Nanoporous MnO{sub x} thin-film electrodes synthesized by electrochemical lithiation/delithiation for supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Xia, Hui; Lai, Man On; Lu, Li [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore)

2011-02-15

Nanoporous MnO{sub x} thin-film electrodes are synthesized using a combination of pulsed laser deposition (PLD) and electrochemical lithiation/delithiation methods. A dense Mn{sub 3}O{sub 4} thin-film deposited by PLD can transform into a nanoporous MnO{sub x} thin-film after electrochemical lithiation/delithiation. A nanoporous MnO{sub x} thin-film electrode exhibits significantly improved supercapacitive performance compared with an as-deposited Mn{sub 3}O{sub 4} thin-film electrode. A MnO{sub x} thin-film finally transforms into a MnO{sub 2} thin-film through an electrochemical oxidation process during continuous cyclic voltammetry scanning. (author)

Amperometric Noise at Thin Film Band Electrodes

DEFF Research Database (Denmark)

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

2012-01-01

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

Facile green synthesis of silver nanodendrite/cellulose acetate thin film electrodes for flexible supercapacitors.

Science.gov (United States)

Devarayan, Kesavan; Park, Jiyoung; Kim, Hak-Yong; Kim, Byoung-Suhk

2017-05-01

In this study, we present a highly efficient and economical solution called as 'in situ hydrogenation' for preparation of highly conductive thin film electrode based on silver nanodendrites. The silver nanodendrite (AgND)/cellulose acetate (CA) thin film electrodes exhibited sheet resistance ranging from 0.32ohm/sq to 122.1ohm/sq which could be controlled by changing the concentration of both silver and polymer. In addition, these electrodes exhibited outstanding toughness during the bending test. Further, these thin film electrodes have great potential for scale-up with an average weight of 3mg/cm 2 and can be also combined with active nanomaterials such as multiwalled carbon nanotubes (MWCNTs) to fabricate AgND/CA/MWCNTs thin film for high-performance flexible supercapacitor electrode. The AgND/CA/MWCNTs electrodes exhibited a maximum specific capacitance of 237F/g at a current density of 0.3A/g. After 1000 cycles, the AgND/MWCNT/CA exhibited a decrease of 16.0% of specific capacitance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electrochemical Biosensor Based on Boron-Doped Diamond Electrodes with Modified Surfaces

OpenAIRE

Yu, Yuan; Zhou, Yanli; Wu, Liangzhuan; Zhi, Jinfang

2012-01-01

Boron-doped diamond (BDD) thin films, as one kind of electrode materials, are superior to conventional carbon-based materials including carbon paste, porous carbon, glassy carbon (GC), carbon nanotubes in terms of high stability, wide potential window, low background current, and good biocompatibility. Electrochemical biosensor based on BDD electrodes have attracted extensive interests due to the superior properties of BDD electrodes and the merits of biosensors, such as specificity, sensitiv...

Self-positioned thin Pb-alloy base electrode Josephson junction

International Nuclear Information System (INIS)

Kuroda, K.; Sato, K.

1986-01-01

A self-positioned thin (SPOT) Pb-alloy base electrode Josephson junction is developed. In this junction, a 50-nm thick Pb-alloy base electrode is restricted within the junction region on an Nb underlayer using a self-alignment technique. The grain size reduction and the base electrode area restriction greatly improve thermal cycling stability, where the thermal cycling tests of 4000 proposed junctions (5 x 5 μm 2 ) showed no failures after 4000 cycles. In addition, the elimination of insulator layer stress on the Pb-alloy base electrode rectifies the problem of size effect on current density. The Nb underlayers also serve to isolate the Pb-alloy base electrodes from the resistors

Roll-to-Roll sputtered ITO/Cu/ITO multilayer electrode for flexible, transparent thin film heaters and electrochromic applications.

Science.gov (United States)

Park, Sung-Hyun; Lee, Sang-Mok; Ko, Eun-Hye; Kim, Tae-Ho; Nah, Yoon-Chae; Lee, Sang-Jin; Lee, Jae Heung; Kim, Han-Ki

2016-09-22

We fabricate high-performance, flexible, transparent electrochromic (EC) films and thin film heaters (TFHs) on an ITO/Cu/ITO (ICI) multilayer electrode prepared by continuous roll-to-roll (RTR) sputtering of ITO and Cu targets. The RTR-sputtered ICI multilayer on a 700 mm wide PET substrate at room temperature exhibits a sheet resistance of 11.8 Ω/square and optical transmittance of 73.9%, which are acceptable for the fabrication of flexible and transparent EC films and TFHs. The effect of the Cu interlayer thickness on the electrical and optical properties of the ICI multilayer was investigated in detail. The bending and cycling fatigue tests demonstrate that the RTR-sputtered ICI multilayer was more flexible than a single ITO film because of high strain failure of the Cu interlayer. The flexible and transparent EC films and TFHs fabricated on the ICI electrode show better performances than reference EC films and TFHs with a single ITO electrode. Therefore, the RTR-sputtered ICI multilayer is the best substitute for the conventional ITO film electrode in order to realize flexible, transparent, cost-effective and large-area EC devices and TFHs that can be used as flexible and smart windows.

Thin, X-ray-Transparent Windows for Imaging Applications with a Pneumatically Pressurized Enclosure

International Nuclear Information System (INIS)

Shu Deming; Wang Jin; Preissner, Curt

2007-01-01

We have developed a novel thin, x-ray-transparent window system for environmental chambers involving pneumatic pressures above 10 bar. The windows allow for x-ray access to fuel sprays injected into a pressurized chamber that mimics realistic internal combustion engine cylinder operating conditions. The design of the window system and its experimental test results are presented in this paper, as well as its further development for in situ x-ray imaging applications in a high-pressure and high-temperature environment

Advances in submerged arc, narrow-gap welding with strip electrodes and thin, dual-wire electrodes

International Nuclear Information System (INIS)

Nies, H.

1990-01-01

Container and tank construction for nuclear installations traditionally is one of the major applications of narrow-gap welding with the submerged arc technique. This type of welding presents one problem, namely to completely and reliably remove the welding slag from the deep and narrow gap. The research report in hand explains the variants of welding techniques that have been tested and describes the results obtained, which primarily are reduced occurrence of faults, i.e. enhanced reliability, and better welding economy. As an alternative to welding with thick wire electrodes, which is the standard method for the applications under review, a new technique has been conceived and extensively tested, which uses thin strip electrodes at longitudinal position in the gap. This submerged arc, dual-wire technique with thin electrodes is characterised by a significantly higher thermal efficiency compared to welding with thick wires, so that the same energy input yields better efficiency of metal deposition. (orig./MM) [de

Thin-layer voltammetry of soluble species on screen-printed electrodes: proof of concept.

Science.gov (United States)

Botasini, S; Martí, A C; Méndez, E

2016-10-17

Thin-layer diffusion conditions were accomplished on screen-printed electrodes by placing a controlled-weight onto the cast solution and allowing for its natural spreading. The restricted diffusive conditions were assessed by cyclic voltammetry at low voltage scan rates and electrochemical impedance spectroscopy. The relationship between the weight exerted over the drop and the thin-layer thickness achieved was determined, in such a way that the simple experimental set-up designed for this work could be developed into a commercial device with variable control of the thin-layer conditions. The experimental results obtained resemble those reported for the voltammetric features of electroactive soluble species employing electrodes modified with carbon nanotubes or graphene layers, suggesting that the attainment of the benefits reported for these nanomaterials could be done simply by forcing the solution to spread over the screen-printed electrodic system to form a thin layer solution. The advantages of thin-layer voltammetry in the kinetic characterization of quasi-reversible and irreversible processes are highlighted.

Metal-electrode-free Window-like Organic Solar Cells with p-Doped Carbon Nanotube Thin-film Electrodes

Science.gov (United States)

Jeon, Il; Delacou, Clement; Kaskela, Antti; Kauppinen, Esko I.; Maruyama, Shigeo; Matsuo, Yutaka

2016-08-01

Organic solar cells are flexible and inexpensive, and expected to have a wide range of applications. Many transparent organic solar cells have been reported and their success hinges on full transparency and high power conversion efficiency. Recently, carbon nanotubes and graphene, which meet these criteria, have been used in transparent conductive electrodes. However, their use in top electrodes has been limited by mechanical difficulties in fabrication and doping. Here, expensive metal top electrodes were replaced with high-performance, easy-to-transfer, aerosol-synthesized carbon nanotubes to produce transparent organic solar cells. The carbon nanotubes were p-doped by two new methods: HNO3 doping via ‘sandwich transfer’, and MoOx thermal doping via ‘bridge transfer’. Although both of the doping methods improved the performance of the carbon nanotubes and the photovoltaic performance of devices, sandwich transfer, which gave a 4.1% power conversion efficiency, was slightly more effective than bridge transfer, which produced a power conversion efficiency of 3.4%. Applying a thinner carbon nanotube film with 90% transparency decreased the efficiency to 3.7%, which was still high. Overall, the transparent solar cells had an efficiency of around 50% that of non-transparent metal-based solar cells (7.8%).

Titanyl phthalocyanine ambipolar thin film transistors making use of carbon nanotube electrodes

Science.gov (United States)

Coppedè, Nicola; Valitova, Irina; Mahvash, Farzaneh; Tarabella, Giuseppe; Ranzieri, Paolo; Iannotta, Salvatore; Santato, Clara; Martel, Richard; Cicoira, Fabio

2014-12-01

The capability of efficiently injecting charge carriers into organic films and finely tuning their morphology and structure is crucial to improve the performance of organic thin film transistors (OTFTs). In this work, we investigate OTFTs employing carbon nanotubes (CNTs) as the source-drain electrodes and, as the organic semiconductor, thin films of titanyl phthalocyanine (TiOPc) grown by supersonic molecular beam deposition (SuMBD). While CNT electrodes have shown an unprecedented ability to improve charge injection in OTFTs, SuMBD is an effective technique to tune film morphology and structure. Varying the substrate temperature during deposition, we were able to grow both amorphous (low substrate temperature) and polycrystalline (high substrate temperature) films of TiOPc. Regardless of the film morphology and structure, CNT electrodes led to superior charge injection and transport performance with respect to benchmark Au electrodes. Vacuum annealing of polycrystalline TiOPc films with CNT electrodes yielded ambipolar OTFTs.

Micromachined Dense Palladium Electrodes for Thin-film Solid Acid Fuel Cells

NARCIS (Netherlands)

Unnikrishnan, S.

2009-01-01

This thesis paves the way towards the microfabrication of a solid acid electrolyte based fuel cell (µSAFC), which has a membrane electrode assembly (MEA) consisting of a thin-film of water soluble electrolyte encapsulated between two dense palladium electrode membranes. This project work

Binder-free manganese oxide/carbon nanomaterials thin film electrode for supercapacitors.

Science.gov (United States)

Wang, Ning; Wu, Chuxin; Li, Jiaxin; Dong, Guofa; Guan, Lunhui

2011-11-01

A ternary thin film electrode was created by coating manganese oxide onto a network composed of single-walled carbon nanotubes and single-walled carbon nanohorns. The electrode exhibited a porous structure, which is a promising architecture for supercapacitors applications. The maximum specific capacitances of 357 F/g for total electrode at 1 A/g were achieved in 0.1 M Na(2)SO(4) aqueous solution.

Modified lead titanate thin films for pyroelectric infrared detectors on gold electrodes

Science.gov (United States)

Ahmed, Moinuddin; Butler, Donald P.

2015-07-01

Pyroelectric infrared detectors provide the advantage of both a wide spectral response and dynamic range, which also has enabled systems to be developed with reduced size, weight and power consumption. This paper demonstrates the deposition of lead zirconium titanate (PZT) and lead calcium titanate (PCT) thin films for uncooled pyroelectric detectors with the utilization of gold electrodes. The modified lead titanate thin films were deposited by pulsed laser deposition on gold electrodes. The PZT and PCT thins films deposited and annealed at temperatures of 650 °C and 550 °C respectively demonstrated the best pyroelectric performance in this work. The thin films displayed a pyroelectric effect that increased with temperature. Poling of the thin films was carried out for a fixed time periods and fixed dc bias voltages at elevated temperature in order to increase the pyroelectric coefficient by establishing a spontaneous polarization of the thin films. Poling caused the pyroelectric current to increase one order of magnitude.

Thin-film electroencephalographic electrodes using multi-walled carbon nanotubes are effective for neurosurgery.

Science.gov (United States)

Awara, Kousuke; Kitai, Ryuhei; Isozaki, Makoto; Neishi, Hiroyuki; Kikuta, Kenichiro; Fushisato, Naoki; Kawamoto, Akira

2014-12-15

Intraoperative morphological and functional monitoring is essential for safe neurosurgery. Functional monitoring is based on electroencephalography (EEG), which uses silver electrodes. However, these electrodes generate metal artifacts as silver blocks X-rays, creating white radial lines on computed tomography (CT) images during surgery. Thick electrodes interfere with surgical procedures. Thus, thinner and lighter electrodes are ideal for intraoperative use. The authors developed thin brain electrodes using carbon nanotubes that were formed into thin sheets and connected to electrical wires. The nanotube sheets were soft and fitted the curve of the head very well. When attached to the head using paste, the impedance of the newly developed electrodes was 5 kΩ or lower, which was similar to that of conventional metal electrodes. These electrodes can be used in combination with intraoperative CT, magnetic resonance imaging (MRI), or cerebral angiography. Somatosensory-evoked potentials, auditory brainstem responses, and visually evoked potentials were clearly identified in ten volunteers. The electrodes, without any artifacts that distort images, did not interfere with X-rays, CT, or MR images. They also did not cause skin damage. Carbon nanotube electrodes may be ideal for neurosurgery.

Titanyl phthalocyanine ambipolar thin film transistors making use of carbon nanotube electrodes

International Nuclear Information System (INIS)

Coppedè, Nicola; Tarabella, Giuseppe; Ranzieri, Paolo; Iannotta, Salvatore; Valitova, Irina; Cicoira, Fabio; Mahvash, Farzaneh; Santato, Clara; Martel, Richard

2014-01-01

The capability of efficiently injecting charge carriers into organic films and finely tuning their morphology and structure is crucial to improve the performance of organic thin film transistors (OTFTs). In this work, we investigate OTFTs employing carbon nanotubes (CNTs) as the source-drain electrodes and, as the organic semiconductor, thin films of titanyl phthalocyanine (TiOPc) grown by supersonic molecular beam deposition (SuMBD). While CNT electrodes have shown an unprecedented ability to improve charge injection in OTFTs, SuMBD is an effective technique to tune film morphology and structure. Varying the substrate temperature during deposition, we were able to grow both amorphous (low substrate temperature) and polycrystalline (high substrate temperature) films of TiOPc. Regardless of the film morphology and structure, CNT electrodes led to superior charge injection and transport performance with respect to benchmark Au electrodes. Vacuum annealing of polycrystalline TiOPc films with CNT electrodes yielded ambipolar OTFTs. (paper)

Polarization Induced Changes in LSM Thin Film Electrode Composition Observed by In Operando Raman Spectroscopy and TOF-SIMS

DEFF Research Database (Denmark)

McIntyre, Melissa D.; Walker, Robert; Traulsen, Marie Lund

2015-01-01

an applied potential.1-3 The presented work explores the polarisation induced changes in LSM electrode composition by utilizing in operando Raman spectroscopy and post mortem ToF-SIMS depth profiling on LSM thin film model electrodes fabricated by pulsed laser deposition on YSZ substrates with a thin (200 nm...... recorded through the LSM thin film electrodes and revealed distinct compositional changes throughout the electrodes (Figure 2). The electrode elements and impurities separated into distinct layers that were more pronounced for the stronger applied polarisations. The mechanism behind this separation...

Preparation of TiO2-based nanotubes/nanoparticles composite thin film electrodes for their electron transport properties

International Nuclear Information System (INIS)

Zhao, Wanyu; Fu, Wuyou; Chen, Jingkuo; Li, Huayang; Bala, Hari; Wang, Xiaodong; Sun, Guang; Cao, Jianliang; Zhang, Zhanying

2015-01-01

The composite thin film electrodes were prepared with one-dimensional (1D) TiO 2 -B nanotubes (NTs) and zero-dimensional TiO 2 nanoparticles (NPs) based on different weight ratios. The electron transport properties of the NTs/NPs composite thin film electrodes applied for dye-sensitized solar cells had been investigated systematically. The results indicated that although the amount of dye adsorption decreased slightly, the devices with the NTs/NPs composite thin film electrodes could obtain higher open-circuit voltage and overall conversion efficiency compared to devices with pure TiO 2 NPs electrodes by rational tuning the weight ratio of TiO 2 -B NTs and TiO 2 NPs. When the weight ratio of TiO 2 -B NTs in the NTs/NPs composite thin film electrodes increased, the density of states and recombination rate decreased. The 1D structure of TiO 2 -B NTs can provide direct paths for electron transport, resulting in higher electron lifetime, electron diffusion coefficient and electron diffusion length. The composite thin film electrodes possess the merits of the rapid electron transport of TiO 2 -B NTs and the high surface area of TiO 2 NPs, which has great applied potential in the field of photovoltaic devices. - Highlights: • The composite thin film electrodes (CTFEs) were prepared with nanotubes and nanoparticles. • The CTFEs possess the rapid electron transport and high surface area. • The CTFEs exhibit lower recombination rate and longer electron life time. • The CTFEs have great applied potential in the field of photovoltaic devices

Improved stability of titanium based boron-doped chemical vapor deposited diamond thin-film electrode by modifying titanium substrate surface

International Nuclear Information System (INIS)

Lim, P.Y.; Lin, F.Y.; Shih, H.C.; Ralchenko, V.G.; Varnin, V.P.; Pleskov, Yu.V.; Hsu, S.F.; Chou, S.S.; Hsu, P.L.

2008-01-01

The film quality and electrochemical properties of BDD (boron-doped diamond) thin films grown by hot-filament chemical vapor deposition technique on titanium substrates that had been subjected to a range of pre-treatment processes were evaluated. The pre-roughened Ti-substrates are shown to support more adherent BDD films. It is evident that acid-etching the Ti-substrate involves surface hydrogenation that enhances nucleation and formation of diamond thereon. The prepared BDD film exhibits wide potential window and electrochemical reversibility. It also demonstrated a better long-term electrochemical stability based on the low variation in voltametric background current upon the exposing of the electrodes to repeated cycles of electrochemical metal deposition/stripping process

A composite thin vacuum window for the CLAS photon tagger at Jefferson lab

International Nuclear Information System (INIS)

Matthews, S.K.; Crannell, Hall; O'Brien, J.T.; Sober, D.I.

1999-01-01

The construction of a thin vacuum window, currently in use on the CLAS photon tagging system at the Thomas Jefferson National Accelerator Facility, is described. A layer of woven Kevlar cloth supports a much thinner membrane of aluminized Mylar. Notable features of this particular window include its overall length (9.6 m), and the fact that the entire load is supported by the epoxy seal with no mechanical clamping around the edges. Results from a diverse program of materials testing, including a clear dependence of leak rate on relative humidity, are also reported

A composite thin vacuum window for the CLAS photon tagger at Jefferson lab

CERN Document Server

Matthews, S K; O'Brien, J T; Sober, D I

1999-01-01

The construction of a thin vacuum window, currently in use on the CLAS photon tagging system at the Thomas Jefferson National Accelerator Facility, is described. A layer of woven Kevlar cloth supports a much thinner membrane of aluminized Mylar. Notable features of this particular window include its overall length (9.6 m), and the fact that the entire load is supported by the epoxy seal with no mechanical clamping around the edges. Results from a diverse program of materials testing, including a clear dependence of leak rate on relative humidity, are also reported.

Catalytic EC′ reaction at a thin film modified electrode

International Nuclear Information System (INIS)

Gerbino, Leandro; Baruzzi, Ana M.; Iglesias, Rodrigo A.

2013-01-01

Numerical simulations of cyclic voltammograms corresponding to a catalytic EC′ reaction taking place at a thin film modified electrode are performed by way of finite difference method. Besides considering the chemical kinetic occurring inside the thin film, the model takes into account the different diffusion coefficients for each species at each of the involved phases, i.e. the thin film layer and bulk solution. The theoretical formulation is given in terms of dimensionless model parameters but a brief discussion of each of these parameters and their relationship to experimental variables is presented. Special emphasis is given to the use of working curve characteristics to quantify diffusion coefficient, homogeneous kinetic constant and thickness of the thin layer in a real system. Validation of the model is made by comparison of experimental results corresponding to the electron charge transfer of Ru(NH 3 ) 6 3+ /Ru(NH 3 ) 6 2+ hemi-couple at a thin film of a cross-linked chitosan film containing an immobilized redox dye

Examining the validity of Stoney-equation for in-situ stress measurements in thin film electrodes using a large-deformation finite-element procedure

Science.gov (United States)

Wen, Jici; Wei, Yujie; Cheng, Yang-Tse

2018-05-01

During the lithiation and delithiation of a thin film electrode, stress in the electrode is deduced from the curvature change of the film using the Stoney equation. The accuracy of such a measurement is conditioned on the assumptions that (a) the mechanical properties of the electrode remain unchanged during lithiation and (b) small deformation holds. Here, we demonstrate that the change in elastic properties can influence the measurement of the stress in thin film electrodes. We consider the coupling between diffusion and deformation during lithiation and delithiation of thin film electrodes and implement the constitutive behavior in a finite-deformation finite element procedure. We demonstrate that both the variation in elastic properties in thin film electrodes and finite-deformation during lithiation and delithiation would challenge the applicability of the Stoney-equation for in-situ stress measurements of thin film electrodes.

Optimized electrode coverage of membrane actuators based on epitaxial PZT thin films

International Nuclear Information System (INIS)

Nguyen, M D; Dekkers, M; Blank, D H A; Rijnders, G; Nazeer, H

2013-01-01

This research presents an optimization of piezoelectric membrane actuators by maximizing the actuator displacement. Membrane actuators based on epitaxial Pb(Zr,Ti)O 3 thin films grown on all-oxide electrodes and buffer layers using silicon technology were fabricated. Electrode coverage was found to be an important factor in the actuation displacement of the piezoelectric membranes. The optimum electrode coverage for maximum displacement was theoretically determined to be 39%, which is in good agreement with the experimental results. Dependences of membrane displacement and optimum electrode coverage on membrane diameter and PZT-film/Si-device-layer thickness ratio have also been investigated. (paper)

Preparation and characterization of flexible asymmetric supercapacitors based on transition-metal-oxide nanowire/single-walled carbon nanotube hybrid thin-film electrodes.

Science.gov (United States)

Chen, Po-Chiang; Shen, Guozhen; Shi, Yi; Chen, Haitian; Zhou, Chongwu

2010-08-24

In the work described in this paper, we have successfully fabricated flexible asymmetric supercapacitors (ASCs) based on transition-metal-oxide nanowire/single-walled carbon nanotube (SWNT) hybrid thin-film electrodes. These hybrid nanostructured films, with advantages of mechanical flexibility, uniform layered structures, and mesoporous surface morphology, were produced by using a filtration method. Here, manganese dioxide nanowire/SWNT hybrid films worked as the positive electrode, and indium oxide nanowire/SWNT hybrid films served as the negative electrode in a designed ASC. In our design, charges can be stored not only via electrochemical double-layer capacitance from SWNT films but also through a reversible faradic process from transition-metal-oxide nanowires. In addition, to obtain stable electrochemical behavior during charging/discharging cycles in a 2 V potential window, the mass balance between two electrodes has been optimized. Our optimized hybrid nanostructured ASCs exhibited a superior device performance with specific capacitance of 184 F/g, energy density of 25.5 Wh/kg, and columbic efficiency of approximately 90%. In addition, our ASCs exhibited a power density of 50.3 kW/kg, which is 10-fold higher than obtained in early reported ASC work. The high-performance hybrid nanostructured ASCs can find applications in conformal electrics, portable electronics, and electrical vehicles.

Ultrahigh PEMFC performance of a thin-film, dual-electrode assembly with tailored electrode morphology.

Science.gov (United States)

Jung, Chi-Young; Kim, Tae-Hyun; Yi, Sung-Chul

2014-02-01

A dual-electrode membrane electrode assembly (MEA) for proton exchange membrane fuel cells with enhanced polarization under zero relative humidity (RH) is fabricated by introducing a phase-separated morphology in an agglomerated catalyst layer of Pt/C (platinum on carbon black) and Nafion. In the catalyst layer, a sufficient level of phase separation is achieved by dispersing the Pt catalyst and the Nafion dispersion in a mixed-solvent system (propane-1,2,3-triol/1-methyl-2-pyrrolidinone).The high polymer chain mobility results in improved water uptake and regular pore-size distribution with small pore diameters. The electrochemical performance of the dual-film electrode assembly with different levels of phase separation is compared to conventional electrode assemblies. As a result, good performance at 0 % RH is obtained because self-humidification is dramatically improved by attaching this dense and phase-separated catalytic overlayer onto the conventional catalyst layer. A MEA prepared using the thin-film, dual-layered electrode exhibits 39-fold increased RH stability and 28-fold improved start-up recovery time during the on-off operation relative to the conventional device. We demonstrate the successful operation of the dual-layered electrode comprised of discriminatively phase-separated agglomerates with an ultrahigh zero RH fuel-cell performance reaching over 95 % performance of a fully humidified MEA. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

DEFF Research Database (Denmark)

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

2018-01-01

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

PEDOT as a Flexible Organic Electrode for a Thin Film Acoustic Energy Harvester.

Science.gov (United States)

Kim, Younghoon; Na, Jongbeom; Park, Chihyun; Shin, Haijin; Kim, Eunkyoung

2015-08-05

An efficient thin film acoustic energy harvester was explored using flexible poly(3,4-ethylene dioxythiophene) (PEDOT) films as electrodes in an all-organic triboelectric generator (AO-TEG). A thin film AO-TEG structured as PEDOT/Kapton//PET/PEDOT was prepared by the solution casting polymerization(SCP) on the dielectric polymer films. As-prepared AO-TEG showed high flexibility and durability due to the strong adhesion between the electrodes and the dielectric polymer. The short-circuit current density (Jsc), open-circuit voltage (Voc), and maximum power density (Pw) reached 50 mA/m(2), 700 V, and 12.9 W/m(2) respectively. The output current density decreased with the increase in the electrode resistance (Re), but the energy loss in the organic electrodes was negligible. The AO-TEG could light up 180 LEDs instantaneously upon touching of the AO-TEG with a palm (∼120 N). With the flexible structure, the AO-TEG was worn as clothes and generated electricity to light LEDs upon regular human movement. Furthermore, the AO-TEG was applicable as a thin film acoustic energy harvester, which used music to generate electricity enough for powering of 5 LEDs. An AO-TEG with a PEDOT electrode (Re = 200 Ω) showed instantaneous peak-to-peak voltage generation of 11 V under a sound pressure level (SPL) of 90-100 dB. The harvested acoustic energy through the AO-TEG was 350 μJ from the 4 min playing of the same single song. This is the first demonstration of a flexible triboelectric generator (TEG) using an organic electrode for harvesting acoustic energy from ambient environment.

Nanostructured manganese oxide thin films as electrode material for supercapacitors

Science.gov (United States)

Xia, Hui; Lai, Man On; Lu, Li

2011-01-01

Electrochemical capacitors, also called supercapacitors, are alternative energy storage devices, particularly for applications requiring high power densities. Recently, manganese oxides have been extensively evaluated as electrode materials for supercapacitors due to their low cost, environmental benignity, and promising supercapacitive performance. In order to maximize the utilization of manganese oxides as the electrode material for the supercapacitors and improve their supercapacitive performance, the nanostructured manganese oxides have therefore been developed. This paper reviews the synthesis of the nanostructured manganese oxide thin films by different methods and the supercapacitive performance of different nanostructures.

Electrode size and boundary condition independent measurement of the effective piezoelectric coefficient of thin films

Directory of Open Access Journals (Sweden)

M. Stewart

2015-02-01

Full Text Available The determination of the piezoelectric coefficient of thin films using interferometry is hindered by bending contributions. Using finite element analysis (FEA simulations, we show that the Lefki and Dormans approximations using either single or double-beam measurements cannot be used with finite top electrode sizes. We introduce a novel method for characterising piezoelectric thin films which uses a differential measurement over the discontinuity at the electrode edge as an internal reference, thereby eliminating bending contributions. This step height is shown to be electrode size and boundary condition independent. An analytical expression is derived which gives good agreement with FEA predictions of the step height.

The Effect of Round Window vs Cochleostomy Surgical Approaches on Cochlear Implant Electrode Position: A Flat-Panel Computed Tomography Study.

Science.gov (United States)

Jiam, Nicole T; Jiradejvong, Patpong; Pearl, Monica S; Limb, Charles J

2016-09-01

The round window insertion (RWI) and cochleostomy approaches are the 2 most common surgical techniques used in cochlear implantation (CI). However, there is no consensus on which approach is ideal for electrode array insertion, in part because visualization of intracochlear electrode position is challenging, so postoperative assessment of intracochlear electrode contact is lacking. To measure and compare electrode array position between RWI and cochleostomy approaches for CI insertion. Retrospective case-comparison study of 17 CI users with Med-El standard-length electrode arrays who underwent flat-panel computed tomography scans after CI surgery at a tertiary referral center. The data was analyzed in October 2015. Flat-panel computed tomography scans were collected between January 1 and August 31, 2013, for 22 electrode arrays. The surgical technique was identified by a combination of operative notes and imaging. Eight cochleae underwent RWI and 14 cochleae underwent cochleostomy approaches anterior and inferior to the round window. Interscalar electrode position and electrode centroid distance to the osseous spiral lamina, lateral bony wall, and central axis of the modiolus. Nine participants were men, and 8, women; the mean age was 54.4 (range, 21-64) years. Electrode position was significantly closer to cochlear neural elements with RWI than cochleostomy approaches. Between the 2 surgical approaches, the RWI technique produced shorter distances between the electrode and the modiolus (mean difference, -0.33 [95% CI, -0.29 to -0.39] mm in the apical electrode; -1.42 [95% CI, -1.24 to -1.57] mm in the basal electrode). This difference, which was most prominent in the first third and latter third of the basal turn, decreased after the basal turn. The RWI approach was associated with an increased likelihood of perimodiolar placement. Opting to use RWI over cochleostomy approaches in CI candidates may position electrodes closer to cochlear neural substrates and

Electrochemical Biosensor Based on Boron-Doped Diamond Electrodes with Modified Surfaces

Directory of Open Access Journals (Sweden)

Yuan Yu

2012-01-01

Full Text Available Boron-doped diamond (BDD thin films, as one kind of electrode materials, are superior to conventional carbon-based materials including carbon paste, porous carbon, glassy carbon (GC, carbon nanotubes in terms of high stability, wide potential window, low background current, and good biocompatibility. Electrochemical biosensor based on BDD electrodes have attracted extensive interests due to the superior properties of BDD electrodes and the merits of biosensors, such as specificity, sensitivity, and fast response. Electrochemical reactions perform at the interface between electrolyte solutions and the electrodes surfaces, so the surface structures and properties of the BDD electrodes are important for electrochemical detection. In this paper, the recent advances of BDD electrodes with different surfaces including nanostructured surface and chemically modified surface, for the construction of various electrochemical biosensors, were described.

Influence of thin film thickness of working electrodes on photovoltaic characteristics of dye-sensitized solar cells

Directory of Open Access Journals (Sweden)

Lai Yeong-Lin

2017-01-01

Full Text Available This paper presents the study of the influence of thin film thickness of working electrodes on the photovoltaic characteristics of dye-sensitized solar cells. Titanium dioxide (TiO2 thin films, with the thickness from 7.67 to 24.3 μm, were used to fabricate the working electrodes of dye-sensitized solar cells (DSSCs. A TiO2 film was coated on a fluorine-doped tin oxide (FTO conductive glass substrate and then sintered in a high-temperature furnace. On the other hand, platinum (Pt solution was coated onto an FTO substrate for the fabrication of the counter electrode of a DSSC. The working electrode immersed in a dye, the counter electrode, and the electrolyte were assembled to complete a sandwich-structure DSSC. The material analysis of the TiO2 films of DSSCs was carried out by scanning electron microscopy (SEM and ultraviolet-visible (UV-Vis spectroscopy, while the photovoltaic characteristics of DSSCs were measured by an AM-1.5 sunlight simulator. The light transmittance characteristics of the TiO2 working electrode depend on the TiO2 film thickness. The thin film thickness of the working electrode also affects the light absorption of a dye and results in the photovoltaic characteristics of the DSSC, including open-circuited voltage (VOC, short-circuited current density (JSC, fill factor, and photovoltaic conversion efficiency.

Chemically fabricated LiFePO{sub 4} thin film electrode for transparent batteries and electrochromic devices

Energy Technology Data Exchange (ETDEWEB)

Béléké, Alexis B. [Institut de recherche d’Hydro-Québec, 1800 Boul. Lionel-Boulet, Varennes, QC J3X 1S3 (Canada); Department of Mining and Materials Engineering, McGill University, M.H. Wong Building, 3610 rue University, Montréal, QC H3A 2B2 (Canada); Faure, Cyril [Institut de recherche d’Hydro-Québec, 1800 Boul. Lionel-Boulet, Varennes, QC J3X 1S3 (Canada); Röder, Manuel [Center for Applied Electrochemistry, Fraunhofer Institute for Silicate Research, Neunerplatz 2, 97083 Würzburg (Germany); Hovington, Pierre [Institut de recherche d’Hydro-Québec, 1800 Boul. Lionel-Boulet, Varennes, QC J3X 1S3 (Canada); Posset, Uwe [Center for Applied Electrochemistry, Fraunhofer Institute for Silicate Research, Neunerplatz 2, 97083 Würzburg (Germany); Guerfi, Abdelbast [Institut de recherche d’Hydro-Québec, 1800 Boul. Lionel-Boulet, Varennes, QC J3X 1S3 (Canada); Zaghib, Karim, E-mail: zaghib.karim@ireq.ca [Institut de recherche d’Hydro-Québec, 1800 Boul. Lionel-Boulet, Varennes, QC J3X 1S3 (Canada)

2016-12-15

Graphical abstract: Simplified diagram of the novel sol-gel approach of preparation of colorless and transparent LiFePO{sub 4} thin film electrode. - Highlights: • Novel sol-gel synthesis of colorless LFP thin film electrode for transparent Li-ion battery. • High performance of the electrode at various current densities: 5, 10, 20, 50 and 100 μA/cm{sup 2}. • LFP nanoparticles exhibit an excellent electro-activity. • Colorless LFP thin film shows a transmittance above 80% versus FTO. • Higher transmittance of LFP electrode a potential candidate for electrochromic devices. - Abstract: We report a new sol-gel approach of synthesis of LiFePO{sub 4} (LFP) thin film and its application as cathode materials for transparent Li-ion battery in half-cell configuration. LFP thin films were obtained from an alcoholic colloidal suspension of iron acetylacetonate (Fe(AcAc){sub 3}) and aqueous lithium dihydrogen phosphate (LiH{sub 2}PO{sub 4}) deposited on fluorine tin oxide (FTO) glass substrate, followed by heating at 450 °C under nitrogen gas for 1 h. X-ray diffraction (XRD) confirmed that the LFP films have an orthorhombic crystal system with space group Pnma (62). Scanning electron microscopy (SEM) shows spherical LFP nanoparticles aggregates homogenously deposited all over the surface of FTO substrate containing 3-D open pores. The electrochemical behaviors of thin film vs Li/Li{sup +} cell were investigated by cyclic voltammetry and galvanostatic charge-discharge measurements. The cycle life was evaluated by running 1000 cycles of charge-discharge at a current density of 20 μA/cm{sup 2}. The transmission spectra reveal 85–90% of transparency versus FTO as reference, which makes it a potential candidate as a complementary electrode in electrochromic devices (ECDs).

Nano-sized copper tungstate thin films as positive electrodes for rechargeable Li batteries

International Nuclear Information System (INIS)

Li Chilin; Fu Zhengwen

2008-01-01

Nano-sized CuWO 4 thin films have been fabricated by radio-frequency (R.F.) sputtering deposition, and are used as positive electrode with both LiClO 4 liquid electrolyte and LiPON solid electrolyte in rechargeable lithium batteries. An initial discharge capacity of 192 and 210 mAh/g is obtainable for CuWO 4 film electrode with and without coated LiPON in liquid electrolyte, respectively. An all-solid-state cell with Li/LiPON/CuWO 4 layers shows a high-volume rate capacity of 145 μAh/cm 2 μm in first discharge, and overcomes the unfavorable electrochemical degradation observed in liquid electrolyte system. A two-step reactive mechanism is investigated by both transmission electron microscopy and selected area electron diffraction techniques. Apart from the extrusion and injection of Cu 2+ /Cu 0 , additional capacity can be achieved by the reversible reactivity of (WO 4 ) 2- framework. The chemical diffusion coefficients of Li intercalation/deintercalation are estimated by cyclic voltammetry. Nano-CuWO 4 thin film is expected to be a promising positive electrode material for high-performance rechargeable thin-film lithium batteries

Magnetron sputtered TiN thin films toward enhanced performance supercapacitor electrodes

KAUST Repository

Wei, Binbin

2018-04-09

Supercapacitors as a new type of energy storage devices bridging the gap between conventional capacitors and batteries have aroused widespread concern. Herein, binder-free titanium nitride (TiN) thin film electrodes for supercapacitors prepared by reactive magnetron sputtering technology are reported. The effect of N2 content on the supercapacitor performance is evaluated. A highest specific capacitance of 27.3 mF cm−2 at a current density of 1.0 mA cm−2, together with excellent cycling performance (98.2% capacitance retention after 20,000 cycles at 2.0 mA cm−2) is achieved in a 0.5 M H2SO4 aqueous electrolyte. More importantly, a symmetric supercapacitor device assembled on the basis of TiN thin films can deliver a maximum energy density of 17.6 mWh cm−3 at a current density of 0.2 mA cm−2 and a maximum power density of 10.8 W cm−3 at a current density of 2 mA cm−2 with remarkable cycling stability. As a consequence, TiN thin films demonstrate great potential as promising supercapacitor electrode materials.

