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.

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.

Thin films by metal-organic precursor plasma spray

International Nuclear Information System (INIS)

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

2009-01-01

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

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

Directory of Open Access Journals (Sweden)

Xue Zhang

2017-07-01

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

The effects of heat treatment on optical, structural, electrochromic and bonding properties of Nb{sub 2}O{sub 5} thin films

Energy Technology Data Exchange (ETDEWEB)

Coşkun, Özlem Duyar, E-mail: duyar@hacettepe.edu.tr [Hacettepe University, Department of Physics Engineering, Thin Film Preparation and Characterization Laboratory, Ankara (Turkey); Demirel, Selen, E-mail: nymph24@gmail.com [Hacettepe University, Department of Physics Engineering, Thin Film Preparation and Characterization Laboratory, Ankara (Turkey); Hacettepe University, Nanotechnology and Nanomedicine Department, Ankara (Turkey); Atak, Gamze, E-mail: gbaser@hacettepe.edu.tr [Hacettepe University, Department of Physics Engineering, Thin Film Preparation and Characterization Laboratory, Ankara (Turkey)

2015-11-05

Nb{sub 2}O{sub 5} thin films were deposited onto heated glass substrates by RF magnetron sputtering using a Nb{sub 2}O{sub 5} target. The films were annealed in air at temperatures between 400 and 700 °C for 6 h. Effects of the crystalline structure on optical, structural, electrochromic and bonding properties of the Nb{sub 2}O{sub 5} thin films were investigated by X-ray diffraction, atomic force microscopy, X-ray photoelectron spectroscopy, optical spectrophotometry and electrochemical measurements. The film refractive index varied between 2.09 and 2.22 at the wavelength of 550 nm depending on the annealing temperature. The decrease of the optical band gap revealed for the films with increasing annealing temperature is attributed to oxygen-ion vacancies in the film structure. The orthorhombic structure of Nb{sub 2}O{sub 5} films resulted in good electrochromic properties with high colouration efficiencies of 19.56 cm{sup 2}/C and 53.24 cm{sup 2}/C at 550 nm and 1000 nm, respectively. The optical, structural and electrochromic properties of the different crystalline polymorphic forms of the Nb{sub 2}O{sub 5} films make them attractive for optical applications. - Highlights: • Stoichiometric Nb{sub 2}O{sub 5} films prepared using RF magnetron sputtering technique. • The different crystalline forms of Nb{sub 2}O{sub 5} thin films obtained by annealing. • The optical, structural and electrochromic properties of the films were investigated. • The optical band gap decreased with increasing annealing temperature. • The orthorhombic T-Nb{sub 2}O{sub 5} films exhibited a higher colouration efficiency.

Preparation and Characterization of Sb2Te3 Thin Films by Coevaporation

Directory of Open Access Journals (Sweden)

Bin Lv

2010-01-01

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

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

Science.gov (United States)

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

2016-11-07

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

Adhesion enhancement of diamond-like carbon thin films on Ti alloys by incorporation of nanodiamond particles

International Nuclear Information System (INIS)

Zhang, C.Z.; Tang, Y.; Li, Y.S.; Yang, Q.

2013-01-01

Coating adherent diamond-like carbon (DLC) thin films directly on Ti alloys is technologically difficult. This research incorporates nanodiamond particles to form a diamond/DLC composite interlayer to enhance the adhesion of DLC thin films on Ti6Al4V substrates. Initially, nanodiamond particles were deposited on Ti6Al4V substrates by microwave plasma enhanced chemical vapor deposition from a methane–hydrogen gas mixture. A DLC thin film was then deposited, on top of the nanodiamond particles, by direct ion beam deposition. Scanning electron microscopy, Atomic force microscopy, X-ray Diffraction and Raman spectroscopy were used to characterize the microstructure and chemical bonding of the deposited particles and films, and Rockwell indentation testing was used to evaluate the adhesion of the deposited films. The results indicate that the pre-deposited nanodiamond particles significantly enhance the interfacial adhesion between the DLC thin film and the Ti6Al4V substrate, possibly by enhanced interfacial bonding, mechanical interlocking, and stress relief. - Highlights: ► Nanodiamond particles were deposited on Ti6Al4V before DLC deposition. ► Diamond/DLC composite film was formed by incorporation of nanodiamond particles. ► Greatly enhanced adhesion of diamond/DLC composite film on Ti6Al4V was achieved. ► Enhanced adhesion is by increased interfacial bonding and mechanical interlocking

Adhesion enhancement of diamond-like carbon thin films on Ti alloys by incorporation of nanodiamond particles

Energy Technology Data Exchange (ETDEWEB)

Zhang, C.Z.; Tang, Y. [Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK, Canada S7N 5A9 (Canada); Li, Y.S. [Plasma Physics Laboratory, University of Saskatchewan, 116 Science Place, Saskatoon, SK, Canada S7N 5E2 (Canada); Yang, Q., E-mail: qiaoqin.yang@usask.ca [Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK, Canada S7N 5A9 (Canada)

2013-01-01

Coating adherent diamond-like carbon (DLC) thin films directly on Ti alloys is technologically difficult. This research incorporates nanodiamond particles to form a diamond/DLC composite interlayer to enhance the adhesion of DLC thin films on Ti6Al4V substrates. Initially, nanodiamond particles were deposited on Ti6Al4V substrates by microwave plasma enhanced chemical vapor deposition from a methane–hydrogen gas mixture. A DLC thin film was then deposited, on top of the nanodiamond particles, by direct ion beam deposition. Scanning electron microscopy, Atomic force microscopy, X-ray Diffraction and Raman spectroscopy were used to characterize the microstructure and chemical bonding of the deposited particles and films, and Rockwell indentation testing was used to evaluate the adhesion of the deposited films. The results indicate that the pre-deposited nanodiamond particles significantly enhance the interfacial adhesion between the DLC thin film and the Ti6Al4V substrate, possibly by enhanced interfacial bonding, mechanical interlocking, and stress relief. - Highlights: ► Nanodiamond particles were deposited on Ti6Al4V before DLC deposition. ► Diamond/DLC composite film was formed by incorporation of nanodiamond particles. ► Greatly enhanced adhesion of diamond/DLC composite film on Ti6Al4V was achieved. ► Enhanced adhesion is by increased interfacial bonding and mechanical interlocking.

Fabrication of hydroxyapatite thin films for biomedical applications using RF magnetron sputtering

International Nuclear Information System (INIS)

Yamaguchi, Tetsuro; Tanaka, Yoshikazu; Ide-Ektessabi, Ari

2006-01-01

The calcium phosphate thin films for medical applications require similar chemical properties as those of natural bone as well as a uniform surface without any defect, such as cracks and pinholes. In this study, the calcium phosphate thin films were fabricated using RF magnetron sputtering deposition technique at discharge power of 200W, 300W and 400W. The target used for the deposition was sintered HAp. RBS analysis showed that the Ca/P ratio increased with the discharge power becoming close to that of Ca/P=1.67 in ideal HAp. XPS analysis revealed the presence of PO 4 3- and OH - bonds in the calcium phosphate films fabricated. The chemical properties of the calcium phosphate thin films were similar to those of ideal HAp. The AFM results revealed that the thin films prepared had a uniform surface

Fabrication of Hydrogenated Amorphous Germanium Thin Layer Film and ItsCharacterization

International Nuclear Information System (INIS)

Agus-Santoso; Lely-Susita RM; Tjipto-Sujitno

2000-01-01

Fabrication of hydrogenated amorphous Germanium thin film by vacuumevaporation method and then deposition with hydrogen atom by glow dischargeplasma radio frequency has been done. This germanium amorphous (a-Ge) thinfilm involves a lot of dangling bonds in the network due to the irregularityof the atomic structures and it will decrease is conductivity. To improve theband properties of (a-Ge) thin film layer a hydrogenated plasma isintroduced. Process of introducing of the hydrogen into the a-Ge film is meanto reduce the dangling bonds so that the best electric conductivity of a Ge:Hthin film will obtained. To identify the hydrogen atom in the sample acharacterization using infrared spectrometer has been done, as well as themeasurement of conductivity of the samples. From the characterization usinginfrared spectroscopy the existence of hydrogen atom was found at absorptionpeak with wave number 1637.5 cm -1 , while the optimum conductivity of thesample 1634.86 Ω -1 cm -1 was achieved at 343 o K. (author)

Modeling of thin films growth processes in the early stage for atoms with covalent bonds

International Nuclear Information System (INIS)

Tupik, V A; Margolin, V I; Su, Chu Trong

2017-01-01

Computer simulation for obtaining thin film’s growth process at an early stage with the proposed model of atoms with isotropic and anisotropic interactions been considered. Carrying out the procedure for analyzing the problem on the basis of the program being implemented, computer simulation of thin film growth processes has been carried out on several examples. The results of computer simulation of the growth process of thin film on a given substrate and an aggregate in a vacuum condition are shown. Some characteristic distributions of the obtained structure have been carried out to evaluate the proposed adequate model and to reflect the high complexity of thin films growth process. (paper)

Nanostructure and bonding of zirconium diboride thin films studied by X-ray spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Stewart, David M., E-mail: david.stewart@maine.edu; Meulenberg, Robert W.; Lad, Robert J., E-mail: rjlad@maine.edu

2015-12-01

Zirconium diboride (ZrB{sub 2}) is an important ceramic due to its extremely high melting temperature of 3245 °C and metallic electrical conductivity, properties that make it an ideal candidate thin film electrode material for high temperature electronics. In this report, thin films of varying B:Zr ratio ranging from 3–0.67 have been grown by e-beam evaporation from elemental sources. X-ray absorption spectra at the Zr K-edge were measured before and after annealing in ultra-high vacuum for 9 h at 1000 °C. Films with compositions near ZrB{sub 2} stoichiometry show X-ray absorption fine structure that can be well modeled by crystalline ZrB{sub 2} with a small portion of a coexisting tetragonal zirconia (t-ZrO{sub 2}) phase. Films far from stoichiometry show substantial disorder beyond the nearest-neighbor distances, and after vacuum annealing exhibit high levels of oxidation. Contributions to the X-ray absorption fine structure from a pure Zr phase are very small compared to ZrB{sub 2} and t-ZrO{sub 2} phases. The fact that nearly stoichiometric (3 < B:Zr < 1.6) as-deposited amorphous films form the same crystalline ZrB{sub 2} nanostructure after annealing is particularly encouraging for high temperature thin film electronics applications, because it would allow the production of highly stable electrodes with e-beam evaporation without the need of any high temperature heating during film growth. - Highlights: • Zr–B thin films of different compositions were grown at low substrate temperatures. • EXAFS analysis indicates a ZrB{sub 2} crystal structure after vacuum annealing. • The coexistence of crystalline and amorphous Zr–B phases is also observed. • Films with excess Zr readily form t-ZrO{sub 2} during deposition, which coexists with ZrB{sub 2}. • Low temperature synthesis routes are important for technological applications.

Reversible Surface Properties of Polybenzoxazine/Silica Nanocomposites Thin Films

Directory of Open Access Journals (Sweden)

Wei-Chen Su

2013-01-01

Full Text Available We report the reversible surface properties (hydrophilicity, hydrophobicity of a polybenzoxazine (PBZ thin film through simple application of alternating UV illumination and thermal treatment. The fraction of intermolecularly hydrogen bonded O–H⋯O=C units in the PBZ film increased after UV exposure, inducing a hydrophilic surface; the surface recovered its hydrophobicity after heating, due to greater O–H⋯N intramolecular hydrogen bonding. Taking advantage of these phenomena, we prepared a PBZ/silica nanocomposite coating through two simple steps; this material exhibited reversible transitions from superhydrophobicity to superhydrophilicity upon sequential UV irradiation and thermal treatment.

Optical properties of diamond like carbon nanocomposite thin films

Science.gov (United States)

Alam, Md Shahbaz; Mukherjee, Nillohit; Ahmed, Sk. Faruque

2018-05-01

The optical properties of silicon incorporated diamond like carbon (Si-DLC) nanocomposite thin films have been reported. The Si-DLC nanocomposite thin film deposited on glass and silicon substrate by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) process. Fourier transformed infrared spectroscopic analysis revealed the presence of different bonding within the deposited films and deconvolution of FTIR spectra gives the chemical composition i.e., sp3/sp2 ratio in the films. Optical band gap calculated from transmittance spectra increased from 0.98 to 2.21 eV with a variation of silicon concentration from 0 to 15.4 at. %. Due to change in electronic structure by Si incorporation, the Si-DLC film showed a broad photoluminescence (PL) peak centered at 467 nm, i.e., in the visible range and its intensity was found to increase monotonically with at. % of Si.

Effect of composition on SILAR deposited CdxZn1-xS thin films

Science.gov (United States)

Ashith V., K.; Gowrish Rao, K.

2018-04-01

In the group of II-VI compound semiconductor, cadmium zinc sulphide (CdxZn1-xS) thin films have broad application in photovoltaic, optoelectronic devices etc. For heterojunction aspects, CdxZn1-xS thin film can be used as heterojunction partner for CdTe as the absorber layer. In this work, CdZnS thin films prepared on glass substrates by Successive Ion Layer Adsorption and Reaction (SILAR) method by varying the composition. The XRD patterns of deposited films showed polycrystalline with the hexagonal phase. The crystallite size of the films was estimated from W-H plot. The bond length of the film varied w.r.to the composition of the CdxZn1-xS films. The urbach energy of the films was calcualted from absorbance data.

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

International Nuclear Information System (INIS)

Lynch, S.J.

1983-01-01

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

Thin-film photovoltaic technology

Energy Technology Data Exchange (ETDEWEB)

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

2010-07-01

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

Evolution of normal stress and surface roughness in buckled thin films

NARCIS (Netherlands)

Palasantzas, G; De Hosson, JTM

2003-01-01

In this work we investigate buckling of compressed elastic thin films, which are bonded onto a viscous layer of finite thickness. It is found that the normal stress exerted by the viscous layer on the elastic film evolves with time showing a minimum at early buckling stages, while it increases at

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

Scanning tunneling spectroscopy of Pb thin films

Energy Technology Data Exchange (ETDEWEB)

Becker, Michael

2010-12-13

films. It is shown how accurate quantitative information about work function differences can be obtained and how these differences depend on the QWSs in the Pb thin films. The electron transport properties and mechanical characteristics of atom-sized metallic contacts are of fundamental interest in view of future nanoscale device technologies. Proximity probes like STM, metal break junctions, and related techniques, together with computational methods for simulating tip-sample interactions, have made it possible to address this question. While the importance of atomic structure and bonding for transport through single-atom junctions has repeatedly been emphasized, investigations of the influence of subsurface bonding properties have been rare. Here, the contact formation of a STM tip approaching Pb(111) thin films supported on Ag(111) substrates is investigated. Contacts on monolayer films are found to differ from contacts made on thicker Pb films. This behavior is explained in terms of different vertical bonding-strengths due to a charge-transfer induced surface dipole. Furthermore, the single-atom contact conductance on Pb(111) films beyond the first monolayer is determined. It is shown that analyses based on hitherto widely used conventional conductance histograms may overestimate the single-atom contact conductance by as much as 20%. (orig.)

Thin film metal sensors in fusion bonded glass chips for high-pressure microfluidics

International Nuclear Information System (INIS)

Andersson, Martin; Ek, Johan; Hedman, Ludvig; Johansson, Fredrik; Sehlstedt, Viktor; Stocklassa, Jesper; Snögren, Pär; Pettersson, Victor; Larsson, Jonas; Vizuete, Olivier; Hjort, Klas; Klintberg, Lena

2017-01-01

High-pressure microfluidics offers fast analyses of thermodynamic parameters for compressed process solvents. However, microfluidic platforms handling highly compressible supercritical CO 2 are difficult to control, and on-chip sensing would offer added control of the devices. Therefore, there is a need to integrate sensors into highly pressure tolerant glass chips. In this paper, thin film Pt sensors were embedded in shallow etched trenches in a glass wafer that was bonded with another glass wafer having microfluidic channels. The devices having sensors integrated into the flow channels sustained pressures up to 220 bar, typical for the operation of supercritical CO 2 . No leakage from the devices could be found. Integrated temperature sensors were capable of measuring local decompression cooling effects and integrated calorimetric sensors measured flow velocities over the range 0.5–13.8 mm s −1 . By this, a better control of high-pressure microfluidic platforms has been achieved. (paper)

Molecular Engineering for Enhanced Charge Transfer in Thin-Film Photoanode.

Science.gov (United States)

Kim, Jeong Soo; Kim, Byung-Man; Kim, Un-Young; Shin, HyeonOh; Nam, Jung Seung; Roh, Deok-Ho; Park, Jun-Hyeok; Kwon, Tae-Hyuk

2017-10-11

We developed three types of dithieno[3,2-b;2',3'-d]thiophene (DTT)-based organic sensitizers for high-performance thin photoactive TiO 2 films and investigated the simple but powerful molecular engineering of different types of bonding between the triarylamine electron donor and the conjugated DTT π-bridge by the introduction of single, double, and triple bonds. As a result, with only 1.3 μm transparent and 2.5-μm TiO 2 scattering layers, the triple-bond sensitizer (T-DAHTDTT) shows the highest power conversion efficiency (η = 8.4%; V OC = 0.73 V, J SC = 15.4 mA·cm -2 , and FF = 0.75) in an iodine electrolyte system under one solar illumination (AM 1.5, 1000 W·m -2 ), followed by the single-bond sensitizer (S-DAHTDTT) (η = 7.6%) and the double-bond sensitizer (D-DAHTDTT) (η = 6.4%). We suggest that the superior performance of T-DAHTDTT comes from enhanced intramolecular charge transfer (ICT) induced by the triple bond. Consequently, T-DAHTDTT exhibits the most active photoelectron injection and charge transport on a TiO 2 film during operation, which leads to the highest photocurrent density among the systems studied. We analyzed these correlations mainly in terms of charge injection efficiency, level of photocharge storage, and charge-transport kinetics. This study suggests that the molecular engineering of a triple bond between the electron donor and the π-bridge of a sensitizer increases the performance of dye-sensitized solar cell (DSC) with a thin photoactive film by enhancing not only J SC through improved ICT but also V OC through the evenly distributed sensitizer surface coverage.

Indium local geometry in In-Sb-Te thin films using XANES and DFT calculations

Science.gov (United States)

Bilovol, V.; Gil Rebaza, A. V.; Mudarra Navarro, A. M.; Errico, L.; Fontana, M.; Arcondo, B.

2017-12-01

In-Sb-Te when is a thin film presents a huge difference in its electrical resistivity when transform from the amorphous (insulating) to the crystalline (conducting) phase. This property made this system one of the main phase-change materials used in the data storage industry. The change in the electrical conductivity is probably associated to a change in the bonding geometry of some of its constituents. To explore this point, we present in this work an study of the bonding geometry of In atoms in In-Sb-Te films by means of In K-edge X-ray absorption near edge structure (XANES) spectroscopy using synchrotron radiation in both as deposited (amorphous) and crystalline thin films obtained as a result of resistance (R) vs temperature (T) measurements. Comparison of the XANES spectra obtained for ternary amorphous films and binary crystalline reference films suggests that in amorphous films the bonding geometry of In atoms is tetrahedral-like. After the thermal annealing has been carried out the differences in the XANES spectra of the as deposited and the annealed films indicate that the bonding geometry of In atoms changes. Based on X-ray diffraction results and ab initio calculations in the framework of the Density Functional Theory (DFT) we show that the new coordination geometry is associated with a tendency of In atoms towards octahedral-like.

Electronic properties and bonding in Zr Hx thin films investigated by valence-band x-ray photoelectron spectroscopy

Science.gov (United States)

Magnuson, Martin; Schmidt, Susann; Hultman, Lars; Högberg, Hans

2017-11-01

The electronic structure and chemical bonding in reactively magnetron sputtered Zr Hx (x =0.15 , 0.30, 1.16) thin films with oxygen content as low as 0.2 at.% are investigated by 4d valence band, shallow 4p core-level, and 3d core-level x-ray photoelectron spectroscopy. With increasing hydrogen content, we observe significant reduction of the 4d valence states close to the Fermi level as a result of redistribution of intensity toward the H 1s-Zr 4d hybridization region at ˜6 eV below the Fermi level. For low hydrogen content (x =0.15 , 0.30), the films consist of a superposition of hexagonal closest-packed metal (α phase) and understoichiometric δ -Zr Hx (Ca F2 -type structure) phases, while for x =1.16 , the films form single-phase Zr Hx that largely resembles that of stoichiometric δ -Zr H2 phase. We show that the cubic δ -Zr Hx phase is metastable as thin film up to x =1.16 , while for higher H contents the structure is predicted to be tetragonally distorted. For the investigated Zr H1.16 film, we find chemical shifts of 0.68 and 0.51 eV toward higher binding energies for the Zr 4 p3 /2 and 3 d5 /2 peak positions, respectively. Compared to the Zr metal binding energies of 27.26 and 178.87 eV, this signifies a charge transfer from Zr to H atoms. The change in the electronic structure, spectral line shapes, and chemical shifts as a function of hydrogen content is discussed in relation to the charge transfer from Zr to H that affects the conductivity by charge redistribution in the valence band.

Biocompatibility of Hydrogen-Diluted Amorphous Silicon Carbide Thin Films for Artificial Heart Valve Coating

Science.gov (United States)

Rizal, Umesh; Swain, Bhabani S.; Rameshbabu, N.; Swain, Bibhu P.

2018-01-01

Amorphous silicon carbide (a-SiC:H) thin films were synthesized using trichloromethylsilane by a hot wire chemical vapor deposition process. The deposited films were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, x-ray diffraction and x-ray photoelectron spectroscopy to confirm its chemical bonding, structural network and composition of the a-SiC:H films. The optical microscopy images reveal that hydrogen dilution increased the surface roughness and pore density of a-SiC:H thin film. The Raman spectroscopy and FTIR spectra reveal chemical network consisting of Si-Si, C-C and Si-C bonds, respectively. The XRD spectroscopy and Raman spectroscopy indicate a-SiC:H still has short-range order. In addition, in vitro cytotoxicity test ensures the behavior of cell-semiconductor hybrid to monitor the proper coordination. The live-dead assays and MTT assay reveal an increase in green nucleus cell, and cell viability is greater than 88%, respectively, showing non-toxic nature of prepared a-SiC:H film. Moreover, the result indicated by direct contact assay, and cell prefers to adhere and proliferate on a-SiC:H thin films having a positive effect as artificial heart valve coating material.

Pyrolyzed thin film carbon

Science.gov (United States)

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

2010-01-01

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

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

Science.gov (United States)

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

2018-04-01

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

thin films

Indian Academy of Sciences (India)

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

The uniformity study of non-oxide thin film at device level using electron energy loss spectroscopy

Science.gov (United States)

Li, Zhi-Peng; Zheng, Yuankai; Li, Shaoping; Wang, Haifeng

2018-05-01

Electron energy loss spectroscopy (EELS) has been widely used as a chemical analysis technique to characterize materials chemical properties, such as element valence states, atoms/ions bonding environment. This study provides a new method to characterize physical properties (i.e., film uniformity, grain orientations) of non-oxide thin films in the magnetic device by using EELS microanalysis on scanning transmission electron microscope. This method is based on analyzing white line ratio of spectra and related extended energy loss fine structures so as to correlate it with thin film uniformity. This new approach can provide an effective and sensitive method to monitor/characterize thin film quality (i.e., uniformity) at atomic level for thin film development, which is especially useful for examining ultra-thin films (i.e., several nanometers) or embedded films in devices for industry applications. More importantly, this technique enables development of quantitative characterization of thin film uniformity and it would be a remarkably useful technique for examining various types of devices for industrial applications.

Effect of hydroxyl bond formation on the adhesion improvement of a polyethylene copper thin film system

International Nuclear Information System (INIS)

Camacho, M.; Blantocas, G.; Ramos, H.

2009-01-01

Formation of hydroxyl bonds on the surface of a gas plasma treated high density polyethylene (HDPE) sheets significantly enhanced the adhesion strength of the polyethylene copper thin film system. Surface treatments using oxygen gas plasmas at varying plasma parameters are applied in this study to identify the most effective plasma parameters that would promote the best adhesion strength. Analysis of gas plasma adulterated HDPE sheets showed best enhancement of polyethylene copper adhesion after an oxygen gas plasma treatment for 60 minutes at 5mA discharge current. Scanning Electron Microscopy Analysis, Fourier Transform Infrared Spectroscopy and Adhesion measurements using Pull out Force Analysis were used to measure the changes in the surface chemistry and surface topology of the HDPE sheets. (author)

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

International Nuclear Information System (INIS)

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

2016-01-01

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

Reactive ion assisted deposition of aluminum oxynitride thin films

International Nuclear Information System (INIS)

Hwangbo, C.K.; Lingg, L.J.; Lehan, J.P.; Macleod, H.A.; Suits, F.

1989-01-01

Optical properties, stoichiometry, chemical bonding states, and crystal structure of aluminum oxynitride (AlO/sub x/N/sub y/) thin films prepared by reactive ion assisted deposition were investigated. The results show that by controlling the amount of reactive gases the refractive index of aluminum oxynitride films at 550 nm is able to be varied from 1.65 to 1.83 with a very small extinction coefficient. Variations of optical constants and chemical bonding states of aluminum oxynitride films are related to the stoichiometry. From an x-ray photoelectron spectroscopy analysis it is observed that our aluminum oxynitride film is not simply a mixture of aluminum oxide and aluminum nitride but a continuously variable compound. The aluminum oxynitride films are amorphous from an x-ray diffraction analysis. A rugate filter using a step index profile of aluminum oxynitride films was fabricated by nitrogen ion beam bombardment of a growing Al film with backfill oxygen pressure as the sole variation. This filter shows a high resistivity to atmospheric moisture adsorption, suggesting that the packing density of aluminum oxynitride films is close to unity and the energetic ion bombardment densifies the film as well as forming the compound

Fabrication of Quench Condensed Thin Films Using an Integrated MEMS Fab on a Chip

Science.gov (United States)

Lally, Richard; Reeves, Jeremy; Stark, Thomas; Barrett, Lawrence; Bishop, David

Atomic calligraphy is a microelectromechanical systems (MEMS)-based dynamic stencil nanolithography technique. Integrating MEMS devices into a bonded stacked array of three die provides a unique platform for conducting quench condensed thin film mesoscopic experiments. The atomic calligraphy Fab on a Chip process incorporates metal film sources, electrostatic comb driven stencil plate, mass sensor, temperature sensor, and target surface into one multi-die assembly. Three separate die are created using the PolyMUMPs process and are flip-chip bonded together. A die containing joule heated sources must be prepared with metal for evaporation prior to assembly. A backside etch of the middle/central die exposes the moveable stencil plate allowing the flux to pass through the stencil from the source die to the target die. The chip assembly is mounted in a cryogenic system at ultra-high vacuum for depositing extremely thin films down to single layers of atoms across targeted electrodes. Experiments such as the effect of thin film alloys or added impurities on their superconductivity can be measured in situ with this process.

Thin Film Microbatteries

International Nuclear Information System (INIS)

Dudney, Nancy J.

2008-01-01

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

Role of carbon in boron suboxide thin films

International Nuclear Information System (INIS)

Music, Denis; Kugler, Veronika M.; Czigany, Zsolt; Flink, Axel; Werner, Oskar; Schneider, Jochen M.; Hultman, Lars; Helmersson, Ulf

2003-01-01

Boron suboxide thin films, with controlled carbon content, were grown by rf dual magnetron sputtering of boron and carbon targets in an argon-oxygen atmosphere. Film composition, structure, mechanical, and electrical properties were evaluated with x-ray photoelectron spectroscopy, Auger electron spectroscopy, x-ray diffraction, transmission electron microscopy, nanoindentation, and high-frequency capacitance-voltage measurements. X-ray amorphous B-O-C films (O/B=0.02) showed an increase in density from 2.0 to 2.4 g/cm 3 as C content was increased from 0 to 0.6 at. % and the film with the highest density had nanocrystalline inclusions. The density increase occurred most likely due to the formation of B-C bonds, which are shorter than B-B bonds. All measured material properties were found to depend strongly on the C content and thus film density. The elastic modulus increased from 188 to 281 GPa with the increasing C content, while the relative dielectric constant decreased from 19.2 to 0.9. Hence, B-O-C films show a potential for protective coatings and even for application in electronic and optical devices

Detecting properties of thin film superconducting bridges made of YBa2Cu3O7-x

International Nuclear Information System (INIS)

Kulikov, V.A.; Matveets, L.V.; Serebryakov, A.Yu.; Laptev, V.N.; Makhov, V.I.; Emel'yanenkov, D.G.; Inkin, Yu.N.

1989-01-01

Results of study of detecting properties of thin film YBa 2 Cu 3 O 7-x bridges, subjected to the effect of 8 mm SHF-radiation are presented. The transition temperatures of bridges were equal to 80-85 K. Current-voltage characteristics and response dependences of bridges with 67, 150 and 425 Ω resistances were measured. It is shown that thin film bridges of YBa 2 Cu 3 O 7-x , representing the system of weak bonds, demonstrate nonstationary Josephson effect and synchronization of weak bonds in bridge volume

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

International Nuclear Information System (INIS)

Rebollo P, B.

2001-01-01

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

Molecular dynamics simulation of thin film interfacial strength dependency on lattice mismatch

International Nuclear Information System (INIS)

Yang, Zhou; Lian, Jie; Wang, Junlan

2013-01-01

Laser-induced thin film spallation experiments have been previously developed to characterize the intrinsic interfacial strength of thin films. In order to gain insights of atomic level thin film debonding processes and the interfacial strength dependence on film/substrate lattice structures, in this study, molecular dynamics simulations of thin film interfacial failure under laser-induced stress waves were performed. Various loading amplitudes and pulse durations were employed to identify the optimum simulation condition. Stress propagation as a function of time was revealed in conjunction with the interface structures. Parametric studies confirmed that while the interfacial strength between a thin film and a substrate does not depend on the film thickness and the duration of the laser pulse, a thicker film and a shorter duration do provide advantage to effectively load the interface to failure. With the optimized simulation condition, further studies were focused on bulk Au/Au bi-crystals with mismatched orientations, and Ni/Al, Cu/Al, Cu/Ag and Cu/Au bi-crystals with mismatched lattices. The interfacial strength was found to decrease with increasing orientation mismatch and lattice mismatch but more significantly dominated by the bonding elements' atomic structure and valence electron occupancy. - Highlights: • Molecular dynamics simulation was done on stress wave induced thin film spallation. • Atomic structure was found to be a primary strength determining factor. • Lattice mismatch was found to be a secondary strength determining factor

Pulsed laser deposition and characterization of cellulase thin films

Science.gov (United States)

Cicco, N.; Morone, A.; Verrastro, M.; Viggiano, V.

2013-08-01

Thin films of cellulase were obtained by pulsed laser deposition (PLD) on an appropriate substrate. Glycoside hydrolase cellulase has received our attention because it emerges among the antifouling enzymes (enzymes being able to remove and prevent the formation of micro-organism biofilms) used in industry and medicine field. Pressed cellulase pellets, used as target material, were ablated with pulses of a Nd-YAG laser working at wavelength of 532 nm. In this work, we evaluated the impact of PLD technique both on molecular structure and hydrolytic activity of cellulase. Characteristic chemical bonds and morphology of deposited layers were investigated by FTIR spectroscopy and SEM respectively. The hydrolytic activity of cellulase thin films was detected by a colorimetric assay.

