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Sample records for generation thin film

  1. Thermochemical hydrogen generation of indium oxide thin films

    Directory of Open Access Journals (Sweden)

    Taekyung Lim

    2017-03-01

    Full Text Available Development of alternative energy resources is an urgent requirement to alleviate current energy constraints. As such, hydrogen gas is gaining attention as a future alternative energy source to address existing issues related to limited energy resources and air pollution. In this study, hydrogen generation by a thermochemical water-splitting process using two types of In2O3 thin films was investigated. The two In2O3 thin films prepared by chemical vapor deposition (CVD and sputtering deposition systems contained different numbers of oxygen vacancies, which were directly related to hydrogen generation. The as-grown In2O3 thin film prepared by CVD generated a large amount of hydrogen because of its abundant oxygen vacancies, while that prepared by sputtering had few oxygen vacancies, resulting in low hydrogen generation. Increasing the temperature of the In2O3 thin film in the reaction chamber caused an increase in hydrogen generation. The oxygen-vacancy-rich In2O3 thin film is expected to provide a highly effective production of hydrogen as a sustainable and efficient energy source.

  2. A high power ZnO thin film piezoelectric generator

    Science.gov (United States)

    Qin, Weiwei; Li, Tao; Li, Yutong; Qiu, Junwen; Ma, Xianjun; Chen, Xiaoqiang; Hu, Xuefeng; Zhang, Wei

    2016-02-01

    A highly efficient and large area piezoelectric ZnO thin film nanogenerator (NG) was fabricated. The ZnO thin film was deposited onto a Si substrate by pulsed laser ablation at a substrate temperature of 500 °C. The deposited ZnO film exhibited a preferred c-axis orientation and a high piezoelectric value of 49.7 pm/V characterized using Piezoelectric Force Microscopy (PFM). Thin films of ZnO were patterned into rectangular power sources with dimensions of 0.5 × 0.5 cm2 with metallic top and bottom electrodes constructed via conventional semiconductor lithographic patterning processes. The NG units were subjected to periodic bending/unbending motions produced by mechanical impingement at a fixed frequency of 100 Hz at a pressure of 0.4 kg/cm2. The output electrical voltage, current density, and power density generated by one ZnO NG were recorded. Values of ∼95 mV, 35 μA cm-2 and 5.1 mW cm-2 were recorded. The level of power density is typical to that produced by a PZT NG on a flexible substrate. Higher energy NG sources can be easily created by adding more power units either in parallel or in series. The thin film ZnO NG technique is highly adaptable with current semiconductor processes, and as such, is easily integrated with signal collecting circuits that are compatible with mass production. A typical application would be using the power harvested from irregular human foot motions to either to operate blue LEDs directly or to drive a sensor network node in mille-power level without any external electric source and circuits.

  3. Metallic Thin-Film Bonding and Alloy Generation

    Science.gov (United States)

    Fryer, Jack Merrill (Inventor); Campbell, Geoff (Inventor); Peotter, Brian S. (Inventor); Droppers, Lloyd (Inventor)

    2016-01-01

    Diffusion bonding a stack of aluminum thin films is particularly challenging due to a stable aluminum oxide coating that rapidly forms on the aluminum thin films when they are exposed to atmosphere and the relatively low meting temperature of aluminum. By plating the individual aluminum thin films with a metal that does not rapidly form a stable oxide coating, the individual aluminum thin films may be readily diffusion bonded together using heat and pressure. The resulting diffusion bonded structure can be an alloy of choice through the use of a carefully selected base and plating metals. The aluminum thin films may also be etched with distinct patterns that form a microfluidic fluid flow path through the stack of aluminum thin films when diffusion bonded together.

  4. Low temperature thin films for next-generation microelectronics (invited)

    NARCIS (Netherlands)

    Schmitz, Jurriaan

    2017-01-01

    In this article the current methodologies for low-temperature thin film deposition in microelectronics are reviewed. The paper discusses the high temperature processes in microchip manufacturing and describes the thermal budget fitting issue. The quest for low temperature deposition techniques is

  5. Acoustic emission generated during scratch test of various thin films

    Czech Academy of Sciences Publication Activity Database

    Boháč, Petr; Tomáštík, J.; Čtvrtlík, R.; Dráb, M.; Koula, V.; Cvrk, K.; Jastrabík, Lubomír

    2014-01-01

    Roč. 19, č. 12 (2014), s. 16635 ISSN 1435-4934 R&D Projects: GA TA ČR TA03010743 Institutional support: RVO:68378271 Keywords : acoustic emission * scratch test * thin films * AE data analysis * mechanical toughness Subject RIV: BI - Acoustics

  6. Active Oxygen Generator by Silent Discharge and Oxidation Power in Formation of Oxide Thin Films

    Science.gov (United States)

    Tanaka, Masaaki; Kawagoe, Yasuyuki; Tsukazaki, Hisashi; Yamanishi, Kenichiro

    We have studied the low pressure silent discharge type active oxygen generator in terms of the application to the formation of oxide thin films. In this paper the oxidation power of active oxygen in the oxide thin film formation is compared with that of oxygen and ozone by forming silicon oxide thin films. It was confirmed that the oxidation power is in turn of active oxygen > ozone > oxygen from the experimental result of the number of x in SiOx thin film. Furthermore we applied active oxygen to the formation of the thin film high temperature super conductor and active oxygen was found to be effective to the formation of the thin film with high performance.

  7. Surface enhanced second harmonic generation from macrocycle, catenane, and rotaxane thin films : Experiments and theory

    NARCIS (Netherlands)

    Arfaoui, I.; Bermudez, V.; Bottari, G.; De Nadai, C.; Jalkanen, J.P.; Kajzar, F.; Leigh, D.A.; Lubomska, M.; Mendoza, S.M.; Niziol, J.; Rudolf, Petra; Zerbetto, F.

    2006-01-01

    Surface enhanced second harmonic generation (SE SHG) experiments on molecular structures, macrocycles, catenanes, and rotaxanes, deposited as monolayers and multilayers by vacuum sublimation on silver, are reported. The measurements show that the molecules form ordered thin films, where the highest

  8. ORGANIC THIN-FILM SOLAR CELLS: NEXT GENERATION LOW ...

    African Journals Online (AJOL)

    Solar energy has the potential to fulfil an important part of the sustainable energy demand for future power generations. Thereby, low-cost organic photovoltaic systems have come into the international researchfocus during thepast ... polymeric solar cells ultra-thin flexible material can be applied to large surfaces by printing ...

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

    International Nuclear Information System (INIS)

    Mizoshiri, Mizue; Mikami, Masashi; Ozaki, Kimihiro

    2013-01-01

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

  10. Thin Film

    African Journals Online (AJOL)

    a

    organic substances. KEY WORDS: Photoelectrocatalysis, Titanium dioxide, Cuprous oxide, Composite thin film, Photo electrode. INTRODUCTION ... reddish p-type semiconductor with a direct band gap of 2.0-2.2 eV [18, 19]. ... Photoelectrocatalytic removal of color from water using TiO2 and TiO2/Cu2O electrodes. Bull.

  11. Stress waves generated in thin metallic films by a Q-switched ruby laser

    Science.gov (United States)

    Yang, L. C.

    1974-01-01

    Investigation results on stress waves generated by Q-switched ruby laser irradiated thin metal films under confinement, studied over a wide range of film materials and film thicknesses, are reviewed. The results indicate that the dependence on these parameters is much weaker than is predicted by heat transfer estimations commonly used to describe the interaction of laser irradiation with unconfined bulk-solid surfaces.

  12. thin films

    Indian Academy of Sciences (India)

    The anionic precursor was 1% H2O2 solution. Both the cationic and anionic precursors were kept at room temperature (∼300 K). One SILAR cycle consists of two steps: (i) adsorption of Sn4+ ions on the substrate surface for 20 s and (ii) reaction with H2O2 solution for 40 s to form stable SnO2:H2O thin film on the substrate.

  13. The influence of thin film grain size on the size of nanoparticles generated during UV femtosecond laser ablation of thin gold films

    International Nuclear Information System (INIS)

    Haustrup, N.; O’Connor, G.M.

    2013-01-01

    The upsurge in the number of thin film products has encouraged studies into every aspect of their fabrication and application. An additional source of industrial interest is the laser ablation of thin films to generate nanoparticles. This technique offers advantages over other fabrication methods, as no chemical pre-cursers are required, thereby giving rise to a pure product. The main disadvantage lies in the difficulty with controlling the size of the nanoparticles. This study aims to clarify the influence of the microstructure of a thin film on its optical properties and also to establish the size relationship between the film grain and the nanoparticles generated during laser ablation. A comprehensive sample set of Gold (Au) films with different grain sizes was achieved using different deposition rates, temperatures, film thicknesses (<100 nm) and substrates: Silica, Quartz and Sapphire. The microstructure of each film was analyzed using Atomic Force Microscopy (AFM). Single femtosecond laser pulses, above the ablation threshold fluence of each film, were applied to generate nanoparticles. Scanning Electron Microscopy (SEM) was used to image the re-deposited nanoparticles, from which the nanoparticle size distribution was established. Results confirm that the film microstructure is directly linked to the nanoparticles generated during laser ablation.

  14. The generation and detection of high flux atomic oxygen for physical vapor deposition thin film growth

    NARCIS (Netherlands)

    Ingle, N.J.C.; Hammond, R.H.; Beasley, M.R.; Blank, David H.A.

    1999-01-01

    The growth of many epitaxial thin-film oxides is significantly enhanced with the use of an oxidizing agent such as atomic oxygen, ozone, or NO2. We developed a flow-through microwave plasma source to generate large atomic oxygen fluxes while maintaining vacuum pressures of less that 1×10¿4 Torr.

  15. Simultaneous solution-based generation and characterization of crystalline bismuth thin film by femtosecond laser spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Liangdong; Keszler, Douglas A.; Fang, Chong, E-mail: Chong.Fang@oregonstate.edu [Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331-4003 (United States); Department of Physics, Oregon State University, 301 Weniger Hall, Corvallis, Oregon 97331-6507 (United States); Saha, Sumit; Liu, Weimin; Wang, Yanli [Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331-4003 (United States)

    2015-08-10

    We demonstrate generation and characterization of crystalline bismuth thin film from triphenyl bismuth in methanol. Upon ultraviolet (267 nm) femtosecond laser irradiation of the solution, a thin film of elemental bismuth forms on the inner side of the sample cuvette, confirmed by detection of the coherent A{sub 1g} optical phonon mode of crystalline bismuth at ∼90 cm{sup −1}. Probe pulses at 267 and 400 nm are used to elucidate the excited state potential energy surface and photochemical reaction coordinate of triphenyl bismuth in solution with femtosecond resolution. The observed phonon mode blueshifts with increasing irradiation time, likely due to the gradual thickening of nascent bismuth thin film to ∼80 nm in 90 min. From transient absorption with the 400 nm probe, we observe a dominant ∼4 ps decay time constant of the excited-state absorption signal, which is attributed to a characteristic metal-ligand bond-weakening/breaking intermediate enroute to crystalline metallic thin film from the solution precursor molecules. Our versatile optical setup thus opens an appealing avenue to characterize the laser-induced crystallization process in situ and prepare high-quality thin films and nanopatterns directly from solution phase.

  16. An automated multidimensional thin film stretching device for the generation of anisotropic polymeric micro- and nanoparticles.

    Science.gov (United States)

    Meyer, Randall A; Meyer, Randall S; Green, Jordan J

    2015-08-01

    Anisotropic polymeric particles are of growing interest for biomaterials applications due to their unique properties. These include the ability for these particles to evade nonspecific cellular uptake and to have enhanced targeted cellular uptake and interaction. One of the most widely used methods for generating anisotropic polymeric particles is the thin film stretching procedure. Despite its theoretical simplicity, this procedure, as it has been implemented to date, can be difficult due to the inconsistent nature of the manual operation of machinery used to stretch the film. We have constructed an automated thin film stretcher for control over biomaterials via thin film stretching in 1D and 2D and as a result, have enabled precise generation of anisotropic polymeric particles. We demonstrate that this device can be utilized to produce anisotropic biodegradable particles of different size, shape, and material consistency. Furthermore, we show that this machine has enabled the scaled up and rapid production of anisotropic polymeric particles, including polymeric microparticles that mimic the shape of red blood cells. Further application of this automated thin film stretching device could allow for significant impact to diverse biomaterial and biomedical applications such as biomimetic particles for immunoengineering and long-circulating particles for controlled release of drugs. © 2015 Wiley Periodicals, Inc.

  17. Particulate generation during pulsed laser deposition of superconductor thin films

    International Nuclear Information System (INIS)

    Singh, R.K.

    1993-01-01

    The nature of evaporation/ablation characteristics during pulsed laser deposition strongly controls the quality of laser-deposited films. To understand the origin of particulates in laser deposited films, the authors have simulated the thermal history of YBa 2 Cu 3 O 7 targets under intense nanosecond laser irradiation by numerically solving the heat flow equation with appropriate boundary conditions. During planar surface evaporation of the target material, the sub-surface temperatures were calculated to be higher than the surface temperatures. While the evaporating surface of the target is constantly being cooled due to the latent heat of vaporization, subsurface superheating occurs due to the finite absorption depth of the laser beam. Sub-surface superheating was found to increase with decreasing absorption coefficient and thermal conductivity of the target, and with increasing energy density. The superheating may lead to sub-surface nucleation and growth of the gaseous phase which can expand rapidly leading to microexplosions and ''volume expulsion'' of material from the target. Experiments conducted by the authors and other research groups suggest a strong relation between degree of sub-surface superheating and particle density in laser-deposited films

  18. Mission Applicability and Benefits of Thin-Film Integrated Power Generation and Energy Storage

    Science.gov (United States)

    Hoffman, David; Raffaelle, Ryne P.; Landis, Geoffrey A.; Hepp, Aloysius F.

    2001-01-01

    This paper discusses the space mission applicability and benefits of a thin-film integrated power generation and energy storage device, i.e., an "Integrated Power Source" or IPS. The characteristics of an IPS that combines thin-film photo-voltaic power generation with thin-film energy storage are described. Mission concepts for a thin-film IPS as a spacecraft main electrical power system, as a decentralized or distributed power source and as an uninterruptible power supply are discussed. For two specific missions, preliminary sizing of an IPS as a main power system is performed and benefits are assessed. IPS developmental challenges that need to be overcome in order to realize the benefits of an IPS are examined. Based on this preliminary assessment, it is concluded that the most likely and beneficial application of an IPS will be as the main power system on a very small "nanosatellite," or in specialized applications serving as a decentralized or distributed power source or uninterruptible power supply.

  19. Second harmonic generation from corona-poled polymer thin films ...

    Indian Academy of Sciences (India)

    2014-02-09

    Feb 9, 2014 ... We characterize thermal stability of second harmonic generation (SHG) properties of four different Y-type polymers poled using corona poling method. These polymers are based on donor–acceptor–donor-type repeating unit with different aromatic moieties acting as donors and dicyanomethylene acting as ...

  20. Second harmonic generation from corona-poled polymer thin films ...

    Indian Academy of Sciences (India)

    2014-02-09

    Feb 9, 2014 ... Abstract. We characterize thermal stability of second harmonic generation (SHG) properties of four different Y-type polymers poled using corona poling method. These polymers are based on donor–acceptor–donor-type repeating unit with different aromatic moieties acting as donors and dicyanomethylene ...

  1. Thin Films

    Directory of Open Access Journals (Sweden)

    M. Benmouss

    2003-01-01

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

  2. Next-generation ionomer encapsulants for thin film technology

    Science.gov (United States)

    Czyzewicz, Robin; Smith, C. Anthony

    2011-09-01

    The characteristic properties of newly developed ionomer-based encapsulants are highlighted along with an in-depth analysis of moisture ingress, electrical and mechanical properties. The mechanical properties of these encapsulants with their high stiffness and strength have been found to allow the use of thinner glass and a possible shift from tempered to annealed glass. Lower-cost mounting options may be explored through full-module stress/deflection measurement capability and competencies developed in world-class finite-element modeling of system parameters. The superior electrical and moisture properties may allow modules to be produced without the use of an additional edge seal. These new materials have improved melt flow properties when compared to other encapsulant families such as EVA or PVB. This allows for faster processing which reduces production cost by shortening the lamination cycle. During the lamination process the sheets show excellent dimensional stability and low shrinkage behavior; and there is no need for curing, thus energy costs are lower due to lower lamination temperature. As advancement of technology proceeds across the entire PV industry, next generation ionomer encapsulants have been developed to keep up with the pace.

  3. MOCVD of thin film photovoltaic solar cells—Next-generation production technology?

    Science.gov (United States)

    Irvine, S. J. C.; Barrioz, V.; Lamb, D.; Jones, E. W.; Rowlands-Jones, R. L.

    2008-11-01

    This paper will review the chalcogenide thin film photovoltaic (PV) solar cells, based on cadmium telluride (CdTe) and copper indium diselenide (CIS) and discuss the potential for metalorganic chemical vapour deposition (MOCVD) to enable more advanced devices in the second generation of CdTe module production. The current generation of production methods is based on physical vapour deposition (PVD) or close-spaced sublimation (CSS). This paper concentrates on the less well-known topic of MOCVD of thin film chalcogenide cells, and in particular that of CdTe. Efficient CdTe PV solar cells (>10% AM1.5) have been demonstrated from deposition of the CdS, CdTe and CdCl 2 films in a single MOCVD chamber. The CdTe layer was doped with As and an additional high As concentration CdTe layer provides effective low resistance contacting without the need for wet etching the surface. The high level of flexibility in using MOCVD has been demonstrated where the CdS window layer has been alloyed with Zn to improve the blue response of the PV device and improve AM1.5 efficiency to 13.3%.

  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. Application of Neutron Measurements to Advance Semiconductor Manufacturing: Next-Generation Lithography and Nanoporous Thin Films

    Science.gov (United States)

    Lin, Eric

    2010-03-01

    As feature sizes in microelectronic devices continue to decrease to sub-32 nm dimensions, new measurement methods are needed to understand the physical phenomena used in state-of-the-art lithography methods that may limit their fabrication and probe the structure and properties of new electronics materials. Neutron (and x-ray) beams have emerged as powerful probes of new manufactured structures with characteristic length scales ranging from (1 to 100) nm in thin films and in the bulk. In particular, X-ray reflectivity (XR), neutron reflectivity (NR), small angle neutron scattering (SANS), and small angle X-ray scattering (SAXS) can be applied in novel ways to address fundamental issues important to the microelectronics industry. This talk with highlight the application of neutron and x-ray measurement methods to investigate important problems in the development of photoresist materials used in lithography and of nanoporous low-dielectric-constant materials needed for next generation integrated circuits. Specific topics include: 1) the direct measurement of the reaction-diffusion front with nanometer resolution from ideal line-edges to probe image blur and roughness from photoacid diffusion 2) identification and measurement of a ``residual swelling fraction'' during the development and 3) measurements of the pore structure of low-dielectric constant thin films. Insights from these studies can provide guidelines and opportunities for the further extension of photoresist technology into the future and the integration of new materials into integrated circuits.

  6. Modeling and Analysis of Entropy Generation in Light Heating of Nanoscaled Silicon and Germanium Thin Films

    Directory of Open Access Journals (Sweden)

    José Ernesto Nájera-Carpio

    2015-07-01

    Full Text Available In this work, the irreversible processes in light heating of Silicon (Si and Germanium (Ge thin films are examined. Each film is exposed to light irradiation with radiative and convective boundary conditions. Heat, electron and hole transport and generation-recombination processes of electron-hole pairs are studied in terms of a phenomenological model obtained from basic principles of irreversible thermodynamics. We present an analysis of the contributions to the entropy production in the stationary state due to the dissipative effects associated with electron and hole transport, generation-recombination of electron-hole pairs as well as heat transport. The most significant contribution to the entropy production comes from the interaction of light with the medium in both Si and Ge. This interaction includes two processes, namely, the generation of electron-hole pairs and the transferring of energy from the absorbed light to the lattice. In Si the following contribution in magnitude comes from the heat transport. In Ge all the remaining contributions to entropy production have nearly the same order of magnitude. The results are compared and explained addressing the differences in the magnitude of the thermodynamic forces, Onsager’s coefficients and transport properties of Si and Ge.

  7. Thin Film Processes

    CERN Document Server

    Vossen, John L.

    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 several key topics presented in the original volume are updated * Emphasizes practical applications of major thin film deposition and etching processes * Helps readers find the appropriate technology for a particular application

  8. Multiple-Color-Generating Cu(In,Ga)(S,Se)2 Thin-Film Solar Cells via Dichroic Film Incorporation for Power-Generating Window Applications.

    Science.gov (United States)

    Yoo, Gang Yeol; Jeong, Jae-Seung; Lee, Soyoung; Lee, Youngki; Yoon, Hee Chang; Chu, Van Ben; Park, Gi Soon; Hwang, Yun Jeong; Kim, Woong; Min, Byoung Koun; Do, Young Rag

    2017-05-03

    There are four prerequisites when applying all types of thin-film solar cells to power-generating window photovoltaics (PVs): high power-generation efficiency, longevity and high durability, semitransparency or partial-light transmittance, and colorful and aesthetic value. Solid-type thin-film Cu(In,Ga)S 2 (CIGS) or Cu(In,Ga)(S,Se) 2 (CIGSSe) PVs nearly meet the first two criteria, making them promising candidates for power-generating window applications if they can transmit light to some degree and generate color with good aesthetic value. In this study, the mechanical scribing process removes 10% of the window CIGSSe thin-film solar cell with vacant line patterns to provide a partial-light-transmitting CIGSSe PV module to meet the third requirement. The last concept of creating distinct colors could be met by the addition of reflectance colors of one-dimensional (1D) photonic crystal (PC) dichroic film on the black part of a partial-light-transmitting CIGSSe PV module. Beautiful violets and blues were created on the cover glass of a black CIGSSe PV module via the addition of 1D PC blue-mirror-yellow-pass dichroic film to improve the aesthetic value of the outside appearance. As a general result from the low external quantum efficiency (EQE) and absorption of CIGSSe PVs below a wavelength of 400 nm, the harvesting efficiency and short-circuit photocurrent of CIGSSe PVs were reduced by only ∼10% without reducing the open-circuit voltage (V OC ) because of the reduced overlap between the absorption spectrum of CIGSSe PV and the reflectance spectrum of the 1D PC blue-mirror-yellow-pass dichroic film. The combined technology of partial-vacancy-scribed CIGSSe PV modules and blue 1D PC dichroic film can provide a simple strategy to be applied to violet/blue power-generating window applications, as such a strategy can improve the transparency and aesthetic value without significantly sacrificing the harvesting efficiency of the CIGSSe PV modules.

  9. Issues related to YIG spintronics - thin film growth, spin pumping efficiency, and spin current generation

    Science.gov (United States)

    Wu, Mingzhong

    2014-03-01

    If a magnetic field is applied to a magnetic material, the field produces a torque on the magnetization of the material and drives it to precess. This precession is similar to the motion of a spinning top where the gravitational field produces a torque, instead of the magnetic field. It turns out that magnetization precession in yttrium iron garnets (YIG) decays slower than in any other known magnetic materials. This fact gives rise to the recent birth of a new paradigm in the discipline of spintronics - ``spintronics using YIG.'' This talk will touch on several topics related to YIG spintronics. The first part will demonstrate the feasibility of the use of pulsed laser deposition and magnetron sputtering to grow low-damping, nanometer-thick YIG films. The second part will address the efficiency of spin angular momentum transfer across YIG/normal metal interfaces. The last part will report on the use of YIG thin films to produce pure spin currents; Detailed discussions will be provided on the comparison between spin current generations using traveling spin waves and uniform ferromagnetic resonance modes, the field dependence of spin current generation, and spin current enhancement in YIG/Pt structures via the use of a thin Cu spacer. This work was supported in part by U.S. National Science Foundation (No. ECCS-1231598), the U.S. Army Research Office (No. W911NF-12-1-0518, No. W911NF-11-C-0075), and the U.S. National Institute of Standards and Technology (No. 60NANB10D011).

  10. Optical thin film devices

    Science.gov (United States)

    Mao, Shuzheng

    1991-11-01

    Thin film devices are applied to almost all modern scientific instruments, and these devices, especially optical thin film devices, play an essential role in the performances of the instruments, therefore, they are attracting more and more attention. Now there are numerous kinds of thin film devices and their applications are very diversified. The 300-page book, 'Thin Film Device and Applications,' by Prof. K. L. Chopra gives some general ideas, and my paper also outlines the designs, fabrication, and applications of some optical thin film devices made in my laboratory. Optical thin film devices have been greatly developed in the recent decades. Prof. A. Thelan has given a number of papers on the theory and techniques, Prof. H. A. Macleod's book, 'Thin Film Optical Filters,' has concisely concluded the important concepts of optical thin film devices, and Prof. J. A. Dobrowobski has proposed many successful designs for optical thin film devices. Recently, fully-automatic plants make it easier to produce thin film devices with various spectrum requirements, and some companies, such as Balzers, Leybold AG, Satis Vacuum AG, etc., have manufactured such kinds of coating plants for research or mass-production, and the successful example is the production of multilayer antireflection coatings with high stability and reproducibility. Therefore, it could be said that the design of optical thin film devices and coating plants is quite mature. However, we cannot expect that every problem has been solved, the R&D work still continues, the competition still continues, and new design concepts, new techniques, and new film materials are continually developed. Meanwhile, the high-price of fully-automatic coating plants makes unpopular, and automatic design of coating stacks is only the technique for optimizing the manual design according to the physical concepts and experience, in addition, not only the optical system, but also working environment should be taken into account when

  11. Thin films on cantilevers

    NARCIS (Netherlands)

    Nazeer, H.

    2012-01-01

    The main goal of the work compiled in this thesis is to investigate thin films for integration in micro electromechanical systems (MEMS). The miniaturization of MEMS actuators and sensors without compromising their performance requires thin films of different active materials with specific

  12. Spontaneous Generation of Electromotive Force in Thin Film Al/Nanosilicon/Al Structures

    Directory of Open Access Journals (Sweden)

    Sergey G. Dorofeev

    2017-10-01

    Full Text Available Contemporary pursuits in electronics include the miniaturization as well as flexibilization of devices. Although there are a large number of different thin and flexible electrochemical batteries, only a few can boast the possibility of working in high humidity conditions. This paper reports on the fabrication of structures consisting of films of silicon nanoparticles encased between two aluminium electrodes. The value of electromotive force (emf measured depends on the temperature of the sample and on the pressure of water vapor in the storage atmosphere and reaches approximately 1 V. Volt-ampere characteristics were investigated at different conditions to yield a model of emf generation in these structures. It was found that the reaction of water with silicon nanoparticles is the prime reason behind emf generation. Such a source may be introduced into electronic paper, and employed in the next generation of smart cards. The structure may also be manufactured directly on the surface of silicon chips, such as on the back of crystals in microschemes.

  13. Outer-selective thin film composite (TFC) hollow fiber membranes for osmotic power generation

    KAUST Repository

    Le, Ngoc Lieu

    2016-01-14

    The pressure-retarded osmosis (PRO) process is a green technique for power generation to respond the world\\'s need of energy sustainability. In this study, we have developed the vital component of the process, i.e. membrane, in the configuration of the outer-selective thin-film composite (TFC) hollow fiber, which is more practical than other configurations in the real applications. The support layer morphology and the formation of the selective polyamide layer have been optimized for a good PRO performance. The results show that the bore fluid with higher amount of the solvent N-methyl-2-pyrrolidone leads to full finger-like hollow fibers, which provide higher flux but lower pressure tolerance. The addition of higher amount of diethylene glycol into the dope solution, improves the pore formation and suppresses the macrovoid formation, while properly lowering the take-up speed increases their wall thickness and pressure tolerance. A simple alcohol-pre-wetting approach on the fiber support leads to a smooth and thin polyamide layer, which is favorable for a high water flux and power density. Its efficiency follows this order: n-propanol>ethanol>methanol>water. The n-propanol pre-wetted TFC membrane can tolerate 17 bar with a peak power density of 9.59 W/m2 at room temperature, using 1 M NaCl solution as the draw solution and DI water as feed. This work demonstrates the potential of outer-selective TFC hollow fiber membranes for energy conversion via PRO process, provides useful database to fabricate suitable support morphology and raise a simple technique to practically form a thin and smooth polyamide layer.

  14. 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...

  15. Carbon thin film thermometry

    Science.gov (United States)

    Collier, R. S.; Sparks, L. L.; Strobridge, T. R.

    1973-01-01

    The work concerning carbon thin film thermometry is reported. Optimum film deposition parameters were sought on an empirical basis for maximum stability of the films. One hundred films were fabricated for use at the Marshall Space Flight Center; 10 of these films were given a precise quasi-continuous calibration of temperature vs. resistance with 22 intervals between 5 and 80 K using primary platinum and germanium thermometers. Sensitivity curves were established and the remaining 90 films were given a three point calibration and fitted to the established sensitivity curves. Hydrogen gas-liquid discrimination set points are given for each film.

  16. Picosecond acoustic transmission measurements. I. Transient grating generation and detection of acoustic responses in thin metal films.

    Science.gov (United States)

    Slayton, Rebecca M; Nelson, Keith A

    2004-02-22

    The technique of impulsive stimulated thermal scattering is extended to backside measurement of acoustic wave packets that have propagated through thin metal films following their generation by pulsed optical excitation, heating, and thermal expansion at the front side. The acoustic transmission measurement at the backside substantially isolates the acoustic responses from thermal and electronic responses of the metal film that often dominate acoustic reflection signals measured from the front side, and permits straightforward measurement of the acoustic response generated by optical excitation at a substrate-thin film interface. It can thus better distinguish among different factors that limit the bandwidth of the acoustic wave packet, an issue of concern in the measurement of high frequency responses. The paper that follows demonstrates the application of the backside measurement to a study of high frequency structural relaxation in the glass-forming liquid glycerol. (c) 2004 American Institute of Physics.

  17. Generation of localized strain in a thin film piezoelectric to control individual magnetoelectric heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Jizhai; Liang, Cheng-Yen; Sepulveda, Abdon; Carman, Gregory P.; Lynch, Christopher S., E-mail: cslynch@seas.ucla.edu [Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, California 90095 (United States); Paisley, Elizabeth A.; Ihlefeld, Jon F. [Electronic, Optical, and Nano Materials Department, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    2015-08-31

    Experimental results demonstrate the ability of a surface electrode pattern to produce sufficient in-plane strain in a PbZr{sub 0.52}Ti{sub 0.48}O{sub 3} (PZT) thin film clamped by a Si substrate to control magnetism in a 1000 nm diameter Ni ring. The electrode pattern and the Ni ring/PZT thin film heterostructure were designed using a finite element based micromagnetics code. The magnetoelectric heterostructures were fabricated on the PZT film using e-beam lithography and characterized using magnetic force microscopy. Application of voltage to the electrodes moved one of the “onion” state domain walls. This method enables the development of complex architectures incorporating strain-mediated multiferroic devices.

  18. Thin film hydrogen sensor

    Science.gov (United States)

    Cheng, Yang-Tse; Poli, Andrea A.; Meltser, Mark Alexander

    1999-01-01

    A thin film hydrogen sensor, includes: a substantially flat ceramic substrate with first and second planar sides and a first substrate end opposite a second substrate end; a thin film temperature responsive resistor on the first planar side of the substrate proximate to the first substrate end; a thin film hydrogen responsive metal resistor on the first planar side of the substrate proximate to the fist substrate end and proximate to the temperature responsive resistor; and a heater on the second planar side of the substrate proximate to the first end.

  19. 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...

  20. Multifunctional thin film surface

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-13

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

  1. Organic thin-film solar cells: next generation low-cost photovoltaic ...

    African Journals Online (AJOL)

    5 illumination (100 mW/cm2) and external quantum efficiency over 50% for organic thin-film photovoltaic cells using a phthalocyanine-fullerene (ZnPc/C60) bulk heterojunction as an active layer, embedded into a p-i-n type architecture with doped wide-gap charge transport layers. The p-i-n architecture allows for the design ...

  2. Holographic image generation with a thin-film resonance caused by chalcogenide phase-change material

    Science.gov (United States)

    Lee, Seung-Yeol; Kim, Yong-Hae; Cho, Seong-M.; Kim, Gi Heon; Kim, Tae-Youb; Ryu, Hojun; Kim, Han Na; Kang, Han Byeol; Hwang, Chi-Young; Hwang, Chi-Sun

    2017-01-01

    The development of digital holography is anticipated for the viewing of 3D images by reconstructing both the amplitude and phase information of the object. Compared to analog holograms written by a laser interference, digital hologram technology has the potential to realize a moving 3D image using a spatial light modulator. However, to ensure a high-resolution 3D image with a large viewing angle, the hologram panel requires a near-wavelength scale pixel pitch with a sufficient large numbers of pixels. In this manuscript, we demonstrate a digital hologram panel based on a chalcogenide phase-change material (PCM) which has a pixel pitch of 1 μm and a panel size of 1.6 × 1.6 cm2. A thin film of PCM encapsulated by dielectric layers can be used for the hologram panel by means of excimer laser lithography. By tuning the thicknesses of upper and lower dielectric layers, a color-selective diffraction panel is demonstrated since a thin film resonance caused by dielectric can affect to the absorption and diffraction spectrum of the proposed hologram panel. We also show reflection color of a small active region (1 μm × 4 μm) made by ultra-thin PCM layer can be electrically changed.

  3. 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

  4. Optical thin film deposition

    International Nuclear Information System (INIS)

    Macleod, H.A.

    1979-01-01

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

  5. Thin Film Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Zweibel, K.

    1998-11-19

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

  6. Epitaxial thin films

    Science.gov (United States)

    Hunt, Andrew Tye; Deshpande, Girish; Lin, Wen-Yi; Jan, Tzyy-Jiuan

    2006-04-25

    Epitatial thin films for use as buffer layers for high temperature superconductors, electrolytes in solid oxide fuel cells (SOFC), gas separation membranes or dielectric material in electronic devices, are disclosed. By using CCVD, CACVD or any other suitable deposition process, epitaxial films having pore-free, ideal grain boundaries, and dense structure can be formed. Several different types of materials are disclosed for use as buffer layers in high temperature superconductors. In addition, the use of epitaxial thin films for electrolytes and electrode formation in SOFCs results in densification for pore-free and ideal gain boundary/interface microstructure. Gas separation membranes for the production of oxygen and hydrogen are also disclosed. These semipermeable membranes are formed by high-quality, dense, gas-tight, pinhole free sub-micro scale layers of mixed-conducting oxides on porous ceramic substrates. Epitaxial thin films as dielectric material in capacitors are also taught herein. Capacitors are utilized according to their capacitance values which are dependent on their physical structure and dielectric permittivity. The epitaxial thin films of the current invention form low-loss dielectric layers with extremely high permittivity. This high permittivity allows for the formation of capacitors that can have their capacitance adjusted by applying a DC bias between their electrodes.

  7. Thermal Cycling Behavior of Zinc Antimonide Thin Films for High Temperature Thermoelectric Power Generation Applications.

    Science.gov (United States)

    Shim, Hyung Cheoul; Woo, Chang-Su; Han, Seungwoo

    2015-08-19

    The zinc antimonide compound ZnxSby is one of the most efficient thermoelectric materials known at high temperatures due to its exceptional low thermal conductivity. For this reason, it continues to be the focus of active research, especially regarding its glass-like atomic structure. However, before practical use in actual surroundings, such as near a vehicle manifold, it is imperative to analyze the thermal reliability of these materials. Herein, we present the thermal cycling behavior of ZnxSby thin films in nitrogen (N2) purged or ambient atmosphere. ZnxSby thin films were prepared by cosputtering and reached a power factor of 1.39 mW m(-1) K(-2) at 321 °C. We found maximum power factor values gradually decreased in N2 atmosphere due to increasing resistivity with repeated cycling, whereas the specimen in air kept its performance. X-ray diffraction and electron microscopy observations revealed that fluidity of Zn atoms leads to nanoprecipitates, porous morphologies, and even growth of a coating layer or fiber structures on the surface of ZnxSby after repetitive heating and cooling cycles. With this in mind, our results indicate that proper encapsulation of the ZnxSby surface would reduce these unwanted side reactions and the resulting degradation of thermoelectric performance.

  8. 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.

  9. Nanoscale chemical and mechanical characterization of thin films:sum frequency generation (SFG) vibrational spectroscopy at buriedinterfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kweskin, Sasha Joseph [Univ. of California, Berkeley, CA (United States)

    2006-01-01

    Sum frequency generation (SFG) surface vibrational spectroscopy was used to characterize interfaces pertinent to current surface engineering applications, such as thin film polymers and novel catalysts. An array of advanced surface science techniques like scanning probe microscopy (SPM), x-ray photoelectron spectroscopy (XPS), gas chromatography (GC) and electron microscopy were used to obtain experimental measurements complementary to SFG data elucidating polymer and catalyst surface composition, surface structure, and surface mechanical behavior. Experiments reported in this dissertation concentrate on three fundamental questions: (1) How does the interfacial molecular structure differ from that of the bulk in real world applications? (2) How do differences in chemical environment affect interface composition or conformation? (3) How do these changes correlate to properties such as mechanical or catalytic performance? The density, surface energy and bonding at a solid interface dramatically alter the polymer configuration, physics and mechanical properties such as surface glass transition, adhesion and hardness. The enhanced sensitivity of SFG at the buried interface is applied to three systems: a series of acrylates under compression, the compositions and segregation behavior of binary polymer polyolefin blends, and the changes in surface structure of a hydrogel as a function of hydration. In addition, a catalytically active thin film of polymer coated nanoparticles is investigated to evaluate the efficacy of SFG to provide in situ information for catalytic reactions involving small mass adsorption and/or product development. Through the use of SFG, in situ total internal reflection (TIR) was used to increase the sensitivity of SFG and provide the necessary specificity to investigate interfaces of thin polymer films and nanostructures previously considered unfeasible. The dynamic nature of thin film surfaces is examined and it is found that the non

  10. 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.

  11. Protein thin film machines.

    Science.gov (United States)

    Federici, Stefania; Oliviero, Giulio; Hamad-Schifferli, Kimberly; Bergese, Paolo

    2010-12-01

    We report the first example of microcantilever beams that are reversibly driven by protein thin film machines fueled by cycling the salt concentration of the surrounding solution. We also show that upon the same salinity stimulus the drive can be completely reversed in its direction by introducing a surface coating ligand. Experimental results are throughout discussed within a general yet simple thermodynamic model.

  12. Development of flexible, free-standing, thin films for additive manufacturing and localized energy generation

    Directory of Open Access Journals (Sweden)

    Billy Clark

    2015-08-01

    Full Text Available Film energetics are becoming increasingly popular because a variety of technologies are driving a need for localized energy generation in a stable, safe and flexible form. Aluminum (Al and molybdenum trioxide (MoO3 composites were mixed into a silicon binder and extruded using a blade casting technique to form flexible free-standing films ideal for localized energy generation. Since this material can be extruded onto a surface it is well suited to additive manufacturing applications. This study examines the influence of 0-35% by mass potassium perchlorate (KClO4 additive on the combustion behavior of these energetic films. Without KClO4 the film exhibits thermal instabilities that produce unsteady energy propagation upon reaction. All films were cast at a thickness of 1 mm with constant volume percent solids to ensure consistent rheological properties. The films were ignited and flame propagation was measured. The results show that as the mass percent KClO4 increased, the flame speed increased and peaked at 0.43 cm/s and 30 wt% KClO4. Thermochemical equilibrium simulations show that the heat of combustion increases with increasing KClO4 concentration up to a maximum at 20 wt% when the heat of combustion plateaus, indicating that the increased chemical energy liberated by the additional KClO4 promotes stable energy propagation. Differential scanning calorimeter and thermogravimetric analysis show that the silicone binder participates as a fuel and reacts with KClO4 adding energy to the reaction and promoting propagation.

  13. Quasi-Monoenergetic Dense and Uniform Electron Bunch Generation from Laser Driven Double-Layer Thin Films

    Science.gov (United States)

    Wang, C.; Roycroft, R.; McCary, E.; Meadows, A.; Blakeney, J.; Serratto, K.; Kuk, D.; Chester, C.; Gao, L.; Fu, H.; Yan, X. Q.; Schreiber, J.; Pomerantz, I.; Bernstein, A.; Quevedo, H.; Dyer, G.; Gaul, E.; Ditmire, T.; Gautier, D. C.; Fernandez, J.; Hegelich, B. M.

    2014-10-01

    We demonstrate that dense, uniform quasi-monoenergetic relativistic electron bunches can be generated from the interaction of a high-intensity laser pulse with a double-layer thin film target. The first layer of the target is a freestanding, nanometer-scale, diamond-like carbon production layer. The second layer is a thin plastic reflection layer which reflects the drive-laser pulse, but allows electrons to pass through. Although no electron bunch is generated from the second layer alone, by adding it behind the first layer we obtained a quasi-monoenergetic bunch along the laser axis, 35 times denser than a bunch from the single layer target. Comparing the angular distribution of the electron spectra from a double-layer target with that of a single-layer target, we observed an increase of the electron cutoff energy at larger angles, which improves the uniformity of created electron bunches.

  14. Development of Flexible, Free-Standing, Thin Films for Additive Manufacturing and Localized Energy Generation

    Science.gov (United States)

    2015-08-10

    12211 Research Triangle Park, NC 27709-2211 aluminum combusiton, polymer binders, extrusion synthesis, reaction mechanisms, energy generation, onset...115, 104106 (2014); 10.1063/1.4868337 Influence of Al/CuO reactive multilayer films additives on exploding foil initiator J. Appl. Phys. 110...toward extrusion type additive manufacturing techniques for 3D printing of energetic materials. This type of manufacturing for the production of energetic

  15. Thin film superconductor magnetic bearings

    Science.gov (United States)

    Weinberger, Bernard R.

    1995-12-26

    A superconductor magnetic bearing includes a shaft (10) that is subject to a load (L) and rotatable around an axis of rotation, a magnet (12) mounted to the shaft, and a stator (14) in proximity to the shaft. The stator (14) has a superconductor thin film assembly (16) positioned to interact with the magnet (12) to produce a levitation force on the shaft (10) that supports the load (L). The thin film assembly (16) includes at least two superconductor thin films (18) and at least one substrate (20). Each thin film (18) is positioned on a substrate (20) and all the thin films are positioned such that an applied magnetic field from the magnet (12) passes through all the thin films. A similar bearing in which the thin film assembly (16) is mounted on the shaft (10) and the magnet (12) is part of the stator (14) also can be constructed.

  16. Origin of high carrier mobility and low residual stress in RF superimposed DC sputtered Al doped ZnO thin film for next generation flexible devices

    Science.gov (United States)

    Kumar, Naveen; Dubey, Ashish; Bahrami, Behzad; Venkatesan, S.; Qiao, Qiquan; Kumar, Mukesh

    2018-04-01

    In this work, the energy and flux of high energetic ions were controlled by RF superimposed DC sputtering process to increase the grain size and suppress grain boundary potential with minimum residual stress in Al doped ZnO (AZO) thin film. AZO thin films were deposited at different RF/(RF + DC) ratios by keeping total power same and were investigated for their electrical, optical, structural and nanoscale grain boundaries potential. All AZO thin film showed high crystallinity and orientation along (002) with peak shift as RF/(RF + DC) ratio increased from 0.0, pure DC, to 1.0, pure RF. This peak shift was correlated with high residual stress in as-grown thin film. AZO thin film grown at mixed RF/(RF + DC) of 0.75 showed high electron mobility, low residual stress and large crystallite size in comparison to other AZO thin films. The nanoscale grain boundary potential was mapped using Kelvin Probe Force Microscopy in all AZO thin film and it was observed that carrier mobility is controlled not only by grains size but also by grain boundary potential. The XPS analysis confirms the variation in oxygen vacancies and zinc interstitials which explain the origin of low grain boundaries potential and high carrier mobility in AZO thin film deposited at 0.75 RF/(RF + DC) ratio. This study proposes a new way to control the grain size and grain boundary potential to further tune the optoelectronic-mechanical properties of AZO thin films for next generation flexible and optoelectronic devices.

  17. Functional organic thin films

    OpenAIRE

    Scharnberg, Michael

    2007-01-01

    Organic thin films are used in many technological and engineering applications nowadays. They find use as coatings, sensors, detectors, as matrix materials in nanocomposites, as self-assembled monolayers for surface functionalization, as low-k dielectrics in integrated circuits and in advanced organic electronic applications like organic light emitting diodes, organic field effect transistors and organic photovoltaics (esp. organic solar cells) and many other applications. OLED displays are n...

  18. Thin film processes

    CERN Document Server

    Vossen, John L

    1978-01-01

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

  19. Power Generation by Zinc Antimonide Thin Film under Various Load Resistances at its Critical Operating Temperature

    DEFF Research Database (Denmark)

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

    Thermoelectric generators (TEGs) use the Seebeck effect in semiconductors for direct conversion of heat to electrical energy. Zinc antimonide films were deposited on polished fused silica substrates by co-sputtering method in Aarhus University. This study focuses on stability of zinc antimonide...... slightly reduces during unload conditions, although it is expected that by eliminating load in each step, the initial amount of voltage exactly repeats. Similar behavior is observed for Seebeck coefficient distribution versus time of working particularly in lower load resistances. Based on variation...

  20. 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.

  1. Generation of DNA profiles from fingerprints developed with columnar thin film technique.

    Science.gov (United States)

    Plazibat, Stephanie L; Roy, Reena; Swiontek, Stephen E; Lakhtakia, Akhlesh

    2015-12-01

    Partial-bloody fingerprints and partial fingerprints with saliva are often encountered at crime scenes, potentially enabling the combination of fingerprint and DNA analyses for absolute identification, provided that the development technique for fingerprint analysis does not inhibit DNA analysis. 36 partial-bloody fingerprints and 30 fingerprints wetted with saliva, all deposited on brass, were first developed using the columnar-thin-film (CTF) technique and then subjected to short tandem repeat (STR) DNA analysis. Equal numbers of samples were subjected to the same DNA analysis without development. Tris (8-hydroxyquinolinato) aluminum, or Alq3, was evaporated to deposit CTFs for development of the prints. DNA was extracted from all 132 samples, quantified, and amplified with AmpFlSTR(®) Identifiler Plus Amplification Kit. Additionally, DNA analyses were conducted on four blood smears on un-fingerprinted brass that had been subjected to CTF deposition and four blood smears on un-fingerprinted brass that had not been subjected to CTF deposition. Complete and concordant autosomal STR profiles of the same quality were obtained from both undeveloped and CTF-developed fingerprints, indicating that CTF development of fingerprints preserves DNA and does not inhibit subsequent DNA analysis. Even when there were no fingerprints, CTF deposition did not lead to inhibition of DNA analysis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Thin-Film Composite Pressure Retarded Osmosis Membranes for Sustainable Power Generation from Salinity Gradients

    KAUST Repository

    Yip, Ngai Yin

    2011-05-15

    Pressure retarded osmosis has the potential to produce renewable energy from natural salinity gradients. This work presents the fabrication of thin-film composite membranes customized for high performance in pressure retarded osmosis. We also present the development of a theoretical model to predict the water flux in pressure retarded osmosis, from which we can predict the power density that can be achieved by a membrane. The model is the first to incorporate external concentration polarization, a performance limiting phenomenon that becomes significant for high-performance membranes. The fabricated membranes consist of a selective polyamide layer formed by interfacial polymerization on top of a polysulfone support layer made by phase separation. The highly porous support layer (structural parameter S = 349 μm), which minimizes internal concentration polarization, allows the transport properties of the active layer to be customized to enhance PRO performance. It is shown that a hand-cast membrane that balances permeability and selectivity (A = 5.81 L m-2 h-1 bar-1, B = 0.88 L m-2 h-1) is projected to achieve the highest potential peak power density of 10.0 W/m2 for a river water feed solution and seawater draw solution. The outstanding performance of this membrane is attributed to the high water permeability of the active layer, coupled with a moderate salt permeability and the ability of the support layer to suppress the undesirable accumulation of leaked salt in the porous support. Membranes with greater selectivity (i.e., lower salt permeability, B = 0.16 L m-2 h-1) suffered from a lower water permeability (A = 1.74 L m-2 h-1 bar-1) and would yield a lower peak power density of 6.1 W/m2, while membranes with a higher permeability and lower selectivity (A = 7.55 L m-2 h-1 bar-1, B = 5.45 L m-2 h-1) performed poorly due to severe reverse salt permeation, resulting in a similar projected peak power density of 6.1 W/m2. © 2011 American Chemical Society.

