Ultrasonic Welding of Thin Alumina and Aluminum Using Inserts

Science.gov (United States)

Ishikuro, Tomoaki; Matsuoka, Shin-Ichi

This paper describes an experimental study of ultrasonic welding of thin ceramics and metals using inserts. Ultrasonic welding has enable the joining of various thick ceramics, such as Al2O3 and ZrO2, to aluminum at room temperature quickly and easily as compared to other welding methods. However, for thin ceramics, which are brittle, welding is difficult to perform without causing damage. In this study, aluminum anodized oxide with different anodizing time was used as thin alumina ceramic. Vapor deposition of aluminum alloys was used to create an effective binder layer for welding at a low pressure and within a short duration in order to prevent damage to the anodic oxide film formed with a short anodizing time. For example, ultrasonic welding of thin Al2O3/Al was accomplished under the following conditions: ultrasonic horn tip amplitude of 30µm, welding pressure of 5MPa, and required duration of 0.1s. However, since the vapor deposition film tends to exfoliate as observed in the anodic oxide film formed with a long anodizing time, welding was difficult.

Optical properties of aluminum nitride thin films grown by direct-current magnetron sputtering close to epitaxy

Energy Technology Data Exchange (ETDEWEB)

Stolz, A. [Institut d' Electronique de Microélectronique et de Nanotechnologie (IEMN), UMR CNRS 8520, PRES Lille, Université Nord de France, Avenue Poincaré, 59652 Villeneuve d' Ascq Cedex (France); Soltani, A., E-mail: ali.soltani@iemn.univ-lille1.fr [Institut d' Electronique de Microélectronique et de Nanotechnologie (IEMN), UMR CNRS 8520, PRES Lille, Université Nord de France, Avenue Poincaré, 59652 Villeneuve d' Ascq Cedex (France); Abdallah, B. [Department of Materials Physics, Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic); Charrier, J. [Fonctions Optiques pour les Technologies de l' informatiON (FOTON), UMR CNRS 6082, 6, rue de Kerampont CS 80518, 22305 Lannion Cedex (France); Deresmes, D. [Institut d' Electronique de Microélectronique et de Nanotechnologie (IEMN), UMR CNRS 8520, PRES Lille, Université Nord de France, Avenue Poincaré, 59652 Villeneuve d' Ascq Cedex (France); Jouan, P.-Y.; Djouadi, M.A. [Institut des Matériaux Jean Rouxel – IMN, UMR CNRS 6502, 2, rue de la Houssinère BP 32229, 44322 Nantes (France); Dogheche, E.; De Jaeger, J.-C. [Institut d' Electronique de Microélectronique et de Nanotechnologie (IEMN), UMR CNRS 8520, PRES Lille, Université Nord de France, Avenue Poincaré, 59652 Villeneuve d' Ascq Cedex (France)

2013-05-01

Low-temperature Aluminum Nitride (AlN) thin films with a thickness of 3 μm were deposited by Direct-Current magnetron sputtering on sapphire substrate. They present optical properties similar to those of epitaxially grown films. Different characterization methods such as X-Ray Diffraction, Transmission Electron Microscopy and Atomic Force Microscopy were used to determine the structural properties of the films such as its roughness and crystallinity. Newton interferometer was used for stress measurement of the films. Non-destructive prism-coupling technique was used to determine refractive index and thickness homogeneity by a mapping on the whole sample area. Results show that AlN films grown on AlGaN layer have a high crystallinity close to epitaxial films, associated to a low intrinsic stress for low thickness. These results highlight that it is possible to grow thick sample with microstructure and optical properties close to epitaxy, even on a large surface. - Highlights: ► Aluminum Nitride sputtering technique with a low temperature growth process ► Epitaxial quality of two microns sputtered Aluminum Nitride film ► Optics as a non-destructive accurate tool for acoustic wave investigation.

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

Science.gov (United States)

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

2017-08-01

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

Preparation of tris(8-hydroxyquinolinato)aluminum thin films by sputtering deposition using powder and pressed powder targets

Science.gov (United States)

Kawasaki, Hiroharu; Ohshima, Tamiko; Yagyu, Yoshihito; Ihara, Takeshi; Tanaka, Rei; Suda, Yoshiaki

2017-06-01

Tris(8-hydroxyquinolinato)aluminum (Alq3) thin films, for use in organic electroluminescence displays, were prepared by a sputtering deposition method using powder and pressed powder targets. Experimental results suggest that Alq3 thin films can be prepared using powder and pressed powder targets, although the films were amorphous. The surface color of the target after deposition became dark brown, and the Fourier transform infrared spectroscopy spectrum changed when using a pressed powder target. The deposition rate of the film using a powder target was higher than that using a pressed powder target. That may be because the electron and ion densities of the plasma generated using the powder target are higher than those when using pressed powder targets under the same deposition conditions. The properties of a thin film prepared using a powder target were almost the same as those of a film prepared using a pressed powder target.

Hydrogen uptake in alumina thin films synthesized from an aluminum plasma stream in an oxygen ambient

International Nuclear Information System (INIS)

Schneider, J.M.; Anders, A.; Hjoervarsson, B.; Petrov, I.; Macak, K.; Helmersson, U.; Sundgren, J.

1999-01-01

We describe the hydrogen uptake during the synthesis of alumina films from H 2 O present in the high vacuum gas background. The hydrogen concentration in the films was determined by the 1 H( 15 N,αγ) 12 C nuclear resonance reaction. Furthermore, we show the presence of hydrogen ions in the plasma stream by time-of-flight mass spectrometry. The hydrogen content increased in both the film and the plasma stream, as the oxygen partial pressure was increased. On the basis of these measurements and thermodynamic considerations, we suggest that an aluminum oxide hydroxide compound is formed, both on the cathode surface as well as in the film. The large scatter in the data reported in the literature for refractive index and chemical stability of alumina thin films can be explained on the basis of the suggested aluminum oxide hydroxide formation. copyright 1999 American Institute of Physics

Phonon transport in a curved aluminum thin film due to laser short pulse irradiation

Science.gov (United States)

Mansoor, Saad Bin; Yilbas, Bekir Sami

2018-05-01

Laser short-pulse heating of a curved aluminum thin film is investigated. The Boltzmann transport equation is incorporated to formulate the heating situation. A Gaussian laser intensity distribution is considered along the film arc and time exponentially decaying of pulse intensity is incorporated in the analysis. The governing equations of energy transport in the electron and lattice sub-systems are coupled through the electron-phonon coupling parameter. To quantify the phonon intensity distribution in the thin film, equivalent equilibrium temperature is introduced, which is associated with the average energy of all phonons around a local point when the phonon energies are redistributed adiabatically to an equilibrium state. It is found the numerical simulations that electron temperature follows similar trend to the spatial distribution of the laser pulse intensity at the film edge. Temporal variation of electron temperature does not follow the laser pulse intensity distribution. The rise of temperature in the electron sub-system is fast while it remains slow in the lattice sub-system.

Piezoelectric actuated micro-resonators based on the growth of diamond on aluminum nitride thin films

International Nuclear Information System (INIS)

Hees, J; Heidrich, N; Pletschen, W; Sah, R E; Wolfer, M; Lebedev, V; Nebel, C E; Ambacher, O; Williams, O A

2013-01-01

Unimorph heterostructures based on piezoelectric aluminum nitride (AlN) and diamond thin films are highly desirable for applications in micro- and nanoelectromechanical systems. In this paper, we present a new approach to combine thin conductive boron-doped as well as insulating nanocrystalline diamond (NCD) with sputtered AlN films without the need for any buffer layers between AlN and NCD or polishing steps. The zeta potentials of differently treated nanodiamond (ND) particles in aqueous colloids are adjusted to the zeta potential of AlN in water. Thereby, the nucleation density for the initial growth of diamond on AlN can be varied from very low (10 8 cm −2 ), in the case of hydrogen-treated ND seeding particles, to very high values of 10 11 cm −2 for oxidized ND particles. Our approach yielding high nucleation densities allows the growth of very thin NCD films on AlN with thicknesses as low as 40 nm for applications such as microelectromechanical beam resonators. Fabricated piezo-actuated micro-resonators exhibit enhanced mechanical properties due to the incorporation of boron-doped NCD films. Highly boron-doped NCD thin films which replace the metal top electrode offer Young’s moduli of more than 1000 GPa. (paper)

Negative permittivity of ZnO thin films prepared from aluminum and gallium doped ceramics via pulsed-laser deposition

DEFF Research Database (Denmark)

Bodea, M. A.; Sbarcea, G.; Naik, G. V.

2013-01-01

Aluminum and gallium doped zinc oxide thin films with negative dielectric permittivity in the near infrared spectral range are grown by pulsed laser deposition. Composite ceramics comprising ZnO and secondary phase Al2O3 or Ga2O3 are employed as targets for laser ablation. Films deposited on glass...

Thin film metrology and microwave loss characterization of indium and aluminum/indium superconducting planar resonators

Science.gov (United States)

McRae, C. R. H.; Béjanin, J. H.; Earnest, C. T.; McConkey, T. G.; Rinehart, J. R.; Deimert, C.; Thomas, J. P.; Wasilewski, Z. R.; Mariantoni, M.

2018-05-01

Scalable architectures characterized by quantum bits (qubits) with low error rates are essential to the development of a practical quantum computer. In the superconducting quantum computing implementation, understanding and minimizing material losses are crucial to the improvement of qubit performance. A new material that has recently received particular attention is indium, a low-temperature superconductor that can be used to bond pairs of chips containing standard aluminum-based qubit circuitry. In this work, we characterize microwave loss in indium and aluminum/indium thin films on silicon substrates by measuring superconducting coplanar waveguide resonators and estimating the main loss parameters at powers down to the sub-photon regime and at temperatures between 10 and 450 mK. We compare films deposited by thermal evaporation, sputtering, and molecular beam epitaxy. We study the effects of heating in a vacuum and ambient atmospheric pressure as well as the effects of pre-deposition wafer cleaning using hydrofluoric acid. The microwave measurements are supported by thin film metrology including secondary-ion mass spectrometry. For thermally evaporated and sputtered films, we find that two-level state are the dominant loss mechanism at low photon number and temperature, with a loss tangent due to native indium oxide of ˜ 5 × 10 - 5 . The molecular beam epitaxial films show evidence of the formation of a substantial indium-silicon eutectic layer, which leads to a drastic degradation in resonator performance.

In situ detection of porosity initiation during aluminum thin film anodizing

Science.gov (United States)

Van Overmeere, Quentin; Nysten, Bernard; Proost, Joris

2009-02-01

High-resolution curvature measurements have been performed in situ during aluminum thin film anodizing in sulfuric acid. A well-defined transition in the rate of internal stress-induced curvature change is shown to allow for the accurate, real-time detection of porosity initiation. The validity of this in situ diagnostic tool was confirmed by a quantitative analysis of the spectral density distributions of the anodized surfaces. These were obtained by analyzing ex situ atomic force microscopy images of surfaces anodized for different times, and allowed to correlate the in situ detected transition in the rate of curvature change with the appearance of porosity.

Low temperature-pyrosol-deposition of aluminum-doped zinc oxide thin films for transparent conducting contacts

Energy Technology Data Exchange (ETDEWEB)

Rivera, M.J. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, Coyoacán, 04510 México, D.F. (Mexico); Ramírez, E.B. [Universidad Autónoma de la Ciudad de México, Calle Prolongación San Isidro Núm. 151, Col. San Lorenzo Tezonco, Iztapalapa, 09790 México, D.F. (Mexico); Juárez, B.; González, J.; García-León, J.M. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, Coyoacán, 04510 México, D.F. (Mexico); Escobar-Alarcón, L. [Departamento de Física, Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, México, D.F. 11801 (Mexico); Alonso, J.C., E-mail: alonso@unam.mx [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, Coyoacán, 04510 México, D.F. (Mexico)

2016-04-30

Aluminum doped-zinc oxide (ZnO:Al) thin films with thickness ~ 1000 nm have been deposited by the ultrasonic spray pyrolysis technique using low substrate temperatures in the range from 285 to 360 °C. The electrical and optical properties of the ZnO:Al (AZO) films were investigated by Uv–vis spectroscopy and Hall effect measurements. The crystallinity and morphology of the films were analyzed using X-ray diffraction (XRD), atomic force microscopy (AFM), and high resolution scanning electron microcopy (SEM). XRD results reveal that all the films are nanocrystalline with a hexagonal wurtzite structure with a preferential orientation in the (002) plane. The size of the grains calculated from Scherrer's formula was in the range from 28 to 35 nm. AFM and SEM analysis reveals that the grains form round and hexagonal shaped aggregates at high deposition temperatures and larger rice shaped aggregates at low temperatures. All the films have a high optical transparency (~ 82%). According to the Hall measurements the AZO films deposited at 360 and 340 °C had resistivities of 2.2 × 10{sup −3}–4.3 × 10{sup −3} Ω cm, respectively. These films were n-type and had carrier concentrations and mobilities of 3.71–2.54 × 10{sup 20} cm{sup −3} and 7.4–5.7 cm{sup 2}/V s, respectively. The figure of merit of these films as transparent conductors was in the range of 2.6 × 10{sup −2} Ω{sup −1}–4.1 × 10{sup −2} Ω{sup −1}. Films deposited at 300 °C and 285 °C, had much higher resistivities. Based on the thermogravimetric analysis of the individual precursors used for film deposition, we speculate on possible film growing mechanisms that can explain the composition and electrical properties of films deposited under the two different ranges of temperatures. - Highlights: • Aluminum doped zinc oxide thin films were deposited at low temperatures by pyrosol. • Low resistivity was achieved from 340 °C substrate temperature. • All films deposited

Molecularly ordered aluminum tris-(8-hydroxyquinoline) thin films grown by hot-wall deposition

Energy Technology Data Exchange (ETDEWEB)

Tapponnier, A. [Nonlinear Optics Laboratory, Institute of Quantum Electronics, Swiss Federal Institute of Technology Zuerich (ETH), CH-8093 Zurich (Switzerland)]. E-mail: axelle@phys.ethz.ch; Khan, R.U.A. [Nonlinear Optics Laboratory, Institute of Quantum Electronics, Swiss Federal Institute of Technology Zuerich (ETH), CH-8093 Zurich (Switzerland); Marcolli, C. [Institute of Atmospheric and Climate Sciences, Swiss Federal Institute of Technology Zuerich (ETH), CH-8092 Zurich (Switzerland); Guenter, P. [Nonlinear Optics Laboratory, Institute of Quantum Electronics, Swiss Federal Institute of Technology Zuerich (ETH), CH-8093 Zurich (Switzerland)

2007-01-22

We report on the growth and microstructural analysis of molecularly ordered thin film layers of aluminum tris-(8-hydroxyquinoline) (Alq{sub 3}) by hot-wall deposition onto amorphous glass substrates. Using transmission electron microscopy (TEM), ordering on a scale of 100 nm was observed. Raman measurements of these films indicated that they corresponded to the {alpha}-polymorph of crystalline Alq{sub 3}, and photoluminescence measurements exhibited a single broad peak centered at 500 nm, which is also consistent with the {alpha}-form. As a comparison, we deposited films of Alq3 using organic molecular beam deposition (OMBD), which exhibited no molecular ordering from the TEM studies. For these films, strong point-to-point variations in the Raman spectrum, and the existence of a double peak in the photoluminescence at 500 and 522 nm were observed. These measurements indicate that the OMBD films possess a mixture of both {alpha} and amorphous phases.

Long-Wave Infrared (LWIR) Molecular Laser-Induced Breakdown Spectroscopy (LIBS) Emissions of Thin Solid Explosive Powder Films Deposited on Aluminum Substrates.

Science.gov (United States)

Yang, Clayton S-C; Jin, Feng; Trivedi, Sudhir B; Brown, Ei E; Hommerich, Uwe; Tripathi, Ashish; Samuels, Alan C

2017-04-01

Thin solid films made of high nitro (NO 2 )/nitrate (NO 3 ) content explosives were deposited on sand-blasted aluminum substrates and then studied using a mercury-cadmium-telluride (MCT) linear array detection system that is capable of rapidly capturing a broad spectrum of atomic and molecular laser-induced breakdown spectroscopy (LIBS) emissions in the long-wave infrared region (LWIR; ∼5.6-10 µm). Despite the similarities of their chemical compositions and structures, thin films of three commonly used explosives (RDX, HMX, and PETN) studied in this work can be rapidly identified in the ambient air by their molecular LIBS emission signatures in the LWIR region. A preliminary assessment of the detection limit for a thin film of RDX on aluminum appears to be much lower than 60 µg/cm 2 . This LWIR LIBS setup is capable of rapidly probing and charactering samples without the need for elaborate sample preparation and also offers the possibility of a simultaneous ultraviolet visible and LWIR LIBS measurement.

Thermal conductivities of thin, sputtered optical films

International Nuclear Information System (INIS)

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

1991-05-01

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

Investigating the effect of sputtering conditions on the physical properties of aluminum thin film and the resulting alumina template

Science.gov (United States)

Taheriniya, Shabnam; Parhizgar, Sara Sadat; Sari, Amir Hossein

2018-06-01

To study the alumina template pore size distribution as a function of Al thin film grain size distribution, porous alumina templates were prepared by anodizing sputtered aluminum thin films. To control the grain size the aluminum samples were sputtered with the rate of 0.5, 1 and 2 Å/s and the substrate temperature was either 25, 75 or 125 °C. All samples were anodized for 120 s in 1 M sulfuric acid solution kept at 1 °C while a 15 V potential was being applied. The standard deviation value for samples deposited at room temperature but with different rates is roughly 2 nm in both thin film and porous template form but it rises to approximately 4 nm with substrate temperature. Samples with the average grain size of 13, 14, 18.5 and 21 nm respectively produce alumina templates with an average pore size of 8.5, 10, 15 and 16 nm in that order which shows the average grain size limits the average pore diameter in the resulting template. Lateral correlation length and grain boundary effect are other factors that affect the pore formation process and pore size distribution by limiting the initial current density.

Thin film soft X-ray absorption filters

International Nuclear Information System (INIS)

Stattin, H.

1992-11-01

This report discusses the composition, reparation and performance of soft x-ray transmission filters for a water window soft x-ray microscope. Unbacked thin films of aluminum, silver and vanadium/aluminum were made by evaporation on a substrate from which they were released. Measured transmittances agree reasonably well with calculations. The report also includes some related theory and discussions about film preparation methods, film contamination and evaluation methods. 33 refs

Remote plasma-enhanced metalorganic chemical vapor deposition of aluminum oxide thin films

NARCIS (Netherlands)

Volintiru, I.; Creatore, M.; Hemmen, van J.L.; Sanden, van de M.C.M.

2008-01-01

Aluminum oxide films were deposited using remote plasma-enhanced metalorganic chemical vapor deposition from oxygen/trimethylaluminum mixtures. Initial studies by in situ spectroscopic ellipsometry demonstrated that the aluminum oxide films deposited at temperatures

AZO Thin Films by Sol-Gel Process for Integrated Optics

Directory of Open Access Journals (Sweden)

Azzedine Boudrioua

2013-07-01

Full Text Available Undoped and aluminum-doped zinc oxide (AZO thin films are prepared by the sol-gel process. Zinc acetate dihydrate, ethanol, and monoethanolamine are used as precursor, solvent, and stabilizer, respectively. In the case of AZO, aluminum nitrate nonahydrate is added to the precursor solution with an atomic percentage equal to 1 and 2 at.% Al. The multi thin layers are deposited by spin-coating onto glass substrates, and are transformed into ZnO upon annealing at 550 °C. Films display a strong preferential orientation, with high values for the Texture Coefficients (TC of the (002 direction (TC(002 ≈ 3. The structural, morphological, and optical properties of the thin films as a function of aluminum content have been investigated using X-Ray Diffraction (XRD, Atomic Force Microscopy (AFM, and Scanning Electronic Microscopy (SEM. Waveguiding properties of the thin films have been also studied using m-lines spectroscopy. The results indicate that the films are monomodes at 632.8 nm with optical propagation optical losses estimated around 1.6 decibel per cm (dB/cm.

Ballistic phonon and thermal radiation transport across a minute vacuum gap in between aluminum and silicon thin films: Effect of laser repetitive pulses on transport characteristics

Science.gov (United States)

Yilbas, B. S.; Ali, H.

2016-08-01

Short-pulse laser heating of aluminum and silicon thin films pair with presence of a minute vacuum gap in between them is considered and energy transfer across the thin films pair is predicted. The frequency dependent Boltzmann equation is used to predict the phonon intensity distribution along the films pair for three cycles of the repetitive short-pulse laser irradiation on the aluminum film surface. Since the gap size considered is within the Casimir limit, thermal radiation and ballistic phonon contributions to energy transfer across the vacuum gap is incorporated. The laser irradiated field is formulated in line with the Lambert's Beer law and it is considered as the volumetric source in the governing equations of energy transport. In order to assess the phonon intensity distribution in the films pair, equivalent equilibrium temperature is introduced. It is demonstrated that thermal separation of electron and lattice sub-systems in the aluminum film, due to the short-pulse laser irradiation, takes place and electron temperature remains high in the aluminum film while equivalent equilibrium temperature for phonons decays sharply in the close region of the aluminum film interface. This behavior is attributed to the phonon boundary scattering at the interface and the ballistic phonon transfer to the silicon film across the vacuum gap. Energy transfer due to the ballistic phonon contribution is significantly higher than that of the thermal radiation across the vacuum gap.

Ballistic phonon and thermal radiation transport across a minute vacuum gap in between aluminum and silicon thin films: Effect of laser repetitive pulses on transport characteristics

Energy Technology Data Exchange (ETDEWEB)

Yilbas, B.S., E-mail: bsyilbas@kfupm.edu.sa; Ali, H.

2016-08-15

Short-pulse laser heating of aluminum and silicon thin films pair with presence of a minute vacuum gap in between them is considered and energy transfer across the thin films pair is predicted. The frequency dependent Boltzmann equation is used to predict the phonon intensity distribution along the films pair for three cycles of the repetitive short-pulse laser irradiation on the aluminum film surface. Since the gap size considered is within the Casimir limit, thermal radiation and ballistic phonon contributions to energy transfer across the vacuum gap is incorporated. The laser irradiated field is formulated in line with the Lambert's Beer law and it is considered as the volumetric source in the governing equations of energy transport. In order to assess the phonon intensity distribution in the films pair, equivalent equilibrium temperature is introduced. It is demonstrated that thermal separation of electron and lattice sub-systems in the aluminum film, due to the short-pulse laser irradiation, takes place and electron temperature remains high in the aluminum film while equivalent equilibrium temperature for phonons decays sharply in the close region of the aluminum film interface. This behavior is attributed to the phonon boundary scattering at the interface and the ballistic phonon transfer to the silicon film across the vacuum gap. Energy transfer due to the ballistic phonon contribution is significantly higher than that of the thermal radiation across the vacuum gap.

Ballistic phonon and thermal radiation transport across a minute vacuum gap in between aluminum and silicon thin films: Effect of laser repetitive pulses on transport characteristics

International Nuclear Information System (INIS)

Yilbas, B.S.; Ali, H.

2016-01-01

Short-pulse laser heating of aluminum and silicon thin films pair with presence of a minute vacuum gap in between them is considered and energy transfer across the thin films pair is predicted. The frequency dependent Boltzmann equation is used to predict the phonon intensity distribution along the films pair for three cycles of the repetitive short-pulse laser irradiation on the aluminum film surface. Since the gap size considered is within the Casimir limit, thermal radiation and ballistic phonon contributions to energy transfer across the vacuum gap is incorporated. The laser irradiated field is formulated in line with the Lambert's Beer law and it is considered as the volumetric source in the governing equations of energy transport. In order to assess the phonon intensity distribution in the films pair, equivalent equilibrium temperature is introduced. It is demonstrated that thermal separation of electron and lattice sub-systems in the aluminum film, due to the short-pulse laser irradiation, takes place and electron temperature remains high in the aluminum film while equivalent equilibrium temperature for phonons decays sharply in the close region of the aluminum film interface. This behavior is attributed to the phonon boundary scattering at the interface and the ballistic phonon transfer to the silicon film across the vacuum gap. Energy transfer due to the ballistic phonon contribution is significantly higher than that of the thermal radiation across the vacuum gap.

Fabrication of a capacitive relative humidity sensor using aluminum thin films deposited on etched printed circuit board

Directory of Open Access Journals (Sweden)

Lee Jacqueline Ann L.

2016-01-01

Full Text Available A capacitive humidity-sensing device was created by thermal evaporation of 99.999% aluminum. The substrate used for the coating was etched double-sided printed circuit board. The etched printed circuit board serves as the dielectric of the capacitor while the aluminum thin films deposited on either side serve as the plates of the capacitor. The capacitance was measured before and after exposure to humidity. The device was then calibrated by comparing the readings of capacitance with that of the relative humidity sensor of the Vernier LabQuest2. It was found that there is a linear relationship between the capacitance and relative humidity given by the equation C=1.418RH+29.139 where C is the capacitance and RH is the relative humidity. The surface of the aluminum films is porous and it is through these pores that water is adsorbed and capillary condensation occurs, thereby causing the capacitance to change upon exposure to humidity.

Atomic-scale epitaxial aluminum film on GaAs substrate

Directory of Open Access Journals (Sweden)

Yen-Ting Fan

2017-07-01

Full Text Available Atomic-scale metal films exhibit intriguing size-dependent film stability, electrical conductivity, superconductivity, and chemical reactivity. With advancing methods for preparing ultra-thin and atomically smooth metal films, clear evidences of the quantum size effect have been experimentally collected in the past two decades. However, with the problems of small-area fabrication, film oxidation in air, and highly-sensitive interfaces between the metal, substrate, and capping layer, the uses of the quantized metallic films for further ex-situ investigations and applications have been seriously limited. To this end, we develop a large-area fabrication method for continuous atomic-scale aluminum film. The self-limited oxidation of aluminum protects and quantizes the metallic film and enables ex-situ characterizations and device processing in air. Structure analysis and electrical measurements on the prepared films imply the quantum size effect in the atomic-scale aluminum film. Our work opens the way for further physics studies and device applications using the quantized electronic states in metals.

Stress and piezoelectric properties of aluminum nitride thin films deposited onto metal electrodes by pulsed direct current reactive sputtering

International Nuclear Information System (INIS)

Dubois, Marc-Alexandre; Muralt, Paul

2001-01-01

Polycrystalline aluminum nitride thin films were deposited onto platinum, aluminum, and titanium electrodes by reactive magnetron sputtering in the pulsed direct current mode. The films exhibited all a columnar microstructure and a c-axis texture. The built-in stress and the piezoelectric properties of these films were studied as a function of both the processing conditions and the electrode material. Stress was found to be very much dependent on the growth conditions, and values ranging from strong compression to high tension were observed. The piezoelectric d 33,f coefficient was shown to rely on substrate quality and ionic bombardment: The nucleation surface must be stable with regard to the nitrogen plasma and present a hexagonal symmetry and, on the other hand, enough energy must be delivered to the growing film through ionic bombardment. [copyright] 2001 American Institute of Physics

Impact of annealing temperature on the mechanical and electrical properties of sputtered aluminum nitride thin films

Energy Technology Data Exchange (ETDEWEB)

Gillinger, M.; Schneider, M.; Bittner, A.; Schmid, U. [Institute of Sensor and Actuator Systems, Vienna University of Technology, Vienna 1040 (Austria); Nicolay, P. [CTR Carinthian Tech Research AG, Villach 9524 (Austria)

2015-02-14

Aluminium nitride (AlN) is a promising material for challenging sensor applications such as process monitoring in harsh environments (e.g., turbine exhaust), due to its piezoelectric properties, its high temperature stability and good thermal match to silicon. Basically, the operational temperature of piezoelectric materials is limited by the increase of the leakage current as well as by enhanced diffusion effects in the material at elevated temperatures. This work focuses on the characterization of aluminum nitride thin films after post deposition annealings up to temperatures of 1000 °C in harsh environments. For this purpose, thin film samples were temperature loaded for 2 h in pure nitrogen and oxygen gas atmospheres and characterized with respect to the film stress and the leakage current behaviour. The X-ray diffraction results show that AlN thin films are chemically stable in oxygen atmospheres for 2 h at annealing temperatures of up to 900 °C. At 1000 °C, a 100 nm thick AlN layer oxidizes completely. For nitrogen, the layer is stable up to 1000 °C. The activation energy of the samples was determined from leakage current measurements at different sample temperatures, in the range between 25 and 300 °C. Up to an annealing temperature of 700 °C, the leakage current in the thin film is dominated by Poole-Frenkel behavior, while at higher annealing temperatures, a mixture of different leakage current mechanisms is observed.

Highly selective single-use fluoride ion optical sensor based on aluminum(III)-salen complex in thin polymeric film

International Nuclear Information System (INIS)

Badr, Ibrahim H.A.; Meyerhoff, Mark E.

2005-01-01

A highly selective optical sensor for fluoride ion based on the use of an aluminum(III)-salen complex as an ionophore within a thin polymeric film is described. The sensor is prepared by embedding the aluminum(III)-salen ionophore and a suitable lipophilic pH-sensitive indicator (ETH-7075) in a plasticized poly(vinyl chloride) (PVC) film. Optical response to fluoride occurs due to fluoride extraction into the polymer via formation of a strong complex with the aluminum(III)-salen species. Co-extraction of protons occurs simultaneously, with protonation of the indicator dye yielding the optical response at 529 nm. Films prepared using dioctylsebacate (DOS) are shown to exhibit better response (e.g., linear range, detection limit, and optical signal stability) compared to those prepared using ortho-nitrophenyloctyl ether (o-NPOE). Films formulated with aluminum(III)-salen and ETH-7075 indicator in 2 DOS:1 PVC, exhibit a significantly enhanced selectivity for fluoride over a wide range of lipophilic anions including salicylate, perchlorate, nitrate, and thiocyanate. The optimized films exhibit a sub-micromolar detection limit, using glycine-phosphate buffer, pH 3.00, as the test sample. The response times of the fluoride optical sensing films are in the range of 1-10 min depending on the fluoride ion concentration in the sample. The sensor exhibits very poor reversibility owing to a high co-extraction constant (log K = 8.5 ± 0.4), indicating that it can best be employed as a single-use transduction device. The utility of the aluminum(III)-salen based fluoride sensitive films as single-use sensors is demonstrated by casting polymeric films on the bottom of standard polypropylene microtiter plate wells (96 wells/plate). The modified microtiter plate optode format sensors exhibit response characteristics comparable to the classical optode films cast on quartz slides. The modified microtiter is utilized for the analysis of fluoride in diluted anti-cavity fluoride rinse

Synthesis of c-axis oriented AlN thin films on different substrates: A review

International Nuclear Information System (INIS)

Iriarte, G.F.; Rodriguez, J.G.; Calle, F.

2010-01-01

Highly c-axis oriented AlN thin films have been deposited by reactive sputtering on different substrates. The crystallographic properties of layered film structures consisting of a piezoelectric layer, aluminum nitride (AlN), synthesized on a variety of substrates, have been examined. Aluminum nitride thin films have been deposited by reactive pulsed-DC magnetron sputtering using an aluminum target in an Ar/N 2 gas mixture. The influence of the most critical deposition parameters on the AlN thin film crystallography has been investigated by means of X-ray diffraction (XRD) analysis of the rocking curve Full-Width at Half Maximum (FWHM) of the AlN-(0 0 0 2) peak. The relationship between the substrate, the synthesis parameters and the crystallographic orientation of the AlN thin films is discussed. A guide is provided showing how to optimize these conditions to obtain highly c-axis oriented AlN thin films on substrates of different nature.