Reactive pulsed laser deposition of Cu2ZnSnS4 thin films in H2S

International Nuclear Information System (INIS)

Surgina, G.D.; Zenkevich, A.V.; Sipaylo, I.P.; Nevolin, V.N.; Drube, W.; Teterin, P.E.; Minnekaev, M.N.

2013-01-01

Cu 2 ZnSnS 4 (CZTS) thin films have been grown by reactive pulsed laser deposition in H 2 S atmosphere, combining the alternate ablation from the metallic (Cu) and alloyed (Zn x Sn) targets at room temperature. The morphological, structural and optical properties of as grown CZTS thin films with varying compositions as well as upon annealing in N 2 atmosphere are investigated by Rutherford backscattering spectrometry, X-ray diffraction, Raman spectroscopy and optical spectrophotometry. The chemical bonding in the “bulk” of the CZTS films is elucidated via hard X-ray photoemission spectroscopy measurements. The formation of the good quality stoichiometric polycrystalline CZTS films is demonstrated upon optimization of the growth parameters. - Highlights: ► The new method of Cu 2 ZnSnS 4 (CZTS) thin films growth in H 2 S was realized. ► CZTS films were grown by pulsed laser deposition from Cu and alloyed Zn–Sn targets. ► The effect of the processing parameters on the CZTS properties was investigated. ► The chemical bonding in the “bulk” of CZTS films was studied

Topotactic synthesis of strontium cobalt oxyhydride thin film with perovskite structure

Science.gov (United States)

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

2015-10-01

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

Topotactic synthesis of strontium cobalt oxyhydride thin film with perovskite structure

Directory of Open Access Journals (Sweden)

Tsukasa Katayama

2015-10-01

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

Ceramic Composite Thin Films

Science.gov (United States)

Ruoff, Rodney S. (Inventor); Stankovich, Sasha (Inventor); Dikin, Dmitriy A. (Inventor); Nguyen, SonBinh T. (Inventor)

2013-01-01

A ceramic composite thin film or layer includes individual graphene oxide and/or electrically conductive graphene sheets dispersed in a ceramic (e.g. silica) matrix. The thin film or layer can be electrically conductive film or layer depending the amount of graphene sheets present. The composite films or layers are transparent, chemically inert and compatible with both glass and hydrophilic SiOx/silicon substrates. The composite film or layer can be produced by making a suspension of graphene oxide sheet fragments, introducing a silica-precursor or silica to the suspension to form a sol, depositing the sol on a substrate as thin film or layer, at least partially reducing the graphene oxide sheets to conductive graphene sheets, and thermally consolidating the thin film or layer to form a silica matrix in which the graphene oxide and/or graphene sheets are dispersed.

Influence of silver incorporation on the structural and electrical properties of diamond-like carbon thin films.

Science.gov (United States)

Dwivedi, Neeraj; Kumar, Sushil; Carey, J David; Tripathi, R K; Malik, Hitendra K; Dalai, M K

2013-04-10

A simple approach is proposed for obtaining low threshold field electron emission from large area diamond-like carbon (DLC) thin films by sandwiching either Ag dots or a thin Ag layer between DLC and nitrogen-containing DLC films. The introduction of silver and nitrogen is found to reduce the threshold field for emission to under 6 V/μm representing a near 46% reduction when compared with unmodified films. The reduction in the threshold field is correlated with the morphology, microstructure, interface, and bonding environment of the films. We find modifications to the structure of the DLC films through promotion of metal-induced sp2 bonding and the introduction of surface asperities, which significantly reduce the value of the threshold field. This can lead to the next-generation, large-area simple and inexpensive field emission devices.

Laser Raman microprobe spectroscopy as a diagnostic for the characterisation of diamond and diamond like carbon (DLC) thin films

International Nuclear Information System (INIS)

Johnston, C.

1990-10-01

Invariably when manufacturing an artificial diamond film a mixture of carbon is deposited - tetragonally bonded (diamond), trigonally bonded (graphite) and other allotropic crystalline forms and amorphous carbons. This imposes a need for careful analysis to determine exactly what carbon types constitute the films. Raman spectroscopy is particularly sensitive to crystal and atomic structure and has a number of advantages which make it one of the most useful techniques for interrogating diamond and DLC thin films. Although Raman spectroscopy alone cannot fully characterise the film, it can give more information than simply what particular form of carbon or other impurities are present in the film. It can be used to determine the ratio of sp 2 to sp 3 bonding within the film, and to some extent the crystallite or domain size and the internal stress of the film. The use of laser Raman microprobe spectroscopy as a diagnostic tool in the analysis of diamond and DLC thin films is demonstrated for a variety of carbon films on various substrates and the characterisation of these films is discussed. (author)

High temperature annealing effects on chromel (Ni90Cr10) thin films and interdiffusion study for sensing applications

International Nuclear Information System (INIS)

Datta, Arindom; Cheng Xudong; Miller, Michael A.; Li Xiaochun

2008-01-01

Metal embedded thin film thermocouples are very attractive for various applications in harsh environments. One promising technique to embed thin films micro sensors is diffusion bonding, which requires high temperatures and pressures typically in a vacuum. In this study, high temperature annealing effects on chromel (Ni90Cr10) thin film, an important sensor material as one of the components in type K thermocouple, were investigated in a diffusion bonding environment. Annealing was carried out at 800 deg. C for one hour in a diffusion bonder under vacuum without applying pressure. Under such conditions; surface, interface and interdiffusion phenomena were investigated using different characterization techniques including X-ray Diffraction, X-ray Photoelectron Spectroscopy, Scanning Electron Microscopy, and Energy Dispersive Spectroscopy. Results indicate that the present combination of dielectrics is quite reliable and Ni90Cr10 films of 500 nm thickness can be used for applications at least up to 800 deg. C due to a protective thin chromium oxide layer formation on top of the sensor film during annealing

Host thin films incorporating nanoparticles

Science.gov (United States)

Qureshi, Uzma

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

Highly uniform resistive switching properties of amorphous InGaZnO thin films prepared by a low temperature photochemical solution deposition method.

Science.gov (United States)

Hu, Wei; Zou, Lilan; Chen, Xinman; Qin, Ni; Li, Shuwei; Bao, Dinghua

2014-04-09

We report on highly uniform resistive switching properties of amorphous InGaZnO (a-IGZO) thin films. The thin films were fabricated by a low temperature photochemical solution deposition method, a simple process combining chemical solution deposition and ultraviolet (UV) irradiation treatment. The a-IGZO based resistive switching devices exhibit long retention, good endurance, uniform switching voltages, and stable distribution of low and high resistance states. Electrical conduction mechanisms were also discussed on the basis of the current-voltage characteristics and their temperature dependence. The excellent resistive switching properties can be attributed to the reduction of organic- and hydrogen-based elements and the formation of enhanced metal-oxide bonding and metal-hydroxide bonding networks by hydrogen bonding due to UV irradiation, based on Fourier-transform-infrared spectroscopy, X-ray photoelectron spectroscopy, and Field emission scanning electron microscopy analysis of the thin films. This study suggests that a-IGZO thin films have potential applications in resistive random access memory and the low temperature photochemical solution deposition method can find the opportunity for further achieving system on panel applications if the a-IGZO resistive switching cells were integrated with a-IGZO thin film transistors.

NMR characterization of thin films

Science.gov (United States)

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

2010-06-15

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

NMR characterization of thin films

Science.gov (United States)

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

2008-11-25

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

Photo-induced hydrophilicity of TiO2-xNx thin films on PET plates

International Nuclear Information System (INIS)

Chou, H.-Y.; Lee, E.-K.; You, J.-W.; Yu, S.-S.

2007-01-01

TiO 2-x N x thin films were deposited on PET (polyethylene terephthalate) plates by sputtering a TiN target in a N 2 /O 2 plasma and without heating. X-ray photoemission spectroscopy (XPS) was used to investigate the N 1s, Ti 2p core levels and the nitrogen composition in the TiO 2-x N x films. The results indicate that Ti-O-N bonds are formed in the thin films. Two nitrogen states, substitution and interstitial nitrogen atoms, were attributed to peaks at 396 and 399 eV, respectively. It was observed that the nitrogen atoms occupy both the substitutive and interstitial sites in respective of the nitrogen content in the thin films. UV-VIS absorption spectroscopy of PET coated thin films shows a significant shift of the absorption edge to lower energy in the visible-light region. UV and visible-light irradiation are used to activate PET coated thin films for the development of hydrophilicity. The photo-induced surface wettability conversion reaction of the thin films has been investigated by means of water contact angle measurement. PET plates coated with TiO 2-x N x thin films are found to exhibit lower water contact angle than non-coated plates when the surface is illuminated with UV and visible light. The effects of nitrogen doping on photo-generated hydrophilicity of the thin films are investigated in this work

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.

Structural features of spin-coated thin films of binary AsxS100−x chalcogenide glass system

International Nuclear Information System (INIS)

Cook, J.; Slang, S.; Golovchak, R.; Jain, H.; Vlcek, M.; Kovalskiy, A.

2015-01-01

Spin-coating technology offers a convenient method for fabricating photostable chalcogenide glass thin films that are especially attractive for applications in IR optics. In this paper we report the structure of spin-coated As x S 100−x (x = 30, 35, 40) thin films as determined using high resolution X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy, especially in relation to composition (i.e. As/S ratio) and preparation process variables. It was observed that As atoms during preparation have a tendency to precipitate out in close to stoichiometric compositions. The mechanism of bonding between the inorganic matrix and organic residuals is discussed based on the experimental data. A weak interaction between S ions and amine-based clusters is proposed as the basis of structural organization of the organic–inorganic interface. - Highlights: • As–S spin-coated chalcogenide thin films with different As/S were fabricated. • XPS measurements support the cluster-like structure of spin-coated films. • As 2 O 3 was confirmed as the composition of precipitate formed during dissolution. • Lack of As–As bonds explains the observed photostability of the thin films

Adhesion strength of lead zirconate titanate sol-gel thin films

Energy Technology Data Exchange (ETDEWEB)

Berfield, Thomas A., E-mail: tom.berfield@louisville.edu [Department of Mechanical Engineering, University of Louisville, Louisville, KY 40292 (United States); Kitey, Rajesh [Department of Aerospace Engineering, Indian Institute of Technology Kanpur, Kanpur (India); Kandula, Soma S. [Intel Corporation, Portland, OR (United States)

2016-01-01

The adhesion strength between a thin film and substrate is often the critical parameter that controls the initiation as well as the mode of film failure. In this work, a laser-based spallation method is used to determine the adhesion strength of “as deposited” lead zirconate titanate (PZT) sol-gel thin films on the two functionally different substrates. For the first case, PZT sol-gel film is deposited onto bare Si/SiO{sub 2} substrates via spin casting. The extremely high adhesion strength between the film and the substrate necessitated an additional platinum mass superlayer to be deposited on top of the PZT film in order to induce interfacial failure. For the superlayer film system, a hybrid experimental/numerical method is employed for determining the substrate/film interfacial strength, quantified to be in the range of 460–480 MPa. A second substrate variation with lower adhesion strength is also prepared by applying a self-assembled octadecyltrichlorosilane (ODS) monolayer to the Si/SiO{sub 2} substrate prior to the film deposition. For the monolayer-coated substrate case, the adhesion strength is observed to be significantly lower (54.7 MPa) when compared to the earlier case. - Highlights: • A non-contact laser spallation method is used to determine PZT film adhesion. • A mediated self-assembled monolayer is shown to greatly reduce interface strength. • Adhesion strength for even well-bonded thin films was found using a superlayer.

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.

Thin-film solar cells

International Nuclear Information System (INIS)

Aberle, Armin G.

2009-01-01

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

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

International Nuclear Information System (INIS)

Watanabe, S.

1984-01-01

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

Comparison of Ultrasonic Welding and Thermal Bonding for the Integration of Thin Film Metal Electrodes in Injection Molded Polymeric Lab-on-Chip Systems for Electrochemistry

Directory of Open Access Journals (Sweden)

Marco Matteucci

2016-10-01

Full Text Available We compare ultrasonic welding (UW and thermal bonding (TB for the integration of embedded thin-film gold electrodes for electrochemical applications in injection molded (IM microfluidic chips. The UW bonded chips showed a significantly superior electrochemical performance compared to the ones obtained using TB. Parameters such as metal thickness of electrodes, depth of electrode embedding, delivered power, and height of energy directors (for UW, as well as pressure and temperature (for TB, were systematically studied to evaluate the two bonding methods and requirements for optimal electrochemical performance. The presented technology is intended for easy and effective integration of polymeric Lab-on-Chip systems to encourage their use in research, commercialization and education.

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

Topotactic synthesis of strontium cobalt oxyhydride thin film with perovskite structure

Energy Technology Data Exchange (ETDEWEB)

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

2015-10-15

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

Si-based thin film coating on Y-TZP: Influence of deposition parameters on adhesion of resin cement

Energy Technology Data Exchange (ETDEWEB)

Queiroz, José Renato Cavalcanti, E-mail: joserenatocq@hotmail.com [Potiguar University, Department of Biotechnology, Natal (Brazil); Nogueira Junior, Lafayette [São Paulo State University, Department of Prosthodontics and Dental Materials, São José dos Campos (Brazil); Massi, Marcos [Federal University of São Paulo, Institute of Science and Technology, São José dos Campos (Brazil); Silva, Alecssandro de Moura; Bottino, Marco Antonio [São Paulo State University, Department of Prosthodontics and Dental Materials, São José dos Campos (Brazil); Sobrinho, Argemiro Soares da Silva [Technological Institute of Aeronautics, Department of Physics, São José dos Campos (Brazil); Özcan, Mutlu [University of Zurich, Dental Materials Unit, Center for Dental and Oral Medicine, Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, Zurich (Switzerland)

2013-10-01

This study evaluated the influence of deposition parameters for Si-based thin films using magnetron sputtering for coating zirconia and subsequent adhesion of resin cement. Zirconia ceramic blocks were randomly divided into 8 groups and specimens were either ground finished and polished or conditioned using air-abrasion with alumina particles coated with silica. In the remaining groups, the polished specimens were coated with Si-based film coating with argon/oxygen magnetron discharge at 8:1 or 20:1 flux. In one group, Si-based film coating was performed on air-abraded surfaces. After application of bonding agent, resin cement was bonded. Profilometry, goniometry, Energy Dispersive X-ray Spectroscopy and Rutherford Backscattering Spectroscopy analysis were performed on the conditioned zirconia surfaces. Adhesion of resin cement to zirconia was tested using shear bond test and debonded surfaces were examined using Scanning Electron Microscopy. Si-based film coating applied on air-abraded rough zirconia surfaces increased the adhesion of the resin cement (22.78 ± 5.2 MPa) compared to those of other methods (0–14.62 MPa) (p = 0.05). Mixed type of failures were more frequent in Si film coated groups on either polished or air-abraded groups. Si-based thin films increased wettability compared to the control group but did not change the roughness, considering the parameters evaluated. Deposition parameters of Si-based thin film and after application of air-abrasion influenced the initial adhesion of resin cement to zirconia.

Si-based thin film coating on Y-TZP: Influence of deposition parameters on adhesion of resin cement

International Nuclear Information System (INIS)

Queiroz, José Renato Cavalcanti; Nogueira Junior, Lafayette; Massi, Marcos; Silva, Alecssandro de Moura; Bottino, Marco Antonio; Sobrinho, Argemiro Soares da Silva; Özcan, Mutlu

2013-01-01

This study evaluated the influence of deposition parameters for Si-based thin films using magnetron sputtering for coating zirconia and subsequent adhesion of resin cement. Zirconia ceramic blocks were randomly divided into 8 groups and specimens were either ground finished and polished or conditioned using air-abrasion with alumina particles coated with silica. In the remaining groups, the polished specimens were coated with Si-based film coating with argon/oxygen magnetron discharge at 8:1 or 20:1 flux. In one group, Si-based film coating was performed on air-abraded surfaces. After application of bonding agent, resin cement was bonded. Profilometry, goniometry, Energy Dispersive X-ray Spectroscopy and Rutherford Backscattering Spectroscopy analysis were performed on the conditioned zirconia surfaces. Adhesion of resin cement to zirconia was tested using shear bond test and debonded surfaces were examined using Scanning Electron Microscopy. Si-based film coating applied on air-abraded rough zirconia surfaces increased the adhesion of the resin cement (22.78 ± 5.2 MPa) compared to those of other methods (0–14.62 MPa) (p = 0.05). Mixed type of failures were more frequent in Si film coated groups on either polished or air-abraded groups. Si-based thin films increased wettability compared to the control group but did not change the roughness, considering the parameters evaluated. Deposition parameters of Si-based thin film and after application of air-abrasion influenced the initial adhesion of resin cement to zirconia.

Growth and characterization of MMA/SiO2 hybrid low-k thin films for ...

Indian Academy of Sciences (India)

We have successfully incorporated MMA monomer and eliminated the polymerization step to lower the dielectric constant of deposited thin film. The presence of peak of C=C bond in Fourier transform infrared (FTIR) spectra and carbon peak in energy dispersive (EDAX) spectra confirms the incorporation of carbon in the film ...

Spin ice Thin Film: Surface Ordering, Emergent Square ice, and Strain Effects

Science.gov (United States)

Jaubert, L. D. C.; Lin, T.; Opel, T. S.; Holdsworth, P. C. W.; Gingras, M. J. P.

2017-05-01

Motivated by recent realizations of Dy2 Ti2 O7 and Ho2 Ti2 O7 spin ice thin films, and more generally by the physics of confined gauge fields, we study a model spin ice thin film with surfaces perpendicular to the [001] cubic axis. The resulting open boundaries make half of the bonds on the interfaces inequivalent. By tuning the strength of these inequivalent "orphan" bonds, dipolar interactions induce a surface ordering equivalent to a two-dimensional crystallization of magnetic surface charges. This surface ordering may also be expected on the surfaces of bulk crystals. For ultrathin films made of one cubic unit cell, once the surfaces have ordered, a square ice phase is stabilized over a finite temperature window. The square ice degeneracy is lifted at lower temperature and the system orders in analogy with the well-known F transition of the 6-vertex model. To conclude, we consider the addition of strain effects, a possible consequence of interface mismatches at the film-substrate interface. Our simulations qualitatively confirm that strain can lead to a smooth loss of Pauling entropy upon cooling, as observed in recent experiments on Dy2 Ti2 O7 films.

Correlation between the dielectric constant and X-ray diffraction pattern of Si-O-C thin films with hydrogen bonds

International Nuclear Information System (INIS)

Oh, Teresa; Oh, Kyoung Suk; Lee, Kwang-Man; Choi, Chi Kyu

2004-01-01

The amorphous structure of organic-inorganic hybrid type Si-O-C thin films was studied using the first principles molecular-dynamics method with density functional techniques. The correlation between the dielectric constant and the degree of amorphous structure in organic-inorganic hybrid type Si-O-C thin films was studied. Si-O-C thin films were deposited by high-density plasma chemical vapor deposition using bis-trimethylsilylmethane and oxygen precursors. As-deposited films and films annealed at 500 deg. C were analyzed by X-ray diffraction (XRD). For quantitative analysis, the X-ray diffraction patterns of the samples were transformed to the radial distribution function (RDF) using Fourier analysis. Hybrid type Si-O-C thin films can be divided into three types using their amorphous structure and the dielectric constant: those with organic, hybrid, and inorganic properties

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

Science.gov (United States)

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

2016-09-01

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

Nanometre-scale 3D defects in Cr2AlC thin films.

Science.gov (United States)

Chen, Y T; Music, D; Shang, L; Mayer, J; Schneider, J M

2017-04-20

MAX-phase Cr 2 AlC containing thin films were synthesized by magnetron sputtering in an industrial system. Nanometre-scale 3D defects are observed near the boundary between regions of Cr 2 AlC and of the disordered solid solution (CrAl) x C y . Shrinkage of the Cr-Cr interplanar distance and elongation of the Cr-Al distance in the vicinity of the defects are detected using transmission electron microscopy. The here observed deformation surrounding the defects was described using density functional theory by comparing the DOS of bulk Cr 2 AlC with the DOS of a strained and unstrained Cr 2 AlC(0001) surface. From the partial density of states analysis, it can be learned that Cr-C bonds are stronger than Cr-Al bonds in bulk Cr 2 AlC. Upon Cr 2 AlC(0001) surface formation, both bonds are weakened. While the Cr-C bonds recover their bulk strength as Cr 2 AlC(0001) is strained, the Cr-Al bonds experience only a partial recovery, still being weaker than their bulk counterparts. Hence, the strain induced bond strengthening in Cr 2 AlC(0001) is larger for Cr d - C p bonds than for Cr d - Al p bonds. The here observed changes in bonding due to the formation of a strained surface are consistent with the experimentally observed elongation of the Cr-Al distance in the vicinity of nm-scale 3D defects in Cr 2 AlC thin films.

Dielectric aluminium phosphate thin films. Couches minces dielectriques de phosphate d'aluminium

Energy Technology Data Exchange (ETDEWEB)

Daviero, S. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France)); Avinens, C. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France)); Ibanez, A. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France)); Giuntini, J.C. (Lab. Physicochimie des Materiaux Solides, 34 -Montpellier (France)); Philippot, E. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France))

1993-04-01

Aluminium phosphate thin films on silicium substrate have been carried out from tributylphosphate and aluminium acetylacetonate precursors in solution through the ''pyrosol'' process. It can be observed a large range of chemical analysis in terms of experimental conditions. These thin films have been characterized by X-ray diffraction and infrared spectrometry. Their electrical characteristics, defined from direct current and alternative current measurements, are quite different to those of the crystallized phosphate and can be explained by P-O and Al-O ''dangling bond'' existence. (orig.).

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

Studies on the high electronic energy deposition in polyaniline thin films

International Nuclear Information System (INIS)

Deshpande, N.G.; Gudage, Y.G.; Vyas, J.C.; Singh, F.; Sharma, Ramphal

2008-01-01

We report here the physico-chemical changes brought about by high electronic energy deposition of gold ions in HCl doped polyaniline (PANI) thin films. PANI thin films were synthesized by in situ polymerization technique. The as-synthesized PANI thin films of thickness 160 nm were irradiated using Au 7+ ion of 100 MeV energy at different fluences, namely, 5 x 10 11 ions/cm 2 and 5 x 10 12 ions/cm 2 , respectively. A significant change was seen after irradiation in electrical and photo conductivity, which may be related to increased carrier concentration, and structural modifications in the polymer film. In addition, the high electronic energy deposition showed other effects like cross-linking of polymer chains, bond breaking and creation of defect sites. AFM observations revealed mountainous type features in all (before and after irradiation) PANI samples. The average size (diameter) and density of such mountainous clusters were found to be related with the ion fluence. The AFM profiles also showed change in the surface roughness of the films with respect to irradiation, which is one of the peculiarity of the high electronic energy deposition technique

Thin-film magnetless Faraday rotators for compact heterogeneous integrated optical isolators

Science.gov (United States)

Karki, Dolendra; Stenger, Vincent; Pollick, Andrea; Levy, Miguel

2017-06-01

This report describes the fabrication, characterization, and transfer of ultra-compact thin-film magnetless Faraday rotators to silicon photonic substrates. Thin films of magnetization latching bismuth-substituted rare-earth iron garnets were produced from commercially available materials by mechanical lapping, dice polishing, and crystal-ion-slicing. Eleven- μ m -thick films were shown to retain the 45 ° Faraday rotation of the bulk material to within 2 ° at 1.55 μ m wavelength without re-poling. Anti-reflection coated films evince 0.09 dB insertion loses and better than -20 dB extinction ratios. Lower extinction ratios than the bulk are ascribed to multimode propagation. Significantly larger extinction ratios are predicted for single-mode waveguides. Faraday rotation, extinction ratios, and insertion loss tests on He-ion implanted slab waveguides of the same material yielded similar results. The work culminated with bond alignment and transfer of 7 μ m -thick crystal-ion-sliced 50 × 480 μ m 2 films onto silicon photonic substrates.

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.

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

Pulsed laser deposition of SiC thin films at medium substrate temperatures

International Nuclear Information System (INIS)

Katharria, Y.S.; Kumar, Sandeep; Choudhary, R.J.; Prakash, Ram; Singh, F.; Lalla, N.P.; Phase, D.M.; Kanjilal, D.

2008-01-01

Systematic studies of thin silicon carbide (SiC) films deposited on Si (100) substrates using pulsed laser deposition technique at room temperature, 370 deg. C and 480 deg. C are carried out. X-ray photoelectron spectroscopy showed the formation of SiC bonds in the films at these temperatures along with some graphitic carbon clusters. Fourier transform infrared analysis also confirmed the formation of SiC nanocrystallites in the films. Transmission electron microscopy and electron diffraction were used to study the structural properties of nanocrystallites formed in the films. Surface morphological analysis using atomic force microscopy revealed the growth of smooth films

Performance of a polymer electrolyte membrane fuel cell with thin film catalyst electrodes

Energy Technology Data Exchange (ETDEWEB)

Chun, Young Gab; Kim, Chang Soo; Peck, Dong Hyun; Shin, Dong Ryul [Korea Institute of Energy Research, Taejon (Korea, Republic of)

1998-03-15

In order to develop a kW-class polymer electrolyte membrane fuel cell (PEMFC), several electrodes have been fabricated by different catalyst layer preparation procedures and evaluated based on the cell performance. Conventional carbon paper and carbon cloth electrodes were fabricated using a ptfe-bonded Pt/C electrol catalyst by coating and rolling methods. Thin-film catalyst/ionomer composite layers were also formed on the membrane by direct coating and transfer printing techniques. The performance evaluation with catalyst layer preparation methods was carried out using a large or small electrode single cell. Conventional and thin film membrane and electrode assemblies (MEAs) with small electrode area showed a performance of 350 and 650 mA/cm{sup 2} at 0.6 V, respectively. The performance of direct coated thin film catalyst layer with 300 cm{sup 2} MEAs was higher than those of the conventional and transfer printing technique MEAs. The influence of some characteristic parameters of the thin film electrode on electrochemical performance was examined. Various other aspects of overall operation of PEMFC stacks were also discussed. (orig.)

The electrical properties of low pressure chemical vapor deposition Ga doped ZnO thin films depending on chemical bonding configuration

Energy Technology Data Exchange (ETDEWEB)

Jung, Hanearl [School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Kim, Doyoung [School of Electrical and Electronic Engineering, Ulsan College, 57 Daehak-ro, Nam-gu, Ulsan 680-749 (Korea, Republic of); Kim, Hyungjun, E-mail: hyungjun@yonsei.ac.kr [School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of)

2014-04-01

Highlights: • Undoped and Ga doped ZnO thin films were deposited using DEZ and TMGa. • Effects of Ga doping using TMGa in Ga doped ZnO were investigated. • Degraded properties from excessive doping were analyzed using chemical bondings. - Abstract: The electrical and chemical properties of low pressure chemical vapor deposition (LP-CVD) Ga doped ZnO (ZnO:Ga) films were systematically investigated using Hall measurement and X-ray photoemission spectroscopy (XPS). Diethylzinc (DEZ) and O{sub 2} gas were used as precursor and reactant gas, respectively, and trimethyl gallium (TMGa) was used as a Ga doping source. Initially, the electrical properties of undoped LP-CVD ZnO films depending on the partial pressure of DEZ and O{sub 2} ratio were investigated using X-ray diffraction (XRD) by changing partial pressure of DEZ from 40 to 140 mTorr and that of O{sub 2} from 40 to 80 mTorr. The resistivity was reduced by Ga doping from 7.24 × 10{sup −3} Ω cm for undoped ZnO to 2.05 × 10{sup −3} Ω cm for Ga doped ZnO at the TMG pressure of 8 mTorr. The change of electric properties of Ga doped ZnO with varying the amount of Ga dopants was systematically discussed based on the structural crystallinity and chemical bonding configuration, analyzed by XRD and XPS, respectively.

Silicon solar cell performance deposited by diamond like carbon thin film ;Atomic oxygen effects;

Science.gov (United States)

Aghaei, Abbas Ail; Eshaghi, Akbar; Karami, Esmaeil

2017-09-01

In this research, a diamond-like carbon thin film was deposited on p-type polycrystalline silicon solar cell via plasma-enhanced chemical vapor deposition method by using methane and hydrogen gases. The effect of atomic oxygen on the functioning of silicon coated DLC thin film and silicon was investigated. Raman spectroscopy, field emission scanning electron microscopy, atomic force microscopy and attenuated total reflection-Fourier transform infrared spectroscopy were used to characterize the structure and morphology of the DLC thin film. Photocurrent-voltage characteristics of the silicon solar cell were carried out using a solar simulator. The results showed that atomic oxygen exposure induced the including oxidation, structural changes, cross-linking reactions and bond breaking of the DLC film; thus reducing the optical properties. The photocurrent-voltage characteristics showed that although the properties of the fabricated thin film were decreased after being exposed to destructive rays, when compared with solar cell without any coating, it could protect it in atomic oxygen condition enhancing solar cell efficiency up to 12%. Thus, it can be said that diamond-like carbon thin layer protect the solar cell against atomic oxygen exposure.

Structural, optoelectronic, luminescence and thermal properties of Ga-doped zinc oxide thin films

International Nuclear Information System (INIS)

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

2012-01-01

Highlights: ► The ecofriendly deposition of Ga-doped zinc oxide. ► Influence of Ga doping onto physicochemical properties in aqueous media. ► Electron–phonon coupling by Raman. ► Chemical bonding structure and valence band analysis by XPS. - Abstract: Ga-doped ZnO thin films are synthesized by chemical spray pyrolysis onto corning glass substrates in aqueous media. The influence of gallium doping on to the photoelectrochemical, structural, Raman, XPS, morphological, optical, electrical, photoluminescence and thermal properties have been investigated in order to achieve good quality films. X-ray diffraction study depicts the films are polycrystalline and fit well with hexagonal (wurtzite) crystal structure with strong orientations along the (0 0 2) and (1 0 1) planes. Presence of E 2 high mode in Raman spectra indicates that the gallium doping does not change the wurtzite structure. The coupling strength between electron and LO phonon has experimentally estimated. In order to understand the chemical bonding structure and electronic states of the Ga-doped ZnO thin films XPS analysis have been studied. SEM images shows the films are adherent, compact, densely packed with hexagonal flakes and spherical grains. Optical transmittance and reflectance measurements have been carried out. Room temperature PL spectra depict violet, blue and green emission in deposited films. The specific heat and thermal conductivity study shows the phonon conduction behavior is dominant in these polycrystalline films.

Evaluation of unencapsulated ceramic monolithic and MOS thin-film capacitors (25 to 3000C)

International Nuclear Information System (INIS)

Nance, W.R.