  3. Thin-film solar cell

    NARCIS (Netherlands)

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

    1998-01-01

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

  4. Ferromagnetic thin films

    Science.gov (United States)

    Krishnan, Kannan M.

    1994-01-01

    A ferromagnetic .delta.-Mn.sub.1-x Ga.sub.x thin film having perpendicular anisotropy is described which comprises: (a) a GaAs substrate, (b) a layer of undoped GaAs overlying said substrate and bonded thereto having a thickness ranging from about 50 to about 100 nanometers, (c) a layer of .delta.-Mn.sub.1-x Ga.sub.x overlying said layer of undoped GaAs and bonded thereto having a thickness ranging from about 20 to about 30 nanometers, and (d) a layer of GaAs overlying said layer of .delta.-Mn.sub.1-x Ga.sub.x and bonded thereto having a thickness ranging from about 2 to about 5 nanometers, wherein x is 0.4 .+-.0.05.

  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. A COMPARISON OF THE ENVIRONMENTAL IMPACT OF SOLAR POWER GENERATION USING MULTICRYSTALLINE SILICON AND THIN FILM OF AMORPHOUS SILICON SOLAR CELLS: CASE STUDY IN THAILAND

    Directory of Open Access Journals (Sweden)

    Wasin Khaenson

    2017-07-01

    Full Text Available This paper studies the environmental impact of two different forms of solar power generation in Thailand - that of multicrystalline silicon solar cells, and that of thin film amorphous silicon solar cells. It takes as its study two of the largest solar cell power plants of their kind in Thailand; a multicrystalline silicon plant in the north (generating 90 MW and a thin film amorphous silicon plant in the centre (generating 55 MW. The Life Cycle Assessment tool (LCA was used to assess the environmental impact of each stage of the process, from the manufacture of the cells, through to their transportation, installation and eventual recycling. The functional unit of the study was the generation of 1 kWh of power transmitted and distributed by the Electricity Generating Authority of Thailand (EGAT and Provincial Electricity Authority (PEA. The environmental impact results were calculated in terms of eco-points (Pt per functional unit of 1 kWh. The characterised data for 1 kWh of solar power generation was then compared with data for 1 kWh of combined cycle and thermal power generation (both in Thailand, using the same set of characterisation factors. After analyzing the results, both forms of solar power energy generation were found to impact upon the studied categories of Human Health, Ecosystem Quality and Resource Depletion, whilst also highlighting the importance of the solar cell module recycling process in decreasing the overall environmental impact. When the two solar cell technologies were compared, the overall impact of the multicrystalline silicon solar cell was found to be higher than that of the thin film amorphous silicon solar cell. Furthermore, when assessing the overall impact against non-renewable power generating technologies such as combined cycle and thermal power generation, the thin film amorphous silicon solar cells were found to have the lowest environmental impact of all technologies studied.

  7. Interfaces and thin films physics

    International Nuclear Information System (INIS)

    Equer, B.

    1988-01-01

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

  8. Computer simulations analysis for determining the polarity of charge generated by high energy electron irradiation of a thin film

    DEFF Research Database (Denmark)

    Malac, Marek; Hettler, Simon; Hayashida, Misa

    2017-01-01

    Detailed simulations are necessary to correctly interpret the charge polarity of electron beam irradiated thin film patch. Relying on systematic simulations we provide guidelines and movies to interpret experimentally the polarity of the charged area, to be understood as the sign of the electrost...

  9. Additives to silane for thin film silicon photovoltaic devices

    Science.gov (United States)

    Hurley, Patrick Timothy; Ridgeway, Robert Gordon; Hutchison, Katherine Anne; Langan, John Giles

    2013-09-17

    Chemical additives are used to increase the rate of deposition for the amorphous silicon film (.alpha.Si:H) and/or the microcrystalline silicon film (.mu.CSi:H). The electrical current is improved to generate solar grade films as photoconductive films used in the manufacturing of Thin Film based Photovoltaic (TFPV) devices.

  10. Thin-Film Power Transformers

    Science.gov (United States)

    Katti, Romney R.

    1995-01-01

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

  11. Organic thin-film solar cells: Next generation low-cost photovoltaic ...

    African Journals Online (AJOL)

    user

    players, car stereos, televisions and many other consumer tools that require colour displays. The operation principle of organic light emitting diodes comprises four consecutive fundamental steps as shown in Fig. 1(a) below: (1) opposite sign charge carrier injection, (2) charge carriers transport, (3) generation of excitons, ...

  12. On the determination of χ(2) in thin films: a comparison of one-beam second-harmonic generation measurement methodologies

    Science.gov (United States)

    Hermans, Artur; Kieninger, Clemens; Koskinen, Kalle; Wickberg, Andreas; Solano, Eduardo; Dendooven, Jolien; Kauranen, Martti; Clemmen, Stéphane; Wegener, Martin; Koos, Christian; Baets, Roel

    2017-03-01

    The determination of the second-order susceptibility (χ(2)) of thin film samples can be a delicate matter since well-established χ(2) measurement methodologies such as the Maker fringe technique are best suited for nonlinear materials with large thicknesses typically ranging from tens of microns to several millimeters. Here we compare two different second-harmonic generation setups and the corresponding measurement methodologies that are especially advantageous for thin film χ(2) characterization. This exercise allows for cross-checking the χ(2) obtained for identical samples and identifying the main sources of error for the respective techniques. The development of photonic integrated circuits makes nonlinear thin films of particular interest, since they can be processed into long waveguides to create efficient nonlinear devices. The investigated samples are ABC-type nanolaminates, which were reported recently by two different research groups. However, the subsequent analysis can be useful for all researchers active in the field of thin film χ(2) characterization.

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

    KAUST Repository

    Singh, Devendra

    2017-11-24

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

  14. Pyroelectric coupling in thin film photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Karpov, Victor G.; Shvydka, Diana [Department of Physics and Astronomy, University of Toledo, OH (United States)

    2007-07-15

    We propose a theory of thin film photovoltaics in which one of the polycrystalline films is made of a pyroelectric material grains such as CdS. That film is shown to generate strong polarization improving the device open circuit voltage. Implications and supporting facts for the major photovoltaic types based on CdTe and CuIn(Ga)Se{sub 2} absorber layers are discussed. Band diagram of a pyroelectric (CdS) based PV junction. Arrows represent the charge carrier photo-generation. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Generalized bipolariton model. propagation of a ultrashort laser pulse through a thin semiconductor film in the conditions of two-photon generation of biexcitons

    International Nuclear Information System (INIS)

    Igor Beloussov

    2013-01-01

    A generalized bipolariton model is proposed. Bipolaritons is formed from virtual excitons of four kinds. There exists both attractive and repulsive interaction between these excitons, though only excitons of a specific type can interact with light. A substantial difference between conventional and our models is shown for the case of nonlinear transmission/reflection of ultrashort laser pulses by a thin semiconductor film under two-photon generation of biexcitons. (author)

  16. Beryllium thin films for resistor applications

    Science.gov (United States)

    Fiet, O.

    1972-01-01

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

  17. Lattice Mismatch in Crystalline Nanoparticle Thin Films.

    Science.gov (United States)

    Gabrys, Paul A; Seo, Soyoung E; Wang, Mary X; Oh, EunBi; Macfarlane, Robert J; Mirkin, Chad A

    2018-01-10

    For atomic thin films, lattice mismatch during heteroepitaxy leads to an accumulation of strain energy, generally causing the films to irreversibly deform and generate defects. In contrast, more elastically malleable building blocks should be better able to accommodate this mismatch and the resulting strain. Herein, that hypothesis is tested by utilizing DNA-modified nanoparticles as "soft," programmable atom equivalents to grow a heteroepitaxial colloidal thin film. Calculations of interaction potentials, small-angle X-ray scattering data, and electron microscopy images show that the oligomer corona surrounding a particle core can deform and rearrange to store elastic strain up to ±7.7% lattice mismatch, substantially exceeding the ±1% mismatch tolerated by atomic thin films. Importantly, these DNA-coated particles dissipate strain both elastically through a gradual and coherent relaxation/broadening of the mismatched lattice parameter and plastically (irreversibly) through the formation of dislocations or vacancies. These data also suggest that the DNA cannot be extended as readily as compressed, and thus the thin films exhibit distinctly different relaxation behavior in the positive and negative lattice mismatch regimes. These observations provide a more general understanding of how utilizing rigid building blocks coated with soft compressible polymeric materials can be used to control nano- and microstructure.

  18. Preparation of thin vyns films

    International Nuclear Information System (INIS)

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

    1965-01-01

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

  19. Laser applications in thin-film photovoltaics

    OpenAIRE

    Bartlome, R.; Strahm, B.; Sinquin, Y.; Feltrin, A.; Ballif, C.

    2009-01-01

    We review laser applications in thin-film photovoltaics (thin-film Si, CdTe, and Cu(In,Ga)Se2 solar cells). Lasers are applied in this growing field to manufacture modules, to monitor Si deposition processes, and to characterize opto-electrical properties of thin films. Unlike traditional panels based on crystalline silicon wafers, the individual cells of a thin-film photovoltaic module can be serially interconnected by laser scribing during fabrication. Laser scribing applications are descri...

  20. Nanocrystal thin film fabrication methods and apparatus

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. study in polymer thin films

    Indian Academy of Sciences (India)

    TECS

    carry out a careful study of steady state conduction of poly- styrene (PS) thin film thermo-electrets sandwiched be- tween metal electrodes both in doped and undoped forms. 2. Experimental. 2.1 Sample preparation. Polystyrene supplied by Polymer Chemical Industry,. Mumbai and naphthalene by S.G. Sisco Pvt Ltd., New ...

  2. Magnetization in permalloy thin films

    Indian Academy of Sciences (India)

    1VES College of Arts, Science and Commerce, Sindhi Society, Chembur, Mumbai 400 071,. India. 2UGC-DAE Consortium for Scientific Research, R5 Shed, ... gas alone, while PNR measurements on 5 and 10% sample show splitting in the spin-up and spin-down reflectivity. Keywords. Permalloy; NiFe thin films; NiFe ...

  3. The role of Ar plasma treatment in generating oxygen vacancies in indium tin oxide thin films prepared by the sol-gel process

    International Nuclear Information System (INIS)

    Hwang, Deuk-Kyu; Misra, Mirnmoy; Lee, Ye-Eun; Baek, Sung-Doo; Myoung, Jae-Min; Lee, Tae Il

    2017-01-01

    Highlights: • Indium tin oxide thin film with about 41 nm thickness was obtained by the sol-gel process. • Thin film exhibited low resistivity. • Sheet resistance of thin film decreases with Ar plasma treatment time. • Ar plasma treatment on thin film does not alter the crystal structure and optical properties of the ITO thin-film. • There is no significant change in oxygen vacancies after 20 min of plasma treatment. - Abstract: Argon (Ar) plasma treatment was carried out to reduce the sheet resistance of indium tin oxide (ITO) thin films. The Ar plasma treatment did not cause any significant changes to the crystal structure, surface morphology, or optical properties of the ITO thin films. However, an X-ray photoelectron spectroscopy study confirmed that the concentration of oxygen vacancies in the film dramatically increased with the plasma treatment time. Thus, we concluded that the decrease in the sheet resistance was caused by the increase in the oxygen vacancy concentration in the film. Furthermore, to verify how the concentration of oxygen vacancies in the film increased with the Ar plasma treatment time, cumulative and continuous plasma treatments were conducted. The oxygen vacancies were found to be created by surface heating via the outward thermal diffusion of oxygen atoms from inside the film.

  4. Thin-film photovoltaic power generation offers decreasing greenhouse gas emissions and increasing environmental co-benefits in the long term.

    Science.gov (United States)

    Bergesen, Joseph D; Heath, Garvin A; Gibon, Thomas; Suh, Sangwon

    2014-08-19

    Thin-film photovoltaic (PV) technologies have improved significantly recently, and similar improvements are projected into the future, warranting reevaluation of the environmental implications of PV to update and inform policy decisions. By conducting a hybrid life cycle assessment using the most recent manufacturing data and technology roadmaps, we compare present and projected environmental, human health, and natural resource implications of electricity generated from two common thin-film PV technologies-copper indium gallium selenide (CIGS) and cadmium telluride (CdTe)-in the United States (U.S.) to those of the current U.S. electricity mix. We evaluate how the impacts of thin films can be reduced by likely cost-reducing technological changes: (1) module efficiency increases, (2) module dematerialization, (3) changes in upstream energy and materials production, and (4) end-of-life recycling of balance of system (BOS). Results show comparable environmental and resource impacts for CdTe and CIGS. Compared to the U.S. electricity mix in 2010, both perform at least 90% better in 7 of 12 and at least 50% better in 3 of 12 impact categories, with comparable land use, and increased metal depletion unless BOS recycling is ensured. Technological changes, particularly efficiency increases, contribute to 35-80% reductions in all impacts by 2030.

  5. Microstructure of Thin Films

    Science.gov (United States)

    1990-02-07

    resultant film could be varied right up to virtually pure aluminum oxide simply by varying the background oxygen pressure. More recently we have been...aT , m..a, lot,, o ,,f,02,d I4 k -1-1..... autocovariance lengths, less than 0.5 um, indicate that , 514n, ob0 o p’,Ofclllc....,,o,,oy0,1- agua sblrt

  6. Cubic erbium trihydride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Adams, D.P., E-mail: dpadams@sandia.gov; Rodriguez, M.A.; Romero, J.A.; Kotula, P.G.; Banks, J.

    2012-07-31

    High-purity, erbium hydride thin films have been deposited onto {alpha}-Al{sub 2}O{sub 3} and oxidized Si by reactive sputtering methods. Rutherford backscattering spectrometry and elastic recoil detection show that films deposited at temperatures of 35, 150 and 275 Degree-Sign C have a composition of 3H:1Er. Erbium trihydride films consist of a face-centered cubic erbium sub-lattice with a lattice parameter in the range of 5.11-5.20 A. The formation of cubic ErH{sub 3} is intriguing, because previous studies demonstrate a single trihydride phase with a hexagonal metal sub-lattice. The formation of a stable, cubic trihydride phase is attributed to a large, in-plane stress resulting from ion beam sputter deposition. - Highlights: Black-Right-Pointing-Pointer Cubic erbium trihydride thin films produced by ion beam sputter deposition. Black-Right-Pointing-Pointer Face-centered cubic metal sub-lattice verified by X-ray and electron diffraction. Black-Right-Pointing-Pointer Composition evaluated using four different techniques. Black-Right-Pointing-Pointer Film stress monitored during deposition. Black-Right-Pointing-Pointer Formation of cubic erbium trihydride attributed to a large, in-plane film stress.

  7. 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.

  8. Factors affecting surface and release properties of thin PDMS films

    DEFF Research Database (Denmark)

    Vudayagiri, Sindhu; Junker, Michael Daniel; Skov, Anne Ladegaard

    2013-01-01

    Polydimethysiloxane (PDMS) elastomers are commonly used as dielectric electroactive polymers (DEAP). DEAP films are used in making actuators, generators and sensors. In the large scale manufacture of DEAP films, release of films from the substrate (carrier web) induces some defects and pre......-strain in the films which affect the overall performance of the films. The current research is directed towards investigating factors affecting the peel force and release of thin, corrugated polydimethylsiloxane films used in DEAP films. It has been shown that doping the PDMS films with small quantities...

  9. Plasmon generation in sputtered Ga-doped MgZnO thin films for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Awasthi, Vishnu; Garg, Vivek; Sengar, Brajendra S.; Sharma, Pankaj; Mukherjee, Shaibal, E-mail: shaibal@iiti.ac.in [Hybrid Nanodevice Research Group (HNRG), Electrical Engineering, Indian Institute of Technology, Indore 453552 (India); Pandey, Sushil Kumar [Department of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai 400076 (India); Kumar, Shailendra [Indus Synchrotron Utilization Division, Raja Ramanna Center for Advanced Technology, Indore 452013 (India); Mukherjee, C. [Laser System Engineering Division, Raja Ramanna Center for Advanced Technology, Indore 452013 (India)

    2016-06-21

    The crystalline, electrical, morphological, optical properties and plasmonic behaviour of Ga doped MgZnO (GMZO) thin films grown at different substrate temperatures (200–600 °C) by a dual ion beam sputtering (DIBS) system are investigated. Transmittance value of more than ∼94% in 400–1000 nm region is observed for all GMZO films. The particle plasmon features can be detected in the absorption coefficient spectra of GMZO grown at 500 and 600 °C in the form of a peak at ∼4.37 eV, which corresponds to a plasmon resonance peak of nanoclusters formed in GMZO. The presence of such plasmonic features is confirmed by ultraviolet photoelectron spectroscopy measurements. The values of particle plasmon resonance energy of various nanoclusters are in the range of solar spectrum, and these can easily be tuned and excited at the desirable wavelengths while optimizing the efficiency of solar cells (SCs) by simple alteration of DIBS growth temperature. These nanoclusters are extremely promising to enhance the optical scattering and trapping of the incident light, which increases the optical path length in the absorber layer of cost-effective SCs and eventually increases its efficiency.

  10. Polycrystalline thin films : A review

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-09-01

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

  11. Thin films of soft matter

    CERN Document Server

    Kalliadasis, Serafim

    2007-01-01

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

  12. Flexible thin film magnetoimpedance sensors

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-10-01

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

  13. Flexible thin film magnetoimpedance sensors

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  14. The state of the art of thin-film photovoltaics

    International Nuclear Information System (INIS)

    Surek, T.

    1993-10-01

    Thin-film photovoltaic technologies, based on materials such as amorphous or polycrystalline silicon, copper indium diselenide, cadmium telluride, and gallium arsenide, offer the potential for significantly reducing the cost of electricity generated by photovoltaics. The significant progress in the technologies, from the laboratory to the marketplace, is reviewed. The common concerns and questions raised about thin films are addressed. Based on the progress to date and the potential of these technologies, along with continuing investments by the private sector to commercialize the technologies, one can conclude that thin-film PV will provide a competitive alternative for large-scale power generation in the future

  15. Piezoelectric MEMS: Ferroelectric thin films for MEMS applications

    Science.gov (United States)

    Kanno, Isaku

    2018-04-01

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

  16. Multiferroic oxide thin films and heterostructures

    KAUST Repository

    Lu, Chengliang

    2015-05-26

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

  17. Thermally stable antireflective coatings based on nanoporous organosilicate thin films.

    Science.gov (United States)

    Kim, Suhan; Cho, Jinhan; Char, Kookheon

    2007-06-05

    Thermally stable nanoporous organosilicate thin films were realized by the microphase separation of pore-generating polymers mixed with an organosilicate matrix to be antireflective coatings (ARCs), for which a thin film with a refractive index (n) of 1.23 for zero reflection is required. The refractive index of such nanoporous organosilicate films can be tuned from 1.39 down to 1.23 by incorporating nanopores within the films. With a nanoporous single layer with n approximately 1.23, the light transmittance of the glass above 99.8% was achieved in the visible range (lambda approximately 550 nm). To overcome the limitation on the narrow wavelength for high transmittance imposed by a single antireflective nanoporous thin film, bilayer thin films with different refractive indices were prepared by placing a high refractive index layer with a refractive index of 1.45 below the nanoporous thin film. UV-vis transmittance of a glass coated with the bilayer films was compared with nanoporous single-layer films and it is demonstrated that the novel broadband antireflection coatings in a wide range of visible wavelength can be easily obtained by the organosilicate bilayer thin films described in this study. Also, ARCs developed in this study demonstrate excellent AR durability owing to the hydrophobic nature of the organosilicate matrix.

  18. Optimization of charge-carrier generation in amorphous-silicon thin-film tandem solar cell backed by two-dimensional metallic surface-relief grating

    Science.gov (United States)

    Civiletti, Benjamin J.; Anderson, Tom H.; Ahmad, Faiz; Monk, Peter B.; Lakhtakia, Akhlesh

    2017-08-01

    The rigorous coupled-wave approach was implemented in a three-dimensional setting to calculate the chargecarrier-generation rate in a thin-film solar cell with multiple amorphous-silicon p-i-n junctions. The solar cell comprised a front antireflection window; three electrically isolated p-i-n junctions in tandem; and a periodically corrugated silver back-reflector with hillock-shaped corrugations arranged on a hexagonal lattice. The differential evolution algorithm (DEA) was used to maximize the charge-carrier-generation rate over a set of selected optical and electrical parameters. This optimization exercise minimized the bandgap of the topmost i-layer but all other parameters turned out to be uninfluential. More importantly, the exercise led to a configuration that would very likely render the solar cell inefficient. Therefore, another optimization exercise was conducted to maximize power density. The resulting configuration was optimal over all parameters.

  19. Organic Thin Films for Photonics Applications

    National Research Council Canada - National Science Library

    Thorner, John

    1999-01-01

    The Organic Thin Films for Photonics Applications Topical Meeting provided an interdisciplinary forum for the presentation and discussion of new and previously unpublished results on advanced organic...

  20. 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.

  1. 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.

  2. Progress in thin film techniques

    International Nuclear Information System (INIS)

    Weingarten, W.

    1996-01-01

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

  3. Thin film solar energy collector

    Science.gov (United States)

    Aykan, Kamran; Farrauto, Robert J.; Jefferson, Clinton F.; Lanam, Richard D.

    1983-11-22

    A multi-layer solar energy collector of improved stability comprising: (1) a substrate of quartz, silicate glass, stainless steel or aluminum-containing ferritic alloy; (2) a solar absorptive layer comprising silver, copper oxide, rhodium/rhodium oxide and 0-15% by weight of platinum; (3) an interlayer comprising silver or silver/platinum; and (4) an optional external anti-reflective coating, plus a method for preparing a thermally stable multi-layered solar collector, in which the absorptive layer is undercoated with a thin film of silver or silver/platinum to obtain an improved conductor-dielectric tandem.

  4. Minerals deposited as thin films

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  5. Exploring Two-Dimensional Transport Phenomena in Metal Oxide Heterointerfaces for Next-Generation, High-Performance, Thin-Film Transistor Technologies.

    Science.gov (United States)

    Labram, John G; Lin, Yen-Hung; Anthopoulos, Thomas D

    2015-11-04

    In the last decade, metal oxides have emerged as a fascinating class of electronic material, exhibiting a wide range of unique and technologically relevant characteristics. For example, thin-film transistors formed from amorphous or polycrystalline metal oxide semiconductors offer the promise of low-cost, large-area, and flexible electronics, exhibiting performances comparable to or in excess of incumbent silicon-based technologies. Atomically flat interfaces between otherwise insulating or semiconducting complex oxides, are also found to be highly conducting, displaying 2-dimensional (2D) charge transport properties, strong correlations, and even superconductivity. Field-effect devices employing such carefully engineered interfaces are hoped to one day compete with traditional group IV or III-V semiconductors for use in the next-generation of high-performance electronics. In this Concept article we provide an overview of the different metal oxide transistor technologies and potential future research directions. In particular, we look at the recent reports of multilayer oxide thin-film transistors and the possibility of 2D electron transport in these disordered/polycrystalline systems and discuss the potential of the technology for applications in large-area electronics. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Thin liquid films dewetting and polymer flow

    CERN Document Server

    Blossey, Ralf

    2012-01-01

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

  7. Pulse electrodeposition of Prussian Blue thin films

    International Nuclear Information System (INIS)

    Najafisayar, P.; Bahrololoom, M.E.

    2013-01-01

    The effects of pulse electrodeposition parameters like peak current density and frequency on the electrochemical properties of Prussian Blue thin films were investigated. Electrochemical Impedance Spectroscopy, Cyclic Voltammetry and Chronoamperometry tests were carried out on Prussian Blue thin films which were pulse electrodeposited on Indium Tin Oxide coated glass substrates. The results showed that increase in the peak current densities and using higher pulsating frequencies during electrodeposition decreases the charge transfer resistance of the thin films while the diffusion coefficient of electroactive species in the films is increased as a consequence of using the same pulsating parameters. In addition, pulse electrodeposition technique does not alter deposition mechanism and morphology of the Prussian Blue thin films. - Highlights: • Prussian Blue thin films were pulse electrodeposited onto the ITO coated glass. • Pulse current condition affected thin films' electrochemical properties. • High pulsating current and frequency lower thin films' charge transfer resistance. • High pulsating current and frequency increase diffusion coefficient in thin films

  8. Thin Film Evaporation of Receding Meniscus within Micro Pillar Arrays

    Science.gov (United States)

    Alhosani, Mohamed H.; Alsheghri, Ammar A.; Alghaferi, Amal; Zhang, Tiejun

    2015-03-01

    Evaporation is a key process in power generation, water desalination, and thermal management applications. It has been proved that hydrophilic micro structured surfaces can enhance the convection heat transfer by promoting high-performance thin film evaporation and enlarging the total heat transfer surface area. When depositing a water droplet on hydrophilic structured surfaces, two distinct regions can be observed, a) central region with water level higher than the micro pillar height (droplet region), b) thin film region as a result of liquid meniscus receding among micro structures. In this study, we are able to probe the physics of thin film evaporation of receding liquid meniscus among micro pillar arrays with different pillar heights, spacings and diameters. Heat transfer is systematically studied in the droplet and thin film region for each sample. Also, Young-Laplace equation and kinetic theory of mass transport are used to model the thin film evaporation around micro pillars. With the proposed model, the shape of meniscus around micro pillars and the diameter of droplet/extended thin film region can be predicted and compared with the experimental measurement. The model can also be extended to model thin film evaporation of meniscus within nano structured surfaces. Supported by cooperative agreement between Masdar Inst and MIT.

  9. Excimer Laser Deposition of PLZT Thin Films

    National Research Council Canada - National Science Library

    Petersen, GAry

    1991-01-01

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

  10. Permalloy Thin-film Magnetic Sensors

    NARCIS (Netherlands)

    Groenland, J.P.J.; Eijkel, C.J.M.; Fluitman, J.H.J.; de Ridder, R.M.

    1992-01-01

    An introduction to the theory of the anisotropic magnetoresistance effect in ferromagnetic thin films is given, ending in a treatment of the minimalization of the free energy which is the result of the intrinsic and extrinsic anisotropies of the thin-film structure. The anisotropic magnetoresistance

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

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Structural, electrical and optical characteristics of CdTe thin films prepared by a chemical deposi- tion method, successive ionic layer adsorption and reaction (SILAR), are described. For deposition of CdTe thin films, cadmium acetate was used as cationic and sodium tellurite as anionic precursor in aqueous me-.

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

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 29; Issue 2. Characterization of nanocrystalline ... Structural, electrical and optical characteristics of CdTe thin films prepared by a chemical deposition method, successive ionic layer adsorption and reaction (SILAR), are described. For deposition of CdTe thin films, ...

  13. Laser thermoreflectance for semiconductor thin films metrology

    Science.gov (United States)

    Gailly, P.; Hastanin, J.; Duterte, C.; Hernandez, Y.; Lecourt, J.-B.; Kupisiewicz, A.; Martin, P.-E.; Fleury-Frenette, K.

    2012-06-01

    We present a thermoreflectance-based metrology concept applied to compound semiconductor thin films off-line characterization in the solar cells scribing process. The presented thermoreflectance setup has been used to evaluate the thermal diffusivity of thin CdTe films and to measure eventual changes in the thermal properties of 5 μm CdTe films ablated by nano and picosecond laser pulses. The temperature response of the CdTe thin film to the nanosecond heating pulse has been numerically investigated using the finite-difference time-domain (FDTD) method. The computational and experimental results have been compared.

  14. Nanostructured thin films and coatings functional properties

    CERN Document Server

    Zhang, Sam

    2010-01-01

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

  15. Micromechanics of substrate-supported thin films

    Science.gov (United States)

    He, Wei; Han, Meidong; Wang, Shibin; Li, Lin-An; Xue, Xiuli

    2017-09-01

    The mechanical properties of metallic thin films deposited on a substrate play a crucial role in the performance of micro/nano-electromechanical systems (MEMS/NEMS) and flexible electronics. This article reviews ongoing study on the mechanics of substrate-supported thin films, with emphasis on the experimental characterization techniques, such as the rule of mixture and X-ray tensile testing. In particular, the determination of interfacial adhesion energy, film deformation, elastic properties and Bauschinger effect are discussed.

  16. Thin film bioreactors in space

    Science.gov (United States)

    Hughes-Fulford, M.; Scheld, H. W.

    Studies from the Skylab, SL-3 and D-1 missions have demonstrated that biological organisms grown in microgravity have changes in basic cellular functions such as DNA, mRNA and protein synthesis, cytoskeleton synthesis, glucose utilization and cellular differentiation. Since microgravity could affect prokaryotic and eukaryotic cells at a subcellular and molecular level, space offers us an opportunity to learn more about basic biological systems with one important variable removed. The thin film bioreactor will facilitate the handling of fluids in microgravity, under constant temperature and will allow multiple samples of cells to be grown with variable conditions. Studies on cell cultures grown in microgravity would enable us to identify and quantify changes in basic biological function in microgravity which are needed to develop new applications of orbital research and future biotechnology.

  17. BDS thin film damage competition

    Energy Technology Data Exchange (ETDEWEB)

    Stolz, C J; Thomas, M D; Griffin, A J

    2008-10-24

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

  18. Method of producing thin cellulose nitrate film

    International Nuclear Information System (INIS)

    Lupica, S.B.

    1975-01-01

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

  19. Achievement report for fiscal 1997 on development of technologies for practical photovoltaic system under New Sunshine Program. Manufacture of thin-film solar cell / low-cost and large-area module / next-generation thin-film solar cell (Manufacture of thin-film polycrystalline solar module); 1997 nendo taiyoko hatsuden system jitsuyoka gijutsu kaihatsu seika hokokusho. Usumaku taiyo denchi no seizo gijutsu kaihatsu, tei cost daimenseki module seizo gijutsu kaihatsu, jisedai usumaku taiyo denchi no seizo gijutsu kaihatsu (usumaku takessho taiyo denchi module no seizo gijutsu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    Fiscal 1997 is the first year of another 4-year-long research and development phase. In addition to researches for improving on thin-film polycrystalline Si cell efficiency that have been under way, new efforts are started, which include the development of practicality-conscious thin film producing technologies aiming at higher throughput and yield and the development of modularization process technologies which are necessary for putting thin-film cells to practical use. Concerning the formation of a power generation layer on a polycrystalline Si thin film formed by the ZMR (zone-melting recrystallization) process, studies are conducted for improvement on its throughput and yield using a new CVD (chemical vapor deposition) unit. A method of modularization is evaluated, which involves a laminate of a thin-film cell attached to a resin-coated, reinforced glass substrate and an EVA (ethylene vinyl acetate) back film. A remarkable achievement is earned toward the practicalization of technologies of thin film formation enhanced in quality and throughput and technologies of thin film modularization. (NEDO)

  20. Polycrystalline-thin-film thermophotovoltaic cells

    Science.gov (United States)

    Dhere, Neelkanth G.

    1996-02-01

    Thermophotovoltaic (TPV) cells convert thermal energy to electricity. Modularity, portability, silent operation, absence of moving parts, reduced air pollution, rapid start-up, high power densities, potentially high conversion efficiencies, choice of a wide range of heat sources employing fossil fuels, biomass, and even solar radiation are key advantages of TPV cells in comparison with fuel cells, thermionic and thermoelectric convertors, and heat engines. The potential applications of TPV systems include: remote electricity supplies, transportation, co-generation, electric-grid independent appliances, and space, aerospace, and military power applications. The range of bandgaps for achieving high conversion efficiencies using low temperature (1000-2000 K) black-body or selective radiators is in the 0.5-0.75 eV range. Present high efficiency convertors are based on single crystalline materials such as In1-xGaxAs, GaSb, and Ga1-xInxSb. Several polycrystalline thin films such as Hg1-xCdxTe, Sn1-xCd2xTe2, and Pb1-xCdxTe, etc., have great potential for economic large-scale applications. A small fraction of the high concentration of charge carriers generated at high fluences effectively saturates the large density of defects in polycrystalline thin films. Photovoltaic conversion efficiencies of polycrystalline thin films and PV solar cells are comparable to single crystalline Si solar cells, e.g., 17.1% for CuIn1-xGaxSe2 and 15.8% for CdTe. The best recombination-state density Nt is in the range of 10-15-10-16 cm-3 acceptable for TPV applications. Higher efficiencies may be achieved because of the higher fluences, possibility of bandgap tailoring, and use of selective emitters such as rare earth oxides (erbia, holmia, yttria) and rare earth-yttrium aluminium garnets. As compared to higher bandgap semiconductors such as CdTe, it is easier to dope the lower bandgap semiconductors. TPV cell development can benefit from the more mature PV solar cell and opto

  1. 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 of the dev......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...... predicts optical losses based on structure of the gold films....

  2. Plasmonic modes in thin films: quo vadis?

    Directory of Open Access Journals (Sweden)

    Antonio ePolitano

    2014-07-01

    Full Text Available Herein, we discuss the status and the prospect of plasmonic modes in thin films. Plasmons are collective longitudinal modes of charge fluctuation in metal samples excited by an external electric field. Surface plasmons (SPs are waves that propagate along the surface of a conductor with applications in magneto-optic data storage, optics, microscopy, and catalysis. In thin films the electronic response is influenced by electron quantum confinement. Confined electrons modify the dynamical screening processes at the film/substrate interface by introducing novel properties with potential applications and, moreover, they affect both the dispersion relation of SP frequency and the damping processes of the SP.Recent calculations indicate the emergence of acoustic surface plasmons (ASP in Ag thin films exhibiting quantum well states and in graphene films. The slope of the dispersion of ASP decreases with film thickness. We also discuss open issues in research on plasmonic modes in graphene/metal interfaes.

  3. Stabilized thin film heterostructure for electrochemical applications

    DEFF Research Database (Denmark)

    2015-01-01

    The invention provides a method for the formation of a thin film multi-layered heterostructure upon a substrate, said method comprising the steps of: a. providing a substrate; b. depositing a buffer layer upon said substrate, said buffer layer being a layer of stable ionic conductor (B); c...... or less; and e. repeating steps b. and c. a total of N times, such that N repeating pairs of layers (A/B) are built up, wherein N is 1 or more. The invention also provides a thin film multi-layered heterostructure as such, and the combination of a thin film multi-layered heterostructure and a substrate...

  4. Macro stress mapping on thin film buckling

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  5. Study of zinc oxide thin film characteristics

    OpenAIRE

    Johari Shazlina; Muhammad Nazalea Yazmin; Zakaria Mohd Rosydi

    2017-01-01

    This paper presents the characterization of ZnO thin films with the thickness of 8nm, 30nm, and 200nm. The thin films were prepared using sol-gel method and has been deposited onto different substrate of silicon wafer, glass and quartz. The thin films were annealed at 400, 500 and 600°C. By using UV-Vis, the optical transmittance measurement were recorded by using a single beam spectrophotometer in the wavelength 250nm to 800nm. However, the transmittance in the visible range is hardly influe...

  6. Thin Films for Advanced Glazing Applications

    Directory of Open Access Journals (Sweden)

    Ann-Louise Anderson

    2016-09-01

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

  7. Synthesis of thin films by the pyrosol process

    Directory of Open Access Journals (Sweden)

    Tucić Aleksandar

    2002-01-01

    Full Text Available Among many aerosol routes, the Pyrosol process, due to its simplicity, low cost and quality of obtained films, represents a promising technique for the synthesis of thin films. The pyrosol process is based on the transport and pyrolysls of an aerosol of processor solution, generated in an ultrasonic atomizer, on a heated substrate. The theoretical principles of the pyrosol process are presented in this paper, as well as the influence of some synthesis parameters on the deposition of SnO2 thin films.

  8. High density nonmagnetic cobalt in thin films

    OpenAIRE

    Banu, Nasrin; Singh, Surendra; Basu, Saibal; Roy, Anupam; Movva, Hema C. P.; Dev, B. N.

    2017-01-01

    Recently high density (HD) nonmagnetic (NM) cobalt has been discovered in a cobalt thin film, grown on Si(111). This cobalt film had a natural cobalt oxide at the top. The oxide layer forms when the film is taken out of the electron-beam deposition chamber and exposed to air. Thin HD NM cobalt layers were found near the cobalt/silicon and the cobalt-oxide/cobalt interfaces, while the thicker mid-depth region of the film was hcp cobalt with normal density and normal magnetic moment. If an ultr...

  9. Performance Characterization of Monolithic Thin Film Resistors

    Science.gov (United States)

    Yin, Rong

    Thin film resistors have a large resistance range and stable performance under high temperature operating condition. Thin film resistors trimmed by laser beam are able to achieve very high precision on resistance value. As a result, thin film resistors have been widely used to improve the performance of integrated circuits such as operational amplifier, analog-to-digital (A/D) and digital -to-analog (D/A) converters, etc. In this dissertation, a new class of thin film resistors, silicon chrome (SiCr) thin film resistors, has been investigated at length. From thin film characterization to aging behavior modelling, we have carried out a series of engineering activities. The characteristics of the SiCr thin film incorporated into three bipolar processes were first determined. After laser trimming, we have measured a couple of physical parameters of the SiCr film in the heat affected zone (HAZ). This is the first time the sheet resistance and the temperature coefficient of resistance (TCR) of thin film in the HAZ have been characterized. Both thermal and d.c. load accelerated aging tests were performed. The test structures were subjected to the aging for 1000 hours. Based on the test data, we not only evaluated the classical thermal aging model for untrimmed thin film resistors, but also established several empirical thermal aging models for trimmed resistors and d.c. load aging models for both trimmed and untrimmed thin film resistors. All the experiments were carried out for both conventional bar resistors and our new Swiss Cheese (SC) resistors. For the first time, the performance of laser trimmed SC resistors, which was experimentally evaluated, shown a clear superiority over that of trimmed bar resistors. Besides these experiments, we have examined different die attach techniques and their effects on thin film resistors. Also, we have developed a number of hardware systems and software tools, such as a temperature controller, d.c. current source, temperature

  10. Thermal conductivity model for nanoporous thin films

    Science.gov (United States)

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

    2018-03-01

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

  11. Reflectometric monitoring of the dissolution process of thin polymeric films.

    Science.gov (United States)

    Laitinen, Riikka; Räty, Jukka; Korhonen, Kristiina; Ketolainen, Jarkko; Peiponen, Kai-Erik

    2017-05-15

    Pharmaceutical thin films are versatile drug-delivery platforms i.e. allowing transdermal, oral, sublingual and buccal administration. However, dissolution testing of thin films is challenging since the commonly used dissolution tests for conventional dosage forms correspond rather poorly to the physiological conditions at the site of administration. Here we introduce a traditional optical reflection method for monitoring the dissolution behavior of thin polymeric films. The substances, e.g. drug molecules, released from the film generate an increase in the refractive index in the liquid medium which can be detected by reflectance monitoring. Thin EUDRAGIT ® RL PO poly(ethyl acrylate-co-methyl methacrylate-co trimethylammonioethyl methacrylate chloride) (RLPO) films containing the model drug perphenazine (PPZ) were prepared by spraying on a glass substrate. The glass substrates were placed inside the flow cell in the reflectometer which was then filled with phosphate buffer solution. Dissolution was monitored by measuring the reflectance of the buffer liquid. The method was able to detect the distinctive dissolution characteristics of different film formulations and measured relatively small drug concentrations. In conclusion, it was demonstrated that a traditional optical reflection method can provide valuable information about the dissolution characteristics of thin polymeric films in low liquid volume surroundings. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Robust outer-selective thin-film composite polyethersulfone hollow fiber membranes with low reverse salt flux for renewable salinity-gradient energy generation

    KAUST Repository

    Cheng, Zhen Lei

    2016-01-08

    This study reports outer-selective thin-film composite (TFC) hollow fiber membranes with extremely low reverse salt fluxes and robustness for harvesting salinity-gradient energy from pressure retarded osmosis (PRO) processes. Almost defect-free polyamide layers with impressive low salt permeabilities were synthesized on top of robust polyethersulfone porous supports. The newly developed TFC-II membrane shows a maximum power density of 7.81 W m−2 using 1 M NaCl and DI water as feeds at 20 bar. Reproducible data obtained in the 2nd and 3rd runs confirm its stability under high hydraulic pressure differences. Comparing to other PRO membranes reported in the literature, the newly developed membrane exhibits not only the smallest slope between water flux decline and ΔPΔP increase but also the lowest ratio of reverse salt flux to water flux. Thus, the effective osmotic driving force could be well maintained even under high pressure operations. For the first time, the effect of feed pressure buildup induced by feed flowrate was evaluated towards PRO performance. A slight increment in feed pressure buildup was found to be beneficial to water flux and power density up to 10.06 W m−2 without comprising the reverse salt flux. We believe this study may open up new perspectives on outer-selective PRO hollow fiber membranes and provide useful insights to understand and design next-generation outer-selective TFC hollow fiber membranes for osmotic power generation.

  13. Fabrication of a thermoelectric generator on a polymer-coated substrate via laser-induced forward transfer of chalcogenide thin films

    International Nuclear Information System (INIS)

    Feinaeugle, M; Sones, C L; Eason, R W; Koukharenko, E

    2013-01-01

    We have demonstrated the fabrication of a thermoelectric energy harvesting device via laser-induced forward transfer of intact solid thin films. Thermoelectric chalcogenide materials, namely bismuth telluride (Bi 2 Te 3 ), bismuth selenide (Bi 2 Se 3 ) and bismuth antimony telluride (Bi 0.5 Sb 1.5 Te 3 ), were sequentially printed using a nanosecond excimer laser onto an elastomeric polydimethylsiloxane-coated glass substrate to form thermocouples connected in series creating a thermoelectric generator. The resulting generator Seebeck coefficient and series resistance per leg pair were measured to be 0.17 mV K −1 and 10 kΩ respectively. It was shown that laser-induced forward transfer allows device fabrication from inorganic semiconductor compounds on inexpensive elastic polymer substrates and demonstrates the ability to print materials with pre-defined thermoelectric properties. This allows the rapid manufacturing of a complete thermoelectric device on mm 2 -areas with μm-scale precision, without the need of further lithographic steps. (paper)

  14. Thin film production method and apparatus

    Science.gov (United States)

    Loutfy, Raouf O.; Moravsky, Alexander P.; Hassen, Charles N.

    2010-08-10

    A method for forming a thin film material which comprises depositing solid particles from a flowing suspension or aerosol onto a filter and next adhering the solid particles to a second substrate using an adhesive.

  15. Highly stretchable wrinkled gold thin film wires.

    Science.gov (United States)

    Kim, Joshua; Park, Sun-Jun; Nguyen, Thao; Chu, Michael; Pegan, Jonathan D; Khine, Michelle

    2016-02-08

    With the growing prominence of wearable electronic technology, there is a need to improve the mechanical reliability of electronics for more demanding applications. Conductive wires represent a vital component present in all electronics. Unlike traditional planar and rigid electronics, these new wearable electrical components must conform to curvilinear surfaces, stretch with the body, and remain unobtrusive and low profile. In this paper, the piezoresistive response of shrink induced wrinkled gold thin films under strain demonstrates robust conductive performance in excess of 200% strain. Importantly, the wrinkled metallic thin films displayed negligible change in resistance of up to 100% strain. The wrinkled metallic wires exhibited consistent performance after repetitive strain. Importantly, these wrinkled thin films are inexpensive to fabricate and are compatible with roll to roll manufacturing processes. We propose that these wrinkled metal thin film wires are an attractive alternative to conventional wires for wearable applications.

  16. Epitaxy, thin films and superlattices

    International Nuclear Information System (INIS)

    Jagd Christensen, Morten

    1997-05-01

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

  17. Epitaxy, thin films and superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Jagd Christensen, Morten

    1997-05-01

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

  18. A flow-through aqueous standard generation system for thin film microextraction investigations of UV filters and biocides partitioning to different environmental compartments.

    Science.gov (United States)

    Ahmadi, Fardin; Sparham, Chris; Pawliszyn, Janusz

    2017-11-01

    In this paper problems associated with preparation of aqueous standard of highly hydrophobic compounds such as partial precipitation, being lost on the surfaces, low solubility in water and limited sample volume for accurate determination of their distribution coefficients are addressed. The following work presents two approaches that utilize blade thin film microextraction (TFME) to investigate partitioning of UV filters and biocides to humic acid (dissolved organic carbon) and sediment. A steady-state concentration of target analytes in water was generated using a flow-through aqueous standard generation (ASG) system. Dialysis membranes, a polytetrafluoroethylene permeation tube, and a frit porous (0.5 μm) coated by epoxy glue were basic elements used for preparation of the ASG system. In the currently presented study, negligible depletion TFME using hydrophilic-lipophilic balance (HLB) and octadecyl silica-based (C18) sorbents was employed towards the attainment of free concentration values of target analytes in the studied matrices. Thin film geometry provided a large volume of extraction phase, which improved the sensitivity of the method towards highly matrix-bound analytes. Extractions were performed in the equilibrium regime so as to prevent matrix effects and with aims to reach maximum method sensitivity for all analytes under study. Partitioning of analytes on dissolved organic carbon (DOC) was investigated in ASG to facilitate large sample volume conditions. Binding percentages and DOC distribution coefficients (Log K DOC ) ranged from 20 to 98% and 3.71-6.72, respectively. Furthermore, sediment-water partition coefficients (K d ), organic-carbon normalized partition coefficients (Log K OC ), and DOC distribution coefficients (Log K DOC ) were investigated in slurry sediment, and ranged from 33 to 2860, 3.31-5.24 and 4.52-5.75 Lkg -1 , respectively. The obtained results demonstrated that investigations utilizing ASG and TFME can yield reliable binding

  19. Thin Film Approaches to the SRF Cavity Problem: Fabrication and Characterization of Superconducting Thin Films

    Science.gov (United States)

    Beringer, Douglas B.