Magnetron sputtered TiN thin films toward enhanced performance supercapacitor electrodes

KAUST Repository

Wei, Binbin; Liang, Hanfeng; Zhang, Dongfang; Qi, Zhengbing; Shen, Hao; Wang, Zhoucheng

2018-01-01

Supercapacitors as a new type of energy storage devices bridging the gap between conventional capacitors and batteries have aroused widespread concern. Herein, binder-free titanium nitride (TiN) thin film electrodes for supercapacitors prepared by reactive magnetron sputtering technology are reported. The effect of N2 content on the supercapacitor performance is evaluated. A highest specific capacitance of 27.3 mF cm−2 at a current density of 1.0 mA cm−2, together with excellent cycling performance (98.2% capacitance retention after 20,000 cycles at 2.0 mA cm−2) is achieved in a 0.5 M H2SO4 aqueous electrolyte. More importantly, a symmetric supercapacitor device assembled on the basis of TiN thin films can deliver a maximum energy density of 17.6 mWh cm−3 at a current density of 0.2 mA cm−2 and a maximum power density of 10.8 W cm−3 at a current density of 2 mA cm−2 with remarkable cycling stability. As a consequence, TiN thin films demonstrate great potential as promising supercapacitor electrode materials.

Roll-to-Roll Production of Transparent Silver-Nanofiber-Network Electrodes for Flexible Electrochromic Smart Windows.

Science.gov (United States)

Lin, Sen; Bai, Xiaopeng; Wang, Haiyang; Wang, Haolun; Song, Jianan; Huang, Kai; Wang, Chang; Wang, Ning; Li, Bo; Lei, Ming; Wu, Hui

2017-11-01

Electrochromic smart windows (ECSWs) are considered as the most promising alternative to traditional dimming devices. However, the electrode technology in ECSWs remains stagnant, wherein inflexible indium tin oxide and fluorine-doped tin oxide are the main materials being used. Although various complicated production methods, such as high-temperature calcination and sputtering, have been reported, the mass production of flexible and transparent electrodes remains challenging. Here, a nonheated roll-to-roll process is developed for the continuous production of flexible, extralarge, and transparent silver nanofiber (AgNF) network electrodes. The optical and mechanical properties, as well as the electrical conductivity of these products (i.e., 12 Ω sq -1 at 95% transmittance) are comparable with those AgNF networks produced via high-temperature sintering. Moreover, the as-prepared AgNF network is successfully assembled into an A4-sized ECSW with short switching time, good coloration efficiency, and flexibility. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hydrothermally formed three-dimensional nanoporous Ni(OH)2 thin-film supercapacitors.

Science.gov (United States)

Yang, Yang; Li, Lei; Ruan, Gedeng; Fei, Huilong; Xiang, Changsheng; Fan, Xiujun; Tour, James M

2014-09-23

A three-dimensional nanoporous Ni(OH)2 thin-film was hydrothermally converted from an anodically formed porous layer of nickel fluoride/oxide. The nanoporous Ni(OH)2 thin-films can be used as additive-free electrodes for energy storage. The nanoporous layer delivers a high capacitance of 1765 F g(-1) under three electrode testing. After assembly with porous activated carbon in asymmetric supercapacitor configurations, the devices deliver superior supercapacitive performances with capacitance of 192 F g(-1), energy density of 68 Wh kg(-1), and power density of 44 kW kg(-1). The wide working potential window (up to 1.6 V in 6 M aq KOH) and stable cyclability (∼90% capacitance retention over 10,000 cycles) make the thin-film ideal for practical supercapacitor devices.

Electrochemical Deposition of CdTe Semiconductor Thin Films for Solar Cell Application Using Two-Electrode and Three-Electrode Configurations: A Comparative Study

Directory of Open Access Journals (Sweden)

O. K. Echendu

2016-01-01

Full Text Available Thin films of CdTe semiconductor were electrochemically deposited using two-electrode and three-electrode configurations in potentiostatic mode for comparison. Cadmium sulphate and tellurium dioxide were used as cadmium and tellurium sources, respectively. The layers obtained using both configurations exhibit similar structural, optical, and electrical properties with no specific dependence on any particular electrode configuration used. These results indicate that electrochemical deposition (electrodeposition of CdTe and semiconductors in general can equally be carried out using two-electrode system as well as the conventional three-electrode system without compromising the essential qualities of the materials produced. The results also highlight the advantages of the two-electrode configuration in process simplification, cost reduction, and removal of a possible impurity source in the growth system, especially as the reference electrode ages.

Pt/AlPO{sub 4} nanocomposite thin-film electrodes for ethanol electrooxidation

Energy Technology Data Exchange (ETDEWEB)

Oh, Yuhong; Kang, Joonhyeon; Nam, Seunghoon; Byun, Sujin [WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of); Park, Byungwoo, E-mail: byungwoo@snu.ac.kr [WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of)

2012-07-16

The enhanced catalytic properties toward ethanol electrooxidation on Pt/AlPO{sub 4} nanocomposite thin-film electrodes were investigated. The Pt/AlPO{sub 4} nanocomposites with various Al/Pt ratios (0.27, 0.57, and 0.96) were fabricated by a co-sputtering method. All of the Pt/AlPO{sub 4} nanocomposites showed a negative shift in the onset potential and a higher current density than those of pure Pt electrode for the electrooxidation of ethanol. Among the various Pt/AlPO{sub 4} nanocomposite thin-film electrodes, the electrode with an atomic ratio of Al to Pt of 0.57 showed the highest electrocatalytic activity for ethanol electrooxidation. The activation enthalpy for the optimum Pt/AlPO{sub 4} nanocomposite was approximately 0.05 eV lower than that of pure Pt. It is believed that the enhancement in catalytic activity is due to the electron-rich Pt resulting from the Fermi-energy difference between Pt and AlPO{sub 4}. - Highlights: Black-Right-Pointing-Pointer The enhanced ethanol electrooxidation on Pt/AlPO{sub 4} nanocomposites is investigated. Black-Right-Pointing-Pointer The Pt/AlPO{sub 4} exhibits higher current density and lower onset potential than pure Pt. Black-Right-Pointing-Pointer The activation enthalpy for optimum Pt/AlPO{sub 4} electrode is {approx}0.05 eV lower than pure Pt. Black-Right-Pointing-Pointer XPS shows electron-rich Pt due to Fermi-energy difference between Pt and AlPO{sub 4}.

Graphene-Decorated Nanocomposites for Printable Electrodes in Thin Wafer Devices

Science.gov (United States)

Bakhshizadeh, N.; Sivoththaman, S.

2017-12-01

Printable electrodes that induce less stress and require lower curing temperatures compared to traditional screen-printed metal pastes are needed in thin wafer devices such as future solar cells, and in flexible electronics. The synthesis of nanocomposites by incorporating graphene nanopowders as well as silver nanowires into epoxy-based electrically conductive adhesives (ECA) is examined to improve electrical conductivity and to develop alternate printable electrode materials that induce less stress on the wafer. For the synthesized graphene and Ag nanowire-decorated ECA nanocomposites, the curing kinetics were studied by dynamic and isothermal differential scanning calorimetry measurements. Thermogravimetric analysis on ECA, ECA-AG and ECA/graphene nanopowder nanocomposites showed that the temperatures for onset of decomposition are higher than their corresponding glass transition temperature ( T g) indicating an excellent thermal resistance. Printed ECA/Ag nanowire nanocomposites showed 90% higher electrical conductivity than ECA films, whereas the ECA/graphene nanocomposites increased the conductivity by over two orders of magnitude. Scanning electron microscopy results also revealed the effect of fillers morphology on the conductivity improvement and current transfer mechanisms in nanocomposites. Residual stress analysis performed on Si wafers showed that the ECA and nanocomposite printed wafers are subjected to much lower stress compared to those printed with metallic pastes. The observed parameters of low curing temperature, good thermal resistance, reasonably high conductivity, and low residual stress in the ECA/graphene nanocomposite makes this material a promising alternative in screen-printed electrode formation in thin substrates.

Percolation effects in supercapacitors with thin, transparent carbon nanotube electrodes.

Science.gov (United States)

King, Paul J; Higgins, Thomas M; De, Sukanta; Nicoloso, Norbert; Coleman, Jonathan N

2012-02-28

We have explored the effects of percolation on the properties of supercapacitors with thin nanotube networks as electrodes. We find the equivalent series resistance, R(ESR), and volumetric capacitance, C(V), to be thickness independent for relatively thick electrodes. However, once the electrode thickness falls below a threshold thickness (∼100 nm for R(ESR) and ∼20 nm for C(V)), the properties of the electrode become thickness dependent. We show the thickness dependence of both R(ESR) and C(V) to be consistent with percolation theory. While this is expected for R(ESR), that the capacitance follows a percolation scaling law is not. This occurs because, for sparse networks, the capacitance is proportional to the fraction of nanotubes connected to the main network. This fraction, in turn, follows a percolation scaling law. This allows us to understand and quantify the limitations on the achievable capacitance for transparent supercapacitors. We find that supercapacitors with thickness independent R(ESR) and C(V) occupy a well-defined region of the Ragone plot. However, supercapacitors whose electrodes are limited by percolation occupy a long tail to lower values of energy and power density. For example, replacing electrodes with transparency of T = 80% with thinner networks displaying T = 97% will result in a 20-fold reduction of both power and energy density.

Demand-type gas supply system for rocket borne thin-window proportional counters

Science.gov (United States)

Acton, L. W.; Caravalho, R.; Catura, R. C.; Joki, E. G.

1977-01-01

A simple closed loop control system has been developed to maintain the gas pressure in thin-window proportional counters during rocket flights. This system permits convenient external control of detector pressure and system flushing rate. The control system is activated at launch with the sealing of a reference volume at the existing system pressure. Inflight control to plus or minus 2 torr at a working pressure of 760 torr has been achieved on six rocket flights.

Functionalization of indium-tin-oxide electrodes by laser-nanostructured gold thin films for biosensing applications

Energy Technology Data Exchange (ETDEWEB)

Grochowska, Katarzyna, E-mail: kgrochowska@imp.gda.pl [Centre for Plasma and Laser Engineering, The Szewalski Institute, Polish Academy of Sciences, 14 Fiszera St, 80-231 Gdańsk (Poland); Siuzdak, Katarzyna [Centre for Plasma and Laser Engineering, The Szewalski Institute, Polish Academy of Sciences, 14 Fiszera St, 80-231 Gdańsk (Poland); Karczewski, Jakub [Solid State Physics Department, Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, 11/12 Narutowicza St, 80-233, Gdańsk (Poland); Śliwiński, Gerard [Centre for Plasma and Laser Engineering, The Szewalski Institute, Polish Academy of Sciences, 14 Fiszera St, 80-231 Gdańsk (Poland)

2015-12-01

Graphical abstract: - Highlights: • ITO electrodes modified by NP arrays prepared by laser dewetting of thin Au films. • Enhanced activity, linear response and high sensitivity towards glucose. • Promising biosensor material AuNP-modified ITO of improved performance. - Abstract: The production and properties of the indium-tin-oxide (ITO) electrodes functionalized by Au nanoparticle (NP) arrays of a relatively large area formed by pulsed laser nanostructuring of thin gold films are reported and discussed. The SEM inspection of modified electrodes reveals the presence of the nearly spherical and disc-shaped particles of dimensions in the range of 40–120 nm. The NP-array geometry can be controlled by selection of the laser processing conditions. It is shown that particle size and packing density of the array are important factors which determine the electrode performance. In the case of NP-modified electrodes the peak current corresponding to the glucose direct oxidation process shows rise with increasing glucose concentration markedly higher comparing to the reference Au disc electrode. The detection limit reaches 12 μM and linear response of the sensor is observed from 0.1 to 47 mM that covers the normal physiological range of the blood sugar detection.

Annealing Effect on the Photoelectrochemical Properties of BiVO_4 Thin Film Electrodes

International Nuclear Information System (INIS)

Siti Nur Farhana Mohd Nasir; Mohd Asri Mat Teridi; Mehdi Ebadi; Sagu, J.S.

2015-01-01

Monoclinic bismuth vanadate (BiVO_4) thin film electrodes were fabricated on fluorine-doped tin oxide via aerosol-assisted chemical vapour deposition (AACVD). Annealing and without annealing effect of thin films were analysed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), ultraviolet-visible spectrophotometry (UV-Vis) and current voltage measurement. All BiVO_4 thin films showed an anodic photocurrent. The sample of BiVO_4 annealed at 400 degree Celsius exhibited the highest photocurrent density of 0.44 mAcm"-"2 vs. Ag/ AgCl at 1.23 V. (author)

Preferential growth and enhanced dielectric properties of Ba0.7Sr0.3TiO3 thin films with preannealed Pt bottom electrode

International Nuclear Information System (INIS)

Zhu Xiaohong; Ren Yinjuan; Zhang Caiyun; Zhu Jiliang; Zhu Jianguo; Xiao Dingquan; Defaÿ, Emmanuel; Aïd, Marc

2013-01-01

Ba 0.7 Sr 0.3 TiO 3 (BST) thin films, about 100 nm in thickness, were prepared on unannealed and 700 °C-preannealed Pt bottom electrodes by the ion beam sputtering and post-deposition annealing method. It was found that the preannealed Pt layer has a more compact structure, making it not only a bottom electrode but also a good template for high-quality BST thin film growth. The BST films deposited on preannealed Pt bottom electrodes showed (0 0 l)-preferred orientation, dense and uniform microstructure with no intermediate phase formed at the film/electrode interface, and thus enhanced dielectric properties. As a result, the typical relative dielectric constant and tunability (under a dc electric field of 1 MV cm −1 ) reach 180 and 50.1%, respectively, for the BST thin films with preannealed Pt bottom electrodes, which are significantly higher than those (166 and 41.3%, respectively) for the BST thin films deposited on unannealed Pt bottom electrodes. (paper)

Preferential growth and enhanced dielectric properties of Ba0.7Sr0.3TiO3 thin films with preannealed Pt bottom electrode

Science.gov (United States)

Zhu, Xiaohong; Defaÿ, Emmanuel; Aïd, Marc; Ren, Yinjuan; Zhang, Caiyun; Zhu, Jiliang; Zhu, Jianguo; Xiao, Dingquan

2013-03-01

Ba0.7Sr0.3TiO3 (BST) thin films, about 100 nm in thickness, were prepared on unannealed and 700 °C-preannealed Pt bottom electrodes by the ion beam sputtering and post-deposition annealing method. It was found that the preannealed Pt layer has a more compact structure, making it not only a bottom electrode but also a good template for high-quality BST thin film growth. The BST films deposited on preannealed Pt bottom electrodes showed (0 0 l)-preferred orientation, dense and uniform microstructure with no intermediate phase formed at the film/electrode interface, and thus enhanced dielectric properties. As a result, the typical relative dielectric constant and tunability (under a dc electric field of 1 MV cm-1) reach 180 and 50.1%, respectively, for the BST thin films with preannealed Pt bottom electrodes, which are significantly higher than those (166 and 41.3%, respectively) for the BST thin films deposited on unannealed Pt bottom electrodes.

Ultra-Thin Optically Transparent Carbon Electrodes Produced from Layers of Adsorbed Proteins

Science.gov (United States)

Alharthi, Sarah A.; Benavidez, Tomas E.; Garcia, Carlos D.

2013-01-01

This work describes a simple, versatile, and inexpensive procedure to prepare optically transparent carbon electrodes, using proteins as precursors. Upon adsorption, the protein-coated substrates were pyrolyzed under reductive conditions (5% H2) to form ultra-thin, conductive electrodes. Because proteins spontaneously adsorb to interfaces forming uniform layers, the proposed method does not require a precise control of the preparation conditions, specialized instrumentation, or expensive precursors. The resulting electrodes were characterized by a combination of electrochemical, optical, and spectroscopic means. As a proof-of-concept, the optically-transparent electrodes were also used as substrate for the development of an electrochemical glucose biosensor. The proposed films represent a convenient alternative to more sophisticated, and less available, carbon-based nanomaterials. Furthermore, these films could be formed on a variety of substrates, without classical limitations of size or shape. PMID:23421732

Layered Cu-based electrode for high-dielectric constant oxide thin film-based devices

International Nuclear Information System (INIS)

Fan, W.; Saha, S.; Carlisle, J.A.; Auciello, O.; Chang, R.P.H.; Ramesh, R.

2003-01-01

Ti-Al/Cu/Ta multilayered electrodes were fabricated on SiO 2 /Si substrates by ion beam sputtering deposition, to overcome the problems of Cu diffusion and oxidation encountered during the high dielectric constant (κ) materials integration. The Cu and Ta layers remained intact through the annealing in oxygen environment up to 600 deg. C. The thin oxide layer, formed on the Ti-Al surface, effectively prevented the oxygen penetration toward underneath layers. Complex oxide (Ba x Sr 1-x )TiO 3 (BST) thin films were grown on the layered Ti-Al/Cu/Ta electrodes using rf magnetron sputtering. The deposited BST films exhibited relatively high permittivity (150), low dielectric loss (0.007) at zero bias, and low leakage current -8 A/cm 2 at 100 kV/cm

Electrochromics for smart windows: Oxide-based thin films and devices

Energy Technology Data Exchange (ETDEWEB)

Granqvist, Claes G.

2014-08-01

Electrochromic (EC) smart windows are able to vary their throughput of visible light and solar energy by the application of an electrical voltage and are able to provide energy efficiency and indoor comfort in buildings. Section 1 explains why this technology is important and timely by first outlining today's precarious situation concerning increasing energy use and associated effects on the world's climate, and this section also underscores the great importance of enhancing the energy efficiency of buildings by letting them function more in harmony with the environment—particularly its varying temperature—than is possible with current mainstream technologies. This same chapter also surveys recent work on the energy savings and other benefits that are possible with EC-based technologies. Section 2 then provides some notes on the history of the EC effect and its applications. Section 3 presents a generic design for the oxide-based EC devices that are most in focus for present-day applications and research. This design includes five superimposed layers with a centrally-positioned electrolyte connecting two oxide films—at least one of which having EC properties—and with transparent electrical conductors surrounding the three-layer structure in the middle. It is emphasized that this construction can be viewed as a thin-film electrical battery whose charging state is manifested as optical absorption. Also discussed are six well known hurdles for the implementation of these EC devices, as well as a number of practical constructions of EC-based smart windows. Section 4 is an in-depth discussion of various aspects of EC oxides. It begins with a literature survey for 2007–2013, which updates earlier reviews, and is followed by a general discussion of optical and electronic effects and, specifically, on charge transfer absorption in tungsten oxide. Ionic effects are then treated with foci on the inherent nanoporosity of the important EC oxides and on the

Electrochromics for smart windows: Oxide-based thin films and devices

International Nuclear Information System (INIS)

Granqvist, Claes G.

2014-01-01

Electrochromic (EC) smart windows are able to vary their throughput of visible light and solar energy by the application of an electrical voltage and are able to provide energy efficiency and indoor comfort in buildings. Section 1 explains why this technology is important and timely by first outlining today's precarious situation concerning increasing energy use and associated effects on the world's climate, and this section also underscores the great importance of enhancing the energy efficiency of buildings by letting them function more in harmony with the environment—particularly its varying temperature—than is possible with current mainstream technologies. This same chapter also surveys recent work on the energy savings and other benefits that are possible with EC-based technologies. Section 2 then provides some notes on the history of the EC effect and its applications. Section 3 presents a generic design for the oxide-based EC devices that are most in focus for present-day applications and research. This design includes five superimposed layers with a centrally-positioned electrolyte connecting two oxide films—at least one of which having EC properties—and with transparent electrical conductors surrounding the three-layer structure in the middle. It is emphasized that this construction can be viewed as a thin-film electrical battery whose charging state is manifested as optical absorption. Also discussed are six well known hurdles for the implementation of these EC devices, as well as a number of practical constructions of EC-based smart windows. Section 4 is an in-depth discussion of various aspects of EC oxides. It begins with a literature survey for 2007–2013, which updates earlier reviews, and is followed by a general discussion of optical and electronic effects and, specifically, on charge transfer absorption in tungsten oxide. Ionic effects are then treated with foci on the inherent nanoporosity of the important EC oxides and on the

Ready fabrication of thin-film electrodes from building nanocrystals for micro-supercapacitors.

Science.gov (United States)

Chen, Zheng; Weng, Ding; Wang, Xiaolei; Cheng, Yanhua; Wang, Ge; Lu, Yunfeng

2012-04-18

Thin-film pseudocapacitor electrodes with ultrafast lithium storage kinetics, high capacitance and excellent cycling stability were fabricated from monodispersed TiO(2) building nanocrystals, providing a novel approach towards next-generation micro-supercapacitor applications. This journal is © The Royal Society of Chemistry 2012

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

Science.gov (United States)

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

2018-05-09

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

Effect of Tin Electrode (Sn, Electrode Distance and Thin Layer Size of Zinc Phthalocyanine (ZnPc to Resistance Changes With Ozone Exposure

Directory of Open Access Journals (Sweden)

Agustina Mogi

2018-01-01

Full Text Available This study was aimed to determine the effect of tin electrode distances and the thickness of a thin layer of ZnPc (Zinc phtyalocyanine toward changes in resistance with ozone exposure. Tin deposition on the glass surface was conducted using spraying method. The reaction between ozone and ZnPc produces electrical properties that can be read through the resistance value of the multimeter. Based on this study, it was investigated that the smaller a distance between the electrode and the thicker deposition of ZnPc lead to the less resistance. This showed that a thin layer of the conductivity increases along with the longer exposure to ozone gas. The movement of electrons with the hole was free.

Microcrystalline silicon carbide alloys prepared with HWCVD as highly transparent and conductive window layers for thin film solar cells

International Nuclear Information System (INIS)

Finger, F.; Astakhov, O.; Bronger, T.; Carius, R.; Chen, T.; Dasgupta, A.; Gordijn, A.; Houben, L.; Huang, Y.; Klein, S.; Luysberg, M.; Wang, H.; Xiao, L.

2009-01-01

Crystalline silicon carbide alloys have a very high potential as transparent conductive window layers in thin-film solar cells provided they can be prepared in thin-film form and at compatible deposition temperatures. The low-temperature deposition of such material in microcrystalline form (μc-Si:C:H) was realized by use of monomethylsilane precursor gas diluted in hydrogen with the Hot-Wire Chemical Vapor Deposition process. A wide range of deposition parameters has been investigated and the structural, electronic and optical properties of the μc-SiC:H thin films have been studied. The material, which is strongly n-type from unintentional doping, has been used as window layer in n-side illuminated microcrystalline silicon solar cells. High short-circuit current densities are obtained due to the high transparency of the material resulting in a maximum solar cell conversion efficiency of 9.2%.

Electroplating of CdTe Thin Films from Cadmium Sulphate Precursor and Comparison of Layers Grown by 3-Electrode and 2-Electrode Systems

Directory of Open Access Journals (Sweden)

Imyhamy M. Dharmadasa

2017-01-01

Full Text Available Electrodeposition of CdTe thin films was carried out from the late 1970s using the cadmium sulphate precursor. The solar energy group at Sheffield Hallam University has carried out a comprehensive study of CdTe thin films electroplated using cadmium sulfate, cadmium nitrate and cadmium chloride precursors, in order to select the best electrolyte. Some of these results have been published elsewhere, and this manuscript presents the summary of the results obtained on CdTe layers grown from cadmium sulphate precursor. In addition, this research program has been exploring the ways of eliminating the reference electrode, since this is a possible source of detrimental impurities, such as K+ and Ag+ for CdS/CdTe solar cells. This paper compares the results obtained from CdTe layers grown by three-electrode (3E and two-electrode (2E systems for their material properties and performance in CdS/CdTe devices. Thin films were characterized using a wide range of analytical techniques for their structural, morphological, optical and electrical properties. These layers have also been used in device structures; glass/FTO/CdS/CdTe/Au and CdTe from both methods have produced solar cells to date with efficiencies in the region of 5%–13%. Comprehensive work carried out to date produced comparable and superior devices fabricated from materials grown using 2E system.

In and Ga Codoped ZnO Film as a Front Electrode for Thin Film Silicon Solar Cells

Directory of Open Access Journals (Sweden)

Duy Phong Pham

2014-01-01

Full Text Available Doped ZnO thin films have attracted much attention in the research community as front-contact transparent conducting electrodes in thin film silicon solar cells. The prerequisite in both low resistivity and high transmittance in visible and near-infrared region for hydrogenated microcrystalline or amorphous/microcrystalline tandem thin film silicon solar cells has promoted further improvements of this material. In this work, we propose the combination of major Ga and minor In impurities codoped in ZnO film (IGZO to improve the film optoelectronic properties. A wide range of Ga and In contents in sputtering targets was explored to find optimum optical and electrical properties of deposited films. The results show that an appropriate combination of In and Ga atoms in ZnO material, followed by in-air thermal annealing process, can enhance the crystallization, conductivity, and transmittance of IGZO thin films, which can be well used as front-contact electrodes in thin film silicon solar cells.

Build-up of a liquid hydrogen target with extremely thin windows

International Nuclear Information System (INIS)

Jaeckle, V.G.

1992-06-01

Small hydrogen targets with only a few cubic millimeters of liquid have many advantages in experiments on accelerators with phase-space cooled particle beams. In order to achieve good suppression of systematic errors by secondary reactions in the target and in the target windows, the thickness of the foil window for a 1 mm target may only be 0.3 μm. A pressure difference of 200 mbar permits the use of such thin foils (with a diameter of 6 mm). A purely mechanical pressure control unit was built, which consists of soft bellows and a loading weight. The pressure difference from a vacuum, which is in the bellows, is set by the weight on the bellows. The working parameters were chosen so that deuterium, nitrogen and oxygen can be used. The pressure variations in the cell are only ± 2.5 mbar. A mixing of gaseous and liquid hydrogen in the target cell and the formation of bubbles due to free convection can be prevented. A quiet volume of liquid hydrogen free of bubbles was obtained. (orig./HP) [de

Amperometric detection and electrochemical oxidation of aliphatic amines and ammonia on silver-lead oxide thin-film electrodes

Energy Technology Data Exchange (ETDEWEB)

Ge, Jisheng [Iowa State Univ., Ames, IA (United States)

1996-01-08

This thesis comprises three parts: Electrocatalysis of anodic oxygen-transfer reactions: aliphatic amines at mixed Ag-Pb oxide thin-film electrodes; oxidation of ammonia at anodized Ag-Pb eutectic alloy electrodes; and temperature effects on oxidation of ethylamine, alanine, and aquated ammonia.

Indium sulfide thin films as window layer in chemically deposited solar cells

Energy Technology Data Exchange (ETDEWEB)

Lugo-Loredo, S. [Universidad Autónoma de Nuevo León, UANL, Fac. de Ciencias Químicas, Av. Universidad S/N Ciudad Universitaria San Nicolás de Los Garza Nuevo León, C.P. 66451 (Mexico); Peña-Méndez, Y., E-mail: yolapm@gmail.com [Universidad Autónoma de Nuevo León, UANL, Fac. de Ciencias Químicas, Av. Universidad S/N Ciudad Universitaria San Nicolás de Los Garza Nuevo León, C.P. 66451 (Mexico); Calixto-Rodriguez, M. [Universidad Tecnológica Emiliano Zapata del Estado de Morelos, Av. Universidad Tecnológica No. 1, C.P. 62760 Emiliano Zapata, Morelos (Mexico); Messina-Fernández, S. [Universidad Autónoma de Nayarit, Ciudad de la Cultura “Amado Nervo” S/N, C.P. 63190 Tepic, Nayarit (Mexico); Alvarez-Gallegos, A. [Universidad Autónoma del Estado de Morelos, Centro de Investigación en Ingeniería y Ciencias Aplicadas, Av. Universidad 1001, C.P. 62209, Cuernavaca Morelos (Mexico); Vázquez-Dimas, A.; Hernández-García, T. [Universidad Autónoma de Nuevo León, UANL, Fac. de Ciencias Químicas, Av. Universidad S/N Ciudad Universitaria San Nicolás de Los Garza Nuevo León, C.P. 66451 (Mexico)

2014-01-01

Indium sulfide (In{sub 2}S{sub 3}) thin films have been synthesized by chemical bath deposition technique onto glass substrates using In(NO{sub 3}){sub 3} as indium precursor and thioacetamide as sulfur source. X-ray diffraction studies have shown that the crystalline state of the as-prepared and the annealed films is β-In{sub 2}S{sub 3}. Optical band gap values between 2.27 and 2.41 eV were obtained for these films. The In{sub 2}S{sub 3} thin films are photosensitive with an electrical conductivity value in the range of 10{sup −3}–10{sup −7} (Ω cm){sup −1}, depending on the film preparation conditions. We have demonstrated that the In{sub 2}S{sub 3} thin films obtained in this work are suitable candidates to be used as window layer in thin film solar cells. These films were integrated in SnO{sub 2}:F/In{sub 2}S{sub 3}/Sb{sub 2}S{sub 3}/PbS/C–Ag solar cell structures, which showed an open circuit voltage of 630 mV and a short circuit current density of 0.6 mA/cm{sup 2}. - Highlights: • In{sub 2}S{sub 3} thin films were deposited using the Chemical Bath Deposition technique. • A direct energy band gap between 2.41 to 2.27 eV was evaluated for the In{sub 2}S{sub 3} films. • We made chemically deposited solar cells using the In{sub 2}S{sub 3} thin films.

Thin Cryogenic X-ray Windows

CERN Document Server

Niinikoski, T O; Davenport, M; Elias, N; Aune, S; Franz, J

2009-01-01

We describe the construction and tests of cryogenic X-ray windows of 47 mm diameter made of 15 ìm thick polypropylene foil glued on a UHV flange and supported with a strongback mesh machined by electro-erosion. These hermetic windows of the solar axion telescope of the CAST experiment at CERN withstand the static and dynamic pressures of the buffer gas that are normally below 130 mbar, but may reach 1.2 bar when the magnet quenches. They were tested at 60 K up to 3.5 bar static pressure without permanent deformation.

Contact Resistance Reduction of ZnO Thin Film Transistors (TFTs) with Saw-Shaped Electrode

KAUST Repository

Park, Woojin

2018-05-15

We report a saw-shaped electrode architecture ZnO thin film transistor (TFT) for effectively increase channel width. Such a saw-shaped electrode has ~2 times longer contact line at the contact metal/ZnO channel junction. We experimentally observed an enhancement in the output drive current by 50% and reduction in the contact resistance by over 50%, when compared to a typical shaped electrode ZnO TFT consuming the same chip area. This performance enhancement is attributed to extension of channel width. This technique can contribute to device performance enhancement and especially reduction in the contact resistance which is a serious challenge.

Fabrication of flexible polymer dispersed liquid crystal films using conducting polymer thin films as the driving electrodes

International Nuclear Information System (INIS)

Kim, Yang-Bae; Park, Sucheol; Hong, Jin-Who

2009-01-01

Conducting polymers exhibit good mechanical and interfacial compatibility with plastic substrates. We prepared an optimized coating formulation based on poly(3,4-ethylenedioxythiophene) (PEDOT) and 3-(trimethoxysilyl)propyl acrylate and fabricated a transparent electrode on poly(ethylene terephthalate) (PET) substrate. The surface resistances and transmittance of the prepared thin films were 500-600 Ω/□ and 87% at 500 nm, respectively. To evaluate the performance of the conducting polymer electrode, we fabricated a five-layer flexible polymer-dispersed liquid crystal (PDLC) device as a PET-PEDOT-PDLC-PEDOT-PET flexible film. The prepared PDLC device exhibited a low driving voltage (15 VAC), high contrast ratio (60:1), and high transmittance in the ON state (60%), characteristics that are comparable with those of conventional PDLC film based on indium tin oxide electrodes. The fabrication of conducting polymer thin films as the driving electrodes in this study showed that such films can be used as a substitute for an indium tin oxide electrode, which further enhances the flexibility of PDLC film

Mechanical measurements on lithium phosphorous oxynitride coated silicon thin film electrodes for lithium-ion batteries during lithiation and delithiation

Energy Technology Data Exchange (ETDEWEB)

Al-Obeidi, Ahmed, E-mail: alobeidi@mit.edu; Thompson, Carl V., E-mail: reiner.moenig@kit.edu, E-mail: cthomp@mit.edu [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Kramer, Dominik, E-mail: dominik.kramer@kit.edu; Mönig, Reiner, E-mail: reiner.moenig@kit.edu, E-mail: cthomp@mit.edu [Institute for Applied Materials, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU), Helmholtzstraße 11, 89081 Ulm (Germany); Boles, Steven T., E-mail: steven.t.boles@polyu.edu.hk [Institute for Applied Materials, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Hong Kong Polytechnic University, 11 Yuk Choi Rd, Hung Hom (Hong Kong)

2016-08-15

The development of large stresses during lithiation and delithiation drives mechanical and chemical degradation processes (cracking and electrolyte decomposition) in thin film silicon anodes that complicate the study of normal electrochemical and mechanical processes. To reduce these effects, lithium phosphorous oxynitride (LiPON) coatings were applied to silicon thin film electrodes. Applying a LiPON coating has two purposes. First, the coating acts as a stable artificial solid electrolyte interphase. Second, it limits mechanical degradation by retaining the electrode's planar morphology during cycling. The development of stress in LiPON-coated electrodes was monitored using substrate curvature measurements. LiPON-coated electrodes displayed highly reproducible cycle-to-cycle behavior, unlike uncoated electrodes which had poorer coulombic efficiency and exhibited a continual loss in stress magnitude with continued cycling due to film fracture. The improved mechanical stability of the coated silicon electrodes allowed for a better investigation of rate effects and variations of mechanical properties during electrochemical cycling.

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

International Nuclear Information System (INIS)

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

2016-01-01

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

Postbuckling behavior of windows subjected to synchrotron radiation x-rays

International Nuclear Information System (INIS)

Wang, Z.; Kuzay, T.M.; Sharma, S.K.

1993-01-01

Analyses performed on two Be windows (250 and 100 μm thick) show that the additional postbuckling strength still exists after initial window buckling and this part can be used by a thin window design in the working stage. However, the load factor to complate failure is not as big as the load factor to failure of a uniformly compressed window (the case for a thick window where buckling stress is larger than yielding stress of the window material). That is, the load factor of a thin window to collapse is not as large as that of a thick window without buckling. Hence, unless there is a special need for a thin window, buckling of the windows in normal working stage should not be recommended. Although shakedown was not considered, a similar conclusion can be expected for that case

Chemical synthesis of α-La{sub 2}S{sub 3} thin film as an advanced electrode material for supercapacitor application

Energy Technology Data Exchange (ETDEWEB)

Patil, S.J.; Kumbhar, V.S.; Patil, B.H.; Bulakhe, R.N.; Lokhande, C.D., E-mail: l_chandrakant@yahoo.com

2014-10-25

Highlights: • The simple, chemical method used for synthesis of lanthanum sulphide thin films. • The lanthanum sulphide thin film surface exhibited porous microstructure. • The lanthanum sulphide thin film electrode is used for supercapacitor application. - Abstract: α-La{sub 2}S{sub 3} thin films have been synthesized for the first time by successive ionic layer adsorption and reaction (SILAR) method and used for supercapacitor application. These films are characterized for crystal structure, surface morphology and wettability studies using X-ray diffraction (XRD), Fourier Transform-Raman (FT-Raman) spectroscopy, scanning electron microscopy (SEM) and contact angle measurements. The electrochemical supercapacitive performance of α-La{sub 2}S{sub 3} electrode is evaluated by cyclic voltammetry (CV), galvanostatic charge discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. From the electrochemical study, it is seen that α-La{sub 2}S{sub 3} electrode delivers high specific capacitance of 256 F g{sup −1} at scan rate of 5 mV s{sup −1} with cycling stability of 85% over 1000 cycles. Such La{sub 2}S{sub 3} electrode has great application in supercapacitor device for energy storage.

Thin, Flexible Supercapacitors Made from Carbon Nanofiber Electrodes Decorated at Room Temperature with Manganese Oxide Nanosheets

OpenAIRE

Nataraj, S. K.; Song, Q.; Al-Muhtaseb, S. A.; Dutton, S. E.; Zhang, Q.; Sivaniah, E.