1982-01-01

Several commercial monolithic ceramic and thin-film MOS chip capacitors were evaluated for use in high temperature (300 0 C) geothermal instrumentation. Characteristics of the commonly used dielectric materials (NPO, X7R, BX) and temperature dependence of the insulation resistance are briefly discussed. Some ceramic capacitors with NPO dielectric materials had insulation resistances above 10 megohms at 300 0 C and less than 2% change in capacitance from 25 0 C to 300 0 C, while the X7R and BX dielectric materials exhibited insulation resistances below 10 megohm and changes in capacitance greater then 50%. The thin-film capacitors showed good stability at 300 0 C. However, during aging, bonds and bond pads presented a problem causing intermittently open circuits for some of the devices

Experimental and ab initio investigations on textured Li–Mn–O spinel thin film cathodes

Energy Technology Data Exchange (ETDEWEB)

Fischer, J., E-mail: Julian.Fischer@kit.edu [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials (IAM), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Music, D. [RWTH Aachen University, Materials Chemistry, Kopernikusstrasse 10, 52074 Aachen (Germany); Bergfeldt, T.; Ziebert, C.; Ulrich, S.; Seifert, H.J. [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials (IAM), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

2014-12-01

This paper describes the tailored preparation of nearly identical lithium–manganese–oxide thin film cathodes with different global grain orientations. The thin films were synthesized by rf magnetron sputtering from a LiMn{sub 2}O{sub 4}-target in a pure argon plasma. Under appropriate processing conditions, thin films with a cubic spinel structure and a nearly similar density and surface topography but different grain orientation, i.e. (111)- and (440)-textured films, were achieved. The chemical composition was determined by inductively coupled plasma optical emission spectroscopy and carrier gas hot extraction. The constitution- and microstructure were evaluated by X-ray diffraction and Raman spectroscopy. The surface morphology and roughness were investigated by scanning electron and atomic force microscopy. The differently textured films represent an ideal model system for studying potential effects of grain orientation on the lithium ion diffusion and electrochemical behavior in LiMn{sub 2}O{sub 4}-based thin films. They are nearly identical in their chemical composition, atomic bonding behavior, surface-roughness, morphology and thickness. Our initial ab initio molecular dynamics data indicate that Li ion transport is faster in (111)-textured structure than in (440)-textured one. - Highlights: • Thin film model system of differently textured cubic Li–Mn–O spinels. • Investigation of the Li–Mn–O thin film mass density by X-ray reflectivity. • Ab initio molecular dynamics simulation on Li ion diffusion in LiMn{sub 2}O{sub 4}.

Experimental and ab initio investigations on textured Li–Mn–O spinel thin film cathodes

International Nuclear Information System (INIS)

Fischer, J.; Music, D.; Bergfeldt, T.; Ziebert, C.; Ulrich, S.; Seifert, H.J.

2014-01-01

This paper describes the tailored preparation of nearly identical lithium–manganese–oxide thin film cathodes with different global grain orientations. The thin films were synthesized by rf magnetron sputtering from a LiMn 2 O 4 -target in a pure argon plasma. Under appropriate processing conditions, thin films with a cubic spinel structure and a nearly similar density and surface topography but different grain orientation, i.e. (111)- and (440)-textured films, were achieved. The chemical composition was determined by inductively coupled plasma optical emission spectroscopy and carrier gas hot extraction. The constitution- and microstructure were evaluated by X-ray diffraction and Raman spectroscopy. The surface morphology and roughness were investigated by scanning electron and atomic force microscopy. The differently textured films represent an ideal model system for studying potential effects of grain orientation on the lithium ion diffusion and electrochemical behavior in LiMn 2 O 4 -based thin films. They are nearly identical in their chemical composition, atomic bonding behavior, surface-roughness, morphology and thickness. Our initial ab initio molecular dynamics data indicate that Li ion transport is faster in (111)-textured structure than in (440)-textured one. - Highlights: • Thin film model system of differently textured cubic Li–Mn–O spinels. • Investigation of the Li–Mn–O thin film mass density by X-ray reflectivity. • Ab initio molecular dynamics simulation on Li ion diffusion in LiMn 2 O 4

Effects of lithium doping on microstructure, electrical properties, and chemical bonds of sol-gel derived NKN thin films

International Nuclear Information System (INIS)

Lin, Chun-Cheng; Chen, Chan-Ching; Weng, Chung-Ming; Chu, Sheng-Yuan; Hong, Cheng-Shong; Tsai, Cheng-Che

2015-01-01

Highly (100/110) oriented lead-free Li x (Na 0.5 K 0.5 ) 1−x NbO 3 (LNKN, x = 0, 0.02, 0.04, and 0.06) thin films are fabricated on Pt/Ti/SiO 2 /Si substrates via a sol-gel processing method. The lithium (Li) dopants modify the microstructure and chemical bonds of the LNKN films, and therefore improve their electrical properties. The optimal values of the remnant polarization (P r  = 14.3 μC/cm 2 ), piezoelectric coefficient (d 33  = 48.1 pm/V), and leakage current (<10 −5 A/cm 2 ) are obtained for a lithium addition of x = 0.04 (i.e., 4 at. %). The observation results suggest that the superior electrical properties are the result of an improved crystallization, a larger grain size, and a smoother surface morphology. It is shown that the ion transport mechanism is dominated by an Ohmic behavior under low electric fields and the Poole-Frenkel emission effect under high electric fields

Structural and optical investigation of Te-based chalcogenide thin films

Energy Technology Data Exchange (ETDEWEB)

Sharma, Rita, E-mail: reetasharma2012@gmail.com; Sharma, Shaveta; Thangaraj, R.; Mian, M. [Semiconductors Laboratory, Department of Physics, GND University, Amritsar (India); Chander, Ravi [Applied Science Deptt. Govt. Polytechnic College Amritsar (India); Kumar, Praveen [Department of Physics, DAV University, Sarmastipur, Jalandhar-144012 (India)

2015-05-15

We report the structural and optical properties of thermally evaporated Bi{sub 2}Te{sub 3}, In{sub 2}Te{sub 3} and InBiTe{sub 3} films by using X-ray diffraction, optical and Raman Spectroscopy techniques. The as-prepared thin films were found to be Semi-crystalline by X-ray diffraction. Particle Size and Strain has been calculated from XRD data. The optical constants, film thickness, refractive index and optical band gap (E{sub g}) has been reported for In{sub 2}Te{sub 3}, InBiTe{sub 3} films. Raman Spectroscopy was performed to investigate the effect of Bi, In, on lattice vibration and chemical bonding in Te based chalcogenide glassy alloys.

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.

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...

Note: Automatic layer-by-layer spraying system for functional thin film coatings

Science.gov (United States)

Seo, Seongmin; Lee, Sangmin; Park, Yong Tae

2016-03-01

In this study, we have constructed an automatic spray machine for producing polyelectrolyte multilayer films containing various functional materials on wide substrates via the layer-by-layer (LbL) assembly technique. The proposed machine exhibits advantages in terms of automation, process speed, and versatility. Furthermore, it has several features that allow a fully automated spraying operation, such as various two-dimensional spraying paths, control of the flow rate and operating speed, air-assist fan-shaped twin-fluid nozzles, and an optical display. The robot uniformly sprays aqueous mixtures containing complementary (e.g., oppositely charged, capable of hydrogen bonding, or capable of covalent bonding) species onto a large-area substrate. Between each deposition of opposite species, samples are spray-rinsed with deionized water and blow-dried with air. The spraying, rinsing, and drying areas and times are adjustable by a computer program. Twenty-bilayer flame-retardant thin films were prepared in order to compare the performance of the spray-assisted LbL assembly with a sample produced by conventional dipping. The spray-coated film exhibited a reduction of afterglow time in vertical flame tests, indicating that the spray-LbL technique is a simple method to produce functional thin film coatings.

Semiconducting Properties of Nanostructured Amorphous Carbon Thin Films Incorporated with Iodine by Thermal Chemical Vapor Deposition

Science.gov (United States)

Kamaruzaman, Dayana; Ahmad, Nurfadzilah; Annuar, Ishak; Rusop, Mohamad

2013-11-01

Nanostructured iodine-post doped amorphous carbon (a-C:I) thin films were prepared from camphor oil using a thermal chemical vapor deposition (TCVD) technique at different doping temperatures. The structural properties of the films were studied by field-emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), Raman, and Fourier transform infrared (FTIR) studies. FESEM and EDS studies showed successful iodine doping. FTIR and Raman studies showed that the a-C:I thin films consisted of a mixture of sp2- and sp3-bonded carbon atoms. The optical and electrical properties of a-C:I thin films were determined by UV-vis-NIR spectroscopy and current-voltage (I-V) measurement respectively. The optical band gap of a-C thin films decreased upon iodine doping. The highest electrical conductivity was found at 400 °C doping. Heterojunctions are confirmed by rectifying the I-V characteristics of an a-C:I/n-Si junction.

Biomimetic thin film synthesis

Energy Technology Data Exchange (ETDEWEB)

Graff, G.L.; Campbell, A.A.; Gordon, N.R.

1995-05-01

The purpose of this program is to develop a new process for forming thin film coatings and to demonstrate that the biomimetic thin film technology developed at PNL is useful for industrial applications. In the biomimetic process, mineral deposition from aqueous solution is controlled by organic functional groups attached to the underlying substrate surface. The coatings process is simple, benign, inexpensive, energy efficient, and particularly suited for temperature sensitive substrate materials (such as polymers). In addition, biomimetic thin films can be deposited uniformly on complex shaped and porous substrates providing a unique capability over more traditional line-of-sight methods.

Chemical bonding characteristics of Ge2Sb2Te5 for thin films

International Nuclear Information System (INIS)

Shin, Min-Jung; Choi, Doo-Jin; Kang, Myung-Jin; Choi, Se-Young; Jang, In-Woo; Lee, Kye-Nam; Park, Young-Jin

2004-01-01

The chalcogenide-based phase change memory has been suggested as an alternative non-volatile memory device at the 180 nm technology node. These materials appear to have a reversible phase change between amorphous and crystalline phases. A sputtered Ge 2 Sb 2 Te 5 film is deposited on a (100) Si substrate. In order to investigate the crystallization tendency at a certain temperature, we use X-ray diffraction and X-ray photoelectron spectroscopy. The film morphology is observed by using atomic forces microscopy. Grain growth and a phase transition from cubic to hexagonal occurs when the films are heated from 170 .deg. C and 380 .deg. C, and Ge-Te and Te-Sb bonds increased with annealing.

Thin Film Photovoltaic Partnership Project | Photovoltaic Research | NREL

Science.gov (United States)

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

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...

Fracture properties of hydrogenated amorphous silicon carbide thin films

International Nuclear Information System (INIS)

Matsuda, Y.; King, S.W.; Bielefeld, J.; Xu, J.; Dauskardt, R.H.

2012-01-01

The cohesive fracture properties of hydrogenated amorphous silicon carbide (a-SiC:H) thin films in moist environments are reported. Films with stoichiometric compositions (C/Si ≈ 1) exhibited a decreasing cohesive fracture energy with decreasing film density similar to other silica-based hybrid organic–inorganic films. However, lower density a-SiC:H films with non-stoichiometric compositions (C/Si ≈ 5) exhibited much higher cohesive fracture energy than the films with higher density stoichiometric compositions. One of the non-stoichiometric films exhibited fracture energy (∼9.5 J m −2 ) greater than that of dense silica glasses. The increased fracture energy was due to crack-tip plasticity, as demonstrated by significant pileup formation during nanoindentation and a fracture energy dependence on film thickness. The a-SiC:H films also exhibited a very low sensitivity to moisture-assisted cracking compared with other silica-based hybrid films. A new atomistic fracture model is presented to describe the observed moisture-assisted cracking in terms of the limited Si-O-Si suboxide bond formation that occurs in the films.

Structural features of spin-coated thin films of binary As{sub x}S{sub 100−x} chalcogenide glass system

Energy Technology Data Exchange (ETDEWEB)

Cook, J. [Austin Peay State University, Clarksville, TN 37075 (United States); Slang, S. [Faculty of Chemical Technology, University of Pardubice, 53210 Pardubice (Czech Republic); Golovchak, R. [Austin Peay State University, Clarksville, TN 37075 (United States); Jain, H. [International Materials Institute for New Functionality in Glass, Lehigh University, Bethlehem, PA 18015 (United States); Vlcek, M. [Faculty of Chemical Technology, University of Pardubice, 53210 Pardubice (Czech Republic); Kovalskiy, A., E-mail: kovalskyya@apsu.edu [Austin Peay State University, Clarksville, TN 37075 (United States)

2015-08-31

Spin-coating technology offers a convenient method for fabricating photostable chalcogenide glass thin films that are especially attractive for applications in IR optics. In this paper we report the structure of spin-coated As{sub x}S{sub 100−x} (x = 30, 35, 40) thin films as determined using high resolution X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy, especially in relation to composition (i.e. As/S ratio) and preparation process variables. It was observed that As atoms during preparation have a tendency to precipitate out in close to stoichiometric compositions. The mechanism of bonding between the inorganic matrix and organic residuals is discussed based on the experimental data. A weak interaction between S ions and amine-based clusters is proposed as the basis of structural organization of the organic–inorganic interface. - Highlights: • As–S spin-coated chalcogenide thin films with different As/S were fabricated. • XPS measurements support the cluster-like structure of spin-coated films. • As{sub 2}O{sub 3} was confirmed as the composition of precipitate formed during dissolution. • Lack of As–As bonds explains the observed photostability of the thin films.

Ab Initio Guided Low Temperature Synthesis Strategy for Smooth Face–Centred Cubic FeMn Thin Films

Directory of Open Access Journals (Sweden)

Friederike Herrig

2018-05-01

Full Text Available The sputter deposition of FeMn thin films with thicknesses in the range of hundred nanometres and beyond requires relatively high growth temperatures for the formation of the face-centred cubic (fcc phase, which results in high thin film roughness. A low temperature synthesis strategy, based on local epitaxial growth of a 100 nm thick fcc FeMn film as well as a Cu nucleation layer on an α-Al2O3 substrate at 160 °C, enables roughness values (Ra as low as ~0.6 nm, which is in the same order of magnitude as the pristine substrate (~0.1 nm. The synthesis strategy is guided by ab initio calculations, indicating very strong interfacial bonding of the Cu nucleation layer to an α-Al2O3 substrate (work of separation 5.48 J/m²—which can be understood based on the high Cu coordination at the interface—and between fcc FeMn and Cu (3.45 J/m². Accompanied by small lattice misfits between these structures, the strong interfacial bonding is proposed to enable the local epitaxial growth of a smooth fcc FeMn thin film. Based on the here introduced synthesis strategy, the implementation of fcc FeMn based thin film model systems for materials with interface dominated properties such as FeMn steels containing κ-carbide precipitates or secondary phases appears meaningful.

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...

Hydrogenated amorphous silicon thin film anode for proton conducting batteries

Science.gov (United States)

Meng, Tiejun; Young, Kwo; Beglau, David; Yan, Shuli; Zeng, Peng; Cheng, Mark Ming-Cheng

2016-01-01

Hydrogenated amorphous Si (a-Si:H) thin films deposited by chemical vapor deposition were used as anode in a non-conventional nickel metal hydride battery using a proton-conducting ionic liquid based non-aqueous electrolyte instead of alkaline solution for the first time, which showed a high specific discharge capacity of 1418 mAh g-1 for the 38th cycle and retained 707 mAh g-1 after 500 cycles. A maximum discharge capacity of 3635 mAh g-1 was obtained at a lower discharge rate, 510 mA g-1. This electrochemical discharge capacity is equivalent to about 3.8 hydrogen atoms stored in each silicon atom. Cyclic voltammogram showed an improved stability 300 mV below the hydrogen evolution potential. Both Raman spectroscopy and Fourier transform infrared spectroscopy studies showed no difference to the pre-existing covalent Si-H bond after electrochemical cycling and charging, indicating a non-covalent nature of the Si-H bonding contributing to the reversible hydrogen storage of the current material. Another a-Si:H thin film was prepared by an rf-sputtering deposition followed by an ex-situ hydrogenation, which showed a discharge capacity of 2377 mAh g-1.

The effect of solvent upon molecularly thin rotaxane film formation

Energy Technology Data Exchange (ETDEWEB)

Farrell, Alan A. [Nanoscale Function Group, Centre for Research on Adaptive Nanostructures and Nanodevices, University of Dublin, Trinity College, Dublin 2 (Ireland)]. E-mail: farrelaa@tcd.ie; Kay, Euan R. [School of Chemistry, University of Edinburgh, The King' s Buildings, West Mains Road, Edinburgh EH9 3 JJ (United Kingdom); Bottari, Giovanni [School of Chemistry, University of Edinburgh, The King' s Buildings, West Mains Road, Edinburgh EH9 3 JJ (United Kingdom); Leigh, David A. [School of Chemistry, University of Edinburgh, The King' s Buildings, West Mains Road, Edinburgh EH9 3 JJ (United Kingdom); Jarvis, Suzanne P. [Nanoscale Function Group, Centre for Research on Adaptive Nanostructures and Nanodevices, University of Dublin, Trinity College, Dublin 2 (Ireland)

2007-05-15

We have investigated variations in molecularly thin rotaxane films deposited by solvent evaporation, using atomic force microscopy (AFM). Small changes in rotaxane structure result in significant differences in film morphology. The addition of exo-pyridyl moietes to the rotaxane macrocycle results in uniform domains having orientations corresponding to the underlying substrate lattice, while a larger, less symmetric molecule results in a greater lattice mismatch and smaller domain sizes. We have measured differences in film heights both as a function of the solvent of deposition and as a function of surface coverage of rotaxanes. Based on these observations we describe how the use of solvents with higher hydrogen-bond basicity results in films which are more likely to favour sub-molecular motion.

Development in fiscal 1999 of technologies to put photovoltaic power generation systems into practical use. Development of thin film solar cell manufacturing technologies (Development of technologies to manufacture applied type thin film solar cells with new structure and development of high-efficiency hybrid thin film/sheet solar cells); 1999 nendo taiyoko hatsuden system jitsuyoka gijutsu kaihatsu seika hokokusho. Usumaku taiyo denchi no seizo gijutsu kaihatsu (oyogata shin kozo usumaku taiyo denchi no seizo gijutsu kaihatsu (kokoritsu hybrid gata usumaku / sheet taiyo denchi no seizo gijutsu kaihatsu))

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

With an objective to develop low-cost and high-efficiency hybrid thin film/sheet solar cells, research and development has been performed. This paper summarizes the achievements in fiscal 1999. The research is related to a hybrid construction, in which the upper cells of amorphous silicon thin film are formed on the lower cells bonded with micro-crystalline silicon thin film relative to a poly-crystalline silicon sheet. In the technology to form the upper cells, a pin-construction using amorphous silicon thin film made by using the plasma CVD process was adopted, whereas an open circuit voltage of 1.45V, a short circuit current of 13.6 mA/cm{sup 2}, and a conversion efficiency of 13.5% were obtained. In the technology to form the substrate for the lower cells, formation of flat silicon thin plate that can be peeled off was identified as a result of adopting the construction in which a graphite substrate is provided on a rotating cooling body of 12-prism type. With regard to the technology to bond and form the lower cells, electrical properties of hetero-bonded cells were discussed, and an open circuit voltage of 0.605V and a conversion efficiency of 14.3% were obtained as a result of enhancing the film quality and optimizing the film thickness. (NEDO)

A new in situ technique for studying deformation and fracture in thin film ductile/brittle laminates

International Nuclear Information System (INIS)

Hackney, S.A.; Milligan, W.W.

1991-01-01

A new technique for studying deformation and fracture of thin film ductile/brittle laminates is described. The laminates are prepared by sputtering a brittle coating on top of an electropolished TEM thin foil. The composites are then strained in situ in the TEM. In this preliminary investigation, the composites consisted of a ductile aluminum substrate and a brittle silicon coating. Cracks in the brittle film grew discontinuously in bursts several micrometers in length. The crack opening displacement initiated plastic deformation in the ductile film, thus dissipating energy and allowing crack arrest. The interface was well bonded, and delamination was not observed. Due to the good interfacial bond and the crack opening behind the crack tip, it was possible to study very large plastic deformations and ductile fracture in the aluminum in situ, without buckling of the foil. The possibility of micromechanical modeling of the fracture behavior is briefly discussed. (orig.)

Self-Limited Growth in Pentacene Thin Films.

Science.gov (United States)

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

2017-04-05

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

Investigation of structure, adhesion strength, wear performance and corrosion behavior of platinum/ruthenium/nitrogen doped diamond-like carbon thin films with respect to film thickness

Energy Technology Data Exchange (ETDEWEB)

Khun, N.W. [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Liu, E., E-mail: MEJLiu@ntu.edu.sg [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

2011-03-15

Research highlights: {yields} Sputtered PtRuN-DLC thin films were fabricated with different film thicknesses. {yields} The graphitization of the films increased with increased film thickness. {yields} The wear resistance of the films increased though their adhesion strength decreased. {yields} The corrosion potentials of the films shifted to more negative values. {yields} However, the corrosion currents of the films decreased. - Abstract: In this study, the corrosion performance of platinum/ruthenium/nitrogen doped diamond-like carbon (PtRuN-DLC) thin films deposited on p-Si substrates using a DC magnetron sputtering deposition system in a 0.1 M NaCl solution was investigated using potentiodynamic polarization test in terms of film thickness. The effect of the film thickness on the chemical composition, bonding structure, surface morphology, adhesion strength and wear resistance of the PtRuN-DLC films was studied using X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, atomic force microscopy (AFM), micro-scratch test and ball-on-disc tribotest, respectively. It was found that the wear resistance of the PtRuN-DLC films apparently increased with increased film thickness though the adhesion strength of the films decreased. The corrosion results revealed that the increased concentration of sp{sup 2} bonds in the PtRuN-DLC films with increased film thickness shifted the corrosion potentials of the films to more negative values but the decreased porosity density in the films significantly decreased the corrosion currents of the films.

Investigation of structure, adhesion strength, wear performance and corrosion behavior of platinum/ruthenium/nitrogen doped diamond-like carbon thin films with respect to film thickness

International Nuclear Information System (INIS)

Khun, N.W.; Liu, E.

2011-01-01

Research highlights: → Sputtered PtRuN-DLC thin films were fabricated with different film thicknesses. → The graphitization of the films increased with increased film thickness. → The wear resistance of the films increased though their adhesion strength decreased. → The corrosion potentials of the films shifted to more negative values. → However, the corrosion currents of the films decreased. - Abstract: In this study, the corrosion performance of platinum/ruthenium/nitrogen doped diamond-like carbon (PtRuN-DLC) thin films deposited on p-Si substrates using a DC magnetron sputtering deposition system in a 0.1 M NaCl solution was investigated using potentiodynamic polarization test in terms of film thickness. The effect of the film thickness on the chemical composition, bonding structure, surface morphology, adhesion strength and wear resistance of the PtRuN-DLC films was studied using X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, atomic force microscopy (AFM), micro-scratch test and ball-on-disc tribotest, respectively. It was found that the wear resistance of the PtRuN-DLC films apparently increased with increased film thickness though the adhesion strength of the films decreased. The corrosion results revealed that the increased concentration of sp 2 bonds in the PtRuN-DLC films with increased film thickness shifted the corrosion potentials of the films to more negative values but the decreased porosity density in the films significantly decreased the corrosion currents of the films.

Suppression of interfacial voids formation during silane (SiH4)-based silicon oxide bonding with a thin silicon nitride capping layer

Science.gov (United States)

Lee, Kwang Hong; Bao, Shuyu; Wang, Yue; Fitzgerald, Eugene A.; Seng Tan, Chuan

2018-01-01

The material properties and bonding behavior of silane-based silicon oxide layers deposited by plasma-enhanced chemical vapor deposition were investigated. Fourier transform infrared spectroscopy was employed to determine the chemical composition of the silicon oxide films. The incorporation of hydroxyl (-OH) groups and moisture absorption demonstrates a strong correlation with the storage duration for both as-deposited and annealed silicon oxide films. It is observed that moisture absorption is prevalent in the silane-based silicon oxide film due to its porous nature. The incorporation of -OH groups and moisture absorption in the silicon oxide films increase with the storage time (even in clean-room environments) for both as-deposited and annealed silicon oxide films. Due to silanol condensation and silicon oxidation reactions that take place at the bonding interface and in the bulk silicon, hydrogen (a byproduct of these reactions) is released and diffused towards the bonding interface. The trapped hydrogen forms voids over time. Additionally, the absorbed moisture could evaporate during the post-bond annealing of the bonded wafer pair. As a consequence, defects, such as voids, form at the bonding interface. To address the problem, a thin silicon nitride capping film was deposited on the silicon oxide layer before bonding to serve as a diffusion barrier to prevent moisture absorption and incorporation of -OH groups from the ambient. This process results in defect-free bonded wafers.

Geometric structure of thin SiO xN y films on Si(100)

Science.gov (United States)

Behrens, K.-M.; Klinkenberg, E.-D.; Finster, J.; Meiwes-Broer, K.-H.

1998-05-01

Thin films of amorphous stoichometric SiO xN y are deposited on radiation-heated Si(100) by rapid thermal low-pressure chemical vapour deposition. We studied the whole range of possible compositions. In order to determine the geometric structure, we used EXAFS and photoelectron spectroscopy. Tetrahedrons constitute the short-range units with a central Si atom connected to N and O. The distribution of the possible tetrahedrons can be described by a mixture of the Random Bonding Model and the Random Mixture Model. For low oxygen contents x/( x+ y)≤0.3, the geometric structure of the film is almost the structure of a-Si 3N 4, with the oxygen preferably on top of Si-N 3 triangles. Higher oxygen contents induce changes in the bond lengths, bond angles and coordination numbers.

Structural study of thin films prepared from tungstate glass matrix by Raman and X-ray absorption spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Montanari, Bianca; Barbosa, Anne J.; Ribeiro, Sidney J.L.; Messaddeq, Younes [Departamento de Quimica Geral e Inorganica, Instituto de Quimica, UNESP, CP 355, CEP 14800-900 Araraquara, SP (Brazil); Poirier, Gael [Departamento de Ciencias Exatas, UNIFAL-MG, CEP 37130-000 Alfenas, MG (Brazil)], E-mail: gael@unifal-mg.edu.br; Li, Maximo S. [Instituto de Fisica, USP, CP 369, CEP 13560-970 Sao Carlos, SP (Brazil)

2008-06-30

Thin films were prepared using glass precursors obtained in the ternary system NaPO{sub 3}-BaF{sub 2}-WO{sub 3} and the binary system NaPO{sub 3}-WO{sub 3} with high concentrations of WO{sub 3} (above 40% molar). Vitreous samples have been used as a target to prepare thin films. Such films were deposited using the electron beam evaporation method onto soda-lime glass substrates. Several structural characterizations were performed by Raman spectroscopy and X-ray Absorption Near Edge Spectroscopy (XANES) at the tungsten L{sub I} and L{sub III} absorption edges. XANES investigations showed that tungsten atoms are only sixfold coordinated (octahedral WO{sub 6}) and that these films are free of tungstate tetrahedral units (WO{sub 4}). In addition, Raman spectroscopy allowed identifying a break in the linear phosphate chains as the amount of WO{sub 3} increases and the formation of P-O-W bonds in the films network indicating the intermediary behavior of WO{sub 6} octahedra in the film network. Based on XANES data, we suggested a new attribution of several Raman absorption bands which allowed identifying the presence of W-O{sup -} and W=O terminal bonds and a progressive apparition of W-O-W bridging bonds for the most WO{sub 3} concentrated samples (above 40% molar) attributed to the formation of WO{sub 6} clusters.

Hybrid thin films derived from UV-curable acrylate-modified waterborne polyurethane and monodispersed colloidal silica

Directory of Open Access Journals (Sweden)

C. H. Yang

2012-01-01

Full Text Available Hybrid thin films containing nano-sized inorganic domains were synthesized from UV-curable acrylate-modified waterborne polyurethane (WPU-AC and monodispersed colloidal silica with coupling agent. The coupling agent, 3-(trimethoxysilylpropyl methacrylate (MSMA, was bonded onto colloidal silica first, and then mixed with WPU-AC to form a precursor solution. This precursor was spin coated, dried and UV-cured to generate the hybrid films. The silica content in the hybrid thin films was varied from 0 to 30 wt%. Experimental results showed the aggregation of silica particles in the hybrid films. Thus, the silica domain in the hybrid films was varied from 30 to 50 nm by the different ratios of MSMAsilica to WPU-AC. The prepared hybrid films from the crosslinked WPU-AC/MSMA-silica showed much better thermal stability and mechanical properties than pure WPU-AC.

Thin films for precision optics

International Nuclear Information System (INIS)

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

1983-01-01

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

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.

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

Photoluminescence properties of BaMoO4 amorphous thin films

International Nuclear Information System (INIS)

Marques, Ana Paula Azevedo; Melo, Dulce M.A. de; Longo, Elson; Paskocimas, Carlos A.; Pizani, Paulo S.; Leite, Edson R.

2005-01-01

BaMoO 4 amorphous and crystalline thin films were prepared from polymeric precursors. The BaMoO 4 was deposited onto Si wafers by means of the spinning technique. The structure and optical properties of the resulting films were characterized by FTIR reflectance spectra, X-ray diffraction (XRD), atomic force microscopy (AFM) and optical reflectance. The bond Mo-O present in BaMoO 4 was confirmed by FTIR reflectance spectra. XRD characterization showed that thin films heat-treated at 600 and 200 deg. C presented the scheelite-type crystalline phase and amorphous, respectively. AFM analyses showed a considerable variation in surface morphology by comparing samples heat-treated at 200 and 600 deg. C. The reflectivity spectra showed two bands, positioned at 3.38 and 4.37 eV that were attributed to the excitonic state of Ba 2+ and electronic transitions within MoO 2- 4 , respectively. The optical band gaps of BaMoO 4 were 3.38 and 2.19 eV, for crystalline (600 deg. C/2 h) and amorphous (200 deg. C/8 h) films, respectively. The room-temperature luminescence spectra revealed an intense single-emission band in the visible region. The PL intensity of these materials was increased upon heat-treatment. The excellent optical properties observed for BaMoO 4 amorphous thin films suggested that this material is a highly promising candidate for photoluminescent applications

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

Science.gov (United States)

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

Effects of lithium doping on microstructure, electrical properties, and chemical bonds of sol-gel derived NKN thin films

Energy Technology Data Exchange (ETDEWEB)

Lin, Chun-Cheng [Department of Electrical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Department of Mathematic and Physical Sciences, R.O.C. Air Force Academy, Kaohsiung 820, Taiwan (China); Chen, Chan-Ching; Weng, Chung-Ming [Department of Electrical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Chu, Sheng-Yuan, E-mail: chusy@mail.ncku.edu.tw [Department of Electrical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 701, Taiwan (China); Hong, Cheng-Shong [Department of Electronic Engineering, National Kaohsiung Normal University, Kaohsiung 802, Taiwan (China); Tsai, Cheng-Che [Department of Digital Game and Animation Design, Tung-Fang Design University, Kaohsiung 829, Taiwan (China)

2015-02-28

Highly (100/110) oriented lead-free Li{sub x}(Na{sub 0.5}K{sub 0.5}){sub 1−x}NbO{sub 3} (LNKN, x = 0, 0.02, 0.04, and 0.06) thin films are fabricated on Pt/Ti/SiO{sub 2}/Si substrates via a sol-gel processing method. The lithium (Li) dopants modify the microstructure and chemical bonds of the LNKN films, and therefore improve their electrical properties. The optimal values of the remnant polarization (P{sub r} = 14.3 μC/cm{sup 2}), piezoelectric coefficient (d{sub 33} = 48.1 pm/V), and leakage current (<10{sup −5} A/cm{sup 2}) are obtained for a lithium addition of x = 0.04 (i.e., 4 at. %). The observation results suggest that the superior electrical properties are the result of an improved crystallization, a larger grain size, and a smoother surface morphology. It is shown that the ion transport mechanism is dominated by an Ohmic behavior under low electric fields and the Poole-Frenkel emission effect under high electric fields.