    Superconducting Radio Frequency (SRF) cavities are responsible for the acceleration of charged particles to relativistic velocities in most modern linear accelerators, such as those employed at high-energy research facilities like Thomas Jefferson National Laboratory's CEBAF and the LHC at CERN. Recognizing SRF as primarily a surface phenomenon enables the possibility of applying thin films to the interior surface of SRF cavities, opening a formidable tool chest of opportunities by combining and designing materials that offer greater benefit. Thus, while improvements in radio frequency cavity design and refinements in cavity processing techniques have improved accelerator performance and efficiency - 1.5 GHz bulk niobium SRF cavities have achieved accelerating gradients in excess of 35 MV/m - there exist fundamental material bounds in bulk superconductors limiting the maximally sustained accelerating field gradient (approximately 45 MV/m for Niobium) where inevitable thermodynamic breakdown occurs. With state of the art niobium based cavity design fast approaching these theoretical limits, novel material innovations must be sought in order to realize next generation SRF cavities. One proposed method to improve SRF performance is to utilize thin film superconducting-insulating-superconducting (SIS) multilayer structures to effectively magnetically screen a bulk superconducting layer such that it can operate at higher field gradients before suffering critically detrimental SRF losses. This dissertation focuses on the production and characterization of thin film superconductors for such SIS layers for radio-frequency applications.

  20. Laser processing for thin-film photovoltaics

    Science.gov (United States)

    Compaan, Alvin D.

    1995-04-01

    Over the past decade major advances have occurred in the field of thin- film photovoltaics (PV) with many of them a direct consequence of the application of laser processing. Improved cell efficiencies have been achieved in crystalline and polycrystalline Si, in hydrogenated amorphous silicon, and in two polycrystalline thin-film materials. The use of lasers in photovoltaics includes laser hole drilling for emitter wrap-through, laser trenching for buried bus lines, and laser texturing of crystalline and polycrystalline Si cells. In thin-film devices, laser scribing is gaining increased importance for module interconnects. Pulsed laser recrystallization of boron-doped hydrogenated amorphous silicon is used to form highly conductive p-layers in p-i-n amorphous silicon cells and in thin-film transistors. Optical beam melting appears to be an attractive method for forming metal semiconductor alloys for contact formation. Finally, pulsed lasers are used for deposition of the entire semiconductor absorber layer in two types of polycrystalline thin-film cells-those based on copper indium diselenide and those based on cadmium telluride. In our lab we have prepared and studied heavily doped polycrystalline silicon thin films and also have used laser physical vapor deposition (LPVD) to prepare 'all-LPVD' CdS/CdTe solar cells on glass with efficiencies tested at NREL at 10.5%. LPVD is highly flexible and ideally suited for prototyping PV cells using ternary or quaternary alloys and for exploring new dopant combinations.

  1. Laser applications in thin-film photovoltaics

    Science.gov (United States)

    Bartlome, R.; Strahm, B.; Sinquin, Y.; Feltrin, A.; Ballif, C.

    2010-08-01

    We review laser applications in thin-film photovoltaics (thin-film Si, CdTe, and Cu(In,Ga)Se2 solar cells). Lasers are applied in this growing field to manufacture modules, to monitor Si deposition processes, and to characterize opto-electrical properties of thin films. Unlike traditional panels based on crystalline silicon wafers, the individual cells of a thin-film photovoltaic module can be serially interconnected by laser scribing during fabrication. Laser scribing applications are described in detail, while other laser-based fabrication processes, such as laser-induced crystallization and pulsed laser deposition, are briefly reviewed. Lasers are also integrated into various diagnostic tools to analyze the composition of chemical vapors during deposition of Si thin films. Silane (SiH4), silane radicals (SiH3, SiH2, SiH, Si), and Si nanoparticles have all been monitored inside chemical vapor deposition systems. Finally, we review various thin-film characterization methods, in which lasers are implemented.

  2. Large-area homogeneous periodic surface structures generated on the surface of sputtered boron carbide thin films by femtosecond laser processing

    International Nuclear Information System (INIS)

    Serra, R.; Oliveira, V.; Oliveira, J.C.; Kubart, T.; Vilar, R.; Cavaleiro, A.

    2015-01-01

    Highlights: • Large-area LIPSS were formed by femtosecond laser processing B-C films surface. • The LIPSS spatial period increases with laser fluence (140–200 nm). • Stress-related sinusoidal-like undulations were formed on the B-C films surface. • The undulations amplitude (down to a few nanometres) increases with laser fluence. • Laser radiation absorption increases with surface roughness. - Abstract: Amorphous and crystalline sputtered boron carbide thin films have a very high hardness even surpassing that of bulk crystalline boron carbide (≈41 GPa). However, magnetron sputtered B-C films have high friction coefficients (C.o.F) which limit their industrial application. Nanopatterning of materials surfaces has been proposed as a solution to decrease the C.o.F. The contact area of the nanopatterned surfaces is decreased due to the nanometre size of the asperities which results in a significant reduction of adhesion and friction. In the present work, the surface of amorphous and polycrystalline B-C thin films deposited by magnetron sputtering was nanopatterned using infrared femtosecond laser radiation. Successive parallel laser tracks 10 μm apart were overlapped in order to obtain a processed area of about 3 mm 2 . Sinusoidal-like undulations with the same spatial period as the laser tracks were formed on the surface of the amorphous boron carbide films after laser processing. The undulations amplitude increases with increasing laser fluence. The formation of undulations with a 10 μm period was also observed on the surface of the crystalline boron carbide film processed with a pulse energy of 72 μJ. The amplitude of the undulations is about 10 times higher than in the amorphous films processed at the same pulse energy due to the higher roughness of the films and consequent increase in laser radiation absorption. LIPSS formation on the surface of the films was achieved for the three B-C films under study. However, LIPSS are formed under different

  3. Large-area homogeneous periodic surface structures generated on the surface of sputtered boron carbide thin films by femtosecond laser processing

    Energy Technology Data Exchange (ETDEWEB)

    Serra, R., E-mail: ricardo.serra@dem.uc.pt [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra (Portugal); Oliveira, V. [ICEMS-Instituto de Ciência e Engenharia de Materiais e Superfícies, Avenida Rovisco Pais no 1, 1049-001 Lisbon (Portugal); Instituto Superior de Engenharia de Lisboa, Avenida Conselheiro Emídio Navarro no 1, 1959-007 Lisbon (Portugal); Oliveira, J.C. [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra (Portugal); Kubart, T. [The Ångström Laboratory, Solid State Electronics, P.O. Box 534, SE-751 21 Uppsala (Sweden); Vilar, R. [Instituto Superior de Engenharia de Lisboa, Avenida Conselheiro Emídio Navarro no 1, 1959-007 Lisbon (Portugal); Instituto Superior Técnico, Avenida Rovisco Pais no 1, 1049-001 Lisbon (Portugal); Cavaleiro, A. [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra (Portugal)

    2015-03-15

    Highlights: • Large-area LIPSS were formed by femtosecond laser processing B-C films surface. • The LIPSS spatial period increases with laser fluence (140–200 nm). • Stress-related sinusoidal-like undulations were formed on the B-C films surface. • The undulations amplitude (down to a few nanometres) increases with laser fluence. • Laser radiation absorption increases with surface roughness. - Abstract: Amorphous and crystalline sputtered boron carbide thin films have a very high hardness even surpassing that of bulk crystalline boron carbide (≈41 GPa). However, magnetron sputtered B-C films have high friction coefficients (C.o.F) which limit their industrial application. Nanopatterning of materials surfaces has been proposed as a solution to decrease the C.o.F. The contact area of the nanopatterned surfaces is decreased due to the nanometre size of the asperities which results in a significant reduction of adhesion and friction. In the present work, the surface of amorphous and polycrystalline B-C thin films deposited by magnetron sputtering was nanopatterned using infrared femtosecond laser radiation. Successive parallel laser tracks 10 μm apart were overlapped in order to obtain a processed area of about 3 mm{sup 2}. Sinusoidal-like undulations with the same spatial period as the laser tracks were formed on the surface of the amorphous boron carbide films after laser processing. The undulations amplitude increases with increasing laser fluence. The formation of undulations with a 10 μm period was also observed on the surface of the crystalline boron carbide film processed with a pulse energy of 72 μJ. The amplitude of the undulations is about 10 times higher than in the amorphous films processed at the same pulse energy due to the higher roughness of the films and consequent increase in laser radiation absorption. LIPSS formation on the surface of the films was achieved for the three B-C films under study. However, LIPSS are formed under

  4. Thin Film Approaches to the SRF Cavity Problem Fabrication and Characterization of Superconducting Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Beringer, Douglas [College of William and Mary, Williamsburg, VA (United States)

    2017-08-01

    Superconducting Radio Frequency (SRF) cavities are responsible for the acceleration of charged particles to relativistic velocities in most modern linear accelerators, such as those employed at high-energy research facilities like Thomas Jefferson National Laboratory’s CEBAF and the LHC at CERN. Recognizing SRF as primarily a surface phenomenon enables the possibility of applying thin films to the interior surface of SRF cavities, opening a formidable tool chest of opportunities by combining and designing materials that offer greater performance benefit. Thus, while improvements in radio frequency cavity design and refinements in cavity processing techniques have improved accelerator performance and efficiency – 1.5 GHz bulk niobium SRF cavities have achieved accelerating gradients in excess of 35 MV/m – there exist fundamental material bounds in bulk superconductors limiting the maximally sustained accelerating field gradient (≈ 45 MV/m for Nb) where inevitable thermodynamic breakdown occurs. With state of the art Nb based cavity design fast approaching these theoretical limits, novel material innovations must be sought in order to realize next generation SRF cavities. One proposed method to improve SRF performance is to utilize thin film superconducting-insulating-superconducting (SIS) multilayer structures to effectively magnetically screen a bulk superconducting layer such that it can operate at higher field gradients before suffering critically detrimental SRF losses. This dissertation focuses on the production and characterization of thin film superconductors for such SIS layers for radio frequency applications. Correlated studies on structure, surface morphology and superconducting properties of epitaxial Nb and MgB2 thin films are presented.

  5. Antibacterial Properties of Titanate Nano fiber Thin Films Formed on a Titanium Plate

    International Nuclear Information System (INIS)

    Yada, M.; Inoue, Y.; Morita, T.; Torikai, T.; Watari, T.; Noda, I.; Hotokebuchi, T.

    2013-01-01

    A sodium titanate nano fiber thin film and a silver nanoparticle/silver titanate nano fiber thin film formed on the surface of a titanium plate exhibited strong antibacterial activities against methicillin-resistant Staphylococcus aureus, which is one of the major bacteria causing in-hospital infections. Exposure of the sodium titanate nano fiber thin film to ultraviolet rays generated a high antibacterial activity due to photo catalysis and the sodium titanate nano fiber thin film immediately after its synthesis possessed a high antibacterial activity even without exposure to ultraviolet rays. Elution of silver from the silver nanoparticle/silver titanate nano fiber thin film caused by the silver ion exchange reaction was considered to contribute substantially to the strong antibacterial activity. The titanate nano fiber thin films adhered firmly to titanium. Therefore, these titanate nano fiber thin film/titanium composites will be extremely useful as implant materials that have excellent antibacterial activities.

  6. Humidity sensing characteristics of hydrotungstite thin films

    Indian Academy of Sciences (India)

    Wintec

    variety of tungstate materials, such as thick-film manga- nese tungstate, have been applied as humidity sensors. (Qu and Mayer 1997). The humidity sensing characteristics of bulk metal oxide–tungsten oxide systems have also been studied in the literature (Ichinose 1993). Thin films of tungsten oxide have been prepared ...

  7. A thin film magnetoresistive angle detector

    NARCIS (Netherlands)

    Eijkel, C.J.M.; Wieberdink, Johan W.; Fluitman, J.H.J.; Popma, T.J.A.; Groot, Peter; Leeuwis, Henk

    1990-01-01

    An overview is given of the results of our research on a contactless angle detector based on the anisotropic magnetoresistance effect (AMR effect) in a permalloy thin film. The results of high-temperature annealing treatment of the pemalloy film are discussed. Such a treatment suppresses the effects

  8. 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.

  9. Pressureless Bonding Using Sputtered Ag Thin Films

    Science.gov (United States)

    Oh, Chulmin; Nagao, Shijo; Suganuma, Katsuaki

    2014-12-01

    To improve the performance and reliability of power electronic devices, particularly those built around next-generation wide-bandgap semiconductors such as SiC and GaN, the bonding method used for packaging must change from soldering to solderless technology. Because traditional solders are problematic in the harsh operating conditions expected for emerging high-temperature power devices, we propose a new bonding method in this paper, namely a pressureless, low-temperature bonding process in air, using abnormal grain growth on sputtered Ag thin films to realize extremely high temperature resistance. To investigate the mechanisms of this bonding process, we characterized the microstructural changes in the Ag films over various bonding temperatures and times. We measured the bonding properties of the specimens by a die-shear strength test, as well as by x-ray diffraction measurements of the residual stress in the Ag films to show how the microstructural developments were essential to the bonding technology. Sound bonds with high die strength can be achieved only with abnormal grain growth at optimum bonding temperature and time. Pressureless bonding allows for production of reliable high-temperature power devices for a wide variety of industrial, energy, and environmental applications.

  10. Dimensional scaling of perovskite ferroelectric thin films

    Science.gov (United States)

    Keech, Ryan R.

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

  11. Measurements of acoustic properties for thin films

    International Nuclear Information System (INIS)

    Kushibiki, J.; Maehara, H.; Chubachi, N.

    1982-01-01

    A measurement method for determining thin-film acoustic properties, such as characteristic acoustic impedance, sound velocity, density, and stiffness constant, is developed with a simple measurement principle and high measurement accuracy. The acoustic properties are determined from a maximum reflection loss and a center frequency obtained through a frequency response of the reflection loss for an acoustic transmission line composed of a sapphire/film/water system by using the acoustic pulse mode measurement system in the UHF range. The determination of the acoustic properties is demonstrated for sputtered fused quartz film, low-expansion borosilicate glass films, and chalcogenide glass films of evaporated As 2 S 3 and As 2 Se 3 , within the measurement accuracy around 1--2%. It is also found that the acoustic properties of thin films are generally different from those of bulk materials, depending on the fabrication techniques and conditions

  12. Large grain gallium arsenide thin films

    Science.gov (United States)

    Chu, S. S.; Chu, T. L.; Firouzi, H.; Han, Y. X.; Chen, W. J.; Wang, Q. H.

    Polycrystalline gallium arsenide films deposited on tungsten/graphite substrates have been used for the fabrication of thin film solar cells. Gallium arsenide films deposited on foreign substrates of 10 microns or less thickness exhibit, in most cases, pronounced shunting effects due to grain boundaries. MOS solar cells of 9 sq cm area with an AM1 efficiency of 8.5 percent and p(+)/n/n(+) homojunction solar cells of 1 sq cm area with an AM1 efficiency of 8.8 percent have been prepared. However, in order to further improve the conversion efficiency before the development of effective passivation techniques, gallium arsenide films with large and uniform grain structure are necessary. The large grain gallium arsenide films have been prepared by using (1) the arsine treatment of a thin layer of molten gallium on the substrate surface and (2) the recrystallized germanium films on tungsten/graphite as substrates.

  13. Structural and Electrochemical Properties of Lithium Nickel Oxide Thin Films

    Directory of Open Access Journals (Sweden)

    Gyu-bong Cho

    2014-01-01

    Full Text Available LiNiO2 thin films were fabricated by RF magnetron sputtering. The microstructure of the films was determined by X-ray diffraction and field-emission scanning electron microscopy. The electrochemical properties were investigated with a battery cycler using coin-type half-cells. The LiNiO2 thin films annealed below 500°C had the surface carbonate. The results suggest that surface carbonate interrupted the Li intercalation and deintercalation during charge/discharge. Although the annealing process enhanced the crystallization of LiNiO2, the capacity did not increase. When the annealing temperature was increased to 600°C, the FeCrNiO4 oxide phase was generated and the discharge capacity decreased due to an oxygen deficiency in the LiNiO2 thin film. The ZrO2-coated LiNiO2 thin film provided an improved discharge capacity compared to bare LiNiO2 thin film suggesting that the improved electrochemical characteristic may be attributed to the inhibition of surface carbonate by ZrO2 coating layer.

  14. Electrochemical fabrication of nanoporous polypyrrole thin films

    International Nuclear Information System (INIS)

    Li Mei; Yuan Jinying; Shi Gaoquan

    2008-01-01

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

  15. Polymer surfaces, interfaces and thin films

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-11-01

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

  16. Polymer surfaces, interfaces and thin films

    International Nuclear Information System (INIS)

    Stamm, M.

    1996-01-01

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

  17. Porous La0.6Sr0.4CoO3-δ thin film cathodes for large area micro solid oxide fuel cell power generators

    DEFF Research Database (Denmark)

    Garbayo, A.; Esposito, Vincenzo; Sanna, Simone

    2014-01-01

    Porous La0.6Sr0.4CoO3-δ thin films were fabricated by pulsed laser deposition for being used as a cathode for micro solid oxide fuel cell applications as MEMS power generators. Symmetrical La0.6Sr0.4CoO3-δ/ yttria-stabilized zirconia/La0.6Sr0.4CoO3-δ free-standing membranes were fabricated using...... silicon as a substrate. A novel large-area membrane design based on grids of doped-silicon slabs was used. Thermomechanical stability of the tri-layer membranes was ensured in the intermediate range of temperatures up to 700 °C. In-plane conductivity of ca. 300 S cm-1 was measured for the cathode within...... the whole range of application temperatures. Finally, area specific resistance values below 0.3 Ω cm2 were measured for the cathode/electrolyte bi-layer at 700 °C in the exact final micro solid oxide fuel cell device configuration, thus presenting La0.6Sr0.4CoO3-δ as a good alternative for fabricating...

  18. Nanostructured hematite thin films for photoelectrochemical water splitting

    Science.gov (United States)

    Maabong, Kelebogile; Machatine, Augusto G. J.; Mwankemwa, Benard S.; Braun, Artur; Bora, Debajeet K.; Toth, Rita; Diale, Mmantsae

    2018-04-01

    Nanostructured hematite thin films prepared by dip coating technique were investigated for their photoelectrochemical activity for generation of hydrogen from water splitting. Structural, morphological and optical analyses of the doped/undoped films were performed by X-ray diffraction, high resolution field emission-scanning electron microscopy, UV-vis spectrophotometry and Raman spectroscopy. The photoelectrochemical measurements of the films showed enhanced photoresponse and cathodic shift of the onset potential upon Ti doping indicating improved transfer of photoholes at the semiconductor-electrolyte interface. Films doped with 1 at% Ti produced 0.72 mA/cm2 at 1.23 V vs RHE which is 2 times higher than current density for the pure film (0.30 mA/cm2, at 1.23 V vs RHE). Gas chromatography analysis of the films also showed enhanced hydrogen evolution at 1 at% Ti with respect to pure film.

  19. Restructuring in block copolymer thin films

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  20. 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

  1. Critical behavior of ferromagnetic Ising thin films

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  2. Magnetostrictive thin films prepared by RF sputtering

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  3. Dynamics of Polymer Thin Film Mixtures

    Science.gov (United States)

    Besancon, Brian M.; Green, Peter F.; Soles, Christopher L.

    2006-03-01

    We examined the influence of film thickness and composition on the glass transition temperature (Tg) and mean square atomic displacements (MSD) of thin film mixtures of deuterated polystyrene (dPS) and tetramethyl bisphenol-A polycarbonate (TMPC) on Si/SiOx substrates using incoherent elastic neutron scattering (ICNS). The onset of dissipative motions, such as those associated with the glass transition and sub-Tg relaxations, are manifested as ``kinks'' in the curve of elastic intensity (or MSD) versus temperature. From the relevant kinks, the Tg was determined as a function of composition and of film thickness. The dependence of the Tg on film thickness exhibited qualitatively similar trends, at a given composition, as determined by the ICNS and ellipsometry measurements. However, with increasing PS content, the values of Tg measured by INS were consistently larger then those measured by ellipsometry. These results are examined in light of existing models on the thin film glass transition and component blend dynamics.

  4. Thin Films in the Photovoltaic Industry

    International Nuclear Information System (INIS)

    Jaeger-Waldau, A.

    2008-03-01

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

  5. All-solution-processed flexible thin film piezoelectric nanogenerator

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Sung Yun; Kim, Sunyoung; Kim, Kyongjun [Program in Nano Science and Technology, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 151-744 (Korea, Republic of); Lee, Ju-Hyuck; Kim, Sang-Woo [SKKU Advanced Institute of Nanotechnology, School of Advanced Materials Science and Engineering, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of); Kang, Chong-Yun; Yoon, Seok-Jin [Electronic Materials Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Kim, Youn Sang [Program in Nano Science and Technology, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 151-744 (Korea, Republic of); Advanced Institutes of Convergence Technology, 864-1 Iui-dong, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-270 (Korea, Republic of)

    2012-11-27

    An all-solution-processed flexible thin film piezoelectric nanogenerator is demonstrated using reactive zinc hydroxo-condensation and a screen-printing method. The highly elastic thin film allows the piezoelectric energy to be generated through the mechanical rolling and muscle stretching of the piezoelectric unit. This flexible all solution-processed nanogenerator is promising for use in future energy harvesters such as wearable human patches and mobile electronics. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Surface tension gradient enhanced thin film flow for particle deposition

    Science.gov (United States)

    Gilchrist, James; Joshi, Kedar; Muangnapoh, Tanyakorn; Stever, Michael

    2015-11-01

    We investigate the effect of varying concentration in binary mixtures of water and ethanol as the suspending medium for micron-scale silica particles on convective deposition. By pulling a suspension along a substrate, a thin film is created that results in enhanced evaporation of the solvent and capillary forces that order particles trapped in the thin film. In pure water or pure ethanol, assembly and deposition is easily understood by a simply flux balance first developed by Dimitrov and Nagayama in 1996. In solvent mixtures having only a few percent of ethanol, Marangoni stresses from the concentration gradient set by unbalanced solvent evaporation dominates the thin film flow. The thin film profile is similar to that found in ``tears of wine'' where the particles are deposited in the thin film between the tears and the reservoir. A simple model describes the 10x increase of deposition speed found in forming well-ordered monolayers of particles. At higher ethanol concentrations, lateral instabilities also generated by Marangoni stresses cause nonuniform deposition in the form of complex streaks that mirror sediment deposits in larger scale flows. We acknowledge funding from the NSF Scalable Nanomanufacturing Program under grant No. 1120399.

  7. 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

  8. Thermal conductivity of dielectric thin films

    International Nuclear Information System (INIS)

    Lambropoulos, J.C.; Jolly, M.R.; Amaden, C.A.; Gilman, S.E.; Sinicropi, M.J.; Diakomihalis, D.; Jacobs, S.D.

    1989-05-01

    A direct reading thermal comparator has been used to measure the thermal conductivity of dielectric thin film coatings. In the past, the thermal comparator has been used extensively to measure the thermal conductivity of bulk solids, liquids, and gases. The technique has been extended to thin film materials by making experimental improvements and by the application of an analytical heat flow model. Our technique also allows an estimation of the thermal resistance of the film/substrate interface which is shown to depend on the method of film deposition. The thermal conductivity of most thin films was found to be several orders of magnitude lower than that of the material in bulk form. This difference is attributed to structural disorder of materials deposited in thin film form. The experimentation to date has centered primarily on optical coating materials. These coatings, used to enhance the optical properties of components such as lenses and mirrors, are damaged by thermal loads applied in high-power laser applications. It has been widely postulated that there may be a correlation between the thermal conductivity and the damage threshold of these materials. 31 refs., 11 figs., 8 tabs

  9. High throughput growth and characterization of thin film materials

    Science.gov (United States)

    Mao, Samuel S.

    2013-09-01

    It usually takes more than 10 years for a new material from initial research to its first commercial application. Therefore, accelerating the pace of discovery of new materials is critical to tackling challenges in areas ranging from clean energy to national security. As discovery of new materials has not kept pace with the product design cycles in many sectors of industry, there is a pressing need to develop and utilize high throughput screening and discovery technologies for the growth and characterization of new materials. This article presents two distinctive types of high throughput thin film material growth approaches, along with a number of high throughput characterization techniques, established in the author's group. These approaches include a second-generation "discrete" combinatorial semiconductor discovery technology that enables the creation of arrays of individually separated thin film semiconductor materials of different compositions, and a "continuous" high throughput thin film material screening technology that enables the realization of ternary alloy libraries with continuously varying elemental ratios.

  10. Organic thin films and surfaces directions for the nineties

    CERN Document Server

    Ulman, Abraham

    1995-01-01

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

  11. Domains in Ferroic Crystals and Thin Films

    CERN Document Server

    Tagantsev, Alexander K; Fousek, Jan

    2010-01-01

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

  12. 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.

  13. Solid surfaces, interfaces and thin films

    CERN Document Server

    Lüth, Hans

    2015-01-01

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

  14. Solid Surfaces, Interfaces and Thin Films

    CERN Document Server

    Lüth, Hans

    2010-01-01

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

  15. Capillary stress in microporous thin films

    Energy Technology Data Exchange (ETDEWEB)

    Samuel, J.; Hurd, A.J.; Frink, L.J.D.; Swol, F. van [Sandia National Labs., Albuquerque, NM (United States); Brinker, C.J. [Sandia National Labs., Albuquerque, NM (United States). Ceramic Processing Science Dept.]|[Univ. of New Mexico, Albuquerque, NM (United States). Center for Micro Engineering Ceramics; Raman, N.K. [Univ. of New Mexico, Albuquerque, NM (United States). Center for Micro Engineered Ceramics

    1996-06-01

    Development of capillary stress in porous xerogels, although ubiquitous, has not been systematically studied. The authors have used the beam bending technique to measure stress isotherms of microporous thin films prepared by a sol-gel route. The thin films were prepared on deformable silicon substrates which were then placed in a vacuum system. The automated measurement was carried out by monitoring the deflection of a laser reflected off the substrate while changing the overlying relative pressure of various solvents. The magnitude of the macroscopic bending stress was found to reach a value of 180 MPa at a relative pressure of methanol, P/Po = 0.001. The observed stress is determined by the pore size distribution and is an order of magnitude smaller in mesoporous thin films. Density Functional Theory (DFT) indicates that for the microporous materials, the stress at saturation is compressive and drops as the relative pressure is reduced.

  16. Vibration welding system with thin film sensor

    Science.gov (United States)

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

    2014-03-18

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

  17. Formation and photopatterning of nanoporous titania thin films

    International Nuclear Information System (INIS)

    Park, Oun-Ho; Cheng, Joy Y.; Kim, Hyun Suk; Rice, Philip M.; Topuria, Teya; Miller, Robert D.; Kim, Ho-Cheol

    2007-01-01

    Photopatternable nanoporous titania thin films were generated from mixtures of an organic diblock copolymer, poly(styrene-b-ethylene oxide) (PS-b-PEO), and an oligomeric titanate (OT) prepared from a chelated titanium isopropoxide. The PS-b-PEO templates well-defined microdomains in thin films of the mixtures, which upon thermal treatment at 450 deg. C, become nanopores in titania. Average pore size and porosity are controlled by the molecular weight and loading level of the PS-b-PEO, respectively. Patterns of nanoporous titania were created by selectively exposing UV light on the mixture films. The UV irradiation destroys the chelating bond and induces the cross-linking reaction of the OT. Subsequent wet development followed by thermal treatment gives patterned nanoporous films of anatase phase titania

  18. The future of rare earth thin films

    International Nuclear Information System (INIS)

    Gasgnier, M.

    1986-01-01

    This paper presents some recent applications in the rare earth field and also may be, some of the future new developments of laboratory works. The field of investigations will concern only materials which contain at least one rare earth element (lanthanide series, from La to Lu, Sc and Y). After a rapid survey of the experimental procedures relative to the preparation and to the analytical characterization of thin films, technological applications in various fields of research are briefly reviewed: for polycrystalline metals (superconductors, neutron absorption, photovoltaic effect...), alloys (hydrogen storage, superconductors) and compounds (target for intense neutron sources, radiology...) and for amorphous magnetic thin films. 81 refs [fr

  19. Intrinsically conductive polymer thin film piezoresistors

    DEFF Research Database (Denmark)

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

    2008-01-01

    We report on the piezoresistive effect in the intrinsically conductive polymer, polyaniline. A process recipe for indirect patterning of thin film polyaniline has been developed. Using a specially designed chip, the polyaniline thin films have been characterised with respect to resistivity...... and strain sensitivity using two- and four-point measurement method. We have found that polyaniline has a negative gauge factor of K = -4.9, which makes it a candidate for piezoresistive read-out in polymer based MEMS-devices. (C) 2007 Elsevier B.V. All rights reserved....

  20. Micro-sensor thin-film anemometer

    Science.gov (United States)

    Sheplak, Mark (Inventor); McGinley, Catherine B. (Inventor); Spina, Eric F. (Inventor); Stephens, Ralph M. (Inventor); Hopson, Jr., Purnell (Inventor); Cruz, Vincent B. (Inventor)

    1996-01-01

    A device for measuring turbulence in high-speed flows is provided which includes a micro-sensor thin-film probe. The probe is formed from a single crystal of aluminum oxide having a 14.degree. half-wedge shaped portion. The tip of the half-wedge is rounded and has a thin-film sensor attached along the stagnation line. The bottom surface of the half-wedge is tilted upward to relieve shock induced disturbances created by the curved tip of the half-wedge. The sensor is applied using a microphotolithography technique.

  1. A generalized theory of thin film growth

    Science.gov (United States)

    Du, Feng; Huang, Hanchen

    2018-03-01

    This paper reports a theory of thin film growth that is generalized for arbitrary incidence angle during physical vapor deposition in two dimensions. The accompanying kinetic Monte Carlo simulations serve as verification. A special theory already exists for thin film growth with zero incidence angle, and another theory also exists for nanorod growth with a glancing angle. The theory in this report serves as a bridge to describe the transition from thin film growth to nanorod growth. In particular, this theory gives two critical conditions in analytical form of critical coverage, ΘI and ΘII. The first critical condition defines the onset when crystal growth or step dynamics stops following the wedding cake model for thin film growth. The second critical condition defines the onset when multiple-layer surface steps form to enable nanorod growth. Further, this theory also reveals a critical incidence angle, below which nanorod growth is impossible. The critical coverages, together with the critical incidence angle, defines a phase diagram of thin growth versus nanorod growth.

  2. Morphology of Cellulose and Cellulose Blend Thin FilmsMorphology of cellulose and cellulose blend thin films

    Science.gov (United States)

    Lu, Rui

    Cellulose is the most abundant, renewable, biocompatible and biodegradable natural polymer. Cellulose exhibits excellent chemical and mechanical stability, which makes it useful for applications such as construction, filtration, bio-scaffolding and packaging. It is useful to study amorphous cellulose as most reactions happen in the non-crystalline regions first and at the edge of crystalline regions. In this study, amorphous thin films of cotton linter cellulose with various thicknesses were spincoated on silicon wafers from cellulose solutions in dimethyl sulfoxide / ionic liquid mixtures. Optical microscopy and atomic force microscopy indicated that the morphology of as-cast films was sensitive to the film preparation conditions. A sample preparation protocol with low humidity system was developed to achieve featureless smooth films over multiple length scales from nanometers to tens of microns. X-ray reflectivity, X-ray diffraction, Fourier transform infrared spectroscopy and high resolution sum-frequency generation vibrational spectroscopy were utilized to confirm that there were no crystalline regions in the films. One- and three- layer models were used to analyze the X-ray reflectivity data to obtain information about roughness, density and interfacial roughness as a function of film thickness from 10-100nm. Stability tests of the thin films were conducted under harsh conditions including hot water, acid and alkali solutions. The stability of thin films of cellulose blended with the synthetic polymer, polyacrylonitrile, was also investigated. The blend thin films improved the etching resistance to alkali solutions and retained the stability in hot water and acid solutions compared to the pure cellulose films.

  3. Fabrication of PDMS/SWCNT thin films as saturable absorbers

    International Nuclear Information System (INIS)

    Hernandez-Romano, I; Sanchez-Mondragon, J J; Davila-Rodriguez, J; Delfyett, P J; May-Arrioja, D A

    2011-01-01

    We present a novel technique to fabricate a saturable absorber thin film based on Polydimethylsiloxane doped with Single Wall Carbon Nanotubes. Using this film a passive mode-locked fiber laser in a standard ring cavity configuration was built by inserting the film between two angled connectors. Self-starting passively mode-locked laser operation was easily observed. The generated pulses have a width of 1.26 ps at a repetition rate of 22.7 MHz with an average power of 4.89 mW.

  4. Perovskite Thin Films via Atomic Layer Deposition

    KAUST Repository

    Sutherland, Brandon R.

    2014-10-30

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

  5. Silver buffer layers for YBCO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Azoulay, J. [Tel Aviv Univ. (Israel). Center for Technol. Education Holon

    1999-09-01

    A simple economical conventional vacuum system was used for evaporation of YBCO thin films on as-deposited unbuffered Ag layers on MgO substrates. The subsequent heat treatment was carried out in low oxygen partial pressure at a relative low temperature and short dwelling time. The films thus obtained were characterized for electrical properties using dc four probe electrical measurements and inspected for structural properties and chemical composition by scanning electron microscopy (SEM). (orig.)

  6. Mechanical integrity of thin films

    International Nuclear Information System (INIS)

    Hoffman, R.W.

    1979-01-01

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

  7. Mesoscale simulations of confined Nafion thin films

    Science.gov (United States)

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

    2017-12-01

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

  8. Magnetocaloric effect of thin Terbium films

    Science.gov (United States)

    Mello, V. D.; Anselmo, D. H. A. L.; Vasconcelos, M. S.; Almeida, N. S.

    2017-12-01

    We report a theoretical study of the magnetocaloric effect of Terbium (Tb) thin films due to finite size and surface effects in the helimagnetic phase, corresponding to a temperature range from TC=219 K to TN=231 K, for external fields of the order of kOe. For a Tb thin film of 6 monolayers submitted to an applied field (ΔH =30 kOe, ΔH =50 kOe and ΔH = 70 kOe) we report a significative change in adiabatic temperature, ΔT / ΔH , near the Néel temperature, of the order ten times higher than that observed for Tb bulk. On the other hand, for small values of the magnetic field, large thickness effects are found. For external field strength around few kOe, we have found that the thermal caloric efficiency increases remarkably for ultrathin films. For an ultrathin film with 6 monolayers, we have found ΔT / ΔH = 43 K/T while for thicker films, with 20 monolayers, ΔT / ΔH = 22 K/T. Our results suggest that thin films of Tb are a promising material for magnetocaloric effect devices for applications at intermediate temperatures.

  9. Some physical properties of ZnO thin films prepared by RF sputtering technique

    Energy Technology Data Exchange (ETDEWEB)

    Ekem, N.; Korkmaz, S.; Pat, S.; Cetin, E.N.; Ozmumcu, M. [Eskisehir Osmangazi University, Physics Department, 26480 Meselik, Eskisehir (Turkey); Balbag, M.Z. [Eskisehir Osmangazi University, Education Faculty, Physics Education, 26480 Meselik, Eskisehir (Turkey)

    2009-06-15

    ZnO thin films were deposited with RF sputtering using pure Zn target. In order to generate oxidation process of Zn, Ar:O{sub 2} gas mixing in (9:1), (7:3) and (5:5) ratios of Ar:O{sub 2} was used. To characterize ZnO thin films thickness and transparency were measured using optical method, and refractive index and band gap energies were calculated. Electrical conductivity of the ZnO thin films was also determined. AFM images were used to determine surface morphology of produced ZnO thin films. (author)

  10. Optical characterization of niobium pentoxide thin films

    International Nuclear Information System (INIS)

    Pawlicka, A.

    1996-01-01

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

  11. Correlated dewetting patterns in thin polystyrene films

    CERN Document Server

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

    2003-01-01

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

  12. Tailored piezoelectric thin films for energy harvester

    NARCIS (Netherlands)

    Wan, X.

    2013-01-01

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

  13. Reliability growth of thin film resistors contact

    Directory of Open Access Journals (Sweden)

    Lugin A. N.

    2010-10-01

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

  14. Thermoviscoelastic models for polyethylene thin films

    DEFF Research Database (Denmark)

    Li, Jun; Kwok, Kawai; Pellegrino, Sergio

    2016-01-01

    This paper presents a constitutive thermoviscoelastic model for thin films of linear low-density polyethylene subject to strains up to yielding. The model is based on the free volume theory of nonlinear thermoviscoelasticity, extended to orthotropic membranes. An ingredient of the present approach...

  15. Incipient plasticity in metallic thin films

    NARCIS (Netherlands)

    Soer, W. A.; De Hosson, J. Th. M.; Minor, A. M.; Shan, Z.; Asif, S. A. Syed; Warren, O. L.

    2007-01-01

    The authors have compared the incipient plastic behaviors of Al and Al-Mg thin films during indentation under load control and displacement control. In Al-Mg, solute pinning limits the ability of dislocations to propagate into the crystal and thus substantially affects the appearance of plastic

  16. Thin film hydrous metal oxide catalysts

    Science.gov (United States)

    Dosch, Robert G.; Stephens, Howard P.

    1995-01-01

    Thin film (metal oxide catalysts are prepared by 1) synthesis of a hydrous metal oxide, 2) deposition of the hydrous metal oxide upon an inert support surface, 3) ion exchange with catalytically active metals, and 4) activating the hydrous metal oxide catalysts.

  17. Polyaniline. Thin films and colloidal dispersions

    Czech Academy of Sciences Publication Activity Database

    Stejskal, Jaroslav; Sapurina, I.

    2005-01-01

    Roč. 77, č. 5 (2005), s. 815-826 ISSN 0033-4545 R&D Projects: GA MŠk ME 539; GA AV ČR IAA4050313 Grant - others:IUPAC project 2002-019-1-400 Keywords : polyaniline * thin films * dispersions Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.679, year: 2005

  18. A ferroelectric transparent thin-film transistor

    NARCIS (Netherlands)

    Prins, MWJ; GrosseHolz, KO; Muller, G; Cillessen, JFM; Giesbers, JB; Weening, RP; Wolf, RM

    1996-01-01

    Operation is demonstrated of a field-effect transistor made of transparant oxidic thin films, showing an intrinsic memory function due to the usage of a ferroelectric insulator. The device consists of a high mobility Sb-doped n-type SnO2 semiconductor layer, PbZr0.2Ti0.8Os3 as a ferroelectric

  19. Flexoelectricity in barium strontium titanate thin film

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Seol Ryung; Huang, Wenbin; Yuan, Fuh-Gwo; Jiang, Xiaoning, E-mail: xjiang5@ncsu.edu [Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Shu, Longlong [Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Electronic Materials Research Laboratory, International Center for Dielectric Research, Xi' an Jiao Tong University, Xi' an, Shaanxi 710049 (China); Maria, Jon-Paul [Department of Material Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2014-10-06

    Flexoelectricity, the linear coupling between the strain gradient and the induced electric polarization, has been intensively studied as an alternative to piezoelectricity. Especially, it is of interest to develop flexoelectric devices on micro/nano scales due to the inherent scaling effect of flexoelectric effect. Ba{sub 0.7}Sr{sub 0.3}TiO{sub 3} thin film with a thickness of 130 nm was fabricated on a silicon wafer using a RF magnetron sputtering process. The flexoelectric coefficients of the prepared thin films were determined experimentally. It was revealed that the thin films possessed a transverse flexoelectric coefficient of 24.5 μC/m at Curie temperature (∼28 °C) and 17.44 μC/m at 41 °C. The measured flexoelectric coefficients are comparable to that of bulk BST ceramics, which are reported to be 10–100 μC/m. This result suggests that the flexoelectric thin film structures can be effectively used for micro/nano-sensing devices.

  20. Flexoelectricity in barium strontium titanate thin film

    International Nuclear Information System (INIS)

    Kwon, Seol Ryung; Huang, Wenbin; Yuan, Fuh-Gwo; Jiang, Xiaoning; Shu, Longlong; Maria, Jon-Paul

    2014-01-01

    Flexoelectricity, the linear coupling between the strain gradient and the induced electric polarization, has been intensively studied as an alternative to piezoelectricity. Especially, it is of interest to develop flexoelectric devices on micro/nano scales due to the inherent scaling effect of flexoelectric effect. Ba 0.7 Sr 0.3 TiO 3 thin film with a thickness of 130 nm was fabricated on a silicon wafer using a RF magnetron sputtering process. The flexoelectric coefficients of the prepared thin films were determined experimentally. It was revealed that the thin films possessed a transverse flexoelectric coefficient of 24.5 μC/m at Curie temperature (∼28 °C) and 17.44 μC/m at 41 °C. The measured flexoelectric coefficients are comparable to that of bulk BST ceramics, which are reported to be 10–100 μC/m. This result suggests that the flexoelectric thin film structures can be effectively used for micro/nano-sensing devices.

  1. 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

  2. Functional planar thin film optical waveguide lasers

    Czech Academy of Sciences Publication Activity Database

    Jelínek, Miroslav

    2012-01-01

    Roč. 9, č. 2 (2012), 91-99 ISSN 1612-2011 R&D Projects: GA ČR(CZ) GAP106/10/1477 Institutional research plan: CEZ:AV0Z10100522 Keywords : waveguide laser * planar waveguides * thin films * pulsed laser deposition * optical waveguides * laser materials Subject RIV: BH - Optics, Masers, Lasers Impact factor: 7.714, year: 2012

  3. Low Cost High Performance Zinc Antimonide Thin Films for Thermoelectric Applications

    DEFF Research Database (Denmark)

    Sun, Ye; Christensen, Mogens; Johnsen, Simon

    2012-01-01

    Zinc antimonide thin films with high thermoelectric performance are produced by a simple sputtering method. The phase-pure Zn4Sb3 and ZnSb thin films fulfill the key requirements for commercial TE power generation: cheap elements, cheap fabrication method, high performance and thermal stability...

  4. Dielectric loss of strontium titanate thin films

    Science.gov (United States)

    Dalberth, Mark Joseph

    1999-12-01

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

  5. Gravitationally driven drainage of thin films

    Science.gov (United States)

    Naire, Shailesh

    In this thesis we develop theory for an experiment done by Snow and coworkers at Dow Corning that involves a vertically-oriented, thinned polyurethane film with silicone surfactant, draining under gravity. We present the mathematical formulation for a 1+1- and 2+1-dimensional model to study the evolution of a vertically-oriented thin liquid film draining under gravity when there is an insoluble surfactant with finite surface viscosity on its free surface. This formulation has all the ingredients that include: surface tension, gravity, surface viscosity, the Marangoni effect, convective and diffusive surfactant transport; essential to describe the behavior of a vertical draining film with surfactant. We study a hierarchy of mathematical models with increasing complexity starting with the flat film model where gravity balances viscous shear and surface tension is neglected, this is generalized to include surface tension. We further generalize to incorporate variable surface viscosity and more complicated constitutive laws for surface tension as a function of surfactant concentration. Lubrication theory is employed to derive three coupled nonlinear partial differential equations (PDEs) describing the free surface shape, a component of surface velocity and the surfactant transport at leading order. A large surface viscosity limit recovers the tangentially-immobile model; for small surface viscosity, the film is mobile. Transition from a mobile to an immobile film is observed for intermediate values of surface viscosity and Marangoni number. The above models reproduce a number of features observed in experiments, these include film shapes and thinning rates which can be correlated to experiment. The 2+1-dimensional model for simplified surface properties has also been studied. Numerical experiments were performed to understand the stability of the system to perturbations across the film. An instability was seen in the mobile case; this was caused by a competition

  6. 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.

  7. Study of zinc oxide thin film characteristics

    Directory of Open Access Journals (Sweden)

    Johari Shazlina

    2017-01-01

    Full Text Available This paper presents the characterization of ZnO thin films with the thickness of 8nm, 30nm, and 200nm. The thin films were prepared using sol-gel method and has been deposited onto different substrate of silicon wafer, glass and quartz. The thin films were annealed at 400, 500 and 600°C. By using UV-Vis, the optical transmittance measurement were recorded by using a single beam spectrophotometer in the wavelength 250nm to 800nm. However, the transmittance in the visible range is hardly influenced by the film thickness, substrate used and annealed temperature and the averages are all above 80%. On surface morphology observed by AFM and FESEM, the results show that the increase of film thickness and annealed temperature will increase the mean grain size, surface-to-volume ration and RMS roughness. Besides that, higher annealing temperature cause the crystalline quality to gradually improve and the wurtzite structure of ZnO can be seen more clearly. Nonetheless, the substrate used had no effect on surface morphology, yet the uniformity of deposition on silicon wafer is better than glass and quartz.

  8. Practical design and production of optical thin films

    CERN Document Server

    Willey, Ronald R

    2002-01-01

    Fundamentals of Thin Film Optics and the Use of Graphical Methods in Thin Film Design Estimating What Can Be Done Before Designing Fourier Viewpoint of Optical Coatings Typical Equipment for Optical Coating Production Materials and Process Know-How Process Development Monitoring and Control of Thin Film Growth Appendix: Metallic and Semiconductor Material Graphs Author IndexSubject Index

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

    Indian Academy of Sciences (India)

    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 and bulk hosts are also discussed. Keywords. Alkali metal; thin films; magnetism; density functional ...

  10. Optical and electrical properties of nickel xanthate thin films

    Indian Academy of Sciences (India)

    Keywords. Nickel xanthate thin film; organometallic thin film; chemical bath deposition. Abstract. Nickel xanthate thin films (NXTF) were successfully deposited by chemical bath deposition, on to amorphous glass substrates, as well as on - and -silicon, indium tin oxide and poly(methyl methacrylate). The structure of the ...

  11. Electrochemical fabrication of nanoporous polypyrrole thin films

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-04-30

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

  12. Physical-chemical characterization and biological assessment of simple and lithium-doped biological-derived hydroxyapatite thin films for a new generation of metallic implants

    Science.gov (United States)

    Popescu, A. C.; Florian, P. E.; Stan, G. E.; Popescu-Pelin, G.; Zgura, I.; Enculescu, M.; Oktar, F. N.; Trusca, R.; Sima, L. E.; Roseanu, A.; Duta, L.

    2018-05-01

    We report on the synthesis by PLD of simple and lithium-doped biological-origin hydroxyapatite (HA) films. The role of doping reagents (Li2CO3, Li3PO4) on the morphology, structure, chemical composition, bonding strength and cytocompatibility of the films was investigated. SEM investigations of the films evidenced a surface morphology consisting of particles with mean diameters of (5-7) μm. GIXRD analyses demonstrated that the synthesized structures consisted of HA phase only, with different degrees of crystallinity, mainly influenced by the doping reagent type. After only three days of immersion in simulated body fluid, FTIR spectra showed a remarkable growth of a biomimetic apatitic film, indicative of a high biomineralization capacity of the coatings. EDS analyses revealed a quasi-stoichiometric target-to-substrate transfer, the values inferred for the Ca/P ratio corresponding to a biological apatite. All synthesized structures displayed a hydrophilic behavior, suitable for attachment of osteoblast cells. In vitro cell viability tests showed that the presence of Li2CO3 and Li3PO4 as doping reagents promoted the hMSC growth on film surfaces. Taking into consideration these enhanced characteristics, corroborated with a low fabrication cost generated by sustainable resources, one should consider the lithium-doped biological-derived materials as promising prospective solutions for a next generation of coated implants with rapid osteointegration.

  13. Thin film diamond microstructure applications

    Science.gov (United States)

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

    1991-01-01

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

  14. Pulsed laser deposition of high Tc superconducting thin films

    International Nuclear Information System (INIS)

    Singh, R.K.; Narayan, J.