2013-01-01

We report the fabrication and electrochemical performance of a flexible thin film supercapacitor with a novel nanostructured composite electrode. The electrode was prepared by in situ coprecipitation of two-dimensional (2D) MnO2 nanosheets at room temperature in the presence of carbon nanofibers (CNFs). The highest specific capacitance of 142 F/g was achieved for CNFs-MnO2 electrodes in sandwiched assembly with PVA-H4SiW12O40nH2O polyelectrolyte separator. Peer Reviewed

All-organic polymer-dispersed liquid crystal light-valves integrated with electroactive anthraquinone-2-sulfonate-doped polypyrrole thin films as driving electrodes

International Nuclear Information System (INIS)

Wang, Pen-Cheng; Yu, Jing-Yu; Li, Kuan-Hsun

2011-01-01

Highlights: → Fabrication of flexible semi-transparent all-polymer electrodes under ambient conditions without using a CVD system. → Characterization of the above electrodes based on anthraquinone-2-sulfonate-doped polypyrrole thin films. → Demonstration of all-organic liquid crystal light-valves with polypyrrole thin films as the driving electrodes. - Abstract: All-organic PDLC (polymer-dispersed liquid crystal) light-valves using all-polymer conductive substrates containing thin films of polypyrrole doped with anthraquinone-2-sulfonate (AQSA - ) as the driving electrodes were fabricated in this study. The all-polymer conductive substrates were prepared under ambient conditions by in situ depositing polypyrrole thin films on blank flexible poly(ethylene terephthalate), or PET, substrates from aqueous media in which oxidative polymerization of pyrrole was taking place. The obtained flexible all-polymer conductive substrates were semi-transparent with cohesive coatings of AQSA - doped polypyrrole thin films (thickness ∼55 nm). The all-polymer flexible conductive substrates had sheet resistivity ∼40 kΩ □ -1 and T% transparency against air ∼78% at 600 nm. The light-valves fabricated using the above all-polymer conductive substrates showed ∼50% transparency against air at 600 nm when 4 V μm -1 electric field was applied.

Title: Using Alignment and 2D Network Simulations to Study Charge Transport Through Doped ZnO Nanowire Thin Film Electrodes

KAUST Repository

Phadke, Sujay

2011-09-30

Factors affecting charge transport through ZnO nanowire mat films were studied by aligning ZnO nanowires on substrates and coupling experimental measurements with 2D nanowire network simulations. Gallium doped ZnO nanowires were aligned on thermally oxidized silicon wafer by shearing a nanowire dispersion in ethanol. Sheet resistances of nanowire thin films that had current flowing parallel to nanowire alignment direction were compared to thin films that had current flowing perpendicular to nanowire alignment direction. Perpendicular devices showed ∼5 fold greater sheet resistance than parallel devices supporting the hypothesis that aligning nanowires would increase conductivity of ZnO nanowire electrodes. 2-D nanowire network simulations of thin films showed that the device sheet resistance was dominated by inter-wire contact resistance. For a given resistivity of ZnO nanowires, the thin film electrodes would have the lowest possible sheet resistance if the inter-wire contact resistance was one order of magnitude lower than the single nanowire resistance. Simulations suggest that the conductivity of such thin film devices could be further enhanced by using longer nanowires. Solution processed Gallium doped ZnO nanowires are aligned on substrates using an innovative shear coating technique. Nanowire alignment has shown improvement in ZnO nanowire transparent electrode conductivity. 2D network simulations in conjunction with electrical measurements have revealed different regimes of operation of nanowire thin films and provided a guideline for improving electrical performance of nanowire electrodes. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thin, Flexible Supercapacitors Made from Carbon Nanofiber Electrodes Decorated at Room Temperature with Manganese Oxide Nanosheets

Directory of Open Access Journals (Sweden)

S. K. Nataraj

2013-01-01

Full Text Available We report the fabrication and electrochemical performance of a flexible thin film supercapacitor with a novel nanostructured composite electrode. The electrode was prepared by in situ coprecipitation of two-dimensional (2D MnO2 nanosheets at room temperature in the presence of carbon nanofibers (CNFs. The highest specific capacitance of 142 F/g was achieved for CNFs-MnO2 electrodes in sandwiched assembly with PVA-H4SiW12O40·nH2O polyelectrolyte separator.

Comparison of lead zirconate titanate thin films on ruthenium oxide and platinum electrodes

OpenAIRE

Bursill, Les A.; Reaney, Ian M.; Vijay, Dilip P.; Desu, Seshu B.

1994-01-01

High-resolution and bright- and dark-field transmission electron microscopy are used to characterize and compare the interface structures and microstructure of PZT/RuO2/SiO2/Si and PZT/Pt/Ti/SiO2/Si ferroelectric thin films, with a view to understanding the improved fatigue characteristics of PZT thin films with RuO2 electrodes. The RuO2/PZT interface consists of a curved pseudoperiodic minimal surface. The interface is chemically sharp with virtually no intermixing of RuO2 and PZT, as eviden...

Depositing bulk or micro-scale electrodes

Science.gov (United States)

Shah, Kedar G.; Pannu, Satinderpall S.; Tolosa, Vanessa; Tooker, Angela C.; Sheth, Heeral J.; Felix, Sarah H.; Delima, Terri L.

2016-11-01

Thicker electrodes are provided on microelectronic device using thermo-compression bonding. A thin-film electrical conducting layer forms electrical conduits and bulk depositing provides an electrode layer on the thin-film electrical conducting layer. An insulating polymer layer encapsulates the electrically thin-film electrical conducting layer and the electrode layer. Some of the insulating layer is removed to expose the electrode layer.

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.

Effect of multi-layered bottom electrodes on the orientation of strontium-doped lead zirconate titanate thin films

Energy Technology Data Exchange (ETDEWEB)

Bhaskaran, M. [Microelectronics and Materials Technology Centre, School of Electrical and Computer Engineering, RMIT University, GPO Box 2476V, Melbourne, Victoria 3001 (Australia)], E-mail: madhu.bhaskaran@gmail.com; Sriram, S. [Microelectronics and Materials Technology Centre, School of Electrical and Computer Engineering, RMIT University, GPO Box 2476V, Melbourne, Victoria 3001 (Australia); Mitchell, D.R.G.; Short, K.T. [Institute of Materials Engineering, Australian Nuclear Science and Technology Organisation (ANSTO), PMB 1, Menai, New South Wales 2234 (Australia); Holland, A.S. [Microelectronics and Materials Technology Centre, School of Electrical and Computer Engineering, RMIT University, GPO Box 2476V, Melbourne, Victoria 3001 (Australia)

2008-09-30

This article discusses the results from X-ray diffraction (XRD) analysis of piezoelectric strontium-doped lead zirconate titanate (PSZT) thin films deposited on multi-layer coatings on silicon. The films were deposited by RF magnetron sputtering on a metal coated substrate. The aim was to exploit the pronounced piezoelectric effect that is theoretically expected normal to the substrate. This work highlighted the influence that the bottom electrode architecture exerts on the final crystalline orientation of the deposited thin films. A number of bottom electrode architectures were used, with the uppermost metal layer on which PSZT was deposited being gold or platinum. The XRD analysis revealed that the unit cell of the PSZT thin films deposited on gold and on platinum were deformed, relative to expected unit cell dimensions. Experimental results have been used to estimate the unit cell parameters. The XRD results were then indexed based on these unit cell parameters. The choice and the thickness of the intermediate adhesion layers influenced the relative intensity, and in some cases, the presence of perovskite peaks. In some cases, undesirable reactions between the bottom electrode layers were observed, and layer architectures to overcome these reactions are also discussed.

Anodic oxidation of anthraquinone dye Alizarin Red S at Ti/BDD electrodes

Energy Technology Data Exchange (ETDEWEB)

Sun Jianrui; Lu Haiyan [College of Chemistry, Jilin University, Changchun 130012 (China); Du Lili [State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Lin Haibo, E-mail: lhb910@jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130012 (China); State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun 130012 (China); Li Hongdong, E-mail: hdli@jlu.edu.cn [State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China)

2011-05-15

The boron-doped diamond (BDD) thin-film electrode with high quality using industrially titanium plate (Ti/BDD) as substrate has been prepared and firstly used in the oxidation of anthraquinone dye Alizarin Red S (ARS) in wastewaters. The Ti/BDD electrodes are shown to have high concentration of sp{sup 3}-bonded carbon and wide electrochemical window. The results of the cyclic voltammetries show that BDD has unique properties such as high anodic stability and the production of active intermediates at the high potential. The oxidation regions of ARS and water are significantly separated at the Ti/BDD electrode, and the peak current increases linearly with increasing ARS concentration. The bulk electrolysis shows that removal of chemical oxygen demand (COD) and color can be completely reached and the electrooxidation of ARS behaves as a mass-transfer-controlled process at the Ti/BDD electrode. It is demonstrated that the performances of the Ti/BDD electrode for anodic oxidation ARS have been significantly improved with respect to the traditional electrodes.

LiFePO_4_−_xN_y thin-film electrodes coated on carbon fiber-modified current collectors for pseudocapacitors

International Nuclear Information System (INIS)

Chiu, Kuo-Feng; Su, Shih-Hsuan; Leu, Hoang-Jyh; Huang, Wei-Chieh

2015-01-01

LiFePO_4_−_xN_y thin films were sputter-deposited on micron carbon fibers (MCFs) under a gas mixture of N_2/Ar/H_2 as electrode materials in pseudocapacitors. The MCFs were fabricated by thermal chemical vapor deposition on stainless steel substrates as current collectors. Various amounts of N_2 were introduced by controlling the flow ratios of N_2 to Ar/H_2. The LiFePO_4_−_xN_y thin films coated on the surfaces of MCFs were observed by field emission scanning electron microscopy. The electrochemical properties of the LiFePO_4_−_xN_y thin films were characterized using cyclic voltammetry and charge–discharge processes. The LiFePO_4_−_xN_y thin-film electrode deposited under the optimal N_2 contents exhibited a high specific capacitance of 722 F/g at 1 A/g. Even at a current of 20 A/g, the electrode delivered a capacitance of 298 F/g. The pseudocapacitors using LiFePO_4_−_xN_y thin-film electrodes showed no significant capacitance fading after 1000 cycles at 1 A/g. The results indicated that nitrogen doping improved the electrochemical performances of LiFePO_4, demonstrating the potential of LiFePO_4_−_xN_y as an active material in pseudocapacitors. - Highlights: • LiFePO_4_−_xN_y thin films were sputter-deposited on micron carbon fibers (MCFs). • MCFs only act as a three-dimensional current collector in this system. • The pseudocapacitor exhibits a high specific capacitance.

Physical characterization of amorphous In-Ga-Zn-O thin-film transistors with direct-contact asymmetric graphene electrode

Directory of Open Access Journals (Sweden)

Jaewook Jeong

2014-09-01

Full Text Available High performance a-IGZO thin-film transistors (TFTs are fabricated using an asymmetric graphene drain electrode structure. A-IGZO TFTs (channel length = 3 μm were successfully demonstrated with a saturation field-effect mobility of 6.6 cm2/Vs without additional processes between the graphene and a-IGZO layer. The graphene/a-IGZO junction exhibits Schottky characteristics and the contact property is affected not only by the Schottky barrier but also by the parasitic resistance from the depletion region under the graphene electrode. Therefore, to utilize the graphene layer as S/D electrodes for a-IGZO TFTs, an asymmetric electrode is essential, which can be easily applied to the conventional pixel electrode structure.

Effect of top electrode material on radiation-induced degradation of ferroelectric thin film structures

Energy Technology Data Exchange (ETDEWEB)

Brewer, Steven J.; Bassiri-Gharb, Nazanin [G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Deng, Carmen Z.; Callaway, Connor P. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Paul, McKinley K. [G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Woodward Academy, College Park, Georgia 30337 (United States); Fisher, Kenzie J. [G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Riverwood International Charter School, Atlanta, Georgia 30328 (United States); Guerrier, Jonathon E.; Jones, Jacob L. [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Rudy, Ryan Q.; Polcawich, Ronald G. [Army Research Laboratory, Adelphi, Maryland 20783 (United States); Glaser, Evan R.; Cress, Cory D. [Naval Research Laboratory, Washington, DC 20375 (United States)

2016-07-14

The effects of gamma irradiation on the dielectric and piezoelectric responses of Pb[Zr{sub 0.52}Ti{sub 0.48}]O{sub 3} (PZT) thin film stacks were investigated for structures with conductive oxide (IrO{sub 2}) and metallic (Pt) top electrodes. The samples showed, generally, degradation of various key dielectric, ferroelectric, and electromechanical responses when exposed to 2.5 Mrad (Si) {sup 60}Co gamma radiation. However, the low-field, relative dielectric permittivity, ε{sub r}, remained largely unaffected by irradiation in samples with both types of electrodes. Samples with Pt top electrodes showed substantial degradation of the remanent polarization and overall piezoelectric response, as well as pinching of the polarization hysteresis curves and creation of multiple peaks in the permittivity-electric field curves post irradiation. The samples with oxide electrodes, however, were largely impervious to the same radiation dose, with less than 5% change in any of the functional characteristics. The results suggest a radiation-induced change in the defect population or defect energy in PZT with metallic top electrodes, which substantially affects motion of internal interfaces such as domain walls. Additionally, the differences observed for stacks with different electrode materials implicate the ferroelectric–electrode interface as either the predominant source of radiation-induced effects (Pt electrodes) or the site of healing for radiation-induced defects (IrO{sub 2} electrodes).

Transparent ambipolar organic thin film transistors based on multilayer transparent source-drain electrodes

Energy Technology Data Exchange (ETDEWEB)

Zhang, Nan; Hu, Yongsheng, E-mail: huyongsheng@ciomp.ac.cn, E-mail: liuxy@ciomp.ac.cn; Lin, Jie; Li, Yantao; Liu, Xingyuan, E-mail: huyongsheng@ciomp.ac.cn, E-mail: liuxy@ciomp.ac.cn [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)

2016-08-08

A fabrication method for transparent ambipolar organic thin film transistors with transparent Sb{sub 2}O{sub 3}/Ag/Sb{sub 2}O{sub 3} (SAS) source and drain electrodes has been developed. A pentacene/N,N′-ditridecylperylene-3,4,9,10-tetracarboxylic di-imide (PTCDI-C13) bilayer heterojunction is used as the active semiconductor. The electrodes are deposited by room temperature electron beam evaporation. The devices are fabricated without damaging the active layers. The SAS electrodes have high transmittance (82.5%) and low sheet resistance (8 Ω/sq). High performance devices with hole and electron mobilities of 0.3 cm{sup 2}/V s and 0.027 cm{sup 2}/V s, respectively, and average visible range transmittance of 72% were obtained. These transistors have potential for transparent logic integrated circuit applications.

Probing-models for interdigitated electrode systems with ferroelectric thin films

Science.gov (United States)

Nguyen, Cuong H.; Nigon, Robin; Raeder, Trygve M.; Hanke, Ulrik; Halvorsen, Einar; Muralt, Paul

2018-05-01

In this paper, a new method to characterize ferroelectric thin films with interdigitated electrodes is presented. To obtain accurate properties, all parasitic contributions should be subtracted from the measurement results and accurate models for the ferroelectric film are required. Hence, we introduce a phenomenological model for the parasitic capacitance. Moreover, two common analytical models based on conformal transformations are compared and used to calculate the capacitance and the electric field. With a thin film approximation, new simplified electric field and capacitance formulas are derived. By using these formulas, more consistent CV, PV and stress-field loops for samples with different geometries are obtained. In addition, an inhomogeneous distribution of the permittivity due to the non-uniform electric field is modelled by finite element simulation in an iterative way. We observed that this inhomogeneous distribution can be treated as a homogeneous one with an effective value of the permittivity.

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.

Clean graphene electrodes on organic thin-film devices via orthogonal fluorinated chemistry.

Science.gov (United States)

Beck, Jonathan H; Barton, Robert A; Cox, Marshall P; Alexandrou, Konstantinos; Petrone, Nicholas; Olivieri, Giorgia; Yang, Shyuan; Hone, James; Kymissis, Ioannis

2015-04-08

Graphene is a promising flexible, highly transparent, and elementally abundant electrode for organic electronics. Typical methods utilized to transfer large-area films of graphene synthesized by chemical vapor deposition on metal catalysts are not compatible with organic thin-films, limiting the integration of graphene into organic optoelectronic devices. This article describes a graphene transfer process onto chemically sensitive organic semiconductor thin-films. The process incorporates an elastomeric stamp with a fluorinated polymer release layer that can be removed, post-transfer, via a fluorinated solvent; neither fluorinated material adversely affects the organic semiconductor materials. We used Raman spectroscopy, atomic force microscopy, and scanning electron microscopy to show that chemical vapor deposition graphene can be successfully transferred without inducing defects in the graphene film. To demonstrate our transfer method's compatibility with organic semiconductors, we fabricate three classes of organic thin-film devices: graphene field effect transistors without additional cleaning processes, transparent organic light-emitting diodes, and transparent small-molecule organic photovoltaic devices. These experiments demonstrate the potential of hybrid graphene/organic devices in which graphene is deposited directly onto underlying organic thin-film structures.

Prototype solid-state electrochromic window devices

International Nuclear Information System (INIS)

Dao, L.H.; Nguyen, M.T.

1989-01-01

This paper discusses electrochromic smart windows which are prospective devices for the control of light transmission in response to the variation of brightness of the environment. The fabrication of electrochromic windows based on cathodically coloring transition metal oxides and anodically coloring conducting polymers are described. The device consists of gel or glassy polymer electrolytes sandwiches by a pair of transparent conducting glass coated respectively with a thin film of WO 3 or MoO 3 prepared by electrodeposition, and with a thin film of ploy(aniline) derivatives obtained by electropolymerization or solution casting. The electrochromic properties of the five-layer smart window devices are presented

Protein-modified nanocrystalline diamond thin films for biosensor applications.

Science.gov (United States)

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

2004-10-01

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

Structure and properties of PZT thin films on strontium ruthenate and calcium ruthenate electrodes

International Nuclear Information System (INIS)

Wu, T.-J.; Tsai, D.-S.

2004-01-01

PZT thin films have been prepared via metalorganic CVD (MOCVD) on four substrates of conducting oxides of ruthenates, SrRuO 3 /Pt/Ti/SiO 2 /Si(1 0 0), SrRuO 3 /SiO 2 /Si(1 0 0), CaRuO 3 /Pt/Ti/SiO 2 /Si(1 0 0), CaRuO 3 /SiO 2 /Si(1 0 0). The conducting ruthenate layers were also grown using MOCVD. Ferroelectric properties of polarization fatigue and leakage current density are measured. The internal strain of PZT thin crystal which is mainly constrained by the bottom electrode seems to be the decisive factor in ferroelectric properties. The internal strain of PZT is represented by its tetragonality ratio. The PZT thin film in the capacitor Au/PZT/SrRuO 3 /Pt/Ti/SiO 2 /Si, with the largest tetragonality ratio 1.026, exhibits an optimum combination of large polarization, less fatigue, and low leakage current density. Both SrRuO 3 and CaRuO 3 are good diffusion barriers to prevent interdiffusion of cations between the ferroelectric and the electrode. The slightly higher intermixing at the CaRuO 3 -to-Pt/Ti interface is owing to the high annealing temperature needed in CaRuO 3 synthesis

Fundamentals of vanadium dioxide thin films as possible components of intelligent windows

Directory of Open Access Journals (Sweden)

Wu, Z. P.

1999-03-01

Full Text Available In this paper, the research on the vanadium dioxide thin film, which can be used as intelligent windows, is reviewed, including the basic properties of V₂, energy band structure, model of electronic energy and the origin of metal-to-insulator transition (MIT. Finally, the problems existing in the research and the possibility of application for VO₂, as an intelligent thermochromic window are briefly discussed.

En este artículo se revisan las investigaciones realizadas en películas delgadas de dióxido de vanadio que pueden ser usadas en componentes de ventanas inteligentes, incluyendo las propiedades básicas del VO₂, tales como su estructura de bandas, modelo energético de tipo electrónico y el origen del fenómeno de la transición: metal-aislador (MIT en la literatura inglesa que constituye la base de las aplicaciones de estas películas. Finalmente, los problemas que hay en la investigación actual de este tipo de películas, así como sus posibles aplicaciones en ventanas inteligentes de tipo termocrómico, se discuten brevemente.

Polarization Induced Changes in LSM Thin Film Electrode Composition Observed by In Operando Raman Spectroscopy and TOF-SIMS

DEFF Research Database (Denmark)

McIntyre, Melissa D.; Traulsen, Marie Lund; Norrman, Kion

2015-01-01

Polarization induced changes in LSM electrode composition were investigated by utilizing in operando Raman spectroscopy and post mortem TOF-SIMS depth profiling. Experiments were conducted on cells with 160 nm thick (La0.85Sr0.15)0.9MnO3±δ thin film electrodes in 10% O2 at 700 °C under various...

Transparent Wood Smart Windows: Polymer Electrochromic Devices Based on Poly(3,4-Ethylenedioxythiophene):Poly(Styrene Sulfonate) Electrodes.

Science.gov (United States)

Lang, Augustus W; Li, Yuanyuan; De Keersmaecker, Michel; Shen, D Eric; Österholm, Anna M; Berglund, Lars; Reynolds, John R

2018-03-09

Transparent wood composites, with their high strength and toughness, thermal insulation, and excellent transmissivity, offer a route to replace glass for diffusely transmitting windows. Here, conjugated-polymer-based electrochromic devices (ECDs) that switch on-demand are demonstrated using transparent wood coated with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as a transparent conducting electrode. These ECDs exhibit a vibrant magenta-to-clear color change that results from a remarkably colorless bleached state. Furthermore, they require low energy and power inputs of 3 mWh m -2 at 2 W m -2 to switch due to a high coloration efficiency (590 cm 2  C -1 ) and low driving voltage (0.8 V). Each device component is processed with high-throughput methods, which highlights the opportunity to apply this approach to fabricate mechanically robust, energy-efficient smart windows on a large scale. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Low mass large aperture vacuum window development at CEBAF

International Nuclear Information System (INIS)

Keppel, C.

1995-01-01

Large aperture low mass vacuum windows are being developed for the HMS (High Momentum Spectrometer) and SOS (Short Orbit Spectrometer) spectrometers in Hall C at CEBAF. Because multiple scattering degrades the performance of a spectrometer it is important that the volume be evacuated and that the entrance and exit windows be as low mass as possible. The material used for such windows must be thin and light enough so as to have minimum effect of the beam, and at the same time, be thick and strong enough to operate reliably and safely. To achieve these goals, composite vacuum windows have been constructed of a thin sheet of Mylar with a reinforcing fabric. Reinforcing fabrics such as Kevlar and Spectra are available with tensile strengths significantly greater than that of Mylar. A thin layer of Myler remains necessary since the fabrics cannot achieve any sort of vacuum seal. The design, fabrication, testing, and operating experience with such composite windows for the Hall C spectrometers will be discussed

Transparent conductive zinc oxide basics and applications in thin film solar cells

CERN Document Server

Klein, Andreas; Rech, Bernd

2008-01-01

Zinc oxide (ZnO) belongs to the class of transparent conducting oxides which can be used as transparent electrodes in electronic devices or heated windows. In this book the material properties of, the deposition technologies for, and applications of zinc oxide in thin film solar cells are described in a comprehensive manner. Structural, morphological, optical and electronic properties of ZnO are treated in this review. The editors and authors of this book are specialists in deposition, analysis and fabrication of thin-film solar cells and especially of ZnO. This book is intended as an overview and a data collection for students, engineers and scientist.

Comparison of lead zirconate titanate thin films on ruthenium oxide and platinum electrodes

International Nuclear Information System (INIS)

Bursill, L.A.; Reaney, I.M.

1994-01-01

High-resolution and bright- and dark-field transmission electron microscopy are used to characterize and compare the interface structures and microstructure of PZT/RuO 2 /SiO 2 /Si and PZT/Pt/Ti/SiO 2 /Si ferroelectric thin films, with a view to understanding the improved fatigue characteristics of PZT thin films with RuO 2 electrodes. The RuO 2 /PZT interface consists of a curved pseudoperiodic minimal surface. The interface is chemically sharp with virtually no intermixing of RuO 2 and PZT, as evidenced by the atomic resolution images as well as energy dispersive X-ray analysis. A nanocrystalline pyrochlore phase Pb 2 ZrTiO 7-x (x ≠ 1) was found on the top surface of the PZT layer. The PZT/Pt/Ti/SiO 2 /Si thin film was well-crystallized and showed sharp interfaces throughout. Possible reasons for the improved fatigue characteristics of PZT/RuO 2 /SiO 2 /Si thin films are discussed. 13 refs; 7 figs

Comparison of lead zirconate titanate thin films on ruthenium oxide and platinum electrodes

Energy Technology Data Exchange (ETDEWEB)

Bursill, L A; Reaney, I M

1994-12-31

High-resolution and bright- and dark-field transmission electron microscopy are used to characterize and compare the interface structures and microstructure of PZT/RuO{sub 2}/SiO{sub 2}/Si and PZT/Pt/Ti/SiO{sub 2}/Si ferroelectric thin films, with a view to understanding the improved fatigue characteristics of PZT thin films with RuO{sub 2} electrodes. The RuO{sub 2}/PZT interface consists of a curved pseudoperiodic minimal surface. The interface is chemically sharp with virtually no intermixing of RuO{sub 2} and PZT, as evidenced by the atomic resolution images as well as energy dispersive X-ray analysis. A nanocrystalline pyrochlore phase Pb{sub 2}ZrTiO{sub 7-x} (x {ne} 1) was found on the top surface of the PZT layer. The PZT/Pt/Ti/SiO{sub 2}/Si thin film was well-crystallized and showed sharp interfaces throughout. Possible reasons for the improved fatigue characteristics of PZT/RuO{sub 2}/SiO{sub 2}/Si thin films are discussed. 13 refs; 7 figs.

Improving electrochemical performance of flexible thin film electrodes with micropillar array structures

International Nuclear Information System (INIS)

Myllymaa, Sami; Myllymaa, Katja; Lappalainen, Reijo; Pirinen, Sami; Pakkanen, Tapani A; Pakkanen, Tuula T; Suvanto, Mika

2012-01-01

For reliable function, bioelectrodes require a stable, low-impedance contact with the target tissue. In biosignal monitoring applications, in which low ion current densities are recorded, it is important to minimize electrode contact impedances. Recently, several flexible electrode concepts have been introduced for single-patient use. These electrodes conform well on the patient skin enabling an artifact-free, low-noise recording. In this study, polydimethylsiloxane (PDMS) elastomer was used as an electrode substrate material. One half of the substrates were surface-patterned with micropillars produced by using micro-working robot-made mold inserts and a replica molding technique. The substrates were subsequently coated with thin films of titanium (Ti), copper (Cu), silver (Ag) or silver–silver chloride (Ag/AgCl). Electrical impedance spectroscopy studies revealed that the micropillar structure caused statistically significant reductions in impedance modulus and phase for each coating candidate. The relative effect was strongest for pure Ag, for which the values of the real part (Z′) and the imaginary part (Z″) decreased to less than one tenth of the original (smooth) values. However, Ag/AgCl, as expected, proved to be a superior electrode material. Coating with chloride drastically reduced the interfacial impedance compared to pure Ag. Further significant reduction was achieved by the micropillars, since the phase angle declined from 10–13° (for smooth samples, f < 50 Hz) to a value as low as 5°. Equivalent circuit modeling was used to obtain a better understanding of phenomena occurring at various electrode–electrolyte interfaces. The knowledge obtained in this study will be exploited in the further development of flexible electrodes and miniaturized biointerfaces with improved electrochemical characteristics. (paper)

Microwave-assisted low temperature fabrication of ZnO thin film electrodes for solar energy harvesting

Energy Technology Data Exchange (ETDEWEB)

Nirmal Peiris, T.A.; Sagu, Jagdeep S.; Hazim Yusof, Y.; Upul Wijayantha, K.G., E-mail: U.Wijayantha@lboro.ac.uk

2015-09-01

Metallic Zn thin films were electrodeposited on fluorine-doped tin oxide (FTO) glass substrates and oxidized under air by conventional radiant and microwave post-annealing methods to obtain ZnO thin film electrodes. The temperature of each post-annealing method was varied systematically and the photoelectrochemical (PEC) performance of electrodes was evaluated. The best photocurrent density achieved by the conventional radiant annealing method at 425 °C for 15 min was 93 μA cm{sup −2} at 1.23 V vs. NHE and the electrode showed an incident photon-to-electron conversion efficiency (IPCE) of 28.2%. X-ray diffractogram of this electrode showed that the oxidation of Zn to ZnO was not completed during the radiant annealing process as evident by the presence of metallic Zn in the electrode. For the electrode oxidized from Zn to ZnO under microwave irradiation, a photocurrent of 130 μA cm{sup −2} at 1.23 V vs. NHE and IPCE of 35.6% was observed after annealing for just 3 min, during which the temperature reached 250 °C. The photocurrent was 40% higher for the microwave annealed sample; this increase was attributed to higher surface area by preserving the nanostructure, confirmed by SEM surface topographical analysis, and better conversion yields to crystalline ZnO. Overall, it was demonstrated that oxidation of Zn to ZnO can be accomplished by microwave annealing five times faster than that of conventional annealing, thus resulting in a ~ 75% power saving. This study shows that microwave processing of materials offers significant economic and performance advantages for industrial scale up. - Highlights: • Conversion of Zn to ZnO by microwave and radiant annealing was conducted. • Microwave conversion was 5 times faster compared to radiant annealing. • Photoelectrochemical performance of microwave annealed ZnO was 40% higher. • Microwave annealing results in a 75% energy saving.

The Development of 6061-Aluminum Windows for the MICE Liquid Absorber

International Nuclear Information System (INIS)

Lau, W.; Yang, S.Q.; Green, M.A.; Ishimoto, S.; Swanson, J.

2005-01-01

The thin windows for the Muon Ionization Cooling Experiment (MICE) liquid Absorber will be fabricated from 6061-T6-aluminum. The absorber and vacuum vessel thin windows are 300-mm in diameter and are 180 mm thick at the center. The windows are designed for an internal burst pressure of 0.68 MPa (100 psig) when warm. The MICE experiment design calls for changeable windows on the absorber, so a bolted window design was adopted. Welded windows offer some potential advantages over bolted windows when they are on the absorber itself. This report describes the bolted window and its seal. This report also describes an alternate window that is welded directly to the absorber body. The welded window design presented permits the weld to be ground off and re-welded. This report presents a thermal FEA analysis of the window seal-weld, while the window is being welded. Finally, the results of a test of a welded-window are presented

Spectroelectrochemical study of the adsorption of acetate anions at gold single crystal and thin-film electrodes

International Nuclear Information System (INIS)

Berna, Antonio; Delgado, Jose Manuel; Orts, Jose Manuel; Rodes, Antonio; Feliu, Juan Miguel

2008-01-01

Acetate adsorption at gold electrodes is studied in perchloric acid solutions by cyclic voltammetry and in-situ infrared spectroscopy. External reflection measurements, performed with gold single crystal electrodes, are combined with Surface Enhanced Infrared Reflection Absorption Spectroscopy experiments under attenuated total reflection conditions (ATR-SEIRAS) carried out with sputtered gold thin-film electrodes. Theoretical harmonic IR frequencies of acetate species adsorbed with different geometries on Au clusters with (1 1 1), (1 0 0) and (1 1 0) orientations have been obtained from B3LYP/LANL2DZ, 6-31 + G* calculations. The theoretical and experimental results confirm that, irrespective of the surface crystallographic orientation, bonding of acetate to the surface involves the two oxygen atoms of the carboxylate group, with the OCO plane perpendicular to the metal surface. DFT calculations reveal also that the total charge of the metal cluster-acetate supermolecule has small effect on the vibrational frequencies of adsorbed acetate species. Both the external and the internal reflection measurements show the co-adsorption of acetate and perchlorate anions. Step-scan measurements carried out with the gold thin-film electrodes have allowed the monitoring of the time-dependent behaviour of perchlorate, acetate and water bands in potential step experiments. Acetate adsorption under those conditions is shown to involve perchlorate desorption and to follow a Langmuir-type kinetics. The step-scan spectra also show the rise and decay of transient water structures with parallel time-dependent shifts of the background intensity in the infrared spectra

Pulsed voltage deposited lead selenide thin film as efficient counter electrode for quantum-dot-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Jin, Bin Bin [Key Laboratory of Macromolecular Science of Shaanxi Province & School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062 (China); Department of Chemical Engineering, Institute of Chemical Industry, Shaanxi Institute of Technology, Xi’an 710300 (China); Wang, Ye Feng [Key Laboratory of Macromolecular Science of Shaanxi Province & School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062 (China); Wang, Xue Qing [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); Zeng, Jing Hui, E-mail: jhzeng@ustc.edu [Key Laboratory of Macromolecular Science of Shaanxi Province & School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062 (China)

2016-04-30

Highlights: • PbSe thin film is deposited on FTO glass by a pulse voltage electrodeposition method. • The thin film is used as counter electrode (CE) in quantum dot-sensitized solar cell. • Superior electrocatalytic activity and stability in the polysulfide electrolyte is received. • The narrow band gap characteristics and p-type conductivity enhances the cell efficiency. • An efficiency of 4.67% is received for the CdS/CdSe co-sensitized solar cells. - Abstract: Lead selenide (PbSe) thin films were deposited on fluorine doped tin oxide (FTO) glass by a facile one-step pulse voltage electrodeposition method, and used as counter electrode (CE) in CdS/CdSe quantum dot-sensitized solar cells (QDSSCs). A power conversion efficiency of 4.67% is received for the CdS/CdSe co-sensitized solar cells, which is much better than that of 2.39% received using Pt CEs. The enhanced performance is attributed to the extended absorption in the near infrared region, superior electrocatalytic activity and p-type conductivity with a reflection of the incident light at the back electrode in addition. The physical and chemical properties were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), reflectance spectra, electrochemical impedance spectroscopy (EIS) and Tafel polarization measurements. The present work provides a facile pathway to an efficient CE in the QDSSCs.

Wrinkled Graphene–AgNWs Hybrid Electrodes for Smart Window

Directory of Open Access Journals (Sweden)

Ki-Woo Jun

2017-02-01

Full Text Available Over the past few years, there has been an increasing demand for stretchable electrodes for flexible and soft electronic devices. An electrode in such devices requires special functionalities to be twisted, bent, stretched, and deformed into variable shapes and also will need to have the capacity to be restored to the original state. In this study, we report uni- or bi-axially wrinkled graphene–silver nanowire hybrid electrodes comprised of chemical vapor deposition (CVD-grown graphene and silver nanowires. A CVD-grown graphene on a Cu-foil was transferred onto a biaxially pre-strained elastomer substrate and silver nanowires were sprayed on the transferred graphene surface. The pre-strained film was relaxed uni-(or bi-axially to produce a wrinkled structure. The bi-axially wrinkled graphene and silver nanowires hybrid electrodes were very suitable for high actuating performance of electro-active dielectric elastomers compared with the wrinkle-free case. Present results show that the optical transparency of the highly stretchable electrode can be successfully tuned by modulating input voltages.

Microstructure of thin film platinum electrodes on yttrium stabilized zirconia prepared by sputter deposition

Energy Technology Data Exchange (ETDEWEB)

Toghan, Arafat, E-mail: arafat.toghan@pci.uni-hannover.de [Institute of Physical Chemistry and Electrochemistry, Leibniz University of Hannover, Callinstrasse 3-3a, D-30167 Hannover (Germany); Khodari, M. [Chemistry Department, Faculty of Science, South Valley University, Qena, 83523 (Egypt); Steinbach, F.; Imbihl, R. [Institute of Physical Chemistry and Electrochemistry, Leibniz University of Hannover, Callinstrasse 3-3a, D-30167 Hannover (Germany)

2011-09-01

(111) oriented thin film Pt electrodes were prepared on single crystals of yttrium-stabilized zirconia (YSZ) by sputter deposition of platinum. The electrodes were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), atomic force microscopy (AFM) and by profilometry. SEM images of the as-sputtered platinum film show a compact amorphous Pt film covering uniformly the substrate. Upon annealing at 1123 K, gaps and pores at the interface develop leading to a partial dewetting of the Pt film. Increasing the annealing temperature to 1373 K transforms the polycrystalline Pt film into single crystalline grains exhibiting a (111) orientation towards the substrate.

Fatigue-resistant epitaxial Pb(Zr,Ti)O3 capacitors on Pt electrode with ultra-thin SrTiO3 template layers

International Nuclear Information System (INIS)

Takahara, Seiichi; Morimoto, Akiharu; Kawae, Takeshi; Kumeda, Minoru; Yamada, Satoru; Ohtsubo, Shigeru; Yonezawa, Yasuto

2008-01-01

Lead zirconate-titanate Pb(Zr,Ti)O 3 (PZT) capacitors with Pt bottom electrodes were prepared on MgO substrates by pulsed laser deposition (PLD) technique employing SrTiO 3 (STO) template layer. Perovskite PZT thin films are prepared via stoichiometric target using the ultra-thin STO template layers while it is quite difficult to obtain the perovskite PZT on Pt electrode via stoichiometric target in PLD process. The PZT capacitor prepared with the STO template layer showed good hysteresis and leakage current characteristics, and it showed an excellent fatigue resistance. The ultra-thin STO template layers were characterized by angle-resolved X-ray photoelectron spectroscopy measurement. The effect of the STO template layer is discussed based on the viewpoint of the perovskite nucleation and diffusion of Pb and O atoms

Stability enhancement of an electrically tunable colloidal photonic crystal using modified electrodes with a large electrochemical potential window

Energy Technology Data Exchange (ETDEWEB)

Shim, HongShik [Samsung Advanced Institute of Technology, Yongin-Si, Gyeonggi-do (Korea, Republic of); Department of Chemistry, Seoul National University, Seoul (Korea, Republic of); Gyun Shin, Chang; Heo, Chul-Joon; Jeon, Seog-Jin; Jin, Haishun; Woo Kim, Jung; Jin, YongWan; Lee, SangYoon; Gyu Han, Moon, E-mail: moongyu.han@samsung.com, E-mail: jinklee@snu.ac.kr [Samsung Advanced Institute of Technology, Yongin-Si, Gyeonggi-do (Korea, Republic of); Lim, Joohyun; Lee, Jin-Kyu, E-mail: moongyu.han@samsung.com, E-mail: jinklee@snu.ac.kr [Department of Chemistry, Seoul National University, Seoul (Korea, Republic of)

2014-02-03

The color tuning behavior and switching stability of an electrically tunable colloidal photonic crystal system were studied with particular focus on the electrochemical aspects. Photonic color tuning of the colloidal arrays composed of monodisperse particles dispersed in water was achieved using external electric field through lattice constant manipulation. However, the number of effective color tuning cycle was limited due to generation of unwanted ions by electrolysis of the water medium during electrical switching. By introducing larger electrochemical potential window electrodes, such as conductive diamond-like carbon or boron-doped diamond, the switching stability was appreciably enhanced through reducing the number of ions generated.

