The as-deposited films had oxygen incorporated during sputter deposition, which helped to stabilize the amorphous phase. After annealing in air at 300 °C for short times (5 min) this oxygen was found to segregate to the surface or buried interface. Annealing at 300 °C for longer times leads to significant composition variation in both vertical and lateral directions, and formation of a surface oxide layer that consists primarily of Zr and Al oxides. Surface oxide formation was initially limited by back-diffusion of Cu and Ni ( 30 min). The oxidation properties are largely consistent with previous observations of Zr–Cu–Al–Ni metallic glasses, however some discrepancies were observed which could be explained by the unique sample geometry of the amorphous metal thin films. - Highlights: • Thermal oxidation of amorphous Zr–Cu–Al–Ni thin films was investigated. • Significant short-range inhomogeneities were observed in the amorphous films. • An accumulation of Cu and Ni occurs at the oxide/metal interface. • Diffusion of Zr was found to limit oxide film growth.

  20. Metallic and Ceramic Thin Film Thermocouples for Gas Turbine Engines

    Directory of Open Access Journals (Sweden)

    Otto J. Gregory

    2013-11-01

    Full Text Available Temperatures of hot section components in today’s gas turbine engines reach as high as 1,500 °C, making in situ monitoring of the severe temperature gradients within the engine rather difficult. Therefore, there is a need to develop instrumentation (i.e., thermocouples and strain gauges for these turbine engines that can survive these harsh environments. Refractory metal and ceramic thin film thermocouples are well suited for this task since they have excellent chemical and electrical stability at high temperatures in oxidizing atmospheres, they are compatible with thermal barrier coatings commonly employed in today’s engines, they have greater sensitivity than conventional wire thermocouples, and they are non-invasive to combustion aerodynamics in the engine. Thin film thermocouples based on platinum:palladium and indium oxynitride:indium tin oxynitride as well as their oxide counterparts have been developed for this purpose and have proven to be more stable than conventional type-S and type-K thin film thermocouples. The metallic and ceramic thin film thermocouples described within this paper exhibited remarkable stability and drift rates similar to bulk (wire thermocouples.

  1. Superconductor-Metal-Insulator transition in two dimensional Ta thin Films

    Science.gov (United States)

    Park, Sun-Gyu; Kim, Eunseong

    2013-03-01

    Superconductor-insulator transition has been induced by tuning film thickness or magnetic field. Recent electrical transport measurements of MoGe, Bi, Ta thin films revealed an interesting intermediate metallic phase which intervened superconducting and insulating phases at certain range of magnetic field. Especially, Ta thin films show the characteristic IV behavior at each phase and the disorder tuned intermediate metallic phase [Y. Li, C. L. Vicente, and J. Yoon, Physical Review B 81, 020505 (2010)]. This unexpected metallic phase can be interpreted as a consequence of vortex motion or contribution of fermionic quasiparticles. In this presentation, we report the scaling behavior during the transitions in Ta thin film as well as the transport measurements in various phases. Critical exponents v and z are obtained in samples with wide ranges of disorder. These results reveal new universality class appears when disorder exceeds a critical value. Dynamical exponent z of Superconducting sample is found to be 1, which is consistent with theoretical prediction of unity. z in a metallic sample is suddenly increased to be approximately 2.5. This critical exponent is much larger than the value found in other system and theoretical prediction. We gratefully acknowledge the financial support by the National Research Foundation of Korea through the Creative Research Initiatives.

  2. A comparison of surface properties of metallic thin film photocathodes

    CERN Document Server

    Mistry, Sonal; Valizadeh, Reza; Jones, L.B; Middleman, Keith; Hannah, Adrian; Militsyn, B.L; Noakes, Tim

    2017-01-01

    In this work the preparation of metal photocathodes by physical vapour deposition magnetron sputtering has been employed to deposit metallic thin films onto Cu, Mo and Si substrates. The use of metallic cathodes offers several advantages: (i) metal photocathodes present a fast response time and a relative insensitivity to the vacuum environment (ii) metallic thin films when prepared and transferred in vacuum can offer smoother and cleaner emitting surfaces. The photocathodes developed here will ultimately be used in S-band Normal Conducting RF (NCRF) guns such as that used in VELA (Versatile Electron Linear Accelerator) and the proposed CLARA (Compact Linear Accelerator for Research and Applications) Free Electron Laser test facility. The samples grown on Si substrates were used to investigate the morphology and thickness of the film. The samples grown onto Cu and Mo substrates were analysed and tested as photocathodes in a surface characterisation chamber, where X-Ray Photoelectron spectroscopy (XPS) was emp...

  3. Thin film pc-Si by aluminium induced crystallization on metallic substrate

    Directory of Open Access Journals (Sweden)

    Cayron C.

    2013-04-01

    Full Text Available Thin film polycrystalline silicon (pc-Si on flexible metallic substrates is promising for low cost production of photovoltaic solar cells. One of the attractive methods to produce pc-Si solar cells consists in thickening a large-grained seed layer by epitaxy. In this work, the deposited seed layer is made by aluminium induced crystallization (AIC of an amorphous silicon (a-Si thin film on metallic substrates (Ni/Fe alloy initially coated with a tantalum nitride (TaN conductive diffusion barrier layer. Effect of the thermal budget on the AIC grown pc-Si seed layer was investigated in order to optimize the process (i.e. the quality of the pc-Si thin film. Structural and optical characterizations were carried out using optical microscopy, μ-Raman and Electron Backscatter Diffraction (EBSD. At optimal thermal annealing conditions, the continuous AIC grown pc-Si thin film showed an average grain size around 15 μm. The grains were preferably (001 oriented which is favorable for its epitaxial thickening. This work proves the feasibility of the AIC method to grow large grains pc-Si seed layer on TaN coated metal substrates. These results are, in terms of grains size, the finest obtained by AIC on metallic substrates.

  4. Semi-transparent a-IGZO thin-film transistors with polymeric gate dielectric.

    Science.gov (United States)

    Hyung, Gun Woo; Wang, Jian-Xun; Li, Zhao-Hui; Koo, Ja-Ryong; Kwon, Sang Jik; Cho, Eou-Sik; Kim, Young Kwan

    2013-06-01

    We report the fabrication of semi-transparent a-IGZO-based thin-film transistors (TFTs) with crosslinked poly-4-vinylphenol (PVP) gate dielectric layers on PET substrate and thermally-evaporated Al/Ag/Al source and drain (S&D) electrodes, which showed a transmittance of 64% at a 500-nm wavelength and sheet resistance of 16.8 omega/square. The semi-transparent a-IGZO TFTs with a PVP layer exhibited decent saturation mobilities (maximum approximately 5.8 cm2Ns) and on/off current ratios of approximately 10(6).

  5. 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.

  6. Preparation of self-supporting thin metal target films

    International Nuclear Information System (INIS)

    Wang Xiuying; Ge Suxian; Yin Jianhua; Yin Xu; Jin Genming

    1989-01-01

    The preparation method and equipment for thin metal self-supporting target without oil contamination are described. The influence of target films contaminated by oil vapor on accuracy of nuclear-physics experimental data are also discussed. The analytical results on carbon content in the prepared films of three elements show that the equipment is very effective for eliminating contamination

  7. Nanomechanical investigation of thin-film electroceramic/metal-organic framework multilayers

    Science.gov (United States)

    Best, James P.; Michler, Johann; Liu, Jianxi; Wang, Zhengbang; Tsotsalas, Manuel; Maeder, Xavier; Röse, Silvana; Oberst, Vanessa; Liu, Jinxuan; Walheim, Stefan; Gliemann, Hartmut; Weidler, Peter G.; Redel, Engelbert; Wöll, Christof

    2015-09-01

    Thin-film multilayer stacks of mechanically hard magnetron sputtered indium tin oxide (ITO) and mechanically soft highly porous surface anchored metal-organic framework (SURMOF) HKUST-1 were studied using nanoindentation. Crystalline, continuous, and monolithic surface anchored MOF thin films were fabricated using a liquid-phase epitaxial growth method. Control over respective fabrication processes allowed for tuning of the thickness of the thin film systems with a high degree of precision. It was found that the mechanical indentation of such thin films is significantly affected by the substrate properties; however, elastic parameters were able to be decoupled for constituent thin-film materials (EITO ≈ 96.7 GPa, EHKUST-1 ≈ 22.0 GPa). For indentation of multilayer stacks, it was found that as the layer thicknesses were increased, while holding the relative thickness of ITO and HKUST-1 constant, the resistance to deformation was significantly altered. Such an observation is likely due to small, albeit significant, changes in film texture, interfacial roughness, size effects, and controlling deformation mechanism as a result of increasing material deposition during processing. Such effects may have consequences regarding the rational mechanical design and utilization of MOF-based hybrid thin-film devices.

  8. A Semi-Analytical Extraction Method for Interface and Bulk Density of States in Metal Oxide Thin-Film Transistors.

    Science.gov (United States)

    Chen, Weifeng; Wu, Weijing; Zhou, Lei; Xu, Miao; Wang, Lei; Ning, Honglong; Peng, Junbiao

    2018-03-11

    A semi-analytical extraction method of interface and bulk density of states (DOS) is proposed by using the low-frequency capacitance-voltage characteristics and current-voltage characteristics of indium zinc oxide thin-film transistors (IZO TFTs). In this work, an exponential potential distribution along the depth direction of the active layer is assumed and confirmed by numerical solution of Poisson's equation followed by device simulation. The interface DOS is obtained as a superposition of constant deep states and exponential tail states. Moreover, it is shown that the bulk DOS may be represented by the superposition of exponential deep states and exponential tail states. The extracted values of bulk DOS and interface DOS are further verified by comparing the measured transfer and output characteristics of IZO TFTs with the simulation results by a 2D device simulator ATLAS (Silvaco). As a result, the proposed extraction method may be useful for diagnosing and characterising metal oxide TFTs since it is fast to extract interface and bulk density of states (DOS) simultaneously.

  9. A Semi-Analytical Extraction Method for Interface and Bulk Density of States in Metal Oxide Thin-Film Transistors

    Directory of Open Access Journals (Sweden)

    Weifeng Chen

    2018-03-01

    Full Text Available A semi-analytical extraction method of interface and bulk density of states (DOS is proposed by using the low-frequency capacitance–voltage characteristics and current–voltage characteristics of indium zinc oxide thin-film transistors (IZO TFTs. In this work, an exponential potential distribution along the depth direction of the active layer is assumed and confirmed by numerical solution of Poisson’s equation followed by device simulation. The interface DOS is obtained as a superposition of constant deep states and exponential tail states. Moreover, it is shown that the bulk DOS may be represented by the superposition of exponential deep states and exponential tail states. The extracted values of bulk DOS and interface DOS are further verified by comparing the measured transfer and output characteristics of IZO TFTs with the simulation results by a 2D device simulator ATLAS (Silvaco. As a result, the proposed extraction method may be useful for diagnosing and characterising metal oxide TFTs since it is fast to extract interface and bulk density of states (DOS simultaneously.

  10. Thin films by metal-organic precursor plasma spray

    International Nuclear Information System (INIS)

    Schulz, Douglas L.; Sailer, Robert A.; Payne, Scott; Leach, James; Molz, Ronald J.

    2009-01-01

    While most plasma spray routes to coatings utilize solids as the precursor feedstock, metal-organic precursor plasma spray (MOPPS) is an area that the authors have investigated recently as a novel route to thin film materials. Very thin films are possible via MOPPS and the technology offers the possibility of forming graded structures by metering the liquid feed. The current work employs metal-organic compounds that are liquids at standard temperature-pressure conditions. In addition, these complexes contain chemical functionality that allows straightforward thermolytic transformation to targeted phases of interest. Toward that end, aluminum 3,5-heptanedionate (Al(hd) 3 ), triethylsilane (HSi(C 2 H 5 ) 3 or HSiEt 3 ), and titanium tetrakisdiethylamide (Ti(N(C 2 H 5 ) 2 ) 4 or Ti(NEt 2 ) 4 ) were employed as precursors to aluminum oxide, silicon carbide, and titanium nitride, respectively. In all instances, the liquids contain metal-heteroatom bonds envisioned to provide atomic concentrations of the appropriate reagents at the film growth surface, thus promoting phase formation (e.g., Si-C bond in triethylsilane, Ti-N bond in titanium amide, etc.). Films were deposited using a Sulzer Metco TriplexPro-200 plasma spray system under various experimental conditions using design of experiment principles. Film compositions were analyzed by glazing incidence x-ray diffraction and elemental determination by x-ray spectroscopy. MOPPS films from HSiEt 3 showed the formation of SiC phase but Al(hd) 3 -derived films were amorphous. The Ti(NEt 2 ) 4 precursor gave MOPPS films that appear to consist of nanosized splats of TiOCN with spheres of TiO 2 anatase. While all films in this study suffered from poor adhesion, it is anticipated that the use of heated substrates will aid in the formation of dense, adherent films.

  11. Nanomechanical investigation of thin-film electroceramic/metal-organic framework multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Best, James P., E-mail: james.best@empa.ch, E-mail: engelbert.redel@kit.edu, E-mail: christof.woell@kit.edu; Michler, Johann; Maeder, Xavier [Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Mechanics of Materials and Nanostructures, Feuerwerkerstrasse 39, CH-3602 Thun (Switzerland); Liu, Jianxi; Wang, Zhengbang; Tsotsalas, Manuel; Liu, Jinxuan; Gliemann, Hartmut; Weidler, Peter G.; Redel, Engelbert, E-mail: james.best@empa.ch, E-mail: engelbert.redel@kit.edu, E-mail: christof.woell@kit.edu; Wöll, Christof, E-mail: james.best@empa.ch, E-mail: engelbert.redel@kit.edu, E-mail: christof.woell@kit.edu [Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Röse, Silvana [Preparative Macromolecular Chemistry, Institute for Chemical Technology and Polymer Chemistry (ICTP), Karlsruhe Institute of Technology (KIT), Engesserstrasse 18, 76128 Karlsruhe (Germany); Institute for Biological Interfaces (IBG), Karlsruhe Institute of Technology (KIT), Herrmann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Oberst, Vanessa [Institute of Applied Materials (IAM), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Walheim, Stefan [Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2015-09-07

    Thin-film multilayer stacks of mechanically hard magnetron sputtered indium tin oxide (ITO) and mechanically soft highly porous surface anchored metal-organic framework (SURMOF) HKUST-1 were studied using nanoindentation. Crystalline, continuous, and monolithic surface anchored MOF thin films were fabricated using a liquid-phase epitaxial growth method. Control over respective fabrication processes allowed for tuning of the thickness of the thin film systems with a high degree of precision. It was found that the mechanical indentation of such thin films is significantly affected by the substrate properties; however, elastic parameters were able to be decoupled for constituent thin-film materials (E{sub ITO} ≈ 96.7 GPa, E{sub HKUST−1} ≈ 22.0 GPa). For indentation of multilayer stacks, it was found that as the layer thicknesses were increased, while holding the relative thickness of ITO and HKUST-1 constant, the resistance to deformation was significantly altered. Such an observation is likely due to small, albeit significant, changes in film texture, interfacial roughness, size effects, and controlling deformation mechanism as a result of increasing material deposition during processing. Such effects may have consequences regarding the rational mechanical design and utilization of MOF-based hybrid thin-film devices.

  12. Nanomechanical investigation of thin-film electroceramic/metal-organic framework multilayers

    International Nuclear Information System (INIS)

    Best, James P.; Michler, Johann; Maeder, Xavier; Liu, Jianxi; Wang, Zhengbang; Tsotsalas, Manuel; Liu, Jinxuan; Gliemann, Hartmut; Weidler, Peter G.; Redel, Engelbert; Wöll, Christof; Röse, Silvana; Oberst, Vanessa; Walheim, Stefan

    2015-01-01

    Thin-film multilayer stacks of mechanically hard magnetron sputtered indium tin oxide (ITO) and mechanically soft highly porous surface anchored metal-organic framework (SURMOF) HKUST-1 were studied using nanoindentation. Crystalline, continuous, and monolithic surface anchored MOF thin films were fabricated using a liquid-phase epitaxial growth method. Control over respective fabrication processes allowed for tuning of the thickness of the thin film systems with a high degree of precision. It was found that the mechanical indentation of such thin films is significantly affected by the substrate properties; however, elastic parameters were able to be decoupled for constituent thin-film materials (E ITO  ≈ 96.7 GPa, E HKUST−1  ≈ 22.0 GPa). For indentation of multilayer stacks, it was found that as the layer thicknesses were increased, while holding the relative thickness of ITO and HKUST-1 constant, the resistance to deformation was significantly altered. Such an observation is likely due to small, albeit significant, changes in film texture, interfacial roughness, size effects, and controlling deformation mechanism as a result of increasing material deposition during processing. Such effects may have consequences regarding the rational mechanical design and utilization of MOF-based hybrid thin-film devices

  13. Two-dimensional models for the optical response of thin films

    Science.gov (United States)

    Li, Yilei; Heinz, Tony F.

    2018-04-01

    In this work, we present a systematic study of 2D optical models for the response of thin layers of material under excitation by normally incident light. The treatment, within the framework of classical optics, analyzes a thin film supported by a semi-infinite substrate, with both the thin layer and the substrate assumed to exhibit local, isotropic linear response. Starting from the conventional three-dimensional (3D) slab model of the system, we derive a two-dimensional (2D) sheet model for the thin film in which the optical response is described by a sheet optical conductivity. We develop criteria for the applicability of this 2D sheet model for a layer with an optical thickness far smaller than the wavelength of the light. We examine in detail atomically thin semi-metallic and semiconductor van-der-Waals layers and ultrathin metal films as representative examples. Excellent agreement of the 2D sheet model with the 3D slab model is demonstrated over a broad spectral range from the radio frequency limit to the near ultraviolet. A linearized version of system response for the 2D model is also presented for the case where the influence of the optically thin layer is sufficiently weak. Analytical expressions for the applicability and accuracy of the different optical models are derived, and the appropriateness of the linearized treatment for the materials is considered. We discuss the advantages, as well as limitations, of these models for the purpose of deducing the optical response function of the thin layer from experiment. We generalize the theory to take into account in-plane anisotropy, layered thin film structures, and more general substrates. Implications of the 2D model for the transmission of light by the thin film and for the implementation of half- and totally absorbing layers are discussed.

  14. 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.

  15. Rare earth metals, rare earth hydrides, and rare earth oxides as thin films

    International Nuclear Information System (INIS)

    Gasgnier, M.

    1980-01-01

    The review deals with pure rare earth materials such as rare earth metals, rare earth hydrides, and rare earth oxides as thin films. Several preparation techniques, control methods, and nature of possible contaminations of thin films are described. These films can now be produced in an extremely well-known state concerning chemical composition, structure and texture. Structural, electric, magnetic, and optical properties of thin films are studied and discussed in comparison with the bulk state. The greatest contamination of metallic rare earth thin films is caused by reaction with hydrogen or with water vapour. The compound with an f.c.c. structure is the dihydride LnH 2 (Ln = lanthanides). The oxygen contamination takes place after annealing at higher temperatures. Then there appears a compound with a b.c.c. structure which is the C-type sesquioxide C-Ln 2 O 3 . At room atmosphere dihydride light rare earth thin films are converted to hydroxide Ln(OH) 3 . For heavy rare earth thin films the oxinitride LnNsub(x)Osub(y) is observed. The LnO-type compound was never seen. The present review tries to set the stage anew for the investigations to be undertaken in the future especially through the new generations of electron microscopes

  16. Transparent and conductive electrodes by large-scale nanostructuring of noble metal thin-films

    DEFF Research Database (Denmark)

    Linnet, Jes; Runge Walther, Anders; Wolff, Christian

    grid, and nano-wire thin-films [1]. The indium and carbon films do not match the chemical stability nor the electrical performance of the noble metals, and many metal films are not uniform in material distribution leading to significant surface roughness and randomized transmission haze. We demonstrate...

  17. Method for nanomodulation of metallic thin films following the replica-antireplica process based on porous alumina membranes

    Energy Technology Data Exchange (ETDEWEB)

    Palma, J.L. [Departamento de Ciencias Básicas, Facultad de Ingeniería, Universidad Central de Chile, Santa Isabel 1186, 8330601 Santiago (Chile); Center for the Development of Nanoscience and Nanotechnology (CEDENNA), 9170124 Santiago (Chile); Denardin, J.C.; Escrig, J. [Departamento de Física, Universidad de Santiago de Chile (USACH), Avda. Ecuador 3493, 9170124 Santiago (Chile); Center for the Development of Nanoscience and Nanotechnology (CEDENNA), 9170124 Santiago (Chile)

    2017-03-15

    In this paper we have introduced a method for modulation of metallic thin films by sputtering of metals on anodized aluminum templates. Using a high deposition rate during deposition of the non-magnetic metal on the Al pattern, we have separated the two metallic surfaces and, thus, imprinted a pattern of nanohills on a non-magnetic metallic film, such as Au, Ag or Cu. The morphology of the nanostructured metallic films was determined by scanning electron microscopy. Thus, we have confirmed that the ordering degree of the Al template remained after the replication process. Additionally, and as an example of use of these films, we have prepared Supermalloy thin films deposited by sputtering onto these nanostructured non-magnetic metals. The room temperature magnetic behavior of these thin films is also studied. Interestingly, we have found that when the external magnetic field is applied out of plane of the substrate, the coercivity increases linearly as we increase the radius of the nanohills. These soft magnetic films can open new opportunities for magnetic field sensor applications. - Highlights: • A very soft magnetic film is investigated on ordered nanohills. • It is possible to imprint a metallic pattern directly from the etched aluminum foil. • These nanopatterned substrates add an additional degree of freedom. • A method for modulation of metallic thin films.

  18. Thin metal films in resistivity-based chemical sensing

    Czech Academy of Sciences Publication Activity Database

    Podešva, Pavel; Foret, František

    2013-01-01

    Roč. 9, č. 4 (2013), s. 642-652 ISSN 1573-4110 R&D Projects: GA ČR(CZ) GAP301/11/2055 Institutional support: RVO:68081715 Keywords : voltohmmetric sensing * chemiresistor * thin metal film * gas sensing Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.194, year: 2013

  19. High mobility single-crystalline-like GaAs thin films on inexpensive flexible metal substrates by metal-organic chemical vapor deposition

    International Nuclear Information System (INIS)

    Dutta, P.; Rathi, M.; Gao, Y.; Yao, Y.; Selvamanickam, V.; Zheng, N.; Ahrenkiel, P.; Martinez, J.

    2014-01-01

    We demonstrate heteroepitaxial growth of single-crystalline-like n and p-type doped GaAs thin films on inexpensive, flexible, and light-weight metal foils by metal-organic chemical vapor deposition. Single-crystalline-like Ge thin film on biaxially textured templates made by ion beam assisted deposition on metal foil served as the epitaxy enabling substrate for GaAs growth. The GaAs films exhibited strong (004) preferred orientation, sharp in-plane texture, low grain misorientation, strong photoluminescence, and a defect density of ∼10 7  cm −2 . Furthermore, the GaAs films exhibited hole and electron mobilities as high as 66 and 300 cm 2 /V-s, respectively. High mobility single-crystalline-like GaAs thin films on inexpensive metal substrates can pave the path for roll-to-roll manufacturing of flexible III-V solar cells for the mainstream photovoltaics market.

  20. High mobility single-crystalline-like GaAs thin films on inexpensive flexible metal substrates by metal-organic chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, P., E-mail: pdutta2@central.uh.edu; Rathi, M.; Gao, Y.; Yao, Y.; Selvamanickam, V. [Department of Mechanical Engineering, University of Houston, Houston, Texas 77204 (United States); Zheng, N.; Ahrenkiel, P. [Department of Nanoscience and Nanoengineering, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701 (United States); Martinez, J. [Materials Evaluation Laboratory, NASA Johnson Space Center, Houston, Texas 77085 (United States)

    2014-09-01

    We demonstrate heteroepitaxial growth of single-crystalline-like n and p-type doped GaAs thin films on inexpensive, flexible, and light-weight metal foils by metal-organic chemical vapor deposition. Single-crystalline-like Ge thin film on biaxially textured templates made by ion beam assisted deposition on metal foil served as the epitaxy enabling substrate for GaAs growth. The GaAs films exhibited strong (004) preferred orientation, sharp in-plane texture, low grain misorientation, strong photoluminescence, and a defect density of ∼10{sup 7 }cm{sup −2}. Furthermore, the GaAs films exhibited hole and electron mobilities as high as 66 and 300 cm{sup 2}/V-s, respectively. High mobility single-crystalline-like GaAs thin films on inexpensive metal substrates can pave the path for roll-to-roll manufacturing of flexible III-V solar cells for the mainstream photovoltaics market.

  1. Transparent and conductive electrodes by large-scale nano-structuring of noble metal thin-films

    DEFF Research Database (Denmark)

    Linnet, Jes; Runge Walther, Anders; Wolff, Christian

    2018-01-01

    grid, and nano-wire thin-films. The indium and carbon films do not match the chemical stability nor the electrical performance of the noble metals, and many metal films are not uniform in material distribution leading to significant surface roughness and randomized transmission haze. We demonstrate...

  2. Electrochemical characterization of Zr-based thin film metallic glass in hydrochloric aqueous solution

    International Nuclear Information System (INIS)

    Chuang, Ching-Yen; Liao, Yi-Chia; Lee, Jyh-Wei; Li, Chia-Lin; Chu, Jinn P.; Duh, Jenq-Gong

    2013-01-01

    Recently thin film metallic glass represents a class of promising engineering materials for structural applications. In this work, the Zr-based thin film metallic glass (TFMG) was fabricated on the Si and AISI 420 substrates using a Zr–Cu–Ni–Al alloy and pure Zr metal targets by a pulsed DC magnetron sputtering system. The chemical compositions, crystalline structures, microstructures and corrosion behavior in hydrochloric (HCl) aqueous solutions of Zr-based TFMGs were investigated. The results showed that the surface morphologies of Zr-based TFMG were very smooth. A compact and dense structure without columnar structure was observed. The amorphous structure of Zr-based TFMG was characterized by the X-ray diffractometer and transmission electron microscopy analyses. After the potentiodynamic polarization test, the better corrosion resistance was achieved for the Zr-based TFMG coated AISI 420 in 1 mM HCl aqueous solution. Based on the surface morphologies and chemical analysis results of the corroded surfaces, the pitting, crevice corrosion and filiform corrosion were found. The corrosion mechanisms of the Zr-based TFMG were discussed in this work. - Highlights: ► Zr-based thin film metallic glass with amorphous structure. ► Better corrosion resistance of Zr-based thin film metallic glass observed. ► Pitting, crevice and filiform corrosion reactions revealed. ► The Cu-rich corrosion products found in the pit. ► Nanowire and flaky corrosion products formed adjacent to the filiform corrosion path

  3. 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.

  4. Epitaxially influenced boundary layer model for size effect in thin metallic films

    International Nuclear Information System (INIS)

    Bazant, Zdenek P.; Guo Zaoyang; Espinosa, Horacio D.; Zhu Yong; Peng Bei

    2005-01-01

    It is shown that the size effect recently observed by Espinosa et al., [J. Mech. Phys. Solids51, 47 (2003)] in pure tension tests on free thin metallic films can be explained by the existence of a boundary layer of fixed thickness, located at the surface of the film that was attached onto the substrate during deposition. The boundary layer is influenced by the epitaxial effects of crystal growth on the dislocation density and texture (manifested by prevalent crystal plane orientations). This influence is assumed to cause significantly elevated yield strength. Furthermore, the observed gradual postpeak softening, along with its size independence, which is observed in short film strips subjected to pure tension, is explained by slip localization, originating at notch-like defects, and by damage, which can propagate in a stable manner when the film strip under pure tension is sufficiently thin and short. For general applications, the present epitaxially influenced boundary layer model may be combined with the classical strain-gradient plasticity proposed by Gao et al., [J. Mech. Phys. Solids 47, 1239 (1999)], and it is shown that this combination is necessary to fit the test data on both pure tension and bending of thin films by one and the same theory. To deal with films having different crystal grain sizes, the Hall-Petch relation for the yield strength dependence on the grain size needs to be incorporated into the combined theory. For very thin films, in which a flattened grain fills the whole film thickness, the Hall-Petch relation needs a cutoff, and the asymptotic increase of yield strength with diminishing film thickness is then described by the extension of Nix's model of misfit dislocations by Zhang and Zhou [J. Adv. Mater. 38, 51 (2002)]. The final result is a proposal of a general theory for strength, size effect, hardening, and softening of thin metallic films

  5. Epitaxially influenced boundary layer model for size effect in thin metallic films

    Science.gov (United States)

    Bažant, Zdeněk P.; Guo, Zaoyang; Espinosa, Horacio D.; Zhu, Yong; Peng, Bei

    2005-04-01

    It is shown that the size effect recently observed by Espinosa et al., [J. Mech. Phys. Solids51, 47 (2003)] in pure tension tests on free thin metallic films can be explained by the existence of a boundary layer of fixed thickness, located at the surface of the film that was attached onto the substrate during deposition. The boundary layer is influenced by the epitaxial effects of crystal growth on the dislocation density and texture (manifested by prevalent crystal plane orientations). This influence is assumed to cause significantly elevated yield strength. Furthermore, the observed gradual postpeak softening, along with its size independence, which is observed in short film strips subjected to pure tension, is explained by slip localization, originating at notch-like defects, and by damage, which can propagate in a stable manner when the film strip under pure tension is sufficiently thin and short. For general applications, the present epitaxially influenced boundary layer model may be combined with the classical strain-gradient plasticity proposed by Gao et al., [J. Mech. Phys. Solids 47, 1239 (1999)], and it is shown that this combination is necessary to fit the test data on both pure tension and bending of thin films by one and the same theory. To deal with films having different crystal grain sizes, the Hall-Petch relation for the yield strength dependence on the grain size needs to be incorporated into the combined theory. For very thin films, in which a flattened grain fills the whole film thickness, the Hall-Petch relation needs a cutoff, and the asymptotic increase of yield strength with diminishing film thickness is then described by the extension of Nix's model of misfit dislocations by Zhang and Zhou [J. Adv. Mater. 38, 51 (2002)]. The final result is a proposal of a general theory for strength, size effect, hardening, and softening of thin metallic films.

  6. Electronic hybridisation implications for the damage-tolerance of thin film metallic glasses.

    Science.gov (United States)

    Schnabel, Volker; Jaya, B Nagamani; Köhler, Mathias; Music, Denis; Kirchlechner, Christoph; Dehm, Gerhard; Raabe, Dierk; Schneider, Jochen M

    2016-11-07

    A paramount challenge in materials science is to design damage-tolerant glasses. Poisson's ratio is commonly used as a criterion to gauge the brittle-ductile transition in glasses. However, our data, as well as results in the literature, are in conflict with the concept of Poisson's ratio serving as a universal parameter for fracture energy. Here, we identify the electronic structure fingerprint associated with damage tolerance in thin film metallic glasses. Our correlative theoretical and experimental data reveal that the fraction of bonds stemming from hybridised states compared to the overall bonding can be associated with damage tolerance in thin film metallic glasses.

  7. Quantum-classical transition in the electron dynamics of thin metal films

    International Nuclear Information System (INIS)

    Jasiak, R; Manfredi, G; Hervieux, P-A; Haefele, M

    2009-01-01

    The quantum electrons dynamics in a thin metal film is studied numerically using the self-consistent Wigner-Poisson equations. The initial equilibrium is computed from the Kohn-Sham equations at finite temperature, and then mapped into the phase-space Wigner function. The time-dependent results are compared systematically with those obtained previously with a classical approach (Vlasov-Poisson equations). It is found that, for large excitations, the quantum and classical dynamics display the same low-frequency oscillations due to ballistic electrons bouncing back and forth on the film surfaces. However, below a certain excitation energy (roughly corresponding to one quantum of plasmon energy ℎω p ), the quantum and classical results diverge, and the ballistic oscillations are no longer observed. These results provide an example of a quantum-classical transition that may be observed with current pump-probe experiments on thin metal films.

  8. Spontaneous magnetization of thin films of ordered and disordered alloys of transition metals

    International Nuclear Information System (INIS)

    Nguyen Nhat Khanh.

    1989-12-01

    A method of calculation of spontaneous magnetization of thin films of transition metal alloys is described. The method is based on the Hubbard model for d electrons. Use of the Bragg-Williams approximation and two-dimensional canonical transformations has allowed to calculate the magnetization. Results for a Ni 3 Fe thin film are presented. (author). 11 refs, 1 fig

  9. High-frequency electromagnetic properties of soft magnetic metal-polyimide hybrid thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Woo [Nano-Materials Research Center, Korea Institute of Science and Technology, 39-1 Haweoulgog-dong, Sungbuk-gu, Seoul 136-791 (Korea, Republic of)]. E-mail: swkim@kist.re.kr; Yoon, Chong S. [Division of Advanced Materials Science, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2007-09-15

    Although there are a lot of demands for suppression of unwanted high-frequency electromagnetic noise in highly integrated electronic devices such as mobile phones and notebook computers, electromagnetic thin films that effectively work in the high-frequency range have still been underdeveloped. Soft magnetic metal-polyimide (PI) hybrid films with high electrical resistivity were prepared by thermal imidization and selective oxidation between the metal alloy layer and polyamic acid (PAA) layer. Electromagnetic properties of the hybrid thin films in the radio-frequency range were characterized by using the microstrip line method and were correlated with their material parameters. Although anisotropy field of the CoFe/NiFe hybrid film was two times lower than that of the NiFe hybrid film, the saturation magnetization of the CoFe/NiFe hybrid film was three times higher than that of the NiFe hybrid film. The CoFe/NiFe hybrid film showed higher power loss in the frequency range of 3-6 GHz compared to the NiFe hybrid film. The high power loss of the CoFe/NiFe hybrid film was caused by high relative permeability and high ferromagnetic resonance (FMR) frequency due to high saturation magnetization.

  10. High-frequency electromagnetic properties of soft magnetic metal-polyimide hybrid thin films

    International Nuclear Information System (INIS)

    Kim, Sang Woo; Yoon, Chong S.

    2007-01-01

    Although there are a lot of demands for suppression of unwanted high-frequency electromagnetic noise in highly integrated electronic devices such as mobile phones and notebook computers, electromagnetic thin films that effectively work in the high-frequency range have still been underdeveloped. Soft magnetic metal-polyimide (PI) hybrid films with high electrical resistivity were prepared by thermal imidization and selective oxidation between the metal alloy layer and polyamic acid (PAA) layer. Electromagnetic properties of the hybrid thin films in the radio-frequency range were characterized by using the microstrip line method and were correlated with their material parameters. Although anisotropy field of the CoFe/NiFe hybrid film was two times lower than that of the NiFe hybrid film, the saturation magnetization of the CoFe/NiFe hybrid film was three times higher than that of the NiFe hybrid film. The CoFe/NiFe hybrid film showed higher power loss in the frequency range of 3-6 GHz compared to the NiFe hybrid film. The high power loss of the CoFe/NiFe hybrid film was caused by high relative permeability and high ferromagnetic resonance (FMR) frequency due to high saturation magnetization

  11. Quantum-classical transition in the electron dynamics of thin metal films

    Energy Technology Data Exchange (ETDEWEB)

    Jasiak, R; Manfredi, G; Hervieux, P-A [Institut de Physique et Chimie des Materiaux, CNRS and Universite de Strasbourg, BP 43, F-67034 Strasbourg (France); Haefele, M [INRIA Nancy Grand-Est and Institut de Recherche en Mathematiques Avancees, 7 rue Rene Descartes, F-67084 Strasbourg (France)], E-mail: Giovanni.Manfredi@ipcms.u-strasbg.fr

    2009-06-15

    The quantum electrons dynamics in a thin metal film is studied numerically using the self-consistent Wigner-Poisson equations. The initial equilibrium is computed from the Kohn-Sham equations at finite temperature, and then mapped into the phase-space Wigner function. The time-dependent results are compared systematically with those obtained previously with a classical approach (Vlasov-Poisson equations). It is found that, for large excitations, the quantum and classical dynamics display the same low-frequency oscillations due to ballistic electrons bouncing back and forth on the film surfaces. However, below a certain excitation energy (roughly corresponding to one quantum of plasmon energy {Dirac_h}{omega}{sub p}), the quantum and classical results diverge, and the ballistic oscillations are no longer observed. These results provide an example of a quantum-classical transition that may be observed with current pump-probe experiments on thin metal films.

  12. Nanoscale strengthening mechanisms in metallic thin film systems

    Science.gov (United States)

    Schoeppner, Rachel Lynn

    Nano-scale strengthening mechanisms for thin films were investigated for systems governed by two different strengthening techniques: nano-laminate strengthening and oxide dispersion strengthening. Films were tested under elevated temperature conditions to investigate changes in deformation mechanisms at different operating temperatures, and the structural stability. Both systems exhibit remarkable stability after annealing and thus long-term reliability. Nano-scale metallic multilayers with smaller layer thicknesses show a greater relative resistance to decreasing strength at higher temperature testing conditions than those with larger layer thicknesses. This is seen in both Cu/Ni/Nb multilayers as well as a similar tri-component bi-layer system (Cu-Ni/Nb), which removed the coherent interface from the film. Both nanoindentation and micro-pillar compression tests investigated the strain-hardening ability of these two systems to determine what role the coherent interface plays in this mechanism. Tri-layer films showed a higher strain-hardening ability as the layer thickness decreased and a higher strain-hardening exponent than the bi-layer system: verifying the presence of a coherent interface increases the strain-hardening ability of these multilayer systems. Both systems exhibited hardening of the room temperature strength after annealing, suggesting a change in microstructure has occurred, unlike that seen in other multilayer systems. Oxide dispersion strengthened Au films showed a marked increase in hardness and wear resistance with the addition of ZnO particles. The threshold for stress-induced grain-refinement as opposed to grain growth is seen at concentrations of at least 0.5 vol%. These systems exhibited stable microstructures during thermal cycling in films containing at least 1.0%ZnO. Nanoindentation experiments show the drop in hardness following annealing is almost completely attributed to the resulting grain growth. Four-point probe resistivity

  13. Magnetoelectric coupling effect in transition metal modified polycrystalline BiFeO3 thin films

    International Nuclear Information System (INIS)

    Sreenivas Puli, Venkata; Kumar Pradhan, Dhiren; Gollapudi, Sreenivasulu; Coondoo, Indrani; Panwar, Neeraj; Adireddy, Shiva; Chrisey, Douglas B.; Katiyar, Ram S.

    2014-01-01

    Rare-earth (Sm) and transition metal (Co) modified polycrystalline BiFeO 3 (BFO) thin films have been deposited on Pt/TiO 2 /SiO 2 /Si substrate successfully through pulsed laser deposition (PLD) technique. Piezoelectric, leakage current and temperature dependent dielectric and magnetic behaviour were investigated for the films. Typical “butterfly-shaped” loop were observed in BSFCO films with an effective piezoelectric constant (d 33 ) ∼94 pm/V at 0.6 MV/cm. High dielectric constant ∼900 and low dielectric loss ∼0.25 were observed at room temperature. M–H loops have shown relatively high saturation magnetization ∼35 emu/cm 3 at a maximum field of H ∼20 kOe. Enhanced magnetoelectric coupling response is observed under applied magnetic field. The multiferroic, piezoelectric, leakage current behaviours were explored. Such studies should be helpful in designing multiferroic materials based on BSFCO films. - Highlights: • Transition metal modified polycrystalline BiFeO 3 thin films prepared using PLD. • High ME-coupling response was observed in co-substituted BiFeO 3 thin films. • High magnetization ∼35 emu/cm 3 at a maximum field of H ∼20 kOe. • Low leakage current might be due to co-substitution in BiFeO 3 thin films. • A notable piezoelectric constant d 33 ∼94 pm/V was found in BiFeO 3 thin films

  14. Elaboration of strontium ruthenium oxide thin films on metal substrates by chemical solution deposition

    International Nuclear Information System (INIS)

    Seveno, R.; Braud, A.; Gundel, H.W.

    2005-01-01

    In order to improve the structural interface between a metal substrate and a lead zirconate titanate (Pb(ZrTi)O 3 , PZT) ferroelectric thin film, the elaboration of strontium ruthenium oxide (SrRuO 3 ) by chemical solution deposition is studied. The SrRuO 3 thin films were realized by multiple spin-coating technique and the temperature of the rapid thermal annealing process was optimized. The crystallization behavior was examined by X-ray diffraction; surface analyses using scanning electron microscope and atomic force microscope techniques showed the influence of the SrRuO 3 layer at the interface PZT/metal on the morphology of the ferroelectric thin film. From the electrical measurements, a coercive electric field around 25 kV/cm and a remanent polarization of approximately 30 μC/cm were found

  15. 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

  16. Hard X-ray photoemission spectroscopy of transition-metal oxide thin films and interfaces

    International Nuclear Information System (INIS)

    Wadati, H.; Fujimori, A.

    2013-01-01

    Highlights: •Photoemission spectroscopy is a powerful technique to study the electronic structures of transition-metal oxides. •Hard X-ray photoemission spectroscopy (HXPES) is a new type of photoemission spectroscopy which can probe bulk states. •HXPES is very suitable for studying oxide thin films such as the composition dependence and the film thickness dependence. -- Abstract: Photoemission spectroscopy is a powerful experimental technique to study the electronic structures of solids, especially of transition-metal oxides. Recently, hard X-ray photoemission spectroscopy (HXPES) has emerged as a more relevant experimental technique to obtain clear information about bulk states. Here, we describe how HXPES can be conveniently applied to study the interesting subjects on oxide thin films such as the composition dependence and the film thickness dependence of the electronic structures and the interfacial electronic structure of multilayers

  17. Structure of the Buried Metal-Molecule Interface in Organic Thin Film Devices

    DEFF Research Database (Denmark)

    Hansen, Christian Rein; Sørensen, Thomas Just; Glyvradal, Magni

    2009-01-01

    By use of specular X-ray reflectivity (XR) the structure of a metal-covered organic thin film device is measured with angstrom resolution. The model system is a Langmuir-Blodgett (LB) film, sandwiched between a silicon substrate and a top electrode consisting of 25 Å titanium and 100 Å aluminum....... By comparison of XR data for the five-layer Pb2+ arachidate LB film before and after vapor deposition of the Ti/Al top electrode, a detailed account of the structural damage to the organic film at the buried metal-molecule interface is obtained. We find that the organized structure of the two topmost LB layers...

  18. Implantable polymer/metal thin film structures for the localized treatment of cancer by Joule heating

    Science.gov (United States)

    Kan-Dapaah, Kwabena; Rahbar, Nima; Theriault, Christian; Soboyejo, Wole

    2015-04-01

    This paper presents an implantable polymer/metal alloy thin film structure for localized post-operative treatment of breast cancer. A combination of experiments and models is used to study the temperature changes due to Joule heating by patterned metallic thin films embedded in poly-dimethylsiloxane. The heat conduction within the device and the surrounding normal/cancerous breast tissue is modeled with three-dimensional finite element method (FEM). The FEM simulations are used to explore the potential effects of device geometry and Joule heating on the temperature distribution and lesion (thermal dose). The FEM model is validated using a gel model that mimics biological media. The predictions are also compared to prior results from in vitro studies and relevant in vivo studies in the literature. The implications of the results are discussed for the potential application of polymer/metal thin film structures in hyperthermic treatment of cancer.

  19. Elaboration of strontium ruthenium oxide thin films on metal substrates by chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Seveno, R. [Universite de Nantes, Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique (IREENA), 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex 3 (France)]. E-mail: raynald.seveno@univ-nantes.fr; Braud, A. [Universite de Nantes, Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique (IREENA), 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex 3 (France); Gundel, H.W. [Universite de Nantes, Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique (IREENA), 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex 3 (France)

    2005-12-22

    In order to improve the structural interface between a metal substrate and a lead zirconate titanate (Pb(ZrTi)O{sub 3}, PZT) ferroelectric thin film, the elaboration of strontium ruthenium oxide (SrRuO{sub 3}) by chemical solution deposition is studied. The SrRuO{sub 3} thin films were realized by multiple spin-coating technique and the temperature of the rapid thermal annealing process was optimized. The crystallization behavior was examined by X-ray diffraction; surface analyses using scanning electron microscope and atomic force microscope techniques showed the influence of the SrRuO{sub 3} layer at the interface PZT/metal on the morphology of the ferroelectric thin film. From the electrical measurements, a coercive electric field around 25 kV/cm and a remanent polarization of approximately 30 {mu}C/cm were found.

  20. A study of using femtosecond LIBS in analyzing metallic thin film-semiconductor interface

    Science.gov (United States)

    Galmed, A. H.; Kassem, A. K.; von Bergmann, H.; Harith, M. A.

    2011-01-01

    Metals and metal alloys are usually employed as interconnections to guide electrical signals between components into the very large scale integrated (VLSI) devices. These devices demand higher complexity, better performance and lower cost. Thin film is a common geometry for these metallic applications, requiring a substrate for rigidity. Accurate depth profile analysis of coatings is becoming increasingly important with expanding industrial use in technological fields. A number of articles devoted to LIBS applications for depth-resolved analysis have been published in recent years. In the present work, we are studying the ability of femtosecond LIBS to make depth profiling for a Ti thin film of thickness 213 nm deposited onto a silicon (100) substrate before and after thermal annealing. The measurements revealed that an average ablation rates of 15 nm per pulse have been achieved. The thin film was examined using X-Ray Diffraction (XRD) and Atomic Force Microscope (AFM), while the formation of the interface was examined using Rutherford Back Scattering (RBS) before and after annealing. To verify the depth profiling results, a theoretical simulation model is presented that gave a very good agreement with the experimental results.

  1. Differential reflectometry of thin film metal oxides on copper, tungsten, molybdenum and chromium

    International Nuclear Information System (INIS)

    Urban, F.K. III; Hummel, R.E.; Verink, E.D. Jr.

    1982-01-01

    A differential reflectometry study was undertaken to investigate the characteristics of thin oxide films on metal substrates. The oxides were produced by heating pure metals of copper, tungsten, molybdenum and chromium in dry oxygen. A new 'halfpolishing' technique was applied to obtain specimens with a step in oxide thickness in order to make them suitable for differential reflectometry. It was found that oxides formed this way yielded the same differential reflectograms as by electrochemical oxidation. A mathematical model involving the interaction of light with a thin corrosion product on metal substrates was applied to generate computer calculated differential reflectograms utilizing various optical constants and thicknesses of the assumed film. Three different thickness ranges have been identified. (a) For large film thicknesses, the differential reflectograms are distinguished by a sequence of interference peaks. (b) If the product of thickness and refraction index of the films is smaller than about 40 nm, no interference peaks are present. Any experimentally observed peaks in differential reflectograms of these films are caused entirely by electron interband transitions. (c) In an intermediate thickness range, superposition of interference and interband peaks are observed. (author)

  2. Current-induced metal-insulator transition in VO x thin film prepared by rapid-thermal-annealing

    International Nuclear Information System (INIS)

    Cho, Choong-Rae; Cho, SungIl; Vadim, Sidorkin; Jung, Ranju; Yoo, Inkyeong

    2006-01-01

    The phenomenon of metal-insulator transition (MIT) in polycrystalline VO x thin films and their preparations have been studied. The films were prepared by sputtering of vanadium thin films succeeded by Rapid Thermal Annealing (RTA) in oxygen ambient at 500 deg. C. Crystalline, compositional, and morphological characterizations reveal a continuous change of phase from vanadium metal to the highest oxide phase, V 2 O 5 , with the time of annealing. Electrical MIT switching has been observed in these films. Sweeping mode, electrode area, and temperature dependent MIT has been studied in Pt/VO x /Pt vertical structure. The important parameters for MIT in VO x have been found to be the current density and the electric field, which depend on carrier density in the films

  3. Formation mechanisms of metallic Zn nanodots by using ZnO thin films deposited on n-Si substrates

    International Nuclear Information System (INIS)

    Yuk, J. M.; Lee, J. Y.; Kim, Y.; No, Y. S.; Kim, T. W.; Choi, W. K.

    2010-01-01

    High-resolution transmission electron microscopy and energy dispersive x-ray spectroscopy results showed that metallic Zn nanodots (NDs) were fabricated through transformation of ZnO thin films by deposition of SiO x on ZnO/n-Si (100) heterostructures. The Zn NDs with various sizes and densities were formed due to the occurrence of the mass diffusion of atoms along the grain boundaries in the ZnO thin films. The fabrication mechanisms of metallic Zn NDs through transformation of ZnO thin films deposited on n-Si substrates are described on the basis of the experimental results.

  4. Mechanical properties of vapor-deposited thin metallic films: a status report

    International Nuclear Information System (INIS)

    Adler, P.H.

    1982-01-01

    The mechanical properties of vapor-deposited thin metallic films are being studied in conjunction with the target fabrication group associated with the laser-fusion energy program. The purpose of the work is to gain an understanding as to which metals are structurally best suited to contain a glass microsphere filled with deuterium-tritium (D-T) gas at large internal pressures

  5. Bi-axially crumpled silver thin-film electrodes for dielectric elastomer actuators

    International Nuclear Information System (INIS)

    Low, Sze-Hsien; Lau, Gih-Keong

    2014-01-01

    Metal thin films, which have high conductivity, are much stiffer and may fracture at a much lower strain than dielectric elastomers. In order to fabricate compliant electrodes for use in dielectric elastomer actuators (DEAs), metal thin films have been formed into either zigzag patterns or corrugations, which favour bending and only allow uniaxial DEA deformations. However, biaxially compliant electrodes are desired in order to maximize generated forces of DEA. In this paper, we present crumpled metal thin-film electrodes that are biaxially compliant and have full area coverage over the dielectric elastomer. These crumpled metal thin-film electrodes are more stretchable than flat metal thin films; they remain conductive beyond 110% radial strain. Also, crumpling reduced the stiffening effect of metal thin films on the soft elastomer. As such, DEAs using crumpled metal thin-film electrodes managed to attain relatively high actuated area strains of up to 128% at 1.8 kV (102 Vμm −1 ). (paper)

  6. Magnetoelectric coupling effect in transition metal modified polycrystalline BiFeO{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sreenivas Puli, Venkata, E-mail: pvsri123@gmail.com [Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118 (United States); Department of Physics and Institute of Functional Nanomaterials, University of Puerto Rico, San Juan, PR 00936 (United States); Kumar Pradhan, Dhiren [Department of Physics and Institute of Functional Nanomaterials, University of Puerto Rico, San Juan, PR 00936 (United States); Gollapudi, Sreenivasulu [Department of Physics, Oakland University, Rochester, MI 48309-4401 (United States); Coondoo, Indrani [Department of Materials and Ceramic and CICECO, University of Aveiro, 3810-193 Aveiro (Portugal); Panwar, Neeraj [Department of Physics, Central University of Rajasthan, Bandar Sindri, Kishangarh 305801, Rajasthan (India); Adireddy, Shiva; Chrisey, Douglas B. [Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118 (United States); Katiyar, Ram S. [Department of Physics and Institute of Functional Nanomaterials, University of Puerto Rico, San Juan, PR 00936 (United States)

    2014-11-15

    Rare-earth (Sm) and transition metal (Co) modified polycrystalline BiFeO{sub 3} (BFO) thin films have been deposited on Pt/TiO{sub 2}/SiO{sub 2}/Si substrate successfully through pulsed laser deposition (PLD) technique. Piezoelectric, leakage current and temperature dependent dielectric and magnetic behaviour were investigated for the films. Typical “butterfly-shaped” loop were observed in BSFCO films with an effective piezoelectric constant (d{sub 33}) ∼94 pm/V at 0.6 MV/cm. High dielectric constant ∼900 and low dielectric loss ∼0.25 were observed at room temperature. M–H loops have shown relatively high saturation magnetization ∼35 emu/cm{sup 3} at a maximum field of H ∼20 kOe. Enhanced magnetoelectric coupling response is observed under applied magnetic field. The multiferroic, piezoelectric, leakage current behaviours were explored. Such studies should be helpful in designing multiferroic materials based on BSFCO films. - Highlights: • Transition metal modified polycrystalline BiFeO{sub 3} thin films prepared using PLD. • High ME-coupling response was observed in co-substituted BiFeO{sub 3} thin films. • High magnetization ∼35 emu/cm{sup 3} at a maximum field of H ∼20 kOe. • Low leakage current might be due to co-substitution in BiFeO{sub 3} thin films. • A notable piezoelectric constant d{sub 33} ∼94 pm/V was found in BiFeO{sub 3} thin films.

  7. Work function and quantum efficiency study of metal oxide thin films on Ag(100)

    Science.gov (United States)

    Chang, V.; Noakes, T. C. Q.; Harrison, N. M.

    2018-04-01

    Increasing the quantum efficiency (QE) of metal photocathodes is in the design and development of photocathodes for free-electron laser applications. The growth of metal oxide thin films on certain metal surfaces has previously been shown to reduce the work function (WF). Using a photoemission model B. Camino et al. [Comput. Mater. Sci. 122, 331 (2016), 10.1016/j.commatsci.2016.05.025] based on the three-step model combined with density functional theory calculations we predict that the growth of a finite number of MgO(100) or BaO(100) layers on the Ag(100) surface increases significantly the QE compared with the clean Ag(100) surface for a photon energy of 4.7 eV. Different mechanisms for affecting the QE are identified for the different metal oxide thin films. The addition of MgO(100) increases the QE due to the reduction of the WF and the direct excitation of electrons from the Ag surface to the MgO conduction band. For BaO(100) thin films, an additional mechanism is in operation as the oxide film also photoemits at this energy. We also note that a significant increase in the QE for photons with an energy of a few eV above the WF is achieved due to an increase in the inelastic mean-free path of the electrons.

  8. Effects of accelerated degradation on metal supported thin film-based solid oxide fuel cell

    DEFF Research Database (Denmark)

    Reolon, R. P.; Sanna, S.; Xu, Yu

    2018-01-01

    A thin film-based solid oxide fuel cell is deposited on a Ni-based metal porous support by pulsed laser deposition with a multi-scale-graded microstructure design. The fuel cell, around 1 μm in thickness, is composed of a stabilized-zirconia/doped-ceria bi-layered dense electrolyte and nanostruct......A thin film-based solid oxide fuel cell is deposited on a Ni-based metal porous support by pulsed laser deposition with a multi-scale-graded microstructure design. The fuel cell, around 1 μm in thickness, is composed of a stabilized-zirconia/doped-ceria bi-layered dense electrolyte......, electrochemical performances are steady, indicating the stability of the cell. Under electrical load, a progressive degradation is activated. Post-test analysis reveals both mechanical and chemical degradation of the cell. Cracks and delamination of the thin films promote a significant nickel diffusion and new...

  9. A method for thickness determination of thin films of amalgamable metals by total-reflection X-ray fluorescence

    International Nuclear Information System (INIS)

    Bennun, L.; Greaves, E.D.; Barros, H.; Diaz-Valdes, J.

    2009-01-01

    A method for thickness determination of thin amalgamable metallic films by total-reflection X-ray fluorescence (TXRF) is presented. The peak's intensity in TXRF spectra are directly related to the surface density of the sample, i.e. to its thickness in a homogeneous film. Performing a traditional TXRF analysis on a thin film of an amalgamated metal, and determining the relative peak intensity of a specific metal line, the layer thickness can be precisely obtained. In the case of gold thickness determination, mercury and gold peaks overlap, hence we have developed a general data processing scheme to achieve the most precise results.

  10. Low-Dimensional Nanomaterials as Active Layer Components in Thin-Film Photovoltaics

    Science.gov (United States)

    Shastry, Tejas Attreya

    Thin-film photovoltaics offer the promise of cost-effective and scalable solar energy conversion, particularly for applications of semi-transparent solar cells where the poor absorption of commercially-available silicon is inadequate. Applications ranging from roof coatings that capture solar energy to semi-transparent windows that harvest the immense amount of incident sunlight on buildings could be realized with efficient and stable thin-film solar cells. However, the lifetime and efficiency of thin-film solar cells continue to trail their inorganic silicon counterparts. Low-dimensional nanomaterials, such as carbon nanotubes and two-dimensional metal dichalcogenides, have recently been explored as materials in thin-film solar cells due to their exceptional optoelectronic properties, solution-processability, and chemical inertness. Thus far, issues with the processing of these materials has held back their implementation in efficient photovoltaics. This dissertation reports processing advances that enable demonstrations of low-dimensional nanomaterials in thin-film solar cells. These low-dimensional photovoltaics show enhanced photovoltaic efficiency and environmental stability in comparison to previous devices, with a focus on semiconducting single-walled carbon nanotubes as an active layer component. The introduction summarizes recent advances in the processing of carbon nanotubes and their implementation through the thin-film photovoltaic architecture, as well as the use of two-dimensional metal dichalcogenides in photovoltaic applications and potential future directions for all-nanomaterial solar cells. The following chapter reports a study of the interaction between carbon nanotubes and surfactants that enables them to be sorted by electronic type via density gradient ultracentrifugation. These insights are utilized to construct of a broad distribution of carbon nanotubes that absorb throughout the solar spectrum. This polychiral distribution is then shown

  11. Black metal thin films by deposition on dielectric antireflective moth-eye nanostructures

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Caringal, Gideon Peter; Clausen, Jeppe Sandvik

    2015-01-01

    Although metals are commonly shiny and highly reflective, we here show that thin metal films appear black when deposited on a dielectric with antireflective moth-eye nanostructures. The nanostructures were tapered and close-packed, with heights in the range 300-600 nm, and a lateral, spatial...... frequency in the range 5-7 mu m(-1). A reflectance in the visible spectrum as low as 6%, and an absorbance of 90% was observed for an Al film of 100 nm thickness. Corresponding experiments on a planar film yielded 80% reflectance and 20% absorbance. The observed absorbance enhancement is attributed...... to a gradient effect causing the metal film to be antireflective, analogous to the mechanism in dielectrics and semiconductors. We find that the investigated nanostructures have too large spatial frequency to facilitate efficient coupling to the otherwise non-radiating surface plasmons. Applications...

  12. Study of thin metal films and oxide materials for nanoelectronics applications

    OpenAIRE

    De Los Santos Valladares, Luis

    2012-01-01

    Appendix A Pages 132-134 have been removed from this online version of the thesis for publisher copyright reasons. These had contained page images from the cover of Nanotechnology, Vol. 21, Nov 2010 and its corresponding web alert Different types of thin metal films and oxide materials are studied for their potential application in nanoelectronics: gold and copper films, nickel nanoelectrodes, oxide nanograin superconductors, carboxyl ferromagnetic microspheres and graphene oxide...

  13. Assembly of metallic nanoparticle arrays on glass via nanoimprinting and thin-film dewetting

    Directory of Open Access Journals (Sweden)

    Sun-Kyu Lee

    2017-05-01

    Full Text Available We propose a nanofabrication process to generate large-area arrays of noble metal nanoparticles on glass substrates via nanoimprinting and dewetting of metallic thin films. Glass templates were made via pattern transfer from a topographic Si mold to an inorganically cross-linked sol–gel (IGSG resist on glass using a two-layer polydimethylsiloxane (PDMS stamp followed by annealing, which turned the imprinted resist into pure silica. The transparent, topographic glass successfully templated the assembly of Au and Ag nanoparticle arrays via thin-film deposition and dewetting at elevated temperatures. The microstructural and mechanical characteristics that developed during the processes were discussed. The results are promising for low-cost mass fabrication of devices for several photonic applications.

  14. Assembly of metallic nanoparticle arrays on glass via nanoimprinting and thin-film dewetting.

    Science.gov (United States)

    Lee, Sun-Kyu; Hwang, Sori; Kim, Yoon-Kee; Oh, Yong-Jun

    2017-01-01

    We propose a nanofabrication process to generate large-area arrays of noble metal nanoparticles on glass substrates via nanoimprinting and dewetting of metallic thin films. Glass templates were made via pattern transfer from a topographic Si mold to an inorganically cross-linked sol-gel (IGSG) resist on glass using a two-layer polydimethylsiloxane (PDMS) stamp followed by annealing, which turned the imprinted resist into pure silica. The transparent, topographic glass successfully templated the assembly of Au and Ag nanoparticle arrays via thin-film deposition and dewetting at elevated temperatures. The microstructural and mechanical characteristics that developed during the processes were discussed. The results are promising for low-cost mass fabrication of devices for several photonic applications.

  15. Laser deposition rates of thin films of selected metals and alloys

    DEFF Research Database (Denmark)

    Cazzaniga, Andrea Carlo; Canulescu, Stela; Schou, Jørgen

    Thin films of Cu, Zn and Sn as well as mixtures of these elements have been produced by Pulsed Laser Deposition (PLD). The deposition rate of single and multicomponent metallic targets was determined. The strength of PLD is that the stoichiometry of complex compounds, even of complicated alloys...... or metal oxides, can be preserved from target to film. We apply this technique to design films of a mixture of Cu, Zn and Sn, which are constituents of the chalcogenide CZTS, which has a composition close to Cu2ZnSnS4. This compound is expected to be an important candidate for absorbers in new solar cells...... for alloys of the different elements as well as compounds with S will be presented....

  16. Enhanced Absorption in Organic Thin-Films from Imprinted Concave Nanostructures

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Rubahn, Horst-Günter; Madsen, Morten

    2017-01-01

    In this work, a rapid, replicable method for imprinting concave nanostructures to be used as functional light-trapping nanostructures in organic thin-films is presented. Porous anodic alumina templates were fabricated both by anodization of thick Al foils and by anodization of submicrometer thin Al...... patterns and used for imprinting of spin coated photoresist on glass substrates. We have investigated semi-periodic and aperiodic imprinted large concave patterns fabricated from rigid masters after anodization of Al in H3PO4. We show that metal covered imprinted concaves show enhancement in absorption...