    1990-01-01

    This paper reports on the pulsed laser evaporation (PLE) technique for deposition of thin films characterized by a number of unique properties. Based on the experimental characteristics, a theoretical model is developed which considers the formation and anisotropic three dimensional expansion of the laser generated plasma. This model explains most of the experimental features observed in PLE. We have also employed the PLE technique for in-situ fabrication of YBa 2 Cu 3 O 7 superconducting thin films on different substrates in the temperature range of 500--650 degrees C. At temperatures below 600 degrees C, a biased interposing ring between the substrate and the target was found to significantly improve the superconducting properties. The minimum ion channeling yields were between 3--3.5% for films deposited on (100) SrTiO 3 and (100) LaAlO 3 substrates

  15. Evidence for surface-generated photocurrent in (Bi,Sb)2Se3and(Bi,Sb)2Te3 thin films

    Science.gov (United States)

    Pan, Yu; Richardella, Anthony; Yao, Bing; Lee, Joon Sue; Flanagan, Thomas; Kandala, Abhinav; Samarth, Nitin; Yeats, Andrew; Mintun, Peter; Awschalom, David

    2015-03-01

    Illumination with circularly polarized light is known produce a helicity-dependent photocurrent in topological insulators such as Bi2Se3 [e.g. Nature Nanotech. 7, 96 (2012)]. However, the exact origin of this effect is still unclear since it is observed with photons well above the bulk band gap. We report measurements of the polarization-dependent photocurrent in a series of (Bi,Sb)2Se3 thin films with different carrier concentrations and find that the photocurrent is enhanced as we increase the population of the surface states. This finding is supported by a study of helicity-dependent photocurrents in back-gated (Bi,Sb)2Te3 thin films, where the chemical potential is varied electrostatically. By illuminating our samples at different wavelengths, we show that the helicity-dependent photocurrent is enhanced when the photon energy approaches the energy difference between the lowest and first excited (unoccupied) topological surface states. This leads us to attribute the helicity-dependent photocurrent in topological insulators to optical excitations between these two spin-textured surface states. We will also discuss experiments imaging the spatial variation of these helicity-dependent photocurrents. This work is supported by ONR.

  16. Flexible magnetic thin films and devices

    Science.gov (United States)

    Sheng, Ping; Wang, Baomin; Li, Runwei

    2018-01-01

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

  17. Nanocomposite thin films for triggerable drug delivery.

    Science.gov (United States)

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

    2018-05-01

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

  18. Thin-film cadmium telluride solar cells

    Science.gov (United States)

    Chu, T. L.

    1987-10-01

    Cadmium telluride, with a room-temperature band-gap energy of 1.5 eV, is a promising thin-film photovoltaic material. The major objective of this research has been to demonstrate thin-film CdTe heterojunction solar cells with a total area greater than 1 sq cm and photovoltaic efficiencies of 13 percent or more. Thin-film p-CdTe/CdS/SnO2:F/glass solar cells with an AM1.5 efficiency of 10.5 percent have been reported previously. This report contains results of work done on: (1) the deposition, resistivity control, and characterization of p-CdTe films by the close-spaced sublimation process; (2) the deposition of large-band-gap window materials; (3) the electrical properties of CdS/CdTe heterojunctions; (4) the formation of stable, reproducible, ohmic contacts (such as p-HgTe) to p-CdTe; and (5) the preparation and evaluation of heterojunction solar cells.

  19. Nanostructured thin film coatings with different strengthening effects

    Directory of Open Access Journals (Sweden)

    Panfilov Yury

    2017-01-01

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

  20. Thin film bismuth iron oxides useful for piezoelectric devices

    Science.gov (United States)

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

    2016-05-31

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

  1. Investigation of electrodeposited cuprous oxide thin films

    Science.gov (United States)

    Mortensen, Emma L.

    This dissertation focuses on improvements to electrodeposited cuprous oxide as a candidate for the absorber layer for a thin film solar cell that could be integrated into a mechanical solar cell stack. Cuprous oxide (Cu2O) is an earth abundant material that has a bandgap of 2 eV with absorption coefficients around 102-106 cm-1. This bandgap is not optimized for use as a single-junction solar cell, but could be ideal for use in a tandem solar cell device. The theoretical efficiency of a material with a bandgap of 2.0 eV is 20%. The greatest actual efficiency that has been achieved for a Cu2O solar cell is only 8.1%. For the present work the primary focus has been on improving the microstructure of the absorber layer film. The Cu2O films were fabricated using electrodeposition. A seeding layer was developed using gold (Au); which was manipulated into nano-islands and used as the substrate for the Cu2O electrodeposition. The films were characterized and compared to determine the growth mechanism of each film using scanning electron microscopy (SEM). X-ray diffraction (XRD) was used to establish and compare the chemical phases that were present in each of the films. The crystal structure of the Cu2O film grown on gold was explored using transmission electron microscopy (TEM), and this helped confirm the effect that the gold had on the growth of Cu2O. The Tauc method was then used to determine the bandgap of the films of Cu2O grown on both substrates and this showed that the Au based Cu2O film was a superior film. Electrical tests were also completed using a solar simulator and this established that the film grown on gold exhibited photoconductivity that was not seen on the film without gold. In addition, for this thesis, a method for depositing an n-type Cu2O film, based on a Cu-metal solution-boiling process, was investigated. Three forms of copper were tested: a sheet of copper, electrodeposited copper, and sputtered copper. The chemical phases were observed using

  2. Electrical evaluation of crack generation in SiN{sub x} and SiO{sub x}N{sub y} thin-film encapsulation layers for OLED displays

    Energy Technology Data Exchange (ETDEWEB)

    Park, Eun Kil [Department of Materials Science and Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Display Research Center, Samsung Display Co., Ltd., Yongin-City, Gyeonggi-Do 446-711 (Korea, Republic of); Kim, Sungmin [Department of Materials Science and Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Heo, Jaeyeong, E-mail: jheo@jnu.ac.kr [Department of Materials Science and Engineering, and the Optoelectronics Convergence Research Center, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Kim, Hyeong Joon, E-mail: thinfilm@snu.ac.kr [Department of Materials Science and Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

    2016-05-01

    Highlights: • Crack generation in encapsulation layers were detected by leakage current. • Atomic concentration of SiO{sub x}N{sub y} films affected the bending reliability. • The shapes of the crack tips were affected by the stoichiometry of the SiO{sub x}N{sub y} films. - Abstract: By measuring leakage current density, we detected crack generation in silicon nitride (SiN{sub x}) and silicon oxynitride (SiO{sub x}N{sub y}) thin-film encapsulation layers, and correlated with the films’ water vapor permeability characteristics. After repeated bending cycles, both the changes in water vapor transmission rate and leakage current density were directly proportional to the crack density. Thick SiN{sub x} films had better water vapor barrier characteristics in their pristine state, but cyclic loading led to fast failure. Varying the atomic concentration of the SiO{sub x}N{sub y} films affected their bending reliability. We attribute these differences to changes in the shape of the crack tip as the oxygen content varies.

  3. Deposition and characterization of CuInS2 thin films deposited over copper thin films

    Science.gov (United States)

    Thomas, Titu; Kumar, K. Rajeev; Kartha, C. Sudha; Vijayakumar, K. P.

    2015-06-01

    Simple, cost effective and versatile spray pyrolysis method is effectively combined with vacuum evaporation for the deposition of CuIns2 thin films for photovoltaic applications. In the present study In2s3 was spray deposited over vacuum evaporated Cu thin films and Cu was allowed to diffuse in to the In2S3 layer to form CuInS2. To analyse the dependence of precursor volume on the formation of CuInS2 films structural, electrical and morphological analzes are carried out. Successful deposition of CuInS2thin films with good crystallinity and morphology with considerably low resistivity is reported in this paper.

  4. 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

  5. Optical thin films and coatings from materials to applications

    CERN Document Server

    Flory, Francois

    2013-01-01

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

  6. Thin Films for X-ray Optics

    Science.gov (United States)

    Conley, Raymond

    Laue lens, however my advancements in MLL fabrication technology led to new generations of deposition instruments that were better suited. In order to re-purpose the APS Rotary Deposition System, a concept to upgrade the machine with a suborbital planetary is discussed. The APS Modular Deposition System (MDS) is the state of the art instrument that was designed to keep APS at the forefront of x-ray optics technology for the foreseeable future. By including flexibility in the design, the machine is ideally suited for research on all types of multilayers and thin-films for x-ray optics applications. A new method for in-situ surface metrology is presented which relies on the infrastructure provided by the MDS. The chapter concludes with discussion on several types of reflective multilayers that span a broad range of x-ray wavelengths, from soft x-rays (below 5-10 keV) to hard x-rays (above 5-10keV). A method for fabrication of precision elliptically-figured mirrors called profile coating (conceived at the APS) is covered in Chapter 3. Profile-coating is a technique where a specially shaped mask is designed to partially obscure the sputtering source in order to produce a coating with a specially defined film thickness profile perpendicular to substrate translation. Source shape modeling and mask calculation is presented. Initially, Au was used as the filler material for profile coating, however I found that Pt offered better performance. Rh has also been used to fabricate profile-coated KB mirrors. Performance and commissioning results for the APS profile-coating deposition system (another machine designed by myself) is included. Chapter 4 covers my work on multilayer Laue lens. Motivation and current status are presented, and the nomenclature we devised to name the various MLL types is listed. Following this, a theoretical overview is provided. Important advancements I have spearhead in this field are included, such as the introduction of metal silicides, reactive

  7. Substrate heater for thin film deposition

    Science.gov (United States)

    Foltyn, Steve R.

    1996-01-01

    A substrate heater for thin film deposition of metallic oxides upon a target substrate configured as a disk including means for supporting in a predetermined location a target substrate configured as a disk, means for rotating the target substrate within the support means, means for heating the target substrate within the support means, the heating means about the support means and including a pair of heating elements with one heater element situated on each side of the predetermined location for the target substrate, with one heater element defining an opening through which desired coating material can enter for thin film deposition and with the heating means including an opening slot through which the target substrate can be entered into the support means, and, optionally a means for thermal shielding of the heating means from surrounding environment is disclosed.

  8. Quantifying clustering in disordered carbon thin films

    International Nuclear Information System (INIS)

    Carey, J.D.

    2006-01-01

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

  9. Thin film photovoltaic panel and method

    Science.gov (United States)

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

    1991-06-11

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

  10. Domain switching of fatigued ferroelectric thin films

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  11. Thin film metallization for micro-bimetallic actuators

    Science.gov (United States)

    Gorrell, Jonathan Frank

    In this study, eleven different thin film metallization systems were evaluated for use in micro-bimetallic actuators for microelectromechanical structures. These films were evaporated or sputtered onto silicon wafers. The film stress and stress relaxation were determined by measuring changes in the wafer curvature. The phases and micro-structure of these films were evaluated with, scanning electron microscopy, transmission electron microscopy, Auger electron spectroscopy, electron probe micro-analysis, X-ray diffraction and line shape analysis, and atomic force microscopy. Bimetallic actuator may be operated to generate either force or displacement. The displacement mode is dominated by the coefficient of thermal expansion while the force mode is a function of both Young's modulus and coefficient of thermal expansion of the active layer material. In both modes the maximum displacement or force is determined by the material's yield strength. A figure of merit was developed to aid in material selection. The 5052 aluminum alloy films showed that solid solution strengthening can double the yield strength of a thin film. The T201 aluminum alloy films showed that precipitates can increase yield strength by 2.5 times. The 2090 alloy film oxidized during the first heating. Based on isothermal stress relaxation data and changes in the micro-structure of the 5052 and T201 alloy thin films, two mechanisms involving logarithmic creep have been postulated to cause stress relaxation. One mechanism is movement of dislocations in slip systems that terminate at the surface while the other is dislocations moving in slip systems that terminate at grain boundaries. Copper gold intermetallics films oxidized and plastically deformed before the order-disorder transformation occurred, but showed that ordered intermetallics have a lower stress relaxation rate than the solid solution phase. The Alsb3Ti films showed no stress relaxation at 450sp°C, plastically deformed only above 500sp

  12. Structural and nonlinear optical properties of as-grown and annealed metallophthalocyanine thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zawadzka, A., E-mail: azawa@fizyka.umk.pl [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun (Poland); Płóciennik, P.; Strzelecki, J. [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun (Poland); Pranaitis, M.; Dabos-Seignon, S.; Sahraoui, B. [LUNAM Université, Université d' Angers, CNRS UMR 6200, Laboratoire MOLTECH-Anjou, 2 bd Lavoisier, 49045 Angers cedex (France)

    2013-10-31

    The paper presents the Third Harmonic Generation investigation of four metallophtalocyanine (MPc, M = Cu, Co, Mg and Zn) thin films. The investigated films were fabricated by Physical Vapor Deposition in high vacuum onto quartz substrates. MPc thin films were annealed after fabrication in ambient atmosphere for 12 h at the temperature equal to 150 °C or 250 °C. The Third Harmonic Generation spectra were measured to investigate the nonlinear optical properties and their dependence on the structure of the thin film after the annealing process. This approach allowed us to determine the electronic contribution of the third-order nonlinear optical susceptibility χ{sup <3>}{sub elec} of these MPc films and to investigate two theoretical models for explanation of the observed results. We find that the annealing process significantly changes the optical and structural properties of MPc thin films. - Highlights: • Metallophtalocyanine thin films were grown by Physical Vapor Deposition technique. • MPcs thin films were undergone an annealing process in ambient atmosphere. • Third Harmonic spectra were measured to investigate nonlinear optical properties. • The third order nonlinear optical susceptibility χ{sup <3>}{sub elec} was determined. • We report changing both nonlinear optical and structural properties of thin films.

  13. Thin films for gas sensors

    Science.gov (United States)

    Pires, Jose Miguel Alves Correia

    Nos ultimos anos tem-se assistido a um aumento dos investimentos na investigacao de novos materiais para aplicacao em sensores. Apesar de ja existir um bom numero de dispositivos explorados comercialmente, muitas vezes, quer devido aos elevados custos de producao, quer devido a uma crescente exigencia do ponto de vista das caracteristicas de funcionamento, continua a ser necessario procurar novos materiais ou novas formas de producao que permitam baixar os custos e melhorar o desempenho dos dispositivos. No campo dos sensores de gases tem-se verificado continuos avancos nos ultimos anos. Continua todavia a ser necessario conhecer melhor, tanto os processos de producao dos materiais, como os mecanismos que regulam a sensibilidade dos dispositivos aos gases, de modo a orientar adequadamente a investigacao dos novos materiais, nomeadamente no que se refere a optimizacao dos parâmetros que nao satisfazem ainda os requisitos do mercado. Um dos materiais que tem mostrado melhores qualidades para aplicacao em sensores de gases de tipo resistivo e o dioxido de estanho. Este material tem sido produzido sob diversas formas e usando diferentes tecnicas, como sejam: sol-gel [1], pulverizacao catodica (sputtering) por magnetrao [2-4], sinterizacao de pos [5, 6], ablacao laser [7] ou RGTO [8]. Os resultados obtidos revelam que as caracteristicas dos dispositivos sao muito dependentes das tecnicas usadas na sua producao. A deposicao usando sputtering reactivo por magnetrao e uma tecnica que permite obter filmes finos de oxido de estanho com diferentes caracteristicas, quer do ponto de vista da estrutura, quer da composicao, e por isso, tambem, com diferentes sensibilidades aos gases. No âmbito deste trabalho, foram produzidos filmes de SnO2 usando sputtering DC reactivo com diferentes condicoes de deposicao. Os substratos usados foram lâminas de vidro e o alvo foi estanho com 99.9% de pureza. Foi estudada a influencia da atmosfera de deposicao, da pressao parcial do O2, da

  14. Ordered Nanomaterials Thin Films via Supported Anodized Alumina Templates

    Directory of Open Access Journals (Sweden)

    Mohammed eES-SOUNI

    2014-10-01

    Full Text Available Supported anodized alumina template films with highly ordered porosity are best suited for fabricating large area ordered nanostructures with tunable dimensions and aspect ratios. In this paper we first discuss important issues for the generation of such templates, including required properties of the Al/Ti/Au/Ti thin film heterostructure on a substrate for high quality templates. We then show examples of anisotropic nanostructure films consisting of noble metals using these templates, discuss briefly their optical properties and their applications to molecular detection using surface enhanced Raman spectroscopy. Finally we briefly address the possibility to make nanocomposite films, exemplary shown on a plasmonic-thermochromic nanocomposite of VO2-capped Au-nanorods.

  15. The carbonization of thin polyaniline films

    Czech Academy of Sciences Publication Activity Database

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

    2012-01-01

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

  16. Thin film interfaces for microelectrochemical sensors

    Science.gov (United States)

    Tvarozek, Vladimir; Ivanic, Rastislav; Jakubec, Andrej; Novotny, Ivan; Rehacek, Vlastimil

    2001-09-01

    Planar microelectrochemical chips with thin film electodes of different shapes and arrangement, have been developed and fabricated. Micro electrochemical cell with closely vertically spaced electrodes allows to exploit the effect of redox recycling and an increase of collection efficiency for a high current amplification. PC simulations of electro- mechanical properties of sl-BLM is useful tool for evaluation and prediction of BLM behavior. Non-symmetric microelectrode arrays were designed and fabricated for electrical monitoring of human skin.

  17. Thin-film silicon solar cell technology

    Czech Academy of Sciences Publication Activity Database

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

    2004-01-01

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

  18. Mesoscale simulations of confined Nafion thin films

    OpenAIRE

    Vanya, Peter; Sharman, Jonathan; Elliott, James A.

    2017-01-01

    The morphology and transport properties of thin films of the ionomer Nafion, with thicknesses on the order of the bulk cluster size, have been investigated as a model system to explain the anomalous behaviour of catalyst/electrode-polymer interfaces in membrane-electrode assemblies. We have employed dissipative particle dynamics (DPD) to investigate the interaction of water and fluorocarbon chains with carbon and quartz as confining materials for a wide range of operational water contents and...

  19. Mesoscale simulations of confined Nafion thin films

    OpenAIRE

    Vanya, Peter; Sharman, J; Elliott, James Arthur

    2017-01-01

    The morphology and transport properties of thin films of the ionomer Nafion, with thicknesses on the order of the bulk cluster size, have been investigated as a model system to explain the anomalous behaviour of catalyst/electrode-polymer interfaces in membrane electrode assemblies. We have employed dissipative particle dynamics (DPD) to investigate the interaction of water and fluorocarbon chains with carbon and quartz as confining materials for a wide range of operational water contents and...

  20. Optical characterization of thin solid films

    CERN Document Server

    Ohlídal, Miloslav

    2018-01-01

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

  1. Resonance-type thickness dependence of optical second-harmonic generation in thin films of the topological insulator B i2S e3

    Science.gov (United States)

    Glinka, Yuri D.; Babakiray, Sercan; Johnson, Trent A.; Holcomb, Mikel B.; Lederman, David

    2015-05-01

    Optical second-harmonic generation (SHG) has been measured in a reflection from the nanometer-thick films (6 to 40 nm) of the topological insulator B i2S e3 using 1.51 eV (820 nm) Ti:Sapphire laser photons and revealed a strong dependence of the integral SHG intensity on the film thickness. The integral SHG intensity was determined by area integration of the SHG rotational anisotropy patterns measured for different input-output light polarization geometries. A ˜100-fold enhancement of the integral SHG intensity with decreasing film thickness has been suggested to result from the dc-electric-field-induced SHG (EFISHG) effects. Two sources of dynamically created dc electric field were proposed: (i) the capacitor-type dc electric field that gradually increases with decreasing film thickness from 40 to 6 nm due to a dynamical imbalance of photoexcited long-lived carriers between the opposite-surface Dirac surface states and (ii) a dc electric field associated with a nonlinearly excited Dirac plasmon, which is responsible for the resonant enhancement of the integral SHG intensity for the 10 nm thick film with a Lorentz-shaped resonance of ˜1.6 nm full width at half maximum. In addition to the general SHG enhancement trends with decreasing film thickness, a relative decrease of the out-of-plane contribution with respect to the in-plane contribution was observed. Using a theoretical treatment of the measured SHG rotational anisotropy patterns, this effect has been suggested to result from the joint contributions of the linear and quadratic dc electric field effects to the EFISHG response.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  3. Molecular tailoring of interfaces for thin film on substrate systems

    Science.gov (United States)

    Grady, Martha Elizabeth

    to use more conventional interfacial fracture testing techniques. Self-assembled monolayers (SAMs) provide an enabling platform for molecular tailoring of the chemical and physical properties of an interface in an on-demand fashion. The SAM end-group functionality is systematically varied and the corresponding effect on interfacial adhesion between a transfer printed gold (Au) film and a fused silica substrate is measured. SAMs with four different end groups are investigated: methyl, amine, bromine and thiol. In addition to these four end groups, mixed monolayers of increasing molar ratio of thiol to methyl SAMs in solution are investigated. There is a strong dependence of interfacial chemistry on the adhesion strength of Au films. In addition to the chemical functionality of the SAM, surface roughness of the underlying substrate also has a significant impact on the interfacial strength. Thin films of mechanochemically active polymer are subjected to laser-generated, high amplitude acoustic pulses. Stress wave propagation through the film produces large amplitude stresses (>100 MPa) in short time frames (10-20 ns), leading to very high strain-rates (ca. 107-108 s -1). The polymer system, spiropyran (SP)- linked polystyrene (PS), undergoes a force-induced chemical reaction causing fluorescence and color change. Activation of SP is evident via a fluorescence signal in thin films subject to high strain-rates. In contrast, quasi-static loading of bulk SP-linked PS samples failed to result in SP activation. Mechanoresponsive coatings have potential to indicate deformation under shockwave loading conditions. In addition to SP-linked polymer films, the activation of spiropyran interfacial molecules with different side groups is characterized as they adsorb onto a SAM platform with preferential amine terminating chemistry. The reactivity of SP monolayers due to UV irradiation is evaluated by water contact angle goniometry and fluorescence spectroscopy. Side groups on the

  4. Aluminum nitride and nanodiamond thin film microstructures

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  5. Multiferroic RMnO3 thin films

    Science.gov (United States)

    Fontcuberta, Josep

    2015-03-01

    Multiferroic materials have received an astonishing attention in the last decades due to expectations that potential coupling between distinct ferroic orders could inspire new applications and new device concepts. As a result, a new knowledge on coupling mechanisms and materials science has dramatically emerged. Multiferroic RMnO3 perovskites are central to this progress, providing a suitable platform to tailor spin-spin and spin-lattice interactions. With views towards applications, the development of thin films of multiferroic materials have also progressed enormously and nowadays thin-film manganites are available, with properties mimicking those of bulk compounds. Here we review achievements on the growth of hexagonal and orthorhombic RMnO3 epitaxial thin films and the characterization of their magnetic and ferroelectric properties, we discuss some challenging issues, and we suggest some guidelines for future research and developments. En ce qui concerne les applications, le développement de films minces de matériaux multiferroïques a aussi énormément progressé, et de nos jours des films minces de manganites avec des propriétés similaires à celles des matériaux massifs existent. Nous passons en revue ici les résultats obtenus dans le domaine de la croissance de couches minces épitaxiés de RMnO3 hexagonal et orthorhombique et de la caractérisation de leurs propriétés magnétiques et ferroélectriques. Nous discutons certains enjeux et proposons quelques idées pour des recherches et développements futurs.

  6. Wide-bandgap CIAS thin-film photovoltaics with transparent back contacts for next generation single and multi-junction devices

    International Nuclear Information System (INIS)

    Woods, Lawrence M.; Kalla, Ajay; Gonzalez, Damian; Ribelin, Rosine

    2005-01-01

    This paper discusses the performance, testing, and problems of copper indium aluminum diselenide (CIAS) thin-film devices with CIAS co-evaporated in a large-area moving substrate deposition system on transparent back contact technology. The CIAS alloy is being developed for use as a wide-bandgap radiation-resistant semiconductor for application as both a high-voltage single-junction photovoltaic (PV) cell using low-cost thin-films on lightweight flexible substrates, and as a top cell in efficient two-terminal monolithic tandem (multi-junction) PV cells. After significant development, it appears that conventionally formed CIAS devices experience a drop-off in performance with CIAS bandgaps above 1.5 eV, in addition to decreased zero bias depletion widths, and increased J L (V) effects with increasing CIAS bandgap. However, the performance drop-off is above the single-junction optimum bandgap, and higher-bandgap devices have not been tested with better-matched buffer layers. This paper also discusses CIAS devices with transparent back contacts. A wide-bandgap CIAS device with infra-red (IR) transparent back contacts and substrates can offer better performance over standard CIGS devices by being better tuned to the optimum bandgap for AM0 solar spectrum, reduced ohmic losses, and temperature dependencies compared to that typical of low-bandgap CIS alloys, reduced operating temperature with better IR transparency, the option of backside light collection with a suitable visibly transparent substrate, and is a precursor for use as a top cell in a monolithic tandem device configuration. CIAS devices with transparent back contacts show no loss in performance compared to standard Mo back contacts

  7. Thin-film calorimetry. In-situ characterization of materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Omelcenko, Alexander; Wulfmeier, Hendrik; Albrecht, Daniel; Fritze, Holger [Clausthal Univ. of Technology, Goslar (Germany). Inst. of Energy Research and Physical Technologies; El Mofid, Wassima; Ivanov, Svetlozar; Bund, Andreas [Ilmenau Univ. of Technology (Germany). Dept. of Electrochemistry

    2017-11-15

    Thin-film calorimetry allows for qualitative and quantitative in-situ analysis of thermodynamic properties of thin films and thin-film systems from room temperature up to 1000 C. It is based on highly sensitive piezoelectric langasite resonators which serve simultaneously as planar temperature sensors and substrates for the films of interest. Generation or consumption of heat during phase transformations of the films cause deviations from the regular course of the resonance frequency. Thermodynamic data such as phase transformation temperatures and enthalpies are extracted from these deviations. Thin-film calorimetry on Sn and Al thin films is performed to prove the concept. The results demonstrate high reproducibility of the measurement approach and are in agreement with literature data obtained by established calorimetric techniques. The calibration of the system is done in different atmospheres by application of defined heat pulses via heating structures. The latter replace the films of interest and simulate phase transformations to provide detailed analysis of the heat transfer mechanisms occurring in the measurement system. Based on this analysis, a data evaluation concept is developed. Application-relevant studies are performed on thin films of the lithium-ion battery materials NMC(A), NCA, LMO, and MoS{sub 2}. Their phase transformation temperatures and enthalpies are evaluated in oxidizing and reducing atmospheres. Furthermore, their thermodynamic stability ranges are presented. Finally, measurements on all-solid-state thin-film batteries during electrochemical cycling are performed. They demonstrate the suitability of the system for in-situ investigations.

  8. Multiferroicity in oxide thin films and heterostructures

    International Nuclear Information System (INIS)

    Glavic, Artur

    2012-01-01

    In this work a variety of different systems of transition metal oxides ABO 3 (perovskite materials, where B stands for a transition metal and A for a rare earth element) were produced as thin films and heterostructures and analyzed for the structural, magnetic and ferroelectric properties. For the epitaxial film preparation mostly pulse laser deposition (PLD) was applied. For one series high pressure oxide sputter deposition was used as well. The bulk multiferroics TbMnO 3 and DyMnO 3 , which develop their electric polarization due to a cycloidal magnetic order, have been prepared as single layers with thicknesses between 2 and 200 nm on YAlO 3 substrates using PLD and sputter deposition. The structural characterization of the surfaces and crystal structure where performed using X-ray reflectometry and diffraction, respectively. These yielded low surface roughness and good epitaxial growth. The magnetic behavior was macroscopically measured with SQUID magnetometry and microscopically with polarized neutron diffraction and resonant magnetic X-ray scattering. While all investigated samples showed antiferromagnetic order, comparable with the collinear magnetic phase of their bulk materials, only the sputter deposited samples exhibited the multiferroic low temperature cycloidal order. The investigation of the optical second harmonic generation in a TbMnO 3 sample could proof the presence of a ferroelectric order in the low temperature phase. The respective transition temperatures of the thin films have been very similar to those of the bulk materials. In contrast an increase in the rare earth ordering temperature has been observed, which reduces the Mn order slightly, an effect not known from bulk TbMnO 3 crystals. The coupling of the antiferromagnetic order in TbMnO 3 to ferromagnetic layers of LaCoO 3 was investigated in super-lattices containing 20 bilayers produced with PLD on the same substrates. The SQUID magnetometry yielded a strong influence of the

  9. 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.

  10. Thermal properties of methyltrimethoxysilane aerogel thin films

    Directory of Open Access Journals (Sweden)

    Leandro N. Acquaroli

    2016-10-01

    Full Text Available Aerogels are light and porous solids whose properties, largely determined by their nanostructure, are useful in a wide range of applications, e.g., thermal insulation. In this work, as-deposited and thermally treated air-filled silica aerogel thin films synthesized using the sol-gel method were studied for their thermal properties using the 3-omega technique, at ambient conditions. The thermal conductivity and diffusivity were found to increase as the porosity of the aerogel decreased. Thermally treated films show a clear reduction in thermal conductivity compared with that of as-deposited films, likely due to an increase of porosity. The smallest thermal conductivity and diffusivity found for our aerogels were 0.019 W m−1 K−1 and 9.8 × 10-9 m2 s−1. A model was used to identify the components (solid, gaseous and radiative of the total thermal conductivity of the aerogel.

  11. Deposition and characterization of ZnSe nanocrystalline thin films

    Science.gov (United States)

    Temel, Sinan; Gökmen, F. Özge; Yaman, Elif; Nebi, Murat

    2018-02-01

    ZnSe nanocrystalline thin films were deposited at different deposition times by using the Chemical Bath Deposition (CBD) technique. Effects of deposition time on structural, morphological and optical properties of the obtained thin films were characterized. X-ray diffraction (XRD) analysis was used to study the structural properties of ZnSe nanocrystalline thin films. It was found that ZnSe thin films have a cubic structure with a preferentially orientation of (111). The calculated average grain size value was about 28-30 nm. The surface morphology of these films was studied by the Field Emission Scanning Electron Microscope (FESEM). The surfaces of the thin films were occurred from small stacks and nano-sized particles. The band gap values of the ZnSe nanocrystalline thin films were determined by UV-Visible absorption spectrum and the band gap values were found to be between 2.65-2.86 eV.

  12. High performance thin-film composite forward osmosis membrane.

    Science.gov (United States)

    Yip, Ngai Yin; Tiraferri, Alberto; Phillip, William A; Schiffman, Jessica D; Elimelech, Menachem

    2010-05-15

    Recent studies show that osmotically driven membrane processes may be a viable technology for desalination, water and wastewater treatment, and power generation. However, the absence of a membrane designed for such processes is a significant obstacle hindering further advancements of this technology. This work presents the development of a high performance thin-film composite membrane for forward osmosis applications. The membrane consists of a selective polyamide active layer formed by interfacial polymerization on top of a polysulfone support layer fabricated by phase separation onto a thin (40 mum) polyester nonwoven fabric. By careful selection of the polysulfone casting solution (i.e., polymer concentration and solvent composition) and tailoring the casting process, we produced a support layer with a mix of finger-like and sponge-like morphologies that give significantly enhanced membrane performance. The structure and performance of the new thin-film composite forward osmosis membrane are compared with those of commercial membranes. Using a 1.5 M NaCl draw solution and a pure water feed, the fabricated membranes produced water fluxes exceeding 18 L m(2-)h(-1), while consistently maintaining observed salt rejection greater than 97%. The high water flux of the fabricated thin-film composite forward osmosis membranes was directly related to the thickness, porosity, tortuosity, and pore structure of the polysulfone support layer. Furthermore, membrane performance did not degrade after prolonged exposure to an ammonium bicarbonate draw solution.

  13. High Performance Thin-Film Composite Forward Osmosis Membrane

    KAUST Repository

    Yip, Ngai Yin

    2010-05-15

    Recent studies show that osmotically driven membrane processes may be a viable technology for desalination, water and wastewater treatment, and power generation. However, the absence of a membrane designed for such processes is a significant obstacle hindering further advancements of this technology. This work presents the development of a high performance thin-film composite membrane for forward osmosis applications. The membrane consists of a selective polyamide active layer formed by interfacial polymerization on top of a polysulfone support layer fabricated by phase separation onto a thin (40 μm) polyester nonwoven fabric. By careful selection of the polysulfone casting solution (i.e., polymer concentration and solvent composition) and tailoring the casting process, we produced a support layer with a mix of finger-like and sponge-like morphologies that give significantly enhanced membrane performance. The structure and performance of the new thin-film composite forward osmosis membrane are compared with those of commercial membranes. Using a 1.5 M NaCl draw solution and a pure water feed, the fabricated membranes produced water fluxes exceeding 18 L m2-h-1, while consistently maintaining observed salt rejection greater than 97%. The high water flux of the fabricated thin-film composite forward osmosis membranes was directly related to the thickness, porosity, tortuosity, and pore structure of the polysulfone support layer. Furthermore, membrane performance did not degrade after prolonged exposure to an ammonium bicarbonate draw solution. © 2010 American Chemical Society.

  14. Surface enhanced SHG from macrocycle, catenane and rotaxane thin films : experiments and theory.

    NARCIS (Netherlands)

    Arfaoui, I.; Bermudez, V.; De Nadai, C.; Jalkanen, J.-P.; Kajzar, F.; Leigh, D.A.; Lubomska, M.; Mendoza, S.M.; Niziol, J.; Rudolf, Petra; Zerbetto, F.; Grote, JG; Kaino, T; Kajzar, F

    2005-01-01

    Surface enhanced second harmonic generation experiments on supramolecules: macrocycles, catenanes and rotaxanes, monolayers and multilayers deposited by vacuum evaporation on silver layers are reported and described. The measurements show that the molecules are ordered in thin films. The highest

  15. A Homogenized Free Energy Model for Hysteresis in Thin-film Shape Memory Alloys

    National Research Council Canada - National Science Library

    Massad, Jordan E; Smith, Ralph C

    2004-01-01

    Thin-film shape memory alloys (SMAs) have become excellent candidates for microactuator fabrication in MEMS due to their capability to achieve very high work densities, produce large deformations, and generate high stresses...

  16. Thin film polycrystalline silicon photoelectric converter and fabricating method; Hakumaku takkesho shirikon koden henkan sochi oyobi sono seizo hoho

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, K. [Kobe (Japan); Suzuki, T. [Kobe (Japan); Yoshimi, M. [Kobe (Japan)

    1995-04-07

    This invention relates to a fabricating method for a thin film polycrystalline silicon photoelectric converter which has a large area and can be produced at low cost. Successive formation of mono-conductive polycrystalline silicon thin film and reverse conducting polycrystalline silicon thin film on a translucent substrate requires no vapor phase epitaxial growth, and the film formation temperature for silicon thin film can be lowered. Orientation of the monocrystalline silicon thin film to any of the surface bearings of (100), (111), and (110) results in the function of determining the orientation of the reverse conducting polycrystalline silicon thin film formed thereon. This orientation is effective to obtain excellent characteristics, and results in effective surface orientation of the entire power generating area. In addition, the supporting substrate and the surface protective film of the solar cell can be combined by orienting the translucent substrate side to the light incident side. 2 figs., 1 tab.

  17. 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

  18. Photoelectrochemical (PEC) studies on CdSe thin films ...

    Indian Academy of Sciences (India)

    TECS

    Abstract. Thin films of CdSe were deposited by potentiostatic mode on different substrates such as stainless steel, titanium and fluorine tin–oxide (FTO) coated glass using non-aqueous bath. The preparative parameters were optimized to get good quality CdSe thin films. These films were characterized by X-ray diffraction.

  19. Oriented growth of thin films of samarium oxide by MOCVD

    Indian Academy of Sciences (India)

    Unknown

    Infrared spectroscopic study reveals that films grown above 600°C are free of carbon. Keywords. MOCVD; thin films .... Simultaneous thermogravimetry and differential thermal analysis (TG/DTA) of the complex was carried ..... quality thin films of rare earth oxides by MOCVD, using the phenanthroline adducts of pentadionate ...

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

    Indian Academy of Sciences (India)

    In the present work, dynamics of a thin film spreading due to a thermocapillary stress is mod- eled within lubrication approximation. In microscale flows, the large surface to volume ratios allow interfacial stresses to exert a driving influence. This ability to drive thin film using thermo- capillary stress is used to spread film for ...

  1. Structural characterization of vacuum evaporated ZnSe thin films

    Indian Academy of Sciences (India)

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

  2. Investigations of Si Thin Films as Anode of Lithium-Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qingliu [Department of Chemical; Shi, Bing; Bareño, Javier; Liu, Yuzi; Maroni, Victor A.; Zhai, Dengyun; Dees, Dennis W.; Lu, Wenquan

    2018-01-22

    Amorphous silicon thin films having various thicknesses were investigated as a negative electrode material for lithium-ion batteries. Electrochemical characterization of the 20 nm thick thin silicon film revealed a very low first cycle Coulombic efficiency, which can be attributed to the silicon oxide layer formed on both the surface of the as-deposited Si thin film and the interface between the Si and the substrate. Among the investigated films, the 100 nm Si thin film demonstrated the best performance in terms of first cycle efficiency and cycle life. Observations from scanning electron microscopy demonstrated that the generation of cracks was inevitable in the cycled Si thin films, even as the thickness of the film was as little as 20 nm, which was not predicted by previous modeling work. However, the cycling performance of the 20 and 100 nm silicon thin films was not detrimentally affected by these cracks. The poor capacity retention of the 1 mu m silicon thin film was attributed to the delamination.

  3. The radiation response of mesoporous nanocrystalline zirconia thin films

    Energy Technology Data Exchange (ETDEWEB)

    Manzini, Ayelén M.; Alurralde, Martin A. [Comisión Nacional de Energía Atómica, Centro Atómico Constituyentes, Av. General Paz 1499, 1650 San Martin, Provincia de Buenos Aires (Argentina); Giménez, Gustavo [Instituto Nacional de Tecnología Industrial - CMNB, Av. General Paz 5445, 1650 San Martín, Provincia de Buenos Aires (Argentina); Luca, Vittorio, E-mail: vluca@cnea.gov.ar [Comisión Nacional de Energía Atómica, Centro Atómico Constituyentes, Av. General Paz 1499, 1650 San Martin, Provincia de Buenos Aires (Argentina)

    2016-12-15

    The next generation of nuclear systems will require materials capable of withstanding hostile chemical, physical and radiation environments over long time-frames. Aside from its chemical and physical stability, crystalline zirconia is one of the most radiation tolerant materials known. Here we report the first ever study of the radiation response of nanocrystalline and mesoporous zirconia and Ce{sup 3+}-stabilized nanocrystalline zirconia (Ce{sub 0.1}Zr{sub 0.9}O{sub 2}) thin films supported on silicon wafers. Zirconia films prepared using the block copolymer Brij-58 as the template had a thickness of around 60–80 nm. In the absence of a stabilizing trivalent cation they consisted of monoclinic and tetragonal zirconia nanocrystals with diameters in the range 8–10 nm. Films stabilized with Ce{sup 3+} contained only the tetragonal phase. The thin films were irradiated with iodine ions of energies of 70 MeV and 132 keV at low fluences (10{sup 13} - 10{sup 14} cm{sup −2}) corresponding to doses of 0.002 and 1.73 dpa respectively, and at 180 keV and high fluences (2 × 10{sup 16} cm{sup −2}) corresponding to 82.4 dpa. The influence of heavy ion irradiation on the nanocrystalline structure was monitored through Rietveld analysis of grazing incidence X-ray diffraction (GIXRD) patterns recorded at angles close to the critical angle to ensure minimum contribution to the diffraction pattern from the substrate. Irradiation of the mesoporous nanocrystalline zirconia thin films with 70 MeV iodine ions, for which electronic energy loss is dominant, resulted in slight changes in phase composition and virtually no change in crystallographic parameters as determined by Rietveld analysis. Iodine ion bombardment in the nuclear energy loss regime (132–180 keV) at low fluences did not provoke significant changes in phase composition or crystallographic parameters. However, at 180 keV and high fluences the monoclinic phase was totally eliminated from the GIXRD

  4. Porous Organic Cage Thin Films and Molecular-Sieving Membranes.

    Science.gov (United States)

    Song, Qilei; Jiang, Shan; Hasell, Tom; Liu, Ming; Sun, Shijing; Cheetham, Anthony K; Sivaniah, Easan; Cooper, Andrew I

    2016-04-06

    Porous organic cage molecules are fabricated into thin films and molecular-sieving membranes. Cage molecules are solution cast on various substrates to form amorphous thin films, with the structures tuned by tailoring the cage chemistry and processing conditions. For the first time, uniform and pinhole-free microporous cage thin films are formed and demonstrated as molecular-sieving membranes for selective gas separation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Solution processed pentacene thin films and their structural properties

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  6. Ultrashort pulse laser deposition of thin films

    Science.gov (United States)

    Perry, Michael D.; Banks, Paul S.; Stuart, Brent C.

    2002-01-01

    Short pulse PLD is a viable technique of producing high quality films with properties very close to that of crystalline diamond. The plasma generated using femtosecond lasers is composed of single atom ions with no clusters producing films with high Sp.sup.3 /Sp.sup.2 ratios. Using a high average power femtosecond laser system, the present invention dramatically increases deposition rates to up to 25 .mu.m/hr (which exceeds many CVD processes) while growing particulate-free films. In the present invention, deposition rates is a function of laser wavelength, laser fluence, laser spot size, and target/substrate separation. The relevant laser parameters are shown to ensure particulate-free growth, and characterizations of the films grown are made using several diagnostic techniques including electron energy loss spectroscopy (EELS) and Raman spectroscopy.

  7. Review of the fundamentals of thin-film growth.

    Science.gov (United States)

    Kaiser, Norbert

    2002-06-01

    The properties of a thin film of a given material depend on the film's real structure. The real structure is defined as the link between a thin film's deposition parameters and its properties. To facilitate engineering the properties of a thin film by manipulating its real structure, thin-film formation is reviewed as a process starting with nucleation followed by coalescence and subsequent thickness growth, all stages of which can be influenced by deposition parameters. The focus in this review is on dielectric and metallic films and their optical properties. In contrast to optoelectronics all these film growth possibilities for the engineering of novel optical films with extraordinary properties are just beginning to be used.

  8. Progress on thin-film sensors for space propulsion technology

    Science.gov (United States)

    Kim, Walter S.

    1987-01-01

    The objective is to develop thin-film thermocouples for Space Shuttle Main Engine (SSME) components. Thin-film thermocouples have been developed for aircraft gas turbine engines and are in use for temperature measurement on turbine blades to 1800 F. The technology established for aircraft gas turbine engines will be adapted to the materials and environment encountered in the SSME. Specific goals are to expand the existing in-house thin-film sensor technology and to test the survivability and durability of thin-film sensors in the SSME environment.

  9. 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

  10. Sputtering materials for VLSI and thin film devices

    CERN Document Server

    Sarkar, Jaydeep

    2010-01-01

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

  11. Crystalline thin films: The electrochemical atomic layer deposition (ECALD) view

    CSIR Research Space (South Africa)

    Modibedi, M

    2011-09-01

    Full Text Available Electrochemical atomic layer deposition technique is selected as one of the methods to prepare thin films for various applications, including electrocatalytic materials and compound....

  12. Thin-Film Materials Synthesis and Processing Facility

    Data.gov (United States)

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

  13. Seebeck effect of some thin film carbides

    International Nuclear Information System (INIS)

    Beensh-Marchwicka, G.; Prociow, E.

    2002-01-01

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

  14. TEM characterization of nanodiamond thin films.

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-05-01

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

  15. Thin Film Photovoltaics: Markets and Industry

    OpenAIRE

    Jäger-Waldau, Arnulf

    2012-01-01

    Since 2000, total PV production increased almost by two orders of magnitude, with a compound annual growth rate of over 52%. The most rapid growth in annual cell and module production over the last five years could be observed in Asia, where China and Taiwan together now account for about 60% of worldwide production. Between 2005 and 2009, thin film production capacity and volume increased more than the overall industry but did not keep up in 2010 and 2011 due to the rapid price decline for s...

  16. Thin-film optical shutter. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Matlow, S.L.

    1981-02-01

    A specific embodiment of macroconjugated macromolecules, the poly (p-phenylene)'s, has been chosen as the one most likely to meet all of the requirements of the Thin Film Optical Shutter project (TFOS). The reason for this choice is included. In order to be able to make meaningful calculations of the thermodynamic and optical properties of the poly (p-phenylene)'s a new quantum mechanical method was developed - Equilibrium Bond Length (EBL) Theory. Some results of EBL Theory are included.

  17. Thin molecular films of supramolecular porphyrins

    Directory of Open Access Journals (Sweden)

    KOITI ARAKI

    2000-03-01

    Full Text Available A relevant series of symmetric supramolecular porphyrins has been obtained by attaching four [Ru II(bipy2Cl] groups to the pyridyl substituents of meso-tetra(4-pyridylporphyrin and its metallated derivatives. These compounds display a rich electrochemistry and versatile catalytic, electrocatalytic and photochemical properties, associated with the ruthenium-bipyridine and the porphyrin complexes. These properties can be transferred to the electrodes by attaching thin molecular films of the compounds, by dip-coating, electrostatic assembly or electropolymerization. In this way, the interesting properties of those supermolecules and supramolecular assemblies can be used to prepare molecular devices and sensors.

  18. Infrared control coating of thin film devices

    Energy Technology Data Exchange (ETDEWEB)

    Berland, Brian Spencer; Stowell, Jr., Michael Wayne; Hollingsworth, Russell

    2017-02-28

    Systems and methods for creating an infrared-control coated thin film device with certain visible light transmittance and infrared reflectance properties are disclosed. The device may be made using various techniques including physical vapor deposition, chemical vapor deposition, thermal evaporation, pulsed laser deposition, sputter deposition, and sol-gel processes. In particular, a pulsed energy microwave plasma enhanced chemical vapor deposition process may be used. Production of the device may occur at speeds greater than 50 Angstroms/second and temperatures lower than 200.degree. C.

  19. Influence of strain/stress on the nonlinear-optical properties of sprayed deposited ZnO:Al thin films

    Energy Technology Data Exchange (ETDEWEB)

    Bahedi, K., E-mail: bahedikhadija@yahoo.fr [Laboratoire Optoelectronique et Physico-chimie des Materiaux.Unite de recherche associe au CNRST-URAC-14. Universite Ibn Tofail, Faculte des Sciences BP 133 Kenitra 14000 (Morocco); Addou, M.; Jouad, M. El; Sofiani, Z. [Laboratoire Optoelectronique et Physico-chimie des Materiaux.Unite de recherche associe au CNRST-URAC-14. Universite Ibn Tofail, Faculte des Sciences BP 133 Kenitra 14000 (Morocco); Oauzzani, H. EL; Sahraoui, B. [Institute of Sciences and Molecular Technologies of Angers, MOLTECH Anjou - UMR CNRS 6200, 2 bd Lavoisier 49045 ANGERS cedex2 (France)

    2011-07-01

    Nanocrystalline ZnO:Al thin films were deposited by reactive chemical pulverization spray pyrolysis technique on heated glass substrates at 450 deg. C to study their crystalline structure, composition, strain, stress, roughness characteristics and nonlinear optical susceptibility as a function of Al concentration (0, 2, 3, 5 at.%). The films were characterized by X-ray diffractometer (XRD), EDAX 9100 analyser, atomic force microscopy (AFM) and third harmonic generation (THG). The Al (3 at.%) doped ZnO thin films exhibited the lower strain/stress than undoped films. The nonlinear properties of the ZnO:Al thin films have been found to be influenced by the films strain/stress.