Lithium-Ion (de)insertion reaction of Germanium thin-film electrodes : an electrochemical and in situ XRD study

NARCIS (Netherlands)

Baggetto, L.; Notten, P.H.L.

2009-01-01

Germanium is a promising negative electrode candidate for lithium-ion thin-film batteries because of its very high theoretical storage capacity. When assuming full conversion of the material into the room-temperature equilibrium lithium saturated germanium phase, a theoretical capacity of or of

Enhancement of the electrical characteristics of thin-film transistors with indium-zinc-tin oxide/Ag/indium-zinc-tin oxide multilayer electrodes

Science.gov (United States)

Oh, Dohyun; Yun, Dong Yeol; Cho, Woon-Jo; Kim, Tae Whan

2014-08-01

Transparent indium-zinc-tin oxide (IZTO)-based thin-film transistors (TFTs) with IZTO/Ag/IZTO multilayer electrodes were fabricated on glass substrates using a tilted dual-target radio-frequency magnetron sputtering system. The IZTO TFTs with IZTO/Ag/IZTO multilayer electrodes exhibited a high optical transmittance in a visible region. The threshold voltage, the mobility, and the on/off-current ratio of the TFTs with IZTO/Ag/IZTO multilayer electrodes were enhanced in comparison with those of the TFTs with ITO electrodes. The source/drain contact resistance of the IZTO TFTs with IZTO/Ag/IZTO multilayer electrodes was smaller than that of the IZTO TFTs with ITO electrodes, resulting in enhancement of their electrical characteristics.

New method for characterizing electron mediators in microbial systems using a thin-layer twin-working electrode cell.

Science.gov (United States)

Hassan, Md Mahamudul; Cheng, Ka Yu; Ho, Goen; Cord-Ruwisch, Ralf

2017-01-15

Microbial biofilms are significant ecosystems where the existence of redox gradients drive electron transfer often via soluble electron mediators. This study describes the use of two interfacing working electrodes (WEs) to simulate redox gradients within close proximity (250µm) for the detection and quantification of electron mediators. By using a common counter and reference electrode, the potentials of the two WEs were independently controlled to maintain a suitable "voltage window", which enabled simultaneous oxidation and reduction of electron mediators as evidenced by the concurrent anodic and cathodic currents, respectively. To validate the method, the electrochemical properties of different mediators (hexacyanoferrate, HCF, riboflavin, RF) were characterized by stepwise shifting the "voltage window" (ranging between 25 and 200mV) within a range of potentials after steady equilibrium current of both WEs was established. The resulting differences in electrical currents between the two WEs were recorded across a defined potential spectrum (between -1V and +0.5V vs. Ag/AgCl). Results indicated that the technique enabled identification (by the distinct peak locations at the potential scale) and quantification (by the peak of current) of the mediators for individual species as well as in an aqueous mixture. It enabled a precise determination of mid-potentials of the externally added mediators (HCF, RF) and mediators produced by pyocyanin-producing Pseudomonas aeruginosa (WACC 91) culture. The twin working electrode described is particularly suitable for studying mediator-dependent microbial electron transfer processes or simulating redox gradients as they exist in microbial biofilms. Copyright © 2016 Elsevier B.V. All rights reserved.

Silicon-based thin films as bottom electrodes in chalcogenide nonvolatile memories

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung-Yun [IT Convergence and Components Laboratory, Electronics and Telecommunications Research Institute (ETRI), Yuseong-gu, Daejeon 305-350 (Korea, Republic of)], E-mail: seungyun@etri.re.kr; Yoon, Sung-Min; Choi, Kyu-Jeong; Lee, Nam-Yeal; Park, Young-Sam; Ryu, Sang-Ouk; Yu, Byoung-Gon; Kim, Sang-Hoon; Lee, Sang-Heung [IT Convergence and Components Laboratory, Electronics and Telecommunications Research Institute (ETRI), Yuseong-gu, Daejeon 305-350 (Korea, Republic of)

2007-10-31

The effect of the electrical resistivity of a silicon-germanium (SiGe) thin film on the phase transition in a GeSbTe (GST) chalcogenide alloy and the manufacturing aspect of the fabrication process of a chalcogenide memory device employing the SiGe film as bottom electrodes were investigated. While p-type SiGe bottom electrodes were formed using in situ doping techniques, n-type ones could be made in a different manner where phosphorus atoms diffused from highly doped silicon underlayers to undoped SiGe films. The p-n heterojunction did not form between the p-type GST and n-type SiGe layers, and the semiconduction type of the SiGe alloys did not influence the memory device switching. It was confirmed that an optimum resistivity value existed for memory operation in spite of proportionality of Joule heating to electrical resistivity. The very high resistivity of the SiGe film had no effect on the reduction of reset current, which might result from the resistance decrease of the SiGe alloy at high temperatures.

Graphene-based electrodes for enhanced organic thin film transistors based on pentacene.

Science.gov (United States)

Basu, Sarbani; Lee, Mu Chen; Wang, Yeong-Her

2014-08-21

This paper presents 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) and pentacene-based organic thin film transistors (OTFTs) with monolayer graphene source-drain (S-D) electrodes. The electrodes are patterned using conventional photolithographic techniques combined with reactive ion etching. The monolayer graphene film grown by chemical vapor deposition on Cu foil was transferred on a Si dioxide surface using a polymer-supported transfer method to fabricate bottom-gate, bottom-contact OTFTs. The pentacene OTFTs with graphene S-D contacts exhibited superior performance with a mobility of 0.1 cm(2) V(-1) s(-1) and an on-off ratio of 10(5) compared with OTFTs with Au-based S-D contacts, which had a mobility of 0.01 cm(2) V(-1) s(-1) and an on-off ratio of 10(3). The crystallinity, grain size, and microscopic defects (or the number of layers of graphene films) of the TIPS-pentacene/pentacene films were analyzed by X-ray diffraction spectroscopy, atomic force microscopy, and Raman spectroscopy, respectively. The feasibility of using graphene as an S-D electrode in OTFTs provides an alternative material with high carrier injection efficiency, chemical stability, and excellent interface properties with organic semiconductors, thus exhibiting improved device performance of C-based electronic OTFTs at a reduced cost.

Layer-by-layer assembled polyaniline nanofiber/multiwall carbon nanotube thin film electrodes for high-power and high-energy storage applications.

Science.gov (United States)

Hyder, Md Nasim; Lee, Seung Woo; Cebeci, Fevzi Ç; Schmidt, Daniel J; Shao-Horn, Yang; Hammond, Paula T

2011-11-22

Thin film electrodes of polyaniline (PANi) nanofibers and functionalized multiwall carbon nanotubes (MWNTs) are created by layer-by-layer (LbL) assembly for microbatteries or -electrochemical capacitors. Highly stable cationic PANi nanofibers, synthesized from the rapid aqueous phase polymerization of aniline, are assembled with carboxylic acid functionalized MWNT into LbL films. The pH-dependent surface charge of PANi nanofibers and MWNTs allows the system to behave like weak polyelectrolytes with controllable LbL film thickness and morphology by varying the number of bilayers. The LbL-PANi/MWNT films consist of a nanoscale interpenetrating network structure with well developed nanopores that yield excellent electrochemical performance for energy storage applications. These LbL-PANi/MWNT films in lithium cell can store high volumetric capacitance (~238 ± 32 F/cm(3)) and high volumetric capacity (~210 mAh/cm(3)). In addition, rate-dependent galvanostatic tests show LbL-PANi/MWNT films can deliver both high power and high energy density (~220 Wh/L(electrode) at ~100 kW/L(electrode)) and could be promising positive electrode materials for thin film microbatteries or electrochemical capacitors. © 2011 American Chemical Society

Lipase immobilized on nanostructured cerium oxide thin film coated on transparent conducting oxide electrode for butyrin sensing

International Nuclear Information System (INIS)

Panky, Sreedevi; Thandavan, Kavitha; Sivalingam, Durgajanani; Sethuraman, Swaminathan; Krishnan, Uma Maheswari; Jeyaprakash, Beri Gopalakrishnan; Rayappan, John Bosco Balaguru

2013-01-01

Nanostructured cerium oxide (CeO 2 ) thin films were deposited on transparent conducting oxide (TCO) substrate using spray pyrolysis technique with cerium nitrate salt, Ce(NO 3 ) 3 ·6H 2 O as precursor. Fluorine doped cadmium oxide (CdO:F) thin film prepared using spray pyrolysis technique acts as the TCO film and hence the bare electrode. The structural, morphological and elemental characterizations of the films were carried out using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray analysis (EDX) respectively. The diffraction peak positions in XRD confirmed the formation of highly crystalline ceria with cubic structure and FE-SEM images showed uniform adherent films with granular morphology. The band gaps of CeO 2 and TCO were found to be 3.2 eV and 2.6 eV respectively. Lipase enzyme was physisorbed on the surface of CeO 2 /TCO film to form the lipase/nano-CeO 2 /TCO bioelectrode. Sensing studies were carried out using cyclic voltammetry and amperometry, with lipase/nano-CeO 2 /TCO as working electrode and tributyrin as substrate. The mediator-free biosensor with nanointerface exhibited excellent linearity (0.33–1.98 mM) with a lowest detection limit of 2 μM with sharp response time of 5 s and a shelf life of about 6 weeks. -- Graphical abstract: Nanostructured cerium oxide thin films were deposited on transparent conducting oxide (TCO) substrate using spray pyrolysis technique. Fluorine doped cadmium oxide (CdO:F) thin film acts as the TCO film and hence the working electrode. Lipase enzyme was physisorbed on the surface of CeO 2 /TCO film and hence the lipase/nano-CeO 2 /TCO bioelectrode has been fabricated. Sensing studies were carried out using cyclic voltammetry and amperometry with tributyrin as substrate. The mediator-free biosensor with nanointerface exhibited excellent linearity (0.33–1.98 mM) with a lowest detection limit of 2 μM with sharp response time of 5 s and a shelf life of about 6

Reduction of methanol crossover by thin cracked metal barriers at the interface between membrane and electrode in direct methanol fuel cells

Science.gov (United States)

Kim, Sungjun; Jang, Segeun; Kim, Sang Moon; Ahn, Chi-Yeong; Hwang, Wonchan; Cho, Yong-Hun; Sung, Yung-Eun; Choi, Mansoo

2017-09-01

This work reports the successful reduction in methanol crossover by creating a thin cracked metal barrier at the interface between a Nafion® membrane and an electrode in direct methanol fuel cells (DMFCs). The cracks are generated by simple mechanical stretching of a metal deposited Nafion® membrane as a result of the elastic mismatch between the two attached surfaces. The cracked metal barriers with varying strains (∼0.5 and ∼1.0) are investigated and successfully incorporated into the DMFC. Remarkably, the membrane electrode assembly with the thin metal crack exhibits comparable ohmic resistance as well as reduction of methanol crossover, which enhanced the device performance.

Effects of the top-electrode preparation method on the ferroelectric properties of Pt/Pb(Zr,Ti)O3/Pt thin film capacitors

International Nuclear Information System (INIS)

Lee, Eun Gu; Lee, Jae Gab; Kim, Sun Jae

2006-01-01

The deformation in the hysteresis loop of Pt/PZT/Pt thin-film capacitors due to deposition and patterning of the top electrode has been investigated. The PZT film was aged during the deposition of the top electrode and was positively poled during reactive ion etching (RIE). The PZT film having sputtered top electrode was very sensitive to the RIE process. The film with a thinner top electrode showed less initial switching polarization due to less compressive stress, but better fatigue characteristics due to an enhanced partial-switching region.

Stripping analysis of nanomolar perchlorate in drinking water with a voltammetric ion-selective electrode based on thin-layer liquid membrane.

Science.gov (United States)

Kim, Yushin; Amemiya, Shigeru

2008-08-01

A highly sensitive analytical method is required for the assessment of nanomolar perchlorate contamination in drinking water as an emerging environmental problem. We developed the novel approach based on a voltammetric ion-selective electrode to enable the electrochemical detection of "redox-inactive" perchlorate at a nanomolar level without its electrolysis. The perchlorate-selective electrode is based on the submicrometer-thick plasticized poly(vinyl chloride) membrane spin-coated on the poly(3-octylthiophene)-modified gold electrode. The liquid membrane serves as the first thin-layer cell for ion-transfer stripping voltammetry to give low detection limits of 0.2-0.5 nM perchlorate in deionized water, commercial bottled water, and tap water under a rotating electrode configuration. The detection limits are not only much lower than the action limit (approximately 246 nM) set by the U.S. Environmental Protection Agency but also are comparable to the detection limits of the most sensitive analytical methods for detecting perchlorate, that is, ion chromatography coupled with a suppressed conductivity detector (0.55 nM) or electrospray ionization mass spectrometry (0.20-0.25 nM). The mass transfer of perchlorate in the thin-layer liquid membrane and aqueous sample as well as its transfer at the interface between the two phases were studied experimentally and theoretically to achieve the low detection limits. The advantages of ion-transfer stripping voltammetry with a thin-layer liquid membrane against traditional ion-selective potentiometry are demonstrated in terms of a detection limit, a response time, and selectivity.

Information transfer using wearable thin electrotactile displays with microneedle electrodes

Science.gov (United States)

Tezuka, Mayuko; Kitamura, Norihide; Miki, Norihisa

2016-06-01

Tactile sensation is considered as a promising information transfer tool that can replace or compensate for sight and hearing information. In this study, we developed a sheet-type electrotactile display with microneedle electrodes. This flexible and thin display is suitable for wearable applications. It can present tactile sensation to the skin at a low voltage by penetrating the stratum corneum with microneedles. As a proof-of-concept experiment of transferring information via tactile sensation, we first tried to convey signals of two patterns using a single display. Next, we attempted to use multiple displays and experimentally investigated the spatial resolution of the tactile sensation on the forearm. Finally, 3-bit information was successfully transferred by three devices attached to the forearm.

First report on synthesis of ZnFe_2O_4 thin film using successive ionic layer adsorption and reaction: Approach towards solid-state symmetric supercapacitor device

International Nuclear Information System (INIS)

Raut, Shrikant S.; Sankapal, Babasaheb R.

2016-01-01

Highlights: • First report on synthesis of ZnFe_2O_4 thin film using SILAR method. • ZnFe_2O_4 electrode yields the specific capacitance of 471 Fg"−"1 at a scan rate of 5 mV s"−"1 in 1 M NaOH aqueous solution. • Solid-state symmetric supercapacitor device based on ZnFe_2O_4 sandwiched in polyvinyl alcohol (PVA)–LiClO_4 gel electrolyte exhibits voltage windows of 1.0 V. • ZnFe_2O_4-SSS supercapacitor device shows good energy and power density with long cycle life. - Abstract: ZnFe_2O_4 thin film has been synthesized by a simple and low cost successive ionic layer adsorption and reaction (SILAR) method without the use of surfactant or template. The nanoplate composed of nanoparticles with porous surface morphology has been revealed which is beneficial towards supercapacitor application. Formed ZnFe_2O_4 thin film has been tested as an electrode material for supercapacitor through electrochemical analysis. First attempt for SILAR synthesized ZnFe_2O_4 thin film exhibited a specific capacitance of 471 Fg"−"1 at a scan rate of 5 mVs"−"1 in 1 M NaOH aqueous solution. Further, ZnFe_2O_4 solid-state symmetric (SSS) supercapacitor device demonstrated voltage window of 1.0 V with specific capacitance of 32 Fg"−"1, energy density of 4.47 Whkg"−"1 and power density of 277 Wkg"−"1 at 1 Ag"−"1 current density. Such high performance capacitive behavior indicates ZnFe_2O_4 thin film is promising and low cost electrode material towards energy storage devices for various portable electronic systems.

A chip-type thin-layer electrochemical cell coupled with capillary electrophoresis for online separation of electrode reaction products

Energy Technology Data Exchange (ETDEWEB)

He, Jian-Bo, E-mail: jbhe@hfut.edu.cn; Cui, Ting; Zhang, Wen-Wen; Deng, Ning

2013-07-05

Graphical abstract: -- Highlights: •A new coupling of thin-layer electrolysis with capillary electrophoresis (CE). •Rapid electrolysis, direct sampling followed by online CE separation. •At least 13 products of quercetin oxidation were separated. •Thermodynamic and kinetic parameters were determined from CE peak areas. -- Abstract: A coupling technique of thin-layer electrolysis with high-performance capillary electrophoresis/UV–vis technique(EC/HPCE/UV–vis) is developed for online separation and determination of electrode reaction products. A chip-type thin-layer electrolytic (CTE) cell was designed and fabricated, which contains a capillary channel and a background electrolyte reservoir, allowing rapid electrolysis, direct sampling and online electrophoretic separation. This chip-type setup was characterized based on an electrophoresis expression of Nernst equation that was applied to the redox equilibrium of o-tolidine at different potentials. The utility of the method was demonstrated by separating and determining the electro-oxidation products of quercetin in different pH media. Two main products were always found in the studied time, potential and pH ranges. The variety of products increased not only with increasing potential but also with increasing pH value, and in total, at least 13 products were observed in the electropherograms. This work illustrates a novel example of capillary electrophoresis used online with thin-layer electrolysis to separate and detect electrode reaction products.

A chip-type thin-layer electrochemical cell coupled with capillary electrophoresis for online separation of electrode reaction products

International Nuclear Information System (INIS)

He, Jian-Bo; Cui, Ting; Zhang, Wen-Wen; Deng, Ning

2013-01-01

Graphical abstract: -- Highlights: •A new coupling of thin-layer electrolysis with capillary electrophoresis (CE). •Rapid electrolysis, direct sampling followed by online CE separation. •At least 13 products of quercetin oxidation were separated. •Thermodynamic and kinetic parameters were determined from CE peak areas. -- Abstract: A coupling technique of thin-layer electrolysis with high-performance capillary electrophoresis/UV–vis technique(EC/HPCE/UV–vis) is developed for online separation and determination of electrode reaction products. A chip-type thin-layer electrolytic (CTE) cell was designed and fabricated, which contains a capillary channel and a background electrolyte reservoir, allowing rapid electrolysis, direct sampling and online electrophoretic separation. This chip-type setup was characterized based on an electrophoresis expression of Nernst equation that was applied to the redox equilibrium of o-tolidine at different potentials. The utility of the method was demonstrated by separating and determining the electro-oxidation products of quercetin in different pH media. Two main products were always found in the studied time, potential and pH ranges. The variety of products increased not only with increasing potential but also with increasing pH value, and in total, at least 13 products were observed in the electropherograms. This work illustrates a novel example of capillary electrophoresis used online with thin-layer electrolysis to separate and detect electrode reaction products

Cu2Sb thin film electrodes prepared by pulsed laser deposition f or lithium batteries

Energy Technology Data Exchange (ETDEWEB)

Song, Seung-Wan; Reade, Ronald P.; Cairns, Elton J.; Vaughey, Jack T.; Thackeray, Michael M.; Striebel, Kathryn A.

2003-08-01

Thin films of Cu2Sb, prepared on stainless steel and copper substrates with a pulsed laser deposition technique at room temperature, have been evaluated as electrodes in lithium cells. The electrodes operate by a lithium insertion/copper extrusion reaction mechanism, the reversibility of which is superior when copper substrates are used, particularly when electrochemical cycling is restricted to the voltage range 0.65-1.4 V vs. Li/Li+. The superior performance of Cu2Sb films on copper is attributed to the more active participation of the extruded copper in the functioning of the electrode. The continual and extensive extrusion of copper on cycling the cells leads to the isolation of Li3Sb particles and a consequent formation of Sb. Improved cycling stability of both types of electrodes was obtained when cells were cycled between 0.65 and 1.4 V. A low-capacity lithium-ion cell with Cu2Sb and LiNi0.8Co0.15Al0.05O2 electrodes, laminated from powders, shows excellent cycling stability over the voltage range 3.15 - 2.2 V, the potential difference corresponding to approximately 0.65-1.4 V for the Cu2Sb electrode vs. Li/Li+. Chemical self-discharge of lithiated Cu2Sb electrodes by reaction with the electrolyte was severe when cells were allowed to relax on open circuit after reaching a lower voltage limit of 0.1 V. The solid electrolyte interphase (SEI) layer formed on Cu2Sb electrodes after cells had been cycled between 1.4 and 0.65 V vs. Li/Li+ was characterized by Fourier-transform infrared spectroscopy; the SEI layer contributes to the large irreversible capacity loss on the initial cycle of these cells. The data contribute to a better understanding of the electrochemical behavior of intermetallic electrodes in rechargeable lithium batteries.

Mechanistic interaction study of thin oxide dielectric with conducting organic electrode

International Nuclear Information System (INIS)

Sharma, Himani; Sethi, Kanika; Raj, P. Markondeya; Gerhardt, R.A.; Tummala, Rao

2012-01-01

Highlights: ► Thin film-oxide dielectric-organic electrode interface studies for investigating the leakage mechanism. ► XPS to elucidate chemical-structural changes on dielectric oxide surface. ► Correlates structural characterization data with capacitor leakage current and impedance spectroscopy characteristics. - Abstract: This paper aims at understanding the interaction of intrinsic conducting polymer, PEDT, with ALD-deposited Al 2 O 3 and thermally oxidized Ta 2 O 5 dielectrics, and the underlying mechanisms for increase in leakage currents in PEDT-based capacitors. Conducting polymers offer several advantages as electrodes for high surface area capacitors because of their lower resistance, self-healing and enhanced conformality. However, capacitors with in situ polymerized PEDT show poor electrical properties that are attributed to the interfacial interaction between the organic electrode and the oxide dielectric. This study focuses on characterizing these interactions. A combination of compositional, structural and electrical characterization techniques was applied to polymer-solid-state-capacitor to understand the interfacial chemical behavior and dielectric property deterioration of alumina and tantalum-oxide films. XPS and impedance studies were employed to understand the stiochiometric and compositional changes that occur in the dielectric film on interaction with in situ deposited PEDT. Based on the observations from several complimentary techniques, it is concluded that tantalum-pentoxide has more resistance towards chemical interaction with in situ polymerized PEDT. The thermally oxidized Ta 2 O 5 -PEDT system showed leakage current of 280 nA μF −1 at 3 V with a breakdown voltage of 30 V. On the other hand, Al 2 O 3 -PEDT capacitor showed leakage current of 50 μA μF −1 and a breakdown voltage of 40 V. The study reports direct evidence for the mechanism of resistivity drop in alumina dielectric with in situ polymerized PEDT electrode.

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Effect of Source/Drain Electrodes on the Electrical Properties of Silicon–Tin Oxide Thin-Film Transistors

Directory of Open Access Journals (Sweden)

Xianzhe Liu

2018-05-01

Full Text Available Ultra-high definition displays have become a trend for the current flat plane displays. In this study, the contact properties of amorphous silicon–tin oxide thin-film transistors (a-STO TFTs employed with source/drain (S/D electrodes were analyzed. Ohmic contact with a good device performance was achieved when a-STO was matched with indium-tin-oxide (ITO or Mo electrodes. The acceptor-like densities of trap states (DOS of a-STO TFTs were further investigated by using low-frequency capacitance–voltage (C–V characteristics to understand the impact of the electrode on the device performance. The reason of the distinct electrical performances of the devices with ITO and Mo contacts was attributed to different DOS caused by the generation of local defect states near the electrodes, which distorted the electric field distribution and formed an electrical potential barrier hindering the flow of electrons. It is of significant importance for circuit designers to design reliable integrated circuits with SnO2-based devices applied in flat panel displays.

Electrochemical behavior of LiCoO2 as aqueous lithium-ion battery electrodes

KAUST Repository

Ruffo, Riccardo

2009-02-01

Despite the large number of studies on the behavior of LiCoO2 in organic electrolytes and its recent application as a positive electrode in rechargeable water battery prototypes, a little information is available about the lithium intercalation reaction in this layered compound in aqueous electrolytes. This work shows that LiCoO2 electrodes can be reversibly cycled in LiNO3 aqueous electrolytes for tens of cycles at remarkably high rates with impressive values specific capacity higher than 100 mAh/g, and with a coulomb efficiency greater than 99.7%. Stable and reproducible cycling measurements have been made using a simple cell design that can be easily applied to the study of other intercalation materials, assuming that they are stable in water and that their intercalation potential range matches the electrochemical stability window of the aqueous electrolyte. The experimental arrangement uses a three-electrode flooded cell in which another insertion compound acts as a reversible source and sink of lithium ions, i.e., as the counter electrode. A commercial reference electrode is also present. Both the working and the counter electrodes have been prepared as thin layers on a metallic substrate using the procedures typical for the study of electrodes for lithium-ion batteries in organic solvent electrolytes. © 2008 Elsevier B.V. All rights reserved.

Radiation-transparent windows, method for imaging fluid transfers

Science.gov (United States)

Shu, Deming [Darien, IL; Wang, Jin [Burr Ridge, IL

2011-07-26

A thin, x-ray-transparent window system for environmental chambers involving pneumatic pressures above 40 bar is presented. The window allows for x-ray access to such phenomena as fuel sprays injected into a pressurized chamber that mimics realistic internal combustion engine cylinder operating conditions.

Thermo-mechanical failure criteria for x-ray windows and filters and comparison with experiments

International Nuclear Information System (INIS)

Wang, Z.; Kuzay, T.M.

1993-01-01

Synchrotron x-ray windows are vacuum separators and are usually made of thin beryllium metal. Filters are provided upstream of the window to filter out the soft x-rays to protect the window from overheating and failing. The filters are made of thin carbon products or sometimes beryllium, the same material as the window. Because the window is a vacuum separator, understanding its potential structural failure under thermal load is very important. Current structural failure models for the brazed windows and filters under thermal stresses are not very accurate. Existing models have been carefully examined and found to be inconsistent with the actual failure modes of windows tested. Due to the thinness of the filter/window, the most likely failure mode is thermal buckling. In fact, recent synchrotron tests conducted in Japan on window failures bear out this position. In this paper, failure criteria for filters/windows are proposed, and analyses are performed and compared with the experimental results from various sources. A consistent result is found between the analysis and reported experiments. A series of additional analyses based on the proposed failure criteria is also carried out for filter and window designs for the third generation synchrotron beamline front ends. Comparative results are presented here

Lipase immobilized on nanostructured cerium oxide thin film coated on transparent conducting oxide electrode for butyrin sensing

Energy Technology Data Exchange (ETDEWEB)

Panky, Sreedevi; Thandavan, Kavitha [Centre for Nanotechnology and Advanced Biomaterials (CeNTAB), SASTRA University, Thanjavur 613 401, Tamil Nadu (India); School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, Tamil Nadu (India); Sivalingam, Durgajanani [Centre for Nanotechnology and Advanced Biomaterials (CeNTAB), SASTRA University, Thanjavur 613 401, Tamil Nadu (India); School of Electrical and Electronics Engineering, SASTRA University, Thanjavur 613 401, Tamil Nadu (India); Sethuraman, Swaminathan; Krishnan, Uma Maheswari [Centre for Nanotechnology and Advanced Biomaterials (CeNTAB), SASTRA University, Thanjavur 613 401, Tamil Nadu (India); School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, Tamil Nadu (India); Jeyaprakash, Beri Gopalakrishnan [Centre for Nanotechnology and Advanced Biomaterials (CeNTAB), SASTRA University, Thanjavur 613 401, Tamil Nadu (India); School of Electrical and Electronics Engineering, SASTRA University, Thanjavur 613 401, Tamil Nadu (India); Rayappan, John Bosco Balaguru, E-mail: rjbosco@ece.sastra.edu [Centre for Nanotechnology and Advanced Biomaterials (CeNTAB), SASTRA University, Thanjavur 613 401, Tamil Nadu (India); School of Electrical and Electronics Engineering, SASTRA University, Thanjavur 613 401, Tamil Nadu (India)

2013-01-15

Nanostructured cerium oxide (CeO{sub 2}) thin films were deposited on transparent conducting oxide (TCO) substrate using spray pyrolysis technique with cerium nitrate salt, Ce(NO{sub 3}){sub 3}{center_dot}6H{sub 2}O as precursor. Fluorine doped cadmium oxide (CdO:F) thin film prepared using spray pyrolysis technique acts as the TCO film and hence the bare electrode. The structural, morphological and elemental characterizations of the films were carried out using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray analysis (EDX) respectively. The diffraction peak positions in XRD confirmed the formation of highly crystalline ceria with cubic structure and FE-SEM images showed uniform adherent films with granular morphology. The band gaps of CeO{sub 2} and TCO were found to be 3.2 eV and 2.6 eV respectively. Lipase enzyme was physisorbed on the surface of CeO{sub 2}/TCO film to form the lipase/nano-CeO{sub 2}/TCO bioelectrode. Sensing studies were carried out using cyclic voltammetry and amperometry, with lipase/nano-CeO{sub 2}/TCO as working electrode and tributyrin as substrate. The mediator-free biosensor with nanointerface exhibited excellent linearity (0.33-1.98 mM) with a lowest detection limit of 2 {mu}M with sharp response time of 5 s and a shelf life of about 6 weeks. -- Graphical abstract: Nanostructured cerium oxide thin films were deposited on transparent conducting oxide (TCO) substrate using spray pyrolysis technique. Fluorine doped cadmium oxide (CdO:F) thin film acts as the TCO film and hence the working electrode. Lipase enzyme was physisorbed on the surface of CeO{sub 2}/TCO film and hence the lipase/nano-CeO{sub 2}/TCO bioelectrode has been fabricated. Sensing studies were carried out using cyclic voltammetry and amperometry with tributyrin as substrate. The mediator-free biosensor with nanointerface exhibited excellent linearity (0.33-1.98 mM) with a lowest detection limit of 2 {mu}M with sharp

InP solar cell with window layer

Science.gov (United States)

Jain, Raj K. (Inventor); Landis, Geoffrey A. (Inventor)

1994-01-01

The invention features a thin light transmissive layer of the ternary semiconductor indium aluminum arsenide (InAlAs) as a front surface passivation or 'window' layer for p-on-n InP solar cells. The window layers of the invention effectively reduce front surface recombination of the object semiconductors thereby increasing the efficiency of the cells.

Energy harvesting using ionic electro-active polymer thin films with Ag-based electrodes

International Nuclear Information System (INIS)

Anand, S V; Arvind, K; Bharath, P; Roy Mahapatra, D

2010-01-01

In this paper we employ the phenomenon of bending deformation induced transport of cations via the polymer chains in the thickness direction of an electro-active polymer (EAP)–metal composite thin film for mechanical energy harvesting. While EAPs have been applied in the past in actuators and artificial muscles, promising applications of such materials in hydrodynamic and vibratory energy harvesting are reported in this paper. For this, functionalization of EAPs with metal electrodes is the key factor in improving the energy harvesting efficiency. Unlike Pt-based electrodes, Ag-based electrodes have been deposited on an EAP membrane made of Nafion. The developed ionic metal polymer composite (IPMC) membrane is subjected to a dynamic bending load, hydrodynamically, and evaluated for the voltage generated against an external electrical load. An increase of a few orders of magnitude has been observed in the harvested energy density and power density in air, deionized water and in electrolyte solutions with varying concentrations of sodium chloride (NaCl) as compared to Pt-based IPMC performances reported in the published literature. This will have potential applications in hydrodynamic and residual environmental energy harvesting to power sensors and actuators based on micro-and nano-electro-mechanical systems (MEMS and NEMS) for biomedical, aerospace and oceanic applications

Spray deposited CeO2–TiO2 counter electrode for electrochromic ...

Indian Academy of Sciences (India)

application in smart window technology. The technological requirement of smart windows includes the electrochromic working electrode and ion storage layer that should be optically passive after intercalation/deintercalation process. There are only few materials which are used as an optically passive counter electrode with ...

Electrochromic Windows: Advanced Processing Technology

Energy Technology Data Exchange (ETDEWEB)

SAGE Electrochromics, Inc

2006-12-13

This project addresses the development of advanced fabrication capabilities for energy saving electrochromic (EC) windows. SAGE EC windows consist of an inorganic stack of thin films deposited onto a glass substrate. The window tint can be reversibly changed by the application of a low power dc voltage. This property can be used to modulate the amount of light and heat entering buildings (or vehicles) through the glazings. By judicious management of this so-called solar heat gain, it is possible to derive significant energy savings due to reductions in heating lighting, and air conditioning (HVAC). Several areas of SAGE’s production were targeted during this project to allow significant improvements to processing throughput, yield and overall quality of the processing, in an effort to reduce the cost and thereby improve the market penetration. First, the overall thin film process was optimized to allow a more robust set of operating points to be used, thereby maximizing the yield due to the thin film deposition themselves. Other significant efforts aimed at improving yield were relating to implementing new procedures and processes for the manufacturing process, to improve the quality of the substrate preparation, and the quality of the IGU fabrication. Furthermore, methods for reworking defective devices were developed, to enable devices which would otherwise be scrapped to be made into useful product. This involved the in-house development of some customized equipment. Finally, the improvements made during this project were validated to ensure that they did not impact the exceptional durability of the SageGlass® products. Given conservative estimates for cost and market penetration, energy savings due to EC windows in residences in the US are calculated to be of the order 0.026 quad (0.026×1015BTU/yr) by the year 2017.

Characterization of Optic Properties ZnO:Al Thin Film on Glass Substrate for Solar Cell Window

International Nuclear Information System (INIS)

Wiryoadi; Yunanto; Bambang Siswanto; Sri Sulamdari; Sudjatmoko

2002-01-01

It has been characterized a ZnO:Al thin film growth using sputtering technique for solar cell window. The aims of this research is to get a ZnO:Al thin film that can be used as a TCO (Transparent Conducting Oxide) on amorphous silicon solar cell. To get an optimum properties, deposition process has been done for various parameters, such as composition/concentration of Al, substrate temperature, gas pressure and deposition time. Based on experiments result, it is found that the optimum result was achieved at temperature 450 o C, gas pressure 6 x 10 -2 torr and time 1.5 hours. From optical properties (transmittance) measurements using UV-vis, it was found that the optimum results was achieved at temperature 450 o C. At this conditions, wave length (500 - 800) nm, the transmittance was (50 - 82) %, at pressure 6 x 10 -2 torr the transmittance was (50 - 80) % and at deposition time 1.5 hours was (49 - 81) %. For ZnO thin film, was at wave length (500 - 800) nm, the transmittance was (78 - 80) %. From micro structure analysis using SEM, it was found that the thickness layer of ZnO was 1.5 μm and 1.3 μm for ZnO: Al. While from surface morphology it was found that for ZnO thin layer the grains was distributed homogeneously, while for ZnO: Al the grains was distributed unhomogeneously. (author)

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

Science.gov (United States)

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

2016-06-01

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

Modification of Patterned Nanoporous Gold Thin Film Electrodes via Electro-annealing and Electrochemical Etching

Science.gov (United States)

Dorofeeva, Tatiana

Nanostructured materials have had a major impact on various fields, including medicine, catalysis, and energy storage, for the major part due to unique phenomena that arise at nanoscale. For this reason, there is a sustained need for new nanostructured materials, techniques to pattern them, and methods to precisely control their nanostructure. To that end, the primary focus of this dissertation is to demonstrate novel techniques to fabricate and tailor the morphology of a class of nanoporous metals, obtained by a process known as dealloying. In this process, while the less noble constituent of an alloy is chemically dissolved, surface-diffusion of the more noble constituent leads to self-assembly of a bicontinuous ligament network with characteristic porosity of ˜70% and ligament diameter of 10s of nanometers. As a model material produced by dealloying, this work employ nanoporous gold (np-Au), which has attracted significant attention of desirable features, such as high effective surface area, electrical conductivity, well-defined thiol-based surface modification strategies, microfabrication-compatibility, and biocompatibility. The most commonly method used to modify the morphology of np-Au is thermal treatment, where the enhanced diffusivity of the surface atoms leads to ligament (and consequently pore) coarsening. This method, however, is not conducive to modifying the morphology of thin films at specific locations on the film, which is necessary for creating devices that may need to contain different morphologies on a single device. In addition, coarsening attained by thermal treatment also leads to an undesirable reduction in effective surface area. In response to these challenges, this work demonstrates two different techniques that enables in situ modification of np-Au thin film electrodes obtained by sputter-deposition of a precursors silver-rich gold-silver alloy. The first method, referred to as electro-annealing, is achieved by injecting electrical

Electrochemical deposition of molybdenum sulfide thin films on conductive plastic substrates as platinum-free flexible counter electrodes for dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Cheng, Chao-Kuang; Hsieh, Chien-Kuo, E-mail: jack_hsieh@mail.mcut.edu.tw

2015-06-01

In this study, pulsed electrochemical deposition (pulsed ECD) was used to deposit molybdenum sulfide (MoS{sub x}) thin films on indium tin oxide/polyethylene naphthalate (ITO/PEN) substrates as flexible counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). The surface morphologies and elemental distributions of the prepared MoS{sub x} thin films were examined using field-emission scanning electron microscope (FE-SEM) equipped with energy-dispersive X-ray spectroscopy. The chemical states and crystallinities of the prepared MoS{sub x} thin films were examined by X-ray photoelectron spectroscopy and X-ray diffraction, respectively. The optical transmission (T (%)) properties of the prepared MoS{sub x} samples were determined by ultraviolet–visible spectrophotometry. Cyclic voltammetry (CV) and Tafel-polarization measurements were performed to analyze the electrochemical properties and catalytic activities of the thin films for redox reactions. The FE-SEM results showed that the MoS{sub x} thin films were deposited uniformly on the ITO/PEN flexible substrates via the pulsed ECD method. The CV and Tafel-polarization curve measurements demonstrated that the deposited MoS{sub x} thin films exhibited excellent performances for the reduction of triiodide ions. The photoelectric conversion efficiency (PCE) of the DSSC produced with the pulsed ECD MoS{sub x} thin-film CE was examined by a solar simulator. In combination with a dye-sensitized TiO{sub 2} working electrode and an iodine-based electrolyte, the DSSC with the MoS{sub x} flexible CE showed a PCE of 4.39% under an illumination of AM 1.5 (100 mW cm{sup −2}). Thus, we report that the MoS{sub x} thin films are active catalysts for triiodide reduction. The MoS{sub x} thin films are prepared at room temperature and atmospheric pressure and in a simple and rapid manner. This is an important practical contribution to the production of flexible low-cost thin-film CEs based on plastic substrates. The MoS{sub x

Prediction of transmittance spectra for transparent composite electrodes with ultra-thin metal layers

Energy Technology Data Exchange (ETDEWEB)

Zhao, Zhao; Alford, T. L., E-mail: TA@asu.edu [School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, Arizona 85287 (United States); Khorasani, Arash Elhami [ON Semiconductor Corp., Phoenix, Arizona 85005 (United States); Theodore, N. D. [CHD-Fab, Freescale Semiconductor Inc., Tempe, Arizona 85224 (United States); Dhar, A. [Intel Corp., 2501 NW 229th Ave, Hillsboro, Oregon 97124 (United States)

2015-11-28

Recent interest in indium-free transparent composite-electrodes (TCEs) has motivated theoretical and experimental efforts to better understand and enhance their electrical and optical properties. Various tools have been developed to calculate the optical transmittance of multilayer thin-film structures based on the transfer-matrix method. However, the factors that affect the accuracy of these calculations have not been investigated very much. In this study, two sets of TCEs, TiO{sub 2}/Au/TiO{sub 2} and TiO{sub 2}/Ag/TiO{sub 2}, were fabricated to study the factors that affect the accuracy of transmittance predictions. We found that the predicted transmittance can deviate significantly from measured transmittance for TCEs that have ultra-thin plasmonic metal layers. The ultrathin metal layer in the TCE is typically discontinuous. When light interacts with the metallic islands in this discontinuous layer, localized surface plasmons are generated. This causes extra light absorption, which then leads to the actual transmittance being lower than the predicted transmittance.