Superhydrophobic honeycomb-like cobalt stearate thin films on aluminum with excellent anti-corrosion properties

Science.gov (United States)

Xiong, Jiawei; Sarkar, D. K.; Chen, X.-Grant

2017-06-01

Superhydrophobic cobalt stearate thin films with excellent anti-corrosion properties were successfully fabricated on aluminum substrates via electrodeposition process. The water-repellent properties were attributed to the honeycomb-like micro-nano structure as well as low surface energy of cobalt stearate. The correlation between the surface morphology, composition as well as wetting properties and the molar ratio of inorganic cobalt salt (Co(NO3)2) and organic stearic acid (SA) abbreviated as Co/SA, in the electrolyte were studied carefully. The optimum superhydrophobic surface obtained on the electrodeposited cathodic aluminum substrate, in the mixed ethanolic solution with Co/SA molar ratio of 0.2, was found to have a maximum contact angle of 161°. The polarization resistance of superhydrophobic aluminum substrates was calculated as high as 1591 kΩ cm2, which is determined to be two orders of magnitude larger than that of the as-received aluminum substrate as 27 kΩ cm2. Electrochemical impedance spectroscopy (EIS) was also employed to evaluate the corrosion resistance properties of these samples. Furthermore, electrical equivalent circuits (EEC) have been suggested in order to better understand the corrosion phenomena on these surfaces based on the corresponding EIS data.

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.

Influence of aluminum nitride interlayers on crystal orientation and piezoelectric property of aluminum nitride thin films prepared on titanium electrodes

International Nuclear Information System (INIS)

Kamohara, Toshihiro; Akiyama, Morito; Ueno, Naohiro; Nonaka, Kazuhiro; Kuwano, Noriyuki

2007-01-01

Highly c-axis-oriented aluminum nitride (AlN) thin films have been prepared on titanium (Ti) bottom electrodes by using AlN interlayers. The AlN interlayers were deposited between Ti electrodes and silicon (Si) substrates, such as AlN/Ti/AlN/Si. The crystallinity and crystal orientation of the AlN films and Ti electrodes strongly depended on the thickness of the AlN interlayers. Although the sputtering conditions were the same, the X-ray diffraction intensity of AlN (0002) and Ti (0002) planes drastically increased, and the full-width at half-maximum (FWHM) of the X-ray rocking curves decreased from 5.1 o to 2.6 o and from 3.3 o to 2.0 o , respectively. Furthermore, the piezoelectric constant d 33 of the AlN films was significantly improved from - 0.2 to - 4.5 pC/N

Characterization of low-temperature microwave loss of thin aluminum oxide formed by plasma oxidation

Energy Technology Data Exchange (ETDEWEB)

Deng, Chunqing, E-mail: cdeng@uwaterloo.ca; Otto, M.; Lupascu, A., E-mail: alupascu@uwaterloo.ca [Institute for Quantum Computing, Department of Physics and Astronomy, and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

2014-01-27

We report on the characterization of microwave loss of thin aluminum oxide films at low temperatures using superconducting lumped resonators. The oxide films are fabricated using plasma oxidation of aluminum and have a thickness of 5 nm. We measure the dielectric loss versus microwave power for resonators with frequencies in the GHz range at temperatures from 54 to 303 mK. The power and temperature dependence of the loss are consistent with the tunneling two-level system theory. These results are relevant to understanding decoherence in superconducting quantum devices. The obtained oxide films are thin and robust, making them suitable for capacitors in compact microwave resonators.

Enhanced c-axis orientation of aluminum nitride thin films by plasma-based pre-conditioning of sapphire substrates for SAW applications

Science.gov (United States)

Gillinger, M.; Shaposhnikov, K.; Knobloch, T.; Stöger-Pollach, M.; Artner, W.; Hradil, K.; Schneider, M.; Kaltenbacher, M.; Schmid, U.

2018-03-01

Aluminum nitride (AlN) on sapphire has been investigated with two different pretreatments prior to sputter deposition of the AlN layer to improve the orientation and homogeneity of the thin film. An inverse sputter etching of the substrate in argon atmosphere results in an improvement of the uniformity of the alignment of the AlN grains and hence, in enhanced electro-mechanical AlN film properties. This effect is demonstrated in the raw measurements of SAW test devices. Additionally, the impulse response of several devices shows that a poor AlN thin film layer quality leads to a higher signal damping during the transduction of energy in the inter-digital transducers. As a result, the triple-transit signal cannot be detected at the receiver.

An anode with aluminum doped on zinc oxide thin films for organic light emitting devices

International Nuclear Information System (INIS)

Xu Denghui; Deng Zhenbo; Xu Ying; Xiao Jing; Liang Chunjun; Pei Zhiliang; Sun Chao

2005-01-01

Doped zinc oxides are attractive alternative materials as transparent conducting electrode because they are nontoxic and inexpensive compared with indium tin oxide (ITO). Transparent conducting aluminum-doped zinc oxide (AZO) thin films have been deposited on glass substrates by DC reactive magnetron sputtering method. Films were deposited at a substrate temperature of 150-bar o C in 0.03 Pa of oxygen pressure. The electrical and optical properties of the film with the Al-doping amount of 2 wt% in the target were investigated. For the 300-nm thick AZO film deposited using a ZnO target with an Al content of 2 wt%, the lowest electrical resistivity was 4x10 -4 Ωcm and the average transmission in the visible range 400-700 nm was more than 90%. The AZO film was used as an anode contact to fabricate organic light-emitting diodes. The device performance was measured and the current efficiency of 2.9 cd/A was measured at a current density of 100 mA/cm 2

Thermal Stress Behavior of Micro- and Nano-Size Aluminum Films

International Nuclear Information System (INIS)

Hanabusa, T.; Kusaka, K.; Nishida, M.

2008-01-01

In-situ observation of thermal stresses in thin films deposited on silicon substrate was made by X-ray and synchrotron radiation. Specimens prepared in this experiment were micro- and nano-size thin aluminum films with and without passivation film. The thickness of the film was 1 micrometer for micro-size films and 10, 20 and 50 nanometer for nano-size films. The stress measurement in micro-size films was made by X-ray radiation whereas the measurement of nano-size films was made by synchrotron radiation. Residual stress measurement revealed tensile stresses in all as-deposited films. Thermal stresses were measured in a series of heating- and cooling-stage. Thermal stress behavior of micro-size films revealed hysteresis loop during a heating and cooling process. The width of a hysteresis loop was larger in passivated film that unpassivated film. No hysteresis loops were observed in nano-size films with SiO 2 passivation. Strengthning mechanism in thin films was discussed on a passivation film and a film thickness

Weld Repair of Thin Aluminum Sheet

Science.gov (United States)

Beuyukian, C. S.; Mitchell, M. J.

1986-01-01

Weld repairing of thin aluminum sheets now possible, using niobium shield and copper heat sinks. Refractory niobium shield protects aluminum adjacent to hole, while copper heat sinks help conduct heat away from repair site. Technique limits tungsten/inert-gas (TIG) welding bombardment zone to melt area, leaving surrounding areas around weld unaffected. Used successfully to repair aluminum cold plates on Space Shuttle, Commercial applications, especially in sealing fractures, dents, and holes in thin aluminum face sheets or clad brazing sheet in cold plates, heat exchangers, coolers, and Solar panels. While particularly suited to thin aluminum sheet, this process also used in thicker aluminum material to prevent surface damage near weld area.

Stoichiometry and characterization of aluminum oxynitride thin films grown by ion-beam-assisted pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Zabinski, J.S. [Materials and Manufacturing Directorate, Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Dayton, Ohio 45433 (United States); Hu, J.J. [Materials and Manufacturing Directorate, Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Dayton, Ohio 45433 (United States)], E-mail: Jianjun.Hu@WPAFB.AF.MIL; Bultman, J.E. [Materials and Manufacturing Directorate, Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Dayton, Ohio 45433 (United States); Pierce, N.A. [Propulsion Directorate, Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Dayton, Ohio 45433 (United States); Voevodin, A.A. [Materials and Manufacturing Directorate, Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Dayton, Ohio 45433 (United States)

2008-07-31

Oxides are inherently stable in air at elevated temperatures and may serve as wear resistant matrices for solid lubricants. Aluminum oxide is a particularly good candidate for a matrix because it has good diffusion barrier properties and modest hardness. Most thin film deposition techniques that are used to grow alumina require high temperatures to impart crystallinity. Crystalline films are about twice as hard as amorphous ones. Unfortunately, the mechanical properties of most engineering steels are degraded at temperatures above 250-350 deg. C. This work is focused on using energetic reactive ion bombardment during simultaneous pulsed laser deposition to enhance film crystallization at low temperatures. Alumina films were grown at several background gas pressures and temperatures, with and without Ar ion bombardment. The films were nearly stoichiometric except for depositions in vacuum. Using nitrogen ion bombardment, nitrogen was incorporated into the films and formed the Al-O-N matrix. Nitrogen concentration could be controlled through selection of gas pressure and ion energy. Crystalline Al-O-N films were grown at 330 deg. C with a negative bias voltage to the substrate, and showed improved hardness in comparison to amorphous films.

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

Science.gov (United States)

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

2012-02-01

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

Preparation of Aluminum Nanomesh Thin Films from an Anodic Aluminum Oxide Template as Transparent Conductive Electrodes

Science.gov (United States)

Li, Yiwen; Chen, Yulong; Qiu, Mingxia; Yu, Hongyu; Zhang, Xinhai; Sun, Xiao Wei; Chen, Rui

2016-02-01

We have employed anodic aluminum oxide as a template to prepare ultrathin, transparent, and conducting Al films with a unique nanomesh structure for transparent conductive electrodes. The anodic aluminum oxide template is obtained through direct anodization of a sputtered Al layer on a glass substrate, and subsequent wet etching creates the nanomesh metallic film. The optical and conductive properties are greatly influenced by experimental conditions. By tuning the anodizing time, transparent electrodes with appropriate optical transmittance and sheet resistance have been obtained. The results demonstrate that our proposed strategy can serve as a potential method to fabricate low-cost TCEs to replace conventional indium tin oxide materials.

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

Science.gov (United States)

Carradero-Santiago, Carolyn; Vedrine-Pauléus, Josee

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

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

Directory of Open Access Journals (Sweden)

Franklin Che

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

Nanoporous anodic aluminum oxide as a promising material for the electrostatically-controlled thin film interference filter

International Nuclear Information System (INIS)

Lo, Pei-Hsuan; Lee, Chih-Chun; Fang, Weileun; Luo, Guo-Lun

2015-01-01

This study presents the approach to implement the electrostatically-controlled thin film optical filter by using a nanoporous anodic aluminum oxide (np-AAO) layer as the key suspended micro structure. The bi-stable optical filter operates in the visible spectral range. In this work, the presented bi-stable optical filter has averaged reflectivity of 60%, and the central wavelengths are 580 and 690 nm respectively for on and off states. The presented np-AAO layer offers the following merits for the thin film optical filter: (1) material properties of np-AAO film, such as refractive index, elastic modulus and dielectric constant, can be easily changed by a low temperature pore-widening process, (2) in-use stiction of the suspended np-AAO structure can be reduced by the small contact area of nanoporous textures, (3) driving (pull-in) voltage can be reduced due to a large dielectric constant (ε AAO is 7.05) and small stiffness of np-AAO film and (4) dielectric charging can be reduced by the np-AAO material; thus the offset voltage is small. The study reports the design, fabrication and experimental results of the bi-stable optical filter to demonstrate the advantages of the presented device. The np-AAO material also has the potential for applications of other electrostatic drive micro devices. (paper)

Combined optical gain and degradation measurements in DCM2 doped Tris-(8-hydroxyquinoline)aluminum thin-films

Science.gov (United States)

Čehovski, Marko; Döring, Sebastian; Rabe, Torsten; Caspary, Reinhard; Kowalsky, Wolfgang

2016-04-01

Organic laser sources offer the opportunity to integrate flexible and widely tunable lasers in polymer waveguide circuits, e.g. for Lab-on-Foil applications. Therefore, it is necessary to understand gain and degradation processes for long-term operation. In this paper we address the challenge of life-time (degradation) measurements of photoluminescence (PL) and optical gain in thin-film lasers. The well known guest-host system of aluminum-chelate Alq3 (Tris-(8-hydroxyquinoline)aluminum) as host material and the laser dye DCM2 (4-(Dicyanomethylene)-2- methyl-6-julolidyl-9-enyl-4H-pyran) as guest material is employed as laser active material. Sample layers have been built up by co-evaporation in an ultrahigh (UHV) vacuum chamber. 200nm thick films of Alq3:DCM2 with different doping concentrations have been processed onto glass and thermally oxidized silicon substrates. The gain measurements have been performed by the variable stripe length (VSL) method. This measurement technique allows to determine the thin-film waveguide gain and loss, respectively. For the measurements the samples were excited with UV irradiation (ƛ = 355nm) under nitrogen atmosphere by a passively Q-switched laser source. PL degradation measurements with regard to the optical gain have been done at laser threshold (approximately 3 μJ/cm2), five times above laser threshold and 10 times above laser threshold. A t50-PL lifetime of > 107 pulses could be measured at a maximum excitation energy density of 32 μJ/cm2. This allows for a detailed analysis of the gain degradation mechanism and therefore of the stimulated cross section. Depending on the DCM2 doping concentration C the stimulated cross section was reduced by 35 %. Nevertheless, the results emphasizes the necessity of the investigation of degradation processes in organic laser sources for long-term applications.

Formation of aluminum films on silicon by ion beam deposition: a comparison with ionized cluster beam deposition

International Nuclear Information System (INIS)

Zuhr, R.A.; Haynes, T.E.; Galloway, M.D.; Tanaka, S.; Yamada, A.; Yamada, I.

1991-01-01

The direct ion beam deposition (IBD) technique has been used to study the formation of oriented aluminum films on single crystal silicon substrates. In the IBD process, thin film growth is accomplished by decelerating a magnetically analyzed ion beam to low energies (10-200 eV) for direct deposition onto the substrate under UHV conditions. The aluminum-on-silicon system is one which has been studied extensively by ionized cluster beam (ICB) deposition. This technique has produced intriguing results for aluminum, with oriented crystalline films being formed at room temperature in spite of the 25% mismatch in lattice constant between aluminum and silicon. In this work, we have studied the formation of such films by IBD, with emphasis on the effects of ion energy, substrate temperature, and surface cleanliness. Oriented films have been grown on Si(111) at temperatures from 40 to 300degC and with ion energies of 30-120 eV per ion. Completed films were analyzed by ion scattering, X-ray diffraction, scanning-electron microscopy, and optical microscopy. Results achieved for thin films grown by IBD are comparable to those for similar films grown by ICB deposition. (orig.)

Nanoscale aluminum dimples for light-trapping in organic thin-films

DEFF Research Database (Denmark)

Goszczak, Arkadiusz Jaroslaw; Adam, Jost; Cielecki, Pawel Piotr

Integration of nanostructures in organic solar cells (OSCs) has been investigated intensively in the past few years as an alternative way for enhancing the power conversion efficiency of the devices. Incorporating structured electrodes in the solar cell architecture holds potential for light...... absorption improvement in the active layer of the devices. A prospective, cheap and large-scale compatible method for structuring the electrodes in OSCs arises by the use of anodic aluminum oxide (AAO) membranes. In the present work, aluminum films of high purity and low roughness are formed via e...

Crystallization kinetics of amorphous aluminum-tungsten thin films

Energy Technology Data Exchange (ETDEWEB)

Car, T.; Radic, N. [Rugjer Boskovic Inst., Zagreb (Croatia). Div. of Mater. Sci.; Ivkov, J. [Institute of Physics, Bijenicka 46, P.O.B. 304, HR-10000 Zagreb (Croatia); Babic, E.; Tonejc, A. [Faculty of Sciences, Physics Department, Bijenicka 32, P.O.B. 162, HR-10000 Zagreb (Croatia)

1999-01-01

Crystallization kinetics of the amorphous Al-W thin films under non-isothermal conditions was examined by continuous in situ electrical resistance measurements in vacuum. The estimated crystallization temperature of amorphous films in the composition series of the Al{sub 82}W{sub 18} to Al{sub 62}W{sub 38} compounds ranged from 800 K to 920 K. The activation energy for the crystallization and the Avrami exponent were determined. The results indicated that the crystallization mechanism in films with higher tungsten content was a diffusion-controlled process, whereas in films with the composition similar to the stoichiometric compound (Al{sub 4}W), the interface-controlled crystallization probably occurred. (orig.) With 4 figs., 1 tab., 26 refs.

Electrically conductive aluminum oxide thin film used as cobalt catalyst-support layer in vertically aligned carbon nanotube growth

International Nuclear Information System (INIS)

Azam, Mohd Asyadi; Ismail, Syahriza; Mohamad, Noraiham; Isomura, Kazuki; Shimoda, Tatsuya

2015-01-01

This paper will present the unique characteristics of aluminum oxide (Al–O) and cobalt catalyst included in aligned carbon nanotube (CNT) electrode system of energy storage device, namely electrochemical capacitor. Electrical conductivity and nanostructure of the thermally oxidized Al–O used as catalyst-support layer in vertically grown single-walled CNTs were studied. Al–O films were characterized by means of current–voltage measurement and high resolution transmission electron microscopy analysis. The Al–O support layer was found to be conductive, with a relatively low resistance and, approximately 20 nm film thickness of Al–O is suggested to be too thin to form insulating barrier. The scanning TEM—annular dark field analysis confirmed that the nanosized cobalt catalyst particles distributed on Al–O surfaces and also embedded inside the Al–O film structure. (paper)

Dewetting of polymer thin films on modified curved surfaces: preparation of polymer nanoparticles with asymmetric shapes by anodic aluminum oxide templates.

Science.gov (United States)

Liu, Chih-Ting; Tsai, Chia-Chan; Chu, Chien-Wei; Chi, Mu-Huan; Chung, Pei-Yun; Chen, Jiun-Tai

2018-04-18

We study the dewetting behaviors of poly(methyl methacrylate) (PMMA) thin films coated in the cylindrical nanopores of anodic aluminum oxide (AAO) templates by thermal annealing. Self-assembled monolayers (SAMs) of n-octadecyltrichlorosilane (ODTS) are introduced to modify the pore surfaces of the AAO templates to induce the dewetting process. By using scanning electron microscopy (SEM), the dewetting-induced morphology transformation from the PMMA thin films to PMMA nanoparticles with asymmetric shapes can be observed. The sizes of the PMMA nanoparticles can be controlled by the original PMMA solution concentrations. The dewetting phenomena on the modified nanopores are explained by taking into account the excess intermolecular interaction free energy (ΔG). This work opens a new possibility for creating polymer nanoparticles with asymmetric shapes in confined geometries.

Plasticity mechanisms in ultrafine grained freestanding aluminum thin films revealed by in-situ transmission electron microscopy nanomechanical testing

International Nuclear Information System (INIS)

Idrissi, Hosni; Kobler, Aaron; Amin-Ahmadi, Behnam; Schryvers, Dominique; Coulombier, Michael; Pardoen, Thomas; Galceran, Montserrat; Godet, Stéphane; Raskin, Jean-Pierre; Kübel, Christian

2014-01-01

In-situ bright field transmission electron microscopy (TEM) nanomechanical tensile testing and in-situ automated crystallographic orientation mapping in TEM were combined to unravel the elementary mechanisms controlling the plasticity of ultrafine grained Aluminum freestanding thin films. The characterizations demonstrate that deformation proceeds with a transition from grain rotation to intragranular dislocation glide and starvation plasticity mechanism at about 1% deformation. The grain rotation is not affected by the character of the grain boundaries. No grain growth or twinning is detected

Plasticity mechanisms in ultrafine grained freestanding aluminum thin films revealed by in-situ transmission electron microscopy nanomechanical testing

Energy Technology Data Exchange (ETDEWEB)

Idrissi, Hosni, E-mail: hosni.idrissi@ua.ac.be [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Institute of Mechanics, Materials and Civil Engineering, Université catholique de Louvain, Place Sainte Barbe 2, B-1348 Louvain-La-Neuve (Belgium); Kobler, Aaron [Institute of Nanotechnology (INT) and Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology - KIT, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Joint Research Laboratory Nanomaterials (KIT and TUD) at Technische Universität Darmstadt (TUD), Petersenstr. 32, 64287 Darmstadt (Germany); Amin-Ahmadi, Behnam; Schryvers, Dominique [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Coulombier, Michael; Pardoen, Thomas [Institute of Mechanics, Materials and Civil Engineering, Université catholique de Louvain, Place Sainte Barbe 2, B-1348 Louvain-La-Neuve (Belgium); Galceran, Montserrat; Godet, Stéphane [Matters and Materials Department, Université Libre de Bruxelles, 50 Av. FD Roosevelt CP194/03, 1050 Brussels (Belgium); Raskin, Jean-Pierre [Information and Communications Technologies, Electronics and Applied Mathematics (ICTEAM), Microwave Laboratory, Université catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Kübel, Christian [Institute of Nanotechnology (INT) and Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology - KIT, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

2014-03-10

In-situ bright field transmission electron microscopy (TEM) nanomechanical tensile testing and in-situ automated crystallographic orientation mapping in TEM were combined to unravel the elementary mechanisms controlling the plasticity of ultrafine grained Aluminum freestanding thin films. The characterizations demonstrate that deformation proceeds with a transition from grain rotation to intragranular dislocation glide and starvation plasticity mechanism at about 1% deformation. The grain rotation is not affected by the character of the grain boundaries. No grain growth or twinning is detected.

Electrochemical Deposition of Lanthanum Telluride Thin Films and Nanowires

Science.gov (United States)

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

2013-03-01

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

1/f noise in titanium doped aluminum thin film deposited by electron beam evaporation method and its dependence on structural variation with temperature

Science.gov (United States)

Ananda, P.; Vedanayakam, S. Victor; Thyagarajan, K.; Nandakumar, N.

2018-05-01

A brief review of Titanium doped Aluminum film has many attractive properties such as thermal properties and 1/f noise is highlighted. The thin film devices of Titanium doped alluminium are specially used in aerospace technology, automotive, biomedical fields also in microelectronics. In this paper, we discus on 1/f noise and nonlinear effects in titanium doped alluminium thin films deposited on glass substrate using electron beam evaporation for different current densities on varying temperatures of the film. The plots are dawn for 1/f noise of the films at different temperatures ranging from 300°C to 450°C and the slopes are determined. The studies shows a higher order increment in FFT amplitude of low frequency 1/f noise in thin films at annealing temperature 400°C. In this technology used in aerospace has been the major field of application of titanium doped alluminium, being one of the major challenges of the development of new alloys with improved strength at high temperature, wide chord Titanium doped alluminium fan blades increases the efficiency while reducing 1/f noise. Structural properties of XRD is identified.

Effect of the Milling Time of the Precursors on the Physical Properties of Sprayed Aluminum-Doped Zinc Oxide (ZnO:Al Thin Films

Directory of Open Access Journals (Sweden)

María De La Luz Olvera

2012-08-01

Full Text Available Aluminum doped zinc oxide (ZnO:Al thin films were deposited on soda-lime glass substrates by the chemical spray technique. The atomization of the solution was carried out by ultrasonic excitation. Six different starting solutions from both unmilled and milled Zn and Al precursors, dissolved in a mix of methanol and acetic acid, were prepared. The milling process was carried out using a planetary ball mill at a speed of 300 rpm, and different milling times, namely, 15, 25, 35, 45, and 60 min. Molar concentration, [Al]/[Zn] atomic ratio, deposition temperature and time, were kept at constant values; 0.2 M, 3 at.%, 475 °C, and 10 min, respectively. Results show that, under the same deposition conditions, electrical resistivities of ZnO:Al thin films deposited from milled precursors are lower than those obtained for films deposited from unmilled precursors. X-ray diffraction analysis revealed that all films display a polycrystalline structure, fitting well with the hexagonal wurtzite structure. Changes in surface morphology were observed by scanning electron microscopy (SEM as well, since films deposited from unmilled precursors show triangular shaped grains, in contrast to films deposited from 15 and 35 min milled precursors that display thin slices with hexagonal shapes. The use of milled precursors to prepare starting solutions for depositing ZnO:Al thin films by ultrasonic pyrolysis influences their physical properties.

Comparative study of zinc oxide and aluminum doped zinc oxide transparent thin films grown by direct current magnetron sputtering

International Nuclear Information System (INIS)

Suchea, M.; Christoulakis, S.; Katsarakis, N.; Kitsopoulos, T.; Kiriakidis, G.

2007-01-01

Pure and aluminum (Al) doped zinc oxide (ZnO and ZAO) thin films have been grown using direct current (dc) magnetron sputtering from pure metallic Zn and ceramic ZnO targets, as well as from Al-doped metallic ZnAl2at.% and ceramic ZnAl2at.%O targets at room temperature (RT). The effects of target composition on the film's surface topology, crystallinity, and optical transmission have been investigated for various oxygen partial pressures in the sputtering atmosphere. It has been shown that Al-doped ZnO films sputtered from either metallic or ceramic targets exhibit different surface morphology than the undoped ZnO films, while their preferential crystalline growth orientation revealed by X-ray diffraction remains always the (002). More significantly, Al-doping leads to a larger increase of the optical transmission and energy gap (E g ) of the metallic than of the ceramic target prepared films

Characterization of Alq3 thin films by a near-field microwave microprobe.

Science.gov (United States)

Hovsepyan, Artur; Lee, Huneung; Sargsyan, Tigran; Melikyan, Harutyun; Yoon, Youngwoon; Babajanyan, Arsen; Friedman, Barry; Lee, Kiejin

2008-09-01

We observed tris-8-hydroxyquinoline aluminum (Alq3) thin films dependence on substrate heating temperatures by using a near-field microwave microprobe (NFMM) and by optical absorption at wavelengths between 200 and 900 nm. The changes of absorption intensity at different substrate heating temperatures are correlated to the changes in the sheet resistance of Alq3 thin films.

Deposition and characterization of NbAIN thin films by reactive magnetron sputtering

International Nuclear Information System (INIS)

Carvalho, R.G.; Felix, L.C.; Fernandez, D.A.R.; Fontes Junior, A.S.; Oliveira, G.B.; Tentardini, E.K.

2016-01-01

The objective of this work was to study NbAlN thin films and the influence of variation in the concentration of aluminum in the crystal structure and oxidation resistance of these coatings. The thin films were deposited by reactive magnetron sputtering and characterized by Grazing Incidence X-ray Diffraction (GIXRD), Energy Dispersive Spectroscopy (EDS) and oxidation tests at high temperatures. NbAlN thin films were deposited and present at concentration of 10, 20 and 42 at% Al. The NbAlN crystalline phase obtained was the δ-NbN, however it was observed a shift of the peaks in the patterns obtained GIXRD of regions for larger angles for these samples, indicating the formation of a solid solution. The higher oxidation resistance temperature was 700° C for the sample with 42 in at% Al. From the SEM analysis it was possible to observe the surface of the film after oxidation, all films showed defects, however the amount of such defects was lower in samples with higher aluminum concentrations. (author)

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

Antibacterial and barrier properties of oriented polymer films with ZnO thin films applied with atomic layer deposition at low temperatures

International Nuclear Information System (INIS)

Vähä-Nissi, Mika; Pitkänen, Marja; Salo, Erkki; Kenttä, Eija; Tanskanen, Anne; Sajavaara, Timo; Putkonen, Matti; Sievänen, Jenni; Sneck, Asko; Rättö, Marjaana; Karppinen, Maarit; Harlin, Ali

2014-01-01

Concerns on food safety, and need for high quality and extended shelf-life of packaged foods have promoted the development of antibacterial barrier packaging materials. Few articles have been available dealing with the barrier or antimicrobial properties of zinc oxide thin films deposited at low temperature with atomic layer deposition (ALD) onto commercial polymer films typically used for packaging purposes. The purpose of this paper was to study the properties of ZnO thin films compared to those of aluminum oxide. It was also possible to deposit ZnO thin films onto oriented polylactic acid and polypropylene films at relatively low temperatures using ozone instead of water as an oxidizing precursor for diethylzinc. Replacing water with ozone changed both the structure and the chemical composition of films deposited on silicon wafers. ZnO films deposited with ozone contained large grains covered and separated probably by a more amorphous and uniform layer. These thin films were also assumed to contain zinc salts of carboxylic acids. The barrier properties of a 25 nm ZnO thin film deposited with ozone at 100 °C were quite close to those obtained earlier with ALD Al 2 O 3 of similar apparent thickness on similar polymer films. ZnO thin films deposited at low temperature indicated migration of antibacterial agent, while direct contact between ZnO and Al 2 O 3 thin films and bacteria promoted antibacterial activity. - Highlights: • Thin films were grown from diethylzinc also with ozone instead of water at 70 and 100 °C. • ZnO films deposited with diethylzinc and ozone had different structures and chemistries. • Best barrier properties obtained with zinc oxide films close to those obtained with Al 2 O 3 • Ozone as oxygen source provided better barrier properties at 100 °C than water. • Both aluminum and zinc oxide thin films showed antimicrobial activity against E. coli

Antibacterial and barrier properties of oriented polymer films with ZnO thin films applied with atomic layer deposition at low temperatures

Energy Technology Data Exchange (ETDEWEB)

Vähä-Nissi, Mika, E-mail: mika.vaha-nissi@vtt.fi [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland); Pitkänen, Marja; Salo, Erkki; Kenttä, Eija [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland); Tanskanen, Anne, E-mail: Anne.Tanskanen@aalto.fi [Aalto University, School of Chemical Technology, Department of Chemistry, Laboratory of Inorganic Chemistry, P.O. Box 16100, FI-00076 Aalto (Finland); Sajavaara, Timo, E-mail: timo.sajavaara@jyu.fi [University of Jyväskylä, Department of Physics, P.O. Box 35, FI-40014 Jyväskylä (Finland); Putkonen, Matti; Sievänen, Jenni; Sneck, Asko; Rättö, Marjaana [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland); Karppinen, Maarit, E-mail: Maarit.Karppinen@aalto.fi [Aalto University, School of Chemical Technology, Department of Chemistry, Laboratory of Inorganic Chemistry, P.O. Box 16100, FI-00076 Aalto (Finland); Harlin, Ali [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland)

2014-07-01

Concerns on food safety, and need for high quality and extended shelf-life of packaged foods have promoted the development of antibacterial barrier packaging materials. Few articles have been available dealing with the barrier or antimicrobial properties of zinc oxide thin films deposited at low temperature with atomic layer deposition (ALD) onto commercial polymer films typically used for packaging purposes. The purpose of this paper was to study the properties of ZnO thin films compared to those of aluminum oxide. It was also possible to deposit ZnO thin films onto oriented polylactic acid and polypropylene films at relatively low temperatures using ozone instead of water as an oxidizing precursor for diethylzinc. Replacing water with ozone changed both the structure and the chemical composition of films deposited on silicon wafers. ZnO films deposited with ozone contained large grains covered and separated probably by a more amorphous and uniform layer. These thin films were also assumed to contain zinc salts of carboxylic acids. The barrier properties of a 25 nm ZnO thin film deposited with ozone at 100 °C were quite close to those obtained earlier with ALD Al{sub 2}O{sub 3} of similar apparent thickness on similar polymer films. ZnO thin films deposited at low temperature indicated migration of antibacterial agent, while direct contact between ZnO and Al{sub 2}O{sub 3} thin films and bacteria promoted antibacterial activity. - Highlights: • Thin films were grown from diethylzinc also with ozone instead of water at 70 and 100 °C. • ZnO films deposited with diethylzinc and ozone had different structures and chemistries. • Best barrier properties obtained with zinc oxide films close to those obtained with Al{sub 2}O{sub 3} • Ozone as oxygen source provided better barrier properties at 100 °C than water. • Both aluminum and zinc oxide thin films showed antimicrobial activity against E. coli.

Angular dependence of preferential sputtering and composition in aluminum--copper thin films

International Nuclear Information System (INIS)

Rudeck, P.J.; Harper, J.M.E.; Fryer, P.M.