  20. A generalized "cut and projection" algorithm for the generation of quasiperiodic plasmonic concentrators for high efficiency ultra-thin film photovoltaics.

    Science.gov (United States)

    Flanigan, Patrick W; Ostfeld, Aminy E; Serrino, Natalie G; Ye, Zhen; Pacifici, Domenico

    2013-02-11

    This report will present a generalized two-dimensional quasiperiodic (QP) tiling algorithm based on de Bruijn's "cut and projection" method for use in plasmonic concentrator (PC) / photovoltaic hybrid devices to produce wide-angle, polarization-insensitive, and broadband light absorption enhancement. This algorithm can be employed with any PC consisting of point-like scattering objects, and can be fine-tuned to achieve a high spatial density of points and high orders of local and long-range rotational symmetry. Simulations and experimental data demonstrate this enhancement in ultra-thin layers of organic photovoltaic materials resting on metallic films etched with arrays of shallow sub-wavelength nanoholes. These devices work by coupling the incident light to surface plasmon polariton (SPP) modes that propagate along the dielectric / metal interface. This effectively increases the scale of light-matter interaction, and can also result in constructive interference between propagating SPP waves. By comparing PCs made with random, periodic, and QP arrangements, it is clear that QP is superior in intensifying the local fields and enhancing absorption in the active layer.

  1. Optical emission spectroscopy study of the expansion dynamics of a laser generated plasma during the deposition of thin films by laser ablation

    Directory of Open Access Journals (Sweden)

    Fazio, Enza

    2007-09-01

    Full Text Available The dynamics of the expanding plasma produced by excimer laser ablation of different materials such as silicon, silicon carbide, graphite and tin powder were studied by means of time integrated, spatially resolved emission spectroscopy and fast photography imaging of the expanding plasma. Experiments were performed both in vacuum and in different pure background atmosphere (i.e. oxygen or nitrogen and, finally, in gaseous mixtures (i.e. in O2/Ar and N2/Ar mixtures. These investigations were performed to gather information on the nature of the chemical species present in the plasma and on the occurrence of chemical reactions during the interaction between the plasma and the background gas. Then, we tried to correlate the plasma expansion dynamics to the structural and physical properties of the deposited materials. Experimental results clearly indicate that there is a strong correlation between the plasma expansion dynamics and the structural properties of the deposited thin films. In this respect, the investigations performed by means of fast photography and of optical emission spectroscopy revealed themselves as powerful tools for an efficient control of the deposition process itself.

  2. High power impulse magnetron sputtering of CIGS thin films for high efficiency thin film solar cells

    Czech Academy of Sciences Publication Activity Database

    Olejníček, Jiří; Hubička, Zdeněk; Kohout, Michal; Kšírová, Petra; Kment, Štěpán; Brunclíková, Michaela; Čada, Martin; Darveau, S.A.; Exstrom, C.L.

    2014-01-01

    Roč. 1, č. 3 (2014), s. 135-137 ISSN 2336-2626 R&D Projects: GA MŠk LH12045 Institutional support: RVO:68378271 Keywords : CIGS * HiPIMS * emission spectroscopy * thin films * magnetron sputtering Subject RIV: BL - Plasma and Gas Discharge Physics http://fyzika.feld.cvut.cz/misc/ppt/articles/2014/olejnicek.pdf

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

    Indian Academy of Sciences (India)

    matrix. The methodology can be used to produce free-standing films. Optical limiting capability of the nanoparticle-embedded polymer film is demonstrated. Keywords. Polar crystal; uniaxial orientational order; thin film; second harmonic gen- eration; silver nanoparticle; polyvinyl alcohol; free-standing film; optical limiter.

  4. 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.

  5. Characterization of ultrasonic spray pyrolysed ruthenium oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-11-21

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

  6. Engineering helimagnetism in MnSi thin films

    Directory of Open Access Journals (Sweden)

    S. L. Zhang

    2016-01-01

    Full Text Available Magnetic skyrmion materials have the great advantage of a robust topological magnetic structure, which makes them stable against the superparamagnetic effect and therefore a candidate for the next-generation of spintronic memory devices. Bulk MnSi, with an ordering temperature of 29.5 K, is a typical skyrmion system with a propagation vector periodicity of ∼18 nm. One crucial prerequisite for any kind of application, however, is the observation and precise control of skyrmions in thin films at room-temperature. Strain in epitaxial MnSi thin films is known to raise the transition temperature to 43 K. Here we show, using magnetometry and x-ray spectroscopy, that the transition temperature can be raised further through proximity coupling to a ferromagnetic layer. Similarly, the external field required to stabilize the helimagnetic phase is lowered. Transmission electron microscopy with element-sensitive detection is used to explore the structural origin of ferromagnetism in these Mn-doped substrates. Our work suggests that an artificial pinning layer, not limited to the MnSi/Si system, may enable room temperature, zero-field skyrmion thin-film systems, thereby opening the door to device applications.

  7. Engineering helimagnetism in MnSi thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S. L.; Hesjedal, T., E-mail: Thorsten.Hesjedal@physics.ox.ac.uk [Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, OX1 3PU (United Kingdom); Chalasani, R.; Kohn, A. [Department of Materials Science and Engineering, Tel Aviv University, Ramat Aviv 6997801, Tel Aviv (Israel); Baker, A. A. [Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, OX1 3PU (United Kingdom); Magnetic Spectroscopy Group, Diamond Light Source, Didcot, OX11 0DE (United Kingdom); Steinke, N.-J. [ISIS, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0QX (United Kingdom); Figueroa, A. I.; Laan, G. van der [Magnetic Spectroscopy Group, Diamond Light Source, Didcot, OX11 0DE (United Kingdom)

    2016-01-15

    Magnetic skyrmion materials have the great advantage of a robust topological magnetic structure, which makes them stable against the superparamagnetic effect and therefore a candidate for the next-generation of spintronic memory devices. Bulk MnSi, with an ordering temperature of 29.5 K, is a typical skyrmion system with a propagation vector periodicity of ∼18 nm. One crucial prerequisite for any kind of application, however, is the observation and precise control of skyrmions in thin films at room-temperature. Strain in epitaxial MnSi thin films is known to raise the transition temperature to 43 K. Here we show, using magnetometry and x-ray spectroscopy, that the transition temperature can be raised further through proximity coupling to a ferromagnetic layer. Similarly, the external field required to stabilize the helimagnetic phase is lowered. Transmission electron microscopy with element-sensitive detection is used to explore the structural origin of ferromagnetism in these Mn-doped substrates. Our work suggests that an artificial pinning layer, not limited to the MnSi/Si system, may enable room temperature, zero-field skyrmion thin-film systems, thereby opening the door to device applications.

  8. Mechanics of fragmentation of crocodile skin and other thin films

    Science.gov (United States)

    Qin, Zhao; Pugno, Nicola M.; Buehler, Markus J.

    2014-01-01

    Fragmentation of thin layers of materials is mediated by a network of cracks on its surface. It is commonly seen in dehydrated paintings or asphalt pavements and even in graphene or other two-dimensional materials, but is also observed in the characteristic polygonal pattern on a crocodile's head. Here, we build a simple mechanical model of a thin film and investigate the generation and development of fragmentation patterns as the material is exposed to various modes of deformation. We find that the characteristic size of fragmentation, defined by the mean diameter of polygons, is strictly governed by mechanical properties of the film material. Our result demonstrates that skin fragmentation on the head of crocodiles is dominated by that it features a small ratio between the fracture energy and Young's modulus, and the patterns agree well with experimental observations. Understanding this mechanics-driven process could be applied to improve the lifetime and reliability of thin film coatings by mimicking crocodile skin. PMID:24862190

  9. Optical characterization of a-Si:H thin films grown by Hg-Photo-CVD

    International Nuclear Information System (INIS)

    Barhdadi, A.; Karbal, S.; M'Gafad, N.; Benmakhlouf, A.; Chafik El Idrissi, M.; Aka, B.M.

    2006-08-01

    Mercury-Sensitized Photo-Assisted Chemical Vapor Deposition (Hg-Photo-CVD) technique opens new possibilities for reducing thin film growth temperature and producing novel semiconductor materials suitable for the future generation of high efficiency thin film solar cells onto low cost flexible plastic substrates. This paper provides some experimental data resulting from the optical characterization of hydrogenated amorphous silicon thin films grown by this deposition technique. Experiments have been performed on both as-deposited layers and thermal annealed ones. (author) [fr

  10. Glassy dynamics and heterogeneity of polymer thin films

    International Nuclear Information System (INIS)

    Kanaya, Toshiji; Inoue, Rintaro; Kawashima, Kazuko; Miyazaki, Tsukasa; Matsuba, Go; Nishida, Koji; Tsukushi, Itaru; Shibata, Kaoru; Hino, Masahiro

    2009-01-01

    We review our recent studies on glassy dynamics and glass transition of polymer thin films using neutron and X-ray reflectivity and inelastic neutron techniques. In the last decade extensive studies have been performed on polymer thin films to reveal very interesting but unusual properties such as reduction in the glass transition temperature T g with film thickness and negative thermal expansivity for thin films below about 25 nm, and often some contradictory experimental results have been reported. It is believed that a key to solve the controversial situation is to disclose heterogeneous structure or multi-layer structure in polymer thin films. In the review, therefore, we summarize our recent experimental results by neutron and X-ray reflectivity and inelastic neutron scattering, focusing on the dynamic heterogeneity in polymer thin films. (author)

  11. Novel doped hydroxyapatite thin films obtained by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Duta, L. [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, 409 Atomistilor Street, Magurele (Romania); Oktar, F.N. [Department of Bioengineering, Faculty of Engineering, Marmara University, Goztepe, Istanbul 34722 (Turkey); Department of Medical Imaging Technics, Vocational School of Health Services, Marmara University, Uskudar, Istanbul 34668 (Turkey); Nanotechnology and Biomaterials Application and Research Centre, Marmara University, Istanbul (Turkey); Stan, G.E. [National Institute of Materials Physics, 105 Bis Atomistilor Street, Magurele (Romania); Popescu-Pelin, G.; Serban, N.; Luculescu, C. [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, 409 Atomistilor Street, Magurele (Romania); Mihailescu, I.N., E-mail: ion.mihailescu@inflpr.ro [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, 409 Atomistilor Street, Magurele (Romania)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer HA coatings synthesized by pulsed laser deposition. Black-Right-Pointing-Pointer Comparative study of commercial vs. animal origin materials. Black-Right-Pointing-Pointer HA coatings of animal origin were rougher and more adherent to substrates. Black-Right-Pointing-Pointer Animal origin films can be considered as promising candidates for implant coatings. - Abstract: We report on the synthesis of novel ovine and bovine derived hydroxyapatite thin films on titanium substrates by pulsed laser deposition for a new generation of implants. The calcination treatment applied to produce the hydroxyapatite powders from ovine/bovine bones was intended to induce crystallization and to prohibit the transmission of diseases. The deposited films were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy. Pull-off adherence and profilometry measurements were also carried out. X-ray diffraction ascertained the polycrystalline hydroxyapatite nature of the powders and films. Fourier transform infrared spectroscopy evidenced the vibrational bands characteristic to a hydroxyapatite material slightly carbonated. The micrographs of the films showed a uniform distribution of spheroidal particulates with a mean diameter of {approx}2 {mu}m. Pull-off measurements demonstrated excellent bonding strength values between the hydroxyapatite films and the titanium substrates. Because of their physical-chemical properties and low cost fabrication from renewable resources, we think that these new coating materials could be considered as a prospective competitor to synthetic hydroxyapatite used for implantology applications.

  12. Ta-based amorphous metal thin films

    Energy Technology Data Exchange (ETDEWEB)

    McGlone, John M., E-mail: mcglone@eecs.oregonstate.edu [School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR 97331-5501 (United States); Olsen, Kristopher R. [Department of Chemistry, Oregon State University, Corvallis, OR 97331-4003 (United States); Stickle, William F.; Abbott, James E.; Pugliese, Roberto A.; Long, Greg S. [Hewlett-Packard Company, Corvallis, OR, 97333 (United States); Keszler, Douglas A. [Department of Chemistry, Oregon State University, Corvallis, OR 97331-4003 (United States); Wager, John F. [School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR 97331-5501 (United States)

    2015-11-25

    With their lack of grains and grain boundaries, amorphous metals are known to possess advantageous mechanical properties and enhanced chemical stability relative to crystalline metals. Commonly, however, they exhibit poor high-temperature stability because of their metastable nature. Here, we describe two new Ta-based ternary metal thin films that retain thermal stability to 600 °C and above. The new thin-film compositions, Ta{sub 2}Ni{sub 2}Si{sub 1} and Ta{sub 2}Mo{sub 2}Si{sub 1}, are amorphous, exhibiting ultra-smooth surfaces (<0.4 nm) and resistivities typical of amorphous metals (224 and 177 μΩ cm, respectively). - Highlights: • New Ta-based amorphous metals were sputter deposited from individual targets. • As-deposited amorphous structure was confirmed through diffraction techniques. • Electrical and surface properties were characterized and possess smooth surfaces. • No evidence of crystallization up to 600 °C (TaNiSi) and 800 °C (TaMoSi). • Ultra-smooth surfaces remained unchanged up to crystallization temperature.

  13. Stable organic thin-film transistors

    Science.gov (United States)

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

    2018-01-01

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

  14. Metal nanoparticles for thin film solar cells

    DEFF Research Database (Denmark)

    Gritti, Claudia

    Among the different renewable ways to produce energy, photovoltaic cells have a big potential and the research is now focusing on getting higher efficiency and at the same time saving the manufacturing costs improving the performance of thin film solar cells. The spectral distribution in the infr......Among the different renewable ways to produce energy, photovoltaic cells have a big potential and the research is now focusing on getting higher efficiency and at the same time saving the manufacturing costs improving the performance of thin film solar cells. The spectral distribution...... characterized. Spectral responses are measured and in two types of measured GaAs solar cells (with Au and Ag nanoparticles) there was no clear efficiency enhancement in the NIR spectral range. In the case of Au nanoparticles it could be explained in similar way to the absorption data: the effect being broad...... cells spectral response to longer wavelengths, through possibly cheap and simple technologies: EBL can be substituted by colloidal solutions implementation and electroless plating is not expensive and results to be effective within a broad set of parameters (size, shape, density). Another application...

  15. Flexoelectric rotation of polarization in ferroelectric thin films.

    Science.gov (United States)

    Catalan, G; Lubk, A; Vlooswijk, A H G; Snoeck, E; Magen, C; Janssens, A; Rispens, G; Rijnders, G; Blank, D H A; Noheda, B

    2011-10-16

    Strain engineering enables modification of the properties of thin films using the stress from the substrates on which they are grown. Strain may be relaxed, however, and this can also modify the properties thanks to the coupling between strain gradient and polarization known as flexoelectricity. Here we have studied the strain distribution inside epitaxial films of the archetypal ferroelectric PbTiO(3), where the mismatch with the substrate is relaxed through the formation of domains (twins). Synchrotron X-ray diffraction and high-resolution scanning transmission electron microscopy reveal an intricate strain distribution, with gradients in both the vertical and, unexpectedly, the horizontal direction. These gradients generate a horizontal flexoelectricity that forces the spontaneous polarization to rotate away from the normal. Polar rotations are a characteristic of compositionally engineered morphotropic phase boundary ferroelectrics with high piezoelectricity; flexoelectricity provides an alternative route for generating such rotations in standard ferroelectrics using purely physical means.

  16. Polycystalline silicon thin films for electronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, Christian Claus

    2012-01-15

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

  17. Piezoelectric Response Evaluation of ZnO Thin Film Prepared by RF Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    Cheng Da-Long

    2017-01-01

    Full Text Available The most important parameter of piezoelectric materials is piezoelectric coefficient (d33. In this study, the piezoelectric ZnO thin films were deposited on the SiNx/Si substrate. The 4 inches substrate is diced into 8 cm× 8 cm piece. During the deposition process, a zinc target (99.999 wt% of 2 inches diameter was used. The vertical distance between the target and the substrate holder was fixed at 5 cm. The piezoelectric response of zinc oxide (ZnO thin films were obtained by using a direct measurement system. The system adopts a mini impact tip to generate an impulsive force and read out the piezoelectric signals immediately. Experimentally, a servo motor is used to produce a fixed quantity of force, for giving an impact against to the piezoelectric film. The ZnO thin films were deposited using the reactive radio frequency (RF magnetron sputtering method. The electric charges should be generated because of the material’s extrusion. This phenomenon was investigated through the oscilloscope by one shot trigger. It was apparent that all ZnO films exhibit piezoelectric responses evaluated by our measurement system, however, its exhibit a significant discrepancy. The piezoelectric responses of ZnO thin film at various deposition positions were measured and the crystal structures of the sputtering pressure were also discussed. The crystalline characteristics of ZnO thin films are investigated through the XRD and SEM. The results show the ZnO thin film exhibits good crystalline pattern and surface morphology with controlled sputtering condition. The ZnO thin films sputtered using 2 inches target present various piezoelectric responses. With the exactly related position, a best piezoelectric response of ZnO thin film can be achieved.

  18. The role of microstructural phenomena in magnetic thin films

    Energy Technology Data Exchange (ETDEWEB)

    Laughlin, D.E.; Lambeth, D.N.

    1992-12-31

    The subject is germane to magnetic recording media. Results during the first 2 years are presented under the following headings: atomic resolution TEM of CoNiCr films; CoNiCr and CoCrTa thin films; development of texture; and CoSm/Cr thin films. The HREM results showed that defects in Co-based films may be responsible for higher coercivity. Findings are presented on the effects of Cr interlayers on the microstructure of the second Co-based film in Co/Cr/Co/Cr multilayer films. Proposed research plans are outlined.

  19. The role of microstructural phenomena in magnetic thin films

    Energy Technology Data Exchange (ETDEWEB)

    Laughlin, D.E.; Lambeth, D.N.

    1992-01-01

    The subject is germane to magnetic recording media. Results during the first 2 years are presented under the following headings: atomic resolution TEM of CoNiCr films; CoNiCr and CoCrTa thin films; development of texture; and CoSm/Cr thin films. The HREM results showed that defects in Co-based films may be responsible for higher coercivity. Findings are presented on the effects of Cr interlayers on the microstructure of the second Co-based film in Co/Cr/Co/Cr multilayer films. Proposed research plans are outlined.

  20. PZT thin films for piezoelectric MEMS mechanical energy harvesting

    Science.gov (United States)

    Yeager, Charles

    This thesis describes the optimization of piezoelectric Pb(ZrxTi 1-x)O3 (PZT) thin films for energy generation by mechanical energy harvesting, and self-powered micro-electro-mechanical systems (MEMS). For this purpose, optimization of the material was studied, as was the incorporation of piezoelectric films into low frequency mechanical harvesters. A systematic analysis of the energy harvesting figure of merit was made. As a figure of merit (e31,ƒ)2/epsilon r (transverse piezoelectric coefficient squared over relative permittivity) was utilized. PZT films of several tetragonal compositions were grown on CaF2, MgO, SrTiO3, and Si substrates, thereby separating the dependence of composition on domain orientation. To minimize artifacts associated with composition gradients, and to extend the temperature growth window, PZT films were grown by metal organic chemical vapor deposition (MOCVD). Using this method, epitaxial {001} films achieved c-domain textures above 90% on single crystal MgO and CaF2 substrates. This could be tailored via the thermal stresses established by the differences in thermal expansion coefficients of the film and the substrate. The single-domain e31,ƒ for PZT thin films was determined to exceed -12 C/m2 in the tetragonal phase field for x ≥ 0.19, nearly twice the phenomenologically modeled value. The utilization of c-domain PZT films is motivated by a figure of merit above 0.8 C2/m4 for (001) PZT thin films. Increases to the FoM via doping and hot poling were also quantified; a 1% Mn doping reduced epsilonr by 20% without decreasing the piezoelectric coefficient. Hot poling a device for one hour above 120°C also resulted in a 20% reduction in epsilonr ; furthermore, 1% Mn doping reduced epsilonr by another 12% upon hot poling. Two methods for fabricating thin film mechanical energy harvesting devices were investigated. It was found that phosphoric acid solutions could be used to pattern MgO crystals, but this was typically accompanied by

  1. Laser scribing of polycrystalline thin films

    Science.gov (United States)

    Compaan, A. D.; Matulionis, I.; Nakade, S.

    2000-07-01

    We have investigated the use of several different types of lasers for scribing of the polycrystalline materials used for thin-film solar cells: CdTe, CuInGaSe 2 (CIGS), ZnO, SnO 2, Mo, Al, and Au. The lasers included four different neodymium-yttrium-aluminum garnet (Nd:YAG) (both 1064 and 532 nm wavelengths), a Cu vapor (511/578 nm), an XeCl excimer (308 nm), and a KrF excimer (248 nm). Pulse durations ranged from ˜0.1 to ˜250 ns. We found that the fundamental and frequency-doubled wavelengths of the Nd:YAG systems work well for almost all of the above materials except for the transparent conductor ZnO. The diode-laser-pumped Nd:YAG was particularly convenient to use. For ZnO the uv wavelengths of the two excimer lasers produced good results. Pulse duration was found generally not to be critical except for the case of CIGS on Mo where longer pulse durations (≥250 ns) are advantageous. The frequently observed problem of ridge formation along the edges of scribe lines in the semiconductor films can be eliminated by control of intensity gradients at the film through adjustment of the focus conditions.

  2. Magnetism of FePt Thin Films

    Science.gov (United States)

    Alqhtany, Norah H.

    Materials with large magnetic anisotropy have received significant attention from the scientific community due to its advantages in technological applications. Equiatomic FePt has been identified as such a material which could possibly be a potential candidate for ultra- high density magnetic recording and other applications like permanent magnets. FePt thin films exhibit ordered L10 texture with high magnetocrystalline anisotropy and high saturation magnetization which seem lucrative for technological applications. This thesis presents an investigation of structural and magnetic properties of granular and epitaxial FePt films with L10 phase prepared by DC sputtering on different substrates (SrTiO3 and glass). X-ray Diffraction (XRD), Atomic Force Microscopy/Magnetic Force Microscopy (AFM/MFM) and Vibrating Sample Magnetometer (VSM) were employed in characterization process. The measurements obtained from these equipment were significant in establishing the relationship between the microstructure and the magnetic properties of these films. The symmetry and magnitude of magnetic anisotropy has also been analyzed and discussed in detail.

  3. Surface microtopography of thin silver films

    Science.gov (United States)

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

    1991-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-08-05

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

  5. Optical approach to thermopower and conductivity measurements in thin-film semiconductors

    International Nuclear Information System (INIS)

    Dersch, H.; Amer, N.M.

    1984-01-01

    An optical beam deflection technique is applied to measure the Joule and Peltier heat generated by electric currents through thin-film semiconductors. The method yields a spatially resolved conductivity profile and allows the determination of Peltier coefficients. Results obtained on doped hydrogenated amorphous silicon films are presented

  6. 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)

  7. Use of thin films in high-temperature superconducting bearings.

    Energy Technology Data Exchange (ETDEWEB)

    Hull, J. R.; Cansiz, A.

    1999-09-30

    In a PM/HTS bearing, locating a thin-film HTS above a bulk HTS was expected to maintain the large levitation force provided by the bulk with a lower rotational drag provided by the very high current density of the film. For low drag to be achieved, the thin film must shield the bulk from inhomogeneous magnetic fields. Measurement of rotational drag of a PM/HTS bearing that used a combination of bulk and film HTS showed that the thin film is not effective in reducing the rotational drag. Subsequent experiments, in which an AC coil was placed above the thin-film HTS and the magnetic field on the other side of the film was measured, showed that the thin film provides good shielding when the coil axis is perpendicular to the film surface but poor shielding when the coil axis is parallel to the surface. This is consistent with the lack of reduction in rotational drag being due to a horizontal magnetic moment of the permanent magnet. The poor shielding with the coil axis parallel to the film surface is attributed to the aspect ratio of the film and the three-dimensional nature of the current flow in the film for this coil orientation.

  8. Structural and Optical Properties of Nanoscale Galinobisuitite Thin Films

    Directory of Open Access Journals (Sweden)

    Omar H. Abd-Elkader

    2014-01-01

    Full Text Available Galinobisuitite thin films of (Bi2S3(PbS were prepared using the chemical bath deposition technique (CBD. Thin films were prepared by a modified chemical deposition process by allowing the triethanolamine (TEA complex of Bi3+ and Pb2+ to react with S2− ions, which are released slowly by the dissociation of the thiourea (TU solution. The films are polycrystalline and the average crystallite size is 35 nm. The composition of the films was measured using the atomic absorption spectroscopy (AAS technique. The films are very adherent to the substrates. The crystal structure of Galinobisuitite thin films was calculated by using the X-ray diffraction (XRD technique. The surface morphology and roughness of the films were studied using scanning electron microscopes (SEM, transmission electron microscopes (TEM and stylus profilers respectively. The optical band gaps of the films were estimated from optical measurements.

  9. Magnetic thin films for high-density recording

    NARCIS (Netherlands)

    Lodder, J.C.

    1996-01-01

    Magnetic and magneto-optic recording technologies are continuing to evolve at a rapid pace resulting in longer playing times and more data being stored in ever decreasing volumes. Thin-film media are playing an important role in this process. Three different type of thin-film media are discussed

  10. Bonding of a niobium wire to a niobium thin film

    NARCIS (Netherlands)

    Jaszczuk, W.; Jaszczuk, W.; ter Brake, Hermanus J.M.; Flokstra, Jakob; Veldhuis, Dick; Stammis, R.; Rogalla, Horst

    1991-01-01

    A method for bonding a niobium wire to a niobium thin film is described. The bonds are to be used as superconducting connections between wire-wound gradiometers and thin-film coupling coils on DC SQUIDS. The method is characterized by two steps. Firstly, the hardness of the niobium wire is reduced

  11. 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 ...

  12. Ferroelectricity in Sodium Nitrite Thin Films | Britwum | Journal of the ...

    African Journals Online (AJOL)

    Investigations have been conducted on the ferroelectric property of thin films of NaNO2. The thin films were prepared with the dip coating technique. The phase transition was investigated by observing the change in the dielectric constant with temperature change. The presence of ferro-electricity was investigated with a ...

  13. Electrical properties of epitaxially grown VOx thin films

    NARCIS (Netherlands)

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

    2003-01-01

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

  14. Stoichiometry control in oxide thin films by pulsed laser deposition

    NARCIS (Netherlands)

    Groenen, R.

    2017-01-01

    A general challenge in the synthesis of complex oxide nanostructures and thin films is the control of the stoichiometry and herewith control of thin film properties. Pulsed Laser Deposition (PLD) is widely known for its potential for growing near stoichiometric highly crystalline complex metal oxide

  15. 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

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

    African Journals Online (AJOL)

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

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

    Indian Academy of Sciences (India)

    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 form perfectly polar assemblies in their crystalline state are found to organize as uniaxially oriented crystallites in vapor deposited thin films on glass substrate.

  18. Optical characteristics of transparent samarium oxide thin films ...

    Indian Academy of Sciences (India)

    Transparent metal oxide thin films of samarium oxide (Sm 2 O 3 ) were prepared on pre-cleaned fused optically flat quartz substrates by radio-frequency (RF) sputtering technique. The as-deposited thin films were annealed at different temperatures (873, 973 and 1073 K) for 4 h in air under normal atmospheric pressure.

  19. Thermal properties and stabilities of polymer thin films

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  20. Dip-coated hydrotungstite thin films as humidity sensors

    Indian Academy of Sciences (India)

    Unknown

    Dip-coated hydrotungstite thin films as humidity sensors. G V KUNTE, UJWALA AIL, S A SHIVASHANKAR and A M UMARJI*. Materials Research Centre, Indian Institute of Science, Bangalore 560 012, India. MS received 6 December 2004; revised 28 February 2005. Abstract. Thin films of a hydrated phase of tungsten ...

  1. Thermal stability of gold-PS nanocomposites thin films

    Indian Academy of Sciences (India)

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

  2. 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 ...

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

    Science.gov (United States)

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

    2017-11-01

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

  4. Josephson soliton oscillators in a superconducting thin film resonator

    DEFF Research Database (Denmark)

    Holm, J.; Mygind, Jesper; Pedersen, Niels Falsig

    1993-01-01

    Josephson soliton oscillators integrated in a resonator consisting of two closely spaced coplanar superconducting microstrips have been investigated experimentally. Pairs of long 1-D Josephson junctions with a current density of about 1000 A/cm2 were made using the Nb-AlOx-Nb trilayer technique....... Different modes of half-wave resonances in the thin-film structure impose different magnetic field configurations at the boundaries of the junctions. The DC I-V characteristic shows zero-field steps with a number of resonator-induced steps. These structures are compared to RF-induced steps generated...

  5. Modifying thin film diamond for electronic applications

    International Nuclear Information System (INIS)

    Baral, B.

    1999-01-01

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

  6. Thin Films of Quasicrystals: Optical, Electronic, and Mechanical Properties

    Science.gov (United States)

    Symko, Orest G.

    1998-03-01

    In order to extend some of the unusual properties of quasicrystals toward practical applications and to study fundamental aspects of these properties, we have developed a technology for the deposition of high quality thin films of quasicrystals on a variety of substrates. Mechanical support for the thin films is provided by the substrate as bulk quasicrystals are brittle. We have applied the thin films to studies of their optical, electrical, and mechanical properties as well as to coatings of biomedical devices. An important characteristic of a quasicrystal is its pseudogap in the electronic density of states; it is determined directly from optical transmission measurements. Optical and mechanical characteristics of the thin films provide strong support for the cluster nature of quasicrystals and emphasize their importance for coatings. When used in biomedical devices, thin film quasicrystalline coatings show remarkable strength, low friction, and non-stick behavior. This work was in collaboration with W. Park, E. Abdel-Rahman, and T. Klein.

  7. Nanocoatings and ultra-thin films technologies and applications

    CERN Document Server

    Tiginyanu, Ion

    2011-01-01

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

  8. Thermoluminescence of thin films deposited by laser ablation

    International Nuclear Information System (INIS)

    Escobar A, L.; Camps, E.; Arrieta, A.; Romero, S.; Gonzalez, P.R.; Olea M, O.; Diaz E, R.

    2003-01-01

    Materials in thin film form have received great attention in the last few years mainly because of their singular properties, which may differ significantly from their bulk attributes making them attractive for a wide variety of applications. In particular, thermoluminescence (Tl) properties of thin films have been studied recently owing to their potential applications in detection for both ionizing and non ionizing radiation. The aim of the present work is to report the synthesis and characterization of C Nx, aluminum oxide and titanium oxide thin films. Thermoluminescence response of the obtained thin films was studied after subject thin films to UV radiation (254 nm) as well as to gamma radiation (Co-60). Thermoluminescence glow curves exhibited a peak centered at 150 C for CN x whereas for titanium oxide the glow curve shows a maximum peaking at 171 C. Characterization of the physical properties of the deposited materials is presented. (Author)

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

    CERN Document Server

    Jacob, W; Schwarz-Selinger, T

    2000-01-01

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

  10. Thin films and coatings toughening and toughness characterization

    CERN Document Server

    Zhang, Sam

    2015-01-01

    Thin Films and Coatings: Toughening and Toughness Characterization captures the latest developments in the toughening of hard coatings and in the measurement of the toughness of thin films and coatings. Featuring chapters contributed by experts from Australia, China, Czech Republic, Poland, Singapore, Spain, and the United Kingdom, this first-of-its-kind book:Presents the current status of hard-yet-tough ceramic coatingsReviews various toughness evaluation methods for films and hard coatingsExplores the toughness and toughening mechanisms of porous thin films and laser-treated surfacesExamines

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  12. Zeolite thin films: from computer chips to space stations.

    Science.gov (United States)

    Lew, Christopher M; Cai, Rui; Yan, Yushan

    2010-02-16

    Zeolites are a class of crystalline oxides that have uniform and molecular-sized pores (3-12 A in diameter). Although natural zeolites were first discovered in 1756, significant commercial development did not begin until the 1950s when synthetic zeolites with high purity and controlled chemical composition became available. Since then, major commercial applications of zeolites have been limited to catalysis, adsorption, and ion exchange, all using zeolites in powder form. Although researchers have widely investigated zeolite thin films within the last 15 years, most of these studies were motivated by the potential application of these materials as separation membranes and membrane reactors. In the last decade, we have recognized and demonstrated that zeolite thin films can have new, diverse, and economically significant applications that others had not previously considered. In this Account, we highlight our work on the development of zeolite thin films as low-dielectric constant (low-k) insulators for future generation computer chips, environmentally benign corrosion-resistant coatings for aerospace alloys, and hydrophilic and microbiocidal coatings for gravity-independent water separation in space stations. Although these three applications might not seem directly related, they all rely on the ability to fine-tune important macroscopic properties of zeolites by changing their ratio of silicon to aluminum. For example, pure-silica zeolites (PSZs, Si/Al = infinity) are hydrophobic, acid stable, and have no ion exchange capacity, while low-silica zeolites (LSZs, Si/Al zeolites that have not been exploited before, such as a higher elastic modulus, hardness, and heat conductivity than those of amorphous porous silicas, and microbiocidal capabilities derived from their ion exchange capacities. Finally, we briefly discuss our more recent work on polycrystalline zeolite thin films as promising biocompatible coatings and environmentally benign wear-resistant and

  13. Novel photon management for thin-film photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Menon, Rajesh [Univ. of Utah, Salt Lake City, UT (United States)

    2016-11-11

    The objective of this project is to enable commercially viable thin-film photovoltaics whose efficiencies are increased by over 10% using a novel optical spectral-separation technique. A thin planar diffractive optic is proposed that efficiently separates the solar spectrum and assigns these bands to optimal thin-film sub-cells. An integrated device that is comprised of the optical element, an array of sub-cells and associated packaging is proposed.

  14. Patterns and conformations in molecularly thin films

    Science.gov (United States)

    Basnet, Prem B.

    Molecularly thin films have been a subject of great interest for the last several years because of their large variety of industrial applications ranging from micro-electronics to bio-medicine. Additionally, molecularly thin films can be used as good models for biomembrane and other systems where surfaces are critical. Many different kinds of molecules can make stable films. My research has considered three such molecules: a polymerizable phospholipid, a bent-core molecules, and a polymer. One common theme of these three molecules is chirality. The phospolipid molecules studied here are strongly chiral, which can be due to intrinsically chiral centers on the molecules and also due to chiral conformations. We find that these molecules give rise to chiral patterns. Bent-core molecules are not intrinsically chiral, but individual molecules and groups of molecules can show chiral structures, which can be changed by surface interactions. One major, unconfirmed hypothesis for the polymer conformation at surface is that it forms helices, which would be chiral. Most experiments were carried out at the air/water interface, in what are called Langmuir films. Our major tools for studying these films are Brewster Angle Microscopy (BAM) coupled with the thermodynamic information that can be deduced from surface pressure isotherms. Phospholipids are one of the important constituents of liposomes -- a spherical vesicle com-posed of a bilayer membrane, typically composed of a phospholipid and cholesterol bilayer. The application of liposomes in drug delivery is well-known. Crumpling of vesicles of polymerizable phospholipids has been observed. With BAM, on Langmuir films of such phospholipids, we see novel spiral/target patterns during compression. We have found that both the patterns and the critical pressure at which they formed depend on temperature (below the transition to a i¬‘uid layer). Bent-core liquid crystals, sometimes knows as banana liquid crystals, have drawn

  15. Preparation and optical characterization of DNA-riboflavin thin films

    Science.gov (United States)

    Paulson, Bjorn; Shin, Inchul; Kong, Byungjoo; Sauer, Gregor; Dugasani, Sreekantha Reddy; Khazaeinezhad, Reza; Jung, Woohyun; Joo, Boram; Oh, Kyunghwan

    2016-09-01

    Thin films of DNA biopolymer thin film are fabricated by a drop casting process on glass and silicon substrates, as well as freestanding. The refractive index is measured by elliposmetry and in bulk DNA film the refractive index is shown to be increased in the 600 to 900 nm DNA transparency window by doping with riboflavin. Further analysis with FT-IR, Raman, and XRD are used to determine whether binding between riboflavin and DNA occurs.

  16. Pulsed laser deposition and characterisation of thin superconducting films

    Energy Technology Data Exchange (ETDEWEB)

    Morone, A. [CNR, zona industriale di Tito Scalo, Potenza (Italy). Istituto per i Materiali Speciali

    1996-09-01

    Same concepts on pulsed laser deposition of thin films will be discussed and same examples of high transition temperature (HTc) BiSrCaCuO (BISCO) and low transition temperature NbN/MgO/NbN multilayers will be presented. X-ray and others characterizations of these films will be reported and discussed. Electrical properties of superconducting thin films will be realized as a function of structural and morphological aspect.

  17. 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.

  18. Thin films of mixed metal compounds

    Science.gov (United States)

    Mickelsen, R.A.; Chen, W.S.

    1985-06-11

    Disclosed is a thin film heterojunction solar cell, said heterojunction comprising a p-type I-III-IV[sub 2] chalcopyrite substrate and an overlying layer of an n-type ternary mixed metal compound wherein said ternary mixed metal compound is applied to said substrate by introducing the vapor of a first metal compound to a vessel containing said substrate from a first vapor source while simultaneously introducing a vapor of a second metal compound from a second vapor source of said vessel, said first and second metals comprising the metal components of said mixed metal compound; independently controlling the vaporization rate of said first and second vapor sources; reducing the mean free path between vapor particles in said vessel, said gas being present in an amount sufficient to induce homogeneity of said vapor mixture; and depositing said mixed metal compound on said substrate in the form of a uniform composition polycrystalline mixed metal compound. 5 figs.

  19. Printed Thin Film Transistors: Research from China.

    Science.gov (United States)

    Tong, Sichao; Sun, Jia; Yang, Junliang

    2018-03-01

    Thin film transistors (TFTs) have experienced tremendous development during the past decades and show great potential applications in flat displays, sensors, radio frequency identification tags, logic circuit, and so on. The printed TFTs are the key components for rapid development and commercialization of printed electronics. The researchers in China play important roles to accelerate the development and commercialization of printed TFTs. In this review, we comprehensively summarize the research progress of printed TFTs on rigid and flexible substrates from China. The review will focus on printing techniques of TFTs, printed TFTs components including semiconductors, dielectrics and electrodes, as well as fully-printed TFTs and printed flexible TFTs. Furthermore, perspectives on the remaining challenges and future developments are proposed as well.

  20. Superconducting fluctuations in molybdenum nitride thin films

    Science.gov (United States)

    Baskaran, R.; Thanikai Arasu, A. V.; Amaladass, E. P.; Vaidhyanathan, L. S.; Baisnab, D. K.

    2018-02-01

    MoN thin films have been deposited using reactive sputtering. The change in resistance near superconducting transition temperature at various magnetic fields has been analyzed based on superconducting fluctuations in the system. The Aslamazov and Larkin scaling theory has been utilized to analyze the conductance change. The results indicate that most of the measurements show two dimensional (2D) nature and exhibit scaling behavior at lower magnetic fields (7T). We have also analyzed our data based on the model in which there is no explicit dependence of Tc. These analyses also substantiate a crossover from a 2D nature to a 3D at larger fields. Analysis using lowest Landau level scaling theory for a 2D system exhibit scaling behavior and substantiate our observations. The broadening at low resistance part has been explained based on thermally activated flux flow model and show universal behavior. The dependence of Uo on magnetic field indicates both single and collective vortex behavior.

  1. Review of Zinc Oxide Thin Films

    Science.gov (United States)

    2014-12-23

    Chemical Properties ZnO occurs  as white powder  known  as  zinc white or  as  the mineral  zincite.  Zinc  oxide   is  an  amphoteric   oxide .  It  is...AFRL-OSR-VA-TR-2015-0044 Review of Zinc Oxide Thin Films Tom Otiti COLLEGE OF COMPUTING AND INFORMATION SCIENCE MAKERERE U Final Report 12/23/2014...COVERED (From - To)      01-07-2011 to 30-06-2014 4.  TITLE AND SUBTITLE ZINC OXIDE MATERIALS FOR PHOTOVOLTAIC APPLICATIONS 5a.  CONTRACT NUMBER 5b

  2. Amperometric noise at thin film band electrodes.

    Science.gov (United States)

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

    2012-09-18

    Background current noise is often a significant limitation when using constant-potential amperometry for biosensor application such as amperometric recordings of transmitter release from single cells through exocytosis. In this paper, we fabricated thin-film electrodes of gold and conductive polymers and measured the current noise in physiological buffer solution for a wide range of different electrode areas. The noise measurements could be modeled by an analytical expression, representing the electrochemical cell as a resistor and capacitor in series. The studies revealed three domains; for electrodes with low capacitance, the amplifier noise dominated, for electrodes with large capacitances, the noise from the resistance of the electrochemical cell was dominant, while in the intermediate region, the current noise scaled with electrode capacitance. The experimental results and the model presented here can be used for choosing an electrode material and dimensions and when designing chip-based devices for low-noise current measurements.

  3. Optical properties of aluminum oxide thin films and colloidal nanostructures

    International Nuclear Information System (INIS)

    Koushki, E.; Mousavi, S.H.; Jafari Mohammadi, S.A.; Majles Ara, M.H.; Oliveira, P.W. de

    2015-01-01

    In this work, we prepared thin films of aluminum oxide (Al 2 O 3 ) with different thicknesses, using a wet chemical process. The Al 2 O 3 nanoparticles with an average size of 40 nm were dispersed in water and deposited on soda glass substrates. The morphology of the resulting thin films was characterized by means of scanning electron microscopy. The optical properties of the thin films were studied by measuring reflectance and transmittance. A theoretical description of the reflection and transmission mechanism of the films was developed by measuring the thickness and spectral behavior of the refractive index. Numerical evaluations were used for modeling the optical spectra of the thin films of alumina. By fitting numerical curves to the experimental data, the extinction coefficient and refractive index were obtained. The dielectric constant and optical properties of the colloidal solution of the particles were also studied. - Highlights: • Optical properties of alumina thin films and nanocolloids were investigated. • New theoretical depiction of transmission and reflection from the thin films was evaluated. • Interference in reflection from thin films was studied. • Real and imaginary parts of the dielectric constant for alumina nanoparticles were calculated. • Using a novel method, evaluation of optical dispersion and UV–visible absorption were performed.

  4. Optical properties of aluminum oxide thin films and colloidal nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Koushki, E., E-mail: ehsan.koushki@yahoo.com [Photonics Laboratory, Physics Faculty, Kharazmi University, Tehran (Iran, Islamic Republic of); Physics Department, Hakim Sabzevari University, Sabzevar (Iran, Islamic Republic of); Mousavi, S.H. [INM—Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken (Germany); Jafari Mohammadi, S.A. [INM—Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken (Germany); Department of Chemistry, College of Science, Islamshahr Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Majles Ara, M.H. [Photonics Laboratory, Physics Faculty, Kharazmi University, Tehran (Iran, Islamic Republic of); Oliveira, P.W. de [INM—Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken (Germany)

    2015-10-01

    In this work, we prepared thin films of aluminum oxide (Al{sub 2}O{sub 3}) with different thicknesses, using a wet chemical process. The Al{sub 2}O{sub 3} nanoparticles with an average size of 40 nm were dispersed in water and deposited on soda glass substrates. The morphology of the resulting thin films was characterized by means of scanning electron microscopy. The optical properties of the thin films were studied by measuring reflectance and transmittance. A theoretical description of the reflection and transmission mechanism of the films was developed by measuring the thickness and spectral behavior of the refractive index. Numerical evaluations were used for modeling the optical spectra of the thin films of alumina. By fitting numerical curves to the experimental data, the extinction coefficient and refractive index were obtained. The dielectric constant and optical properties of the colloidal solution of the particles were also studied. - Highlights: • Optical properties of alumina thin films and nanocolloids were investigated. • New theoretical depiction of transmission and reflection from the thin films was evaluated. • Interference in reflection from thin films was studied. • Real and imaginary parts of the dielectric constant for alumina nanoparticles were calculated. • Using a novel method, evaluation of optical dispersion and UV–visible absorption were performed.

  5. Glass transition and thermal expansivity of polystyrene thin films

    International Nuclear Information System (INIS)

    Inoue, R.; Kanaya, T.; Miyazaki, T.; Nishida, K.; Tsukushi, I.; Shibata, K.

    2006-01-01

    We have studied glass transition temperature and thermal expansivity of polystyrene thin films supported on silicon substrate using X-ray reflectivity and inelastic neutron scattering techniques. In annealing experiments, we have found that the reported apparent negative expansivity of polymer thin films is caused by unrelaxed structure due to insufficient annealing. Using well-annealed films, we have evaluated glass transition temperature T g and thermal expansivity as a function of film thickness. The glass transition temperature decreases with film thickness and is constant below about 10 nm, suggesting the surface glass transition temperature of 355 K, which is lower than that in bulk. We have also found that the thermal expansivity in the glassy state decreases with film thickness even after annealing. The decrease has been attributed to hardening of harmonic force constant arising from chain confinement in a thin film. This idea has been confirmed in the inelastic neutron scattering measurements

  6. Glass transition and thermal expansivity of polystyrene thin films

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, R. [Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011 (Japan); Kanaya, T. [Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011 (Japan)]. E-mail: kanaya@scl.kyoto-u.ac.jp; Miyazaki, T. [Nitto Denko Corporation, 1-1-2 Shimohozumi, Ibaraki, Osaka-fu 567-8680 (Japan); Nishida, K. [Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011 (Japan); Tsukushi, I. [Chiba Institute of Technology, Narashino, Chiba-ken 275-0023 (Japan); Shibata, K. [Japan Atomic Energy Research Institute, Tokai, Ibaraki-ken 319-1195 (Japan)

    2006-12-20

    We have studied glass transition temperature and thermal expansivity of polystyrene thin films supported on silicon substrate using X-ray reflectivity and inelastic neutron scattering techniques. In annealing experiments, we have found that the reported apparent negative expansivity of polymer thin films is caused by unrelaxed structure due to insufficient annealing. Using well-annealed films, we have evaluated glass transition temperature T {sub g} and thermal expansivity as a function of film thickness. The glass transition temperature decreases with film thickness and is constant below about 10 nm, suggesting the surface glass transition temperature of 355 K, which is lower than that in bulk. We have also found that the thermal expansivity in the glassy state decreases with film thickness even after annealing. The decrease has been attributed to hardening of harmonic force constant arising from chain confinement in a thin film. This idea has been confirmed in the inelastic neutron scattering measurements.

  7. Sensing of volatile organic compounds by copper phthalocyanine thin films

    Science.gov (United States)

    Ridhi, R.; Saini, G. S. S.; Tripathi, S. K.

    2017-02-01

    Thin films of copper phthalocyanine have been deposited by thermal evaporation technique. We have subsequently exposed these films to the vapours of methanol, ethanol and propanol. Optical absorption, infrared spectra and electrical conductivities of these films before and after exposure to chemical vapours have been recorded in order to study their sensing mechanisms towards organic vapours. These films exhibit maximum sensing response to methanol while low sensitivities of the films towards ethanol and propanol have been observed. The changes in sensitivities have been correlated with presence of carbon groups in the chemical vapours. The effect of different types of electrodes on response-recovery times of the thin film with organic vapours has been studied and compared. The electrodes gap distance affects the sensitivity as well as response-recovery time values of the thin films.