Filter and window behavior for the Advanced Photon Source beamline front end

International Nuclear Information System (INIS)

Wang, Zhibi; Kuzay, T.M.; Shu, Deming; Dejus, R.

1993-01-01

Synchrotron x-ray windows are vacuum separators and are usually made of thin beryllium metal. Filters are provided upstream to absorb the soft x-rays so that the window is protected from overheating, which could result in failure. The filters are made of thin carbon products or sometimes beryllium, the same material as the window. Because the window is a vacuum separator, understanding its potential structural failure under thermal load is of utmost importance. The planned insertion devices and bending magnets for the Advanced Photon Source (APS) generate very high heat fluxes. To guarantee the integrity of the filter and window, extensive investigations have been carried out on both components. The material selection for filters and windows from among the possible candidate materials was investigated first. Then a series of thermal and structural analyses were performed on the filter and window. Results are presented from power absorption, analytical results from thermal, and structural analyses as well as application of the failure criteria suggested by Wang and Kuzay to the filters and windows

Transparent and flexible electrodes and supercapacitors using polyaniline/single-walled carbon nanotube composite thin films

Science.gov (United States)

Ge, Jun; Cheng, Guanghui; Chen, Liwei

2011-08-01

Large-scale transparent and flexible electronic devices have been pursued for potential applications such as those in touch sensors and display technologies. These applications require that the power source of these devices must also comply with transparent and flexible features. Here we present transparent and flexible supercapacitors assembled from polyaniline (PANI)/single-walled carbon nanotube (SWNT) composite thin film electrodes. The ultrathin, optically homogeneous and transparent, electrically conducting films of the PANI/SWNT composite show a large specific capacitance due to combined double-layer capacitance and pseudo-capacitance mechanisms. A supercapacitor assembled using electrodes with a SWNT density of 10.0 µg cm-2 and 59 wt% PANI gives a specific capacitance of 55.0 F g-1 at a current density of 2.6 A g-1, showing its possibility for transparent and flexible energy storage.

Bilayered Oxide thin films for transparent electrode application

Science.gov (United States)

Dutta, Titas; Narayan, Jagdish

2008-10-01

Ga doped ZnO films with electrical and optical properties comparable to indium tin oxide (ITO) is a promising candidate for transparent conducting oxides (TCOs) because of its superior stability in hydrogen environment, benign nature and relatively inexpensive supply. However, ZnO based TCO films suffer from low work function, which is a critical parameter for device applications. We report here the growth of a novel bilayered structure consisting of very thin (few monolayers) ITO, MoOx layer on Zn0.95Ga0.05O film for transparent electrode applications by using pulsed laser deposition technique at different temperatures and oxygen partial pressure. The characteristics of the ITO film and the heterostructure have been investigated in detail using XRD, TEM, XPS, and electrical and optical property measurements. It is envisaged that the overall transmittance and the resistivity are dictated by the thicker layer of ZnGa0.05O beneath the ITO layer. Hence, this study is aimed to improve the surface characteristics without affecting the overall transmittance and sheet resistance. This will enhance the transport of the carriers across the heterojunction in the device, thus, resulting in the increase in device efficiency.

Exfoliated thin Bi{sub 2}MoO{sub 6} nanosheets supported on WO{sub 3} electrode for enhanced photoelectrochemical water splitting

Energy Technology Data Exchange (ETDEWEB)

Ma, Ying; Jia, Yulong; Wang, Lina [State Key Laboratory for Oxo Synthesis & Selective Oxidation, and National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, CAS, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Yang, Min [State Key Laboratory for Oxo Synthesis & Selective Oxidation, and National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, CAS, Lanzhou 730000 (China); Bi, Yingpu, E-mail: yingpubi@licp.cas.cn [State Key Laboratory for Oxo Synthesis & Selective Oxidation, and National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, CAS, Lanzhou 730000 (China); Qi, Yanxing, E-mail: qiyx@licp.cas.cn [State Key Laboratory for Oxo Synthesis & Selective Oxidation, and National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, CAS, Lanzhou 730000 (China)

2016-12-30

Highlights: • Thin Bi{sub 2}MoO{sub 6} nanosheets were prepared by microwave assisted ultrasonic separation. • The thin Bi{sub 2}MoO{sub 6} nanosheets could be more favorable to charge shift and separation. • The WO{sub 3}/thin Bi{sub 2}MoO{sub 6} exhibits superior photoelectric activity than WO{sub 3}/Bi{sub 2}MoO{sub 6} film. • The efficient photoelectric property results from facilitated charge separation. - Abstract: Thin Bi{sub 2}MoO{sub 6} nanosheets are obtained by a microwave-assisted ultrasonic separation process. After exfoliation, the thinner and uniform nanosheets with a thickness of about 10 nm were obtained. The exfoliated nanosheets would provide many amazing functionalities such as high electron mobility and quantum Hall effects. Therefore, thin Bi{sub 2}MoO{sub 6} supported on WO{sub 3} electrode (WO{sub 3}/thin Bi{sub 2}MoO{sub 6}) exhibits facilitated charge separation than pure WO{sub 3} film and the un-exfoliated Bi{sub 2}MoO{sub 6} nanosheets supported on WO{sub 3} electrode (WO{sub 3}/Bi{sub 2}MoO{sub 6}). As a result, WO{sub 3}/thin Bi{sub 2}MoO{sub 6} shows remarkably stable photocurrent density of 2.2 mA/cm{sup 2} at 0.8 V{sub SCE} in 0.1 M Na{sub 2}SO{sub 4} which is higher than that of that of WO{sub 3} (1.1 mA/cm{sup 2}) and WO{sub 3}/Bi{sub 2}MoO{sub 6} (1.5 mA/cm{sup 2}).

S Sensors: Fumarate-Based fcu-MOF Thin Film Grown on a Capacitive Interdigitated Electrode

KAUST Repository

Yassine, Omar

2016-10-31

Herein we report the fabrication of an advanced sensor for the detection of hydrogen sulfide (H2S) at room temperature, using thin films of rare-earth metal (RE)-based metal-organic framework (MOF) with underlying fcu topology. This unique MOF-based sensor is made via the insitu growth of fumarate-based fcu-MOF (fum-fcu-MOF) thin film on a capacitive interdigitated electrode. The sensor showed a remarkable detection sensitivity for H2S at concentrations down to 100ppb, with the lower detection limit around 5ppb. The fum-fcu-MOF sensor exhibits a highly desirable detection selectivity towards H2S vs. CH4, NO2, H2, and C7H8 as well as an outstanding H2S sensing stability as compared to other reported MOFs. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design of large aperture, low mass vacuum windows

International Nuclear Information System (INIS)

Leonhardt, W.J.; Mapes, M.

1993-01-01

Large vacuum vessels are employed downstream of fixed targets in High Energy Physics experiments to provide a long path for particles to traverse without interacting with air molecules. These vessels generally have a large aperture opening known as a vacuum window which employs a thin membrane to preserve the vacuum environment yet allows the particles to pass through with a minimal effect on them. Several large windows have been built using a composite of Kevlar/Mylar including circular windows to a diameter of 96.5 cm and rectangular windows up to 193 cm x 86 cm. This paper describes the design, fabrication, testing and operating experience with these windows and relates the actual performance to theoretical predictions

Design of large aperture, low mass vacuum windows

International Nuclear Information System (INIS)

Mapes, M.; Leonhardt, W.J.

1993-01-01

Large aperture, low mass, thin vacuum windows are required to minimize beam loss in the beam lines of particle accelerators as the products of nuclear collisions move from upstream targets to downstream detectors. This article describes the design, fabrication, testing, and operating experience of a large rectangular vacuum window, 122 cmx61 cm, and two circular windows of 91.4 and 96.5 cm diam. These window designs utilize a composite Kevlar 29 fabric and Mylar laminate as a window material with a typical combined thickness of 0.35 mm. Data for several material thicknesses are also presented. The windows are usually designed to withstand a pressure differential of two to three atmospheres to achieve the required factor of safety. These windows are typically used in the medium vacuum range of 10 -4 Torr. The equations used to predict the behavior of the window material will also be discussed

Multicenter surgical experience evaluation on the Mid-Scala electrode and insertion tools.

Science.gov (United States)

Gazibegovic, Dzemal; Bero, Eva M

2017-02-01

The HiFocus Mid-Scala electrode is intended to improve hearing for individuals with severe-to-profound hearing loss by providing extended electrical coverage of the cochlea while minimizing trauma related to insertion. The electrode is appropriate for use with a wide range of surgical techniques, including either a cochleostomy or round window insertion, and the use of either a free-hand or tool-assisted approach. The objective of this survey was to evaluate how the HiFocus Mid-Scala electrode and insertion tools was used across a population of cochlear implant recipients of differing ages, audiologic profiles, and anatomical characteristics. The intent was to understand the type and frequency of surgical techniques applicable with the electrode, and to provide guidelines for clinical practice. Two questionnaires were completed by surgeons at implant centres located in the United States, Europe, and Asia. Before any surgeries were conducted, surgeons completed a questionnaire that assessed their overall cochlear implant surgical practice and preferences. Following each HiFocus Mid-Scala electrode insertion, surgeons completed a questionnaire that summarized their experience during that surgical procedure. Questionnaires were completed by 32 surgeons from 16 centres for a total of 143 surgeries (112 adults, 31 children). Most surgeons (62 %) preferred to insert the electrode via the round window or an extended round window compared with a cochleostomy (16 %), whereas the remaining 22 % indicated that they made an insertion choice based on presenting anatomy. Sixty-nine percent preferred a free-hand approach over using insertion tools. In 32 procedures, surgeons elected to deviate from an intended round window insertion to either an extended round window or cochleostomy approach.

Preparation of Li4Ti5O12 electrode thin films by a mist CVD process with aqueous precursor solution

Directory of Open Access Journals (Sweden)

Kiyoharu Tadanaga

2015-03-01

Full Text Available Spinel Li4Ti5O12 thin films were prepared by a mist CVD process, using an aqueous solution of lithium nitrate and a water-soluble titanium lactate complex as the source of Li and Ti, respectively. In this process, mist particles ultrasonically atomized from a source aqueous solution were transferred by nitrogen gas to a heating substrate to prepare thin films. Scanning electron microscopy observation showed that thin films obtained by this process were dense and smooth, and thin films with a thickness of about 500 nm were obtained. In the X-ray diffraction analysis, formation of Li4Ti5O12 spinel phase was confirmed in the obtained thin film sintered at 700 °C for 4 h. The cell with the thin films as an electrode exhibited a capacity of about 110 mAh g−1, and the cell showed good cycling performance during 10 cycles.

The impact of round window vs cochleostomy surgical approaches on interscalar excursions in the cochlea: Preliminary results from a flat-panel computed tomography study

Directory of Open Access Journals (Sweden)

Nicole T. Jiam

2016-09-01

Full Text Available Objective: To evaluate incidence of interscalar excursions between round window (RW and cochleostomy approaches for cochlear implant (CI insertion. Methods: This was a retrospective case-comparison. Flat-panel CT (FPCT scans for 8 CI users with Med-El standard length electrode arrays were collected. Surgical technique was identified by a combination of operative notes and FPCT imaging. Four cochleae underwent round window insertion and 4 cochleae underwent cochleostomy approaches anterior and inferior to the round window. Results: In our pilot study, cochleostomy approaches were associated with a higher likelihood of interscalar excursion. Within the cochleostomy group, we found 29% of electrode contacts (14 of 48 electrodes to be outside the scala tympani. On the other hand, 8.5% of the electrode contacts (4 of 47 electrodes in the round window insertion group were extra-scalar to the scala tympani. These displacements occurred at a mean angle of occurrence of 364° ± 133°, near the apex of the cochlea. Round window electrode displacements tend to localize at angle of occurrences of 400° or greater. Cochleostomy electrodes occurred at an angle of occurrence of 19°–490°. Conclusions: Currently, the optimal surgical approach for standard CI electrode insertion is highly debated, to a certain extent due to a lack of post-operative assessment of intracochlear electrode contact. Based on our preliminary findings, cochleostomy approach is associated with an increased likelihood of interscalar excursions, and these findings should be further evaluated with future prospective studies. Keywords: Cochlear implantation, Round window insertion, Cochleostomy, Interscalar excursion, Electrode position, Flat-panel computed tomography, Surgical approach

Electrode patterning of ITO thin films by high repetition rate fiber laser

International Nuclear Information System (INIS)

Lin, H.K.; Hsu, W.C.

2014-01-01

Indium tin oxide (ITO) thin films are deposited on glass substrates using a radio frequency magnetron sputtering system. As-deposited ITO thin film was 100 nm in thickness and a transmittance of ITO film on glass substrate was 79% at 550 nm. Conductive electrodes are then patterned on the ITO films using a high repetition rate fiber laser system followed by a wet chemical etching process. The electrical, optical and structural properties of the patterned samples are evaluated by means of a four-point probe technique, spectrophotometer, X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results show that the samples annealed with a pulse repetition rate of 150 kHz or 400 kHz have a low sheet resistivity of 21 Ω/□ and a high optical transmittance of 90%. In addition, it is shown that a higher pulse repetition rate reduces both the residual stress and the surface roughness of the patterned specimens. Therefore, the present results suggest that a pulse repetition rate of 400 kHz represents the optimal processing condition for the patterning of crack-free ITO-coated glass substrates with good electrical and optical properties.

Electrode patterning of ITO thin films by high repetition rate fiber laser

Energy Technology Data Exchange (ETDEWEB)

Lin, H.K., E-mail: HKLin@mail.npust.edu.tw; Hsu, W.C.

2014-07-01

Indium tin oxide (ITO) thin films are deposited on glass substrates using a radio frequency magnetron sputtering system. As-deposited ITO thin film was 100 nm in thickness and a transmittance of ITO film on glass substrate was 79% at 550 nm. Conductive electrodes are then patterned on the ITO films using a high repetition rate fiber laser system followed by a wet chemical etching process. The electrical, optical and structural properties of the patterned samples are evaluated by means of a four-point probe technique, spectrophotometer, X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results show that the samples annealed with a pulse repetition rate of 150 kHz or 400 kHz have a low sheet resistivity of 21 Ω/□ and a high optical transmittance of 90%. In addition, it is shown that a higher pulse repetition rate reduces both the residual stress and the surface roughness of the patterned specimens. Therefore, the present results suggest that a pulse repetition rate of 400 kHz represents the optimal processing condition for the patterning of crack-free ITO-coated glass substrates with good electrical and optical properties.

Investigation of cooling methods and thickness considerations in the filter/window assembly for synchrotron radiation beamlines

International Nuclear Information System (INIS)

Wang, Z.; Kuzay, T.M.; Hahn, U.

1993-01-01

Synchrotron x-ray windows are vacuum separators and are usually made of thin beryllium metal. Filters are provided upstream to absorb the soft x-rays so that the window can be protected from overheating, which could result in failure. The filters are made of thin carbon products or sometimes beryllium, the same material as the window. When the synchrotron x-rays pass through a filter or window, part of the photons will be absorbed by the filter or window. The absorbed photons cause heat to build up within the filter or window. Successful filter and window designs should effectively dissipate the heat generated by the absorbed photons and guarantee the safety of the filter and window. The cooling methods typically used in a filter or window design are conduction and radiation cooling or a combination of the two. The different cooling methods were first examined with regard to efficiency and effectiveness in different temperature ranges. Analysis results are presented for temperature distribution and corresponding thermal stresses in the filter and window. Another important issue to be resolved in designing a filter/window assembly is how to select the thickness of the filters and windows. This paper focuses on the criteria for choosing the thickness of a filter: whether it is better to use a few thick filters or a series of thin ones; how to determine the minimum/maximum thickness; and the difference in thickness considerations for the window versus the filter. Numerical investigations are presented

Investigation of nanoporous platinum thin films fabricated by reactive sputtering: Application as micro-SOFC electrode

Science.gov (United States)

Jung, WooChul; Kim, Jae Jin; Tuller, Harry L.

2015-02-01

Highly porous Pt thin films, with nano-scale porosity, were fabricated by reactive sputtering. The strategy involved deposition of thin film PtOx at room temperature, followed by the subsequent decomposition of the oxide by rapid heat treatment. The resulting films exhibited percolating Pt networks infiltrated with interconnected nanosized pores, critical for superior solid oxide fuel cell cathode performance. This approach is particularly attractive for micro-fabricated solid oxide fuel cells, since it enables fabrication of the entire cell stack (anode/electrolyte/cathode) within the sputtering chamber, without breaking vacuum. In this work, the morphological, crystallographic and chemical properties of the porous electrode were systematically varied by control of deposition conditions. Oxygen reduction reaction kinetics were investigated by means of electrochemical impedance spectroscopy, demonstrating the critical role of nano-pores in achieving satisfactory micro-SOFC cathode performance.

Materials science and integration bases for fabrication of (BaxSr1-x)TiO3 thin film capacitors with layered Cu-based electrodes

Science.gov (United States)

Fan, W.; Kabius, B.; Hiller, J. M.; Saha, S.; Carlisle, J. A.; Auciello, O.; Chang, R. P. H.; Ramesh, R.

2003-11-01

The synthesis and fundamental material properties of layered TiAl/Cu/Ta electrodes were investigated to achieve the integration of Cu electrodes with high-dielectric constant (κ) oxide thin films for application to the fabrication of high-frequency devices. The Ta layer is an excellent diffusion barrier to inhibit deleterious Cu diffusion into the Si substrate, while the TiAl layer provides an excellent barrier against oxygen diffusion into the Cu layer to inhibit Cu oxidation during the growth of the high-κ layer in an oxygen atmosphere. Polycrystalline (BaxSr1-x)TiO3 (BST) thin films were grown on the Cu-based bottom electrode by rf magnetron sputtering at temperatures in the range 400-600 °C in oxygen, to investigate the performance of BST/Cu-based capacitors. Characterization of the Cu-based layered structure using surface analytical methods showed that two amorphous oxide layers were formed on both sides of the TiAl barrier, such that the oxide layer on the free surface of the TiAl layer correlates with TiAlOx, while the oxide layer at the TiAl/Cu interface is an Al2O3-rich layer. This double amorphous barrier layer structure effectively prevents oxygen penetration towards the underlying Cu and Ta layers. The TiAlOx interfacial layer, which has a relatively low dielectric constant compared with BST, reduced the total capacitance of the BST thin film capacitors. In addition, the layered electrode-oxide interface roughening observed during the growth of BST films at high temperature, due to copper grain growth, resulted in large dielectric loss on the fabricated BST capacitors. These problems were solved by growing the BST layer at 450 °C followed by a rapid thermal annealing at 700 °C. This process significantly reduced the thickness of the TiAlOx layer and interface roughness resulting in BST capacitors exhibiting properties suitable for the fabrication of high-performance high-frequency devices. In summary, relatively high dielectric constant (280), low

Materials science and integration bases for fabrication of (BaxSr1-x)TiO3 thin film capacitors with layered Cu-based electrodes

International Nuclear Information System (INIS)

Fan, W.; Kabius, B.; Hiller, J.M.; Saha, S.; Carlisle, J.A.; Auciello, O.; Chang, R.P.H.; Ramesh, R.

2003-01-01

The synthesis and fundamental material properties of layered TiAl/Cu/Ta electrodes were investigated to achieve the integration of Cu electrodes with high-dielectric constant (κ) oxide thin films for application to the fabrication of high-frequency devices. The Ta layer is an excellent diffusion barrier to inhibit deleterious Cu diffusion into the Si substrate, while the TiAl layer provides an excellent barrier against oxygen diffusion into the Cu layer to inhibit Cu oxidation during the growth of the high-κ layer in an oxygen atmosphere. Polycrystalline (Ba x Sr 1-x )TiO 3 (BST) thin films were grown on the Cu-based bottom electrode by rf magnetron sputtering at temperatures in the range 400-600 deg. C in oxygen, to investigate the performance of BST/Cu-based capacitors. Characterization of the Cu-based layered structure using surface analytical methods showed that two amorphous oxide layers were formed on both sides of the TiAl barrier, such that the oxide layer on the free surface of the TiAl layer correlates with TiAlO x , while the oxide layer at the TiAl/Cu interface is an Al 2 O 3 -rich layer. This double amorphous barrier layer structure effectively prevents oxygen penetration towards the underlying Cu and Ta layers. The TiAlO x interfacial layer, which has a relatively low dielectric constant compared with BST, reduced the total capacitance of the BST thin film capacitors. In addition, the layered electrode-oxide interface roughening observed during the growth of BST films at high temperature, due to copper grain growth, resulted in large dielectric loss on the fabricated BST capacitors. These problems were solved by growing the BST layer at 450 deg. C followed by a rapid thermal annealing at 700 deg. C. This process significantly reduced the thickness of the TiAlO x layer and interface roughness resulting in BST capacitors exhibiting properties suitable for the fabrication of high-performance high-frequency devices. In summary, relatively high

Spray pyrolysed Ru:TiO2 thin film electrodes prepared for electrochemical supercapacitor

Science.gov (United States)

Fugare, B. Y.; Thakur, A. V.; Kore, R. M.; Lokhande, B. J.

2018-04-01

Ru doped TiO2 thin films are prepared by using 0.06 M aqueous solution of potassium titanium oxalate (pto), and 0.005 M aqueous solution of ruthenium tri chloride (RuCl3) precursors. The deposition was carried on stainless steel (SS) by using well known ultrasonic spray pyrolysis technique (USPT) at 723° K by maintaining the spray rate 12 cc/min and compressed air flow rate 10 Lmin-1. Prepared Ru:TiO2 thin films were characterized by structurally, morphologically and electrochemically. Deposited RuO2 shows amorphous structure and TiO2 shows tetragonal crystal structure with rutile as prominent phase at very low decomposition temperature. SEM micrographs of RuO2 exhibits porous, interconnected, spherical grains type morphology and TiO2 shows porous, nanorods and nanoplates like morphology and also Ru doped TiO2 shows porous, spherical, granular and nanorods type morphology. The electrochemical cyclic voltammetery shows mixed capacitive behavior. The achieved highest value of specific capacitance 2692 F/g was Ru doped TiO2 electrode in 0.5 M H2SO4.

Spectroelectrochemical properties of ultra-thin indium tin oxide films under electric potential modulation

Energy Technology Data Exchange (ETDEWEB)

Han, Xue, E-mail: x0han004@louisville.edu; Mendes, Sergio B., E-mail: sbmend01@louisville.edu

2016-03-31

In this work, the spectroscopic properties of ultra-thin ITO films are characterized under an applied electric potential modulation. To detect minute spectroscopic features, the ultra-thin ITO film was coated over an extremely sensitive single-mode integrated optical waveguide, which provided a long pathlength with more than adequate sensitivity for optical interrogation of the ultra-thin film. Experimental configurations with broadband light and several laser lines at different modulation schemes of an applied electric potential were utilized to elucidate the nature of intrinsic changes. The imaginary component of the refractive index (absorption coefficient) of the ultra-thin ITO film is unequivocally shown to have a dependence on the applied potential and the profile of this dependence changes substantially even for wavelengths inside a small spectral window (500–600 nm). The characterization technique and the data reported here can be crucial to several applications of the ITO material as a transparent conductive electrode, as for example in spectroelectrochemical investigations of surface-confined redox species. - Highlights: • Optical waveguides are applied for spectroscopic investigations of ultra-thin films. • Ultra-thin ITO films in aqueous environment are studied under potential modulation. • Unique spectroscopic features of ultra-thin ITO films are unambiguously observed.

Compact UHV valve with field replaceable windows

International Nuclear Information System (INIS)

Johnson, E.D.; Freeman, J.; Powell, F.

1991-01-01

There are many applications in synchrotron radiation research where window valves can be usefully employed. Examples include gas cells for monochromator calibration, filters for high order light rejection, and as vacuum isolation elements between machine and experimental vacua. Often these devices are fairly expensive, and have only fixed (ie non-removable) windows. The development of a new type of seal technology by VAT for their series 01 valves provides a gate surface which is free from obstructions due to internal mechanical elements. This feature allows a threaded recess to be machined into the gate to receive a removable window frame which can carry standard size Luxel thin film windows. The combination of these features results in a DN 40 (2.75in. conflat flange) valve which provides a clear aperture of 21mm diameter for the window material. 8 refs., 2 figs

All conducting polymer electrodes for asymmetric solid-state supercapacitors

KAUST Repository

Kurra, Narendra; Wang, Ruiqi; Alshareef, Husam N.

2015-01-01

electrode material. In addition, the high stability of PEDOT in its oxidised state makes it capable to exhibit electrochemical activity in a wide potential window. This can qualify PEDOT to be used as a negative electrode in fabricating asymmetric solid

A computation study on the interplay between surface morphology and electrochemical performance of patterned thin film electrodes for Li-ion batteries

Science.gov (United States)

Gur, Sourav; Frantziskonis, George N.; Aifantis, Katerina E.

2017-08-01

Recent experiments illustrate that the morphology of the electrode surface impacts the voltage - capacity curves and long term cycling performance of Li-ion batteries. The present study systematically explores the role of the electrode surface morphology and uncertainties in the reactions that occur during electrochemical cycling, by performing kinetic Monte Carlo (kMC) simulations using the lattice Boltzmann method (LBM). This allows encoding of the inherent stochasticity at discrete microscale reaction events over the deterministic mean field reaction dynamics that occur in Li-ion cells. The electrodes are taken to be dense thin films whose surfaces are patterned with conical, trapezoidal, dome-shaped, or pillar-shaped structures. It is shown that the inherent perturbations in the reactions together with the characteristics of the electrode surface configuration can significantly improve battery performance, mainly because patterned surfaces, as opposed to flat surfaces, result in a smaller voltage drop. The most efficient pattern was the trapezoidal, which is consistent with experimental evidence on Si patterned electrodes.

Digital simulation of anodic stripping voltammetry from thin film electrodes

International Nuclear Information System (INIS)

Magallanes, J.F.

1984-01-01

The anodic stripping voltammetry (ASV) is routinely applied to control of Cu(II) in heavy water in the primary cooling loop of the Nuclear Power Reactor. The anodic stripping voltammetry (ASV) is a very well-known technique in electroanalytical chemistry. However, due to the complexity of the phenomena, it is practised with the fundamentals of empiric considerations. A geometric model for the anodic stripping voltammetry (ASV) from thin film electrodes which can be calculated by explicit digital simulation method is proposed as a possibility of solving the electrochemically reversible, cuasi-reversible and irreversible reactions under linear potential scan and multiple potential scans. (Until now the analytical mathematical method was applied to reversible reactions). All the results are compared with analytical solutions and experimental results and it permits to conclude that the anodic stripping voltammetry (ASV) can be studied with the simplicity and potentialities of explicit digital simulation methods. (M.E.L.) [es

Ion transport and phase transformation in thin film intercalation electrodes

Energy Technology Data Exchange (ETDEWEB)

Wunde, Fabian; Nowak, Susann; Muerter, Juliane; Hadjixenophontos, Efi; Berkemeier, Frank; Schmitz, Guido [Stuttgart Univ. (Germany). Inst. fuer Materialwissenschaft

2017-11-15

Thin film battery electrodes of the olivine structure LiFePO{sub 4} and the spinel phase LiMn{sub 2}O{sub 4} are deposited through ion-beam sputtering. The intercalation kinetics is studied by cyclo-voltammetry using variation of the cycling rate over 4 to 5 orders of magnitude. The well-defined layer geometry allows a detailed quantitative analysis. It is shown that LiFePO{sub 4} clearly undergoes phase separation during intercalation, although the material is nano-confined and very high charging rates are applied. We present a modified Randles-Sevcik evaluation adapted to phase-separating systems. Both the charging current and the overpotential depend on the film thickness in a systematic way. The analysis yields evidence that the grain boundaries are important short circuit paths for fast transport. They increase the electrochemical active area with increasing layer thickness. Evidence is obtained that the grain boundaries in LiFePO{sub 4} have the character of an ion-conductor of vanishing electronic conductivity.

Transparent and flexible supercapacitors with single walled carbon nanotube thin film electrodes.

Science.gov (United States)

Yuksel, Recep; Sarioba, Zeynep; Cirpan, Ali; Hiralal, Pritesh; Unalan, Husnu Emrah

2014-09-10

We describe a simple process for the fabrication of transparent and flexible, solid-state supercapacitors. Symmetric electrodes made up of binder-free single walled carbon nanotube (SWCNT) thin films were deposited onto polydimethylsiloxane substrates by vacuum filtration followed by a stamping method, and solid-state supercapacitor devices were assembled using a gel electrolyte. An optical transmittance of 82% was found for 0.02 mg of SWCNTs, and a specific capacitance of 22.2 F/g was obtained. The power density can reach to 41.5 kW · kg(-1) and shows good capacity retention (94%) upon cycling over 500 times. Fabricated supercapacitors will be relevant for the realization of transparent and flexible devices with energy storage capabilities, displays and touch screens in particular.

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.

Discharge amplified photo-emission from ultra-thin films applied to tuning work function of transparent electrodes in organic opto-electronic devices

International Nuclear Information System (INIS)

Gentle, A.R.; Smith, G.B.; Watkins, S.E.

2013-01-01

A novel photoemission technique utilising localised discharge amplification of photo-yield is reported. It enables fast, accurate measurement of work function and ionisation potential for ultra-thin buffer layers vacuum deposited onto single and multilayer transparent conducting electrodes for organic solar cells and OLED's. Work function in most traditional transparent electrodes has to be raised to maximise charge transfer while high transmittance and high conductance must be retained. Results are presented for a range of metal oxide buffers, which achieve this goal. This compact photo-yield spectroscopy tool with its fast turn-around has been a valuable development aid since ionisation potential can vary significantly as deposition conditions change slightly, and as ultra-thin films grow. It has also been useful in tracking the impact of different post deposition cleaning treatments along with some storage and transport protocols, which can adversely reduce ionisation potential and hence subsequent device performance.

Direct Inkjet Printing of Silver Source/Drain Electrodes on an Amorphous InGaZnO Layer for Thin-Film Transistors.

Science.gov (United States)

Ning, Honglong; Chen, Jianqiu; Fang, Zhiqiang; Tao, Ruiqiang; Cai, Wei; Yao, Rihui; Hu, Shiben; Zhu, Zhennan; Zhou, Yicong; Yang, Caigui; Peng, Junbiao

2017-01-10

Printing technologies for thin-film transistors (TFTs) have recently attracted much interest owing to their eco-friendliness, direct patterning, low cost, and roll-to-roll manufacturing processes. Lower production costs could result if electrodes fabricated by vacuum processes could be replaced by inkjet printing. However, poor interfacial contacts and/or serious diffusion between the active layer and the silver electrodes are still problematic for achieving amorphous indium-gallium-zinc-oxide (a-IGZO) TFTs with good electrical performance. In this paper, silver (Ag) source/drain electrodes were directly inkjet-printed on an amorphous a-IGZO layer to fabricate TFTs that exhibited a mobility of 0.29 cm²·V -1 ·s -1 and an on/off current ratio of over 10⁵. To the best of our knowledge, this is a major improvement for bottom-gate top-contact a-IGZO TFTs with directly printed silver electrodes on a substrate with no pretreatment. This study presents a promising alternative method of fabricating electrodes of a-IGZO TFTs with desirable device performance.

Direct Inkjet Printing of Silver Source/Drain Electrodes on an Amorphous InGaZnO Layer for Thin-Film Transistors

Directory of Open Access Journals (Sweden)

Honglong Ning

2017-01-01

Full Text Available Printing technologies for thin-film transistors (TFTs have recently attracted much interest owing to their eco-friendliness, direct patterning, low cost, and roll-to-roll manufacturing processes. Lower production costs could result if electrodes fabricated by vacuum processes could be replaced by inkjet printing. However, poor interfacial contacts and/or serious diffusion between the active layer and the silver electrodes are still problematic for achieving amorphous indium–gallium–zinc–oxide (a-IGZO TFTs with good electrical performance. In this paper, silver (Ag source/drain electrodes were directly inkjet-printed on an amorphous a-IGZO layer to fabricate TFTs that exhibited a mobility of 0.29 cm2·V−1·s−1 and an on/off current ratio of over 105. To the best of our knowledge, this is a major improvement for bottom-gate top-contact a-IGZO TFTs with directly printed silver electrodes on a substrate with no pretreatment. This study presents a promising alternative method of fabricating electrodes of a-IGZO TFTs with desirable device performance.

Design of Rose Bengal/FTO optical thin film system as a novel nonlinear media for infrared blocking windows

Directory of Open Access Journals (Sweden)

S.M. El-Bashir

Full Text Available Rose Bengal (RB is a new organic semiconductor with the highly stable layer, was deposited on highly cleaned conductive glass substrate known as (FTO glass with different thickness in the range from 80 to 292 nm. XRD showed an entirely amorphous structure of the studied film thicknesses. The observed peaks are the indexed peaks for FTO layer. Spectrophotometric data as transmittance, reflectance, and absorbance were used for the analysis the optical constant of RB/FTO optical thin film system. Refractive index was calculated using Fresnel’s equation with the aid of reflectance and absorption index. The dielectric constant, dielectric loss and dissipation factor were discussed and analyzed according to the applied optical theories. Nonlinear parameters such as third order nonlinear optical susceptibility and the nonlinear refractive index were calculated based on the linear refractive index of the applications of this material in nonlinear media. The results showed that Rose Bengal is a proving material for wide scale optoelectronic applications such as infrared blocking windows. Keywords: Rose Bengal, Dielectric parameters, Linear/nonlinear optics, Dye/FTO, IR blocking windows

Area-Selective ZnO Thin Film Deposition on Variable Microgap Electrodes and Their Impact on UV Sensing

Directory of Open Access Journals (Sweden)

Q. Humayun

2013-01-01

Full Text Available ZnO thin films were deposited on patterned gold electrodes using the sol-gel spin coating technique. Conventional photolithography process was used to obtain the variable microgaps of 30 and 43 μm in butterfly topology by using zero-gap chrome mask. The structural, morphological, and electrical properties of the deposited thin films were characterized by X-ray diffraction (XRD, scanning electron microscope (SEM, and Keithley SourceMeter, respectively. The current-voltage (I-V characterization was performed to investigate the effect of UV light on the fabricated devices. The ZnO fabricated sensors showed a photo to dark current (Iph/Id ratios of 6.26 for 30 μm and 5.28 for 43 μm gap electrodes spacing, respectively. Dynamic responses of both fabricated sensors were observed till 1V with good reproducibility. At the applied voltage of 1 V, the response time was observed to be 4.817 s and 3.704 s while the recovery time was observed to be 0.3738 s and 0.2891 s for 30 and 43 μm gaps, respectively. The signal detection at low operating voltages suggested that the fabricated sensors could be used for miniaturized devices with low power consumption.