Nanocrystal thin film fabrication methods and apparatus

Science.gov (United States)

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

2018-01-09

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

Testing Bonds Between Brittle And Ductile Films

Science.gov (United States)

Wheeler, Donald R.; Ohsaki, Hiroyuki

1989-01-01

Simple uniaxial strain test devised to measure intrinsic shear strength. Brittle film deposited on ductile stubstrate film, and combination stretched until brittle film cracks, then separates from substrate. Dimensions of cracked segments related in known way to tensile strength of brittle film and shear strength of bond between two films. Despite approximations and limitations of technique, tests show it yields semiquantitative measures of bond strengths, independent of mechanical properties of substrates, with results reproducible with plus or minus 6 percent.

AES study of the reaction between a thin Fe-film and β-SiC (100) surface

International Nuclear Information System (INIS)

Mizokawa, Yusuke; Nakanishi, Shigemitsu; Miyase, Sunao

1989-01-01

The solid state reaction between thin Fe-films and β-SiC(100) in UHV has been studied using AES. Even at room temperature, the reaction between the thin Fe-film and SiC occurred and formed Fe-silicide and graphite with a minor product of Fe-carbide (Fe 3 C). The reaction proceeded with an increase of Fe-coverage to some extent. With annealing of 15 A-Fe-film/SiC below 540degC, the Fe-silicide formation was accelerated, but because the amount of available Fe was small, the dissolved carbon atoms were forced to form not the Fe-carbide but the graphite phase. Above 640degC, the Fe-silicide started to decompose and the carbon atoms diffused to the surface and formed surface graphite layers. With annealing at 1080degC, the free-Si segregats at the surface and formed Si-Si bonds, as well as the Si-C bonds consuming the surface graphite phase. (author)

Slow positron beam study of hydrogen ion implanted ZnO thin films

Science.gov (United States)

Hu, Yi; Xue, Xudong; Wu, Yichu

2014-08-01

The effects of hydrogen related defect on the microstructure and optical property of ZnO thin films were investigated by slow positron beam, in combination with x-ray diffraction, infrared and photoluminescence spectroscopy. The defects were introduced by 90 keV proton irradiation with doses of 1×1015 and 1×1016 ions cm-2. Zn vacancy and OH bonding (VZn+OH) defect complex were identified in hydrogen implanted ZnO film by positron annihilation and infrared spectroscopy. The formation of these complexes led to lattice disorder in hydrogen implanted ZnO film and suppressed the luminescence process.

Bonding topologies in diamondlike amorphous-carbon films

Energy Technology Data Exchange (ETDEWEB)

Siegal, M. P. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Provencio, P. N. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Tallant, D. R. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Simpson, R. L. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Kleinsorge, B. [Department of Engineering, Cambridge University, Cambridge CB2 1PZ, (United Kingdom); Milne, W. I. [Department of Engineering, Cambridge University, Cambridge CB2 1PZ, (United Kingdom)

2000-04-10

The carbon ion energy used during filtered cathodic vacuum arc deposition determines the bonding topologies of amorphous-carbon (a-C) films. Regions of relatively low density occur near the substrate/film and film/surface interfaces; their thicknesses increase with deposition energy. The ion subplantation growth results in mass density gradients in the bulk portion of a-C in the growth direction; density decreases with distance from the substrate for films grown using ion energies <60 eV and increases for films grown using ion energies >160 eV. Films grown between these energies are the most diamondlike with relatively uniform bulk density and the highest optical transparencies. Bonding topologies evolve with increasing growth energy consistent with the propagation of subplanted carbon ions inducing a partial transformation of {sigma}- to {pi}-bonded carbon atoms. (c) 2000 American Institute of Physics.

Functionalized carbon nanotubes in ZnO thin films for photoinactivation of bacteria

International Nuclear Information System (INIS)

Akhavan, O.; Azimirad, R.; Safa, S.

2011-01-01

Highlights: → Unfunctionalized and functionalized MWCNT/ZnO thin films were synthesized by sol-gel method. → Zn-O-C carbonaceous bonds formed in the functionalized MWCNT/ZnO thin films. → The functionalized MWCNT/ZnO had stronger photoinactivation of the bacteria than the unfunctionalize type. → 10 wt% functionalized MWCNT content had the optimum antibacterial property. - Abstract: Two types of unfunctionalized and functionalized multi-wall carbon nanotubes (MWCNTs) were prepared to be applied in fabrication of MWCNT-ZnO nanocomposite thin films with various MWCNT contents. X-ray photoelectron spectroscopy indicated formation of functional groups on surface of the functionalized MWCNTs in the MWCNT-ZnO nanocomposite. Formation of the effective carbonaceous bonds between the ZnO and the MWCNTs was also investigated through photoinactivation of Escherichia coli bacteria on surface of the both unfunctionalized and functionalized MWCNT-ZnO nanocomposites. The functionalized MWCNT-ZnO nanocomposites showed significantly stronger photoinactivation of the bacteria than the unfunctionalized ones, for all of the various MWCNT contents (from 2 to 30 wt%). While the functionalized MWCNT-ZnO nanocomposites with the optimum MWCNT content of 10 wt% inactivated whole of the bacteria after 10 min UV-visible light irradiation, the unfunctionalized ones could inactivate only 63% of the bacteria under the same conditions. The significant enhancement of the photoinactivation of the bacteria onto the surface of the functionalized MWCNT-ZnO nanocomposites was assigned to charge transfer through Zn-O-C bands formed between the Zn atoms of the ZnO film and oxygen atoms of the carboxylic functional groups of the functionalized MWCNTs.

Spin-Ice Thin Films: Large-N Theory and Monte Carlo Simulations

Science.gov (United States)

Lantagne-Hurtubise, Étienne; Rau, Jeffrey G.; Gingras, Michel J. P.

2018-04-01

We explore the physics of highly frustrated magnets in confined geometries, focusing on the Coulomb phase of pyrochlore spin ices. As a specific example, we investigate thin films of nearest-neighbor spin ice, using a combination of analytic large-N techniques and Monte Carlo simulations. In the simplest film geometry, with surfaces perpendicular to the [001] crystallographic direction, we observe pinch points in the spin-spin correlations characteristic of a two-dimensional Coulomb phase. We then consider the consequences of crystal symmetry breaking on the surfaces of the film through the inclusion of orphan bonds. We find that when these bonds are ferromagnetic, the Coulomb phase is destroyed by the presence of fluctuating surface magnetic charges, leading to a classical Z2 spin liquid. Building on this understanding, we discuss other film geometries with surfaces perpendicular to the [110] or the [111] direction. We generically predict the appearance of surface magnetic charges and discuss their implications for the physics of such films, including the possibility of an unusual Z3 classical spin liquid. Finally, we comment on open questions and promising avenues for future research.

Preparation and characterization of B-C-N hybrid thin films

International Nuclear Information System (INIS)

Uddin, Md. Nizam; Shimoyama, Iwao; Sekiguchi, Tetsuhiro; Baba, Yuji; Nath, Krishna G.; Nagano, Masamitsu

2006-06-01

Two dimensional thin films composed of boron, carbon and nitrogen (B-C-N hybrid) were synthesized by ion beam deposition, and their electronic and geometrical structures were characterized by core-level spectroscopy using synchrotron radiation. B-C-N hybrid thin films were grown from ion beam plasma of borazine on highly oriented pyrolitic graphite (HOPG) at various temperatures. The films were characterized in-situ by X-ray photoelectron spectroscopy (XPS) and near edge X-ray absorption fine structure (NEXAFS). XPS study suggested that B, N and C atoms in the deposited films were in a wide variety of chemical bonds e.g., B-C, B-N, N-C, and B-C-N. It was found that B-C-N hybrid formation was enhanced at high temperature, and that the B-C-N component was dominantly synthesized at low boron content. In the NEXAFS spectra, the resonance peaks from B 1s to unoccupied π * -like orbitals were clearly observed. The polarization dependence of the B 1s → π * resonance peaks confirmed that the highly oriented graphite-like B-C-N hybrids surely exist at low boron content. (author)

Origin of stress in radio frequency magnetron sputtered zinc oxide thin films

Science.gov (United States)

Menon, Rashmi; Gupta, Vinay; Tan, H. H.; Sreenivas, K.; Jagadish, C.

2011-03-01

Highly c-axis oriented ZnO thin films have been deposited on silicon substrates by planar rf magnetron sputtering under varying pressure (10-50 mTorr) and oxygen percentage (50-100%) in the reactive gas (Ar + O2) mixture. The as-grown films were found to be stressed over a wide range from -1 × 1011 to -2 × 108 dyne/cm2 that in turn depends strongly on the processing conditions, and the film becomes stress free at a unique combination of sputtering pressure and reactive gas composition. Raman spectroscopy and photoluminescence (PL) analyses identified the origin of stress as lattice distortion due to defects introduced in the ZnO thin film. FTIR study reveals that Zn-O bond becomes stronger with the increase in oxygen fraction in the reactive gas mixture. The lattice distortion or stress depends on the type of defects introduced during deposition. PL spectra show the formation of a shoulder in band emission with an increase in the processing pressure and are related to the presence of stress. The ratio of band emission to defect emission decreases with the increase in oxygen percentage from 50 to 100%. The studies show a correlation of stress with the structural, vibrational, and photoluminescence properties of the ZnO thin film. The systematic study of the stress will help in the fabrication of efficient devices based on ZnO film.

Characterizations of photoconductivity of graphene oxide thin films

Directory of Open Access Journals (Sweden)

Shiang-Kuo Chang-Jian

2012-06-01

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

Bonding topologies in diamondlike amorphous-carbon films

International Nuclear Information System (INIS)

Siegal, M. P.; Provencio, P. N.; Tallant, D. R.; Simpson, R. L.; Kleinsorge, B.; Milne, W. I.

2000-01-01

The carbon ion energy used during filtered cathodic vacuum arc deposition determines the bonding topologies of amorphous-carbon (a-C) films. Regions of relatively low density occur near the substrate/film and film/surface interfaces; their thicknesses increase with deposition energy. The ion subplantation growth results in mass density gradients in the bulk portion of a-C in the growth direction; density decreases with distance from the substrate for films grown using ion energies 160 eV. Films grown between these energies are the most diamondlike with relatively uniform bulk density and the highest optical transparencies. Bonding topologies evolve with increasing growth energy consistent with the propagation of subplanted carbon ions inducing a partial transformation of σ- to π-bonded carbon atoms. (c) 2000 American Institute of Physics

Development of neutron diffuse scattering analysis code by thin film and multilayer film

International Nuclear Information System (INIS)

Soyama, Kazuhiko

2004-01-01

To research surface structure of thin film and multilayer film by neutron, a neutron diffuse scattering analysis code using DWBA (Distorted-Wave Bron Approximation) principle was developed. Subjects using this code contain the surface and interface properties of solid/solid, solid/liquid, liquid/liquid and gas/liquid, and metal, magnetism and polymer thin film and biomembran. The roughness of surface and interface of substance shows fractal self-similarity and its analytical model is based on DWBA theory by Sinha. The surface and interface properties by diffuse scattering are investigated on the basis of the theoretical model. The calculation values are proved to be agreed with the experimental values. On neutron diffuse scattering by thin film, roughness of surface of thin film, correlation function, neutron propagation by thin film, diffuse scattering by DWBA theory, measurement model, SDIFFF (neutron diffuse scattering analysis program by thin film) and simulation results are explained. On neutron diffuse scattering by multilayer film, roughness of multilayer film, principle of diffuse scattering, measurement method and simulation examples by MDIFF (neutron diffuse scattering analysis program by multilayer film) are explained. (S.Y.)To research surface structure of thin film and multilayer film by neutron, a neutron diffuse scattering analysis code using DWBA (Distorted-Wave Bron Approximation) principle was developed. Subjects using this code contain the surface and interface properties of solid/solid, solid/liquid, liquid/liquid and gas/liquid, and metal, magnetism and polymer thin film and biomembran. The roughness of surface and interface of substance shows fractal self-similarity and its analytical model is based on DWBA theory by Sinha. The surface and interface properties by diffuse scattering are investigated on the basis of the theoretical model. The calculation values are proved to be agreed with the experimental values. On neutron diffuse scattering

Aquatic biofouling prevention by electrically charged nanocomposite polymer thin film membranes.

Science.gov (United States)

de Lannoy, Charles-François; Jassby, David; Gloe, Katie; Gordon, Alexander D; Wiesner, Mark R

2013-03-19

Electrically conductive polymer-nanocomposite (ECPNC) tight nanofiltration (NF) thin film membranes were demonstrated to have biofilm-preventing capabilities under extreme bacteria and organic material loadings. A simple route to the creation and application of these polyamide-carbon nanotube thin films is also reported. These thin films were characterized with SEM and TEM as well as FTIR to demonstrate that the carbon nanotubes are embedded within the polyamide and form ester bonds with trimesoyl chloride, one of the monomers of polyamide. These polymer nanocomposite thin film materials boast high electrical conductivity (∼400 S/m), good NaCl rejection (>95%), and high water permeability. To demonstrate these membranes' biofouling capabilities, we designed a cross-flow water filtration vessel with insulated electrical leads connecting the ECPNC membranes to an arbitrary waveform generator. In all experiments, conducted in highly bacterially contaminated LB media, flux tests were run until fluxes decreased by 45 ± 3% over initial flux. Biofilm-induced, nonreversible flux decline was observed in all control experiments and a cross-flow rinse with the feed solution failed to induce flux recovery. In contrast, flux decrease for the ECPNC membranes with an electric potential applied to their surface was only caused by deposition of bacteria rather than bacterial attachment, and flux was fully recoverable following a short rinse with the feed solution and no added cleaning agents. The prevention of biofilm formation on the ECPNC membranes was a long-term effect, did not decrease with use, and was highly reproducible.

Thin film tritium dosimetry

Science.gov (United States)

Moran, Paul R.

1976-01-01

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

Z-scan measurement for nonlinear absorption property of rGO/ZnO:Al thin film

Science.gov (United States)

Sreeja, V. G.; Anila, E. I.

2018-04-01

We report the fabrication of reduced graphene oxide integrated aluminium doped zinc oxide (rGO/ZnO:Al) composite thin film on a glass substrate by spin coating technique. The effect of rGO on structural and linear optical properties of rGO/ZnO:Al composite thin film was explored with the help of X-Ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and UV-Vis absorption spectroscopy. Structural studies reveals that the composite film has hexagonal wurtzite structure with a strong bonding between rGO and ZnO:Al material. The band gap energy of ZnO:Al thin film was red shifted by the addition of rGO. The Nonlinear absorption property was investigated by open aperture Z-scan technique by using Q switched Nd-YAG laser at 532nm. The Z-scan results showed that the composite film demonstrates reverse saturable absorption property with a nonlinear absorption coefficient, β, of 12.75×10-7m/w. The results showed that investigated rGO/ZnO:Al thin film is a promising material suitable for the applications in absorbing type optical devices such as optical limiters, optical switches and protection of the optical sensors in the field of nonlinear optics.

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.

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

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.

Optical characterisation of sputtered hydrogenated amorphous silicon thin films

International Nuclear Information System (INIS)

Mellassi, K.; Chafik El Idrissi, M.; Chouiyakh, A.; Rjeb, A.; Barhdadi, A.

2000-09-01

The present work is devoted to the study of some optical properties of hydrogenated amorphous silicon (a-Si:H) thin films prepared by radio-frequency cathodic sputtering technique. It is essentially focused on investigating separately the effects of increasing partial hydrogen pressure during the deposition stage, and the effects of post deposition thermal annealing on the main optical parameters of the deposited layers (refraction index, optical gap Urbach energy, etc.). We show that low hydrogen pressures allow a saturation of the dangling bonds in the material, while high pressures lead to the creation of new defects. We also show that thermal annealing under moderate temperatures allows a good improvement of the structural quality of deposited films. (author)

The effect of air thinning on dentin adhesive bond strength.

Science.gov (United States)

Hilton, T J; Schwartz, R S

1995-01-01

The purpose of this study was to determine if air thinning three dentin adhesives would affect bond strength to dentin. Ninety human molars were mounted in acrylic and the occlusal surfaces ground to expose a flat dentin surface. Thirty teeth were randomly assigned to one of the following dentin bonding agent/composite combinations: A) Universal Bond 3/TPH (Caulk), B) All-Bond 2/Bis-Fil-P (Bisco), and C) Scotchbond Multi-Purpose/Z-100 (3m). The primers were applied following the manufacturers' instructions. The adhesives were applied by two methods. A thin layer of adhesive was applied with a brush to 15 specimens in each group and light cured. Adhesive was brushed on to the remaining 15 teeth in the group, air thinned for 3 seconds, and then polymerized. The appropriate composite was applied in 2 mm increments and light cured utilizing a 5 mm-in-diameter split Teflon mold. Following 3 months of water storage, all groups were shear tested to failure on an Instron Universal Testing Machine. Bond strength was significantly higher in all groups when the dentin bonding agent was painted on without being air thinned. Scotchbond Multi-Purpose had significantly higher bond strength than All-Bond 2, which had significantly higher bond strength than Universal Bond 3.

Operating method of amorphous thin film semiconductor element

Energy Technology Data Exchange (ETDEWEB)

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

1988-05-31

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

Temperature dependence of LRE-HRE-TM thin films

Science.gov (United States)

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

2003-04-01

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

Growth and characterization of nitrogen-doped TiO2 thin films prepared by reactive pulsed laser deposition

International Nuclear Information System (INIS)

Sauthier, G.; Ferrer, F.J.; Figueras, A.; Gyoergy, E.

2010-01-01

Nitrogen-doped titanium dioxide (TiO 2 ) thin films were grown on (001) SiO 2 substrates by reactive pulsed laser deposition. A KrF* excimer laser source (λ = 248 nm, τ FWHM ≅ 10 ns, ν = 10 Hz) was used for the irradiations of pressed powder targets composed by both anatase and rutile phase TiO 2 . The experiments were performed in a controlled reactive atmosphere consisting of oxygen or mixtures of oxygen and nitrogen gases. The obtained thin film crystal structure was investigated by X-ray diffraction, while their chemical composition as well as chemical bonding states between the elements were studied by X-ray photoelectron spectroscopy. An interrelation was found between nitrogen concentration, crystalline structure, bonding states between the elements, and the formation of titanium oxinitride compounds. Moreover, as a result of the nitrogen incorporation in the films a continuous red-shift of the optical absorption edge accompanied by absorption in the visible spectral range between 400 and 500 nm wavelength was observed.

Application-related properties of giant magnetostrictive thin films

International Nuclear Information System (INIS)

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

2002-01-01

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

Preparation of LiMn2O4 cathode thin films for thin film lithium secondary batteries by a mist CVD process

International Nuclear Information System (INIS)

Tadanaga, Kiyoharu; Yamaguchi, Akihiro; Sakuda, Atsushi; Hayashi, Akitoshi; Tatsumisago, Masahiro; Duran, Alicia; Aparacio, Mario

2014-01-01

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

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

Origin of stress in radio frequency magnetron sputtered zinc oxide thin films

International Nuclear Information System (INIS)

Menon, Rashmi; Gupta, Vinay; Sreenivas, K.; Tan, H. H.; Jagadish, C.

2011-01-01

Highly c-axis oriented ZnO thin films have been deposited on silicon substrates by planar rf magnetron sputtering under varying pressure (10-50 mTorr) and oxygen percentage (50-100%) in the reactive gas (Ar + O 2 ) mixture. The as-grown films were found to be stressed over a wide range from -1 x 10 11 to -2 x 10 8 dyne/cm 2 that in turn depends strongly on the processing conditions, and the film becomes stress free at a unique combination of sputtering pressure and reactive gas composition. Raman spectroscopy and photoluminescence (PL) analyses identified the origin of stress as lattice distortion due to defects introduced in the ZnO thin film. FTIR study reveals that Zn-O bond becomes stronger with the increase in oxygen fraction in the reactive gas mixture. The lattice distortion or stress depends on the type of defects introduced during deposition. PL spectra show the formation of a shoulder in band emission with an increase in the processing pressure and are related to the presence of stress. The ratio of band emission to defect emission decreases with the increase in oxygen percentage from 50 to 100%. The studies show a correlation of stress with the structural, vibrational, and photoluminescence properties of the ZnO thin film. The systematic study of the stress will help in the fabrication of efficient devices based on ZnO film.

Effect of native oxide layers on copper thin-film tensile properties: A reactive molecular dynamics study

Energy Technology Data Exchange (ETDEWEB)

Skarlinski, Michael D., E-mail: michael.skarlinski@rochester.edu [Materials Science Program, University of Rochester, Rochester, New York 14627 (United States); Quesnel, David J. [Materials Science Program, University of Rochester, Rochester, New York 14627 (United States); Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627 (United States)

2015-12-21

Metal-oxide layers are likely to be present on metallic nano-structures due to either environmental exposure during use, or high temperature processing techniques such as annealing. It is well known that nano-structured metals have vastly different mechanical properties from bulk metals; however, difficulties in modeling the transition between metallic and ionic bonding have prevented the computational investigation of the effects of oxide surface layers. Newly developed charge-optimized many body [Liang et al., Mater. Sci. Eng., R 74, 255 (2013)] potentials are used to perform fully reactive molecular dynamics simulations which elucidate the effects that metal-oxide layers have on the mechanical properties of a copper thin-film. Simulated tensile tests are performed on thin-films while using different strain-rates, temperatures, and oxide thicknesses to evaluate changes in yield stress, modulus, and failure mechanisms. Findings indicate that copper-thin film mechanical properties are strongly affected by native oxide layers. The formed oxide layers have an amorphous structure with lower Cu-O bond-densities than bulk CuO, and a mixture of Cu{sub 2}O and CuO charge character. It is found that oxidation will cause modifications to the strain response of the elastic modulii, producing a stiffened modulii at low temperatures (<75 K) and low strain values (<5%), and a softened modulii at higher temperatures. While under strain, structural reorganization within the oxide layers facilitates brittle yielding through nucleation of defects across the oxide/metal interface. The oxide-free copper thin-film yielding mechanism is found to be a tensile-axis reorientation and grain creation. The oxide layers change the observed yielding mechanism, allowing for the inner copper thin-film to sustain an FCC-to-BCC transition during yielding. The mechanical properties are fit to a thermodynamic model based on classical nucleation theory. The fit implies that the oxidation of the

Effect of substrate temperature on corrosion performance of nitrogen doped amorphous carbon thin films in NaCl solution

Energy Technology Data Exchange (ETDEWEB)

Khun, N.W. [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Liu, E., E-mail: MEJLiu@ntu.edu.s [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

2009-07-01

Nitrogen doped amorphous carbon (a-C:N) thin films were deposited on p-Si substrates by DC magnetron sputtering at varying substrate temperature from room temperature (RT) to 300 {sup o}C. The bonding structure, surface morphology and adhesion strength of the a-C:N films were investigated by using X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, atomic force microscopy (AFM) and micro-scratch testing. The corrosion behavior of the a-C:N films was evaluated by potentiodynamic polarization test in a 0.6 M NaCl solution. The results indicated that the corrosion resistance of the films depended on the sp{sup 3}-bonded cross-link structure that was significantly affected by the substrate temperature.

Effect of substrate temperature on corrosion performance of nitrogen doped amorphous carbon thin films in NaCl solution

International Nuclear Information System (INIS)

Khun, N.W.; Liu, E.

2009-01-01

Nitrogen doped amorphous carbon (a-C:N) thin films were deposited on p-Si substrates by DC magnetron sputtering at varying substrate temperature from room temperature (RT) to 300 o C. The bonding structure, surface morphology and adhesion strength of the a-C:N films were investigated by using X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, atomic force microscopy (AFM) and micro-scratch testing. The corrosion behavior of the a-C:N films was evaluated by potentiodynamic polarization test in a 0.6 M NaCl solution. The results indicated that the corrosion resistance of the films depended on the sp 3 -bonded cross-link structure that was significantly affected by the substrate temperature.

Semiconductor-nanocrystal/conjugated polymer thin films

Science.gov (United States)

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

2014-06-17

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

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...

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.

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

Novel chemical analysis for thin films

International Nuclear Information System (INIS)

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

1991-01-01

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

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.

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.

Thin films: Past, present, future

Energy Technology Data Exchange (ETDEWEB)

Zweibel, K

1995-04-01

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

Non-linear optics of nano-scale pentacene thin film

Science.gov (United States)

Yahia, I. S.; Alfaify, S.; Jilani, Asim; Abdel-wahab, M. Sh.; Al-Ghamdi, Attieh A.; Abutalib, M. M.; Al-Bassam, A.; El-Naggar, A. M.

2016-07-01

We have found the new ways to investigate the linear/non-linear optical properties of nanostructure pentacene thin film deposited by thermal evaporation technique. Pentacene is the key material in organic semiconductor technology. The existence of nano-structured thin film was confirmed by atomic force microscopy and X-ray diffraction. The wavelength-dependent transmittance and reflectance were calculated to observe the optical behavior of the pentacene thin film. It has been observed the anomalous dispersion at wavelength λ 800. The non-linear refractive index of the deposited films was investigated. The linear optical susceptibility of pentacene thin film was calculated, and we observed the non-linear optical susceptibility of pentacene thin film at about 6 × 10-13 esu. The advantage of this work is to use of spectroscopic method to calculate the liner and non-liner optical response of pentacene thin films rather than expensive Z-scan. The calculated optical behavior of the pentacene thin films could be used in the organic thin films base advanced optoelectronic devices such as telecommunications devices.

Oxidation of ruthenium thin films using atomic oxygen

Energy Technology Data Exchange (ETDEWEB)

McCoy, A.P.; Bogan, J.; Brady, A.; Hughes, G.

2015-12-31

In this study, the use of atomic oxygen to oxidise ruthenium thin films is assessed. Atomic layer deposited (ALD) ruthenium thin films (~ 3 nm) were exposed to varying amounts of atomic oxygen and the results were compared to the impact of exposures to molecular oxygen. X-ray photoelectron spectroscopy studies reveal substantial oxidation of metallic ruthenium films to RuO{sub 2} at exposures as low as ~ 10{sup 2} L at 575 K when atomic oxygen was used. Higher exposures of molecular oxygen resulted in no metal oxidation highlighting the benefits of using atomic oxygen to form RuO{sub 2}. Additionally, the partial oxidation of these ruthenium films occurred at temperatures as low as 293 K (room temperature) in an atomic oxygen environment. - Highlights: • X-ray photoelectron spectroscopy study of the oxidation of Ru thin films • Oxidation of Ru thin films using atomic oxygen • Comparison between atomic oxygen and molecular oxygen treatments on Ru thin films • Fully oxidised RuO{sub 2} thin films formed with low exposures to atomic oxygen.

Deposition and characterization of aluminum magnesium boride thin film coatings

Science.gov (United States)

Tian, Yun

Boron-rich borides are a special group of materials possessing complex structures typically comprised of B12 icosahedra. All of the boron-rich borides sharing this common structural unit exhibit a variety of exceptional physical and electrical properties. In this work, a new ternary boride compound AlMgB14, which has been extensively studied in bulk form due to its novel mechanical properties, was fabricated into thin film coatings by pulsed laser deposition (PLD) technology. The effect of processing conditions (laser operating modes, vacuum level, substrate temperature, and postannealing, etc.) on the composition, microstructure evolution, chemical bonding, and surface morphology of AlMgB14 thin film coatings has been investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectrometry; the mechanical, electrical, and optical properties of AlMgB14 thin films have been characterized by nanoindentation, four-point probe, van der Pauw Hall measurement, activation energy measurement, and UV-VIS-NIR spectrophotometer. Experimental results show that AlMgB14 films deposited in the temperature range of 300 K - 873 K are amorphous. Depositions under a low vacuum level (5 x 10-5 Torr) can introduce a significant amount of C and O impurities into AlMgB14 films and lead to a complex oxide glass structure. Orthorhombic AlMgB14 phase cannot be obtained by subsequent high temperature annealing. By contrast, the orthorhombic AlMgB 14 crystal structure can be attained via high temperature-annealing of AlMgB14 films deposited under a high vacuum level (boride films, high vacuum level-as deposited AlMgB14 films also possess a low n-type electrical resistivity, which is a consequence of high carrier concentration and moderate carrier mobility. The operative electrical transport mechanism and doping behavior for high vacuum level-as deposited AlMgB14

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.

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

Remarkable changes in interface O vacancy and metal-oxide bonds in amorphous indium-gallium-zinc-oxide thin-film transistors by long time annealing at 250 °C

International Nuclear Information System (INIS)

Chowdhury, Md Delwar Hossain; Um, Jae Gwang; Jang, Jin

2014-01-01

We have studied the effect of long time post-fabrication annealing on negative bias illumination stress (NBIS) of amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film-transistors. Annealing for 100 h at 250 °C increased the field effect mobility from 14.7 cm 2 /V s to 17.9 cm 2 /V s and reduced the NBIS instability remarkably. Using X-ray photoelectron spectroscopy, the oxygen vacancy and OH were found to exist at the interfaces of a-IGZO with top and bottom SiO 2 . Long time annealing helps to decrease the vacancy concentration and increase the metal-oxygen bonds at the interfaces; this leads to increase in the free carrier concentrations in a-IGZO and field-effect mobility. X-ray reflectivity measurement indicated the increment of a-IGZO film density of 5.63 g cm −3 to 5.83 g cm −3 (3.4% increase) by 100 h annealing at 250 °C. The increase in film density reveals the decrease of O vacancy concentration and reduction of weak metal-oxygen bonds in a-IGZO, which substantially helps to improve the NBIS stability

TaN interface properties and electric field cycling effects on ferroelectric Si-doped HfO2 thin films

International Nuclear Information System (INIS)

Lomenzo, Patrick D.; Nishida, Toshikazu; Takmeel, Qanit; Zhou, Chuanzhen; Fancher, Chris M.; Jones, Jacob L.; Lambers, Eric; Rudawski, Nicholas G.; Moghaddam, Saeed

2015-01-01

Ferroelectric HfO 2 -based thin films, which can exhibit ferroelectric properties down to sub-10 nm thicknesses, are a promising candidate for emerging high density memory technologies. As the ferroelectric thickness continues to shrink, the electrode-ferroelectric interface properties play an increasingly important role. We investigate the TaN interface properties on 10 nm thick Si-doped HfO 2 thin films fabricated in a TaN metal-ferroelectric-metal stack which exhibit highly asymmetric ferroelectric characteristics. To understand the asymmetric behavior of the ferroelectric characteristics of the Si-doped HfO 2 thin films, the chemical interface properties of sputtered TaN bottom and top electrodes are probed with x-ray photoelectron spectroscopy. Ta-O bonds at the bottom electrode interface and a significant presence of Hf-N bonds at both electrode interfaces are identified. It is shown that the chemical heterogeneity of the bottom and top electrode interfaces gives rise to an internal electric field, which causes the as-grown ferroelectric domains to preferentially polarize to screen positively charged oxygen vacancies aggregated at the oxidized bottom electrode interface. Electric field cycling is shown to reduce the internal electric field with a concomitant increase in remanent polarization and decrease in relative permittivity. Through an analysis of pulsed transient switching currents, back-switching is observed in Si-doped HfO 2 thin films with pinched hysteresis loops and is shown to be influenced by the internal electric field

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...