  8. Thin film characterization by resonantly excited internal standing waves

    Energy Technology Data Exchange (ETDEWEB)

    Di Fonzio, S. [SINCROTRONE TRIESTE, Trieste (Italy)

    1996-09-01

    This contribution describes how a standing wave excited in a thin film can be used for the characterization of the properties of the film. By means of grazing incidence X-ray reflectometry one can deduce the total film thickness. On the other hand in making use of a strong resonance effect in the electric field intensity distribution inside a thin film on a bulk substrate one can learn more about the internal structure of the film. The profile of the internal standing wave is proven by diffraction experiments. The most appropriate non-destructive technique for the subsequent thin film characterization is angularly dependent X-ray fluorescence analysis. The existence of the resonance makes it a powerful tool for the detection of impurities and of ultra-thin maker layers, for which the position can be determined with very high precision (about 1% of the total film thickness). This latter aspect will be discussed here on samples which had a thin Ti marker layer at different positions in a carbon film. Due to the resonance enhancement it was still possible to perform these experiments with a standard laboratory x-ray tube and with standard laboratory tool for marker or impurity detection in thin films.

  9. Dip-coated hydrotungstite thin films as humidity sensors

    Indian Academy of Sciences (India)

    Thin films of a hydrated phase of tungsten oxide, viz. hydrotungstite, have been prepared on glass substrates by dip-coating method using ammonium tungstate precursor solution. X-ray diffraction shows the films to have a strong -axis orientation. The resistance of the films is observed to be sensitive to the humidity content ...

  10. Electrical Conductivity of CUXS Thin Film Deposited by Chemical ...

    African Journals Online (AJOL)

    Thin films of CuxS have successfully been deposited on glass substrates using the Chemical Bath Deposition (CBD) technique. The films were then investigated for their electrical properties. The results showed that the electrical conductivities of the CuxS films with different molarities (n) of thiourea (Tu), determined using ...

  11. Strain-induced properties of epitaxial VOx thin films

    NARCIS (Netherlands)

    Rata, AD; Hibma, T

    We have grown VOx thin films on different substrates in order to investigate the influence of epitaxial strain on the transport properties. We found that the electric conductivity is much larger for films grown under compressive strain on SrTiO3 substrates, as compared to bulk material and VOx films

  12. Thin-film cryogenic resistors from aluminium alloys

    Science.gov (United States)

    Tadros, N. N.; Holdeman, L. B.

    The temperature dependence of the resistances of thin films sputtered from three commercially available aluminium alloys (5052, 5086, 5456) has been measured in the temperature range 1.5-4.2 K. The 5052-alloy films had a positive temperature coefficient of resistance (TCR) throughout this temperature range, whereas films of the other two alloys had a negative TCR.

  13. OPTIMISATION OF SPRAY DEPOSITED Sno2 THIN FILM FOR ...

    African Journals Online (AJOL)

    Dr Obe

    1987-09-01

    Sep 1, 1987 ... ABSTRACT. The use of conducting tin-oxide (SnO2 ) films for fabrication of solar cell is becoming increasingly important because of reasonably high efficiency and ease in fabrication. The role of the thin-oxide film is very critical for high efficiency. Resistivity, thickness and transmittance of the film should be ...

  14. Photoluminescence-based quality control for thin film absorber layers of photovoltaic devices

    Science.gov (United States)

    Repins, Ingrid L.; Kuciauskas, Darius

    2015-07-07

    A time-resolved photoluminescence-based system providing quality control during manufacture of thin film absorber layers for photovoltaic devices. The system includes a laser generating excitation beams and an optical fiber with an end used both for directing each excitation beam onto a thin film absorber layer and for collecting photoluminescence from the absorber layer. The system includes a processor determining a quality control parameter such as minority carrier lifetime of the thin film absorber layer based on the collected photoluminescence. In some implementations, the laser is a low power, pulsed diode laser having photon energy at least great enough to excite electron hole pairs in the thin film absorber layer. The scattered light may be filterable from the collected photoluminescence, and the system may include a dichroic beam splitter and a filter that transmit the photoluminescence and remove scattered laser light prior to delivery to a photodetector and a digital oscilloscope.

  15. Resistive switching in polycrystalline YMnO3 thin films

    Directory of Open Access Journals (Sweden)

    A. Bogusz

    2014-10-01

    Full Text Available We report a unipolar, nonvolatile resistive switching in polycrystalline YMnO3 thin films grown by pulsed laser deposition and sandwiched between Au top and Ti/Pt bottom electrodes. The ratio of the resistance in the OFF and ON state is larger than 103. The observed phenomena can be attributed to the formation and rupture of conductive filaments within the multiferroic YMnO3 film. The generation of conductive paths under applied electric field is discussed in terms of the presence of grain boundaries and charged domain walls inherently formed in hexagonal YMnO3. Our findings suggest that engineering of the ferroelectric domains might be a promising route for designing and fabrication of novel resistive switching devices.

  16. Protein-modified nanocrystalline diamond thin films for biosensor applications.

    Science.gov (United States)

    Härtl, Andreas; Schmich, Evelyn; Garrido, Jose A; Hernando, Jorge; Catharino, Silvia C R; Walter, Stefan; Feulner, Peter; Kromka, Alexander; Steinmüller, Doris; Stutzmann, Martin

    2004-10-01

    Diamond exhibits several special properties, for example good biocompatibility and a large electrochemical potential window, that make it particularly suitable for biofunctionalization and biosensing. Here we show that proteins can be attached covalently to nanocrystalline diamond thin films. Moreover, we show that, although the biomolecules are immobilized at the surface, they are still fully functional and active. Hydrogen-terminated nanocrystalline diamond films were modified by using a photochemical process to generate a surface layer of amino groups, to which proteins were covalently attached. We used green fluorescent protein to reveal the successful coupling directly. After functionalization of nanocrystalline diamond electrodes with the enzyme catalase, a direct electron transfer between the enzyme's redox centre and the diamond electrode was detected. Moreover, the modified electrode was found to be sensitive to hydrogen peroxide. Because of its dual role as a substrate for biofunctionalization and as an electrode, nanocrystalline diamond is a very promising candidate for future biosensor applications.

  17. Spatially resolved photoconductive properties of profiled polycrystalline silicon thin films

    Science.gov (United States)

    Savenije, Tom J.; van Veenendaal, Patrick A. T. T.; de Haas, Matthijs P.; Warman, John M.; Schropp, Ruud E. I.

    2002-05-01

    To study the mobility and lifetime of charge carriers in thin film polycrystalline silicon deposited by hot-wire chemical vapor deposition, time-resolved microwave conductivity measurements have been performed. Using this technique the change in conductivity in the polycrystalline silicon films after pulsed excitation can be monitored on a nanosecond time scale, without the use of electrodes. Due to the different penetration depths of the laser wavelengths used (320, 500, and 690 nm) combined with illumination from different sides, the photoconductivity in different regions within the sample can be measured. Four different samples of polycrystalline silicon deposited on Corning glass have been studied: Poly1 (highly defective), Poly2 (device quality) and profiled layers of Poly1 and Poly2. For front or back illumination, the conductivity transients for the Poly1 film are very similar and show that lifetimes of the charge carriers generated are less than 1 ns. For the Poly2 film the mobility in the interfacial substrate region (μ=0.17 cm2/V s) is more than 1 order of magnitude lower than in the top region (μ=3.8 cm2/V s). The formation of a thin Poly1 film on the surface of the Corning substrate, acting as a seed layer for the Poly2 layer, followed by the deposition of the Poly2 layer, results in only a relatively small increase in the mobility in the region close to the substrate as compared to the bare Poly2 layer, while the mobility in the top region remains approximately constant.

  18. Photoinduced conductivity in tin dioxide thin films

    International Nuclear Information System (INIS)

    Muraoka, Y.; Takubo, N.; Hiroi, Z.

    2009-01-01

    The effects of ultraviolet light irradiation on the conducting properties of SnO 2-x thin films grown epitaxially on TiO 2 or Al 2 O 3 single-crystal substrates are studied at room temperature. A large increase in conductivity by two to four orders of magnitude is observed with light irradiation in an inert atmosphere and remains after the light is removed. The high-conducting state reverts to the original low-conducting state by exposing it to oxygen gas. These reversible phenomena are ascribed to the desorption and adsorption of negatively charged oxygen species at the grain boundaries, which critically change the mobility of electron carriers already present inside grains by changing the potential barrier height at the grain boundary. The UV light irradiation provides us with an easy and useful route to achieve a high-conducting state even at low carrier density in transparent conducting oxides and also to draw an invisible conducting wire or a specific pattern on an insulating film.

  19. Electrodeposition of thin Pd-Ag films

    International Nuclear Information System (INIS)

    Hasler, P.; Allmendinger, T.

    1993-01-01

    Thin Pd-Ag layers were electroplated preferably on brass and on nickel substrates using a two-compartment cell separated by an anion exchange membrane. The weakly alkaline electrolyte contained glycine-glycinate as the major complexing agents. The plating experiments were usually carried out without stirring, at different potentials and temperatures and in the absence or in the presence of sodium benzaldehyde-2,4-disulphonate (BDS). The samples were characterized by scanning electron microscopy and light microscopy. Their compositions were determined analytically by the inductively coupled plasma technique. In addition, the film porosity was tested. Electrodeposition in almost limiting current conditions for both components and without simultaneous hydrogen evolution led to deposits with compositions being in good agreement with the molar metal ratio in the electrolyte (77:23). The best results were achieved between 0 and -50 mV with respect to a reversible hydrogen electrode at 0 C in the presence of BDS. These deposits were bright, had good adherence and exhibited no pores at a film thickness of 1.2 μm. At too negative potentials, the deposits became black and powdery. (orig.)

  20. Polymer Based Thin Film Screen Preparation Technique

    Science.gov (United States)

    Valais, I.; Michail, C.; Fountzoula, C.; Fountos, G.; Saatsakis, G.; Karabotsos, A.; Panayiotakis, G. S.; Kandarakis, I.

    2017-11-01

    Phosphor screens, mainly prepared by electrophoresis, demonstrate brightness equal to the standard sedimentation on glass or quartz substrate process and are capable of very high resolution. Nevertheless, they are very fragile, the shape of the screen is limited to the substrate shape and in order to achieve adequate surface density for application in medical imaging, a significant quantity of the phosphor will be lost. Fluorescent films prepared by the dispersion of phosphor particles into a polymer matrix could solve the above disadvantages. The aim of this study is to enhance the stability of phosphor screens via the incorporation of phosphor particles into a PMMA (PolyMethyl MethAcrylate) matrix. PMMA is widely used as a plastic optical fiber, it shows almost nearly no dispersion effects and it is transparent in the whole visible spectral range. Different concentrations of PMMA in MMA (Methyl Methacrylate) were examined and a 37.5 % w/w solution was used for the preparation of the thin polymer film, since optical quality characteristics were found to depend on PMMA in MMA concentration. Scanning Electron Microscopy (SEM) images of the polymer screens demonstrated high packing density and uniform distribution of the phosphor particles. This method could be potentially used for phosphor screen preparation of any size and shape.

  1. Electroluminescence of doped organic thin films

    Science.gov (United States)

    Tang, C. W.; VanSlyke, S. A.; Chen, C. H.

    1989-05-01

    Electroluminescent (EL) devices are constructed using multilayer organic thin films. The basic structure consists of a hole-transport layer and a luminescent layer. The hole-transport layer is an amorphous diamine film in which the only mobile carrier is the hole. The luminescent layer consists of a host material, 8-hydroxyquinoline aluminum (Alq), which predominantly transports electrons. High radiance has been achieved at an operating voltage of less than 10 V. By doping the Alq layer with highly fluorescent molecules, the EL efficiency has been improved by about a factor of 2 in comparison with the undoped cell. Representative dopants are coumarins and DCMs. The EL quantum efficiency of the doped system is about 2.5%, photon/electron. The EL colors can be readily tuned from the blue-green to orange-red by a suitable choice of dopants as well as by changing the concentration of the dopant. In the doped system the electron-hole recombination and emission zones can be confined to about 50 Å near the hole-transport interface. In the undoped Alq, the EL emission zone is considerably larger due to exciton diffusion. The multilayer doped EL structure offers a simple means for the direct determination of exciton diffusion length.

  2. Preparation of B1-(Cr,Ga)N thin films by pulsed laser deposition

    Science.gov (United States)

    Mizuno, Yusei; Nakayama, Tadachika; Suematsu, Hisayuki; Suzuki, Tsuneo

    2018-02-01

    Cr–Ga–N thin films were prepared on (100)-oriented MgO single-crystal substrates by pulsed laser deposition at various substrate temperatures. An ablation plasma, generated by irradiating a Cr–10 at. % Ga alloy target with a Nd:YAG laser, was applied to the substrates to deposit the Cr–Ga–N thin films. Rutherford backscattering spectroscopy revealed that the ratio of the amount of Ga to the amount of Cr plus Ga (hereafter Cr+Ga) in all Cr–Ga–N thin films was approximately 10 at. %. X-ray diffraction and microstructural observation indicated that Cr–Ga–N thin films deposited at substrate temperatures (T sub) above 773 K contained two crystal phases: B1 (NaCl type)-CrN and B4 (würtzite type)-GaN. By contrast, Cr–Ga–N thin films deposited at a T sub of 673 K grew epitaxially and were composed of a single B1-(Cr,Ga)N phase, synthesized by substituting some of the Cr atoms in B1-CrN with Ga atoms. The epitaxial B1-(Cr,Ga)N thin films showed a higher hardness than epitaxial CrN films.

  3. 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

  4. Subtractive fabrication of ferroelectric thin films with precisely controlled thickness

    Science.gov (United States)

    Ievlev, Anton V.; Chyasnavichyus, Marius; Leonard, Donovan N.; Agar, Joshua C.; Velarde, Gabriel A.; Martin, Lane W.; Kalinin, Sergei V.; Maksymovych, Petro; Ovchinnikova, Olga S.

    2018-04-01

    The ability to control thin-film growth has led to advances in our understanding of fundamental physics as well as to the emergence of novel technologies. However, common thin-film growth techniques introduce a number of limitations related to the concentration of defects on film interfaces and surfaces that limit the scope of systems that can be produced and studied experimentally. Here, we developed an ion-beam based subtractive fabrication process that enables creation and modification of thin films with pre-defined thicknesses. To accomplish this we transformed a multimodal imaging platform that combines time-of-flight secondary ion mass spectrometry with atomic force microscopy to a unique fabrication tool that allows for precise sputtering of the nanometer-thin layers of material. To demonstrate fabrication of thin-films with in situ feedback and control on film thickness and functionality we systematically studied thickness dependence of ferroelectric switching of lead-zirconate-titanate, within a single epitaxial film. Our results demonstrate that through a subtractive film fabrication process we can control the piezoelectric response as a function of film thickness as well as improve on the overall piezoelectric response versus an untreated film.

  5. Junctionless Thin-Film Transistors Gated by an H₃PO₄-Incorporated Chitosan Proton Conductor.

    Science.gov (United States)

    Liu, Huixuan; Xun, Damao

    2018-04-01

    We fabricated an H3PO4-incorporated chitosan proton conductor film that exhibited the electric double layer effect and showed a high specific capacitance of 4.42 μF/cm2. Transparent indium tin oxide thin-film transistors gated by H3PO4-incorporated chitosan films were fabricated by sputtering through a shadow mask. The operating voltage was as low as 1.2 V because of the high specific capacitance of the H3PO4-incorporated chitosan dielectrics. The junctionless transparent indium tin oxide thin film transistors exhibited good performance, including an estimated current on/off ratio and field-effect mobility of 1.2 × 106 and 6.63 cm2V-1s-1, respectively. These low-voltage thin-film electric-double-layer transistors gated by H3PO4-incorporated chitosan are promising for next generation battery-powered "see-through" portable sensors.

  6. Enhancement of Ammonia Sensitivity in Swift Heavy Ion Irradiated Nanocrystalline SnO2 Thin Films

    Directory of Open Access Journals (Sweden)

    Sanju Rani

    2008-01-01

    Full Text Available Swift heavy ion irradiation is an effective technique to induce changes in the microstructure and electronic energy levels of materials leading to significant modification of properties. Here we report enhancement of ammonia (NH3 sensitivity of SnO2 thin films subjected to high-energy Ni+ ion irradiation. Sol-gel-derived SnO2 thin films (100 nm thickness were exposed to 75 MeV Ni+ ion irradiation, and the gas response characteristics of irradiated films were studied as a function of ion fluence. The irradiated films showed p-type conductivity with a much higher response to NH3 compared to other gases such as ethanol. The observed enhancement of NH3 sensitivity is discussed in context of ion beam generated electronic states in the SnO2 thin films.

  7. Electron field emission from amorphous semiconductor thin films

    International Nuclear Information System (INIS)

    Forrest, R.D.

    2001-01-01

    The flat panel display market requires new and improved technologies in order to keep up with the requirements of modem lifestyles. Electron field emission from thin film amorphous semiconductors is potentially such a technology. For this technology to become viable, improvements in the field emitting properties of these materials must be achieved. To this end, it is important that a better understanding of the emission mechanisms responsible is attained. Amorphous carbon thin films, amorphous silicon thin films and other materials have been deposited, in-house and externally. These materials have been characterised using ellipsometry, profilometry, optical absorption, scanning electron microscopy, atomic force microscopy, electron paramagnetic resonance and Rutherford backscattering spectroscopy. An experimental system for evaluating the electron field emitting performance of thin films has been developed. In the process of developing thin film cathodes in this study, it has been possible to add a new and potentially more useful semiconductor, namely amorphous silicon, to the family of cold cathode emitters. Extensive experimental field emission data from amorphous carbon thin films, amorphous silicon thin films and other materials has been gathered. This data has been used to determine the mechanisms responsible for the observed electron emission. Preliminary computer simulations using appropriate values for the different material properties have exhibited emission mechanisms similar to those identified by experiment. (author)

  8. Plasma polymerised thin films for flexible electronic applications

    International Nuclear Information System (INIS)

    Jacob, Mohan V.; Olsen, Natalie S.; Anderson, Liam J.; Bazaka, Kateryna; Shanks, Robert A.

    2013-01-01

    The significant advancement and growth of organic and flexible electronic applications demand materials with enhanced properties. This paper reports the fabrication of a nonsynthetic polymer thin film using radio frequency plasma polymerisation of 3,7-dimethyl-1,6-octadien-3-ol. The fabricated optically transparent thin film exhibited refractive index of approximately 1.55 at 500 nm and rate of deposition was estimated to be 40 nm/min. The surface morphology and chemical properties of the thin films were also reported in this paper. The optical band gap of the material is around 2.8 eV. The force of adhesion and Young's modulus of the linalool polymer thin films were measured using force-displacement curves obtained from a scanning probe microscope. The friction coefficient of linalool polymer thin films was measured using the nanoscratch test. The calculated Young's modulus increased linearly with increase in input power while the friction coefficient decreased. - Highlights: • Fabrication of a novel polymer thin film from non-synthetic source • The surface, optical and chemical properties are reported. • The fabricated thin film is transparent and smooth. • An environmentally friendly material • Candidate for flexible electronics as dielectric layer or as an encapsulation layer

  9. Plasma polymerised thin films for flexible electronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, Mohan V., E-mail: mohan.jacob@jcu.edu.au [Electronic Materials Research Lab, School of Engineering and Physical Sciences, James Cook University, Townsville 4811 (Australia); Olsen, Natalie S.; Anderson, Liam J.; Bazaka, Kateryna [Electronic Materials Research Lab, School of Engineering and Physical Sciences, James Cook University, Townsville 4811 (Australia); Shanks, Robert A. [Applied Sciences, RMIT University, GPO Box 2476V, Melbourne 3001 (Australia)

    2013-11-01

    The significant advancement and growth of organic and flexible electronic applications demand materials with enhanced properties. This paper reports the fabrication of a nonsynthetic polymer thin film using radio frequency plasma polymerisation of 3,7-dimethyl-1,6-octadien-3-ol. The fabricated optically transparent thin film exhibited refractive index of approximately 1.55 at 500 nm and rate of deposition was estimated to be 40 nm/min. The surface morphology and chemical properties of the thin films were also reported in this paper. The optical band gap of the material is around 2.8 eV. The force of adhesion and Young's modulus of the linalool polymer thin films were measured using force-displacement curves obtained from a scanning probe microscope. The friction coefficient of linalool polymer thin films was measured using the nanoscratch test. The calculated Young's modulus increased linearly with increase in input power while the friction coefficient decreased. - Highlights: • Fabrication of a novel polymer thin film from non-synthetic source • The surface, optical and chemical properties are reported. • The fabricated thin film is transparent and smooth. • An environmentally friendly material • Candidate for flexible electronics as dielectric layer or as an encapsulation layer.

  10. 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

  11. The effect of film thickness and molecular structure on order and disorder in thin films of compositionally asymmetric block copolymers

    Science.gov (United States)

    Mishra, Vindhya

    Directed self-assembly of thin film block copolymers offer a high throughput-low cost route to produce next generation lithographic devices, if one can bring the defect densities in the self assembled patterns below tolerance limits. However, the ability to control the nanoscale structure or morphology in thin film block copolymers presents challenges due to confinement effects on equilibrium behavior. Using structure characterization techniques such as grazing incidence small angle X-ray scattering (GISAXS), transmission electron and atomic force microscopy as well as self-consistent field theory, we have investigated how film thickness, annealing temperature and block copolymer structure affects the equilibrium behavior of asymmetric block copolymer films. Our studies have revealed the complicated dependence of order-disorder transitions, order-order transitions and symmetry transitions on film thickness. We found that the thickness dependent transition in the packing symmetry of spherical morphology diblock copolymers can be suppressed by blending with a small amount of majority block homopolymer, which allowed us to resolve the driving force behind this transition. Defect densities in, and the order-disorder transition temperature of, thin films of graphoepitaxially aligned diblock copolymer cylinders showed surprising sensitivity to the microdomain spacing. Methods to mitigate defect formation in thin films have been identified. The challenge of quantification of structural order in these systems was overcome using GISAXS, which allowed us to study the phenomena of disordering in two and three dimensions. Through studies on block copolymers which exhibit an order-order transition in bulk, we found that that subtle differences in the packing frustration of the spherical and cylindrical phases as well as the higher configurational entropy of free chain ends at the surface can drive the equilibrium configuration in thin films away from the stable bulk structure

  12. The applications of electron accelerator. Liquid, thin film and gases

    International Nuclear Information System (INIS)

    Khairul Zaman Hj Mohd Dahlan; Kamaruddin Hashim; Zulkafli Ghazali

    2004-01-01

    As indicated by the results of this study, low energy electron beam accelerator of 200 keV to 500 keV can be utilized to irradiate thin hydrogel film in the range of 60 to 500 μm thickness. However, the industrial applications of this technology will depend on its applications. For thin films, cosmetic use such as faced mask is possible. The production of sago hydrogel for cosmetic used is in the process of commercialization in Malaysia. As for electron beam treatment of industrial wastewater in particular the effluent from the textile industry is still at infancy. Further work is necessary in order to have a base line data before the commercialization is taken place. Malaysia has also embarked on the electron beam treatment of flue gases and has completed the semi-pilot scale study by using 1.0 MeV electron accelerator voltage and 400 cum flue gas generated from diesel generator. This study was conducted together with the TNB Research, the research institute belongs to the electrical power company in Malaysia. For technology transfer and commercialization, MINT is planned to promote this technology to Independent Power Producers (IPP) in Malaysia. (author)

  13. Development of Flexible Electrochromic Device with Thin-Film Configuration

    Science.gov (United States)

    Yoshimura, Hideo; Sakaguchi, Tomonori; Koshida, Nobuyoshi

    2007-04-01

    As we reported previously, the carrier accumulation mechanism is very useful for obtaining a quick-response electrochromic (EC) device with the inorganic-thin-film configuration. To confirm the availability of this concept for flexible substrates, the EC device has been fabricated on a polymeric film. The device is composed of a top semitransparent electrode, an electrolytic thin Ta2O5 film, a very thin SiO2 film, a thin amorphous WO3 film, and an indium-tin-oxide-coated poly(ethylene terephthalate) (PET) film. The experimental results show that the insertion of thin SiO2 film significantly accelerates the EC coloration as in the case of glass substrates. In accordance with cyclic voltammogram analyses, the enhanced EC kinetics is associated with an increased EC efficiency owing to the carrier accumulation effect of thin SiO2 film. The present result is potentially useful for development of flexible paper-like EC display devices and simple optical control systems.

  14. Multifunctional Parylene-C Microfibrous Thin Films

    Science.gov (United States)

    Chindam, Chandraprakash

    Towards sustainable development, multifunctional products have many advantageous over single-function products: reduction in number of parts, raw material, assembly time, and cost involved in a product's life cycle. My goal for this thesis was to demonstrate the multifunctionalities of Parylene-C microfibrous thin films. To achieve this goal, I chose Parylene C, a polymer, because the fabrication of periodic mediums of Parylene C in the form of microfibrous thin films (muFTFs) was already established. A muFTFs is a parallel arrangement of identical micrometer-sized fibers of shapes cylindrical, chevronic, or helical. Furthermore, Parylene C had three existing functions: in medical-device industries as corrosion-resistive coatings, in electronic industries as electrically insulating coatings, and in biomedical research for tissue-culture substrates. As the functionalities of a material are dependent on the microstructure and physical properties, the investigation made for this thesis was two-fold: (1) Experimentally, I determined the wetting, mechanical, and dielectric properties of columnar muFTFs and examined the microstructural and molecular differences between bulk films and muFTFs. (2) Using physical properties of bulk film, I computationally determined the elastodynamic and determined the electromagnetic filtering capabilities of Parylene-C muFTFs. Several columnar muFTFs of Parylene C were fabricated by varying the monomer deposition angle. Following are the significant experimental findings: 1. Molecular and microstructural characteristics: The dependence of the microfiber inclination angle on the monomer deposition angle was classified into four regimes of two different types. X-ray diffraction experiments indicated that the columnar muFTFs contain three crystal planes not evident in bulk Parylene-C films and that the columnar muFTFs are less crystalline than bulk films. Infrared absorbance spectra revealed that the atomic bonding is the same in all

  15. Fabrication and Film Qualification of Sr Modified Pb(Ca) TiO3 Thin Films

    International Nuclear Information System (INIS)

    Naw Hla Myat San; Khin Aye Thwe; Than Than Win; Yin Maung Maung; Ko Ko Kyaw Soe

    2011-12-01

    Strontium and calcium - modified lead titanate (Pb0.7 Ca0.15 Sr0.15 ) TiO3 (PCST)thin films were prepared by using spin coating technique. Phase transition of PCST was interpreted by means of Er-T characteristics. Process temperature dependence on micro-structure of PCST film was studied. Charge conduction mechanism of PCST thin film was also investigated for film qualification.

  16. Molecular simulation of freestanding amorphous nickel thin films

    Energy Technology Data Exchange (ETDEWEB)

    Dong, T.Q. [Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, UMR 8208 CNRS, 5 Boulevard Descartes, 77454 Marne-la-Vallée, Cedex 2 (France); Hoang, V.V., E-mail: vvhoang2002@yahoo.com [Department of Physics, Institute of Technology, National University of Ho Chi Minh City, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City (Viet Nam); Lauriat, G. [Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, UMR 8208 CNRS, 5 Boulevard Descartes, 77454 Marne-la-Vallée, Cedex 2 (France)

    2013-10-31

    Size effects on glass formation in freestanding Ni thin films have been studied via molecular dynamics simulation with the n-body Gupta interatomic potential. Atomic mechanism of glass formation in the films is determined via analysis of the spatio-temporal arrangements of solid-like atoms occurred upon cooling from the melt. Solid-like atoms are detected via the Lindemann ratio. We find that solid-like atoms initiate and grow mainly in the interior of the film and grow outward. Their number increases with decreasing temperature and at a glass transition temperature they dominate in the system to form a relatively rigid glassy state of a thin film shape. We find the existence of a mobile surface layer in both liquid and glassy states which can play an important role in various surface properties of amorphous Ni thin films. We find that glass formation is size independent for models containing 4000 to 108,000 atoms. Moreover, structure of amorphous Ni thin films has been studied in details via coordination number, Honeycutt–Andersen analysis, and density profile which reveal that amorphous thin films exhibit two different parts: interior and surface layer. The former exhibits almost the same structure like that found for the bulk while the latter behaves a more porous structure containing a large amount of undercoordinated sites which are the origin of various surface behaviors of the amorphous Ni or Ni-based thin films found in practice. - Highlights: • Glass formation is analyzed via spatio-temporal arrangements of solid-like atoms. • Amorphous Ni thin film exhibits two different parts: surface and interior. • Mobile surface layer enhances various surface properties of the amorphous Ni thin films. • Undercoordinated sites play an important role in various surface activities.

  17. Nanoscale phenomena in ferroelectric thin films

    Science.gov (United States)

    Ganpule, Chandan S.

    Ferroelectric materials are a subject of intense research as potential candidates for applications in non-volatile ferroelectric random access memories (FeRAM), piezoelectric actuators, infrared detectors, optical switches and as high dielectric constant materials for dynamic random access memories (DRAMs). With current trends in miniaturization, it becomes important that the fundamental aspects of scaling of ferroelectric and piezoelectric properties in these devices be studied thoroughly and their impact on the device reliability assessed. In keeping with this spirit of miniaturization, the dissertation has two broad themes: (a) Scaling of ferroelectric and piezoelectric properties and (b) The key reliability issue of retention loss. The thesis begins with a look at results on scaling studies of focused-ion-beam milled submicron ferroelectric capacitors using a variety of scanning probe characterization tools. The technique of piezoresponse microscopy, which is rapidly becoming an accepted form of domain imaging in ferroelectrics, has been used in this work for another very important application: providing reliable, repeatable and quantitative numbers for the electromechanical properties of submicron structures milled in ferroelectric films. This marriage of FIB and SPM based characterization of electromechanical and electrical properties has proven unbeatable in the last few years to characterize nanostructures qualitatively and quantitatively. The second half of this dissertation focuses on polarization relaxation in FeRAMs. In an attempt to understand the nanoscale origins of back-switching of ferroelectric domains, the time dependent relaxation of remnant polarization in epitaxial lead zirconate titanate (PbZr0.2Ti0.8O 3, PZT) ferroelectric thin films (used as a model system), containing a uniform 2-dimensional grid of 90° domains (c-axis in the plane of the film) has been examined using voltage modulated scanning force microscopy. A novel approach of

  18. Stability of tetraphenyl butadiene thin films in liquid xenon

    International Nuclear Information System (INIS)

    Sanguino, P.; Balau, F.; Botelho do Rego, A.M.; Pereira, A.; Chepel, V.

    2016-01-01

    Tetraphenyl butadiene (TPB) is widely used in particle detectors as a wavelength shifter. In this work we studied the stability of TPB thin films when immersed in liquid xenon (LXe). The thin films were deposited on glass and quartz substrates by thermal evaporation. Morphological and chemical surface properties were monitored before and after immersion into LXe by scanning electron microscopy and X-ray photoelectron spectroscopy. No appreciable changes have been detected with these two methods. Grain size and surface chemical composition were found to be identical before and after submersion into LXe. However, the film thickness, measured via optical transmission in the ultraviolet–visible wavelength regions, decreased by 1.6 μg/cm 2 (24%) after immersion in LXe during 20 h. These results suggest the necessity of using a protective thin film over the Tetraphenyl butadiene when used as a wavelength shifter in LXe particle detectors. - Highlights: • Stability of tetraphenyl butadiene (TPB) thin films immersed in liquid xenon (LXe). • Thermally evaporated TPB thin films were immersed in LXe for 20 h. • Film morphology and chemical surface properties remained unchanged. • Surface density of the films decreased by 1.6 μg/cm 2 (24%) after immersion in LXe. • For using in LXe particle detectors, TPB films should be protected with a coating.

  19. Buckling of Thin Films in Nano-Scale

    Directory of Open Access Journals (Sweden)

    Li L.A.

    2010-06-01

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

  20. Buckling of Thin Films in Nano-Scale

    Science.gov (United States)

    Wang, S.; Jia, H. K.; Sun, J.; Ren, X. N.; Li, L. A.

    2010-06-01

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

  1. Principles of electron backscattering by solids and thin films

    International Nuclear Information System (INIS)

    Niedrig, H.

    1977-01-01

    The parameters concerning the electron backscattering from thin films and solids (atomic scattering cross-section, atomic number, single/multiple scattering, film thickness of self-supporting films and of surface films on bulk substrates, scattering angular distribution, angle of incidence, diffraction effects) are described. Their influence on some important contrast mechanisms in scanning electron microscopy (thickness contrast, Z/material contrast, tilting/topography contrast, orientation contrast) is discussed. The main backscattering electron detection systems are briefly described. (orig.) [de

  2. Modification of thin film properties by ion bombardment during deposition

    International Nuclear Information System (INIS)

    Harper, J.M.E.; Cuomo, J.J.; Gambino, R.J.; Kaufman, H.R.

    1984-01-01

    Many thin film deposition techniques involve some form of energetic particle bombardment of the growing film. The degree of bombardment greatly influences the film composition, structure and other properties. While in some techniques the degree of bombardment is secondary to the original process design, in recent years more deposition systems are being designed with the capability for controlled ion bombardment of thin films during deposition. The highest degree of control is obtained with ion beam sources which operate independently of the vapor source providing the thin film material. Other plasma techniques offer varying degrees of control of energetic particle bombardment. Deposition methods involving ion bombardment are described, and the basic processes with which film properties are modified by ion bombardment are summarized. (Auth.)

  3. Rapid protein immobilization for thin film continuous flow biocatalysis.

    Science.gov (United States)

    Britton, Joshua; Raston, Colin L; Weiss, Gregory A

    2016-08-09

    A versatile enzyme immobilization strategy for thin film continuous flow processing is reported. Here, non-covalent and glutaraldehyde bioconjugation are used to immobilize enzymes on the surfaces of borosilicate reactors. This approach requires only ng of protein per reactor tube, with the stock protein solution readily recycled to sequentially coat >10 reactors. Confining reagents to thin films during immobilization reduced the amount of protein, piranha-cleaning solution, and other reagents by ∼96%. Through this technique, there was no loss of catalytic activity over 10 h processing. The results reported here combines the benefits of thin film flow processing with the mild conditions of biocatalysis.

  4. Plasma polymerized hexamethyldisiloxane thin films for corrosion protection

    Science.gov (United States)

    Saloum, S.; Alkhaled, B.; Alsadat, W.; Kakhia, M.; Shaker, S. A.

    2018-01-01

    This study focused on the corrosion protection performance of plasma polymerized HMDSO thin films in two different corrosive medias, 0.3M NaCl and 0.3M H2SO4. The pp-HMDSO thin films were deposited on steel substrates for electrochemical tests using the potentiodynamic polarization technique, they were deposited also on aluminum and silicon substrates to investigate their resistance to corrosion, through the analysis of the degradation of microhardness and morphology, respectively, after immersion of the substrates for one week in the corrosive media. The results showed promising corrosion protection properties of the pp-HMDSO thin films.

  5. Optical modeling and simulation of thin-film photovoltaic devices

    CERN Document Server

    Krc, Janez

    2013-01-01

    In wafer-based and thin-film photovoltaic (PV) devices, the management of light is a crucial aspect of optimization since trapping sunlight in active parts of PV devices is essential for efficient energy conversions. Optical modeling and simulation enable efficient analysis and optimization of the optical situation in optoelectronic and PV devices. Optical Modeling and Simulation of Thin-Film Photovoltaic Devices provides readers with a thorough guide to performing optical modeling and simulations of thin-film solar cells and PV modules. It offers insight on examples of existing optical models

  6. Organic nanostructured thin film devices and coatings for clean energy

    CERN Document Server

    Zhang, Sam

    2010-01-01

    Authored by leading experts from around the world, the three-volume Handbook of Nanostructured Thin Films and Coatings gives scientific researchers and product engineers a resource as dynamic and flexible as the field itself. The first two volumes cover the latest research and application of the mechanical and functional properties of thin films and coatings, while the third volume explores the cutting-edge organic nanostructured devices used to produce clean energy. This third volume, Organic Nanostructured Thin Film Devices and Coatings for Clean Energy, addresses various aspects of the proc

  7. Copper zinc tin sulfide-based thin film solar cells

    CERN Document Server

    Ito, Kentaro

    2014-01-01

    Beginning with an overview and historical background of Copper Zinc Tin Sulphide (CZTS) technology, subsequent chapters cover properties of CZTS thin films, different preparation methods of CZTS thin films, a comparative study of CZTS and CIGS solar cell, computational approach, and future applications of CZTS thin film solar modules to both ground-mount and rooftop installation. The semiconducting compound (CZTS) is made up earth-abundant, low-cost and non-toxic elements, which make it an ideal candidate to replace Cu(In,Ga)Se2 (CIGS) and CdTe solar cells which face material scarcity and tox

  8. Characterisation of thin films by phase modulated spectroscopic ellipsometry

    International Nuclear Information System (INIS)

    Bhattacharyya, D.; Das, N.C.

    1998-07-01

    A wide variety of thin film coatings, deposited by different techniques and with potential applications in various important areas, have been characterised by the Phase Modulated Spectroscopic Ellipsometer, installed recently in the Spectroscopy Division, B.A.R.C. The Phase Modulated technique provides a faster and more accurate data acquisition process than the conventional ellipsometry. The measured Ellipsometry spectra are fitted with theoretical spectra generated assuming an appropriate model regarding the sample. The fittings have been done objectively by minimising the squared difference (χ 2 ) between the measured and calculated values of the ellipsometric parameters and thus accurate information have been derived regarding the thickness and optical constants (viz, the refractive index and extinction coefficient) of the different layers, the surface roughness and the inhomogeneities present in the layers. Measurements have been done on (i) ion-implanted Si-wafers to investigate the formation of SiC layers, (ii) phenyl- silane coating on glass to investigate the surface modifications achieved for better adsorption of rhodamine dye on glass, (iii) GaN films on quartz to investigate the formation of high quality GaN layers by sputtering of GaAs targets, (iv) Diamond-like-coating (DLC) samples prepared by Chemical Vapour Deposition (CVD) to investigate the optical properties which would ultimately lead to an accurate estimation of the ratio of sp 3 and sp 2 bonded carbon atoms in the films and (v) SS 304 under different surface treatments to investigate the growth of different passive films. (author)

  9. Multifunctional Ceramic Nanostructure Thin Films Prepared by Solution Processing

    Science.gov (United States)

    Shim, Jong Hyun

    Oxide semiconductor coatings have been studied for the development of their nanostructures that can be tailored for multifunctional surface properties. We employed solution processing methods such as chemical bath deposition and hydrothermal process to deposit TiO2 and ZnO thin film nanostructures on various substrates including transparent conductive oxides (TCOs), polymers (polycarbonate, Teflon), and metals (stainless steels, Ti). In particular, low dimensional nanostructures (1D, 2D) were tailored by different solution process conditions. Especially, the 1D TiO2 nanorod structure were shown to grow via a non-classical crystallization way. The performances of vertically aligned TiO2 (rutile) nanorod thin films were evaluated for its use as a photoanode in dye sensitized solar cell (DSSC) and as a photocatalytic surface for organic dye degradation. In addition, densely packed 2-dimensional rutile nanoblade structure was examined for a high-k dielectric layer. And the vertically aligned ZnO nanorod thin films were grown as photocatalytic coatings and antimicrobial surfaces. The latter aspect resulted from the strong photocatalytic behavior, as well as the nanoshape effects. To control the nano- and microstructures of TiO2 and ZnO through process parameters, we used the degree of 'supersaturation' that was calculated from aqueous thermodynamics. When the thermodynamics data were not available, it was obtained through experimental measurements. In an effort to maximize the photo-responsive capacity, the hybrid structures consisting of TiO2/ZnO and ZnO/P3HT[Poly(3-hexylthiophene-2,5-diyl)] were investigated for further enhancement of the photoanode properties and photocurrent generation, respectively. This work shows that highly multifunctional oxide surface properties can be made possible through the developments of low-temperature, solution-grown nanostructures with precise process controls.

  10. Ultrashort-pulse laser ablation of gold thin film targets: Theory and experiment

    International Nuclear Information System (INIS)

    Amoruso, S.; Nedyalkov, N.N.; Wang, X.; Ausanio, G.; Bruzzese, R.; Atanasov, P.A.

    2014-01-01

    Laser ablation of a gold thin film irradiated by ultrashort pulses is studied using molecular-dynamics simulations, and compared with that of a bulk target. A film thickness comparable to the ballistic electron depth in gold (≈ 100 nm) is considered, evidencing a significant change of the temperature spatial profile inside the target material, which eventually influences the material decomposition. Particular emphasis is given to the process of nanoparticle generation. The simulations indicate a more uniform heating of the sample in the case of the thin film, which is accompanied by a more homogeneous size distribution of the nanoparticles produced in the ablation process. An experimental characterization of the ultrashort-pulse ablation process is also carried out. The produced nanoparticles are collected on suitable substrates, and atomic force microscopy analysis of less than one layer deposits is performed. An ≈ 2 × narrowing of the nanoparticles equivalent to spherical diameter size distribution is observed in the case of ablation of the gold thin film, in fairly good agreement with the theoretical predictions. Moreover, interesting changes of the nanoparticle shape are evidenced, which are correlated to the changes in the nanoparticle ablation plume dynamics, as studied by time-gated imaging of its self-emission. Our findings suggest ultrashort-pulse laser ablation of thin films as a viable route to achieve a more uniform nanoparticle size distribution. - Highlights: • Nanoparticle generation at fs laser ablation of Au bulk target and thin film is studied. • The spatial confinement in depth at thin film geometry results in homogeneous heating. • Narrower and more homogeneous particle size distribution is observed for thin film

  11. Swift heavy ion induced modifications in optical and electrical properties of cadmium selenide thin films

    Science.gov (United States)

    Choudhary, Ritika; Chauhan, Rishi Pal

    2017-07-01

    The modification in various properties of thin films using high energetic ion beam is an exciting area of basic and applied research in semiconductors. In the present investigations, cadmium selenide (CdSe) thin films were deposited on ITO substrate using electrodeposition technique. To study the swift heavy ion (SHI) induced effects, the deposited thin films were irradiated with 120 MeV heavy Ag9+ ions using pelletron accelerator facility at IUAC, New Delhi, India. Structural phase transformation in CdSe thin film from metastable cubic phase to stable hexagonal phase was observed after irradiation leading to decrease in the band gap from 2.47 eV to 2.12 eV. The phase transformation was analyzed through X-ray diffraction patterns. During SHI irradiation, Generation of high temperature and pressure by thermal spike along the trajectory of incident ions in the thin films might be responsible for modification in the properties of thin films.[Figure not available: see fulltext.

  12. Tools to synthesize the learning of thin films

    International Nuclear Information System (INIS)

    Rojas, Roberto; Fuster, Gonzalo; Sluesarenko, Viktor

    2011-01-01

    After a review of textbooks written for undergraduate courses in physics, we have found that discussions on thin films are mostly incomplete. They consider the reflected and not the transmitted light for two instead of the four types of thin films. In this work, we complement the discussion in elementary textbooks, by analysing the phase differences required to match the conditions for constructive and destructive interference, in the reflected and transmitted light in four types of thin films. We consider thin films with varied sequences in the refractive index, which we identify as barriers, wells and stairs (up and down). Also, we use the conservation of energy in order to understand the complementary colour fringes observed in the reflected and transmitted light through thin films. We analyse systematically the phase changes by introducing a phase table and we synthesize the results in a circular diagram matching 16 physical situations of interference and their corresponding conditions on the film thickness. The phase table and the circular diagram are a pair of tools easily assimilated by students, and useful to organize, analyse and activate the knowledge about thin films.

  13. Radiation Effects in Interfaces and Thin Films

    Science.gov (United States)

    Mairov, Alexander

    One of the key approaches to developing materials with greater radiation damage resistance is to introduce a large fraction of internal interfaces. Interfaces act as sinks for recombination of radiation-induced defects and as sites for accumulation of helium bubbles, thereby diverting them away from grain boundaries, where they can induce embrittlement. The beneficial role of interfaces in mitigating radiation damage has been demonstrated in nanoscale multilayered structures and in nanograined materials. Another more common example is oxide dispersion strengthened (ODS) steels and nanostructured ferritic alloys (NFA) where a fine distribution of particles (clusters) of varying stoichiometries (e.g., Y2Ti2O7, Y2TiO 5, Y2O3, TiO2 and Y-Ti-O non-stoichiometric oxides) not only confer high creep strength, but also high radiation damage tolerance due to the large area of metal/oxide interfaces. However, the efficacy of these interfaces to act as defect sinks depends on their compositional and physical stability under radiation. With this background, this work focused on the stability of interfaces between Ti, TiO2, and Y2O 3 thin film deposited on Fe-12%Cr substrates after irradiation with 5MeV Ni+2 ions at various temperatures. TEM and STEM-EDS methods were used to understand the compositional changes at the interfaces. Additionally, accumulation of implanted helium at epitaxial and non-epitaxial Fe/Y 2O3 interfaces was also studied. Finally, the study was extended to study irradiation effects (up to 150 dpa) in novel Al2O 3 nanoceramic films with immediate potential applications as coatings for corrosion protection in the harsh high temperature environments of Gen IV reactors. This research is expected to have implications in the development of radiation damage tolerant nanostructured alloys for nuclear reactors while also expanding the scientific knowledge-base in the area of radiation stability of interfaces in solids and protective coatings.

  14. Electrochromic performances of nonstoichiometric NiO thin films

    International Nuclear Information System (INIS)

    Moulki, H.; Faure, C.; Mihelčič, M.; Vuk, A. Šurca; Švegl, F.; Orel, B.; Campet, G.; Alfredsson, M.; Chadwick, A.V.; Gianolio, D.; Rougier, A.

    2014-01-01

    Electrochromic (EC) performances of Ni 3+ containing NiO thin films, called modified NiO thin films, prepared either by pulsed laser deposition or by chemical route are reported. When cycled in lithium based electrolyte, the comparison of the EC behavior of nonstoichiometric NiO thin films points out a larger optical contrast for the films synthesized by chemical route with the absence of an activation period on early electrochemical cycling due in particular to a larger porosity. Herein we demonstrate faster kinetics for modified NiO thin films cycled in lithium ion free electrolyte. Finally, X-ray absorption spectroscopy is used for a preliminary understanding of the mechanism involved in this original EC behavior linked to the film characteristics including their disorder character, the presence of Ni 3+ and their porous morphology. - Highlights: • Nonstoichiometric NiO thin films • Electrochromic performances in lithium free electrolyte • X-ray absorption spectroscopy investigation of as-deposited films and upon cycling

  15. Strain-induced phenomenon in complex oxide thin films

    Science.gov (United States)

    Haislmaier, Ryan

    Complex oxide materials wield an immense spectrum of functional properties such as ferroelectricity, ferromagnetism, magnetoelectricity, optoelectricity, optomechanical, magnetoresistance, superconductivity, etc. The rich coupling between charge, spin, strain, and orbital degrees of freedom makes this material class extremely desirable and relevant for next generation electronic devices and technologies which are trending towards nanoscale dimensions. Development of complex oxide thin film materials is essential for realizing their integration into nanoscale electronic devices, where theoretically predicted multifunctional capabilities of oxides could add tremendous value. Employing thin film growth strategies such as epitaxial strain and heterostructure interface engineering can greatly enhance and even unlock novel material properties in complex oxides, which will be the main focus of this work. However, physically incorporating oxide materials into devices remains a challenge. While advancements in molecular beam epitaxy (MBE) of thin film oxide materials has led to the ability to grow oxide materials with atomic layer precision, there are still major limitations such as controlling stoichiometric compositions during growth as well as creating abrupt interfaces in multi-component layered oxide structures. The work done in this thesis addresses ways to overcome these limitations in order to harness intrinsic material phenomena. The development of adsorption-controlled stoichiometric growth windows of CaTiO3 and SrTiO3 thin film materials grown by hybrid MBE where Ti is supplied using metal-organic titanium tetraisopropoxide material is thoroughly outlined. These growth windows enable superior epitaxial strain-induced ferroelectric and dielectric properties to be accessed as demonstrated by chemical, structural, electrical, and optical characterization techniques. For tensile strained CaTiO3 and compressive strained SrTiO 3 films, the critical effects of

  16. Degradation process in organic thin film devices fabricated using ...

    Indian Academy of Sciences (India)

    hexylthiophene); organic semiconductors; conducting polymers; degradation. ... The stability of regioregular poly(3-hexylthiophene 2,5-diyl) (P3HT) thin films sandwiched between indium tin oxide (ITO) and aluminium (Al) electrodes have ...