Atomic layer deposition of absorbing thin films on nanostructured electrodes for short-wavelength infrared photosensing

International Nuclear Information System (INIS)

Xu, Jixian; Sutherland, Brandon R.; Hoogland, Sjoerd; Fan, Fengjia; Sargent, Edward H.; Kinge, Sachin

2015-01-01

Atomic layer deposition (ALD), prized for its high-quality thin-film formation in the absence of high temperature or high vacuum, has become an industry standard for the large-area deposition of a wide array of oxide materials. Recently, it has shown promise in the formation of nanocrystalline sulfide films. Here, we demonstrate the viability of ALD lead sulfide for photodetection. Leveraging the conformal capabilities of ALD, we enhance the absorption without compromising the extraction efficiency in the absorbing layer by utilizing a ZnO nanowire electrode. The nanowires are first coated with a thin shunt-preventing TiO 2 layer, followed by an infrared-active ALD PbS layer for photosensing. The ALD PbS photodetector exhibits a peak responsivity of 10 −2  A W −1 and a shot-derived specific detectivity of 3 × 10 9  Jones at 1530 nm wavelength

Screen-printed carbon electrode modified on its surface with amorphous carbon nitride thin film: Electrochemical and morphological study

Energy Technology Data Exchange (ETDEWEB)

Ghamouss, F. [Universite de Nantes, UMR 6006-CNRS, FR-2465-CNRS, Laboratoire d' Analyse isotopique et Electrochimique de Metabolismes (LAIEM) (France); Tessier, P.-Y. [Universite de Nantes, UMR CNRS 6502, Institut des Materiaux Jean Rouxel - IMN Faculte des Sciences and des Techniques de Nantes, 2 rue de la Houssiniere, 44322 Nantes Cedex 3 (France); Djouadi, A. [Universite de Nantes, UMR CNRS 6502, Institut des Materiaux Jean Rouxel - IMN Faculte des Sciences and des Techniques de Nantes, 2 rue de la Houssiniere, 44322 Nantes Cedex 3 (France); Besland, M.-P. [Universite de Nantes, UMR CNRS 6502, Institut des Materiaux Jean Rouxel - IMN Faculte des Sciences and des Techniques de Nantes, 2 rue de la Houssiniere, 44322 Nantes Cedex 3 (France); Boujtita, M. [Universite de Nantes, UMR 6006-CNRS, FR-2465-CNRS, Laboratoire d' Analyse isotopique et Electrochimique de Metabolismes (LAIEM) (France)]. E-mail: mohammed.boujtita@univ-nantes.fr

2007-04-20

The surface of a screen-printed carbon electrode (SPCE) was modified by using amorphous carbon nitride (a-CN {sub x}) thin film deposited by reactive magnetron sputtering. Scanning electron microscopy and photoelectron spectroscopy measurements were used to characterise respectively the morphology and the chemical structure of the a-CN {sub x} modified electrodes. The incorporation of nitrogen in the amorphous carbon network was demonstrated by X ray photoelectron spectroscopy. The a-CN {sub x} layers were deposited on both carbon screen-printed electrode (SPCE) and silicon (Si) substrates. A comparative study showed that the nature of substrate, i.e. SPCE and Si, has a significant effect on both the surface morphology of deposited a-CN {sub x} film and their electrochemical properties. The improvement of the electrochemical reactivity of SPCE after a-CN {sub x} film deposition was highlighted both by comparing the shapes of voltammograms and calculating the apparent heterogeneous electron transfer rate constant.

Enhanced performance of amorphous In-Ga-Zn-O thin-film transistors using different metals for source/drain electrodes

Science.gov (United States)

Pyo, Ju-Young; Cho, Won-Ju

2017-09-01

In this paper, we propose an amorphous indium gallium zinc oxide (a-IGZO) thin-film transistor (TFT) with off-planed source/drain electrodes. We applied different metals for the source/drain electrodes with Ni and Ti to control the work function as high and low. When we measured the configuration of Ni to drain and source to Ti, the a-IGZO TFT showed increased driving current, decreased leakage current, a high on/off current ratio, low subthreshold swing, and high mobility. In addition, we conducted a reliability test with a gate bias stress test at various temperatures. The results of the reliability test showed the Ni drain and Ti drain had an equivalent effective energy barrier height. Thus, we confirmed that the proposed off-planed structure improved the electrical characteristics of the fabricated devices without any degradation of characteristics. Through the a-IGZO TFT with different source/drain electrode metal engineering, we realized high-performance TFTs for next-generation display devices.

Growth of Sr2CrReO6 epitaxial thin films by pulsed laser deposition

International Nuclear Information System (INIS)

Orna, J.; Morellon, L.; Algarabel, P.A.; Pardo, J.A.; Magen, C.; Varela, M.; Pennycook, S.J.; De Teresa, J.M.; Ibarra, M.R.

2010-01-01

We report the growth, structural, magnetic, and electrical transport properties of epitaxial Sr 2 CrReO 6 thin films. We have succeeded in depositing films with a high crystallinity and a relatively large cationic order in a narrow window of growth parameters. The epitaxy relationship is Sr 2 CrReO 6 (SCRO) (0 0 1) [1 0 0]-parallel SrTiO 3 (STO) (0 0 1) [1 1 0] as determined by high-resolution X-ray diffraction and scanning transmission electron microscopy (STEM). Typical values of saturation magnetization of M S (300 K)=1 μ B /f.u. and ρ (300 K)=2.8 mΩ cm have been obtained in good agreement with previous published results in sputtered epitaxial thin films. We estimate that the antisite defects concentration in our thin films is of the order of 14%, and the measured Curie temperature is T C =481(2) K. We believe these materials be of interest as electrodes in spintronic devices.

Top-Contact Pentacene-Based Organic Thin Film Transistor (OTFT) with N, N'-Bis(3-Methyl Phenyl)- N, N'-Diphenyl Benzidine (TPD)/Au Bilayer Source-Drain Electrode

Science.gov (United States)

Borthakur, Tribeni; Sarma, Ranjit

2018-01-01

A top-contact Pentacene-based organic thin film transistor (OTFT) with N, N'-Bis (3-methyl phenyl)- N, N'-diphenyl benzidine (TPD)/Au bilayer source-drain electrode is reported. The devices with TPD/Au bilayer source-drain (S-D) electrodes show better performance than the single layer S-D electrode OTFT devices. The field-effect mobility of 4.13 cm2 v-1 s-1, the on-off ratio of 1.86 × 107, the threshold voltage of -4 v and the subthreshold slope of .27 v/decade, respectively, are obtained from the device with a TPD/Au bilayer source-drain electrode.

Composite carbon foam electrode

Science.gov (United States)

Mayer, Steven T.; Pekala, Richard W.; Kaschmitter, James L.

1997-01-01

Carbon aerogels used as a binder for granularized materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid particles being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivty and power to system energy.

Uniform thin film electrode made of low-temperature-sinterable silver nanoparticles: optimized extent of ligand exchange from oleylamine to acrylic acid

Energy Technology Data Exchange (ETDEWEB)

Lee, Yung Jong; Kim, Na Rae; Lee, Changsoo; Lee, Hyuck Mo, E-mail: hmlee@kaist.ac.kr [Department of Materials Science and Engineering (Korea, Republic of)

2017-02-15

Lowering the sintering temperature of nanoparticles in the electrode deposition process holds both academic and industrial interest because of the potential applications of such electrodes in polymer devices and flexible electronics. In addition, achieving uniform electrode formation after ligand exchange is equally important as lowering the sintering temperature. Here, we report a simple chemical treatment by the addition of ligand-exchanging interfaces to lower the sintering temperature; we also determine the optimum extent of ligand exchange for crack-free electrode formation. First, we investigated the structural change of Ag thin films with respect to the concentration of acrylic acid (AA) solutions. Second, we used thermal analysis to evaluate the effects of changes in the sintering temperature. We observed that the resulting conductivity of the Ag patterns was only one order of magnitude lower than that of bulk Ag when the patterns were sintered at 150 °C. The simple chemical treatment developed in this work for solution-processed Ag electrode formation can be adopted for flexible electronics, which would eliminate the need for vacuum and high-temperature processes.

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

Temperature Profile of IR Blocking Windows Used in Cryogenic X-Ray Spectrometers

International Nuclear Information System (INIS)

Friedrich, S.; Funk, T.; Drury, O.; Labov, S.E.

2000-01-01

Cryogenic high-resolution X-ray spectrometers are typically operated with thin IR blocking windows to reduce radiative heating of the detector while allowing good x-ray transmission. We have estimated the temperature profile of these IR blocking windows under typical operating conditions. We show that the temperature in the center of the window is raised due to radiation from the higher temperature stages. This can increase the infrared photon flux onto the detector, thereby increasing the IR noise and decreasing the cryostat hold time. The increased window temperature constrains the maximum window size and the number of windows required. We discuss the consequences for IR blocking window design

Effect of deposition temperature on the properties of Al-doped ZnO films prepared by pulsed DC magnetron sputtering for transparent electrodes in thin-film solar cells

Science.gov (United States)

Kim, Doo-Soo; Park, Ji-Hyeon; Shin, Beom-Ki; Moon, Kyeong-Ju; Son, Myoungwoo; Ham, Moon-Ho; Lee, Woong; Myoung, Jae-Min

2012-10-01

A simple but scalable approach to the production of surface-textured Al-doped ZnO(AZO) films for low-cost transparent electrode applications in thin-film solar cells is introduced in this study by combining pulsed dc magnetron sputtering (PDMS) with wet etching in sequence. First, structural, electrical, and optical properties of the AZO films prepared by a PDMS were investigated as functions of deposition temperature to obtain transparent electrode films that can be used as indium-free alternative to ITO electrodes. Increase in the deposition temperature to 230 °C accompanied the improvement in crystalline quality and doping efficiency, which enabled the lowest electrical resistivity of 4.16 × 10-4 Ω cm with the carrier concentration of 1.65 × 1021 cm-3 and Hall mobility of 11.3 cm2/V s. The wet etching of the films in a diluted HCl solution resulted in surface roughening via the formation of crater-like structures without significant degradation in the electrical properties, which is responsible for the enhanced light scattering capability required for anti-reflective electrodes in thin film solar cells.

Atomic layer deposition of absorbing thin films on nanostructured electrodes for short-wavelength infrared photosensing

Energy Technology Data Exchange (ETDEWEB)

Xu, Jixian; Sutherland, Brandon R.; Hoogland, Sjoerd; Fan, Fengjia; Sargent, Edward H., E-mail: ted.sargent@utoronto.ca [Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Road, Toronto, Ontario M5S 3G4 (Canada); Kinge, Sachin [Advanced Technology, Materials and Research, Research and Development, Hoge Wei 33- Toyota Technical Centre, B-1930 Zaventem (Belgium)

2015-10-12

Atomic layer deposition (ALD), prized for its high-quality thin-film formation in the absence of high temperature or high vacuum, has become an industry standard for the large-area deposition of a wide array of oxide materials. Recently, it has shown promise in the formation of nanocrystalline sulfide films. Here, we demonstrate the viability of ALD lead sulfide for photodetection. Leveraging the conformal capabilities of ALD, we enhance the absorption without compromising the extraction efficiency in the absorbing layer by utilizing a ZnO nanowire electrode. The nanowires are first coated with a thin shunt-preventing TiO{sub 2} layer, followed by an infrared-active ALD PbS layer for photosensing. The ALD PbS photodetector exhibits a peak responsivity of 10{sup −2} A W{sup −1} and a shot-derived specific detectivity of 3 × 10{sup 9} Jones at 1530 nm wavelength.

Gold nanoparticles embedded electropolymerized thin film of pyrimidine derivative on glassy carbon electrode for highly sensitive detection of l-cysteine.

Science.gov (United States)

Kannan, Ayyadurai; Sevvel, Ranganathan

2017-09-01

This paper demonstrates the fabrication of novel gold nanoparticles incorporated poly (4-amino-6-hydroxy-2-mercaptopyrimidine) (Nano-Au/Poly-AHMP) film modified glassy carbon electrode and it is employed for highly sensitive detection of l-cysteine (CYS). The modified electrode was characterized by scanning electron microscope (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). SEM images of modified electrode revealed the homogeneous distribution of gold nanoparticles on poly (4-amino-6-hydroxy-2-mercaptopyrimidine) thin film modified glassy carbon electrode. The modified electrode was successfully utilized for highly selective and sensitive determination of l-cysteine at physiological pH7.0. The present electrochemical sensor successfully resolved the voltammetric signals of ascorbic acid (AA) and l-cysteine with peak separation of 0.510V. To the best of our knowledge, this is the first report of larger peak separation between AA and CYS. Wide linear concentration ranges (2μM-500μM), low detection limit (0.020μM), an excellent reproducibility and stability are achieved for cysteine sensing with this Nano-Au/Poly-AHMP/GCE. Copyright © 2017 Elsevier B.V. All rights reserved.

Systems and methods for producing low work function electrodes

Science.gov (United States)

Kippelen, Bernard; Fuentes-Hernandez, Canek; Zhou, Yinhua; Kahn, Antoine; Meyer, Jens; Shim, Jae Won; Marder, Seth R.

2015-07-07

According to an exemplary embodiment of the invention, systems and methods are provided for producing low work function electrodes. According to an exemplary embodiment, a method is provided for reducing a work function of an electrode. The method includes applying, to at least a portion of the electrode, a solution comprising a Lewis basic oligomer or polymer; and based at least in part on applying the solution, forming an ultra-thin layer on a surface of the electrode, wherein the ultra-thin layer reduces the work function associated with the electrode by greater than 0.5 eV. According to another exemplary embodiment of the invention, a device is provided. The device includes a semiconductor; at least one electrode disposed adjacent to the semiconductor and configured to transport electrons in or out of the semiconductor.

Design of large aperture, low mass vacuum windows

International Nuclear Information System (INIS)

Leonhardt, W.J.; Mapes, M.

1993-01-01

Large vacuum vessels are employed downstream of fixed targets in High Energy Physics experiments to provide a long path for particles to transverse without interacting with air molecules. These vessels generally have a large aperture opening known as a open-quotes vacuum windowclose quotes which employs a thin membrane to preserve the vacuum environment yet allows the particles to pass through with a minimal effect on them. Several large windows have been built using a composite of Kevlar/Mylar including circular windows to a diameter of 96.5 cm and rectangular windows up to 193 cm x 86 cm. This paper describes the design, fabrication, testing and operating experience with these windows and relates the actual performance to theoretical predictions

Gate voltage and drain current stress instabilities in amorphous In–Ga–Zn–O thin-film transistors with an asymmetric graphene electrode

Directory of Open Access Journals (Sweden)

Joonwoo Kim

2015-09-01

Full Text Available The gate voltage and drain current stress instabilities in amorphous In–Ga–Zn–O thin-film transistors (a-IGZO TFTs having an asymmetric graphene electrode structure are studied. A large positive shift in the threshold voltage, which is well fitted to a stretched-exponential equation, and an increase in the subthreshold slope are observed when drain current stress is applied. This is due to an increase in temperature caused by power dissipation in the graphene/a-IGZO contact region, in addition to the channel region, which is different from the behavior in a-IGZO TFTs with a conventional transparent electrode.

Preparation of PZT thin films on YBCO electrodes by KrF excimer laser ablation technique

International Nuclear Information System (INIS)

Kurogi, H.; Yamagata, Y.; Ebihara, K.

1998-01-01

Pb(Zr X Ti 1-X )O 3 (PZT) films have excellent ferroelectric, optical, piezoelectric, and pyroelectric properties. We prepared PZT thin films by the excimer laser ablation technique. A pulsed KrF excimer laser (Lambda Physik LPX305icc, pulse duration of 25 ns, λ=248 nm, 850 mJ Max.) was used to ablate the bulk targets. We investigated the influence of bottom electrode materials on the characteristics of the PZT thin films prepared on Pt and YBCO underlayers. The X-ray diffraction (XRD) patterns showed that the PZT films prepared with a laser fluence of 2 Jcm -2 on YBCO/MgO(100) substrate at a wide temperature range of 550-680 C have a perovskite (001) structure. At the same laser fluence, the PZT films prepared on Pt/MgO(100) substrate have a perovskite (001) structure only at 650 C. The polarization-electric field (P-E) characteristics and fatigue properties of PZT thin films were measured by the Sawyer-Tower circuit. The remnant polarization and coercive field have been found to be P r =15 μC cm -2 , 30 μC cm -2 and E c =200 kV cm -1 , 100 kV cm -1 for Au/PZT/Pt/MgO and Au/PZT/YBCO/MgO correspondingly. The remnant polarization of Au/PZT/YBCO/MgO thin film was reduced to one-half after about 10 8 cycles of switching. (orig.)

Ternary semitransparent organic solar cells with a laminated top electrode.

Science.gov (United States)

Makha, Mohammed; Testa, Paolo; Anantharaman, Surendra Babu; Heier, Jakob; Jenatsch, Sandra; Leclaire, Nicolas; Tisserant, Jean-Nicolas; Véron, Anna C; Wang, Lei; Nüesch, Frank; Hany, Roland

2017-01-01

Tinted and colour-neutral semitransparent organic photovoltaic elements are of interest for building-integrated applications in windows, on glass roofs or on facades. We demonstrate a semitransparent organic photovoltaic cell with a dry-laminated top electrode that achieves a uniform average visible transmittance of 51% and a power conversion efficiency of 3%. The photo-active material is based on a majority blend composed of a visibly absorbing donor polymer and a fullerene acceptor, to which a selective near-infrared absorbing cyanine dye is added as a minority component. Our results show that organic ternary blends are attractive for the fabrication of semitransparent solar cells in general, because a guest component with a complementary absorption can compensate for the inevitably reduced current generation capability of a high-performing binary blend when applied as a thin, semitransparent film.

Chronic cranial window with access port for repeated cellular manipulations, drug application, and electrophysiology

Directory of Open Access Journals (Sweden)

Christopher Joel Roome

2014-11-01

Full Text Available Chronic cranial windows have been instrumental in advancing optical studies in vivo, permitting long-term, high-resolution imaging in various brain regions. However, once a window is attached it is difficult to regain access to the brain under the window for cellular manipulations. Here we describe a simple device that combines long term in vivo optical imaging with direct brain access via glass or quartz pipettes and metal, glass, or quartz electrodes for cellular manipulations like dye or drug injections and electrophysiological stimulations or recordings while keeping the craniotomy sterile. Our device comprises a regular cranial window glass coverslip with a drilled access hole later sealed with biocompatible silicone. This chronic cranial window with access port is cheap, easy to manufacture, can be mounted just as the regular chronic cranial window, and is self-sealing after retraction of the pipette or electrode. We demonstrate that multiple injections can be performed through the silicone port by repetitively bolus loading calcium sensitive dye into mouse barrel cortex and recording spontaneous cellular activity over a period of weeks. As an example to the extent of its utility for electrophysiological recording, we describe how simple removal of the silicone seal can permit patch pipette access for whole-cell patch clamp recordings in vivo. During these chronic experiments we do not observe any infections under the window or impairment of animal health.

Improved performance of inkjet-printed Ag source/drain electrodes for organic thin-film transistors by overcoming the coffee ring effects

Science.gov (United States)

Liu, Cheng-Fang; Lin, Yan; Lai, Wen-Yong; Huang, Wei

2017-11-01

Inkjet printing is a promising technology for the scalable fabrication of organic electronics because of the material conservation and facile patterning as compared with other solution processing techniques. In this study, we have systematically investigated the cross-sectional profile control of silver (Ag) electrode via inkjet printing. A facile methodology for achieving inkjet-printed Ag source/drain with improved profiles is developed. It is demonstrated that the printing conditions such as substrate temperature, drop spacing and printing layers affect the magnitude of the droplet deposition and the rate of evaporation, which can be optimized to greatly reduce the coffee ring effects for improving the inkjet-printed electrode profiles. Ag source/drain electrodes with uniform profiles were successfully inkjet-printed and incorporated into organic thin-film transistors (OTFTs). The resulting devices showed superior electrical performance than those without special treatments. It is noted to mention that the strategy for modulating the inkjet-printed Ag electrodes in this work does not demand the ink formulation or complicated steps, which is beneficial for scaling up the printing techniques for potential large-area/mass manufacturing.

Current distribution effects in AC impedance spectroscopy of electroceramic point contact and thin film model electrodes

DEFF Research Database (Denmark)

Nielsen, Jimmi; Jacobsen, Torben

2010-01-01

the primary current distribution to the DC current distribution restricted to the Three-Phase-Boundary (TPB) zone introduces an error in the determination of the reaction resistance, Rreac = Z(freq. → 0) − Z(freq. → ∞). The error is estimated for different width of the effective TPB zone and a rule of thumb...... regarding its significance is provided. The associated characteristic impedance spectrum shape change is simulated and its origin discussed. Furthermore, the characteristic shape of impedance spectra of thin electroceramic film electrodes with lateral ohmic resistance is studied as a function...

Deposition Time and Thermal Cycles of Fabricating Thin-wall Steel Parts by Double Electrode GMAW Based Additive Manufacturing

Directory of Open Access Journals (Sweden)

Yang Dongqing

2017-01-01

Full Text Available The deposition time for fabricating the thin-wall part as well as the peak temperature of the substrate during the process was analyzed in the double electrode gas metal arc welding (DE-GMAW based additive manufacturing (AM. The total deposition time and the interlayer idle time of the manufacturing process decreased with the increasing of the bypass current under the same interlayer temperature and the same deposition rate. The thermal cycling curves illustrated that the peak temperature of the substrate was lower in the DE-GMAW base AM under the same conditions. When depositing the thin-wall parts, the DE-GMAW based AM can reduce the heat input to the substrate and improve the fabrication efficiency, compared with the GMAW based AM.

Insights on Capacitive Interdigitated Electrodes Coated with MOF Thin Films: Humidity and VOCs Sensing as a Case Study

KAUST Repository

Sapsanis, Christos

2015-07-24

A prototypical metal-organic framework (MOF), a 2D periodic porous structure based on the assembly of copper ions and benzene dicarboxylate (bdc) ligands (Cu(bdc)·xH2O), was grown successfully as a thin film on interdigitated electrodes (IDEs). IDEs have been used for achieving planar CMOS-compatible low-cost capacitive sensing structures for the detection of humidity and volatile organic compounds (VOCs). Accordingly, the resultant IDEs coated with the Cu(bdc)·xH2O thin film was evaluated, for the first time, as a capacitive sensor for gas sensing applications. A fully automated setup, using LabVIEW interfaces to experiment conduction and data acquisition, was developed in order to measure the associated gas sensing performance.

Mechanical Safety Subcommittee Guideline for Design of Thin Windows Regarding Roark’s Edge Condition Coefficient

Energy Technology Data Exchange (ETDEWEB)

Ader, C. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Voirin, E. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); McGee, M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Nobrega, L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2017-06-15

An error was found in an edge stress coefficient used to calculate stresses in thin windows. This error is present in “Roark’s Formulas for Stress and Strain” 7th and 8th Edition. The 6th Edition is correct. This guideline specially discusses a major difference in regards to a coefficient used in calculating the edge stress in “Roark’s Formulas for Stress and Strain” 6th Edition compared to the 7th and 8th Editions. In Chapter 10: Flat Plates under “Circular plates under distributed load producing large deflections,” Case 3, which is “Fixed and held. Uniform pressure q over entire plate.” The coefficient for a fixed edge condition in the 6th Edition1 K4 = 0.476 while in the 7th and 8th Edition2, the coefficient is 1.73 which is significant difference.

Metal ion analysis in contaminated water samples using anodic stripping voltammetry and a nanocrystalline diamond thin-film electrode

International Nuclear Information System (INIS)

Sonthalia, Prerna; McGaw, Elizabeth; Show, Yoshiyuki; Swain, Greg M.

2004-01-01

Boron-doped nanocrystalline diamond thin-film electrodes were employed for the detection and quantification of Ag (I), Cu (II), Pb (II), Cd (II), and Zn (II) in several contaminated water samples using anodic stripping voltammetric (ASV). Diamond is an alternate electrode that possesses many of the same attributes as Hg and, therefore, appears to be a viable material for this electroanalytical measurement. The nanocrystalline form has been found to perform slightly better than the more conventional microcrystalline form of diamond in this application. Differential pulse voltammetry (DPASV) was used to detect these metal ions in lake water, well water, tap water, wastewater treatment sludge, and soil. The electrochemical results were compared with data from inductively coupled plasma mass spectrometric (ICP-MS) and or atomic absorption spectrometric (AAS) measurements of the same samples. Diamond is shown to function well in this electroanalytical application, providing a wide linear dynamic range, a low limit of quantitation, excellent response precision, and good response accuracy. For the analysis of Pb (II), bare diamond provided a response nearly identical to that obtained with a Hg-coated glassy carbon electrode

Study of electrochemical properties of thin film materials obtained using plasma technologies for production of electrodes for pacemakers

International Nuclear Information System (INIS)

Obrezkov, O I; Vinogradov, V P; Krauz, V I; Mozgrin, D V; Guseva, I A; Andreev, E S; Zverev, A A; Starostin, A L

2016-01-01

Studies of thin film materials (TFM) as coatings of tips of pacemaker electrodes implanted into the human heart have been performed. TFM coatings were deposited in vacuum by arc magnetron discharge plasma, by pulsed discharge of “Plasma Focus”, and by electron beam evaporation. Simulation of electric charge transfer to the heart in physiological blood- imitator solution and determination of electrochemical properties of the coatings were carried out. TFM of highly developed surface of contact with tissue was produced by argon plasma spraying of titanium powder with subsequent coating by titanium nitride in vacuum arc assisted by Ti ion implantation. The TFM coatings of pacemaker electrode have passed necessary clinical tests and were used in medical practice. They provide low voltage myocardium stimulation thresholds within the required operating time. (paper)

Fabrication of TiNb{sub 2}O{sub 7} thin film electrodes for Li-ion micro-batteries by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Daramalla, V. [Materials Research Centre, Indian Institute of Science, Bengalore 560012 (India); Penki, Tirupathi Rao; Munichandraiah, N. [Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bengalore 560012 (India); Krupanidhi, S.B., E-mail: sbk@mrc.iisc.ernet.in [Materials Research Centre, Indian Institute of Science, Bengalore 560012 (India)

2016-11-15

Graphical abstract: The TiNb{sub 2}O{sub 7} thin film electrodes as anode material in Li-ion rechargeable micro-batteries are successfully demonstrated. The pulsed laser deposited TiNb{sub 2}O{sub 7} thin film electrode delivers high discharge specific capacity of 143 μAh μm{sup −1} cm{sup −2} at 50 μA cm{sup −2} current density, with 92% coulombic efficiency. The thin films are very stable in crystal structure, with good fast reversible reaction at average Li-insertion voltage 1.65 V. - Highlights: • TiNb{sub 2}O{sub 7} thin films fabricated by pulsed laser deposition. • TiNb{sub 2}O{sub 7} as anode thin films demonstrated successfully. • High discharge specific capacity with 92% coulombic efficiency. • Excellent crystal stability and good reversible reaction. - Abstract: Pulsed laser deposited TiNb{sub 2}O{sub 7} thin films are demonstrated as anode materials in rechargeable Li-ion micro-batteries. The monoclinic and chemically pure TiNb{sub 2}O{sub 7} films in different morphologies were successfully deposited at 750 °C. The single phase formation was confirmed by grazing incident X-ray diffraction, micro-Raman spectroscopy, high resolution transmission electron microscopy, field emission scanning electron microscopy and X-ray photoelectron spectroscopy. The oxygen partial pressure during the deposition significantly influenced the properties of TiNb{sub 2}O{sub 7} films. The TiNb{sub 2}O{sub 7} thin films exhibited excellent stability with fast kinetics reversible reaction. The TiNb{sub 2}O{sub 7} films showed initial discharge specific capacity of 176, 143 μAh μm{sup −1} cm{sup −2} at 30, 50 μA cm{sup −2} current densities respectively with 92% coulombic efficiency in a non-aqueous electrolyte consisting of Li{sup +} ions. The high discharge specific capacity of TiNb{sub 2}O{sub 7} thin films may be attributed to nanometer grain size with high roughness which offers high surface area for Li-diffusion during charge and discharge

Iridium Oxide-reduced Graphene Oxide Nanohybrid Thin Film Modified Screen-printed Electrodes as Disposable Electrochemical Paper Microfluidic pH Sensors.

Science.gov (United States)

Yang, Jiang; Kwak, Tae-Joon; Zhang, Xiaodong; McClain, Robert; Chang, Woo-Jin; Gunasekaran, Sundaram

2016-11-22

A facile, controllable, inexpensive and green electrochemical synthesis of IrO2-graphene nanohybrid thin films is developed to fabricate an easy-to-use integrated paper microfluidic electrochemical pH sensor for resource-limited settings. Taking advantages from both pH meters and strips, the pH sensing platform is composed of hydrophobic barrier-patterned paper micropad (µPAD) using polydimethylsiloxane (PDMS), screen-printed electrode (SPE) modified with IrO2-graphene films and molded acrylonitrile butadiene styrene (ABS) plastic holder. Repetitive cathodic potential cycling was employed for graphene oxide (GO) reduction which can completely remove electrochemically unstable oxygenated groups and generate a 2D defect-free homogeneous graphene thin film with excellent stability and electronic properties. A uniform and smooth IrO2 film in nanoscale grain size is anodically electrodeposited onto the graphene film, without any observable cracks. The resulting IrO2-RGO electrode showed slightly super-Nernstian responses from pH 2-12 in Britton-Robinson (B-R) buffers with good linearity, small hysteresis, low response time and reproducibility in different buffers, as well as low sensitivities to different interfering ionic species and dissolved oxygen. A simple portable digital pH meter is fabricated, whose signal is measured with a multimeter, using high input-impedance operational amplifier and consumer batteries. The pH values measured with the portable electrochemical paper-microfluidic pH sensors were consistent with those measured using a commercial laboratory pH meter with a glass electrode.

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

Low Temperature Synthesis of Fluorine-Doped Tin Oxide Transparent Conducting Thin Film by Spray Pyrolysis Deposition.

Science.gov (United States)

Ko, Eun-Byul; Choi, Jae-Seok; Jung, Hyunsung; Choi, Sung-Churl; Kim, Chang-Yeoul

2016-02-01

Transparent conducting oxide (TCO) is widely used for the application of flat panel display like liquid crystal displays and plasma display panel. It is also applied in the field of touch panel, solar cell electrode, low-emissivity glass, defrost window, and anti-static material. Fluorine-doped tin oxide (FTO) thin films were fabricated by spray pyrolysis of ethanol-added FTO precursor solutions. FTO thin film by spray pyrolysis is very much investigated and normally formed at high temperature, about 500 degrees C. However, these days, flexible electronics draw many attentions in the field of IT industry and the research for flexible transparent conducting thin film is also required. In the industrial field, indium-tin oxide (ITO) film on polymer substrate is widely used for touch panel and displays. In this study, we investigated the possibility of FTO thin film formation at relatively low temperature of 250 degrees C. We found out that the control of volume of input precursor and exhaust gases could make it possible to form FTO thin film with a relatively low electrical resistance, less than 100 Ohm/sq and high optical transmittance about 88%.

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Heparin molecularly imprinted polymer thin flm on gold electrode by plasma-induced graft polymerization for label-free biosensor.

Science.gov (United States)

Orihara, Kouhei; Hikichi, Atsushi; Arita, Tomohiko; Muguruma, Hitoshi; Yoshimi, Yasuo

2018-03-20

Heparin, a highly sulfated glycosaminoglycan, is an important biomaterial having biological and therapeutic functionalities such as anticoagulation, regeneration, and protein stabilization. This study addresses a label-free quartz crystal microbalance (QCM) biosensor for heparin detection based on a macromolecularly imprinted polymer (MIP) as an artificial recognition element. We demonstrate the novel strategy for MIP in the form of thin film on a gold (Au) electrode with the plasma-induced graft polymerization (PIP) technique. The procedure of PIP is as follows: (i) Hexamethyldisiloxane plasma-polymerized thin film (PPF) as a pre-coating scaffold of active species for PIP (post-polymerization) is deposited on an Au electrode. (ii) The PPF/Au electrode is soaked in an water solution containing heparin (template), (2-(methacryloxy)-ethyl)trimethylammonium chloride acrylamide (functional monomer), acrylamide, and N,N-methylenebisacrylamide (crosslinker). Double bonds of monomer and crosslinker attacked by residually active species in pre-coating PPF cause radical chain reaction. Consequently, a growing polymer network of 20 nm thickness of PIP-MIP thin film is formed and grafted on the PPF/Au surface. (iii) The PIP-MIP/PPF/Au is washed by sodium chloride solution so as to remove the template. Non-imprinted polymer (NIP) is carried out like the same procedure without a template. The AFM, XPS, and QCM measurements show that the PIP process facilitates macromolecularly surface imprinting of template heparin where the template is easily removed and is rapidly rebound to PIP-MIP without a diffusional barrier. The heparin-PIP-MIP specifically binds to heparin compared with heparin analog chondroitin sulfate C (selective factor: 4.0) and a detectable range of heparin in the presence of CS (0.1 wt%) was 0.001-0.1 wt%. The PIP-NIP does not show selectivity between them. The evaluated binding kinetics are association (k a  = 350 ± 100 M -1  s -1

Preparation of PZT thin films on YBCO electrodes by KrF excimer laser ablation technique

Energy Technology Data Exchange (ETDEWEB)

Kurogi, H; Yamagata, Y; Ebihara, K [Kumamoto Univ. (Japan). Dept. of Electr. Eng. and Comput. Sci.; Inoue, N [Kyushu Electric Power Co., Inc., Suizenji, 1-6-36, Kumamoto 862 (Japan)

1998-03-01

Pb(Zr{sub X}Ti{sub 1-X})O{sub 3} (PZT) films have excellent ferroelectric, optical, piezoelectric, and pyroelectric properties. We prepared PZT thin films by the excimer laser ablation technique. A pulsed KrF excimer laser (Lambda Physik LPX305icc, pulse duration of 25 ns, {lambda}=248 nm, 850 mJ Max.) was used to ablate the bulk targets. We investigated the influence of bottom electrode materials on the characteristics of the PZT thin films prepared on Pt and YBCO underlayers. The X-ray diffraction (XRD) patterns showed that the PZT films prepared with a laser fluence of 2 Jcm{sup -2} on YBCO/MgO(100) substrate at a wide temperature range of 550-680 C have a perovskite (001) structure. At the same laser fluence, the PZT films prepared on Pt/MgO(100) substrate have a perovskite (001) structure only at 650 C. The polarization-electric field (P-E) characteristics and fatigue properties of PZT thin films were measured by the Sawyer-Tower circuit. The remnant polarization and coercive field have been found to be P{sub r}=15 {mu}C cm{sup -2}, 30 {mu}C cm{sup -2} and E{sub c}=200 kV cm{sup -1}, 100 kV cm{sup -1} for Au/PZT/Pt/MgO and Au/PZT/YBCO/MgO correspondingly. The remnant polarization of Au/PZT/YBCO/MgO thin film was reduced to one-half after about 10{sup 8} cycles of switching. (orig.) 7 refs.

Performance evaluation of symmetric supercapacitor based on cobalt hydroxide [Co(OH)2] thin film electrodes

International Nuclear Information System (INIS)

Jagadale, A.D.; Kumbhar, V.S.; Dhawale, D.S.; Lokhande, C.D.

2013-01-01

In the present investigation, we have successfully assembled symmetric supercapacitor device based on cobalt hydroxide [Co(OH) 2 ] thin film electrodes using 1 M KOH as an electrolyte. Initially, potentiodynamic electrodeposition method is employed for the preparation of Co(OH) 2 thin films onto stainless steel substrate. These films are characterized for structural and morphological elucidations using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The XRD reveals formation of β-Co(OH) 2 material with hexagonal crystal structure. The SEM images show formation of nanoflakes like microstructure with average flake width 100 nm. Electrochemical characterizations of Co(OH) 2 based symmetric supercapacitor cell are carried out using cyclic voltammetry, charge–discharge and electrochemical impedance spectroscopy (EIS) techniques. In the performance evaluation the maximum values of specific capacitance, specific energy and specific power are encountered as 44 F g −1 , 3.96 Wh kg −1 and 42 kW kg −1 . The value of equivalent series resistance (ESR) is estimated as 2.3 Ω using EIS

Potentiometric NO2 Sensors Based on Thin Stabilized Zirconia Electrolytes and Asymmetric (La0.8Sr0.20.95MnO3 Electrodes

Directory of Open Access Journals (Sweden)

Jie Zou

2015-07-01

Full Text Available Here we report on a new architecture for potentiometric NO2 sensors that features thin 8YSZ electrolytes sandwiched between two porous (La0.8Sr0.20.95MnO3 (LSM95 layers—one thick and the other thin—fabricated by the tape casting and co-firing techniques. Measurements of their sensing characteristics show that reducing the porosity of the supporting LSM95 reference electrodes can increase the response voltages. In the meanwhile, thin LSM95 layers perform better than Pt as the sensing electrode since the former can provide higher response voltages and better linear relationship between the sensitivities and the NO2 concentrations over 40–1000 ppm. The best linear coefficient can be as high as 0.99 with a sensitivity value of 52 mV/decade as obtained at 500 °C. Analysis of the sensing mechanism suggests that the gas phase reactions within the porous LSM95 layers are critically important in determining the response voltages.