  17. Metal-insulator phase transition in a VO2 thin film observed with terahertz spectroscopy

    DEFF Research Database (Denmark)

    Jepsen, Peter Uhd; Fischer, Bernd M.; Thoman, Andreas

    2006-01-01

    We investigate the dielectric properties of a thin VO2 film in the terahertz frequency range in the vicinity of the semiconductor-metal phase transition. Phase-sensitive broadband spectroscopy in the frequency region below the phonon bands of VO2 gives insight into the conductive properties...... of the film during the phase transition. We compare our experimental data with models proposed for the evolution of the phase transition. The experimental data show that the phase transition occurs via the gradual growth of metallic domains in the film, and that the dielectric properties of the film...

  18. All-metallic electrically gated 2H-TaSe2 thin-film switches and logic circuits

    International Nuclear Information System (INIS)

    Renteria, J.; Jiang, C.; Yan, Z.; Samnakay, R.; Goli, P.; Pope, T. R.; Salguero, T. T.; Wickramaratne, D.; Lake, R. K.; Khitun, A. G.; Balandin, A. A.

    2014-01-01

    We report the fabrication and performance of all-metallic three-terminal devices with tantalum diselenide thin-film conducting channels. For this proof-of-concept demonstration, the layers of 2H-TaSe 2 were exfoliated mechanically from single crystals grown by the chemical vapor transport method. Devices with nanometer-scale thicknesses exhibit strongly non-linear current-voltage characteristics, unusual optical response, and electrical gating at room temperature. We have found that the drain-source current in thin-film 2H-TaSe 2 –Ti/Au devices reproducibly shows an abrupt transition from a highly resistive to a conductive state, with the threshold tunable via the gate voltage. Such current-voltage characteristics can be used, in principle, for implementing radiation-hard all-metallic logic circuits. These results may open new application space for thin films of van der Waals materials

  19. All-metallic electrically gated 2H-TaSe2 thin-film switches and logic circuits

    Science.gov (United States)

    Renteria, J.; Samnakay, R.; Jiang, C.; Pope, T. R.; Goli, P.; Yan, Z.; Wickramaratne, D.; Salguero, T. T.; Khitun, A. G.; Lake, R. K.; Balandin, A. A.

    2014-01-01

    We report the fabrication and performance of all-metallic three-terminal devices with tantalum diselenide thin-film conducting channels. For this proof-of-concept demonstration, the layers of 2H-TaSe2 were exfoliated mechanically from single crystals grown by the chemical vapor transport method. Devices with nanometer-scale thicknesses exhibit strongly non-linear current-voltage characteristics, unusual optical response, and electrical gating at room temperature. We have found that the drain-source current in thin-film 2H-TaSe2-Ti/Au devices reproducibly shows an abrupt transition from a highly resistive to a conductive state, with the threshold tunable via the gate voltage. Such current-voltage characteristics can be used, in principle, for implementing radiation-hard all-metallic logic circuits. These results may open new application space for thin films of van der Waals materials.

  20. Characterization of PZT thin films on metal substrates

    International Nuclear Information System (INIS)

    Dutschke, A.

    2008-01-01

    Lead zirconate titanate (PbZr x Ti 1-x O 3 ,PZT) is one of the most applied ceramic materials because of its distinctive piezo- and ferroelectric properties. Prepared as thin films on flexible, metallic substrates it can be used for various applications as strain gauges, key switches, vibration dampers, microactuators and ultrasonic transducers. The aim of this work is to analyze the microstructure and the phase-content of PZT-thin films deposited on temperature- und acid-resistant hastelloy-sheets, to correlate the results with the ferroelectric and dielectric properties. It is demonstrated, that the specific variation of the microstructure can be achieved by different thermal treatments and the selective addition of Neodymium as dopant. Nd-doping leads to a shift of the maximum nucleation rate towards reduced temperatures and a decrease in the rate of growth compared to undoped films. The PZT-films are prepared by a sol-gel-process in fourfold multilayers with a composition near the morphotropic phase boundary, where the tetragonal und rhombohedral perovskite-phases coexist. The crystallisation in Nd-doped and undoped films takes place heterogeneously, preferentially at the interfaces and on the surface of the multilayered films as well as on the inner surface of pores within the films. For the first time, the Zr:Ti fluctuation phenomena emerging in sol-gel derived PZT films is related to the microstructure and the local phase content on a nanometer scale. In this connection it is proved, that long-distance Zr:Ti gradients arise preferentially before and during the crystallisation of the pyrochlore phase. During the following crystallisation of the perovskite phase, the crystallites grow across these gradients without modifying them. It is pointed out that the fluctuation in the Zr:Ti ratio has only minor influence on the amount of the tetragonal or rhombohedral distortion of the crystallites after the transition from the para- to the ferroelectric state due to

  1. Correlation of morphology and barrier properties of thin microwave plasma polymer films on metal substrate

    International Nuclear Information System (INIS)

    Barranco, V.; Carpentier, J.; Grundmeier, G.

    2004-01-01

    The barrier properties of thin model organosilicon plasma polymers layers on iron are characterised by means of electrochemical impedance spectroscopy (EIS). Tailored thin plasma polymers of controlled morphology and chemical composition were deposited from a microwave discharge. By the analysis of the obtained impedance diagrams, the evolution of the water uptake φ, coating resistance and polymer capacitance with immersion time were monitored and the diffusion coefficients of the water through the films were calculated. The impedance data correlated well with the chemical structure and morphology of the plasma polymer films with a thickness of less than 100 nm. The composition of the films were determined by means of infrared reflection absorption spectroscopy (IRRAS), X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The morphology of the plasma polymer surface and the interface between the plasma polymer and the metal were characterised using atomic force microscopy (AFM). It could be shown that, at higher pressure, the film roughness increases which is probably due to the adsorption of plasma polymer nanoparticles formed in the plasma bulk and the faster film growth. This leads to voids with a size of a few tens of nanometers at the polymer/metal interface. The film roughness increases from the interface to the outer surface of the film. By lowering the pressure and thereby slowing the deposition rate, the plasma polymers perfectly imitate the substrate topography and lead to an excellent blocking of the metal surface. Moreover, the ratio of siloxane bonds to methyl-silyl groups increases which implies that the crosslink density is higher at lower deposition rate. The EIS data consistently showed higher coating resistance as well as lower interfacial capacitance values and a better stability over time for the film deposited at slower pressure. The diffusion coefficient of water in thin and ultra-thin plasma

  2. Optimization of synthesis protocols to control the nanostructure and the morphology of metal oxide thin films for memristive applications

    Energy Technology Data Exchange (ETDEWEB)

    Baldi, G., E-mail: giacomo.baldi@cnr.it; Bosi, M.; Attolini, G.; Berzina, T.; Mosca, R.; Ponraj, J. S.; Iannotta, S. [IMEM-CNR Institute, Parco Area delle Scienze 37/A, I-43124 Parma (Italy); Giusti, G.; Nozar, P.; Toccoli, T.; Verucchi, R. [IMEM-CNR Institute, Via alla Cascata 56/C, Povo – I-38123 Trento (Italy); Collini, C.; Lorenzelli, L. [FBK Bruno Kessler Foundation, Via Sommarive 18, I-38123 Trento (Italy)

    2015-03-10

    We propose a multi-technique approach based on in-vacuum synthesis of metal oxides to optimize the memristive properties of devices that use a metal oxide thin film as insulating layer. Pulsed Microplasma Cluster Source (PMCS) is based on supersonic beams seeded by clusters of the metal oxide. Nanocrystalline TiO{sub 2} thin films can be grown at room temperature, controlling the oxide stoichiometry from titanium metal up to a significant oxygen excess. Pulsed Electron beam Deposition (PED) is suitable to grow crystalline thin films on large areas, a step towards producing device arrays with controlled morphology and stoichiometry. Atomic Layer Deposition (ALD) is a powerful technique to grow materials layer-by-layer, finely controlling the chemical and structural properties of the film up to thickness of 50-80 nm. We will present a few examples of metal-insulator-metal structures showing a pinched hysteresis loop in their current-voltage characteristic. The structure, stoichiometry and morphology of the metal oxide layer, either aluminum oxide or titanium dioxide, is investigated by means of scanning electron microscopy (SEM) and by Raman scattering.

  3. Thin Film Microbatteries

    International Nuclear Information System (INIS)

    Dudney, Nancy J.

    2008-01-01

    aerosol spray coating, for one or more components of the battery. The active materials used for the thin film cathodes and anodes are familiar intercalation compounds, but the microstructures and often the cycling properties of the thin films may be quite distinct from those of battery electrodes formed from powders. The thin film cathodes are dense and homogeneous with no added phases such as binders or electrolytes. When deposited at ambient temperatures, the films of cathodes, such as LiCoO 2 , V 2 O 5 , LiMn 2 O4 , LiFePO 4 are amorphous or nanocrystalline. But even in this form, they often act as excellent cathodes with large specific capacities and good stability for hundreds to thousands of cycles. Annealing the cathode films at temperatures of 300 to 800 C may be used to induce crystallization and grain growth of the desired intercalation compound. Crystallizing the cathode film generally improves the Li chemical diffusivity in the electrode material, and hence the power delivered by the battery, by 1-2 orders of magnitude. The microstructure is also tailored by the deposition and heat treatment. Figure 3 shows a fracture edge of an annealed LiCoO 2 cathode film on an alumina substrate. The columnar microstructure, which is typical of a vapor deposited film, sinters at high temperatures leaving small fissures between the dense columns. Such crystalline films also may have a preferred crystallographic orientation. For LiCoO 2 films the crystallographic texture differs for films deposited by sputtering versus pulse laser ablation processes. To improve the manufacturability of the thin film batteries, it would be beneficial to eliminate or minimize the temperature or duration of the annealing step. Several efforts have lead to low temperature fabrication of thin film batteries on polyimide substrates, but the battery capacity and rate are lower than those treated at high temperatures. For the battery anode, many designs use a vapor-deposited metallic lithium film as

  4. Spin-Hall conductivity and electric polarization in metallic thin films

    KAUST Repository

    Wang, Xuhui

    2013-02-21

    We predict theoretically that when a normal metallic thin film (without bulk spin-orbit coupling, such as Cu or Al) is sandwiched by two insulators, two prominent effects arise due to the interfacial spin-orbit coupling: a giant spin-Hall conductivity due to the surface scattering and a transverse electric polarization due to the spin-dependent phase shift in the spinor wave functions.

  5. Spin-Hall conductivity and electric polarization in metallic thin films

    KAUST Repository

    Wang, Xuhui; Xiao, Jiang; Manchon, Aurelien; Maekawa, Sadamichi

    2013-01-01

    We predict theoretically that when a normal metallic thin film (without bulk spin-orbit coupling, such as Cu or Al) is sandwiched by two insulators, two prominent effects arise due to the interfacial spin-orbit coupling: a giant spin-Hall conductivity due to the surface scattering and a transverse electric polarization due to the spin-dependent phase shift in the spinor wave functions.

  6. Photovoltaic effect in transition metal modified polycrystalline BiFeO3 thin films

    International Nuclear Information System (INIS)

    Puli, Venkata Sreenivas; Chrisey, Douglas B; Pradhan, Dhiren Kumar; Katiyar, Rajesh Kumar; Misra, Pankaj; Scott, J F; Katiyar, Ram S; Coondoo, Indrani; Panwar, Neeraj

    2014-01-01

    We report photovoltaic (PV) effect in multiferroic Bi 0.9 Sm 0.1 Fe 0.95 Co 0.05 O 3 (BSFCO) thin films. Transition metal modified polycrystalline BiFeO 3 (BFO) thin films have been deposited on Pt/TiO 2 /SiO 2 /Si substrate successfully through pulsed laser deposition (PLD). PV response is observed under illumination both in sandwich and lateral electrode configurations. The open-circuit voltage (V oc ) and the short-circuit current density (J sc ) of the films in sandwich electrode configuration under illumination are measured to be 0.9 V and −0.051 µA cm −2 . Additionally, we report piezoresponse for BSFCO films, which confirms ferroelectric piezoelectric behaviour. (paper)

  7. Water-Mediated Photochemical Treatments for Low-Temperature Passivation of Metal-Oxide Thin-Film Transistors.

    Science.gov (United States)

    Heo, Jae Sang; Jo, Jeong-Wan; Kang, Jingu; Jeong, Chan-Yong; Jeong, Hu Young; Kim, Sung Kyu; Kim, Kwanpyo; Kwon, Hyuck-In; Kim, Jaekyun; Kim, Yong-Hoon; Kim, Myung-Gil; Park, Sung Kyu

    2016-04-27

    The low-temperature electrical passivation of an amorphous oxide semiconductor (AOS) thin-film transistor (TFT) is achieved by a deep ultraviolet (DUV) light irradiation-water treatment-DUV irradiation (DWD) method. The water treatment of the first DUV-annealed amorphous indium-gallium-zinc-oxide (a-IGZO) thin film is likely to induce the preferred adsorption of water molecules at the oxygen vacancies and leads to subsequent hydroxide formation in the bulk a-IGZO films. Although the water treatment initially degraded the electrical performance of the a-IGZO TFTs, the second DUV irradiation on the water-treated devices may enable a more complete metal-oxygen-metal lattice formation while maintaining low oxygen vacancies in the oxide films. Overall, the stable and dense metal-oxygen-metal (M-O-M) network formation could be easily achieved at low temperatures (below 150 °C). The successful passivation of structural imperfections in the a-IGZO TFTs, such as hydroxyl group (OH-) and oxygen vacancies, mainly results in the enhanced electrical performances of the DWD-processed a-IGZO TFTs (on/off current ratio of 8.65 × 10(9), subthreshold slope of 0.16 V/decade, an average mobility of >6.94 cm(2) V(-1) s(-1), and a bias stability of ΔVTH IGZO TFTs.

  8. 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.

  9. Epitaxial Oxide Thin Films Grown by Solid Source Metal-Organic Chemical Vapor Deposition.

    Science.gov (United States)

    Lu, Zihong

    1995-01-01

    The conventional liquid source metal-organic chemical vapor deposition (MOCVD) technique is capable of producing large area, high quality, single crystal semiconductor films. However, the growth of complex oxide films by this method has been hampered by a lack of suitable source materials. While chemists have been actively searching for new source materials, the research work reported here has demonstrated the successful application of solid metal-organic sources (based on tetramethylheptanedionate) to the growth of high quality thin films of binary compound cerium dioxide (CeO_2), and two more complex materials, the ternary compound lithium niobate (LiNbO_3), with two cations, and the quaternary compound strontium barium niobate (SBN), with three cations. The growth of CeO_2 thin films on (1012)Al_2O_3 substrates has been used as a model to study the general growth behavior of oxides. Factors affecting deposition rate, surface morphology, out-of-plane mosaic structure, and film orientation have been carefully investigated. A kinetic model based on gas phase prereaction is proposed to account for the substrate temperature dependence of film orientation found in this system. Atomically smooth, single crystal quality cerium dioxide thin films have been obtained. Superconducting YBCO films sputtered on top of solid source MOCVD grown thin cerium dioxide buffer layers on sapphire have been shown to have physical properties as good as those of YBCO films grown on single crystal MgO substrates. The thin film growth of LiNbO_3 and Sr_{1-x}Ba _{x}Nb_2 O_6 (SBN) was more complex and challenging. Phase purity, transparency, in-plane orientation, and the ferroelectric polarity of LiNbO _3 films grown on sapphire substrates was investigated. The first optical quality, MOCVD grown LiNbO _3 films, having waveguiding losses of less than 2 dB/cm, were prepared. An important aspect of the SBN film growth studies involved finding a suitable single crystal substrate material. Mg

  10. Revealing the relationships between chemistry, topology and stiffness of ultrastrong Co-based metallic glass thin films: A combinatorial approach

    International Nuclear Information System (INIS)

    Schnabel, Volker; Köhler, Mathias; Evertz, Simon; Gamcova, Jana; Bednarcik, Jozef; Music, Denis; Raabe, Dierk; Schneider, Jochen M.

    2016-01-01

    An efficient way to study the relationship between chemical composition and mechanical properties of thin films is to utilize the combinatorial approach, where spatially resolved mechanical property measurements are conducted along a concentration gradient. However, for thin film glasses many properties including the mechanical response are affected by chemical topology. Here a novel method is introduced which enables spatially resolved short range order analysis along concentration gradients of combinatorially synthesized metallic glass thin films. For this purpose a CoZrTaB metallic glass film of 3 μm thickness is deposited on a polyimide foil, which is investigated by high energy X-ray diffraction in transmission mode. Through the correlative chemistry-topology-stiffness investigation, we observe that an increase in metalloid concentration from 26.4 to 32.7 at% and the associated formation of localized (hybridized) metal – metalloid bonds induce a 10% increase in stiffness. Concomitantly, along the same composition gradient, a metalloid-concentration-induced increase in first order metal - metal bond distances of 1% is observed, which infers itinerant (metallic) bond weakening. Hence, the metalloid concentration induced increase in hybridized bonding dominates the corresponding weakening of metallic bonds.

  11. All-metallic electrically gated 2H-TaSe{sub 2} thin-film switches and logic circuits

    Energy Technology Data Exchange (ETDEWEB)

    Renteria, J.; Jiang, C.; Yan, Z. [Nano-Device Laboratory, Department of Electrical Engineering, Bourns College of Engineering, University of California–Riverside, Riverside, California 92521 (United States); Samnakay, R.; Goli, P. [Materials Science and Engineering Program, Bourns College of Engineering, University of California–Riverside, Riverside, California 92521 (United States); Pope, T. R.; Salguero, T. T. [Department of Chemistry, University of Georgia, Athens, Georgia 30602 (United States); Wickramaratne, D.; Lake, R. K. [Laboratory for Terascale and Terahertz Electronics, Department of Electrical Engineering, Bourns College of Engineering, University of California–Riverside, Riverside, California 92521 (United States); Khitun, A. G. [Nano-Device Laboratory, Department of Electrical Engineering, Bourns College of Engineering, University of California–Riverside, Riverside, California 92521 (United States); Materials Science and Engineering Program, Bourns College of Engineering, University of California–Riverside, Riverside, California 92521 (United States); Balandin, A. A., E-mail: balandin@ee.ucr.edu [Nano-Device Laboratory, Department of Electrical Engineering, Bourns College of Engineering, University of California–Riverside, Riverside, California 92521 (United States); Department of Chemistry, University of Georgia, Athens, Georgia 30602 (United States)

    2014-01-21

    We report the fabrication and performance of all-metallic three-terminal devices with tantalum diselenide thin-film conducting channels. For this proof-of-concept demonstration, the layers of 2H-TaSe{sub 2} were exfoliated mechanically from single crystals grown by the chemical vapor transport method. Devices with nanometer-scale thicknesses exhibit strongly non-linear current-voltage characteristics, unusual optical response, and electrical gating at room temperature. We have found that the drain-source current in thin-film 2H-TaSe{sub 2}–Ti/Au devices reproducibly shows an abrupt transition from a highly resistive to a conductive state, with the threshold tunable via the gate voltage. Such current-voltage characteristics can be used, in principle, for implementing radiation-hard all-metallic logic circuits. These results may open new application space for thin films of van der Waals materials.

  12. Solution processed metal oxide thin film hole transport layers for high performance organic solar cells

    Science.gov (United States)

    Steirer, K. Xerxes; Berry, Joseph J.; Chesin, Jordan P.; Lloyd, Matthew T.; Widjonarko, Nicodemus Edwin; Miedaner, Alexander; Curtis, Calvin J.; Ginley, David S.; Olson, Dana C.

    2017-01-10

    A method for the application of solution processed metal oxide hole transport layers in organic photovoltaic devices and related organic electronics devices is disclosed. The metal oxide may be derived from a metal-organic precursor enabling solution processing of an amorphous, p-type metal oxide. An organic photovoltaic device having solution processed, metal oxide, thin-film hole transport layer.

  13. 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

  14. The properties of metal contacts on TiO2 thin films produced by reactive magnetron sputtering

    Directory of Open Access Journals (Sweden)

    Brus V. V.

    2010-10-01

    Full Text Available The article deals with research on volt-ampere characteristics of metal contacts (Al, Cr, In, Mo, Ti on titanium dioxide thin films and influence of annealing in vacuum on their electric properties. Volt-ampere characteristics measurements were taken by three-probe method. There was established that indium contact on TiO2 thin films possessed sharply defined ohmic properties.

  15. 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.

  16. Semiconductor/metal nanocomposites formed by in situ reduction method in multilayer thin films

    International Nuclear Information System (INIS)

    Song Yanli; Wang Enbo; Tian Chungui; Mao Baodong; Wang Chunlei

    2009-01-01

    A layer-by-layer adsorption and in situ reduction method was adopted for synthesizing semiconductor/metal nanocomposites in multilayer ultra-thin films. Alternate adsorption of ZnO nanoparticles modified with poly(ethyleneimine), hydrogentetrachloroaurate and poly(styrenesulfonate) sodium results in the formation of ZnO/AuCl 4 - -loaded multilayer films. In situ reduction of the incorporated metal ions by heating yields ZnO/Au nanocomposites in the films. UV-vis absorption spectroscopy and X-ray photoelectron spectroscopy were used to characterize the components of the composite films. UV-vis spectra indicate regular growth of the films. The electrochemistry behavior of the multilayer films was studied in detail on indium tin oxide electrode. The combined results suggest that the layer-by-layer adsorption and subsequent reduction method used here provides an effective way to synthesize ZnO/Au nanocomposites in the polymer matrix

  17. 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

  18. Influence of various thickness metallic interlayers on opto-electric and mechanical properties of AZO thin films on PET substrates

    Science.gov (United States)

    Chang, R. C.; Li, T. C.; Lin, C. W.

    2012-02-01

    Various thickness metallic interlayers to improve the opto-electric and mechanical properties of aluminum-doped zinc oxide (AZO) thin films deposited on flexible polyethylene terephtalate (PET) substrates are studied. The effects of the interlayers on the resistance and transmittance of the AZO thin films are discussed. The result shows that the metallic interlayers effectively improve the electric resistance but reduce the optical transmittance of the AZO thin films. These phenomena become more obvious as the interlayer thickness increases. However, the AZO with an aluminum interlayer still behaves an acceptable transmittance. Moreover, mechanical tests indicate that the aluminum interlayer increases the hardness and modulus, and reduce the residual stress of the AZO thin films. In contrast, the silver and copper interlayers decrease the AZO's mechanical properties. Comparing to those without any interlayer, the results show that the best interlayer is the 6 nm thick aluminum film.

  19. 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.

  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. Preparation of SrIrO{sub 3} thin films by using metal-organic aerosol deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Esser, Sebastian; Schneider, Melanie; Moshnyaga, Vasily; Gegenwart, Philipp [1. Physikalisches Institut, Georg-August-Universitaet Goettingen (Germany)

    2013-07-01

    The interplay between spin-orbit coupling and electronic correlations could lead to interesting novel states in iridium oxide materials. We focus on the perovskite phase of SrIrO{sub 3} because Moon et al. [1] showed by using optical spectroscopy and first-principles calculations that the last member of the Ruddlesden-Popper series Sr{sub n+1}Ir{sub n}O{sub 3n+1} (n = ∞) is close to the Mott transition. By using metal-organic aerosol deposition technique we have grown SrIrO{sub 3} thin films on (111)-oriented SrTiO{sub 3} substrates. The cubic symmetry of the SrTiO{sub 3} substrate ensured that the SrIrO{sub 3} thin film grew in the monoclinic perovskite phase. The X-ray diffraction results suggest that SrIrO{sub 3} thin films in perovskite structure were obtained and these show out of plane epitaxy with monoclinic (002){sub m}-orientation. The temperature dependence of the electrical resistivity of these SrIrO{sub 3} thin films were investigated and metallic behavior was observed down to 50 K.

  2. 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

  3. Numerical analysis of short-pulse laser interactions with thin metal film

    Directory of Open Access Journals (Sweden)

    E. Majchrzak

    2010-10-01

    Full Text Available Thin metal film subjected to a short-pulse laser heating is considered. The hyperbolic two-temperature model describing the temporal andspatial evolution of the lattice and electrons temperatures is discussed. At the stage of numerical computations the finite difference method is used. In the final part of the paper the examples of computations are shown.

  4. Laser assisted modification and chemical metallization of electron-beam deposited ceria thin films

    International Nuclear Information System (INIS)

    Krumov, E.; Starbov, N.; Starbova, K.; Perea, A.; Solis, J.

    2009-01-01

    Excimer laser processing is applied for tailoring the surface morphology and phase composition of CeO 2 ceramic thin films. E-beam evaporation technique is used to deposit samples on stainless steel and silicate glass substrates. The films are then irradiated with ArF* excimer laser pulses under different exposure conditions. Scanning electron microscopy, optical spectrophotometry, X-ray diffractometry and EDS microanalysis are used to characterize the non-irradiated and laser-processed films. Upon UV laser exposure there is large increase of the surface roughness that is accompanied by photo-darkening and ceria reduction. It is shown that the laser induced changes in the CeO 2 films facilitate the deposition of metal nano-aggregates in a commercial copper electroless plating bath. The significance of laser modification as a novel approach for the production of CeO 2 based thin film catalysts is discussed.

  5. Laser assisted modification and chemical metallization of electron-beam deposited ceria thin films

    Energy Technology Data Exchange (ETDEWEB)

    Krumov, E., E-mail: emodk@clf.bas.bg [Central Laboratory of Photoprocesses ' Acad. Jordan Malinowski' , Bulgarian Academy of Sciences, Acad. Georgy Bonchev Str., bl. 109, 1113 Sofia (Bulgaria); Starbov, N.; Starbova, K. [Central Laboratory of Photoprocesses ' Acad. Jordan Malinowski' , Bulgarian Academy of Sciences, Acad. Georgy Bonchev Str., bl. 109, 1113 Sofia (Bulgaria); Perea, A.; Solis, J. [Instituto de Optica ' Daza de Valdes' , CSIC, 28006 Madrid (Spain)

    2009-11-15

    Excimer laser processing is applied for tailoring the surface morphology and phase composition of CeO{sub 2} ceramic thin films. E-beam evaporation technique is used to deposit samples on stainless steel and silicate glass substrates. The films are then irradiated with ArF* excimer laser pulses under different exposure conditions. Scanning electron microscopy, optical spectrophotometry, X-ray diffractometry and EDS microanalysis are used to characterize the non-irradiated and laser-processed films. Upon UV laser exposure there is large increase of the surface roughness that is accompanied by photo-darkening and ceria reduction. It is shown that the laser induced changes in the CeO{sub 2} films facilitate the deposition of metal nano-aggregates in a commercial copper electroless plating bath. The significance of laser modification as a novel approach for the production of CeO{sub 2} based thin film catalysts is discussed.

  6. Metal Oxides Doped PPY-PVA Blend Thin Films Based Gas Sensor

    Directory of Open Access Journals (Sweden)

    D. B. DUPARE

    2009-02-01

    Full Text Available Synthesis of metal oxides doped polypyrrole–polyvinyl alcohol blend thin films by in situ chemical oxidative polymerization, using microwave oven on glass substrate for development of Ammonia and Trimethyl ammine hazardous gas sensor. The all experimental process carried out at room temperature(304 K. These polymer materials were characterized by Chemical analyses, spectral studies (UV-visible and IR and conductivity measurement by four –probe technique. The surface morphology as observed in the SEM image was observed to be uniformly covering the entire substrate surface. The sensor was used for different concentration (ppm of TMA and Ammonia gas investigation at room temperature (304 k. This study found to possess improved electrical, mechanical and environmental stability metal oxides doped PPY-PVA films.

  7. 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.

  8. Electrical conductivity dependence of thin metallic films of Au and Pd as a top electrode in capacitor applications

    International Nuclear Information System (INIS)

    Nazarpour, S.; Langenberg, E.; Jambois, O.; Ferrater, C.; Garcia-Cuenca, M.V.; Polo, M.C.; Varela, M.

    2009-01-01

    Electrical conductivity dependence of thin metallic films of Au and Pd over the different perovskites was investigated. It is found from electrical properties that crystallographic growth orientation of Au and Pd thin layers attained from X-ray diffraction results indicate the slop of current (I)-voltage (V) plots. Besides, surface morphology and topography was considered using Field Emission Scanning Electron Microscopy and Atomic Force Microscopy, respectively. Obtained results showed the Stranski-Krastanov growth of the Pd and Au. Indeed, diminishing of the root-mean-square roughness of Pd/BiMnO 3 /SrTiO 3 following by Au deposition should be concerned due to growth of Au onto the crack-like parts of the substrate. These crack-like parts appeared due to parasitic phases of the Bi-Mn-O system mainly Mn 3 O 4 (l 0 l) and Mn 3 O 4 (0 0 4 l). The different response in the electrical properties of heterostructures suggests that electrical conductance of the Au and Pd thin metallic films have the crystallographic orientation dependence. Furthermore, polycrystallinity of the thin metallic films are desired in electrode applications due to increase the conductivity of the metallic layers.

  9. Chemical resistance of thin film materials based on metal oxides grown by atomic layer deposition

    International Nuclear Information System (INIS)

    Sammelselg, Väino; Netšipailo, Ivan; Aidla, Aleks; Tarre, Aivar; Aarik, Lauri; Asari, Jelena; Ritslaid, Peeter; Aarik, Jaan

    2013-01-01

    Etching rate of technologically important metal oxide thin films in hot sulphuric acid was investigated. The films of Al-, Ti-, Cr-, and Ta-oxides studied were grown by atomic layer deposition (ALD) method on silicon substrates from different precursors in large ranges of growth temperatures (80–900 °C) in order to reveal process parameters that allow deposition of coatings with higher chemical resistance. The results obtained demonstrate that application of processes that yield films with lower concentration of residual impurities as well as crystallization of films in thermal ALD processes leads to significant decrease of etching rate. Crystalline films of materials studied showed etching rates down to values of < 5 pm/s. - Highlights: • Etching of atomic layer deposited thin metal oxide films in hot H 2 SO 4 was studied. • Smallest etching rates of < 5 pm/s for TiO 2 , Al 2 O 3 , and Cr 2 O 3 were reached. • Highest etching rate of 2.8 nm/s for Al 2 O 3 was occurred. • Remarkable differences in etching of non- and crystalline films were observed

  10. Metal-enhanced fluorescence of mixed coumarin dyes by silver and gold nanoparticles: Towards plasmonic thin-film luminescent solar concentrator

    Energy Technology Data Exchange (ETDEWEB)

    El-Bashir, S.M., E-mail: elbashireg@yahoo.com [Department of Physics and Astronomy, Science College, King Saud University, Riyadh, KSA (Saudi Arabia); Department of Physics Faculty of Science, Benha University (Egypt); Barakat, F.M.; AlSalhi, M.S. [Department of Physics and Astronomy, Science College, King Saud University, Riyadh, KSA (Saudi Arabia)

    2013-11-15

    Poly(methyl methacrylate) (PMMA) nanocomposite films doped with mixed coumarin dyestuffs and noble metal nanoparticles (60 nm silver and 100 nm gold) were prepared by spin coating technique. The effect of silver and gold nanoparticles on the film properties was studied by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV–vis absorption and fluorescence spectroscopy measurements. DSC measurements indicated the increase of the glass transition temperature of the films by increasing nanogold concentration, recommending their promising thermal stability towards hot climates. It was found that the fluorescence signals of the mixed coumarin dyes were amplified by 5.4 and 7.15 folds as a result of metal enhanced fluorescence (MEF). The research outcomes offered a potential application of these films in solar energy conversion by plasmonic thin film luminescent solar concentrator (PTLSC). -- Graphical abstract: Plasmonic thin film luminescent solar concentrators. Highlights: • Metal enhanced fluorescence was achieved for mixed coumarin dyes doped in PMMA nanocomposite films. • The amplification of the fluorescence signals is dependent on the concentration of silver and gold nanoparticles. • These films is considered as potential candidates for plasmonic thin film luminescent solar concentrators (PTLSCs)

  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. Control of in-plane texture of body centered cubic metal thin films

    International Nuclear Information System (INIS)

    Harper, J.M.; Rodbell, K.P.; Colgan, E.G.; Hammond, R.H.

    1997-01-01

    We show that dramatically different in-plane textures can be produced in body centered cubic (bcc) metal thin films deposited on amorphous substrates under different deposition conditions. The crystallographic orientation distribution of polycrystalline bcc metal thin films on amorphous substrates often has a strong left-angle 110 right-angle fiber texture, indicating that {110} planes are parallel to the substrate plane. When deposition takes place under bombardment by energetic ions or atoms at an off-normal angle of incidence, the left-angle 110 right-angle fiber texture develops an in-plane texture, indicating nonrandom azimuthal orientations of the crystallites. Three orientations in Nb films have been observed under different deposition geometries, in which the energetic particle flux coincides with channeling directions in the bcc crystal structure. In-plane orientations in Mo films have also been obtained in magnetron sputtering systems with various configurations. These are described, and an example is given in which the in-plane orientation of Mo films deposited in two different in-line magnetron sputtering systems differs by a 90 degree rotation. In these two cases, there is a strong left-angle 110 right-angle fiber texture, but the in-plane left-angle 100 right-angle direction is oriented parallel to the scan direction in one system, and perpendicular to the scan direction in the other system. The conditions which produce such different in-plane textures in two apparently similar sputtering systems are discussed. copyright 1997 American Institute of Physics

  13. On the spherical nanoindentation creep of metallic glassy thin films at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, T.H.; Ye, J.H. [Institution of Micro/Nano-Mechanical Testing Technology & Application, College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310014 (China); Feng, Y.H. [State Key Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Ma, Y., E-mail: may@zjut.edu.cn [Institution of Micro/Nano-Mechanical Testing Technology & Application, College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310014 (China)

    2017-02-08

    Metallic glassy thin films with eight kind of compositions were successfully prepared on Si substrate by magnetron sputtering. The room-temperature creep tests were performed at plastic regions for each sample relying on spherical nanoindetation. The creep deformations were studied by recording the total creep displacement and strain after 2000 s holding. More pronounced creep deformation was observed in the sample with lower glass transition temperature (T{sub g}). Strain rate sensitivity (SRS) was then calculated from the steady-state creep and exhibited a negative correlation with increasing T{sub g}. It is suggested that creep mechanism of the nano-sized metallic glass was T{sub g}-dependent, according to the demarcation of SRS values. Based on the obtained SRS, shear transformation zone (STZ) size in each sample could be estimated. The results indicated that an STZ involves about 25–60 atoms for the employed eight samples and is strongly tied to T{sub g}. The characteristic of STZ size in metallic glassy thin films was discussed in terms of applied method and deformation modes.

  14. TXRF analysis of trace metals in thin silicon nitride films

    International Nuclear Information System (INIS)

    Vereecke, G.; Arnauts, S.; Verstraeten, K.; Schaekers, M.; Heyrts, M.M.

    2000-01-01

    As critical dimensions of integrated circuits continue to decrease, high dielectric constant materials such as silicon nitride are being considered to replace silicon dioxide in capacitors and transistors. The achievement of low levels of metal contamination in these layers is critical for high performance and reliability. Existing methods of quantitative analysis of trace metals in silicon nitride require high amounts of sample (from about 0.1 to 1 g, compared to a mass of 0.2 mg for a 2 nm thick film on a 8'' silicon wafer), and involve digestion steps not applicable to films on wafers or non-standard techniques such as neutron activation analysis. A novel approach has recently been developed to analyze trace metals in thin films with analytical techniques currently used in the semiconductor industry. Sample preparation consists of three steps: (1) decomposition of the silicon nitride matrix by moist HF condensed at the wafer surface to form ammonium fluosilicate. (2) vaporization of the fluosilicate by a short heat treatment at 300 o C. (3) collection of contaminants by scanning the wafer surface with a solution droplet (VPD-DSC procedure). The determination of trace metals is performed by drying the droplet on the wafer and by analyzing the residue by TXRF, as it offers the advantages of multi-elemental analysis with no dilution of the sample. The lower limits of detection for metals in 2 nm thick films on 8'' silicon wafers range from about 10 to 200 ng/g. The present study will focus on the matrix effects and the possible loss of analyte associated with the evaporation of the fluosilicate salt, in relation with the accuracy and the reproducibility of the method. The benefits of using an internal standard will be assessed. Results will be presented from both model samples (ammonium fluoride contaminated with metallic salts) and real samples (silicon nitride films from a production tool). (author)

  15. Effects of thickness on the nanocrystalline structure and semiconductor-metal transition characteristics of vanadium dioxide thin films

    International Nuclear Information System (INIS)

    Luo, Zhenfei; Zhou, Xun; Yan, Dawei; Wang, Du; Li, Zeyu; Yang, Cunbang; Jiang, Yadong

    2014-01-01

    Nanocrystalline vanadium dioxide (VO 2 ) thin films were grown on glass substrates by using reactive direct current magnetron sputtering and in situ thermal treatments at low preparation temperatures (≤ 350 °C). The VO 2 thin films were characterized by grazing-incidence X-ray diffraction, field emission scanning electron microscope, transmission electron microscopy and spectroscopic ellipsometry (SE). The semiconductor-metal transition (SMT) characteristics of the films were investigated by four-point probe resistivity measurements and infrared spectrometer equipped with heating pads. The testing results showed that the crystal structure, morphology, grain size and semiconductor-metal transition temperature (T SMT ) significantly changed as the film thickness decreased. Multilayer structures were observed in the particles of thinner films whose average particle size is much larger than the film thickness and average VO 2 grain size. A competition mechanism between the suppression effect of decreased thickness and coalescence of nanograins was proposed to understand the film growth and the formation of multilayer structure. The value of T SMT was found to decrease as average VO 2 grain size became smaller, and SE results showed that small nanograin size significantly affected the electronic structure of VO 2 film. - Highlights: • Nanocrystalline vanadium dioxide thin films were prepared. • Multilayer structures were observed in the films with large particles. • The transition temperature of the film is correlated with its electronic structure

  16. 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

  17. Selective Metallization of Well Aligned PS-b-P2VP Block Copolymers in Thin Films and in Confined Geometries

    Science.gov (United States)

    Sievert, James D.; Watkins, James J.; Russell, Thomas P.

    2006-03-01

    Well aligned, microphase-separated structures of styrene-2-vinylpyridine block copolymers are being used as templates for macromolecule-metal nanocomposites. These composites are either prepared as thin films or confined in nanoporous aluminum oxide membranes. Under optimal conditions, templates are prepared as thin films or confined nanorods and metallized without disturbing the ordered structure. We have developed a procedure that deposits metal within the polymer using supercritical carbon dioxide-soluble metal precursors. The use of supercritical carbon dioxide allows for selective metallization of the polymer at or below the glass transition, without disrupting the morphology. In addition, similar procedures have been investigated using metal salts and acids. Using these techniques, metals and metal-sulfides including silver, gold, platinum and zinc sulfide have been selectively deposited.

  18. Surface structure determinations of crystalline ionic thin films grown on transition metal single crystal surfaces by low energy electron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Joel Glenn [Univ. of California, Berkeley, CA (United States)

    2000-05-01

    The surface structures of NaCl(100), LiF(100) and alpha-MgCl2(0001) adsorbed on various metal single crystals have been determined by low energy electron diffraction (LEED). Thin films of these salts were grown on metal substrates by exposing the heated metal surface to a molecular flux of salt emitted from a Knudsen cell. This method of investigating thin films of insulators (ionic salts) on a conducting substrate (metal) circumvents surface charging problems that plagued bulk studies, thereby allowing the use of electron-based techniques to characterize the surface.

  19. Synthesis and mechanical properties of Fe–Nb–B thin-film metallic glasses

    International Nuclear Information System (INIS)

    Yao, J.H.; Hostert, C.; Music, D.; Frisk, A.; Björck, M.; Schneider, J.M.

    2012-01-01

    Fe–Nb–B thin-film metallic glasses (TFMGs) were synthesized via a combinatorial sputtering approach to probe the property–composition correlation. The boron content was found to dominate the mechanical properties of the TFMGs. The ∼10% smaller strength of Fe–Nb–B TFMGs compared to existing bulk metallic glass with similar composition may be attributed to the absence of a network-like structure based on (Fe,M) 23 B 6 phase due to the extreme quenching conditions employed.

  20. Nanocomposite metal amorphous-carbon thin films deposited by hybrid PVD and PECVD technique.

    Science.gov (United States)

    Teixeira, V; Soares, P; Martins, A J; Carneiro, J; Cerqueira, F

    2009-07-01

    Carbon based films can combine the properties of solid lubricating graphite structure and hard diamond crystal structure, i.e., high hardness, chemical inertness, high thermal conductivity and optical transparency without the crystalline structure of diamond. Issues of fundamental importance associated with nanocarbon coatings are reducing stress, improving adhesion and compatibility with substrates. In this work new nanocomposite coatings with improved toughness based in nanocrystalline phases of metals and ceramics embedded in amorphous carbon matrix are being developed within the frame of a research project: nc-MeNxCy/a-C(Me) with Me = Mo, Si, Al, Ti, etc. Carbide forming metal/carbon (Me/C) composite films with Me = Mo, W or Ti possess appropriate properties to overcome the limitation of pure DLC films. These novel coating architectures will be adopted with the objective to decrease residual stress, improve adherence and fracture toughness, obtain low friction coefficient and high wear-resistance. Nanocomposite DLC's films were deposited by hybrid technique using a PVD-Physically Vapor Deposition (magnetron sputtering) and Plasma Enhanced Chemical Vapor Deposition (PECVD), by the use of CH4 gas. The parameters varied were: deposition time, substrate temperature (180 degrees C) and dopant (Si + Mo) of the amorphous carbon matrix. All the depositions were made on silicon wafers and steel substrates precoated with a silicon inter-layer. The characterisation of the film's physico-mechanical properties will be presented in order to understand the influence of the deposition parameters and metal content used within the a-C matrix in the thin film properties. Film microstructure and film hybridization state was characterized by Raman Spectroscopy. In order to characterize morphology SEM and AFM will be used. Film composition was measured by Energy-Dispersive X-ray analysis (EDS) and by X-ray photoelectron spectroscopy (XPS). The contact angle for the produced DLC's on

  1. Tracking metal ions with polypyrrole thin films adhesively bonded to diazonium-modified flexible ITO electrodes.

    Science.gov (United States)

    Lo, Momath; Diaw, Abdou K D; Gningue-Sall, Diariatou; Aaron, Jean-Jacques; Oturan, Mehmet A; Chehimi, Mohamed M

    2018-05-09

    Adhesively bonded polypyrrole thin films doped with benzene sulfonic acid (BSA) were electrodeposited on aminobenzenediazonium-modified flexible ITO electrodes and further employed for the detection of Pb 2+ , Cu 2+ , and Cd 2+ metal ions in aqueous medium. The aminophenyl (AP) adhesive layer was grafted to ITO by electroreduction of the in situ generated parent diazonium compound. Polypyrrole (PPy) thin films exhibited remarkable adhesion to aminophenyl (ITO-AP). The strongly adherent polypyrrole films exhibited excellent electroactivity in the doped state with BSA which itself served to chelate the metal ions in aqueous medium. The surface of the resulting, modified flexible electrode was characterized by XPS, SEM, and electrochemical methods. The ITO-AP-PPy electrodes were then used for the simultaneous detection of Cu 2+ , Cd 2+ , and Pb 2+ by differential pulse voltammetry (DPV). The detection limits were 11.1, 8.95, and 0.99 nM for Cu 2+ , Cd 2+ , and Pb 2+ , respectively. In addition, the modified electrodes displayed a good reproducibility, making them suitable for the determination of heavy metals in real wastewater samples.

  2. Copper Benzenetricarboxylate Metal-Organic Framework Nucleation Mechanisms on Metal Oxide Powders and Thin Films formed by Atomic Layer Deposition.

    Science.gov (United States)

    Lemaire, Paul C; Zhao, Junjie; Williams, Philip S; Walls, Howard J; Shepherd, Sarah D; Losego, Mark D; Peterson, Gregory W; Parsons, Gregory N

    2016-04-13

    Chemically functional microporous metal-organic framework (MOF) crystals are attractive for filtration and gas storage applications, and recent results show that they can be immobilized on high surface area substrates, such as fiber mats. However, fundamental knowledge is still lacking regarding initial key reaction steps in thin film MOF nucleation and growth. We find that thin inorganic nucleation layers formed by atomic layer deposition (ALD) can promote solvothermal growth of copper benzenetricarboxylate MOF (Cu-BTC) on various substrate surfaces. The nature of the ALD material affects the MOF nucleation time, crystal size and morphology, and the resulting MOF surface area per unit mass. To understand MOF nucleation mechanisms, we investigate detailed Cu-BTC MOF nucleation behavior on metal oxide powders and Al2O3, ZnO, and TiO2 layers formed by ALD on polypropylene substrates. Studying both combined and sequential MOF reactant exposure conditions, we find that during solvothermal synthesis ALD metal oxides can react with the MOF metal precursor to form double hydroxy salts that can further convert to Cu-BTC MOF. The acidic organic linker can also etch or react with the surface to form MOF from an oxide metal source, which can also function as a nucleation agent for Cu-BTC in the mixed solvothermal solution. We discuss the implications of these results for better controlled thin film MOF nucleation and growth.

  3. Study of metal/ZnO based thin film ultraviolet photodetectors: The effect of induced charges on the dynamics of photoconductivity relaxation

    Science.gov (United States)

    Yadav, Harish Kumar; Sreenivas, K.; Gupta, Vinay

    2010-02-01

    Ultraviolet photoconductivity relaxation in ZnO thin films deposited by rf magnetron sputtering are investigated. Effect of oxygen partial pressure in the reactive gas mixture and film thickness on the photoconductivity transients is studied. A different photodetector configuration comprising ZnO thin film with an ultrathin overlayer of metals like Cu, Al, Sn, Au, Cr, and Te was designed and tested. Photoresponse signal were found to be stronger (four to seven times) in these configurations than the pure ZnO thin films. Sn(30 nm)/ZnO sample exhibits highest responsivity of ˜8.57 kV/W whereas Te(20 nm)/ZnO structure presents highest sensitivity of ˜31.3×103 compared to unloaded ZnO thin film. Enhancement in the photoresponse of ZnO thin films is attributed to the change in surface conductivity due to induced charge carriers at the interface because of the difference in work function and oxygen affinity values of metal overlayer with the underlying semiconducting layer. Charge carrier transfer from the metal layer to ZnO creates a surplus of electrons at the interface; a fraction of which are captured by the defect centers (traps) at the surface whereas the remaining one represents free carriers in the conduction band and are responsible for the enhanced photoconductivity.

  4. Metal-insulator transition in tin doped indium oxide (ITO thin films: Quantum correction to the electrical conductivity

    Directory of Open Access Journals (Sweden)

    Deepak Kumar Kaushik

    2017-01-01

    Full Text Available Tin doped indium oxide (ITO thin films are being used extensively as transparent conductors in several applications. In the present communication, we report the electrical transport in DC magnetron sputtered ITO thin films (prepared at 300 K and subsequently annealed at 673 K in vacuum for 60 minutes in low temperatures (25-300 K. The low temperature Hall effect and resistivity measurements reveal that the ITO thin films are moderately dis-ordered (kFl∼1; kF is the Fermi wave vector and l is the electron mean free path and degenerate semiconductors. The transport of charge carriers (electrons in these disordered ITO thin films takes place via the de-localized states. The disorder effects lead to the well-known ‘metal-insulator transition’ (MIT which is observed at 110 K in these ITO thin films. The MIT in ITO thin films is explained by the quantum correction to the conductivity (QCC; this approach is based on the inclusion of quantum-mechanical interference effects in Boltzmann’s expression of the conductivity of the disordered systems. The insulating behaviour observed in ITO thin films below the MIT temperature is attributed to the combined effect of the weak localization and the electron-electron interactions.

  5. Metal-insulator transition in tin doped indium oxide (ITO) thin films: Quantum correction to the electrical conductivity

    Science.gov (United States)

    Kaushik, Deepak Kumar; Kumar, K. Uday; Subrahmanyam, A.

    2017-01-01

    Tin doped indium oxide (ITO) thin films are being used extensively as transparent conductors in several applications. In the present communication, we report the electrical transport in DC magnetron sputtered ITO thin films (prepared at 300 K and subsequently annealed at 673 K in vacuum for 60 minutes) in low temperatures (25-300 K). The low temperature Hall effect and resistivity measurements reveal that the ITO thin films are moderately dis-ordered (kFl˜1; kF is the Fermi wave vector and l is the electron mean free path) and degenerate semiconductors. The transport of charge carriers (electrons) in these disordered ITO thin films takes place via the de-localized states. The disorder effects lead to the well-known `metal-insulator transition' (MIT) which is observed at 110 K in these ITO thin films. The MIT in ITO thin films is explained by the quantum correction to the conductivity (QCC); this approach is based on the inclusion of quantum-mechanical interference effects in Boltzmann's expression of the conductivity of the disordered systems. The insulating behaviour observed in ITO thin films below the MIT temperature is attributed to the combined effect of the weak localization and the electron-electron interactions.

  6. 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.

  7. Patterning of metallic electrodes on flexible substrates for organic thin-film transistors using a laser thermal printing method

    International Nuclear Information System (INIS)

    Chen, Kun-Tso; Lin, Yu-Hsuan; Ho, Jeng-Rong; Chen, Chih-Kant; Liu, Sung-Ho; Liao, Jin-Long; Cheng, Hua-Chi

    2011-01-01

    We report on a laser thermal printing method for transferring patterned metallic thin films on flexible plastic substrates using a pulsed CO 2 laser. Aluminium and silver line patterns, with micrometre scale resolution on poly(ethylene terephthalate) substrates, are shown. The printed electrodes demonstrate good conductivity and fulfil the properties for bottom-contact organic thin-film transistors. In addition to providing the energy for transferring the film, the absorption of laser light results in a rise in the temperature of the film and the substrate. This also further anneals the film and softens the plastic substrate. Consequently, it is possible to obtain a film with better surface morphology and with its film thickness implanted in part into the plastic surface. This implantation reveals excellent characteristics in adhesion and flexure resistance. Being feasible to various substrates and executable at ambient temperatures renders this approach a potential alternative for patterning metallic electrodes.

  8. Low-temperature CVD of iron, cobalt, and nickel nitride thin films from bis[di(tert-butyl)amido]metal(II) precursors and ammonia

    International Nuclear Information System (INIS)

    Cloud, Andrew N.; Abelson, John R.; Davis, Luke M.; Girolami, Gregory S.

    2014-01-01

    Thin films of late transition metal nitrides (where the metal is iron, cobalt, or nickel) are grown by low-pressure metalorganic chemical vapor deposition from bis[di(tert-butyl)amido]metal(II) precursors and ammonia. These metal nitrides are known to have useful mechanical and magnetic properties, but there are few thin film growth techniques to produce them based on a single precursor family. The authors report the deposition of metal nitride thin films below 300 °C from three recently synthesized M[N(t-Bu) 2 ] 2 precursors, where M = Fe, Co, and Ni, with growth onset as low as room temperature. Metal-rich phases are obtained with constant nitrogen content from growth onset to 200 °C over a range of feedstock partial pressures. Carbon contamination in the films is minimal for iron and cobalt nitride, but similar to the nitrogen concentration for nickel nitride. X-ray photoelectron spectroscopy indicates that the incorporated nitrogen is present as metal nitride, even for films grown at the reaction onset temperature. Deposition rates of up to 18 nm/min are observed. The film morphologies, growth rates, and compositions are consistent with a gas-phase transamination reaction that produces precursor species with high sticking coefficients and low surface mobilities

  9. Study of oxide/metal/oxide thin films for transparent electronics and solar cells applications by spectroscopic ellipsometry

    Directory of Open Access Journals (Sweden)

    Mihaela Girtan

    2017-05-01

    Full Text Available A comprehensive study of a class of Oxide/Metal/Oxide (Oxide = ITO, AZO, TiO2 and Bi2O3, Metal = Au thin films was done by correlating the spectrophotometric studies with the ellispometric models. Films were deposited by successive sputtering from metallic targets In:Sn, Zn:Al, Ti and Bi in reactive atmosphere (for the oxide films and respective inert atmosphere (for the metallic Au interlayer films on glass substrates. The measurements of optical constants n—the refractive index and k—the extinction coefficient, at different incident photon energies for single oxide films and also for the three layers films oxide/metal/oxide samples were made using the spectroscopic ellipsometry (SE technique. The ellipsometry modelling process was coupled with the recorded transmission spectra data of a double beam spectrophotometer and the best fitting parameters were obtained not only by fitting the n and k experimental data with the dispersion fitting curves as usual is practiced in the most reported data in literature, but also by comparing the calculated the transmission coefficient from ellipsometry with the experimental values obtained from direct spectrophotometry measurements. In this way the best dispersion model was deduced for each sample. Very good correlations were obtained for the other different thin films characteristics such as the films thickness, optical band gap and electrical resistivity obtained by other measurements and calculation techniques. The ellipsometric modelling, can hence give the possibility in the future to predict, by ellipsometric simulations, the proper device architecture in function of the preferred optical and electrical properties.

  10. Effects of thickness on the nanocrystalline structure and semiconductor-metal transition characteristics of vanadium dioxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Zhenfei, E-mail: zhfluo8@yahoo.com [Terahertz Research Center, China Academy of Engineering Physics, Mianyang Sichuan 621900 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang Sichuan 621900 (China); Zhou, Xun, E-mail: zx_zky@yahoo.com [Terahertz Research Center, China Academy of Engineering Physics, Mianyang Sichuan 621900 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang Sichuan 621900 (China); Yan, Dawei [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang Sichuan 621900 (China); Wang, Du; Li, Zeyu [Terahertz Research Center, China Academy of Engineering Physics, Mianyang Sichuan 621900 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang Sichuan 621900 (China); Yang, Cunbang [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang Sichuan 621900 (China); Jiang, Yadong [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China)

    2014-01-01

    Nanocrystalline vanadium dioxide (VO{sub 2}) thin films were grown on glass substrates by using reactive direct current magnetron sputtering and in situ thermal treatments at low preparation temperatures (≤ 350 °C). The VO{sub 2} thin films were characterized by grazing-incidence X-ray diffraction, field emission scanning electron microscope, transmission electron microscopy and spectroscopic ellipsometry (SE). The semiconductor-metal transition (SMT) characteristics of the films were investigated by four-point probe resistivity measurements and infrared spectrometer equipped with heating pads. The testing results showed that the crystal structure, morphology, grain size and semiconductor-metal transition temperature (T{sub SMT}) significantly changed as the film thickness decreased. Multilayer structures were observed in the particles of thinner films whose average particle size is much larger than the film thickness and average VO{sub 2} grain size. A competition mechanism between the suppression effect of decreased thickness and coalescence of nanograins was proposed to understand the film growth and the formation of multilayer structure. The value of T{sub SMT} was found to decrease as average VO{sub 2} grain size became smaller, and SE results showed that small nanograin size significantly affected the electronic structure of VO{sub 2} film. - Highlights: • Nanocrystalline vanadium dioxide thin films were prepared. • Multilayer structures were observed in the films with large particles. • The transition temperature of the film is correlated with its electronic structure.

  11. Multi-layer thin-film electrolytes for metal supported solid oxide fuel cells

    Science.gov (United States)

    Haydn, Markus; Ortner, Kai; Franco, Thomas; Uhlenbruck, Sven; Menzler, Norbert H.; Stöver, Detlev; Bräuer, Günter; Venskutonis, Andreas; Sigl, Lorenz S.; Buchkremer, Hans-Peter; Vaßen, Robert

    2014-06-01

    A key to the development of metal-supported solid oxide fuel cells (MSCs) is the manufacturing of gas-tight thin-film electrolytes, which separate the cathode from the anode. This paper focuses the electrolyte manufacturing on the basis of 8YSZ (8 mol.-% Y2O3 stabilized ZrO2). The electrolyte layers are applied by a physical vapor deposition (PVD) gas flow sputtering (GFS) process. The gas-tightness of the electrolyte is significantly improved when sequential oxidic and metallic thin-film multi-layers are deposited, which interrupt the columnar grain structure of single-layer electrolytes. Such electrolytes with two or eight oxide/metal layers and a total thickness of about 4 μm obtain leakage rates of less than 3 × 10-4 hPa dm3 s-1 cm-2 (Δp: 100 hPa) at room temperature and therefore fulfill the gas tightness requirements. They are also highly tolerant with respect to surface flaws and particulate impurities which can be present on the graded anode underground. MSC cell tests with double-layer and multilayer electrolytes feature high power densities more than 1.4 W cm-2 at 850 °C and underline the high potential of MSC cells.

  12. Thermal Stability of Copper-Aluminum Alloy Thin Films for Barrierless Copper Metallization on Silicon Substrate

    Science.gov (United States)

    Wang, C. P.; Dai, T.; Lu, Y.; Shi, Z.; Ruan, J. J.; Guo, Y. H.; Liu, X. J.

    2017-08-01

    Copper thin films with thickness of about 500 nm doped with different aluminum concentrations have been prepared by magnetron sputtering on Si substrate and their crystal structure, microstructure, and electrical resistivity after annealing at various temperatures (200°C to 600°C) for 1 h or at 400°C for different durations (1 h to 11 h) investigated by grazing-incidence x-ray diffraction (GIXRD) analysis, scanning electron microscopy (SEM), and four-point probe (FPP) measurements. Cu-1.8Al alloy thin film exhibited good thermal stability and low electrical resistivity (˜5.0 μΩ cm) after annealing at 500°C for 1 h or 400°C for 7 h. No copper silicide was observed at the Cu-Al/Si interface by GIXRD analysis or SEM for this sample. This result indicates that doping Cu thin film with small amounts of Al can achieve high thermal stability and low electrical resistivity, suggesting that Cu-1.8Al alloy thin film could be used for barrierless Cu metallization on Si substrate.

  13. 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

  14. Pulsed injection metal organic chemical vapour deposition and characterisation of thin CaO films

    International Nuclear Information System (INIS)

    Borges, R.P.; Ferreira, P.; Saraiva, A.; Goncalves, R.; Rosa, M.A.; Goncalves, A.P.; Silva, R.C. da; Magalhaes, S.; Lourenco, M.J.V.; Santos, F.J.V.; Godinho, M.

    2009-01-01

    Thin films of CaO were grown on silicon (Si) and lanthanum aluminate (LaAlO 3 ) substrates by pulsed injection metal-organic chemical vapour deposition in a vertical injection MOCVD system. Growth parameters were systematically varied to study their effect on film growth and quality and to determine the optimal growth conditions for this material. Film quality and growth rate were evaluated by atomic force microscopy, X-ray diffraction and Rutherford Backscattering Spectroscopy measurements. Optimised conditions allowed growing transparent, single phase films textured along the (0 0 l) direction.

  15. Local, atomic-level elastic strain measurements of metallic glass thin films by electron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Ebner, C. [Physics of Nanostructured Materials, Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna (Austria); Sarkar, R. [Department of Materials Science and Engineering, School for Engineering of Matter Transport and Energy, Arizona State University, Tempe 85287 (United States); Rajagopalan, J. [Department of Materials Science and Engineering, School for Engineering of Matter Transport and Energy, Arizona State University, Tempe 85287 (United States); Department of Mechanical and Aerospace Engineering, School for Engineering of Matter Transport and Energy, Arizona State University, Tempe 85287 (United States); Rentenberger, C., E-mail: christian.rentenberger@univie.ac.at [Physics of Nanostructured Materials, Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna (Austria)

    2016-06-15

    A novel technique is used to measure the atomic-level elastic strain tensor of amorphous materials by tracking geometric changes of the first diffuse ring of selected area electron diffraction patterns (SAD). An automatic procedure, which includes locating the centre and fitting an ellipse to the diffuse ring with sub-pixel precision is developed for extracting the 2-dimensional strain tensor from the SAD patterns. Using this technique, atomic-level principal strains from micrometre-sized regions of freestanding amorphous Ti{sub 0.45}Al{sub 0.55} thin films were measured during in-situ TEM tensile deformation. The thin films were deformed using MEMS based testing stages that allow simultaneous measurement of the macroscopic stress and strain. The calculated atomic-level principal strains show a linear dependence on the applied stress, and good correspondence with the measured macroscopic strains. The calculated Poisson’s ratio of 0.23 is reasonable for brittle metallic glasses. The technique yields a strain accuracy of about 1×10{sup −4} and shows the potential to obtain localized strain profiles/maps of amorphous thin film samples. - Highlights: • A TEM method to measure elastic strain in metallic glass films is proposed. • Method is based on tracking geometric changes in TEM diffraction patterns. • An automatic procedure is developed for extracting the local strain tensor. • Atomic-level strain in amorphous TiAl film was analysed during in-situ deformation. • Capability of the method to obtain micrometer scale strain profiles/maps is shown.