High-density plasma etching characteristics of indium-gallium-zinc oxide thin films in CF4/Ar plasma

International Nuclear Information System (INIS)

Joo, Young-Hee; Kim, Chang-Il

2015-01-01

We investigated the etching process of indium-gallium-zinc oxide (IGZO) thin films in an inductively coupled plasma system. The dry etching characteristics of the IGZO thin films were studied by varying the CF 4 /Ar gas mixing ratio, RF power, DC-bias voltage, and process pressure. We determined the following optimized process conditions: an RF power of 700 W, a DC-bias voltage of − 150 V, and a process pressure of 2 Pa. A maximum etch rate of 25.63 nm/min for the IGZO thin films was achieved in a plasma with CF 4 /Ar(= 25:75), and the selectivity of IGZO to Al and TiN was found to be 1.3 and 0.7, respectively. We determined the ionic composition of the CF 4 /Ar plasma using optical emission spectroscopy. Analysis of chemical reactions at the IGZO thin film surfaces was performed using X-ray photoelectron spectroscopy. - Highlights: • IGZO thin film was etched by CF 4 /Ar plasma as a function of gas mixing ratio. • IGZO bonds were broken Ar + sputtering and then reacted with the C-F x radicals. • The physical sputtering is dominant in etch control compared with chemical etching

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.

Effect of oxygen deficiency on electronic properties and local structure of amorphous tantalum oxide thin films

Energy Technology Data Exchange (ETDEWEB)

Denny, Yus Rama [Department of Physics Education, University of Sultan Ageng Tirtayasa, Banten 42435 (Indonesia); Firmansyah, Teguh [Department of Electrical Engineering, University of Sultan Ageng Tirtayasa, Banten 42435 (Indonesia); Oh, Suhk Kun [Department of Physics, Chungbuk National University, Cheongju 28644 (Korea, Republic of); Kang, Hee Jae, E-mail: hjkang@cbu.ac.kr [Department of Physics, Chungbuk National University, Cheongju 28644 (Korea, Republic of); Yang, Dong-Seok [Department of Physics Education, Chungbuk National University, Cheongju 28644 (Korea, Republic of); Heo, Sung; Chung, JaeGwan; Lee, Jae Cheol [Analytical Engineering Center, Samsung Advanced Institute of Technology, Suwon 16678 (Korea, Republic of)

2016-10-15

Highlights: • The effect of oxygen flow rate on electronic properties and local structure of tantalum oxide thin films was studied. • The oxygen deficiency induced the nonstoichiometric state a-TaOx. • A small peak at 1.97 eV above the valence band side appeared on nonstoichiometric Ta{sub 2}O{sub 5} thin films. • The oxygen flow rate can change the local electronic structure of tantalum oxide thin films. - Abstract: The dependence of electronic properties and local structure of tantalum oxide thin film on oxygen deficiency have been investigated by means of X-ray photoelectron spectroscopy (XPS), Reflection Electron Energy Loss Spectroscopy (REELS), and X-ray absorption spectroscopy (XAS). The XPS results showed that the oxygen flow rate change results in the appearance of features in the Ta 4f at the binding energies of 23.2 eV, 24.4 eV, 25.8, and 27.3 eV whose peaks are attributed to Ta{sup 1+}, Ta{sup 2+}, Ta{sup 3+}/Ta{sup 4+}, and Ta{sup 5+}, respectively. The presence of nonstoichiometric state from tantalum oxide (TaOx) thin films could be generated by the oxygen vacancies. In addition, XAS spectra manifested both the increase of coordination number of the first Ta-O shell and a considerable reduction of the Ta-O bond distance with the decrease of oxygen deficiency.

Photoinduced hydrophobic surface of graphene oxide thin films

International Nuclear Information System (INIS)

Zhang Xiaoyan; Song Peng; Cui Xiaoli

2012-01-01

Graphene oxide (GO) thin films were deposited on transparent conducting oxide substrates and glass slides by spin coating method at room temperature. The wettability of GO thin films before and after ultraviolet (UV) irradiation was characterized with water contact angles, which increased from 27.3° to 57.6° after 3 h of irradiation, indicating a photo-induced hydrophobic surface. The UV–vis absorption spectra, Raman spectroscopy, X-ray photoelectron spectroscopy, and conductivity measurements of GO films before and after UV irradiation were taken to study the mechanism of photoinduced hydrophobic surface of GO thin films. It is demonstrated that the photoinduced hydrophobic surface is ascribed to the elimination of oxygen-containing functional groups on GO molecules. This work provides a simple strategy to control the wettability properties of GO thin films by UV irradiation. - Highlights: ► Photoinduced hydrophobic surface of graphene oxide thin films has been demonstrated. ► Elimination of oxygen-containing functional groups in graphene oxide achieved by UV irradiation. ► We provide novel strategy to control surface wettability of GO thin films by UV irradiation.

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)

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...

Interfacial slippage effect on the surface instability of a thin elastic film under van der Waals force

International Nuclear Information System (INIS)

Pan Xiahui; Yu Shouwen; Feng Xiqiao; Huang Shiqing

2009-01-01

This paper studies the surface instability of an elastic thin solid film lying on a rigid substrate and subjected to van der Waals-like surface interactions. The effect of film-substrate interfacial slippage is accounted for by using a simplified linear cohesive interface model. It is found that the interfacial slippage generally plays a destabilizing role in the surface instability of the thin film. For highly compressible films with Poisson's ratio smaller than 0.25, the surface wrinkling behaviour previously inconceivable in the case of a perfectly bonded interface is now feasible if film-substrate interface slipping is permitted. In addition, our linear perturbation analysis shows that the critical conditions for the onset of surface instability can be modulated by adjusting the slippery stiffness of the interface. The result might be helpful for developing novel techniques to create micro-/nanosized surface patterns.

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

Self-organized nanocrack networks: a pathway to enlarge catalytic surface area in sputtered ceramic thin films, showcased for photocatalytic TiO2

Science.gov (United States)

Henkel, B.; Vahl, A.; Aktas, O. C.; Strunskus, T.; Faupel, F.

2018-01-01

Sputter deposited photocatalytic thin films offer high adherence and mechanical stability, but typically are outperformed in their photocatalytic properties by colloidal TiO2 nanostructures, which in turn typically suffer from problematic removal. Here we report on thermally controlled nanocrack formation as a feasible and batch applicable approach to enhance the photocatalytic performance of well adhering, reactively sputtered TiO2 thin films. Networks of nanoscopic cracks were induced into tailored columnar TiO2 thin films by thermal annealing. These deep trenches are separating small bundles of TiO2 columns, adding their flanks to the overall catalytically active surface area. The variation of thin film thickness reveals a critical layer thickness for initial nanocrack network formation, which was found to be about 400 nm in case of TiO2. The columnar morphology of the as deposited TiO2 layer with weak bonds between respective columns and with strong bonds to the substrate is of crucial importance for the formation of nanocrack networks. A beneficial effect of nanocracking on the photocatalytic performance was experimentally observed. It was correlated by a simple geometric model for explaining the positive impact of the crack induced enlargement of active surface area on photocatalytic efficiency. The presented method of nanocrack network formation is principally not limited to TiO2 and is therefore seen as a promising candidate for utilizing increased surface area by controlled crack formation in ceramic thin films in general.

Preparation of Oleyl Phosphate-Modified TiO2/Poly(methyl methacrylate Hybrid Thin Films for Investigation of Their Optical Properties

Directory of Open Access Journals (Sweden)

Masato Fujita

2015-01-01

Full Text Available TiO2 nanoparticles (NPs modified with oleyl phosphate were synthesized through stable Ti–O–P bonds and were utilized to prepare poly(methyl methacrylate- (PMMA- based hybrid thin films via the ex situ route for investigation of their optical properties. After surface modification of TiO2 NPs with oleyl phosphate, IR and 13C CP/MAS NMR spectroscopy showed the presence of oleyl groups. The solid-state 31P MAS NMR spectrum of the product revealed that the signal due to oleyl phosphate (OP shifted upon reaction, indicating formation of covalent Ti–O–P bonds. The modified TiO2 NPs could be homogeneously dispersed in toluene, and the median size was 16.1 nm, which is likely to be sufficient to suppress Rayleigh scattering effectively. The TEM images of TiO2/PMMA hybrid thin films also showed a homogeneous dispersion of TiO2 NPs, and they exhibited excellent optical transparency even though the TiO2 content was 20 vol%. The refractive indices of the OP-modified TiO2/PMMA hybrid thin films changed higher with increases in TiO2 volume fraction, and the hybrid thin film with 20 vol% of TiO2 showed the highest refractive index (n = 1.86.

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.

Influence of precursor concentration on physical properties of CdO thin films prepared by spray pyrolysis technique using nebulizer

Energy Technology Data Exchange (ETDEWEB)

Anitha, M.; Amalraj, L.; Anitha, N. [Virudhunagar Hindu Nadar' s Senthikumara Nadar College (Autonomous), Department of Physics, Virudhunagar, Tamilnadu (India)

2017-12-15

Cadmium oxide (CdO) thin films were prepared with different concentrations of precursor solution (0.05, 0.1, 0.15, 0.2 and 0.25 M, respectively) at the optimized temperature (200 C) using the nebulized spray pyrolysis technique to obtain better crystallinity in polycrystalline thin films on amorphous glass substrates. The XRD characterization of those samples revealed a preferential orientation along the (111) plane having a cubic structure. The scanning electron microscopy (SEM) analysis displayed that all the as-deposited thin films have spherical shaped grains. The transmittance of the as-deposited CdO thin films had decreased from 88 to 71% for longer wavelength regions (600-900 nm) as the precursor concentration had increased and then increased for higher precursor concentration. The optical band gap was found to lie between 2.45 and 2.40 eV belonging to direct transition for those thin films. The presence of Cd-O bond (540 cm{sup -1}) was confirmed by FTIR spectrum. The emission properties of CdO thin films were studied by luminescence spectrum recorded at room temperature. A maximum carrier concentration and minimum resistivity values of 4.743 x 10{sup 19} cm{sup -3} and 1.06 x 10{sup -3} Ω-cm, respectively, were obtained for 0.2 M precursor concentration. These CdO thin films have high optical transmittance and high room temperature conductivity, which can be used as the TCO and Solar cell (window layer) material. (orig.)

Influence of the radio-frequency power on the physical and optical properties of plasma polymerized cyclohexane thin films

Energy Technology Data Exchange (ETDEWEB)

Manaa, C., E-mail: chadlia.el.manaa@gmail.com [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); Lejeune, M. [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Kouki, F. [Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); Durand-Drouhin, O. [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Bouchriha, H. [Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); and others

2014-06-02

We investigate in the present study the effects of the radio-frequency plasma power on the opto-electronical properties of the polymeric amorphous hydrogenated carbon thin films deposited at room temperature and different radio-frequency powers by plasma-enhanced chemical vapor deposition method using cyclohexane as precursor. A combination of U.V.–Visible and infrared transmission measurements is applied to characterize the bonding and electronic properties of these films. Some film properties namely surface roughness, contact angle, surface energy, and optical properties are found to be significantly influenced by the radio-frequency power. The changes in these properties are analyzed within the microstructural modifications occurring during growth. - Highlights: • Effects of the radio-frequency power on the optoelectronic properties of thin films • Elaboration of plasma polymerized thin films using cyclohexane as precursor gas • The use of U.V.–Visible-infrared transmission, and optical gap • Study of the surface topography of the films by using Atomic Force microscopy • The use of a capacitively coupled plasma enhanced chemical vapor deposition method.

Influence of the radio-frequency power on the physical and optical properties of plasma polymerized cyclohexane thin films

International Nuclear Information System (INIS)

Manaa, C.; Lejeune, M.; Kouki, F.; Durand-Drouhin, O.; Bouchriha, H.

2014-01-01

We investigate in the present study the effects of the radio-frequency plasma power on the opto-electronical properties of the polymeric amorphous hydrogenated carbon thin films deposited at room temperature and different radio-frequency powers by plasma-enhanced chemical vapor deposition method using cyclohexane as precursor. A combination of U.V.–Visible and infrared transmission measurements is applied to characterize the bonding and electronic properties of these films. Some film properties namely surface roughness, contact angle, surface energy, and optical properties are found to be significantly influenced by the radio-frequency power. The changes in these properties are analyzed within the microstructural modifications occurring during growth. - Highlights: • Effects of the radio-frequency power on the optoelectronic properties of thin films • Elaboration of plasma polymerized thin films using cyclohexane as precursor gas • The use of U.V.–Visible-infrared transmission, and optical gap • Study of the surface topography of the films by using Atomic Force microscopy • The use of a capacitively coupled plasma enhanced chemical vapor deposition method

Electrical and optical properties of a n-type ZnO thin film deposited on a Si substrate by using a double RF Co-sputtering method

Energy Technology Data Exchange (ETDEWEB)

Lee, Jonghyun; Choi, Wonjoon; Kim, Chaeok; Hong, Jinpyo; Nahm, Tschanguh [Hanyang University, Seoul (Korea, Republic of); Cheong, Hyeonsik [Sogang University, Seoul (Korea, Republic of)

2006-09-15

Outstanding n-type ZnO thin films were prepared on Si substrates by utilizing a double RF cosputtering method. Our unique double RF technique has many attractive merits for synthesizing ZnO thin films with excellent optoelectronic properties at various temperatures. The ZnO thin films were also post-annealed at various temperatures. The X-ray diffraction patterns and X-ray photoelectron spectroscopy indicated well-grown ZnO films with a (002) orientation and with gorgeous chemically bond states, respectively. In addition, photoluminescence measurements indicated a band-gap of 3.4 eV in the ZnO films. The scanning electron microscopy images showed that the as-grown ZnO thin film had hexagonal column shapes, such as hexagonal rods. The ZnO film exhibited an UV light response with a cut-off wavelength of {approx}370 nm at room temperature.

Durability Evaluation of a Thin Film Sensor System With Enhanced Lead Wire Attachments on SiC/SiC Ceramic Matrix Composites

Science.gov (United States)

Lei, Jih-Fen; Kiser, J. Douglas; Singh, Mrityunjay; Cuy, Mike; Blaha, Charles A.; Androjna, Drago

2000-01-01

An advanced thin film sensor system instrumented on silicon carbide (SiC) fiber reinforced SiC matrix ceramic matrix composites (SiC/SiC CMCs), was evaluated in a Mach 0.3 burner rig in order to determine its durability to monitor material/component surface temperature in harsh environments. The sensor system included thermocouples in a thin film form (5 microns thick), fine lead wires (75 microns diameter), and the bonds between these wires and the thin films. Other critical components of the overall system were the heavy, swaged lead wire cable (500 microns diameter) that contained the fine lead wires and was connected to the temperature readout, and ceramic attachments which were bonded onto the CMCs for the purpose of securing the lead wire cables, The newly developed ceramic attachment features a combination of hoops made of monolithic SiC or SiC/SiC CMC (which are joined to the test article) and high temperature ceramic cement. Two instrumented CMC panels were tested in a burner rig for a total of 40 cycles to 1150 C (2100 F). A cycle consisted of rapid heating to 1150 C (2100 F), a 5 minute hold at 1150 C (2100 F), and then cooling down to room temperature in 2 minutes. The thin film sensor systems provided repeatable temperature measurements for a maximum of 25 thermal cycles. Two of the monolithic SiC hoops debonded during the sensor fabrication process and two of the SiC/SiC CMC hoops failed during testing. The hoops filled with ceramic cement, however, showed no sign of detachment after 40 thermal cycle test. The primary failure mechanism of this sensor system was the loss of the fine lead wire-to-thin film connection, which either due to detachment of the fine lead wires from the thin film thermocouples or breakage of the fine wire.

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.

On the structural and optical properties of sputtered hydrogenated amorphous silicon thin films

International Nuclear Information System (INIS)

Barhdadi, A.; Chafik El ldrissi, M.

2002-08-01

The present work is essentially focused on the study of optical and structural properties of hydrogenated amorphous silicon thin films (a-Si:H) prepared by radio-frequency cathodic sputtering. We examine separately the influence of hydrogen partial pressure during film deposition, and the effect of post-deposition thermal annealings on the main optical characteristics of the layers such as refraction index, optical gap and Urbach energy. Using the grazing X-rays reflectometry technique, thin film structural properties are examined immediately after films deposition as well as after surface oxidation or annealing. We show that low hydrogen pressures allow a saturation of dangling bonds in the layers, while high doses lead to the creation of new defects. We show also that thermal annealing under moderate temperatures improves the structural quality of the deposited layers. For the films examined just after deposition, the role of hydrogen appears in the increase of their density. For those analysed after a short stay in the ambient, hydrogen plays a protective role against the oxidation of their surfaces. This role disappears for a long time stay in the ambient. (author)

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.

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.

Thin films of molecular materials synthesized from C32H20N10M (M Co, Pb, Fe): Film formation, electrical and optical properties

International Nuclear Information System (INIS)

Rodriguez, A.; Sanchez Vergara, M.E.; Garcia Montalvo, V.; Ortiz, A.; Alvarez, J.R.

2010-01-01

In this work, the synthesis of molecular materials formed from metallic phthalocyanines and 1,4-phenylenediamine is reported. The powder and thin film (∼80-115 nm thickness) samples of the synthesized materials, deposited by vacuum thermal evaporation, show the same intra-molecular bonds in the IR spectroscopy studies, which suggests that the thermal evaporation process does not alter these bonds. The morphology of the deposited films was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM) and their optical and electrical properties were studied as well. The optical parameters have been investigated using spectrophotometric measurements of transmittance in the wavelength range 200-1200 nm. The absorption spectra recorded in the UV-vis region for the deposited samples showed two bands, namely the Q and Soret bands. The optical activation energy was calculated and found to be 3.41 eV for the material with cobalt, 3.34 eV for the material including lead and 3.5 eV for the material with iron. The effect of temperature on conductivity was measured for the thin films and the corresponding conduction processes are discussed in this work.

Bonding topologies in diamondlike amorphous-carbon films

Energy Technology Data Exchange (ETDEWEB)

SIEGAL,MICHAEL P.; PROVENCIO,PAULA P.; TALLANT,DAVID R.; SIMPSON,REGINA L.; KLEINSORGE,B.; MILNE,W.I.

2000-01-27

The carbon ion energy used during filtered cathodic vacuum arc deposition determines the bonding topologies of amorphous-carbon (a-C) films. Regions of relatively low density occur near the substrate/film and film/surface interfaces and their thicknesses increase with increasing deposition energy. The ion subplantation growth results in mass density gradients in the bulk portion of a-C in the growth direction; density decreases with distance from the substrate for films grown using ion energies < 60 eV and increases for films grown using ion energies > 160 eV. Films grown between these energies are the most diamondlike with relatively uniform bulk density and the highest optical transparencies. Bonding topologies evolve with increasing growth energy consistent with the propagation of subplanted carbon ions inducing a partial transformation of 4-fold to 3-fold coordinated carbon atoms.

High-density plasma etching characteristics of indium-gallium-zinc oxide thin films in CF{sub 4}/Ar plasma

Energy Technology Data Exchange (ETDEWEB)

Joo, Young-Hee; Kim, Chang-Il

2015-05-29

We investigated the etching process of indium-gallium-zinc oxide (IGZO) thin films in an inductively coupled plasma system. The dry etching characteristics of the IGZO thin films were studied by varying the CF{sub 4}/Ar gas mixing ratio, RF power, DC-bias voltage, and process pressure. We determined the following optimized process conditions: an RF power of 700 W, a DC-bias voltage of − 150 V, and a process pressure of 2 Pa. A maximum etch rate of 25.63 nm/min for the IGZO thin films was achieved in a plasma with CF{sub 4}/Ar(= 25:75), and the selectivity of IGZO to Al and TiN was found to be 1.3 and 0.7, respectively. We determined the ionic composition of the CF{sub 4}/Ar plasma using optical emission spectroscopy. Analysis of chemical reactions at the IGZO thin film surfaces was performed using X-ray photoelectron spectroscopy. - Highlights: • IGZO thin film was etched by CF{sub 4}/Ar plasma as a function of gas mixing ratio. • IGZO bonds were broken Ar{sup +} sputtering and then reacted with the C-F{sub x} radicals. • The physical sputtering is dominant in etch control compared with chemical etching.

Zirconium doped TiO{sub 2} thin films deposited by chemical spray pyrolysis

Energy Technology Data Exchange (ETDEWEB)

Juma, A. [Laboratory of Thin Film Chemical Technologies, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Department of Physics and Astronomy, Botswana International University of Science and Technology, Private bag 16, Palapye (Botswana); Oja Acik, I., E-mail: ilona.oja@ttu.ee [Laboratory of Thin Film Chemical Technologies, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Oluwabi, A.T.; Mere, A. [Laboratory of Thin Film Chemical Technologies, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Mikli, V.; Danilson, M. [Chair of Semiconductor Materials Technology, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Krunks, M. [Laboratory of Thin Film Chemical Technologies, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia)

2016-11-30

Highlights: • Mean crystallite size of TiO{sub 2}:Zr film decreases with increasing [Zr] in the solution. • Zr doping supresses the anatase to rutile transformation process in TiO{sub 2} films. • Band gap of TiO{sub 2}:Zr film is 3.4 eV irrespective of the annealing temperature. - Abstract: Chemical spray pyrolysis (CSP) is a flexible deposition technique that allows for mixing of the precursor solutions in different proportions suitable for doping thin films. The CSP method was used to dope TiO{sub 2} thin films with Zr by adding zirconium(IV) acetylacetonate into a solution of titanium(IV) isopropoxide in ethanol stabilized by acetylacetone at [Zr]/[Ti] of 0, 5, 10 and 20 at%. The Zr-doped TiO{sub 2} thin films were uniform and homogeneous showing much smaller grains than the undoped TiO{sub 2} films. Zr stabilized the anatase phase to temperatures above 800 °C depending on Zr concentration in the spray solution. The concentration of Zr determined by XPS was 6.4 at% for the thin film deposited from the 20 at% solution. According to AFM studies, Zr doping decreased the root mean square roughness of TiO{sub 2} film from 5.9 to 1.1 nm. An XRD study of samples with the highest Zr amount showed the ZrTiO{sub 4} phase started forming after annealing at 800 °C. The optical band gap for TiO{sub 2} decreased from 3.3 eV to 3.0 eV after annealing at 800 °C but for the TiO{sub 2}:Zr(20) film it remained at 3.4 eV. The dielectric constant increased by more than four times with Zr-doping and this was associated with the change in the bond formations caused by substitution of Ti by Zr in the lattice.

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.

Epitaxial growth and electronic structure of oxyhydride SrVO2H thin films

Science.gov (United States)

Katayama, Tsukasa; Chikamatsu, Akira; Yamada, Keisuke; Shigematsu, Kei; Onozuka, Tomoya; Minohara, Makoto; Kumigashira, Hiroshi; Ikenaga, Eiji; Hasegawa, Tetsuya

2016-08-01

Oxyhydride SrVO2H epitaxial thin films were fabricated on SrTiO3 substrates via topotactic hydridation of oxide SrVO3 films using CaH2. Structural and composition analyses suggested that the SrVO2H film possessed one-dimensionally ordered V-H--V bonds along the out-of-plane direction. The synthesis temperature could be lowered by reducing the film thickness, and the SrVO2H film was reversible to SrVO3 by oxidation through annealing in air. Photoemission and X-ray absorption spectroscopy measurements revealed the V3+ valence state in the SrVO2H film, indicating that the hydrogen existed as hydride. Furthermore, the electronic density of states was highly suppressed at the Fermi energy, consistent with the prediction that tetragonal distortion induces metal to insulation transition.

Mechanism of bonding and debonding using surface activated bonding method with Si intermediate layer

Science.gov (United States)

Takeuchi, Kai; Fujino, Masahisa; Matsumoto, Yoshiie; Suga, Tadatomo

2018-04-01

Techniques of handling thin and fragile substrates in a high-temperature process are highly required for the fabrication of semiconductor devices including thin film transistors (TFTs). In our previous study, we proposed applying the surface activated bonding (SAB) method using Si intermediate layers to the bonding and debonding of glass substrates. The SAB method has successfully bonded glass substrates at room temperature, and the substrates have been debonded after heating at 450 °C, in which TFTs are fabricated on thin glass substrates for LC display devices. In this study, we conducted the bonding and debonding of Si and glass in order to understand the mechanism in the proposed process. Si substrates are also successfully bonded to glass substrates at room temperature and debonded after heating at 450 °C using the proposed bonding process. By the composition analysis of bonding interfaces, it is clarified that the absorbed water on the glass forms interfacial voids and cause the decrease in bond strength.

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

Resistivity of thiol-modified gold thin films

Energy Technology Data Exchange (ETDEWEB)

Correa-Puerta, Jonathan [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Av. Universidad 330, Curauma, Valparaíso (Chile); Del Campo, Valeria [Departamento de Física, Universidad Técnica Federico Santa María, Av. España 1680, Valparaiso 2390123 (Chile); Henríquez, Ricardo, E-mail: ricardo.henriquez@usm.cl [Departamento de Física, Universidad Técnica Federico Santa María, Av. España 1680, Valparaiso 2390123 (Chile); Häberle, Patricio [Departamento de Física, Universidad Técnica Federico Santa María, Av. España 1680, Valparaiso 2390123 (Chile)

2014-11-03

In this work, we study the effect of thiol self assembled monolayers on the electrical resistivity of metallic thin films. The analysis is based on the Fuchs–Sondheimer–Lucas theory and on electrical transport measurements. We determined resistivity change due to dodecanethiol adsorption on gold thin films. For this purpose, we controlled the deposition and annealing temperatures of the films to change the surface topography and to diminish the effect of electron grain boundary scattering. Results show that the electrical response to the absorption of thiols strongly depends on the initial topography of the surface. - Highlights: • We study the effect of self assembled monolayers on the resistivity of thin films. • Fuchs–Sondheimer theory reproduces the resistivity increase due to thiol deposition. • We determined resistivity change due to dodecanethiol deposition on gold thin films. • The electrical response strongly depends on the substrate surface topography.

Structural and optical studies of 100 MeV Au irradiated thin films of tin oxide

Science.gov (United States)

Jaiswal, Manoj Kumar; Kanjilal, D.; Kumar, Rajesh

2013-11-01

Thin films of tin(IV) oxide (SnO2) of 100 nm thickness were grown on silicon (1 0 0) matrices by electron beam evaporation deposition technique under high vacuum. The thicknesses of these films were monitored by piezo-sensor attached to the deposition chamber. Nanocrystallinity is achieved in these thin films by 100 MeV Au8+ using 1 pnA current at normal incidence with ion fluences varying from 1 × 1011 ions/cm2 to 5 × 1013 ions/cm2. Swift Heavy Ion beam irradiation was carried out by using 15 UD Pelletron Accelerator at IUAC, New Delhi, India. Optical studies of pristine and ion irradiated thin films were characterized by UV-Visible spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy. Prominent peak at 610 cm-1 in FTIR spectrum confirmed the O-Sn-O bonding of tin(IV) oxide. For Surface topographical studies and grain size calculations, these films were characterized by Atomic Force Microscope (AFM) using Nanoscope III-A. Crystallinity and phase transformation due to irradiation of pristine and irradiated films were characterized by Glancing Angle X-ray Diffraction (GAXRD) using Brucker-D8 advance model. GAXRD results show improvement in crystallinity and phase transformation due to swift heavy ion irradiation. Grain size distribution was verified by AFM and GAXRD results. Swift heavy ion induced modifications in thin films of SnO2 were confirmed by the presence of prominent peaks at 2θ values of 30.65°, 32.045°, 43.94°, 44.96° and 52.36° in GAXRD spectrum.

Effects of substrate temperature on structural and electrical properties of SiO2-matrix boron-doped silicon nanocrystal thin films

International Nuclear Information System (INIS)

Huang, Junjun; Zeng, Yuheng; Tan, Ruiqin; Wang, Weiyan; Yang, Ye; Dai, Ning; Song, Weijie

2013-01-01

In this work, silicon-rich SiO 2 (SRSO) thin films were deposited at different substrate temperatures (T s ) and then annealed by rapid thermal annealing to form SiO 2 -matrix boron-doped silicon-nanocrystals (Si-NCs). The effects of T s on the micro-structure and electrical properties of the SiO 2 -matrix boron-doped Si-NC thin films were investigated using Raman spectroscopy and Hall measurements. Results showed that the crystalline fraction and dark conductivity of the SiO 2 -matrix boron-doped Si-NC thin films both increased significantly when the T s was increased from room temperature to 373 K. When the T s was further increased from 373 K to 676 K, the crystalline fraction of 1373 K-annealed thin films decreased from 52.2% to 38.1%, and the dark conductivity reduced from 8 × 10 −3 S/cm to 5.5 × 10 −5 S/cm. The changes in micro-structure and dark conductivity of the SiO 2 -matrix boron-doped Si-NC thin films were most possibly due to the different amount of Si-O 4 bond in the as-deposited SRSO thin films. Our work indicated that there was an optimal T s , which could significantly increase the crystallization and conductivity of Si-NC thin films. Also, it was illumined that the low-resistivity SiO 2 -matrix boron-doped Si-NC thin films can be achieved under the optimal substrate temperatures, T s .

Simultaneous thermal stability and phase change speed improvement of Sn15Sb85 thin film through erbium doping

Science.gov (United States)

Zou, Hua; Zhu, Xiaoqin; Hu, Yifeng; Sui, Yongxing; Sun, Yuemei; Zhang, Jianhao; Zheng, Long; Song, Zhitang

2016-12-01

In general, there is a trade off between the phase change speed and thermal stability in chalcogenide phase change materials, which leads to sacrifice the one in order to ensure the other. For improving the performance, doping is a widely applied technological process. Here, we fabricated Er doped Sn15Sb85 thin films by magnetron sputtering. Compared with the pure Sn15Sb85, we show that Er doped Sn15Sb85 thin films exhibit simultaneous improvement over the thermal stability and the phase change speed. Thus, our results suggest that Er doping provides the opportunity to solve the contradiction. The main reason for improvement of both thermal stability and crystallization speed is due to the existence of Er-Sb and Er-Sn bonds in Er doped Sn15Sb85 films. Hence, Er doped Sn15Sb85 thin films are promising candidates for the phase change memory application, and this method could be extended to other lanthanide-doped phase change materials.

Investigation of corrosion behavior of nitrogen doped and platinum/ruthenium doped diamond-like carbon thin films in Hank's solution

International Nuclear Information System (INIS)

Khun, N.W.; Liu, E.