1989-01-01

The copper concentration in aluminum--copper alloys can be altered by ion bombardment during film deposition. We have measured the sputtering yields of aluminum and copper in Al--Cu alloys as a function of the Cu concentration (5--13 at. %) and the angle of ion incidence (0--40 0 from normal). During deposition, the films were partially resputtered by 500-eV Ar + ion bombardment from a Kaufman ion source. We found that the Cu sputtering yield decreases by up to a factor of 10 in the alloy, relative to elemental Cu. The Al sputtering yield remains close to the elemental value. The net effect is a strong preferential sputtering of Al relative to Cu, which enhances the Cu concentration in an ion bombarded film. The Al/Cu sputtering yield ratio for normal incidence ion bombardment ranges from 3 to 5 as a function of Cu concentration. This ratio decreases with increasing angle of incidence to as low as 2 for 40 0 incident ions. However, since a higher fraction of the film is resputtered from a sloping surface, a higher Cu concentration is found on a sloping surface relative to a flat surface. These results show that in multicomponent film deposition under ion bombardment, the film composition will vary as a function of the surface topography. We will also show how the level of argon left trapped in the films varies inversely with respect to the ion flux

Heterojunction solar cell with 6% efficiency based on an n-type aluminum-gallium-oxide thin film and p-type sodium-doped Cu2O sheet

Science.gov (United States)

Minami, Tadatsugu; Nishi, Yuki; Miyata, Toshihiro

2015-02-01

In this paper, we describe efforts to enhance the efficiency of Cu2O-based heterojunction solar cells fabricated with an aluminum-gallium-oxide (Al-Ga-O) thin film as the n-type layer and a p-type sodium (Na)-doped Cu2O (Cu2O:Na) sheet prepared by thermally oxidizing copper sheets. The optimal Al content [X; Al/(Ga + Al) atomic ratio] of an AlX-Ga1-X-O thin-film n-type layer was found to be approximately 2.5 at. %. The optimized resistivity was approximately 15 Ω cm for n-type AlX-Ga1-X-O/p-type Cu2O:Na heterojunction solar cells. A MgF2/AZO/Al0.025-Ga0.975-O/Cu2O:Na heterojunction solar cell with 6.1% efficiency was fabricated using a 60-nm-thick n-type oxide thin-film layer and a 0.2-mm-thick Cu2O:Na sheet with the optimized resistivity.

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Nanocrystalline CdTe thin films by electrochemical synthesis

Directory of Open Access Journals (Sweden)

Ramesh S. Kapadnis

2013-03-01

Full Text Available Cadmium telluride thin films were deposited onto different substrates as copper, Fluorine-doped tin oxide (FTO, Indium tin oxide (ITO, Aluminum and zinc at room temperature via electrochemical route. The morphology of the film shows the nanostructures on the deposited surface of the films and their growth in vertical direction. Different nanostructures developed on different substrates. The X-ray diffraction study reveals that the deposited films are nanocrystalline in nature. UV-Visible absorption spectrum shows the wide range of absorption in the visible region. Energy-dispersive spectroscopy confirms the formation of cadmium telluride.

The thickness of DLC thin film affects the thermal conduction of HPLED lights

Science.gov (United States)

Hsu, Ming Seng; Huang, Jen Wei; Shyu, Feng Lin

2016-09-01

Thermal dissipation had an important influence in the quantum effect and life of light emitting diodes (LED) because it enabled heat transfer away from electric devices to the aluminum plate for heat removal. In the industrial processing, the quality of the thermal dissipation was decided by the gumming technique between the PCB and aluminum plate. In this study, we made the ceramic thin films of diamond like carbon (DLC) by vacuum sputtering between the substrate and high power light emitting diodes (HPLED) light to check the influence of heat transfer by DLC thin films. The ceramic dielectric coatings were characterized by several subsequent analyses, especially the measurement of real work temperature of HPLEDs. The X-Ray photoelectron spectroscopy (XPS) patterns revealed that ceramic phases were successfully grown onto the substrate. At the same time, the real work temperatures showed the thickness of DLC thin film coating effectively affected the thermal conduction of HPLEDs.

Physical properties and heterojunction device demonstration of aluminum-doped ZnO thin films synthesized at room ambient via sol-gel method

Energy Technology Data Exchange (ETDEWEB)

Karaagac, Hakan, E-mail: hkaraagac@ucdavis.edu [Department of Electrical and Computer Engineering, University of California at Davis, Davis, CA 95616 (United States); Yengel, Emre; Saif Islam, M. [Department of Electrical and Computer Engineering, University of California at Davis, Davis, CA 95616 (United States)

2012-04-25

Highlights: Black-Right-Pointing-Pointer Undoped and Al doped ZnO (AZO) thin films were successfully prepared using sol-gel technique. Black-Right-Pointing-Pointer Structural analysis has revealed that Al doping has a significant influence on preferential orientation. Black-Right-Pointing-Pointer It has been observed that wrinkles forms on the surface of films when annealed with a fast heat ramp up rate. Black-Right-Pointing-Pointer Optical analysis has revealed that that the band gap energy of ZnO thin film increases with increasing Al doping concentration. Black-Right-Pointing-Pointer The lowest resistivity is observed for 1% Al ZnO thin film, which is 2.2 Multiplication-Sign 10{sup -2} ({Omega} cm). - Abstract: ZnO and some of its ternary wide-bandgap alloys offer interesting opportunities for designing materials with tunable band gaps, strong piezoresistivity and controlled electrical conductance with high optical transparency. Synthesizing these materials on arbitrary substrates using low-cost and unconventional techniques can help in integrating semiconductors with different physical, electrical, and optical characteristics on a single substrate for heterogeneous integration of multifunctional devices. Here we report the successful synthesis of aluminum (Al) doped ZnO (AZO) thin films on soda-lime glass, silicon and fluorine doped tin oxide (FTO) pre-coated glass substrates by using sol-gel deposition method at ambient condition. X-ray diffraction (XRD) analysis revealed that varying degree of Al doping significantly impacts the crystal orientation, semiconductor bandgap and optical transparency of the film. Crystal structure of the film is also found to be strongly correlated to the characteristics of the substrate material. The impact of heating rate during post annealing process is studied and optimized in order to improve the surface morphology of the deposited films. Optical characterizations have revealed that bandgap energy of AZO films can be tuned

Measurement of quasiparticle transport in aluminum films using tungsten transition-edge sensors

International Nuclear Information System (INIS)

Yen, J. J.; Shank, B.; Cabrera, B.; Moffatt, R.; Redl, P.; Young, B. A.; Tortorici, E. C.; Brink, P. L.; Cherry, M.; Tomada, A.; Kreikebaum, J. M.

2014-01-01

We report on experimental studies of phonon sensors which utilize quasiparticle diffusion in thin aluminum films connected to tungsten transition-edge-sensors (TESs) operated at 35 mK. We show that basic TES physics and a simple physical model of the overlap region between the W and Al films in our devices enables us to accurately reproduce the experimentally observed pulse shapes from x-rays absorbed in the Al films. We further estimate quasiparticle loss in Al films using a simple diffusion equation approach. These studies allow the design of phonon sensors with improved performance.

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-07-15

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

Plastic properties of thin films on substrates as measured by submicron indentation hardness and substrate curvature techniques

International Nuclear Information System (INIS)

Doerner, M.F.; Gardner, D.S.; Nix, W.D.

1986-01-01

Substrate curvature and submicron indentation measurements have been used recently to study plastic deformation in thin films on substrates. In the present work both of these techniques have been employed to study the strength of aluminum and tungsten thin films on silicon substrates. In the case of aluminum films on silicon substrates, the film strength is found to increase with decreasing thickness. Grain size variations with film thickness do not account for the variations in strength. Wafer curvature measurements give strengths higher than those predicted from hardness measurements suggesting the substrate plays a role in strengthening the film. The observed strengthening effect with decreased thickness may be due to image forces on dislocations in the film due to the elastically stiffer silicon substrate. For sputtered tungsten films, where the substrate is less stiff than the film, the film strength decreases with decreasing film thickness

Reaction of Tri-methylaluminum on Si (001) Surface for Initial Aluminum Oxide Thin-Film Growth

International Nuclear Information System (INIS)

Kim, Dae Hee; Kim, Dae Hyun; Jeong, Yong Chan; Seo, Hwa Il; Kim, Yeong Cheol

2010-01-01

We studied the reaction of tri-methylaluminum (TMA) on hydroxyl (OH)-terminated Si (001) surfaces for the initial growth of aluminum oxide thin-films using density functional theory. TMA was adsorbed on the oxygen atom of OH due to the oxygen atom's lone pair electrons. The adsorbed TMA reacted with the hydrogen atom of OH to produce a di-methylaluminum group (DMA) and methane with an energy barrier of 0.50 eV. Low energy barriers in the range of 0 - 0.11 eV were required for DMA migration to the inter-dimer, intra-dimer, and inter-row sites on the surface. A unimethylaluminum group (UMA) was generated at each site with low energy barriers in the range of 0.21 - 0.25 eV. Among the three sites, the inter-dimer site was the most probable for UMA formation

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.

Propagation of bulk longitudinal waves in thin films using laser ultrasonics

Energy Technology Data Exchange (ETDEWEB)

Kim, Yun Young [Dept. of Mechanical Engineering, Dong-eui University, Busan (Korea, Republic of)

2016-08-15

This paper presents the investigation of the propagation behavior of bulk longitudinal waves generated by an ultrafast laser system in thin films. A train of femtosecond laser pulses was focused onto the surface of a 150-nm thick metallic (chromium or aluminum) film on a silicon substrate to excite elastic waves, and the change in thermoreflectance at the spot was monitored to detect the arrival of echoes from the film/substrate interface. The experimental results show that the film material characteristics such as the wave velocity and Young's modulus can be evaluated through curve-fitting in numerical solutions. The material properties of nanoscale thin films are difficult to measure using conventional techniques. Therefore, this research provides an effective method for the nondestructive characterization of nanomaterials.

Improvement of Self-Heating of Indium Gallium Zinc Aluminum Oxide Thin-Film Transistors Using Al2O3 Barrier Layer

Science.gov (United States)

Jian, Li-Yi; Lee, Hsin-Ying; Lin, Yung-Hao; Lee, Ching-Ting

2018-02-01

To study the self-heating effect, aluminum oxide (Al2O3) barrier layers of various thicknesses have been inserted between the channel layer and insulator layer in bottom-gate-type indium gallium zinc aluminum oxide (IGZAO) thin-film transistors (TFTs). Each IGZAO channel layer was deposited on indium tin oxide (ITO)-coated glass substrate by using a magnetron radiofrequency cosputtering system with dual targets composed of indium gallium zinc oxide (IGZO) and Al. The 3 s orbital of Al cation provided an extra transport pathway and widened the conduction-band bottom, thus increasing the electron mobility of the IGZAO films. The Al-O bonds were able to sustain the oxygen stability of the IGZAO films. The self-heating behavior of the resulting IGZAO TFTs was studied by Hall measurements on the IGZAO films as well as the electrical performance of the IGZAO TFTs with Al2O3 barrier layers of various thicknesses at different temperatures. IGZAO TFTs with 50-nm-thick Al2O3 barrier layer were stressed by positive gate bias stress (PGBS, at gate-source voltage V GS = 5 V and drain-source voltage V DS = 0 V); at V GS = 5 V and V DS = 10 V, the threshold voltage shifts were 0.04 V and 0.2 V, respectively, much smaller than for the other IGZAO TFTs without Al2O3 barrier layer, which shifted by 0.2 V and 1.0 V when stressed under the same conditions.

The strength limits of ultra-thin copper films

Energy Technology Data Exchange (ETDEWEB)

Wiederhirn, Guillaume

2007-07-02

Elucidating size effects in ultra-thin films is essential to ensure the performance and reliability of MEMS and electronic devices. In this dissertation, the influence of a capping layer on the mechanical behavior of copper (Cu) films was analyzed. Passivation is expected to shut down surface diffusion and thus to alter the contributions of dislocation- and diffusion-based plasticity in thin films. Experiments were carried out on 25 nm to 2 {mu}m thick Cu films magnetron-sputtered onto amorphous-silicon nitride coated silicon (111) substrates. These films were capped with 10 nm of aluminum oxide or silicon nitride passivation without breaking vacuum either directly after Cu deposition or after a 500 C anneal. The evolution of thermal stresses in these films was investigated mainly by the substrate curvature method between -160 C and 500 C. Negligible differences were detected for the silicon nitride vs. the aluminum oxide passivated Cu films. The processing parameters associated with the passivation deposition also had no noticeable effect on the stress-temperature behavior of the Cu. However, the thermomechanical behavior of passivated Cu films strongly depended on the Cu film thickness. For films in the micrometer range, the influence of the passivation layer was not significant, which suggests that the Cu deformed mainly by dislocation plasticity. However, diffusional creep plays an increasing role with decreasing film thickness since it becomes increasingly difficult to nucleate dislocations in smaller grains. Size effects were investigated by plotting the stress at room temperature after thermal cycling as a function of the inverse film thickness. Between 2 {mu}m and 200 nm, the room temperature stress was inversely proportional to the film thickness. The passivation exerted a strong effect on Cu films thinner than 100 nm by effectively shutting down surface diffusion mechanisms. Since dislocation processes were also shut off in these ultra-thin films, they

Laser short-pulse heating of an aluminum thin film: Energy transfer in electron and lattice sub-systems

Energy Technology Data Exchange (ETDEWEB)

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

2015-08-15

Laser short-pulse heating of an aluminum thin film is considered and energy transfer in the film is formulated using the Boltzmann equation. Since the heating duration is short and the film thickness is considerably small, thermal separation of electron and lattice sub-systems is incorporated in the analysis. The electron–phonon coupling is used to formulate thermal communication of both sub-systems during the heating period. Equivalent equilibrium temperature is introduced to account for the average energy of all phonons around a local point when they redistribute adiabatically to an equilibrium state. Temperature predictions of the Boltzmann equation are compared with those obtained from the two-equation model. It is found that temperature predictions from the Boltzmann equation differ slightly from the two-equation model results. Temporal variation of equivalent equilibrium temperature does not follow the laser pulse intensity in the electron sub-system. The time occurrence of the peak equivalent equilibrium temperature differs for electron and lattice sub-systems, which is attributed to phonon scattering in the irradiated field in the lattice sub-system. In this case, time shift is observed for occurrence of the peak temperature in the lattice sub-system.

Laser short-pulse heating of an aluminum thin film: Energy transfer in electron and lattice sub-systems

International Nuclear Information System (INIS)

Bin Mansoor, Saad; Sami Yilbas, Bekir

2015-01-01

Laser short-pulse heating of an aluminum thin film is considered and energy transfer in the film is formulated using the Boltzmann equation. Since the heating duration is short and the film thickness is considerably small, thermal separation of electron and lattice sub-systems is incorporated in the analysis. The electron–phonon coupling is used to formulate thermal communication of both sub-systems during the heating period. Equivalent equilibrium temperature is introduced to account for the average energy of all phonons around a local point when they redistribute adiabatically to an equilibrium state. Temperature predictions of the Boltzmann equation are compared with those obtained from the two-equation model. It is found that temperature predictions from the Boltzmann equation differ slightly from the two-equation model results. Temporal variation of equivalent equilibrium temperature does not follow the laser pulse intensity in the electron sub-system. The time occurrence of the peak equivalent equilibrium temperature differs for electron and lattice sub-systems, which is attributed to phonon scattering in the irradiated field in the lattice sub-system. In this case, time shift is observed for occurrence of the peak temperature in the lattice sub-system

AES study of growth process of al thin films on uranium dioxide

International Nuclear Information System (INIS)

Zhou Wei; Liu Kezhao; Yang Jiangrong; Xiao Hong

2009-01-01

Metallic uranium was exposed to 40 languirs of oxygen at room temperature in order to form UO 2 on the surface of metallic U. And thin layers of aluminum on UO 2 were prepared by sputter deposition under ultra high vacuum conditions. Process of Al thin film growth and its interaction with UO 2 were investigated by auger electron spectroscopy (AES) and electron energy loss spectroscopy (EELS). It was shown that the Al thin film growth underwent via the Volmer-Weber (VW) mode. At room temperature, Al and UO 2 interact with each other, electrons transfer occurres from Al atoms to uranium ions, and a few of Al 2 O 3 exist in the region of UO 2 /Al interface due to O 2 adsorption to the surface. Inter-diffusion between UO 2 and Al is observable. Aluminum diffuses into interface region of UO 2 and U. It results in the formation of a coexistence regime containing uranium oxide, metallic U and Al. (authors)

Nanomechanical characterization of multilayered thin film structures for digital micromirror devices

International Nuclear Information System (INIS)

Wei Guohua; Bhushan, Bharat; Joshua Jacobs, S.

2004-01-01

The digital micromirror device (DMD), used for digital projection displays, comprises a surface-micromachined array of up to 2.07 million aluminum micromirrors (14 μm square and 15 μm pitch), which switch forward and backward thousands of times per second using electrostatic attraction. The nanomechanical properties of the thin-film structures used are important to the performance of the DMD. In this paper, the nanomechanical characterization of the single and multilayered thin film structures, which are of interest in DMDs, is carried out. The hardness, Young's modulus and scratch resistance of TiN/Si, SiO 2 /Si, Al alloy/Si, TiN/Al alloy/Si and SiO 2 /TiN/Al alloy/Si thin-film structures were measured using nanoindentation and nanoscratch techniques, respectively. The residual (internal) stresses developed during the thin film growth were estimated by measuring the radius of curvature of the sample before and after deposition. To better understand the nanomechanical properties of these thin film materials, the surface and interface analysis of the samples were conducted using X-ray photoelectron spectroscopy. The nanomechanical properties of these materials are analyzed and the impact of these properties on micromirror performance is discussed

Molecular dynamics modeling on the role of initial void geometry in a thin aluminum film under uniaxial tension

International Nuclear Information System (INIS)

Cui, Yi; Chen, Zengtao

2015-01-01

The effect of initial void geometry on damage progression in a thin aluminum film under uniaxial load is studied via molecular dynamics (MD) method. The embedded voids are with different initial geometries regarding shape, porosity and intervoid ligament distance (ILD). Major simulations are run upon twelve MD geometries with each containing 8–27 million atoms. The corresponding stress–strain relation is monitored during the microstructure evolution of the specimens. The critical stress to trigger the dislocation emission is found in line with the prediction of the Lubarda model. The simulation results reveal that the initial void geometry has substantial impact on the stress–strain relation especially for a specimen with larger initial porosity. (paper)

Nonlinear optical parameters of nanocrystalline AZO thin film measured at different substrate temperatures

Energy Technology Data Exchange (ETDEWEB)

Jilani, Asim, E-mail: asim.jilane@gmail.com [Centre of Nanotechnology, King Abdulaziz University, Jeddah (Saudi Arabia); Abdel-wahab, M.Sh [Centre of Nanotechnology, King Abdulaziz University, Jeddah (Saudi Arabia); Materials Science and Nanotechnology Department, Faculty of Postgraduate Studies for Advanced Sciences, Beni -Suef University, Beni-Suef (Egypt); Al-ghamdi, Attieh A. [Centre of Nanotechnology, King Abdulaziz University, Jeddah (Saudi Arabia); Dahlan, Ammar sadik [Department of architecture, faculty of environmental design, King Abdulaziz University, Jeddah (Saudi Arabia); Yahia, I.S. [Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha (Saudi Arabia); Nano-Science & Semiconductor Labs, Department of Physics, Faculty of Education, Ain Shams University, Roxy, 11757 Cairo (Egypt)

2016-01-15

The 2.2 wt% of aluminum (Al)-doped zinc oxide (AZO) transparent and preferential c-axis oriented thin films were prepared by using radio frequency (DC/RF) magnetron sputtering at different substrate temperature ranging from room temperature to 200 °C. For structural analysis, X-ray Diffraction (XRD) and Atomic Force Electron Microscope (AFM) was used for morphological studies. The optical parameters such as, optical energy gap, refractive index, extinction coefficient, dielectric loss, tangent loss, first and third order nonlinear optical properties of transparent films were investigated. High transmittance above 90% and highly homogeneous surface were observed in all samples. The substrate temperature plays an important role to get the best transparent conductive oxide thin films. The substrate temperature at 150 °C showed the growth of highly transparent AZO thin film. Energy gap increased with the increased in substrate temperature of Al doped thin films. Dielectric constant and loss were found to be photon energy dependent with substrate temperature. The change in substrate temperature of Al doped thin films also affect the non-liner optical properties of thin films. The value of χ{sup (3)} was found to be changed with the grain size of the thin films that directly affected by the substrate temperature of the pure and Al doped ZnO thin films.

SEM and XPS study of layer-by-layer deposited polypyrrole thin films

Science.gov (United States)

Pigois-Landureau, E.; Nicolau, Y. F.; Delamar, M.

1996-01-01

Layer-by-layer deposition of thin films (a few nm) of polypyrrole was carried out on various substrates such as silver, platinum, electrochemically oxidized aluminum and pretreated glass. SEM micrographs showed that the deposited layers nucleate by an island-type mechanism on hydrated alumina and KOH-pretreated (hydrophilic) glass before forming a continuous film. However, continuous thin films are obtained on chromic acid pretreated (hydrophobic) glass and sputtered Ag or Pt on glass after only 3-4 deposition cycles. The mean deposition rate evaluated by XPS for the first deposition cycles on Ag and Pt is 3 and 4 nm/cycle, respectively, in agreement with previous gravimetric determinations on thicker films, proving the constancy of the deposition rate. The XPS study of the very thin films obtained by a few deposition cycles shows that the first polypyrrole layers are dedoped by hydroxydic (basic) substrate surfaces.

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-03-15

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

Measurement setup for the magnetic penetration depth and superfluid stiffness in thin superconducting films

Energy Technology Data Exchange (ETDEWEB)

Fuchs, Lorenz; Brunner, Markus Christopher Paul; Schneider, Ina; Kronfeldner, Klaus; Strunk, Christoph [Institute for exp. and appl. Physics, University of Regensburg (Germany); Bousquet, Jessica; Bustarret, Etienne [Institut NEEL, Grenoble (France)

2015-07-01

A mutual inductance measurement setup has been established in order to determine the magnetic penetration depths of thin film superconductors. By measuring the variation of the mutual inductance M, the temperature dependent penetration depth can be evaluated. The setup has been characterized using thin aluminum and niobium films as a reference. Temperature dependence of λ of B-doped diamond films is determined down to 0.3 K and compared with theoretical expectations. The impact of the doping ratio B/C and film thickness on λ and T{sub c} is investigated. Correlation between the film impedance σ = σ{sub 1} - i σ{sub 2} and λ is examined.

In-situ monitoring of the growth of nanostructured aluminum thin film

Czech Academy of Sciences Publication Activity Database

Novotný, Michal; Bulíř, Jiří; Lančok, Ján; Pokorný, Petr; Bodnár, Michal

2011-01-01

Roč. 5, č. 5 (2011), "051503-1"-"051503-10" ISSN 1934-2608 R&D Projects: GA AV ČR IAA100100718; GA AV ČR IAA100100729; GA ČR GP202/09/P324 Institutional research plan: CEZ:AV0Z10100522 Keywords : aluminum ultrathin film * magnetron sputtering * in-situ monitoring * electrical conductivity * spectral ellipsometry * optical emission spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.570, year: 2011

Exploration of Al-Doped ZnO in Photovoltaic Thin Films

Science.gov (United States)

Ciccarino, Christopher; Sahiner, M. Alper

The electrical properties of Al doped ZnO-based thin films represent a potential advancement in the push for increasing solar cell efficiency. Doping with Aluminum will theoretically decrease resistivity of the film and therefore achieve this potential as a viable option in the P-N junction phase of photovoltaic cells. The n-type semi-conductive characteristics of the ZnO layer will theoretically be optimized with the addition of Aluminum carriers. In this study, Aluminum doping concentrations ranging from 1-3% by mass were produced, analyzed, and compared. Films were developed onto ITO coated glass using the Pulsed Laser Deposition technique. Target thickness was 250 nm and ellipsometry measurements showed uniformity and accuracy in this regard. Active dopant concentrations were determined using Hall Effect measurements. Efficiency measurements showed possible applications of this doped compound, with upwards of 7% efficiency measured, using a Keithley 2602 SourceMeter set-up. XRD scans showed highly crystalline structures, with effective Al intertwining of the hexagonal wurtzile ZnO molecular structure. This alone indicates a promising future of collaboration between these two materials.

DLC and AlN thin films influence the thermal conduction of HPLED light

Science.gov (United States)

Hsu, Ming Seng; Hsu, Ching Yao; Huang, Jen Wei; Shyu, Feng Lin

2015-08-01

Thermal dissipation had an important influence in the effect and life of light emitting diodes (LED) because it enables transfer the heat away from electric device to the aluminum plate that can be used for heat removal. In the industrial processing, the quality of the thermal dissipation decides by the gumming technique between the PCB and aluminum plate. In this study, we fabricated double layer ceramic thin films of diamond like carbon (DLC) and alumina nitride (AlN) by vacuum sputtering soldered the substrate of high power light emitting diodes (HPLED) light to check the heat conduction. The ceramic dielectric coatings were characterized by several subsequent analyses, especially the measurement of real work temperature. The X-Ray photoelectron spectroscopy (XPS) patterns reveal those ceramic phases were successfully grown onto the substrate. The work temperatures show DLC and AlN films coating had limited the heat transfer by the lower thermal conductivity of these ceramic films. Obviously, it hadn't transferred heat and limited work temperature of HPLED better than DLC thin film only.

Auger electron spectroscopy study on interaction between aluminum thin layers and uranium substrate

International Nuclear Information System (INIS)

Zhou Wei; Liu Kezhao; Yang Jiangrong; Xiao Hong; Jiang Chunli; Lu Lei

2005-01-01

Aluminum thin layers on uranium were prepared by sputter deposition at room temperature in ultra high vacuum analysis chamber. Interaction between U and Al, and growth mode were investigated by Auger electron spectroscopy (AES) and electron energy loss spectroscopy (EELS). It is shown that Al thin film growth follows the volmer-weber (VW) mode. At room temperature, Al and U interact with each other, resulting in interdiffusion action and formation of U-Al alloys at U/Al interface. Annealing promotes interaction and interdiffusion between U and Al, and UAl x maybe formed at interface. (authors)

Improved conductivity of ZnO thin films by exposure to an atmospheric hydrogen plasma

NARCIS (Netherlands)

Illiberi, A.; Kniknie, B.; Deelen, J. van; Steijvers, H.L.A.H.; Habets, D.; Simons, P.J.P.M.; Janssen, A.C.; Beckers, E.H.A.

2012-01-01

Aluminum-doped zinc oxide (ZnOx:Al) films have been deposited on a moving glass substrate by a high throughput metalorganic chemical vapor deposition process at atmospheric pressure. Thin (< 250 nm) ZnOx:Al films have a poor crystalline quality, due to a small grain size and the presence of

SEM and XPS study of layer-by-layer deposited polypyrrole thin films

International Nuclear Information System (INIS)

Pigois-Landureau, E.; Nicolau, Y.F.; Delamar, M.

1996-01-01

Layer-by-layer deposition of thin films (a few nm) of polypyrrole was carried out on various substrates such as silver, platinum, electrochemically oxidized aluminum and pretreated glass. SEM micrographs showed that the deposited layers nucleate by an island-type mechanism on hydrated alumina and KOH-pretreated (hydrophilic) glass before forming a continuous film. However, continuous thin films are obtained on chromic acid pretreated (hydrophobic) glass and sputtered Ag or Pt on glass after only 3 endash 4 deposition cycles. The mean deposition rate evaluated by XPS for the first deposition cycles on Ag and Pt is 3 and 4 nm/cycle, respectively, in agreement with previous gravimetric determinations on thicker films, proving the constancy of the deposition rate. The XPS study of the very thin films obtained by a few deposition cycles shows that the first polypyrrole layers are dedoped by hydroxydic (basic) substrate surfaces. copyright 1996 American Institute of Physics

Highly flexible transparent thin film heaters based on silver nanowires and aluminum zinc oxides

Energy Technology Data Exchange (ETDEWEB)

Cheong, Hahn-Gil; Kim, Jin-Hoon; Song, Jun-Hyuk; Jeong, Unyong; Park, Jin-Woo, E-mail: jwpark09@yonsei.ac.kr

2015-08-31

In this work, we developed highly flexible transparent film heaters (f-TFHs) composed of Ag nanowire networks (AgNWs) and aluminum zinc oxide (AZO). Uniform AgNWs were roll-to-roll coated on polyethylene terephthalate (PET) substrates using the Mayer rod method, and AZO was sputter-deposited atop the AgNWs at room temperature. The sheet resistance (R{sub s}) and transparency (T{sub opt}) of the AZO-coated AgNWs changed only slightly compared with the uncoated AgNWs. AZO is thermally less conductive than the heat pipes, but increases the thermal efficiency of the heaters blocking the heat convection through the air. Based on Joule heating, a higher average film temperature (T{sub ave}) is attained at a fixed electric potential drop between electrodes (ϕ) as the R{sub s} of the film decreases. Our experimental results revealed that T{sub ave} of the hybrid f-TFH is higher than AgNWs when the ratio of the area coverage of AgNWs to AZO is over a certain value. When a ϕ as low as 3 V/cm was applied to 5 cm × 5 cm f-TFHs, the maximum temperature of the hybrid film was over 100 °C, which is greater than that of AgNWs by more than 30 °C. Furthermore, uniform heating throughout the surfaces is achieved in the hybrid films while heating begins in small areas where densities of the nanowires (NWs) are the highest in the bare network. The non-uniform heating decreases the lifetime of f-TFHs by forming hot spots. Cyclic bending test results indicated that the hybrid films were as flexible as the AgNWs, and the R{sub s} of the hybrid films changes only slightly until 5000 cycles. Combined with the high-throughput coating technology presented here, the hybrid films will provide a robust and scalable strategy for large-area f-TFHs with highly enhanced performance. - Highlights: • We developed highly efficient flexible thin film heaters based on Ag nanowires and AZO composites. • In the composite, AZO plays an important role as an insulation blanket to block heat loss to

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

KAUST Repository

Yue, Weisheng

2016-04-07

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

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

KAUST Repository

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

2016-01-01

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

Deposition and characterization of TaAIN thin films by reactive magnetron sputtering

International Nuclear Information System (INIS)

Oliveira, G.B.; Fernandez, D.R.; Fontes Junior, A.S.; Felix, L.C.; Tentardini, E.K.; Silva Junior, A.H. da

2016-01-01

Phase stability, oxidation resistance and great mechanical properties are the main objectives when synthesizing protective coatings. The tantalum nitride (TaN) has aroused interest because of its high temperature stability, chemical inertness and thermal conductivity. However, it has a low hardness value when compared to other coatings. Researches has shown that one way to improvements in the properties of a thin film is by adding other elements in the deposition process. Therefore, the objective of this study was to deposit thin films of TaAlN by magnetron sputtering, changing the aluminum concentration of 2, 5, 7, to 14%. Then the coatings were characterized by EDS, RBS, GIXRD and nanohardness. In this study was found that the aluminum deposited did not change the oxidation resistance of the coating, and the highest value of hardness was 28 GPa for the sample with 14 at.%. (author)

High Dielectric Performance of Solution-Processed Aluminum Oxide-Boron Nitride Composite Films

Science.gov (United States)

Yu, Byoung-Soo; Ha, Tae-Jun

2018-04-01

The material compositions of oxide films have been extensively investigated in an effort to improve the electrical characteristics of dielectrics which have been utilized in various electronic devices such as field-effect transistors, and storage capacitors. Significantly, solution-based compositions have attracted considerable attention as a highly effective and practical technique to replace vacuum-based process in large-area. Here, we demonstrate solution-processed composite films consisting of aluminum oxide (Al2O3) and boron nitride (BN), which exhibit remarkable dielectric properties through the optimization process. The leakage current of the optimized Al2O3-BN thin films was decreased by a factor of 100 at 3V, compared to pristine Al2O3 thin film without a loss of the dielectric constant or degradation of the morphological roughness. The characterization by X-ray photoelectron spectroscopy measurements revealed that the incorporation of BN with an optimized concentration into the Al2O3 dielectric film reduced the density of oxygen vacancies which act as defect states, thereby improving the dielectric characteristics.