  16. Fabrication of metallic nanoparticles by spinodal dewetting of thin films: A high-throughput approach

    Energy Technology Data Exchange (ETDEWEB)

    Michalak, William D.; Miller, James B. [U.S. Department of Energy, National Energy Technology Laboratory, Pittsburgh, PA 15262 (United States); Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Yolcu, Cem [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Gellman, Andrew J., E-mail: gellman@cmu.edu [U.S. Department of Energy, National Energy Technology Laboratory, Pittsburgh, PA 15262 (United States); Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213 (United States)

    2012-11-01

    Metal nanoparticles on structured supports are used in a variety of technological applications including biosensing, energy harvesting, and electronics. In every case, the functions and properties of the metallic nanostructures depend on both their composition and structure (i.e. size, shape, and spatial distribution). Among the challenges to the development of metal nanoparticles for these applications is the characterization of relationships between their structure and their functional properties over multiple structural degrees of freedom spanning a large range of values. In this work, a method for creating a morphological gradient of metal nanoparticles on a substrate is described. The approach, suited for high-throughput fabrication and characterization, is based on spinodal dewetting of a metallic thin film from its substrate. Through control of initial film thickness, anneal temperature, and anneal time, spinodal dewetting results in supported nanoparticles with well-defined and controlled structure. The approach is demonstrated through its application to preparation of Pd nanoparticles on a silicon nitride substrate. The morphologies of the particles were characterized by scanning electron and atomic force microscopies. Free energy-based stability and topological analyses were used to confirm the dewetting mechanism. In addition, the stability theory provides a connection to the thermophysical properties of the resulting nanoparticle array. The dewetting approach is general to any metal/support system and provides an alternative, inexpensive, and robust means to rapidly create metal nanostructures with control of morphology. It shows promise for large scale production of metal nanoparticles structures, as well as understanding basic stability properties of thin metal films. - Highlights: Black-Right-Pointing-Pointer Pd dewetting from SiN occurs by a spinodal dewetting mechanism. Black-Right-Pointing-Pointer Dewetting occurs at temperatures well below the

  17. Fabrication of metallic nanoparticles by spinodal dewetting of thin films: A high-throughput approach

    International Nuclear Information System (INIS)

    Michalak, William D.; Miller, James B.; Yolcu, Cem; Gellman, Andrew J.

    2012-01-01

    Metal nanoparticles on structured supports are used in a variety of technological applications including biosensing, energy harvesting, and electronics. In every case, the functions and properties of the metallic nanostructures depend on both their composition and structure (i.e. size, shape, and spatial distribution). Among the challenges to the development of metal nanoparticles for these applications is the characterization of relationships between their structure and their functional properties over multiple structural degrees of freedom spanning a large range of values. In this work, a method for creating a morphological gradient of metal nanoparticles on a substrate is described. The approach, suited for high-throughput fabrication and characterization, is based on spinodal dewetting of a metallic thin film from its substrate. Through control of initial film thickness, anneal temperature, and anneal time, spinodal dewetting results in supported nanoparticles with well-defined and controlled structure. The approach is demonstrated through its application to preparation of Pd nanoparticles on a silicon nitride substrate. The morphologies of the particles were characterized by scanning electron and atomic force microscopies. Free energy-based stability and topological analyses were used to confirm the dewetting mechanism. In addition, the stability theory provides a connection to the thermophysical properties of the resulting nanoparticle array. The dewetting approach is general to any metal/support system and provides an alternative, inexpensive, and robust means to rapidly create metal nanostructures with control of morphology. It shows promise for large scale production of metal nanoparticles structures, as well as understanding basic stability properties of thin metal films. - Highlights: ► Pd dewetting from SiN occurs by a spinodal dewetting mechanism. ► Dewetting occurs at temperatures well below the melting point of Pd. ► Spinodal dewetting allows

  18. Phenomenological understanding of dewetting and embedding of noble metal nanoparticles in thin films induced by ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Jai, E-mail: jai.gupta1983@gmail.com [Department of Chemistry, MMH College (Ch. Charan Singh University Meerut), Ghaiziabad 201001 (India); Chemical Physics of Materials, Université Libre de Bruxelles, Campus de la Plaine, CP 243, B-1050 Bruxelles (Belgium); Tripathi, A. [Inter University Accelerator Centre, Aruna Asif Ali Marg, New Delhi 110067 (India); Gautam, Sanjeev; Chae, K.H.; Song, Jonghan [Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 136–791 (Korea, Republic of); Rigato, V. [INFN Laboratori Nazionali di Legnaro, Via Romea. 4, 35020 Legnaro, Padova (Italy); Tripathi, Jalaj [Department of Chemistry, MMH College (Ch. Charan Singh University Meerut), Ghaiziabad 201001 (India); Asokan, K. [Inter University Accelerator Centre, Aruna Asif Ali Marg, New Delhi 110067 (India)

    2014-10-15

    The present experimental work provides the phenomenological approach to understand the dewetting in thin noble metal films with subsequent formation of nanoparticles (NPs) and embedding of NPs induced by ion irradiation. Au/polyethyleneterepthlate (PET) bilayers were irradiated with 150 keV Ar ions at varying fluences and were studied using scanning electron microscopy (SEM) and cross-sectional transmission electron microscopy (X-TEM). Thin Au film begins to dewet from the substrate after irradiation and subsequent irradiation results in spherical nanoparticles on the surface that at a fluence of 5 × 10{sup 16} ions/cm{sup 2} become embedded into the substrate. In addition to dewetting in thin films, synthesis and embedding of metal NPs by ion irradiation, the present article explores fundamental thermodynamic principles that govern these events systematically under the effect of irradiation. The results are explained on the basis of ion induced sputtering, thermal spike inducing local melting and of thermodynamic driving forces by minimization of the system free energy where contributions of surface and interfacial energies are considered with subsequent ion induced viscous flow in substrate. - Highlights: • Phenomenological interpretation of dewetting and embedding of metal NPs in thin film. • Exploring fundamental thermodynamic principles under influence of ion irradiation. • Ion induced surface/interface microstructural changes using SEM/X-TEM. • Ion induced sputtering, thermal spike induced local melting. • Thermodynamic driving forces relate to surface and interfacial energies.

  19. Determination of magnetic properties of multilayer metallic thin films

    International Nuclear Information System (INIS)

    Birlikseven, C.

    2000-01-01

    In recent year, Giant Magnetoresistance Effect has been attracting an increasingly high interest. High sensitivity magnetic field detectors and high sensitivity read heads of magnetic media can be named as important applications of these films. In this work, magnetic and electrical properties of single layer and thin films were investigated. Multilayer thin films were supplied by Prof. Dr. A. Riza Koeymen from Texas University. Multilayer magnetic thin films are used especially for magnetic reading and magnetic writing. storing of large amount of information into small areas become possible with this technology. Single layer films were prepared using the electron beam evaporation technique. For the exact determination of film thicknesses, a careful calibration of the thicknesses was made. Magnetic properties of the multilayer films were studied using the magnetization, magnetoresistance measurements and ferromagnetic resonance technique. Besides, by fitting the experimental results to the theoretical models, effective magnetization and angles between the ferromagnetic layers were calculated. The correspondence between magnetization and magnetoresistance was evaluated. To see the effect of anisotropic magnetoresistance in the magnetoresistance measurements, a new experimental set-up was build and measurements were taken in this set-up. A series of soft permalloy thin films were made, and temperature dependent resistivity, magnetoresistance, anisotropic magnetoresistance and magnetization measurements were taken

  20. Deposition of highly (111)-oriented PZT thin films by using metal organic chemical deposition

    CERN Document Server

    Bu, K H; Choi, D K; Seong, W K; Kim, J D

    1999-01-01

    Lead zirconate titanate (PZT) thin films have been grown on Pt/Ta/SiNx/Si substrates by using metal organic chemical vapor deposition with Pb(C sub 2 H sub 5) sub 4 , Zr(O-t-C sub 4 H sub 9) sub 4 , and Ti(O-i-C sub 3 H sub 7) sub 4 as source materials and O sub 2 as an oxidizing gas. The Zr fraction in the thin films was controlled by varying the flow rate of the Zr source material. The crystal structure and the electrical properties were investigated as functions of the composition. X-ray diffraction analysis showed that at a certain range of Zr fraction, highly (111)-oriented PZT thin films with no pyrochlore phases were deposited. On the other hand, at low Zr fractions, there were peaks from Pb-oxide phases. At high Zr fractions, peaks from pyrochlore phase were seen. The films also showed good electrical properties, such as a high dielectric constant of more than 1200 and a low coercive voltage of 1.35 V.

  1. Study of metal/ZnO based thin film ultraviolet photodetectors: The effect of induced charges on the dynamics of photoconductivity relaxation

    International Nuclear Information System (INIS)

    Yadav, Harish Kumar; Sreenivas, K.; Gupta, Vinay

    2010-01-01

    Ultraviolet photoconductivity relaxation in ZnO thin films deposited by rf magnetron sputtering are investigated. Effect of oxygen partial pressure in the reactive gas mixture and film thickness on the photoconductivity transients is studied. A different photodetector configuration comprising ZnO thin film with an ultrathin overlayer of metals like Cu, Al, Sn, Au, Cr, and Te was designed and tested. Photoresponse signal were found to be stronger (four to seven times) in these configurations than the pure ZnO thin films. Sn(30 nm)/ZnO sample exhibits highest responsivity of ∼8.57 kV/W whereas Te(20 nm)/ZnO structure presents highest sensitivity of ∼31.3x10 3 compared to unloaded ZnO thin film. Enhancement in the photoresponse of ZnO thin films is attributed to the change in surface conductivity due to induced charge carriers at the interface because of the difference in work function and oxygen affinity values of metal overlayer with the underlying semiconducting layer. Charge carrier transfer from the metal layer to ZnO creates a surplus of electrons at the interface; a fraction of which are captured by the defect centers (traps) at the surface whereas the remaining one represents free carriers in the conduction band and are responsible for the enhanced photoconductivity.

  2. Improvement in interfacial characteristics of low-voltage carbon nanotube thin-film transistors with solution-processed boron nitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Jun-Young; Ha, Tae-Jun, E-mail: taejunha0604@gmail.com

    2017-08-15

    Highlights: • We demonstrate the potential of solution-processed boron nitride (BN) thin films for nanoelectronics. • Improved interfacial characteristics reduced the leakage current by three orders of magnitude. • The BN encapsulation improves all the device key metrics of low-voltage SWCNT-TFTs. • Such improvements were achieved by reduced interaction of interfacial localized states. - Abstract: In this article, we demonstrate the potential of solution-processed boron nitride (BN) thin films for high performance single-walled carbon nanotube thin-film transistors (SWCNT-TFTs) with low-voltage operation. The use of BN thin films between solution-processed high-k dielectric layers improved the interfacial characteristics of metal-insulator-metal devices, thereby reducing the current density by three orders of magnitude. We also investigated the origin of improved device performance in SWCNT-TFTs by employing solution-processed BN thin films as an encapsulation layer. The BN encapsulation layer improves the electrical characteristics of SWCNT-TFTs, which includes the device key metrics of linear field-effect mobility, sub-threshold swing, and threshold voltage as well as the long-term stability against the aging effect in air. Such improvements can be achieved by reduced interaction of interfacial localized states with charge carriers. We believe that this work can open up a promising route to demonstrate the potential of solution-processed BN thin films on nanoelectronics.

  3. Phase coexistence in the metal-insulator transition of a VO2 thin film

    International Nuclear Information System (INIS)

    Chang, Y.J.; Koo, C.H.; Yang, J.S.; Kim, Y.S.; Kim, D.H.; Lee, J.S.; Noh, T.W.; Kim, Hyun-Tak; Chae, B.G.

    2005-01-01

    Vanadium dioxide (VO 2 ) shows a metal-insulator transition (MIT) near room temperature, accompanied by an abrupt resistivity change. Since the MIT of VO 2 is known to be a first order phase transition, it is valuable to check metallic and insulating phase segregation during the MIT process. We deposited (100)-oriented epitaxial VO 2 thin films on R-cut sapphire substrates. From the scanning tunneling spectroscopy (STS) spectra, we could distinguish metallic and insulating regions by probing the band gap. Optical spectroscopic analysis also supported the view that the MIT in VO 2 occurs through metal and insulator phase coexistence

  4. High Precision Metal Thin Film Liftoff Technique

    Science.gov (United States)

    Brown, Ari D. (Inventor); Patel, Amil A. (Inventor)

    2015-01-01

    A metal film liftoff process includes applying a polymer layer onto a silicon substrate, applying a germanium layer over the polymer layer to create a bilayer lift off mask, applying a patterned photoresist layer over the germanium layer, removing an exposed portion of the germanium layer, removing the photoresist layer and a portion of the polymer layer to expose a portion of the substrate and create an overhanging structure of the germanium layer, depositing a metal film over the exposed portion of the substrate and the germanium layer, and removing the polymer and germanium layers along with the overlaying metal film.

  5. Metallic transport and large anomalous Hall effect at room temperature in ferrimagnetic Mn4N epitaxial thin film

    International Nuclear Information System (INIS)

    Shen, Xi; Shigematsu, Kei; Chikamatsu, Akira; Fukumura, Tomoteru; Hirose, Yasushi; Hasegawa, Tetsuya

    2014-01-01

    We report the electrical transport properties of ferrimagnetic Mn 4 N (001) epitaxial thin films grown by pulsed laser deposition on MgO (001) substrates. The Mn 4 N thin films were tetragonally distorted with a ratio of out-of-plane to in-plane lattice constants of 0.987 and showed perpendicular magnetic anisotropy with an effective magnetic anisotropy constant of 0.16 MJ/m 3 , which is comparable with that of a recently reported molecular-beam-epitaxy-grown film. The thin films exhibited metallic transport with a room temperature resistivity of 125 μΩ cm in addition to a large anomalous Hall effect with a Hall angle tangent of 0.023.

  6. Extending the 3ω method: thermal conductivity characterization of thin films.

    Science.gov (United States)

    Bodenschatz, Nico; Liemert, André; Schnurr, Sebastian; Wiedwald, Ulf; Ziemann, Paul

    2013-08-01

    A lock-in technique for measurement of thermal conductivity and volumetric heat capacity of thin films is presented. The technique is based on the 3ω approach using electrical generation and detection of oscillatory heat along a thin metal strip. Thin films are deposited onto the backside of commercial silicon nitride membranes, forming a bilayer geometry with distinct thermal parameters. Stepwise comparison to an adapted heat diffusion model delivers these parameters for both layers. Highest sensitivity is found for metallic thin films.

  7. Thin-film composite materials as a dielectric layer for flexible metal-insulator-metal capacitors.

    Science.gov (United States)

    Tiwari, Jitendra N; Meena, Jagan Singh; Wu, Chung-Shu; Tiwari, Rajanish N; Chu, Min-Ching; Chang, Feng-Chih; Ko, Fu-Hsiang

    2010-09-24

    A new organic-organic nanoscale composite thin-film (NCTF) dielectric has been synthesized by solution deposition of 1-bromoadamantane and triblock copolymer (Pluronic P123, BASF, EO20-PO70-EO20), in which the precursor solution has been achieved with organic additives. We have used a sol-gel process to make a metal-insulator-metal capacitor (MIM) comprising a nanoscale (10 nm-thick) thin-film on a flexible polyimide (PI) substrate at room temperature. Scanning electron microscope and atomic force microscope revealed that the deposited NCTFs were crack-free, uniform, highly resistant to moisture absorption, and well adhered on the Au-Cr/PI. The electrical properties of 1-bromoadamantane-P123 NCTF were characterized by dielectric constant, capacitance, and leakage current measurements. The 1-bromoadamantane-P123 NCTF on the PI substrate showed a low leakage current density of 5.5 x 10(-11) A cm(-2) and good capacitance of 2.4 fF at 1 MHz. In addition, the calculated dielectric constant of 1-bromoadamantane-P123 NCTF was 1.9, making them suitable candidates for use in future flexible electronic devices as a stable intermetal dielectric. The electrical insulating properties of 1-bromoadamantane-P123 NCTF have been improved due to the optimized dipole moments of the van der Waals interactions.

  8. Thin sensing layer based on semi-conducting β-cyclodextrin rotaxane for toxic metals detection

    Energy Technology Data Exchange (ETDEWEB)

    Teka, S.; Gaied, A.; Jaballah, N. [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Université de Monastir, Faculté des Sciences de Monastir, Bd. de l' Environnement, 5019 Monastir (Tunisia); Xiaonan, S. [Université Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR 7086 CNRS, 15 rue J-A de Baı̈ f, 75205 Paris Cedex 13 (France); Majdoub, M., E-mail: mustapha.majdoub@fsm.rnu.tn [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Université de Monastir, Faculté des Sciences de Monastir, Bd. de l' Environnement, 5019 Monastir (Tunisia)

    2016-02-15

    Highlights: • Microwave-assisted synthesis of rotaxane based on anthracene and β-cyclodextrin. • Morphological and optical characterization of thin solid film. • Elaboration of impedimetric gold/rotaxane sensor. • Investigation of the membrane sensitivity towards Hg{sup 2+}, Cu{sup 2+} and Pb{sup 2+} cations. - Abstract: An impedimetric sensor based on a new semi-conducting rotaxane has been described for detection of toxic cations. The rotaxane, consists on a π-conjugated material encapsulated into β-cyclodextrin (β-CD); it has been synthesized via the Williamson reaction under microwaves irradiation. The supramolecular structure of the compound was confirmed by NMR and FT-IR spectroscopies. A thin solid film of the rotaxane was deposited by spin-coating to develop a new electrochemical sensor. The morphological properties of the organic membrane were evaluated using contact angle measurements and atomic force microscopy. The gold/rotaxane/solution interfaces were investigated by electrochemical impedance spectroscopy and the obtained data were fitted using an equivalent electrical circuit. The response of the gold/rotaxane membrane towards Hg{sup 2+}, Cu{sup 2+} and Pb{sup 2+} cations was studied and the results showed a good sensitivity to the mercury cations.

  9. Metal-assisted chemical etching of CIGS thin films for grain size analysis

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Chaowei [Research and Development Centre, Hanergy Thin Film Power Group Limited, Chengdu (China); Loi, Huu-Ha; Duong, Anh; Parker, Magdalena [Failure Analysis Department, MiaSole Hi-Tech Corp., Santa Clara, CA (United States)

    2016-09-15

    Grain size of the CIGS absorber is an important monitoring factor in the CIGS solar cell manufacturing. Electron backscatter diffraction (EBSD) analysis is commonly used to perform CIGS grain size analysis in the scanning electron microscope (SEM). Although direct quantification on SEM image using the average grain intercept (AGI) method is faster and simpler than EBSD, it is hardly applicable on CIGS thin films. The challenge is that, not like polycrystalline silicon, to define grain boundaries by selective chemical etching is not easily realizable for the multi-component CIGS alloy. In this Letter, we present direct quantification of CIGS thin film grain size using the AGI method by developing metal-assisted wet chemical etching process to define CIGS grain boundaries. The calculated value is similar to EBSD result. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Unidirectional oxide hetero-interface thin-film diode

    International Nuclear Information System (INIS)

    Park, Youngmin; Lee, Eungkyu; Lee, Jinwon; Lim, Keon-Hee; Kim, Youn Sang

    2015-01-01

    The unidirectional thin-film diode based on oxide hetero-interface, which is well compatible with conventional thin-film fabrication process, is presented. With the metal anode/electron-transporting oxide (ETO)/electron-injecting oxide (EIO)/metal cathode structure, it exhibits that electrical currents ohmically flow at the ETO/EIO hetero-interfaces for only positive voltages showing current density (J)-rectifying ratio of ∼10 5 at 5 V. The electrical properties (ex, current levels, and working device yields) of the thin-film diode (TFD) are systematically controlled by changing oxide layer thickness. Moreover, we show that the oxide hetero-interface TFD clearly rectifies an AC input within frequency (f) range of 10 2  Hz < f < 10 6  Hz, providing a high feasibility for practical applications

  11. Unidirectional oxide hetero-interface thin-film diode

    Energy Technology Data Exchange (ETDEWEB)

    Park, Youngmin; Lee, Eungkyu; Lee, Jinwon; Lim, Keon-Hee [Program in Nano Science and Technology, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, Youn Sang, E-mail: younskim@snu.ac.kr [Program in Nano Science and Technology, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 151-742 (Korea, Republic of); Advanced Institute of Convergence Technology, Gyeonggi-do 443-270 (Korea, Republic of)

    2015-10-05

    The unidirectional thin-film diode based on oxide hetero-interface, which is well compatible with conventional thin-film fabrication process, is presented. With the metal anode/electron-transporting oxide (ETO)/electron-injecting oxide (EIO)/metal cathode structure, it exhibits that electrical currents ohmically flow at the ETO/EIO hetero-interfaces for only positive voltages showing current density (J)-rectifying ratio of ∼10{sup 5} at 5 V. The electrical properties (ex, current levels, and working device yields) of the thin-film diode (TFD) are systematically controlled by changing oxide layer thickness. Moreover, we show that the oxide hetero-interface TFD clearly rectifies an AC input within frequency (f) range of 10{sup 2} Hz < f < 10{sup 6} Hz, providing a high feasibility for practical applications.

  12. Thin films of metal oxides on metal single crystals: Structure and growth by scanning tunneling microscopy

    International Nuclear Information System (INIS)

    Galloway, H.C.

    1995-12-01

    Detailed studies of the growth and structure of thin films of metal oxides grown on metal single crystal surfaces using Scanning Tunneling Microscopy (STM) are presented. The oxide overlayer systems studied are iron oxide and titanium oxide on the Pt(III) surface. The complexity of the metal oxides and large lattice mismatches often lead to surface structures with large unit cells. These are particularly suited to a local real space technique such as scanning tunneling microscopy. In particular, the symmetry that is directly observed with the STM elucidates the relationship of the oxide overlayers to the substrate as well as distinguishing, the structures of different oxides

  13. Microstructural, thermal and mechanical behavior of co-sputtered binary Zr–Cu thin film metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Apreutesei, M. [MATEIS Laboratory-INSA de Lyon, Bât. B. Pascal, 7 Avenue Jean Capelle, 69621 Villeurbanne Cedex (France); Steyer, P., E-mail: philippe.steyer@insa-lyon.fr [MATEIS Laboratory-INSA de Lyon, Bât. B. Pascal, 7 Avenue Jean Capelle, 69621 Villeurbanne Cedex (France); Joly-Pottuz, L. [MATEIS Laboratory-INSA de Lyon, Bât. B. Pascal, 7 Avenue Jean Capelle, 69621 Villeurbanne Cedex (France); Billard, A. [LERMPS-UTBM, Site de Montbéliard, 90010 Belfort Cédex (France); Qiao, J.; Cardinal, S. [MATEIS Laboratory-INSA de Lyon, Bât. B. Pascal, 7 Avenue Jean Capelle, 69621 Villeurbanne Cedex (France); Sanchette, F. [LASMIS-UTT, UMR CNRS 6279, 12 rue Marie Curie, CS 42060, 10004 Troyes Cedex (France); Pelletier, J.M.; Esnouf, C. [MATEIS Laboratory-INSA de Lyon, Bât. B. Pascal, 7 Avenue Jean Capelle, 69621 Villeurbanne Cedex (France)

    2014-06-30

    Bulk metallic glasses have attracted considerable attention over the last decades for their outstanding mechanical features (high strength, super-elasticity) and physico-chemical properties (corrosion resistance). Recently, some attempts to assign such original behavior from bulk materials to modified surfaces have been reported in the literature based on multicomponent alloys. In this paper we focused on the opportunity to form a metallic glass coating from the binary Zr–Cu system using a magnetron co-sputtering physical vapor deposition process. The composition of the films can be easily controlled by the relative intensities applied to both pure targets, which made possible the study of the whole Zr–Cu system (from 13.4 to 85.0 at.% Cu). The chemical composition of the films was obtained by energy dispersive X-ray spectroscopy, and their microstructure was characterized by scanning and transmission electron microscopy. The thermal stability of the films was deduced from an in situ X-ray diffraction analysis (from room temperature up to 600 °C) and correlated with the results of the differential scanning calorimetry technique. Their mechanical properties were determined by nanoindentation experiments. - Highlights: • We reported deposition of Zr-Cu thin film metallic glasses by co-sputtering • Films were XRD-amorphous in a wide composition range (33.3 – 85.0 at.% Cu) • Microstructure investigation revealed some local nanodomains • We examined the thermal stability by means of in situ X-ray diffraction • Nanoindentation was used to obtained mechanical properties of thin films.

  14. Thin-Film Photovoltaic Cells: Long-Term Metal(loid) Leaching at Their End-of-Life

    NARCIS (Netherlands)

    Zimmermann, Y.S.; Schäffer, A.; Corvini, P.F.X.; Lenz, M.

    2013-01-01

    The photovoltaic effect of thin-film copper indium gallium selenide cells (CIGS) is conferred by the latter elements. Organic photovoltaic cells (OPV), relying on organic light-absorbing molecules, also contain a variety of metals (e.g., Zn, Al, In, Sn, Ag). The environmental impact of such

  15. Antimicrobial and anti-biofilm properties of polypropylene meshes coated with metal-containing DLC thin films.

    Science.gov (United States)

    Cazalini, Elisa M; Miyakawa, Walter; Teodoro, Guilherme R; Sobrinho, Argemiro S S; Matieli, José E; Massi, Marcos; Koga-Ito, Cristiane Y

    2017-06-01

    A promising strategy to reduce nosocomial infections related to prosthetic meshes is the prevention of microbial colonization. To this aim, prosthetic meshes coated with antimicrobial thin films are proposed. Commercial polypropylene meshes were coated with metal-containing diamond-like carbon (Me-DLC) thin films by the magnetron sputtering technique. Several dissimilar metals (silver, cobalt, indium, tungsten, tin, aluminum, chromium, zinc, manganese, tantalum, and titanium) were tested and compositional analyses of each Me-DLC were performed by Rutherford backscattering spectrometry. Antimicrobial activities of the films against five microbial species (Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis) were also investigated by a modified Kirby-Bauer test. Results showed that films containing silver and cobalt have inhibited the growth of all microbial species. Tungsten-DLC, tin-DLC, aluminum-DLC, zinc-DLC, manganese-DLC, and tantalum-DLC inhibited the growth of some strains, while chromium- and titanium-DLC weakly inhibited the growth of only one tested strain. In-DLC film showed no antimicrobial activity. The effects of tungsten-DLC and cobalt-DLC on Pseudomonas aeruginosa biofilm formation were also assessed. Tungsten-DLC was able to significantly reduce biofilm formation. Overall, the experimental results in the present study have shown new approaches to coating polymeric biomaterials aiming antimicrobial effect.

  16. Two-dimensional discrete dislocation models of deformation in polycrystalline thin metal films on substrates

    International Nuclear Information System (INIS)

    Hartmaier, Alexander; Buehler, Markus J.; Gao, Huajian

    2005-01-01

    The time-dependent irreversible deformation of polycrystalline thin metal films on substrates is investigated using two-dimensional discrete dislocation dynamics models incorporating essential parameters determined from atomistic studies. The work is focused on the mechanical properties of uncapped films, where diffusive processes play an important role. The simulations incorporate dislocation climb along the grain boundary as well as conservative glide. Despite of severe limitations of the two-dimensional dislocation models, the simulation results are found to largely corroborate experimental findings on different dominant deformation mechanisms at different film thicknesses

  17. Characteristics of indirect laser-induced plasma from a thin film of oil on a metallic substrate

    Science.gov (United States)

    Xiu, Jun-Shan; Bai, Xue-Shi; Motto-Ros, Vincent; Yu, Jin

    2015-04-01

    Optical emissions from the major and trace elements embodied in a transparent gel prepared from cooking oil were detected after the gel was spread in a thin film on a metallic substrate. Such emissions are due to the indirect breakdown of the coating layer. The generated plasma, a mixture of substances from the substrate, the layer, and the ambient gas, was characterized using emission spectroscopy. The characteristics of the plasma formed on the metal with and without the coating layer were investigated. The results showed that Al emission induced from the aluminum substrates coated with oil films extends away from the target surface to ablate the oil film. This finally formed a bifurcating circulation of aluminum vapor against a spherical confinement wall in the front of the plume, which differed from the evolution of the plasma induced from the uncoated aluminum target. The strongest emissions of elements from the oil films can be observed at 2 mm above the target after a detection delay of 1.0 μs. A high temperature zone has been observed in the plasma after the delay of 1.0 μs for the plasma induced from the coated metal. This higher temperature determined in the plasma allows the consideration of the sensitive detection of trace elements in liquids, gels, biological samples, or thin films.

  18. Mechanical properties of metal-organic frameworks: An indentation study on epitaxial thin films

    Science.gov (United States)

    Bundschuh, S.; Kraft, O.; Arslan, H. K.; Gliemann, H.; Weidler, P. G.; Wöll, C.

    2012-09-01

    We have determined the hardness and Young's modulus of a highly porous metal-organic framework (MOF) using a standard nanoindentation technique. Despite the very low density of these films, 1.22 g cm-3, Young's modulus reaches values of almost 10 GPa for HKUST-1, demonstrating that this porous coordination polymer is substantially stiffer than normal polymers. This progress in characterizing mechanical properties of MOFs has been made possible by the use of high quality, oriented thin films grown using liquid phase epitaxy on modified Au substrates.

  19. 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.

  20. 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.

  1. 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

  2. Hanle Magnetoresistance in Thin Metal Films with Strong Spin-Orbit Coupling.

    Science.gov (United States)

    Vélez, Saül; Golovach, Vitaly N; Bedoya-Pinto, Amilcar; Isasa, Miren; Sagasta, Edurne; Abadia, Mikel; Rogero, Celia; Hueso, Luis E; Bergeret, F Sebastian; Casanova, Fèlix

    2016-01-08

    We report measurements of a new type of magnetoresistance in Pt and Ta thin films. The spin accumulation created at the surfaces of the film by the spin Hall effect decreases in a magnetic field because of the Hanle effect, resulting in an increase of the electrical resistance as predicted by Dyakonov [Phys. Rev. Lett. 99, 126601 (2007)]. The angular dependence of this magnetoresistance resembles the recently discovered spin Hall magnetoresistance in Pt/Y(3)Fe(5)O(12) bilayers, although the presence of a ferromagnetic insulator is not required. We show that this Hanle magnetoresistance is an alternative simple way to quantitatively study the coupling between charge and spin currents in metals with strong spin-orbit coupling.

  3. 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

  4. Ambiguous Role of Growth-Induced Defects on the Semiconductor-to-Metal Characteristics in Epitaxial VO2/TiO2 Thin Films.

    Science.gov (United States)

    Mihailescu, Cristian N; Symeou, Elli; Svoukis, Efthymios; Negrea, Raluca F; Ghica, Corneliu; Teodorescu, Valentin; Tanase, Liviu C; Negrila, Catalin; Giapintzakis, John

    2018-04-25

    Controlling the semiconductor-to-metal transition temperature in epitaxial VO 2 thin films remains an unresolved question both at the fundamental as well as the application level. Within the scope of this work, the effects of growth temperature on the structure, chemical composition, interface coherency and electrical characteristics of rutile VO 2 epitaxial thin films grown on TiO 2 substrates are investigated. It is hereby deduced that the transition temperature is lower than the bulk value of 340 K. However, it is found to approach this value as a function of increased growth temperature even though it is accompanied by a contraction along the V 4+ -V 4+ bond direction, the crystallographic c-axis lattice parameter. Additionally, it is demonstrated that films grown at low substrate temperatures exhibit a relaxed state and a strongly reduced transition temperature. It is suggested that, besides thermal and epitaxial strain, growth-induced defects may strongly affect the electronic phase transition. The results of this work reveal the difficulty in extracting the intrinsic material response to strain, when the exact contribution of all strain sources cannot be effectively determined. The findings also bear implications on the limitations in obtaining the recently predicted novel semi-Dirac point phase in VO 2 /TiO 2 multilayer structures.

  5. Semi-transparent ordered TiO_2 nanostructures prepared by anodization of titanium thin films deposited onto the FTO substrate

    International Nuclear Information System (INIS)

    Szkoda, Mariusz; Lisowska-Oleksiak, Anna; Grochowska, Katarzyna; Skowroński, Łukasz; Karczewski, Jakub; Siuzdak, Katarzyna

    2016-01-01

    Highlights: • High quality titanium coatings were doposited using industrial magnetron sputtering equipment. • Semi-transparent TiO_2 were prepared via anodization realized in various conditions. • Depending on electrolyte type, ordered tubular or porous TiO_2 layers were obtained. • Prepared material can act as semiconducting layer in photovoltaic cells. - Abstract: In a significant amount of cases, the highly ordered TiO_2 nanotube arrays grow through anodic oxidation of a titanium metal plate immersed in electrolyte containing fluoride ions. However, for some practical applications, e.g. solar cells or electrochromic windows, the semi-transparent TiO_2 formed directly on the transparent, conductive substrate is very much desired. This work shows that high-quality Ti coating could be formed at room temperature using an industrial magnetron sputtering system within 50 min. Under optimized conditions, the anodization process was performed on 2 μm titanium films deposited onto the FTO (fluorine-tin-oxide) support. Depending on the electrolyte type, highly ordered tubular or porous titania layers were obtained. The fabricated samples, after their thermal annealing, were investigated using scanning electron microscopy, Raman spectroscopy and UV–vis spectroscopy in order to investigate their morphology, crystallinity and absorbance ability. The photocurrent response curves indicate that materials are resistant to the photocorrosion process and their activity is strongly connected to optical properties. The most transparent TiO_2 films were fabricated when Ti was anodized in water electrolyte, whereas the highest photocurrent densities (12 μA cm"−"2) were registered for titania received after Ti anodization in ethylene glycol solution. The obtained results are of significant importance in the production of thin, semi-transparent titania nanostructures on a commercial scale.

  6. Coupled Optical Tamm States in a Planar Dielectric Mirror Structure Containing a Thin Metal Film

    International Nuclear Information System (INIS)

    Zhou Hai-Chun; Yang Guang; Lu Pei-Xiang; Wang Kai; Long Hua

    2012-01-01

    The coupling between two optical Tamm states (OTSs) with the same eigenenergy is numerically investigated in a planar dielectric mirror structure containing a thin metal film. The reflectivity map in this structure at normal incidence is obtained by applying the transfer matrix method. Two splitting branches appear in the photonic bandgap region when both adjacent dielectric layers of metal film are properly set. The splitting energy of two branches strongly depends on the thickness of the metal film. According to the electric field distribution in this structure, it is found that the high-energy branch corresponds to the antisymmetric coupling between two OTSs, while the low-energy branch is associated with the symmetric coupling between two OTSs. Moreover, the optical difference frequency of two branches is located in a broad terahertz region. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  7. Rhenium Alloys as Ductile Substrates for Diamond Thin-Film Electrodes.

    Science.gov (United States)

    Halpern, Jeffrey M; Martin, Heidi B

    2014-02-01

    Molybdenum-rhenium (Mo/Re) and tungsten-rhenium (W/Re) alloys were investigated as substrates for thin-film, polycrystalline boron-doped diamond electrodes. Traditional, carbide-forming metal substrates adhere strongly to diamond but lose their ductility during exposure to the high-temperature (1000°C) diamond, chemical vapor deposition environment. Boron-doped semi-metallic diamond was selectively deposited for up to 20 hours on one end of Mo/Re (47.5/52.5 wt.%) and W/Re (75/25 wt.%) alloy wires. Conformal diamond films on the alloys displayed grain sizes and Raman signatures similar to films grown on tungsten; in all cases, the morphology and Raman spectra were consistent with well-faceted, microcrystalline diamond with minimal sp 2 carbon content. Cyclic voltammograms of dopamine in phosphate-buffered saline (PBS) showed the wide window and low baseline current of high-quality diamond electrodes. In addition, the films showed consistently well-defined, dopamine electrochemical redox activity. The Mo/Re substrate regions that were uncoated but still exposed to the diamond-growth environment remained substantially more flexible than tungsten in a bend-to-fracture rotation test, bending to the test maximum of 90° and not fracturing. The W/Re substrates fractured after a 27° bend, and the tungsten fractured after a 21° bend. Brittle, transgranular cleavage fracture surfaces were observed for tungsten and W/Re. A tension-induced fracture of the Mo/Re after the prior bend test showed a dimple fracture with a visible ductile core. Overall, the Mo/Re and W/Re alloys were suitable substrates for diamond growth. The Mo/Re alloy remained significantly more ductile than traditional tungsten substrates after diamond growth, and thus may be an attractive metal substrate for more ductile, thin-film diamond electrodes.

  8. The origin of magnetism in transition metal-doped ZrO2 thin films: Experiment and theory

    KAUST Repository

    Hong, Nguyenhoa

    2013-10-04

    We have investigated the magnetic properties of Fe/Co/Ni-doped ZrO 2 laser ablated thin films in comparison with the known results of Mn-doped ZrO2, which is thought to be a promising material for spintronics applications. It is found that doping with a transition metal can induce room temperature ferromagnetism in \\'fake\\' diamond. Theoretical analysis based on density functional theory confirms the experimental measurements, by revealing that the magnetic moments of Mn- and Ni-doped ZrO2 thin films are much larger than that of Fe- or Co-doped ZrO2 thin films. Most importantly, our calculations confirm that Mn- and Ni-doped ZrO2 show a ferromagnetic ground state in comparison to Co- and Fe-doped ZrO 2, which favor an antiferromagnetic ground state. © 2013 IOP Publishing Ltd.

  9. Metallic transport and large anomalous Hall effect at room temperature in ferrimagnetic Mn{sub 4}N epitaxial thin film

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Xi; Shigematsu, Kei [Department of Chemistry, The University of Tokyo, Tokyo 113-0033 (Japan); Chikamatsu, Akira, E-mail: chikamatsu@chem.s.u-tokyo.ac.jp; Fukumura, Tomoteru [Department of Chemistry, The University of Tokyo, Tokyo 113-0033 (Japan); CREST, Japan Science and Technology Agency (JST), Tokyo 113-0033 (Japan); Hirose, Yasushi; Hasegawa, Tetsuya [Department of Chemistry, The University of Tokyo, Tokyo 113-0033 (Japan); CREST, Japan Science and Technology Agency (JST), Tokyo 113-0033 (Japan); Kanagawa Academy of Science and Technology (KAST), Kawasaki 213-0012 (Japan)

    2014-08-18

    We report the electrical transport properties of ferrimagnetic Mn{sub 4}N (001) epitaxial thin films grown by pulsed laser deposition on MgO (001) substrates. The Mn{sub 4}N thin films were tetragonally distorted with a ratio of out-of-plane to in-plane lattice constants of 0.987 and showed perpendicular magnetic anisotropy with an effective magnetic anisotropy constant of 0.16 MJ/m{sup 3}, which is comparable with that of a recently reported molecular-beam-epitaxy-grown film. The thin films exhibited metallic transport with a room temperature resistivity of 125 μΩ cm in addition to a large anomalous Hall effect with a Hall angle tangent of 0.023.

  10. Mechanical properties of ultra thin metallic films revealed by synchrotron techniques

    Energy Technology Data Exchange (ETDEWEB)

    Gruber, Patric Alfons

    2007-07-20

    A prerequisite for the study of the scaling behavior of mechanical properties of ultra thin films is a suitable testing technique. Therefore synchrotron-based in situ testing techniques were developed and optimized in order to characterize the stress evolution in ultra thin metallic films on compliant polymer substrates during isothermal tensile tests. Experimental procedures for polycrystalline as well as single crystalline films were established. These techniques were used to systematically investigate the influence of microstructure, film thickness (20 to 1000 nm) and temperature (-150 to 200 C) on the mechanical properties. Passivated and unpassivated Au and Cu films as well as single crystalline Au films on polyimide substrates were tested. Special care was also dedicated to the microstructural characterization of the samples which was very important for the correct interpretation of the results of the mechanical tests. Down to a film thickness of about 100 to 200 nm the yield strength increased for all film systems (passivated and unpassivated) and microstructures (polycrystalline and singlecrystalline). The influence of different interfaces was smaller than expected. This could be explained by a dislocation source model based on the nucleation of perfect dislocations. For polycrystalline films the film thickness as well as the grain size distribution had to be considered. For smaller film thicknesses the increase in flow stress was weaker and the deformation behavior changed because the nucleation of perfect dislocations became unfavorable. Instead, the film materials used alternative mechanisms to relieve the high stresses. For regular and homogeneous deformation the total strain was accommodated by the nucleation and motion of partial dislocations. If the deformation was localized due to initial cracks in a brittle interlayer or local delamination, dislocation plasticity was not effective enough to relieve the stress concentration and the films showed

  11. A nanohole in a thin metal film as an efficient nonlinear optical element

    International Nuclear Information System (INIS)

    Konstantinova, T. V.; Melent’ev, P. N.; Afanas’ev, A. E.; Kuzin, A. A.; Starikov, P. A.; Baturin, A. S.; Tausenev, A. V.; Konyashchenko, A. V.; Balykin, V. I.

    2013-01-01

    The nonlinear optical properties of single nanoholes and nanoslits fabricated in gold and aluminum nanofilms are studied by third harmonic generation (THG). It is shown that the extremely high third-order optical susceptibility of aluminum and the presence of strong plasmon resonance of a single nanohole in an aluminum film make possible an efficient nanolocalized radiation source at the third harmonic frequency. The THG efficiency for a single nanohole in a thin metal film can be close to unity for an exciting laser radiation intensity on the order of 10 13 W/cm 2

  12. Compositional ratio effect on the surface characteristics of CuZn thin films

    Science.gov (United States)

    Choi, Ahrom; Park, Juyun; Kang, Yujin; Lee, Seokhee; Kang, Yong-Cheol

    2018-05-01

    CuZn thin films were fabricated by RF co-sputtering method on p-type Si(100) wafer with various RF powers applied on metallic Cu and Zn targets. This paper aimed to determine the morphological, chemical, and electrical properties of the deposited CuZn thin films by utilizing a surface profiler, atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), UV photoelectron spectroscopy (UPS), and a 4-point probe. The thickness of the thin films was fixed at 200 ± 8 nm and the roughness of the thin films containing Cu was smaller than pure Zn thin films. XRD studies confirmed that the preferred phase changed, and this tendency is dependent on the ratio of Cu to Zn. AES spectra indicate that the obtained thin films consisted of Cu and Zn. The high resolution XPS spectra indicate that as the content of Cu increased, the intensities of Zn2+ decreased. The work function of CuZn thin films increased from 4.87 to 5.36 eV. The conductivity of CuZn alloy thin films was higher than pure metallic thin films.

  13. Experiments and numerical modeling of fast flowing liquid metal thin films under spatially varying magnetic field conditions

    Science.gov (United States)

    Narula, Manmeet Singh

    Innovative concepts using fast flowing thin films of liquid metals (like lithium) have been proposed for the protection of the divertor surface in magnetic fusion devices. However, concerns exist about the possibility of establishing the required flow of liquid metal thin films because of the presence of strong magnetic fields which can cause flow disrupting MHD effects. A plan is underway to design liquid lithium based divertor protection concepts for NSTX, a small spherical torus experiment at Princeton. Of these, a promising concept is the use of modularized fast flowing liquid lithium film zones, as the divertor (called the NSTX liquid surface module concept or NSTX LSM). The dynamic response of the liquid metal film flow in a spatially varying magnetic field configuration is still unknown and it is suspected that some unpredicted effects might be lurking. The primary goal of the research work being reported in this dissertation is to provide qualitative and quantitative information on the liquid metal film flow dynamics under spatially varying magnetic field conditions, typical of the divertor region of a magnetic fusion device. The liquid metal film flow dynamics have been studied through a synergic experimental and numerical modeling effort. The Magneto Thermofluid Omnibus Research (MTOR) facility at UCLA has been used to design several experiments to study the MHD interaction of liquid gallium films under a scaled NSTX outboard divertor magnetic field environment. A 3D multi-material, free surface MHD modeling capability is under development in collaboration with HyPerComp Inc., an SBIR vendor. This numerical code called HIMAG provides a unique capability to model the equations of incompressible MHD with a free surface. Some parts of this modeling capability have been developed in this research work, in the form of subroutines for HIMAG. Extensive code debugging and benchmarking exercise has also been carried out. Finally, HIMAG has been used to study the

  14. Influence of thin film nickel pretreatment on catalytic thermal chemical vapor deposition of carbon nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Tiggelaar, R.M. [Mesoscale Chemical Systems, MESA" + Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Thakur, D.B.; Nair, H.; Lefferts, L.; Seshan, K. [Catalytic Processes and Materials, MESA" + Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Gardeniers, J.G.E., E-mail: j.g.e.gardeniers@utwente.nl [Mesoscale Chemical Systems, MESA" + Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)

    2013-05-01

    Nickel and other metal nanoparticles are known to be active as catalysts in the synthesis of carbon nanofibers. In this paper we investigate how dewetting and break-up of nickel thin films depends on film thickness, film–substrate interaction and pretreatment conditions. This is evaluated for films evaporated on oxidized silicon and fused silica substrates with or without tantalum coating, which were subsequently exposed to different pretreatment atmospheres (vacuum, nitrogen, air and hydrogen; 1 h, 650 °C). Atomic force microscopy, scanning electron microscopy and energy dispersive X-ray analysis were used to characterize the films. Pretreated Ni films were subjected to a thermal catalytic chemical vapor deposition procedure with brief ethylene exposures (0.5–3 min, 635 °C). It was found that only on the spherical nanoparticles originating from a hydrogen pretreatment of a Ni film with Ta adhesion layer, homogeneously distributed, randomly-oriented, well-attached, and semi-crystalline carbon nanofibers be synthesized. - Highlights: • On the formation of nanoparticles required for carbon nanofiber (CNF) synthesis • Various evaporated thin films on oxidized silicon and fused silica: Ni and Ni/Ta • Pretreatment of nickel-based thin films in vacuum, nitrogen, air and hydrogen • Only on reduced Ni/Ta fast – within 3 min – initiation of CNF nucleation and growth.

  15. Metal-insulator transition in SrTi1−xVxO3 thin films

    International Nuclear Information System (INIS)

    Gu, Man; Wolf, Stuart A.; Lu, Jiwei

    2013-01-01

    Epitaxial SrTi 1−x V x O 3 (0 ≤ x ≤ 1) thin films were grown on (001)-oriented (LaAlO 3 ) 0.3 (Sr 2 AlTaO 6 ) 0.7 (LSAT) substrates using the pulsed electron-beam deposition technique. The transport study revealed a temperature driven metal-insulator transition (MIT) at 95 K for x = 0.67. The films with higher vanadium concentration (x > 0.67) were metallic corresponding to a Fermi liquid system. In the insulating phase (x < 0.67), the resistivity behavior was governed by Mott's variable range hopping mechanism. The possible mechanisms for the induced MIT are discussed, including the effects of electron correlation, lattice distortion, and Anderson localization

  16. Improved conductivity of infinite-layer LaNiO2 thin films by metal organic decomposition

    International Nuclear Information System (INIS)

    Ikeda, Ai; Manabe, Takaaki; Naito, Michio

    2013-01-01

    Highlights: •LaNiO 2 films were synthesized by metal organic decomposition and topotactic reduction. •Room-temperature resistivity as low as 0.6 mΩ cm was achieved for infinite-layer LaNiO 2 . •Lattice matched substrates are important in obtaining high conductivity. -- Abstract: Infinite-layer LaNiO 2 thin films were synthesized by metal organic decomposition and subsequent topotactic reduction in hydrogen, and their transport properties were investigated. LaNiO 2 is isostructural to SrCuO 2 , the parent compound of high-T c Sr 0.9 La 0.1 CuO 2 with T c = 44 K, and has 3d 9 configuration, which is very rare in oxides but common to high-T c copper oxides. The bulk synthesis of LaNiO 2 is not easy, but we demonstrate in this article that the thin-film synthesis of LaNiO 2 is rather easy, thanks to a large-surface-to-volume ratio, which makes oxygen diffusion prompt. Our refined synthesis conditions produced highly conducting films of LaNiO 2 . The resistivity of the best film is as low as 640 μΩ cm at 295 K and decreases with temperature down to 230 K but it shows a gradual upturn at lower temperatures

  17. Site-selective electroless nickel plating on patterned thin films of macromolecular metal complexes.

    Science.gov (United States)

    Kimura, Mutsumi; Yamagiwa, Hiroki; Asakawa, Daisuke; Noguchi, Makoto; Kurashina, Tadashi; Fukawa, Tadashi; Shirai, Hirofusa

    2010-12-01

    We demonstrate a simple route to depositing nickel layer patterns using photocross-linked polymer thin films containing palladium catalysts, which can be used as adhesive interlayers for fabrication of nickel patterns on glass and plastic substrates. Electroless nickel patterns can be obtained in three steps: (i) the pattern formation of partially quaterized poly(vinyl pyridine) by UV irradiation, (ii) the formation of macromolecular metal complex with palladium, and (iii) the nickel metallization using electroless plating bath. Metallization is site-selective and allows for a high resolution. And the resulting nickel layered structure shows good adhesion with glass and plastic substrates. The direct patterning of metallic layers onto insulating substrates indicates a great potential for fabricating micro/nano devices.

  18. Gas Sensing Properties of Metal Doped WO3 Thin Film Sensors Prepared by Pulsed Laser Deposition and DC Sputtering Process

    Science.gov (United States)

    Bhuiyan, Md. Mosharraf Hossain; Ueda, Tsuyoshi; Ikegami, Tomoaki; Ebihara, Kenji

    2006-10-01

    Tungsten trioxide (WO3) thin films gas sensors were prepared by the KrF excimer pulsed laser deposition (PLD) method. The films were prepared on the quartz glass, silicon and also on the Al2O3 sensor substrates with platinum interdigitated electrodes. The effect of doping of the platinum (Pt), palladium (Pd) or gold (Au) on the WO3 thin film was also investigated. These metals were doped to the WO3 thin film by the DC sputtering process during the PLD. The substrate temperature and the oxygen pressure were 400 °C and 100 mTorr, respectively, during the deposition. The films were characterized by atomic force microscopy (AFM) and X-ray diffraction (XRD). The sensitivity of the prepared sensors to 60 ppm NO gas was examined using the two terminal resistance method in a chamber at atmospheric pressure and operating temperatures of 25-350 °C. The sensitivity of the WO3 thin films doped with Pt, Pd, or Au was found to be higher than that of the undoped WO3 thin film.

  19. 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.

  20. Refractive-index change caused by electrons in amorphous AsS and AsSe thin films doped with different metals by photodiffusion

    International Nuclear Information System (INIS)

    Nordman, Olli; Nordman, Nina; Pashkevich, Valfrid

    2001-01-01

    The refractive-index change caused by electrons was measured in amorphous AsS and AsSe thin films. Films were coated with different metals. Diffraction gratings were written by electron-beam lithography. The interactions of electrons in films with and without the photodiffusion of overcoated metal were compared. Incoming electrons caused metal atom and ion diffusion in both investigated cases. The metal diffusion was dependent on the metal and it was found to influence the refractive index. In some cases lateral diffusion of the metal was noticed. The conditions for applications were verified. Copyright 2001 Optical Society of America

  1. 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

  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. Semiconductor- to metallic-like behavior in Bi thin films on KCl substrate

    International Nuclear Information System (INIS)

    Bui, Thanh Nhan; Raskin, Jean-Pierre; Hackens, Benoit

    2016-01-01

    Bi thin films, with a thickness of 100 nm, are deposited by electron-beam evaporation on a freshly cleaved (100) KCl substrate. The substrate temperature during film growth (T_d_e_p) ranges from room temperature up to 170 °C. Films deposited at room temperature exhibit a maze-like microstructure typical of the rhombohedral (110) texture, as confirmed by X-ray diffraction. For T_d_e_p above 80 °C, a different microstructure appears, characterized by concentric triangular shapes corresponding to the trigonal (111) texture. Temperature dependence of the resistivity shows a transition from a semiconductor-like behavior for films deposited at room temperature to a metallic-like behavior for T_d_e_p above 80 °C. From magnetoresistance measurements between room temperature and 1.6 K, we extract the electron and hole mobilities, concentrations, and mean free paths, which allow to draw a complete picture of the transport properties of both types of films.

  4. Piezoelectric characterization of Pb(Zr,Ti)O3 thin films deposited on metal foil substrates by dip coating

    Science.gov (United States)

    Hida, Hirotaka; Hamamura, Tomohiro; Nishi, Takahito; Tan, Goon; Umegaki, Toshihito; Kanno, Isaku

    2017-10-01

    We fabricated the piezoelectric bimorphs composed of Pb(Zr,Ti)O3 (PZT) thin films on metal foil substrates. To efficiently inexpensively manufacture piezoelectric bimorphs with high flexibility, 1.2-µm-thick PZT thin films were directly deposited on both surfaces of 10- and 20-µm-thick bare stainless-steel (SS) foil substrates by dip coating with a sol-gel solution. We confirmed that the PZT thin films deposited on the SS foil substrates at 500 °C or above have polycrystalline perovskite structures and the measured relative dielectric constant and dielectric loss were 323-420 and 0.12-0.17, respectively. The PZT bimorphs were demonstrated by comparing the displacements of the cantilever specimens driven by single- and double-side PZT thin films on the SS foil substrates under the same applied voltage. We characterized the piezoelectric properties of the PZT bimorphs and the calculated their piezoelectric coefficient |e 31,f| to be 0.3-0.7 C/m2.

  5. 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.

  6. Relative SHG measurements of metal thin films: Gold, silver, aluminum, cobalt, chromium, germanium, nickel, antimony, titanium, titanium nitride, tungsten, zinc, silicon and indium tin oxide

    Directory of Open Access Journals (Sweden)

    Franklin Che

    Full Text Available We have experimentally measured the surface second-harmonic generation (SHG of sputtered gold, silver, aluminum, zinc, tungsten, copper, titanium, cobalt, nickel, chromium, germanium, antimony, titanium nitride, silicon and indium tin oxide thin films. The second-harmonic response was measured in reflection using a 150 fs p-polarized laser pulse at 1561 nm. We present a clear comparison of the SHG intensity of these films relative to each other. Our measured relative intensities compare favorably with the relative intensities of metals with published data. We also report for the first time to our knowledge the surface SHG intensity of tungsten and antimony relative to that of well known metallic thin films such as gold and silver. Keywords: Surface second-harmonic generation, Nonlinear optics, Metal thin films

  7. 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.

  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. Plasma Processing of Metallic and Semiconductor Thin Films in the Fisk Plasma Source

    Science.gov (United States)

    Lampkin, Gregory; Thomas, Edward, Jr.; Watson, Michael; Wallace, Kent; Chen, Henry; Burger, Arnold

    1998-01-01

    The use of plasmas to process materials has become widespread throughout the semiconductor industry. Plasmas are used to modify the morphology and chemistry of surfaces. We report on initial plasma processing experiments using the Fisk Plasma Source. Metallic and semiconductor thin films deposited on a silicon substrate have been exposed to argon plasmas. Results of microscopy and chemical analyses of processed materials are presented.

  10. Metal induced crystallization of amorphous silicon thin films studied by x-ray absorption fine structure spectroscopy

    International Nuclear Information System (INIS)

    Naidu, K Lakshun; Mohiddon, Md Ahamad; Dalba, G; Krishna, M Ghanashyam; Rocca, F

    2013-01-01

    The role of thin metallic layer (Chromium or Nickel) in the crystallization of a-Si film has been studied using X-ray absorption fine structure spectroscopy (XAFS). The films were grown at different substrate temperatures in two different geometrical structures : (a) a 200 nm metal layer (Cr or Ni) was deposited on fused silica (FS) followed by 400 nm of a-Si and (b) the 400 nm a-Si layer was deposited on FS followed by 200 nm of metal layer. XAFS measurements at Cr K-edge and Ni K-edge were done at BM08 – GILDA beamline of the European Synchrotron Research Facility (ESRF, Grenoble, F) in fluorescence mode. To understand the evolution of the local structure of Cr/Ni diffusing from bottom to top and from top to bottom, total reflection and higher incidence angles were employed. The relative content of metal, metal oxide and metal silicides compounds on the upper surface and/or in the bulk of different films has been evaluated as a function of thermal treatment.

  11. Semi-transparent ordered TiO{sub 2} nanostructures prepared by anodization of titanium thin films deposited onto the FTO substrate

    Energy Technology Data Exchange (ETDEWEB)

    Szkoda, Mariusz, E-mail: mariusz-szkoda@wp.pl [Department of Chemistry and Technology of Functional Materials, Faculty of Chemistry, Gdańsk University of Technology, Narutowicza 11/12, Gdańsk 80-233 (Poland); Lisowska-Oleksiak, Anna [Department of Chemistry and Technology of Functional Materials, Faculty of Chemistry, Gdańsk University of Technology, Narutowicza 11/12, Gdańsk 80-233 (Poland); Grochowska, Katarzyna [Centre for Plasma and Laser Engineering, Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Science, Fiszera 14, 80-231 Gdańsk (Poland); Skowroński, Łukasz [Institute of Mathematics and Physics, UTP University of Science and Technology, Kaliskiego 7, 85-796 Bydgoszcz (Poland); Karczewski, Jakub [Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk (Poland); Siuzdak, Katarzyna [Centre for Plasma and Laser Engineering, Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Science, Fiszera 14, 80-231 Gdańsk (Poland)

    2016-09-15

    Highlights: • High quality titanium coatings were doposited using industrial magnetron sputtering equipment. • Semi-transparent TiO{sub 2} were prepared via anodization realized in various conditions. • Depending on electrolyte type, ordered tubular or porous TiO{sub 2} layers were obtained. • Prepared material can act as semiconducting layer in photovoltaic cells. - Abstract: In a significant amount of cases, the highly ordered TiO{sub 2} nanotube arrays grow through anodic oxidation of a titanium metal plate immersed in electrolyte containing fluoride ions. However, for some practical applications, e.g. solar cells or electrochromic windows, the semi-transparent TiO{sub 2} formed directly on the transparent, conductive substrate is very much desired. This work shows that high-quality Ti coating could be formed at room temperature using an industrial magnetron sputtering system within 50 min. Under optimized conditions, the anodization process was performed on 2 μm titanium films deposited onto the FTO (fluorine-tin-oxide) support. Depending on the electrolyte type, highly ordered tubular or porous titania layers were obtained. The fabricated samples, after their thermal annealing, were investigated using scanning electron microscopy, Raman spectroscopy and UV–vis spectroscopy in order to investigate their morphology, crystallinity and absorbance ability. The photocurrent response curves indicate that materials are resistant to the photocorrosion process and their activity is strongly connected to optical properties. The most transparent TiO{sub 2} films were fabricated when Ti was anodized in water electrolyte, whereas the highest photocurrent densities (12 μA cm{sup −2}) were registered for titania received after Ti anodization in ethylene glycol solution. The obtained results are of significant importance in the production of thin, semi-transparent titania nanostructures on a commercial scale.

  12. Improved conductivity of infinite-layer LaNiO2 thin films by metal organic decomposition

    Science.gov (United States)

    Ikeda, Ai; Manabe, Takaaki; Naito, Michio

    2013-12-01

    Infinite-layer LaNiO2 thin films were synthesized by metal organic decomposition and subsequent topotactic reduction in hydrogen, and their transport properties were investigated. LaNiO2 is isostructural to SrCuO2, the parent compound of high-Tc Sr0.9La0.1CuO2 with Tc = 44 K, and has 3d9 configuration, which is very rare in oxides but common to high-Tc copper oxides. The bulk synthesis of LaNiO2 is not easy, but we demonstrate in this article that the thin-film synthesis of LaNiO2 is rather easy, thanks to a large-surface-to-volume ratio, which makes oxygen diffusion prompt. Our refined synthesis conditions produced highly conducting films of LaNiO2. The resistivity of the best film is as low as 640 μΩ cm at 295 K and decreases with temperature down to 230 K but it shows a gradual upturn at lower temperatures.

  13. A nanohole in a thin metal film as an efficient nonlinear optical element

    Energy Technology Data Exchange (ETDEWEB)

    Konstantinova, T. V.; Melent' ev, P. N.; Afanas' ev, A. E. [Russian Academy of Sciences, Institute of Spectroscopy (Russian Federation); Kuzin, A. A.; Starikov, P. A.; Baturin, A. S. [Moscow Institute of Physics and Technology (Russian Federation); Tausenev, A. V.; Konyashchenko, A. V. [OOO Avesta-proekt (Russian Federation); Balykin, V. I., E-mail: balykin@isan.tyroitsk.ru [Russian Academy of Sciences, Institute of Spectroscopy (Russian Federation)

    2013-07-15

    The nonlinear optical properties of single nanoholes and nanoslits fabricated in gold and aluminum nanofilms are studied by third harmonic generation (THG). It is shown that the extremely high third-order optical susceptibility of aluminum and the presence of strong plasmon resonance of a single nanohole in an aluminum film make possible an efficient nanolocalized radiation source at the third harmonic frequency. The THG efficiency for a single nanohole in a thin metal film can be close to unity for an exciting laser radiation intensity on the order of 10{sup 13} W/cm{sup 2}.

  14. Photovoltaic properties of in-doped CDTE thin films deposited on metallic substrates

    International Nuclear Information System (INIS)

    Wagah F Mohamad; Khalid K Mohammed

    2006-01-01

    CDTE is a promising photovoltaic material due to its nearly optimum band gap and high optical absorption coefficient. This study looks into the effect of indium doping of the CdTe thin film deposited on stainless steel substrate. The conventional cells are usually manufactured on glass substrate and offer no weight advantage over single crystal cells. Since the metal foil support can be as thin as (40-60) μm and the weight saving is significant. The spectral response of the photo current with and without indium doping was studied in detail and compared with theory. The sub gap response of the resulted structure is particularly strong and extends to wavelengths up to 1000 nm

  15. Fracture resistance of dental nickel–titanium rotary instruments with novel surface treatment: Thin film metallic glass coating

    Directory of Open Access Journals (Sweden)

    Chih-Wen Chi

    2017-05-01

    Conclusion: The novel surface treatment of Ti-Zr-B thin film metallic glass on dental NiTi rotary files can effectively improve the fatigue fracture resistance by offering a smooth coated surface with amorphous microstructure.