2011-01-01

Undoped (DLC), nitrogen-doped (N-DLC) and platinum/ruthenium doped diamond-like carbon (PtRu-DLC) thin films were deposited on p-Si (100) substrates using a DC magnetron sputtering deposition system. The chemical composition, bonding structure, surface morphology and adhesion strength of the films were characterized using X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, atomic force microscopy (AFM) and micro-scratch test, respectively. The corrosion behavior of the films in a Hank's solution was investigated using potentiodynamic polarization test. The corrosion results revealed that the PtRu-DLC film had the highest corrosion potential among the films used in this study. Highlights: → DLC thin films were deposited on Si substrates via dc magnetron sputtering. → Some DLC films were doped with N and/or Pt/Ru. → The film corrosion behavior was studied in a Hank solution with polarization test. → The PtRu-DLC film showed the highest corrosion potential among the films studied.

Influence of Thin-Film Adhesives in Pullout Tests Between Nickel-Titanium Shape Memory Alloy and Carbon Fiber-Reinforced Polymer Matrix Composites

Science.gov (United States)

Quade, Derek J.; Jana, Sadhan; McCorkle, Linda S.

2018-01-01

Strips of nickel-titanium (NiTi) shape memory alloy (SMA) and carbon fiber-reinforced polymer matrix composite (PMC) were bonded together using multiple thin film adhesives and their mechanical strengths were evaluated under pullout test configuration. Tensile and lap shear tests were conducted to confirm the deformation of SMAs at room temperature and to evaluate the adhesive strength between the NiTi strips and the PMC. Optical and scanning electron microscopy techniques were used to examine the interfacial bonding after failure. Simple equations on composite tensile elongation were used to fit the experimental data on tensile properties. ABAQUS models were generated to show the effects of enhanced bond strength and the distribution of stress in SMA and PMC. The results revealed that the addition of thin film adhesives increased the average adhesive strength between SMA and PMC while halting the room temperature shape memory effect within the pullout specimen.

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-08-15

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

Morphology and oxygen incorporation effect on antimicrobial activity of silver thin films

Energy Technology Data Exchange (ETDEWEB)

Rebelo, Rita, E-mail: ritarebelo@det.uminho.pt [2C2T, University of Minho, Campus de Azurém, 4800-058 Guimarães (Portugal); GRF-CFUM, University of Minho, Campus de Azurém, 4800-058 Guimarães (Portugal); CEB, Center for Biological Engineering, LIBRO—Laboratório de Biofilmes Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-335 Braga (Portugal); Manninen, N.K. [GRF-CFUM, University of Minho, Campus de Azurém, 4800-058 Guimarães (Portugal); SEG-CEMUC, University of Coimbra, 3030-788 Coimbra (Portugal); Fialho, Luísa [GRF-CFUM, University of Minho, Campus de Azurém, 4800-058 Guimarães (Portugal); Henriques, Mariana [CEB, Center for Biological Engineering, LIBRO—Laboratório de Biofilmes Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-335 Braga (Portugal); Carvalho, Sandra [GRF-CFUM, University of Minho, Campus de Azurém, 4800-058 Guimarães (Portugal); SEG-CEMUC, University of Coimbra, 3030-788 Coimbra (Portugal)

2016-05-15

Highlights: • Ag and Ag{sub x}O thin films were deposited by non-reactive and reactive pulsed DC magnetron sputtering. • Coatings were characterized chemically, physically and structurally. • In order to verify the antibacterial behavior of the coatings, halo inhibition zone tests were realized for Staphylococcus epidermidis and Staphylococcus aureus. • Ag{sub x}O coating presented antibacterial behavior. - Abstract: Ag and Ag{sub x}O thin films were deposited by non-reactive and reactive pulsed DC magnetron sputtering, respectively, with the final propose of functionalizing the SS316L substrate with antibacterial properties. The coatings were characterized chemically, physically and structurally. The coatings nanostructure was assessed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), while the coatings morphology was determined by scanning electron microscopy (SEM). The XRD and XPS analyses suggested that Ag thin film is composed by metallic Ag, which crystallizes in fcc-Ag phase, while the Ag{sub x}O thin film showed both metallic Ag and Ag−O bonds, which crystalize in fcc-Ag and silver oxide phases. The SEM results revealed that Ag thin film formed a continuous layer, while Ag{sub x}O layer was composed of islands with hundreds of nanometers surrounded by small nanoparticles with tens of nanometers. The surface wettability and surface tension parameters were determined by contact angle measurements, being found that Ag and Ag{sub x}O surfaces showed very similar behavior, with all the surfaces showing a hydrophobic character. In order to verify the antibacterial behavior of the coatings, halo inhibition zone tests were realized for Staphylococcus epidermidis and Staphylococcus aureus. Ag coatings did not show antibacterial behavior, contrarily to Ag{sub x}O coating, which presented antibacterial properties against the studied bacteria. The presence of silver oxide phase along with the development of different morphology was

Characterization of nanocrystalline cadmium telluride thin films ...

Indian Academy of Sciences (India)

Unknown

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

Photoluminescence properties of perovskite multilayer thin films

Energy Technology Data Exchange (ETDEWEB)

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

2016-07-01

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

Optical characteristics of the thin-film scintillator detector

International Nuclear Information System (INIS)

Muga, L.; Burnsed, D.

1976-01-01

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

Influence of Ge addition on the morphology and properties of TiN thin films deposited by magnetron sputtering

International Nuclear Information System (INIS)

Sandu, C.S.; Sanjines, R.; Benkahoul, M.; Parlinska-Wojtan, M.; Karimi, A.; Levy, F.

2006-01-01

Thin films of TM-X-N (TM stands for early transition metal and X = Si, Al, etc.) are used as protective coatings. The most investigated among the ternary composite systems is Ti-Si-N. The system Ti-Ge-N has been chosen to extend the knowledge about the formation of nanocomposite films. Ti-Ge-N thin films were deposited by reactive magnetron sputtering on Si and WC-Co substrates at T s = 240 deg. C, from confocal Ti and Ge targets in mixed Ar/N 2 atmosphere. The nitrogen partial pressure and the power on the Ti target were kept constant, while the power on the Ge target was varied in order to obtain various Ge concentrations in the films. No presence of Ge-N bonds was detected, while X-ray photoelectron spectroscopy measurements revealed the presence of Ti-Ge bonds. Transmission Electron Microscopy investigations have shown important changes induced by Ge addition in the morphology and structure of Ti-Ge-N films. Electron Energy-Loss Spectrometry study revealed a significant increase of Ge content at the grain boundaries. The segregation of Ge atoms to the TiN crystallite surface appears to be responsible for limitation of crystal growth and formation of a TiGe y amorphous phase

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-05-01

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

Fractal and multifractal analysis of LiF thin film surface

International Nuclear Information System (INIS)

Yadav, R.P.; Dwivedi, S.; Mittal, A.K.; Kumar, M.; Pandey, A.C.

2012-01-01

Highlights: ► Fractal and multifractal analysis of surface morphologies of the LiF thin films. ► Complexity and roughness of the LiF thin films increases as thickness increases. ► LiF thin films are multifractal in nature. ► Strength of the multifractality increases with thickness of the film. - Abstract: Fractal and multifractal analysis is performed on the atomic force microscopy (AFM) images of the surface morphologies of the LiF thin films of thickness 10 nm, 20 nm, and 40 nm, respectively. Autocorrelation function, height–height correlation function, and two-dimensional multifractal detrended fluctuation analysis (MFDFA) are used for characterizing the surface. It is found that the interface width, average roughness, lateral correlation length, and fractal dimension of the LiF thin film increase with the thickness of the film, whereas the roughness exponent decreases with thickness. Thus, the complexity and roughness of the LiF thin films increases as thickness increases. It is also demonstrated that the LiF thin films are multifractal in nature. Strength of the multifractality increases with thickness of the film.

Properties of amorphous silicon thin films synthesized by reactive particle beam assisted chemical vapor deposition

International Nuclear Information System (INIS)

Choi, Sun Gyu; Wang, Seok-Joo; Park, Hyeong-Ho; Jang, Jin-Nyoung; Hong, MunPyo; Kwon, Kwang-Ho; Park, Hyung-Ho

2010-01-01

Amorphous silicon thin films were formed by chemical vapor deposition of reactive particle beam assisted inductively coupled plasma type with various reflector bias voltages. During the deposition, the substrate was heated at 150 o C. The effects of reflector bias voltage on the physical and chemical properties of the films were systematically studied. X-ray diffraction and Raman spectroscopy results showed that the deposited films were amorphous and the films under higher reflector voltage had higher internal energy to be easily crystallized. The chemical state of amorphous silicon films was revealed as metallic bonding of Si atoms by using X-ray photoelectron spectroscopy. An increase in reflector voltage induced an increase of surface morphology of films and optical bandgap and a decrease of photoconductivity.

Growth of amorphous TeOx (2≤x≤3) thin film by radio frequency sputtering

International Nuclear Information System (INIS)

Dewan, Namrata; Gupta, Vinay; Sreenivas, K.; Katiyar, R. S.

2007-01-01

Thin films of Tellurium oxide TeO x over a wide range of x (2 to 3) were prepared by radio frequency diode sputtering at room temperature on corning glass and quartz substrate. The deposited films are amorphous in nature and IR spectroscopy reveals the formation of Te-O bond. X-ray photoelectron spectroscopy shows the variation in the stoichiometry of TeO x film from x=2 to 3 with an increase in oxygen percentage (25 to 100%) in processing sputtering gas composition. Raman spectroscopy depicts the formation of TeO 3 trigonal pyramid besides TeO 4 disphenoid in the amorphous TeO x film with increase in the value of x. The varying stoichiometry of TeO x thin film (x=2 to 3) was found to influence the optical, electrical, and elastic properties. The optical band gap of film increases from 3.8 to 4.2 eV with increasing x and is attributed to the decrease in density. The elastic constants (C 11 and C 44 ) of the deposited films are lower than the corresponding value reported for TeO 2 single crystal

Preparation and characterization of vanadium oxide thin films

Energy Technology Data Exchange (ETDEWEB)

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

2013-04-16

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

Laser nanostructuring of ZnO thin films

Energy Technology Data Exchange (ETDEWEB)

Nedyalkov, N., E-mail: nned@ie.bas.bg [Department of Electronics and Electrical Engineering, Keio University, 3-14-1 Hiyoshi Kohoku-ku, Yokohama-shi, Kanagawa-ken 223-8522 (Japan); Institute of Electronics, Bulgarian Academy of Sciences, Tzarigradsko shousse 72, Sofia 1784 (Bulgaria); Koleva, M.; Nikov, R.; Atanasov, P. [Institute of Electronics, Bulgarian Academy of Sciences, Tzarigradsko shousse 72, Sofia 1784 (Bulgaria); Nakajima, Y.; Takami, A.; Shibata, A.; Terakawa, M. [Department of Electronics and Electrical Engineering, Keio University, 3-14-1 Hiyoshi Kohoku-ku, Yokohama-shi, Kanagawa-ken 223-8522 (Japan)

2016-06-30

Highlights: • Nanosecond laser pulse nanostructuring of ZnO thin films on metal substrate is demonstrated. • Two regimes of the thin film modification are observed depending on the applied laser fluence. • At high fluence regime the ZnO film is homogeneously decomposed into nanosized particles. • The characteristic size of the formed nanostructures corresponds to the domain size of the thin film. - Abstract: In this work, results on laser processing of thin zinc oxide films deposited on metal substrate are presented. ZnO films are obtained by classical nanosecond pulsed laser deposition method in oxygen atmosphere on tantalum substrate. The produced films are then processed by nanosecond laser pulses at wavelength of 355 nm. The laser processing parameters and the film thickness are varied and their influence on the fabricated structures is estimated. The film morphology after the laser treatment is found to depend strongly on the laser fluence as two regimes are defined. It is shown that at certain conditions (high fluence regime) the laser treatment of the film leads to formation of a discrete nanostructure, composed of spherical like nanoparticles with narrow size distribution. The dynamics of the melt film on the substrate and fast cooling are found to be the main mechanisms for fabrication of the observed structures. The demonstrated method is an alternative way for direct fabrication of ZnO nanostructures on metal which can be easy implemented in applications as resistive sensor devices, electroluminescent elements, solar cell technology.

Remarkable changes in interface O vacancy and metal-oxide bonds in amorphous indium-gallium-zinc-oxide thin-film transistors by long time annealing at 250 °C

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, Md Delwar Hossain; Um, Jae Gwang; Jang, Jin, E-mail: jjang@khu.ac.kr [Advanced Display Research Center and Department of Information Display, Kyung Hee University, Seoul 130-701 (Korea, Republic of)

2014-12-08

We have studied the effect of long time post-fabrication annealing on negative bias illumination stress (NBIS) of amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film-transistors. Annealing for 100 h at 250 °C increased the field effect mobility from 14.7 cm{sup 2}/V s to 17.9 cm{sup 2}/V s and reduced the NBIS instability remarkably. Using X-ray photoelectron spectroscopy, the oxygen vacancy and OH were found to exist at the interfaces of a-IGZO with top and bottom SiO{sub 2}. Long time annealing helps to decrease the vacancy concentration and increase the metal-oxygen bonds at the interfaces; this leads to increase in the free carrier concentrations in a-IGZO and field-effect mobility. X-ray reflectivity measurement indicated the increment of a-IGZO film density of 5.63 g cm{sup −3} to 5.83 g cm{sup −3} (3.4% increase) by 100 h annealing at 250 °C. The increase in film density reveals the decrease of O vacancy concentration and reduction of weak metal-oxygen bonds in a-IGZO, which substantially helps to improve the NBIS stability.

Effect of Precursor Concentration on Structural Optical and Electrical Properties of NiO Thin Films Prepared by Spray Pyrolysis

Directory of Open Access Journals (Sweden)

Rafia Barir

2017-01-01

Full Text Available Undoped nickel oxide (NiO thin films were deposited on 500°C heated glass substrates using spray pyrolysis method at (0.015–0.1 M range of precursor. The latter was obtained by decomposition of nickel nitrate hexahydrate in double distilled water. Effect of precursor concentration on structural, optical, and electrical properties of NiO thin films was investigated. X-ray diffraction (XRD shows the formation of NiO under cubic structure with single diffraction peak along (111 plane at 2θ=37.24°. When precursor concentration reaches 0.1 M, an increment in NiO crystallite size over 37.04 nm was obtained indicating the product nano structure. SEM images reveal that beyond 0.04 M as precursor concentration the substrate becomes completely covered with NiO and thin films exhibit formation of nano agglomerations at the top of the sample surface. Ni-O bonds vibrations modes in the product of films were confirmed by FT-IR analysis. Transparency of the films ranged from 57 to 88% and band gap energy of the films decreases from 3.68 to 3.60 eV with increasing precursor concentration. Electrical properties of the elaborated NiO thin films were correlated to the precursor concentration.

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...

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...

Linear and nonlinear optical properties of Sb-doped GeSe2 thin films

Science.gov (United States)

Zhang, Zhen-Ying; Chen, Fen; Lu, Shun-Bin; Wang, Yong-Hui; Shen, Xiang; Dai, Shi-Xun; Nie, Qiu-Hua

2015-06-01

Sb-doped GeSe2 chalcogenide thin films are prepared by the magnetron co-sputtering method. The linear optical properties of as-deposited films are derived by analyzing transmission spectra. The refractive index rises and the optical band gap decreases from 2.08 eV to 1.41 eV with increasing the Sb content. X-ray photoelectron spectra further confirm the formation of a covalent Sb-Se bond. The third-order nonlinear optical properties of thin films are investigated under femtosecond laser excitation at 800 nm. The results show that the third-order nonlinear optical properties are enhanced with increasing the concentration of Sb. The nonlinear refraction indices of these thin films are measured to be on the order of 10-18 m2/W with a positive sign and the nonlinear absorption coefficients are obtained to be on the order of 10-10 m/W. These excellent properties indicate that Sb-doped Ge-Se films have a good prospect in the applications of nonlinear optical devices. Project supported by the National Key Basic Research Program of China (Grant No. 2012CB722703), the National Natural Science Foundation of China (Grant No. 61377061), the Young Leaders of Academic Climbing Project of the Education Department of Zhejiang Province, China (Grant No. pd2013092), the Program for Innovative Research Team of Ningbo City, China (Grant No. 2009B217), and the K. C. Wong Magna Fund in Ningbo University, China.

Nanosphere lithography applied to magnetic thin films

Science.gov (United States)

Gleason, Russell

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

Bandtail characteristics in InN thin films

International Nuclear Information System (INIS)

Shen, W.Z.; Jiang, L.F.; Yang, H.F.; Meng, F.Y.; Ogawa, H.; Guo, Q.X.

2002-01-01

The Urbach bandtail characteristics in InN thin films grown by radio-frequency magnetron sputtering on sapphire (0001) substrates have been investigated both theoretically and experimentally. The bandtail parameter in InN thin films has been obtained by temperature-dependent transmission spectra, with the aid of a detailed calculation of the transmission profile. A bandtail model based on the calculation of density of occupied states and the carrier-phonon interaction has been employed to analyze the temperature-dependent bandtail characteristics. The bandtail parameter is in the range of 90-120 meV in the InN thin film. It is found that the carrier-phonon interaction in InN is weak and the structural disorder contribution (∼90 meV) dominates over the interactive terms. The high structural disorder in InN thin films may relate to the high nonradiative recombination centers

Thin films of mixed metal compounds

Science.gov (United States)

Mickelsen, Reid A.; Chen, Wen S.

1985-01-01

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

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.

Preparation and properties of antimony thin film anode materials

Institute of Scientific and Technical Information of China (English)

SU Shufa; CAO Gaoshao; ZHAO Xinbing

2004-01-01

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

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.

Chemical vapour deposition of thin-film dielectrics

International Nuclear Information System (INIS)

Vasilev, Vladislav Yu; Repinsky, Sergei M

2005-01-01

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

Residual stress in spin-cast polyurethane thin films

Energy Technology Data Exchange (ETDEWEB)

Zhang, Hong; Zhang, Li, E-mail: lizhang@mae.cuhk.edu.hk [Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin N.T., Hong Kong (China); Chow Yuk Ho Technology Centre for Innovative Medicine, The Chinese University of Hong Kong, Shatin N.T., Hong Kong (China)

2015-01-19

Residual stress is inevitable during spin-casting. Herein, we report a straightforward method to evaluate the residual stress in as-cast polyurethane thin films using area shrinkage measurement of films in floating state, which shows that the residual stress is independent of radial location on the substrate and decreased with decreasing film thickness below a critical value. We demonstrate that the residual stress is developed due to the solvent evaporation after vitrification during spin-casting and the polymer chains in thin films may undergo vitrification at an increased concentration. The buildup of residual stress in spin-cast polymer films provides an insight into the size effects on the nature of polymer thin films.

Tunable silver-shell dielectric core nano-beads array for thin-film solar cell application

Energy Technology Data Exchange (ETDEWEB)

Chou Chau, Yuan-Fong, E-mail: a0920146302@gmail.com, E-mail: chou.fong@ubd.edu.bn; Lim, Chee Ming [Universiti Brunei Darussalam, Centre for Advanced Material and Energy Sciences (Brunei) (Brunei Darussalam); Chiang, Chien-Ying [National Taipei University of Technology, Department of Electro-Optical Engineering (China); Voo, Nyuk Yoong; Muhammad Idris, Nur Syafi’ie; Chai, Siew Ung [Universiti Brunei Darussalam, Centre for Advanced Material and Energy Sciences (Brunei) (Brunei Darussalam)

2016-04-15

The absorbance spectra of thin-film solar cells (TFSCs) can be enhanced by constructing the tunable periodic Ag-shell nano-bead (PASNB) arrays in the active material. In this paper, we investigated a plasmonic thin-film solar cell (TFSC) which composed of the arrays of PASNB deposited onto a crystalline silicon layer. By performing three-dimensional finite element method, we demonstrate that near field coupling among the PASNB arrays results in SPR modes with enhanced absorbance and field intensity. The proposed structure can significantly enhance the plasmonic activity in a wide range of incident light and enlarge working wavelength of absorbance in the range of near-UV, visible and near-infrared. We show that the sensitivity of the PASNB arrays reveals a linear relationship with the thickness of Ag-shell nano-bead (ASNB) for both the anti-bonding and bonding modes in the absorbance spectra. The broadband of absorbance spectra could be expanded as a wide range by varying the thickness of ASNB while the particle size is kept constant. Simulation results suggest this alternative scheme to the design and improvements on plasmonic enhanced TFSCs can be extended to other nanophotonic applications.

Electronic excitation induced modifications of optical and morphological properties of PCBM thin films

Energy Technology Data Exchange (ETDEWEB)

Sharma, T. [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Singhal, R., E-mail: rsinghal.phy@mnit.ac.in [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Vishnoi, R. [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Department of Physics, Vardhman (P.G.) College, Bijnor 246701, U.P. (India); Sharma, P. [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Patra, A.; Chand, S. [National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012 (India); Lakshmi, G.B.V.S. [Inter University Accelerator Centre, Post Box No. 10502, New Delhi 110067 (India); Biswas, S.K. [Department of Metallurgical and Materials Engineering, Malaviya National Institute of Technology, Jaipur 302017 (India)

2016-07-15

Highlights: • Spin casted PCBM thin films are irradiated by 90 MeV Ni{sup 7+} ion beam. • The decrease in band gap was found after irradiation. • There is a decomposition of molecular bond due to ion irradiation. • Roughness is also found to be dependent on incident ion fluence. - Abstract: Phenyl C{sub 61} butyric acid methyl ester (PCBM) is a fullerene derivative and most commonly used in organic photovoltaic devices both as electron acceptor and transporting material due to high electron mobility. PCBM is easy to spin caste on some substrate as it is soluble in chlorobenzene. In this study, the spin coated thin films of PCBM (on two different substrate, glass and double sided silicon) were irradiated using 90 MeV Ni{sup 7+} swift heavy ion beam at low fluences ranging from 1 × 10{sup 9} to 1 × 10{sup 11} ions/cm{sup 2} to study the effect of ion beam irradiation. The pristine and irradiated PCBM thin films were characterized by UV–visible absorption spectroscopy and fourier transform infrared spectroscopy (FTIR) to investigate the optical properties before and after irradiation. These thin films were further analyzed using atomic force microscopy (AFM) to investigate the morphological modifications which are induced by energetic ions. The variation in optical band gap after irradiation was measured using Tauc’s relation from UV–visible absorption spectra. A considerable change was observed with increasing fluence in optical band gap of irradiated thin films of PCBM with respect to the pristine film. The decrease in FTIR band intensity of C{sub 60} cage reveals the polymerization reaction due to high energy ion impact. The roughness is also found to be dependent on incident fluences. This study throws light for the application of PCBM in organic solar cells in form of ion irradiation induced nanowires of PCBM for efficient charge carrier transportation in active layer.

Simulated Thin-Film Growth and Imaging

Science.gov (United States)

Schillaci, Michael

2001-06-01

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

Nanostructured thin films as functional coatings

Energy Technology Data Exchange (ETDEWEB)

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

2010-06-15

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

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.

Thin film ceramic thermocouples

Science.gov (United States)

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

2011-01-01

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

Photoluminescence of electron beam evaporated CaS:Bi thin films

CERN Document Server

Smet, P F; Poelman, D R; Meirhaeghe, R L V

2003-01-01

For the first time, the photoluminescence (PL) of electron beam evaporated CaS:Bi thin films is reported. Luminescent CaS:Bi powder prepared out of aqueous solutions was used as source material. The influence of substrate temperature on the PL and the morphology of thin films is discussed, and an optimum is determined. Substrate temperatures between 200 deg. C and 300 deg. C lead to good quality thin films with sufficient PL intensity. As-deposited thin films show two emission bands, peaking at 450 and 530 nm. Upon annealing the emission intensity increases, and annealing at 800 deg. C is sufficient to obtain a homogeneously blue emitting thin film (CIE colour coordinates (0.17; 0.12)), thanks to a single remaining emission band at 450 nm. The influence of ambient temperature on the PL of CaS:Bi powder and thin films was also investigated and it was found that CaS:Bi thin films show a favourable thermal quenching behaviour near room temperature.

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.

In-situ ATR-FTIR for characterization of thin biorelated polymer films

International Nuclear Information System (INIS)

Müller, M.; Torger, B.; Bittrich, E.; Kaul, E.; Ionov, L.; Uhlmann, P.; Stamm, M.

2014-01-01

We present and review in-situ-attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic data from thin biorelated polymer films useful for the modification and functionalization of polymer and inorganic materials and discuss their applications related to life sciences. A special ATR mirror attachment operated by the single-beam-sample-reference (SBSR) concept and housing a homebuilt thermostatable flow cell was used, which allows for appropriate background compensation and signal to noise ratio. ATR-FTIR data on the reactive deposition of dopamine on inorganic model surfaces are shown. Information on the structure and deposition pathway for such bioinspired melanin-like films is provided. ATR-FTIR data on thermosensitive polymer brushes of poly(N-isopropylacrylamide) (PNIPAAM) is then presented. The thermotropic hydration and hydrogen bonding behavior of PNIPAAM brush films is described. Finally, ATR-FTIR data on biorelated polyelectrolyte multilayers (PEM) are given together with details on PEM growth and detection. Applications of these latter films for biopassivation/activation and local drug delivery are addressed

Structural and optical studies of 100 MeV Au irradiated thin films of tin oxide

Energy Technology Data Exchange (ETDEWEB)

Jaiswal, Manoj Kumar [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110 078 (India); Kanjilal, D. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Kumar, Rajesh, E-mail: rajeshkumaripu@gmail.com [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110 078 (India)

2013-11-01

Thin films of tin(IV) oxide (SnO{sub 2}) of 100 nm thickness were grown on silicon (1 0 0) matrices by electron beam evaporation deposition technique under high vacuum. The thicknesses of these films were monitored by piezo-sensor attached to the deposition chamber. Nanocrystallinity is achieved in these thin films by 100 MeV Au{sup 8+} using 1 pnA current at normal incidence with ion fluences varying from 1 × 10{sup 11} ions/cm{sup 2} to 5 × 10{sup 13} ions/cm{sup 2}. Swift Heavy Ion beam irradiation was carried out by using 15 UD Pelletron Accelerator at IUAC, New Delhi, India. Optical studies of pristine and ion irradiated thin films were characterized by UV–Visible spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy. Prominent peak at 610 cm{sup −1} in FTIR spectrum confirmed the O–Sn–O bonding of tin(IV) oxide. For Surface topographical studies and grain size calculations, these films were characterized by Atomic Force Microscope (AFM) using Nanoscope III-A. Crystallinity and phase transformation due to irradiation of pristine and irradiated films were characterized by Glancing Angle X-ray Diffraction (GAXRD) using Brucker-D8 advance model. GAXRD results show improvement in crystallinity and phase transformation due to swift heavy ion irradiation. Grain size distribution was verified by AFM and GAXRD results. Swift heavy ion induced modifications in thin films of SnO{sub 2} were confirmed by the presence of prominent peaks at 2θ values of 30.65°, 32.045°, 43.94°, 44.96° and 52.36° in GAXRD spectrum.

Effect of ozone treatment on the optical and electrical properties of HfSiO thin films

International Nuclear Information System (INIS)

Geng, Yang; Yang, Wen; Zhu, Shang-Bin; Zhang, Yuan; Sun, Qing-Qing; Lu, Hong-Liang; Zhang, David Wei

2014-01-01

The effect of room temperature ozone oxidation treatment on thin HfSiO film grown by atomic layer deposition (ALD) has been investigated. The optical and electrical properties with different post-ozone oxidation time were characterized. The evolution of ozone interacting with HfSiO films was clearly illuminated. Ozone can repair the lossy chemical bonds and vacancies, resulting in the improvement of packing density and polarizability of HfSiO films. With more ozone entering the HfSiO films, the refractive index, dielectric constant, and interfacial properties can be greatly upgraded. Furthermore, the frequency dispersion of ALD-HfSiO film can be improved after O 3 treatment time for 8 min. (orig.)

Deposition of organosilicone thin film from hexamethyldisiloxane (HMDSO) with 50 kHz/33 MHz dual-frequency atmospheric-pressure plasma jet

Science.gov (United States)

Li, Jiaojiao; Yuan, Qianghua; Chang, Xiaowei; Wang, Yong; Yin, Guiqin; Dong, Chenzhong

2017-04-01

The deposition of organosilicone thin films from hexamethyldisiloxane(HMDSO) by using a dual-frequency (50 kHz/33 MHz) atmospheric-pressure micro-plasma jet with an admixture of a small volume of HMDSO and Ar was investigated. The topography was measured by using scanning electron microscopy. The chemical bond and composition of these films were analyzed by Fourier transform infrared spectroscopy (FTIR) and x-ray photoelectron spectroscopy. The results indicated that the as-deposited film was constituted by silicon, carbon, and oxygen elements, and FTIR suggested the films are organosilicon with the organic component (-CH x ) and hydroxyl functional group(-OH) connected to the Si-O-Si backbone. Thin-film hardness was recorded by an MH-5-VM Digital Micro-Hardness Tester. Radio frequency power had a strong impact on film hardness and the hardness increased with increasing power.

Accurate measurement of the piezoelectric coefficient of thin films by eliminating the substrate bending effect using spatial scanning laser vibrometry

International Nuclear Information System (INIS)

Leighton, Glenn J T; Huang, Zhaorong

2010-01-01

One of the major difficulties in measuring the piezoelectric coefficient d 33,f for thin films is the elimination of the contribution from substrate bending. We show by theoretical analysis and experimental measurements that by bonding thin film piezoelectric samples to a substantial holder, the substrate bending can be minimized to a negligible level. Once the substrate bending can be effectively eliminated, single-beam laser scanning vibrometry can be used to measure the precise strain distribution of a piezoelectric thin film under converse actuation. A significant strain increase toward the inside edge of the top electrode (assuming a fully covered bottom electrode) and a corresponding strain peak in the opposite direction just outside the electrode edge were observed. These peaks were found to increase with the increasing Poisson's ratio and transverse piezoelectric coefficient of the piezoelectric thin film. This is due to the non-continuity of the electric field at the edge of the top electrode, which leads to the concentration of shear stress and electric field in the vicinity of the electrode edge. The measured d 33,f was found to depend not only on the material properties such as the electromechanical coefficients of the piezoelectric thin films and elastic coefficients of the thin film and the substrate, but also on the geometry factors such as the thickness of the piezoelectric films, the dimensions of the electrode, and also the thickness of the substrate

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

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.

Field ion microscope studies on thin films

International Nuclear Information System (INIS)

Cavaleru, A.; Scortaru, A.

1976-01-01

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

Comprehensive review on the development of high mobility in oxide thin film transistors

Science.gov (United States)

Choi, Jun Young; Lee, Sang Yeol

2017-11-01

Oxide materials are one of the most advanced key technology in the thin film transistors (TFTs) for the high-end of device applications. Amorphous oxide semiconductors (AOSs) have leading technique for flat panel display (FPD), active matrix organic light emitting display (AMOLED) and active matrix liquid crystal display (AMLCD) due to their excellent electrical characteristics, such as field effect mobility ( μ FE ), subthreshold swing (S.S) and threshold voltage ( V th ). Covalent semiconductor like amorphous silicon (a-Si) is attributed to the anti-bonding and bonding states of Si hybridized orbitals. However, AOSs have not grain boundary and excellent performances originated from the unique characteristics of AOS which is the direct orbital overlap between s orbitals of neighboring metal cations. High mobility oxide TFTs have gained attractive attention during the last few years and today in display industries. It is progressively developed to increase the mobility either by exploring various oxide semiconductors or by adopting new TFT structures. Mobility of oxide thin film transistor has been rapidly increased from single digit to higher than 100 cm2/V·s in a decade. In this review, we discuss on the comprehensive review on the mobility of oxide TFTs in a decade and propose bandgap engineering and novel structure to enhance the electrical characteristics of oxide TFTs.