Thermally Annealed Iron (Oxide) Thin Film on an Alumina Barrier Layer, by XPS

Energy Technology Data Exchange (ETDEWEB)

Madaan, Nitesh; Kanyal, Supriya S.; Jensen, David S.; Vail, Michael A.; Dadson, Andrew; Engelhard, Mark H.; Linford, Matthew R.

2013-09-06

Herein we show characterization of an Fe thin film on Al_2O_3 after thermal annealing under H_2 using Al Ka X-rays. The XPS survey spectrum, narrow Fe 2p scan, and valence band regions are presented. The survey spectrum shows aluminum signals due to exposure of the underlying Al_2O_3 film during Fe nanoparticle formation.

Effect of contact metals on the piezoelectric properties of aluminum nitride thin films

Energy Technology Data Exchange (ETDEWEB)

Harman, J.P.; Kabulski, A. (West Virginia U., Morgantown, WV); Pagan, V.R. (West Virginia U., Morgantown, WV); Famouri, K. (West Virginia U., Morgantown, WV); Kasarla, K.R.; Rodak, L.E. (West Virginia U., Morgantown, WV); Hensel, J.P.; Korakakis, D.

2008-07-01

The converse piezoelectric response of aluminum nitride evaluated using standard metal insulator semiconductor structures has been found to exhibit a linear dependence on the work function of the metal used as the top electrode. The apparent d33 of the 150–1100 nm films also depends on the dc bias applied to the samples.

Effect of contact metals on the piezoelectric properties of aluminum nitride thin films

Energy Technology Data Exchange (ETDEWEB)

Harman, J.; Kabulski, A.; Pagán, V. R.; Famouri, P.; Kasarla, K. R.; Rodak, L. E.; Peter Hensel, J.; Korakakis, D.

2008-01-01

The converse piezoelectric response of aluminum nitride evaluated using standard metal insulator semiconductor structures has been found to exhibit a linear dependence on the work function of the metal used as the top electrode. The apparent d33 of the 150–1100 nm films also depends on the dc bias applied to the samples.

Memory and Electrical Properties of (100-Oriented AlN Thin Films Prepared by Radio Frequency Magnetron Sputtering

Directory of Open Access Journals (Sweden)

Maw-Shung Lee

2014-01-01

Full Text Available The (100-oriented aluminum nitride (AlN thin films were well deposited onto p-type Si substrate by radio frequency (RF magnetron sputtering method. The optimal deposition parameters were the RF power of 350 W, chamber pressure of 9 mTorr, and nitrogen concentration of 50%. Regarding the physical properties, the microstructure of as-deposited (002- and (100-oriented AlN thin films were obtained and compared by XRD patterns and TEM images. For electrical properties analysis, we found that the memory windows of (100-oriented AlN thin films are better than those of (002-oriented thin films. Besides, the interface and interaction between the silicon and (100-oriented AlN thin films was serious important problem. Finally, the current transport models of the as-deposited and annealed (100-oriented AlN thin films were also discussed. From the results, we suggested and investigated that large memory window of the annealed (100-oriented AlN thin films was induced by many dipoles and large electric field applied.

Periodic domain inversion in x-cut single-crystal lithium niobate thin film

Energy Technology Data Exchange (ETDEWEB)

Mackwitz, P., E-mail: peterm@mail.upb.de; Rüsing, M.; Berth, G.; Zrenner, A. [Department Physik, Universität Paderborn, 33095 Paderborn (Germany); Center for Optoelectronics and Photonics Paderborn, 33095 Paderborn (Germany); Widhalm, A.; Müller, K. [Department Physik, Universität Paderborn, 33095 Paderborn (Germany)

2016-04-11

We report the fabrication of periodically poled domain patterns in x-cut lithium niobate thin-film. Here, thin films on insulator have drawn particular attention due to their intrinsic waveguiding properties offering high mode confinement and smaller devices compared to in-diffused waveguides in bulk material. In contrast to z-cut thin film lithium niobate, the x-cut geometry does not require back electrodes for poling. Further, the x-cut geometry grants direct access to the largest nonlinear and electro-optical tensor element, which overall promises smaller devices. The domain inversion was realized via electric field poling utilizing deposited aluminum top electrodes on a stack of LN thin film/SiO{sub 2} layer/Bulk LN, which were patterned by optical lithography. The periodic domain inversion was verified by non-invasive confocal second harmonic microscopy. Our results show domain patterns in accordance to the electrode mask layout. The second harmonic signatures can be interpreted in terms of spatially, overlapping domain filaments which start their growth on the +z side.

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.

Characteristics of sputtered Al-doped ZnO films for transparent electrodes of organic thin-film transistor

International Nuclear Information System (INIS)

Park, Yong Seob; Kim, Han-Ki

2011-01-01

Aluminum-doped ZnO (AZO) thin-films were deposited with various RF powers at room temperature by radio frequency (RF) magnetron sputtering method. The electrical properties of the AZO film were improved with the increasing RF power. These results can be explained by the improvement of the crystallinity in the AZO film. We fabricated the organic thin-film transistor (OTFT) of the bottom gate structure using pentacene active and poly-4-vinyl phenol gate dielectric layers on the indium tin oxide gate electrode, and estimated the device properties of the OTFTs including drain current-drain voltage (I D -V D ), drain current-gate voltage (I D -V G ), threshold voltage (V T ), on/off ratio and field effect mobility. The AZO film that grown at 160 W RF power exhibited low resistivity (1.54 x 10 -3 Ω.cm), high crystallinity and uniform surface morphology. The pentacene thin-film transistor using the AZO film that's fabricated at 160 W RF power exhibited good device performance such as the mobility of 0.94 cm 2 /V s and the on/off ratio of ∼ 10 5 . Consequently, the performance of the OTFT such as larger field-effect carrier mobility was determined the conductivity of the AZO source/drain (S/D) electrode. AZO films prepared at room temperature by the sputtering method are suitable for the S/D electrodes in the OTFTs.

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

Attachment of lead wires to thin film thermocouples mounted on high temperature materials using the parallel gap welding process

Science.gov (United States)

Holanda, Raymond; Kim, Walter S.; Pencil, Eric; Groth, Mary; Danzey, Gerald A.

1990-01-01

Parallel gap resistance welding was used to attach lead wires to sputtered thin film sensors. Ranges of optimum welding parameters to produce an acceptable weld were determined. The thin film sensors were Pt13Rh/Pt thermocouples; they were mounted on substrates of MCrAlY-coated superalloys, aluminum oxide, silicon carbide and silicon nitride. The entire sensor system is designed to be used on aircraft engine parts. These sensor systems, including the thin-film-to-lead-wire connectors, were tested to 1000 C.

On-Orbit Demonstration of a Lithium-Ion Capacitor and Thin-Film Multijunction Solar Cells

Science.gov (United States)

Kukita, Akio; Takahashi, Masato; Shimazaki, Kazunori; Kobayashi, Yuki; Sakai, Tomohiko; Toyota, Hiroyuki; Takahashi, Yu; Murashima, Mio; Uno, Masatoshi; Imaizumi, Mitsuru

2014-08-01

This paper describes an on-orbit demonstration of the Next-generation Small Satellite Instrument for Electric power systems (NESSIE) on which an aluminum- laminated lithium-ion capacitor (LIC) and a lightweight solar panel called KKM-PNL, which has space solar sheets using thin-film multijunction solar cells, were installed. The flight data examined in this paper covers a period of 143 days from launch. We verified the integrity of an LIC constructed using a simple and lightweight mounting method: no significant capacitance reduction was observed. We also confirmed that inverted metamorphic multijunction triple-junction thin-film solar cells used for evaluation were healthy at 143 days after launch, because their degradation almost matched the degradation predictions for dual-junction thin-film solar cells.

Design of Faraday cup ion detectors built by thin film deposition

Energy Technology Data Exchange (ETDEWEB)

Szalkowski, G.A., E-mail: gszalkowski3@gatech.edu [Department of Nuclear Engineering, Georgia Institute of Technology, 770 State St., Atlanta, GA 30332 (United States); Darrow, D.S., E-mail: ddarrow@pppl.gov [Princeton Plasma Physics Laboratory, P. O. Box 451, Princeton, NJ 08543 (United States); Cecil, F.E., E-mail: fcecil@mines.edu [Department of Physics, Colorado School of Mines, Golden, CO 80401 (United States)

2017-03-11

Thin film Faraday cup detectors can provide measurements of fast ion loss from magnetically confined fusion plasmas. These multilayer detectors can resolve the energy distribution of the lost ions in addition to giving the total loss rate. Prior detectors were assembled from discrete foils and insulating sheets. Outlined here is a design methodology for creating detectors using thin film deposition that are suited to particular scientific goals. The intention is to use detectors created by this method on the Joint European Torus (JET) and the National Spherical Torus Experiment-Upgrade (NSTX-U). The detectors will consist of alternating layers of aluminum and silicon dioxide, with layer thicknesses chosen to isolate energies of interest. Thin film deposition offers the advantage of relatively simple and more mechanically robust construction compared to other methods, as well as allowing precise control of film thickness. Furthermore, this depositional fabrication technique places the layers in intimate thermal contact, providing for three-dimensional conduction and dissipation of the ion-produced heating in the layers, rather than the essentially two-dimensional heat conduction in the discrete foil stack implementation.

Thermoluminescence of thin films deposited by laser ablation; Termoluminiscencia de peliculas delgadas depositadas por ablacion laser

Energy Technology Data Exchange (ETDEWEB)

Escobar A, L.; Camps, E.; Arrieta, A.; Romero, S.; Gonzalez, P.R.; Olea M, O.; Diaz E, R. [Depto. de Fisica, ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

2003-07-01

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

Magnetic resonance in spin glasses, superconductivity of thin aluminum films and models for transport properties of one dimensional systems

International Nuclear Information System (INIS)

Elliott, J.H.

1983-01-01

This thesis reports on three separate investigations in solid state physics. The first is electron paramagnetic resonance in the spin glass Ag:Mn. EPR measurements were performed at two resonance frequencies, concentrating on temperatures above the glass transition temperature. The measured linewidth appears to diverge at T/sub g/ for low resonance frequencies. These results will be compared with recently proposed phenomenological and microscopic theories. The second topic reported in this thesis is the superconducting transition of thin aluminum films. These films were investigated as a function of grain size and thickness. The transition temperature was enhanced over the bulk value, in agreement with many previous investigations of granular aluminum. The third topic reported in this thesis is an extension of the variable rate hopping theory applied in one dimension to N-ME-Qn(TCNQ) 2 . This model is a classical one used to explain both the dc and ac electrical conductivity of organic conductors. The temperature dependence of the model does not agree with experiment at low temperatures. Tunneling has been added to the hopping. This increases the conductivity at low temperatures, and results in excellent agreement with the experimental conductivity over the measured temperature range. The model also predicts that the frequency dependence of the conductivity varies as ω/sup .5/ at low frequencies. This long time tail prediction agrees with the measured dielectric constant of N-Me-iso-Qn(TCNQ) 2

Detection of charge storage on molecular thin films of tris(8-hydroxyquinoline) aluminum (Alq3) by Kelvin force microscopy: a candidate system for high storage capacity memory cells.

Science.gov (United States)

Paydavosi, Sarah; Aidala, Katherine E; Brown, Patrick R; Hashemi, Pouya; Supran, Geoffrey J; Osedach, Timothy P; Hoyt, Judy L; Bulović, Vladimir

2012-03-14

Retention and diffusion of charge in tris(8-hydroxyquinoline) aluminum (Alq(3)) molecular thin films are investigated by injecting electrons and holes via a biased conductive atomic force microscopy tip into the Alq(3) films. After the charge injection, Kelvin force microscopy measurements reveal minimal changes with time in the spatial extent of the trapped charge domains within Alq(3) films, even for high hole and electron densities of >10(12) cm(-2). We show that this finding is consistent with the very low mobility of charge carriers in Alq(3) thin films (<10(-7) cm(2)/(Vs)) and that it can benefit from the use of Alq(3) films as nanosegmented floating gates in flash memory cells. Memory capacitors using Alq(3) molecules as the floating gate are fabricated and measured, showing durability over more than 10(4) program/erase cycles and the hysteresis window of up to 7.8 V, corresponding to stored charge densities as high as 5.4 × 10(13) cm(-2). These results demonstrate the potential for use of molecular films in high storage capacity nonvolatile memory cells. © 2012 American Chemical Society

Development of alpha spectroscopy method with solid state nuclear track detector using aluminium thin films

International Nuclear Information System (INIS)

Dwaikat, N.

2015-10-01

This work presents the development of alpha spectroscopy method with Solid-state nuclear track detectors using aluminum thin films. The resolution of this method is high, and it is able to discriminate between alpha particles at different incident energy. It can measure the exact number of alpha particles at specific energy without needing a calibration of alpha track diameter versus alpha energy. This method was tested by using Cf-252 alpha standard source at energies 5.11 MeV, 3.86 MeV and 2.7 MeV, which produced by the variation of detector -standard source distance. On front side, two detectors were covered with two Aluminum thin films and the third detector was kept uncovered. The thickness of Aluminum thin films was selected carefully (using SRIM 2013) such that one of the films will block the lower two alpha particles (3.86 MeV and 2.7 MeV) and the alpha particles at higher energy (5.11 MeV) can penetrate the film and reach the detectors surface. The second thin film will block alpha particles at lower energy of 2.7 MeV and allow alpha particles at higher two energies (5.11 MeV and 3.86 MeV) to penetrate and produce tracks. For uncovered detector, alpha particles at three different energies can produce tracks on it. For quality assurance and accuracy, the detectors were mounted on thick enough copper substrates to block exposure from the backside. The tracks on the first detector are due to alpha particles at energy of 5.11 MeV. The difference between the tracks number on the first detector and the tracks number on the second detector is due to alpha particles at energy of 3.8 MeV. Finally, by subtracting the tracks number on the second detector from the tracks number on the third detector (uncovered), we can find the tracks number due to alpha particles at energy 2.7 MeV. After knowing the efficiency calibration factor, we can exactly calculate the activity of standard source. (Author)

Development of alpha spectroscopy method with solid state nuclear track detector using aluminium thin films

Energy Technology Data Exchange (ETDEWEB)

Dwaikat, N., E-mail: ndwaikat@kfupm.edu.sa [King Fahd University of Petroleum and Minerals, College of Sciences, Department of Physics, Dhahran 31261 (Saudi Arabia)

2015-10-15

This work presents the development of alpha spectroscopy method with Solid-state nuclear track detectors using aluminum thin films. The resolution of this method is high, and it is able to discriminate between alpha particles at different incident energy. It can measure the exact number of alpha particles at specific energy without needing a calibration of alpha track diameter versus alpha energy. This method was tested by using Cf-252 alpha standard source at energies 5.11 MeV, 3.86 MeV and 2.7 MeV, which produced by the variation of detector -standard source distance. On front side, two detectors were covered with two Aluminum thin films and the third detector was kept uncovered. The thickness of Aluminum thin films was selected carefully (using SRIM 2013) such that one of the films will block the lower two alpha particles (3.86 MeV and 2.7 MeV) and the alpha particles at higher energy (5.11 MeV) can penetrate the film and reach the detectors surface. The second thin film will block alpha particles at lower energy of 2.7 MeV and allow alpha particles at higher two energies (5.11 MeV and 3.86 MeV) to penetrate and produce tracks. For uncovered detector, alpha particles at three different energies can produce tracks on it. For quality assurance and accuracy, the detectors were mounted on thick enough copper substrates to block exposure from the backside. The tracks on the first detector are due to alpha particles at energy of 5.11 MeV. The difference between the tracks number on the first detector and the tracks number on the second detector is due to alpha particles at energy of 3.8 MeV. Finally, by subtracting the tracks number on the second detector from the tracks number on the third detector (uncovered), we can find the tracks number due to alpha particles at energy 2.7 MeV. After knowing the efficiency calibration factor, we can exactly calculate the activity of standard source. (Author)

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

KAUST Repository

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

2013-01-01

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

Simulation of transformations of thin metal films heated by nanosecond laser pulses

Science.gov (United States)

Balandin, V. Yu.; Niedrig, R.; Bostanjoglo, O.

1995-01-01

The ablation of free-standing thin aluminum films by a nanosecond laser pulse was investigated by time-resolved transmission electron microscopy and numerical simulation. It was established that thin film geometry is particularly suited to furnish information on the mechanism of evaporation and the surface tension of the melt. In the case of aluminum the surface tension sigma as function of temperature can be approximated by two linear sections with a coefficient -0.3 x 10(exp -3) N/K m from the melting point 933 K up to 3000 K and -0.02 x 10(exp -3) N/K m above 3000 K, respectively, with sigma(993 K) = 0.9 N/m and sigma(8500 K) = 0. At lower pulse energies the films disintegrated predominantly by thermocapillary flow. Higher pulse energies produced volume evaporation, and a nonmonotonous flow, explained by recoil from evaporating atoms and thermocapillarity. The familiar equations of energy and motion, which presuppose separate and coherent vapor and liquid phases, were not adequate to describe the ablation of the hottest zone. Surface evaporation seemed to be marginal at all laser pulse energies used.

Effect of Al-doped on physical properties of ZnO Thin films grown by spray pyrolysis on SnO2: F/glass

Directory of Open Access Journals (Sweden)

Castagné M.

2012-06-01

Full Text Available Transparent conducting thin films of aluminum-doped zinc oxide (ZnO:Al have been deposited on SnO2:F/glass by the chemical spray technique, starting from zinc acetate (CH3CO22Zn.2H2O and aluminum chloride AlCl3. The effect of changing the aluminum-to-zinc ratio y from 0 to 3 at.%, has been thoroughly investigated. It was found that the optical and electrical properties of Al doped ZnO films improved with the addition of aluminum in the spray solution until y=2%. At this Al doping percentage, the thin layers have a resistivity equal to 4.1 × 10−4 Ω.cm and a transmittance of about 90 % in the region [600-1000] nm. XRD patterns confirm that the films have polycristalline nature and a wurtzite (hexagonal structure which characterized with (100, (002 and (101 principal orientations. The undoped films have (002 as the preferred orientation but Al doped ones have (101 as the preferred orientation. Beyond y= 1%, peak intensities decrease considerably.

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.)

Electrical properties of AlN{sub x}O{sub y} thin films prepared by reactive magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Borges, J., E-mail: joelborges@fisica.uminho.pt [Centro de Fisica, Universidade do Minho, 4710-057 Braga (Portugal); Martin, N. [Institut FEMTO-ST, Departement MN2S, UMR 6174 (CNRS, UFC, ENSMM, UTBM) 32, Avenue de l' Observatoire 25044 BESANCON Cedex (France); Barradas, N.P.; Alves, E. [Instituto Superior Tecnico, Instituto Tecnologico Nuclear, E.N. 10, 2686-953 Sacavem (Portugal); Eyidi, D.; Beaufort, M.F.; Riviere, J.P. [Institut PPRIME, UPR 3346 CNRS-Universite de Poitiers-ENSMA, Departement de Physique et Mecanique des Materiaux, BP 30179 86962 Chasseneuil-Futuroscope Cedex (France); Vaz, F.; Marques, L. [Centro de Fisica, Universidade do Minho, 4710-057 Braga (Portugal)

2012-08-31

Direct current magnetron sputtering was used to produce AlN{sub x}O{sub y} thin films, using an aluminum target, argon and a mixture of N{sub 2} + O{sub 2} (17:3) as reactive gases. The partial pressure of the reactive gas mixture was increased, maintaining the discharge current constant. Within the two identified regimes of the target (metallic and compound), four different tendencies for the deposition rate were found and a morphological evolution from columnar towards cauliflower-type, ending up as dense and featureless-type films. The structure was found to be Al-type (face centered cubic) and the structural characterization carried out by X-ray diffraction and transmission electron microscopy suggested the formation of an aluminum-based polycrystalline phase dispersed in an amorphous aluminum oxide/nitride (or oxynitride) matrix. This type of structure, composition, morphology and grain size, were found to be strongly correlated with the electrical response of the films, which showed a gradual transition between metallic-like responses towards semiconducting and even insulating-type behaviors. A group of films with high aluminum content revealed a sharp decrease of the temperature coefficient of resistance (TCR) as the concentration ratio of non-metallic/aluminum atomic ratio increased. Another group of samples, where the non-metallic content became more important, revealed a smooth transition between positive and negative values of TCR. In order to test whether the oxynitride films have a unique behavior or simply a transition between the typical responses of aluminum and of those of the correspondent nitride and oxide, the electrical properties of the ternary oxynitride system were compared with AlN{sub x} and AlO{sub y} systems, prepared in similar conditions. - Highlights: Black-Right-Pointing-Pointer AlN{sub x}O{sub y} thin films were produced using magnetron sputtering. Black-Right-Pointing-Pointer AlN{sub x}O{sub y} film morphology, composition and

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.

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

Science.gov (United States)

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

2015-04-01

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

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 ...

Parametric study of thin film evaporation from nanoporous membranes

Science.gov (United States)

Wilke, Kyle L.; Barabadi, Banafsheh; Lu, Zhengmao; Zhang, TieJun; Wang, Evelyn N.

2017-10-01

The performance and lifetime of advanced electronics are often dictated by the ability to dissipate heat generated within the device. Thin film evaporation from nanoporous membranes is a promising thermal management approach, which reduces the thermal transport distance across the liquid film while also providing passive capillary pumping of liquid to the evaporating interface. In this work, we investigated the dependence of thin film evaporation from nanoporous membranes on a variety of geometric parameters. Anodic aluminum oxide membranes were used as experimental templates, where pore radii of 28-75 nm, porosities of 0.1-0.35, and meniscus locations down to 1 μm within the pore were tested. We demonstrated different heat transfer regimes and observed more than an order of magnitude increase in dissipated heat flux by operating in the pore-level evaporation regime. The pore diameter had little effect on pore-level evaporation performance due to the negligible conduction resistance from the pore wall to the evaporating interface. The dissipated heat flux scaled with porosity as the evaporative area increased. Furthermore, moving the meniscus as little as 1 μm into the pore decreased the dissipated heat flux by more than a factor of two due to the added resistance to vapor escaping the pore. The experimental results elucidate thin film evaporation from nanopores and confirm findings of recent modeling efforts. This work also provides guidance for the design of future thin film evaporation devices for advanced thermal management. Furthermore, evaporation from nanopores is relevant to water purification, chemical separations, microfluidics, and natural processes such as transpiration.

Ion irradiation of AZO thin films for flexible electronics

Energy Technology Data Exchange (ETDEWEB)

Boscarino, Stefano; Torrisi, Giacomo; Crupi, Isodiana [IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy); Alberti, Alessandra [CNR-IMM, via Strada VIII 5, 95121 Catania (Italy); Mirabella, Salvatore; Ruffino, Francesco [IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy); Terrasi, Antonio, E-mail: antonio.terrasi@ct.infn.it [IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy)

2017-02-01

Highlights: • Evidence of electrical good quality AZO ultra thin films without thermal annealing. • Evidence of the main role of Oxygen vs. structural parameters in controlling the electrical performances of AZO. • Evidence of the role of the ion irradiation in improving the electrical properties of AZO ultra thin films. • Synthesis of AZO thin films on flexible/plastic substrates with good electrical properties without thermal processes. - Abstract: Aluminum doped Zinc oxide (AZO) is a promising transparent conductor for solar cells, displays and touch-screen technologies. The resistivity of AZO is typically improved by thermal annealing at temperatures not suitable for plastic substrates. Here we present a non-thermal route to improve the electrical and structural properties of AZO by irradiating the TCO films with O{sup +} or Ar{sup +} ion beams (30–350 keV, 3 × 10{sup 15}–3 × 10{sup 16} ions/cm{sup 2}) after the deposition on glass and flexible polyethylene naphthalate (PEN). X-ray diffraction, optical absorption, electrical measurements, Rutherford Backscattering Spectrometry and Atomic Force Microscopy evidenced an increase of the crystalline grain size and a complete relief of the lattice strain upon ion beam irradiation. Indeed, the resistivity of thin AZO films irradiated at room temperature decreased of two orders of magnitude, similarly to a thermal annealing at 400 °C. We also show that the improvement of the electrical properties does not simply depend on the strain or polycrystalline domain size, as often stated in the literature.

Analysis of chemical dissolution of the barrier layer of porous oxide on aluminum thin films using a re-anodizing technique

Energy Technology Data Exchange (ETDEWEB)

Vrublevsky, I. [Department of Microelectronics, Belarusian State University of Informatics and Radioelectronics, 6 Brovka street, Minsk 220013 (Belarus)]. E-mail: nil-4-2@bsuir.edu.by; Parkoun, V. [Department of Microelectronics, Belarusian State University of Informatics and Radioelectronics, 6 Brovka street, Minsk 220013 (Belarus); Sokol, V. [Department of Microelectronics, Belarusian State University of Informatics and Radioelectronics, 6 Brovka street, Minsk 220013 (Belarus); Schreckenbach, J. [Institut fuer Chemie, Technische Universitaet Chemnitz, Chemnitz D-09107 (Germany)

2005-09-30

Chemical dissolution of the barrier layer of porous oxide formed on thin aluminum films (99.9% purity) in the 4% oxalic acid after immersion in 2 mol dm{sup -3} sulphuric acid at 50 deg. C has been studied. The barrier layer thickness before and after dissolution was calculated using a re-anodizing technique. It has been shown that above 57 V the change in the growth mechanism of porous alumina films takes place. As a result, the change in the amount of regions in the barrier oxide with different dissolution rates is observed. The barrier oxide contains two layers at 50 V: the outer layer with the highest dissolution rate and the inner layer with a low dissolution rate. Above 60 V the barrier oxide contains three layers: the outer layer with a high dissolution rate, the middle layer with the highest dissolution rate and the inner layer with a low dissolution rate. We suggest that the formation of the outer layer of barrier oxide with a high dissolution rate is linked with the injection of protons or H{sub 3}O{sup +} ions from the electrolyte into the oxide film at the anodizing voltages above 57 V.

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

Broadband THz pulse emission and transmission properties of nanostructured Pt thin films

Energy Technology Data Exchange (ETDEWEB)

Hu, Mingzhe [Department of Physics and Electronics, Liupanshui Normal University, Liupanshui, Guizhou 553004 (China); College of Electronics and Information, Guizhou University, Huaxi 550025, Guiyang, Guizhou (China); Mu, Kaijun; Zhang, Cunlin [Department of Physics, Capital Normal University, Yuquan Road 100082, Beijing (China); Gu, Haoshuang, E-mail: guhs@hubu.edu.cn [Department of Electronic Sci& Tech, Hubei University, Xueyuan Road 430062, Wuhan, Hubei (China); Ding, Zhao [College of Electronics and Information, Guizhou University, Huaxi 550025, Guiyang, Guizhou (China)

2015-10-01

The THz transmission and emitting properties of a composite metallic nanostructure, composed of Ag nanowires electrodeposited in an anodic aluminum oxide (AAO) template and a Pt thin film, were investigated by using a femtosecond pulse laser irradiation. The microstructure of the above sub-wavelength nanostructure was investigated by XRD, SEM, AFM and TEM. The results indicated that the thickness of the Pt thin film was about 200 nm and the Ag nanowire array had a sparse and random distribution inside the AAO template, with a length distribution in the range of 10–25 μm. The THz radiation properties of above sub-wavelength nanostructure indicated that the generated THz fluence from the Pt film was a magnitude of μW scale with a broadband frequency range and its subsequent transmission could be significantly improved by the better impedance matching property of the Ag nanowire embedded AAO film compared with that of the empty AAO film.

Damp heat stability and annealing behavior of aluminum doped zinc oxide films prepared by magnetron sputtering

International Nuclear Information System (INIS)

Tohsophon, T.; Huepkes, J.; Calnan, S.; Reetz, W.; Rech, B.; Beyer, W.; Sirikulrat, N.

2006-01-01

The damp heat stability and subsequent vacuum annealing behavior of aluminum doped zinc oxide (AZO) films was investigated using Hall effect measurements, X-ray diffraction (XRD) and optical spectrometry techniques. The AZO films were deposited on glass or silicon wafers using reactive and non-reactive magnetron sputtering from metallic and ceramic targets, respectively. Additionally, we characterized surface textured AZO films, which are used as light scattering transparent conductive oxide (TCO) in silicon thin film solar cells. For all films a degradation of the electrical film properties was found after the damp heat treatment. For thick compact films, with large grain size, only a small increase in the electrical resistivity was observed, whereas less compact films prepared at high deposition pressures or very thin films (< 300 nm) showed an increase in resistivity by up to a factor of three already after 300 h. The conductivity degradation during damp heat treatment could be largely reversed by annealing in vacuum. However, annealing temperatures of at least 150 deg. C were required. Possible mechanisms explaining the experimental results are discussed

Experimental investigation on photoelectric properties of ZAO thin film deposited on flexible substrate by magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Hao, Ming [School of Mechanical Engineering and Automation, Northeastern University, 3-11 WenHua Rd., 319#, Shenyang, 110004 (China); Liu, Kun, E-mail: kliu@mail.neu.edu.cn [School of Mechanical Engineering and Automation, Northeastern University, 3-11 WenHua Rd., 319#, Shenyang, 110004 (China); Liu, Xinghua [Hubei Aerospace Industry Technology Academe Special Vehicle Technology Center, Wuhan (China); Wang, Dongyang; Ba, Dechun; Xie, Yuanhua; Du, Guangyu; Ba, Yaoshuai [School of Mechanical Engineering and Automation, Northeastern University, 3-11 WenHua Rd., 319#, Shenyang, 110004 (China)

2016-12-01

Highlights: • ZAO thin films were deposited on PET substrate. • A set of experimental parameters were systematically investigated. • Change rule of film photoelectric properties was obtained. • ZAO films with optimal properties were obtained at our working conditions. - Abstract: Transparent conductive ZAO (Zinc Aluminum Oxide) films on flexible substrates have a great potential for low-cost mass-production solar cells. ZAO thin films were achieved on flexible PET (polyethylene terephthalate) substrates by RF magnetron sputtering technology. The surface morphology and element content, the transmittance and the sheet resistance of the films were measured to determine the optical process parameters. The results show that the ZAO thin film shows the best parameters in terms of photoelectric performance including sputtering power, working pressure, sputtering time, substrate temperature (100 W, 1.5 Pa, 60 min, 125 °C). The sheet resistance of 510 Ω and transmittance in visible region of 92% were obtained after characterization. Surface morphology was uniform and compact with a good crystal grain.

Experimental investigation on photoelectric properties of ZAO thin film deposited on flexible substrate by magnetron sputtering

International Nuclear Information System (INIS)

Hao, Ming; Liu, Kun; Liu, Xinghua; Wang, Dongyang; Ba, Dechun; Xie, Yuanhua; Du, Guangyu; Ba, Yaoshuai

2016-01-01

Highlights: • ZAO thin films were deposited on PET substrate. • A set of experimental parameters were systematically investigated. • Change rule of film photoelectric properties was obtained. • ZAO films with optimal properties were obtained at our working conditions. - Abstract: Transparent conductive ZAO (Zinc Aluminum Oxide) films on flexible substrates have a great potential for low-cost mass-production solar cells. ZAO thin films were achieved on flexible PET (polyethylene terephthalate) substrates by RF magnetron sputtering technology. The surface morphology and element content, the transmittance and the sheet resistance of the films were measured to determine the optical process parameters. The results show that the ZAO thin film shows the best parameters in terms of photoelectric performance including sputtering power, working pressure, sputtering time, substrate temperature (100 W, 1.5 Pa, 60 min, 125 °C). The sheet resistance of 510 Ω and transmittance in visible region of 92% were obtained after characterization. Surface morphology was uniform and compact with a good crystal grain.