  16. Time-Resolved In Situ Liquid-Phase Atomic Force Microscopy and Infrared Nanospectroscopy during the Formation of Metal-Organic Framework Thin Films.

    Science.gov (United States)

    Mandemaker, Laurens D B; Filez, Matthias; Delen, Guusje; Tan, Huanshu; Zhang, Xuehua; Lohse, Detlef; Weckhuysen, Bert M

    2018-04-19

    Metal-organic framework (MOF) thin films show unmatched promise as smart membranes and photocatalytic coatings. However, their nucleation and growth resulting from intricate molecular assembly processes are not well understood yet are crucial to control the thin film properties. Here, we directly observe the nucleation and growth behavior of HKUST-1 thin films by real-time in situ AFM at different temperatures in a Cu-BTC solution. In combination with ex situ infrared (nano)spectroscopy, synthesis at 25 °C reveals initial nucleation of rapidly growing HKUST-1 islands surrounded by a continuously nucleating but slowly growing HKUST-1 carpet. Monitoring at 13 and 50 °C shows the strong impact of temperature on thin film formation, resulting in (partial) nucleation and growth inhibition. The nucleation and growth mechanisms as well as their kinetics provide insights to aid in future rational design of MOF thin films.

  17. A Method to Extract the Intrinsic Mechanical Properties of Soft Metallic Thin Films Based on Nanoindentation Continuous Stiffness Measurement Technique

    International Nuclear Information System (INIS)

    Zhou, X Y; Jiang, Z D; Wang, H R; Zhu, Q

    2006-01-01

    In order to determine accurately the intrinsic hardness of the soft metallic thin film on a hard substrate using nanoindentation, a proper methodology irrespective of several important effects the Oliver-Pharr method concerns is described. First, the original analysis data such as the load, P, and contact stiffness, S, as a function of the indentation depth, h, are acquired by means of the continuous stiffness measurement (CSM) technique. By CSM, the complicating effects including indentation creep behaviour of metal materials as well as thermal drift on the measured results are avoided effectively. Then, the hardness of film-only is calculated via a material characteristic parameter, P/S 2 , which is independent of the contact area, A, based on the constant modulus assumption method. In this way, the influences of the substrate contribution and material pile-up behaviour needn't be accounted for. Guided by above ideas, moreover, a 504 nm Au film on the glass substrate system was chosen to study. The results show that the hardness of Au thin film is 1.6±1 GPa, which agree well with the literature. While the composite hardness measured by Oliver-Pharr method is between 2∼3GPa, obviously, which is overestimated. This implies the present methodology is a more accurate and simple way for extracting the true hardness of the soft metallic thin films

  18. Combustion synthesized indium-tin-oxide (ITO) thin film for source/drain electrodes in all solution-processed oxide thin-film transistors

    International Nuclear Information System (INIS)

    Tue, Phan Trong; Inoue, Satoshi; Takamura, Yuzuru; Shimoda, Tatsuya

    2016-01-01

    We report combustion solution synthesized (SCS) indium-tin-oxide (ITO) thin film, which is a well-known transparent conductive oxide, for source/drain (S/D) electrodes in solution-processed amorphous zirconium-indium-zinc-oxide TFT. A redox-based combustion synthetic approach is applied to ITO thin film using acetylacetone as a fuel and metal nitrate as oxidizer. The structural and electrical properties of SCS-ITO precursor solution and thin films were systematically investigated with changes in tin concentration, indium metal precursors, and annealing conditions such as temperature, time, and ambient. It was found that at optimal conditions the SCS-ITO thin film exhibited high crystalline quality, atomically smooth surface (RMS ∝ 4.1 Aa), and low electrical resistivity (4.2 x 10 -4 Ω cm). The TFT using SCS-ITO film as the S/D electrodes showed excellent electrical properties with negligible hysteresis. The obtained ''on/off'' current ratio, subthreshold swing factor, subthreshold voltage, and field-effect mobility were 5 x 10 7 , 0.43 V/decade, 0.7 V, and 2.1 cm 2 /V s, respectively. The performance and stability of the SCS-ITO TFT are comparable to those of the sputtered-ITO TFT, emphasizing that the SCS-ITO film is a promising candidate for totally solution-processed oxide TFTs. (orig.)

  19. Thin film electronic devices with conductive and transparent gas and moisture permeation barriers

    Science.gov (United States)

    Simpson, Lin Jay

    2013-12-17

    A thin film stack (100, 200) is provided for use in electronic devices such as photovoltaic devices. The stack (100, 200) may be integrated with a substrate (110) such as a light transmitting/transmissive layer. A electrical conductor layer (120, 220) is formed on a surface of the substrate (110) or device layer such as a transparent conducting (TC) material layer (120,220) with pin holes or defects (224) caused by manufacturing. The stack (100) includes a thin film (130, 230) of metal that acts as a barrier for environmental contaminants (226, 228). The metal thin film (130,230) is deposited on the conductor layer (120, 220) and formed from a self-healing metal such as a metal that forms self-terminating oxides. A permeation plug or block (236) is formed in or adjacent to the thin film (130, 230) of metal at or proximate to the pin holes (224) to block further permeation of contaminants through the pin holes (224).

  20. Enhanced Absorption in Organic Thin-Films from Imprinted Concave Nanostructures

    Directory of Open Access Journals (Sweden)

    Arkadiusz Jarosław GOSZCZAK

    2017-02-01

    Full Text Available In this work, a rapid, replicable method for imprinting concave nanostructures to be used as functional light-trapping nanostructures in organic thin-films is presented. Porous anodic alumina templates were fabricated both by anodization of thick Al foils and by anodization of submicrometer thin Al films evaporated via e-beam evaporation on Si substrates. The template formation leads to natural patterning of the underlying Al layers that are used as rigid masters for stamp fabrication, after selective etching of the porous anodic alumina. PDMS stamps were made after replicating the Al concave patterns and used for imprinting of spin coated photoresist on glass substrates. We have investigated semi-periodic and aperiodic imprinted large concave patterns fabricated from rigid masters after anodization of Al in H3PO4. We show that metal covered imprinted concaves show enhancement in absorption that is attributed to field enhancement and diffuse scattering, leading to efficient light trapping for a selected active layer material (P3HT:PCBM.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14188

  1. 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.

  2. Decoding Nucleation and Growth of Zeolitic Imidazolate Framework Thin Films with Atomic Force Microscopy and Vibrational Spectroscopy.

    Science.gov (United States)

    Öztürk, Zafer; Filez, Matthias; Weckhuysen, Bert M

    2017-08-10

    The synthesis of metal-organic framework (MOF) thin films has garnered significant attention during the past decade. By better understanding the parameters governing the nucleation and growth of such thin films, their properties can be rationally tuned, empowering their application as (reactive) membranes. Here, a combined AFM-vibrational spectroscopy research strategy is employed to detail the chemistries governing the nucleation and growth of zeolitic imidazolate framework (ZIF) thin films, in particular isostructural Co-ZIF-67 and Zn-ZIF-8. First, a single step direct synthesis approach is used to investigate the influence of different synthesis parameters -metal/linker ratio, temperature, and metal type- on the thin film nucleation and growth behaviour. While the metal/linker ratio has a pronounced effect on the thin film nucleation rate, the temperature mainly influences the growth kinetics of nuclei forming the thin film. In addition, the nucleation and growth of ZIF thin films is shown to be highly dependent on the electronegativity of the metal type. Thin-film thickness control can be achieved by using a multistep synthesis strategy, implying repetitive applications of single step deposition under identical synthesis conditions, for which a growth mechanism is proposed. This study provides insight into the influence of synthesis parameters on the ZIF thin film properties, using tools at hand to rationally tune MOF thin film properties. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  3. Electrodeposition of Metal Matrix Composites and Materials Characterization for Thin-Film Solar Cells

    Science.gov (United States)

    2017-12-04

    Air Mass CNT Carbon Nanotubes DIV Dark Current -Voltage DMA Dynamic Mechanical Analysis EL Electroluminescence FEM Finite Element Method IMM...AFRL-RV-PS- AFRL-RV-PS- TR-2017-0174 TR-2017-0174 ELECTRODEPOSITION OF METAL MATRIX COMPOSITES AND MATERIALS CHARACTERIZATION FOR THIN-FILM SOLAR...research which is exempt from public affairs security and policy review in accordance with AFI 61-201, paragraph 2.3.5.1. This report is available to

  4. Defect-mediated magnetism of transition metal doped zinc oxide thin films

    Science.gov (United States)

    Roberts, Bradley Kirk

    Magnetism in transition metal doped wide band-gap materials is of interest to further the fundamental science of materials and future spintronics applications. Large inter-dopant separations require mediation of ferromagnetism by some method; carrier-mediated mechanisms are typically applicable to dilute magnetic semiconductors with low Curie temperatures. Dilute magnetic oxides, commonly with poor conductivity and TC above room temperature, cannot be described within this theory. Recent experiment and theory developments suggest that ferromagnetic exchange in these materials can be mediated by defects. This research includes experimental results justifying and developing this approach. Thin films of Cr doped ZnO (band gap ˜3.3 eV) were deposited with several processing variations to enhance the effects of either 0-dimensional (vacancy, hydrogen-related defect) or two-dimensional defects (surface/interface) and thereby affect magnetism and conductivity. We observe surface magnetism in dielectric thin films of oxygen-saturated ZnO:Cr with spontaneous magnetic moment and conductance dropping approximately exponentially with increasing thickness. Uniform defect concentrations would not result in such magnetic ordering behavior indicating that magnetism is mediated either by surface defects or differing concentrations of point defects near the surface. Polarized neutron reflectivity profiling confirms a magnetically active region of ˜8 nm at the film surface. Hydrogen is notoriously present as a defect and carrier dopant in ZnO, and artificial introduction of hydrogen in dielectric ZnO:Cr films results in varying electronic and magnetic behavior. Free carriers introduced with hydrogen doping are not spin-polarized requiring an alternative explanation for ferromagnetism. We find from positron annihilation spectroscopy measurements that hydrogen doping increases the concentration of an altered VZn-related defect (a preliminary interpretation) throughout the film, which

  5. Topotactic Metal-Insulator Transition in Epitaxial SrFeOx Thin Films.

    Science.gov (United States)

    Khare, Amit; Shin, Dongwon; Yoo, Tae Sup; Kim, Minu; Kang, Tae Dong; Lee, Jaekwang; Roh, Seulki; Jung, In-Ho; Hwang, Jungseek; Kim, Sung Wng; Noh, Tae Won; Ohta, Hiromichi; Choi, Woo Seok

    2017-10-01

    Topotactic phase transformation enables structural transition without losing the crystalline symmetry of the parental phase and provides an effective platform for elucidating the redox reaction and oxygen diffusion within transition metal oxides. In addition, it enables tuning of the emergent physical properties of complex oxides, through strong interaction between the lattice and electronic degrees of freedom. In this communication, the electronic structure evolution of SrFeO x epitaxial thin films is identified in real-time, during the progress of reversible topotactic phase transformation. Using real-time optical spectroscopy, the phase transition between the two structurally distinct phases (i.e., brownmillerite and perovskite) is quantitatively monitored, and a pressure-temperature phase diagram of the topotactic transformation is constructed for the first time. The transformation at relatively low temperatures is attributed to a markedly small difference in Gibbs free energy compared to the known similar class of materials to date. This study highlights the phase stability and reversibility of SrFeO x thin films, which is highly relevant for energy and environmental applications exploiting the redox reactions. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Improved conductivity of infinite-layer LaNiO{sub 2} thin films by metal organic decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Ai [Department of Applied Physics, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Koganei, Tokyo 184-8588 (Japan); Research Fellow of the Japan Society for the Promotion of Science (Japan); Manabe, Takaaki [National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba, Ibaraki 305-8565 (Japan); Naito, Michio, E-mail: minaito@cc.tuat.ac.jp [Department of Applied Physics, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Koganei, Tokyo 184-8588 (Japan)

    2013-12-15

    Highlights: •LaNiO{sub 2} films were synthesized by metal organic decomposition and topotactic reduction. •Room-temperature resistivity as low as 0.6 mΩ cm was achieved for infinite-layer LaNiO{sub 2}. •Lattice matched substrates are important in obtaining high conductivity. -- Abstract: Infinite-layer LaNiO{sub 2} thin films were synthesized by metal organic decomposition and subsequent topotactic reduction in hydrogen, and their transport properties were investigated. LaNiO{sub 2} is isostructural to SrCuO{sub 2}, the parent compound of high-T{sub c} Sr{sub 0.9}La{sub 0.1}CuO{sub 2} with T{sub c} = 44 K, and has 3d{sup 9} configuration, which is very rare in oxides but common to high-T{sub c} copper oxides. The bulk synthesis of LaNiO{sub 2} is not easy, but we demonstrate in this article that the thin-film synthesis of LaNiO{sub 2} is rather easy, thanks to a large-surface-to-volume ratio, which makes oxygen diffusion prompt. Our refined synthesis conditions produced highly conducting films of LaNiO{sub 2}. The resistivity of the best film is as low as 640 μΩ cm at 295 K and decreases with temperature down to 230 K but it shows a gradual upturn at lower temperatures.

  7. Thin films of molecular materials synthesized from fisher's carbene ferrocenyl: Film formation and electrical properties

    International Nuclear Information System (INIS)

    Sanchez-Vergara, M.E.; Ortiz, A.; Alvarez-Toledano, C.; Moreno, A.; Alvarez, J.R.

    2008-01-01

    The synthesis of materials from Fisher's carbene ferrocenyl of the elements chromium, molybdenum and tungsten was carried out. The Fisher's compounds that were synthesized included the following combinations of two different metallic atoms: iron with chromium, iron with molybdenum and iron with tungsten. The molecular solids' preparation was done in electro-synthesis cells with platinum electrodes. Thin films were prepared by vacuum thermal evaporation on quartz substrates and crystalline silicon wafers. Pellets and thin films from these compounds were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive spectroscopy, atomic force microscopy and ellipsometry. The powder and thin films synthesized from these materials show the same intra-molecular bonds shown by infrared spectroscopy results, suggesting that thermal evaporation does not alter these bonds in spite of the thin films being amorphous, in contrast with other bimetallic complexes where material decomposition occurs. The differences in the conductivity values of the prepared films are very small, so they may be attributed to the different metallic ions employed in each case. The tungsten complex exhibits a higher conductivity than the molybdenum and chromium complexes at room temperature. Electrical conductivity values found for thin films are higher than for pellets made of the same molecular materials

  8. Electrical four-point probing of spherical metallic thin films coated onto micron sized polymer particles

    Energy Technology Data Exchange (ETDEWEB)

    Pettersen, Sigurd R., E-mail: sigurd.r.pettersen@ntnu.no, E-mail: jianying.he@ntnu.no; Stokkeland, August Emil; Zhang, Zhiliang; He, Jianying, E-mail: sigurd.r.pettersen@ntnu.no, E-mail: jianying.he@ntnu.no [NTNU Nanomechanical Lab, Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway); Kristiansen, Helge [NTNU Nanomechanical Lab, Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway); Conpart AS, Dragonveien 54, NO-2013 Skjetten (Norway); Njagi, John; Goia, Dan V. [Center for Advanced Materials Processing, Clarkson University, Potsdam, New York 13699-5814 (United States); Redford, Keith [Conpart AS, Dragonveien 54, NO-2013 Skjetten (Norway)

    2016-07-25

    Micron-sized metal-coated polymer spheres are frequently used as filler particles in conductive composites for electronic interconnects. However, the intrinsic electrical resistivity of the spherical thin films has not been attainable due to deficiency in methods that eliminate the effect of contact resistance. In this work, a four-point probing method using vacuum compatible piezo-actuated micro robots was developed to directly investigate the electric properties of individual silver-coated spheres under real-time observation in a scanning electron microscope. Poly(methyl methacrylate) spheres with a diameter of 30 μm and four different film thicknesses (270 nm, 150 nm, 100 nm, and 60 nm) were investigated. By multiplying the experimental results with geometrical correction factors obtained using finite element models, the resistivities of the thin films were estimated for the four thicknesses. These were higher than the resistivity of bulk silver.

  9. Growth, Properties and Applications of Mo Ox Thin-Films Deposited by Reactive Sputtering

    DEFF Research Database (Denmark)

    Fernandes Cauduro, André Luis

    properties of metal-oxide thin films through surface defect engineering is vital to fine-tune their optoelectronic properties, and thus also their integration in novel optoelectronic devices. In this work, MoOx thin-films with various different phases and compositions were prepared by direct-current reactive...... molecules DBP and C70 are also covered in this work. The devices show interesting characteristics for very thin layers of the as-deposited MoOx films, displaying similar device efficiencies as those of in situ prepared MoOx thin-films formed from thermal evaporation. For the annealed MoOx films......Transition metal-oxide (TMOs) thin-films are commonly used in optoelectronic devices such as in photovoltaics and light emitting diodes, using both organic, inorganic and hybrid technologies. In such devices, TMOs typically act as an interfacial layer, where its functionality is to facilitate hole...

  10. Electric Transport Phenomena of Nanocomposite Organic Polymer Thin Films

    Science.gov (United States)

    Jira, Nicholas C.; Sabirianov, Ildar; Ilie, Carolina C.

    We discuss herein the nanocomposite organic thin film diodes for the use of plasmonic solar cells. This experimental work follows the theoretical calculations done for plasmonic solar cells using the MNPBEM toolbox for MatLab. These calculations include dispersion curves and amount of light scattering cross sections for different metallic nanoparticles. This study gives us clear ideas on what to expect from different metals, allowing us to make the best choice on what to use to obtain the best results. One specific technique for light trapping in thin films solar cells utilizes metal nanoparticles on the surface of the semiconductor. The characteristics of the metal, semiconductor interface allows for light to be guided in between them causing it to be scattered, allowing for more chances of absorption. The samples were fabricated using organic thin films made from polymers and metallic nanoparticles, more specifically Poly(1-vinylpyrrolidone-co-2-dimethylaminoethyl methacrylate) copolymer and silver or gold nanoparticles. The two fabrication methods applied include spin coating and Langmuir-Blodgett technique. The transport properties are obtained by analyzing the I-V curves. We will also discuss the resistance, resistivity, conductance, density of charge carriers. SUNY Oswego SCAC Grant.

  11. 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.

  12. Synthesis and characterization of nanoporous strontium-doped lanthanum cobaltite thin film using metal organic chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jun-Sik [Department of Mechanical Convergence Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Kim, Young-Beom, E-mail: ybkim@hanyang.ac.kr [Department of Mechanical Convergence Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Institute of Nano Science and Technology, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2016-01-29

    By employing strontium as a dopant of lanthanum cobaltite (LaCoO{sub 3}), strontium-doped lanthanum cobaltite (La{sub 1−x}Sr{sub x}CoO{sub 3−δ}, LSC) thin film was fabricated using a metal organic chemical solution deposition (MOCSD) method. Lanthanum nitrate hexahydrate [La(NO{sub 3}){sub 3}6H{sub 2}O], strontium acetate [Sr(CH{sub 3}COO){sub 2}], and cobalt acetate tetrahydrate [Co(CH{sub 3}COO){sub 2}4H{sub 2}O] were used as precursors. The coating process was performed through a spin coating method on a substrate, which were then heat treated under various temperature conditions. Electrical properties, microstructures, and crystalline structures with respect to sintering temperature were analyzed. According to these analyses, the change in surface morphology, phase shift, and conductive properties were closely related, which could explain their respective behaviors. Furthermore, sintered strontium-doped lanthanum perovskite oxides showed various conductivities according to the amount of dopant. With the molar ratio of strontium that is stoichiometrically equivalent to lanthanum (La{sub 0.5}Sr{sub 0.5}CoO{sub 3−δ}) thin film showed the best conductivity in the sintering temperature range of 650–700 °C, with perovskite phases formed at this temperature condition. As the electrically conductive properties of the thin film are a function of thickness, the films were coated several times to a thickness of approximately 300 nm, with the lowest resistivity (approximately 9.06 × 10{sup −4} Ω cm) observed at the optimized sintering temperature and solution composition. - Highlights: • LSC thin film was fabricated by metal organic chemical solution deposition (MOCSD). • The film shows good agreement on the electrical conductivity of LSC by conventional methods. • The properties of LSC film are influenced by the surface morphology and crystalline phase. • Optimal molar ratio of strontium for the highest conductivity was investigated.

  13. Functional Design of Dielectric-Metal-Dielectric-Based Thin-Film Encapsulation with Heat Transfer and Flexibility for Flexible Displays.

    Science.gov (United States)

    Kwon, Jeong Hyun; Choi, Seungyeop; Jeon, Yongmin; Kim, Hyuncheol; Chang, Ki Soo; Choi, Kyung Cheol

    2017-08-16

    In this study, a new and efficient dielectric-metal-dielectric-based thin-film encapsulation (DMD-TFE) with an inserted Ag thin film is proposed to guarantee the reliability of flexible displays by improving the barrier properties, mechanical flexibility, and heat dissipation, which are considered to be essential requirements for organic light-emitting diode (OLED) encapsulation. The DMD-TFE, which is composed of Al 2 O 3 , Ag, and a silica nanoparticle-embedded sol-gel hybrid nanocomposite, shows a water vapor transmission rate of 8.70 × 10 -6 g/m 2 /day and good mechanical reliability at a bending radius of 30 mm, corresponding to 0.41% strain for 1000 bending cycles. The electrical performance of a thin-film encapsulated phosphorescent organic light-emitting diode (PHOLED) was identical to that of a glass-lid encapsulated PHOLED. The operational lifetimes of the thin-film encapsulated and glass-lid encapsulated PHOLEDs are 832 and 754 h, respectively. After 80 days, the thin-film encapsulated PHOLED did not show performance degradation or dark spots on the cell image in a shelf-lifetime test. Finally, the difference in lifetime of the OLED devices in relation to the presence and thickness of a Ag film was analyzed by applying various TFE structures to fluorescent organic light-emitting diodes (FOLEDs) that could generate high amounts of heat. To demonstrate the difference in heat dissipation effect among the TFE structures, the saturated temperatures of the encapsulated FOLEDs were measured from the back side surface of the glass substrate, and were found to be 67.78, 65.12, 60.44, and 39.67 °C after all encapsulated FOLEDs were operated at an initial luminance of 10 000 cd/m 2 for sufficient heat generation. Furthermore, the operational lifetime tests of the encapsulated FOLED devices showed results that were consistent with the measurements of real-time temperature profiles taken with an infrared camera. A multifunctional hybrid thin-film encapsulation

  14. Two-scale homogenization to determine effective parameters of thin metallic-structured films

    Science.gov (United States)

    Marigo, Jean-Jacques

    2016-01-01

    We present a homogenization method based on matched asymptotic expansion technique to derive effective transmission conditions of thin structured films. The method leads unambiguously to effective parameters of the interface which define jump conditions or boundary conditions at an equivalent zero thickness interface. The homogenized interface model is presented in the context of electromagnetic waves for metallic inclusions associated with Neumann or Dirichlet boundary conditions for transverse electric or transverse magnetic wave polarization. By comparison with full-wave simulations, the model is shown to be valid for thin interfaces up to thicknesses close to the wavelength. We also compare our effective conditions with the two-sided impedance conditions obtained in transmission line theory and to the so-called generalized sheet transition conditions. PMID:27616916

  15. The effect of polyimide imidization conditions on adhesion strength of thin metal films on polyimide substrates

    CERN Document Server

    Yoo, S H

    1999-01-01

    The effects of Ar sup + RF plasma precleaning and polyimide curing conditions on the peel strength between Al thin films and polyimides have been studied. The BPDA-PDA polyimide precursor of PI-2611 (Du pont) was spin-coated and cured under various imidization conditions. The cured polyimide substrates were in-situ AR sup + RF plasma cleaned prior to metal deposition. Al-1 % Si-0.5 % Cu thin films were deposited onto the polyimide substrates by using DC magnetron sputtering. The peel strength was enhanced by Ar sup + RF plasma precleaning. The Al/modified PI specimen failed cohesively in the polyimide. The polyimide curing conditions strongly affect the peel strength in the Al/modified PI system.

  16. Topotactic synthesis of strontium cobalt oxyhydride thin film with perovskite structure

    Science.gov (United States)

    Katayama, Tsukasa; Chikamatsu, Akira; Kamisaka, Hideyuki; Yokoyama, Yuichi; Hirata, Yasuyuki; Wadati, Hiroki; Fukumura, Tomoteru; Hasegawa, Tetsuya

    2015-10-01

    The substitution of hydride anions (H-) into transition metal oxides has recently become possible through topotactic reactions or high-pressure synthesis methods. However, the fabrication of oxyhydrides is still difficult because of their inherently less-stable frameworks. In this study, we successfully fabricated perovskite SrCoOxHy thin films via the topotactic hydride doping of brownmillerite SrCoO2.5 epitaxial thin films with CaH2. The perovskite-type cation framework was maintained during the topotactic treatment owing to epitaxial stabilization. Structural and chemical analyses accompanied by X-ray absorption spectroscopy measurements revealed that the doped hydride ions form a two-dimensional network of Co-H--Co bonds, in contrast to other reported perovskite oxyhydrides, SrMO3-xHx (M = Cr, Ti, V). The SrCoOxHy thin film exhibited insulating behavior and had a direct band gap of 2.1 eV. Thus, topotactic hydride doping of transition-metal-oxide thin films on suitable substrates is a promising method for the synthesis of new transition metal oxyhydrides.

  17. Topotactic synthesis of strontium cobalt oxyhydride thin film with perovskite structure

    Directory of Open Access Journals (Sweden)

    Tsukasa Katayama

    2015-10-01

    Full Text Available The substitution of hydride anions (H− into transition metal oxides has recently become possible through topotactic reactions or high-pressure synthesis methods. However, the fabrication of oxyhydrides is still difficult because of their inherently less-stable frameworks. In this study, we successfully fabricated perovskite SrCoOxHy thin films via the topotactic hydride doping of brownmillerite SrCoO2.5 epitaxial thin films with CaH2. The perovskite-type cation framework was maintained during the topotactic treatment owing to epitaxial stabilization. Structural and chemical analyses accompanied by X-ray absorption spectroscopy measurements revealed that the doped hydride ions form a two-dimensional network of Co-H−-Co bonds, in contrast to other reported perovskite oxyhydrides, SrMO3−xHx (M = Cr, Ti, V. The SrCoOxHy thin film exhibited insulating behavior and had a direct band gap of 2.1 eV. Thus, topotactic hydride doping of transition-metal-oxide thin films on suitable substrates is a promising method for the synthesis of new transition metal oxyhydrides.

  18. Theoretical studies of epitaxially grown Co and Ni thin films on (111) metallic substrates

    Czech Academy of Sciences Publication Activity Database

    Zelený, Martin; Šob, Mojmír

    2008-01-01

    Roč. 77, č. 15 (2008), 155435/1-155435/6 ISSN 1098-0121 R&D Projects: GA AV ČR IAA1041302; GA ČR GD106/05/H008; GA MŠk OC 147 Institutional research plan: CEZ:AV0Z20410507 Keywords : Thin metallic films * Ab initio calculations * Electronic structure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.322, year: 2008

  19. 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.

  20. Strategies to prepare TiO2 thin films, doped with transition metal ions, that exhibit specific physicochemical properties to support osteoblast cell adhesion and proliferation

    International Nuclear Information System (INIS)

    Dhayal, Marshal; Kapoor, Renu; Sistla, Pavana Goury; Pandey, Ravi Ranjan; Kar, Satabisha; Saini, Krishan Kumar; Pande, Gopal

    2014-01-01

    Metal ion doped titanium oxide (TiO 2 ) thin films, as bioactive coatings on metal or other implantable materials, can be used as surfaces for studying the cell biological properties of osteogenic and other cell types. Bulk crystallite phase distribution and surface carbon–oxygen constitution of thin films, play an important role in determining the biological responses of cells that come in their contact. Here we present a strategy to control the polarity of atomic interactions between the dopant metal and TiO 2 molecules and obtain surfaces with smaller crystallite phases and optimal surface carbon–oxygen composition to support the maximum proliferation and adhesion of osteoblast cells. Our results suggest that surfaces, in which atomic interactions between the dopant metals and TiO 2 were less polar, could support better adhesion, spreading and proliferation of cells. - Highlights: • Electrochemical properties of dopants control the nature of TiO 2 thin films. • A model explains the correlation of dopant properties and behaviour of TiO 2 films. • Dopants with less polar interaction with TiO 2 exhibit better biological activity

  1. Synthesis and characterization of three-dimensional transition metal ions doped zinc oxide based dilute magnetic semiconductor thin films

    Science.gov (United States)

    Samanta, Kousik

    Dilute magnetic semiconductors (DMS), especially 3d-transition metal (TM) doped ZnO based DMS materials are the most promising candidates for optoelectronics and spintronics applications; e.g. in spin light emitting diode (SLED), spin transistors, and spin field effect transistors (SFET), etc. In the present dissertation, thin films of Zn1-xTMxO (TM = Co2+, Cu2+, and Mn2+) were grown on (0001) oriented Al2O3 substrates by pulsed laser deposition (PLD) technique. The films were highly c-axis oriented, nearly single crystalline, and defects free for a limited concentration of the dilution of transition metal ions. In particular, we have obtained single crystalline phases of Zn1-xTMxO thin films for up to 10, 3, and 5 stoichiometric percentages of Co2+, Cu2+, and Mn2+ respectively. Raman micro-probe system was used to understand the structural and lattice dynamical properties at different physical conditions. The confinement of optical phonons in the disorder lattice was explained by alloy potential fluctuation (APF) using a spatial correlation (SC) model. The detailed analysis of the optical phonon behavior in disorder lattice confirmed the substitution of the transition metal ions in Zn 2+ site of the ZnO host lattice. The secondary phases of ZnCo 2O4, CuO, and ZnMn2O4 were detected in higher Co, Cu, and Mn doped ZnO thin films respectively; where as, XRD did not detect these secondary phases in the same samples. Room temperature ferromagnetism was observed in Co2+ and Cu2+ ions doped ZnO thin films with maximum saturation magnetization (Ms) of 1.0 and 0.76 muB respectively. The origin of the observed ferromagnetism in Zn1-xCoxO thin films was tested by the controlled introduction of shallow donors (Al) in Zn0.9-x Co0.1O:Alx (x = 0.005 and 0.01) thin films. The saturation magnetization for the 10% Co-doped ZnO (1.0 muB /Co) at 300K reduced (˜0.25 muB/Co) due to Al doping. The observed ferromagnetism and the reduction due to Al doping can be explained by the Bound

  2. The growth of the metallic ZrNx thin films on P-GaN substrate by pulsed laser deposition

    Science.gov (United States)

    Gu, Chengyan; Sui, Zhanpeng; Li, Yuxiong; Chu, Haoyu; Ding, Sunan; Zhao, Yanfei; Jiang, Chunping

    2018-03-01

    Although metal nitride thin films have attractive prospects in plasmonic applications due to its stable properties in harsh environments containing high temperatures, shock, and contaminants, the effect of deposition parameters on the properties of the metallic ZrN grown on III-N semiconductors by pulse laser deposition still lacks of detailed exploration. Here we have successfully prepared metallic ZrNx films on p-GaN substrate by pulsed laser deposition in N2 ambient of various pressures at a fixed substrate temperature (475 °C). It is found that the films exhibit quite smooth surfaces and (111) preferred orientation. The X-ray photoelectron spectroscopy measurements indicate that carbon contamination can be completely removed and oxygen contamination is significantly reduced on the film surfaces after cleaning using Ar+ sputtering. The N/Zr ratio increases from 0.64 to 0.75 when the N2 pressure increases from 0.5 Pa to 3 Pa. The optical reflectivity spectra measured by the UV-vis-NIR spectrophotometer show that the ZrNx is a typical and good metallic-like material and its metallic properties can be tuned with changing the film compositions.

  3. 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...

  4. TI--CR--AL--O thin film resistors

    Science.gov (United States)

    Jankowski, Alan F.; Schmid, Anthony P.

    2000-01-01

    Thin films of Ti--Cr--Al--O are used as a resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O.sub.2. Resistivity values from 10.sup.4 to 10.sup.10 Ohm-cm have been measured for Ti--Cr--Al--O film Ti--Cr--Al--O as a thin film resistor has been found to be thermodynamically stable, unlike other metal-oxide films. The Ti--Cr--Al--O film can be used as a vertical or lateral resistor, for example, as a layer beneath a field emission cathode in a flat panel display; or used to control surface emissivity, for example, as a coating on an insulating material such as vertical wall supports in flat panel displays.

  5. Semi-metallic polymers

    DEFF Research Database (Denmark)

    Bubnova, Olga; Khan, Zia Ullah; Wang, Hui

    2014-01-01

    Polymers are lightweight, flexible, solution-processable materials that are promising for low-cost printed electronics as well as for mass-produced and large-area applications. Previous studies demonstrated that they can possess insulating, semiconducting or metallic properties; here we report...... that polymers can also be semi-metallic. Semi-metals, exemplified by bismuth, graphite and telluride alloys, have no energy bandgap and a very low density of states at the Fermi level. Furthermore, they typically have a higher Seebeck coefficient and lower thermal conductivities compared with metals, thus being...... a Fermi glass to a semi-metal. The high Seebeck value, the metallic conductivity at room temperature and the absence of unpaired electron spins makes polymer semi-metals attractive for thermoelectrics and spintronics....

  6. Semi-transparent gold film as simultaneous surface heater and resistance thermometer for nucleate boiling studies

    International Nuclear Information System (INIS)

    Oker, E.; Merte, H. Jr.

    1981-01-01

    A large (22 x 25 mm) semi-transparent thin film of gold, approximately 400 A in thickness, is deposited on a glass substrate for simultaneous use as a heat source and resistance thermometer. Construction techniques and calibration procedures are described, and a sample application to a transient boiling process is included with simultaneous high speed photographs taken through the thin film from beneath

  7. Study of 'liquid gold' coatings: Thermal decomposition and formation of metallic thin films

    International Nuclear Information System (INIS)

    Deram, V.; Turrell, S.; Darque-Ceretti, E.; Aucouturier, M.

    2006-01-01

    Organo-metallic solutions called liquid gold are largely used to obtain thin gilded films which are employed for decorative, technological and functional uses. However, these films often prove to be fragile with respect to use, resulting in loss of brilliance or even eventual film removal. An understanding of the behaviour of the layers requires good knowledge of the materials themselves. The present work was undertaken to better understand the evolution of the structural properties of liquid gold as it undergoes heat-processing. Accordingly, we followed the thermal decomposition processes of liquid gold coatings and the formation of the gilded metal layer using a combination of experimental techniques. First, thermal analyses coupled with mass spectrometry and infrared spectroscopy gave information concerning the decomposition of the organic medium. It has been found that the process of film formation can be decomposed into three steps, the second of which is an abrupt transition between 300 and 350 deg. C. Details on this transition have been obtained using real-time X-ray Diffraction and Rutherford Backscattering Spectrometry. Above 350 deg. C, the microstructure of the coating is reorganized to obtain a final layer which contains particles, of the size of a few hundreds nanometers, as shown by Transmission Electron Microscopy

  8. Applicability of X-ray fluorescence spectroscopy as method to determine thickness and composition of stacks of metal thin films: A comparison with imaging and profilometry

    International Nuclear Information System (INIS)

    Vrielink, J.A.M.; Tiggelaar, R.M.; Gardeniers, J.G.E.; Lefferts, L.

    2012-01-01

    In this work the applicability of X-ray fluorescence spectroscopy (XRF) for fast, accurate and non-destructive determination of the thickness of a variety of single-layer and multi-layer metal thin films deposited on glass and silicon is investigated. Data obtained with XRF is compared with information from profilometry and images from scanning electron microscopy (SEM). Whereas thickness determinations based on profilometry and cross-sectional SEM-imaging have restrictions with respect to thickness of metal stacks or hardness of the metals, XRF has no such limitations. Moreover, XRF can discriminate between sublayers in a multi-layer film, and can also be utilized for compositional analysis and density estimations. Good agreement between thickness data obtained with XRF, profilometry and SEM-images is found, under the justifiable assumption that the density of sputter-deposited and evaporated thin films is ca. 5% below that of bulk metals. Similar XRF-results are found for non-patterned areas (64 mm 2 metal) as well as lithographically patterned areas containing a series of small metal lines (total metal surface ca. 8 mm 2 ). As a consequence, it is concluded that XRF is a versatile technique for analysis, verification, control or evaluation of the thickness, density or (elemental) composition of thin metal film line-patterns, during their fabrication as well as prior or post to applications.

  9. Ultrahigh stability of atomically thin metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Cao, C. R.; Huang, K. Q.; Zhao, N. J.; Sun, Y. T.; Bai, H. Y.; Gu, L., E-mail: l.gu@iphy.ac.cn, E-mail: dzheng@iphy.ac.cn, E-mail: whw@iphy.ac.cn; Zheng, D. N., E-mail: l.gu@iphy.ac.cn, E-mail: dzheng@iphy.ac.cn, E-mail: whw@iphy.ac.cn; Wang, W. H., E-mail: l.gu@iphy.ac.cn, E-mail: dzheng@iphy.ac.cn, E-mail: whw@iphy.ac.cn [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-07-07

    We report the fabrication and study of thermal stability of atomically thin ZrCu-based metallic glass films. The ultrathin films exhibit striking dynamic properties, ultrahigh thermal stability, and unique crystallization behavior with discrete crystalline nanoparticles sizes. The mechanisms for the remarkable high stability and crystallization behaviors are attributed to the dewetting process of the ultrathin film. We demonstrated a promising avenue for understanding some fundamental issues such as glassy structure, crystallization, deformation, and glass formation through atomic resolution imaging of the two dimensional like metallic glasses.

  10. Dewetting of thin films on flexible substrates via direct-write laser exposure

    Science.gov (United States)

    Ferrer, Anthony Jesus

    Microelectromechanical systems (MEMS) have enabled a wide variety of technologies both in the consumer space and in industrial/research areas. At the market level, such devices advance by the invention and innovation of production techniques. Additionally, there has been increased demand for flexible versions of such MEMS devices. Thin film patterning, represents a key technology for the realization of such flexible electronics. Patterns and methods that can be directly written into the thin film allow for design modification on the fly with the need for harsh chemicals and long etching steps. Laser-induced dewetting has the potential to create patterns in thin films at both the microscopic and nanoscopic level without wasting deposited material. This thesis presents the first demonstration of high-speed direct-write patterning of metallic thin films that uses a laser-induced dewetting phenomenon to prevent material loss. The ability to build film material with this technique is explored using various scanning geometries. Finally, demonstrations of direct-write dewetting of a variety of thin films will be presented with special consideration for high melting point metals deposited upon polymer substrates.

  11. 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

  12. Reliability of vibration energy harvesters of metal-based PZT thin films

    Science.gov (United States)

    Tsujiura, Y.; Suwa, E.; Kurokawa, F.; Hida, H.; Kanno, I.

    2014-11-01

    This paper describes the reliability of piezoelectric vibration energy harvesters (PVEHs) of Pb(Zr,Ti)O3 (PZT) thin films on metal foil cantilevers. The PZT thin films were directly deposited onto the Pt-coated stainless-steel (SS430) cantilevers by rf-magnetron sputtering, and we observed their aging behavior of power generation characteristics under the resonance vibration condition for three days. During the aging measurement, there was neither fatigue failure nor degradation of dielectric properties in our PVEHs (length: 13 mm, width: 5.0 mm, thickness: 104 μm) even under a large excitation acceleration of 25 m/s2. However, we observed clear degradation of the generated electric voltage depending on excitation acceleration. The decay rate of the output voltage was 5% from the start of the measurement at 25 m/s2. The transverse piezoelectric coefficient (e31,f) also degraded with almost the same decay rate as that of the output voltage; this indicates that the degradation of output voltage was mainly caused by that of piezoelectric properties. From the decay curves, the output powers are estimated to degrade 7% at 15 m/s2 and 36% at 25 m/s2 if we continue to excite the PVEHs for 30 years.

  13. Reliability of vibration energy harvesters of metal-based PZT thin films

    International Nuclear Information System (INIS)

    Tsujiura, Y; Suwa, E; Kurokawa, F; Hida, H; Kanno, I

    2014-01-01

    This paper describes the reliability of piezoelectric vibration energy harvesters (PVEHs) of Pb(Zr,Ti)O 3 (PZT) thin films on metal foil cantilevers. The PZT thin films were directly deposited onto the Pt-coated stainless-steel (SS430) cantilevers by rf-magnetron sputtering, and we observed their aging behavior of power generation characteristics under the resonance vibration condition for three days. During the aging measurement, there was neither fatigue failure nor degradation of dielectric properties in our PVEHs (length: 13 mm, width: 5.0 mm, thickness: 104 μm) even under a large excitation acceleration of 25 m/s 2 . However, we observed clear degradation of the generated electric voltage depending on excitation acceleration. The decay rate of the output voltage was 5% from the start of the measurement at 25 m/s 2 . The transverse piezoelectric coefficient (e 31,f ) also degraded with almost the same decay rate as that of the output voltage; this indicates that the degradation of output voltage was mainly caused by that of piezoelectric properties. From the decay curves, the output powers are estimated to degrade 7% at 15 m/s 2 and 36% at 25 m/s 2 if we continue to excite the PVEHs for 30 years

  14. Antimicrobial properties of Zr–Cu–Al–Ag thin film metallic glass

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hsien-Wei; Hsu, Kai-Chieh; Chan, Yu-Chen [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan (China); Duh, Jenq-Gong, E-mail: jgd@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan (China); Lee, Jyh-Wei [Department of Materials Engineering, Ming Chi University of Technology, Taipei, Taiwan (China); Center for Thin Film Technologies and Applications, Mingchi University of Technology, Taipei, Taiwan (China); Jang, Jason Shian-Ching [Department of Mechanical Engineering, Institute of Materials Science and Engineering, National Central University, Chung-Li, Taiwan (China); Chen, Guo-Ju [Department of Materials Science and Engineering, I-Shou University, Kaohsiung, Taiwan (China)

    2014-06-30

    Metallic glass as a prominent class of structure and multifunctional materials exhibits several unique properties in mechanical, electrochemical, and thermal properties. This study aimed to realize the advantage of biomedical application and to promote the attainable size of metallic glasses by the physical vapor deposition. The Zr–Cu–Al–Ag thin film metallic glass (TFMG) was deposited on silicon wafer and SUS304 stainless steel substrates by magnetron sputtering with single target. For X-ray diffraction analysis, all TFMGs revealed typical broad peaks around the incident angle of 30 to 50°, suggesting that coatings possess amorphous structure. In addition, diffuse halo ring patterns of transmission electron microscopy indicated a fine amorphorization for TFMG via sputtering process. The variation of surface roughness showed that TFMG derived from higher power of metallic targets revealed rougher morphology. Besides, the roughness of SUS304 stainless steel substrate significantly reduced from 7 nm to about 1 nm after TFMGs were deposited. The microbes of Candida albicans, Escherichia coli, and Pseudomonas aeruginosa were used and cultivated on the TFMG coatings with medium to investigate the antimicrobial properties. In the incubation experiment, the growth of each microbe was recorded by a digital photography system and the growth area was calculated by image processing software. The growth area of the microbes on the TFMG was mostly smaller than that on SUS304 stainless steel ones within incubation time of 72 h, indicating that the TFMGs reveal better antimicrobial capability. Moreover, the coatings exhibit a particularly long-term antimicrobial effect for P. aeruginosa. In summary, the Zr–Cu–Al–Ag prepared by sputtering with a single target device presented superior glass forming ability, and coatings with copper and silver constituents revealed significantly antimicrobial properties. Besides, the surface roughness is another factor to affect the

  15. Antimicrobial properties of Zr–Cu–Al–Ag thin film metallic glass

    International Nuclear Information System (INIS)

    Chen, Hsien-Wei; Hsu, Kai-Chieh; Chan, Yu-Chen; Duh, Jenq-Gong; Lee, Jyh-Wei; Jang, Jason Shian-Ching; Chen, Guo-Ju

    2014-01-01

    Metallic glass as a prominent class of structure and multifunctional materials exhibits several unique properties in mechanical, electrochemical, and thermal properties. This study aimed to realize the advantage of biomedical application and to promote the attainable size of metallic glasses by the physical vapor deposition. The Zr–Cu–Al–Ag thin film metallic glass (TFMG) was deposited on silicon wafer and SUS304 stainless steel substrates by magnetron sputtering with single target. For X-ray diffraction analysis, all TFMGs revealed typical broad peaks around the incident angle of 30 to 50°, suggesting that coatings possess amorphous structure. In addition, diffuse halo ring patterns of transmission electron microscopy indicated a fine amorphorization for TFMG via sputtering process. The variation of surface roughness showed that TFMG derived from higher power of metallic targets revealed rougher morphology. Besides, the roughness of SUS304 stainless steel substrate significantly reduced from 7 nm to about 1 nm after TFMGs were deposited. The microbes of Candida albicans, Escherichia coli, and Pseudomonas aeruginosa were used and cultivated on the TFMG coatings with medium to investigate the antimicrobial properties. In the incubation experiment, the growth of each microbe was recorded by a digital photography system and the growth area was calculated by image processing software. The growth area of the microbes on the TFMG was mostly smaller than that on SUS304 stainless steel ones within incubation time of 72 h, indicating that the TFMGs reveal better antimicrobial capability. Moreover, the coatings exhibit a particularly long-term antimicrobial effect for P. aeruginosa. In summary, the Zr–Cu–Al–Ag prepared by sputtering with a single target device presented superior glass forming ability, and coatings with copper and silver constituents revealed significantly antimicrobial properties. Besides, the surface roughness is another factor to affect the

  16. Ultra thin metallic coatings to control near field radiative heat transfer

    Science.gov (United States)

    Esquivel-Sirvent, R.

    2016-09-01

    We present a theoretical calculation of the changes in the near field radiative heat transfer between two surfaces due to the presence of ultra thin metallic coatings on semiconductors. Depending on the substrates, the radiative heat transfer is modulated by the thickness of the ultra thin film. In particular we consider gold thin films with thicknesses varying from 4 to 20 nm. The ultra-thin film has an insulator-conductor transition close to a critical thickness of dc = 6.4 nm and there is an increase in the near field spectral heat transfer just before the percolation transition. Depending on the substrates (Si or SiC) and the thickness of the metallic coatings we show how the near field heat transfer can be increased or decreased as a function of the metallic coating thickness. The calculations are based on available experimental data for the optical properties of ultrathin coatings.

  17. Thin film heat flux sensors for accurate transient and unidirectional heat transfer analysis

    International Nuclear Information System (INIS)

    Azerou, B; Garnier, B; Lahmar, J

    2012-01-01

    Heat flux measurement is needed in many heat transfer studies. For the best unbiased heat flux sensors (HFS), the heat flux is obtained using temperature measurements at different locations and also an inverse heat conduction method (function specification...) in order to calculate the heat flux. Systematic errors can come from the uncertainty in the wire thermocouples locations and from errors in the knowledge of distances between two consecutive wire thermocouples. The main idea in this work is to use thin film thermoresistances deposited on a flexible thin polymer substrate instead of wire thermocouples welded on metallic sample. The interest of using thin film thermoresistances instead of wire thermocouples is a lower disturbance due to the smaller thickness of the thin film sensors (typically less than 1μm) and a much better knowledge of the distances between the different thin film thermoresistances which are precisely defined in the mask used for the metallic thin film pattern fabrication. In this paper, we present the fabrication of the new heat flux sensor with thin film thermoresistances, the study of the effect of the self heating (due to Joule effect in thermoresistances) and the performances of this new HFS with the comparison with classical HFS using wire thermocouples. For this study, a symmetric experimental setup is used with metallic samples equipped with an etched foil heater and both classical and new HFS. For several heating conditions, it appears that a better accuracy is always obtained with the new HFS using thin film thermoresistances.

  18. Resistivity behavior of optimized PbTiO3 thin films prepared by spin coating method

    Science.gov (United States)

    Nurbaya, Z.; Wahid, M. H.; Rozana, M. D.; Alrokayan, S. A. H.; Khan, H. A.; Rusop, M.

    2018-05-01

    Th is study presents the resistivity behavior of PbTiO3 thin films which were prepared towards metal-insulator-metal capacitor device fabrication. The PbTiO3 thin films were prepared through sol-gel spin coating method that involved various deposition parameters that is (1) different molar concentration of PbTiO3 solutions, (2) various additional PbAc-content in PbTiO3 solutions, and (3) various annealing temperature on PbTiO3 thin films. Hence, an electrical measurement of current versus voltage was done to determine the resistivity behavior of PbTiO3 thin films.

  19. Bi2O3 nanoparticles encapsulated in surface mounted metal-organic framework thin films

    Science.gov (United States)

    Guo, Wei; Chen, Zhi; Yang, Chengwu; Neumann, Tobias; Kübel, Christian; Wenzel, Wolfgang; Welle, Alexander; Pfleging, Wilhelm; Shekhah, Osama; Wöll, Christof; Redel, Engelbert

    2016-03-01

    We describe a novel procedure to fabricate a recyclable hybrid-photocatalyst based on Bi2O3@HKUST-1 MOF porous thin films. Bi2O3 nanoparticles (NPs) were synthesized within HKUST-1 (or Cu3(BTC)2) surface-mounted metal-organic frame-works (SURMOFs) and characterized using X-ray diffraction (XRD), a quartz crystal microbalance (QCM) and transmission electron microscopy (TEM). The Bi2O3 semiconductor NPs (diameter 1-3 nm)/SURMOF heterostructures exhibit superior photo-efficiencies compared to NPs synthesized using conventional routes, as demonstrated via the photodegradation of the nuclear fast red (NFR) dye.We describe a novel procedure to fabricate a recyclable hybrid-photocatalyst based on Bi2O3@HKUST-1 MOF porous thin films. Bi2O3 nanoparticles (NPs) were synthesized within HKUST-1 (or Cu3(BTC)2) surface-mounted metal-organic frame-works (SURMOFs) and characterized using X-ray diffraction (XRD), a quartz crystal microbalance (QCM) and transmission electron microscopy (TEM). The Bi2O3 semiconductor NPs (diameter 1-3 nm)/SURMOF heterostructures exhibit superior photo-efficiencies compared to NPs synthesized using conventional routes, as demonstrated via the photodegradation of the nuclear fast red (NFR) dye. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00532b

  20. In-Plane Impedance Spectroscopy measurements in Vanadium Dioxide thin films

    Science.gov (United States)

    Ramirez, Juan; Patino, Edgar; Schmidt, Rainer; Sharoni, Amos; Gomez, Maria; Schuller, Ivan

    2012-02-01

    In plane Impedance Spectroscopy measurements have been done in Vanadium Dioxide thin films in the range of 100 Hz to 1 MHz. Our measurements allows distinguishing between the resistive and capacitive response of the Vanadium Dioxide films across the metal-insulator transition. A non ideal RC behavior was found in our thin films from room temperature up to 334 K. Around the MIT, an increase of the total capacitance is observed. A capacitor-network model is able to reproduce the capacitance changes across the MIT. Above the MIT, the system behaves like a metal as expected, and a modified equivalent circuit is necessary to describe the impedance data adequately.

  1. Directed self-assembly of nanoporous metallic- and bimetallic nanoparticle thin films

    Energy Technology Data Exchange (ETDEWEB)

    Pietsch, Torsten [Fachbereich Physik, Universitaet Konstanz (Germany); Gindy, Nabil; Fahmi, Amir [Department of Mechanical, Materials and Manufacturing Engineering, University of Nottingham (United Kingdom)

    2010-07-01

    Nanoporous thin films attracted considerable interest due to potential applications in optical coatings, catalysis, sensors as well as electronic devices. Recently, such films were prepared by post deposition treatments. The present study is focused on the fabrication of nanoporous thin films via directed self-assembly of hybrid materials. Due to the nature of this process no additional treatments are necessary to develop the pores. Hierarchical nanoporous structures are fabricated directly via deposition of polymer templated Au-nanoparticles onto hydrophilic substrates. These films exhibit two different pore diameters and a total pore density of more than 10{sup 10} holes per cm{sup 2}. Control over the pore size is achieved by changing the molecular weight of the PS-b-P4VP diblock copolymer. Moreover, the porous morphology is used as a template to fabricate bimetallic nanostructured thin films. Such well-defined nanostructures, not only exhibit unique physical properties but also provide control over the hydrophobicity of the coated surfaces.

  2. Fabrication and non-covalent modification of highly oriented thin films of a zeolite-like metal-organic framework (ZMOF) with rho topology

    KAUST Repository

    Shekhah, Osama

    2015-01-01

    Here we report the fabrication of the first thin film of a zeolite-like metal-organic framework (ZMOF) with rho topology (rho-ZMOF-1, ([In48(HImDC)96]48-)n) in a highly oriented fashion on a gold-functionalized substrate. The oriented rho-ZMOF-1 film was functionalized by non-covalent modification via post-synthetic exchange of different probe molecules, such as acridine yellow, methylene blue, and Nile red. In addition, encapsulation of a porphyrin moiety was achieved via in situ synthesis and construction of the rho-ZMOF. Adsorption kinetics of volatile organic compounds on rho-ZMOF-1 thin films was also investigated. This study suggests that rho-ZMOF-1 thin films can be regarded as a promising platform for various applications such as sensing and catalysis. This journal is

  3. Transferred metal electrode films for large-area electronic devices

    International Nuclear Information System (INIS)

    Yang, Jin-Guo; Kam, Fong-Yu; Chua, Lay-Lay

    2014-01-01

    The evaporation of metal-film gate electrodes for top-gate organic field-effect transistors (OFETs) limits the minimum thickness of the polymer gate dielectric to typically more than 300 nm due to deep hot metal atom penetration and damage of the dielectric. We show here that the self-release layer transfer method recently developed for high-quality graphene transfer is also capable of giving high-quality metal thin-film transfers to produce high-performance capacitors and OFETs with superior dielectric breakdown strength even for ultrathin polymer dielectric films. Dielectric breakdown strengths up to 5–6 MV cm −1 have been obtained for 50-nm thin films of polystyrene and a cyclic olefin copolymer TOPAS ® (Zeon). High-quality OFETs with sub-10 V operational voltages have been obtained this way using conventional polymer dielectrics and a high-mobility polymer semiconductor poly[2,5-bis(3-tetradecylthiophene-2-yl)thieno[3,2-b]thiophene-2,5-diyl]. The transferred metal films can make reliable contacts without damaging ultrathin polymer films, self-assembled monolayers and graphene, which is not otherwise possible from evaporated or sputtered metal films

  4. Topotactic synthesis of strontium cobalt oxyhydride thin film with perovskite structure

    Energy Technology Data Exchange (ETDEWEB)

    Katayama, Tsukasa [Department of Chemistry, The University of Tokyo, Tokyo 113-0033 (Japan); Chikamatsu, Akira, E-mail: chikamatsu@chem.s.u-tokyo.ac.jp; Kamisaka, Hideyuki [Department of Chemistry, The University of Tokyo, Tokyo 113-0033 (Japan); CREST, Japan Science and Technology Agency (JST), Tokyo 113-0033 (Japan); Yokoyama, Yuichi; Hirata, Yasuyuki; Wadati, Hiroki [Institute for Solid State Physics, The University of Tokyo, Chiba 277-8581 (Japan); Fukumura, Tomoteru [CREST, Japan Science and Technology Agency (JST), Tokyo 113-0033 (Japan); Department of Chemistry, Tohoku University, Miyagi 980-8578 (Japan); Hasegawa, Tetsuya [Department of Chemistry, The University of Tokyo, Tokyo 113-0033 (Japan); CREST, Japan Science and Technology Agency (JST), Tokyo 113-0033 (Japan); Kanagawa Academy of Science and Technology (KAST), Kawasaki 213-0012 (Japan)

    2015-10-15

    The substitution of hydride anions (H{sup −}) into transition metal oxides has recently become possible through topotactic reactions or high-pressure synthesis methods. However, the fabrication of oxyhydrides is still difficult because of their inherently less-stable frameworks. In this study, we successfully fabricated perovskite SrCoO{sub x}H{sub y} thin films via the topotactic hydride doping of brownmillerite SrCoO{sub 2.5} epitaxial thin films with CaH{sub 2}. The perovskite-type cation framework was maintained during the topotactic treatment owing to epitaxial stabilization. Structural and chemical analyses accompanied by X-ray absorption spectroscopy measurements revealed that the doped hydride ions form a two-dimensional network of Co-H{sup −}-Co bonds, in contrast to other reported perovskite oxyhydrides, SrMO{sub 3−x}H{sub x} (M = Cr, Ti, V). The SrCoO{sub x}H{sub y} thin film exhibited insulating behavior and had a direct band gap of 2.1 eV. Thus, topotactic hydride doping of transition-metal-oxide thin films on suitable substrates is a promising method for the synthesis of new transition metal oxyhydrides.

  5. Structure and electronic properties of ordered binay thin-film compounds of rare earths with transition metals

    International Nuclear Information System (INIS)

    Schneider, W.

    2004-01-01

    The present thesis deals with preparation of structurally ordered thin-film compounds of the rare-earths Ce and Dy with the transition metals Pd, Rh, and Ni as well as with investigations of their crystalline and electronic structures. Typically 10 nm-thick films were grown in-situ by deposition of the rare-earth metals onto single crystalline transitionmetal substrates or alternatively by codeposition of both constituents onto a W(110) single crystal. In both cases deposition was followed by short-term annealing at temperatures of 400-1000 C to achieve crystalline order. The latter was analyzed by means of low-energy electron-diffraction (LEED) and evaluated on the basis of a simple kinematic theory. The electronic structure was investigated by means of angle-resolved photoemission (ARPES), partially exploiting synchrotron radiation from BESSY. The studies concentrate mainly on the behavior of the valence bands as a function of structure and composition of the thin films, particularly under consideration of surface phenomena. Measured energy dispersions were compared with results of LDA-LCAO calculations performed in the framework of this thesis. Observed shifts of the energy bands by up to 1 eV are attributed in the light of a simple model to incomplete screening of the photoemission final states. (orig.)

  6. Energetic Surface Smoothing of Complex Metal-Oxide Thin Films

    International Nuclear Information System (INIS)

    Willmott, P.R.; Herger, R.; Schlepuetz, C.M.; Martoccia, D.; Patterson, B.D.

    2006-01-01

    A novel energetic smoothing mechanism in the growth of complex metal-oxide thin films is reported from in situ kinetic studies of pulsed laser deposition of La 1-x Sr x MnO 3 on SrTiO 3 , using x-ray reflectivity. Below 50% monolayer coverage, prompt insertion of energetic impinging species into small-diameter islands causes them to break up to form daughter islands. This smoothing mechanism therefore inhibits the formation of large-diameter 2D islands and the seeding of 3D growth. Above 50% coverage, islands begin to coalesce and their breakup is thereby suppressed. The energy of the incident flux is instead rechanneled into enhanced surface diffusion, which leads to an increase in the effective surface temperature of ΔT≅500 K. These results have important implications on optimal conditions for nanoscale device fabrication using these materials

  7. Influence of oxygen flow rate on metal-insulator transition of vanadium oxide thin films grown by RF magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xu; Liu, Xinkun; Li, Haizhu; Huang, Mingju [Henan University, Key Lab of Informational Opto-Electronical Materials and Apparatus, School of Physics and Electronics, Kaifeng (China); Zhang, Angran [South China Normal University, Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, Guangzhou (China)

    2017-03-15

    High-quality vanadium oxide (VO{sub 2}) films have been fabricated on Si (111) substrates by radio frequency (RF) magnetron sputtering deposition method. The sheet resistance of VO{sub 2} has a significant change (close to 5 orders of magnitude) in the process of the metal-insulator phase transition (MIT). The field emission-scanning electron microscope (FE-SEM) results show the grain size of VO{sub 2} thin films is larger with the increase of oxygen flow. The X-ray diffraction (XRD) results indicate the thin films fabricated at different oxygen flow rates grow along the (011) crystalline orientation. As the oxygen flow rate increases from 3 sccm to 6 sccm, the phase transition temperature of the films reduces from 341 to 320 K, the width of the thermal hysteresis loop decreases from 32 to 9 K. The thin films fabricated in the condition of 5 sccm have a high temperature coefficient of resistance (TCR) -3.455%/K with a small resistivity of 2.795 ρ/Ω cm. (orig.)