  17. Modeling surface imperfections in thin films and nanostructured surfaces

    DEFF Research Database (Denmark)

    Hansen, Poul-Erik; Madsen, J. S.; Jensen, S. A.

    2017-01-01

    Accurate scatterometry and ellipsometry characterization of non-perfect thin films and nanostructured surfaces are challenging. Imperfections like surface roughness make the associated modelling and inverse problem solution difficult due to the lack of knowledge about the imperfection...

  18. Property elucidation of vacuum-evaporated zinc telluride thin film ...

    Indian Academy of Sciences (India)

    J U Ahamed

    2017-08-31

    ZnTe) thin film on glass substrate in order to investigate the ... photovoltaic solar cells, light-emitting diodes, laser diodes, microwave devices .... integrated intensity ratio of a super lattice peak to a fun- damental peak. Comparing ...

  19. Chemical solution deposition of functional oxide thin films

    CERN Document Server

    Schneller, Theodor; Kosec, Marija

    2014-01-01

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

  20. Self-organized structures in soft confined thin films

    Indian Academy of Sciences (India)

    organized creation of mesostructures in soft materials like thin films of polymeric liquids and elas- tic solids. These very small scale, highly confined systems are inherently unstable and thus self-organize into ordered structures which can be ...

  1. Broadband back grating design for thin film solar cells

    KAUST Repository

    Janjua, Bilal

    2013-01-01

    In this paper, design based on tapered circular grating structure was studied, to provide broadband enhancement in thin film amorphous silicon solar cells. In comparison to planar structure an absorption enhancement of ~ 7% was realized.

  2. Laser Induced Chemical Vapor Deposition of Thin Films

    National Research Council Canada - National Science Library

    Zahavi, Joseph

    1995-01-01

    .... It completes the information which was given in the previous two progress reports. Basically, the aim of the first year was to study the possibility of deposition of silicon nitride thin films from silane and ammonia at low temperatures...

  3. Thin carbon film serves as UV bandpass filter

    Science.gov (United States)

    1966-01-01

    Thin carbon film deposited on a 70 percent transparent screen provides a filter for narrow-band detectors in the extreme ultraviolet. The filter also suppresses scattered light and light of unwanted orders in vacuum spectrographs.

  4. Simple gun for vapor deposition of organic thin films

    International Nuclear Information System (INIS)

    Sato, N.; Seki, K.; Inokuchi, H.

    1987-01-01

    A simple evaporation gun for preparing organic thin films was fabricated using commercially available parts of an electron gun for a TV Braun tube. The device permits sample heating to be easily controlled because of the small heat capacity

  5. A thin film hydroponic system for plant studies

    Science.gov (United States)

    Hines, Robert; Prince, Ralph; Muller, Eldon; Schuerger, Andrew

    1990-01-01

    The Land Pavillion, EPCOT Center, houses a hydroponic, thin film growing system identical to that residing in NASA's Biomass Production Chamber at Kennedy Space Center. The system is targeted for plant disease and nutrition studies. The system is described.

  6. Thin films of xyloglucans for BSA adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Jo, T.A. [Department of Biochemistry and Molecular Biology, Federal University of Parana, Curitiba, PR (Brazil); Laboratory of Biopolymers, Department of Chemistry, Federal University of Parana, Curitiba, PR (Brazil); Petri, D.F.S. [Institute of Chemistry, University of Sao Paulo, Sao Paulo, SP (Brazil); Valenga, F. [Department of Biochemistry and Molecular Biology, Federal University of Parana, Curitiba, PR (Brazil); Laboratory of Biopolymers, Department of Chemistry, Federal University of Parana, Curitiba, PR (Brazil); Lucyszyn, N. [Laboratory of Biopolymers, Department of Chemistry, Federal University of Parana, Curitiba, PR (Brazil); Sierakowski, M.-R. [Laboratory of Biopolymers, Department of Chemistry, Federal University of Parana, Curitiba, PR (Brazil)], E-mail: mariarita.sierakowski@ufpr.br

    2009-03-01

    In this work, XG extracted from Tamarindus indica (XGT) and Copaifera langsdorffii (XGC) seeds were deposited onto Si wafers as thin films. The characteristics of XGT and XGC adsorbed layers were compared with a commercial XG sample (TKP, Tamarind kernel powder) by ellipsometry and atomic force microscopy (AFM). Moreover, the adsorption of oxidized derivative of XGT (To60) onto amino-terminated Si wafers and the immobilization of bovine serum albumin (BSA) onto polysaccharides covered wafers, as a function of pH, were also investigated. The XG samples presented molar ratios Glc:Xyl:Gal of 2.4:2.1:1 (XGC); 2.8: 2.3: 1 (XGT) and 1.9:1.9:1 (TKP). The structure of XGT and XGC was determined by O-methy alditol acetate derivatization and showed similar features, but XGC confirmed the presence of more {alpha}-D-Xyl branches due to more {beta}-D-Gal ends. XGT deposited onto Si adsorbed as fibers and small entities uniformly distributed, as evidenced by AFM, while TPK and XGC formed larger aggregates. The thickness of To60 onto amino-terminated surface was similar to that determined for XGT onto Si wafers. A maximum in the adsorbed amount of BSA occurred close to its isoelectric point (5.5). These findings indicate that XGT and To60 are potential materials for the development of biomaterials and biotechnological devices.

  7. Degradation analysis of thin film photovoltaic modules

    Energy Technology Data Exchange (ETDEWEB)

    Radue, C., E-mail: chantelle.radue@nmmu.ac.z [Department of Physics, PO Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth 6031 (South Africa); Dyk, E.E. van [Department of Physics, PO Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth 6031 (South Africa)

    2009-12-01

    Five thin film photovoltaic modules were deployed outdoors under open circuit conditions after a thorough indoor evaluation. Two technology types were investigated: amorphous silicon (a-Si:H) and copper indium gallium diselenide (CIGS). Two 14 W a-Si:H modules, labelled Si-1 and Si-2, were investigated. Both exhibited degradation, initially due to the well-known light-induced degradation described by Staebler and Wronski [Applied Physics Letters 31 (4) (1977) 292], and thereafter due to other degradation modes such as cell degradation. The various degradation modes contributing to the degradation of the a-Si:H modules will be discussed. The initial maximum power output (P{sub MAX}) of Si-1 was 9.92 W, with the initial light-induced degradation for Si-1 approx30% and a total degradation of approx42%. For Si-2 the initial P{sub MAX} was 7.93 W, with initial light-induced degradation of approx10% and a total degradation of approx17%. Three CIGS modules were investigated: two 20 W modules labelled CIGS-1 and CIGS-2, and a 40 W module labelled CIGS-3. CIGS-2 exhibited stable performance while CIGS-1 and CIGS-3 exhibited degradation. CIGS is known to be stable over long periods of time, and thus the possible reasons for the degradation of the two modules are discussed.

  8. Degradation analysis of thin film photovoltaic modules

    International Nuclear Information System (INIS)

    Radue, C.; Dyk, E.E. van

    2009-01-01

    Five thin film photovoltaic modules were deployed outdoors under open circuit conditions after a thorough indoor evaluation. Two technology types were investigated: amorphous silicon (a-Si:H) and copper indium gallium diselenide (CIGS). Two 14 W a-Si:H modules, labelled Si-1 and Si-2, were investigated. Both exhibited degradation, initially due to the well-known light-induced degradation described by Staebler and Wronski [Applied Physics Letters 31 (4) (1977) 292], and thereafter due to other degradation modes such as cell degradation. The various degradation modes contributing to the degradation of the a-Si:H modules will be discussed. The initial maximum power output (P MAX ) of Si-1 was 9.92 W, with the initial light-induced degradation for Si-1 ∼30% and a total degradation of ∼42%. For Si-2 the initial P MAX was 7.93 W, with initial light-induced degradation of ∼10% and a total degradation of ∼17%. Three CIGS modules were investigated: two 20 W modules labelled CIGS-1 and CIGS-2, and a 40 W module labelled CIGS-3. CIGS-2 exhibited stable performance while CIGS-1 and CIGS-3 exhibited degradation. CIGS is known to be stable over long periods of time, and thus the possible reasons for the degradation of the two modules are discussed.

  9. Thin wetting film lens-less imaging

    International Nuclear Information System (INIS)

    Allier, C.P.; Poher, V.; Coutard, J.G.; Hiernard, G.; Dinten, J.M.

    2011-01-01

    Lens-less imaging has recently attracted a lot of attention as a compact, easy-to-use method to image or detect biological objects like cells, but failed at detecting micron size objects like bacteria that often do not scatter enough light. In order to detect single bacterium, we have developed a method based on a thin wetting film that produces a micro-lens effect. Compared with previously reported results, a large improvement in signal to noise ratio is obtained due to the presence of a micro-lens on top of each bacterium. In these conditions, standard CMOS sensors are able to detect single bacterium, e.g. E. coli, Bacillus subtilis and Bacillus thuringiensis, with a large signal to noise ratio. This paper presents our sensor optimization to enhance the SNR; improve the detection of sub-micron objects; and increase the imaging FOV, from 4.3 mm 2 to 12 mm 2 to 24 mm 2 , which allows the detection of bacteria contained in 0.5 μl to 4 μl to 10 μl, respectively. (authors)

  10. Trends and new applications in thin films

    International Nuclear Information System (INIS)

    1996-01-01

    The proceedings of this symposium comprise 95 communications from which 64 were selected and fall into the scope of INIS subject categories, and 1 was selected for ETDE indexing. The selected communications deal with the techniques used for thin films preparation using chemical or physical vapor deposition techniques (plasma-arc or jet spraying, cathode sputtering, reactive DC or RF magnetron sputtering, plasma-ion deposition, ion implantation, electron or ion beam spraying, ion beam assisted plasma etching, dynamic ion mixing, distributed electron cyclotron resonance plasma sputtering, laser induced plasma sputtering etc..). The effects and interactions with the substrates (ion implantation, crystal growth, crystal-phase transformations, microstructures, penetration depth, changes in lattice parameters etc..) are analysed using various techniques such as grazing incidence X-ray diffraction, X-ray reflectometry, X-ray and angle resolved electron spectroscopy, Auger electron spectroscopy, Rutherford backscattering spectroscopy, SEM, TEM, IR absorption spectroscopy, UV or visible emission spectroscopy, conversion electron Moessbauer spectroscopy, X-ray fluorescence, mass spectroscopy, optical ellipsometry etc.. Mechanical tests such as scratch, microhardness and wear tests are also performed on the coatings to analyse their mechanical properties. (J.S.)

  11. Silicon Thin-Film Solar Cells

    Directory of Open Access Journals (Sweden)

    Guy Beaucarne

    2007-01-01

    with plasma-enhanced chemical vapor deposition (PECVD. In spite of the fundamental limitation of this material due to its disorder and metastability, the technology is now gaining industrial momentum thanks to the entry of equipment manufacturers with experience with large-area PECVD. Microcrystalline Si (also called nanocrystalline Si is a material with crystallites in the nanometer range in an amorphous matrix, and which contains less defects than amorphous silicon. Its lower bandgap makes it particularly appropriate as active material for the bottom cell in tandem and triple junction devices. The combination of an amorphous silicon top cell and a microcrystalline bottom cell has yielded promising results, but much work is needed to implement it on large-area and to limit light-induced degradation. Finally thin-film polysilicon solar cells, with grain size in the micrometer range, has recently emerged as an alternative photovoltaic technology. The layers have a grain size ranging from 1 μm to several tens of microns, and are formed at a temperature ranging from 600 to more than 1000∘C. Solid Phase Crystallization has yielded the best results so far but there has recently been fast progress with seed layer approaches, particularly those using the aluminum-induced crystallization technique.

  12. Inverse bilayer magnetoelectric thin film sensor

    Energy Technology Data Exchange (ETDEWEB)

    Yarar, E.; Piorra, A.; Quandt, E., E-mail: eq@tf.uni-kiel.de [Chair for Inorganic Functional Materials, Institute for Materials Science, Faculty of Engineering, Kiel University, Kaiserstraße 2, D-24143 Kiel (Germany); Salzer, S.; Höft, M.; Knöchel, R. [Microwave Laboratory, Institute of Electrical and Information Engineering, Faculty of Engineering, Kiel University, Kaiserstraße 2, D-24143 Kiel (Germany); Hrkac, V.; Kienle, L. [Chair for Synthesis and Real Structure, Institute for Materials Science, Faculty of Engineering, Kiel University, Kaiserstraße 2, D-24143 Kiel (Germany)

    2016-07-11

    Prior investigations on magnetoelectric (ME) thin film sensors using amorphous FeCoSiB as a magnetostrictive layer and AlN as a piezoelectric layer revealed a limit of detection (LOD) in the range of a few pT/Hz{sup 1/2} in the mechanical resonance. These sensors are comprised of a Si/SiO{sub 2}/Pt/AlN/FeCoSiB layer stack, as dictated by the temperatures required for the deposition of the layers. A low temperature deposition route of very high quality AlN allows the reversal of the deposition sequence, thus allowing the amorphous FeCoSiB to be deposited on the very smooth Si substrate. As a consequence, the LOD could be enhanced by almost an order of magnitude reaching 400 fT/Hz{sup 1/2} at the mechanical resonance of the sensor. Giant ME coefficients (α{sub ME}) as high as 5 kV/cm Oe were measured. Transmission electron microscopy investigations revealed highly c-axis oriented growth of the AlN starting from the Pt-AlN interface with local epitaxy.

  13. Thin film deposition using rarefied gas jet

    Science.gov (United States)

    Pradhan, Sahadev, , Dr.

    2017-06-01

    The rarefied gas jet of aluminium is studied at Mach number Ma = (Uj /√{ kbTj / mg }) in the range .01 PVD) process for the development of the highly oriented pure metallic aluminum thin film with uniform thickness and strong adhesion on the surface of the substrate in the form of ionic plasma, so that the substrate can be protected from corrosion and oxidation and thereby enhance the lifetime and safety, and to introduce the desired surface properties for a given application. Here, H is the characteristic dimension, U_j and T_j are the jet velocity and temperature, n_d is the number density of the jet, m and d are the molecular mass and diameter, and kbis the Boltzmann constant. An important finding is that the capture width (cross-section of the gas jet deposited on the substrate) is symmetric around the centerline of the substrate, and decreases with increased Mach number due to an increase in the momentum of the gas molecules. DSMC simulation results reveals that at low Knudsen number ((Kn=0.01); shorter mean free paths), the atoms experience more collisions, which direct them toward the substrate. However, the atoms also move with lower momentum at low Mach number, which allows scattering collisions to rapidly direct the atoms to the substrate.

  14. Magnetostatic excitations in thin ferrite films

    International Nuclear Information System (INIS)

    Zil'berman, P.E.; Lugovskoi, A.V.

    1987-01-01

    The authors discuss the influence of the exchange interaction and dissipative processes in thin ferrite films on the eigenfrequency spectrum of magnetostatic standing waves and on the dispersion relation and attenuation of magnetostatic traveling waves. For the first time they obtain explicitly the dispersion relation for magnetostatic waves (MSWs) in a tangential saturating magnetic field H 0 to second order (inclusive) in the exchange interaction parameter λ. The authors obtain computer solutions for this equation in the complex frequency (ω) plane (for standing waves) or wave-number (q) plane (for traveling waves). The authors show that the dispersion relation constructed from the standing-wave spectrum is different from that of the traveling waves if λ≠0, even if dissipation is neglected. The traveling waves have auxiliary branches of the dispersion relation with weak damping near the spin-wave-resonance (SWR) frequencies. Dissipation has only a relatively weak effect on the frequency spectrum of the standing waves, shifting it upward. For the traveling waves, however, dissipation leads to qualitative changes in the structure of the dispersion relation, giving rise to new branches, forbidden bands, reentrant and anomalous-dispersion regions

  15. 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.

  16. Crystalline Indium Sulphide thin film by photo accelerated deposition technique

    Science.gov (United States)

    Dhanya, A. C.; Preetha, K. C.; Deepa, K.; Remadevi, T. L.

    2015-02-01

    Indium sulfide thin films deserve special attention because of its potential application as buffer layers in CIGS based solar cells. Highly transparent indium sulfide (InS) thin films were prepared using a novel method called photo accelerated chemical deposition (PCD). Ultraviolet source of 150 W was used to irradiate the solution. Compared to all other chemical methods, PCD scores its advantage for its low cost, flexible substrate and capable of large area of deposition. Reports on deposition of high quality InS thin films at room temperature are very rare in literature. The precursor solution was initially heated to 90°C for ten minutes and then deposition was carried out at room temperature for two hours. The appearance of the film changed from lemon yellow to bright yellow as the deposition time increased. The sample was characterized for its structural and optical properties. XRD profile showed the polycrystalline behavior of the film with mixed phases having crystallite size of 17 nm. The surface morphology of the films exhibited uniformly distributed honey comb like structures. The film appeared to be smooth and the value of extinction coefficient was negligible. Optical measurements showed that the film has more than 80% transmission in the visible region. The direct band gap energy was 2.47eV. This method is highly suitable for the synthesis of crystalline and transparent indium sulfide thin films and can be used for various photo voltaic applications.

  17. Heat Transfer Issues in Thin-Film Thermal Radiation Detectors

    Science.gov (United States)

    Barry, Mamadou Y.

    1999-01-01

    The Thermal Radiation Group at Virginia Polytechnic Institute and State University has been working closely with scientists and engineers at NASA's Langley Research Center to develop accurate analytical and numerical models suitable for designing next generation thin-film thermal radiation detectors for earth radiation budget measurement applications. The current study provides an analytical model of the notional thermal radiation detector that takes into account thermal transport phenomena, such as the contact resistance between the layers of the detector, and is suitable for use in parameter estimation. It was found that the responsivity of the detector can increase significantly due to the presence of contact resistance between the layers of the detector. Also presented is the effect of doping the thermal impedance layer of the detector with conducting particles in order to electrically link the two junctions of the detector. It was found that the responsivity and the time response of the doped detector decrease significantly in this case. The corresponding decrease of the electrical resistance of the doped thermal impedance layer is not sufficient to significantly improve the electrical performance of the detector. Finally, the "roughness effect" is shown to be unable to explain the decrease in the thermal conductivity often reported for thin-film layers.

  18. Development of plasma assisted thermal vapor deposition technique for high-quality thin film

    Science.gov (United States)

    Lee, Kang-Il; Choi, Yong Sup; Park, Hyun Jae

    2016-12-01

    The novel technique of Plasma-Assisted Vapor Deposition (PAVD) is developed as a new deposition method for thin metal films. The PAVD technique yields a high-quality thin film without any heating of the substrate because evaporated particles acquire energy from plasma that is confined to the inside of the evaporation source. Experiments of silver thin film deposition have been carried out in conditions of pressure lower than 10-3 Pa. Pure silver plasma generation is verified by the measurement of the Ag-I peak using optical emission spectroscopy. A four point probe and a UV-VIS spectrophotometer are used to measure the electrical and optical properties of the silver film that is deposited by PAVD. For an ultra-thin silver film with a thickness of 6.5 nm, we obtain the result of high-performance silver film properties, including a sheet resistance visible-range transmittance >75%. The PAVD-film properties show a low sheet resistance of 30% and the same transmittance with conventional thermal evaporation film. In the PAVD source, highly energetic particles and UV from plasma do not reach the substrate because the plasma is completely shielded by the optimized nozzle of the crucible. This new PAVD technique could be a realistic solution to improve the qualities of transparent electrodes for organic light emission device fabrication without causing damage to the organic layers.

  19. Structural And Optical Properties Of VOx Thin Films

    Directory of Open Access Journals (Sweden)

    Schneider K.

    2015-06-01

    Full Text Available VOx thin films were deposited on Corning glass, fused silica and Ti foils by means of rf reactive sputtering from a metallic vanadium target. Argon-oxygen gas mixtures of different compositions controlled by the flow rates were used for sputtering. Influence of the oxygen partial pressure in the sputtering chamber on the structural and optical properties of thin films has been investigated.

  20. Health, safety and environmental issues in thin film manufacturing

    OpenAIRE

    Alsema, E.A.; Baumann, A.E.; Hill, R.; Patterson, M.H.

    1997-01-01

    An investigation is made of Health, Safety and Environmental (HSE) aspects for the manufacturing, use and decommissioning of CdTe, CIS and a-Si modules. Issues regarding energy requirements, resource availability, emissions of toxic materials, occupational health and safety and module waste treatment are reviewed. Waste streams in thin film module manufacturing are analyzed in detail and treatment methods are discussed. Finally the technological options for thin film module recycling are inve...

  1. Growth of cuprate high temperature superconductor thin films

    Directory of Open Access Journals (Sweden)

    H-U Habermeier

    2006-09-01

    Full Text Available   This paper reviews briefly the development of physical vapour deposition based HTS thin film preparation technologies to today’s state-of-the-art methods. It covers the main trends of in-situ process and growth control. The current activities to fabricate tapes for power applications as well as to tailor interfaces in cuprate are described. Some future trends in HTS thin film research, both for science as well as application driven activities are outlined.

  2. Simple flash evaporator for making thin films of compounds

    Energy Technology Data Exchange (ETDEWEB)

    Hemanadhan, M.; Bapanayya, Ch.; Agarwal, S. C. [Department of Physics, Indian Institute of Technology, Kanpur 208016 (India)

    2010-07-15

    A simple and compact arrangement for flash evaporation is described. It uses a cell phone vibrator for powder dispensing that can be incorporated into a vacuum deposition chamber without any major alterations. The performance of the flash evaporation system is checked by making thin films of the optical memory chalcogenide glass Ge{sub 2}Sb{sub 2}Te{sub 5} (GST). Energy dispersive x-ray analysis shows that the flash evaporation preserves the stoichiometry in thin films.

  3. Optical thin-film technology: past, present, future

    Science.gov (United States)

    Strickland, William P.

    1990-12-01

    The evolution of the vacuum coating industry is reviewed. Vacuum science progressed slowly until the late nineteenth century due to an incomplete understanding of vacuum and lack of applications. Edison's invention of the light bulb launched the vacuum industry and increased developmentof improved vacuum systems. The thin film optical coating industry arose from the needs of the German and U.S. military efforts during World War II. The author presents his experience in thin film coating from 1939 to the present.

  4. Thin film bulk acoustic wave devices : performance optimization and modeling

    OpenAIRE

    Pensala, Tuomas

    2011-01-01

    Thin film bulk acoustic wave (BAW) resonators and filters operating in the GHz range are used in mobile phones for the most demanding filtering applications and complement the surface acoustic wave (SAW) based filters. Their main advantages are small size and high performance at frequencies above 2 GHz. This work concentrates on the characterization, performance optimization, and modeling techniques of thin film BAW devices. Laser interferometric vibration measurements together with plat...

  5. The 1989 progress report: interface physics and thin films

    International Nuclear Information System (INIS)

    Equer, B.

    1989-01-01

    The 1989 progress report of the laboratory of Interface Physics and Thin Films of the Polytechnic School (France) is presented. The properties and the interfaces of thin films, which show optoelectronic activity, are studied. The materials investigated are hydrogenated amorphous silicon compounds, amorphous compounds of silicon-germanium, silicon-carbon and silicon-mitrogen. The techniques developed for manufacturing and characterizing those materials are included. The published papers, the conferences and the Laboratory staff are listed [fr

  6. Liquid phase epitaxial growth of heterostructured hierarchical MOF thin films

    KAUST Repository

    Chernikova, Valeriya

    2017-05-10

    Precise control of epitaxial growth of MOF-on-MOF thin films, for ordered hierarchical tbo-type structures is demonstrated. The heterostructured MOF thin film was fabricated by successful sequential deposition of layers from two different MOFs. The 2-periodic layers, edge-transitive 4,4-square lattices regarded as supermolecular building layers, were commendably cross-linked using a combination of inorganic/organic and organic pillars.

  7. Thermomagnetic marking of rare-earth-transition-metal thin films

    Science.gov (United States)

    Bartholomeusz, Brian Josef

    1989-01-01

    Analytical derivation of temperature profiles in laser-irradiated thin-film structures is hindered by the nature of the heat source terms and by the geometrical complexity that often exists. This study utilizes a combined Laplace-transform-Fourier-integral method to obtain approximate solutions for a number of simple cases. The results are used to study the thermomagnetic marking process in rare-earth-transition-metal (RE-TM) thin films, and the predictions are compared with experimental observations.

  8. CO2 gas sensitivity of sputtered zinc oxide thin films

    Indian Academy of Sciences (India)

    TECS

    Abstract. For the first time, sputtered zinc oxide (ZnO) thin films have been used as a CO2 gas sensor. Zinc oxide thin films have been synthesized using reactive d.c. sputtering method for gas sensor applications, in the deposition temperature range from 130–153°C at a chamber pressure of 8⋅5 mbar for 18 h. Argon and ...

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

    KAUST Repository

    Santiso, José

    2010-10-24

    This paper reviews the recent advances in the use of thin films, mostly epitaxial, for fundamental studies of materials for solid oxide fuel cell (SOFC) applications. These studies include the influence of film microstructure, crystal orientation and strain in oxide ionic conducting materials used as electrolytes, such as fluorites, and in mixed ionic and electronic conducting materials used as electrodes, typically oxides with perovskite or perovskite-related layered structures. The recent effort towards the enhancement of the electrochemical performance of SOFC materials through the deposition of artificial film heterostructures is also presented. These thin films have been engineered at a nanoscale level, such as the case of epitaxial multilayers or nanocomposite cermet materials. The recent progress in the implementation of thin films in SOFC devices is also reported. © 2010 Springer-Verlag.

  10. Silver nanowire-based transparent, flexible, and conductive thin film

    Directory of Open Access Journals (Sweden)

    Liu Cai-Hong

    2011-01-01

    Full Text Available Abstract The fabrication of transparent, conductive, and uniform silver nanowire films using the scalable rod-coating technique is described in this study. Properties of the transparent conductive thin films are investigated, as well as the approaches to improve the performance of transparent silver nanowire electrodes. It is found that silver nanowires are oxidized during the coating process. Incubation in hydrogen chloride (HCl vapor can eliminate oxidized surface, and consequently, reduce largely the resistivity of silver nanowire thin films. After HCl treatment, 175 Ω/sq and approximately 75% transmittance are achieved. The sheet resistivity drops remarkably with the rise of the film thickness or with the decrease of transparency. The thin film electrodes also demonstrated excellent flexible stability, showing < 2% resistance change after over 100 bending cycles.

  11. The role of demagnetizing factors in the occurrence of vortex avalanches in Nb thin films

    Energy Technology Data Exchange (ETDEWEB)

    Colauto, F; Ortiz, W A [Grupo de Supercondutividade e Magnetismo, Departamento de Fisica, Universidade Federal de Sao Carlos, C P 676, 13565-905, Sao Carlos, SP (Brazil); Patino, E J; Aprilli, M, E-mail: fcolauto@df.ufscar.b [Laboratoire de Physique des Solides, Universite Paris-Sud, C.N.R.S., 91405 Orsay cedex (France)

    2009-03-01

    Under specific circumstances, magnetic flux penetrates into superconducting thin films as dendritic flux jumps. The phenomenon has a thermomagnetic origin, where flux motion generates heat that suppresses flux pining and facilitates further flux motion. We have studied the thickness influence on the flux stability for very thin Nb films, 20, 40, 60, and 80 nm, through dc-magnetometry. The thicker the film; the higher is the threshold field where instabilities first take place. Due to the demagnetizing factor in a perpendicular geometry, the effective magnetic field at the border of the film is largely amplified. For thin specimens, a linear dependence between the threshold field and the thickness is expected and has been actually observed. When normalized by the sample aspect ratio, the effective threshold magnetic field is nearly the same for all specimens studied.

  12. Femtosecond pulsed laser deposition of cobalt ferrite thin films

    Science.gov (United States)

    Dascalu, Georgiana; Pompilian, Gloria; Chazallon, Bertrand; Caltun, Ovidiu Florin; Gurlui, Silviu; Focsa, Cristian

    2013-08-01

    The insertion of different elements in the cobalt ferrite spinel structure can drastically change the electric and magnetic characteristics of CoFe2O4 bulks and thin films. Pulsed Laser Deposition (PLD) is a widely used technique that allows the growth of thin films with complex chemical formula. We present the results obtained for stoichiometric and Gadolinium-doped cobalt ferrite thin films deposited by PLD using a femtosecond laser with 1 kHz repetition rate. The structural properties of the as obtained samples were compared with other thin films deposited by ns-PLD. The structural characteristics and chemical composition of the samples were investigated using profilometry, Raman spectroscopy, X-Ray diffraction measurements and ToF-SIMS analysis. Cobalt ferrite thin films with a single spinel structure and a preferential growth direction have been obtained. The structural analysis results indicated the presence of internal stress for all the studied samples. By fs-PLD, uniform thin films were obtained in a short deposition time.

  13. Thin films as an emerging platform for drug delivery

    Directory of Open Access Journals (Sweden)

    Sandeep Karki

    2016-10-01

    Full Text Available Pharmaceutical scientists throughout the world are trying to explore thin films as a novel drug delivery tool. Thin films have been identified as an alternative approach to conventional dosage forms. The thin films are considered to be convenient to swallow, self-administrable, and fast dissolving dosage form, all of which make it as a versatile platform for drug delivery. This delivery system has been used for both systemic and local action via several routes such as oral, buccal, sublingual, ocular, and transdermal routes. The design of efficient thin films requires a comprehensive knowledge of the pharmacological and pharmaceutical properties of drugs and polymers along with an appropriate selection of manufacturing processes. Therefore, the aim of this review is to provide an overview of the critical factors affecting the formulation of thin films, including the physico-chemical properties of polymers and drugs, anatomical and physiological constraints, as well as the characterization methods and quality specifications to circumvent the difficulties associated with formulation design. It also highlights the recent trends and perspectives to develop thin film products by various companies.

  14. Stretchable Kirigami Polyvinylidene Difluoride Thin Films for Energy Harvesting: Design, Analysis, and Performance

    Science.gov (United States)

    Hu, Nan; Chen, Dajing; Wang, Dong; Huang, Shicheng; Trase, Ian; Grover, Hannah M.; Yu, Xiaojiao; Zhang, John X. J.; Chen, Zi

    2018-02-01

    Kirigami, a modified form of origami which includes cutting, has been used to improve material stretchability and compliance. However, this technique is, so far, underexplored in patterning piezoelectric materials towards developing efficient and mechanically flexible thin-film energy generators. Motivated by existing kirigami-based applications, we introduce interdigitated cuts to polyvinylidene fluoride (PVDF) films to evaluate the effect on voltage generation and stretchability. Our results from theoretical analysis, numerical simulations, and experimental tests show that kirigami PVDF films exhibit an extended strain range while still maintaining significant voltage generation compared to films without cuts. Various cutting patterns are studied, and it is found that films with denser cuts have a larger voltage output. This kirigami design can enhance the properties of existing piezoelectric materials and help to integrate tunable PVDF generators into biomedical devices.

  15. Properties of MoO3 thin film polymorphs

    International Nuclear Information System (INIS)

    McCarron, E.M.; Carcia, P.F.

    1987-01-01

    Thin film polymorphs of molybdenum trioxide have been synthesized by RF sputtering. Films deposited on thermally floating substrates are polycrystalline and exhibit preferred orientation. Depending upon the oxygen partial pressure maintained during sputtering, the films can be made to crystallize in either the thermodynamically stable orthorhombic α MoO 3 form (unique 2D-layered structure) or the metastable monoclinic β MoO 3 phase (3D ReO 3 -related structure). Metastable β films can be converted thermally to the α phase and the transformation appears topotactic. Films deposited on the cooled substrates are amorphous. A correlation between the particular phase formed and adatom mobility is noted

  16. Processing-Structure Correlation in DC Sputtered Molybdenum Thin Films

    Science.gov (United States)

    Khan, Majid; Islam, Mohammad; Akram, Aftab; Manzoor, Umair

    2013-12-01

    Molybdenum thin films were sputter deposited under different conditions of DC power and chamber pressure. The structure and topography of the films were investigated using AFM, SEM and XRD techniques. Van der Pauw method and tape test were employed to determine electrical resistivity and interfacial strength to the substrate, respectively. All the films are of sub-micron thickness with maximum growth rate of 78 nm/min and crystallite size in the range of 4 to 21 nm. The films produced at high power and low pressure exhibit compressive residual strains, low electrical resistivity and poor adhesion to the glass substrate, whereas the converse is true for films produced at high pressure.

  17. The deposition of magnesium fluoride (MGF 2 ) thin films by ...

    African Journals Online (AJOL)

    The Chemical Bath Deposition (CBD) technique was successfully employed in the growth of magnesium fluoride (MgF2) thin films. The films were characterized and optimized. The characterization included: the optical and solid state properties such as the transmittance (T)/reflectance (R) absorbance (A) spectra which ...

  18. Reorientation of magnetic anisotropy in epitaxial cobalt ferrite thin films

    NARCIS (Netherlands)

    Lisfi, A.; Williams, C.M.; Nguyen, L.T.; Lodder, J.C.; Coleman, A.; Corcoran, H.; Johnson, A.; Chang, P.; Abhishek Kumar, A.K.; Kumar, A.; Morgan, W.

    2007-01-01

    Spin reorientation has been observed in CoFe2O4 thin single crystalline films epitaxially grown on (100) MgO substrate upon varying the film thickness. The critical thickness for such a spin-reorientation transition was estimated to be 300 nm. The reorientation is driven by a structural transition

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

    Indian Academy of Sciences (India)

    Thin films based on two very different metal-organic systems are developed and some nonlinear optical ... capability of the nanoparticle-embedded polymer film is demonstrated. Keywords. Polar crystal; uniaxial ... systems promising candidates for a wide range of electronic, magnetic and optical applications. However ...

  20. Oriented growth of thin films of samarium oxide by MOCVD

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Thin films of Sm2O3 have been grown on Si(100) and fused quartz by low-pressure chemical va- pour deposition using an adducted β-diketonate precursor. The films on quartz are cubic, with no preferred orientation at lower growth temperatures (~ 550°C), while they grow with a strong (111) orientation as the.

  1. Experimental and Theoretical Approaches to Thin Film Lubrication Problems

    NARCIS (Netherlands)

    Lee-Prudhoe, I.; Venner, C.H.; Cann, P.M.; Spikes, H.; Snidle, R.W.; Evans, H.P.

    2006-01-01

    The last fifty years have seen tremendous advances in the field of thin film lubrication. This is particularly true of steady-state Elastohydrodynamic lubrication (EHL) where the accurate measurement of film thickness combined with advanced numerical modelling methods has been very successful.

  2. Oxide ferroelectric thin films: synthesis from organometallic compounds and properties

    International Nuclear Information System (INIS)

    Vertoprakhov, Vladimir N; Nikulina, Lyubov' D; Igumenov, Igor K

    2005-01-01

    Chemical methods for the preparation of oxide ferroelectric thin films from organometallic compounds published over the last 10-15 years are considered systematically and generalised. Layers of these films are promising for the creation of non-volatile memory elements and for use in nano- and microelectronic devices.

  3. 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

  4. Ultra thin films of nanocrystalline Ge studied by AFM and ...

    Indian Academy of Sciences (India)

    Initial growth stages of the ultra thin films of germanium (Ge) prepared by ion beam sputter deposition have been studied using atomic force microscope (AFM) and interference enhanced Raman scattering. The growth of the films follows Volmer-Weber growth mechanism. Analysis of the AFM images shows that Ostwald ...

  5. Optical Properties of Lead Silver Sulphide Ternary Thin Films ...

    African Journals Online (AJOL)

    Optical Properties of Lead Silver Sulphide Ternary Thin Films Deposited by Chemical Bath Method. ... The optical properties studied include reflectance, absorption coefficient, thickness, refractive index, extinction coefficient, optical conductivity and band gap energy. The films showed very high absorbance in the UV region, ...

  6. Conductance of perovskite oxide thin films and interfaces

    NARCIS (Netherlands)

    Mubeen Dildar, Ishrat

    2013-01-01

    This thesis deals with the properties of doped perovskite manganites in the form of thin films, and with interfaces between insulating perovskites. The first question we investigate has to do with the strong reduction of the metal-insulator (MI) transition temperature when the films are strained.In

  7. WO/sub 3/ thin films for practical electrochromic windows

    International Nuclear Information System (INIS)

    Goldner, R.B.; Wong, K.; Foley, G.; Norton, P.; Wamboldt, L.; Seward, G.; Haas, T.; Chapman, R.

    1986-01-01

    This paper shows that practical spectrally-selective transmittance modulation can be achieved with thin (50-100nm) WO/sub 3/ films, and therefore such films should be useful for fabricating electrochromic windows. The transmittance and reflectance modulation results are compared with theoretical predictions. The results indicate an excess intraband absorptance, which is attributed to free electron scattering arising from extended defects

  8. Magnetic hysteresis measurements of thin films under isotropic stress.

    Science.gov (United States)

    Holland, Patrick; Dubey, Archana; Geerts, Wilhelmus

    2000-10-01

    Nowadays, ferromagnetic thin films are widely applied in devices for information technology (credit cards, video recorder tapes, floppies, hard disks) and sensors (air bags, anti-breaking systems, navigation systems). Thus, with the increase in the use of magnetic media continued investigation of magnetic properties of materials is necessary to help in determining the useful properties of materials for new or improved applications. We are currently interested in studying the effect of applied external stress on Kerr hysteresis curves of thin magnetic films. The Ni and NiFe films were grown using DC magnetron sputtering with Ar as the sputter gas (pAr=4 mTorr; Tsub=55-190 C). Seed and cap layers of Ti were used on all films for adhesion and oxidation protection, respectively. A brass membrane pressure cell was designed to apply in-plane isotropic stress to thin films. In this pressure cell, gas pressure is used to deform a flexible substrate onto which a thin magnetic film has been sputtered. The curvature of the samples could be controlled by changing the gas pressure to the cell. Magneto-Optical in-plane hysteresis curves at different values of strain were measured. The results obtained show that the stress sensitivity is dependent on the film thickness. For the 500nm NiFe films, the coercivity strongly decreased as a function of the applied stress.

  9. 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

  10. Unusual strain relaxation in Cu thin films on Ni(001)

    DEFF Research Database (Denmark)

    Rasmussen, F.B.; Baker, J.; Nielsen, M.

    1997-01-01

    Surface x-ray diffraction has been used to study the growth of thin Cu films on Ni(001). We give direct evidence for the formation of embedded wedges with internal {111} facets in the film, as recently suggested by Muller et al. [Phys. Rev. Lett. 76, 2358 (1996)]. The unusual strain distribution...

  11. Epitaxial oxide thin films by pulsed laser deposition: Retrospect and ...

    Indian Academy of Sciences (India)

    Epitaxial thin films of high c cuprates, metallic, ferroelectric, ferromagnetic, dielectric oxides, super conduc tor-metal-superconductor Josephson junctions and oxide superlattices have been made by PLD. In this article, an overview of preparation, characterization and properties of epitaxial oxide films and their applications ...

  12. Sputter-deposited low reflectance vanadium oxide-molybdenum oxide thin films on silicon

    Science.gov (United States)

    Nayak, Manish Kumar; Esther, A. Carmel Mary; Bera, Parthasarathi; Dey, Arjun

    2017-09-01

    A single layer antireflective, smart, crystalline and nanocolumnar pulsed RF magnetron sputtered vanadium oxide-molybdenum oxide thin film on silicon is proposed for the alternate antireflective material for silicon based futuristic solar cell application. The VO-MO film with 130 nm thickness grown at 200 W shows significant low reflectance (1% within the 500-600 nm region). The VO-MO film with lowest reflectance shows a phase transition at around 55 °C which is beneficial due to film inherent variable IR emittance behaviour which may be helpful for eliminating excess heat load generated during in-service of silicon solar cell.

  13. 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.

  14. Thermoanalytical study of the decomposition of yttrium trifluoroacetate thin films

    Energy Technology Data Exchange (ETDEWEB)

    Eloussifi, H. [GRMT, GRMT, Department of Physics, University of Girona, Campus Montilivi, E17071 Girona, Catalonia (Spain); Laboratoire de Chimie Inorganique, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax (Tunisia); Farjas, J., E-mail: jordi.farjas@udg.cat [GRMT, GRMT, Department of Physics, University of Girona, Campus Montilivi, E17071 Girona, Catalonia (Spain); Roura, P. [GRMT, GRMT, Department of Physics, University of Girona, Campus Montilivi, E17071 Girona, Catalonia (Spain); Ricart, S.; Puig, T.; Obradors, X. [Institut de Ciència de Materials de Barcelona (CSIC), Campus UAB, 08193 Bellaterra, Catalonia (Spain); Dammak, M. [Laboratoire de Chimie Inorganique, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax (Tunisia)

    2013-10-31

    We present the use of the thermal analysis techniques to study yttrium trifluoroacetate thin films decomposition. In situ analysis was done by means of thermogravimetry, differential thermal analysis, and evolved gas analysis. Solid residues at different stages and the final product have been characterized by X-ray diffraction and scanning electron microscopy. The thermal decomposition of yttrium trifluoroacetate thin films results in the formation of yttria and presents the same succession of intermediates than powder's decomposition, however, yttria and all intermediates but YF{sub 3} appear at significantly lower temperatures. We also observe a dependence on the water partial pressure that was not observed in the decomposition of yttrium trifluoroacetate powders. Finally, a dependence on the substrate chemical composition is discerned. - Highlights: • Thermal decomposition of yttrium trifluoroacetate films. • Very different behavior of films with respect to powders. • Decomposition is enhanced in films. • Application of thermal analysis to chemical solution deposition synthesis of films.

  15. Thermoanalytical study of the decomposition of yttrium trifluoroacetate thin films

    International Nuclear Information System (INIS)

    Eloussifi, H.; Farjas, J.; Roura, P.; Ricart, S.; Puig, T.; Obradors, X.; Dammak, M.

    2013-01-01

    We present the use of the thermal analysis techniques to study yttrium trifluoroacetate thin films decomposition. In situ analysis was done by means of thermogravimetry, differential thermal analysis, and evolved gas analysis. Solid residues at different stages and the final product have been characterized by X-ray diffraction and scanning electron microscopy. The thermal decomposition of yttrium trifluoroacetate thin films results in the formation of yttria and presents the same succession of intermediates than powder's decomposition, however, yttria and all intermediates but YF 3 appear at significantly lower temperatures. We also observe a dependence on the water partial pressure that was not observed in the decomposition of yttrium trifluoroacetate powders. Finally, a dependence on the substrate chemical composition is discerned. - Highlights: • Thermal decomposition of yttrium trifluoroacetate films. • Very different behavior of films with respect to powders. • Decomposition is enhanced in films. • Application of thermal analysis to chemical solution deposition synthesis of films

  16. Conductance Thin Film Model of Flexible Organic Thin Film Device using COMSOL Multiphysics

    Science.gov (United States)

    Carradero-Santiago, Carolyn; Vedrine-Pauléus, Josee

    We developed a virtual model to analyze the electrical conductivity of multilayered thin films placed above a graphene conducting and flexible polyethylene terephthalate (PET) substrate. The organic layers of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as a hole conducting layer, poly(3-hexylthiophene-2,5-diyl) (P3HT), as a p-type, phenyl-C61-butyric acid methyl ester (PCBM) and as n-type, with aluminum as a top conductor. COMSOL Multiphysics was the software we used to develop the virtual model to analyze potential variations and conductivity through the thin-film layers. COMSOL Multiphysics software allows simulation and modeling of physical phenomena represented by differential equations such as heat transfer, fluid flow, electromagnetism, and structural mechanics. In this work, using the AC/DC, electric currents module we defined the geometry of the model and properties for each of the six layers: PET/graphene/PEDOT:PSS/P3HT/PCBM/aluminum. We analyzed the model with varying thicknesses of graphene and active layers (P3HT/PCBM). This simulation allowed us to analyze the electrical conductivity, and visualize the model with varying voltage potential, or bias across the plates, useful for applications in solar cell devices.

  17. ITO induced tunability of surface plasmon resonance of silver thin film

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Ruijin; Wang, Xianhai; Ji, Jialin; Tao, Chunxian [Engineering Research Center of Optical Instrument and System, Ministry of Education and Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, No. 516 Jungong Road, Shanghai 200093 (China); Zhang, Daohua [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Zhang, Dawei, E-mail: dwzhang@usst.edu.cn [Engineering Research Center of Optical Instrument and System, Ministry of Education and Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, No. 516 Jungong Road, Shanghai 200093 (China)

    2015-11-30

    Highlights: • The localized surface plasmon resonance of silver thin film was generated by ITO buffer layer. • The tunability of surface plasmon resonance wavelength was realized by varying silver thin film thickness. • Raman scattering intensity varies with silver layer thickness. • FDTD calculation results of electronic field distribution are consistent with those of experiments. - Abstract: A series of silver films with various thicknesses were deposited on ITO covered silica substrates by magnetron sputtering at room temperature. The tunability of the surface plasmon resonance wavelength was realized by varying the thickness of silver thin film. By adjusting the silver layer thickness from 5 to 40 nm, the resonance wavelength shows a blueshift, which is due to a change in the electromagnetic field coupling strength from the localized surface plasmons excited between the silver thin film and ITO layer. In contrast, when the ITO layer is absent from the system, no noticeable shift in the resonance wavelength is observed upon varying the silver thin film thickness.