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

Science.gov (United States)

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

2017-08-01

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

Modeling of metal thin film growth: Linking angstrom-scale molecular dynamics results to micron-scale film topographies

Science.gov (United States)

Hansen, U.; Rodgers, S.; Jensen, K. F.

2000-07-01

A general method for modeling ionized physical vapor deposition is presented. As an example, the method is applied to growth of an aluminum film in the presence of an ionized argon flux. Molecular dynamics techniques are used to examine the surface adsorption, reflection, and sputter reactions taking place during ionized physical vapor deposition. We predict their relative probabilities and discuss their dependence on energy and incident angle. Subsequently, we combine the information obtained from molecular dynamics with a line of sight transport model in a two-dimensional feature, incorporating all effects of reemission and resputtering. This provides a complete growth rate model that allows inclusion of energy- and angular-dependent reaction rates. Finally, a level-set approach is used to describe the morphology of the growing film. We thus arrive at a computationally highly efficient and accurate scheme to model the growth of thin films. We demonstrate the capabilities of the model predicting the major differences on Al film topographies between conventional and ionized sputter deposition techniques studying thin film growth under ionized physical vapor deposition conditions with different Ar fluxes.

Aluminum-doped Zn O polycrystalline films prepared by co-sputtering of a Zn O-Al target

Energy Technology Data Exchange (ETDEWEB)

Becerril, M.; Silva L, H.; Guillen C, A.; Zelaya A, O. [Instituto Politecnico Nacional, Centro de Investigacion y de Estudios Avanzados, Departamento de Fisica, Apdo. Postal 14-740, 07000 Mexico D. F. (Mexico)

2014-07-01

Aluminum-doped Zinc oxide polycrystalline thin films (Azo) were grown on 7059 Corning glass substrates at room temperature by co-sputtering from a Zn O-Al target. The target was designed as follows, high purity elemental Aluminum was evaporated onto a Zn O target covering small areas. The structural, optical and electrical properties were analyzed as a function of Al content. The Al doped Zn O polycrystalline films showed an n-type conductivity. It was found that the electrical resistivity drops and the carrier concentration increases as a consequence of Al incorporation within the Zn O lattice. In both cases, the changes are of several orders of magnitude. From the results, we conclude that, using these Zn O-Al targets, n-type Al doped Zn O polycrystalline films with high transmittance and low resistivity can be obtained. The crystalline structure of the films was determined by X-ray diffraction. Atomic Force Microscopy images were obtained with an Auto probe C P (Veeco Metrology Group) Microscope. (Author)

Evaluating Origin of Electron Traps in Tris(8-hydroxyquinoline) Aluminum Thin Films using Thermally Stimulated Current Technique

OpenAIRE

Matsushima, Toshinori; Adachi, Chihaya

2008-01-01

We measured the energy distributions and concentrations of electron traps in O_2-unexposed and O_2-exposed tris(8-hydroxyquinoline) aluminum (Alq_3) films using a thermally stimulated current (TSC) technique to investigate how doping O_2 molecules in Alq_3 films affect the films' electron trap and electron transport characteristics. The results of our TSC studies revealed that Alq_3 films have an electron trap distribution with peak depths ranging from 0.075 to 0.1 eV and peak widths ranging ...

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

Directory of Open Access Journals (Sweden)

Hui-Ying Li

2015-02-01

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

Transparent conductive ZnO layers on polymer substrates: Thin film deposition and application in organic solar cells

Energy Technology Data Exchange (ETDEWEB)

Dosmailov, M. [Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Leonat, L.N. [Linz Institute for Organic Solar Cells (LIOS)/Institute of Physical Chemistry, Johannes Kepler University Linz, A-4040 Linz (Austria); Patek, J. [Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Roth, D.; Bauer, P. [Institute of Experimental Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Scharber, M.C.; Sariciftci, N.S. [Linz Institute for Organic Solar Cells (LIOS)/Institute of Physical Chemistry, Johannes Kepler University Linz, A-4040 Linz (Austria); Pedarnig, J.D., E-mail: johannes.pedarnig@jku.at [Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria)

2015-09-30

Aluminum doped ZnO (AZO) and pure ZnO thin films are grown on polymer substrates by pulsed-laser deposition and the optical, electrical, and structural film properties are investigated. Laser fluence, substrate temperature, and oxygen pressure are varied to obtain transparent, conductive, and stoichiometric AZO layers on polyethylene terephthalate (PET) that are free of cracks. At low fluence (1 J/cm{sup 2}) and low pressure (10{sup −3} mbar), AZO/PET samples of high optical transmission in the visible range, low electrical sheet resistance, and high figure of merit (FOM) are produced. AZO films on fluorinated ethylene propylene have low FOM. The AZO films on PET substrates are used as electron transport layer in inverted organic solar cell devices employing P3HT:PCBM as photovoltaic polymer-fullerene bulk heterojunction. - Highlights: • Aluminum doped and pure ZnO thin films are grown on polyethylene terephthalate. • Growth parameters laser fluence, temperature, and gas pressure are optimized. • AZO films on PET have high optical transmission and electrical conductance (FOM). • Organic solar cells on PET using AZO as electron transport layer are made. • Power conversion efficiency of these OSC devices is measured.

Effects of crystallinity and impurities on the electrical conductivity of Li–La–Zr–O thin films

Energy Technology Data Exchange (ETDEWEB)

Park, Joong Sun, E-mail: parkj@anl.gov [Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Cheng, Lei [Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Department of Material Sciences and Engineering, University of California, Berkeley, CA 94720 (United States); Zorba, Vassilia [Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Mehta, Apurva [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Cabana, Jordi [Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Department of Chemistry, University of Illinois at Chicago, IL 60607 (United States); Chen, Guoying; Doeff, Marca M.; Richardson, Thomas J. [Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Park, Jung Hoon [Department of Nano-Science and Technology, University of Seoul, Seoul (Korea, Republic of); Son, Ji-Won [High-Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136–791 (Korea, Republic of); Hong, Wan-Shick, E-mail: wshong@uos.ac.kr [Department of Nano-Science and Technology, University of Seoul, Seoul (Korea, Republic of)

2015-02-02

We present a study of the fabrication of thin films from a Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} (LLZO) target using pulsed laser deposition. The effects of substrate temperatures and impurities on electrochemical properties of the films were investigated. The thin films of Li–La–Zr–O were deposited at room temperature and higher temperatures on a variety of substrates. Deposition above 600 °C resulted in a mixture of cubic and tetragonal phases of LLZO, as well as a La{sub 2}Zr{sub 2}O{sub 7} impurity, and resulted in aluminum enrichment at the surface when Al-containing substrates were used. Films deposited at 600 °C exhibited the highest room temperature conductivity, 1.61 × 10{sup −6} S/cm. The chemical stability toward metallic lithium was also studied using X-ray photoelectron spectroscopy, which showed that the oxidation state of zirconium remained at + 4 following physical contact with heated lithium metal. - Highlights: • Thin film Li–La–Zr–O was deposited by pulsed laser deposition using Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12}. • Deposition above 600 °C resulted in cubic and tetragonal phases of Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12}. • Aluminum migration from the substrate to the film surface was observed. • The chemical stability toward lithium was studied by X-ray photoelectron spectroscopy.

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.

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

DEFF Research Database (Denmark)

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

2009-01-01

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

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

Science.gov (United States)

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

2017-06-01

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

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

Solvent influence upon structure & throughput of poly vinyledene fluoride thin film nano-patterns by imprint lithography

Science.gov (United States)

Sankar, M. S. Ravi; Gangineni, R. B.

2018-04-01

This work aims at understanding the solvent influence upon the throughput and structure of poly vinyledene fluoride (PVDF)nano-patterned films. The PVDF thin films are deposited by spin coating method using Dimethylsulfoxide (DMSO), Tetrahydrofuran (THF) and 2-butanone solvents. The nano-patterns are realized by imprinting SONY 700 MB CD aluminum constructions on PVDF thin filmsusing imprint lithography technique under ambient annealing temperature and pressure. Surface morphology &imprint pattern transfer quality is evaluated with Atomic force microscopy (AFM). Raman spectroscopy is used for evaluating the structural evolutions with respect to solvent & patterning.

Atomic layer deposition of Al-incorporated Zn(O,S) thin films with tunable electrical properties

International Nuclear Information System (INIS)

Park, Helen Hejin; Jayaraman, Ashwin; Heasley, Rachel; Yang, Chuanxi; Hartle, Lauren; Gordon, Roy G.; Mankad, Ravin; Haight, Richard; Gunawan, Oki; Mitzi, David B.

2014-01-01

Zinc oxysulfide, Zn(O,S), films grown by atomic layer deposition were incorporated with aluminum to adjust the carrier concentration. The electron carrier concentration increased up to one order of magnitude from 10 19 to 10 20 cm −3 with aluminum incorporation and sulfur content in the range of 0 ≤ S/(Zn+Al) ≤ 0.16. However, the carrier concentration decreased by five orders of magnitude from 10 19 to 10 14 cm −3 for S/(Zn+Al) = 0.34 and decreased even further when S/(Zn+Al) > 0.34. Such tunable electrical properties are potentially useful for graded buffer layers in thin-film photovoltaic applications

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.

Air-Impregnated Nanoporous Anodic Aluminum Oxide Layers for Enhancing the Corrosion Resistance of Aluminum.

Science.gov (United States)

Jeong, Chanyoung; Lee, Junghoon; Sheppard, Keith; Choi, Chang-Hwan

2015-10-13

Nanoporous anodic aluminum oxide layers were fabricated on aluminum substrates with systematically varied pore diameters (20-80 nm) and oxide thicknesses (150-500 nm) by controlling the anodizing voltage and time and subsequent pore-widening process conditions. The porous nanostructures were then coated with a thin (only a couple of nanometers thick) Teflon film to make the surface hydrophobic and trap air in the pores. The corrosion resistance of the aluminum substrate was evaluated by a potentiodynamic polarization measurement in 3.5 wt % NaCl solution (saltwater). Results showed that the hydrophobic nanoporous anodic aluminum oxide layer significantly enhanced the corrosion resistance of the aluminum substrate compared to a hydrophilic oxide layer of the same nanostructures, to bare (nonanodized) aluminum with only a natural oxide layer on top, and to the latter coated with a thin Teflon film. The hydrophobic nanoporous anodic aluminum oxide layer with the largest pore diameter and the thickest oxide layer (i.e., the maximized air fraction) resulted in the best corrosion resistance with a corrosion inhibition efficiency of up to 99% for up to 7 days. The results demonstrate that the air impregnating the hydrophobic nanopores can effectively inhibit the penetration of corrosive media into the pores, leading to a significant improvement in corrosion resistance.

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.

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

KAUST Repository

Abutaha, Anas I.

2013-02-06

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

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

Structural and dielectric characterization of sputtered Tantalum Titanium Oxide thin films for high temperature capacitor applications

Energy Technology Data Exchange (ETDEWEB)

Rouahi, A., E-mail: rouahi_ahlem@yahoo.fr [Univ. Grenoble Alpes, G2Elab, F-38000 (France); Laboratoire Matériaux Organisation et Propriétés (LMOP), Université de Tunis El Manar, 2092 Tunis (Tunisia); Challali, F. [Laboratoire des Sciences des Procédés et des Matériaux (LSPM)-CNRS-UPR3407, Université Paris13, 99 Avenue Jean-Baptiste Clément, 93430, Villetaneuse (France); Dakhlaoui, I. [Laboratoire Matériaux Organisation et Propriétés (LMOP), Université de Tunis El Manar, 2092 Tunis (Tunisia); Vallée, C. [CNRS, LTM, CEA-LETI, F-38000 Grenoble (France); Salimy, S. [Institut des Matériaux Jean Rouxel (IMN) UMR CNRS 6502, Université de Nantes, 2, rue de la Houssinière, B.P. 32229, 44322, Nantes, Cedex 3 (France); Jomni, F.; Yangui, B. [Laboratoire Matériaux Organisation et Propriétés (LMOP), Université de Tunis El Manar, 2092 Tunis (Tunisia); Besland, M.P.; Goullet, A. [Institut des Matériaux Jean Rouxel (IMN) UMR CNRS 6502, Université de Nantes, 2, rue de la Houssinière, B.P. 32229, 44322, Nantes, Cedex 3 (France); Sylvestre, A. [Univ. Grenoble Alpes, G2Elab, F-38000 (France)

2016-05-01

In this study, the dielectric properties of metal-oxide-metal capacitors based on Tantalum Titanium Oxide (TiTaO) thin films deposited by reactive magnetron sputtering on aluminum bottom electrode are investigated. The structure of the films was characterized by Atomic Force Microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The dielectric properties of TiTaO thin films were studied by complex impedance spectroscopy over a wide frequency range (10{sup -2} - to 10{sup 5} Hz) and temperatures in -50 °C to 325 °C range. The contributions of different phases, phases’ boundaries and conductivity effect were highlighted by Cole – Cole diagram (ε” versus ε’). Two relaxation processes have been identified in the electric modulus plot. A first relaxation process appears at low temperature with activation energy of 0.37 eV and it is related to the motion of Ti{sup 4+} (Skanavi’s model). A second relaxation process at high temperature is related to Maxwell-Wagner-Sillars relaxation with activation energy of 0.41 eV. - Highlights: • Titanium Tantalum Oxide thin films are grown on Aluminum substrate. • The existence of phases was confirmed by X-ray photoelectron spectroscopy. • Conductivity effect appears in Cole-Cole plot. • At low temperatures, a relaxation phenomenon obeys to Skanavi’s model. • Maxwell-Wagner-Sillars polarization is processed at high temperatures.

Thin film removal mechanisms in ns-laser processing of photovoltaic materials

International Nuclear Information System (INIS)

Bovatsek, J.; Tamhankar, A.; Patel, R.S.; Bulgakova, N.M.; Bonse, J.

2010-01-01

The removal of thin films widely used in photovoltaics (amorphous silicon, tin oxide, zinc oxide, aluminum, and molybdenum) is studied experimentally using multi-kHz Q-switched solid-state lasers at 532 nm and 1064 nm wavelengths. The processing ('scribing') is performed through the film-supporting glass plate at scribing speeds of the order of m/s. The dependence of the film removal threshold on the laser pulse duration (8 ns to 40 ns) is investigated and the results are complemented by a multi-layer thermal model used for numerical simulations of the laser-induced spatio-temporal temperature field within the samples. Possible film removal mechanisms are discussed upon consideration of optical, geometrical, thermal and mechanical properties of the layers.

Influence of laser pulse frequency on the microstructure of aluminum nitride thin films synthesized by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Antonova, K., E-mail: krasa@issp.bas.bg [Institute of Solid State Physics, Bulgarian Academy of Sciences, Tzarigradsko Chaussee 72, Sofia 1784 (Bulgaria); Duta, L. [National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Street, 077125 Magurele (Romania); Szekeres, A. [Institute of Solid State Physics, Bulgarian Academy of Sciences, Tzarigradsko Chaussee 72, Sofia 1784 (Bulgaria); Stan, G.E. [National Institute of Materials Physics, 105 bis Atomistilor Street, 077125 Magurele (Romania); Mihailescu, I.N. [National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Street, 077125 Magurele (Romania); Anastasescu, M.; Stroescu, H.; Gartner, M. [Institute of Physical Chemistry, “Ilie Murgulescu”, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania)

2017-02-01

Highlights: • Study of pulsed laser deposited AlN films at different laser pulse frequencies. • Higher laser pulse frequency promotes nanocrystallites formation at temperature 450 °C. • AFM and GIXRD detect randomly oriented wurtzite AlN structures. • Characterization of the nanocrystallites’ orientation by FTIR reflectance spectra. • Berreman effect is registered in p-polarised radiation at large incidence angles. - Abstract: Aluminum Nitride (AlN) thin films were synthesized on Si (100) wafers at 450 °C by pulsed laser deposition. A polycrystalline AlN target was multipulsed irradiated in a nitrogen ambient, at different laser pulse repetition rate. Grazing Incidence X-Ray Diffraction and Atomic Force Microscopy analyses evidenced nanocrystallites with a hexagonal lattice in the amorphous AlN matrix. The thickness and optical constants of the layers were determined by infrared spectroscopic ellipsometry. The optical properties were studied by Fourier Transform Infrared reflectance spectroscopy in polarised oblique incidence radiation. Berreman effect was observed around the longitudinal phonon modes of the crystalline AlN component. Angular dependence of the A{sub 1}LO mode frequency was analysed and connected to the orientation of the particles’ optical axis to the substrate surface normal. The role of the laser pulse frequency on the layers’ properties is discussed on this basis.

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

Experimental investigation on photoelectric properties of ZAO thin film deposited on flexible substrate by magnetron sputtering

Science.gov (United States)

Hao, Ming; Liu, Kun; Liu, Xinghua; Wang, Dongyang; Ba, Dechun; Xie, Yuanhua; Du, Guangyu; Ba, Yaoshuai

2016-12-01

Transparent conductive ZAO (Zinc Aluminum Oxide) films on flexible substrates have a great potential for low-cost mass-production solar cells. ZAO thin films were achieved on flexible PET (polyethylene terephthalate) substrates by RF magnetron sputtering technology. The surface morphology and element content, the transmittance and the sheet resistance of the films were measured to determine the optical process parameters. The results show that the ZAO thin film shows the best parameters in terms of photoelectric performance including sputtering power, working pressure, sputtering time, substrate temperature (100 W, 1.5 Pa, 60 min, 125 °C). The sheet resistance of 510 Ω and transmittance in visible region of 92% were obtained after characterization. Surface morphology was uniform and compact with a good crystal grain.

Corrosion control of aluminum surfaces by polypyrrole films: influence of electrolyte

Directory of Open Access Journals (Sweden)

Andréa Santos Liu

2007-06-01

Full Text Available Polypyrrole (PPy films were galvanostatically deposited on 99.9 wt. (% aluminum electrodes from aqueous solutions containing each carboxylic acid: tartaric, oxalic or citric. Scanning Electron Microscopy (SEM was used to analyze the morphology of the aluminum surfaces coated with the polymeric films. It was observed that the films deposited from tartaric acid medium presented higher homogeneity than those deposited from oxalic and citric acid. Furthermore, the corrosion protection of aluminum surfaces by PPy films was also investigated by potentiodynamic polarization experiments.

Enhanced field emission from Si doped nanocrystalline AlN thin films

International Nuclear Information System (INIS)

Thapa, R.; Saha, B.; Chattopadhyay, K.K.

2009-01-01

Si doped and undoped nanocrystalline aluminum nitride thin films were deposited on various substrates by direct current sputtering technique. X-ray diffraction analysis confirmed the formation of phase pure hexagonal aluminum nitride with a single peak corresponding to (1 0 0) reflection of AlN with lattice constants, a = 0.3114 nm and c = 0.4986 nm. Energy dispersive analysis of X-rays confirmed the presence of Si in the doped AlN films. Atomic force microscopic studies showed that the average particle size of the film prepared at substrate temperature 200 deg. C was 9.5 nm, but when 5 at.% Si was incorporated the average particle size increased to ∼21 nm. Field emission study indicated that, with increasing Si doping concentration, the emission characteristics have been improved. The turn-on field (E to ) was 15.0 (±0.7) V/μm, 8.0 (±0.4) V/μm and 7.8 (±0.5) V/μm for undoped, 3 at.% and 5 at.% Si doped AlN films respectively and the maximum current density of 0.27 μA/cm 2 has been observed for 5 at.% Si doped nanocrystalline AlN film. It was also found that the dielectric properties were highly dependent on Si doping.

Optical and electrical properties of TiOPc doped Alq{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Ramar, M.; Suman, C. K., E-mail: sumanck@nplindia.org; Tyagi, Priyanka; Srivastava, R. [CSIR-Network of Institutes for Solar Energy CSIR - National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi -110012 (India)

2015-06-24

The Titanyl phthalocyanine (TiOPc) was doped in Tris (8-hydroxyquinolinato) aluminum (Alq3) with different concentration. The thin film of optimized doping concentration was studied extensively for optical and electrical properties. The optical properties, studied using ellipsometry, absorption and photoluminescence. The absorption peak of Alq{sub 3} and TiOPc was observed at 387 nm and 707 nm and the photo-luminescence intensity (PL) peak of doped thin film was observed at 517 nm. The DC and AC electrical properties of the thin film were studied by current density-voltage (J-V) characteristics and impedance over a frequency range of 100 Hz - 1 MHz. The electron mobility calculated from trap-free space-charge limited region (SCLC) is 0.17×10{sup −5} cm{sup 2}/Vs. The Cole-Cole plots shows that the TiOPc doped Alq{sub 3} thin film can be represented by a single parallel resistance R{sub P} and capacitance C{sub P} network with a series resistance R{sub S} (10 Ω). The value of R{sub P} and C{sub P} at zero bias was 1587 Ω and 2.568 nF respectively. The resistance R{sub P} decreases with applied bias whereas the capacitance C{sub P} remains almost constant.

Atomic layer deposition of Al-incorporated Zn(O,S) thin films with tunable electrical properties

Energy Technology Data Exchange (ETDEWEB)

Park, Helen Hejin; Jayaraman, Ashwin; Heasley, Rachel; Yang, Chuanxi; Hartle, Lauren; Gordon, Roy G., E-mail: gordon@chemistry.harvard.edu [Harvard University, Cambridge, Massachusetts 02138 (United States); Mankad, Ravin; Haight, Richard; Gunawan, Oki [IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Mitzi, David B. [IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Duke University, Durham, North Carolina 27708 (United States)

2014-11-17

Zinc oxysulfide, Zn(O,S), films grown by atomic layer deposition were incorporated with aluminum to adjust the carrier concentration. The electron carrier concentration increased up to one order of magnitude from 10{sup 19} to 10{sup 20} cm{sup −3} with aluminum incorporation and sulfur content in the range of 0 ≤ S/(Zn+Al) ≤ 0.16. However, the carrier concentration decreased by five orders of magnitude from 10{sup 19} to 10{sup 14} cm{sup −3} for S/(Zn+Al) = 0.34 and decreased even further when S/(Zn+Al) > 0.34. Such tunable electrical properties are potentially useful for graded buffer layers in thin-film photovoltaic applications.

Deposition and characterization of TaAIN thin films by reactive magnetron sputtering; Deposicao e caracterizacao de filmes finos de TaAIN depositados por magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Oliveira, G.B.; Fernandez, D.R.; Fontes Junior, A.S.; Felix, L.C.; Tentardini, E.K. [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Departamento de Ciencia e Engenharia de Materiais; Hubler, R. [Pontificia Universidade Catolica do Rio Grande do Sul (PUC-RS), RS (Brazil); Silva Junior, A.H. da, E-mail: brito-g@hotmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), RS (Brazil)

2016-07-01

Phase stability, oxidation resistance and great mechanical properties are the main objectives when synthesizing protective coatings. The tantalum nitride (TaN) has aroused interest because of its high temperature stability, chemical inertness and thermal conductivity. However, it has a low hardness value when compared to other coatings. Researches has shown that one way to improvements in the properties of a thin film is by adding other elements in the deposition process. Therefore, the objective of this study was to deposit thin films of TaAlN by magnetron sputtering, changing the aluminum concentration of 2, 5, 7, to 14%. Then the coatings were characterized by EDS, RBS, GIXRD and nanohardness. In this study was found that the aluminum deposited did not change the oxidation resistance of the coating, and the highest value of hardness was 28 GPa for the sample with 14 at.%. (author)

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

Surface-potential undulation of Alq3 thin films prepared on ITO, Au, and n-Si.

Science.gov (United States)

Ozasa, Kazunari; Ito, Hiromi; Maeda, Mizuo; Hara, Masahiko

2012-01-01

The surface potential (SP) morphology on thin films of tris(8-hydroxyquinolinato) aluminum (Alq3) was investigated with Kelvin probe force microscopy. Thin Alq3 films of 100 nm were prepared on ITO/glass substrates, Au/mica substrates, and n-Si substrates. Cloud-like morphologies of the SP undulation with 200-400 nm in lateral size were observed for all three types of the substrates. New larger peaks were observed in the cloud-like morphologies when the surfaces were exposed shortly to a light, while the SP average was reduced monotonically. The nonuniform distribution of charged traps and mobility was deduced from the SP undulation morphology and its photoexposure dependences.

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.

Nitrate ions as cathodic alkalization promoters for the electro-assisted deposition of sol-gel thin films

Energy Technology Data Exchange (ETDEWEB)

Ding Shangzhi; Liu Liang [Department of Chemistry, Yuquan Campus, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Hu Jiming [Department of Chemistry, Yuquan Campus, Zhejiang University, Hangzhou, Zhejiang 310027 (China)], E-mail: kejmhu@zju.edu.cn; Zhang Jianqing; Cao Chunan [Department of Chemistry, Yuquan Campus, Zhejiang University, Hangzhou, Zhejiang 310027 (China); State Key Laboratory for Corrosion and Protection, Shenyang 110016 (China)

2008-08-15

Nitrate was used as a promoter to prepare dodecyltrimethoxysilane thin films on aluminum substrates. With the addition of nitrate into silane sol-gel precursors, the electro-assisted formation of silane films was facilitated, as indicated by electrochemical impedance spectroscopy, scanning electron microscopy and secondary-ion mass spectroscopy, due to the promotion in cathodic alkalization. However, an extra-high concentration of nitrate would be harmful because of the salting-out effect in precursors and the soluble nitrate remaining in silane films.

Fabrication of amplitude-phase type diffractive optical elements in aluminium films

Science.gov (United States)

Fomchenkov, S. A.; Butt, M. A.

2017-11-01

In the course of studies have been conducted a method of forming the phase diffractive optical elements (DOEs) by direct laser writing in thin films of aluminum. The quality of the aluminum films were investigated depending on the parameters of magnetron sputtering process. Moreover, the parameters of the laser writing process in thin films of aluminum were optimized. The structure of phase diffractive optical elements was obtained by the proposed method.

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

Atomic layer deposition of Al-doped ZnO thin films

Energy Technology Data Exchange (ETDEWEB)

Tynell, Tommi; Yamauchi, Hisao; Karppinen, Maarit; Okazaki, Ryuji; Terasaki, Ichiro [Department of Chemistry, Aalto University, FI-00076 Aalto (Finland); Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)

2013-01-15

Atomic layer deposition has been used to fabricate thin films of aluminum-doped ZnO by depositing interspersed layers of ZnO and Al{sub 2}O{sub 3} on borosilicate glass substrates. The growth characteristics of the films have been investigated through x-ray diffraction, x-ray reflection, and x-ray fluorescence measurements, and the efficacy of the Al doping has been evaluated through optical reflectivity and Seebeck coefficient measurements. The Al doping is found to affect the carrier density of ZnO up to a nominal Al dopant content of 5 at. %. At nominal Al doping levels of 10 at. % and higher, the structure of the films is found to be strongly affected by the Al{sub 2}O{sub 3} phase and no further carrier doping of ZnO is observed.

Impact of Gate Dielectric in Carrier Mobility in Low Temperature Chalcogenide Thin Film Transistors for Flexible Electronics

KAUST Repository

Salas-Villasenor, A. L.; Mejia, I.; Hovarth, J.; Alshareef, Husam N.; Cha, D. K.; Ramirez-Bon, R.; Gnade, B. E.; Quevedo-Lopez, M. A.

2010-01-01

Cadmium sulfide thin film transistors were demonstrated as the n-type device for use in flexible electronics. CdS thin films were deposited by chemical bath deposition (70° C) on either 100 nm HfO2 or SiO2 as the gate dielectrics. Common gate transistors with channel lengths of 40-100 μm were fabricated with source and drain aluminum top contacts defined using a shadow mask process. No thermal annealing was performed throughout the device process. X-ray diffraction results clearly show the hexagonal crystalline phase of CdS. The electrical performance of HfO 2 /CdS -based thin film transistors shows a field effect mobility and threshold voltage of 25 cm2 V-1 s-1 and 2 V, respectively. Improvement in carrier mobility is associated with better nucleation and growth of CdS films deposited on HfO2. © 2010 The Electrochemical Society.

Impact of Gate Dielectric in Carrier Mobility in Low Temperature Chalcogenide Thin Film Transistors for Flexible Electronics

KAUST Repository

Salas-Villasenor, A. L.

2010-06-29

Cadmium sulfide thin film transistors were demonstrated as the n-type device for use in flexible electronics. CdS thin films were deposited by chemical bath deposition (70° C) on either 100 nm HfO2 or SiO2 as the gate dielectrics. Common gate transistors with channel lengths of 40-100 μm were fabricated with source and drain aluminum top contacts defined using a shadow mask process. No thermal annealing was performed throughout the device process. X-ray diffraction results clearly show the hexagonal crystalline phase of CdS. The electrical performance of HfO 2 /CdS -based thin film transistors shows a field effect mobility and threshold voltage of 25 cm2 V-1 s-1 and 2 V, respectively. Improvement in carrier mobility is associated with better nucleation and growth of CdS films deposited on HfO2. © 2010 The Electrochemical Society.

P-doped strontium titanate grown using two target pulsed laser deposition for thin film solar cells

Science.gov (United States)

Man, Hamdi

Thin-film solar cells made of Mg-doped SrTiO3 p-type absorbers are promising candidates for clean energy generation. This material shows p-type conductivity and also demonstrates reasonable absorption of light. In addition, p-type SrTiO3 can be deposited as thin films so that the cost can be lower than the competing methods. In this work, Mg-doped SrTiO3 (STO) thin-films were synthesized and analyzed in order to observe their potential to be employed as the base semiconductor in photovoltaic applications. Mg-doped STO thin-films were grown by using pulsed laser deposition (PLD) using a frequency quadrupled Yttrium Aluminum Garnet (YAG) laser and with a substrate that was heated by back surface absorption of infrared (IR) laser light. The samples were characterized using X-ray photoelectron spectroscopy (XPS) and it was observed that Mg atoms were doped successfully in the stoichiometry. Reflection high energy electron diffraction (RHEED) spectroscopy proved that the thin films were polycrystalline. Kelvin Probe work function measurements indicated that the work function of the films were 4.167 eV after annealing. UV/Vis Reflection spectroscopy showed that Mg-doped STO thin-films do not reflect significantly except in the ultraviolet region of the spectrum where the reflection percentage increased up to 80%. Self-doped STO thin-films, Indium Tin Oxide (ITO) thin films and stainless steel foil (SSF) were studied in order to observe their characteristics before employing them in Mg-doped STO based solar cells. Self-doped STO thin films were grown using PLD and the results showed that they are capable of serving as the n-type semiconductor in solar cell applications with oxygen vacancies in their structure and low reflectivity. Indium Tin Oxide thin-films grown by PLD system showed low 25-50 ?/square sheet resistance and very low reflection features. Finally, commercially available stainless steel foil substrates were excellent substrates for the inexpensive growth of

Structural, Morphological, and LPG Sensing Properties of Al-Doped ZnO Thin Film Prepared by SILAR

Directory of Open Access Journals (Sweden)

Shampa Mondal

2013-01-01

Full Text Available Undoped and aluminum doped zinc oxide (AZO thin films were deposited on glass substrates by successive ion layer adsorption and reaction (SILAR technique from ammonium zincate complex. The thin films are characterized by X-ray diffraction (XRD and scanning electron microscopy (SEM for their structural and morphological studies. Both undoped and Al-doped film show strong preferred c-axis orientation. The texture coefficient (TC of the film along (002 direction increases due to Al incorporation. SEM micrograph shows round shaped particles for pure ZnO. However AZO films show particles with off spherical shape and compact interconnected grains. Sensitivity of the film in presence of 80% LEL (lower explosive limit of LPG increases with temperature and is maximum at 325°C. Significantly high sensitivity of 87% with reasonably fast response was observed for 1% Al-doped ZnO (AZO film in presence of 1.6 vol% LPG at 325°C.