Thin film adhesion modification by MeV ions

International Nuclear Information System (INIS)

Sugden, S.

1991-08-01

The adhesion of thin films, and in particular the way in which such adhesion may be improved by irradiation, is rather poorly understood. The radiation enhanced adhesion effect has been investigated through the use of Ultra High Vacuum sample preparation, analysis and irradiation techniques, in order to gain control over surface and interface composition. In the systems studied, Au on Ta, Au on Si and Ag on Si, films deposited on atomically clean surfaces show good adhesion, and no evidence of enhancement due to irradiation is observed in the case of such clean interfaces. The results are entirely consistent with radiation enhanced adhesion being due to radiolytic effects on contaminant containing layers at the film/substrate interface. In addition, on silicon substrates the observations highlight the superiority of thermal cleaning over low energy sputtering as a route for producing a clean surface. A model of the radiation enhanced adhesion observations for dirty interface systems is developed, which takes into account the two dimensional nature of the ion energy deposition process. All the observations on such systems are broadly consistent with an activation energy for the process of approximately 5 eV. This value is sufficiently large to bring about chemical bonding rearrangement at the critical film/substrate interface. (Author)

The Structure and Stability of Molybdenum Ditelluride Thin Films

Directory of Open Access Journals (Sweden)

Zhouling Wang

2014-01-01

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

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

Thin films prepared from tungstate glass matrix

Energy Technology Data Exchange (ETDEWEB)

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

2008-01-30

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

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.

Significant questions in thin liquid film heat transfer

International Nuclear Information System (INIS)

Bankoff, S.G.

1994-01-01

Thin liquid films appear in many contexts, such as the cooling of gas turbine blade tips, rocket engines, microelectronics arrays, and hot fuel element surfaces in hypothetical nuclear reactor accidents. Apart from these direct cooling applications of thin liquid layers, thin films form a crucial element in determining the allowable heat flux limits in boiling. This is because the last stages of dryout almost invariably involve the rupture of a residual liquid film, either as a microlayer underneath the bubbles, or a thin annular layer in a high-quality burnout scenario. The destabilization of these thin films under the combined actions of shear stress, evaporation, and thermocapillary effects is quite complex. The later stages of actual rupture to form dry regions, which then expand, resulting in possible overheating, are even more complex and less well understood. However, significant progress has been made in understanding the behavior of these thin films, which are subject to competing instabilities prior to actual rupture. This will be reviewed briefly. Recent work on the advance, or recession, of contact lines will also be described briefly, and significant questions that still remain to be answered will be discussed. 68 refs., 7 figs

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.

Synthesis and characterization thin films of conductive polymer (PANI) for optoelectronic device application

Science.gov (United States)

Jarad, Amer N.; Ibrahim, Kamarulazizi; Ahmed, Nasser M.

2016-07-01

In this work we report preparation and investigation of structural and optical properties of polyaniline conducting polymer. By using sol-gel in spin coating technique to synthesize thin films of conducting polymer polyaniline (PANI). Conducting polymer polyaniline was synthesized by the chemical oxidative polymerization of aniline monomers. The thin films were characterized by technique: Hall effect, High Resolution X-ray diffraction (HR-XRD), Fourier transform infrared (FTIR) spectroscopy, Field emission scanning electron microscopy (FE-SEM), and UV-vis spectroscopy. Polyaniline conductive polymer exhibit amorphous nature as confirmed by HR-XRD. The presence of characteristic bonds of polyaniline was observed from FTIR spectroscopy technique. Electrical and optical properties revealed that (p-type) conductivity PANI with room temperature, the conductivity was 6.289×10-5 (Ω.cm)-1, with tow of absorption peak at 426,805 nm has been attributed due to quantized size of polyaniline conducting polymer.

Synthesis and characterization thin films of conductive polymer (PANI) for optoelectronic device application

Energy Technology Data Exchange (ETDEWEB)

Jarad, Amer N., E-mail: amer78malay@yahoo.com.my; Ibrahim, Kamarulazizi, E-mail: kamarul@usm.my; Ahmed, Nasser M., E-mail: nas-tiji@yahoo.com [Nano-optoelectronic Research and Technology Laboratory School of physics, University of Sains Malaysia, 11800 Pulau Pinang (Malaysia)

2016-07-06

In this work we report preparation and investigation of structural and optical properties of polyaniline conducting polymer. By using sol-gel in spin coating technique to synthesize thin films of conducting polymer polyaniline (PANI). Conducting polymer polyaniline was synthesized by the chemical oxidative polymerization of aniline monomers. The thin films were characterized by technique: Hall effect, High Resolution X-ray diffraction (HR-XRD), Fourier transform infrared (FTIR) spectroscopy, Field emission scanning electron microscopy (FE-SEM), and UV-vis spectroscopy. Polyaniline conductive polymer exhibit amorphous nature as confirmed by HR-XRD. The presence of characteristic bonds of polyaniline was observed from FTIR spectroscopy technique. Electrical and optical properties revealed that (p-type) conductivity PANI with room temperature, the conductivity was 6.289×10{sup −5} (Ω.cm){sup −1}, with tow of absorption peak at 426,805 nm has been attributed due to quantized size of polyaniline conducting polymer.

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.

Layer-by-Layer Self-Assembled Graphene Multilayer Films via Covalent Bonds for Supercapacitor Electrodes

Directory of Open Access Journals (Sweden)

Xianbin Liu

2015-05-01

Full Text Available To maximize the utilization of its single-atom thin nature, a facile scheme to fabricate graphene multilayer films via a layer-by-layer self-assembled process was presented. The structure of multilayer films was constructed by covalently bonding graphene oxide (GO using p-phenylenediamine (PPD as a covalent cross-linking agent. The assembly process was confirmed to be repeatable and the structure was stable. With the π-π conjugated structure and a large number of spaces in the framework, the graphene multi‐ layer films exhibited excellent electrochemical perform‐ ance. The uniform ultrathin electrode exhibited a capacitance of 41.71 μF/cm2 at a discharge current of 0.1 μA/cm2, and displayed excellent stability of 88.9 % after 1000 charge-discharge cycles.

Dual mechanical behaviour of hydrogen in stressed silicon nitride thin films

International Nuclear Information System (INIS)

Volpi, F.; Braccini, M.; Pasturel, A.; Devos, A.; Raymond, G.; Morin, P.

2014-01-01

In the present article, we report a study on the mechanical behaviour displayed by hydrogen atoms and pores in silicon nitride (SiN) films. A simple three-phase model is proposed to relate the physical properties (stiffness, film stress, mass density, etc.) of hydrogenated nanoporous SiN thin films to the volume fractions of hydrogen and pores. This model is then applied to experimental data extracted from films deposited by plasma enhanced chemical vapour deposition, where hydrogen content, stress, and mass densities range widely from 11% to 30%, −2.8 to 1.5 GPa, and 2.0 to 2.8 g/cm 3 , respectively. Starting from the conventional plotting of film's Young's modulus against film porosity, we first propose to correct the conventional calculation of porosity volume fraction with the hydrogen content, thus taking into account both hydrogen mass and concentration. The weight of this hydrogen-correction is found to evolve linearly with hydrogen concentration in tensile films (in accordance with a simple “mass correction” of the film density calculation), but a clear discontinuity is observed toward compressive stresses. Then, the effective volume occupied by hydrogen atoms is calculated taking account of the bond type (N-H or Si-H bonds), thus allowing a precise extraction of the hydrogen volume fraction. These calculations applied to tensile films show that both volume fractions of hydrogen and porosity are similar in magnitude and randomly distributed against Young's modulus. However, the expected linear dependence of the Young's modulus is clearly observed when both volume fractions are added. Finally, we show that the stiffer behaviour of compressive films cannot be only explained on the basis of this (hydrogen + porosity) volume fraction. Indeed this stiffness difference relies on a dual mechanical behaviour displayed by hydrogen atoms against the film stress state: while they participate to the stiffness in compressive films, hydrogen atoms mainly

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.

Removable Thin Films used for the Abatement and Mitigation of Beryllium

International Nuclear Information System (INIS)

Lumia, M.; Gentile, C.; Creek, K.; Sandoval, R.

2003-01-01

The use of removable thin films for the abatement of hazardous particulates has many advantages. Removable thin films are designed to trap and fix particulates in the film's matrix by adhesion. Thin films can be applied to an existing contaminated area to fix and capture the particulates for removal. The nature of the removable thin films, after sufficient cure time, is such that it can typically be removed as one continuous entity. The removable thin films can be applied to almost any surface type with a high success rate of removal

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.

Thin Film Photovoltaic/Thermal Solar Panels

Institute of Scientific and Technical Information of China (English)

David JOHNSTON

2008-01-01

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

Phonon transport across nano-scale curved thin films

Energy Technology Data Exchange (ETDEWEB)

Mansoor, Saad B.; Yilbas, Bekir S., E-mail: bsyilbas@kfupm.edu.sa

2016-12-15

Phonon transport across the curve thin silicon film due to temperature disturbance at film edges is examined. The equation for radiative transport is considered via incorporating Boltzmann transport equation for the energy transfer. The effect of the thin film curvature on phonon transport characteristics is assessed. In the analysis, the film arc length along the film centerline is considered to be constant and the film arc angle is varied to obtain various film curvatures. Equivalent equilibrium temperature is introduced to assess the phonon intensity distribution inside the curved thin film. It is found that equivalent equilibrium temperature decay along the arc length is sharper than that of in the radial direction, which is more pronounced in the region close to the film inner radius. Reducing film arc angle increases the film curvature; in which case, phonon intensity decay becomes sharp in the close region of the high temperature edge. Equivalent equilibrium temperature demonstrates non-symmetric distribution along the radial direction, which is more pronounced in the near region of the high temperature edge.

Phonon transport across nano-scale curved thin films

International Nuclear Information System (INIS)

Mansoor, Saad B.; Yilbas, Bekir S.

2016-01-01

Phonon transport across the curve thin silicon film due to temperature disturbance at film edges is examined. The equation for radiative transport is considered via incorporating Boltzmann transport equation for the energy transfer. The effect of the thin film curvature on phonon transport characteristics is assessed. In the analysis, the film arc length along the film centerline is considered to be constant and the film arc angle is varied to obtain various film curvatures. Equivalent equilibrium temperature is introduced to assess the phonon intensity distribution inside the curved thin film. It is found that equivalent equilibrium temperature decay along the arc length is sharper than that of in the radial direction, which is more pronounced in the region close to the film inner radius. Reducing film arc angle increases the film curvature; in which case, phonon intensity decay becomes sharp in the close region of the high temperature edge. Equivalent equilibrium temperature demonstrates non-symmetric distribution along the radial direction, which is more pronounced in the near region of the high temperature edge.

Emergent Topological Phenomena in Thin Films of Pyrochlore Iridates

Science.gov (United States)

Yang, Bohm-Jung; Nagaosa, Naoto

2014-06-01

Because of the recent development of thin film and artificial superstructure growth techniques, it is possible to control the dimensionality of the system, smoothly between two and three dimensions. In this Letter we unveil the dimensional crossover of emergent topological phenomena in correlated topological materials. In particular, by focusing on the thin film of pyrochlore iridate antiferromagnets grown along the [111] direction, we demonstrate that the thin film can have a giant anomalous Hall conductance, proportional to the thickness of the film, even though there is no Hall effect in 3D bulk material. Moreover, in the case of ultrathin films, a quantized anomalous Hall conductance can be observed, despite the fact that the system is an antiferromagnet. In addition, we uncover the emergence of a new topological phase, the nontrivial topological properties of which are hidden in the bulk insulator and manifest only in thin films. This shows that the thin film of correlated topological materials is a new platform to search for unexplored novel topological phenomena.

Investigation of corrosion behavior of nitrogen doped and platinum/ruthenium doped diamond-like carbon thin films in Hank's solution

Energy Technology Data Exchange (ETDEWEB)

Khun, N.W.; Liu, E., E-mail: MEJLiu@ntu.edu.sg

2011-10-10

Undoped (DLC), nitrogen-doped (N-DLC) and platinum/ruthenium doped diamond-like carbon (PtRu-DLC) thin films were deposited on p-Si (100) substrates using a DC magnetron sputtering deposition system. The chemical composition, bonding structure, surface morphology and adhesion strength of the films were characterized using X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, atomic force microscopy (AFM) and micro-scratch test, respectively. The corrosion behavior of the films in a Hank's solution was investigated using potentiodynamic polarization test. The corrosion results revealed that the PtRu-DLC film had the highest corrosion potential among the films used in this study. Highlights: {yields} DLC thin films were deposited on Si substrates via dc magnetron sputtering. {yields} Some DLC films were doped with N and/or Pt/Ru. {yields} The film corrosion behavior was studied in a Hank solution with polarization test. {yields} The PtRu-DLC film showed the highest corrosion potential among the films studied.

Thermoelectric effects of amorphous Ga-Sn-O thin film

Science.gov (United States)

Matsuda, Tokiyoshi; Uenuma, Mutsunori; Kimura, Mutsumi

2017-07-01

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

Study of optical properties of vacuum evaporated carbon nanotube containing Se80Te16Cu4 thin films

Science.gov (United States)

Upadhyay, A. N.; Tiwari, R. S.; Singh, Kedar

2016-08-01

Thin films of Se80Te16Cu4 glassy alloy and 3 wt.% of carbon nanotubes (CNTs) containing Se80Te16Cu4 glassy composite were deposited on clean glass substrate by thermal evaporation technique. The scanning electron microscope and energy dispersive x-ray analysis were performed to investigate the surface morphology and elemental composition of as synthesised samples. The reflectance and transmittance spectra of as-deposited thin films were recorded (200-1100 nm) by using UV/VIS/NIR spectrophotometer. The optical band gap and optical constants such as absorption coefficient (α), refractive index (n) and extinction coefficient (k) of Se80Te16Cu4 and 3 wt.% CNTs-Se80Te16Cu4 glassy composite thin films were calculated. It is observed that optical properties alter due to CNTs incorporation in Se80Te16Cu4 glassy alloy. Effect on optical properties due to CNTs incorporation can be explained in terms of concentration of unsaturated bonds/defects in the localised states.

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.

XRay Study of Transfer Printed Pentacene Thin Films

International Nuclear Information System (INIS)

Shao, Y.; Solin, S. A.; Hines, D. R.; Williams, E. D.

2007-01-01

We investigated the structural properties and transfer properties of pentacene thin films fabricated by thermal deposition and transfer printing onto SiO2 and plastic substrates, respectively. The dependence of the crystallite size on the printing time, temperature and pressure were measured. The increases of crystalline size were observed when pentacene thin films were printed under specific conditions, e.g. 120 deg. C and 600 psi and can be correlated with the improvement of the field effect mobility of pentacene thin-film transistors

Thin films of molecular materials synthesized from C{sub 32}H{sub 20}N{sub 10}M (M Co, Pb, Fe): Film formation, electrical and optical properties

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, A. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, A.P. 70-360, Coyoacan, 04510 Mexico, D.F. (Mexico); Sanchez Vergara, M.E., E-mail: elena.sanchez@anahuac.mx [Coordinacion de Ingenieria Mecatronica, Facultad de Ingenieria, Universidad Anahuac del Norte, Avenida Lomas Anahuac 46, Colonia Lomas Anahuac, 52786, Huixquilucan, Estado de Mexico (Mexico); Garcia Montalvo, V. [Instituto de Quimica, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, 04510 Mexico, D.F. (Mexico); Ortiz, A. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, A.P. 70-360, Coyoacan, 04510 Mexico, D.F. (Mexico); Alvarez, J.R. [Instituto Tecnologico y de Estudios Superiores de Monterrey, Campus Ciudad de Mexico, Calle del Puente 222, Colonia Ejidos de Huipulco, 14380 Mexico, D.F. (Mexico)

2010-03-15

In this work, the synthesis of molecular materials formed from metallic phthalocyanines and 1,4-phenylenediamine is reported. The powder and thin film ({approx}80-115 nm thickness) samples of the synthesized materials, deposited by vacuum thermal evaporation, show the same intra-molecular bonds in the IR spectroscopy studies, which suggests that the thermal evaporation process does not alter these bonds. The morphology of the deposited films was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM) and their optical and electrical properties were studied as well. The optical parameters have been investigated using spectrophotometric measurements of transmittance in the wavelength range 200-1200 nm. The absorption spectra recorded in the UV-vis region for the deposited samples showed two bands, namely the Q and Soret bands. The optical activation energy was calculated and found to be 3.41 eV for the material with cobalt, 3.34 eV for the material including lead and 3.5 eV for the material with iron. The effect of temperature on conductivity was measured for the thin films and the corresponding conduction processes are discussed in this work.

Macro stress mapping on thin film buckling

Energy Technology Data Exchange (ETDEWEB)

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

2002-11-06

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

Structural and optical properties of amorphous oxygenated iron boron nitride thin films produced by reactive co-sputtering

International Nuclear Information System (INIS)

Essafti, A.; Abouelaoualim, A.; Fierro, J.L.G.; Ech-chamikh, E.

2009-01-01

Amorphous oxygenated iron boron nitride (a-FeBN:O) thin films were prepared by reactive radio-frequency (RF) sputtering, from hexagonal boron nitride chips placed on iron target, under a total pressure of a gas mixture of argon and oxygen maintained at 1 Pa. The films were deposited onto silicon and glass substrates, at room temperature. The power of the generator RF was varied from 150 to 350 W. The chemical and structural analyses were investigated using X-ray photoelectron spectroscopy (XPS), energy dispersive of X-ray and X-ray reflectometry (XRR). The optical properties of the films were obtained from the optical transmittance and reflectance measurements in the ultraviolet-visible-near infrared wavelengths range. XPS reveals the presence of boron, nitrogen, iron and oxygen atoms and also the formation of different chemical bonds such as Fe-O, B-N, B-O and the ternary BNO phase. This latter phase is predominant in the deposited films as observed in the B 1s and N 1s core level spectra. As the RF power increases, the contribution of N-B bonds in the as-deposited films decreases. The XRR results show that the mass density of a-FeBN:O thin films increases from 2.6 to 4.12 g/cm 3 with increasing the RF power from 150 to 350 W. This behavior is more important for films deposited at RF power higher than 150 W, and has been associated with the enhancement of iron atoms in the film structure. The optical band gap decreases from 3.74 to 3.12 eV with increasing the RF power from 150 to 350 W.

Optical properties of Ar ions irradiated nanocrystalline ZrC and ZrN thin films

Energy Technology Data Exchange (ETDEWEB)

Martin, C. [Ramapo College of New Jersey, Mahwah, NJ 07430 (United States); Miller, K.H. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Makino, H. [Research Institute, Kochi University of Technology, Kami, Kochi, 782-8502 (Japan); Craciun, D. [National Institute for Laser, Plasma, and Radiation Physics, Bucharest-Magurele (Romania); Simeone, D. [CEA/DEN/DANS/DM2S/SERMA/LEPP-LRC CARMEN CEN Saclay France & CNRS/ SPMS UMR8785 LRC CARMEN, Ecole Centrale de Paris, F92292, Chatenay Malabry (United States); Craciun, V., E-mail: valentin.craciun@inflpr.ro [National Institute for Laser, Plasma, and Radiation Physics, Bucharest-Magurele (Romania)

2017-05-15

Employing wide spectral range (0.06–6 eV) optical reflectance measurements and high energy X-ray photoemission spectroscopy (HE-XPS), we studied the effect of 800 keV Ar ion irradiation on optical and electronic properties of nanocrystalline ZrC and ZrN thin films, which were obtain by the pulsed laser deposition technique. Both in ZrC and ZrN, we observed that irradiation affects the optical properties of the films mostly at low frequencies, which is dominated by the free carriers response. In both materials, we found a significant reduction in the free carriers scattering rate and an increase of the zero frequency conductivity, i.e. possible increase in mobility, at higher irradiation fluence. This is consistent with our previous findings that irradiation affects the crystallite size and the micro-strain, but it does not induce major changes in the chemical bonding. HE-XPS investigations further confirms the stability of the Zr-C and Zr-N bonds, despite a small increase in the surface region of the Zr-O bonds fraction with increasing irradiation fluence.

Epitaxial growth and electronic structure of oxyhydride SrVO{sub 2}H thin films

Energy Technology Data Exchange (ETDEWEB)

Katayama, Tsukasa; Chikamatsu, Akira, E-mail: chikamatsu@chem.s.u-tokyo.ac.jp; Yamada, Keisuke; Onozuka, Tomoya [Department of Chemistry, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan); Shigematsu, Kei [Kanagawa Academy of Science and Technology, Kawasaki, Kanagawa 213-0012 (Japan); Minohara, Makoto; Kumigashira, Hiroshi [Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Ikenaga, Eiji [Japan Synchrotron Radiation Research Institute (JASRI)/SPring-8, Mikazuki-cho, Hyogo 679-5198 (Japan); Hasegawa, Tetsuya [Department of Chemistry, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan); Kanagawa Academy of Science and Technology, Kawasaki, Kanagawa 213-0012 (Japan)

2016-08-28

Oxyhydride SrVO{sub 2}H epitaxial thin films were fabricated on SrTiO{sub 3} substrates via topotactic hydridation of oxide SrVO{sub 3} films using CaH{sub 2}. Structural and composition analyses suggested that the SrVO{sub 2}H film possessed one-dimensionally ordered V-H{sup −}-V bonds along the out-of-plane direction. The synthesis temperature could be lowered by reducing the film thickness, and the SrVO{sub 2}H film was reversible to SrVO{sub 3} by oxidation through annealing in air. Photoemission and X-ray absorption spectroscopy measurements revealed the V{sup 3+} valence state in the SrVO{sub 2}H film, indicating that the hydrogen existed as hydride. Furthermore, the electronic density of states was highly suppressed at the Fermi energy, consistent with the prediction that tetragonal distortion induces metal to insulation transition.

Theoretical investigation of the thermodynamic properties of metallic thin films

International Nuclear Information System (INIS)

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

2015-01-01

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

Theoretical investigation of the thermodynamic properties of metallic thin films

Energy Technology Data Exchange (ETDEWEB)

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

2015-05-29

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

Tuning the electronic properties at the surface of BaBiO{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Ferreyra, C. [GIyA y INN, CNEA, Av.Gral Paz 1499, (1650), San Martín, Buenos Aires (Argentina); Departamento de Física, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina); Guller, F.; Llois, A. M.; Vildosola, V. [GIyA y INN, CNEA, Av.Gral Paz 1499, (1650), San Martín, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Marchini, F.; Williams, F. J. [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Departamento de Química Inorgánica, Analítica y Química-Física, INQUIMAE-CONICET, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, Buenos Aires (Argentina); Lüders, U. [CRISMAT, CNRS UMR 6508, ENSICAEN, 6 Boulevard Maréchal Juin, 14050 Caen Cedex 4 (France); Albornoz, C. [GIyA y INN, CNEA, Av.Gral Paz 1499, (1650), San Martín, Buenos Aires (Argentina); Leyva, A. G. [GIyA y INN, CNEA, Av.Gral Paz 1499, (1650), San Martín, Buenos Aires (Argentina); Escuela de Ciencia y Tecnología, UNSAM, Campus Miguelete, (1650), San Martín, Buenos Aires (Argentina); and others

2016-06-15

The presence of 2D electron gases at surfaces or interfaces in oxide thin films remains a hot topic in condensed matter physics. In particular, BaBiO{sub 3} appears as a very interesting system as it was theoretically proposed that its (001) surface should become metallic if a Bi-termination is achieved (Vildosola et al., PRL 110, 206805 (2013)). Here we report on the preparation by pulsed laser deposition and characterization of BaBiO{sub 3} thin films on silicon. We show that the texture of the films can be tuned by controlling the growth conditions, being possible to stabilize strongly (100)-textured films. We find significant differences on the spectroscopic and transport properties between (100)-textured and non-textured films. We rationalize these experimental results by performing first principles calculations, which indicate the existence of electron doping at the (100) surface. This stabilizes Bi ions in a 3+ state, shortens Bi-O bonds and reduces the electronic band gap, increasing the surface conductivity. Our results emphasize the importance of surface effects on the electronic properties of perovskites, and provide strategies to design novel oxide heterostructures with potential interface-related 2D electron gases.

Effect of solution concentration on MEH-PPV thin films

Science.gov (United States)

Affendi, I. H. H.; Sarah, M. S. P.; Alrokayan, Salman A. H.; Khan, Haseeb A.; Rusop, M.

2018-05-01

MEH-PPV thin films were prepared with a mixture of THF (tetrahydrofuran) solution deposited by spin coating method. The surface topology of MEH-PPV thin film were characterize by atomic force microscopy (AFM) and optical properties of absorption spectra were characterized by using Ultraviolet-visible-near-infrared (UV-Vis-NIR). The MEH-PPV concentration variation affects the surface and optical properties of the thin film where 0.5 mg/ml MEH-PPV concentration have a good surface topology provided the same film also gives the highest absorption coefficient were then deposited to a TiO2 thin film forming composite layer. The composite layer then shows low current flow of short circuit current of Isc = -5.313E-7 A.

Thermionic vacuum arc (TVA) technique for magnesium thin film deposition

Energy Technology Data Exchange (ETDEWEB)

Balbag, M.Z., E-mail: zbalbag@ogu.edu.t [Eskisehir Osmangazi University, Education Faculty, Primary Education, Meselik Campus, Eskisehir 26480 (Turkey); Pat, S.; Ozkan, M.; Ekem, N. [Eskisehir Osmangazi University, Art and Science Faculty, Physics Department, Eskisehir 26480 (Turkey); Musa, G. [Ovidius University, Physics Department, Constanta (Romania)

2010-08-15

In this study, magnesium thin films were deposited on glass substrate by the Thermionic Vacuum Arc (TVA) technique for the first time. We present a different technique for deposition of high-quality magnesium thin films. By means of this technique, the production of films is achieved by condensing the plasma of anode material generated using Thermionic Vacuum Arc (TVA) under high vacuum conditions onto the surface to be coated. The crystal orientation and morphology of the deposited films were investigated by using XRD, EDX, SEM and AFM. The aim of this study is to search the use of TVA technique to coat magnesium thin films and to determine some of the physical properties of the films generated. Furthermore, this study will contribute to the scientific studies which search the thin films of magnesium or the compounds containing magnesium. In future, this study will be preliminary work to entirely produce magnesium diboride (MgB{sub 2}) superconductor thin film with the TVA technique.

Perovskite phase thin films and method of making

Science.gov (United States)

Boyle, Timothy J.; Rodriguez, Mark A.

2000-01-01

The present invention comprises perovskite-phase thin films, of the general formula A.sub.x B.sub.y O.sub.3 on a substrate, wherein A is selected from beryllium, magnesium, calcium, strontium, and barium or a combination thereof; B is selected from niobium and tantalum or a combination thereof; and x and y are mole fractions between approximately 0.8 and 1.2. More particularly, A is strontium or barium or a combination thereof and B is niobium or tantalum or a combination thereof. Also provided is a method of making a perovskite-phase thin film, comprising combining at least one element-A-containing compound, wherein A is selected from beryllium, magnesium, calcium, strontium or barium, with at least one element-B-containing compound, wherein B niobium or tantalum, to form a solution; adding a solvent to said solution to form another solution; spin-coating the solution onto a substrate to form a thin film; and heating the film to form the perovskite-phase thin film.

Properties of RF-Sputtered PZT Thin Films with Ti/Pt Electrodes

Directory of Open Access Journals (Sweden)

Cui Yan

2014-01-01

Full Text Available Effect of annealing temperature and thin film thickness on properties of Pb(Zr0.53Ti0.47O3 (PZT thin film deposited via radiofrequency magnetron sputtering technique onto Pt/Ti/SiO2/Si substrate was investigated. Average grain sizes of the PZT thin film were measured by atomic force microscope; their preferred orientation was studied through X-ray diffraction analysis. Average residual stress in the thin film was estimated according to the optimized Stoney formula, and impedance spectroscopy characterization was performed via an intelligent LCR measuring instrument. Average grain sizes of PZT thin films were 60 nm~90 nm and their average roughness was less than 2 nm. According to X-ray diffraction analysis, 600°C is the optimal annealing temperature to obtain the PZT thin film with better crystallization. Average residual stress showed that thermal mismatch was the decisive factor of residual stress in Pt/Ti/SiO2/Si substrate; the residual stress in PZT thin film decreased as their thickness increased and increased with annealing temperature. The dielectric constant and loss angle tangent were extremely increased with the thickness of PZT thin films. The capacitance of the device can be adjusted according to the thickness of PZT thin films.

Substrate-HTcS thin film interaction studies by (S)TEM

NARCIS (Netherlands)

Ramaekers, P.P.J.; Klepper, D.; Kitazawa, K.; Ishiguro, T.

1989-01-01

This paper concerns with compatibility aspects beween HTcS thin film either their substrates. The influence of substrate-thin film interaction and thin film microstructure on the superconducting properties is discussed. In this respect, data based on (S)TEM observations are presented. It is

Type of precursor and synthesis of silicon oxycarbide (SiOxCyH) thin films with a surfatron microwave oxygen/argon plasma

International Nuclear Information System (INIS)

Walkiewicz-Pietrzykowska, Agnieszka; Espinos, J. P.; Gonzalez-Elipe, Agustin R.

2006-01-01

Siliconelike thin films (i.e., SiO x C y H z ) were prepared in a microwave plasma enhanced chemical vapor deposition reactor from structurally different organosilicon precursors [i.e., hexamethyldisiloxane (HMDSO), dimethylsilane (DMS), and tetramethylsilane (TMS)]. The films were deposited at room temperature by using different oxygen/argon ratios in the plasma gas. By changing the type of precursor and the relative concentration of oxygen in the plasma, thin films with different compositions (i.e., O/C ratio) and properties are obtained. In general, raising the oxygen concentration in the plasma produces the progressive removal of the organic moieties from the films whose composition and structure then approach those of silicon dioxide. The deposition rate was highly dependent on the type of precursor, following the order HMDSO>>DMS>TMS. The polarizabilities, optical band gaps, and surface free energy of the films also depended on the thin film composition and structure. It is proposed that the Si-O bonds existing in HMDSO is the main factor controlling the distinct reactivity of this precursor and is also responsible for the different compositions and properties of the SiO x C y H z thin films prepared with very low or no oxygen in the plasma gas

Low-field vortex dynamics in various high-Tc thin films

Indian Academy of Sciences (India)

Abstract. We present a novel ac susceptibility technique for the study of vortex creep in supercon- ducting thin films. With this technique we study the dynamics of dilute vortices in c-axis oriented. Y-123, Hg-1212, and Tl-1212 thin films, as well as a-axis oriented Hg-1212 thin films. Results on the Hg-1212 and Tl-1212 thin ...

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.