  18. Impact of X-ray irradiation on PMMA thin films

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Saman, E-mail: saman.khan343@gmail.com [Physics Department, University of Engineering and Technology, Lahore (Pakistan); Rafique, Muhammad Shahid [Physics Department, University of Engineering and Technology, Lahore (Pakistan); Anjum, Safia [Physics Department, Lahore College for Woman University, Lahore (Pakistan); Hayat, Asma [Physics Department, University of Engineering and Technology, Lahore (Pakistan); Iqbal, Nida [Faculty of Biomedical Engineering and Health Science, Universiti Teknologi Malaysia (UTM) (Malaysia)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer PMMA thin films were deposited at 300 Degree-Sign C and 500 Degree-Sign C using PLD technique. Black-Right-Pointing-Pointer These films were irradiated with different fluence of laser produced X-rays. Black-Right-Pointing-Pointer Irradiation affects the ordered packing as well as surface morphology of film. Black-Right-Pointing-Pointer Hardness of film decreases up to certain value of X-ray fluence. Black-Right-Pointing-Pointer Absorption in UV-visible range exhibits a non linear behavior. - Abstract: The objective of this project is to explore the effect of X-ray irradiation of thin polymeric films deposited at various substrate temperatures. pulsed laser deposition (PLD) technique is used for the deposition of PMMA thin films on glass substrate at 300 Degree-Sign C and 500 Degree-Sign C. These films have been irradiated with various X-rays fluences ranging from 2.56 to 5.76 mJ cm{sup -2}. Characterization of the films (before and after the irradiation) is done with help of X-ray Diffractrometer, Optical Microscope, Vickers hardness tester and UV-vis spectroscopy techniques. From XRD data, it is revealed that ordered packing has been improved for the films deposited at 300 Degree-Sign C. However after irradiation the films exhibited the amorphous behavior regardless of the X-ray fluence. Film deposited at 500 Degree-Sign C shows amorphous structure before and after irradiation. Hardness and particle size of thin film have also increased with the increasing substrate temperature. However, the irradiation has reverse effect i.e. the particle size as well as the hardness has reduced. Irradiation has also enhanced the absorption in the UV-visible region.

  19. Impact of X-ray irradiation on PMMA thin films

    International Nuclear Information System (INIS)

    Iqbal, Saman; Rafique, Muhammad Shahid; Anjum, Safia; Hayat, Asma; Iqbal, Nida

    2012-01-01

    Highlights: ► PMMA thin films were deposited at 300 °C and 500 °C using PLD technique. ► These films were irradiated with different fluence of laser produced X-rays. ► Irradiation affects the ordered packing as well as surface morphology of film. ► Hardness of film decreases up to certain value of X-ray fluence. ► Absorption in UV–visible range exhibits a non linear behavior. - Abstract: The objective of this project is to explore the effect of X-ray irradiation of thin polymeric films deposited at various substrate temperatures. pulsed laser deposition (PLD) technique is used for the deposition of PMMA thin films on glass substrate at 300 °C and 500 °C. These films have been irradiated with various X-rays fluences ranging from 2.56 to 5.76 mJ cm −2 . Characterization of the films (before and after the irradiation) is done with help of X-ray Diffractrometer, Optical Microscope, Vickers hardness tester and UV–vis spectroscopy techniques. From XRD data, it is revealed that ordered packing has been improved for the films deposited at 300 °C. However after irradiation the films exhibited the amorphous behavior regardless of the X-ray fluence. Film deposited at 500 °C shows amorphous structure before and after irradiation. Hardness and particle size of thin film have also increased with the increasing substrate temperature. However, the irradiation has reverse effect i.e. the particle size as well as the hardness has reduced. Irradiation has also enhanced the absorption in the UV–visible region.

  20. The effect of Argon pressure dependent V thin film on the phase transition process of (020) VO2 thin film

    Science.gov (United States)

    Meng, Yifan; Huang, Kang; Tang, Zhou; Xu, Xiaofeng; Tan, Zhiyong; Liu, Qian; Wang, Chunrui; Wu, Binhe; Wang, Chang; Cao, Juncheng

    2018-01-01

    It has been proved challenging to fabricate the single crystal orientation of VO2 thin film by a simple method. Based on chemical reaction thermodynamic and crystallization analysis theory, combined with our experimental results, we find out that when stoichiometric number of metallic V in the chemical equation is the same, the ratio of metallic V thin film surface average roughness Ra to thin film average particle diameter d decreases with the decreasing sputtering Argon pressure. Meanwhile, the oxidation reaction equilibrium constant K also decreases, which will lead to the increases of oxidation time, thereby the crystal orientation of the VO2 thin film will also become more uniform. By sputtering oxidation coupling method, metallic V thin film is deposited on c-sapphire substrate at 1 × 10-1 Pa, and then oxidized in the air with the maximum oxidation time of 65s, high oriented (020) VO2 thin film has been fabricated successfully, which exhibits ∼4.6 orders sheet resistance change across the metal-insulator transition.

  1. Nanostructured thin films for icephobic applications

    Science.gov (United States)

    Noormohammed, Saleema

    Icing on surfaces such as cables or high voltage insulators often leads to severe safety issues such as power outages in cold winter conditions. Conventional methods used to avoid such icing problems include mechanical deicing where the ice is scraped or broken and chemical deicing where deicers such as ethylene glycol are used. These methods have their own disadvantages of being destructive, expensive and time consuming. A better approach would be to prevent ice from forming in the first place by producing coating materials that are icephobic. Superhydrophobic surfaces, which demonstrate high water-repellency due to the negligible contact area of water with those surfaces, are also expected to minimize the contact area of ice. A low dielectric constant surface is also expected to reduce the adhesion of ice due to the screening of mirror charges, thereby eliminating one of the strongest interaction forces---the electrostatic forces of attraction at the ice-surface interface. In the present research work, both concepts were studied by producing superhydrophobic nanorough low-epsilon dielectric surfaces on aluminum or alumina substrates. Superhydrophobic properties were achieved on surfaces of aluminum or alumina by creating a certain nanoroughness using chemical methods followed by a low surface energy coating of rf-sputtered Teflon or fluoroalkyl-silane (FAS-17) providing a water contact angle greater than 160°. The same behavior is reported even when the nanorough substrates were coated with dielectric thin films of ZnO (lower epsilon) or TiO 2, (higher epsilon). It is found that the superhydrophobic nanorough low surface energy surfaces are also icephobic and the presence of a low dielectric constant surface coating of Teflon (lowest epsilon; epsilon = 2) allows a considerable reduction of the ice adhesion strength even on non-nanotextured surfaces where ice would stick. The superhydrophobic nanorough low-epsilon surfaces also demonstrate morphological and

  2. Optical conductivity of topological insulator thin films

    International Nuclear Information System (INIS)

    Li, L. L.; Xu, W.; Peeters, F. M.

    2015-01-01

    We present a detailed theoretical study on the optoelectronic properties of topological insulator thin film (TITFs). The k·p approach is employed to calculate the energy spectra and wave functions for both the bulk and surface states in the TITF. With these obtained results, the optical conductivities induced by different electronic transitions among the bulk and surface states are evaluated using the energy-balance equation derived from the Boltzmann equation. We find that for Bi 2 Se 3 -based TITFs, three characteristic regimes for the optical absorption can be observed. (i) In the low radiation frequency regime (photon energy ℏω<200 meV), the free-carrier absorption takes place due to intraband electronic transitions. An optical absorption window can be observed. (ii) In the intermediate radiation frequency regime (200<ℏω<300 meV), the optical absorption is induced mainly by interband electronic transitions from surface states in the valance band to surface states in the conduction band and an universal value σ 0 =e 2 /(8ℏ) for the optical conductivity can be obtained. (iii) In the high radiation frequency regime (ℏω>300 meV), the optical absorption can be achieved via interband electronic transitions from bulk and surface states in the valance band to bulk and surface states in the conduction band. A strong absorption peak can be observed. These interesting findings indicate that optical measurements can be applied to identify the energy regimes of bulk and surface states in the TITF

  3. High-throughput characterization of film thickness in thin film materials libraries by digital holographic microscopy

    Directory of Open Access Journals (Sweden)

    Yiu Wai Lai, Michael Krause, Alan Savan, Sigurd Thienhaus, Nektarios Koukourakis, Martin R Hofmann and Alfred Ludwig

    2011-01-01

    Full Text Available A high-throughput characterization technique based on digital holography for mapping film thickness in thin-film materials libraries was developed. Digital holographic microscopy is used for fully automatic measurements of the thickness of patterned films with nanometer resolution. The method has several significant advantages over conventional stylus profilometry: it is contactless and fast, substrate bending is compensated, and the experimental setup is simple. Patterned films prepared by different combinatorial thin-film approaches were characterized to investigate and demonstrate this method. The results show that this technique is valuable for the quick, reliable and high-throughput determination of the film thickness distribution in combinatorial materials research. Importantly, it can also be applied to thin films that have been structured by shadow masking.

  4. Broadband THz pulse emission and transmission properties of nanostructured Pt thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Mingzhe [Department of Physics and Electronics, Liupanshui Normal University, Liupanshui, Guizhou 553004 (China); College of Electronics and Information, Guizhou University, Huaxi 550025, Guiyang, Guizhou (China); Mu, Kaijun; Zhang, Cunlin [Department of Physics, Capital Normal University, Yuquan Road 100082, Beijing (China); Gu, Haoshuang, E-mail: guhs@hubu.edu.cn [Department of Electronic Sci& Tech, Hubei University, Xueyuan Road 430062, Wuhan, Hubei (China); Ding, Zhao [College of Electronics and Information, Guizhou University, Huaxi 550025, Guiyang, Guizhou (China)

    2015-10-01

    The THz transmission and emitting properties of a composite metallic nanostructure, composed of Ag nanowires electrodeposited in an anodic aluminum oxide (AAO) template and a Pt thin film, were investigated by using a femtosecond pulse laser irradiation. The microstructure of the above sub-wavelength nanostructure was investigated by XRD, SEM, AFM and TEM. The results indicated that the thickness of the Pt thin film was about 200 nm and the Ag nanowire array had a sparse and random distribution inside the AAO template, with a length distribution in the range of 10–25 μm. The THz radiation properties of above sub-wavelength nanostructure indicated that the generated THz fluence from the Pt film was a magnitude of μW scale with a broadband frequency range and its subsequent transmission could be significantly improved by the better impedance matching property of the Ag nanowire embedded AAO film compared with that of the empty AAO film.

  5. Thin film characterisation by advanced X-ray diffraction techniques

    International Nuclear Information System (INIS)

    Cappuccio, G.; Terranova, M.L.

    1996-09-01

    The Fifth School on X-ray diffraction from polycrystalline materials was devoted to thin film characterization by advanced X-ray diffraction techniques. Twenty contributions are contained in this volume; all twenty are recorded in the INIS Database. X-ray diffraction is known to be a powerful analytical tool for characterizing materials and understanding their structural features. The aim of these articles is to illustrate the fundamental contribution of modern diffraction techniques (grazing incidence, surface analysis, standing waves, etc.) to the characterization of thin and ultra-thin films, which have become important in many advanced technologies

  6. Thermal oxidation of Ni films for p-type thin-film transistors

    KAUST Repository

    Jiang, Jie

    2013-01-01

    p-Type nanocrystal NiO-based thin-film transistors (TFTs) are fabricated by simply oxidizing thin Ni films at temperatures as low as 400 °C. The highest field-effect mobility in a linear region and the current on-off ratio are found to be 5.2 cm2 V-1 s-1 and 2.2 × 103, respectively. X-ray diffraction, transmission electron microscopy and electrical performances of the TFTs with "top contact" and "bottom contact" channels suggest that the upper parts of the Ni films are clearly oxidized. In contrast, the lower parts in contact with the gate dielectric are partially oxidized to form a quasi-discontinuous Ni layer, which does not fully shield the gate electric field, but still conduct the source and drain current. This simple method for producing p-type TFTs may be promising for the next-generation oxide-based electronic applications. © 2013 the Owner Societies.

  7. Highly Mass-Sensitive Thin Film Plate Acoustic Resonators (FPAR

    Directory of Open Access Journals (Sweden)

    Ventsislav Yantchev

    2011-07-01

    Full Text Available The mass sensitivity of thin aluminum nitride (AlN film S0 Lamb wave resonators is theoretically and experimentally studied. Theoretical predictions based on modal and finite elements method analysis are experimentally verified. Here, two-port 888 MHz synchronous FPARs are micromachined and subsequently coated with hexamethyl-disiloxane(HMDSO-plasma-polymerized thin films of various thicknesses. Systematic data on frequency shift and insertion loss versus film thickness are presented. FPARs demonstrate high mass-loading sensitivity as well as good tolerance towards the HMDSO viscous losses. Initial measurements in gas phase environment are further presented.

  8. Formation of nanomagnetic thin films by dispersed fullerenes

    Science.gov (United States)

    Zheng, Lingyi A.; Lairson, Bruce M.; Barrera, Enrique V.; Shull, Robert D.

    2000-11-01

    A method of forming magnetic materials using dispersed fullerenes in ferromagnetic materials has been studied. Fullerenes (C60) have been integrated into the matrix of Co, Fe, CoFe thin films by thermal vapor codeposition. The size effects and interaction of the C60 molecules to the metallic atoms promote a self-assembly grain growth mode to produce thin films with unique evoluted microstructures characterized by nanosize columnar grains with uniformly dispersed C60 on the grain boundaries. These nanocrystalline films have displayed a series of promising magnetic properties, such as high out of plane remanence, high coercivity, fast magnetic switching, and unusual hysteresis behavior.

  9. Infrared reflectance measurement for InN thin film characterization

    International Nuclear Information System (INIS)

    Fukui, K.; Kugumiya, Y.; Nakagawa, N.; Yamamoto, A.

    2006-01-01

    Infrared reflectance measurements of a series of InN thin films have been performed and attempt to derive carrier concentration and other physical constants for InN thin film characterization. Fitting calculations are performed by use of the dielectric function equation based on phonon-plasmon coupling model. Longitudinal and transverse optical phonon frequencies, plasma frequency and their damping parameters can be derived from fitting. From those results, electrical and phonon properties of InN and characterization of films are discussed. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Morphological Study Of Palladium Thin Films Deposited By Sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Salcedo, K L; Rodriguez, C A [Grupo Plasma Laser y Aplicaciones, Ingenieria Fisica, Universidad Tecnologica de Pereira (Colombia); Perez, F A [WNANO, West Virginia University (United States); Riascos, H [Grupo Plasma Laser y Aplicaciones, Departamento de Fisica, Universidad Tecnologica de Pereira (Colombia)

    2011-01-01

    This paper presents a morphological analysis of thin films of palladium (Pd) deposited on a substrate of sapphire (Al{sub 2}O{sub 3}) at a constant pressure of 3.5 mbar at different substrate temperatures (473 K, 523 K and 573 K). The films were morphologically characterized by means of an Atomic Force Microscopy (AFM); finding a relation between the roughness and the temperature. A morphological analysis of the samples through AFM was carried out and the roughness was measured by simulating the X-ray reflectivity curve using GenX software. A direct relation between the experimental and simulation data of the Palladium thin films was found.

  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. Giant flexoelectric effect in ferroelectric epitaxial thin films.

    Science.gov (United States)

    Lee, D; Yoon, A; Jang, S Y; Yoon, J-G; Chung, J-S; Kim, M; Scott, J F; Noh, T W

    2011-07-29

    We report on nanoscale strain gradients in ferroelectric HoMnO(3) epitaxial thin films, resulting in a giant flexoelectric effect. Using grazing-incidence in-plane x-ray diffraction, we measured strain gradients in the films, which were 6 or 7 orders of magnitude larger than typical values reported for bulk oxides. The combination of transmission electron microscopy, electrical measurements, and electrostatic calculations showed that flexoelectricity provides a means of tuning the physical properties of ferroelectric epitaxial thin films, such as domain configurations and hysteresis curves. © 2011 American Physical Society

  13. Cathodoluminescence study of thin films of high Tc superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Barkay, Z.; Azoulay, J.; Lereah, Y.; Dai, U.; Hess, N.; Racah, D.; Gruenbaum, E.; Deutscher, G. (School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, 69978 Ramat Aviv (Israel))

    1990-10-22

    Cathodoluminescence (CL) of thin films of high {ital T}{sub {ital c}} superconductors was studied in the scanning electron microscope. The depth and the lateral locations of the different phases can be revealed. In thin films, unlike the bulk superconductors, the CL information can be obtained either from the film itself or the substrate by varying the primary beam energy. At high beam energy, substrate defects and slight thickness variations of a single high {ital T}{sub {ital c}} phase are observed. The resolution of the CL measurements improves at low temperatures.

  14. Characterization of Sucrose Thin Films for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    S. L. Iconaru

    2011-01-01

    Full Text Available Sucrose is a natural osmolyte accumulated in the cells of organisms as they adapt to environmental stress. In vitro sucrose increases protein stability and forces partially unfolded structures to refold. Thin films of sucrose (C12H22O11 were deposited on thin cut glass substrates by the thermal evaporation technique (P∼10−5 torr. Characteristics of thin films were put into evidence by Fourier Transform Infrared Spectroscopy (FTIR, X-ray Photoelectron Spectroscopy (XPS, scanning electron microscopy (SEM, and differential thermal analysis and thermal gravimetric analysis (TG/DTA. The experimental results confirm a uniform deposition of an adherent layer. In this paper we present a part of the characteristics of sucrose thin films deposited on glass in medium vacuum conditions, as a part of a culture medium for osteoblast cells. Osteoblast cells were used to determine proliferation, viability, and cytotoxicity interactions with sucrose powder and sucrose thin films. The osteoblast cells have been provided from the American Type Culture Collection (ATCC Centre. The outcome of this study demonstrated the effectiveness of sucrose thin films as a possible nontoxic agent for biomedical applications.

  15. Visualizing Nanoscopic Topography and Patterns in Freely Standing Thin Films

    Science.gov (United States)

    Yilixiati, Subinuer; Zhang, Yiran; Pearsall, Collin; Sharma, Vivek

    Thin liquid films containing micelles, nanoparticles, polyelectrolyte-surfactant complexes and smectic liquid crystals undergo thinning in a discontinuous, step-wise fashion. The discontinuous jumps in thickness are often characterized by quantifying changes in the intensity of reflected monochromatic light, modulated by thin film interference from a region of interest. Stratifying thin films exhibit a mosaic pattern in reflected white light microscopy, attributed to the coexistence of domains with various thicknesses, separated by steps. Using Interferometry Digital Imaging Optical Microscopy (IDIOM) protocols developed in the course of this study, we spatially resolve for the first time, the landscape of stratifying freestanding thin films. In particular, for thin films containing micelles of sodium dodecyl sulfate (SDS), discontinuous, thickness transitions with concentration-dependent steps of 5-25 nm are visualized and analyzed using IDIOM protocols. We distinguish nanoscopic rims, mesas and craters and show that the non-flat features are sculpted by oscillatory, periodic, supramolecular structural forces that arise in confined fluids

  16. Oxide-based thin film transistors for flexible electronics

    Science.gov (United States)

    He, Yongli; Wang, Xiangyu; Gao, Ya; Hou, Yahui; Wan, Qing

    2018-01-01

    The continuous progress in thin film materials and devices has greatly promoted the development in the field of flexible electronics. As one of the most common thin film devices, thin film transistors (TFTs) are significant building blocks for flexible platforms. Flexible oxide-based TFTs are well compatible with flexible electronic systems due to low process temperature, high carrier mobility, and good uniformity. The present article is a review of the recent progress and major trends in the field of flexible oxide-based thin film transistors. First, an introduction of flexible electronics and flexible oxide-based thin film transistors is given. Next, we introduce oxide semiconductor materials and various flexible oxide-based TFTs classified by substrate materials including polymer plastics, paper sheets, metal foils, and flexible thin glass. Afterwards, applications of flexible oxide-based TFTs including bendable sensors, memories, circuits, and displays are presented. Finally, we give conclusions and a prospect for possible development trends. Project supported in part by the National Science Foundation for Distinguished Young Scholars of China (No. 61425020), in part by the National Natural Science Foundation of China (No. 11674162).

  17. Pd thin films on flexible substrate for hydrogen sensor

    Energy Technology Data Exchange (ETDEWEB)

    Öztürk, Sadullah [Fatih Sultan Mehmet Vakıf University, Engineering Faculty, Istanbul (Turkey); Kılınç, Necmettin, E-mail: nkilinc@nigde.edu.tr [Nigde University, Mechatronics Engineering Department, 51245 Nigde (Turkey); Nigde University, Nanotechnology Application and Research Center, 51245 Nigde (Turkey)

    2016-07-25

    In this work, palladium (Pd) thin films were prepared via RF sputtering method with various thicknesses (6 nm, 20 nm and 60 nm) on both a flexible substrate and a hard substrate. Hydrogen (H{sub 2}) sensing properties of Pd films on flexible substrate have been investigated depending on temperatures (25–100 °C) and H{sub 2} concentrations (600 ppm – 10%). The effect of H{sub 2} on structural properties of the films was also studied. The films were characterized by Scanning Electron Microscopy (SEM) and X-ray diffraction. It is found that whole Pd films on hard substrate show permanent structural deformation after exposed to 10% H{sub 2} for 30 min. But, this H{sub 2} exposure does not causes any structural deformation for 6 nm Pd film on flexible substrate and 6 nm Pd film on flexible substrate shows reversible sensor response up to 10% H{sub 2} concentration without any structural deformation. On the other hand, Pd film sensors that have the thicknesses 20 nm and 60 nm on flexible substrate are irreversible for higher H{sub 2} concentration (>2%) with film deformation. The sensor response of 6 nm Pd film on flexible substrate increased with increasing H{sub 2} concentration up 4% and then saturated. The sensitivity of the film decreased with increasing operation temperature. - Highlights: • Pd thin films fabricated by RF sputtering on both flexible and hard substrates. • Structural deformation observed for films on hard substrate after exposing 10% H{sub 2}. • 6 nm Pd film on flexible substrate shows reversible sensor response up to 10% H{sub 2}. • H{sub 2} sensing properties of film on flexible substrate investigated depending on temperature and concentration. • The sensitivity of the film decreased with increasing operation temperature.

  18. Aluminosilicate glass thin films elaborated by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Carlier, Thibault [Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 – UCCS – Unité de Catalyse et Chimie du Solide, F-59000 Lille (France); Saitzek, Sébastien [Univ. Artois, CNRS, Centrale Lille, ENSCL, Univ. Lille, UMR 8181, Unité de Catalyse et de Chimie du Solide (UCCS), F-62300 Lens (France); Méar, François O., E-mail: francois.mear@univ-lille1.fr [Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 – UCCS – Unité de Catalyse et Chimie du Solide, F-59000 Lille (France); Blach, Jean-François; Ferri, Anthony [Univ. Artois, CNRS, Centrale Lille, ENSCL, Univ. Lille, UMR 8181, Unité de Catalyse et de Chimie du Solide (UCCS), F-62300 Lens (France); Huvé, Marielle; Montagne, Lionel [Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 – UCCS – Unité de Catalyse et Chimie du Solide, F-59000 Lille (France)

    2017-03-01

    Highlights: • Successfully deposition of a glassy thin film by PLD. • A good homogeneity and stoichiometry of the coating. • Influence of the deposition temperature on the glassy thin-film structure. - Abstract: In the present work, we report the elaboration of aluminosilicate glass thin films by Pulsed Laser Deposition at various temperatures deposition. The amorphous nature of glass thin films was highlighted by Grazing Incidence X-Ray Diffraction and no nanocristallites were observed in the glassy matrix. Chemical analysis, obtained with X-ray Photoelectron Spectroscopy and Time of Flight Secondary Ion Mass Spectroscopy, showed a good transfer and homogeneous elementary distribution with of chemical species from the target to the film a. Structural studies performed by Infrared Spectroscopy showed that the substrate temperature plays an important role on the bonding configuration of the layers. A slight shift of Si-O modes to larger wavenumber was observed with the synthesis temperature, assigned to a more strained sub-oxide network. Finally, optical properties of thins film measured by Spectroscopic Ellipsometry are similar to those of the bulk aluminosilicate glass, which indicate a good deposition of aluminosilicate bulk glass.

  19. Self-assembly of dodecaphenyl POSS thin films

    Science.gov (United States)

    Handke, Bartosz; Klita, Łukasz; Niemiec, Wiktor

    2017-12-01

    The self-assembly abilities of Dodecaphenyl Polyhedral Oligomeric Silsesquioxane thin films on Si(1 0 0) surfaces were studied. Due to their thermal properties - relatively low sublimation temperature and preservation of molecular structure - cage type silsesquioxanes are ideal material for the preparation of a thin films by Physical Vapor Deposition. The Ultra-High Vacuum environment and the deposition precision of the PVD method enable the study of early stages of thin film growth and its molecular organization. X-ray Reflectivity and Atomic Force Microscopy measurements allow to pursuit size-effects in the structure of thin films with thickness ranges from less than a single molecular layer up to several tens of layers. Thermal treatment of the thin films triggered phase change: from a poorly ordered polycrystalline film into a well-ordered multilayer structure. Self-assembly of the layers is the effect of the π-stacking of phenyl rings, which force molecules to arrange in a superlattice, forming stacks of alternating organic-inorganic layers.

  20. Triplet transport in thin films: fundamentals and applications.

    Science.gov (United States)

    Li, Xin; Tang, Ming Lee

    2017-04-18

    Triplet excitons are key players in multi-excitonic processes like singlet fission and triplet-triplet annihilation based photon upconversion, which may be useful in next-generation photovoltaic devices, photocatalysis and bioimaging. Here, we present an overview of experimental and theoretical work on triplet energy transfer, with a focus on triplet transport in thin films. We start with the theory describing Dexter-mediated triplet energy transfer and the fundamental parameters controlling this process. Then we summarize current experimental methods used to measure the triplet exciton diffusion length. Finally, the use of hierarchically ordered structures to improve the triplet diffusion length is presented, before concluding with an outlook on the remaining challenges.

  1. Robust lanthanide emitters in polyelectrolyte thin films for photonic applications

    Science.gov (United States)

    Greenspon, Andrew S.; Marceaux, Brandt L.; Hu, Evelyn L.

    2018-02-01

    Trivalent lanthanides provide stable emission sources at wavelengths spanning the ultraviolet through the near infrared with uses in telecommunications, lighting, and biological sensing and imaging. We describe a method for incorporating an organometallic lanthanide complex within polyelectrolyte multilayers, producing uniform, optically active thin films on a variety of substrates. These films demonstrate excellent emission with narrow linewidths, stable over a period of months, even when bound to metal substrates. Utilizing different lanthanides such as europium and terbium, we are able to easily tune the resulting wavelength of emission of the thin film. These results demonstrate the suitability of this platform as a thin film emitter source for a variety of photonic applications such as waveguides, optical cavities, and sensors.

  2. Scanning Angle Raman spectroscopy in polymer thin film characterization

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Vy H.T. [Iowa State Univ., Ames, IA (United States)

    2015-12-19

    The focus of this thesis is the application of Raman spectroscopy for the characterization of thin polymer films. Chapter 1 provides background information and motivation, including the fundamentals of Raman spectroscopy for chemical analysis, scanning angle Raman scattering and scanning angle Raman scattering for applications in thin polymer film characterization. Chapter 2 represents a published manuscript that focuses on the application of scanning angle Raman spectroscopy for the analysis of submicron thin films with a description of methodology for measuring the film thickness and location of an interface between two polymer layers. Chapter 3 provides an outlook and future directions for the work outlined in this thesis. Appendix A, contains a published manuscript that outlines the use of Raman spectroscopy to aid in the synthesis of heterogeneous catalytic systems. Appendix B and C contain published manuscripts that set a foundation for the work presented in Chapter 2.

  3. Recent progress of optical thin films in the automobile industry.

    Science.gov (United States)

    Taga, Y

    1993-10-01

    There are increasing demands for the application of optical thin films to transparent substrates such as glass and plastics for windows in automobiles with the view of adding fascinating optical properties to them. These properties include surface hardening of plastics, infrared reflection, ultraviolet absorption, polarization and birefringence, and hydrophobicity. Recent examples of applications of sophisticated thin-film processes of plasma treatment and physical vapor deposition are reviewed. The novelty of the functions provided by physical vapor deposition films together with their durability for practical usage are emphasized as areas in which the thin-film process has a significant impact. Characterization of the modified surface and interface is also included to demonstrate recent advances in surface chemistry. Finally, future challenges for optical modification of transparent substrates in the automobile industry are also discussed.

  4. Thin film encapsulation for flexible AM-OLED: a review

    Science.gov (United States)

    Park, Jin-Seong; Chae, Heeyeop; Chung, Ho Kyoon; In Lee, Sang

    2011-03-01

    Flexible organic light emitting diode (OLED) will be the ultimate display technology to customers and industries in the near future but the challenges are still being unveiled one by one. Thin-film encapsulation (TFE) technology is the most demanding requirement to prevent water and oxygen permeation into flexible OLED devices. As a polymer substrate does not offer the same barrier performance as glass, the TFE should be developed on both the bottom and top side of the device layers for sufficient lifetimes. This work provides a review of promising thin-film barrier technologies as well as the basic gas diffusion background. Topics include the significance of the device structure, permeation rate measurement, proposed permeation mechanism, and thin-film deposition technologies (Vitex system and atomic layer deposition (ALD)/molecular layer deposition (MLD)) for effective barrier films.

  5. Thin-film Rechargeable Lithium Batteries for Implantable Devices

    Science.gov (United States)

    Bates, J. B.; Dudney, N. J.

    1997-05-01

    Thin films of LiCoO{sub 2} have been synthesized in which the strongest x ray reflection is either weak or missing, indicating a high degree of preferred orientation. Thin film solid state batteries with these textured cathode films can deliver practical capacities at high current densities. For example, for one of the cells 70% of the maximum capacity between 4.2 V and 3 V ({approximately}0.2 mAh/cm{sup 2}) was delivered at a current of 2 mA/cm{sup 2}. When cycled at rates of 0.1 mA/cm{sup 2}, the capacity loss was 0.001%/cycle or less. The reliability and performance of Li LiCoO{sub 2} thin film batteries make them attractive for application in implantable devices such as neural stimulators, pacemakers, and defibrillators.

  6. Polycrystalline Thin Film Photovoltaics: Research, Development, and Technologies: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Ullal, H. S.; Zweibel, K.; von Roedern, B.

    2002-05-01

    II-VI binary thin-film solar cells based on cadmium telluride (CdTe) and I-III-VI ternary thin-film solar cells based on copper indium diselenide (CIS) and related materials have been the subject of intense research and development in the past few years. Substantial progress has been made thus far in the area of materials research, device fabrication, and technology development, and numerous applications based on CdTe and CIS have been deployed worldwide. World record efficiency of 16.5% has been achieved by NREL scientists for a thin-film CdTe solar cell using a modified device structure. Also, NREL scientists achieved world-record efficiency of 21.1% for a thin-film CIGS solar cell under a 14X concentration and AM1.5 global spectrum. When measured under a AM1.5 direct spectrum, the efficiency increases to 21.5%. Pathways for achieving 25% efficiency for tandem polycrystalline thin-film solar cells are elucidated. R&D issues relating to CdTe and CIS are reported in this paper, such as contact stability and accelerated life testing in CdTe, and effects of moisture ingress in thin-film CIS devices. Substantial technology development is currently under way, with various groups reporting power module efficiencies in the range of 7.0% to 12.1% and power output of 40.0 to 92.5 W. A number of lessons learned during the scale-up activities of the technology development for fabrication of thin-film power modules are discussed. The major global players actively involved in the technology development and commercialization efforts using both rigid and flexible power modules are highlighted.

  7. Optical and Nonlinear Optical Response of Light Sensor Thin Films

    Directory of Open Access Journals (Sweden)

    S. Z. Weisz

    2005-04-01

    Full Text Available For potential ultrafast optical sensor application, both VO2 thin films andnanocomposite crystal-Si enriched SiO2 thin films grown on fused quartz substrates weresuccessfully prepared using pulsed laser deposition (PLD and RF co-sputteringtechniques. In photoluminescence (PL measurement c-Si/SiO2 film containsnanoparticles of crystal Si exhibits strong red emission with the band maximum rangingfrom 580 to 750 nm. With ultrashort pulsed laser excitation all films show extremelyintense and ultrafast nonlinear optical (NLO response. The recorded holography fromall these thin films in a degenerate-four-wave-mixing configuration shows extremelylarge third-order response. For VO2 thin films, an optically induced semiconductor-tometalphase transition (PT immediately occurred upon laser excitation. it accompanied.It turns out that the fast excited state dynamics was responsible to the induced PT. For c-Si/SiO2 film, its NLO response comes from the contribution of charge carriers created bylaser excitation in conduction band of the c-Si nanoparticles. It was verified byintroducing Eu3+ which is often used as a probe sensing the environment variations. Itturns out that the entire excited state dynamical process associated with the creation,movement and trapping of the charge carriers has a characteristic 500 ps duration.

  8. Picosecond and subpicosecond pulsed laser deposition of Pb thin films

    Directory of Open Access Journals (Sweden)

    F. Gontad

    2013-09-01

    Full Text Available Pb thin films were deposited on Nb substrates by means of pulsed laser deposition (PLD with UV radiation (248 nm, in two different ablation regimes: picosecond (5 ps and subpicosecond (0.5 ps. Granular films with grain size on the micron scale have been obtained, with no evidence of large droplet formation. All films presented a polycrystalline character with preferential orientation along the (111 crystalline planes. A maximum quantum efficiency (QE of 7.3×10^{-5} (at 266 nm and 7 ns pulse duration was measured, after laser cleaning, demonstrating good photoemission performance for Pb thin films deposited by ultrashort PLD. Moreover, Pb thin film photocathodes have maintained their QE for days, providing excellent chemical stability and durability. These results suggest that Pb thin films deposited on Nb by ultrashort PLD are a noteworthy alternative for the fabrication of photocathodes for superconductive radio-frequency electron guns. Finally, a comparison with the characteristics of Pb films prepared by ns PLD is illustrated and discussed.

  9. A dynamic rheological model for thin-film lubrication

    International Nuclear Information System (INIS)

    Zhang Xiang-Jun; Huang Ying; Guo Yan-Bao; Tian Yu; Meng Yong-Gang

    2013-01-01

    In this study, the effects of the non-Newtonian rheological properties of the lubricant in a thin-film lubrication regime between smooth surfaces were investigated. The thin-film lubrication regime typically appears in Stribeck curves with a clearly observable minimum coefficient of friction (COF) and a low-COF region, which is desired for its lower energy dissipation. A dynamic rheology of the lubricant from the hydrodynamic lubrication regime to the thin-film lubrication regime was proposed based on the convected Maxwell constitutive equation. This rheology model includes the increased relaxation time and the yield stress of the confined lubricant thin film, as well as their dependences on the lubricant film thickness. The Deborah number (De number) was adopted to describe the liquid-solid transition of the confined lubricant thin film under shearing. Then a series of Stribeck curves were calculated based on Tichy's extended lubrication equations with a perturbation of the De number. The results show that the minimum COF points in the Stribeck curve correspond to a critical De number of 1.0, indicating a liquid-to-solid transition of the confined lubricant film. Furthermore, the two proposed parameters in the dynamic rheological model, namely negative slipping length b (indicating the lubricant interfacial effect) and the characteristic relaxation time λ 0 , were found to determine the minimum COF and the width of the low-COF region, both of which were required to optimize the shape of the Stribeck curve. The developed dynamic rheological model interprets the correlation between the rheological and interfacial properties of lubricant and its lubrication behavior in the thin-film regime. (condensed matter: structural, mechanical, and thermal properties)

  10. Spin-torque ferromagnetic resonance in arbitrarily magnetized thin films

    Science.gov (United States)

    Sklenar, Joseph

    The spin Hall effect (SHE) in non-magnetic metals can be used to generate spin-transfer-torque (STT), subsequently inducing ferromagnetic resonance (FMR) in magnetic thin films; this experimental method is termed spin-torque ferromagnetic resonance (ST-FMR). Most ST-FMR experiments that are reported have an applied magnetic field in the plane of the sample and the research focuses on material combinations that have large and efficient STT. The most common way ST-FMR signals are detected is through an anisotropic magnetoresistance (AMR) rectification process. In this work we will present ST-FMR results in thin films where the magnetization has both an in-plane and out-of-plane component. The arbitrary magnetization direction is achieved by tipping the applied magnetic field out of the sample plane. We find that when the material system is a permalloy/Pt bilayer, ST-FMR signals are not mirror-symmetric upon magnetic field reversal . This is because the combination of both a STT from the bulk SHE and the Oersted field-like torque from the device do not drive the dynamics in the same manner when the field is reversed. We interpret our results in the Py/Pt experiment by extending an already established ST-FMR lineshape model to describe the general case of arbitrarily magnetized films. We compare and contrast our Py/Pt experiment with another system we measured, a Py/MoS2 bilayer. For the Py/MoS2 system, in-plane experiments suggest that a large STT is present and are comparable to what is observed for the more traditional Py/Pt system . On the other hand, the out-of-plane experiment for the Py/MoS2 system is qualitatively very different from Py/Pt. Our results suggest that ST-FMR experiments for arbitrarily magnetized magnetic films are useful in characterizing STT generated from interface rather than bulk effects. Work at Northwestern was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Materials Science and Engineering Division under grant

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

    Science.gov (United States)

    Thoř, Tomáš; Václavík, Jan

    2016-11-01

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

  12. Commercial Development Of Ovonic Thin Film Solar Cells

    Science.gov (United States)

    Ovshinsky, Stanford R.

    1983-09-01

    subsequent paper) which has clearly demonstrated that the basic barrier to low-cost production has been broken through and that one can now speak realistically of delivering power directly from the sun for under a dollar per peak watt merely by making larger versions of this basic continuous web, large-area thin-film machine. We have made one square foot amorphous silicon alloy PIN devices with conversion efficiencies in the range of 7%, and in the laboratory, we have reported smaller area PIN de-vices in the 10% conversion efficiency range. In addition, much higher energy conversion efficiencies can be obtained within the same process by using multi-cell layered or tandem thin-film solar cell structures (see Figure 1). These devices exhibit enhanced efficiency by utilizing a wider range of the solar spectrum. Since the theoretical maximum efficiency for multi-cell structures is over 60%, one can certainly realistically anticipate the pro-duction of thin-film amorphous photovoltaic devices with efficiencies as high as 30%. Our production device is already a two-cell tandem, as we have solved not only the problems of interfacing the individual cell components but also the difficulties associated with a one foot square format deposited on a continuous web. Figure 2 shows a continuous roll of Ovonic solar cells. Realistic calculations for a three-cell tandem thin-film device using amorphous semiconductor alloys with 1.8eV, 1.5eV, and 1.0eV optical band gaps indicate that solar energy conversion efficiencies of 20-30% can be achieved.

  13. Low thermal emissivity surfaces using AgNW thin films

    Science.gov (United States)

    Pantoja, Elisa; Bhatt, Rajendra; Liu, Anping; Gupta, Mool C.

    2017-12-01

    The properties of silver nanowire (AgNW) films in the optical and infrared spectral regime offer an interesting opportunity for a broad range of applications that require low-emissivity coatings. This work reports a method to reduce the thermal emissivity of substrates by the formation of low-emissivity AgNW coating films from solution. The spectral emissivity was characterized by thermal imaging with an FLIR camera, followed by Fourier transform infrared spectroscopy. In a combined experimental and simulation study, we provide fundamental data of the transmittance, reflectance, haze, and emissivity of AgNW thin films. Emissivity values were finely tuned by modifying the concentration of the metal nanowires in the films. The simulation models based on the transfer matrix method developed for the AgNW thin films provided optical values that show a good agreement with the measurements.

  14. Effects of Gamma Irradiation on Polyvinylidene Fluoride Thin Films

    Science.gov (United States)

    Madivalappa, Shivaraj; Jali, V. M.

    2018-02-01

    Polyvinylidene fluoride thin films were synthesized by Sol-Gel method with spin rate of 3000 rpm for 30 sec on ITO glass substrates and were annealed at 170 C. The films were irradiated by Gamma radiation with different doses (10, 30, 40 and 50 kGy). XRD and FTIR spectra have been obtained to identify the presence of α / β phases. Mean crystallite size was calculated by Scherer’s equation. Different vibrational bands were identified and percentage of β phase was determined by FTIR analysis. Optical properties like band gap, refractive index, optical activation energy have been determined. Surface morphology and compositions of pristine and gamma irradiated PVDF thin films were confirmed respectively, by SEM and Energy dispersive X-ray analysis. The comparison of the structural and optical optical properties of pristine PVDF polymer film has been made with those of the Gamma irradiated films.

  15. Characterization of fully functional spray-on antibody thin films

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa, Jhon [Department of Chemistry, University of South Florida, 4202 E. Fowler Ave., Tampa, FL 33620-5250 (United States); Magaña, Sonia; Lim, Daniel V. [Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 E. Fowler Ave., Tampa, FL 33620-7115 (United States); Schlaf, Rudy, E-mail: schlaf@eng.usf.edu [Department of Electrical Engineering, University of South Florida, 4202 E. Fowler Ave., Tampa, FL 33620-5101 (United States)

    2014-02-15

    The authors recently demonstrated that fully functional Escherichia coli O157:H7 antibody thin films can be prepared using a simple pneumatic nebulizer on glass surface [1]. This paper focuses on the investigation of the morphology and physical properties of these films with the aim to better understand their performance. A series of E. coli O157:H7 antibody spray-on thin films were investigated by ellipsometry, X-ray photoelectron spectroscopy (XPS), immunoassays, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), fluorescence microscopy, atomic force microscope (AFM) and contact angle analysis. These data were compared to measurements on films prepared with the biotin–avidin covalent bonding scheme. The investigation showed that films created by a 2 min pneumatic spray deposition time can capture antigens similar as the avidin–biotin wet-chemical method. The results also suggests that an influential factor for the comparable capture cell ability between sprayed and covalent films is an increased antibody surface coverage for the sprayed films (non-equilibrium technique), which compensates for the lack of its antibody orientation. There was no significant antibody denaturation detected on any of the sprayed films. Both techniques led to the formation of cluster-aggregates, a factor that seems unavoidable due to the natural tendency of protein to cluster. The avidin–biotin bridge films generally had a higher roughness, which manifested itself in a higher wettability compared to the sprayed films.

  16. Characterization of fully functional spray-on antibody thin films

    Science.gov (United States)

    Figueroa, Jhon; Magaña, Sonia; Lim, Daniel V.; Schlaf, Rudy

    2014-02-01

    The authors recently demonstrated that fully functional Escherichia coli O157:H7 antibody thin films can be prepared using a simple pneumatic nebulizer on glass surface [1]. This paper focuses on the investigation of the morphology and physical properties of these films with the aim to better understand their performance. A series of E. coli O157:H7 antibody spray-on thin films were investigated by ellipsometry, X-ray photoelectron spectroscopy (XPS), immunoassays, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), fluorescence microscopy, atomic force microscope (AFM) and contact angle analysis. These data were compared to measurements on films prepared with the biotin-avidin covalent bonding scheme. The investigation showed that films created by a 2 min pneumatic spray deposition time can capture antigens similar as the avidin-biotin wet-chemical method. The results also suggests that an influential factor for the comparable capture cell ability between sprayed and covalent films is an increased antibody surface coverage for the sprayed films (non-equilibrium technique), which compensates for the lack of its antibody orientation. There was no significant antibody denaturation detected on any of the sprayed films. Both techniques led to the formation of cluster-aggregates, a factor that seems unavoidable due to the natural tendency of protein to cluster. The avidin-biotin bridge films generally had a higher roughness, which manifested itself in a higher wettability compared to the sprayed films.

  17. Nanometric thin film membranes manufactured on square meter scale: ultra-thin films for CO 2 capture

    KAUST Repository

    Yave, Wilfredo

    2010-09-01

    Miniaturization and manipulation of materials at nanometer scale are key challenges in nanoscience and nanotechnology. In membrane science and technology, the fabrication of ultra-thin polymer films (defect-free) on square meter scale with uniform thickness (<100 nm) is crucial. By using a tailor-made polymer and by controlling the nanofabrication conditions, we developed and manufactured defect-free ultra-thin film membranes with unmatched carbon dioxide permeances, i.e. >5 m3 (STP) m-2 h -1 bar-1. The permeances are extremely high, because the membranes are made from a CO2 philic polymer material and they are only a few tens of nanometers thin. Thus, these thin film membranes have potential application in the treatment of large gas streams under low pressure like, e.g., carbon dioxide separation from flue gas. © 2010 IOP Publishing Ltd.

  18. Laser-induced vibration of a thin soap film.

    Science.gov (United States)

    Emile, Olivier; Emile, Janine

    2014-09-21

    We report on the vibration of a thin soap film based on the optical radiation pressure force. The modulated low power laser induces a counter gravity flow in a vertical free-standing draining film. The thickness of the soap film is then higher in the upper region than in the lower region of the film. Moreover, the lifetime of the film is dramatically increased by a factor of 2. Since the laser beam only acts mechanically on the film interfaces, such a film can be employed in an optofluidic diaphragm pump, the interfaces behaving like a vibrating membrane and the liquid in-between being the fluid to be pumped. Such a pump could then be used in delicate micro-equipment, in chips where temperature variations are detrimental and even in biological systems.

  19. Polycaprolactone thin films for retinal tissue engineering and drug delivery

    Science.gov (United States)

    Steedman, Mark Rory

    This dissertation focuses on the development of polycaprolactone thin films for retinal tissue engineering and drug delivery. We combined these thin films with techniques such as micro and nanofabrication to develop treatments for age-related macular degeneration (AMD), a disease that leads to the death of rod and cone photoreceptors. Current treatments are only able to slow or limit the progression of the disease, and photoreceptors cannot be regenerated or replaced by the body once lost. The first experiments presented focus on a potential treatment for AMD after photoreceptor death has occurred. We developed a polymer thin film scaffold technology to deliver retinal progenitor cells (RPCs) to the affected area of the eye. Earlier research showed that RPCs destined to become photoreceptors are capable of incorporating into a degenerated retina. In our experiments, we showed that RPC attachment to a micro-welled polycaprolactone (PCL) thin film surface enhanced the differentiation of these cells toward a photoreceptor fate. We then used our PCL thin films to develop a drug delivery device capable of sustained therapeutic release over a multi-month period that would maintain an effective concentration of the drug in the eye and eliminate the need for repeated intraocular injections. We first investigated the biocompatibility of PCL in the rabbit eye. We injected PCL thin films into the anterior chamber or vitreous cavity of rabbit eyes and monitored the animals for up to 6 months. We found that PCL thin films were well tolerated in the rabbit eye, showing no signs of chronic inflammation due to the implant. We then developed a multilayered thin film device containing a microporous membrane. We loaded these devices with lyophilized proteins and quantified drug elution for 10 weeks, finding that both bovine serum albumin and immunoglobulin G elute from these devices with zero order release kinetics. These experiments demonstrate that PCL is an extremely useful

  20. Catalytic EC′ reaction at a thin film modified electrode

    International Nuclear Information System (INIS)

    Gerbino, Leandro; Baruzzi, Ana M.; Iglesias, Rodrigo A.

    2013-01-01

    Numerical simulations of cyclic voltammograms corresponding to a catalytic EC′ reaction taking place at a thin film modified electrode are performed by way of finite difference method. Besides considering the chemical kinetic occurring inside the thin film, the model takes into account the different diffusion coefficients for each species at each of the involved phases, i.e. the thin film layer and bulk solution. The theoretical formulation is given in terms of dimensionless model parameters but a brief discussion of each of these parameters and their relationship to experimental variables is presented. Special emphasis is given to the use of working curve characteristics to quantify diffusion coefficient, homogeneous kinetic constant and thickness of the thin layer in a real system. Validation of the model is made by comparison of experimental results corresponding to the electron charge transfer of Ru(NH 3 ) 6 3+ /Ru(NH 3 ) 6 2+ hemi-couple at a thin film of a cross-linked chitosan film containing an immobilized redox dye