Electrical transport through single-wall carbon nanotube-anodic aluminum oxide-aluminum heterostructures

International Nuclear Information System (INIS)

Kukkola, Jarmo; Rautio, Aatto; Sala, Giovanni; Pino, Flavio; Toth, Geza; Leino, Anne-Riikka; Maeklin, Jani; Jantunen, Heli; Uusimaeki, Antti; Kordas, Krisztian; Gracia, Eduardo; Terrones, Mauricio; Shchukarev, Andrey; Mikkola, Jyri-Pekka

2010-01-01

Aluminum foils were anodized in sulfuric acid solution to form thick porous anodic aluminum oxide (AAO) films of thickness ∼6 μm. Electrodes of carboxyl-functionalized single-wall carbon nanotube (SWCNT) thin films were inkjet printed on the anodic oxide layer and the electrical characteristics of the as-obtained SWCNT-AAO-Al structures were studied. Nonlinear current-voltage transport and strong temperature dependence of conduction through the structure was measured. The microstructure and chemical composition of the anodic oxide layer was analyzed using transmission and scanning electron microscopy as well as x-ray photoelectron spectroscopy. Schottky emission at the SWCNT-AAO and AAO-Al interfaces allowed by impurity states in the anodic aluminum oxide film together with ionic surface conduction on the pore walls of AAO gives a reasonable explanation for the measured electrical conduction. Calcined AAO is proposed as a dielectric material for SWCNT-field effect transistors.

Aluminum-doped zinc oxide thin films grown on various substrates using facing target sputtering system

Science.gov (United States)

Kim, Hwa-Min; Lee, Chang Hyun; Shon, Sun Young; Kim, Bong Hwan

2017-11-01

Aluminum-doped zinc oxide (AZO) films were fabricated on various substrates, such as glass, polyethylene naphthalate (PEN), and polyethylene terephthalate (PET), at room temperature using a facing target sputtering (FTS) system with hetero ZnO and Al2O3 targets, and their electrical and optical properties were investigated. The AZO film on glass exhibited compressive stress while the films on the plastic substrates showed tensile stress. These stresses negatively affected the crystalline quality of the AZO films, and it is suggested that the poor crystalline quality of the films may be related to the neutral Al-based defect complexes formed in the films; these complexes act as neutral impurity scattering centers. AZO films with good optoelectronic properties could be formed on the glass and plastic substrates by the FTS technique using the hetero targets. The AZO films deposited on the glass, PEN, and PET substrates showed very low resistivities, of 5.0 × 10-4 Ω cm, 7.0 × 10-4 Ω cm, and 7.4 × 10-4 Ω cm, respectively. Further, the figure merit of the AZO film formed on the PEN substrate in the visible range (400-700 nm) was significantly higher than that of the AZO film on PET and similar to that of the AZO film on glass. Finally, the average transmittances of the films in the visible range (400-700 nm) were 83.16% (on glass), 76.3% (on PEN), and 78.16% (on PET).

PTFE-ALUMINUM films serve as neutral density filters

Science.gov (United States)

Burks, H. D.

1966-01-01

Polytetrafluoroethylene /PTFE/ films coated with aluminum films act as neutral density filters in the wavelength range 0.3 to 2.1 microns. These filters are effective in the calibration of photometric systems.

Structural and optical characterization of porous anodic aluminum oxide

International Nuclear Information System (INIS)

Galca, Aurelian C.; Kooij, E. Stefan; Wormeester, Herbert; Salm, Cora; Leca, Victor; Rector, Jan H.; Poelsema, Bene

2003-01-01

Spectroscopic ellipsometry and scanning electron microscopy (SEM) experiments are employed to characterize porous aluminum oxide obtained by anodization of thin aluminum films. Rutherford backscattering spectra and x-ray diffraction experiments provide information on the composition and the structure of the samples. Results on our thin film samples with a well-defined geometry show that anodization of aluminum is reproducible and results in a porous aluminum oxide network with randomly distributed, but perfectly aligned cylindrical pores perpendicular to the substrate. The ellipsometry spectra are analyzed using an anisotropic optical model, partly based on the original work by Bruggeman. The model adequately describes the optical response of the anodized film in terms of three physically relevant parameters: the film thickness, the cylinder fraction, and the nanoporosity of the aluminum oxide matrix. Values of the first two quantities, obtained from fitting the spectra, are in perfect agreement with SEM results, when the nanoporosity of the aluminum oxide matrix is taken into account. The validity of our optical model was verified over a large range of cylinder fractions, by widening of the pores through chemical etching in phosphoric acid. While the cylinder fraction increases significantly with etch time and etchant concentration, the nanoporosity remains almost unchanged. Additionally, based on a simple model considering a linear etch rate, the concentration dependence of the etch rate was determined

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...

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.

Fracture Analysis of MWCNT/Epoxy Nanocomposite Film Deposited on Aluminum Substrate.

Science.gov (United States)

Her, Shiuh-Chuan; Chien, Pao-Chu

2017-04-13

Multi-walled carbon nanotube (MWCNT) reinforced epoxy films were deposited on an aluminum substrate by a hot-pressing process. Three-point bending tests were performed to determine the Young's modulus of MWCNT reinforced nanocomposite films. Compared to the neat epoxy film, nanocomposite film with 1 wt % of MWCNT exhibits an increase of 21% in the Young's modulus. Four-point-bending tests were conducted to investigate the fracture toughness of the MWCNT/epoxy nanocomposite film deposited on an aluminum substrate with interfacial cracks. Based on the Euler-Bernoulli beam theory, the strain energy in a film/substrate composite beam is derived. The difference of strain energy before and after the propagation of the interfacial crack are calculated, leading to the determination of the strain energy release rate. Experimental test results show that the fracture toughness of the nanocomposite film deposited on the aluminum substrate increases with the increase in the MWCNT content.

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

Electron beam physical vapor deposition of thin ruby films for remote temperature sensing

International Nuclear Information System (INIS)

Li Wei; Coppens, Zachary J.; Greg Walker, D.; Valentine, Jason G.

2013-01-01

Thermographic phosphors (TGPs) possessing temperature-dependent photoluminescence properties have a wide range of uses in thermometry due to their remote access and large temperature sensitivity range. However, in most cases, phosphors are synthesized in powder form, which prevents their use in high resolution micro and nanoscale thermal microscopy. In the present study, we investigate the use of electron beam physical vapor deposition to fabricate thin films of chromium-doped aluminum oxide (Cr-Al 2 O 3 , ruby) thermographic phosphors. Although as-deposited films were amorphous and exhibited weak photoluminescence, the films regained the stoichiometry and α-Al 2 O 3 crystal structure of the combustion synthesized source powder after thermal annealing. As a consequence, the annealed films exhibit both strong photoluminescence and a temperature-dependent lifetime that decreases from 2.9 ms at 298 K to 2.1 ms at 370 K. Ruby films were also deposited on multiple substrates. To ensure a continuous film with smooth surface morphology and strong photoluminescence, we use a sapphire substrate, which is thermal expansion coefficient and lattice matched to the film. These thin ruby films can potentially be used as remote temperature sensors for probing the local temperatures of micro and nanoscale structures.

Quality improvement of organic thin films deposited on vibrating substrates

Energy Technology Data Exchange (ETDEWEB)

Paredes, Y.A.; Caldas, P.G.; Prioli, R.; Cremona, M., E-mail: cremona@fis.puc-rio.br

2011-12-30

Most of the Organic Light-Emitting Diodes (OLEDs) have a multilayered structure composed of functional organic layers sandwiched between two electrodes. Thin films of small molecules are generally deposited by thermal evaporation onto glass or other rigid or flexible substrates. The interface state between two organic layers in OLED device depends on the surface morphology of the layers and affects deeply the OLED performance. The morphology of organic thin films depends mostly on substrate temperature and deposition rate. Generally, the control of the substrate temperature allows improving the quality of the deposited films. For organic compounds substrate temperature cannot be increased too much due to their poor thermal stability. However, studies in inorganic thin films indicate that it is possible to modify the morphology of a film by using substrate vibration without increasing the substrate temperature. In this work, the effect of the resonance vibration of glass and silicon substrates during thermal deposition in high vacuum environment of tris(8-quinolinolate)aluminum(III) (Alq{sub 3}) and N,N Prime -Bis(naphthalene-2-yl)-N,N Prime -bis(phenyl)-benzidine ({beta}-NPB) organic thin films with different deposition rates was investigated. The vibration used was in the range of hundreds of Hz and the substrates were kept at room temperature during the process. The nucleation and subsequent growth of the organic films on the substrates have been studied by atomic force microscopy technique. For Alq{sub 3} and {beta}-NPB films grown with 0.1 nm/s as deposition rate and using a frequency of 100 Hz with oscillation amplitude of some micrometers, the results indicate a reduction of cluster density and a roughness decreasing. Moreover, OLEDs fabricated with organic films deposited under these conditions improved their power efficiency, driven at 4 mA/cm{sup 2}, passing from 0.11 lm/W to 0.24 lm/W with an increase in their luminance of about 352 cd/m{sup 2

Thin Film & Deposition Systems (Windows)

Data.gov (United States)

Federal Laboratory Consortium — Coating Lab: Contains chambers for growing thin film window coatings. Plasma Applications Coating Lab: Contains chambers for growing thin film window coatings. Solar...

Optimization of the optical and electrical properties of electron beam evaporated aluminum-doped zinc oxide films for opto-electronic applications

Science.gov (United States)

Ali, H. M.; Abd El-Raheem, M. M.; Megahed, N. M.; Mohamed, H. A.

2006-08-01

Aluminum-doped zinc oxide (AZO) thin films have been deposited by electron beam evaporation technique on glass substrates. The structural, electrical and optical properties of AZO films have been investigated as a function of annealing temperature. It was observed that the optical properties such as transmittance, reflectance, optical band gap and refractive index of AZO films were strongly affected by annealing temperature. The transmittance values of 84% in the visible region and 97% in the NIR region were obtained for AZO film annealed at 475 °C. The room temperature electrical resistivity of 4.6×10-3 Ω cm has been obtained at the same temperature of annealing. It was found that the calculated refractive index has been affected by the packing density of the thin films, whereas, the high annealing temperature gave rise to improve the homogeneity of the films. The single-oscillator model was used to analyze the optical parameters such as the oscillator and dispersion energies.

Correlation between hardness and stress in Al-(Nb, Mo, Ta) thin films

Energy Technology Data Exchange (ETDEWEB)

Car, T., E-mail: car@irb.h [Rudjer Boskovic Institute, Division of Materials Science, Bijenicka cesta 54, 10000 Zagreb, P.O.B. 1016 (Croatia); Radic, N. [Rudjer Boskovic Institute, Division of Materials Science, Bijenicka cesta 54, 10000 Zagreb, P.O.B. 1016 (Croatia); Panjan, P.; Cekada, M. [Jozef Stefan Institute, Ljubljana (Slovenia); Tonejc, A. [Department of Physics, Bijenicka cesta 32, 10000 Zagreb, P.O.B. 331 (Croatia)

2009-06-30

The thin films of Al{sub x}Nb{sub 1-x} (95 {>=} x {>=} 20), Al{sub x}Mo{sub x} (90 {>=} x {>=} 20) and Al{sub x}Ta{sub 1-x} (95 {>=} x {>=} 20) were prepared by magnetron codeposition at room temperature. The average film thickness was from 325 to 400 nm, depending on the film composition. The structure of the as-deposited films was examined by the X-ray diffraction. The stress of the films was determined from the substrate deformation by the profilometer, and the microhardness (load 2 mN) was examined by the micro- and nano-hardness device. For the purpose of the examination of the hardness, the samples were deposited onto the sapphire wafers, while the examination of the film stress, was performed by using thin glass substrates. For all the Al-(Nb, Mo, Ta) alloy compositions, the microhardness is predominantly under the influence of the harder element, and monotonically decreases with the increase of the aluminum content. However, the microhardness of the amorphous AlTa films was higher than the bulk value of a harder element (Ta) in the alloy. A simple empirical linear relationship between the Vickers hardness, the bulk value hardness of the transition metal (harder element) and the elastic energy fraction of the identation deformation, was established. The elastic energy fraction in the microhardness is also linearly correlated with the stress in films.

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...

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

KAUST Repository

Chernikova, Valeriya

2016-07-14

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

Room-temperature low-voltage electroluminescence in amorphous carbon nitride thin films

Science.gov (United States)

Reyes, R.; Legnani, C.; Ribeiro Pinto, P. M.; Cremona, M.; de Araújo, P. J. G.; Achete, C. A.

2003-06-01

White-blue electroluminescent emission with a voltage bias less than 10 V was achieved in rf sputter-deposited amorphous carbon nitride (a-CN) and amorphous silicon carbon nitride (a-SiCN) thin-film-based devices. The heterojunction structures of these devices consist of: Indium tin oxide (ITO), used as a transparent anode; amorphous carbon film as an emission layer, and aluminum as a cathode. The thickness of the carbon films was about 250 Å. In all of the produced diodes, a stable visible emission peaked around 475 nm is observed at room temperature and the emission intensity increases with the current density. For an applied voltage of 14 V, the luminance was about 3 mCd/m2. The electroluminescent properties of the two devices are discussed and compared.

Effect of oxygen to argon flow ratio on the properties of Al-doped ZnO films for amorphous silicon thin film solar cell applications

Energy Technology Data Exchange (ETDEWEB)

Lin, Yang-Shih [Department of Materials Science and Engineering, National Chung Hsing University, Taichung 402, Taiwan, ROC (China); Lien, Shui-Yang, E-mail: syl@mdu.edu.tw [Department of Materials Science and Engineering, MingDao University, ChangHua 52345, Taiwan, ROC (China); Huang, Yung-Chuan [Department of Materials Science and Engineering, MingDao University, ChangHua 52345, Taiwan, ROC (China); Wang, Chao-Chun [Department of Materials Science and Engineering, National Chung Hsing University, Taichung 402, Taiwan, ROC (China); Liu, Chueh-Yang [Department of Materials Science and Engineering, MingDao University, ChangHua 52345, Taiwan, ROC (China); Nautiyal, Asheesh [Department of Mechanical Engineering, Yuan Ze University, 135 Yuan-Tung Road, Chungli, 320 Taoyuan, Taiwan, ROC (China); Wuu, Dong-Sing [Department of Materials Science and Engineering, National Chung Hsing University, Taichung 402, Taiwan, ROC (China); Lee, Shuo-Jun [Department of Mechanical Engineering, Yuan Ze University, 135 Yuan-Tung Road, Chungli, 320 Taoyuan, Taiwan, ROC (China)

2013-02-01

Transparent conductive oxide thin films in solar cell fabrication have attracted much attention due to their high conductivity and transmittance. In this paper, we have investigated the aluminum-doped zinc oxide (AZO) thin films prepared by radiofrequency magnetron sputtering on Asahi U-type SnO{sub 2} glass with different O{sub 2}/Ar flow ratios in vacuum chamber. Furthermore, the micro-structural, electrical, and optical properties of AZO/SnO{sub 2} films were studied. The change in O{sub 2}/Ar flow ratios is found to significantly affect the haze value, and slightly affect electrical resistivity and transmittance of the films. Afterward, the fabricated AZO thin films with different O{sub 2}/Ar flow ratios were used for building the solar cell devices. The current–voltage and external quantum efficiency characteristics were investigated for the solar cell devices. The optimized O{sub 2}/Ar flow ratio of 3 for solar device shows the best efficiency of 10.41%, and a 20% increase in short-circuit current density compared to typical Asahi solar cells. - Highlights: ► A thin Al-doped zinc oxide (AZO) film has been deposited on SnO{sub 2} substrates. ► The AZO film deposited at an O{sub 2}/Ar ratio of 3 shows low resistivity and high haze. ► The AZO film contains tiny grains that enhance light scattering. ► The amorphous silicon solar cell with the AZO layer shows a 20% increase in Jsc.

Improvement of amplified spontaneous emission performance by doping tris(8-hydroxyquinoline) aluminum (Alq3) in dye-doped polymer thin films.

Science.gov (United States)

Lu, Wu; You, Han; Fang, Junfeng; Ma, Dongge

2007-04-20

A well-known red fluorescent dye 4-(dicy-anomethylene)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) was codoped with an electron transport organic molecule tris(8-hydroxyquinoline) aluminum (Alq(3)) in a host matrix of polystyrene (PS), and the amplified spontaneous emission (ASE) was studied by optically pumping. It was found that the ASE performance was significantly improved by the introduction of Alq(3). The Alq(3):DCJTB:PS blending thin films showed a low threshold (2.4 microJ/pulse) and a high net gain coefficient (109.95 cm(-1)) compared with the pure DCJTB:PS system (threshold of 15.2 microJ/pulse and gain of 35.94 cm(-1)). The improvement of the ASE performance was considered to be attributable to the effective Föster energy transfer from Alq(3) to DCJTB. Our results demonstrate that the Alq(3):DCJTB could be a promising candidate as gain medium for red organic diode lasers.

Tilted c-Axis Thin-Film Bulk Wave Resonant Pressure Sensors With Improved Sensitivity

OpenAIRE

Anderås, Emil; Katardjiev, Ilia; Yantchev, Ventsislav

2012-01-01

Aluminum nitride thin film bulk wave resonant pressure sensors employing c- and tilted c-axis texture, have been fabricated and tested for their pressure sensitivities. The c-axis tilted FBAR pressure sensors demonstrate substantially higher pressure sensitivity compared to its c-axis oriented counterpart. More specifically the thickness plate quasi-shear resonance has demonstrated the highest pressure sensitivity while further being able to preserve its performance in liquid environment.

Titanium dioxide thin films for high temperature gas sensors

Energy Technology Data Exchange (ETDEWEB)

Seeley, Zachary Mark; Bandyopadhyay, Amit; Bose, Susmita, E-mail: sbose@wsu.ed

2010-10-29

Titanium dioxide (TiO{sub 2}) thin film gas sensors were fabricated via the sol-gel method from a starting solution of titanium isopropoxide dissolved in methoxyethanol. Spin coating was used to deposit the sol on electroded aluminum oxide (Al{sub 2}O{sub 3}) substrates forming a film 1 {mu}m thick. The influence of crystallization temperature and operating temperature on crystalline phase, grain size, electronic conduction activation energy, and gas sensing response toward carbon monoxide (CO) and methane (CH{sub 4}) was studied. Pure anatase phase was found with crystallization temperatures up to 800 {sup o}C, however, rutile began to form by 900 {sup o}C. Grain size increased with increasing calcination temperature. Activation energy was dependent on crystallite size and phase. Sensing response toward CO and CH{sub 4} was dependent on both calcination and operating temperatures. Films crystallized at 650 {sup o}C and operated at 450 {sup o}C showed the best selectivity toward CO.

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.

RBS and NRA of cobalt oxide thin films prepared by the sol-gel process

International Nuclear Information System (INIS)

Andrade, E.; Huerta, L.; Pineda, J.C.; Zavala, E.P.; Barrera, E.; Rocha, M. F.; Vargas, C.A.

2001-01-01

This work presents a study of cobalt oxide thin films produced by the sol-gel process on aluminum and glass substrates. These films have been analyzed using two ion beam analysis (IBA) techniques: a) a standard RBS 4 He 2 MeV and b) nuclear reaction analysis (NRA) using a 1 MeV deuterium beam. The 12 C(d,p 0 ) 13 C nuclear reaction provides information that carbon is incorporated into the film structure, which could be associated to the sinterization film process. Other film measurements such as optical properties, XRD, and SEM were performed in order to complement the IBA analysis. The results show that cobalt oxide film coatings prepared by this technique have good optical properties as solar absorbers and potential uses in solar energy applications

Photoluminescence of ZnO thin films deposited at various substrate temperatures

International Nuclear Information System (INIS)

Kao, Kuo-Sheng; Shih, Wei-Che; Ye, Wei-Tsuen; Cheng, Da-Long

2016-01-01

This study investigated surface acoustic wave devices with an Al/ZnO/Si structure for use in ultraviolet sensors. ZnO thin films were fabricated using a reactive radio frequency magnetron sputtering system. The substrate temperature of ZnO thin films can be varied to obtain highly crystalline properties. The surface morphologies and c-axis preferred orientation of the ZnO thin films were determined using scanning electron microscopy and X-ray diffraction. In addition, bright-field images of ZnO crystallization were investigated using a transmission electron microscope. From photoluminescence analysis, four peaks were obtained at 377.8, 384.9, 391.4, and 403.4 nm. Interdigital transducers of an aluminum electrode were fabricated on the ZnO/Si structure by using a direct current sputtering system and photolithography, combined with the lift-off method, thereby obtaining a surface acoustic wave device. Finally, frequency responses were measured using a network analyzer, and an illuminating test was adopted for the ultraviolet sensor, using a wavelength of 355 nm from a light-emitting diode. The sensitivities of the ultraviolet sensor were also discussed. - Highlights: • The ZnO/Si SAW devices exhibit the Rayleigh and Sezawa modes. • The crystalline of ZnO affects the EHP recombination and generation. • The PL spectrum of ZnO shows Gaussian fitting distributions. • The CTD_U_V is influenced by SAW types and ZnO film characteristics.

Photoluminescence of ZnO thin films deposited at various substrate temperatures

Energy Technology Data Exchange (ETDEWEB)

Kao, Kuo-Sheng [Department of Computer and Communication, SHU-TE University, Kaohsiung, Taiwan (China); Shih, Wei-Che [Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Ye, Wei-Tsuen [Department of Computer and Communication, SHU-TE University, Kaohsiung, Taiwan (China); Cheng, Da-Long, E-mail: dlcheng@stu.edu.tw [Department of Computer and Communication, SHU-TE University, Kaohsiung, Taiwan (China)

2016-04-30

This study investigated surface acoustic wave devices with an Al/ZnO/Si structure for use in ultraviolet sensors. ZnO thin films were fabricated using a reactive radio frequency magnetron sputtering system. The substrate temperature of ZnO thin films can be varied to obtain highly crystalline properties. The surface morphologies and c-axis preferred orientation of the ZnO thin films were determined using scanning electron microscopy and X-ray diffraction. In addition, bright-field images of ZnO crystallization were investigated using a transmission electron microscope. From photoluminescence analysis, four peaks were obtained at 377.8, 384.9, 391.4, and 403.4 nm. Interdigital transducers of an aluminum electrode were fabricated on the ZnO/Si structure by using a direct current sputtering system and photolithography, combined with the lift-off method, thereby obtaining a surface acoustic wave device. Finally, frequency responses were measured using a network analyzer, and an illuminating test was adopted for the ultraviolet sensor, using a wavelength of 355 nm from a light-emitting diode. The sensitivities of the ultraviolet sensor were also discussed. - Highlights: • The ZnO/Si SAW devices exhibit the Rayleigh and Sezawa modes. • The crystalline of ZnO affects the EHP recombination and generation. • The PL spectrum of ZnO shows Gaussian fitting distributions. • The CTD{sub UV} is influenced by SAW types and ZnO film characteristics.

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

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

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.

Friction reducing behavior of stearic acid film on a textured aluminum substrate

Energy Technology Data Exchange (ETDEWEB)

Zhang, Quan [School of Mechanical Engineering, Qingdao Technological University, Qingdao 266033 (China); Wan, Yong, E-mail: wanyong@qtech.edu.cn [School of Mechanical Engineering, Qingdao Technological University, Qingdao 266033 (China); Li, Yang; Yang, Shuyan [School of Mechanical Engineering, Qingdao Technological University, Qingdao 266033 (China); Yao, Wenqing [Analysis Center of Tsinghua University, Beijing 100084 (China)

2013-09-01

A simple two-step process was developed to render the aluminum hydrophobicity with lower friction. The textured aluminum substrate was firstly fabricated by immersed in a sodium hydroxide solution at 100 °C for 1 h. Stearic acid film was then deposited to acquire high hydrophobicity. Scanning electron microscopy, IR spectroscopy and water contact angle measurements were used to analyze the morphological features, chemical structure and hydrophobicity of prepared samples, respectively. Moreover, the friction reducing behavior of the organic–inorganic composite film on aluminum sliding against steel was evaluated in a ball-on-plate configuration. It was found that the stearic acid film on the textured aluminum led to decreased friction with significantly extended life.

Application of anodizing as a pre-treatment for nickel plating on aluminum

International Nuclear Information System (INIS)

Mehmood, M.; Ahmad, J.; Aslam, M.; Iqbal, M.; Akhtar, J.I.

2003-01-01

Effect of anodizing on subsequent electroplating of nickel on aluminum was investigated. Electroplated nickel did not exhibit any adhesion with un-anodized aluminum. Formation of a very thin anodized alumina film prior to nickel plating led to an excellent adhesion between the nickel film and the substrate. If the thickness of the alumina film increased, adhesion of electroplated nickel was significantly deteriorated and became similar to that of un-anodized bare aluminum. The study revealed that deposition proceeded through pores and defects in the insulator alumina film. These pores and defects also acted as nucleation and anchor points for nickel deposit. There was larger number of nucleation/ anchor points on thin alumina films. This provided better adhesion of nickel with the substrate as well as excellent coverage in relatively shorter times. On the other hand, very rough and poorly adherent nickel deposits formed on thick anodized films. Therefore, it may be used as precursor for producing nickel powder with controlled particle size as well as a catalyst with high specific surface area for hydrogenation and dehydrogenation reactions. (author)

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

Directory of Open Access Journals (Sweden)

Sarita Boolchandani

2018-01-01

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

Indigenous unit for bending and twisting tests of ultra-thin films on a flexible substrate

Science.gov (United States)

D'souza, Slavia Deeksha; Hazarika, Pratim; Prakasarao, Ch Surya; Kovendhan, M.; Kumar, R. Arockia; Joseph, D. Paul

2018-04-01

An indigenous unit is designed to test the stability of thin films deposited on to a flexible substrate by inducing a required number of bending and twisting under specific conditions. The unit is designed using aluminum and automated by sending pulse width modulated signals to servo motors using ATmega328 microcontroller. We have tested the unit by imparting stress on to a commercial ITO film deposited on a PET substrate. After a definite number of bending and twisting cycles, the electrical and surface properties are studied and the results are discussed.

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.

Nanopatterning of Crystalline Silicon Using Anodized Aluminum Oxide Templates for Photovoltaics

Science.gov (United States)

Chao, Tsu-An

A novel thin film anodized aluminum oxide templating process was developed and applied to make nanopatterns on crystalline silicon to enhance the optical properties of silicon. The thin film anodized aluminum oxide was created to improve the conventional thick aluminum templating method with the aim for potential large scale fabrication. A unique two-step anodizing method was introduced to create high quality nanopatterns and it was demonstrated that this process is superior over the original one-step approach. Optical characterization of the nanopatterned silicon showed up to 10% reduction in reflection in the short wavelength range. Scanning electron microscopy was also used to analyze the nanopatterned surface structure and it was found that interpore spacing and pore density can be tuned by changing the anodizing potential.

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

Effects of the wet air on the properties of the lanthanum oxide and lanthanum aluminate thin films

International Nuclear Information System (INIS)

Jun, Jin Hyung; Choi, Doo Jin

2006-01-01

Lanthanum oxide and lanthanum aluminate thin films were deposited on Si substrates. The as-grown films were stored in wet ambient and dry ambient for days and annealed after storage and also the structural and the electrical properties of the films were investigated. As the storage time increased, the La 2 O 3 films stored in wet ambient showed rapid reaction with moisture and the properties degraded. In case of the LAO films, although the thickness of the film also increased during hydration, the properties of the film did not so much changed due to the role of the incorporated aluminum. The LAO films showed better hydration resistance characteristics and so more suitable for conventional wet cleaning process in semiconductor fabrication

Industrial Application of Thin Films (TiAl)N Deposited on Thermo-Wells

International Nuclear Information System (INIS)

Velez, G.; Jaramillo, S.; Arango, Y. C.; Devia, D.; Quintero, J.; Devia, A.

2006-01-01

The thermo-well is formed by two layers, one layer is a ceramic and the other layer is anviloy (comprised tungsten). They are used to coat the thermocouple in the control temperature system during the Aluminum-Silicon alloy melting process. After two weeks of continuous work at 750 deg. C of temperature (the alloy temperature), a high wear in this material is observed, affecting the ceramic. (TiAl)N thin films are deposited directly on the anviloy substrates by the PAPVD (Plasma Assisted Physics Vapor Deposition) in arc pulsed technique, using a TiAl target in a mono-vaporizer system, composed by a reactor and a power controlled system. Two opposite electrodes are placed into the reactor and discharge is produced by a controlled power system. The XRD (X-ray diffraction) patterns show the presence of the (TiAl)N thin film peaks. The morphological characteristics are studied by the scanning probe microscopy (SPM)

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.

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.

High spatial resolution grain orientation and strain mapping in thin films using polychromatic submicron x-ray diffraction

Science.gov (United States)

Tamura, N.; MacDowell, A. A.; Celestre, R. S.; Padmore, H. A.; Valek, B.; Bravman, J. C.; Spolenak, R.; Brown, W. L.; Marieb, T.; Fujimoto, H.; Batterman, B. W.; Patel, J. R.

2002-05-01

The availability of high brilliance synchrotron sources, coupled with recent progress in achromatic focusing optics and large area two-dimensional detector technology, has allowed us to develop an x-ray synchrotron technique that is capable of mapping orientation and strain/stress in polycrystalline thin films with submicron spatial resolution. To demonstrate the capabilities of this instrument, we have employed it to study the microstructure of aluminum thin film structures at the granular and subgranular levels. Due to the relatively low absorption of x-rays in materials, this technique can be used to study passivated samples, an important advantage over most electron probes given the very different mechanical behavior of buried and unpassivated materials.

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.

Nitrogen bonding in aluminum oxynitride films

Energy Technology Data Exchange (ETDEWEB)

Wang, Paul W., E-mail: pwang@bradley.edu [Department of Physics, Bradley University, 1501 W. Bradley Ave., Peoria, IL 61625 (United States); Hsu, Jin-Cherng [Department of Physics, Fu Jen Catholic University, Hsinchuang, Taipei Hsien 24205, Taiwan (China); Lin, Yung-Hsin; Chen, Huang-Lu [Graduate Institute of Applied Science and Engineering, Fu Jen Catholic University, Hsinchuang, Taipei Hsien 24205, Taiwan (China)

2010-04-15

Assignment of oxidation states of N{sub 1s} in XPS spectra of aluminum oxynitride by curve fitting is difficult. The XPS curve fitting was previously discussed in the paper published in J. Non-Cryst. Solids, 224 (1998) 31, in which O{sub 1s} photoelectrons from GeO{sub 2} glass were used to illustrate how to fit the XPS spectra. Three different ways were pointed out to eliminate the ambiguity caused by curve fitting such as comparing the data to data from standard samples, investigating the continuous surface modifications caused by slowly sputtering the surface, and monitoring the continuous surface modifications due to gradual increases in surface species under heating, cooling, or irradiation. Our recent work in aluminum oxynitride films provides another example of how to fit the XPS spectra of N{sub 1s} by three different oxidation states of N{sup +}, N{sup 2+}, and N{sup 3+}, by comparison of the measured data to data from previously published results, and by the gradual changes of spectra as functions of the oxygen contents in the films. Three oxidation states in different nitrogen bonding in the aluminum oxynitride, AlO{sub 2}N, Al{sub 2}O{sub 5}N{sub 2}, and AlO{sub 3}N, were clearly deduced.