Gold leaf counter electrodes for dye-sensitized solar cells

Science.gov (United States)

Shimada, Kazuhiro; Toyoda, Takeshi

2018-03-01

In this study, a gold leaf 100 nm thin film is used as the counter electrode in dye-sensitized solar cells. The traditional method of hammering gold foil to obtain a thin gold leaf, which requires only small amounts of gold, was employed. The gold leaf was then attached to the substrate using an adhesive to produce the gold electrode. The proposed approach for fabricating counter electrodes is demonstrated to be facile and cost-effective, as opposed to existing techniques. Compared with electrodes prepared with gold foil and sputtered gold, the gold leaf counter electrode demonstrates higher catalytic activity with a cobalt-complex electrolyte and higher cell efficiency. The origin of the improved performance was investigated by surface morphology examination (scanning electron microscopy), various electrochemical analyses (cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy), and crystalline analysis (X-ray diffractometry).

Voltammetry of Vitamin B12 on a thin self-assembled monolayer modified electrode

International Nuclear Information System (INIS)

Yang Nianjun; Wan Qijin; Wang, Xiaoxia

2005-01-01

Vitamin B 12 showed three reduction waves at a thin self-assembled monolayer of mercaptoacetic acid modified gold electrode at 0.21, 0.16, -0.41 V in a 0.01 mol l -1 HCl solution at a scan rate of 100 mV s -1 . The overall electrode reaction followed an ECE mechanism, leading to a total two-electron exchange. The predominant Co(III) form was reduced directly at 0.21 V by a one-electron transfer accomplished by CN - cleavage into the cyanocob(II)alamin. The latter species then equilibrated with the base-off B 12r , which was immediately reduced into B 12s at 0.16 V. The wave at -0.41 V might be a catalytic hydrogen wave. The cathodic peak currents at 0.21 V were controlled by the diffusion of Vitamin B 12 . On the base of its diffusion behavior, the semi-derivate voltammetric method for the detection of Vitamin B 12 was presented. The semi-derivate voltammetric peak current of the wave at 0.21 V was linear with the content of Vitamin B 12 in the range of 4.0 x 10 -9 to 4.0 x 10 -5 mol l -1 . The detection limit was 1.0 x 10 -9 mol l -1 . The proposed method was applied successfully to determine the content of Vitamin B 12 in pharmaceutical preparations

Process development of ITO source/drain electrode for the top-gate indium-gallium-zinc oxide transparent thin-film transistor

International Nuclear Information System (INIS)

Cheong, Woo-Seok; Yoon, Young-sun; Shin, Jae-Heon; Hwang, Chi-Sun; Chu, Hye Yong

2009-01-01

Indium-tin oxide (ITO) has been widely used as electrodes for LCDs and OLEDs. The applications are expanding to the transparent thin-film transistors (TTFT S ) for the versatile circuits or transparent displays. This paper is related with optimization of ITO source and drain electrode for TTFTs on glass substrates. For example, un-etched ITO remnants, which frequently found in the wet etching process, often originate from unsuitable ITO formation processes. In order to improve them, an ion beam deposition method is introduced, which uses for forming a seed layer before the main ITO deposition. We confirm that ITO films with seed layers are effective to obtain clean and smooth glass surfaces without un-etched ITO remnants, resulting in a good long-run electrical stability of the top-gate indium-gallium-zinc oxide-TTFT.

Ultra-thin solution-based coating of molybdenum oxide on multiwall carbon nanotubes for high-performance supercapacitor electrodes

KAUST Repository

Shakir, Imran

2014-02-01

Uniform and conformal coating of ultrathin molybdenum oxide (MoO 3) thin film onto conducting MWCNTs was successfully synthesized through a facile, nontoxic and generally applicable precipitation method, followed by a simple heat treatment. The ultrathin MoO3 coating enables a fast and reversible redox reaction which improves the specific capacitance by utilizing the maximum number of active sites for the redox reaction, while the high porosity of the MWCNTs facilitates ion migration in the electrolyte and shorten the ion diffusion path. The ultrathin MoO3 coated MWCNTs electrodes show a very high specific capacitance of 1145 Fg -1 in 2 M Na2SO4 aqueous solution when 5 nm thick MoO3 was considered alone despite the low weight percentage of the MoO3 (16wt%). Furthermore, the ultrathin MoO3 coated MWCNTs supercapacitor electrodes exhibited excellent cycling performance of > 97% capacitance retention over 1000 cycles. © 2013 Elsevier Ltd.

Resistive switching near electrode interfaces: Estimations by a current model

Science.gov (United States)

Schroeder, Herbert; Zurhelle, Alexander; Stemmer, Stefanie; Marchewka, Astrid; Waser, Rainer

2013-02-01

The growing resistive switching database is accompanied by many detailed mechanisms which often are pure hypotheses. Some of these suggested models can be verified by checking their predictions with the benchmarks of future memory cells. The valence change memory model assumes that the different resistances in ON and OFF states are made by changing the defect density profiles in a sheet near one working electrode during switching. The resulting different READ current densities in ON and OFF states were calculated by using an appropriate simulation model with variation of several important defect and material parameters of the metal/insulator (oxide)/metal thin film stack such as defect density and its profile change in density and thickness, height of the interface barrier, dielectric permittivity, applied voltage. The results were compared to the benchmarks and some memory windows of the varied parameters can be defined: The required ON state READ current density of 105 A/cm2 can only be achieved for barriers smaller than 0.7 eV and defect densities larger than 3 × 1020 cm-3. The required current ratio between ON and OFF states of at least 10 requests defect density reduction of approximately an order of magnitude in a sheet of several nanometers near the working electrode.

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

DEFF Research Database (Denmark)

Matteucci, Marco; Heiskanen, Arto; Zor, Kinga

2016-01-01

We compare ultrasonic welding (UW) and thermal bonding (TB) for the integration of embedded thin-film gold electrodes for electrochemical applications in injection molded (IM) microfluidic chips. The UW bonded chips showed a significantly superior electrochemical performance compared to the ones ...

Fabrication and Characterisation of Membrane-Based Gold Electrodes

DEFF Research Database (Denmark)

Bakmand, Tanya; Kwasny, Dorota; Dimaki, Maria

2015-01-01

This work presents a versatile, membrane based electrochemical sensor with thin film electrodes fabricated through Ebeam evaporation directly on porous materials (membranes). Here, the fabrication of the electrodes is described along with possible methods for integration in fluidic systems...

Optical properties of vanadium dioxide thin film as a windows thermochromic coating

Directory of Open Access Journals (Sweden)

Wu, Z. P.

2000-06-01

Full Text Available The optical properties of vanadium dioxide (VO₂ thin film have been studied for the potential application of intelligent windows. The results show that VO₂ film deposited on sapphire substrates exhibits good thermochromic effects, its IR transmittance changes 60% before and after phase transition, and has less thickness dependence than UV transmittance. Doping can significantly reduce transition temperature, such as to 30°C for 1.5% Mo doped VO₂.

Se han investigado las propiedades ópticas del dióxido de vanadio (VO₂ aplicado como películas delgadas para posibles aplicaciones en ventanas inteligentes. Cuando el VO₂ se deposita sobre sustratos de zafiro da lugar a efectos termocrómicos considerables; así, su transmitancia en el infrarrojo cambia en un 60 % después de la transición de fase del dióxido de vanadio, teniendo una dependencia menor con el espesor que la transmitancia en el ultravioleta. El efecto de aditivos sobre estas películas de dioxido de vanadio da lugar a una disminución de la temperatura de dicha transición responsable del efecto termocrómico, de manera que se produce a 30°C con el 1,5 % de adición de Mo.

Understanding Windows | Efficient Windows Collaborative

Science.gov (United States)

Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards

Dynamics of rotating and vibrating thin hemispherical shell with mass and damping imperfections and parametrically driven by discrete electrodes

CSIR Research Space (South Africa)

Shatalov, M

2009-05-01

Full Text Available stream_source_info Shatalov2_2009.pdf.txt stream_content_type text/plain stream_size 22572 Content-Encoding UTF-8 stream_name Shatalov2_2009.pdf.txt Content-Type text/plain; charset=UTF-8 1 DYNAMICS OF ROTATING... AND VIBRATING THIN HEMISPHERICAL SHELL WITH MASS AND DAMPING IMPERFECTIONS AND PARAMETRICALLY DRIVEN BY DISCRETE ELECTRODES Michael Shatalov1,2 and Charlotta Coetzee2 1Sensor Science and Technology (SST) of CSIR Material Science and Manufacturing (MSM...

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

Directory of Open Access Journals (Sweden)

Marco Matteucci

2016-10-01

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

Basic electrochemical properties of sputtered gold film electrodes

International Nuclear Information System (INIS)

Libansky, Milan; Zima, Jiri; Barek, Jiri; Reznickova, Alena; Svorcik, Vaclav; Dejmkova, Hana

2017-01-01

Gold nanolayers made by sputtering of pure gold (physical vapour deposition) are commonly used for many biophysical and material applications. However, the use of sputtering method for fabrication of working electrodes for electroanalytical purposes is less common. This paper focuses on the testing and characterization of sputtered working roughened gold nanostructured film electrodes, which fall into category of upcoming desirable new generation of nanostructured gold working electrodes. Gold nanostructured films (80 nm thin) were sputtered onto 50 μm thin PTFE substrates with three different types of treatment: pristine, plasma treated, and plasma treated and subsequently spontaneously grafted with biphenyl-4,4′-dithiol. The characterization of gold nanostructured film electrodes was carried out by examination of the electrode reaction of standard redox probes (ferrocyanide/ferricyanide, hydroquinone/benzoquinone) in different types of supporting electrolytes (BR buffers of various pH, KCl, KNO 3 , H 2 SO 4 ), by exploration of the electrode surface by scanning electron microscopy, by atomic force microscopy accompanied by elementary analysis and contact angle measurements. The testing of electrodes was complemented by an attempt to calculate their real surface areas from Randles-Sevcik equation. All results were compared to conventional bulk gold electrode. The practical applicability of the nanostructured gold electrodes as sensors for the determination of environmental pollutants was verified by voltammetric determination of hydroquinone as a model electrochemically oxidisable organic environmental pollutant.

Simultaneous Automatic Electrochemical Detection of Zinc, Cadmium, Copper and Lead Ions in Environmental Samples Using a Thin-Film Mercury Electrode and an Artificial Neural Network

Directory of Open Access Journals (Sweden)

Jiri Kudr

2014-12-01

Full Text Available In this study a device for automatic electrochemical analysis was designed. A three electrodes detection system was attached to a positioning device, which enabled us to move the electrode system from one well to another of a microtitre plate. Disposable carbon tip electrodes were used for Cd(II, Cu(II and Pb(II ion quantification, while Zn(II did not give signal in this electrode configuration. In order to detect all mentioned heavy metals simultaneously, thin-film mercury electrodes (TFME were fabricated by electrodeposition of mercury on the surface of carbon tips. In comparison with bare electrodes the TMFEs had lower detection limits and better sensitivity. In addition to pure aqueous heavy metal solutions, the assay was also performed on mineralized rock samples, artificial blood plasma samples and samples of chicken embryo organs treated with cadmium. An artificial neural network was created to evaluate the concentrations of the mentioned heavy metals correctly in mixture samples and an excellent fit was observed (R2 = 0.9933.

Potentiometric NO2 Sensors Based on Thin Stabilized Zirconia Electrolytes and Asymmetric (La0.8Sr0.2)0.95MnO3 Electrodes

Science.gov (United States)

Zou, Jie; Zheng, Yangong; Li, Junliang; Zhan, Zhongliang; Jian, Jiawen

2015-01-01

Here we report on a new architecture for potentiometric NO2 sensors that features thin 8YSZ electrolytes sandwiched between two porous (La0.8Sr0.2)0.95MnO3 (LSM95) layers—one thick and the other thin—fabricated by the tape casting and co-firing techniques. Measurements of their sensing characteristics show that reducing the porosity of the supporting LSM95 reference electrodes can increase the response voltages. In the meanwhile, thin LSM95 layers perform better than Pt as the sensing electrode since the former can provide higher response voltages and better linear relationship between the sensitivities and the NO2 concentrations over 40–1000 ppm. The best linear coefficient can be as high as 0.99 with a sensitivity value of 52 mV/decade as obtained at 500 °C. Analysis of the sensing mechanism suggests that the gas phase reactions within the porous LSM95 layers are critically important in determining the response voltages. PMID:26205270

Formulation of Ionic-Liquid Electrolyte To Expand the Voltage Window of Supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Van Aken, Katherine L.; Beidaghi, Majid; Gogotsi, Yury

2015-03-18

An effective method to expand the operating potential window (OPW) of electrochemical capacitors based on formulating the ionic-liquid (IL) electrolytes is reported. Using model electrochemical cells based on two identical onion-like carbon (OLC) electrodes and two different IL electrolytes and their mixtures, it was shown that the asymmetric behavior of the electrolyte cation and anion toward the two electrodes limits the OPW of the cell and therefore its energy density. Also, a general solution to this problem is proposed by formulating the IL electrolyte mixtures to balance the capacitance of electrodes in a symmetric supercapacitor.

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

Comparison of physical and electrical properties of GZO/ZnO buffer layer and GZO as source and drain electrodes of α-IGZO thin-film transistors

Energy Technology Data Exchange (ETDEWEB)

Wu, Jia-Ling; Lin, Han-Yu; Su, Bo-Yuan; Chen, Yu-Cheng [Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Chu, Sheng-Yuan, E-mail: chusy@mail.ncku.edu.tw [Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Liu, Ssu-Yin [Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Chang, Chia-Chiang; Wu, Chin-Jyi [Industrial Technology Research Institute, Mechanical and Systems Research Laboratories, Hsinchu 310, Taiwan (China)

2014-04-01

Highlights: • The electrodes of bi-layer GZO/ ZnO and single-layer GZO in α-IGZO TFT were compared. • The TFT performances of two different structures were systematically investigated. • The bi-layer GZO/100-nm ZnO S/D electrodes showed the better TFT device properties. - Abstract: In this research, top-gate bottom-contact thin-film transistors (TFTs) made with amorphous indium gallium zinc oxide (α-IGZO) active layers were grown using the radio-frequency sputtering technique. Two kinds of source and drain (S/D) electrodes, namely bi-layer GZO/100-nm ZnO buffer layer/Corning 1737 and single-layer GZO/Corning 1737, used in the TFT devices and the electric characteristics of the devices were compared. To explain the differences in the TFT performances with these different S/D electrodes, X-ray reflectivity (XRR) and contact angles were measured. The α-IGZO TFT with the bi-layer GZO/100-nm ZnO buffer layer structure as S/D electrodes exhibited superior device performance compared to that of the TFT with a single-layer GZO structure, with a higher thin film density (5.94 g/cm{sup 3}), lower surface roughness (0.817 nm), and larger surface energy (62.07 mJ/m{sup 2}) and better adhesion properties of neighboring α-IGZO films. In addition, the mechanisms responsible for the GZO/100-nm ZnO buffer layer/Corning 1737 structure S/D electrodes improving the device characteristics were systematically investigated. The α-IGZO TFT saturation mobility, subthreshold voltage, on/off current ratio, and the trap density of the GZO/100-nm ZnO buffer layer/Corning 1737 S/D electrodes were 13.5 cm{sup 2} V{sup −1} S{sup −1}, 0.43 V/decade, 3.56 × 10{sup 7}, and 5.65 × 10{sup 12} eV{sup −1} cm{sup −2}, respectively, indicating the potential of this bi-layer structure to be applied to large-area flat-panel displays.

Comparison of physical and electrical properties of GZO/ZnO buffer layer and GZO as source and drain electrodes of α-IGZO thin-film transistors

International Nuclear Information System (INIS)

Wu, Jia-Ling; Lin, Han-Yu; Su, Bo-Yuan; Chen, Yu-Cheng; Chu, Sheng-Yuan; Liu, Ssu-Yin; Chang, Chia-Chiang; Wu, Chin-Jyi

2014-01-01

Highlights: • The electrodes of bi-layer GZO/ ZnO and single-layer GZO in α-IGZO TFT were compared. • The TFT performances of two different structures were systematically investigated. • The bi-layer GZO/100-nm ZnO S/D electrodes showed the better TFT device properties. - Abstract: In this research, top-gate bottom-contact thin-film transistors (TFTs) made with amorphous indium gallium zinc oxide (α-IGZO) active layers were grown using the radio-frequency sputtering technique. Two kinds of source and drain (S/D) electrodes, namely bi-layer GZO/100-nm ZnO buffer layer/Corning 1737 and single-layer GZO/Corning 1737, used in the TFT devices and the electric characteristics of the devices were compared. To explain the differences in the TFT performances with these different S/D electrodes, X-ray reflectivity (XRR) and contact angles were measured. The α-IGZO TFT with the bi-layer GZO/100-nm ZnO buffer layer structure as S/D electrodes exhibited superior device performance compared to that of the TFT with a single-layer GZO structure, with a higher thin film density (5.94 g/cm 3 ), lower surface roughness (0.817 nm), and larger surface energy (62.07 mJ/m 2 ) and better adhesion properties of neighboring α-IGZO films. In addition, the mechanisms responsible for the GZO/100-nm ZnO buffer layer/Corning 1737 structure S/D electrodes improving the device characteristics were systematically investigated. The α-IGZO TFT saturation mobility, subthreshold voltage, on/off current ratio, and the trap density of the GZO/100-nm ZnO buffer layer/Corning 1737 S/D electrodes were 13.5 cm 2 V −1 S −1 , 0.43 V/decade, 3.56 × 10 7 , and 5.65 × 10 12 eV −1 cm −2 , respectively, indicating the potential of this bi-layer structure to be applied to large-area flat-panel displays

Sculptured platinum nanowire counter electrodes for dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Lee, Hyeonseok [Department of Electrical Engineering, Pennsylvania State University, University Park 16802 (United States); Horn, Mark W., E-mail: MHorn@engr.psu.edu [Department of Engineering Science and Mechanics, Pennsylvania State University, University Park 16802-6812 (United States)

2013-07-01

Sculptured platinum nanowire thin films were formed by oblique angle electron beam evaporation with a 5° vapor incidence angle and incorporated as counter electrodes for dye-sensitized solar cells (DSSCs). For the comparison of the performance, bare fluorine doped tin oxide, planar Pt electrodes and counter electrodes treated with chloroplatinic acid were prepared. The sculptured Pt nanowire electrodes showed five times lower charge transfer resistance (0.121 [Ω∗cm{sup 2}]) than that of Pt planar electrode (0.578 [Ω∗cm{sup 2}]) and when the Pt nanowire electrodes are treated with an H{sub 2}PtCl{sub 6} solution have more than ten times lower charge transfer resistance (0.04025 [Ω∗cm{sup 2}]). Moreover, Pt nanowire films used as a counter electrode lead to enhancement in current density and efficiency in comparison with Pt planar counter electrodes. The conversion efficiency with planar electrodes was 5.1 [%] while the efficiency of DSSC with platinum nanowire counter electrodes reached to 5.63 [%] under AM 1.5 illumination. - Highlights: • Pt sculptured thin films (STFs) fabricated by electron beam evaporator. • The STFs featured higher roughness and lower charge transfer resistance. • Improved performance of dye-sensitized solar cells by Pt STFs counter electrodes.

344 cm x 86 cm low mass vacuum window

International Nuclear Information System (INIS)

Reimers, R.M.; Porter, J.; Meneghetti, J.; Wilde, S.; Miller, R.

1983-08-01

The LBL Heavy Ion Spectrometer System (HISS) superconducting magnet contains a 1 m x 3.45 m x 2 m vacuum tank in its gap. A full aperture thin window was needed to minimize background as the products of nuclear collisions move from upstream targets to downstream detectors. Six windows were built and tested in the development process. The final window's unsupported area is 3m 2 with a 25 cm inward deflection. The design consists of a .11 mm Nylon/aluminum/polypropylene laminate as a gas seal and .55 mm woven aramid fiber for strength. Total mass is 80 milligrams per cm 2 . Development depended heavily on past experience and testing. Safety considerations are discussed

Patterning Method for Silver Nanoparticle Electrodes in Fully Solution-Processed Organic Thin-Film Transistors Using Selectively Treated Hydrophilic and Hydrophobic Surfaces

Science.gov (United States)

Fukuda, Kenjiro; Takeda, Yasunori; Kobayashi, Yu; Shimizu, Masahiro; Sekine, Tomohito; Kumaki, Daisuke; Kurihara, Masato; Sakamoto, Masatomi; Tokito, Shizuo

2013-05-01

Fully solution-processed organic thin-film transistor (OTFT) devices have been fabricated with simple patterning process at a relatively low process temperature of 100 °C. In the patterning process, a hydrophobic amorphous fluoropolymer material, which was used as the gate dielectric layer and the underlying base layer, was treated with an oxygen plasma to selectively change its surface wetting properties from hydrophobic to hydrophilic. Silver source and drain electrodes were successfully formed in the treated areas with highly uniform line widths and without residues between the electrodes. Nonuniformities in the thickness of the silver electrodes originating from the “coffee-ring” effect were suppressed by optimizing the blend of solvents used with the silver nanoparticles, such that the printed electrodes are appropriate for bottom-gate OTFT devices. A fully solution-processed OTFT device using a polymer semiconductor material (PB16TTT) exhibited good electrical performance with no hysteresis in its transfer characteristics and with good linearity in its output characteristics. A relatively high carrier mobility of 0.14 cm2 V-1 s-1 and an on/off ratio of 1×105 were obtained with the fabricated TFT device.

Thin film microelectrodes for electrochemical detection of neurotransmitters

DEFF Research Database (Denmark)

Larsen, Simon Tylsgaard

An important signaling process in the nervous system is the release of chemical messengers called neurotransmitters from neurons. In this thesis alternative thin film electrode materials for applications targeting electrochemical detection of neurotransmitters in chip devices were evaluated...... and conductive polymer microelectrodes made of Pedot:Pss were also fabricated and used successfully to measure transmitter release from cells. The use of different thin film electrodes for low-noise amperometric measurements of single events of transmitter release from neuronal cells was studied....... For this application a very low current noise is needed together with a large temporal resolution. It was shown, that resistive and capacitive properties of thin film electrode materials are determining their usefulness in low-noise amperometric measurements. An analytical expression for the noise was derived...

Thin layer spectroelectrochemical studies of pertechnetate reduction on the gold electrodes in acidic media

International Nuclear Information System (INIS)

Chotkowski, M.; Czerwiński, A.

2014-01-01

The electroreduction of pertechnetate ions has been examined in sulfuric acid solutions (0.5 M ÷ 4 M H 2 SO 4 ) using rotating disc electrodes (Au-RDE) and optically transparent thin layer spectroelectrochemical cells (Au/RVC-OTTLE). Soluble Tc(III,IV) species with absorption bands at 502 nm were found to be formed during the reduction of TcO 4 − . The hydrodynamic experiments (Au-RDE) have shown the influence of the acidity of the solution on the activation energy of the electroreduction of the pertechnetate ions to technetium(III,IV) species. The value of the activation energy calculated for limiting current was found to increase from 12.6 ± 1.1 kJ mol −1 for 4 M H 2 SO 4 to 20.1 ± 0.8 kJ mol −1 for 0.5 M H 2 SO 4 . Such an effect suggests an influence of the acid concentration on the structure of obtained products, which are soluble or insoluble Tc species. Thin layer spectroelectrochemical experiments allowed calculation of the redox standard potentials for Tc 2 O 2 3+ /TcO(OH) (aq) system which was found to be equal to 0.255 V vs. Ag,AgCl (KClsat.)

A Solid-State Thin-Film Ag/AgCl Reference Electrode Coated with Graphene Oxide and Its Use in a pH Sensor

Directory of Open Access Journals (Sweden)

Tae Yong Kim

2015-03-01

Full Text Available In this study, we describe a novel solid-state thin-film Ag/AgCl reference electrode (SSRE that was coated with a protective layer of graphene oxide (GO. This layer was prepared by drop casting a solution of GO on the Ag/AgCl thin film. The potential differences exhibited by the SSRE were less than 2 mV for 26 days. The cyclic voltammograms of the SSRE were almost similar to those of a commercial reference electrode, while the diffusion coefficient of Fe(CN63− as calculated from the cathodic peaks of the SSRE was 6.48 × 10−6 cm2/s. The SSRE was used in conjunction with a laboratory-made working electrode to determine its suitability for practical use. The average pH sensitivity of this combined sensor was 58.5 mV/pH in the acid-to-base direction; the correlation coefficient was greater than 0.99. In addition, an integrated pH sensor that included the SSRE was packaged in a secure digital (SD card and tested. The average sensitivity of the chip was 56.8 mV/pH, with the correlation coefficient being greater than 0.99. In addition, a pH sensing test was also performed by using a laboratory-made potentiometer, which showed a sensitivity of 55.4 mV/pH, with the correlation coefficient being greater than 0.99.

Vacuum-Assisted Low-Temperature Synthesis of Reduced Graphene Oxide Thin-Film Electrodes for High-Performance Transparent and Flexible All-Solid-State Supercapacitors.

Science.gov (United States)

Aytug, Tolga; Rager, Matthew S; Higgins, Wesley; Brown, Forrest G; Veith, Gabriel M; Rouleau, Christopher M; Wang, Hui; Hood, Zachary D; Mahurin, Shannon M; Mayes, Richard T; Joshi, Pooran C; Kuruganti, Teja

2018-04-04

Simple and easily integrated design of flexible and transparent electrode materials affixed to polymer-based substrates hold great promise to have a revolutionary impact on the functionality and performance of energy storage devices for many future consumer electronics. Among these applications are touch sensors, roll-up displays, photovoltaic cells, health monitors, wireless sensors, and wearable communication devices. Here, we report an environmentally friendly, simple, and versatile approach to produce optically transparent and mechanically flexible all-solid-state supercapacitor devices. These supercapacitors were constructed on tin-doped indium oxide coated polyethylene terephthalate substrates by intercalation of a polymer-based gel electrolyte between two reduced graphene oxide (rGO) thin-film electrodes. The rGO electrodes were fabricated simply by drop-casting of graphene oxide (GO) films, followed by a novel low-temperature (≤250 °C) vacuum-assisted annealing approach for the in situ reduction of GO to rGO. A trade-off between the optical transparency and electrochemical performance is determined by the concentration of the GO in the initial dispersion, whereby the highest capacitance (∼650 μF cm -2 ) occurs at a relatively lower optical transmittance (24%). Notably, the all-solid-state supercapacitors demonstrated excellent mechanical flexibility with a capacity retention rate above 90% under various bending angles and cycles. These attributes underscore the potential of the present approach to provide a path toward the realization of thin-film-based supercapacitors as flexible and transparent energy storage devices for a variety of practical applications.

A solid-state thin-film Ag/AgCl reference electrode coated with graphene oxide and its use in a pH sensor.

Science.gov (United States)

Kim, Tae Yong; Hong, Sung A; Yang, Sung

2015-03-17

In this study, we describe a novel solid-state thin-film Ag/AgCl reference electrode (SSRE) that was coated with a protective layer of graphene oxide (GO). This layer was prepared by drop casting a solution of GO on the Ag/AgCl thin film. The potential differences exhibited by the SSRE were less than 2 mV for 26 days. The cyclic voltammograms of the SSRE were almost similar to those of a commercial reference electrode, while the diffusion coefficient of Fe(CN)63- as calculated from the cathodic peaks of the SSRE was 6.48 × 10-6 cm2/s. The SSRE was used in conjunction with a laboratory-made working electrode to determine its suitability for practical use. The average pH sensitivity of this combined sensor was 58.5 mV/pH in the acid-to-base direction; the correlation coefficient was greater than 0.99. In addition, an integrated pH sensor that included the SSRE was packaged in a secure digital (SD) card and tested. The average sensitivity of the chip was 56.8 mV/pH, with the correlation coefficient being greater than 0.99. In addition, a pH sensing test was also performed by using a laboratory-made potentiometer, which showed a sensitivity of 55.4 mV/pH, with the correlation coefficient being greater than 0.99.

Energy deposition in the window of the TOTEM Roman pot for the nominal TOTEM run

CERN Document Server

Dimovasili, E

2005-01-01

The TOTEM Roman Pot needs to be protected from possible accidents. One of the most serious accident scenarios is the beam loss during an asynchronous abort dump. In this case of dump failure it is possible that a deflected bunch hits the Roman Pot, causing severe damage to its thin window. This technical note discusses the results of FLUKA Monte Carlo studies that have been performed in order to calculate the energy deposition and the temperature increase in the thin window due to the nominal LHC bunch.

Strategies of Miniaturised Reference Electrodes Integrated in a Silicon Based “one chip” pH Sensor

OpenAIRE

Simonis, Anette; Lüth, Hans; Wang, Joseph; Schöning, J.

2003-01-01

Different types of Ag/AgCl reference electrodes have been realised by means of thin- and thick-film technique. For inner electrolyte, KCl-containing membranes have been deposited and different coatings have been used to protect the reference electrode from a fast leaching out of KCl. The stability of the potential of the reference electrodes without KClcontaining membranes in 3 M KCl was about 7 hours for thin-film electrodes and up to 90 hours for thick-film electrodes. The reference electro...

Experimental and analytical investigation of an MHD channel window frame

International Nuclear Information System (INIS)

Srinivasan, M.G.; Krajcinovic, D.

1977-01-01

A common design of magnetohydrodynamic (MHD) generator channel emphasizes a series of mutually connected window frames providing the support for electrodes and containing the jet of ionized gases. Structurally, a window frame is a rectangular frame with a cross section in the form of a quadrilateral weakened by one or more holes forming the cooling system. Window frames are joined together to make a beam with a box cross section by means of shear pins. A typical window frame is subjected to a rather severe environment characterized by large pressure and high temperatures. The main sources of stresses and strains would include static and dynamic gas pressures and thermal fields characterized by large gradients across the thickness of frame members. The authors consider only the stresses associated with thermal fields. The actual problem is still a very complex one involving analysis of the heat conduction through the electrode-frame system heated by the gas and cooled by the coolant fluid and determination of stresses (elastic and plastic) in a frame with an irregular cross section. In order to obtain a reasonable qualitative and quantitative insight into the phenomenon, three distinctly different approaches have been used: a large elasto-plastic finite element program was used to determine the stresses in the actual frame, an experiment was performed to establish the stress concentrations around holes needed for the passage of coolant, and a two-bar model was used in order to assess the time dependent behavior of the structure for various loading conditions. (Auth.)

Scalable Fabrication of Integrated Nanophotonic Circuits on Arrays of Thin Single Crystal Diamond Membrane Windows.

Science.gov (United States)

Piracha, Afaq H; Rath, Patrik; Ganesan, Kumaravelu; Kühn, Stefan; Pernice, Wolfram H P; Prawer, Steven

2016-05-11

Diamond has emerged as a promising platform for nanophotonic, optical, and quantum technologies. High-quality, single crystalline substrates of acceptable size are a prerequisite to meet the demanding requirements on low-level impurities and low absorption loss when targeting large photonic circuits. Here, we describe a scalable fabrication method for single crystal diamond membrane windows that achieves three major goals with one fabrication method: providing high quality diamond, as confirmed by Raman spectroscopy; achieving homogeneously thin membranes, enabled by ion implantation; and providing compatibility with established planar fabrication via lithography and vertical etching. On such suspended diamond membranes we demonstrate a suite of photonic components as building blocks for nanophotonic circuits. Monolithic grating couplers are used to efficiently couple light between photonic circuits and optical fibers. In waveguide coupled optical ring resonators, we find loaded quality factors up to 66 000 at a wavelength of 1560 nm, corresponding to propagation loss below 7.2 dB/cm. Our approach holds promise for the scalable implementation of future diamond quantum photonic technologies and all-diamond photonic metrology tools.

Polycrystalline boron-doped diamond electrodes for electrocatalytic and electrosynthetic applications.

Science.gov (United States)

Ivandini, Tribidasari A; Einaga, Yasuaki

2017-01-24

Boron-doped diamond (BDD) electrodes are recognized as being superior to other electrode materials due to their outstanding chemical and dimensional stability, their exceptionally low background current, the extremely wide potential window for water electrolysis that they have, and their excellent biocompatibility. However, whereas these properties have been utilized in the rapid development of electroanalytical applications, very few studies have been done in relation to their applications in electrocatalysis or electrosynthesis. In this report, following on from reports of the electrosynthesis of various products through anodic and cathodic reactions using BDD electrodes, the potential use of these electrodes in electrosynthesis is discussed.

Water-soluble polyelectrolyte-grafted multiwalled carbon nanotube thin films for efficient counter electrode of dye-sensitized solar cells.

Science.gov (United States)

Han, Jinkyu; Kim, Hyunju; Kim, Dong Young; Jo, Seong Mu; Jang, Sung-Yeon

2010-06-22

Water-soluble, polyelectrolyte-grafted multiwalled carbon nanotubes (MWCNTs), MWCNT-g-PSSNa, were synthesized using a "grafting to" route. MWCNT-g-PSSNa thin films fabricated by an electrostatic spray (e-spray) technique were used as the counter electrode (CE) for dye-sensitized solar cells (DSSCs). The e-sprayed MWCNT-g-PSSNa thin-film-based CEs (MWCNT-CE) were uniform over a large area, and the well-exfoliated MWCNTs formed highly interconnected network structures. The electrochemical catalytic activity of the MWCNT-CE at different thicknesses was investigated. The MWCNT-g-PSSNa thin film showed high efficiency as a CE in DSSCs. The power conversion efficiency (PCE) of the DSSCs using the MWCNT-g-PSSNa thin-film-based CE (DSSC-MWCNT) was >6% at a CE film thickness of approximately 0.3 microm. The optimum PCE was >7% at a film thickness of approximately 1 microm, which is 20-50 times thinner than conventional carbon-based CE. The charge transfer resistance at the MWCNT-CE/electrolyte interface was 1.52 Omega cm(2) at a MWCNT-CE thickness of 0.31 microm, which is lower than that of a Pt-CE/electrolyte interface, 1.78 Omega cm(2). This highlights the potential for the low-cost CE fabrication of DSSCs using a facile deposition technique from an environmentally "friendly" solution at low temperatures.

Fluorine doped vanadium dioxide thin films for smart windows

International Nuclear Information System (INIS)

Kiri, Pragna; Warwick, Michael E.A.; Ridley, Ian; Binions, Russell

2011-01-01

Thermochromic fluorine doped thin films of vanadium dioxide were deposited from the aerosol assisted chemical vapour deposition reaction of vanadyl acetylacetonate, ethanol and trifluoroacetic acid on glass substrates. The films were characterised with scanning electron microscopy, variable temperature Raman spectroscopy and variable temperature UV/Vis spectroscopy. The incorporation of fluorine in the films led to an increase in the visible transmittance of the films whilst retaining the thermochromic properties. This approach shows promise for improving the aesthetic properties of vanadium dioxide thin films.

Fabrication of Nickel/nanodiamond/boron-doped diamond electrode for non-enzymatic glucose biosensor

International Nuclear Information System (INIS)

Dai, Wei; Li, Mingji; Gao, Sumei; Li, Hongji; Li, Cuiping; Xu, Sheng; Wu, Xiaoguo; Yang, Baohe

2016-01-01

Highlights: • Nanodiamonds (NDs) were electrophoretically deposited on the BDD film. • The NDs significantly extended the potential window. • Ni/NDs/BDD electrode was prepared by electrodeposition. • The electrode shows good catalytic activity for glucose oxidation. - Abstract: A stable and sensitive non-enzymatic glucose sensor was prepared by modifying a boron-doped diamond (BDD) electrode with nickel (Ni) nanosheets and nanodiamonds (NDs). The NDs were electrophoretically deposited on the BDD surface, and acted as nucleation sites for the subsequent electrodeposition of Ni. The morphology and composition of the modified BDD electrodes were characterized by field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively. The Ni nanosheet-ND modified BDD electrode exhibited good current response towards the non-enzymatic oxidation of glucose in alkaline media. The NDs significantly extended the potential window. The response to glucose was linear over the 0.2–1055.4-μM range. The limit of detection was 0.05 μM, at a signal-to-noise ratio of 3. The Ni nanosheet-ND/BDD electrode exhibited good selectivity, reproducibility and stability. Its electrochemical performance, low cost and simple preparation make it a promising non-enzymatic glucose sensor.

Enhancement of photocurrents due to the oxidation of water and organic compounds at BiZn2VO6 particulate thin film electrodes by treatment with a TiCl4 solution

International Nuclear Information System (INIS)

Liu Haimei; Imanishi, Akihito; Yang Wensheng; Nakato, Yoshihiro

2010-01-01

Photocurrents due to water oxidation at BiZn 2 VO 6 (E g 2.4 eV) particulate thin film electrodes were largely enhanced by pre-treatment with an aqueous TiCl 4 solution. Photocurrents for BiZn 2 VO 6 electrodes with no TiCl 4 treatment were also enhanced by the addition of organic compounds such as methanol and trimethyl amine to the aqueous electrolyte. Interestingly, such enhanced photocurrents by organic compounds were further enhanced by the TiCl 4 pre-treatment. EDAX and SEM investigations showed the formation of a flock-like TiO 2 overlayer on BiZn 2 VO 6 particles after the TiCl 4 treatment. The photocurrent enhancement by the TiCl 4 pre-treatment is thus mainly attributed to the necking effect of the flock-like TiO 2 overlayer, which facilitates the transport of photogenerated electrons within the BiZn 2 VO 6 particulate thin film electrode.