A novel application of the CuI thin film for preparing thin copper nanowires

International Nuclear Information System (INIS)

Shi Shuo; Sun Jialin; Zhang Jianhong; Cao Yang

2005-01-01

We present a novel application of the CuI thin film for preparing thin copper nanowires under a direct current electric field (DCEF). The CuI thin film was used as a medium for transmitting cuprous ions during the growing process of copper nanowires. As electrodes are the source of cuprous ions, high-purity copper films were deposited on both ends of the CuI thin film. At 353 K, under whole solid condition, without any templates, and having applied a DCEF of 1.5x10 4 V/m, cuprous ions were generated at the anode and migrated towards the cathode through the CuI film. At the edge of the cathode, cuprous ions obtained electrons and congregated to form a disordered thin copper nanowires bundle. The SEM images showed that these copper nanowires were from 10 to 20 nm in diameter and several hundred nanometers in length. The effect of the electric field intensity and the growth temperature on the diameter of the nanowires was also studied

Slow positron beam study of hydrogen ion implanted ZnO thin films

International Nuclear Information System (INIS)

Hu, Yi; Xue, Xudong; Wu, Yichu

2014-01-01

The effects of hydrogen related defect on the microstructure and optical property of ZnO thin films were investigated by slow positron beam, in combination with x-ray diffraction, infrared and photoluminescence spectroscopy. The defects were introduced by 90 keV proton irradiation with doses of 1×10 15 and 1×10 16 ions cm −2 . Zn vacancy and OH bonding (V Zn +OH) defect complex were identified in hydrogen implanted ZnO film by positron annihilation and infrared spectroscopy. The formation of these complexes led to lattice disorder in hydrogen implanted ZnO film and suppressed the luminescence process. - Highlights: • Hydrogen introduced by ion implantation can form hydrogen-related defect complex. • V Zn +OH defect complex is identified by positron annihilation and IR spectroscopy. • Irradiation defects suppress the luminescence process

Silicon-integrated thin-film structure for electro-optic applications

Science.gov (United States)

McKee, Rodney A.; Walker, Frederick Joseph

2000-01-01

A crystalline thin-film structure suited for use in any of an number of electro-optic applications, such as a phase modulator or a component of an interferometer, includes a semiconductor substrate of silicon and a ferroelectric, optically-clear thin film of the perovskite BaTiO.sub.3 overlying the surface of the silicon substrate. The BaTiO.sub.3 thin film is characterized in that substantially all of the dipole moments associated with the ferroelectric film are arranged substantially parallel to the surface of the substrate to enhance the electro-optic qualities of the film.

Nitrogen incorporation in sputter deposited molybdenum nitride thin films

Energy Technology Data Exchange (ETDEWEB)

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

2016-03-15

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

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

Science.gov (United States)

Choudhary, Sumita; Narula, Rahul; Gangopadhyay, Subhashis

2018-05-01

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

Optical constant of thin gold films

DEFF Research Database (Denmark)

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

2017-01-01

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

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

CERN Document Server

Tu, K N

1982-01-01

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

A comparative study on microstructure and tribological properties of Si3N4 and TiN thin films produced by IBED method

International Nuclear Information System (INIS)

Zhuang Daming; Liu Jiajun; Zhu Baoliang; Li Wenzhi; Zhang Xushou; Yang Shengrong

1995-01-01

In this paper, the tribological properties of Si 3 N 4 and TiN thin films produced by ion beam enhanced deposition (IBED) method were compared on an SRV friction and wear testing machine. In order to understand the reasons of their excellent properties the microstructure, microhardness and bonding strength with the substrate were analysed by SEM, X-ray diffraction, Knoop hardness test and scratching test methods separately. The results show that the TiN(1) films exhibits the best tribological properties, which are closely related with its higher hardness and bonding strength. (author)

Hall effect of K-doped superconducting thin films

Energy Technology Data Exchange (ETDEWEB)

Son, Eunseon; Lee, Nam Hoon; Kang, Won Nam [Dept. of physics, Sungkyunkwan University, Suwon (Korea, Republic of); Hwang, Tae Jong; Kim, Dong Ho [Dept. of physics, Yeungnam University, Gyeongsan(Korea, Republic of)

2013-09-15

We have studied Hall effect for potassium (K)-doped BaFe{sub 2}As{sub 2}superconducting thin films by analyzing the relation between the longitudinal resistivity (ρ{sub xy}) and the Hall resistivity (ρ{sub xy}). The thin films used in this study were fabricated on Al{sub O3} (000l) substrates by using an ex-situ pulsed laser deposition (PLD) technique under a high-vacuum condition of ∼10{sup -6} Torr. The samples showed the high superconducting transition temperatures (T{sub C}) of ∼40 K. The ρ{sub xx} and ρ{sub xy}the for K-doped BaFeAs{sub 2} thin films were measured by using a physical property measurement system (PPMS) with a temperature sweep (T-sweep) mode at an applied current density of 100 A/cm{sup 2} and at magnetic fields from 0 up to 9 T. We report the T-sweep results of the ρ{sub xx} and the ρ{sub xy} to investigate Hall scaling behavior on the basis of the relation of ρ{sub xy} = A(ρ{sub xy}){sup β}. The ρ{sub xx} values are 3.0 ± 0.2 in the c-axis-oriented K-doped BaFeAs{sub 2} thin films, whereas the thin films with various oriented-directions like a polycrystal showed slightly lower β than that of c-axis-oriented thin films. Interestingly, the β value is decreased with increasing magnetic fields.

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.

Laser-induced damage to thin film dielectric coatings

International Nuclear Information System (INIS)

Walker, T.W.

1980-01-01

The laser-induced damage thresholds of dielectric thin film coatings have been found to be more than an order of magnitude lower than the bulk material damage thresholds. Prior damage studies have been inconclusive in determining the damage mechanism which is operative in thin films. A program was conducted in which thin film damage thresholds were measured as a function of laser wavelength (1.06 μm, 0.53 μm, 0.35 μm and 0.26 μm), laser pulse length (5 and 15 nanoseconds), film materials and film thickness. The large matrix of data was compared to predictions given by avalanche ionization, multiphoton ionization and impurity theories of laser damage. When Mie absorption cross-sections and the exact thermal equations were included into the impurity theory excellent agreement with the data was found. The avalanche and multiphoton damage theories could not account for most parametric variations in the data. For example, the damage thresholds for most films increased as the film thickness decreased and only the impurity theory could account for this behavior. Other observed changes in damage threshold with changes in laser wavelength, pulse length and film material could only be adequately explained by the impurity theory. The conclusion which results from this study is that laser damage in thin film coatings results from absorbing impurities included during the deposition process

Physical Vapor Deposition of Thin Films

Science.gov (United States)

Mahan, John E.

2000-01-01

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

Indium Sulfide and Indium Oxide Thin Films Spin-Coated from Triethylammonium Indium Thioacetate Precursor for n-Channel Thin Film Transistor

Energy Technology Data Exchange (ETDEWEB)

Tung, Duy Dao; Jeong, Hyun Dam [Chonnam Natioal University, Gwangju (Korea, Republic of)

2014-09-15

The In{sub 2}S{sub 3} thin films of tetragonal structure and In{sub 2}O{sub 3} films of cubic structure were synthesized by a spin coating method from the organometallic compound precursor triethylammonium indium thioacetate ([(Et){sub 3}NH]+ [In(SCOCH{sub 3}){sub 4}]''-; TEA-InTAA). In order to determine the electron mobility of the spin-coated TEA-InTAA films, thin film transistors (TFTs) with an inverted structure using a gate dielectric of thermal oxide (SiO{sub 2}) was fabricated. These devices exhibited n-channel TFT characteristics with a field-effect electron mobility of 10.1 cm''2 V''-1s''-1 at a curing temperature of 500 o C, indicating that the semiconducting thin film material is applicable for use in low-cost, solution-processed printable electronics.

Effect of substrate temperature on structural and optical properties of nitrogen doped SnO2 thin film

International Nuclear Information System (INIS)

Thakur, Anup; Kumar, Varinder; Kang, Se Jun; Lee, Ik-Jae; Gautam, Sanjeev; Chae, K. H.; Shin, Hyun Joon

2014-01-01

Nitrogen doped SnO 2 thin films (thickness ∼ 250 nm) were deposited at different substrate temperature by radio frequency (rf) sputtering method. Crystal structure, morphology and optical properties of these films were investigated by x-ray diffraction (XRD), atomic force microscopy (AFM) and UV-VIS-NIR spectrophotometer, respectively. XRD measurement suggests that the film deposited at room temperature was amorphous in nature and films deposited at higher temperature were crystalline in nature. The film deposited at RT and 200 °C have transparency more than 90% in visible region but the film deposited at 400 °C has lesser transparency. Red shift was observed in the absorption edge may be due to decrease in ionicity due to the formation of the Sn-N bond

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.

Fabrication of ATO/Graphene Multi-layered Transparent Conducting Thin Films

Science.gov (United States)

Li, Na; Chen, Fei; Shen, Qiang; Wang, Chuanbin; Zhang, Lianmeng

2013-03-01

A novel transparent conducting oxide based on the ATO/graphene multi-layered thin films has been developed to satisfy the application of transparent conductive electrode in solar cells. The ATO thin films are prepared by pulsed laser deposition method with high quality, namely the sheet resistance of 49.5 Ω/sq and average transmittance of 81.9 %. The prepared graphene sheet is well reduced and shows atomically thin, spotty distributed appearance on the top of the ATO thin films. The XRD and optical micrographs are used to confirm the successfully preparation of the ATO/graphene multi-layered thin films. The Hall measurements and UV-Vis spectrophotometer are conducted to evaluate the sheet resistance and optical transmittance of the innovative structure. It is found that graphene can improve the electrical properties of the ATO thin films with little influence on the optical transmittance.

Fabrication of ATO/Graphene Multi-layered Transparent Conducting Thin Films

International Nuclear Information System (INIS)

Li Na; Chen Fei; Shen Qiang; Wang Chuanbin; Zhang Lianmeng

2013-01-01

A novel transparent conducting oxide based on the ATO/graphene multi-layered thin films has been developed to satisfy the application of transparent conductive electrode in solar cells. The ATO thin films are prepared by pulsed laser deposition method with high quality, namely the sheet resistance of 49.5 Ω/sq and average transmittance of 81.9 %. The prepared graphene sheet is well reduced and shows atomically thin, spotty distributed appearance on the top of the ATO thin films. The XRD and optical micrographs are used to confirm the successfully preparation of the ATO/graphene multi-layered thin films. The Hall measurements and UV-Vis spectrophotometer are conducted to evaluate the sheet resistance and optical transmittance of the innovative structure. It is found that graphene can improve the electrical properties of the ATO thin films with little influence on the optical transmittance.

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)

Subtle Raman signals from nano-diamond and β-SiC thin films

International Nuclear Information System (INIS)

Kuntumalla, Mohan Kumar; Ojha, Harish; Srikanth, Vadali Venkata Satya Siva

2013-01-01

Micro Raman scattering experiments are carried out in pursuit of subtle but discernable signals from nano-diamond and β-SiC thin films. The thin films are synthesized using microwave plasma assisted chemical vapor deposition technique. Raman scattering experiments in conjunction with scanning electron microscopy and x-ray diffraction were carried out to extract microstructure and phase information of the above mentioned thin films. Certain subtle Raman signals have been identified in this work. In the case of nanodiamond thin films, Raman bands at ∼ 485 and ∼ 1220 cm −1 are identified. These bands have been assigned to the nanodiamond present in nanodiamond thin films. In the case of nano β-SiC thin films, optical phonons are identified using surface enhanced Raman scattering. - Highlights: ► Subtle Raman signals from nano-diamond and β-silicon carbide related thin films. ► Raman bands at ∼ 485 and ∼ 1220 cm −1 from nanodiamond thin films are identified. ► Longitudinal optical phonon from nano β-silicon carbide thin films is identified

In vitro behaviour of nanocrystalline silver-sputtered thin films

International Nuclear Information System (INIS)

Piedade, A P; Vieira, M T; Martins, A; Silva, F

2007-01-01

Silver thin films were deposited with different preferential orientations and special attention was paid to the bioreactivity of the surfaces. The study was essentially focused on the evaluation of the films by x-ray diffraction (XRD), atomic force microscopy (AFM), high-resolution transmission electron microscopy (HRTEM), electron probe microanalysis (EPMA) and contact angle measurements. The deposited thin films were characterized before and after immersion in S-enriched simulated human plasma in order to estimate the influence of the preferential crystallographic orientation on the in vitro behaviour. Silver thin films with and without (111) preferential crystallographic orientation were deposited by r.f. magnetron sputtering to yield nanocrystalline coatings, high compact structures, very hydrophobic surfaces and low roughness. These properties reduce the chemisorption of reactive species onto the film surface. The in vitro tests indicate that silver thin films can be used as coatings for biomaterials applications

Ion Beam Assisted Deposition of Thin Epitaxial GaN Films.

Science.gov (United States)

Rauschenbach, Bernd; Lotnyk, Andriy; Neumann, Lena; Poppitz, David; Gerlach, Jürgen W

2017-06-23

The assistance of thin film deposition with low-energy ion bombardment influences their final properties significantly. Especially, the application of so-called hyperthermal ions (energy GaN thin films on (0001)-oriented 6H-SiC substrates at 700 °C. The films are studied in situ by reflection high energy electron diffraction, ex situ by X-ray diffraction, scanning tunnelling microscopy, and high-resolution transmission electron microscopy. It is demonstrated that the film growth mode can be controlled by varying the ion to atom ratio, where 2D films are characterized by a smooth topography, a high crystalline quality, low biaxial stress, and low defect density. Typical structural defects in the GaN thin films were identified as basal plane stacking faults, low-angle grain boundaries forming between w-GaN and z-GaN and twin boundaries. The misfit strain between the GaN thin films and substrates is relieved by the generation of edge dislocations in the first and second monolayers of GaN thin films and of misfit interfacial dislocations. It can be demonstrated that the low-energy nitrogen ion assisted molecular beam epitaxy is a technique to produce thin GaN films of high crystalline quality.

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

Ultrafast atomic layer-by-layer oxygen vacancy-exchange diffusion in double-perovskite LnBaCo2O5.5+δ thin films.

Science.gov (United States)

Bao, Shanyong; Ma, Chunrui; Chen, Garry; Xu, Xing; Enriquez, Erik; Chen, Chonglin; Zhang, Yamei; Bettis, Jerry L; Whangbo, Myung-Hwan; Dong, Chuang; Zhang, Qingyu

2014-04-22

Surface exchange and oxygen vacancy diffusion dynamics were studied in double-perovskites LnBaCo2O5.5+δ (LnBCO) single-crystalline thin films (Ln = Er, Pr; -0.5 atoms in the LnBCO thin films is taking the layer by layer oxygen-vacancy-exchange mechanism. The first principles density functional theory calculations indicate that hydrogen atoms are present in LnBCO as bound to oxygen forming O-H bonds. This unprecedented oscillation phenomenon provides the first direct experimental evidence of the layer by layer oxygen vacancy exchange diffusion mechanism.

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.

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

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-07-15

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

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

International Nuclear Information System (INIS)

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

2015-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-12-01

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

CdS thin films prepared by laser assisted chemical bath deposition

International Nuclear Information System (INIS)

Garcia, L.V.; Mendivil, M.I.; Garcia Guillen, G.; Aguilar Martinez, J.A.; Krishnan, B.; Avellaneda, D.; Castillo, G.A.; Das Roy, T.K.; Shaji, S.

2015-01-01

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

CdS thin films prepared by laser assisted chemical bath deposition

Energy Technology Data Exchange (ETDEWEB)

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

2015-05-01

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

Annealing-induced changes in chemical bonding and surface characteristics of chemical solution deposited Pb{sub 0.95}La{sub 0.05}Zr{sub 0.54}Ti{sub 0.46}O{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Batra, Vaishali [Department of Electrical and Computer Engineering, The University of Alabama, Tuscaloosa, AL 35487 (United States); Ramana, C.V. [Department of Mechanical Engineering, University of Texas at El Paso, El Paso, TX 79968 (United States); Kotru, Sushma, E-mail: skotru@eng.ua.edu [Department of Electrical and Computer Engineering, The University of Alabama, Tuscaloosa, AL 35487 (United States)

2016-08-30

Highlights: • Influence of post-deposition annealing temperature (T{sub a} = 550 and 750 °C) on the chemical valence state and crystalline quality of PLZT thin films was investigated. • XPS analyses demonstrated the shift in binding energies of the constituent atoms which indicated change in chemical state with the change in T{sub a}. • Raman spectra revealed shift in optical modes with the change in T{sub a} indicating the change in phase and crystallinity in the films. • Higher T{sub a} (750 °C) resulted in PLZT films with perovskite structure, nanocrystalline morphology, and better chemical homogeneity. - Abstract: We report the effect of post deposition annealing temperature (T{sub a} = 550 and 750 °C) on the surface morphology, chemical bonding and structural development of lanthanum doped lead zirconate titanate (Pb{sub 0.95}La{sub 0.05}Zr{sub 0.54}Ti{sub 0.46}O{sub 3}; referred to PLZT) thin films prepared using chemical solution deposition method. Atomic force microscopy demonstrates formation of nanocrystallites in the film annealed at T{sub a} = 750 °C. X-ray photoelectron spectroscopy (XPS) analyses indicate that the binding energies (BE) of the Pb 4f, Zr 3d, and Ti 2p doublet experience a positive energy shift at T{sub a} = 750 °C, whereas the BE of O 1s and La 3d doublet show a negative shift with respect to the BE of the films annealed at T{sub a} = 750 °C. Thermal induced crystallization and chemical modification is evident from XPS results. The Ar+ sputtering of the films reveals change in oxidation state and chemical bonding between the constituent atoms, with respect to T{sub a}. Raman spectroscopy used to study phonon-light interactions show shift in longitudinal and transverse optical modes with the change in T{sub a}, confirming the change in phase and crystallinity of these films. The results suggest annealing at T{sub a} = 750 °C yield crystalline perovskite PLZT films, which is essential to obtain photovoltaic response from

Sputtered molybdenum thin films and the application in CIGS solar cells

Energy Technology Data Exchange (ETDEWEB)

Zhou, D.; Zhu, H., E-mail: hongbing1982@hotmail.com; Liang, X.; Zhang, C.; Li, Z.; Xu, Y.; Chen, J.; Zhang, L.; Mai, Y., E-mail: yaohuamai@hbu.edu.cn

2016-01-30

Graphical abstract: - Highlights: • Mo thin films are prepared by magnetron sputtering. • The dynamic deposition rate increases with the increasing discharge power. • The surface structure of Mo films varies with discharge power and working pressure. • High efficiency CIGS thin film solar cell of 15.2% has been obtained. - Abstract: Molybdenum (Mo) thin films are prepared by magnetron sputtering with different discharge powers and working pressures for the application in Cu(In, Ga)Se{sub 2} (CIGS) thin film solar cells as back electrodes. Properties of these Mo thin films are systematically investigated. It is found that the dynamic deposition rate increases with the increasing discharge power while decreases with the increasing working pressure. The highest dynamic deposition rate of 15.1 nm m/min is achieved for the Mo thin film deposited at the discharge power of 1200 W and at the working pressure of 0.15 Pa. The achieved lowest resistivity of 3.7 × 10{sup −5} Ω cm is attributed to the large grains in the compact thin film. The discharge power and working pressure have great influence on the sputtered Mo thin films. High efficiency of 12.5% was achieved for the Cu(In, Ga)Se{sub 2} (CIGS) thin film solar cells with Mo electrodes prepared at 1200 W and low working pressures. By further optimizing material and device properties, the conversion efficiency has reached to 15.2%.

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-08-01

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

The optical properties of plasma polymerized polyaniline thin films

Energy Technology Data Exchange (ETDEWEB)

Goktas, Hilal, E-mail: hilal_goktas@yahoo.com [Canakkale Onsekiz Mart University, Physics Department, 17020 Canakkale (Turkey); Demircioglu, Zahide; Sel, Kivanc [Canakkale Onsekiz Mart University, Physics Department, 17020 Canakkale (Turkey); Gunes, Taylan [Yalova University, Energy Systems Engineering Department, 77100 Yalova (Turkey); Kaya, Ismet [Canakkale Onsekiz Mart University, Chemistry Department, 17020 Canakkale (Turkey)

2013-12-02

We report herein the characterizations of polyaniline thin films synthesized using double discharge plasma system. Quartz glass substrates were coated at a pressure of 80 Pa, 19.0 kV pulsed and 1.5 kV dc potential. The substrates were located at different regions in the reactor to evaluate the influence of the position on the morphological and molecular structure of the obtained thin films. The molecular structure of the thin films was investigated by Fourier transform infrared (FTIR) and UV–visible photospectrometers (UV–vis), and the morphological studies were carried out by scanning electron microscope. The FTIR and UV–vis data revealed that the molecular structures of the synthesized thin films were in the form of leuocoemeraldine and exhibited similar structures with the films produced via chemical or electrochemical methods. The optical energy band gap values of the as-grown samples ranged from 2.5 to 3.1 eV, which indicated that these materials have potential applications in semiconductor devices. The refractive index in the transparent region (from 650 to 1000 nm) steadily decreased from 1.9 to 1.4 and the extinction coefficient was found to be on order of 10{sup −4}. The synthesized thin films showed various degrees of granular morphologies depending on the location of the substrate in the reactor. - Highlights: • Polyaniline thin films were synthesized for the first time via double discharge plasma system. • The films have similar structure to that of the chemically synthesized films. • The morphology of the films could be tuned by this technique. • These materials would have potential applications at semiconductor devices.

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.

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

Flush Mounting Of Thin-Film Sensors

Science.gov (United States)

Moore, Thomas C., Sr.

1992-01-01

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

Lattice cluster theory for dense, thin polymer films.

Science.gov (United States)

Freed, Karl F

2015-04-07

While the application of the lattice cluster theory (LCT) to study the miscibility of polymer blends has greatly expanded our understanding of the monomer scale molecular details influencing miscibility, the corresponding theory for inhomogeneous systems has not yet emerged because of considerable technical difficulties and much greater complexity. Here, we present a general formulation enabling the extension of the LCT to describe the thermodynamic properties of dense, thin polymer films using a high dimension, high temperature expansion. Whereas the leading order of the LCT for bulk polymer systems is essentially simple Flory-Huggins theory, the highly non-trivial leading order inhomogeneous LCT (ILCT) for a film with L layers already involves the numerical solution of 3(L - 1) coupled, highly nonlinear equations for the various density profiles in the film. The new theory incorporates the essential "transport" constraints of Helfand and focuses on the strict imposition of excluded volume constraints, appropriate to dense polymer systems, rather than the maintenance of chain connectivity as appropriate for lower densities and as implemented in self-consistent theories of polymer adsorption at interfaces. The ILCT is illustrated by presenting examples of the computed profiles of the density, the parallel and perpendicular bonds, and the chain ends for free standing and supported films as a function of average film density, chain length, temperature, interaction with support, and chain stiffness. The results generally agree with expected general trends.

Lattice cluster theory for dense, thin polymer films

International Nuclear Information System (INIS)

Freed, Karl F.

2015-01-01

While the application of the lattice cluster theory (LCT) to study the miscibility of polymer blends has greatly expanded our understanding of the monomer scale molecular details influencing miscibility, the corresponding theory for inhomogeneous systems has not yet emerged because of considerable technical difficulties and much greater complexity. Here, we present a general formulation enabling the extension of the LCT to describe the thermodynamic properties of dense, thin polymer films using a high dimension, high temperature expansion. Whereas the leading order of the LCT for bulk polymer systems is essentially simple Flory-Huggins theory, the highly non-trivial leading order inhomogeneous LCT (ILCT) for a film with L layers already involves the numerical solution of 3(L − 1) coupled, highly nonlinear equations for the various density profiles in the film. The new theory incorporates the essential “transport” constraints of Helfand and focuses on the strict imposition of excluded volume constraints, appropriate to dense polymer systems, rather than the maintenance of chain connectivity as appropriate for lower densities and as implemented in self-consistent theories of polymer adsorption at interfaces. The ILCT is illustrated by presenting examples of the computed profiles of the density, the parallel and perpendicular bonds, and the chain ends for free standing and supported films as a function of average film density, chain length, temperature, interaction with support, and chain stiffness. The results generally agree with expected general trends

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,...

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...

12. International conference on thin films (ICTF 12). Book of Abstract

International Nuclear Information System (INIS)

Majkova, E.

2002-09-01

The publication has been set up as a proceedings of the conference dealing with thin films production and study of their properties. The conference was focused on the following topics: (1) Advanced deposition techniques; (2) Thin Film Growth; (3) Diagnostics, Structure - Properties Relationship; (4) Mechanical Properties and Stress; (5) Protective and Functional Coatings; (6) Micropatterning and Nanostructures; (7) EUV and Soft X-Ray Multilayers; (8) Magnetic Thin Films and Multilayers; (9) Organic Thin Films; (10) Thin Films for Electronics and Optics. In this proceedings totally 157 abstracts are published of which 126 are interest for INIS

High stability mechanisms of quinary indium gallium zinc aluminum oxide multicomponent oxide films and thin film transistors

International Nuclear Information System (INIS)

Lee, Ching-Ting; Lin, Yung-Hao; Lin, Jhong-Ham

2015-01-01

Quinary indium gallium zinc aluminum oxide (IGZAO) multicomponent oxide films were deposited using indium gallium zinc oxide (IGZO) target and Al target by radio frequency magnetron cosputtering system. An extra carrier transport pathway could be provided by the 3 s orbitals of Al cations to improve the electrical properties of the IGZO films, and the oxygen instability could be stabilized by the strong Al-O bonds in the IGZAO films. The electron concentration change and the electron mobility change of the IGZAO films for aging time of 10 days under an air environment at 40 °C and 75% humidity were 20.1% and 2.4%, respectively. The experimental results verified the performance stability of the IGZAO films. Compared with the thin film transistors (TFTs) using conventional IGZO channel layer, in conducting the stability of TFTs with IGZAO channel layer, the transconductance g m change, threshold voltage V T change, and the subthreshold swing S value change under the same aging condition were improved to 7.9%, 10.5%, and 14.8%, respectively. Furthermore, the stable performances of the IGZAO TFTs were also verified by the positive gate bias stress. In this research, the quinary IGZAO multicomponent oxide films and that applied in TFTs were the first studied in the literature

High stability mechanisms of quinary indium gallium zinc aluminum oxide multicomponent oxide films and thin film transistors

Energy Technology Data Exchange (ETDEWEB)

Lee, Ching-Ting, E-mail: ctlee@ee.ncku.edu.tw; Lin, Yung-Hao; Lin, Jhong-Ham [Institute of Microelectronics, Department of Electrical Engineering, Research Center for Energy Technology and Strategy (RCETS), National Cheng Kung University, Tainan, Taiwan (China)

2015-01-28

Quinary indium gallium zinc aluminum oxide (IGZAO) multicomponent oxide films were deposited using indium gallium zinc oxide (IGZO) target and Al target by radio frequency magnetron cosputtering system. An extra carrier transport pathway could be provided by the 3 s orbitals of Al cations to improve the electrical properties of the IGZO films, and the oxygen instability could be stabilized by the strong Al-O bonds in the IGZAO films. The electron concentration change and the electron mobility change of the IGZAO films for aging time of 10 days under an air environment at 40 °C and 75% humidity were 20.1% and 2.4%, respectively. The experimental results verified the performance stability of the IGZAO films. Compared with the thin film transistors (TFTs) using conventional IGZO channel layer, in conducting the stability of TFTs with IGZAO channel layer, the transconductance g{sub m} change, threshold voltage V{sub T} change, and the subthreshold swing S value change under the same aging condition were improved to 7.9%, 10.5%, and 14.8%, respectively. Furthermore, the stable performances of the IGZAO TFTs were also verified by the positive gate bias stress. In this research, the quinary IGZAO multicomponent oxide films and that applied in TFTs were the first studied in the literature.

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-01-31

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

NbN thin films for superconducting radio frequency cavities

Science.gov (United States)

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

2012-12-01

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

NbN thin films for superconducting radio frequency cavities

International Nuclear Information System (INIS)

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

2012-01-01

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

Effect of annealing temperature on the supercapacitor behaviour of β-V{sub 2}O{sub 5} thin films

Energy Technology Data Exchange (ETDEWEB)

Jeyalakshmi, K. [Department of Physics, PSNA College of Engineering and Technology, Dindigul 624622 (India); Vijayakumar, S.; Nagamuthu, S. [Department of Physics, Gandhigram Rural Institute, Deemed University, Gandhigram 624302 (India); Muralidharan, G., E-mail: muralg@rediffmail.com [Department of Physics, Gandhigram Rural Institute, Deemed University, Gandhigram 624302 (India)

2013-02-15

Graphical abstract: Display Omitted Highlights: ► Structural, optical, supercapacitor properties of β-V{sub 2}O{sub 5} thin films are reported. ► Influence of annealing temperature on β-V{sub 2}O{sub 5} thin films have been studied. ► Film annealed at 300 °C exhibit lower charge transfer resistance. -- Abstract: Vanadium pentoxide thin films are prepared via sol–gel spin coating method. The films coated on FTO and glass substrates are treated at different temperatures ranging from 250 °C to 400 °C. The structural, optical and electrochemical investigations are made. X-ray diffraction analysis shows the film to be composed of V{sub 2}O{sub 5} in β-phase up to annealing temperature of 350 °C and at 400 °C the structural transformation to α-phase is observed. FTIR spectrum shows the formation of V-O bond. The SEM images reveal the formation of nanopores. Optical absorption studies indicate a band gap of 2.2–2.4 eV. The supercapacitor behaviour is studied using cyclic voltammetery technique and electrochemical impedance analysis. The vanadium pentoxide films annealed at 300 °C for an hour exhibits a maximum specific capacitance of 346 F g{sup −1} at a scan rate of 5 mV s{sup −1}.

Research Progress on Measurement Methods and Influence Factors of Thin-film Stress

Directory of Open Access Journals (Sweden)

MA Yibo

2018-02-01

Full Text Available With the size of thin-film electronic devices decreasing, the film stress became an important reason for the failure of thin film devices. Film stress not only affected the membrane structure, but also associated with film optics, electricity, mechanics and other properties, therefore film stress turned into one hot spot in the research field of thin-film materials. This paper reviewed the latest research progress of film stress, substrate curvature method, X-ray diffraction technique and Raman spectroscopy, several frequently used stress measuring techniques were compared and analyzed, and composition ratios of thin film, substrate types, magnetron sputtering process parameters (sputtering power, work pressure, substrate temperature and annealing etc. factors influencing thin film stress were summarized. It was found that substrate curvature method was suitable for measuring almost all kinds of thin film materials. X-ray diffraction and Raman spectroscopy were just fit for measuring materials with characteristic peaks. Nanoindentation method required extra stress-free samples as comparison experiments. During film fabrication and annealing process, film stress usually transited from compressive to tensile status, and several factors combined together could affect stress, so film stress could be reached the minimum value or even stress-free status through setting appropriate parameters. Finally, combined with film stress research status, accurate stress measurement methods for different materials as a thin-film stress research direction were introduced, and challenges in thin film detection range were pointed out.

Magnetite thin films: A simulational approach

International Nuclear Information System (INIS)

Mazo-Zuluaga, J.; Restrepo, J.

2006-01-01

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