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)

Role of vacancy defects in Al doped ZnO thin films for optoelectronic devices

Science.gov (United States)

Rotella, H.; Mazel, Y.; Brochen, S.; Valla, A.; Pautrat, A.; Licitra, C.; Rochat, N.; Sabbione, C.; Rodriguez, G.; Nolot, E.

2017-12-01

We report on the electrical, optical and photoluminescence properties of industry-ready Al doped ZnO thin films grown by physical vapor deposition, and their evolution after annealing under vacuum. Doping ZnO with Al atoms increases the carrier density but also favors the formation of Zn vacancies, thereby inducing a saturation of the conductivity mechanism at high aluminum content. The electrical and optical properties of these thin layered materials are both improved by annealing process which creates oxygen vacancies that releases charge carriers thus improving the conductivity. This study underlines the effect of the formation of extrinsic and intrinsic defects in Al doped ZnO compound during the fabrication process. The quality and the optoelectronic response of the produced films are increased (up to 1.52 mΩ \\cdotcm and 3.73 eV) and consistent with the industrial device requirements.

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.

Orientationally ordered ridge structures of aluminum films on hydrogen terminated silicon

DEFF Research Database (Denmark)

Quaade, Ulrich; Pantleon, Karen

2006-01-01

Films of aluminum deposited onto Si(100) substrates show a surface structure of parallel ridges. On films deposited on oxidized silicon substrates the direction of the ridges is arbitrary, but on films deposited on hydrogen-terminated Si(100) the ridges are oriented parallel to the < 110 > direct......Films of aluminum deposited onto Si(100) substrates show a surface structure of parallel ridges. On films deposited on oxidized silicon substrates the direction of the ridges is arbitrary, but on films deposited on hydrogen-terminated Si(100) the ridges are oriented parallel to the ... > directions on the silicon substrate. The ridge structure appears when the film thickness is above 500 nm, and increasing the film thickness makes the structure more distinct. Anodic oxidation enhances the structure even further. X-ray diffraction indicates that grains in the film have mostly (110) facets...

Deposition and Characterization of Hermetic, Biocompatible Thin Film Coatings for Implantable, Electrically Active Devices

Science.gov (United States)

Sweitzer, Robyn K.

Retinal prostheses may be used to support patients suffering from Age-related macular degeneration or retinitis pigmentosa. A hermetic encapsulation of the poly(imide )-based prosthesis is important in order to prevent the leakage of water and ions into the electric circuitry embedded in the poly(imide) matrix. The deposition of amorphous aluminum oxide (by sputtering) and diamond like carbon (by pulsed laser ablation and vacuum arc vapor deposition) were studied for the application in retinal prostheses. The resulting thin films were characterized for composition, thickness, adhesion and smoothness by scanning electron microscopy-energy dispersive spectroscopy, atomic force microscopy, profilometry and light microscopy. Electrical stability was evaluated and found to be good. The as-deposited films prevented incursion of salinated fluids into the implant over two (2) three month trials soaking in normal saline at body temperature, Biocompatibility was tested in vivo by implanting coated specimen subretinally in the eye of Yucatan pigs. While amorphous aluminum oxide is more readily deposited with sufficient adhesion quality, biocompatibility studies showed a superior behavior of diamond-like carbon. Amorphous aluminum oxide had more adverse effects and caused more severe damage to the retinal tissue.

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

Fabrication and Corrosion Resistance of Superhydrophobic Hydroxide Zinc Carbonate Film on Aluminum Substrates

Directory of Open Access Journals (Sweden)

Jin Liang

2013-01-01

Full Text Available Superhydrophobic hydroxide zinc carbonate (HZC films were fabricated on aluminum substrate through a convenient in situ deposition process. Firstly, HZC films with different morphologies were deposited on aluminum substrates through immersing the aluminum substrates perpendicularly into aqueous solution containing zinc nitrate hexahydrate and urea. Secondly, the films were then modified with fluoroalkylsilane (FAS: CH3(CF26(CH23Si(OCH33 molecules by immersing in absolute ethanol solution containing FAS. The morphologies, hydrophobicity, chemical compositions, and bonding states of the films were analyzed by scanning electron microscopy (SEM, water contact angle measurement (CA, Fourier transform infrared spectrometer (FTIR, and X-ray photoelectron spectroscopy (XPS, respectively. It was shown by surface morphological observation that HZC films displayed different microstructures such as microporous structure, rose petal-like structure, block-shaped structure, and pinecone-like structure by altering the deposition condition. A highest water contact angle of 156.2° was obtained after FAS modification. Moreover, the corrosion resistance of the superhydrophobic surface on aluminum substrate was investigated using electrochemical impedance spectroscopy (EIS measurements. The EIS measurements’ results revealed that the superhydrophobic surface considerably improved the corrosion resistance of aluminum.

AlN piezoelectric films for sensing and actuation

NARCIS (Netherlands)

Tran, A.T.

2014-01-01

Aluminum Nitride (AlN) is explored as a thin film material for piezoelectric MEMS applications. A pulse DC reactive sputtering technique is used to deposit the AlN thin films and process parameters are optimized to obtain good crystallinity and high c-axis orientation films. A CMOS compatible

Crystallinity and superconductivity of as-grown MgB2 thin films with AlN buffer layers

International Nuclear Information System (INIS)

Tsujimoto, K.; Shimakage, H.; Wang, Z.; Kaya, N.

2005-01-01

The effects of aluminum nitride (AlN) buffer layers on the superconducting properties of MgB 2 thin film were investigated. The AlN buffer layers and as-grown MgB 2 thin films were deposited in situ using the multiple-target sputtering system. The best depositing condition for the AlN/MgB 2 bi-layer occurred when the AlN was deposited on c-cut sapphire substrates at 290 deg. C. The crystallinity of the AlN/MgB 2 bi-layer was studied using the XRD φ-scan and it showed that AlN and MgB 2 had the same in-plane alignment rotated at an angle of 30 deg. as compared to c-cut sapphire. The critical temperature of the MgB 2 film was 29.8 K and the resistivity was 50.0 μΩ cm at 40 K

Electrophoretic deposition of PTFE particles on porous anodic aluminum oxide film and its tribological properties

International Nuclear Information System (INIS)

Zhang, Dongya; Dong, Guangneng; Chen, Yinjuan; Zeng, Qunfeng

2014-01-01

Polytetrafluoroethylene (PTFE) composite film was successfully fabricated by depositing PTFE particles into porous anodic aluminum oxide film using electrophoretic deposition (EPD) process. Firstly, porous anodic aluminum oxide film was synthesized by anodic oxidation process in sulphuric acid electrolyte. Then, PTFE particles in suspension were directionally deposited into the porous substrate. Finally, a heat treatment at 300 °C for 1 h was utilized to enhance PTFE particles adhesion to the substrate. The influence of anodic oxidation parameters on the morphology and micro-hardness of the porous anodic aluminum oxide film was studied and the PTFE particles deposited into the pores were authenticated using energy-dispersive spectrometer (EDS) and scanning electron microscopy (SEM). Tribological properties of the PTFE composite film were investigated under dry sliding. The experimental results showed that the composite film exhibit remarkable low friction. The composite film had friction coefficient of 0.20 which deposited in 15% PTFE emulsion at temperature of 15 °C and current density of 3 A/dm 2 for 35 min. In addition, a control specimen of porous anodic aluminum oxide film and the PTFE composite film were carried out under the same test condition, friction coefficient of the PTFE composite film was reduced by 60% comparing with the control specimen at 380 MPa and 100 mm/s. The lubricating mechanism was that PTFE particles embedded in porous anodic aluminum oxide film smeared a transfer film on the sliding path and the micro-pores could support the supplement of solid lubricant during the sliding, which prolonged the lubrication life of the aluminum alloys.

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

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.

Structural, optical and thermal properties of nanoporous aluminum

International Nuclear Information System (INIS)

Ghrib, Taher

2015-01-01

Highlights: • A simple electrochemical technique is presented and used to manufacture a porous aluminum layer. • Manufactured pores of 40 nm diameter and 200 nm depth are filled by nanocrystal of silicon and graphite. • Dimensions of pores increase with the anodization current which ameliorate the optical and thermal properties. • A new thermal method is presented which permit to determine the pores density and the layer thickness. • All properties show that the manufactured material can be used with success in solar cells. - Abstract: In this work the structural, thermal and optical properties of porous aluminum thin film formed with various intensities of anodization current in sulfuric acid are highlighted. The obtained pores at the surface are filled by sprayed graphite and nanocrystalline silicon (nc-Si) thin films deposited by plasma enhancement chemical vapor deposition (PECVD) which the role is to improve its optical and thermal absorption giving a structure of an assembly of three different media such as deposited thin layer (graphite or silicon)/(porous aluminum layer filled with the deposited layer)/(Al sample). The effect of anodization current on the microstructure of porous aluminum and the effect of the deposited layer were systematically studied by atomic force microscopy (AFM), transmission electron microscopy (TEM) and Raman spectroscopy. The thermal properties such as the thermal conductivity (K) and thermal diffusivity (D) are determined by the photothermal deflection (PTD) technique which is a non destructive technique. Based on this full characterization, it is demonstrated that the thermal and optical characteristics of these films are directly correlated to their micro-structural properties

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)

Influence of sputtering conditions on the optical and electrical properties of laser-annealed and wet-etched room temperature sputtered ZnO:Al thin films

Energy Technology Data Exchange (ETDEWEB)

Boukhicha, Rym, E-mail: rym.boukhicha@polytechnique.edu [CNRS, LPICM, Ecole Polytechnique, 91128 Palaiseau (France); Charpentier, Coralie [CNRS, LPICM, Ecole Polytechnique, 91128 Palaiseau (France); Total S and M — New Energies Division, R and D Division, Department of Solar Energies EN/BO/RD/SOL, Tour Michelet, 24 cours Michelet, La Défense 10, 92069 Paris La Défense Cedex (France); Prod' Homme, Patricia [Total S and M — New Energies Division, R and D Division, Department of Solar Energies EN/BO/RD/SOL, Tour Michelet, 24 cours Michelet, La Défense 10, 92069 Paris La Défense Cedex (France); Roca i Cabarrocas, Pere [CNRS, LPICM, Ecole Polytechnique, 91128 Palaiseau (France); Lerat, Jean-François; Emeraud, Thierry [Photovoltaic Business Unit, Excico Group NV, Kempische Steenweg 305/2, B-3500 Hasselt (Belgium); Johnson, Erik [CNRS, LPICM, Ecole Polytechnique, 91128 Palaiseau (France)

2014-03-31

We explore the influence of the sputtering deposition conditions on the outcome of an excimer laser anneal and chemical etching process with the goal of producing highly textured substrates for thin film silicon solar cells. Aluminum-doped zinc oxide (ZnO:Al) thin films were prepared on glass substrates by radio frequency magnetron sputtering from a ceramic target at room temperature. The effects of the process pressure (0.11–1.2 Pa) and oxygen flow (0–2 sccm) on the optical and electrical properties of ZnO:Al thin films have been studied both before and after an excimer laser annealing treatment followed by a dilute HCl chemical etch. The as-deposited films varied from completely opaque to yellowish. Thin film laser annealing dramatically improves the optical properties of the most opaque thin films. After laser annealing at the optimum fluence, the average transmittance in the visible wavelength range was around 80% for most films, and reasonable electrical performance was obtained for the films deposited at lower pressures and without oxygen flux (7 Ω/□ for films of 1 μm). After etching, all films displayed a dramatic improvement in haze, but only the low pressure, low oxygen films retained acceptable electrical properties (< 11 Ω/□). - Highlights: • Al:ZnO thin films were deposited at room temperature. • The ZnO:Al films were excimer laser annealed and then wet-etched. • The optical and electrical properties were studied in details.

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.

Microstructure and optical properties of nanocrystalline ZnO and ZnO:(Li or Al) thin films

Energy Technology Data Exchange (ETDEWEB)

Oral, A. Yavuz [Department of Materials Science and Engineering, Gebze Institute of Technology, Gebze 41400 (Turkey)]. E-mail: aoral@gyte.edu.tr; Bahsi, Z. Banu [Department of Materials Science and Engineering, Gebze Institute of Technology, Gebze 41400 (Turkey); Aslan, M. Hasan [Department of Physics, Gebze Institute of Technology, Gebze 41400 (Turkey)

2007-03-15

Zinc oxide thin films (ZnO, ZnO:Li, ZnO:Al) were deposited on glass substrates by a sol-gel technique. Zinc acetate, lithium acetate, and aluminum chloride were used as metal ion sources in the precursor solutions. XRD analysis revealed that Li doped and undoped ZnO films formed single phase zincite structure in contrast to Al:ZnO films which did not fully crystallize at the annealing temperature of 550 deg. C. Crystallized films had a grain size under 50 nm and showed c-axis grain orientation. All films had a very smooth surface with RMS surface roughness values between 0.23 and 0.35 nm. Surface roughness and optical band tail values increased by Al doping. Compared to undoped ZnO films, Li doping slightly increased the optical band gap of the films.

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.

Enhanced Electroluminescence from Silicon Quantum Dots Embedded in Silicon Nitride Thin Films Coupled with Gold Nanoparticles in Light Emitting Devices

Directory of Open Access Journals (Sweden)

Ana Luz Muñoz-Rosas

2018-03-01

Full Text Available Nowadays, the use of plasmonic metal layers to improve the photonic emission characteristics of several semiconductor quantum dots is a booming tool. In this work, we report the use of silicon quantum dots (SiQDs embedded in a silicon nitride thin film coupled with an ultra-thin gold film (AuNPs to fabricate light emitting devices. We used the remote plasma enhanced chemical vapor deposition technique (RPECVD in order to grow two types of silicon nitride thin films. One with an almost stoichiometric composition, acting as non-radiative spacer; the other one, with a silicon excess in its chemical composition, which causes the formation of silicon quantum dots imbibed in the silicon nitride thin film. The ultra-thin gold film was deposited by the direct current (DC-sputtering technique, and an aluminum doped zinc oxide thin film (AZO which was deposited by means of ultrasonic spray pyrolysis, plays the role of the ohmic metal-like electrode. We found that there is a maximum electroluminescence (EL enhancement when the appropriate AuNPs-spacer-SiQDs configuration is used. This EL is achieved at a moderate turn-on voltage of 11 V, and the EL enhancement is around four times bigger than the photoluminescence (PL enhancement of the same AuNPs-spacer-SiQDs configuration. From our experimental results, we surmise that EL enhancement may indeed be due to a plasmonic coupling. This kind of silicon-based LEDs has the potential for technology transfer.

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

Correlations between optical properties, microstructure, and processing conditions of Aluminum nitride thin films fabricated by pulsed laser deposition

International Nuclear Information System (INIS)

Baek, Jonghoon; Ma, James; Becker, Michael F.; Keto, John W.; Kovar, Desiderio

2007-01-01

Aluminum nitride (AlN) films were deposited using pulsed laser deposition (PLD) onto sapphire (0001) substrates with varying processing conditions (temperature, pressure, and laser fluence). We have studied the dependence of optical properties, structural properties and their correlations for these AlN films. The optical transmission spectra of the produced films were measured, and a numerical procedure was applied to accurately determine the optical constants for films of non-uniform thickness. The microstructure and texture of the films were studied using various X-ray diffraction techniques. The real part of the refractive index was found to not vary significantly with processing parameters, but absorption was found to be strongly dependent on the deposition temperature and the nitrogen pressure in the deposition chamber. We report that low optical absorption, textured polycrystalline AlN films can be produced by PLD on sapphire substrates at both low and high laser fluence using a background nitrogen pressure of 6.0 x 10 -2 Pa (4.5 x 10 -4 Torr) of 99.9% purity

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-03-10

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

Depth Profiling Analysis of Aluminum Oxidation During Film Deposition in a Conventional High Vacuum System

Science.gov (United States)

Kim, Jongmin; Weimer, Jeffrey J.; Zukic, Muamer; Torr, Douglas G.

1994-01-01

The oxidation of aluminum thin films deposited in a conventional high vacuum chamber has been investigated using x-ray photoelectron spectroscopy (XPS) and depth profiling. The state of the Al layer was preserved by coating it with a protective MgF2 layer in the deposition chamber. Oxygen concentrations in the film layers were determined as a function of sputter time (depth into the film). The results show that an oxidized layer is formed at the start of Al deposition and that a less extensively oxidized Al layer is deposited if the deposition rate is fast. The top surface of the Al layer oxidizes very quickly. This top oxidized layer may be thicker than has been previously reported by optical methods. Maximum oxygen concentrations measured by XPS at each Al interface are related to pressure to rate ratios determined during the Al layer deposition.

Porous and mesh alumina formed by anodization of high purity aluminum films at low anodizing voltage

International Nuclear Information System (INIS)

Abd-Elnaiem, Alaa M.; Mebed, A.M.; El-Said, Waleed Ahmed; Abdel-Rahim, M.A.

2014-01-01

Electrochemical oxidation of high-purity aluminum (Al) films under low anodizing voltages (1–10) V has been conducted to obtain anodic aluminum oxide (AAO) with ultra-small pore size and inter-pore distance. Different structures of AAO have been obtained e.g. nanoporous and mesh structures. Highly regular pore arrays with small pore size and inter-pore distance have been formed in oxalic or sulfuric acids at different temperatures (22–50 °C). It is found that the pore diameter, inter-pore distance and the barrier layer thickness are independent of the anodizing parameters, which is very different from the rules of general AAO fabrication. The brand formation mechanism has been revealed by the scanning electron microscope study. Regular nanopores are formed under 10 V at the beginning of the anodization and then serve as a template layer dominating the formation of ultra-small nanopores. Anodization that is performed at voltages less than 5 V leads to mesh structured alumina. In addition, we have introduced a simple one-pot synthesis method to develop thin walls of oxide containing lithium (Li) ions that could be used for battery application based on anodization of Al films in a supersaturated mixture of lithium phosphate and phosphoric acid as matrix for Li-composite electrolyte. - Highlights: • We develop anodic aluminum oxide (AAO) with small pore size and inter-pore distance. • Applying low anodizing voltages onto aluminum film leads to form mesh structures. • The value of anodizing voltage (1–10 V) has no effect on pore size or inter-pore distance. • Applying anodizing voltage less than 5 V leads to mesh structured AAO. • AAO can be used as a matrix for Li-composite electrolytes

Porous and mesh alumina formed by anodization of high purity aluminum films at low anodizing voltage

Energy Technology Data Exchange (ETDEWEB)

Abd-Elnaiem, Alaa M., E-mail: alaa.abd-elnaiem@science.au.edu.eg [KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh (Saudi Arabia); Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Mebed, A.M. [Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Department of Physics, Faculty of Science, Al-Jouf University, Sakaka 2014 (Saudi Arabia); El-Said, Waleed Ahmed [Department of Chemistry, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Abdel-Rahim, M.A. [Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt)

2014-11-03

Electrochemical oxidation of high-purity aluminum (Al) films under low anodizing voltages (1–10) V has been conducted to obtain anodic aluminum oxide (AAO) with ultra-small pore size and inter-pore distance. Different structures of AAO have been obtained e.g. nanoporous and mesh structures. Highly regular pore arrays with small pore size and inter-pore distance have been formed in oxalic or sulfuric acids at different temperatures (22–50 °C). It is found that the pore diameter, inter-pore distance and the barrier layer thickness are independent of the anodizing parameters, which is very different from the rules of general AAO fabrication. The brand formation mechanism has been revealed by the scanning electron microscope study. Regular nanopores are formed under 10 V at the beginning of the anodization and then serve as a template layer dominating the formation of ultra-small nanopores. Anodization that is performed at voltages less than 5 V leads to mesh structured alumina. In addition, we have introduced a simple one-pot synthesis method to develop thin walls of oxide containing lithium (Li) ions that could be used for battery application based on anodization of Al films in a supersaturated mixture of lithium phosphate and phosphoric acid as matrix for Li-composite electrolyte. - Highlights: • We develop anodic aluminum oxide (AAO) with small pore size and inter-pore distance. • Applying low anodizing voltages onto aluminum film leads to form mesh structures. • The value of anodizing voltage (1–10 V) has no effect on pore size or inter-pore distance. • Applying anodizing voltage less than 5 V leads to mesh structured AAO. • AAO can be used as a matrix for Li-composite electrolytes.

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...

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.

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...

Superconducting structure with layers of niobium nitride and aluminum nitride

International Nuclear Information System (INIS)

Murduck, J.M.; Lepetre, Y.J.; Schuller, I.K.; Ketterson, J.B.

1989-01-01

A superconducting structure is formed by depositing alternate layers of aluminum nitride and niobium nitride on a substrate. Deposition methods include dc magnetron reactive sputtering, rf magnetron reactive sputtering, thin-film diffusion, chemical vapor deposition, and ion-beam deposition. Structures have been built with layers of niobium nitride and aluminum nitride having thicknesses in a range of 20 to 350 Angstroms. Best results have been achieved with films of niobium nitride deposited to a thickness of approximately 70 Angstroms and aluminum nitride deposited to a thickness of approximately 20 Angstroms. Such films of niobium nitride separated by a single layer of aluminum nitride are useful in forming Josephson junctions. Structures of 30 or more alternating layers of niobium nitride and aluminum nitride are useful when deposited on fixed substrates or flexible strips to form bulk superconductors for carrying electric current. They are also adaptable as voltage-controlled microwave energy sources. 8 figs

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

Yttrium aluminum garnet coating on glass substrate

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Camila M.A.; Freiria, Gabriela S.; Faria, Emerson H. de; Rocha, Lucas A.; Ciuffi, Katia J.; Nassar, Eduardo J., E-mail: eduardo.nassar@unifran.edu.br

2016-02-15

Thin luminescent films have seen great technological advances and are applicable in the production of a variety of materials such as sensors, solar cells, photovoltaic devices, optical magnetic readers, waveguides, lasers, and recorders. Systems that contain yttrium aluminum oxide are important hosts for lanthanide ions and serve as light emission devices. This work deals with the deposition of yttrium aluminum garnet (YAG) film doped with Eu{sup 3+} onto a glass substrate obtained by the sol–gel methodology. Spray pyrolysis furnished the yttrium aluminum oxide powder. Dip-coating at a withdrawal speed of 10 mm min{sup −1} and evaporation led to deposition of different numbers of layers of the YAG:Eu{sup 3+} film onto the glass substrate from a YAG:Eu{sup 3+} powder suspension containing ethanol, water, and tetraethylorthosilicate. Photoluminescence, X-ray diffraction, scanning electron microscopy, and transparency measurements aided film characterization. The emission spectra revealed that the number of layers influenced film properties. - Highlights: • The spray pyrolysis was used to obtain luminescent YAG:Eu{sup 3+}. • The matrix was deposited as transparent films. • The YAG:Eu{sup 3+} was deposited by sol–gel process onto glass substrate.

Yttrium aluminum garnet coating on glass substrate

International Nuclear Information System (INIS)

Ferreira, Camila M.A.; Freiria, Gabriela S.; Faria, Emerson H. de; Rocha, Lucas A.; Ciuffi, Katia J.; Nassar, Eduardo J.

2016-01-01

Thin luminescent films have seen great technological advances and are applicable in the production of a variety of materials such as sensors, solar cells, photovoltaic devices, optical magnetic readers, waveguides, lasers, and recorders. Systems that contain yttrium aluminum oxide are important hosts for lanthanide ions and serve as light emission devices. This work deals with the deposition of yttrium aluminum garnet (YAG) film doped with Eu 3+ onto a glass substrate obtained by the sol–gel methodology. Spray pyrolysis furnished the yttrium aluminum oxide powder. Dip-coating at a withdrawal speed of 10 mm min −1 and evaporation led to deposition of different numbers of layers of the YAG:Eu 3+ film onto the glass substrate from a YAG:Eu 3+ powder suspension containing ethanol, water, and tetraethylorthosilicate. Photoluminescence, X-ray diffraction, scanning electron microscopy, and transparency measurements aided film characterization. The emission spectra revealed that the number of layers influenced film properties. - Highlights: • The spray pyrolysis was used to obtain luminescent YAG:Eu 3+ . • The matrix was deposited as transparent films. • The YAG:Eu 3+ was deposited by sol–gel process onto glass substrate.

Self-assembled monolayer exchange reactions as a tool for channel interface engineering in low-voltage organic thin-film transistors.

Science.gov (United States)

Lenz, Thomas; Schmaltz, Thomas; Novak, Michael; Halik, Marcus

2012-10-02

In this work, we compared the kinetics of monolayer self-assembly long-chained carboxylic acids and phosphonic acids on thin aluminum oxide surfaces and investigated their dielectric properties in capacitors and low-voltage organic thin-film transistors. Phosphonic acid anchor groups tend to substitute carboxylic acid molecules on aluminum oxide surfaces and thus allow the formation of mixed or fully exchanged monolayers. With different alkyl chain substituents (n-alkyl or fluorinated alkyl chains), the exchange reaction can be monitored as a function of time by static contact angle measurements. The threshold voltage in α,α'-dihexyl-sexithiophene thin-film transistors composed of such mixed layer dielectrics correlates with the exchange progress and can be tuned from negative to positive values or vice versa depending on the dipole moment of the alkyl chain substituents. The change in the dipole moment with increasing exchange time also shifts the capacitance of these devices. The rate constants for exchange reactions determined by the time-dependent shift of static contact angle, threshold voltage, and capacitance exhibit virtually the same value thus proving the exchange kinetics to be highly controllable. In general, the exchange approach is a powerful tool in interface engineering, displaying a great potential for tailoring of device characteristics.

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.

Development of a novel scintillation-trigger detector for the MTV experiment using aluminum-metallized film tapes

Science.gov (United States)

Tanaka, S.; Ozaki, S.; Sakamoto, Y.; Tanuma, R.; Yoshida, T.; Murata, J.

2014-07-01

A new type of a trigger-scintillation counter array designed for the MTV experiment at TRIUMF-ISAC has been developed, which uses aluminum-metallized film tape for wrapping to achieve the required assembling precision of ±0.5 mm. The MTV experiment uses a cylindrical drift chamber (CDC) as the main electron-tracking detector. The barrel-type trigger counter is placed inside the CDC to generate a trigger signal using 1 mm thick, 300 mm long thin plastic scintillation counters. Detection efficiency and light attenuation compared with conventional wrapping materials are studied.

Development of a novel scintillation-trigger detector for the MTV experiment using aluminum-metallized film tapes

International Nuclear Information System (INIS)

Tanaka, S.; Ozaki, S.; Sakamoto, Y.; Tanuma, R.; Yoshida, T.; Murata, J.

2014-01-01

A new type of a trigger-scintillation counter array designed for the MTV experiment at TRIUMF-ISAC has been developed, which uses aluminum-metallized film tape for wrapping to achieve the required assembling precision of ±0.5 mm. The MTV experiment uses a cylindrical drift chamber (CDC) as the main electron-tracking detector. The barrel-type trigger counter is placed inside the CDC to generate a trigger signal using 1 mm thick, 300 mm long thin plastic scintillation counters. Detection efficiency and light attenuation compared with conventional wrapping materials are studied

Using Mosaicity to Tune Thermal Transport in Polycrystalline AlN Thin Films

KAUST Repository

Singh, Shivkant

2018-05-17

The effect of controlling the c-axis alignment (mosaicity) to the cross-plane thermal transport in textured polycrystalline aluminum nitride (AlN) thin films is experimentally and theoretically investigated. We show that by controlling the sputtering conditions we are able to deposit AlN thin films with varying c-axis grain tilt (mosaicity) from 10° to 0°. Microstructural characterization shows that the films are nearly identical in thickness and grain size, and the difference in mosaicity alters the grain interface quality. This has a significant effect to thermal transport where a thermal conductivity of 4.22 W/mK vs. 8.09 W/mK are measured for samples with tilt angles of 10° vs. 0° respectively. The modified Callaway model was used to fit the theoretical curves to the experimental results using various phonon scattering mechanisms at the grain interface. It was found that using a non-gray model gives an overview of the phonon scattering at the grain boundaries, whereas treating the grain boundary as an array of dislocation lines with varying angle relative to the heat flow, best describes the mechanism of the thermal transport. Lastly, our results show that controlling the quality of the grain interface provides a tuning knob to control thermal transport in polycrystalline materials.

Using Mosaicity to Tune Thermal Transport in Polycrystalline AlN Thin Films

KAUST Repository

Singh, Shivkant; Shervin, Shahab; Sun, Haiding; Yarali, Milad; Chen, Jie; Lin, Ronghui; Li, Kuang-Hui; Li, Xiaohang; Ryou, Jae-Hyun; Mavrokefalos, Anastassios

2018-01-01

The effect of controlling the c-axis alignment (mosaicity) to the cross-plane thermal transport in textured polycrystalline aluminum nitride (AlN) thin films is experimentally and theoretically investigated. We show that by controlling the sputtering conditions we are able to deposit AlN thin films with varying c-axis grain tilt (mosaicity) from 10° to 0°. Microstructural characterization shows that the films are nearly identical in thickness and grain size, and the difference in mosaicity alters the grain interface quality. This has a significant effect to thermal transport where a thermal conductivity of 4.22 W/mK vs. 8.09 W/mK are measured for samples with tilt angles of 10° vs. 0° respectively. The modified Callaway model was used to fit the theoretical curves to the experimental results using various phonon scattering mechanisms at the grain interface. It was found that using a non-gray model gives an overview of the phonon scattering at the grain boundaries, whereas treating the grain boundary as an array of dislocation lines with varying angle relative to the heat flow, best describes the mechanism of the thermal transport. Lastly, our results show that controlling the quality of the grain interface provides a tuning knob to control thermal transport in polycrystalline materials.

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.

Electrochemical Thinning for Anodic Aluminum Oxide and Anodic Titanium Oxide

Energy Technology Data Exchange (ETDEWEB)

Lee, In Hae; Jo, Yun Kyoung; Kim, Yong Tae; Tak, Yong Sug; Choi, Jin Sub [Inha University, Incheon (Korea, Republic of)

2012-05-15

For given electrolytes, different behaviors of anodic aluminum oxide (AAO) and anodic titanium oxide (ATO) during electrochemical thinning are explained by ionic and electronic current modes. Branched structures are unavoidably created in AAO since the switch of ionic to electronic current is slow, whereas the barrier oxide in ATO is thinned without formation of the branched structures. In addition, pore opening can be possible in ATO if chemical etching is performed after the thinning process. The thinning was optimized for complete pore opening in ATO and potential-current behavior is interpreted in terms of ionic current-electronic current switching.

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.

Effects of concentration of reduced graphene oxide on properties of sol–gel prepared Al-doped zinc oxide thin films

Energy Technology Data Exchange (ETDEWEB)

Chou, Ching-Tian; Wang, Fang-Hsing, E-mail: fansen@dragon.nchu.edu.tw; Chen, Wei-Chun

2016-04-30

Reduced-graphene-oxide-incorporated aluminum-doped zinc oxide (AZO:rGO) composite thin films were synthesized on glass substrates by using the sol–gel method. The effect of the rGO concentration (0–3 wt%) on structural, electrical, and optical properties of the composite film was investigated by X-ray diffraction, scanning electron microscopy, atomic force microscopy, Hall-effect measurement, and ultraviolet–visible spectrometry. All of the composite films showed a typical hexagonal wurtzite structure, and the films incorporated with 1 wt% rGO showed the highest (0 0 2) peak intensity. The sheet resistance of the films was effectively reduced by a factor of more than two as the rGO ratio increased from 0 to 1 wt%. However, the sheet resistance increased with a further increase in the rGO ratio. The optical transmittance of the composite film monotonically decreased with increasing the rGO ratio from 0 to 3 wt%. The average optical transmittance (400–700 nm) of the AZO:rGO thin film within 1 wt% rGO was above 81%. - Highlights: • Reduced-graphene-oxide-doped ZnO:Al composite films are synthesized by sol–gel. • All AZO:rGO thin films show a typical hexagonal wurtzite structure. • Sheet resistance of AZO:rGO(1 wt%) film decreases by a factor of more than two. • The average visible transmittance of the AZO:rGO(1 wt%) film was 81%.