  8. Thin films of molecular materials synthesized from fisher's carbene ferrocenyl: Film formation and electrical properties

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Vergara, M.E. [Coordinacion de Ingenieria Mecatronica. Escuela de Ingenieria, Universidad Anahuac del Norte. Avenida Lomas de la Anahuac s/n, Col. Lomas Anahuac, 52786, Huixquilucan (Mexico)], E-mail: elena.sanchez@anahuac.mx; Ortiz, A. [Instituto de Investigaciones en Materiales. Universidad Nacional Autonoma de Mexico. A. P. 70-360, 04510, Mexico, DF (Mexico); Alvarez-Toledano, C.; Moreno, A. [Instituto de Quimica, Universidad Nacional Autonoma de Mexico. Circuito Exterior, Ciudad Universitaria, 04510, Mexico, DF (Mexico); Alvarez, J.R. [Instituto Tecnologico y de Estudios Superiores de Monterrey, Campus Ciudad de Mexico. Calle del Puente 222, Col. Ejidos de Huipulco, 14380, Mexico, DF (Mexico)

    2008-07-31

    The synthesis of materials from Fisher's carbene ferrocenyl of the elements chromium, molybdenum and tungsten was carried out. The Fisher's compounds that were synthesized included the following combinations of two different metallic atoms: iron with chromium, iron with molybdenum and iron with tungsten. The molecular solids' preparation was done in electro-synthesis cells with platinum electrodes. Thin films were prepared by vacuum thermal evaporation on quartz substrates and crystalline silicon wafers. Pellets and thin films from these compounds were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive spectroscopy, atomic force microscopy and ellipsometry. The powder and thin films synthesized from these materials show the same intra-molecular bonds shown by infrared spectroscopy results, suggesting that thermal evaporation does not alter these bonds in spite of the thin films being amorphous, in contrast with other bimetallic complexes where material decomposition occurs. The differences in the conductivity values of the prepared films are very small, so they may be attributed to the different metallic ions employed in each case. The tungsten complex exhibits a higher conductivity than the molybdenum and chromium complexes at room temperature. Electrical conductivity values found for thin films are higher than for pellets made of the same molecular materials.

  9. Gold nanoparticle plasmon resonance in near-field coupled Au NPs layer/Al film nanostructure: Dependence on metal film thickness

    Science.gov (United States)

    Yeshchenko, Oleg A.; Kozachenko, Viktor V.; Naumenko, Antonina P.; Berezovska, Nataliya I.; Kutsevol, Nataliya V.; Chumachenko, Vasyl A.; Haftel, Michael; Pinchuk, Anatoliy O.

    2018-05-01

    We study the effects of coupling between plasmonic metal nanoparticles and a thin metal film by using light extinction spectroscopy. A planar monolayer of gold nanoparticles located near an aluminum thin film (thicknesses within the range of 0-62 nm) was used to analyze the coupling between the monolayer and the thin metal film. SPR peak area increase for polymer coated Au NPs, non-monotonical behavior of the peak area for bare Au NPs, as well as red shift and broadening of SPR at the increase of the Al film thickness have been observed. These effects are rationalized as a result of coupling of the layer of Au NPs with Al film through the field of localized surface plasmons in Au NPs that causes the excitation of collective plasmonic gap mode in the nanostructure. An additional mechanism for bare Au NPs is the non-radiative damping of SPR that is caused by the electrical contact between metal NPs and film.

  10. Solar selective performance of metal nitride/oxynitride based magnetron sputtered thin film coatings: a comprehensive review

    Science.gov (United States)

    Ibrahim, Khalil; Taha, Hatem; Mahbubur Rahman, M.; Kabir, Humayun; Jiang, Zhong-Tao

    2018-03-01

    Since solar-thermal collectors are considered to be the most direct way of converting solar energy into usable forms, in the last few years growing attention has been paid to the development of transition metal nitride and metal oxynitride based thin film selective surfaces for solar-thermal collectors, in order to harvest more solar energy. A solar-thermal energy system, generally, shows very high solar absorption of incident solar radiation from the solar-thermal collectors in the visible range (0.3 to 2.5 μm) and extremely low thermal losses through emission (or high reflection) in the infrared region (≥2.5 μm). The efficiency of a solar-thermal energy conversion system can be improved by the use of solar selective surfaces consisting of novel metallic nanoparticles embedded in metal nitride/oxynitride systems. In order to enhance the effectiveness of solar-thermal devices, solar selective surfaces with high thermal stability are a prerequisite. Over the years, substantial efforts have been made in the field of solar selective surfaces to attain higher solar absorptance and lower thermal emittance in high temperature (above 400 °C) applications. In this article, we review the present state-of-the-art transition metal nitride and/or oxynitride based vacuum sputtered nanostructured thin film coatings, with respect to their optical and solar selective surface applications. We have also summarized the solar selectivity data from recently published investigations, including discussion on some potential applications for these materials.

  11. Expandable and retractable self-rolled structures based on metal/polymer thin film for flow sensing

    Science.gov (United States)

    Zhu, Jianzhong; White, Carl; Saadat, Mehdi; Bart-Smith, Hilary

    2015-11-01

    Most aquatic animals such as fish rely heavily on their ability of detect and respond to ambient flows in order to explore and inhabit various habitats or survive predator-prey encounters. Fish utilize neuromasts in their skin surface and lateral lines in their bodies to align themselves while swimming upstream for migration, avoid obstacles, reduce locomotion cost, and detect flow variations caused by potential predators. In this study, a thin film MEMS sensor analogous to a fish neuromast has been designed for flow sensing. Residual stress arises in many thin film materials during processing. Metal and polymer thin film materials with a significant difference in elastic modular were chosen to form a multiple-layer structure. Upon releasing, the structure rolls into a tube due to mechanical property mismatch. The self-rolled tube can expand or retract, depending on the existence of external force such as flow. An embedded strain sensor detects the deformation of the tube and hence senses the ambient flow. Numerical simulations were conducted to optimize the structural design. Experiments were performed in a flow tank to quantify the performance of the sensor. This research is supported by the Office of Naval Research under the MURI Grant N00014-14-1-0533.

  12. 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/...

  13. Alkali semi-metal films and method and apparatus for fabricating them

    Energy Technology Data Exchange (ETDEWEB)

    Bhandari, Harish B.; Nagarkar, Vivek V.; Ovechkina, Olena E.; Frisch, Henry J.; Attenkofer, Klaus; Smedley, John M.

    2018-03-13

    Methods and systems for fabricating a film, such as, for example, a photocathode, having a tailored band structure and thin-film components that can be tailored for specific applications, such as, for example photocathode having a high quantum efficiency, and simple components fabricated by those methods.

  14. 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.)

  15. Initial liquid metal magnetohydrodynamic thin film flow experiments in the MeGA-loop facility at UCLA

    International Nuclear Information System (INIS)

    Morley, N.B.; Gaizer, A.A.; Tillack, M.S.; Abdou, M.A.

    1995-01-01

    Free surface thin film flows of liquid metal were investigated experimentally in the presence of a coplanar magnetic field. This investigation was performed in a new magnetohydrodynamic (MHD) flow facility, the MeGA-loop, utilizing a low melting temperature lead-bismuth alloy as the working metal. Owing to the relatively low magnetic field produced by the present field coil system, the ordinary hydrodynamic and low MHD interaction regimes only were investigated. At the high flow speeds necessary for self cooling, the importance of a well designed and constructed channel becomes obvious. Partial MHD drag, increasing the film height, is observed as Haβ 2 becomes greater than unity. MHD laminarization of the turbulent film flows is observed when Haβ/Re>0.002, but fully laminar flow was not reached. Suggestions for facility upgrades to achieve greater MHD interaction are presented in the context of these initial results. (orig.)

  16. RHEED transmission mode and pole figures thin film and nanostructure texture analysis

    CERN Document Server

    Wang, Gwo-Ching

    2014-01-01

    This unique book covers the fundamental principle of electron diffraction, basic instrumentation of RHEED, definitions of textures in thin films and nanostructures, mechanisms and control of texture formation, and examples of RHEED transmission mode measurements of texture and texture evolution of thin films and nanostructures. Also presented is a new application of RHEED in the transmission mode called RHEED pole figure technique that can be used to monitor the texture evolution in thin film growth and nanostructures and is not limited to single crystal epitaxial film growth. Details of the construction of RHEED pole figures and the interpretation of observed pole figures are presented.  Materials covered include metals, semiconductors, and thin insulators. This book also: Presents a new application of RHEED in the transmission mode Introduces a variety of textures from metals, semiconductors, compound semiconductors, and their characteristics in RHEED pole figures Provides examples of RHEED measurements o...

  17. Cu-based metal-organic framework thin films: A morphological and photovoltaic study

    Science.gov (United States)

    Khajavian, Ruhollah; Ghani, Kamal

    2018-06-01

    This work explores the layer-by-layer (LbL) fabrication of [Cu2(bdc)2(bpy)]n thin films by using pyridine and acetic acid as capping agents onto mesoporous titania surface. While in the presence of acetic acid highly-ordered crystals with nanoplate morphology are formed, modulation with pyridine gives rise to formation of leaf-like crystals. In addition, processing sequence also matters when modulator is added. According to our results, modulators should be added to metal solution rather than linker/pillar during LbL assembly. These films were subsequently shown to generate photocurrent in a sandwich-type Grätzel solar cell device in response to simulated 1 sun illumination. The results also demonstrated that the device consisted of well-aligned nanoplates exhibits higher power conversion efficiency than the similar cell with disordered leaf-like crystals after iodine loading.

  18. Chemical and Electronic Structure Studies of Refractory and Dielectric Thin Films.

    Science.gov (United States)

    Corneille, Jason Stephen

    This study presents the synthesis and characterization of oxide and refractory thin films under varying conditions. The deposition of the thin films is performed under vacuum conditions. The characterization of the growth, as well as the chemical and electronic properties of the thin films was accomplished using a broad array of surface analytical techniques. These model studies describe the relationship between the preparative processes and the stoichiometry, structure and electronic properties of the film products. From these efforts, the optimal deposition conditions for the production of high quality films have been established. The thin film oxides synthesized and studied here include magnesium oxide, silicon oxide and iron oxide. These oxides were synthesized on a refractory substrate using both post oxidation of thin films as well as reactive vapor deposition of the metals in the presence of an oxygen background. Comparisons and contrasts are presented for the various systems. Metallic magnesium films were grown and characterized as a preliminary study to the synthesis of magnesium oxide. Magnesium oxide (MgO(100)) was synthesized on Mo(100) by evaporating magnesium at a rate of one monolayer per minute in an oxygen background pressure of 1 times 10 ^{-6} Torr at room temperature. The resulting film was found to exhibit spectroscopic characteristics quite similar to those observed for bulk MgO. The acid/base characteristics of the films were studied using carbon monoxide, water and methanol as probe molecules. The film was found to exhibit essentially the same chemical properties as found in analogous powdered catalysts. Silicon dioxide was synthesized by evaporating silicon onto Mo(100) in an oxygen ambient. It is shown that the silicon oxide prepared at room temperature with a silicon deposition rate of {~ }{1.2}A/min and an oxygen pressure of 2 times 10^{ -8} Torr, consisted of predominantly silicon dioxide with a small fraction of suboxides. Annealing to

  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. 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.

  1. Optical properties of amorphous Ba0.7Sr0.3TiO3 thin films obtained by metal organic decomposition technique

    Science.gov (United States)

    Qiu, Fei; Xu, Zhimou

    2009-08-01

    In this study, the amorphous Ba0.7Sr0.3TiO3 (BST0.7) thin films were grown onto fused quartz and silicon substrates at low temperature by using a metal organic decomposition (MOD)-spin-coating procedure. The optical transmittance spectrum of amorphous BST0.7 thin films on fused quartz substrates has been recorded in the wavelength range 190~900 nm. The films were highly transparent for wavelengths longer than 330 nm; the transmission drops rapidly at 330 nm, and the cutoff wavelength occurs at about 260 nm. In addition, we also report the amorphous BST0.7 thin film groove-buried type waveguides with 90° bent structure fabricated on Si substrates with 1.65 μm thick SiO2 thermal oxide layer. The design, fabrication and optical losses of amorphous BST0.7 optical waveguides were presented. The amorphous BST0.7 thin films were grown onto the SiO2/Si substrates by using a metal organic decomposition (MOD)-spin-coating procedure. The optical propagation losses were about 12.8 and 9.4 dB/cm respectively for the 5 and 10 μm wide waveguides at the wavelength of 632.8 nm. The 90° bent structures with a small curvature of micrometers were designed on the basis of a double corner mirror structure. The bend losses were about 1.2 and 0.9 dB respectively for 5 and 10 μm wide waveguides at the wavelength of 632.8 nm. It is expected for amorphous BST0.7 thin films to be used not only in the passive optical interconnection in monolithic OEICs but also in active waveguide devices on the Si chip.

  2. Metallic behavior of NiS thin film under the structural, optical, electrical and ab initio investigation frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Boughalmi, R. [Unité de physique des dispositifs à semi-conducteurs, Faculté des sciences de Tunis, Tunis El Manar University, 2092 Tunis (Tunisia); Rahmani, R. [Laboratoire de Physique des Couches Minces et Matériaux pour l' Electronique (LPC2ME). Département de physique, Faculté des Sciences, Université d' Oran Es-Sénia, Oran (Algeria); Département de physique, Université des Sciences et de la Technologie d' Oran- Mohamed-Boudiaf, Oran (Algeria); Boukhachem, A., E-mail: abdelwaheb.boukhachem@laposte.net [Unité de physique des dispositifs à semi-conducteurs, Faculté des sciences de Tunis, Tunis El Manar University, 2092 Tunis (Tunisia); Amrani, B.; Driss-Khodja, K. [Laboratoire de Physique des Couches Minces et Matériaux pour l' Electronique (LPC2ME). Département de physique, Faculté des Sciences, Université d' Oran Es-Sénia, Oran (Algeria); Amlouk, M. [Unité de physique des dispositifs à semi-conducteurs, Faculté des sciences de Tunis, Tunis El Manar University, 2092 Tunis (Tunisia)

    2015-08-01

    Nickel sulfide (NiS) thin films were deposited on the glass substrates by spray pyrolysis at 250 °C using an aqueous solution which contains nickel chloride hexahydrate and thiourea as precursors. X-ray diffraction analysis confirms that the hexagonal structure is being part of P6{sub 3}/mmc space group of the deposited films with (100) preferred orientation and lattice parameters a = 3.441 Å and c = 5.320 Å. The optical properties, investigated through transmittance and reflectance measurements reveal that the direct band gap energy (Eg) is around 0.55 eV. The electrical study shows a metallic behavior of the current II-VI binary compound. This behavior regarding NiS II-VI binary sulfide was confirmed by numerical studies based on the density functional theory (DFT) were adopted. The ground state quantities, such as lattice parameter, bulk modulus and its pressure derivative as well as the elastic constants were obtained. The values are consistent with the stability of hexagonal structure. The band structure and the states densities of such material were studied. The results show that there is an agreement between experimental and simulation. - Highlights: • NiS thin films are synthesized by Spray pyrolysis. • NiS is a low band gap compound. • These films have interesting electrical properties showing a metallic behavior. • Computational study confirms the electrical measurements.

  3. A novel method to achieve selective emitter for silicon solar cell using low cost pattern-able a-Si thin films as the semi-transparent phosphorus diffusion barrier

    International Nuclear Information System (INIS)

    Chen, Da Ming; Liang, Zong Cun; Zhuang, Lin; Lin, Yang Huan; Shen, Hui

    2012-01-01

    Highlights: ► a-Si thin films as semitransparent phosphorus diffusion barriers for solar cell. ► a-Si thin films on silicon wafers were patterned by the alkaline solution. ► Selective emitter was formed with patterned a-Si as diffusion barrier for solar cell. -- Abstract: Selective emitter for silicon solar cell was realized by employing a-Si thin films as the semi-transparent diffusion barrier. The a-Si thin films with various thicknesses (∼10–40 nm) were deposited by the electron-beam evaporation technique. Emitters with sheet resistances from 37 to 145 Ω/□ were obtained via POCl 3 diffusion process. The thickness of the a-Si diffusion barrier was optimized to be 15 nm for selective emitter in our work. Homemade mask which can dissolve in ethanol was screen-printed on a-Si film to make pattern. The a-Si film was then patterned in KOH solution to form finger-like design. Selective emitter was obtainable with one-step diffusion with patterned a-Si film on. Combinations of sheet resistances for the high-/low-level doped regions of 39.8/112.1, 36.2/88.8, 35.4/73.9 were obtained. These combinations are suitable for screen-printed solar cells. This preparation method of selective emitter based on a-Si diffusion barrier is a promising approach for low cost industrial manufacturing.

  4. Thin film processes II

    CERN Document Server

    Kern, Werner

    1991-01-01

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

  5. Metal thin film growth on multimetallic surfaces: From quaternary metallic glass to binary crystal

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Dapeng [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    The work presented in this thesis mainly focuses on the nucleation and growth of metal thin films on multimetallic surfaces. First, we have investigated the Ag film growth on a bulk metallic glass surface. Next, we have examined the coarsening and decay of bilayer Ag islands on NiAl(110) surface. Third, we have investigated the Ag film growth on NiAl(110) surface using low-energy electron diffraction (LEED). At last, we have reported our investigation on the epitaxial growth of Ni on NiAl(110) surface. Some general conclusions can be drawn as follows. First, Ag, a bulk-crystalline material, initially forms a disordered wetting layer up to 4-5 monolayers on Zr-Ni-Cu-Al metallic glass. Above this coverage, crystalline 3D clusters grow, in parallel with the flatter regions. The cluster density increases with decreasing temperature, indicating that the conditions of island nucleation are far-from-equilibrium. Within a simple model where clusters nucleate whenever two mobile Ag adatoms meet, the temperature-dependence of cluster density yields a (reasonable) upper limit for the value of the Ag diffusion barrier on top of the Ag wetting layer of 0.32 eV. Overall, this prototypical study suggests that it is possible to grow films of a bulk-crystalline metal that adopt the amorphous character of a glassy metal substrate, if film thickness is sufficiently low. Next, the first study of coarsening and decay of bilayer islands has been presented. The system was Ag on NiAl(110) in the temperature range from 185 K to 250 K. The coarsening behavior, has some similarities to that seen in the Ag(110) homoepitaxial system studied by Morgenstern and co-workers. At 185 K and 205 K, coarsening of Ag islands follows a Smoluchowski ripening pathway. At 205 K and 250 K, the terrace diffusion limited Ostwald ripening dominants. The experimental observed temperature for the transition from SR to OR is 205 K. The SR exhibits anisotropic island diffusion and the OR exhibits 1D decay of island

  6. Fabrication of semi-transparent superoleophobic thin film from fabrics and nanoparticle-based hierarchical structure

    Directory of Open Access Journals (Sweden)

    Nishizawa S.

    2013-08-01

    Full Text Available Superoleophobic thin films have many potential applications including fluid transfer, fluid power systems, stain resistant and antifouling materials, and microfluidics among others. Transparency is also desired with superhydrophobicity for their numerous applications; however transparency and oleophobicity are almost incompatible relationship with each other in the point of surface structure. Because oleophobicity required rougher structure at nano-micro scale than hydrophobicity, and these rough structure brings light scattering. So far, there is very few report of the compatible of transparency and superoleophobicity. In this report, we proposed the see-through type fabrics using the nanoparticle-based hierarchical structure thin film for improving both of oleophobicity and transparency. The vacant space between fibrils of fabrics has two important roles: the one is to through the light, another one is to introduce air layer to realize Cassie state of liquid droplet on thin film. To realize the low surface energy and nanoscale rough structure surface on fibrils, we used the spray method with perfluoroalkyl methacrylic copolymer (PMC, silica nano particles and volatile solvent. From the SEM image, the hierarchical structures of nanoparticle were formed uniformly on the fabrics. The transparency of thin film obtained was approximately 61% and the change of transparency between pre-coated fabrics and coated was 11%. From investigation of the surface wettability, the contact angles of oils (rapeseed oil and hexadecane and water droplet on the fabricated film were over 150 degree.

  7. Directed Self-Assembly of Diblock Copolymer Thin Films on Prepatterned Metal Nanoarrays.

    Science.gov (United States)

    Chang, Tongxin; Huang, Haiying; He, Tianbai

    2016-01-01

    The sequential layer by layer self-assembly of block copolymer (BCP) nanopatterns is an effective approach to construct 3D nanostructures. Here large-scale highly ordered metal nano-arrays prepared from solvent annealed thin films of polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) diblock copolymer are used to direct the assembly of the same BCP. The influence of initial loading concentration of metal precursor, the type of metal nanoparticle (gold, platinum, and silver), and the nanoparticle-substrate interaction on the directed assembly behavior of the upper BCP layer have been focused. It is found that the upper BCP film can be completely directed by the gold nanoarray with P2VP domain exclusively located between two adjacent gold nanowires or nanodots, which behaves the same way as on the platinum nanoarray. While the silver nanoarray can be destroyed during the upper BCP self-assembly with the silver nanoparticles assembled into the P2VP domain. Based on the discussions of the surface energy of nanoparticles and the interplay between nanoparticle-substrate interaction and nanoparticle-polymer interaction, it is concluded that the effect of immobilization of nanoparticles on the substrate, together with entropy effect to minimize the energetically unfavorable chain stretching contributes to the most effective alignment between each layer. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Thin metal bilayer for surface plasmon resonance sensors in a multimode plastic optical fiber: the case of palladium and gold metal films

    Science.gov (United States)

    Cennamo, Nunzio; Zuppella, Paola; Bacco, Davide; Corso, Alain J.; Pelizzo, Maria G.; Pesavento, Maria; Zeni, Luigi

    2016-05-01

    A novel sensing platform based on thin metal bilayer for surface plasmon resonance (SPR) in a D-shaped plastic optical fiber (POF) has been designed, implemented and tested. The experimental results are congruent with the numerical studies. This platform has been properly optimized to work in the 1.38 -1.42 refractive index range and it exhibits excellent sensitivity. This refractive index range is very interesting for bio-chemical applications, where the polymer layer are used as receptors (e.g. molecularly imprinted polymer) or to immobilize the bio-receptor on the metal surface. The proposed metallic bilayer is based on palladium and gold films and replaces the traditional gold by exhibiting higher performances. Furthermore, the deposition of the thin bilayer is a single process and no further manufacturing step is required. In fact, in this case the photoresist buffer layer between the POF core and the metal layer, usually required to increase the refractive index range, is no longer necessary.

  9. Metal films with imprinted nanostructures by template stripping

    DEFF Research Database (Denmark)

    Eriksen, René Lynge; Pors, Anders; Dreier, Jes

    We present a novel template stripping procedure for fabricating metal films with imprinted nanostructures. The basic idea is to deposit a gold film onto a nano-structured substrate and subsequently strip the film from the substrate surface thereby revealing imprinted nanostructures in the film...... result is a thin gold film with imprinted nano-cavities....

  10. Microstructure and thermochromic properties of VOX-WOX-VOX ceramic thin films

    International Nuclear Information System (INIS)

    Khamseh, S.; Ghahari, M.; Araghi, H.; Faghihi Sani, M.A.

    2016-01-01

    W-doped VO 2 films have been synthesized via oxygen annealing of V-W-V (vanadium-tungsten-vanadium) multilayered films. The effects of middle layer's thickness of V-W-V multilayered film on structure and properties of VO X -WO X -VO X ceramic thin films were investigated. The as-deposited V-W-V multilayered film showed amorphous-like structure when mixed structure of VO 2 (M) and VO 2 (B) was formed in VO X -WO X -VO X ceramic thin films. Tungsten content of VO X -WO X -VO X ceramic thin films increased with increasing middle layer's thickness. With increasing middle layer's thickness, room temperature square resistance (R sq ) of VO X -WO X -VO X ceramic thin films increased from 65 to 86 kΩ/sq. The VO X -WO X -VO X ceramic thin film with the thinnest middle layer showed significant SMT (semiconductor-metal transition) when SMT became negligible on increasing middle layer's thickness. (orig.)

  11. Structure and electrical properties of Pb(ZrxTi1-x)O3 deposited on textured Pt thin films

    International Nuclear Information System (INIS)

    Hong, Jongin; Song, Han Wook; Lee, Hee Chul; Lee, Won Jong; No, Kwangsoo

    2001-01-01

    The texturing of the bottom electrode plays a key role in the structure and electrical properties of Pb(Zr,Ti)O 3 (PZT) thin films. We fabricated Pt bottom electrodes having a different thickness on MgO single crystals at 600 o C by rf magnetron sputtering. As the thickness of platinum (Pt) thin film increased, the preferred orientation of Pt thin film changed from (200) to (111). PZT thin films were fabricated at 450 o C by electron cyclotron resonance-plasma enhanced metal organic chemical vapor deposition on the textured Pt thin films. The texturing of the bottom electrode caused drastic changes in the C--V characteristics, P--E characteristics, and fatigue characteristics of metal/ferroelectric material/metal (MFM) capacitors. The difference of the electrical properties between the PZT thin films having different texturing was discussed in terms-of the x--y alignment and the interface between electrode and PZT in MFM capacitors. copyright 2001 American Institute of Physics

  12. Experimental study of the plasma fluorination of Y-Ba-Cu-O thin films

    CERN Document Server

    Li Qi; Ji Zheng Ming; Feng Yi Jun; Kang Lin; Yang Sen Zu; Wu Pei Heng; Wang Xiao Shu; Ye Yuda

    2002-01-01

    The authors have experimentally studied the surface modifications of Y-Ba-Cu-O (YBCO) thin films using CF sub 4 plasma. The intensity of the plasma fluorination was controlled by changing the biasing voltage and the time of the plasma treatment. Microstructural analyses reveal that the oxygen content of the YBCO thin films was changed. Transport measurements of sufficient fluorinated YBCO films imply that the films changed totally into an oxygen-deficient semi-conducting state. From these experimental results, the authors believe that plasma fluorination is quite a useful method to form controllable a thin barrier layer in fabricating interface engineered junctions and to form a stable narrow weak-link region in fabricating planar superconductor-normal-superconductor junctions

  13. Thickness and microstructure effects in the optical and electrical properties of silver thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Guowen, E-mail: gding@intermolecular.com; Clavero, César; Schweigert, Daniel; Le, Minh [Intermolecular, Inc., 3011 North First Street, San Jose, CA 95134 (United States)

    2015-11-15

    The optical and electrical response of metal thin films approaching thicknesses in the range of the electron mean free path is highly affected by electronic scattering with the interfaces and defects. Here, we present a theoretical and experimental study on how thickness and microstructure affect the properties of Ag thin films. We are able to successfully model the electrical resistivity and IR optical response using a thickness dependent electronic scattering time. Remarkably, the product of electronic scattering time and resistivity remains constant regardless of the thickness (τx ρ = C), with a value of 59 ± 2 μΩ cm ⋅ fs for Ag films in the investigated range from 3 to 74 nm. Our findings enable us to develop a theoretically framework that allows calculating the optical response of metal thin films in the IR by using their measured thickness and resistivity. An excellent agreement is found between experimental measurements and predicted values. This study also shows the theoretical lower limit for emissivity in Ag thin films according to their microstructure and thickness. Application of the model presented here will allow rapid characterization of the IR optical response of metal thin films, with important application in a broad spectrum of fundamental and industrial applications, including optical coatings, low-emissivity windows and semiconductor industry.

  14. Dielectric Scattering Patterns for Efficient Light Trapping in Thin-Film Solar Cells.

    Science.gov (United States)

    van Lare, Claire; Lenzmann, Frank; Verschuuren, Marc A; Polman, Albert

    2015-08-12

    We demonstrate an effective light trapping geometry for thin-film solar cells that is composed of dielectric light scattering nanocavities at the interface between the metal back contact and the semiconductor absorber layer. The geometry is based on resonant Mie scattering. It avoids the Ohmic losses found in metallic (plasmonic) nanopatterns, and the dielectric scatterers are well compatible with nearly all types of thin-film solar cells, including cells produced using high temperature processes. The external quantum efficiency of thin-film a-Si:H solar cells grown on top of a nanopatterned Al-doped ZnO, made using soft imprint lithography, is strongly enhanced in the 550-800 nm spectral band by the dielectric nanoscatterers. Numerical simulations are in good agreement with experimental data and show that resonant light scattering from both the AZO nanostructures and the embedded Si nanostructures are important. The results are generic and can be applied on nearly all thin-film solar cells.

  15. N-type In/sub 2/S/sub 3/ thin films prepared by gas chalcogenization of metallic electroplated indium: Photoelectrochemical characterization

    Energy Technology Data Exchange (ETDEWEB)

    Herrero, J; Ortega, J

    1988-08-01

    Chalcogenization of electroplated metallic indium films onto Ti substrates has been carried out in a flowing stream of H/sub 2/S at about 350/sup 0/C for 1 h with a pretreatment of 3 h at 130/sup 0/C. X-ray diffraction patterns showed that ..beta..-In/sub 2/S/sub 3/ thin films were grown with a good crystalline quality. Photoelectrochemical characterization of the electrodes was accomplished in aqueous polysulphide solutions, and a energy gap of 2.00 eV was obtained. The flatband potential, V/sub fb/, in the same polysulphide couple was -1.0 V versus SCE. Behaviour of the thin film photocurrent with time was checked, and a photocorrosion reaction proposed.

  16. Magnetic properties of thin films obtained by ion implantation of 3d metals in polyethylene-terephthalate

    International Nuclear Information System (INIS)

    Petukhov, V.Yu.; Ibragimova, M.I.; Khabibullina, N.R; Zheglov, E.P.; Muller, R.

    2002-01-01

    Polymer films containing small metal particles have been attracting particular interest because of their unique properties. Implantation of metal ions in polymers is one of the methods to synthesize metal-polymer nano-composite materials. Ion implantation makes possible the magnetic nano-structures with controlled parameters. Previously, we showed that 3d-metal implantation into numerous polymers (polymethylmethacrylate, phosphorus containing polymethylmethacrylate) resulted in the formation of a composite film consisting of metal nanoparticles buried in an implanted layer. The particles are usually found to be distributed randomly in the surface layer. It has been established that structural peculiarities, phase composition, and magnetic properties of synthesized metal-polymer systems depend on the type of the initial polymer matrix, ion types, as well as conditions of ion implantation. In the present study we have been prepared thin metal-polymer composite films by ion-beam implantation of Fe + and Co + ions in polyethylene terephthalate. The implantation of 40 keV ions at room temperature with doses from 2·10 1 6 to 3·10 17 cm -2 have been performed, with the ion current density not exceeding 10 μA/cm 2 . The magnetic properties have been investigated both by ferromagnetic resonance (FMR) and vibrating sample magnetometry (VSM). FMR spectra were recorded using magnetic radio spectrometer Varian E-12 with frequency of 9.5 GHz at room temperature. The dependencies of FMR spectra on orientation have been measured for all samples. Measurements were carried out for two orientations of the sample, normal direction of the films being either parallel or perpendicular to dc magnetic field. The values of the effective magnetization were calculated from orientation dependencies. Thin ferromagnetic films (TFF) have been shown to form for samples with both implanted ions. For samples implanted with Co + ions, the appearance of FMR lines occurs at doses markedly greater

  17. Molecular dynamics simulation of Cu/Au thin films under temperature gradient

    International Nuclear Information System (INIS)

    Li, Qibin; Peng, Xianghe; Peng, Tiefeng; Tang, Qizhong; Zhang, Xiaomin; Huang, Cheng

    2015-01-01

    Graphical abstract: Heat transportation in the thin films. - Highlights: • The coherent lattice interface is found at thin films after annealing. • The vacancies are observed clearly in the deposit thin films. • The defect and component will influence the energy transportation in the coatings. • The vacancies and lattice mismatch can enlarge the mobility of atoms. • The phonon transportation in thin films has no apparent rule. - Abstract: Three modulation period thin films, 1.8 nm Cu/3.6 nm Au, 2.7 nm Cu/2.7 nm Au and 3.6 nm Cu/1.8 nm Au, are obtained from deposition method and ideal modeling based on lattice constant, to examine their structures and thermophysical characteristics under temperature gradient. The coherent lattice interface is found both at deposit and ideal thin films after annealing. Also, the vacancies are observed clearly in the deposit thin films. The defect and component of thin films will influence the energy transportation in the coatings. The vacancies and lattice mismatch can enlarge the mobility of atoms and result in the failure of coating under the thermal stress. The power spectrum of atoms’ movement has no apparent rule for phonon transportation in thin films. The results are helpful to reveal the micro-mechanism and provide reasonable basis for the failure of metallic coatings.

  18. Molecular dynamics simulation of Cu/Au thin films under temperature gradient

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qibin, E-mail: qibinli@cqu.edu.cn [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030 (China); Chongqing Key Laboratory of Heterogeneous Material Mechanics, Chongqing University, Chongqing 400030 (China); Peng, Xianghe [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030 (China); Peng, Tiefeng, E-mail: pengtiefeng@cqu.edu.cn [State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030 (China); Tang, Qizhong [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); Zhang, Xiaomin [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); Chongqing Key Laboratory of Heterogeneous Material Mechanics, Chongqing University, Chongqing 400030 (China); Huang, Cheng [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China)

    2015-12-01

    Graphical abstract: Heat transportation in the thin films. - Highlights: • The coherent lattice interface is found at thin films after annealing. • The vacancies are observed clearly in the deposit thin films. • The defect and component will influence the energy transportation in the coatings. • The vacancies and lattice mismatch can enlarge the mobility of atoms. • The phonon transportation in thin films has no apparent rule. - Abstract: Three modulation period thin films, 1.8 nm Cu/3.6 nm Au, 2.7 nm Cu/2.7 nm Au and 3.6 nm Cu/1.8 nm Au, are obtained from deposition method and ideal modeling based on lattice constant, to examine their structures and thermophysical characteristics under temperature gradient. The coherent lattice interface is found both at deposit and ideal thin films after annealing. Also, the vacancies are observed clearly in the deposit thin films. The defect and component of thin films will influence the energy transportation in the coatings. The vacancies and lattice mismatch can enlarge the mobility of atoms and result in the failure of coating under the thermal stress. The power spectrum of atoms’ movement has no apparent rule for phonon transportation in thin films. The results are helpful to reveal the micro-mechanism and provide reasonable basis for the failure of metallic coatings.

  19. Domain growth of carbon nanotubes assisted by dewetting of thin catalyst precursor films

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Alok Kumar [Defence Materials and Stores R and D Establishment (DRDO), GT Road, Kanpur 208013 (India); Department of Chemical Engineering, Indian Institute of Technology, Kanpur 208016 (India); Sachan, Priyanka; Samanta, Chandan [Department of Chemical Engineering, Indian Institute of Technology, Kanpur 208016 (India); Mukhopadhyay, Kingsuk [Defence Materials and Stores R and D Establishment (DRDO), GT Road, Kanpur 208013 (India); Sharma, Ashutosh, E-mail: ashutos@iitk.ac.in [Department of Chemical Engineering, Indian Institute of Technology, Kanpur 208016 (India)

    2014-01-01

    We explore self-organized dewetting of ultrathin films of a novel metal complex as a one step surface patterning method to create nanoislands of iron, using which spatially separated carbon nanostructures were synthesized. Dewetting of ultrathin metal complex films was induced by two different methods: liquid solvent exposure and thermal annealing to engender surface patterning. For thermal dewetting, thin films of the iron oleate complex were dewetted at high temperature. In the case of liquid solvent assisted dewetting, the metal complex, mixed with a sacrificial polymer (polystyrene) was spin coated as thin films (<40 nm) and then dewetted under an optimal solution mixture consisting of methyl ethyl ketone, acetone and water. The carrier polymer was then selectively removed to produce the iron metal islands. These metal islands were used for selective growth of discrete patches of multiwall CNTs and CNFs by a chemical vapor deposition (CVD) process. Solvent induced dewetting showed clear advantages over thermal dewetting owing to reduced size of catalyst domains formed by dewetting, an improved control over CNT growth as well as in its ability to immobilize the seed particles. The generic solution mediated dewetting and pattern generation in thin films of various catalytic precursors can thus be a powerful method for selective domain growth of a variety of functional nanomaterials.

  20. Excimer laser assisted re-oxidation of BaTiO3 thin films on Ni metal foils

    International Nuclear Information System (INIS)

    Bharadwaja, S. S. N.; Ko, S. W.; Qu, W.; Clark, T.; Rajashekhar, A.; Motyka, M.; Podraza, N.; Randall, C. A.; Trolier-McKinstry, S.

    2016-01-01

    Excimer laser assisted re-oxidation for reduced, crystallized BaTiO 3 thin films on Ni-foils was investigated. It was found that the BaTiO 3 can be re-oxidized at an oxygen partial pressure of ∼50 mTorr and substrate temperature of 350 °C without forming a NiO x interface layer between the film and base metal foil. The dielectric permittivity of re-oxidized films was >1000 with loss tangent values <2% at 100 Hz, 30 mV rms excitation signal. Electron Energy Loss Spectroscopy indicated that BaTiO 3 thin films can be re-oxidized to an oxygen stoichiometry close to ∼3 (e.g., stoichiometric). High resolution cross sectional transmission electron microscopy showed no evidence of NiO x formation between the BaTiO 3 and the Ni foil upon excimer laser re-oxidation. Spectroscopic ellipsometry studies on laser re-oxidized [001] C and [111] C BaTiO 3 single crystals indicate that the re-oxidation of BaTiO 3 single crystals is augmented by photo-excitation of the ozone, as well as laser pulse induced temperature and local stress gradients

  1. High Performance Infrared Plasmonic Metamaterial Absorbers and Their Applications to Thin-film Sensing

    KAUST Repository

    Yue, Weisheng

    2016-04-07

    Plasmonic metamaterial absorbers (PMAs) have attracted considerable attention for developing various sensing devices. In this work, we design, fabricate and characterize PMAs of different geometrical shapes operating in mid-infrared frequencies, and explore the applications of the PMAs as sensor for thin films. The PMAs, consisting of metal-insulator-metal stacks with patterned gold nanostructured surfaces (resonators), demonstrated high absorption efficiency (87 to 98 %) of electromagnetic waves in the infrared regime. The position and efficiency of resonance absorption are dependent on the shape of the resonators. Furthermore, the resonance wavelength of PMAs was sensitive to the thin film coated on the surface of the PMAs, which was tested using aluminum oxide (Al2O3) as the film. With increase of the Al2O3 thickness, the position of resonance absorption shifted to longer wavelengths. The dependence of the resonant wavelength on thin film thickness makes PMAs a suitable candidate as a sensor for thin films. Using this sensing strategy, PMAs have potential as a new method for thin film detection and in situ monitoring of surface reactions. © 2016 Springer Science+Business Media New York

  2. High Performance Infrared Plasmonic Metamaterial Absorbers and Their Applications to Thin-film Sensing

    KAUST Repository

    Yue, Weisheng; Wang, Zhihong; Yang, Yang; Han, Jiaguang; Li, Jingqi; Guo, Zaibing; Tan, Hua; Zhang, Xixiang

    2016-01-01

    Plasmonic metamaterial absorbers (PMAs) have attracted considerable attention for developing various sensing devices. In this work, we design, fabricate and characterize PMAs of different geometrical shapes operating in mid-infrared frequencies, and explore the applications of the PMAs as sensor for thin films. The PMAs, consisting of metal-insulator-metal stacks with patterned gold nanostructured surfaces (resonators), demonstrated high absorption efficiency (87 to 98 %) of electromagnetic waves in the infrared regime. The position and efficiency of resonance absorption are dependent on the shape of the resonators. Furthermore, the resonance wavelength of PMAs was sensitive to the thin film coated on the surface of the PMAs, which was tested using aluminum oxide (Al2O3) as the film. With increase of the Al2O3 thickness, the position of resonance absorption shifted to longer wavelengths. The dependence of the resonant wavelength on thin film thickness makes PMAs a suitable candidate as a sensor for thin films. Using this sensing strategy, PMAs have potential as a new method for thin film detection and in situ monitoring of surface reactions. © 2016 Springer Science+Business Media New York

  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. 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.

  5. Thermal recrystallization of physical vapor deposition based germanium thin films on bulk silicon (100)

    KAUST Repository

    Hussain, Aftab M.

    2013-08-16

    We demonstrate a simple, low-cost, and scalable process for obtaining uniform, smooth surfaced, high quality mono-crystalline germanium (100) thin films on silicon (100). The germanium thin films were deposited on a silicon substrate using plasma-assisted sputtering based physical vapor deposition. They were crystallized by annealing at various temperatures ranging from 700 °C to 1100 °C. We report that the best quality germanium thin films are obtained above the melting point of germanium (937 °C), thus offering a method for in-situ Czochralski process. We show well-behaved high-κ /metal gate metal-oxide-semiconductor capacitors (MOSCAPs) using this film. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Characterization of PZT thin films on metal substrates; Charakterisierung von PZT-Duennschichten auf Metallsubstraten

    Energy Technology Data Exchange (ETDEWEB)

    Dutschke, A.

    2008-02-02

    Lead zirconate titanate (PbZr{sub x}Ti{sub 1-x}O{sub 3},PZT) is one of the most applied ceramic materials because of its distinctive piezo- and ferroelectric properties. Prepared as thin films on flexible, metallic substrates it can be used for various applications as strain gauges, key switches, vibration dampers, microactuators and ultrasonic transducers. The aim of this work is to analyze the microstructure and the phase-content of PZT-thin films deposited on temperature- und acid-resistant hastelloy-sheets, to correlate the results with the ferroelectric and dielectric properties. It is demonstrated, that the specific variation of the microstructure can be achieved by different thermal treatments and the selective addition of Neodymium as dopant. Nd-doping leads to a shift of the maximum nucleation rate towards reduced temperatures and a decrease in the rate of growth compared to undoped films. The PZT-films are prepared by a sol-gel-process in fourfold multilayers with a composition near the morphotropic phase boundary, where the tetragonal und rhombohedral perovskite-phases coexist. The crystallisation in Nd-doped and undoped films takes place heterogeneously, preferentially at the interfaces and on the surface of the multilayered films as well as on the inner surface of pores within the films. For the first time, the Zr:Ti fluctuation phenomena emerging in sol-gel derived PZT films is related to the microstructure and the local phase content on a nanometer scale. In this connection it is proved, that long-distance Zr:Ti gradients arise preferentially before and during the crystallisation of the pyrochlore phase. During the following crystallisation of the perovskite phase, the crystallites grow across these gradients without modifying them. It is pointed out that the fluctuation in the Zr:Ti ratio has only minor influence on the amount of the tetragonal or rhombohedral distortion of the crystallites after the transition from the para- to the ferroelectric

  7. 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.

  8. 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 ...

  9. Nonlinear current-voltage behavior in PZT thin films

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Mi; Zhang, Weikang; Zhang, Zebin; Li, Shida; Zhang, Ping; Lan, Kuibo [Tianjin University, School of Electrical and Information Engineering, Tianjin (China)

    2017-05-15

    In this paper, Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} (PZT) thin films were prepared by sol-gel synthesis and characterized by X-ray diffraction, field emission scanning electron microscopy and current-voltage measurements. Here, we demonstrate that in addition to the outstanding ferroelectric and dielectric properties, the PZT films also have remarkably nonlinear current-voltage characteristics. Considering the contact of semi-conductive grains in the PZT films, a double Schottky barrier (DSB) model may be responsible for such phenomena. The test results show that with the decrease of annealing temperature and the increase of the film thickness, the threshold voltages (V{sub th}) increase obviously. The maximum V{sub th} value of 60.95 V and the minimum value of 6.9 V in our experiments were obtained from the five-layered samples annealed at 600 C and the two-layered samples annealed at 700 C, respectively. As a result, PZT thin film may lead to efficient switching and sensing devices. (orig.)

  10. Thin Cu film resistivity using four probe techniques: Effect of film thickness and geometrical shapes

    Science.gov (United States)

    Choudhary, Sumita; Narula, Rahul; Gangopadhyay, Subhashis

    2018-05-01

    Precise measurement of electrical sheet resistance and resistivity of metallic thin Cu films may play a significant role in temperature sensing by means of resistivity changes which can further act as a safety measure of various electronic devices during their operation. Four point probes resistivity measurement is a useful approach as it successfully excludes the contact resistance between the probes and film surface of the sample. Although, the resistivity of bulk samples at a particular temperature mostly depends on its materialistic property, however, it may significantly differ in the case of thin films, where the shape and thickness of the sample can significantly influence on it. Depending on the ratio of the film thickness to probe spacing, samples are usually classified in two segments such as (i) thick films or (ii) thin films. Accordingly, the geometric correction factors G can be related to the sample resistivity r, which has been calculated here for thin Cu films of thickness up to few 100 nm. In this study, various rectangular shapes of thin Cu films have been used to determine the shape induced geometric correction factors G. An expressions for G have been obtained as a function of film thickness t versus the probe spacing s. Using these expressions, the correction factors have been plotted separately for each cases as a function of (a) film thickness for fixed linear probe spacing and (b) probe distance from the edge of the film surface for particular thickness. Finally, we compare the experimental results of thin Cu films of various rectangular geometries with the theoretical reported results.

  11. Investigation of ultrafast lattice heating in thin (semi-)metal films using time-resolved electron diffraction; Untersuchung der schnellen Gitteraufheizung in duennen (Halb-)Metallfilmen mit Hilfe zeitaufgeloester Elektronenbeugung

    Energy Technology Data Exchange (ETDEWEB)

    Ligges, Manuel

    2009-07-21

    In the framework of the present thesis the fast lattice heating in thin metal and bismuth layers after optical short-pulse excitation was studied. By irradiation of ultrathin solid films with ultrashort (femtosecond) laser pulses for sort times an extreme nonequilibrium state occurs: The electronic system is strongly excited, while the lattice system remains cold. An energetic exchange between both systems follows, which is based on the electron-phonon interaction and leads to heating of the lattice system. This lattice heating can be observed by means of the Debye-Waller effect in the electron diffraction image. By means of the excitation-interrogation scheme by a series of moment records this lattice heating can be observed time-resolvedly. The experimentally determind time scales for this process permit conclusions on the electron-phonon coupling in the studied materials. In this thesis a time-resolving transmissi9on-electron diffraction experiment with sub-picosecond time resolution was constructed and optimized. By means of this experiment the fast lattice heating in thin gold, silver, copper, and bismuth films was studied. The observed heating behaviour of the metal films shows agreement with theoretical predictions of different model calculations. The results of the measurements on bismuth films show a hitherto not observed coupling behaviour. [German] Im Rahmen der vorliegenden Arbeit wurde die schnelle Gitteraufheizung in duennen Metall- und Wismutschichten nach optischer Kurzimpulsanregung untersucht. Durch Bestrahlung duenner Festkoerperfilme mit ultrakurzen (Femtosekunden-) Laserimpulsen entsteht fuer kurze Zeiten ein extremer Nichtgleichgewichtszustand: Das elektronische System wird stark angeregt, waehrend das Gittersystem kalt bleibt. Es folgt ein energetischer Austausch zwischen beiden Systemen, der auf der Elektron-Phonon-Wechselwirkung beruht und zur Aufheizung des Gittersystems fuehrt. Diese Gitteraufheizung kann anhand des Debye

  12. Li4SiO4-Based Artificial Passivation Thin Film for Improving Interfacial Stability of Li Metal Anodes.

    Science.gov (United States)

    Kim, Ji Young; Kim, A-Young; Liu, Guicheng; Woo, Jae-Young; Kim, Hansung; Lee, Joong Kee

    2018-03-14

    An amorphous SiO 2 (a-SiO 2 ) thin film was developed as an artificial passivation layer to stabilize Li metal anodes during electrochemical reactions. The thin film was prepared using an electron cyclotron resonance-chemical vapor deposition apparatus. The obtained passivation layer has a hierarchical structure, which is composed of lithium silicide, lithiated silicon oxide, and a-SiO 2 . The thickness of the a-SiO 2 passivation layer could be varied by changing the processing time, whereas that of the lithium silicide and lithiated silicon oxide layers was almost constant. During cycling, the surface of the a-SiO 2 passivation layer is converted into lithium silicate (Li 4 SiO 4 ), and the portion of Li 4 SiO 4 depends on the thickness of a-SiO 2 . A minimum overpotential of 21.7 mV was observed at the Li metal electrode at a current density of 3 mA cm -2 with flat voltage profiles, when an a-SiO 2 passivation layer of 92.5 nm was used. The Li metal with this optimized thin passivation layer also showed the lowest charge-transfer resistance (3.948 Ω cm) and the highest Li ion diffusivity (7.06 × 10 -14 cm 2 s -1 ) after cycling in a Li-S battery. The existence of the Li 4 SiO 4 artificial passivation layer prevents the corrosion of Li metal by suppressing Li dendritic growth and improving the ionic conductivity, which contribute to the low charge-transfer resistance and high Li ion diffusivity of the electrode.

  13. The influence of monomer concentration on the optical properties of electrochemically synthesized polypyrrole thin films

    International Nuclear Information System (INIS)

    Thombare, J. V.; Fulari, V. J.; Rath, M. C.; Han, S. H.

    2013-01-01

    Polypyrrole (PPy) thin films were deposited on stainless steel and ITO coated glass substrate at a constant deposition potential of 0.8 V versus saturated calomel electrode (SCE) by using the electrochemical polymerization method. The PPy thin films were deposited at room temperature at various monomer concentrations ranging from 0.1 M to 0.3 M pyrrole. The structural and optical properties of the polypyrrole thin films were investigated using an X-ray diffractometer (XRD), FTIR spectroscopy, scanning electron microscopy (SEM), and ultraviolet—visible (UV—vis) spectroscopy. The XRD results show that polypyrrole thin films have a semi crystalline structure. Higher monomer concentration results in a slight increase of crystallinity. The polypyrrole thin films deposited at higher monomer concentration exhibit high visible absorbance. The refractive indexes of the polypyrrole thin films are found to be in the range of 1 to 1.3 and vary with monomer concentration as well as wavelength. The extinction coefficient decreases slightly with monomer concentration. The electrochemically synthesized polypyrrole thin film shows optical band gap energy of 2.14 eV. (semiconductor materials)

  14. Improvement in crystallization and electrical properties of barium strontium titanate thin films by gold doping using metal-organic deposition method

    International Nuclear Information System (INIS)

    Wang, H.-W.; Nien, S.-W.; Lee, K.-C.; Wu, M.-C.

    2005-01-01

    The effect of gold (Au) on the crystallization, dielectric constant and leakage current density of barium strontium titanate (BST) thin films was investigated. BST thin films with various gold concentrations were prepared via a metal-organic deposition process. The X-ray diffraction shows enhanced crystallization as well as expanded lattice constants for the gold-doped BST films. Thermal analysis reveals that the gold dopant induces more complete decomposition of precursor for the doped films than those of undoped ones. The leakage current density of BST films is greatly reduced by the gold dopant over a range of biases (1-5 V). The distribution of gold was confirmed by electron energy loss spectroscopy and found to be inside the BST grains, not in the grain-boundaries. Gold acted as a catalyst, inducing the nucleation of crystallites and improving the crystallinity of the structure. Its addition is shown to be associated to the improvement of the electrical properties of BST films

  15. Synthesis of Thin Film Composite Metal-Organic Frameworks Membranes on Polymer Supports

    KAUST Repository

    Barankova, Eva

    2017-06-01

    Since the discovery of size-selective metal-organic frameworks (MOF) researchers have tried to manufacture them into gas separation membranes. ZIF-8 became the most studied MOF for membrane applications mainly because of its simple synthesis, good chemical and thermal stability, recent commercial availability and attractive pore size. The aim of this work is to develop convenient methods for growing ZIF thin layers on polymer supports to obtain defect-free ZIF membranes with good gas separation properties. We present new approaches for ZIF membranes preparation on polymers. We introduce zinc oxide nanoparticles in the support as a secondary metal source for ZIF-8 growth. Initially the ZnO particles were incorporated into the polymer matrix and later on the surface of the polymer by magnetron sputtering. In both cases, the ZnO facilitated to create more nucleation opportunities and improved the ZIF-8 growth compared to the synthesis without using ZnO. By employing the secondary seeded growth method, we were able to obtain thin (900 nm) ZIF-8 layer with good gas separation performance. Next, we propose a metal-chelating polymer as a suitable support for growing ZIF layers. Defect-free ZIF-8 films with a thickness of 600 nm could be obtained by a contra-diffusion method. ZIF-8 membranes were tested for permeation of hydrogen and hydrocarbons, and one of the highest selectivities reported so far for hydrogen/propane, and propylene/propane was obtained. Another promising method to facilitate the growth of MOFs on polymeric supports is the chemical functionalization of the support surface with functional groups, which can complex metal ions and which can covalently bond the MOF crystals. We functionalized the surface of a common porous polymeric membrane with amine groups, which took part in the reaction to form ZIF-8 nanocrystals. We observed an enhancement in adhesion between the ZIF layer and the support. The effect of parameters of the contra-diffusion experiment

  16. 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

  17. Low-temperature metal-oxide thin-film transistors formed by directly photopatternable and combustible solution synthesis.

    Science.gov (United States)

    Rim, You Seung; Lim, Hyun Soo; Kim, Hyun Jae

    2013-05-01

    We investigated the formation of ultraviolet (UV)-assisted directly patternable solution-processed oxide semiconductor films and successfully fabricated thin-film transistors (TFTs) based on these films. An InGaZnO (IGZO) solution that was modified chemically with benzoylacetone (BzAc), whose chelate rings decomposed via a π-π* transition as result of UV irradiation, was used for the direct patterning. A TFT was fabricated using the directly patterned IGZO film, and it had better electrical characteristics than those of conventional photoresist (PR)-patterned TFTs. In addition, the nitric acid (HNO3) and acetylacetone (AcAc) modified In2O3 (NAc-In2O3) solution exhibited both strong UV absorption and high exothermic reaction. This method not only resulted in the formation of a low-energy path because of the combustion of the chemically modified metal-oxide solution but also allowed for photoreaction-induced direct patterning at low temperatures.

  18. On the dielectric and optical properties of surface-anchored metal-organic frameworks: A study on epitaxially grown thin films

    Science.gov (United States)

    Redel, Engelbert; Wang, Zhengbang; Walheim, Stefan; Liu, Jinxuan; Gliemann, Hartmut; Wöll, Christof

    2013-08-01

    We determine the optical constants of two highly porous, crystalline metal-organic frameworks (MOFs). Since it is problematic to determine the optical constants for the standard powder modification of these porous solids, we instead use surface-anchored metal-organic frameworks (SURMOFs). These MOF thin films are grown using liquid phase epitaxy (LPE) on modified silicon substrates. The produced SURMOF thin films exhibit good optical properties; these porous coatings are smooth as well as crack-free, they do not scatter visible light, and they have a homogenous interference color over the entire sample. Therefore, spectroscopic ellipsometry (SE) can be used in a straightforward fashion to determine the corresponding SURMOF optical properties. After careful removal of the solvent molecules used in the fabrication process as well as the residual water adsorbed in the voids of this highly porous solid, we determine an optical constant of n = 1.39 at a wavelength of 750 nm for HKUST-1 (stands for Hong Kong University of Science and Technology-1; and was first discovered there) or [Cu3(BTC)2]. After exposing these SURMOF thin films to moisture/EtOH atmosphere, the refractive index (n) increases to n = 1.55-1.6. This dependence of the optical properties on water/EtOH adsorption demonstrates the potential of such SURMOF materials for optical sensing.

  19. Electrical resistivity of thin metal films and multilayers

    International Nuclear Information System (INIS)

    Fenn, M.

    1999-01-01

    The electrical resistivity and temperature coefficient of resistivity (TCR) of thin films and multilayers of Cu, Nb and Zr have been measured over a wide range of layer thicknesses. The structure of the films has been characterised using transmission electron microscopy (TEM) and x-ray reflectivity. The experimental results have been compared with the semiclassical theory due to Dimmich. The values of the grain boundary reflectivity, R, in the single films has been found to be approximately 0.35 for Cu in agreement with the literature. The value of R for Nb and Zr has been found to vary with grain size, although it is approximately 0.55 for Nb and 0.925 for Zr over a wide range of grain sizes, and this is believed to be presented for the first time. The value of the interfacial specularity parameter, p, is not found to have a significant effect compared to R in the single films. Dimmich's theoretical expression for the TCR does not match experiment, but by adapting the resistivity expression of the theory to different temperatures a satisfactory fit has been obtained. It has been concluded that the assumption of the free electron model in the presence of grain boundary scattering is in error. The adapted theory predicts negative TCR in sufficiently thin films with experimentally plausible values of the input parameters, and this is believed to be demonstrated for the first time. The experimental resistivity of the multilayers was much lower than expected from the resistivity of the single films. A theoretical fit to the experimental resistivity and TCR of the multilayers was obtained by adjusting the parameter values obtained from single films, and the value of p was found to be significant. This procedure leads to a contradiction in the value of R for Nb. With a view to extending the above work to magnetic multilayers, an AC susceptometer has been designed, built and tested. The results indicate that this instrument would be suitable for work on magnetic

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

    Directory of Open Access Journals (Sweden)

    Xue Zhang

    2017-07-01

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

  1. Effect of Sr doping on LaTiO3 thin films

    International Nuclear Information System (INIS)

    Vilquin, B.; Kanki, T.; Yanagida, T.; Tanaka, H.; Kawai, T.

    2005-01-01

    We report on the electric properties of La 1-x Sr x TiO 3 (0 ≤ x ≤ 0.5) thin films fabricated by pulsed laser deposition method. Crystallographic measurement of the thin films showed the epitaxial c-axis perovskite structure. The electric property of LaTiO 3 thin film, which is a typical Mott insulative material in bulk, showed insulative behaviour, while the Sr-doped films showed metallic conduction suffering electron-electron scattering. Below x = 0.1, the major carrier type was identified to be hole, and switched to electron with further increasing Sr-doping above x = 0.15. In fact, the switching from p-type to n-type for La 1-x Sr x TiO 3 thin films is first demonstrated in this study. The transition suggests that effective Coulomb gap vanishes due to over-additional Sr doping

  2. Numerical and experimental modeling of liquid metal thin film flows in a quasi-coplanar magentic field

    Energy Technology Data Exchange (ETDEWEB)

    Morley, Neil B. [Univ. of California, Los Angeles, CA (United States)

    1994-01-01

    Liquid metal film protection of plasma-facing surfaces in fusion reactors is proposed in an effort to counter the adverse effects of high heat and particle fluxes from the burning plasma. Concerns still exist about establishing the required flow in presence of strong magnetic fields and plasma momentum flux typical of a reactor environment. In this work, the flow behavior of the film is examined under such conditions. Analysis of MHD equations as they apply to liquid metal flows with a free surface in the fully-developed limit was undertaken. Solution yields data for velocity profiles and uniform film heights vs key design parameters (channel size, magnetic field magnitude/orientation, channel slope, wall conductivity). These results are compared to previous models to determine accuracy of simplifying assumptions, in particular Hartmann averaging of films along {rvec B}. Effect of a plasma momentum flux on the thin films is also analyzed. The plasma momentum is strong enough in the cases examined to seriously upset the film, especially for lighter elements like Li. Ga performed much better and its possible use is bolstered by calculations. In an experiment in the MeGA-loop MHD facility, coplanar, wide film flow was found to be little affected by the magnetic field due to the elongated nature of the film. Both MHD drag and partial laminarization are observed, supporting the fully- developed film model predictions of the onset of MHD drag and duct flow estimations for flow laminarization.

  3. Numerical and experimental modeling of liquid metal thin film flows in a quasi-coplanar magentic field

    International Nuclear Information System (INIS)

    Morley, N.B.

    1994-01-01

    Liquid metal film protection of plasma-facing surfaces in fusion reactors is proposed in an effort to counter the adverse effects of high heat and particle fluxes from the burning plasma. Concerns still exist about establishing the required flow in presence of strong magnetic fields and plasma momentum flux typical of a reactor environment. In this work, the flow behavior of the film is examined under such conditions. Analysis of MHD equations as they apply to liquid metal flows with a free surface in the fully-developed limit was undertaken. Solution yields data for velocity profiles and uniform film heights vs key design parameters (channel size, magnetic field magnitude/orientation, channel slope, wall conductivity). These results are compared to previous models to determine accuracy of simplifying assumptions, in particular Hartmann averaging of films along rvec B. Effect of a plasma momentum flux on the thin films is also analyzed. The plasma momentum is strong enough in the cases examined to seriously upset the film, especially for lighter elements like Li. Ga performed much better and its possible use is bolstered by calculations. In an experiment in the MeGA-loop MHD facility, coplanar, wide film flow was found to be little affected by the magnetic field due to the elongated nature of the film. Both MHD drag and partial laminarization are observed, supporting the fully- developed film model predictions of the onset of MHD drag and duct flow estimations for flow laminarization

  4. Plasmonic versus dielectric enhancement in thin-film solar cells

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard; Mortensen, N. Asger; Sigmund, Ole

    2012-01-01

    to its metallic counterpart. We show that the enhanced normalized short-circuit current for a cell with silicon strips can be increased 4 times compared to the best performance for strips of silver, gold, or aluminium. For this particular case, the simple dielectric grating may outperform its plasmonic......Several studies have indicated that broadband absorption of thin-film solar cells can be enhanced by use of surface-plasmon induced resonances of metallic parts like strips or particles. The metallic parts may create localized modes or scatter incoming light to increase absorption in thin......-film semiconducting material. For a particular case, we show that coupling to the same type of localized slab-waveguide modes can be obtained by a surface modulation consisting of purely dielectric strips. The purely dielectric device turns out to have a significantly higher broadband enhancement factor compared...

  5. Thickness and microstructure effects in the optical and electrical properties of silver thin films

    Directory of Open Access Journals (Sweden)

    Guowen Ding

    2015-11-01

    Full Text Available The optical and electrical response of metal thin films approaching thicknesses in the range of the electron mean free path is highly affected by electronic scattering with the interfaces and defects. Here, we present a theoretical and experimental study on how thickness and microstructure affect the properties of Ag thin films. We are able to successfully model the electrical resistivity and IR optical response using a thickness dependent electronic scattering time. Remarkably, the product of electronic scattering time and resistivity remains constant regardless of the thickness (τx ρ = C, with a value of 59 ± 2 μΩ cm ⋅ fs for Ag films in the investigated range from 3 to 74 nm. Our findings enable us to develop a theoretically framework that allows calculating the optical response of metal thin films in the IR by using their measured thickness and resistivity. An excellent agreement is found between experimental measurements and predicted values. This study also shows the theoretical lower limit for emissivity in Ag thin films according to their microstructure and thickness. Application of the model presented here will allow rapid characterization of the IR optical response of metal thin films, with important application in a broad spectrum of fundamental and industrial applications, including optical coatings, low-emissivity windows and semiconductor industry.

  6. Thin film composition with biological substance and method of making

    International Nuclear Information System (INIS)

    Campbell, A.A.; Song, L.

    1999-01-01

    The invention provides a thin-film composition comprising an underlying substrate of a first material including a plurality of attachment sites; a plurality of functional groups chemically attached to the attachment sites of the underlying substrate; and a thin film of a second material deposited onto the attachment sites of the underlying substrate, and a biologically active substance deposited with the thin-film. Preferably the functional groups are attached to a self assembling monolayer attached to the underlying substrate. Preferred functional groups attached to the underlying substrate are chosen from the group consisting of carboxylates, sulfonates, phosphates, optionally substituted, linear or cyclo, alkyl, alkene, alkyne, aryl, alkylaryl, amine, hydroxyl, thiol, silyl, phosphoryl, cyano, metallocenyl, carbonyl, and polyphosphate. Preferred materials for the underlying substrate are selected from the group consisting of a metal, a metal alloy, a plastic, a polymer, a proteic film, a membrane, a glass or a ceramic. The second material is selected from the group consisting of inorganic crystalline structures, inorganic amorphous structures, organic crystalline structures, and organic amorphous structures. Preferred second materials are phosphates, especially calcium phosphates and most particularly calcium apatite. The biologically active molecule is a protein, peptide, DNA segment, RNA segment, nucleotide, polynucleotide, nucleoside, antibiotic, antimicrobial, radioisotope, chelated radioisotope, chelated metal, metal salt, anti-inflammatory, steroid, nonsteroid anti-inflammatory, analgesic, antihistamine, receptor binding agent, or chemotherapeutic agent, or other biologically active material. Preferably the biologically active molecule is an osteogenic factor consisting of the compositions listed above

  7. Enhanced superconductivity and superconductor to insulator transition in nano-crystalline molybdenum thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Shilpam; Amaladass, E.P. [Condensed Matter Physics Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Sharma, Neha [Surface & Nanoscience Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Harimohan, V. [Condensed Matter Physics Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Amirthapandian, S. [Materials Physics Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Mani, Awadhesh, E-mail: mani@igcar.gov.in [Condensed Matter Physics Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2017-06-01

    Disorder driven superconductor to insulator transition via intermediate metallic regime is reported in nano-crystalline thin films of molybdenum. The nano-structured thin films have been deposited at room temperature using DC magnetron sputtering at different argon pressures. The grain size has been tuned using deposition pressure as the sole control parameter. A variation of particle sizes, room temperature resistivity and superconducting transition has been studied as a function of deposition pressure. The nano-crystalline molybdenum thin films are found to have large carrier concentration but very low mobility and electronic mean free path. Hall and conductivity measurements have been used to understand the effect of disorder on the carrier density and mobilities. Ioffe-Regel parameter is shown to correlate with the continuous metal-insulator transition in our samples. - Highlights: • Thin films of molybdenum using DC sputtering have been deposited on glass. • Argon background pressure during sputtering was used to tune the crystallite sizes of films. • Correlation in deposition pressure, disorder and particle sizes has been observed. • Disorder tuned superconductor to insulator transition along with an intermediate metallic phase has been observed. • Enhancement of superconducting transition temperature and a dome shaped T{sub C} vs. deposition pressure phase diagram has been observed.

  8. Thin-film VO2 submillimeter-wave modulators and polarizers

    International Nuclear Information System (INIS)

    Fan, J.C.C.; Fetterman, H.R.; Bachner, F.J.; Zavracky, P.M.; Parker, C.D.

    1977-01-01

    Submillimeter-wave modulators and switchable polarizers have been fabricated from VO 2 thin films deposited on sapphire substrates. By passing electric current pulses through elements made from these films, the films can be thermally cycled through the insulator-to-metal transition that occurs in VO 2 at about 65 degreeC. In the insulating state, the films are found to have negligible effect on the transmission at submillimeter wavelengths, while above the phase transition the transmission is strongly reduced by the free-electron effects characteristic of a metal. Other possible applications of such switchable VO 2 elements include variable bandpass filters and diffraction grating beam-steering devices

  9. Synthesis and characterization of thin films of nitrided amorphous carbon deposited by laser ablation

    International Nuclear Information System (INIS)

    Rebollo P, B.

    2001-01-01

    The objective of this work is the synthesis and characterization of thin films of amorphous carbon (a-C) and thin films of nitrided amorphous carbon (a-C-N) using the laser ablation technique for their deposit. For this purpose, the physical properties of the obtained films were studied as function of diverse parameters of deposit such as: nitrogen pressure, power density, substrate temperature and substrate-target distance. For the characterization of the properties of the deposited thin films the following techniques were used: a) Raman spectroscopy which has demonstrated being a sensitive technique to the sp 2 and sp 3 bonds content, b) Energy Dispersive Spectroscopy which allows to know semi-quantitatively way the presence of the elements which make up the deposited films, c) Spectrophotometry, for obtaining the absorption spectra and subsequently the optical energy gap of the deposited material, d) Ellipsometry for determining the refraction index, e) Scanning Electron Microscopy for studying the surface morphology of thin films and, f) Profilemetry, which allows the determination the thickness of the deposited thin films. (Author)

  10. Study of 'liquid gold' coatings: Thermal decomposition and formation of metallic thin films

    Energy Technology Data Exchange (ETDEWEB)

    Deram, V. [Laboratoire de Spectrochimie Infrarouge et Raman, Universite des Sciences et Technologies de Lille, UMR CNRS 8516, Bat C5 - 59655 Villeneuve d' Ascq (France) and Ecole Nationale Superieure des Mines de Paris, Centre de Mise en Forme des Materiaux, UMR CNRS 7635, BP 207, 06904 Sophia-Antipolis (France)]. E-mail: virginie.deram@ensmp.fr; Turrell, S. [Laboratoire de Spectrochimie Infrarouge et Raman, Universite des Sciences et Technologies de Lille, UMR CNRS 8516, Bat C5 - 59655 Villeneuve d' Ascq (France); Darque-Ceretti, E. [Ecole Nationale Superieure des Mines de Paris, Centre de Mise en Forme des Materiaux, UMR CNRS 7635, BP 207, 06904 Sophia-Antipolis (France); Aucouturier, M. [Centre de Recherche et de Restauration des Musees de France, UMR CNRS 171, Palais du Louvre, Porte des Lions, 14 quai F. Mitterrand, 75001 Paris Cedex (France)

    2006-09-25

    Organo-metallic solutions called liquid gold are largely used to obtain thin gilded films which are employed for decorative, technological and functional uses. However, these films often prove to be fragile with respect to use, resulting in loss of brilliance or even eventual film removal. An understanding of the behaviour of the layers requires good knowledge of the materials themselves. The present work was undertaken to better understand the evolution of the structural properties of liquid gold as it undergoes heat-processing. Accordingly, we followed the thermal decomposition processes of liquid gold coatings and the formation of the gilded metal layer using a combination of experimental techniques. First, thermal analyses coupled with mass spectrometry and infrared spectroscopy gave information concerning the decomposition of the organic medium. It has been found that the process of film formation can be decomposed into three steps, the second of which is an abrupt transition between 300 and 350 deg. C. Details on this transition have been obtained using real-time X-ray Diffraction and Rutherford Backscattering Spectrometry. Above 350 deg. C, the microstructure of the coating is reorganized to obtain a final layer which contains particles, of the size of a few hundreds nanometers, as shown by Transmission Electron Microscopy.

  11. Resistance switching induced by electric fields in manganite thin films

    International Nuclear Information System (INIS)

    Villafuerte, M; Juarez, G; Duhalde, S; Golmar, F; Degreef, C L; Heluani, S P

    2007-01-01

    In this work, we investigate the polarity-dependent Electric Pulses Induced Resistive (EPIR) switching phenomenon in thin films driven by electric pulses. Thin films of 0.5 Ca 0.5 MnO 3 (manganite) were deposited by PLD on Si substrate. The transport properties at the interface between the film and metallic electrode are characterized in order to study the resistance switching. Sample thermal treatment and electrical field history are important to be considered for get reproducible EPIR effect. Carriers trapping at the interfaces are considered as a possible explanation of our results

  12. Evidence of the semiconductor-metal transition in V{sub 2}O{sub 5} thin films by the pulsed laser photoacoustic method

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Pacheco, A.; Acosta-Najarro, D. R.; Cruz-Manjarrez, H.; Rodriguez-Fernandez, L.; Pineda-Santamaria, J. C; Aguilar-Franco, M. [Instituto de Fisica-Universidad Nacional Autonoma de Mexico, Mexico DF (Mexico); Castaneda-Guzman, R. [Laboratorio de Fotofisica y Peliculas Delgadas, CCADET-UNAM, Mexico DF (Mexico)

    2013-05-14

    In this work, the pulsed photoacoustic technique was used to investigate the semiconductor-metal transition of thin vanadium pentoxide films (V{sub 2}O{sub 5}) under increasing temperature. The V{sub 2}O{sub 5} thin films were simultaneously deposited by RF magnetron sputtering at room temperature, on corning glass and SnO{sub 2}:F/glass substrates, in order to compare the photoacoustic response. The elemental and structural analysis of the V{sub 2}O{sub 5} films was performed by Rutherford backscattering spectroscopy and X-ray diffraction. The optical transmission and band gap were determined using UV-Vis spectroscopy. The electrical properties were measured using four-point probe measurements with the Van der Pauw geometry.

  13. Fabrication of ionic liquid electrodeposited Cu--Sn--Zn--S--Se thin films and method of making

    Science.gov (United States)

    Bhattacharya, Raghu Nath

    2016-01-12

    A semiconductor thin-film and method for producing a semiconductor thin-films comprising a metallic salt, an ionic compound in a non-aqueous solution mixed with a solvent and processing the stacked layer in chalcogen that results in a CZTS/CZTSS thin films that may be deposited on a substrate is disclosed.

  14. Nanopatterned Metallic Films for Use As Transparent Conductive Electrodes in Optoelectronic Devices

    KAUST Repository

    Catrysse, Peter B.; Fan, Shanhui

    2010-01-01

    We investigate the use of nanopatterned metallic films as transparent conductive electrodes in optoelectronic devices. We find that the physics of nanopatterned electrodes, which are often optically thin metallic films, differs from

  15. Organic donor-acceptor thin film systems. Towards optimized growth conditions

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Kerstin Andrea

    2009-06-30

    In this work the preparation of organic donor-acceptor thin films was studied. A chamber for organic molecular beam deposition was designed and integrated into an existing deposition system for metallic thin films. Furthermore, the deposition system was extended by a load-lock with integrated bake-out function, a chamber for the deposition of metallic contacts via stencil mask technique and a sputtering chamber. For the sublimation of the organic compounds several effusion cells were designed. The evaporation characteristic and the temperature profile within the cells was studied. Additionally, a simulation program was developed, which calculates the evaporation characteristics of different cell types. The following processes were integrated: evaporation of particles, migration on the cell walls and collisions in the gas phase. It is also possible to consider a temperature gradient within the cell. All processes can be studied separately and their relative strength can be varied. To verify the simulation results several evaporation experiments with different cell types were employed. The thickness profile of the prepared thin films was measured position-dependently. The results are in good agreement with the simulation. Furthermore, the simulation program was extended to the field of electron beam induced deposition (EBID). The second part of this work deals with the preparation and characterization of organic thin films. The focus hereby lies on the charge transfer salt (BEDT-TTF)(TCNQ), which has three known structure variants. Thin films were prepared by different methods of co-evaporation and were studied with optical microscopy, X-ray diffraction and energy dispersive X-ray spectroscopy (EDX).The formation of the monoclinic phase of (BEDT-TTF)(TCNQ) could be shown. As a last part tunnel structures were prepared as first thin film devices and measured in a He{sub 4} cryostat. (orig.)

  16. Progress in Polycrystalline Thin-Film Cu(In,GaSe2 Solar Cells

    Directory of Open Access Journals (Sweden)

    Udai P. Singh

    2010-01-01

    Full Text Available For some time, the chalcopyrite semiconductor CuInSe2 and its alloy with Ga and/or S [Cu(InGaSe2 or Cu(InGa(Se,S2], commonly referred as CIGS, have been leading thin-film material candidates for incorporation in high-efficiency photovoltaic devices. CuInSe2-based solar cells have shown long-term stability and the highest conversion efficiencies among all thin-film solar cells, reaching 20%. A variety of methods have been reported to prepare CIGS thin film. Efficiency of solar cells depends upon the various deposition methods as they control optoelectronic properties of the layers and interfaces. CIGS thin film grown on glass or flexible (metal foil, polyimide substrates require p-type absorber layers of optimum optoelectronic properties and n-type wideband gap partner layers to form the p-n junction. Transparent conducting oxide and specific metal layers are used for front and back contacts. Progress made in the field of CIGS solar cell in recent years has been reviewed.

  17. Picosecond laser registration of interference pattern by oxidation of thin Cr films

    Energy Technology Data Exchange (ETDEWEB)

    Veiko, Vadim; Yarchuk, Michail [ITMO University, Kronverksky Ave. 49, St. Petersburg, 197101 (Russian Federation); Zakoldaev, Roman, E-mail: zakoldaev@gmail.com [ITMO University, Kronverksky Ave. 49, St. Petersburg, 197101 (Russian Federation); Gedvilas, Mindaugas; Račiukaitis, Gediminas [Center for Physical Sciences and Technology, Savanoriu Ave. 231, LT-02300, Vilnius (Lithuania); Kuzivanov, Michail; Baranov, Alexander [ITMO University, Kronverksky Ave. 49, St. Petersburg, 197101 (Russian Federation)

    2017-05-15

    Highlights: • Periodical patterning of thin films was achieved by combining two technologies. • Selective chemical etching was combined with laser-induced oxidation. • Formation of the protective oxide layer prevented of chromium film from etching. • 1D binary grating with the chromium stripe width of 750 nm was fabricated. - Abstract: The laser oxidation of thin metallic films followed by its selective chemical etching is a promising method for the formation of binary metal structures on the glass substrates. It is important to confirm that even a single ultrashort laser pulse irradiation is able to create the protective oxide layer that makes possible to imprint the thermochemical image. Results of the thermo-chemical treatment of thin chromium films irradiated by picosecond laser pulse utilizing two and four beam interference combined with the chemical etching are presented. The spatial resolution of this method can be high enough due to thermo-chemical sharpening and can be close to the diffraction limit. Micro-Raman spectroscopy was applied for characterization of the chemical composition of the protective oxide layers formed under atmospheric conditions on the surface of thin chromium films.

  18. Direct observation of the lattice precursor of the metal-to-insulator transition in V2O3 thin films by surface acoustic waves

    Science.gov (United States)

    Kündel, J.; Pontiller, P.; Müller, C.; Obermeier, G.; Liu, Z.; Nateprov, A. A.; Hörner, A.; Wixforth, A.; Horn, S.; Tidecks, R.

    2013-03-01

    A surface acoustic wave (SAW) delay line is used to study the metal-to-insulator (MI) transition of V2O3 thin films deposited on a piezoelectric LiNbO3 substrate. Effects contributing to the sound velocity shift of the SAW which are caused by elastic properties of the lattice of the V2O3 films when changing the temperature are separated from those originating from the electrical conductivity. For this purpose the electric field accompanying the elastic wave of the SAW has been shielded by growing the V2O3 film on a thin metallic Cr interlayer (coated with Cr2O3), covering the piezoelectric substrate. Thus, the recently discovered lattice precursor of the MI transition can be directly observed in the experiments, and its fine structure can be investigated.

  19. Nano-crystallization in ZnO-doped In_2O_3 thin films via excimer laser annealing for thin-film transistors

    International Nuclear Information System (INIS)

    Fujii, Mami N.; Ishikawa, Yasuaki; Bermundo, Juan Paolo Soria; Uraoka, Yukiharu; Ishihara, Ryoichi; Cingel, Johan van der; Mofrad, Mohammad R. T.; Kawashima, Emi; Tomai, Shigekazu; Yano, Koki

    2016-01-01

    In a previous work, we reported the high field effect mobility of ZnO-doped In_2O_3 (IZO) thin film transistors (TFTs) irradiated by excimer laser annealing (ELA) [M. Fujii et al., Appl. Phys. Lett. 102, 122107 (2013)]. However, a deeper understanding of the effect of ELA on the IZO film characteristics based on crystallinity, carrier concentrations, and optical properties is needed to control localized carrier concentrations for fabricating self-aligned structures in the same oxide film and to adequately explain the physical characteristics. In the case of as-deposited IZO film used as the channel, a high carrier concentration due to a high density of oxygen vacancies was observed; such a film does not show the required TFT characteristics but can act as a conductive film. We achieved a decrease in the carrier concentration of IZO films by crystallization using ELA. This means that ELA can form localized conductive or semi-conductive areas on the IZO film. We confirmed that the reason for the carrier concentration decrease was the decrease of oxygen-deficient regions and film crystallization. The annealed IZO films showed nano-crystalline phase, and the temperature at the substrate was substantially less than the temperature limit for flexible films such as plastic, which is 50°C. This paves the way for the formation of self-aligned structures and separately formed conductive and semi-conductive regions in the same oxide film.

  20. PREFACE: INERA Workshop: Transition Metal Oxide Thin Films-functional Layers in "Smart windows" and Water Splitting Devices. Parallel session of the 18th International School on Condensed Matter Physics

    Science.gov (United States)

    2014-11-01

    The Special issue presents the papers for the INERA Workshop entitled "Transition Metal Oxides as Functional Layers in Smart windows and Water Splitting Devices", which was held in Varna, St. Konstantin and Elena, Bulgaria, from the 4th-6th September 2014. The Workshop is organized within the context of the INERA "Research and Innovation Capacity Strengthening of ISSP-BAS in Multifunctional Nanostructures", FP7 Project REGPOT 316309 program, European project of the Institute of Solid State Physics at the Bulgarian Academy of Sciences. There were 42 participants at the workshop, 16 from Sweden, Germany, Romania and Hungary, 11 invited lecturers, and 28 young participants. There were researchers present from prestigious European laboratories which are leaders in the field of transition metal oxide thin film technologies. The event contributed to training young researchers in innovative thin film technologies, as well as thin films characterization techniques. The topics of the Workshop cover the field of technology and investigation of thin oxide films as functional layers in "Smart windows" and "Water splitting" devices. The topics are related to the application of novel technologies for the preparation of transition metal oxide films and the modification of chromogenic properties towards the improvement of electrochromic and termochromic device parameters for possible industrial deployment. The Workshop addressed the following topics: Metal oxide films-functional layers in energy efficient devices; Photocatalysts and chemical sensing; Novel thin film technologies and applications; Methods of thin films characterizations; From the 37 abstracts sent, 21 manuscripts were written and later refereed. We appreciate the comments from all the referees, and we are grateful for their valuable contributions. Guest Editors: Assoc. Prof. Dr.Tatyana Ivanova Prof. DSc Kostadinka Gesheva Prof. DSc Hassan Chamatti Assoc. Prof. Dr. Georgi Popkirov Workshop Organizing Committee Prof

  1. Buckling of a stiff thin film on an elastic graded compliant substrate

    Science.gov (United States)

    Chen, Zhou; Chen, Weiqiu; Song, Jizhou

    2017-12-01

    The buckling of a stiff film on a compliant substrate has attracted much attention due to its wide applications such as thin-film metrology, surface patterning and stretchable electronics. An analytical model is established for the buckling of a stiff thin film on a semi-infinite elastic graded compliant substrate subjected to in-plane compression. The critical compressive strain and buckling wavelength for the sinusoidal mode are obtained analytically for the case with the substrate modulus decaying exponentially. The rigorous finite element analysis (FEA) is performed to validate the analytical model and investigate the postbuckling behaviour of the system. The critical buckling strain for the period-doubling mode is obtained numerically. The influences of various material parameters on the results are investigated. These results are helpful to provide physical insights on the buckling of elastic graded substrate-supported thin film.

  2. Photoreactive and Metal-Platable Copolymer Inks for High-Throughput, Room-Temperature Printing of Flexible Metal Electrodes for Thin-Film Electronics.

    Science.gov (United States)

    Yu, You; Xiao, Xiang; Zhang, Yaokang; Li, Kan; Yan, Casey; Wei, Xiaoling; Chen, Lina; Zhen, Hongyu; Zhou, Hang; Zhang, Shengdong; Zheng, Zijian

    2016-06-01

    Photoreactive and metal-platable copolymer inks are reported for the first time to allow high-throughput printing of high-performance flexible electrodes at room temperature. This new copolymer ink accommodates various types of printing technologies, such as soft lithography molding, screen printing, and inkjet printing. Electronic devices including resistors, sensors, solar cells, and thin-film transistors fabricated with these printed electrodes show excellent electrical performance and mechanical flexibility. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Orientation control of chemical solution deposited LaNiO3 thin films

    International Nuclear Information System (INIS)

    Ueno, Kengo; Yamaguchi, Toshiaki; Sakamoto, Wataru; Yogo, Toshinobu; Kikuta, Koichi; Hirano, Shin-ichi

    2005-01-01

    High quality LaNiO 3 (LNO) thin films with preferred orientation could be synthesized on Pt/Ti/SiO 2 /Si substrates at 700 deg. C using the chemical solution deposition method. The homogeneous and stable LNO precursor solutions were prepared using lanthanum isopropoxide and nickel (II) acetylacetonate in a mixed solvent of absolute ethanol and 2-methoxyethanol. The oriented LNO thin films exhibit metallic electro-conduction, and their resistivity at room temperature is sufficiently low for making them an alternative electrode material for functional ceramic thin films

  4. Electric-field driven insulator-metal transition and tunable magnetoresistance in ZnO thin film

    Science.gov (United States)

    Zhang, Le; Chen, Shanshan; Chen, Xiangyang; Ye, Zhizhen; Zhu, Liping

    2018-04-01

    Electrical control of the multistate phase in semiconductors offers the promise of nonvolatile functionality in the future semiconductor spintronics. Here, by applying an external electric field, we have observed a gate-induced insulator-metal transition (MIT) with the temperature dependence of resistivity in ZnO thin films. Due to a high-density carrier accumulation, we have shown the ability to inverse change magnetoresistance in ZnO by ionic liquid gating from 10% to -2.5%. The evolution of photoluminescence under gate voltage was also consistent with the MIT, which is due to the reduction of dislocation. Our in-situ gate-controlled photoluminescence, insulator-metal transition, and the conversion of magnetoresistance open up opportunities in searching for quantum materials and ZnO based photoelectric devices.

  5. Magnesium growth in magnesium deuteride thin films during deuterium desorption

    Energy Technology Data Exchange (ETDEWEB)

    Checchetto, R., E-mail: riccardo.checchetto@unitn.it [Dipartimento di Fisica and CNISM, Università di Trento, Via Sommarive 14, I-38123 Trento (Italy); Miotello, A. [Dipartimento di Fisica and CNISM, Università di Trento, Via Sommarive 14, I-38123 Trento (Italy); Mengucci, P.; Barucca, G. [Dipartimento di Fisica e Ingegneria dei Materiali e del Territorio, Università Politecnica delle Marche, I-60131 Ancona (Italy)

    2013-12-15

    Highlights: ► Highly oriented Pd-capped magnesium deuteride thin films. ► The MgD{sub 2} dissociation was studied at temperatures not exceeding 100 °C. ► The structure of the film samples was analyzed by XRD and TEM. ► The transformation is controlled by the re-growth velocity of the Mg layers. ► The transformation is thermally activated, activation energy value of 1.3 ± 0.1 eV. -- Abstract: Pd- capped nanocrystalline magnesium thin films having columnar structure were deposited on Si substrate by e-gun deposition and submitted to thermal annealing in D{sub 2} atmosphere to promote the metal to deuteride phase transformation. The kinetics of the reverse deuteride to metal transformation was studied by Thermal Desorption Spectroscopy (TDS) while the structure of the as deposited and transformed samples was analyzed by X-rays diffraction and Transmission Electron Microscopy (TEM). In Pd- capped MgD{sub 2} thin films the deuteride to metal transformation begins at the interface between un-reacted Mg and transformed MgD{sub 2} layers. The D{sub 2} desorption kinetics is controlled by MgD{sub 2}/Mg interface effects, specifically the re-growth velocity of the Mg layers. The Mg re-growth has thermally activated character and shows an activation energy value of 1.3 ± 0.1 eV.

  6. Study of thin films of carrier-doped strontium titanate with emphasis on their interfaces with organic thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Naoki [Laboratory of Molecular Aggregation Analysis, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)]. E-mail: naokis@e.kuicr.kyoto-u.ac.jp; Harada, Youichiro [Laboratory of Molecular Aggregation Analysis, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Terashima, Takahito [International Research Center of Elements Science, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Kanda, Ryoko [International Research Center of Elements Science, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Takano, Mikio [International Research Center of Elements Science, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)

    2005-05-15

    Fifty nanometer-thick metal-doped strontium titanate (M:STO, M = La and V) films deposited epitaxially on single crystalline STO substrates were characterized in comparison with indium tin oxide (ITO) covered glasses, to check their applicability to optically transparent anode materials for organic optoelectronic devices. M:STO, in particular V:STO, films turned out to have distinct surface flatness, needfully low electric resistivities and notably large work functions. While their optical transmittances are lower than those of ITOs at this moment, we suggest that M:STO films have a potential to take the place of ITO films. Further, we have observed energy level alignments for copper phthalocyanine thin films at the interface of V:STO.

  7. High speed direct imaging of thin metal film ablation by movie-mode dynamic transmission electron microscopy

    Science.gov (United States)

    Hihath, Sahar; Santala, Melissa K.; Cen, Xi; Campbell, Geoffrey; van Benthem, Klaus

    2016-03-01

    Obliteration of matter by pulsed laser beams is not only prevalent in science fiction movies, but finds numerous technological applications ranging from additive manufacturing over machining of micro- and nanostructured features to health care. Pulse lengths ranging from femtoseconds to nanoseconds are utilized at varying laser beam energies and pulse lengths, and enable the removal of nanometric volumes of material. While the mechanisms for removal of material by laser irradiation, i.e., laser ablation, are well understood on the micrometer length scale, it was previously impossible to directly observe obliteration processes on smaller scales due to experimental limitations for the combination of nanometer spatial and nanosecond temporal resolution. Here, we report the direct observation of metal thin film ablation from a solid substrate through dynamic transmission electron microscopy. Quantitative analysis reveals liquid-phase dewetting of the thin-film, followed by hydrodynamic sputtering of nano- to submicron sized metal droplets. We discovered unexpected fracturing of the substrate due to evolving thermal stresses. This study confirms that hydrodynamic sputtering remains a valid mechanism for droplet expulsion on the nanoscale, while irradiation induced stress fields represent limit laser processing of nanostructured materials. Our results allow for improved safety during laser ablation in manufacturing and medical applications.

  8. 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.

  9. Eddy Current Testing for Detecting Small Defects in Thin Films

    Science.gov (United States)

    Obeid, Simon; Tranjan, Farid M.; Dogaru, Teodor

    2007-03-01

    Presented here is a technique of using Eddy Current based Giant Magneto-Resistance sensor (GMR) to detect surface and sub-layered minute defects in thin films. For surface crack detection, a measurement was performed on a copper metallization of 5-10 microns thick. It was done by scanning the GMR sensor on the surface of the wafer that had two scratches of 0.2 mm, and 2.5 mm in length respectively. In another experiment, metal coatings were deposited over the layers containing five defects with known lengths such that the defects were invisible from the surface. The limit of detection (resolution), in terms of defect size, of the GMR high-resolution Eddy Current probe was studied using this sample. Applications of Eddy Current testing include detecting defects in thin film metallic layers, and quality control of metallization layers on silicon wafers for integrated circuits manufacturing.

  10. EPMA-EDS surface measurements of interdiffusion coefficients between miscible metals in thin films

    International Nuclear Information System (INIS)

    Christien, F.; Pierson, J.F.; Hassini, A.; Capon, F.; Le Gall, R.; Brousse, T.

    2010-01-01

    A new technique is developed to study interdiffusion between two miscible metals. The technique is applied to the Ni-Pd system. It consists in measuring the change of apparent surface composition of a Pd substrate coated with an 800 nm Ni thin film during annealing at a given temperature. The measurement is carried out in-situ inside the chamber of a SEM (scanning electron microscope) by EPMA-EDS (electron probe microanalysis-energy dispersive X-ray spectroscopy). The experimental data are processed using a model that mixes the Fick's diffusion equations and the electron probe microanalysis equation. This process allows the determination of the mean interdiffusion coefficient at a given annealing temperature. The main advantages of the technique are the possible determination of interdiffusion coefficients in thin films and at very low temperature (down to 430 deg. C, i.e. ∼0.4 T m ), which is not achievable with other techniques conventionally used for the study of interdiffusion. The Ni-Pd mean interdiffusion coefficient is shown to follow an Arrhenius law (D-tilde c =6.32x10 -3 exp((178.8kJmol -1 )/(RT) )cm 2 s -1 ) between 430 deg. C and 900 deg. C, in relatively good agreement with previous interdiffusion measurements made on the Ni-Pd system at higher temperature.

  11. Finite-element analysis of the deformation of thin Mylar films due to measurement forces.

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Michael Sean; Robinson, Alex Lockwood; Tran, Hy D.

    2012-01-01

    Significant deformation of thin films occurs when measuring thickness by mechanical means. This source of measurement error can lead to underestimating film thickness if proper corrections are not made. Analytical solutions exist for Hertzian contact deformation, but these solutions assume relatively large geometries. If the film being measured is thin, the analytical Hertzian assumptions are not appropriate. ANSYS is used to model the contact deformation of a 48 gauge Mylar film under bearing load, supported by a stiffer material. Simulation results are presented and compared to other correction estimates. Ideal, semi-infinite, and constrained properties of the film and the measurement tools are considered.

  12. Thin HTSC films produced by a polymer metal precursor technique

    Science.gov (United States)

    Lampe, L. v.; Zygalsky, F.; Hinrichsen, G.

    In precursors the metal ions are combined with acid groups of polymethacrylic acid (PMAA), polyacrylic acid (PAA) or novolac. Compared to thermal degradation temperature of pure polymers those of precursors are low. Precursors films were patterned by UV lithography. Diffractometric investigations showed that the c-axis oriented epitaxial films of YBa 2Cu 3O x and Bi 2Sr 2CaCu 2O x originated from amorphous metal oxide films, which were received after thermal degradation of the precursor. Transition temperatures and current densities were determined by electric resistivity measurements.

  13. Layer-by-layer modification of thin-film metal-semiconductor multilayers with ultrashort laser pulses

    Science.gov (United States)

    Romashevskiy, S. A.; Tsygankov, P. A.; Ashitkov, S. I.; Agranat, M. B.

    2018-05-01

    The surface modifications in a multilayer thin-film structure (50-nm alternating layers of Si and Al) induced by a single Gaussian-shaped femtosecond laser pulse (350 fs, 1028 nm) in the air are investigated by means of atomic-force microscopy (AFM), scanning electron microscopy (SEM), and optical microscopy (OM). Depending on the laser fluence, various modifications of nanometer-scale metal and semiconductor layers, including localized formation of silicon/aluminum nanofoams and layer-by-layer removal, are found. While the nanofoams with cell sizes in the range of tens to hundreds of nanometers are produced only in the two top layers, layer-by-layer removal is observed for the four top layers under single pulse irradiation. The 50-nm films of the multilayer structure are found to be separated at their interfaces, resulting in a selective removal of several top layers (up to 4) in the form of step-like (concentric) craters. The observed phenomenon is associated with a thermo-mechanical ablation mechanism that results in splitting off at film-film interface, where the adhesion force is less than the bulk strength of the used materials, revealing linear dependence of threshold fluences on the film thickness.

  14. Elevated transition temperature in Ge doped VO2 thin films

    Science.gov (United States)

    Krammer, Anna; Magrez, Arnaud; Vitale, Wolfgang A.; Mocny, Piotr; Jeanneret, Patrick; Guibert, Edouard; Whitlow, Harry J.; Ionescu, Adrian M.; Schüler, Andreas

    2017-07-01

    Thermochromic GexV1-xO2+y thin films have been deposited on Si (100) substrates by means of reactive magnetron sputtering. The films were then characterized by Rutherford backscattering spectrometry (RBS), four-point probe electrical resistivity measurements, X-ray diffraction, and atomic force microscopy. From the temperature dependent resistivity measurements, the effect of Ge doping on the semiconductor-to-metal phase transition in vanadium oxide thin films was investigated. The transition temperature was shown to increase significantly upon Ge doping (˜95 °C), while the hysteresis width and resistivity contrast gradually decreased. The precise Ge concentration and the film thickness have been determined by RBS. The crystallinity of phase-pure VO2 monoclinic films was confirmed by XRD. These findings make the use of vanadium dioxide thin films in solar and electronic device applications—where higher critical temperatures than 68 °C of pristine VO2 are needed—a viable and promising solution.

  15. MultiLayer solid electrolyte for lithium thin film batteries

    Science.gov (United States)

    Lee, Se -Hee; Tracy, C. Edwin; Pitts, John Roland; Liu, Ping

    2015-07-28

    A lithium metal thin-film battery composite structure is provided that includes a combination of a thin, stable, solid electrolyte layer [18] such as Lipon, designed in use to be in contact with a lithium metal anode layer; and a rapid-deposit solid electrolyte layer [16] such as LiAlF.sub.4 in contact with the thin, stable, solid electrolyte layer [18]. Batteries made up of or containing these structures are more efficient to produce than other lithium metal batteries that use only a single solid electrolyte. They are also more resistant to stress and strain than batteries made using layers of only the stable, solid electrolyte materials. Furthermore, lithium anode batteries as disclosed herein are useful as rechargeable batteries.

  16. Metal-oxide assisted surface treatment of polyimide gate insulators for high-performance organic thin-film transistors.

    Science.gov (United States)

    Kim, Sohee; Ha, Taewook; Yoo, Sungmi; Ka, Jae-Won; Kim, Jinsoo; Won, Jong Chan; Choi, Dong Hoon; Jang, Kwang-Suk; Kim, Yun Ho

    2017-06-14

    We developed a facile method for treating polyimide-based organic gate insulator (OGI) surfaces with self-assembled monolayers (SAMs) by introducing metal-oxide interlayers, called the metal-oxide assisted SAM treatment (MAST). To create sites for surface modification with SAM materials on polyimide-based OGI (KPI) surfaces, the metal-oxide interlayer, here amorphous alumina (α-Al 2 O 3 ), was deposited on the KPI gate insulator using spin-coating via a rapid sol-gel reaction, providing an excellent template for the formation of a high-quality SAM with phosphonic acid anchor groups. The SAM of octadecylphosphonic acid (ODPA) was successfully treated by spin-coating onto the α-Al 2 O 3 -deposited KPI film. After the surface treatment by ODPA/α-Al 2 O 3 , the surface energy of the KPI thin film was remarkably decreased and the molecular compatibility of the film with an organic semiconductor (OSC), 2-decyl-7-phenyl-[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-C 10 ), was increased. Ph-BTBT-C 10 molecules were uniformly deposited on the treated gate insulator surface and grown with high crystallinity, as confirmed by atomic force microscopy (AFM) and X-ray diffraction (XRD) analysis. The mobility of Ph-BTBT-C 10 thin-film transistors (TFTs) was approximately doubled, from 0.56 ± 0.05 cm 2 V -1 s -1 to 1.26 ± 0.06 cm 2 V -1 s -1 , after the surface treatment. The surface treatment of α-Al 2 O 3 and ODPA significantly decreased the threshold voltage from -21.2 V to -8.3 V by reducing the trap sites in the OGI and improving the interfacial properties with the OSC. We suggest that the MAST method for OGIs can be applied to various OGI materials lacking reactive sites using SAMs. It may provide a new platform for the surface treatment of OGIs, similar to that of conventional SiO 2 gate insulators.

  17. Metal-Organic Framework Thin Film Coated Optical Fiber Sensors: A Novel Waveguide-Based Chemical Sensing Platform.

    Science.gov (United States)

    Kim, Ki-Joong; Lu, Ping; Culp, Jeffrey T; Ohodnicki, Paul R

    2018-02-23

    Integration of optical fiber with sensitive thin films offers great potential for the realization of novel chemical sensing platforms. In this study, we present a simple design strategy and high performance of nanoporous metal-organic framework (MOF) based optical gas sensors, which enables detection of a wide range of concentrations of small molecules based upon extremely small differences in refractive indices as a function of analyte adsorption within the MOF framework. Thin and compact MOF films can be uniformly formed and tightly bound on the surface of etched optical fiber through a simple solution method which is critical for manufacturability of MOF-based sensor devices. The resulting sensors show high sensitivity/selectivity to CO 2 gas relative to other small gases (H 2 , N 2 , O 2 , and CO) with rapid (optical fiber platform which results in an amplification of inherent optical absorption present within the MOF-based sensing layer with increasing values of effective refractive index associated with adsorption of gases.

  18. Ferromagnetism and interlayer exchange coupling in thin metallic films

    Energy Technology Data Exchange (ETDEWEB)

    Kienert, Jochen

    2008-07-15

    This thesis is concerned with the ferromagnetic Kondo lattice (s-d,s-f) model for film geometry. The spin-fermion interaction of this model refers to substances in which localized spins interact with mobile charge carriers like in (dilute) magnetic semiconductors, manganites, or rare-earth compounds. The carrier-mediated, indirect interaction between the localized spins comprises the long-range, oscillatory RKKY exchange interaction in the weak-coupling case and the short-range doubleexchange interaction for strong spin-fermion coupling. Both limits are recovered in this work by mapping the problem onto an effective Heisenberg model. The influence of reduced translational symmetry on the effective exchange interaction and on the magnetic properties of the ferromagnetic Kondo lattice model is investigated. Curie temperatures are obtained for different parameter constellations. The consequences of charge transfer and of lattice relaxation on the magnetic stability at the surface are considered. Since the effective exchange integrals are closely related to the electronic structure in terms of the density of states and of the kinetic energy, the discussion is based on the modifications of these quantities in the dimensionally-reduced case. The important role of spin waves for thin film and surface magnetism is demonstrated. Interlayer exchange coupling represents a particularly interesting and important manifestation of the indirect interaction among localized magnetic moments. The coupling between monatomic layers in thin films is studied in the framework of an RKKY approach. It is decisively determined by the type of in-plane and perpendicular dispersion of the charge carriers and is strongly suppressed above a critical value of the Fermi energy. Finally, the temperature-dependent magnetic stability of thin interlayer-coupled films is addressed and the conditions for a temperature-driven magnetic reorientation transition are discussed. (orig.)

  19. In situ fabrication of electrochemically grown mesoporous metallic thin films by anodic dissolution in deep eutectic solvents.

    Science.gov (United States)

    Renjith, Anu; Roy, Arun; Lakshminarayanan, V

    2014-07-15

    We describe here a simple electrodeposition process of forming thin films of noble metallic nanoparticles such as Au, Ag and Pd in deep eutectic solvents (DES). The method consists of anodic dissolution of the corresponding metal in DES followed by the deposition on the cathodic surface. The anodic dissolution process in DES overcomes the problems associated with copious hydrogen and oxygen evolution on the electrode surface when carried out in aqueous medium. The proposed method utilizes the inherent abilities of DES to act as a reducing medium while simultaneously stabilizing the nanoparticles that are formed. The mesoporous metal films were characterized by SEM, XRD and electrochemical techniques. Potential applications of these substrates in surface enhanced Raman spectroscopy and electrocatalysis have been investigated. A large enhancement of Raman signal of analyte was achieved on the mesoporous silver substrate after removing all the stabilizer molecules from the surface by calcination. The highly porous texture of the electrodeposited film provides superior electro catalytic performance for hydrogen evolution reaction (HER). The mechanisms of HER on the fabricated substrates were studied by Tafel analysis and electrochemical impedance spectroscopy (EIS). Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Chemical vapor deposition based tungsten disulfide (WS2) thin film transistor

    KAUST Repository

    Hussain, Aftab M.

    2013-04-01

    Tungsten disulfide (WS2) is a layered transition metal dichalcogenide with a reported band gap of 1.8 eV in bulk and 1.32-1.4 eV in its thin film form. 2D atomic layers of metal dichalcogenides have shown changes in conductivity with applied electric field. This makes them an interesting option for channel material in field effect transistors (FETs). Therefore, we show a highly manufacturable chemical vapor deposition (CVD) based simple process to grow WS2 directly on silicon oxide in a furnace and then its transistor action with back gated device with room temperature field effect mobility of 0.1003 cm2/V-s using the Schottky barrier contact model. We also show the semiconducting behavior of this WS2 thin film which is more promising than thermally unstable organic materials for thin film transistor application. Our direct growth method on silicon oxide also holds interesting opportunities for macro-electronics applications. © 2013 IEEE.

  1. Failure and fracture of thin film materials for MEMS

    Science.gov (United States)

    Jonnalagadda, Krishna Nagasai

    Design and reliable operation of Microelectromechanical systems (MEMS) depend on the material parameters that influence the failure and fracture properties of brittle and metallic thin films. Failure in brittle materials is quantified by the onset of catastrophic fracture, while in metals, the onset of inelastic deformation is considered as failure as it increases the material compliance. This dissertation research developed new experimental methods to address three aspects on the failure response of these two categories of materials: (a) the role of microstructure and intrinsic stress gradients in the opening mode fracture of mathematically sharp pre-cracks in amorphous and polycrystalline brittle thin films, (b) the critical conditions for mixed mode I/II pre-cracks and their comparison with linear elastic fracture mechanics (LEFM) criteria for crack initiation in homogeneous materials, and (c) the strain rate sensitivity of textured nanocrystalline Au and Pt films with grain sizes of 38 nm and 25 nm respectively. One of the technical objectives of this research was to develop experimental methods and tools that could become standards in MEMS and thin film experimental mechanics. In this regard, a new method was introduced to conduct mode I and mixed mode I/II fracture studies with microscale thin film specimens containing sharp edge pre-cracks. The mode I experiments permitted the direct application of LEFM handbook solutions. On the other hand, the newly introduced mixed mode I/II experiments in thin films were conducted by establishing a new protocol that employs non-standard oblique edge pre-cracks and a numerical analysis based on the J-integral to calculate the stress intensity factors. Similarly, a new experimental protocol has been implemented to carry out experiments with metallic thin films at strain rates that vary by more than six orders of magnitude. The results of mode I fracture experiments concluded that grain inhomogeneity in polycrystalline

  2. 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.

  3. The influence of annealing on yttrium oxide thin film deposited by reactive magnetron sputtering: Process and microstructure

    Directory of Open Access Journals (Sweden)

    Y. Mao

    2017-01-01

    Full Text Available Yttrium oxide thin films were prepared by reactive magnetron sputtering in different deposition condition with various oxygen flow rates. The annealing influence on the yttrium oxide film microstructure is investigated. The oxygen flow shows a hysteresis behavior on the deposition rate. With a low oxygen flow rate, the so called metallic mode process with a high deposition rate (up to 1.4µm/h was achieved, while with a high oxygen flow rate, the process was considered to be in the poisoned mode with an extremely low deposition rate (around 20nm/h. X-ray diffraction (XRD results show that the yttrium oxide films that were produced in the metallic mode represent a mixture of different crystal structures including the metastable monoclinic phase and the stable cubic phase, while the poisoned mode products show a dominating monoclinic phase. The thin films prepared in metallic mode have relatively dense structures with less porosity. Annealing at 600 °C for 15h, as a structure stabilizing process, caused a phase transformation that changes the metastable monoclinic phase to stable cubic phase for both poisoned mode and metallic mode. The composition of yttrium oxide thin films changed from nonstoichiometric to stoichiometric together with a lattice parameter variation during annealing process. For the metallic mode deposition however, cracks were formed due to the thermal expansion coefficient difference between thin film and the substrate material which was not seen in poisoned mode deposition. The yttrium oxide thin films that deposited in different modes give various application options as a nuclear material.

  4. Multi-Material Front Contact for 19% Thin Film Solar Cells

    Directory of Open Access Journals (Sweden)

    Joop van Deelen

    2016-02-01

    Full Text Available The trade-off between transmittance and conductivity of the front contact material poses a bottleneck for thin film solar panels. Normally, the front contact material is a metal oxide and the optimal cell configuration and panel efficiency were determined for various band gap materials, representing Cu(In,GaSe2 (CIGS, CdTe and high band gap perovskites. Supplementing the metal oxide with a metallic copper grid improves the performance of the front contact and aims to increase the efficiency. Various front contact designs with and without a metallic finger grid were calculated with a variation of the transparent conductive oxide (TCO sheet resistance, scribing area, cell length, and finger dimensions. In addition, the contact resistance and illumination power were also assessed and the optimal thin film solar panel design was determined. Adding a metallic finger grid on a TCO gives a higher solar cell efficiency and this also enables longer cell lengths. However, contact resistance between the metal and the TCO material can reduce the efficiency benefit somewhat.

  5. Non-ohmic transport behavior in ultra-thin gold films

    International Nuclear Information System (INIS)

    Alkhatib, A.; Souier, T.; Chiesa, M.

    2011-01-01

    Highlights: → C-AFM study on ultra-thin gold films. → Connection between ultra-thin film morphology and lateral electrical transport. → Transition between ohmic and non-ohmic behavior. → Electrical transition correlation to the film structure continuity. → Direct and indirect tunneling regimes related to discontinuous structures. - Abstract: Structure and local lateral electrical properties of Au films of thicknesses ranging from 10 to 140 nm are studied using conductive atomic force microscopy. Comparison of current maps taken at different thicknesses reveals surprising highly resistive regions (10 10 -10 11 Ω), the density of which increases strongly at lower thickness. The high resistivity is shown to be directly related to discontinuities in the metal sheet. Local I-V curves are acquired to show the nature of electrical behavior relative to thickness. Results show that in Au films of higher thickness the electrical behavior is ohmic, while it is non-ohmic in highly discontinuous films of lower thickness, with the transition happening between 34 and 39 nm. The non-ohmic behavior is explained with tunneling occurring between separated Au islands. The results explain the abrupt increase of electrical resistivity at lower thin film thicknesses.

  6. Electroresistance Effect in Gold Thin Film Induced by Ionic-Liquid-Gated Electric Double Layer

    NARCIS (Netherlands)

    Nakayama, Hiroyasu; Ye, Jianting; Ohtani, Takashi; Fujikawa, Yasunori; Ando, Kazuya; Iwasa, Yoshihiro; Saitoh, Eiji

    Electroresistance effect was detected in a metallic thin film using ionic-liquid-gated electric-double-layer transistors (EDLTs). We observed reversible modulation of the electric resistance of a Au thin film. In this system, we found that an electric double layer works as a nanogap capacitor with

  7. Epitaxial thin film growth of LiH using a liquid-Li atomic template

    International Nuclear Information System (INIS)

    Oguchi, Hiroyuki; Ikeshoji, Tamio; Orimo, Shin-ichi; Ohsawa, Takeo; Shiraki, Susumu; Hitosugi, Taro; Kuwano, Hiroki

    2014-01-01

    We report on the synthesis of lithium hydride (LiH) epitaxial thin films through the hydrogenation of a Li melt, forming abrupt LiH/MgO interface. Experimental and first-principles molecular dynamics studies reveal a comprehensive microscopic picture of the crystallization processes, which sheds light on the fundamental atomistic growth processes that have remained unknown in the vapor-liquid-solid method. We found that the periodic structure that formed, because of the liquid-Li atoms at the film/MgO-substrate interface, serves as an atomic template for the epitaxial growth of LiH crystals. In contrast, films grown on the Al 2 O 3 substrates indicated polycrystalline films with a LiAlO 2 secondary phase. These results and the proposed growth process provide insights into the preparation of other alkaline metal hydride thin films on oxides. Further, our investigations open the way to explore fundamental physics and chemistry of metal hydrides including possible phenomena that emerge at the heterointerfaces of metal hydrides

  8. 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.

  9. 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.

  10. Remote plasma deposition of textured zinc oxide with focus on thin film solar cell applications : material properties, plasma processes and film growth

    NARCIS (Netherlands)

    Groenen, R.

    2005-01-01

    Simultaneously possessing transparency in the visible region, close to that of insulators, and electrical conductivity, close to that of metals, transparent conducting oxide (TCO) thin films form a highly attractive class of materials for a wide variety of applications like thin film solar cells,

  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. Semi-automatic spray pyrolysis deposition of thin, transparent, titania films as blocking layers for dye-sensitized and perovskite solar cells.

    Science.gov (United States)

    Krýsová, Hana; Krýsa, Josef; Kavan, Ladislav

    2018-01-01

    For proper function of the negative electrode of dye-sensitized and perovskite solar cells, the deposition of a nonporous blocking film is required on the surface of F-doped SnO 2 (FTO) glass substrates. Such a blocking film can minimise undesirable parasitic processes, for example, the back reaction of photoinjected electrons with the oxidized form of the redox mediator or with the hole-transporting medium can be avoided. In the present work, thin, transparent, blocking TiO 2 films are prepared by semi-automatic spray pyrolysis of precursors consisting of titanium diisopropoxide bis(acetylacetonate) as the main component. The variation in the layer thickness of the sprayed films is achieved by varying the number of spray cycles. The parameters investigated in this work were deposition temperature (150, 300 and 450 °C), number of spray cycles (20-200), precursor composition (with/without deliberately added acetylacetone), concentration (0.05 and 0.2 M) and subsequent post-calcination at 500 °C. The photo-electrochemical properties were evaluated in aqueous electrolyte solution under UV irradiation. The blocking properties were tested by cyclic voltammetry with a model redox probe with a simple one-electron-transfer reaction. Semi-automatic spraying resulted in the formation of transparent, homogeneous, TiO 2 films, and the technique allows for easy upscaling to large electrode areas. The deposition temperature of 450 °C was necessary for the fabrication of highly photoactive TiO 2 films. The blocking properties of the as-deposited TiO 2 films (at 450 °C) were impaired by post-calcination at 500 °C, but this problem could be addressed by increasing the number of spray cycles. The modification of the precursor by adding acetylacetone resulted in the fabrication of TiO 2 films exhibiting perfect blocking properties that were not influenced by post-calcination. These results will surely find use in the fabrication of large-scale dye-sensitized and perovskite solar

  13. Molecular dynamics simulations of disjoining pressure effects in ultra-thin water films on a metal surface

    Science.gov (United States)

    Hu, Han; Sun, Ying

    2013-11-01

    Disjoining pressure, the excess pressure in an ultra-thin liquid film as a result of van der Waals interactions, is important in lubrication, wetting, flow boiling, and thin film evaporation. The classic theory of disjoining pressure is developed for simple monoatomic liquids. However, real world applications often utilize water, a polar liquid, for which fundamental understanding of disjoining pressure is lacking. In the present study, molecular dynamics (MD) simulations are used to gain insights into the effect of disjoining pressure in a water thin film. Our MD models were firstly validated against Derjaguin's experiments on gold-gold interactions across a water film and then verified against disjoining pressure in an argon thin film using the Lennard-Jones potential. Next, a water thin film adsorbed on a gold surface was simulated to examine the change of vapor pressure with film thickness. The results agree well with the classic theory of disjoining pressure, which implies that the polar nature of water molecules does not play an important role. Finally, the effects of disjoining pressure on thin film evaporation in nanoporous membrane and on bubble nucleation are discussed.

  14. Electron Microscopy Characterization of Vanadium Dioxide Thin Films and Nanoparticles

    Science.gov (United States)

    Rivera, Felipe

    Vanadium dioxide (VO_2) is a material of particular interest due to its exhibited metal to insulator phase transition at 68°C that is accompanied by an abrupt and significant change in its electronic and optical properties. Since this material can exhibit a reversible drop in resistivity of up to five orders of magnitude and a reversible drop in infrared optical transmission of up to 80%, this material holds promise in several technological applications. Solid phase crystallization of VO_2 thin films was obtained by a post-deposition annealing process of a VO_{x,x approx 2} amorphous film sputtered on an amorphous silicon dioxide (SiO_2) layer. Scanning electron microscopy (SEM) and electron-backscattered diffraction (EBSD) were utilized to study the morphology of the solid phase crystallization that resulted from this post-deposition annealing process. The annealing parameters ranged in temperature from 300°C up to 1000°C and in time from 5 minutes up to 12 hours. Depending on the annealing parameters, EBSD showed that this process yielded polycrystalline vanadium dioxide thin films, semi-continuous thin films, and films of isolated single-crystal particles. In addition to these films on SiO_2, other VO_2 thin films were deposited onto a-, c-, and r-cuts of sapphire and on TiO_2(001) heated single-crystal substrates by pulsed-laser deposition (PLD). The temperature of the substrates was kept at ˜500°C during deposition. EBSD maps and orientation imaging microscopy were used to study the epitaxy and orientation of the VO_2 grains deposited on the single crystal substrates, as well as on the amorphous SiO_2 layer. The EBSD/OIM results showed that: 1) For all the sapphire substrates analyzed, there is a predominant family of crystallographic relationships wherein the rutile VO_2{001} planes tend to lie parallel to the sapphire's {10-10} and the rutile VO_2{100} planes lie parallel to the sapphire's {1-210} and {0001}. Furthermore, while this family of

  15. Cost reduction by using micro-fingers in thin film silicon modules

    Energy Technology Data Exchange (ETDEWEB)

    Slooff, L.H.; Bosman, J.; Loffler, J.; Budel, T. [ECN Solar Energy, Petten (Netherlands)

    2013-06-15

    A finite element electrical model is described that can be used to calculate the performance of monolithic thin film photovoltaic modules. The model is suitable for all type of thin film modules, like e.g. p-i-n a-Si:H, CIGS and polymer based modules and it includes losses due to interconnection. Using this model a parameter study is performed for a-Si:H cells with the aim to reduce metal consumption in the cell and interconnection. It is shown that a reduction in metal consumption by a factor 1.3 can be achieved with only marginal loss in performance if short cell are used with very short fingers.

  16. Swift heavy ion induced surface and microstructural evolution in metallic glass thin films

    International Nuclear Information System (INIS)

    Thomas, Hysen; Thomas, Senoy; Ramanujan, Raju V.; Avasthi, D.K.; Al- Omari, I.A.; Al-Harthi, Salim; Anantharaman, M.R.

    2012-01-01

    Swift heavy ion induced changes in microstructure and surface morphology of vapor deposited Fe–Ni based metallic glass thin films have been investigated by using atomic force microscopy, X-ray diffraction and transmission electron microscopy. Ion beam irradiation was carried out at room temperature with 103 MeV Au 9+ beam with fluences ranging from 3 × 10 11 to 3 × 10 13 ions/cm 2 . The atomic force microscopy images were subjected to power spectral density analysis and roughness analysis using an image analysis software. Clusters were found in the image of as-deposited samples, which indicates that the film growth is dominated by the island growth mode. As-deposited films were amorphous as evidenced from X-ray diffraction; however, high resolution transmission electron microscopy measurements revealed a short range atomic order in the samples with crystallites of size around 3 nm embedded in an amorphous matrix. X-ray diffraction pattern of the as-deposited films after irradiation does not show any appreciable changes, indicating that the passage of swift heavy ions stabilizes the short range atomic ordering, or even creates further amorphization. The crystallinity of the as-deposited Fe–Ni based films was improved by thermal annealing, and diffraction results indicated that ion beam irradiation on annealed samples results in grain fragmentation. On bombarding annealed films, the surface roughness of the films decreased initially, then, at higher fluences it increased. The observed change in surface morphology of the irradiated films is attributed to the interplay between ion induced sputtering, volume diffusion and surface diffusion.

  17. The Influence of Doping with Transition Metal Ions on the Structure and Magnetic Properties of Zinc Oxide Thin Films

    Directory of Open Access Journals (Sweden)

    Jenica Neamtu

    2014-01-01

    Full Text Available Zn1−xNixO (x=0.03÷0.10 and Zn1−xFexO (x=0.03÷0.15 thin films were synthesized by sol-gel method. The structure and the surface morphology of zinc oxide thin films doped with transition metal (TM ions have been investigated by X-ray diffraction (XRD and atomic force microscopy (AFM. The magnetic studies were done using vibrating sample magnetometer (VSM at room temperature. Experimental results revealed that the substitution of Ni ions in ZnO wurtzite lattice for the contents x=0.03÷0.10 (Ni2+ leads to weak ferromagnetism of thin films. For Zn1-xFexO with x=0.03÷0.05, the Fe3+ ions are magnetic coupling by superexchange interaction via oxygen ions in wurtzite structure. For x=0.10÷0.15 (Fe3+ one can observe the increasing of secondary phase of ZnFe2O4 spinel. The Zn0.9Fe0.1O film shows a superparamagnetic behavior due to small crystallite sizes and the net spin magnetic moments arisen from the interaction between the iron ions through an oxygen ion in the spinel structure.

  18. 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.

  19. 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.

  20. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-15

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

  2. Nanocomposite oxide thin films grown by pulsed energy beam deposition

    International Nuclear Information System (INIS)

    Nistor, M.; Petitmangin, A.; Hebert, C.; Seiler, W.

    2011-01-01

    Highly non-stoichiometric indium tin oxide (ITO) thin films were grown by pulsed energy beam deposition (pulsed laser deposition-PLD and pulsed electron beam deposition-PED) under low oxygen pressure. The analysis of the structure and electrical transport properties showed that ITO films with a large oxygen deficiency (more than 20%) are nanocomposite films with metallic (In, Sn) clusters embedded in a stoichiometric and crystalline oxide matrix. The presence of the metallic clusters induces specific transport properties, i.e. a metallic conductivity via percolation with a superconducting transition at low temperature (about 6 K) and the melting and freezing of the In-Sn clusters in the room temperature to 450 K range evidenced by large changes in resistivity and a hysteresis cycle. By controlling the oxygen deficiency and temperature during the growth, the transport and optical properties of the nanocomposite oxide films could be tuned from metallic-like to insulating and from transparent to absorbing films.

  3. Development of microforming process combined with thin film transfer printing

    Directory of Open Access Journals (Sweden)

    Koshimizu Kazushi

    2015-01-01

    Full Text Available Microforming receives a lot of attentions in the recent years due to the increased use of microparts in electronics and medical sectors. For the further functionalization of these micro devices, high functional surface with noble metals are strongly required for the devices in bio- and medical fields, such as bio-sensors. To realize the submillimeter structure of metal foils and micro to nanometer structures in one forming process, the present study proposes a combined process of microforming for metal foils and transfer printing of gold (Au thin films. To clarify the availability of the proposed combined process, transferability of Au thin films under micro bulging deformation are investigated. 0.1 mm-thick pure titanium (Ti foils and 100 nm-thick Au films were used as blank and functional materials, respectively. The forming tests of the proposed process were conducted. With increasing strain of Ti foils, Au TP areas increase. By this experiment, it’s confirmed that the hydrogen reduction of oxidation layers and the strain of Ti foil are significant factor for Au TP on Ti foils.

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

    Science.gov (United States)

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

    2018-03-06

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

  5. Conductivity behavior of very thin gold films ruptured by mass transport in photosensitive polymer film

    Energy Technology Data Exchange (ETDEWEB)

    Linde, Felix; Sekhar Yadavalli, Nataraja; Santer, Svetlana [Department of Experimental Physics, Institute for Physics and Astronomy, University of Potsdam, 14476 Potsdam (Germany)

    2013-12-16

    We report on conductivity behavior of very thin gold layer deposited on a photosensitive polymer film. Under irradiation with light interference pattern, the azobenzene containing photosensitive polymer film undergoes deformation at which topography follows a distribution of intensity, resulting in the formation of a surface relief grating. This process is accompanied by a change in the shape of the polymer surface from flat to sinusoidal together with a corresponding increase in surface area. The gold layer placed above deforms along with the polymer and ruptures at a strain of 4%. The rupturing is spatially well defined, occurring at the topographic maxima and minima resulting in periodic cracks across the whole irradiated area. We have shown that this periodic micro-rupturing of a thin metal film has no significant impact on the electrical conductivity of the films. We suggest a model to explain this phenomenon and support this by additional experiments where the conductivity is measured in a process when a single nanoscopic scratch is formed with an AFM tip. Our results indicate that in flexible electronic materials consisting of a polymer support and an integrated metal circuit, nano- and micro cracks do not alter significantly the behavior of the conductivity unless the metal is disrupted completely.