High efficiency copper indium gallium diselenide (CIGS) thin film solar cells

Science.gov (United States)

Rajanikant, Ray Jayminkumar

pressure of 10-5 mbar. The thickness of the film was kept 1 mum for the solar cell device preparation. Rapid Thermal Annealing (RTA) is carried out of CIGS thin film at 500 °C for 2 minutes in the argon atmosphere. Annealing process mainly improves the grain growth of the CIGS and, hence the surface roughness, which is essential for a multilayered semiconductor structure. Thin layer of n-type highly resistive cadmium sulphide (CdS), generally known as a "buffer" layer, is deposited on CIGS layer by thermal and flash evaporation method at the substrate temperature of 100 °C. The CdS thin film plays a crucial role in the formation of the p-n junction and thus the solar cell device performance. The effect of CdS film substrate temperature ranging from 50 °C to 200 °C is observed. At the 100 °C substrate temperature, CdS thin film shows the near to 85 % of transmission in the visible region and resistivity of the order of greater then 20 x 109 Ocm, which are the essential characteristics of buffer layer. The bi-layer structure of ZnO, containing 70 nm i-ZnO and 500 nm aluminum (Al) doped ZnO, act as a transparent front-contact for CIGS thin film solar cell. These layers were deposited using RF magnetron sputtering. i-ZnO thin film acts as an insulating layer, which prevents the recombination of the photo-generated carries and also minimizes the lattice miss match defects between CdS and Al-ZnO. The resistivity of iZnO and Al-ZnO is of the order of 1012 Ocm and 10-4 Ocm, respectively. Al-ZnO thin films act as transparent conducting top electrode having transparency of about 85 % in the visible region. On Al-ZnO layer the finger-type grid pattern of silver (Ag), 200 nm thick, is deposited for the collection of photo-generated carriers. The thin film based multilayered structure Mo / CIGS / CdS / i-ZnO / Al-ZnO / Ag grid of CIGS solar cell is grown one by one on a single glass substrate. As-prepared CIGS solar cell device shows a minute photovoltaic effect. For the further

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.

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.

Advanced properties of Al-doped ZnO films with a seed layer approach for industrial thin film photovoltaic application

International Nuclear Information System (INIS)

Dewald, Wilma; Sittinger, Volker; Szyszka, Bernd; Säuberlich, Frank; Stannowski, Bernd; Köhl, Dominik; Ries, Patrick; Wuttig, Matthias

2013-01-01

Currently sputtered Al-doped ZnO films are transferred to industry for the application in thin film silicon solar modules. These films are known to easily form light trapping structures upon etching which are necessary for absorbers with low absorbance such as μc-Si. Up to now the best structures for high efficiency thin film silicon solar cells were obtained by low rate radio frequency (r.f.) sputtering of ceramic targets. However, for industrial application a high rate process is essential. Therefore a seed layer approach was developed to increase the deposition rate while keeping the desired etch morphology and electrical properties. Aluminum doped ZnO films were deposited dynamically by direct current (d.c.) magnetron sputtering from a ceramic ZnO:Al 2 O 3 target (1 wt.%) onto an additional seed layer prepared by r.f. sputtering. ZnO:Al films were investigated with respect to their optical and electrical properties as well as the morphology created after etching for a-Si/μc-Si solar cells. Additionally atomic force microscopy, scanning electron microscopy, X-ray diffraction and Hall measurements were performed, comparing purely r.f. or d.c. sputtered films with d.c. sputtered films on seed layers. With the seed layer approach it was possible to deposit ZnO:Al films with a visual transmittance of 83.5%, resistivity of 295 μΩ cm, electron mobility of 48.9 cm 2 /Vs and electron density of 4.3 · 10 20 cm −3 from a ceramic target at 330 °C. Etch morphologies with 1 μm lateral structure size were achieved. - Highlights: ► Seed layer approach for dynamic sputter deposition of enhanced quality ZnO:Al. ► A thin radio frequency sputtered ZnO:Al layer assists film nucleation on glass. ► Electron mobility was increased up to 49 cm 2 /Vs due to quasi-epitaxial film growth. ► Etch morphology exhibits 1 μm wide craters for light trapping in solar cells. ► The concept was transferred to a seed layer sputtered with direct current

Advanced properties of Al-doped ZnO films with a seed layer approach for industrial thin film photovoltaic application

Energy Technology Data Exchange (ETDEWEB)

Dewald, Wilma, E-mail: wilma.dewald@ist.fraunhofer.de [Fraunhofer Institute for Surface Engineering and Thin Films IST, Bienroder Weg 54E, 38108 Braunschweig (Germany); Sittinger, Volker; Szyszka, Bernd [Fraunhofer Institute for Surface Engineering and Thin Films IST, Bienroder Weg 54E, 38108 Braunschweig (Germany); Säuberlich, Frank; Stannowski, Bernd [Sontor GmbH, OT Thalheim, Sonnenallee 7-11, 06766 Bitterfeld-Wolfen (Germany); Köhl, Dominik; Ries, Patrick; Wuttig, Matthias [I. Physikalisches Institut (IA), RWTH Aachen, Sommerfeldstraße 14, 52074 Aachen (Germany)

2013-05-01

Currently sputtered Al-doped ZnO films are transferred to industry for the application in thin film silicon solar modules. These films are known to easily form light trapping structures upon etching which are necessary for absorbers with low absorbance such as μc-Si. Up to now the best structures for high efficiency thin film silicon solar cells were obtained by low rate radio frequency (r.f.) sputtering of ceramic targets. However, for industrial application a high rate process is essential. Therefore a seed layer approach was developed to increase the deposition rate while keeping the desired etch morphology and electrical properties. Aluminum doped ZnO films were deposited dynamically by direct current (d.c.) magnetron sputtering from a ceramic ZnO:Al{sub 2}O{sub 3} target (1 wt.%) onto an additional seed layer prepared by r.f. sputtering. ZnO:Al films were investigated with respect to their optical and electrical properties as well as the morphology created after etching for a-Si/μc-Si solar cells. Additionally atomic force microscopy, scanning electron microscopy, X-ray diffraction and Hall measurements were performed, comparing purely r.f. or d.c. sputtered films with d.c. sputtered films on seed layers. With the seed layer approach it was possible to deposit ZnO:Al films with a visual transmittance of 83.5%, resistivity of 295 μΩ cm, electron mobility of 48.9 cm{sup 2}/Vs and electron density of 4.3 · 10{sup 20} cm{sup −3} from a ceramic target at 330 °C. Etch morphologies with 1 μm lateral structure size were achieved. - Highlights: ► Seed layer approach for dynamic sputter deposition of enhanced quality ZnO:Al. ► A thin radio frequency sputtered ZnO:Al layer assists film nucleation on glass. ► Electron mobility was increased up to 49 cm{sup 2}/Vs due to quasi-epitaxial film growth. ► Etch morphology exhibits 1 μm wide craters for light trapping in solar cells. ► The concept was transferred to a seed layer sputtered with direct current.

Effect of hydrogen doping on the properties of Al and F co-doped ZnO films for thin film silicon solar cell applications

Energy Technology Data Exchange (ETDEWEB)

Wang, Fang-Hsing, E-mail: fansen@dragon.nchu.edu.tw; Yang, Tung-Hsin

2016-04-30

Aluminum and fluorine co-doped zinc oxide (AFZO) thin films were prepared in Ar + H{sub 2} atmospheres by rf magnetron sputtering at room temperature. The structural, electrical, and optical properties of the prepared films were investigated using X-ray diffraction, scanning electron microscopy, atomic force microscopy, Hall-effect measurement, X-ray photoelectron spectroscopy, and ultraviolet–visible spectrometry, and their dependence on deposition atmosphere (i.e. H{sub 2} / (H{sub 2} + Ar) ratio) was studied. The resulting films showed a (0 0 2) diffraction peak, indicating a typical wurtzite structure, and the optimal film crystallinity was obtained with the H{sub 2} / (H{sub 2} + Ar) ratio of 3%. The electrical resistivity of AFZO films decreased to 9.16 × 10{sup −4} Ω-cm, which was lower than ZnO:Al and ZnO:F films due to double doping effect of Al and F. The resistivity further decreased to below 5 × 10{sup −4} Ω-cm for the AFZO film with the H{sub 2} / (H{sub 2} + Ar) ratio of 3%–5%. All the films regardless of hydrogen content displayed high transmittances (> 92%) in the visible wavelength range. Applying the developed AFZO films as front transparent electrodes, amorphous Si thin film solar cells were fabricated and the open-circuit voltage, fill factor, and efficiency of the cell with the hydrogenated AFZO film were improved in contrast to those without the hydrogenated film. - Highlights: • H{sub 2} doping improves optoelectronic properties of Al, F co-doped ZnO (AFZO) films. • Resistivity of AFZO films decreases to 4.4 × 10{sup −4} Ω-cm with the 3% H{sub 2}/(Ar + H{sub 2}) ratio. • AFZO films show high average visible transmittances of above 92%. • Efficiency of a-Si thin film solar cells is improved by AFZO:H as front electrode.

High conductivity and transparent aluminum-based multi-layer source/drain electrodes for thin film transistors

Science.gov (United States)

Yao, Rihui; Zhang, Hongke; Fang, Zhiqiang; Ning, Honglong; Zheng, Zeke; Li, Xiaoqing; Zhang, Xiaochen; Cai, Wei; Lu, Xubing; Peng, Junbiao

2018-02-01

In this study, high conductivity and transparent multi-layer (AZO/Al/AZO-/Al/AZO) source/drain (S/D) electrodes for thin film transistors were fabricated via conventional physical vapor deposition approaches, without toxic elements or further thermal annealing process. The 68 nm-thick multi-layer films with excellent optical properties (transparency: 82.64%), good electrical properties (resistivity: 6.64  ×  10-5 Ω m, work function: 3.95 eV), and superior surface roughness (R q   =  0.757 nm with scanning area of 5  ×  5 µm2) were fabricated as the S/D electrodes. Significantly, comprehensive performances of AZO films are enhanced by the insertion of ultra-thin Al layers. The optimal transparent TFT with this multi-layer S/D electrodes exhibited a decent electrical performance with a saturation mobility (µ sat) of 3.2 cm2 V-1 s-1, an I on/I off ratio of 1.59  ×  106, a subthreshold swing of 1.05 V/decade. The contact resistance of AZO/Al/AZO/Al/AZO multi-layer electrodes is as low as 0.29 MΩ. Moreover, the average visible light transmittance of the unpatterned multi-layers constituting a whole transparent TFT could reach 72.5%. The high conductivity and transparent multi-layer S/D electrodes for transparent TFTs possessed great potential for the applications of the green and transparent displays industry.

Characterization of anodic barrier films on tantalum and 1100 aluminum by ISS/SIMS

International Nuclear Information System (INIS)

McCune, R.C.

1978-01-01

Ion scattering spectrometry (ISS) and concurrent secondary ion mass spectrometry (SIMS) were used to determine the depth profiles of anodic barrier oxide films grown on tantalum and type 1100 aluminum. The sputter rate in each case was determined from the film thickness measured by the anodic overvoltage, and the penetration time determined by the decrease in intensity of the metal oxide fragment observed using SIMS. A mixture of helium and neon ions was used to sputter aluminum oxide films in order to observe ion scattering of helium by oxygen, while taking advantage of the higher sputtering rate available with neon. A comparison of sputter rates for helium and neon on tantalum oxide indicated that neon sputtered the film at a rate eight times that of helium. SIMS depth profiling of the residual boron in the anodic aluminum oxide indicated a mixing effect which did not permit adequate resolution of the interface between the oxide film and the underlying metal

Feasibility study of using thin aluminum nitride film as a buffer layer for dual metal gate process

International Nuclear Information System (INIS)

Park, Chang Seo; Cho, Byung Jin; Balasubramanian, N.; Kwong, Dim-Lee

2004-01-01

We evaluated the feasibility of using an ultra thin aluminum nitride (AlN) buffer layer for dual metal gates CMOS process. Since the buffer layer should not affect the thickness of gate dielectric, it should be removed or consumed during subsequent process. In this work, it was shown that a thin AlN dielectric layer would be reacted with initial gate metals and would be consumed during subsequent annealing, resulting in no increase of equivalent oxide thickness (EOT). The reaction of AlN layer with tantalum (Ta) and hafnium (Hf) during subsequent annealing, which was confirmed with X-ray photoelectron spectroscopy (XPS) analysis, shifted the flat-band voltage of AlN buffered MOS capacitors. No contribution to equivalent oxide thickness (EOT) was also an indication showing the full consumption of AIN, which was confirmed with TEM analysis. The work functions of gate metals were modulated through the reaction, suggesting that the consumption of AlN resulted in new thin metal alloys. Finally, it was found that the barrier heights of the new alloys were consistent with their work functions

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.

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

A measuring system for mechanical characterization of thin films based on a compact in situ micro-tensile tester and SEM moiré method

International Nuclear Information System (INIS)

Li, Yanjie; Tang, Minjin; Xie, Huimin; Zhu, Ronghua; Luo, Qiang; Gu, Changzhi

2013-01-01

A measuring system for mechanical characterization of thin films based on a compact in situ micro-tensile tester and scanning electron microscope (SEM) moiré method is proposed. The load is exerted by the tensile tester and the full field strain is measured by SEM moiré method. The configuration of the tensile tester and the principle of SEM moiré method are introduced. In the tensile tester, a lever structure is designed to amplify the displacement imposed by lead–zirconate–titanate (PZT) actuator. The SEM moiré method is applied to measure the strain of the thin film, including both the average strain in the gage section and the local strain distribution at a specific region. As an application, the measuring system is applied to characterize the mechanical property of the free-standing aluminum thin film. The experimental results demonstrate the feasibility of the system and its good application potential for mechanical behavior analysis of film-like materials. (paper)

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.

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

Science.gov (United States)

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

2006-03-01

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

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.

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...

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.

Ion irradiation of AZO thin films for flexible electronics

Science.gov (United States)

Boscarino, Stefano; Torrisi, Giacomo; Crupi, Isodiana; Alberti, Alessandra; Mirabella, Salvatore; Ruffino, Francesco; Terrasi, Antonio

2017-02-01

Aluminum doped Zinc oxide (AZO) is a promising transparent conductor for solar cells, displays and touch-screen technologies. The resistivity of AZO is typically improved by thermal annealing at temperatures not suitable for plastic substrates. Here we present a non-thermal route to improve the electrical and structural properties of AZO by irradiating the TCO films with O+ or Ar+ ion beams (30-350 keV, 3 × 1015-3 × 1016 ions/cm2) after the deposition on glass and flexible polyethylene naphthalate (PEN). X-ray diffraction, optical absorption, electrical measurements, Rutherford Backscattering Spectrometry and Atomic Force Microscopy evidenced an increase of the crystalline grain size and a complete relief of the lattice strain upon ion beam irradiation. Indeed, the resistivity of thin AZO films irradiated at room temperature decreased of two orders of magnitude, similarly to a thermal annealing at 400 °C. We also show that the improvement of the electrical properties does not simply depend on the strain or polycrystalline domain size, as often stated in the literature.

Direct growth of large grain polycrystalline silicon films on aluminum-induced crystallization seed layer using hot-wire chemical vapor deposition

International Nuclear Information System (INIS)

Wu, Bing-Rui; Lo, Shih-Yung; Wuu, Dong-Sing; Ou, Sin-Liang; Mao, Hsin-Yuan; Wang, Jui-Hao; Horng, Ray-Hua

2012-01-01

Large grain polycrystalline silicon (poly-Si) films on glass substrates have been deposited on an aluminum-induced crystallization (AIC) seed layer using hot-wire chemical vapor deposition (HWCVD). A poly-Si seed layer was first formed by the AIC process and a thicker poly-Si film was subsequently deposited upon the seed layer using HWCVD. The effects of AIC annealing parameters on the structural and electrical properties of the poly-Si seed layers were characterized by Raman scattering spectroscopy, field-emission scanning electron microscopy, and Hall measurements. It was found that the crystallinity of seed layer was enhanced with increasing the annealing duration and temperature. The poly-Si seed layer formed at optimum annealing parameters can reach a grain size of 700 nm, hole concentration of 3.5 × 10 18 cm −3 , and Hall mobility of 22 cm 2 /Vs. After forming the seed layer, poly-Si films with good crystalline quality and high growth rate (> 1 nm/s) can be obtained using HWCVD. These results indicated that the HWCVD-deposited poly-Si film on an AIC seed layer could be a promising candidate for thin-film Si photovoltaic applications. - Highlights: ►Poly-Si seed layers are formed by aluminum-induced crystallization (AIC) process. ►Poly-Si on AIC seed layers are prepared by hot-wire chemical vapor deposition. ►AIC process parameters affect structural properties of poly-Si films. ►Increasing the annealing duration and temperature increases the film crystallinity.

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.

Mechanical, Corrosion and Biological Properties of Room-Temperature Sputtered Aluminum Nitride Films with Dissimilar Nanostructure

Directory of Open Access Journals (Sweden)

Cristina Besleaga

2017-11-01

Full Text Available Aluminum Nitride (AlN has been long time being regarded as highly interesting material for developing sensing applications (including biosensors and implantable sensors. AlN, due to its appealing electronic properties, is envisaged lately to serve as a multi-functional biosensing platform. Although generally exploited for its intrinsic piezoelectricity, its surface morphology and mechanical performance (elastic modulus, hardness, wear, scratch and tensile resistance to delamination, adherence to the substrate, corrosion resistance and cytocompatibility are also essential features for high performance sustainable biosensor devices. However, information about AlN suitability for such applications is rather scarce or at best scattered and incomplete. Here, we aim to deliver a comprehensive evaluation of the morpho-structural, compositional, mechanical, electrochemical and biological properties of reactive radio-frequency magnetron sputtered AlN nanostructured thin films with various degrees of c-axis texturing, deposited at a low temperature (~50 °C on Si (100 substrates. The inter-conditionality elicited between the base pressure level attained in the reactor chamber and crystalline quality of AlN films is highlighted. The potential suitability of nanostructured AlN (in form of thin films for the realization of various type of sensors (with emphasis on bio-sensors is thoroughly probed, thus unveiling its advantages and limitations, as well as suggesting paths to safely exploit the remarkable prospects of this type of materials.

Mechanical, Corrosion and Biological Properties of Room-Temperature Sputtered Aluminum Nitride Films with Dissimilar Nanostructure.

Science.gov (United States)

Besleaga, Cristina; Dumitru, Viorel; Trinca, Liliana Marinela; Popa, Adrian-Claudiu; Negrila, Constantin-Catalin; Kołodziejczyk, Łukasz; Luculescu, Catalin-Romeo; Ionescu, Gabriela-Cristina; Ripeanu, Razvan-George; Vladescu, Alina; Stan, George E

2017-11-17

Aluminum Nitride (AlN) has been long time being regarded as highly interesting material for developing sensing applications (including biosensors and implantable sensors). AlN, due to its appealing electronic properties, is envisaged lately to serve as a multi-functional biosensing platform. Although generally exploited for its intrinsic piezoelectricity, its surface morphology and mechanical performance (elastic modulus, hardness, wear, scratch and tensile resistance to delamination, adherence to the substrate), corrosion resistance and cytocompatibility are also essential features for high performance sustainable biosensor devices. However, information about AlN suitability for such applications is rather scarce or at best scattered and incomplete. Here, we aim to deliver a comprehensive evaluation of the morpho-structural, compositional, mechanical, electrochemical and biological properties of reactive radio-frequency magnetron sputtered AlN nanostructured thin films with various degrees of c -axis texturing, deposited at a low temperature (~50 °C) on Si (100) substrates. The inter-conditionality elicited between the base pressure level attained in the reactor chamber and crystalline quality of AlN films is highlighted. The potential suitability of nanostructured AlN (in form of thin films) for the realization of various type of sensors (with emphasis on bio-sensors) is thoroughly probed, thus unveiling its advantages and limitations, as well as suggesting paths to safely exploit the remarkable prospects of this type of materials.

Hydrogen plasma treatment for improved conductivity in amorphous aluminum doped zinc tin oxide thin films

Directory of Open Access Journals (Sweden)

M. Morales-Masis

2014-09-01

Full Text Available Improving the conductivity of earth-abundant transparent conductive oxides (TCOs remains an important challenge that will facilitate the replacement of indium-based TCOs. Here, we show that a hydrogen (H2-plasma post-deposition treatment improves the conductivity of amorphous aluminum-doped zinc tin oxide while retaining its low optical absorption. We found that the H2-plasma treatment performed at a substrate temperature of 50 °C reduces the resistivity of the films by 57% and increases the absorptance by only 2%. Additionally, the low substrate temperature delays the known formation of tin particles with the plasma and it allows the application of the process to temperature-sensitive substrates.

Hydrogen plasma treatment for improved conductivity in amorphous aluminum doped zinc tin oxide thin films

Energy Technology Data Exchange (ETDEWEB)

Morales-Masis, M., E-mail: monica.moralesmasis@epfl.ch; Ding, L.; Dauzou, F. [Photovoltaics and Thin-Film Electronics Laboratory (PVLab), Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne - EPFL, Rue de la Maladière 71b, CH-2002 Neuchatel (Switzerland); Jeangros, Q. [Interdisciplinary Centre for Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland); Hessler-Wyser, A. [Photovoltaics and Thin-Film Electronics Laboratory (PVLab), Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne - EPFL, Rue de la Maladière 71b, CH-2002 Neuchatel (Switzerland); Interdisciplinary Centre for Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland); Nicolay, S. [Centre Suisse d’Electronique et de Microtechnique (CSEM) SA, Rue Jaquet-Droz 1, CH-2002 Neuchatel (Switzerland); Ballif, C. [Photovoltaics and Thin-Film Electronics Laboratory (PVLab), Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne - EPFL, Rue de la Maladière 71b, CH-2002 Neuchatel (Switzerland); Centre Suisse d’Electronique et de Microtechnique (CSEM) SA, Rue Jaquet-Droz 1, CH-2002 Neuchatel (Switzerland)

2014-09-01

Improving the conductivity of earth-abundant transparent conductive oxides (TCOs) remains an important challenge that will facilitate the replacement of indium-based TCOs. Here, we show that a hydrogen (H{sub 2})-plasma post-deposition treatment improves the conductivity of amorphous aluminum-doped zinc tin oxide while retaining its low optical absorption. We found that the H{sub 2}-plasma treatment performed at a substrate temperature of 50 °C reduces the resistivity of the films by 57% and increases the absorptance by only 2%. Additionally, the low substrate temperature delays the known formation of tin particles with the plasma and it allows the application of the process to temperature-sensitive substrates.

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.

Characterization of n and p-type ZnO thin films grown by pulsed filtered cathodic vacuum arc system

International Nuclear Information System (INIS)

Kavak, H.; Erdogan, E.N.; Ozsahin, I.; Esen, R.

2010-01-01

oxidation zinc nitride the film converted to p-type zinc oxide and the film became more transparent. During the oxidation process at each temperature Hall measurements were made to determine carrier type, carrier concentration, mobility and resistivity. Hall effect measurements indicated that ZnO films were p-type, the reliable results obtained for carrier concentration and mobility. Hall effect measurements proved that after annealing at 350 degrees Celsium up to 500 degrees Celsium the film was p-type. By increasing the oxidation temperature over 550 degrees Celsium the ZnO thin films turned into n-type due to the loss of N atoms in the film. Room temperature photoluminescence measurements were performed to investigate doping and impurity level of these films. The deposited best quality n and p type ZnO thin films were used to produce hetero and homojunctions. p-type ZnO deposited on the n-type Si substrate and aluminum or indium was evaporated as metal contacts (n-p). On the other hand n-type ZnO deposited on p-type Si substrate for p-n structure. In the case of homo-junction both n and p-type ZnO thin films were deposited on glass substrates with Al contacts. Current-Voltage characteristics of these devices were determined and the typical result for p-n hetero-junction was shown here

Preparation of thin hexagonal highly-ordered anodic aluminum oxide (AAO) template onto silicon substrate and growth ZnO nanorod arrays by electrodeposition

Science.gov (United States)

Chahrour, Khaled M.; Ahmed, Naser M.; Hashim, M. R.; Elfadill, Nezar G.; Qaeed, M. A.; Bououdina, M.

2014-12-01

In this study, anodic aluminum oxide (AAO) templates of Aluminum thin films onto Ti-coated silicon substrates were prepared for growth of nanostructure materials. Hexagonally highly ordered thin AAO templates were fabricated under controllable conditions by using a two-step anodization. The obtained thin AAO templates were approximately 70 nm in pore diameter and 250 nm in length with 110 nm interpore distances within an area of 3 cm2. The difference between first and second anodization was investigated in details by in situ monitoring of current-time curve. A bottom barrier layer of the AAO templates was removed during dropping the voltage in the last period of the anodization process followed by a wet etching using phosphoric acid (5 wt%) for several minutes at ambient temperature. As an application, Zn nanorod arrays embedded in anodic alumina (AAO) template were fabricated by electrodeposition. Oxygen was used to oxidize the electrodeposited Zn nanorods in the AAO template at 700 °C. The morphology, structure and photoluminescence properties of ZnO/AAO assembly were analyzed using Field-emission scanning electron microscope (FESEM), Energy dispersive X-ray spectroscopy (EDX), Atomic force microscope (AFM), X-ray diffraction (XRD) and photoluminescence (PL).

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

Physical vapor deposition and analysis of copper indium aluminum diselenide thin films for high band gap solar cells

Science.gov (United States)

Haimbodi, Moses Warotua

CuInSe2 films and related alloys have been used to fabricate the highest efficiency thin film solar cells. Alloying CuInSe2 with CuAlSe2 provides a way to engineer the band gap of the resulting films from 1 to 2.7 eV, thereby providing a pathway for improving device performance. In this work, thin films of CuIn1-xAlxSe 2 obtained by multi-source PVD were characterized and investigated for their potential use as high band gap solar cells. The band gap of the films was varied by controlling the [Al]/[Al + In] ratio. Deposition of these films with varying [Cu]/[Al + In] ratios and thickness (1--4 mum) was carried out at substrate temperatures from 350--530°C. CuIn1-xAlxSe2 based solar cells have been fabricated using the structure glass/Mo/CuIn1-xAl xSe2/CdS/ZnO/grid. The effect of varying the band gap on device performance will be discussed. The highest efficiency obtained in this work is 11% using a film with Eg ≈ 1.3 eV. For high Al content, x > 0.3, device-performance decreases mainly due to poor FF similar to that observed in CuIn1-xGaxSe2 devices and is attributed to poor minority carrier collection. For CuIn1-xAlxSe2 films with x = 1, data is analyzed and presented with respect to [Cu]/[Al] and Se to total metal flux ratio, RSe/RM. Phase analysis shows that the resulting films contain different phases that depend on these parameters. Several of these films also contain concentrations of oxygen varying from 12 to 60 at. % as the [Cu]/[Al] ratio decreases. For RSe/R M > 10, a new structure we label as CuxAlySe z was observed. The oxygen content in all of the films obtained under RSe/RM > 10 vary between 1--3 at. %. Based on the Cu-Se, Al-Se, Cu-Al binary and the Cu2Se-Al2Se 3 pseudo-binary phase diagrams, a phenomenological film growth model is presented showing that the film growth kinetics are controlled by the delivery of Se.

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)

Investigation on powder metallurgy Cr-Si-Ta-Al alloy target for high-resistance thin film resistors with low temperature coefficient of resistance

International Nuclear Information System (INIS)

Wang, X.Y.; Zhang, Z.S.; Bai, T.

2010-01-01

The sputtering target for high-resistance thin film resistors plays a decisive role in temperature coefficient of resistance (TCR). Silicon-rich chromium (Cr)-silicon (Si) target was designed and smelted for high-resistance thin film resistors with low TCR. Valve metal tantalum (Ta) and aluminum (Al) were introduced to the Cr-Si target to improve the performance of the target prepared. The measures for grain refining in smelting Cr-Si-Ta-Al target were taken to improve the performance of the prepared target. The mechanism and role of grain refinement were discussed in the paper. The phase structure of the prepared target was detected by X-ray diffraction (XRD). Rate of temperature drop was studied to reduce the internal stress of alloy target and conquer the easy cracking disadvantage of silicon-rich target. The electrical properties of sputtered thin film resistors were tested to evaluate the performance of the prepared target indirectly.

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.

Carbon contaminant in the ion processing of aluminum oxide film

International Nuclear Information System (INIS)

Chaug, Y.; Roy, N.

1989-01-01

Ion processing can induce contamination on the bombarded surface. However, this process is essential for the microelectronics device fabrication. Auger electron spectroscopy has been used to study the simultaneous deposition of carbon impurity during ion bombardment of magnetron rf-sputtering deposited aluminum oxide film. Ion bombardment on aluminum oxide results in a preferential removal of surface oxygen and a formation of a metastable state of aluminum suboxide. Cosputtered implanted carbon contaminant appears to have formed a new state of stoichiometry on the surface of the ion bombarded aluminum oxide and existed as an aluminum carbide. This phase has formed due to the interaction of the implanted carbon and the aluminum suboxide. The Ar + ion sputter etching rate is reduced for the carbon contaminated oxide. The electrical resistance of the aluminum oxide between two gold strips has been measured. It is found that the electrical resistance is also reduced due to the formation of the new stoichiometry on the surface

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.

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.

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.

The preparation and corrosion resistance of Ce and Nd modified anodic films on aluminum

International Nuclear Information System (INIS)

Li Qizheng; Tang Yuming; Zuo Yu

2010-01-01

Rare earth element Ce and Nd modified anodic films were prepared on aluminum surface by a relatively simple method: the aluminum samples were first immersed in Ni(NO 3 ) 2 solutions containing Ce or Nd salts at 90 deg. C, then were dried and anodized. The contents of Ce or Nd in the anodic films were from 0.5% to 0.9%, and about 4-5% Ni was also introduced in the films. The modified anodic films were more compact with much smaller pores and increased hardness. In neutral, acidic and basic NaCl solutions, the rare earth modified films showed obviously improved corrosion resistance. The Ce modified films showed better corrosion resistance than Nd modified films. The cracking resistance of the films under heating was also improved.

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.

Influence of sputtering deposition parameters on electrical and optical properties of aluminium-doped zinc oxide thin films for photovoltaic applications

Science.gov (United States)

Krawczak, Ewelina; Agata, Zdyb; Gulkowski, Slawomir; Fave, Alain; Fourmond, Erwann

2017-11-01

Transparent Conductive Oxides (TCOs) characterized by high visible transmittance and low electrical resistivity play an important role in photovoltaic technology. Aluminum doped zinc oxide (AZO) is one of the TCOs that can find its application in thin film solar cells (CIGS or CdTe PV technology) as well as in other microelectronic applications. In this paper some optical and electrical properties of ZnO:Al thin films deposited by RF magnetron sputtering method have been investigated. AZO layers have been deposited on the soda lime glass substrates with use of variable technological parameters such as pressure in the deposition chamber, power applied and temperature during the process. The composition of AZO films has been investigated by EDS method. Thickness and refraction index of the deposited layers in dependence on certain technological parameters of sputtering process have been determined by spectroscopic ellipsometry. The measurements of transmittance and sheet resistance were also performed.

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.

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.

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

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.

L2O3 NANOSTRUCTURED FILMS CREATION BY METHOD OF ELECTROCHEMICAL ANODIZING

Directory of Open Access Journals (Sweden)

M. V. Zhukov

2013-05-01

Full Text Available Thin oxide films of aluminum were investigated by method of scanning probe microscopy. Electrical parameters of anodizing process were studied on different samples of aluminum to get the most structured oxide. The comparison of surface structure topography was held on oxide films by NTegra scanning probe microscope

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.

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.