  6. Secondary electron emission from metals and semi-conductor compounds

    International Nuclear Information System (INIS)

    Ono, Susumu; Kanaya, Koichi

    1979-01-01

    Attempt was made to present the sufficient solution of the secondary electron yield of metals and semiconductor compounds except insulators, applying the free electron scattering theory to the absorption of secondary electrons generated within a solid target. The paper is divided into the sections describing absorption coefficient and escape depth, quantitative characteristics of secondary yield, angular distribution of secondary electron emission, effect of incident angle to secondary yield, secondary electron yield transmitted, and lateral distribution of secondary electron emission, besides introduction and conclusion. The conclusions are as follows. Based on the exponential power law for screened atomic potential, secondary electron emission due to both primary and backscattered electrons penetrating into metallic elements and semi-conductive compounds is expressed in terms of the ionization loss in the first collision for escaping secondary electrons. The maximum yield and the corresponding primary energy can both consistently be derived as the functions of three parameters: atomic number, first ionization energy and backscattering coefficient. The yield-energy curve as a function of the incident energy and the backscattering coefficient is in good agreement with the experimental results. The energy dependence of the yield in thin films and the lateral distribution of secondary yield are derived as the functions of the backscattering coefficient and the primary energy. (Wakatsuki, Y.)

  7. In situ spectroscopic ellipsometry as a surface sensitive tool to probe thin film growth

    International Nuclear Information System (INIS)

    Liu, C.

    1999-01-01

    Sputtered thin film and multilayer x-ray mirrors are made routinely at the Advanced Photon Source (APS) for the APS users. Precise film growth control and characterization are very critical in fabricating high-quality x-ray mirrors. Film thickness calibrations are carried out using in situ and ex situ spectroscopic ellipsometry, interferometry, and x-ray scattering. To better understand the growth and optical properties of different thin film systems, we have carried out a systematic study of sputtered thin films of Au, Rh, Pg Pd, Cu, and Cr, using in situ ellipsometry. Multiple data sets were obtained in situ for each film material with incremental thicknesses and were analyzed with their correlation in mind. We found that in situ spectroscopic ellipsometry as a surface-sensitive tool can also be used to probe the growth and morphology of the thin film system. This application of in situ spectroscopic ellipsometry for metal thin film systems will be discussed

  8. Mathematical modelling of thin films growth and calculation of coefficients reflection, transmission and absorption waves

    Science.gov (United States)

    Istratov, A. V.; Gerke, M. N.

    2018-01-01

    Progress in nano- and microsystem technology is directly related to the development of thin-film technologies. At the present time, thin metal films can serve as the basis for the creation of new instruments for nanoelectronics. One of the important parameters of thin films affecting the characteristics of devices is their optical properties. That is why the island structures, whose optical properties, can change in a wide range depending on their morphology, are of increasing interest. However, despite the large amount of research conducted by scientists from different countries, many questions about the optimal production and use of thin films remain unresolved.

  9. Thin Film Interference: An Experiment with Microwaves and Paraffin Oil

    Science.gov (United States)

    D'Anna, Michele; Corridoni, Tommaso

    2015-01-01

    Thin film interference manifests itself in a wide range of visually pleasing situations in everyday life (in the colored effects caused by a drop of oil on water, in soap bubbles, etc.) and is also involved in important technical applications (semi-reflecting mirrors, anti-reflection lenses, etc.). Yet, despite its familiarity, high school…

  10. Fabrication and Characterization of CZTS Thin Films Prepared by the Sulfurization of RF-Sputtered Stacked Metal Precursors

    Science.gov (United States)

    Abusnina, Mohamed; Moutinho, Helio; Al-Jassim, Mowafak; DeHart, Clay; Matin, Mohammed

    2014-09-01

    In this work, Cu2ZnSnS4 (CZTS) thin films were prepared by the sulfurization of metal precursors deposited sequentially via radio frequency magnetron sputtering on Mo-coated soda-lime glass. The stack order of the precursors was Mo/Zn/Sn/Cu. Sputtered precursors were annealed in sulfur atmosphere with nine different conditions to study the impact of sulfurization time and substrate temperature on the structural, morphological, and optical properties of the final CZTS films. X-ray fluorescence was used to determine the elemental composition ratio of the metal precursors. Final CZTS films were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). XRD and EDS were combined to investigate the films' structure and to identify the presence of secondary phases. XRD analysis indicated an improvement in film crystallinity with an increase of the substrate temperature and annealing times. Also indicated was the minimization and/or elimination of secondary phases when the films experienced longer annealing time. EDS revealed slight Sn loss in films sulfurized at 550°C; however, an increase of the sulfurization temperature to 600°C did not confirm these results. SEM study showed that films treated with higher temperatures exhibited dense morphology, indicating the completion of the sulfurization process. The estimated absorption coefficient was on the order of 104 cm-1 for all CZTS films, and the values obtained for the optical bandgap energy of the films were between 1.33 eV and 1.52 eV.

  11. Metal-insulator transition in SrTi{sub 1−x}V{sub x}O{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Man [Department of Physics, University of Virginia, 382 McCormick Rd., Charlottesville, Virginia 22904 (United States); Wolf, Stuart A. [Department of Physics, University of Virginia, 382 McCormick Rd., Charlottesville, Virginia 22904 (United States); Department of Materials Science and Engineering, University of Virginia, 395 McCormick Rd., Charlottesville, Virginia 22904 (United States); Lu, Jiwei [Department of Materials Science and Engineering, University of Virginia, 395 McCormick Rd., Charlottesville, Virginia 22904 (United States)

    2013-11-25

    Epitaxial SrTi{sub 1−x}V{sub x}O{sub 3} (0 ≤ x ≤ 1) thin films were grown on (001)-oriented (LaAlO{sub 3}){sub 0.3}(Sr{sub 2}AlTaO{sub 6}){sub 0.7} (LSAT) substrates using the pulsed electron-beam deposition technique. The transport study revealed a temperature driven metal-insulator transition (MIT) at 95 K for x = 0.67. The films with higher vanadium concentration (x > 0.67) were metallic corresponding to a Fermi liquid system. In the insulating phase (x < 0.67), the resistivity behavior was governed by Mott's variable range hopping mechanism. The possible mechanisms for the induced MIT are discussed, including the effects of electron correlation, lattice distortion, and Anderson localization.

  12. Nano-crystallization in ZnO-doped In{sub 2}O{sub 3} thin films via excimer laser annealing for thin-film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Mami N., E-mail: f-mami@ms.naist.jp; Ishikawa, Yasuaki; Bermundo, Juan Paolo Soria; Uraoka, Yukiharu [Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192 (Japan); Ishihara, Ryoichi; Cingel, Johan van der; Mofrad, Mohammad R. T. [Delft University of Technology, Feldmannweg 17, P.O. Box 5053, 2600 GB Delft (Netherlands); Kawashima, Emi; Tomai, Shigekazu; Yano, Koki [Idemitsu Kosan Co., Ltd., 1280 Kami-izumi, Sodegaura, Chiba, 299-0293 (Japan)

    2016-06-15

    In a previous work, we reported the high field effect mobility of ZnO-doped In{sub 2}O{sub 3} (IZO) thin film transistors (TFTs) irradiated by excimer laser annealing (ELA) [M. Fujii et al., Appl. Phys. Lett. 102, 122107 (2013)]. However, a deeper understanding of the effect of ELA on the IZO film characteristics based on crystallinity, carrier concentrations, and optical properties is needed to control localized carrier concentrations for fabricating self-aligned structures in the same oxide film and to adequately explain the physical characteristics. In the case of as-deposited IZO film used as the channel, a high carrier concentration due to a high density of oxygen vacancies was observed; such a film does not show the required TFT characteristics but can act as a conductive film. We achieved a decrease in the carrier concentration of IZO films by crystallization using ELA. This means that ELA can form localized conductive or semi-conductive areas on the IZO film. We confirmed that the reason for the carrier concentration decrease was the decrease of oxygen-deficient regions and film crystallization. The annealed IZO films showed nano-crystalline phase, and the temperature at the substrate was substantially less than the temperature limit for flexible films such as plastic, which is 50°C. This paves the way for the formation of self-aligned structures and separately formed conductive and semi-conductive regions in the same oxide film.

  13. The Microstructures and Electrical Resistivity of (Al, Cr, TiFeCoNiOx High-Entropy Alloy Oxide Thin Films

    Directory of Open Access Journals (Sweden)

    Chun-Huei Tsau

    2015-01-01

    Full Text Available The (Al, Cr, TiFeCoNi alloy thin films were deposited by PVD and using the equimolar targets with same compositions from the concept of high-entropy alloys. The thin films became metal oxide films after annealing at vacuum furnace for a period; and the resistivity of these thin films decreased sharply. After optimum annealing treatment, the lowest resistivity of the FeCoNiOx, CrFeCoNiOx, AlFeCoNiOx, and TiFeCoNiOx films was 22, 42, 18, and 35 μΩ-cm, respectively. This value is close to that of most of the metallic alloys. This phenomenon was caused by delaminating of the alloy oxide thin films because the oxidation was from the surfaces of the thin films. The low resistivity of these oxide films was contributed to the nonfully oxidized elements in the bottom layers and also vanishing of the defects during annealing.

  14. Texture-dependent twin formation in nanocrystalline thin Pd films

    International Nuclear Information System (INIS)

    Wang, B.; Idrissi, H.; Shi, H.; Colla, M.S.; Michotte, S.; Raskin, J.P.; Pardoen, T.; Schryvers, D.

    2012-01-01

    Nanocrystalline Pd films were produced by electron-beam evaporation and sputter deposition. The electron-beam-evaporated films reveal randomly oriented nanograins with a relatively high density of growth twins, unexpected in view of the high stacking fault energy of Pd. In contrast, sputter-deposited films show a clear 〈1 1 1〉 crystallographic textured nanostructure without twins. These results provide insightful information to guide the generation of microstructures with enhanced strength/ductility balance in high stacking fault energy nanocrystalline metallic thin films.

  15. Thickness-dependent radiative properties of Y-Ba-Cu-O thin films

    International Nuclear Information System (INIS)

    Phelan, P.E.; Chen, G.; Tien, C.L.

    1991-01-01

    Some applications of high-temperature superconductors where their thermal radiative behavior is important, such as bolometers, optically-triggered switches and gates, and space-cooled electronics, required the superconductor to be in the form of a very thin film whose radiative behavior cannot be adequately represented by a semi-infinite analysis. Two properties of particular importance are the film absorptance and the combined film/substrate absorptance, which are crucial to the operation of many devices. This paper reports on calculations of the absorptance of superconducting-state Y-Ba-Cu-O films on MgO substrates which suggest that for film thicknesses less than about 50 nm, a decrease in the film thickness leads to an increase in both the film absorptance and the film/substrate absorptance. Furthermore, the film absorptance is maximum at some optimal value of film thickness. Assuming the film to be a smooth, continuous slab with a refractive index equal to that of the bulk Y-Ba-Cu-O is verified, at least in the normal state and for films as thin as 35 nm, by room-temperature reflectance and transmittance measurements

  16. Strain Induced Magnetism in SrRuO3 Epitaxial Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Grutter, A.; Wong, F.; Arenholz, E.; Liberati, M.; Suzuki, Y.

    2010-01-10

    Epitaxial SrRuO{sub 3} thin films were grown on SrTiO{sub 3}, (LaAlO{sub 3}){sub 0.3}(SrAlO{sub 3}){sub 0.7} and LaAlO{sub 3} substrates inducing different biaxial compressive strains. Coherently strained SrRuO{sub 3} films exhibit enhanced magnetization compared to previously reported bulk and thin film values of 1.1-1.6 {micro}{sub B} per formula unit. A comparison of (001) and (110) SrRuO{sub 3} films on each substrate indicates that films on (110) oriented have consistently higher saturated moments than corresponding (001) films. These observations indicate the importance of lattice distortions in controlling the magnetic ground state in this transitional metal oxide.

  17. Optical resonance analysis of reflected long period fiber gratings with metal film overlay

    Science.gov (United States)

    Zhang, Guiju; Cao, Bing; Wang, Chinua; Zhao, Minfu

    2008-11-01

    We present the experimental results of a novel single-ended reflecting surface plasma resonance (SPR) based long period fiber grating (LPFG) sensor. A long period fiber grating sensing device is properly designed and fabricated with a pulsed CO2 laser writing system. Different nm-thick thin metal films are deposited on the fiber cladding and the fiber end facet for the excitation of surface plasma waves (SPWs) and the reflection of the transmission spectrum of the LPFG with doubled interaction between metal-dielectric interfaces of the fiber to enhance the SPW of the all-fiber SPR-LPFG sensing system. Different thin metal films with different thicknesses are investigated. The effect of the excited SPW transmission along the fiber cladding-metal interface with silver and aluminum films is observed. It is found that different thicknesses of the metal overlay show different resonant behaviors in terms of resonance peak situation, bandwidth and energy loss. Within a certain range, thinner metal film shows narrower bandwidth and deeper peak loss.

  18. Topotactic synthesis of strontium cobalt oxyhydride thin film with perovskite structure

    OpenAIRE

    Tsukasa Katayama; Akira Chikamatsu; Hideyuki Kamisaka; Yuichi Yokoyama; Yasuyuki Hirata; Hiroki Wadati; Tomoteru Fukumura; Tetsuya Hasegawa

    2015-01-01

    The substitution of hydride anions (H−) into transition metal oxides has recently become possible through topotactic reactions or high-pressure synthesis methods. However, the fabrication of oxyhydrides is still difficult because of their inherently less-stable frameworks. In this study, we successfully fabricated perovskite SrCoOxHy thin films via the topotactic hydride doping of brownmillerite SrCoO2.5 epitaxial thin films with CaH2. The perovskite-type cation framework was maintained durin...

  19. 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

  20. Magnetoresistance Versus Oxygen Deficiency in Epi-stabilized SrRu1 - x Fe x O3 - δ Thin Films

    Science.gov (United States)

    Dash, Umasankar; Acharya, Susant Kumar; Lee, Bo Wha; Jung, Chang Uk

    2017-03-01

    Oxygen vacancies have a profound effect on the magnetic, electronic, and transport properties of transition metal oxide materials. Here, we studied the influence of oxygen vacancies on the magnetoresistance (MR) properties of SrRu1 - x Fe x O3 - δ epitaxial thin films ( x = 0.10, 0.20, and 0.30). For this purpose, we synthesized highly strained epitaxial SrRu1 - x Fe x O3 - δ thin films with atomically flat surfaces containing different amounts of oxygen vacancies using pulsed laser deposition. Without an applied magnetic field, the films with x = 0.10 and 0.20 showed a metal-insulator transition, while the x = 0.30 thin film showed insulating behavior over the entire temperature range of 2-300 K. Both Fe doping and the concentration of oxygen vacancies had large effects on the negative MR contributions. For the low Fe doping case of x = 0.10, in which both films exhibited metallic behavior, MR was more prominent in the film with fewer oxygen vacancies or equivalently a more metallic film. For semiconducting films, higher MR was observed for more semiconducting films having more oxygen vacancies. A relatively large negative MR ( 36.4%) was observed for the x = 0.30 thin film with a high concentration of oxygen vacancies ( δ = 0.12). The obtained results were compared with MR studies for a polycrystal of (Sr1 - x La x )(Ru1 - x Fe x )O3. These results highlight the crucial role of oxygen stoichiometry in determining the magneto-transport properties in SrRu1 - x Fe x O3 - δ thin films.

  1. All-back-Schottky-contact thin-film photovoltaics

    Science.gov (United States)

    Nardone, Marco

    2016-02-01

    The concept of All-Back-Schottky-Contact (ABSC) thin-film photovoltaic (TFPV) devices is introduced and evaluated using 2D numerical simulation. Reach-through Schottky junctions due to two metals of different work functions in an alternating, side-by-side pattern along the non-illuminated side generate the requisite built-in field. It is shown that our simulation method quantitatively describes existing data for a recently demonstrated heterojunction thin-film cell with interdigitated back contacts (IBCs) of one metal type. That model is extended to investigate the performance of ABSC devices with bimetallic IBCs within a pertinent parameter space. Our calculations indicate that 20% efficiency is achievable with micron-scale features and sufficient surface passivation. Bimetallic, micron-scale IBCs are readily fabricated using photo-lithographic techniques and the ABSC design allows for optically transparent surface passivation layers that need not be electrically conductive. The key advantages of the ABSC-TFPV architecture are that window layers, buffer layers, heterojunctions, and module scribing are not required because both contacts are located on the back of the device.

  2. Controlling the antibacterial activity of CuSn thin films by varying the contents of Sn

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Yujin; Park, Juyun; Kim, Dong-Woo; Kim, Hakjun; Kang, Yong-Cheol, E-mail: yckang@pknu.ac.kr

    2016-12-15

    Highlights: • We deposit CuSn thin films on a Si substrate with various Cu/Sn ratio. • Antibacterial activities of CuSn thin films increased as the ratio of Cu and the contact time increased. • XPS was utilized to assign the chemical environment of CuSn thin films before and after antibacterial test. - Abstract: We investigated antibacterial activity of CuSn thin films against Gram positive Staphylococcus aureus (S. aureus). CuSn thin films with different Cu to Sn ratios were deposited on Si(100) by radio frequency (RF) magnetron sputtering method using Cu and Sn metal anodes. The film thickness was fixed at 200 nm by varying the sputtering time and RF power on the metal targets. The antibacterial test was conducted in various conditions such as different contact times and Cu to Sn ratios in the CuSn films. The antibacterial activities of CuSn thin films increased as the ratio of Cu and the contact time between the film and bacteria suspension increased execpt in the case of CuSn-83. The oxidation states of Cu and Sn and the chemical composition of CuSn thin films before and after the antibacterial test were investigated by X-ray photoelectron spectroscopy (XPS). When the contact time was fixed, the Cu species was further oxidized as the RF power on Cu target increased. The intensity of Sn 3d decreased with increasing Cu ratio. When the sample was fixed, the peak intensity of Sn 3d decreased as the contact time increased due to the permeation of Sn into the cell.

  3. Deposition of Y thin films by nanosecond UV pulsed laser ablation for photocathode application

    International Nuclear Information System (INIS)

    Lorusso, A.; Anni, M.; Caricato, A.P.; Gontad, F.; Perulli, A.; Taurino, A.; Perrone, A.; Chiadroni, E.

    2016-01-01

    In this work, yttrium (Y) thin films have been deposited on Si (100) substrates by the pulsed laser deposition technique. Ex-situ morphological, structural and optical characterisations of such films have been performed by scanning electron microscopy, X-ray diffractometry, atomic force microscopy and ellipsometry. Polycrystalline films with a thickness of 1.2 μm, homogenous with a root mean square roughness of about 2 nm, were obtained by optimised laser irradiation conditions. Despite the relatively high thickness, the films resulted very adherent to the substrates. The high quality of such thin films is important to the synthesis of metallic photocathodes based on Y thin film, which could be used as electron sources of high photoemission performance in radio-frequency guns. - Highlights: • Pulsed laser deposition of Yttrium thin films is investigated. • 1.2 μm thick films were deposited with very low RMS roughness. • The Y thin films were very adherent to the Si substrate • Optical characterisation showed a very high absorption coefficient for the films.

  4. Deposition of Y thin films by nanosecond UV pulsed laser ablation for photocathode application

    Energy Technology Data Exchange (ETDEWEB)

    Lorusso, A. [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce (Italy); Istituto Nazionale di Fisica Nucleare-Lecce, 73100 Lecce (Italy); Anni, M. [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce (Italy); Caricato, A.P. [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce (Italy); Istituto Nazionale di Fisica Nucleare-Lecce, 73100 Lecce (Italy); Gontad, F., E-mail: francisco.gontad@le.infn.it [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce (Italy); Istituto Nazionale di Fisica Nucleare-Lecce, 73100 Lecce (Italy); Perulli, A. [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce (Italy); Taurino, A. [National Research Council, Institute for Microelectronics & Microsystems, 73100 Lecce (Italy); Perrone, A. [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce (Italy); Istituto Nazionale di Fisica Nucleare-Lecce, 73100 Lecce (Italy); Chiadroni, E. [Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare, 00044 Frascati (Italy)

    2016-03-31

    In this work, yttrium (Y) thin films have been deposited on Si (100) substrates by the pulsed laser deposition technique. Ex-situ morphological, structural and optical characterisations of such films have been performed by scanning electron microscopy, X-ray diffractometry, atomic force microscopy and ellipsometry. Polycrystalline films with a thickness of 1.2 μm, homogenous with a root mean square roughness of about 2 nm, were obtained by optimised laser irradiation conditions. Despite the relatively high thickness, the films resulted very adherent to the substrates. The high quality of such thin films is important to the synthesis of metallic photocathodes based on Y thin film, which could be used as electron sources of high photoemission performance in radio-frequency guns. - Highlights: • Pulsed laser deposition of Yttrium thin films is investigated. • 1.2 μm thick films were deposited with very low RMS roughness. • The Y thin films were very adherent to the Si substrate • Optical characterisation showed a very high absorption coefficient for the films.

  5. Direct current magnetron sputtering deposition of InN thin films

    International Nuclear Information System (INIS)

    Cai Xingmin; Hao Yanqing; Zhang Dongping; Fan Ping

    2009-01-01

    In this paper, InN thin films were deposited on Si (1 0 0) and K9 glass by reactive direct current magnetron sputtering. The target was In metal with the purity of 99.999% and the gases were Ar (99.999%) and N 2 (99.999%). The properties of InN thin films were studied. Scanning electron microscopy (SEM) shows that the film surface is very rough and energy dispersive X-ray spectroscopy (EDX) shows that the film contains In, N and very little O. X-ray diffraction (XRD) and Raman scattering reveal that the film mainly contains hexagonal InN. The four-probe measurement shows that InN film is conductive. The transmission measurement demonstrates that the transmission of InN deposited on K9 glass is as low as 0.5% from 400 nm to 800 nm.

  6. Phase formation, thermal stability and magnetic moment of cobalt nitride thin films

    Directory of Open Access Journals (Sweden)

    Rachana Gupta

    2015-09-01

    Full Text Available Cobalt nitride (Co-N thin films prepared using a reactive magnetron sputtering process are studied in this work. During the thin film deposition process, the relative nitrogen gas flow (RN2 was varied. As RN2 increases, Co(N, Co4N, Co3N and CoN phases are formed. An incremental increase in RN2, after emergence of Co4N phase at RN2 = 10%, results in a linear increase of the lattice constant (a of Co4N. For RN2 = 30%, a maximizes and becomes comparable to its theoretical value. An expansion in a of Co4N, results in an enhancement of the magnetic moment, to the extent that it becomes even larger than pure Co. Such larger than pure metal magnetic moment for tetra-metal nitrides (M4N have been theoretically predicted. Incorporation of N atoms in M4N configuration results in an expansion of a (relative to pure metal and enhances the itinerary of conduction band electrons leading to larger than pure metal magnetic moment for M4N compounds. Though a higher (than pure Fe magnetic moment for Fe4N thin films has been evidenced experimentally, higher (than pure Co magnetic moment is evidenced in this work.

  7. Characterization of nanostructured ZnO thin films deposited through vacuum evaporation

    Directory of Open Access Journals (Sweden)

    Jose Alberto Alvarado

    2015-04-01

    Full Text Available This work presents a novel technique to deposit ZnO thin films through a metal vacuum evaporation technique using colloidal nanoparticles (average size of 30 nm, which were synthesized by our research group, as source. These thin films had a thickness between 45 and 123 nm as measured by profilometry. XRD patterns of the deposited thin films were obtained. According to the HRSEM micrographs worm-shaped nanostructures are observed in samples annealed at 600 °C and this characteristic disappears as the annealing temperature increases. The films obtained were annealed from 25 to 1000 °C, showing a gradual increase in transmittance spectra up to 85%. The optical band gaps obtained for these films are about 3.22 eV. The PL measurement shows an emission in the red and in the violet region and there is a correlation with the annealing process.

  8. Influence of metal induced crystallization parameters on the performance of polycrystalline silicon thin film transistors

    International Nuclear Information System (INIS)

    Pereira, L.; Barquinha, P.; Fortunato, E.; Martins, R.

    2005-01-01

    In this work, metal induced crystallization using nickel was employed to obtain polycrystalline silicon by crystallization of amorphous films for thin film transistor applications. The devices were produced through only one lithographic process with a bottom gate configuration using a new gate dielectric consisting of a multi-layer of aluminum oxide/titanium oxide produced by atomic layer deposition. The best results were obtained for TFTs with the active layer of poly-Si crystallized for 20 h at 500 deg. C using a nickel layer of 0.5 nm where the effective mobility is 45.5 cm 2 V -1 s -1 . The threshold voltage, the on/off current ratio and the sub-threshold voltage are, respectively, 11.9 V, 5.55x10 4 and 2.49 V/dec

  9. Indium Tin Oxide thin film gas sensors for detection of ethanol vapours

    International Nuclear Information System (INIS)

    Vaishnav, V.S.; Patel, P.D.; Patel, N.G.

    2005-01-01

    Indium Tin Oxide (ITO: In 2 O 3 + 17% SnO 2 ) thin films grown on alumina substrate at 648 K temperatures using direct evaporation method with two gold pads deposited on the top for electrical contacts were exposed to ethanol vapours (200-2500 ppm). The operating temperature of the sensor was optimized. The sensitivity variation of films having different thickness was studied. The sensitivity of the films deposited on Si substrates was studied. The response of the film with MgO catalytic layer on sensitivity and selectivity was observed. A novel approach of depositing thin stimulating layer of various metals/oxides below the ITO film was tried and tested

  10. Ni-Cr thin film resistor fabrication for GaAs monolithic microwave integrated circuits

    International Nuclear Information System (INIS)

    Vinayak, Seema; Vyas, H.P.; Muraleedharan, K.; Vankar, V.D.

    2006-01-01

    Different Ni-Cr alloys were sputter-deposited on silicon nitride-coated GaAs substrates and covered with a spin-coated polyimide layer to develop thin film metal resistors for GaAs monolithic microwave integrated circuits (MMICs). The contact to the resistors was made through vias in the polyimide layer by sputter-deposited Ti/Au interconnect metal. The variation of contact resistance, sheet resistance (R S ) and temperature coefficient of resistance (TCR) of the Ni-Cr resistors with fabrication process parameters such as polyimide curing thermal cycles and surface treatment given to the wafer prior to interconnect metal deposition has been studied. The Ni-Cr thin film resistors exhibited lower R S and higher TCR compared to the as-deposited Ni-Cr film that was not subjected to thermal cycles involved in the MMIC fabrication process. The change in resistivity and TCR values of Ni-Cr films during the MMIC fabrication process was found to be dependent on the Ni-Cr alloy composition

  11. Fabrication and non-covalent modification of highly oriented thin films of a zeolite-like metal-organic framework (ZMOF) with rho topology

    KAUST Repository

    Shekhah, Osama; Cadiau, Amandine; Eddaoudi, Mohamed

    2015-01-01

    Here we report the fabrication of the first thin film of a zeolite-like metal-organic framework (ZMOF) with rho topology (rho-ZMOF-1, ([In48(HImDC)96]48-)n) in a highly oriented fashion on a gold-functionalized substrate. The oriented rho-ZMOF-1

  12. Epitaxial Pb(Mg1/3Nb2/3)O3 thin films synthesized by metal-organic chemical vapor deposition

    International Nuclear Information System (INIS)

    Bai, G. R.; Streiffer, S. K.; Baumann, P. K.; Auciello, O.; Ghosh, K.; Stemmer, S.; Munkholm, A.; Thompson, Carol; Rao, R. A.; Eom, C. B.

    2000-01-01

    Metal-organic chemical vapor deposition was used to prepare Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) thin films on (001) SrTiO 3 and SrRuO 3 /SrTiO 3 substrates, using solid Mg β-diketonate as the Mg precursor. Parameters including the precursor ratio in the vapor phase, growth temperature, growth rate, and reaction pressure in the reactor chamber were varied in order to determine suitable growth conditions for producing phase-pure, epitaxial PMN films. A cube-on-cube orientation relationship between the thin film and the SrTiO 3 substrate was found, with a (001) rocking curve width of 0.1 degree sign , and in-plane rocking-curve width of 0.8 degree sign . The root-mean-square surface roughness of a 200-nm-thick film on SrTiO 3 was 2 to 3 nm as measured by scanning probe microscopy. The zero-bias dielectric constant and loss measured at room temperature and 10 kHz for a 200-nm-thick film on SrRuO 3 /SrTiO 3 were approximately 1100 and 2%, respectively. The remnant polarization for this film was 16 μC/cm 2 . (c) 2000 American Institute of Physics

  13. Thin film Ag superlens towards lab-on-a-chip integration

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Nielsen, Rasmus Bundgaard; Boltasseva, Alexandra

    2009-01-01

    A thin metal film near-field superlens, as originally suggested by Pendry and realized by Fang et al. and Melville et al., is investigated with emphasis on materials suitable for integration on a lab-on-a-chip platform. A chemically resistant cyclo-olefin copolymer (COC), mr-I-T85 from microresist...... technology, is applied as dielectric matrix/spacer for an Ag thin film superlens. The superlens successfully resolves 80 nm half-pitch gratings when illuminated with UV radiation at a free space wavelength of 365 nm. The superlens design, fabrication and characterization is discussed....

  14. Process for forming epitaxial perovskite thin film layers using halide precursors

    Science.gov (United States)

    Clem, Paul G.; Rodriguez, Mark A.; Voigt, James A.; Ashley, Carol S.

    2001-01-01

    A process for forming an epitaxial perovskite-phase thin film on a substrate. This thin film can act as a buffer layer between a Ni substrate and a YBa.sub.2 Cu.sub.3 O.sub.7-x superconductor layer. The process utilizes alkali or alkaline metal acetates dissolved in halogenated organic acid along with titanium isopropoxide to dip or spin-coat the substrate which is then heated to about 700.degree. C. in an inert gas atmosphere to form the epitaxial film on the substrate. The YBCO superconductor can then be deposited on the layer formed by this invention.

  15. 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

  16. Effect of native oxide layers on copper thin-film tensile properties: A reactive molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Skarlinski, Michael D., E-mail: michael.skarlinski@rochester.edu [Materials Science Program, University of Rochester, Rochester, New York 14627 (United States); Quesnel, David J. [Materials Science Program, University of Rochester, Rochester, New York 14627 (United States); Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627 (United States)

    2015-12-21

    Metal-oxide layers are likely to be present on metallic nano-structures due to either environmental exposure during use, or high temperature processing techniques such as annealing. It is well known that nano-structured metals have vastly different mechanical properties from bulk metals; however, difficulties in modeling the transition between metallic and ionic bonding have prevented the computational investigation of the effects of oxide surface layers. Newly developed charge-optimized many body [Liang et al., Mater. Sci. Eng., R 74, 255 (2013)] potentials are used to perform fully reactive molecular dynamics simulations which elucidate the effects that metal-oxide layers have on the mechanical properties of a copper thin-film. Simulated tensile tests are performed on thin-films while using different strain-rates, temperatures, and oxide thicknesses to evaluate changes in yield stress, modulus, and failure mechanisms. Findings indicate that copper-thin film mechanical properties are strongly affected by native oxide layers. The formed oxide layers have an amorphous structure with lower Cu-O bond-densities than bulk CuO, and a mixture of Cu{sub 2}O and CuO charge character. It is found that oxidation will cause modifications to the strain response of the elastic modulii, producing a stiffened modulii at low temperatures (<75 K) and low strain values (<5%), and a softened modulii at higher temperatures. While under strain, structural reorganization within the oxide layers facilitates brittle yielding through nucleation of defects across the oxide/metal interface. The oxide-free copper thin-film yielding mechanism is found to be a tensile-axis reorientation and grain creation. The oxide layers change the observed yielding mechanism, allowing for the inner copper thin-film to sustain an FCC-to-BCC transition during yielding. The mechanical properties are fit to a thermodynamic model based on classical nucleation theory. The fit implies that the oxidation of the

  17. High-Performance Flexible Thin-Film Transistors Based on Single-Crystal-like Silicon Epitaxially Grown on Metal Tape by Roll-to-Roll Continuous Deposition Process.

    Science.gov (United States)

    Gao, Ying; Asadirad, Mojtaba; Yao, Yao; Dutta, Pavel; Galstyan, Eduard; Shervin, Shahab; Lee, Keon-Hwa; Pouladi, Sara; Sun, Sicong; Li, Yongkuan; Rathi, Monika; Ryou, Jae-Hyun; Selvamanickam, Venkat

    2016-11-02

    Single-crystal-like silicon (Si) thin films on bendable and scalable substrates via direct deposition are a promising material platform for high-performance and cost-effective devices of flexible electronics. However, due to the thick and unintentionally highly doped semiconductor layer, the operation of transistors has been hampered. We report the first demonstration of high-performance flexible thin-film transistors (TFTs) using single-crystal-like Si thin films with a field-effect mobility of ∼200 cm 2 /V·s and saturation current, I/l W > 50 μA/μm, which are orders-of-magnitude higher than the device characteristics of conventional flexible TFTs. The Si thin films with a (001) plane grown on a metal tape by a "seed and epitaxy" technique show nearly single-crystalline properties characterized by X-ray diffraction, Raman spectroscopy, reflection high-energy electron diffraction, and transmission electron microscopy. The realization of flexible and high-performance Si TFTs can establish a new pathway for extended applications of flexible electronics such as amplification and digital circuits, more than currently dominant display switches.

  18. Thickness-modulated anisotropic ferromagnetism in Fe-doped epitaxial HfO2 thin films

    Science.gov (United States)

    Liu, Wenlong; Liu, Ming; Zhang, Ruyi; Ma, Rong; Wang, Hong

    2017-10-01

    Epitaxial tetragonal Fe-doped Hf0.95Fe0.05O2 (FHO) thin films with various thicknesses were deposited on (001)-oriented NdCaAlO4 (NCAO) substrates by using a pulsed laser deposition (PLD) system. The crystal structure and epitaxial nature of the FHO thin films were confirmed by typical x-ray diffraction (XRD) θ-2θ scan and reciprocal space mapping (RSM). The results indicate that two sets of lattice sites exist with two different crystal orientations [(001) and (100)] in the thicker FHO thin films. Further, the intensity of the (100) direction increases with the increase in thicknesses, which should have a significant effect on the anisotropic magnetization of the FHO thin films. Meanwhile, all the FHO thin films possess a tetragonal phase structure. An anisotropy behavior in magnetization has been observed in the FHO thin films. The anisotropic magnetization of the FHO thin films is slowly weakened as the thickness increases. Meanwhile, the saturation magnetization (Ms) of both in-plane and out-of-plane decreases with the increase in the thickness. The change in the anisotropic magnetization and Ms is attributed to the crystal lattice and the variation in the valence of Fe ions. These results indicate that the thickness-modulated anisotropic ferromagnetism of the tetragonal FHO epitaxial thin films is of potential use for the integration of metal-oxide semiconductors with spintronics.

  19. Memory and threshold switching in thin film PMMA polymer

    International Nuclear Information System (INIS)

    Rabah, K.V.O.

    1995-05-01

    Threshold switching between two impedance states have been observed at room temperature in a polymethylmethacrylate (PMMA) thin film sandwiched between two evaporated Al-metal electrodes. The cell's I-V characteristics were found to exhibit memory property. (author). 19 refs, 4 figs

  20. Epitaxial thin film growth of LiH using a liquid-Li atomic template

    Energy Technology Data Exchange (ETDEWEB)

    Oguchi, Hiroyuki, E-mail: oguchi@nanosys.mech.tohoku.ac.jp [Department of Nanomechanics, Tohoku University, Sendai 980-8579 (Japan); Micro System Integration Center (muSIC), Tohoku University, Sendai 980-0845 (Japan); Ikeshoji, Tamio; Orimo, Shin-ichi [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Advanced Institute for Materials Research (AIMR), Tohoku University, Sendai 980-8577 (Japan); Ohsawa, Takeo; Shiraki, Susumu; Hitosugi, Taro [Advanced Institute for Materials Research (AIMR), Tohoku University, Sendai 980-8577 (Japan); Kuwano, Hiroki [Department of Nanomechanics, Tohoku University, Sendai 980-8579 (Japan)

    2014-11-24

    We report on the synthesis of lithium hydride (LiH) epitaxial thin films through the hydrogenation of a Li melt, forming abrupt LiH/MgO interface. Experimental and first-principles molecular dynamics studies reveal a comprehensive microscopic picture of the crystallization processes, which sheds light on the fundamental atomistic growth processes that have remained unknown in the vapor-liquid-solid method. We found that the periodic structure that formed, because of the liquid-Li atoms at the film/MgO-substrate interface, serves as an atomic template for the epitaxial growth of LiH crystals. In contrast, films grown on the Al{sub 2}O{sub 3} substrates indicated polycrystalline films with a LiAlO{sub 2} secondary phase. These results and the proposed growth process provide insights into the preparation of other alkaline metal hydride thin films on oxides. Further, our investigations open the way to explore fundamental physics and chemistry of metal hydrides including possible phenomena that emerge at the heterointerfaces of metal hydrides.

  1. 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.

  2. Investigation of cosputtered W--C thin films as diffusion barriers

    International Nuclear Information System (INIS)

    Yang, H.Y.; Zhao, X.

    1988-01-01

    Polycrystalline thin films of W--C were deposited on single-crystal Si or SiO 2 substrates by rf planar magnetron cosputtering of graphite (C) and W targets. The performance of cosputtered W 75 C 25 thin films as diffusion barriers between a Si substrate and metallic overlayers of Ag, Au, or Al was investigated. Backscattering spectrometry and x-ray diffraction are used to detect metallurgical interactions. Four-point probe measurement of resistance is employed to monitor the electrical stability of the metallization schemes upon thermal annealing in a vacuum for 30 min in temperature ranges from 500 to 700 0 C. The electrical resistivity of W 75 C 25 films is 140 μΩ cm. A W 75 C 25 layer 1100 A thick prevents metallurgical interdiffusion and reaction between Au or Ag overlayers and the Si substrates up to 700 0 C, and between an Al overlayer and the Si substrate up to 450 0 C.tential

  3. Photon confinement in high-efficiency, thin-film III-V solar cells obtained by epitaxial lift-off

    International Nuclear Information System (INIS)

    Schermer, J.J.; Bauhuis, G.J.; Mulder, P.; Haverkamp, E.J.; Deelen, J. van; Niftrik, A.T.J. van; Larsen, P.K.

    2006-01-01

    Using the epitaxial lift-off (ELO) technique, a III-V device structure can be separated from its GaAs substrate by selective wet etching of a thin release layer. The thin-film structures obtained by the ELO process can be cemented or van der Waals bonded on arbitrary smooth surface carriers for further processing. It is shown that the ELO method, initially able to separate millimetre-sized GaAs layers with a lateral etch rate of about 1 mm/h, has been developed to a process capable to free the entire 2-in. epitaxial structures from their substrates with etch rates up to 30 mm/h. With these characteristics the method has a large potential for the production of high efficiency thin-film solar cells. By choosing the right deposition and ELO strategy, the thin-film III-V cells can be adequately processed on both sides allowing for an entire range of new cell structures. In the present work, the performance of semi-transparent bifacial solar cells, produced by the deposition of metal grid contacts on both sides, was evaluated. Reflection of light at the rear side of the bifacial GaAs solar cells was found to result in an enhanced collection probability of the photon-induced carriers compared to that of regular III-V cells on a GaAs substrate. To enhance this effect, thin-film GaAs cells with gold mirror back contacts were prepared. Even in their present premature stage of development, these single-junction thin-film cells reached a record efficiency of 24.5% which is already very close to the 24.9% efficiency that was obtained with a regular GaAs cell on a GaAs substrate. From this it could be concluded that, as a result of the photon confinement, ELO cells require a significantly thinner base layer than regular GaAs cells while at the same time they have the potential to reach a higher efficiency

  4. Fabrication and characterization of optical sensors using metallic core-shell thin film nanoislands for ozone detection

    Science.gov (United States)

    Addanki, Satish; Nedumaran, D.

    2017-07-01

    Core-Shell nanostructures play a vital role in the sensor field owing to their performance improvements in sensing characteristics and well-established synthesis procedures. These nanostructures can be ingeniously tuned to achieve tailored properties for a particular application of interest. In this work, an Ag-Au core-shell thin film nanoislands with APTMS (3-Aminopropyl trimethoxysilane) and PVA (Polyvinyl alcohol) binding agents was modeled, synthesized and characterized. The simulation results were used to fabricate the sensor through chemical route. The results of this study confirmed that the APTMS based Ag-Au core-shell thin film nanoislands offered a better performance over the PVA based Ag-Au core-shell thin film nanoislands. Also, the APTMS based Ag-Au core-shell thin film nanoislands exhibited better sensitivity towards ozone sensing over the other types, viz., APTMS/PVA based Au-Ag core-shell and standalone Au/Ag thin film nanoislands.

  5. AES study of growth process of al thin films on uranium dioxide

    International Nuclear Information System (INIS)

    Zhou Wei; Liu Kezhao; Yang Jiangrong; Xiao Hong

    2009-01-01

    Metallic uranium was exposed to 40 languirs of oxygen at room temperature in order to form UO 2 on the surface of metallic U. And thin layers of aluminum on UO 2 were prepared by sputter deposition under ultra high vacuum conditions. Process of Al thin film growth and its interaction with UO 2 were investigated by auger electron spectroscopy (AES) and electron energy loss spectroscopy (EELS). It was shown that the Al thin film growth underwent via the Volmer-Weber (VW) mode. At room temperature, Al and UO 2 interact with each other, electrons transfer occurres from Al atoms to uranium ions, and a few of Al 2 O 3 exist in the region of UO 2 /Al interface due to O 2 adsorption to the surface. Inter-diffusion between UO 2 and Al is observable. Aluminum diffuses into interface region of UO 2 and U. It results in the formation of a coexistence regime containing uranium oxide, metallic U and Al. (authors)

  6. Growth of KNN thin films for non-linear optical applications

    International Nuclear Information System (INIS)

    Sharma, Shweta; Gupta, Reema; Gupta, Vinay; Tomar, Monika

    2018-01-01

    Two-wave mixing is a remarkable area of research in the field of non-linear optics, finding various applications in the development of opto-electronic devices, photorefractive waveguides, real time holography, etc. Non-linear optical properties of ferroelectric potassium sodium niobate (KNN) thin films have been interrogated using two-wave mixing phenomenon. Regarding this, a-axis oriented K 0.35 Na (1-0.35) NbO 3 thin films were successfully grown on epitaxial matched (100) SrTiO 3 substrate using pulsed laser deposition (PLD) technique. The uniformly distributed Au micro-discs of 200 μm diameter were integrated with KNN/STO thin film to study the plasmonic enhancement in the optical response. Beam amplification has been observed as a result of the two-wave mixing. This is due to the alignment of ferroelectric domains in KNN films and the excitement of plasmons at the metal-dielectric (Au-KNN) interface. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Growth of KNN thin films for non-linear optical applications

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Shweta; Gupta, Reema; Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi (India); Tomar, Monika [Department of Physics, Miranda House University of Delhi (India)

    2018-02-15

    Two-wave mixing is a remarkable area of research in the field of non-linear optics, finding various applications in the development of opto-electronic devices, photorefractive waveguides, real time holography, etc. Non-linear optical properties of ferroelectric potassium sodium niobate (KNN) thin films have been interrogated using two-wave mixing phenomenon. Regarding this, a-axis oriented K{sub 0.35}Na{sub (1-0.35)}NbO{sub 3} thin films were successfully grown on epitaxial matched (100) SrTiO{sub 3} substrate using pulsed laser deposition (PLD) technique. The uniformly distributed Au micro-discs of 200 μm diameter were integrated with KNN/STO thin film to study the plasmonic enhancement in the optical response. Beam amplification has been observed as a result of the two-wave mixing. This is due to the alignment of ferroelectric domains in KNN films and the excitement of plasmons at the metal-dielectric (Au-KNN) interface. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Propagation of bulk longitudinal waves in thin films using laser ultrasonics

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yun Young [Dept. of Mechanical Engineering, Dong-eui University, Busan (Korea, Republic of)

    2016-08-15

    This paper presents the investigation of the propagation behavior of bulk longitudinal waves generated by an ultrafast laser system in thin films. A train of femtosecond laser pulses was focused onto the surface of a 150-nm thick metallic (chromium or aluminum) film on a silicon substrate to excite elastic waves, and the change in thermoreflectance at the spot was monitored to detect the arrival of echoes from the film/substrate interface. The experimental results show that the film material characteristics such as the wave velocity and Young's modulus can be evaluated through curve-fitting in numerical solutions. The material properties of nanoscale thin films are difficult to measure using conventional techniques. Therefore, this research provides an effective method for the nondestructive characterization of nanomaterials.

  9. Crystalline thin films of transition metal hexacyanochromates grown under Langmuir monolayer

    International Nuclear Information System (INIS)

    Bagkar, Nitin; Choudhury, Sipra; Kim, Kyung-Hee; Chowdhury, Prasanta; Lee, Sung-Ik; Yakhmi, J.V.

    2006-01-01

    Crystalline films of cobalt, nickel and iron hexacyanochromates (analogues of Prussian blue) were grown at air-water interface using a surfactant monolayer as a template. These films were transferred on suitable substrates and characterized by X-ray diffraction (XRD), cyclic voltammetry and magnetization measurements. XRD patterns confirmed the formation of oriented crystals in {100} direction for all these films. Magnetization data on nickel and iron hexacyanochromate films indicated ferromagnetic behaviour below Curie temperatures of 72 and 21 K, respectively. The methodology adopted by us to grow crystalline films is useful in obtaining magnetic thin films of analogues of Prussian blue with interesting magnetic properties with respect to transition temperatures and nature of magnetic ordering

  10. Growth of high quality large area MgB2 thin films by reactive evaporation

    OpenAIRE

    Moeckly, Brian H.; Ruby, Ward S.

    2006-01-01

    We report a new in-situ reactive deposition thin film growth technique for the production of MgB2 thin films which offers several advantages over all existing methods and is the first deposition method to enable the production of high-quality MgB2 films for real-world applications. We have used this growth method, which incorporates a rotating pocket heater, to deposit MgB2 films on a variety of substrates, including single-crystalline, polycrystalline, metallic, and semiconductor materials u...

  11. 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

  12. Synthesis, Characterization, and Electrochemical Properties of Polyaniline Thin Films

    Science.gov (United States)

    Rami, Soukaina

    different scenarios. These scenarios included the study in different acid based electrolytes and different gel based electrolytes. The ultra-thin self-assembled PANI films were shown to have a faster switching time, especially for the 1 layer PANI, whereas the color contrast could be observed for the film containing the dye molecule. Also, HCl based electrolyte gave the best electrochemical reversibility compared to other acids used. For the gelatin and PVA based electrolytes, having the same concentration, the results were similar. Hence, the change in the electrolyte consistencies, from liquid to semi-solid, did not change the electrochemical properties of the films. Finally, in the EIS, it was shown that these PANI thin films exhibit a pseudo-capacitance behavior, and as the film thickness grew, the capacitance increased.

  13. Magnetic ground state of SrRuO3 thin film and applicability of standard first-principles approximations to metallic magnetism.

    Science.gov (United States)

    Ryee, Siheon; Han, Myung Joon

    2017-07-05

    A systematic first-principles study has been performed to understand the magnetism of thin film SrRuO 3 which lots of research efforts have been devoted to but no clear consensus has been reached about its ground state properties. The relative t 2g level difference, lattice distortion as well as the layer thickness play together in determining the spin order. In particular, it is important to understand the difference between two standard approximations, namely LDA and GGA, in describing this metallic magnetism. Landau free energy analysis and the magnetization-energy-ratio plot clearly show the different tendency of favoring the magnetic moment formation, and it is magnified when applied to the thin film limit where the experimental information is severely limited. As a result, LDA gives a qualitatively different prediction from GGA in the experimentally relevant region of strain whereas both approximations give reasonable results for the bulk phase. We discuss the origin of this difference and the applicability of standard methods to the correlated oxide and the metallic magnetic systems.

  14. Sputter-deposited Mg-Al-O thin films: linking molecular dynamics simulations to experiments

    International Nuclear Information System (INIS)

    Georgieva, V; Bogaerts, A; Saraiva, M; Depla, D; Jehanathan, N; Lebelev, O I

    2009-01-01

    Using a molecular dynamics model the crystallinity of Mg x Al y O z thin films with a variation in the stoichiometry of the thin film is studied at operating conditions similar to the experimental operating conditions of a dual magnetron sputter deposition system. The films are deposited on a crystalline or amorphous substrate. The Mg metal content in the film ranged from 100% (i.e. MgO film) to 0% (i.e. Al 2 O 3 film). The radial distribution function and density of the films are calculated. The results are compared with x-ray diffraction and transmission electron microscopy analyses of experimentally deposited thin films by the dual magnetron reactive sputtering process. Both simulation and experimental results show that the structure of the Mg-Al-O film varies from crystalline to amorphous when the Mg concentration decreases. It seems that the crystalline Mg-Al-O films have a MgO structure with Al atoms in between.

  15. Chemical solution deposition of YBCO thin film by different polymer additives

    International Nuclear Information System (INIS)

    Wang, W.T.; Li, G.; Pu, M.H.; Sun, R.P.; Zhou, H.M.; Zhang, Y.; Zhang, H.; Yang, Y.; Cheng, C.H.; Zhao, Y.

    2008-01-01

    A polymer-assisted chemical solution deposition approach has been proposed for the preparation of YBCO thin film. Different additives like PVB (polyvinyl butyral), PEG (polyethylene glycol) and PVP (polyvinylpyrrolidone) have been used to adjust the final viscosity of the precursor solution and thus the film formation. In this fluorine-free approach, YBCO has been deposited on single crystal substrates with metal acetates being starting materials. Biaxially textured YBCO thin films have been obtained. However, different additives lead to different microstructure. Dense, smooth and crack-free YBCO film prepared with PVB as additive yields sharp superconducting transition around T c = 90 K as well as high J c (0 T, 77 K) over 3 MA/cm 2

  16. Chemical solution deposition of YBCO thin film by different polymer additives

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.T.; Li, G.; Pu, M.H.; Sun, R.P.; Zhou, H.M.; Zhang, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); Zhang, H. [Department of Physics, Peking University, Beijing 100871 (China); Yang, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); Cheng, C.H. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wale, Sydney, 2052 NSW (Australia); Zhao, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wale, Sydney, 2052 NSW (Australia)], E-mail: yzhao@swjtu.edu.cn

    2008-09-15

    A polymer-assisted chemical solution deposition approach has been proposed for the preparation of YBCO thin film. Different additives like PVB (polyvinyl butyral), PEG (polyethylene glycol) and PVP (polyvinylpyrrolidone) have been used to adjust the final viscosity of the precursor solution and thus the film formation. In this fluorine-free approach, YBCO has been deposited on single crystal substrates with metal acetates being starting materials. Biaxially textured YBCO thin films have been obtained. However, different additives lead to different microstructure. Dense, smooth and crack-free YBCO film prepared with PVB as additive yields sharp superconducting transition around T{sub c} = 90 K as well as high J{sub c} (0 T, 77 K) over 3 MA/cm{sup 2}.

  17. Investigation of high- k yttrium copper titanate thin films as alternative gate dielectrics

    International Nuclear Information System (INIS)

    Monteduro, Anna Grazia; Ameer, Zoobia; Rizzato, Silvia; Martino, Maurizio; Caricato, Anna Paola; Maruccio, Giuseppe; Tasco, Vittorianna; Lekshmi, Indira Chaitanya; Hazarika, Abhijit; Choudhury, Debraj; Sarma, D D

    2016-01-01

    Nearly amorphous high- k yttrium copper titanate thin films deposited by laser ablation were investigated in both metal–oxide–semiconductor (MOS) and metal–insulator–metal (MIM) junctions in order to assess the potentialities of this material as a gate oxide. The trend of dielectric parameters with film deposition shows a wide tunability for the dielectric constant and AC conductivity, with a remarkably high dielectric constant value of up to 95 for the thick films and conductivity as low as 6  ×  10 −10 S cm −1 for the thin films deposited at high oxygen pressure. The AC conductivity analysis points out a decrease in the conductivity, indicating the formation of a blocking interface layer, probably due to partial oxidation of the thin films during cool-down in an oxygen atmosphere. Topography and surface potential characterizations highlight differences in the thin film microstructure as a function of the deposition conditions; these differences seem to affect their electrical properties. (paper)

  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. Clean graphene electrodes on organic thin-film devices via orthogonal fluorinated chemistry.

    Science.gov (United States)

    Beck, Jonathan H; Barton, Robert A; Cox, Marshall P; Alexandrou, Konstantinos; Petrone, Nicholas; Olivieri, Giorgia; Yang, Shyuan; Hone, James; Kymissis, Ioannis

    2015-04-08

    Graphene is a promising flexible, highly transparent, and elementally abundant electrode for organic electronics. Typical methods utilized to transfer large-area films of graphene synthesized by chemical vapor deposition on metal catalysts are not compatible with organic thin-films, limiting the integration of graphene into organic optoelectronic devices. This article describes a graphene transfer process onto chemically sensitive organic semiconductor thin-films. The process incorporates an elastomeric stamp with a fluorinated polymer release layer that can be removed, post-transfer, via a fluorinated solvent; neither fluorinated material adversely affects the organic semiconductor materials. We used Raman spectroscopy, atomic force microscopy, and scanning electron microscopy to show that chemical vapor deposition graphene can be successfully transferred without inducing defects in the graphene film. To demonstrate our transfer method's compatibility with organic semiconductors, we fabricate three classes of organic thin-film devices: graphene field effect transistors without additional cleaning processes, transparent organic light-emitting diodes, and transparent small-molecule organic photovoltaic devices. These experiments demonstrate the potential of hybrid graphene/organic devices in which graphene is deposited directly onto underlying organic thin-film structures.

  20. Nanostructured tungsten trioxide thin films synthesized for photoelectrocatalytic water oxidation: a review.

    Science.gov (United States)

    Zhu, Tao; Chong, Meng Nan; Chan, Eng Seng

    2014-11-01

    The recent developments of nanostructured WO3 thin films synthesized through the electrochemical route of electrochemical anodization and cathodic electrodeposition for the application in photoelectrochemical (PEC) water splitting are reviewed. The key fundamental reaction mechanisms of electrochemical anodization and cathodic electrodeposition methods for synthesizing nanostructured WO3 thin films are explained. In addition, the effects of metal oxide precursors, electrode substrates, applied potentials and current densities, and annealing temperatures on size, composition, and thickness of the electrochemically synthesized nanostructured WO3 thin films are elucidated in detail. Finally, a summary is given for the general evaluation practices used to calculate the energy conversion efficiency of nanostructured WO3 thin films and a recommendation is provided to standardize the presentation of research results in the field to allow for easy comparison of reported PEC efficiencies in the near future. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Schottky contact analysis of photovoltaic chalcopyrite thin film absorbers

    International Nuclear Information System (INIS)

    Schlenker, E.; Mertens, V.; Parisi, J.; Reineke-Koch, R.; Koentges, M.

    2007-01-01

    Current-voltage and capacitance-voltage measurements serve to analyze thermally evaporated Al Schottky contacts on Cu(In, Ga)Se 2 based photovoltaic thin film devices, either taken as grown or etched in a bromine-methanol solution. The characteristics of the Schottky contacts on the as-grown films give evidence for some dielectric layer developing between the metal and the semiconductor. Etching the semiconductor surface prior to evaporation of the Al front contact yields a pure metal-semiconductor behavior, including effects that can be attributed to an additional diode at the Mo contact. Simulations confirm the experimental results

  2. Optical and electrical properties of nickel xanthate thin films

    Indian Academy of Sciences (India)

    Administrator

    metal-xanthate thin films' production, nor their optical, electrical properties and .... vibration of –CH3 at 894 cm–1, (vii) the symmetric bend- ing vibration of C–O–C at 458 .... vity values are the two most important factors, affecting band width.

  3. Recent Advances in Gas Barrier Thin Films via Layer-by-Layer Assembly of Polymers and Platelets.

    Science.gov (United States)

    Priolo, Morgan A; Holder, Kevin M; Guin, Tyler; Grunlan, Jaime C

    2015-05-01

    Layer-by-layer (LbL) assembly has emerged as the leading non-vacuum technology for the fabrication of transparent, super gas barrier films. The super gas barrier performance of LbL deposited films has been demonstrated in numerous studies, with a variety of polyelectrolytes, to rival that of metal and metal oxide-based barrier films. This Feature Article is a mini-review of LbL-based multilayer thin films with a 'nanobrick wall' microstructure comprising polymeric mortar and nano-platelet bricks that impart high gas barrier to otherwise permeable polymer substrates. These transparent, water-based thin films exhibit oxygen transmission rates below 5 × 10(-3) cm(3) m(-2) day(-1) atm(-1) and lower permeability than any other barrier material reported. In an effort to put this technology in the proper context, incumbent technologies such as metallized plastics, metal oxides, and flake-filled polymers are briefly reviewed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. 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.

  5. Bioplasmonic Alloyed Nanoislands Using Dewetting of Bilayer Thin Films.

    Science.gov (United States)

    Kang, Minhee; Ahn, Myeong-Su; Lee, Youngseop; Jeong, Ki-Hun

    2017-10-25

    Unlike monometallic materials, bimetallic plasmonic materials offer extensive benefits such as broadband tuning capability or high environmental stability. Here we report a broad range tuning of plasmon resonance of alloyed nanoislands by using solid-state dewetting of gold and silver bilayer thin films. Thermal dewetting after successive thermal evaporation of thin metal double-layer films readily forms AuAg-alloyed nanoislands with a precise composition ratio. The complete miscibility of alloyed nanoislands results in programmable tuning of plasmon resonance wavelength in a broadband visible range. Such extraordinary tuning capability opens up a new direction for plasmonic enhancement in biophotonic applications such as surface-enhanced Raman scattering or plasmon-enhanced fluorescence.

  6. Fabrication of band gap engineered nanostructured tri-metallic (Mn-Co-Ti) oxide thin films

    Science.gov (United States)

    Mansoor, Muhammad Adil; Yusof, Farazila Binti; Nay-Ming, Huang

    2018-04-01

    In continuation of our previous studies on photoelectrochemical (PEC) properties of titanium based composite oxide thin films, an effort is made to develop thin films of 1:1:2 manganese-cobalt-titanium oxide composite, Mn2O3-Co2O3-4TiO2 (MCT), using Co(OAc)2 and a bimetallic manganese-titanium complex, [Mn2Ti4(TFA)8(THF)6(OH)4(O)2].0.4THF (1), where OAc = acetato, TFA = trifluoroacetato and THF = tetrahydrofuran, via aerosol-assisted chemical vapour deposition (AACVD) technique. The X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) spectroscopic analyses confirmed formation of thin film of Mn2O3-Co2O3-4TiO2 composite material with uniformly distributed agglomerated particles. The average size of 39.5 nm, of the particles embedded inside agglomerates, was estimated by Scherer's equation. Further, UV-Vis spectroscopy was used to estimate the band gap of 2.62 eV for MCT composite thin film.

  7. 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.

  8. Electroresistance effect in gold thin film induced by ionic-liquid-gated electric double layer

    International Nuclear Information System (INIS)

    Nakayama, Hiroyasu; Ohtani, Takashi; Fujikawa, Yasunori; Ando, Kazuya; Saitoh, Eiji; Ye, Jianting; Iwasa, Yoshihiro

    2012-01-01

    Electroresistance effect was detected in a metallic thin film using ionic-liquid-gated electric-double-layer transistors (EDLTs). We observed reversible modulation of the electric resistance of a Au thin film. In this system, we found that an electric double layer works as a nanogap capacitor with 27 (-25) MV cm -1 of electric field by applying only 1.7 V of positive (negative) gate voltage. The experimental results indicate that the ionic-liquid-gated EDLT technique can be used for controlling the surface electronic states on metallic systems. (author)

  9. Structural and optical investigation of Te-based chalcogenide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Rita, E-mail: reetasharma2012@gmail.com; Sharma, Shaveta; Thangaraj, R.; Mian, M. [Semiconductors Laboratory, Department of Physics, GND University, Amritsar (India); Chander, Ravi [Applied Science Deptt. Govt. Polytechnic College Amritsar (India); Kumar, Praveen [Department of Physics, DAV University, Sarmastipur, Jalandhar-144012 (India)

    2015-05-15

    We report the structural and optical properties of thermally evaporated Bi{sub 2}Te{sub 3}, In{sub 2}Te{sub 3} and InBiTe{sub 3} films by using X-ray diffraction, optical and Raman Spectroscopy techniques. The as-prepared thin films were found to be Semi-crystalline by X-ray diffraction. Particle Size and Strain has been calculated from XRD data. The optical constants, film thickness, refractive index and optical band gap (E{sub g}) has been reported for In{sub 2}Te{sub 3}, InBiTe{sub 3} films. Raman Spectroscopy was performed to investigate the effect of Bi, In, on lattice vibration and chemical bonding in Te based chalcogenide glassy alloys.

  10. Deposition of metal chalcogenide thin films by successive ionic layer

    Indian Academy of Sciences (India)

    ) method, has emerged as one of the solution methods to deposit a variety of compound materials in thin film form. The SILAR method is inexpensive, simple and convenient for large area deposition. A variety of substrates such as insulators, ...

  11. A comparative study of ultraviolet photoconductivity relaxation in zinc oxide (ZnO) thin films deposited by different techniques

    International Nuclear Information System (INIS)

    Yadav, Harish Kumar; Gupta, Vinay

    2012-01-01

    Photoresponse characteristics of ZnO thin films deposited by three different techniques namely rf diode sputtering, rf magnetron sputtering, and electrophoretic deposition has been investigated in the metal-semiconductor-metal (MSM) configuration. A significant variation in the crystallinity, surface morphology, and photoresponse characteristics of ZnO thin film with change in growth kinetics suggest that the presence of defect centers and their density govern the photodetector relaxation properties. A relatively low density of traps compared to the true quantum yield is found very crucial for the realization of practical ZnO thin film based ultraviolet (UV) photodetector.

  12. A comparative study of ultraviolet photoconductivity relaxation in zinc oxide (ZnO) thin films deposited by different techniques

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Harish Kumar; Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi, Delhi 110 007 (India)

    2012-05-15

    Photoresponse characteristics of ZnO thin films deposited by three different techniques namely rf diode sputtering, rf magnetron sputtering, and electrophoretic deposition has been investigated in the metal-semiconductor-metal (MSM) configuration. A significant variation in the crystallinity, surface morphology, and photoresponse characteristics of ZnO thin film with change in growth kinetics suggest that the presence of defect centers and their density govern the photodetector relaxation properties. A relatively low density of traps compared to the true quantum yield is found very crucial for the realization of practical ZnO thin film based ultraviolet (UV) photodetector.

  13. Ferroelectric properties of PZT/BFO multilayer thin films prepared using the sol-gel method.

    Science.gov (United States)

    Jo, Seo-Hyeon; Lee, Sung-Gap; Lee, Young-Hie

    2012-01-05

    In this study, Pb(Zr0.52Ti0.48)O3/BiFeO3 [PZT/BFO] multilayer thin films were fabricated using the spin-coating method on a Pt(200 nm)/Ti(10 nm)/SiO2(100 nm)/p-Si(100) substrate alternately using BFO and PZT metal alkoxide solutions. The coating-and-heating procedure was repeated several times to form the multilayer thin films. All PZT/BFO multilayer thin films show a void-free, uniform grain structure without the presence of rosette structures. The relative dielectric constant and dielectric loss of the six-coated PZT/BFO [PZT/BFO-6] thin film were approximately 405 and 0.03%, respectively. As the number of coatings increased, the remanent polarization and coercive field increased. The values for the BFO-6 multilayer thin film were 41.3 C/cm2 and 15.1 MV/cm, respectively. The leakage current density of the BFO-6 multilayer thin film at 5 V was 2.52 × 10-7 A/cm2.

  14. Obtaining and characterization of thin films polyelectrolyte with gold nanoparticles

    International Nuclear Information System (INIS)

    Popiolski, Tatiane M.; Crespo, Janaina S.; Silva, Renato B.

    2011-01-01

    Thin films of polyelectrolytes are manufactured via sequential adsorption of weak polyelectrolytes from aqueous solutions based on electrostatic interaction of oppositely charged polymers. Metal containing polymeric compounds are of particular interest to the production of materials with electrical interface and optical properties. In this sense, the objective of this study was to obtain thin films of weak polyelectrolytes and analyze the distribution of gold nanoparticles stabilized by sodium citrate and by poly (vinylpyrrolidone). The characterization was performed using UV-visible, X-ray diffraction and atomic force microscopy. The techniques of UV-visible and X-ray diffraction was confirmed the presence of gold in the films, the atomic force microscopy images were used to analyze the morphology of the films and check the behavior of the diffusion of gold nanoparticles. (author)

  15. Soft chemistry routes to transparent metal oxide thin films. The case of sol–gel synthesis and structural characterization of Ta2O5 thin films from tantalum chloromethoxide

    International Nuclear Information System (INIS)

    Epifani, Mauro; Zamani, Reza; Arbiol, Jordi; Fabrega, Cristian; Andreu, Teresa; Pace, Giovanni Battista; Siciliano, Pietro; Morante, Joan R.

    2014-01-01

    Ta 2 O 5 thin films were prepared by spin-coating methanol solutions of Ta chloromethoxide. It was prepared by reacting TaCl 5 with methanol, followed by water addition (H 2 O: Ta molar ratio was 16). Thin films were deposited by spin-coating onto SiO 2 /Si substrates, followed by drying at 90 °C and heat-treatment up to 700 °C. The films were characterized by X-ray diffraction, transmission electron microscopy and field emission scanning electron microscopy. Crystallization was obtained only after heating at 700 °C, in the Ta 2 O 5 orthorhombic phase. The resulting films had a thickness of 100 nm. Their structure was constituted by porous crystals with size up to 50 nm, while the pores had a size of about 10 nm. The results demonstrated that TaCl 5 is very convenient precursor for the wet chemical synthesis of Ta 2 O 5 thin films. - Highlights: • Development of convenient solution synthesis of Ta 2 O 5 thin films; • The precursor chemistry was established and related to the synthesis process; • Uniform films crystallized in the most stable orthorombic Ta 2 O 5 phase;

  16. Thin films of molecular metals TTF-TCNQ

    International Nuclear Information System (INIS)

    Fraxedas, J.; Molas, S.; Figueras, A.; Jimenez, I.; Gago, R.; Auban-Senzier, P.; Goffman, M.

    2002-01-01

    We present recent results on the characterization of highly ordered polycrystalline thin films of the charge transfer salt TTF-TCNQ (TTF=tetrathiafulvalene, TCNQ=tetracyanoquinodimethane) prepared by thermal sublimation in high vacuum under different conditions. The increase in orientation and microcrystal size as a function of substrate and annealing temperatures is addressed. A consequence of such an increase is the reduction of the conductivity activation energy, which eventually leads to the observation of the Peierls transition by resistivity measurements. X-ray absorption near edge spectroscopy studies performed with synchrotron radiation reveal directly the influence of charge transfer on unoccupied states near the Fermi level

  17. Thin films of molecular metals TTF-TCNQ

    CERN Document Server

    Fraxedas, J; Figueras, A; Jimenez, I; Gago, R; Auban-Senzier, P; Goffman, M

    2002-01-01

    We present recent results on the characterization of highly ordered polycrystalline thin films of the charge transfer salt TTF-TCNQ (TTF=tetrathiafulvalene, TCNQ=tetracyanoquinodimethane) prepared by thermal sublimation in high vacuum under different conditions. The increase in orientation and microcrystal size as a function of substrate and annealing temperatures is addressed. A consequence of such an increase is the reduction of the conductivity activation energy, which eventually leads to the observation of the Peierls transition by resistivity measurements. X-ray absorption near edge spectroscopy studies performed with synchrotron radiation reveal directly the influence of charge transfer on unoccupied states near the Fermi level.

  18. Ferroelectric and piezoelectric properties of lead-free BaTiO{sub 3} doped Bi{sub 0.5}Na{sub 0.5}TiO{sub 3} thin films from metal-organic solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Acharya, Susant Kumar [Division of Advanced Materials Engineering, Hydrogen and Fuel Cell Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Department of Semiconductor Science and Technology, Basic Research Laboratory (BRL), Semiconductor Physics Research Center (SPRC), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Lee, Sang-Kwon; Hyung, Jung-Hwan [Department of Semiconductor Science and Technology, Basic Research Laboratory (BRL), Semiconductor Physics Research Center (SPRC), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Yang, Yun-Ho; Kim, Bok-Hee [Division of Advanced Materials Engineering, Hydrogen and Fuel Cell Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Ahn, Byung-Guk, E-mail: bkahn@jbnu.ac.kr [Division of Advanced Materials Engineering, Hydrogen and Fuel Cell Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2012-11-05

    Highlights: Black-Right-Pointing-Pointer Lead-free BNT-BT thin films from an optimized metal-organic solution deposition. Black-Right-Pointing-Pointer Phase and microstructure evolution with annealing temperature. Black-Right-Pointing-Pointer A relatively low leakage current density. Black-Right-Pointing-Pointer Good dielectric constant of 613 at a frequency of 1 kHz. Black-Right-Pointing-Pointer High remanent polarization and piezoelectric constant comparable to PZT thin films. - Abstract: Lead-free 0.94Bi{sub 0.5}Na{sub 0.5}TiO{sub 3}-0.06BaTiO{sub 3} (BNT-BT) piezoelectric thin films were prepared by metal-organic solution deposition onto a Pt/Ti/SiO{sub 2}/Si substrate. A dense and well crystallized thin film with a perovskite phase was obtained by annealing these films at 700 Degree-Sign C. Atomic force microscopy showed that these films were smooth and crack-free with an average grain size on the order of 200 nm. Thin films of 356 nm thickness exhibited a small signal dielectric constant and a loss tangent at 1 kHz of 613 and 0.044, respectively. Ferroelectric hysteresis measurements indicated a remanent polarization value of 21.5 {mu}C/cm{sup 2} with a coercive field of 164.5 kV/cm. The leakage current density of the thin film was 4.08 Multiplication-Sign 10{sup -4} A/cm{sup 2} at an applied electric field of 200 kV/cm. A typical butterfly-shaped piezoresponse loop was observed and the effective piezoelectric coefficient (d{sub 33}) of the BNT-BT thin film was approximately 51.6 pm/V.

  19. Thermal Effusivity Determination of Metallic Films of Nanometric Thickness by the Electrical Micropulse Method

    Science.gov (United States)

    Lugo, J. M.; Oliva, A. I.

    2017-02-01

    The thermal effusivity of gold, aluminum, and copper thin films of nanometric thickness (20 nm to 200 nm) was investigated in terms of the films' thickness. The metallic thin films were deposited onto glass substrates by thermal evaporation, and the thermal effusivity was estimated by using experimental parameters such as the specific heat, thermal conductivity, and thermal diffusivity values obtained at room conditions. The specific heat, thermal conductivity, and thermal diffusivity values of the metallic thin films are determined with a methodology based on the behavior of the thermal profiles of the films when electrical pulses of few microseconds are applied at room conditions. For all the investigated materials, the thermal effusivity decreases with decreased thickness. The thermal effusivity values estimated by the presented methodology are consistent with other reported values obtained under vacuum conditions and more elaborated methodologies.

  20. Lens of controllable optical field with thin film metallic glasses for UV-LEDs.

    Science.gov (United States)

    Pan, C T; Chen, Y C; Lin, Po-Hung; Hsieh, C C; Hsu, F T; Lin, Po-Hsun; Chang, C M; Hsu, J H; Huang, J C

    2014-06-16

    In the exposure process of photolithography, a free-form lens is designed and fabricated for UV-LED (Ultraviolet Light-Emitting Diode). Thin film metallic glasses (TFMG) are adopted as UV reflection layers to enhance the irradiance and uniformity. The Polydimethylsiloxane (PDMS) with high transmittance is used as the lens material. The 3-D fast printing is attempted to make the mold of the lens. The results show that the average irradiance can be enhanced by 6.5~6.7%, and high uniformity of 85~86% can be obtained. Exposure on commercial thick photoresist using this UV-LED system shows 3~5% dimensional deviation, lower than the 6~8% deviation for commercial mercury lamp system. This current system shows promising potential to replace the conventional mercury exposure systems.

  1. Growth of conductive HfO{sub 2-x} thin films by reactive molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt, Erwin; Kurian, Jose; Alff, Lambert [Institut fuer Materialwissenschaft, TU Darmstadt (Germany); Kleebe, Hans-Joachim [Institut fuer Angewandte Geowissenschaften, TU Darmstadt (Germany)

    2009-07-01

    Thin films of oxygen deficient hafnium oxide were grown on single crystal c-cut and r-cut sapphire substrates by reactive molecular beam epitaxy. The oxidation conditions during growth were varied within a wide range using RF-activated oxygen. Hafnium oxide thin films were characterized using X-ray diffraction, resistivity measurements ({rho}-T) and transmission electron microscopy (TEM). The results show a dramatic increase in conductivity of the deposited oxygen deficient hafnium oxide thin films with decreasing oxidation conditions during growth. The electrical properties of deficient hafnium oxide thin films varied from insulating over semiconducting to conducting. X-ray diffraction data as well as TEM data rule out the possibility of conductivity due to metallic hafnium.

  2. Reduction of metallosis in hip implant using thin film coating

    Science.gov (United States)

    Rajeshshyam, R.; Chockalingam, K.; Gayathri, V.; Prakash, T.

    2018-04-01

    Hip implant finds its emerging attraction due to it continuous demand over the years. The hip implants (femoral head) and acetabulum cup) mainly fabricated by metals such as stainless steel, cobalt chrome and titanium alloys, other than that ceramics and polyethylene have been used. The metal-on-metal hip implant was found to be best implant material for most of the surgeons due to its high surface finish, low wear rate and low chance of dislocation from its position after implanting. Where in metal based hip implant shows less wear rate of 0.01mm3/year. Metal-on-metal implant finds its advantage over other materials both in its mechanical and physical stability against human load. In M-O-M Cobalt- chromium alloys induce metal allergy. The metal allergy (particulate debris) that is generated by wear, fretting, fragmentation and which is unavoidable when a prosthesis is implanted, can induce an inflammatory reaction in some circumstances. The objectives of this research to evaluate thin film coating with Nano particle additives to reduce the wear leads to regarding metal ion release. Experimental results reveals that thin film Sol-Gel coating with 4wt. % of specimen reduced the cobalt and chromium ion release and reduces the wear rate. Wear rate reduced by 98% for 4wt. % graphene in 20N and 95% for 4wt. % graphene in 10N.

  3. Fabrication of Au/graphene oxide/Ag sandwich structure thin film and its tunable energetics and tailorable optical properties

    OpenAIRE

    Ruijin Hong; Jialin Ji; Chunxian Tao; Daohua Zhang; Dawei Zhang

    2017-01-01

    Au/graphene oxide/Ag sandwich structure thin film was fabricated. The effects of graphene oxide (GO) and bimetal on the structure and optical properties of metal silver films were investigated by X-ray diffraction (XRD), optical absorption, and Raman intensity measurements, respectively. Compared to silver thin film, Au/graphene oxide/Ag sandwich structure composite thin films were observed with wider optical absorption peak and enhanced absorption intensity. The Raman signal for Rhodamine B ...

  4. Nanopatterned Metallic Films for Use As Transparent Conductive Electrodes in Optoelectronic Devices

    KAUST Repository

    Catrysse, Peter B.

    2010-08-11

    We investigate the use of nanopatterned metallic films as transparent conductive electrodes in optoelectronic devices. We find that the physics of nanopatterned electrodes, which are often optically thin metallic films, differs from that of optically thick metallic films. We analyze the optical properties when performing a geometrical transformation that maintains the electrical properties. For one-dimensional patterns of metallic wires, the analysis favors tall and narrow wires. Our design principles remain valid for oblique incidence and readily carry over to two-dimensional patterns. © 2010 American Chemical Society.

  5. Solvothermal growth of a ruthenium metal-organic framework featuring HKUST-1 structure type as thin films on oxide surfaces.

    Science.gov (United States)

    Kozachuk, Olesia; Yusenko, Kirill; Noei, Heshmat; Wang, Yuemin; Walleck, Stephan; Glaser, Thorsten; Fischer, Roland A

    2011-08-14

    Phase-pure crystalline thin films of a mixed-valence Ru(2)(II,III) metal-organic framework with 1,3,5-benzenetricarboxylate (btc) as a linker were solvothermally grown on amorphous alumina and silica surfaces. Based on the Rietveld refinement, the structure of Ru-MOF was assigned to be analogous to [Cu(3)(btc)(2)] (HKUST-1). This journal is © The Royal Society of Chemistry 2011

  6. 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...

  7. Investigations of LRE-HRE-TM thin films for hybrid recording

    Science.gov (United States)

    Li, Zuoyi; Cheng, Xiaomin; Jin, Fang; Li, Zhen; Lin, Gengqi; Yang, Xiaofei

    2005-09-01

    Light rare earth-heavy rare earth-transition metal (LRE-HRE-TM) thin films are a kind of important recording media. A lot of researches have been carried out on the LRE-HRE-TM thin films to improve its properties for data storage application and fruitful results have been achieved. This report gives a glance on the evolution of the research on LRE-HRE-TM recording media. At the same time, combined with the hybrid recording technology, some experimental results obtained on LRE-HRE-TM recording media are discussed, which suggest the promising prospect of the LRE-HRE-TM media in hybrid recording application.

  8. 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.

  9. Decoding Nucleation and Growth of Zeolitic Imidazolate Framework Thin Films with Atomic Force Microscopy and Vibrational Spectroscopy

    NARCIS (Netherlands)

    Ozturk, Zafer; Filez, Matthias; Weckhuysen, Bert M.

    2017-01-01

    The synthesis of metal-organic framework (MOF) thin films has garnered significant attention during the past decade. By better understanding the parameters governing the nucleation and growth of such thin films, their properties can be rationally tuned, empowering their application as (reactive)

  10. Synthesis of electro-active manganese oxide thin films by plasma enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Merritt, Anna R. [Energetics Research Division, Naval Air Warfare Center Weapons Division, China Lake, CA 93555 (United States); Rajagopalan, Ramakrishnan [Department of Engineering, The Pennsylvania State University, Dubois, PA 15801 (United States); Materials Research Institute, The Pennsylvania State University, University Park, PA 16802 (United States); Carter, Joshua D. [Energetics Research Division, Naval Air Warfare Center Weapons Division, China Lake, CA 93555 (United States)

    2014-04-01

    The good stability, cyclability and high specific capacitance of manganese oxide (MnO{sub x}) has recently promoted a growing interest in utilizing MnO{sub x} in asymmetric supercapacitor electrodes. Several literature reports have indicated that thin film geometries of MnO{sub x} provide specific capacitances that are much higher than bulk MnO{sub x} powders. Plasma enhanced chemical vapor deposition (PECVD) is a versatile technique for the production of metal oxide thin films with high purity and controllable thickness. In this work, MnO{sub x} thin films deposited by PECVD from a methylcyclopentadienyl manganese tricarbonyl precursor are presented and the effect of processing conditions on the quality of MnO{sub x} films is described. The film purity and oxidation state of the MnO{sub x} films were studied by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Preliminary electrochemical testing of MnO{sub x} films deposited on carbon fiber electrodes in aqueous electrolytes indicates that the PECVD synthesized films are electrochemically active. - Highlights: • Plasma enhanced chemical vapor deposition of manganese oxide thin films. • Higher plasma power and chamber pressure increase deposition rate. • Manganese oxide thin films are electrochemically active. • Best electrochemical performance observed for pure film with low stress • Lower capacitance observed at higher scan rates despite thin film geometry.

  11. Simple Methods for Production of Nanoscale Metal Oxide Films from Household Sources

    Science.gov (United States)

    Campbell, Dean J.; Baliss, Michelle S.; Hinman, Jordan J.; Ziegenhorn, John W.; Andrews, Mark J.; Stevenson, Keith J.

    2013-01-01

    Production of thin metal oxide films was recently explored as part of an outreach program with a goal of producing nanoscale structures with household items. Household items coated with various metals or titanium compounds can be heated to produce colorful films with nanoscale thicknesses. As part of a materials chemistry laboratory experiment…

  12. 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.

  13. Pilot-scale electron cyclotron resonance-metal organic chemical vapor deposition system for the preparation of large-area fluorine-doped SnO{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Bup Ju [Department of Energy and Environmental Engineering, Shinhan University, 233-1, Sangpae-dong, Dongducheon, Gyeonggi-do 483-777 (Korea, Republic of); Hudaya, Chairul [Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus Baru UI, Depok 16424 (Indonesia); Center for Energy Convergence, Green City Research Institute, Korea Institute of Science and Technology, Hwarangno 14 gil 5, Seoul 136-791 (Korea, Republic of); Department of Energy and Environmental Engineering, Korea University of Science and Technology, 176 Gajungro Yuseong-gu, Daejeon 305-350 (Korea, Republic of); Lee, Joong Kee, E-mail: leejk@kist.re.kr [Center for Energy Convergence, Green City Research Institute, Korea Institute of Science and Technology, Hwarangno 14 gil 5, Seoul 136-791 (Korea, Republic of); Department of Energy and Environmental Engineering, Korea University of Science and Technology, 176 Gajungro Yuseong-gu, Daejeon 305-350 (Korea, Republic of)

    2016-05-15

    The authors report the surface morphology, optical, electrical, thermal and humidity impacts, and electromagnetic interference properties of fluorine-doped tin oxide (SnO{sub 2}:F or “FTO”) thin films on a flexible polyethylene terephthalate (PET) substrate fabricated by a pilot-scale electron cyclotron resonance–metal organic chemical vapor deposition (PS ECR-MOCVD). The characteristics of large area FTO thin films were compared with a commercially available transparent conductive electrode made of tin-doped indium oxide (ITO), prepared with an identical film and PET thickness of 125 nm and 188 μm, respectively. The results revealed that the as-prepared FTO thin films exhibited comparable performances with the incumbent ITO films, including a high optical transmittance of 97% (substrate-subtracted), low electrical resistivity of about 5 × 10{sup −3} Ω cm, improved electrical and optical performances due to the external thermal and humidity impact, and an excellent shielding effectiveness of electromagnetic interference of nearly 2.3 dB. These excellent performances of the FTO thin films were strongly attributed to the design of the PS ECR-MOCVD, which enabled a uniform plasma environment resulting from a proper mixture of electromagnetic profiles and microwave power.

  14. Thin, Conductive, Pyrrolyc film production for radioactive sources backings

    International Nuclear Information System (INIS)

    Rodriguez, L.; Arcos, J.M. los

    1993-01-01

    A procedure for electro polymerization of pyrrole has been set up in order to produce thin, (> 15 μg/cm2) homogeneous (thickness variation < 2%) films, with no need for additional metallization to be used as backings of radioactive sources, having 10-0,4 Kfl/sample, for 35-70 μg/cm . The experimental equipment, reagent and procedure utilized is described as well as the characterization of Pyrrolyc films produced. (Author) 28 refs

  15. Comparative Review on Thin Film Growth of Iron-Based Superconductors

    Directory of Open Access Journals (Sweden)

    Yoshinori Imai

    2017-07-01

    Full Text Available Since the discovery of the novel iron-based superconductors, both theoretical and experimental studies have been performed intensively. Because iron-based superconductors have a smaller anisotropy than high-Tc cuprates and a high superconducting transition temperature, there have been a lot of researchers working on the film fabrication of iron-based superconductors and their application. Accordingly, many novel features have been reported in the films of iron-based superconductors, for example, the fabrication of the epitaxial film with a higher Tc than bulk samples, the extraction of the metastable phase which cannot be obtained by the conventional solid state reaction, and so on. In this paper, we review the progress of research on thin film fabrications of iron-based superconductors, especially the four categories: LnFeAs(O,F (Ln = Lanthanide, AEFe2As2 (AE = Alkaline-earth metal, FeCh (Ch = Chalcogen, and FeSe monolayer. Furthermore, we focus on two important topics in thin films of iron-based superconductors; one is the substrate material for thin film growth on the iron-based superconductors, and the other is the whole phase diagram in FeSe1-xTex which can be obtained only by using film-fabrication technique.

  16. Berkovich Nanoindentation on AlN Thin Films

    Directory of Open Access Journals (Sweden)

    Jian Sheng-Rui

    2010-01-01

    Full Text Available Abstract Berkovich nanoindentation-induced mechanical deformation mechanisms of AlN thin films have been investigated by using atomic force microscopy (AFM and cross-sectional transmission electron microscopy (XTEM techniques. AlN thin films are deposited on the metal-organic chemical-vapor deposition (MOCVD derived Si-doped (2 × 1017 cm−3 GaN template by using the helicon sputtering system. The XTEM samples were prepared by means of focused ion beam (FIB milling to accurately position the cross-section of the nanoindented area. The hardness and Young’s modulus of AlN thin films were measured by a Berkovich nanoindenter operated with the continuous contact stiffness measurements (CSM option. The obtained values of the hardness and Young’s modulus are 22 and 332 GPa, respectively. The XTEM images taken in the vicinity regions just underneath the indenter tip revealed that the multiple “pop-ins” observed in the load–displacement curve during loading are due primarily to the activities of dislocation nucleation and propagation. The absence of discontinuities in the unloading segments of load–displacement curve suggests that no pressure-induced phase transition was involved. Results obtained in this study may also have technological implications for estimating possible mechanical damages induced by the fabrication processes of making the AlN-based devices.

  17. Thin-film encapsulation of organic electronic devices based on vacuum evaporated lithium fluoride as protective buffer layer

    Science.gov (United States)

    Peng, Yingquan; Ding, Sihan; Wen, Zhanwei; Xu, Sunan; Lv, Wenli; Xu, Ziqiang; Yang, Yuhuan; Wang, Ying; Wei, Yi; Tang, Ying

    2017-03-01

    Encapsulation is indispensable for organic thin-film electronic devices to ensure reliable operation and long-term stability. For thin-film encapsulating organic electronic devices, insulating polymers and inorganic metal oxides thin films are widely used. However, spin-coating of insulating polymers directly on organic electronic devices may destroy or introduce unwanted impurities in the underlying organic active layers. And also, sputtering of inorganic metal oxides may damage the underlying organic semiconductors. Here, we demonstrated that by utilizing vacuum evaporated lithium fluoride (LiF) as protective buffer layer, spin-coated insulating polymer polyvinyl alcohol (PVA), and sputtered inorganic material Er2O3, can be successfully applied for thin film encapsulation of copper phthalocyanine (CuPc)-based organic diodes. By encapsulating with LiF/PVA/LiF trilayer and LiF/Er2O3 bilayer films, the device lifetime improvements of 10 and 15 times can be achieved. These methods should be applicable for thin-film encapsulation of all kinds of organic electronic devices. Moisture-induced hole trapping, and Al top electrode oxidation are suggest to be the origins of current decay for the LiF/PVA/LiF trilayer and LiF/Er2O3 bilayer films encapsulated devices, respectively.

  18. 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

  19. Effects of structural modification via high-pressure annealing on solution-processed InGaO films and thin-film transistors

    International Nuclear Information System (INIS)

    Rim, You Seung; Choi, Hyung-Wook; Kim, Kyung Hwan; Kim, Hyun Jae

    2016-01-01

    We investigated the structural modification of solution-processed nanocrystalline InGaO films via high-pressure annealing and fabricated thin-film transistors. The grain size of InGaO films annealed in the presence of oxygen under high pressure was significantly changed compared the films annealed without high pressure ambient. The O1s XPS peak distribution of InGaO films annealed under high pressure at 350 °C showed a peak similar to that of the non-pressure annealed film at 500 °C. The high-pressure annealing process promoted the elimination of organic residues and dehydroxylation of the metal hydroxide (M–OH) complex. We confirmed the improved device performance of high-pressure annealed InGaO-based thin-film transistors owing to the reduction in charge-trap density. (paper)

  20. 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...

  1. Cyclic testing of thin Ni films on a pre-tensile compliant substrate

    Energy Technology Data Exchange (ETDEWEB)

    Wei, He [Department of Mechanics, Tianjin University, 135 Yaguan Rd, Jinnan, 300350 Tianjin (China); Département Physique et Mécanique d es Matériaux, Institut Pprime, CNRS–Université de Poitiers, Bd Marie et Pierre Curie, Futuroscope, 86962 (France); Renault, Pierre-Olivier, E-mail: pierre.olivier.renault@univ-poitiers.fr [Département Physique et Mécanique d es Matériaux, Institut Pprime, CNRS–Université de Poitiers, Bd Marie et Pierre Curie, Futuroscope, 86962 (France); Bourhis, Eric Le [Département Physique et Mécanique d es Matériaux, Institut Pprime, CNRS–Université de Poitiers, Bd Marie et Pierre Curie, Futuroscope, 86962 (France); Wang, Shibin [Department of Mechanics, Tianjin University, 135 Yaguan Rd, Jinnan, 300350 Tianjin (China); Goudeau, Philippe [Département Physique et Mécanique d es Matériaux, Institut Pprime, CNRS–Université de Poitiers, Bd Marie et Pierre Curie, Futuroscope, 86962 (France)

    2017-05-17

    A novel experimental approach to study the cyclic plastic deformation of thin metallic films is presented. 300 nm thick Ni films are deposited on both sides of a pre-tensile soft substrate which allows to deform the films alternately in tension and compression (approximately from +2.7 GPa down to −2 GPa) relative to the as-deposited residual stress state. Nanocrystalline thin films' intrinsic elastic strains (or stresses) and true strains have been measured step by step during two loading/unloading cycles thanks to the X-ray diffraction (XRD) and digital image correlation (DIC) techniques respectively. From the first cyclic deformation, a significant Bauschinger effect is evidenced in the films, however, little or no cyclic hardening is observed during the two cyclic tests.

  2. Gettering of carbon dioxide by erbium thin films

    International Nuclear Information System (INIS)

    Mehrhoff, T.K.

    1980-01-01

    The interaction of carbon dioxide and erbium thin films is characterized at 300 to 900 0 C and 5 x 10 -7 torr. Temperature ramp experiments with thin erbium films indicated a significant reaction above 300 0 C, preceded by desorption of water vapor, hydrogen and nitrogen and/or carbon monoxide from the film surface. The sticking coefficients were plotted as a function of Langmuirs of carbon dioxide exposure. Between 400 and 600 0 C, the length of the exposure was found to be more important than the temperature of the exposure in determining the sticking coefficient. Some evolution of carbon monoxide was noted particularly in the 400 to 500 0 C region. An 80% conversion of carbon dioxide to carbon monoxide was measured at 500 0 C. The film pumping speeds were compared with published vapor pressure data for erbium. This comparison indicated that a significant portion of the pumping action observed at temperatures of 800 0 C and above was due to evaporation of erbium metal

  3. Pulsed Laser Deposition of BaTiO3 Thin Films on Different Substrates

    Directory of Open Access Journals (Sweden)

    Yaodong Yang

    2010-01-01

    Full Text Available We have studied the deposition of BaTiO3 (BTO thin films on various substrates. Three representative substrates were selected from different types of material systems: (i SrTiO3 single crystals as a typical oxide, (ii Si wafers as a semiconductor, and (iii Ni foils as a magnetostrictive metal. We have compared the ferroelectric properties of BTO thin films obtained by pulsed laser deposition on these diverse substrates.

  4. Ab initio molecular dynamics model for density, elastic properties and short range order of Co-Fe-Ta-B metallic glass thin films

    International Nuclear Information System (INIS)

    Hostert, C; Music, D; Schneider, J M; Bednarcik, J; Keckes, J; Kapaklis, V; Hjörvarsson, B

    2011-01-01

    Density, elastic modulus and the pair distribution function of Co-Fe-Ta-B metallic glasses were obtained by ab initio molecular dynamics simulations and measured for sputtered thin films using x-ray reflectivity, nanoindentation and x-ray diffraction using high energy photons. The computationally obtained density of 8.19 g cm -3 for Co 43 Fe 20 Ta 5.5 B 31.5 and 8.42 g cm -3 for Co 45.5 Fe 24 Ta 6 B 24.5 , as well as the Young’s moduli of 273 and 251 GPa, respectively, are consistent with our experiments and literature data. These data, together with the good agreement between the theoretical and the experimental pair distribution functions, indicate that the model established here is useful to describe the density, elasticity and short range order of Co-Fe-Ta-B metallic glass thin films. Irrespective of the investigated variation in chemical composition, (Co, Fe)-B cluster formation and Co-Fe interactions are identified by density-of-states analysis. Strong bonds within the structural units and between the metallic species may give rise to the comparatively large stiffness. (paper)

  5. 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...

  6. Contact resistance and stability study for Au, Ti, Hf and Ni contacts on thin-film Mg2Si

    KAUST Repository

    Zhang, Bo; Zheng, Tao; Wang, Qingxiao; Zhu, Yihan; Alshareef, Husam N.; Kim, Moon J.; Gnade, Bruce E.

    2016-01-01

    We present a detailed study of post-deposition annealing effects on contact resistance of Au, Ti, Hf and Ni electrodes on Mg2Si thin films. Thin-film Mg2Si and metal contacts were deposited using magnetron sputtering. Various post

  7. MOFs for the Sensitive Detection of Ammonia: Deployment of fcu-MOF Thin-Films as Effective Chemical Capacitive Sensors.

    KAUST Repository

    Assen, Ayalew Hussen Assen; Yassine, Omar; Shekhah, Osama; Eddaoudi, Mohamed; Salama, Khaled N.

    2017-01-01

    This work reports on the fabrication and deployment of a select metal-organic framework (MOF) thin film as an advanced chemical capacitive sensor for the sensing/detection of ammonia (NH3) at room temperature. Namely, the MOF thin film sensing layer

  8. Physical and dispersive optical characteristics of ZrON/Si thin-film system

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Yew Hoong [University of Malaya, Centre of Advanced Materials, Department of Mechanical Engineering, Faculty of Engineering, Kuala Lumpur (Malaysia); University of Malaya, Centre of Advanced Manufacturing and Material Processing, Kuala Lumpur (Malaysia); Atuchin, V.V. [Institute of Semiconductor Physics, SB RAS, Laboratory of Optical Materials and Structures, Novosibirsk (Russian Federation); Kruchinin, V.N. [Institute of Semiconductor Physics, SB RAS, Laboratory for Ellipsometry of Semiconductor Materials and Structures, Novosibirsk (Russian Federation); Cheong, Kuan Yew [Universiti Sains Malaysia, Electronic Materials Research Group, School of Materials and Mineral Resources Engineering, Engineering Campus, Seberang Perai Selatan, Penang (Malaysia)

    2014-06-15

    To date, the complex evaluation of physical and dispersive optical characteristics of the ZrON/Si film system has yet been reported. Hence, ZrON thin films have been formed on Si(100) substrates through oxidation/nitridation of sputtered metallic Zr in N{sub 2}O environment at 500, 700, and 900 C. Physical properties of the deposited films have been characterized by X-ray diffractometry (XRD), Fourier transform infrared (FTIR) spectroscopy, reflection high-energy electron diffraction (RHEED), and spectroscopic ellipsometry (SE). It has been shown that ZrON/Si thin films without optical absorption can be prepared by oxidation/nitridation reaction in N{sub 2}O environment at 700-900 C. (orig.)

  9. Development of ΔE-E telescope ERDA with 40 MeV {sup 35}Cl{sup 7+} beam at MALT in the University of Tokyo optimized for analysis of metal oxynitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Harayama, I.; Nagashima, K. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8573 (Japan); Hirose, Y. [Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); CREST, Japan Science and Technology Agency, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Matsuzaki, H. [School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Sekiba, D., E-mail: sekiba@tac.tsukuba.ac.jp [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8573 (Japan); Tandem Accelerator Complex, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8577 (Japan)

    2016-10-01

    We have developed a compact ΔE-E telescope elastic recoil detection analysis (ERDA) system, for the first time at Micro Analysis Laboratory, Tandem Accelerator (MALT) in the University of Tokyo, which consists of a gas ionization chamber and solid state detector (SSD) for the quantitative analysis of light elements. The gas ionization chamber is designed to identify the recoils of O and N from metal oxynitrides thin films irradiated with 40 MeV {sup 35}Cl{sup 7+}. The length of the electrodes along the beam direction is 50 mm optimized to sufficiently separate energy loss of O and N recoils in P10 gas at 6.0 × 10{sup 3} Pa. The performance of the gas ionization chamber was examined by comparing the ERDA results on the SrTaO{sub 2}N thin films with semi-empirical simulation and the chemical compositions previously determined by nuclear reaction analysis (NRA) and Rutherford backscattering spectrometry (RBS). We also confirmed availability of the gas ionization chamber for identifying not only the recoils of O and N but also those of lithium, carbon and fluorine.

  10. Development of CIGS2 thin film solar cells

    International Nuclear Information System (INIS)

    Dhere, Neelkanth G.; Gade, Vivek S.; Kadam, Ankur A.; Jahagirdar, Anant H.; Kulkarni, Sachin S.; Bet, Sachin M.

    2005-01-01

    Research and development of CuIn 1-x Ga x Se 2-y S y (CIGSS) thin-film solar cells on ultralightweight flexible metallic foil substrates is being carried out at FSEC PV Materials Lab for space applications. Earlier, the substrate size was limited to 3 cm x 2.5 cm. Large-area sputtering systems and scrubber for hydrogen selenide and sulfide have been designed and constructed for preparation of CIGSS thin-films on large (15 cm x 10 cm) substrates. A selenization/sulfurization furnace donated by Shell (formerly Siemens) Solar has also been refurbished and upgraded. The sputtering target assembly design was modified for proper clamping of targets and effective cooling. A new design of the magnetic assembly for large-area magnetron sputtering sources was implemented so as to achieve uniform deposition on large area. Lightweight stainless steel foil and ultralightweight titanium foil substrates were utilized to increase the specific power of solar cells. Sol-gel derived SiO 2 layers were coated on titanium foil by dip coating method. Deposition parameters for the preparation of molybdenum back contact layers were optimized so as to minimize the residual stress as well as reaction with H 2 S. Presently large (15 cm x 10 cm) CuIn 1-x Ga x S 2 (CIGS2) thin film solar cells are being prepared on Mo-coated titanium and stainless steel foil by sulfurization of CuGa/In metallic precursors in diluted Ar:H 2 S(4%). Heterojunction partner CdS layers are deposited by chemical bath deposition. The regeneration sequence of ZnO/ZnO:Al targets was optimized for obtaining consistently good-quality, transparent and conducting ZnO/ZnO:Al bilayer by RF magnetron-sputter deposition. Excellent facilities at FSEC PV Materials Lab are one of its kinds and could serve as a nucleus of a small pilot plant for CIGSS thin film solar cell fabrication

  11. Modeling of metal thin film growth: Linking angstrom-scale molecular dynamics results to micron-scale film topographies

    Science.gov (United States)

    Hansen, U.; Rodgers, S.; Jensen, K. F.

    2000-07-01

    A general method for modeling ionized physical vapor deposition is presented. As an example, the method is applied to growth of an aluminum film in the presence of an ionized argon flux. Molecular dynamics techniques are used to examine the surface adsorption, reflection, and sputter reactions taking place during ionized physical vapor deposition. We predict their relative probabilities and discuss their dependence on energy and incident angle. Subsequently, we combine the information obtained from molecular dynamics with a line of sight transport model in a two-dimensional feature, incorporating all effects of reemission and resputtering. This provides a complete growth rate model that allows inclusion of energy- and angular-dependent reaction rates. Finally, a level-set approach is used to describe the morphology of the growing film. We thus arrive at a computationally highly efficient and accurate scheme to model the growth of thin films. We demonstrate the capabilities of the model predicting the major differences on Al film topographies between conventional and ionized sputter deposition techniques studying thin film growth under ionized physical vapor deposition conditions with different Ar fluxes.

  12. Fabrication of Quench Condensed Thin Films Using an Integrated MEMS Fab on a Chip

    Science.gov (United States)

    Lally, Richard; Reeves, Jeremy; Stark, Thomas; Barrett, Lawrence; Bishop, David

    Atomic calligraphy is a microelectromechanical systems (MEMS)-based dynamic stencil nanolithography technique. Integrating MEMS devices into a bonded stacked array of three die provides a unique platform for conducting quench condensed thin film mesoscopic experiments. The atomic calligraphy Fab on a Chip process incorporates metal film sources, electrostatic comb driven stencil plate, mass sensor, temperature sensor, and target surface into one multi-die assembly. Three separate die are created using the PolyMUMPs process and are flip-chip bonded together. A die containing joule heated sources must be prepared with metal for evaporation prior to assembly. A backside etch of the middle/central die exposes the moveable stencil plate allowing the flux to pass through the stencil from the source die to the target die. The chip assembly is mounted in a cryogenic system at ultra-high vacuum for depositing extremely thin films down to single layers of atoms across targeted electrodes. Experiments such as the effect of thin film alloys or added impurities on their superconductivity can be measured in situ with this process.

  13. Ultra-high current density thin-film Si diode

    Science.gov (United States)

    Wang, Qi [Littleton, CO

    2008-04-22

    A combination of a thin-film .mu.c-Si and a-Si:H containing diode structure characterized by an ultra-high current density that exceeds 1000 A/cm.sup.2, comprising: a substrate; a bottom metal layer disposed on the substrate; an n-layer of .mu.c-Si deposited the bottom metal layer; an i-layer of .mu.c-Si deposited on the n-layer; a buffer layer of a-Si:H deposited on the i-layer, a p-layer of .mu.c-Si deposited on the buffer layer; and a top metal layer deposited on the p-layer.

  14. Surface and sub-surface thermal oxidation of ruthenium thin films

    NARCIS (Netherlands)

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

    2014-01-01

    For next generation Extreme UV photolithography, multilayer coatings may require protective capping layers against surface contamination. Ruthenium, as a low-oxidation metal, is often used as a reference material. The oxidation behaviour of Ru thin films has been studied using X-ray reflectometry

  15. High-frequency properties of superconducting Y-Ba-Cu-oxide thin films

    International Nuclear Information System (INIS)

    Ramakrishnan, E.S.; Su, M.; Howng, W.

    1992-01-01

    rf and microwave properties of superconducting YBa 2 Cu 3 O 7-x thin films were measured and analyzed using a coplanar resonator structure. The films were developed by sequential electron-beam evaporation of the metals followed by postanneal processing. dc properties of the films were obtained from resistance-temperature and current-voltage measurements to evaluate the transition temperature and current densities. High-frequency properties were measured from 70 to 10 K and in the frequency range 1--3 GHz to determine the film characteristics as compared to pure copper films on the same substrates

  16. 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.

  17. Enhancement of as-sputtered silver-tantalum oxide thin film coating on biomaterial stainless steel by surface thermal treatment

    Science.gov (United States)

    Alias, Rodianah; Mahmoodian, Reza; Shukor, Mohd Hamdi Abd; Yew, Been Seok; Muhamad, Martini

    2018-04-01

    Stainless steel 316L (SS316L) is extensively used as surgical/clinical tools due to its low carbon content and excellent mechanical characteristic. The fabrication of metal ceramic based on this metallic biomaterial favor its biofunctionality properties. However, instability phase of amorphous thin film lead to degradation, corrosion and oxidation. Thus, thin film coating requires elevated adhesion strength and higher surface hardness to meet clinical tools criteria. In this study, the SS316L was deposited with micron thickness of Ag-TaO thin film by using magnetron sputtering. The microstructure, elemental analysis and phase identification of Ag-TaO thin film were characterized by using FESEM, EDX and XRD, respectively; whereas the micro scratch test and micro hardness test were performed by using Micro Scratch Testing System and Vickers Micro Hardness Tester, respectively. It was found that the coating thin film's adhesion and hardness strength were improved from 672 to 2749 mN and 142 to 158 Hv respectively. It was found that the as-deposited surface were treated at 500 °C of temperatures with 2 °C/min ramping rate enhance 4.1 times of the adhesion strength value. Furthermore, FESEM characterization revealed coarsening structure of the thin film coating which can provide high durability service.

  18. All-organic polymer-dispersed liquid crystal light-valves integrated with electroactive anthraquinone-2-sulfonate-doped polypyrrole thin films as driving electrodes

    International Nuclear Information System (INIS)

    Wang, Pen-Cheng; Yu, Jing-Yu; Li, Kuan-Hsun

    2011-01-01

    Highlights: → Fabrication of flexible semi-transparent all-polymer electrodes under ambient conditions without using a CVD system. → Characterization of the above electrodes based on anthraquinone-2-sulfonate-doped polypyrrole thin films. → Demonstration of all-organic liquid crystal light-valves with polypyrrole thin films as the driving electrodes. - Abstract: All-organic PDLC (polymer-dispersed liquid crystal) light-valves using all-polymer conductive substrates containing thin films of polypyrrole doped with anthraquinone-2-sulfonate (AQSA - ) as the driving electrodes were fabricated in this study. The all-polymer conductive substrates were prepared under ambient conditions by in situ depositing polypyrrole thin films on blank flexible poly(ethylene terephthalate), or PET, substrates from aqueous media in which oxidative polymerization of pyrrole was taking place. The obtained flexible all-polymer conductive substrates were semi-transparent with cohesive coatings of AQSA - doped polypyrrole thin films (thickness ∼55 nm). The all-polymer flexible conductive substrates had sheet resistivity ∼40 kΩ □ -1 and T% transparency against air ∼78% at 600 nm. The light-valves fabricated using the above all-polymer conductive substrates showed ∼50% transparency against air at 600 nm when 4 V μm -1 electric field was applied.

  19. The investigation of ZnO:Al2O3/metal composite back reflectors in amorphous silicon germanium thin film solar cells

    Institute of Scientific and Technical Information of China (English)

    Wang Guang-Hong; Zhao Lei; Yan Bao-Jun; Chen Jing-Wei; Wang Ge; Diao Hong-Wei; Wang Wen-Jing

    2013-01-01

    Different aluminum-doped ZnO (AZO)/metal composite thin films,including AZO/Ag/Al,AZO/Ag/nickelchromium alloy (NiCr),and AZO/Ag/NiCr/Al,are utilized as the back reflectors of p-i-n amorphous silicon germanium thin film solar cells.NiCr is used as diffusion barrier layer between Ag and Al to prevent mutual diffusion,which increases the short circuit current density of solar cell.NiCr and NiCr/Al layers are used as protective layers of Ag layer against oxidation and sulfurization,the higher efficiency of solar cell is achieved.The experimental results show that the performance of a-SiGe solar cell with AZO/Ag/NiCr/Al back reflector is best.The initial conversion efficiency is achieved to be 8.05%.

  20. Extraordinary light transmission through opaque thin metal film with subwavelength holes blocked by metal disks.

    Science.gov (United States)

    Li, Wen-Di; Hu, Jonathan; Chou, Stephen Y

    2011-10-10

    We observed that when subwavelength-sized holes in an optically opaque metal film are completely covered by opaque metal disks larger than the holes, the light transmission through the holes is not reduced, but rather enhanced. Particularly we report (i) the observation of light transmission through the holes blocked by the metal disks up to 70% larger than the unblocked holes; (ii) the observation of tuning the light transmission by varying the coupling strength between the blocking disks and the hole array, or by changing the size of the disks and holes; (iii) the observation and simulation that the metal disk blocker can improve light coupling from free space to a subwavelength hole; and (iv) the simulation that shows the light transmission through subwavelength holes can be enhanced, even though the gap between the disk and the metal film is partially connected with a metal. We believe these finding should have broad and significant impacts and applications to optical systems in many fields.

  1. LPCVD homoepitaxy of Si doped β-Ga2O3 thin films on (010) and (001) substrates

    Science.gov (United States)

    Rafique, Subrina; Karim, Md Rezaul; Johnson, Jared M.; Hwang, Jinwoo; Zhao, Hongping

    2018-01-01

    This paper presents the homoepitaxy of Si-doped β-Ga2O3 thin films on semi-insulating (010) and (001) Ga2O3 substrates via low pressure chemical vapor deposition with a growth rate of ≥1 μm/h. Both high resolution scanning transmission electron microscopy and X-ray diffraction measurements demonstrated high crystalline quality homoepitaxial growth of these thin films. Atomic resolution STEM images of the as-grown β-Ga2O3 thin films on (010) and (001) substrates show high quality material without extended defects or dislocations. The charge carrier transport properties of the as-grown Si-doped β-Ga2O3 thin films were characterized by the temperature dependent Hall measurement using van der Pauw patterns. The room temperature carrier concentrations achieved for the (010) and (001) homoepitaxial thin films were ˜1.2 × 1018 cm-3 and ˜9.5 × 1017 cm-3 with mobilities of ˜72 cm2/V s and ˜42 cm2/V s, respectively.

  2. Preparation and optical properties of gold-dispersed BaTiO3 thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kineri, T; Mori, M [TDK Corp., Tokyo (Japan). R and D Center; Kadono, K; Sakaguchi, T; Miya, M; Wakabayashi, H [Osaka National Research Inst., Osaka (Japan); Tsuchiya, T [Science Univ. of Tokyo, Tokyo (Japan). Faculty of Industrial Science and Technology

    1993-12-01

    Recently, metal or semiconductor-doped glasses were widely studied because of their large resonant third-order nonlinearity. These glasses are utilized in an optical information field as all optical logic devices in the future. The gold-doped glass films or thin layers have a large third-order nonlinear susceptibility [chi] and are prepared by r.f. sputtering method, etc. The optical properties, particularly the refractive index or dielectric constant of the matrix, are very important for the optical nonlinearity of these materials. In this study, gold-dispersed BaTiO3 thin films and gold-dispersed SiO2 thin films are prepared using r.f. magnetron sputtering method, and the optical properties of the films are compared. The [chi] of the films are measured and the effect of the matrix of the films on [chi] is investigated. The headings in the paper are: Introduction, Experimental procedure, Results, Discussion, and Conclusion. 13 refs., 9 figs.

  3. Device and method for luminescence enhancement by resonant energy transfer from an absorptive thin film

    Science.gov (United States)

    Akselrod, Gleb M.; Bawendi, Moungi G.; Bulovic, Vladimir; Tischler, Jonathan R.; Tisdale, William A.; Walker, Brian J.

    2017-12-12

    Disclosed are a device and a method for the design and fabrication of the device for enhancing the brightness of luminescent molecules, nanostructures, and thin films. The device includes a mirror, a dielectric medium or spacer, an absorptive layer, and a luminescent layer. The absorptive layer is a continuous thin film of a strongly absorbing organic or inorganic material. The luminescent layer may be a continuous luminescent thin film or an arrangement of isolated luminescent species, e.g., organic or metal-organic dye molecules, semiconductor quantum dots, or other semiconductor nanostructures, supported on top of the absorptive layer.

  4. Bauschinger effect in thin metal films on compliant substrates

    NARCIS (Netherlands)

    Hoefnagels, J.P.M.; Vlassak, J.J.; Gdoutos, E.E.

    2007-01-01

    Flexible electronic devices such as flexible displays and solar cells draw more and more attention from the industry. In these devices, the functionality is delivered by small-scale structures consisting of thin metal lines and other materials that are integrated on a compliant (e.g. polymer)

  5. First principles investigation of the activity of thin film Pt, Pd and Au surface alloys for oxygen reduction

    DEFF Research Database (Denmark)

    Tripkovic, Vladimir; Hansen, Heine Anton; Rossmeisl, Jan

    2015-01-01

    Further advances in fuel cell technologies are hampered by kinetic limitations associated with the sluggish cathodic oxygen reduction reaction. We have investigated a range of different formulations of binary and ternary Pt, Pd and Au thin films as electrocatalysts for oxygen reduction. The most...... active binary thin films are near-surface alloys of Pt with subsurface Pd and certain PdAu and PtAu thin films with surface and/or subsurface Au. The most active ternary thin films are with pure metal Pt or Pd skins with some degree of Au in the surface and/or subsurface layer and the near-surface alloys...

  6. Methods of making copper selenium precursor compositions with a targeted copper selenide content and precursor compositions and thin films resulting therefrom

    Science.gov (United States)

    Curtis, Calvin J [Lakewood, CO; Miedaner, Alexander [Boulder, CO; van Hest, Marinus Franciscus Antonius Maria; Ginley, David S [Evergreen, CO; Leisch, Jennifer [Denver, CO; Taylor, Matthew [West Simsbury, CT; Stanbery, Billy J [Austin, TX

    2011-09-20

    Precursor compositions containing copper and selenium suitable for deposition on a substrate to form thin films suitable for semi-conductor applications. Methods of forming the precursor compositions using primary amine solvents and methods of forming the thin films wherein the selection of temperature and duration of heating controls the formation of a targeted species of copper selenide.

  7. Characterization of interfaces between metals and organic thin films by electron and ion spectroscopies

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Martin

    2012-01-18

    In this thesis, interfaces between metals and organic thin films have been characterized with photoelectron and ion-scattering spectroscopies. Two different classes of metal/organic interfaces were examined in detail. First, interfaces which can be mainly characterized by relatively weak coordinative interactions between substrate and adsorbate. Second, interfaces which are mostly determined, or even created, by chemical reactions between different adsorbates or between adsorbates and substrate. Typical examples from the first class are metalated tetrapyrrole monolayers on Ag(111) and Au(111) single-crystal substrates. In this study, a focus was set to the interaction between iron and cobalt tetrapyrroles with Ag(111) or Au(111) substrates. A detailed examination of the corresponding photoelectron spectra revealed that the adsorbatesubstrate interaction is associated with a charge transfer from the metallic substrate to the Fe(II) or Co(II) ions within the tetrapyrrole units. The examination of cobalt(II) phthalocyanine monolayers further led to the conclusion that the magnetic moment, as present in unperturbed CoPc molecules, is efficiently quenched by the contact to the Ag(111) surface and the associated charge transfer. Similar investigations on Au(111) substrates gave evidence for possible adsorption site effects, further complicating the adsorbate/substrate interaction. Furthermore the formation of two-dimensional structures of poly(p-phenylene-terephthalamide) (PPTA, trademark Kevlar) on Ag(111) was closely examined. The Ag(111) surface does not only provide the geometrical boundary for the formation of the 2D covalent structures, but, moreover, actively participates in the reaction; after the adsorption of TPC molecules, a scission of the C-Cl bond, in particular at temperatures above 120 K, was evident. The resulting radical fragments appear stable and can act as reaction partners for the co-adsorbed PPD units. The chlorine atoms reside on the surface even

  8. Universal Method for Creating Hierarchical Wrinkles on Thin-Film Surfaces.

    Science.gov (United States)

    Jung, Woo-Bin; Cho, Kyeong Min; Lee, Won-Kyu; Odom, Teri W; Jung, Hee-Tae

    2018-01-10

    One of the most interesting topics in physical science and materials science is the creation of complex wrinkled structures on thin-film surfaces because of their several advantages of high surface area, localized strain, and stress tolerance. In this study, a significant step was taken toward solving limitations imposed by the fabrication of previous artificial wrinkles. A universal method for preparing hierarchical three-dimensional wrinkle structures of thin films on a multiple scale (e.g., nanometers to micrometers) by sequential wrinkling with different skin layers was developed. Notably, this method was not limited to specific materials, and it was applicable to fabricating hierarchical wrinkles on all of the thin-film surfaces tested thus far, including those of metals, two-dimensional and one-dimensional materials, and polymers. The hierarchical wrinkles with multiscale structures were prepared by sequential wrinkling, in which a sacrificial layer was used as the additional skin layer between sequences. For example, a hierarchical MoS 2 wrinkle exhibited highly enhanced catalytic behavior because of the superaerophobicity and effective surface area, which are related to topological effects. As the developed method can be adopted to a majority of thin films, it is thought to be a universal method for enhancing the physical properties of various materials.

  9. Metal-semiconductor transition materials. FeS and VO2 thin films by RF reactive sputtering

    International Nuclear Information System (INIS)

    Fu, Ganhua

    2007-06-01

    In the present work, two MST systems, FeS and VO 2 thin films were investigated. Iron sulfide thin films over a range of composition were prepared by reactive sputtering. The influence of the substrate, sputter power, substrate temperature and stoichiometry on the structure and MST of iron sulfide films was investigated. Iron sulfide films deposited at different temperatures show temperature dependent structure and MST. FeS films on float glass show (110) and (112) orientations when the substrate temperature is 200 and 500 C, respectively. The transition temperature and width of the hysteresis loop determined from the temperature dependent conductivity curves of iron sulfide films decrease with the substrate temperature. Fe and S excess in FeS films both result in the decrease of the transition temperature and width of the hysteresis loop. The vacuum-annealing affects the MST of FeS films significantly. When FeS films were annealed below the deposition temperature, the transition temperature decreases; otherwise increases. The residual stress plays an important role during the annealing process. The higher the residual stress inside the FeS films is, the higher the transition temperature of FeS films. With the increase of the annealing temperature, the residual stress in FeS films is first released and then enhances, which gives rise first to the decrease and then increase of the transition temperature of FeS films. At high substrate temperatures, the residual stress is higher. In addition, the MST of FeS films was influenced by the ambient aging. With the increase of the aging time, the transition temperature first increases and then decreases. FeS films with different thicknesses were prepared. The correlation between the film thickness (grain size) and the MST switching characteristics of FeS films was established. With the decrease of the grain size, the density of grain boundaries increases, causing the increase of the conductivity of the semiconducting phase

  10. Multi-Material Front Contact for 19% Thin Film Solar Cells

    NARCIS (Netherlands)

    Deelen, J. van; Tezsevin, Y.; Barink, M.

    2016-01-01

    The trade-off between transmittance and conductivity of the front contact material poses abottleneck for thin film solar panels. Normally, the front contact material is a metal oxide and the optimal cell configuration and panel efficiency were determined for various band gap materials, representing

  11. Transparent thin-film transistor exploratory development via sequential layer deposition and thermal annealing

    International Nuclear Information System (INIS)

    Hong, David; Chiang, Hai Q.; Presley, Rick E.; Dehuff, Nicole L.; Bender, Jeffrey P.; Park, Cheol-Hee; Wager, John F.; Keszler, Douglas A.

    2006-01-01

    A novel deposition methodology is employed for exploratory development of a class of high-performance transparent thin-film transistor (TTFT) channel materials involving oxides composed of heavy-metal cations with (n - 1)d 10 ns 0 (n ≥ 4) electronic configurations. The method involves sequential radio-frequency sputter deposition of thin, single cation oxide layers and subsequent post-deposition annealing in order to obtain a multi-component oxide thin film. The viability of this rapid materials development methodology is demonstrated through the realization of high-performance TTFTs with channel layers composed of zinc oxide/tin oxide, and tin oxide/indium oxide

  12. 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.

  13. 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

  14. Mn doped GaN thin films and nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Šofer, Z.; Sedmidubský, D.; Huber, Š.; Hejtmánek, Jiří; Macková, Anna; Fiala, R.

    2012-01-01

    Roč. 9, 8-9 (2012), s. 809-824 ISSN 1475-7435 R&D Projects: GA ČR GA104/09/0621 Institutional research plan: CEZ:AV0Z10100521; CEZ:AV0Z10480505 Keywords : GaN nanoparticles * GaN thin films * manganese * transition metals * MOVPE * ion implantations Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.087, year: 2012

  15. General Top-Down Ion Exchange Process for the Growth of Epitaxial Chalcogenide Thin Films and Devices

    KAUST Repository

    Xia, Chuan; Li, Peng; Li, Jun; Jiang, Qiu; Zhang, Xixiang; Alshareef, Husam N.

    2016-01-01

    ) epitaxial chalcogenide metallic and semiconducting films and (2) free-standing chalcogenide films and (3) completed in situ formation of atomically sharp heterojunctions by selective ion exchange. Epitaxial NiCo2S4 thin films prepared by our process show 115

  16. 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

  17. Applying RF Magnetron sputtering to prepare ZnO thin films and their characterization

    International Nuclear Information System (INIS)

    Saad, M.; Kassis, A.

    2009-05-01

    ZnO thin films were prepared using Rf magnetron sputtering under several preparation conditions (different values of deposition pressure, Rf power, substrate temperature). The optical properties of these films were investigated by measuring their transmission in the spectral range (300-1000 nm), and the electrical properties were investigated by measuring their electrical resistance. Results have been discussed in terms of the modified Thornton model for sputtered thin metal oxide films. Preparation conditions for depositing the highly resistive transparent i-ZnO buffer layer and the highly conducting transparent n-ZnO window layer for solar cells were proposed. (author)

  18. Voltammetric Thin-Layer Ionophore-Based Films: Part 2. Semi-Empirical Treatment.

    Science.gov (United States)

    Yuan, Dajing; Cuartero, Maria; Crespo, Gaston A; Bakker, Eric

    2017-01-03

    This work reports on a semiempirical treatment that allows one to rationalize and predict experimental conditions for thin-layer ionophore-based films with cation-exchange capacity read out with cyclic voltammetry. The transition between diffusional mass transport and thin-layer regime is described with a parameter (α), which depends on membrane composition, diffusion coefficient, scan rate, and electrode rotating speed. Once the thin-layer regime is fulfilled (α = 1), the membrane behaves in some analogy to a potentiometric sensor with a second discrimination variable (the applied potential) that allows one to operate such electrodes in a multianalyte detection mode owing to the variable applied ion-transfer potentials. The limit of detection of this regime is defined with a second parameter (β = 2) and is chosen in analogy to the definition of the detection limit for potentiometric sensors provided by the IUPAC. The analytical equations were validated through the simulation of the respective cyclic voltammograms under the same experimental conditions. While simulations of high complexity and better accuracy satisfactorily reproduced the experimental voltammograms during the forward and backward potential sweeps (companion paper 1), the semiempirical treatment here, while less accurate, is of low complexity and allows one to quite easily predict relevant experimental conditions for this emergent methodology.

  19. Extremely Efficient Design of Organic Thin Film Solar Cells via Learning-Based Optimization

    Directory of Open Access Journals (Sweden)

    Mine Kaya

    2017-11-01

    Full Text Available Design of efficient thin film photovoltaic (PV cells require optical power absorption to be computed inside a nano-scale structure of photovoltaics, dielectric and plasmonic materials. Calculating power absorption requires Maxwell’s electromagnetic equations which are solved using numerical methods, such as finite difference time domain (FDTD. The computational cost of thin film PV cell design and optimization is therefore cumbersome, due to successive FDTD simulations. This cost can be reduced using a surrogate-based optimization procedure. In this study, we deploy neural networks (NNs to model optical absorption in organic PV structures. We use the corresponding surrogate-based optimization procedure to maximize light trapping inside thin film organic cells infused with metallic particles. Metallic particles are known to induce plasmonic effects at the metal–semiconductor interface, thus increasing absorption. However, a rigorous design procedure is required to achieve the best performance within known design guidelines. As a result of using NNs to model thin film solar absorption, the required time to complete optimization is decreased by more than five times. The obtained NN model is found to be very reliable. The optimization procedure results in absorption enhancement greater than 200%. Furthermore, we demonstrate that once a reliable surrogate model such as the developed NN is available, it can be used for alternative analyses on the proposed design, such as uncertainty analysis (e.g., fabrication error.

  20. 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.