Novel thin/tunable gas diffusion electrodes with ultra-low catalyst loading for hydrogen evolution reactions in proton exchange membrane electrolyzer cells

Energy Technology Data Exchange (ETDEWEB)

Kang, Zhenye; Yang, Gaoqiang; Mo, Jingke; Li, Yifan; Yu, Shule; Cullen, David A.; Retterer, Scott T.; Toops, Todd J.; Bender, Guido; Pivovar, Bryan S.; Green, Johney B.; Zhang, Feng-Yuan

2018-05-01

Proton exchange membrane electrolyzer cells (PEMECs) have received great attention for hydrogen/oxygen production due to their high efficiencies even at low-temperature operation. Because of the high cost of noble platinum-group metal (PGM) catalysts (Ir, Ru, Pt, etc.) that are widely used in water splitting, a PEMEC with low catalyst loadings and high catalyst utilizations is strongly desired for its wide commercialization. In this study, the ultrafast and multiscale hydrogen evolution reaction (HER) phenomena in an operating PEMEC is in-situ observed for the first time. The visualization results reveal that the HER and hydrogen bubble nucleation mainly occur on catalyst layers at the rim of the pores of the thin/tunable liquid/gas diffusion layers (TT-LGDLs). This indicates that the catalyst material of the conventional catalyst-coated membrane (CCM) that is located in the middle area of the LGDL pore is underutilized/inactive. Based on this discovery, a novel thin and tunable gas diffusion electrode (GDE) with a Pt catalyst thickness of 15 nm and a total thickness of about 25 um has been proposed and developed by taking advantage of advanced micro/nano manufacturing. The novel thin GDEs are comprehensively characterized both ex-situ and in-situ, and exhibit excellent PEMEC performance. More importantly, they achieve catalyst mass activity of up to 58 times higher than conventional CCM at 1.6 V under the operating conditions of 80 degrees C and 1 atm. This study demonstrates a promising concept for PEMEC electrode development, and provides a direction of future catalyst designs and fabrications for electrochemical devices.

Electrochemical behavior of LiCoO2 as aqueous lithium-ion battery electrodes

KAUST Repository

Ruffo, Riccardo; Wessells, Colin; Huggins, Robert A.; Cui, Yi

2009-01-01

.e., as the counter electrode. A commercial reference electrode is also present. Both the working and the counter electrodes have been prepared as thin layers on a metallic substrate using the procedures typical for the study of electrodes for lithium-ion batteries

Wet chemical preparation of YVO{sub 4}:Eu thin films as red-emitting phosphor layers for fully transparent flat dielectric discharge lamp

Energy Technology Data Exchange (ETDEWEB)

Klausch, A. [Institute for Inorganic Chemistry, Dresden University of Technology, Mommsenstr. 6, 01069 Dresden (Germany); Althues, H. [Fraunhofer Institute for Material and Beam Technology Winterbergstr. 28, 01309 Dresden (Germany); Freudenberg, T. [Leibniz Institute for Solid State and Materials Research, Helmholtzstrasse 20, 01069 Dresden (Germany); Kaskel, S., E-mail: Stefan.Kaskel@chemie.tu-dresden.de [Institute for Inorganic Chemistry, Dresden University of Technology, Mommsenstr. 6, 01069 Dresden (Germany)

2012-04-30

Highly transparent YVO{sub 4}:Eu thin films were deposited via dip coating of liquid nanoparticle dispersions on glass substrates. Annealing of the nanoparticle layers resulted in restructuring of the material into oriented crystalline films. The crystallinity was confirmed using powder X-ray diffraction. Film thickness was adjusted to 467 nm by multiple deposition. The resulting coatings show > 99% absorbance for wavelength below 300 nm and > 90% transmission in the visible spectral range. Under UV-light excitation a bright red photoluminescence with a quantum efficiency of 20% is observed. A planar, transparent dielectric barrier discharge lamp was constructed using YVO{sub 4}:Eu coated glasses and transparent electrodes made from antimony-doped tin dioxide thin films. - Highlights: Black-Right-Pointing-Pointer Preparation of highly transparent Eu{sup 3+} doped YVO{sub 4} phosphor thin films. Black-Right-Pointing-Pointer Improved crystallinity and optical properties through heat treatment. Black-Right-Pointing-Pointer Red emitting films on glass substrates were combined with antimony tin oxide thin films. Black-Right-Pointing-Pointer Fully transparent, planar gas discharge lamp as prototype for a light emitting window.

Highly transparent front electrodes with metal fingers for p-i-n thin-film silicon solar cells

Directory of Open Access Journals (Sweden)

Moulin Etienne

2015-01-01

Full Text Available The optical and electrical properties of transparent conductive oxides (TCOs, traditionally used in thin-film silicon (TF-Si solar cells as front-electrode materials, are interlinked, such that an increase in TCO transparency is generally achieved at the cost of reduced lateral conductance. Combining a highly transparent TCO front electrode of moderate conductance with metal fingers to support charge collection is a well-established technique in wafer-based technologies or for TF-Si solar cells in the substrate (n-i-p configuration. Here, we extend this concept to TF-Si solar cells in the superstrate (p-i-n configuration. The metal fingers are used in conjunction with a millimeter-scale textured foil, attached to the glass superstrate, which provides an antireflective and retroreflective effect; the latter effect mitigates the shadowing losses induced by the metal fingers. As a result, a substantial increase in power conversion efficiency, from 8.7% to 9.1%, is achieved for 1-μm-thick microcrystalline silicon solar cells deposited on a highly transparent thermally treated aluminum-doped zinc oxide layer combined with silver fingers, compared to cells deposited on a state-of-the-art zinc oxide layer.

Towards Flexible Transparent Electrodes Based on Carbon and Metallic Materials

Directory of Open Access Journals (Sweden)

Minghui Luo

2017-01-01

Full Text Available Flexible transparent electrodes (FTEs with high stability and scalability are in high demand for the extremely widespread applications in flexible optoelectronic devices. Traditionally, thin films of indium thin oxide (ITO served the role of FTEs, but film brittleness and scarcity of materials limit its further application. This review provides a summary of recent advances in emerging transparent electrodes and related flexible devices (e.g., touch panels, organic light-emitting diodes, sensors, supercapacitors, and solar cells. Mainly focusing on the FTEs based on carbon nanomaterials (e.g., carbon nanotubes and graphene and metal materials (e.g., metal grid and metal nanowires, we discuss the fabrication techniques, the performance improvement, and the representative applications of these highly transparent and flexible electrodes. Finally, the challenges and prospects of flexible transparent electrodes will be summarized.

Window Glazing Types | Efficient Windows Collaborative

Science.gov (United States)

Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards

Window Frame Types | Efficient Windows Collaborative

Science.gov (United States)

Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards

Window Operator Types | Efficient Windows Collaborative

Science.gov (United States)

Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards

Si(Li) detectors with thin dead layers for low energy x-ray detection

International Nuclear Information System (INIS)

Rossington, C.S.; Walton, J.T.; Jaklevic, J.M.

1990-10-01

Regions of incomplete charge collection, or ''dead layers'', are compared for Si(Li) detectors fabricated with Au and Pd entrance window electrodes. The dead layers were measured by characterizing the detector spectral response to x-ray energies above and below the Si Kα absorption edge. It was found that Si(Li) detectors with Pd electrodes exhibit consistently thinner effective Si dead layers than those with Au electrodes. Furthermore, it is demonstrated that the minimum thickness required for low resistivity Pd electrodes is thinner than that required for low resistivity Au electrodes, which further reduces the signal attenuation in Pd/Si(Li) detectors. A model, based on Pd compensation of oxygen vacancies in the SiO 2 at the entrance window Si(Li) surface, is proposed to explain the observed differences in detector dead layer thickness. Electrode structures for optimum Si(Li) detector performance at low x-ray energies are discussed. 18 refs., 8 figs., 1 tab

High power density supercapacitor electrodes of carbon nanotube films by electrophoretic deposition

International Nuclear Information System (INIS)

Du Chunsheng; Pan Ning

2006-01-01

Carbon nanotube thin films have been successfully fabricated by the electrophoretic deposition technique. The supercapacitors built from such thin film electrodes have a very small equivalent series resistance, and a high specific power density over 20 kW kg -1 was thus obtained. More importantly, the supercapacitors showed superior frequency response. Our study also demonstrated that these carbon nanotube thin films can serve as coating layers over ordinary current collectors to drastically enhance the electrode performance, indicating a huge potential in supercapacitor and battery manufacturing

Compliant Electrode and Composite Material for Piezoelectric Wind and Mechanical Energy Conversions

Science.gov (United States)

Chen, Bin (Inventor)

2015-01-01

A thin film device for harvesting energy from wind. The thin film device includes one or more layers of a compliant piezoelectric material formed from a composite of a polymer and an inorganic material, such as a ceramic. Electrodes are disposed on a first side and a second side of the piezoelectric material. The electrodes are formed from a compliant material, such as carbon nanotubes or graphene. The thin film device exhibits improved resistance to structural fatigue upon application of large strains and repeated cyclic loadings.

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

Science.gov (United States)

2014-11-01

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

Capacitor with a composite carbon foam electrode

Science.gov (United States)

Mayer, Steven T.; Pekala, Richard W.; Kaschmitter, James L.

1999-01-01

Carbon aerogels used as a binder for granularized materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid partides being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivity and power to system energy.

Direct growth of metal-organic frameworks thin film arrays on glassy carbon electrode based on rapid conversion step mediated by copper clusters and hydroxide nanotubes for fabrication of a high performance non-enzymatic glucose sensing platform.

Science.gov (United States)

Shahrokhian, Saeed; Khaki Sanati, Elnaz; Hosseini, Hadi

2018-07-30

The direct growth of self-supported metal-organic frameworks (MOFs) thin film can be considered as an effective strategy for fabrication of the advanced modified electrodes in sensors and biosensor applications. However, most of the fabricated MOFs-based sensors suffer from some drawbacks such as time consuming for synthesis of MOF and electrode making, need of a binder or an additive layer, need of expensive equipment and use of hazardous solvents. Here, a novel free-standing MOFs-based modified electrode was fabricated by the rapid direct growth of MOFs on the surface of the glassy carbon electrode (GCE). In this method, direct growth of MOFs was occurred by the formation of vertically aligned arrays of Cu clusters and Cu(OH) 2 nanotubes, which can act as both mediator and positioning fixing factor for the rapid formation of self-supported MOFs on GCE surface. The effect of both chemically and electrochemically formed Cu(OH) 2 nanotubes on the morphological and electrochemical performance of the prepared MOFs were investigated. Due to the unique properties of the prepared MOFs thin film electrode such as uniform and vertically aligned structure, excellent stability, high electroactive surface area, and good availability to analyte and electrolyte diffusion, it was directly used as the electrode material for non-enzymatic electrocatalytic oxidation of glucose. Moreover, the potential utility of this sensing platform for the analytical determination of glucose concentration was evaluated by the amperometry technique. The results proved that the self-supported MOFs thin film on GCE is a promising electrode material for fabricating and designing non-enzymatic glucose sensors. Copyright © 2018 Elsevier B.V. All rights reserved.

Geometrical contribution to the anomalous Nernst effect in TbFeCo thin films

Science.gov (United States)

Ando, Ryo; Komine, Takashi

2018-05-01

The geometrical contribution to the anomalous Nernst effect in magnetic thin films was experimentally investigated by varying the aspect ratios and electrode configurations. The bar-type electrode configuration induces a short-circuit current near both edges of electrodes and decreases the effective Nernst voltage, while the point-contact (PC) electrode exploits the intrinsic Nernst voltage. In a sample with PC electrodes, as the sample width along the transverse direction of the thermal flow increases, the Nernst voltage increases monotonically. Thus, a much wider element with PC electrodes enables us to bring out a larger Nernst voltage by utilizing perpendicularly magnetized thin films.

A novel ultra-thin 3D detector-For plasma diagnostics at JET and ITER tokamaks

International Nuclear Information System (INIS)

Garcia, Francisco; Pelligrini, G.; Balbuena, J.; Lozano, M.; Orava, R.; Ullan, M.

2009-01-01

A novel ultra-thin silicon detector called U3DTHIN has been designed and built for applications that range from Neutral Particle Analyzers (NPA) used in Corpuscular Diagnostics of High Temperature Plasma to very low X-ray spectroscopy. The main purpose of this detector is to provide a state-of-the-art solution to upgrade the current detector system of the NPAs at JET and also to pave the road for the future detection systems of the ITER experimental reactor. Currently the NPAs use a very thin scintillator-photomultiplier tube [F. Garcia, S.S. Kozlovsky, D.V. Balin, Background Properties of CEM, MCP and PMT detectors at n-γ irradiation. Preprint PNPI-2392, Gatchina, 2000, p. 9 ; F. Garcia, S.S. Kozlovsky, V.V. Ianovsky, Scintillation Detectors with Low Sensitivity to n-γ Background. Preprint PNPI-2391, Gatchina, 2000, p. 8 ], and their main drawbacks are poor energy resolution, intrinsic scintillator nonlinearity, and relative low count rate capability and finally poor signal-to-background discrimination for the low-energy channels. The proposed new U3DTHIN detector is based on very thin sensitive substrate, which will provide nearly 100% detection efficiency for ions and at the same time very low sensitivity for neutron and gamma backgrounds. To achieve a very fast collection of the charge carriers generated by the incident ions, a 3D electrode structure [S. Parker, C. Kenney, J. Segal, Nucl. Instr. and Meth. A 395 (1997) 328 ; G. Pellegrini, P. Roy, A. Al-Ajili, R. Bates, L. Haddad, M. Horn, K. Mathieson, J. Melone, V. O'Shea, K.M. Smith, Nucl. Instr. and Meth. A 487 (2002) 19 ] has been introduced in the sensitive volume of the detector. The geometry of the electrode is known to be rad-hard. One of the most innovative features of these detectors is the optimal combination of the thin entrance window and the sensitive substrate thickness, which allows a very large dynamic range for ion detection. GEANT4 simulations were performed to find the losses of energy in

Dioxythiophene-based polymer electrodes for supercapacitor modules.

Science.gov (United States)

Liu, David Y; Reynolds, John R

2010-12-01

We report on the electrochemical and capacitive behaviors of poly(2,2-dimethyl-3,4-propylene-dioxythipohene) (PProDOT-Me2) films as polymeric electrodes in Type I electrochemical supercapacitors. The supercapacitor device displays robust capacitive charging/discharging behaviors with specific capacitance of 55 F/g, based on 60 μg of PProDOT-Me2 per electrode, that retains over 85% of its storage capacity after 32 000 redox cycles at 78% depth of discharge. Moreover, an appreciable average energy density of 6 Wh/kg has been calculated for the device, along with well-behaved and rapid capacitive responses to 1.0 V between 5 to 500 mV s(-1). Tandem electrochemical supercapacitors were assembled in series, in parallel, and in combinations of the two to widen the operating voltage window and to increase the capacitive currents. Four supercapacitors coupled in series exhibited a 4.0 V charging/discharging window, whereas assembly in parallel displayed a 4-fold increase in capacitance. Combinations of both serial and parallel assembly with six supercapacitors resulted in the extension of voltage to 3 V and a 2-fold increase in capacitive currents. Utilization of bipolar electrodes facilitated the encapsulation of tandem supercapacitors as individual, flexible, and lightweight supercapacitor modules.

Influence of the optical window on the performance of TCO/CdS/CdTe solar cells

Energy Technology Data Exchange (ETDEWEB)

Gordillo, G [Universidad Nacional de Colombia, Bogota (Colombia). Dept. de Fisica; Grizalez, M [Univ. de la Amazonia, Florencia (Colombia); Moreno, L C [Dept. de Quimica, Univ. Nacional de Colombia, Bogota (Colombia); Landazabal, F [Dept. de Fisica, Univ. de Cundinamarca, Fusagasuga (Colombia)

2000-07-01

Thin film solar cells, with structure TCO/CdS/CdTe/Cu, were fabricated using the transparent conducting oxides (TCOs) SnO{sub 2}:F, deposited by spray pyrolysis, and ZnO, deposited by reactive evaporation, as transparent electrodes. The TCO/CdS system with the CdS layer deposited by CBD (chemical bath deposition) method acts in the cell as an optical window and the CdTe deposited by CSS (close space sublimation) method acts as absorber layer, being the unique active layer of the cell. Details of the technological aspects of the solar cells fabrication as well as a discussion to explain the effect of the TCO layer on the solar cell performance will be given. The best results obtained in this work were: open circuit voltage of 0.57 V, short circuit current of 13 mA/cm{sup 2}, fill factor of 0.63 and conversion efficiency of 5.8%. (orig.)

Fabrication and characterization of p{sup +}-i-p{sup +} type organic thin film transistors with electrodes of highly doped polymer

Energy Technology Data Exchange (ETDEWEB)

Tadaki, Daisuke [Graduate School of Biomedical Engineering, Tohoku University, Sendai 980-8579 (Japan); Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Sendai 980-8577 (Japan); CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Ma, Teng; Niwano, Michio, E-mail: niwano@riec.tohoku.ac.jp [Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Sendai 980-8577 (Japan); CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Zhang, Jinyu; Iino, Shohei [Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Sendai 980-8577 (Japan); Hirano-Iwata, Ayumi [Graduate School of Biomedical Engineering, Tohoku University, Sendai 980-8579 (Japan); CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Kimura, Yasuo [CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Tokyo University of Technology, Hachioji, Tokyo 192-0982 (Japan); Rosenberg, Richard A. [Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439 (United States)

2016-04-21

Organic thin film transistors (OTFTs) have been explored because of their advantageous features such as light-weight, flexible, and large-area. For more practical application of organic electronic devices, it is very important to realize OTFTs that are composed only of organic materials. In this paper, we have fabricated p{sup +}-i-p{sup +} type of OTFTs in which an intrinsic (i) regioregular poly (3-hexylthiophene) (P3HT) layer is used as the active layer and highly doped p-type (p{sup +}) P3HT is used as the source and drain electrodes. The 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F{sub 4}-TCNQ) was used as the p-type dopant. A fabricating method of p{sup +}-i-p{sup +} OTFTs has been developed by using SiO{sub 2} and aluminum films as capping layers for micro-scaled patterning of the p{sup +}-P3HT electrodes. The characteristics of the OTFTs were examined using the photoelectron spectroscopy and electrical measurements. We demonstrated that the fabricated p{sup +}-i-p{sup +} OTFTs work with carrier injection through a built-in potential at p{sup +}/i interfaces. We found that the p{sup +}-i-p{sup +} OTFTs exhibit better FET characteristics than the conventional P3HT-OTFT with metal (Au) electrodes, indicating that the influence of a carrier injection barrier at the interface between the electrode and the active layer was suppressed by replacing the metal electrodes with p{sup +}-P3HT layers.

Sulfonated Polyaniline Coated Mercury Film Electrodes for Voltammetric Analysis of Metals in Water

Directory of Open Access Journals (Sweden)

Denise Alves Fungaro

2001-11-01

Full Text Available The electrochemical polymerization of 2-aminobenzenesulfonic acid with and without aniline has been carried by cyclic potencial sweep in sulfuric acid solution at the glassy carbon electrode. The polymer and copolymer formed have been characterized voltammetrically. The sulfonated polyaniline coated mercury thin-film electrodes have been evaluated for use with anodic stripping voltammetry. The electrodes were tested and compared with a conventional thin-film mercury electrode. Calibration plots showed linearity up to 10-7 mol L-1. Detection limits for zinc, lead and cadmium test species are very similar at around 12 nmol L-1. Applications to analysis of waters samples are demonstrated.

SILAR deposited Bi2S3 thin film towards electrochemical supercapacitor

Science.gov (United States)

Raut, Shrikant S.; Dhobale, Jyotsna A.; Sankapal, Babasaheb R.

2017-03-01

Bi2S3 thin film electrode has been synthesized by simple and low cost successive ionic layer adsorption and reaction (SILAR) method on stainless steel (SS) substrate at room temperature. The formation of interconnected nanoparticles with nanoporous surface morphology has been achieved and which is favourable to the supercapacitor applications. Electrochemical supercapacitive performance of Bi2S3 thin film electrode has been performed through cyclic voltammetry, charge-discharge and stability studies in aqueous Na2SO4 electrolyte. The Bi2S3 thin film electrode exhibits the specific capacitance of 289 Fg-1 at 5 mVs-1 scan rate in 1 M Na2SO4 electrolyte.

Sputtered carbon as a corrosion barrier for x-ray detector windows

Energy Technology Data Exchange (ETDEWEB)

Rowley, Joseph; Pei, Lei; Davis, Robert C., E-mail: davis@byu.edu; Vanfleet, Richard R. [Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602 (United States); Liddiard, Steven; Harker, Mallorie; Abbott, Jonathan [Moxtek, Inc., 452 W 1260 N, Orem, Utah 84057 (United States)

2016-09-15

Sputtered amorphous carbon thin films were explored as corrosion resistant coatings on aluminum thin films to be incorporated into x-ray detector windows. The requirements for this application include high corrosion resistance, low intrinsic stress, high strains at failure, and high x-ray transmission. Low temperature sputtering was used because of its compatibility with the rest of the window fabrication process. Corrosion resistance was tested by exposure of carbon coated and uncoated Al thin films to humidity. Substrate curvature and bulge testing measurements were used to determine intrinsic stress and ultimate strain at failure. The composition and bonding of the carbon films were further characterized by electron energy loss spectroscopy, Raman spectroscopy, and carbon, hydrogen, and nitrogen elemental analyses. Samples had low compressive stress (down to.08 GPa), a high strain at failure (3%), and a low fraction of sp{sup 3} carbon–carbon bonds (less than 5%). The high breaking strain and excellent x-ray transmission of these sputtered carbon films indicate that they will work well as corrosion barriers in this application.

Wrinkle-free graphene electrodes in zinc tin oxide thin-film transistors for large area applications

Science.gov (United States)

Lee, Se-Hee; Kim, Jae-Hee; Park, Byeong-Ju; Park, Jozeph; Kim, Hyun-Suk; Yoon, Soon-Gil

2017-02-01

Wrinkle-free graphene was used to form the source-drain electrodes in thin film transistors based on a zinc tin oxide (ZTO) semiconductor. A 10 nm thick titanium adhesion layer was applied prior to transferring a conductive graphene film on top of it by chemical detachment. The formation of an interlayer oxide between titanium and graphene allows the achievement of uniform surface roughness over the entire substrate area. The resulting devices were thermally treated in ambient air, and a substantial decrease in field effect mobility is observed with increasing annealing temperature. The increase in electrical resistivity of the graphene film at higher annealing temperatures may have some influence, however the growth of the oxide interlayer at the ZTO/Ti boundary is suggested to be most influential, thereby inducing relatively high contact resistance.

Theoretical vibro-acoustic modeling of acoustic noise transmission through aircraft windows

Science.gov (United States)

Aloufi, Badr; Behdinan, Kamran; Zu, Jean

2016-06-01

In this paper, a fully vibro-acoustic model for sound transmission across a multi-pane aircraft window is developed. The proposed model is efficiently applied for a set of window models to perform extensive theoretical parametric studies. The studied window configurations generally simulate the passenger window designs of modern aircraft classes which have an exterior multi-Plexiglas pane, an interior single acrylic glass pane and a dimmable glass ("smart" glass), all separated by thin air cavities. The sound transmission loss (STL) characteristics of three different models, triple-, quadruple- and quintuple-paned windows identical in size and surface density, are analyzed for improving the acoustic insulation performances. Typical results describing the influence of several system parameters, such as the thicknesses, number and spacing of the window panes, on the transmission loss are then investigated. In addition, a comparison study is carried out to evaluate the acoustic reduction capability of each window model. The STL results show that the higher frequencies sound transmission loss performance can be improved by increasing the number of window panels, however, the low frequency performance is decreased, particularly at the mass-spring resonances.

pH sensing in aqueous solutions using a MnO2 thin film electrodeposited on a glassy carbon electrode

International Nuclear Information System (INIS)

Cherchour, N.; Deslouis, C.; Messaoudi, B.; Pailleret, A.

2011-01-01

An electrolysis technique at a constant potential was used to develop a highly reproducible and fast elaboration method of adherent manganese dioxide thin films on a glassy carbon electrode from aqueous solutions containing sulfuric acid and manganese sulfate. The resulting films were found to have a nanostructured character presumably due rather to birnessite (δ-MnO 2 ) than to γ-MnO 2 , as suggested by their Raman and XRD signatures. They lead to modified electrodes that present an obvious although complex pH dependent potentiometric response. This sensor indeed showed a single slope non-Nernstian linear behaviour over the 1.5-12 pH range for increasing pH direction ('trace'), whereas a Nernstian two slopes linear behaviour was observed for decreasing pH direction ('re-trace'). Preliminary EIS experiments carried out at a pH value of 1.8 seem to reveal a sensitivity mechanism based on proton insertion process at least at highly acidic pH values.

Mobility Enhancement in Amorphous In-Ga-Zn-O Thin-Film Transistor by Induced Metallic in Nanoparticles and Cu Electrodes.

Science.gov (United States)

Hu, Shiben; Ning, Honglong; Lu, Kuankuan; Fang, Zhiqiang; Li, Yuzhi; Yao, Rihui; Xu, Miao; Wang, Lei; Peng, Junbiao; Lu, Xubing

2018-03-27

In this work, we fabricated a high-mobility amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) based on alumina oxide (Al 2 O 3 ) passivation layer (PVL) and copper (Cu) source/drain electrodes (S/D). The mechanism of the high mobility for a-IGZO TFT was proposed and experimentally demonstrated. The conductivity of the channel layer was significantly improved due to the formation of metallic In nanoparticles on the back channel during Al 2 O 3 PVL sputtering. In addition, Ar atmosphere annealing induced the Schottky contact formation between the Cu S/D and the channel layer caused by Cu diffusion. In conjunction with high conductivity channel and Schottky contact, the a-IGZO TFT based on Cu S/D and Al 2 O 3 PVL exhibited remarkable mobility of 33.5-220.1 cm 2 /Vs when channel length varies from 60 to 560 μ m. This work presents a feasible way to implement high mobility and Cu electrodes in a-IGZO TFT, simultaneously.

A concept for switchable, energy-generating ‘smart’ windows

NARCIS (Netherlands)

Debije, M.G.

2010-01-01

Smart’ windows, mostly based on chromogenic events triggered chemically, electrically or otherwise, are able to variably control the amount of light that passes into a room space, but make no use of the rejected light. Photovoltaic ‘windows’ such as those based on thin films or tiled photovoltaic

Organic Light-Emitting Diodes on Solution-Processed Graphene Transparent Electrodes

KAUST Repository

Wu, Junbo; Agrawal, Mukul; Becerril, Héctor A.; Bao, Zhenan; Liu, Zunfeng; Chen, Yongsheng; Peumans, Peter

2010-01-01

Theoretical estimates indicate that graphene thin films can be used as transparent electrodes for thin-film devices such as solar cells and organic light-emitting diodes, with an unmatched combination of sheet resistance and transparency. We

Oxygen Reduction Reaction Activity of Platinum Thin Films with Different Densities

Energy Technology Data Exchange (ETDEWEB)

Ergul, Busra; Begum, Mahbuba; Kariuki, Nancy; Myers, Deborah J.; Karabacak, Tansel

2017-08-24

Platinum thin films with different densities were grown on glassy carbon electrodes by high pressure sputtering deposition and evaluated as oxygen reduction reaction catalysts for polymer electrolyte fuel cells using cyclic voltammetry and rotating disk electrode techniques in aqueous perchloric acid electrolyte. The electrochemically active surface area, ORR mass activity (MA) and specific activity (SA) of the thin film electrodes were obtained. MA and SA were found to be higher for low-density films than for high-density film.

Thermal, structural, and fabrication aspects of diamond windows for high power synchrotron x-ray beamlines

International Nuclear Information System (INIS)

Khounsary, A.M.; Phillips, W.

1992-01-01

Recent advances in chemical vapor deposition (CVD) technology have made it possible to produce thin free-standing diamond foils that can be used as the window material in high heat load, synchrotron beamlines. Numerical simulations suggest that these windows can offer an attractive and at times the only altemative to beryllium windows for use in third generation x-ray synchrotron radiation beamlines. Utilization, design, and fabrication aspects of diamond windows for high heat load x-ray beamlines are discussed, as are the microstructure characteristics bearing on diamond's performance in this role. Analytic and numerical results are also presented to provide a basis for the design and testing of such windows

Effect of deposition temperature on the properties of Al-doped ZnO films prepared by pulsed DC magnetron sputtering for transparent electrodes in thin-film solar cells

International Nuclear Information System (INIS)

Kim, Doo-Soo; Park, Ji-Hyeon; Shin, Beom-Ki; Moon, Kyeong-Ju; Son, Myoungwoo; Ham, Moon-Ho; Lee, Woong; Myoung, Jae-Min

2012-01-01

Highlights: ► Surface-textured AZO films were achieved by combining PDMS method with wet etching. ► The AZO film deposited at 230 °C by PDMS exhibited the best performance. ► It is due to the higher plasma density supplied from PDMS system. ► Wet etching of the films produces a crater-like rough surface morphology. - Abstract: A simple but scalable approach to the production of surface-textured Al-doped ZnO(AZO) films for low-cost transparent electrode applications in thin-film solar cells is introduced in this study by combining pulsed dc magnetron sputtering (PDMS) with wet etching in sequence. First, structural, electrical, and optical properties of the AZO films prepared by a PDMS were investigated as functions of deposition temperature to obtain transparent electrode films that can be used as indium-free alternative to ITO electrodes. Increase in the deposition temperature to 230 °C accompanied the improvement in crystalline quality and doping efficiency, which enabled the lowest electrical resistivity of 4.16 × 10 −4 Ω cm with the carrier concentration of 1.65 × 10 21 cm −3 and Hall mobility of 11.3 cm 2 /V s. The wet etching of the films in a diluted HCl solution resulted in surface roughening via the formation of crater-like structures without significant degradation in the electrical properties, which is responsible for the enhanced light scattering capability required for anti-reflective electrodes in thin film solar cells.

Insulating electrodes: a review on biopotential front ends for dielectric skin–electrode interfaces

International Nuclear Information System (INIS)

Spinelli, Enrique; Haberman, Marcelo

2010-01-01

Insulating electrodes, also known as capacitive electrodes, allow acquiring biopotentials without galvanic contact with the body. They operate with displacement currents instead of real charge currents, and the electrolytic electrode–skin interface is replaced by a dielectric film. The use of insulating electrodes is not the end of electrode interface problems but the beginning of new ones: coupling capacitances are of the order of pF calling for ultra-high input impedance amplifiers and careful biasing, guarding and shielding techniques. In this work, the general requirements of front ends for capacitive electrodes are presented and the different contributions to the overall noise are discussed and estimated. This analysis yields that noise bounds depend on features of the available devices as current and voltage noise, but the final noise level also depends on parasitic capacitances, requiring a careful shield and printed circuit design. When the dielectric layer is placed on the skin, the present-day amplifiers allow achieving noise levels similar to those provided by wet electrodes. Furthermore, capacitive electrode technology allows acquiring high quality ECG signals through thin clothes. A prototype front end for capacitive electrodes was built and tested. ECG signals were acquired with these electrodes in direct contact with the skin and also through cotton clothes 350 µm thick. They were compared with simultaneously acquired signals by means of wet electrodes and no significant differences were observed between both output signals

High Electrocatalytic Response of a Mechanically Enhanced NbC Nanocomposite Electrode Towards Hydrogen Evolution Reaction

KAUST Repository

Coy, Emerson

2017-08-22

Resistant and efficient electrocatalysts for hydrogen evolution reaction (HER) are desired to replace scarce and commercially expensive platinum electrodes. Thin film electrodes of metal-carbides are a promising alternative due to their reduced price and similar catalytic properties. However, most of the studied structures to date neglect long lasting chemical and structural stability, focusing only on electrochemical efficiency. Herein we report on a new approach to easily deposit and control the micro/nanostructure of thin film electrodes based on niobium carbide (NbC) and their electrocatalytic response. We will show that, by improving the mechanical properties of the NbC electrodes, microstructure and mechanical resilience can be obtained whilst maintaining high electro catalytic response. We also address the influence of other parameters such as conductivity and chemical composition on the overall performance of the thin film electrodes. Finally, we show that nanocomposite NbC electrodes are promising candidates towards HER , and furthermore, that the methodology presented here is suitable to produce other transition metal carbides (TM-C) with improved catalytic and mechanical properties.

Proper Installation of Replacement Windows | Efficient Windows

Science.gov (United States)

Collaborative Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring

Chemical synthesis of porous web-structured CdS thin films for photosensor applications

Energy Technology Data Exchange (ETDEWEB)

Gosavi, S.R., E-mail: srgosavi.taloda@gmail.com [C. H. C. Arts, S. G. P. Commerce, and B. B. J. P. Science College, Taloda, Dist., Nandurbar 425413, M. S. (India); Nikam, C.P. [B.S.S.P.M.S. Arts, Commerce and Science College, Songir, Dist., Dhule 424309, M. S. (India); Shelke, A.R.; Patil, A.M. [Department of Physics, Shivaji University, Kolhapur 416004, M.S. (India); Ryu, S.-W. [Department of Physics, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Bhat, J.S. [Department of Physics, Karnatak University, Dharwad 580003 (India); Deshpande, N.G., E-mail: nicedeshpande@yahoo.co.in [Department of Physics, Shivaji University, Kolhapur 416004, M.S. (India)

2015-06-15

The photo-activity of chemically deposited cadmium sulphide (CdS) thin film has been studied. The simple chemical route nucleates the CdS films with size up to the mean free path of the electron. Growth Kinematics of crystalline hexagonal CdS phase in the thin film form was monitored using X-ray diffraction. The time limitation set for the formation of the amorphous/nano-crystalline material is 40 and 60 min. Thereafter enhancement of the crystalline orientation along the desired plane was identified. Web-like porous structured surface morphology of CdS thin film over the entire area is observed. With decrease in synthesis time, increase of band gap energy i.e., a blue spectral shift was seen. The activation energy of CdS thin film at low and high temperature region was examined. It is considered that this activation energy corresponds to the donor levels associated with shallow traps or surface states of CdS thin film. The photo-electrochemical performance of CdS thin films in polysulphide electrolyte showed diode-like characteristics. Exposure of light on the CdS electrode increases the photocurrent. This suggests the possibility of production of free carriers via excited ions and also the light harvesting mechanism due to porous web-structured morphology. These studies hint that the obtained CdS films can work as a photosensor. - Highlights: • Photoactivity of chemically synthesized cadmium sulphide (CdS) thin films was studied. • Web-like porous structured surface morphology of CdS thin film over the entire area was observed. • Blue spectral shift with lowering of the synthesis time suggests films can act as a window layer over the absorber layer. • Porous web-structured CdS thin films can be useful in light harvesting.

Chemical synthesis of porous web-structured CdS thin films for photosensor applications

International Nuclear Information System (INIS)

Gosavi, S.R.; Nikam, C.P.; Shelke, A.R.; Patil, A.M.; Ryu, S.-W.; Bhat, J.S.; Deshpande, N.G.

2015-01-01

The photo-activity of chemically deposited cadmium sulphide (CdS) thin film has been studied. The simple chemical route nucleates the CdS films with size up to the mean free path of the electron. Growth Kinematics of crystalline hexagonal CdS phase in the thin film form was monitored using X-ray diffraction. The time limitation set for the formation of the amorphous/nano-crystalline material is 40 and 60 min. Thereafter enhancement of the crystalline orientation along the desired plane was identified. Web-like porous structured surface morphology of CdS thin film over the entire area is observed. With decrease in synthesis time, increase of band gap energy i.e., a blue spectral shift was seen. The activation energy of CdS thin film at low and high temperature region was examined. It is considered that this activation energy corresponds to the donor levels associated with shallow traps or surface states of CdS thin film. The photo-electrochemical performance of CdS thin films in polysulphide electrolyte showed diode-like characteristics. Exposure of light on the CdS electrode increases the photocurrent. This suggests the possibility of production of free carriers via excited ions and also the light harvesting mechanism due to porous web-structured morphology. These studies hint that the obtained CdS films can work as a photosensor. - Highlights: • Photoactivity of chemically synthesized cadmium sulphide (CdS) thin films was studied. • Web-like porous structured surface morphology of CdS thin film over the entire area was observed. • Blue spectral shift with lowering of the synthesis time suggests films can act as a window layer over the absorber layer. • Porous web-structured CdS thin films can be useful in light harvesting

Roll-to-Roll Laser-Printed Graphene-Graphitic Carbon Electrodes for High-Performance Supercapacitors.

Science.gov (United States)

Kang, Sangmin; Lim, Kyungmi; Park, Hyeokjun; Park, Jong Bo; Park, Seong Chae; Cho, Sung-Pyo; Kang, Kisuk; Hong, Byung Hee

2018-01-10

Carbon electrodes including graphene and thin graphite films have been utilized for various energy and sensor applications, where the patterning of electrodes is essentially included. Laser scribing in a DVD writer and inkjet printing were used to pattern the graphene-like materials, but the size and speed of fabrication has been limited for practical applications. In this work, we devise a simple strategy to use conventional laser-printer toner materials as precursors for graphitic carbon electrodes. The toner was laser-printed on metal foils, followed by thermal annealing in hydrogen environment, finally resulting in the patterned thin graphitic carbon or graphene electrodes for supercapacitors. The electrochemical cells made of the graphene-graphitic carbon electrodes show remarkably higher energy and power performance compared to conventional supercapacitors. Furthermore, considering the simplicity and scalability of roll-to-roll (R2R) electrode patterning processes, the proposed method would enable cheaper and larger-scale synthesis and patterning of graphene-graphitic carbon electrodes for various energy applications in the future.

Performance Standards for Windows | Efficient Windows Collaborative

Science.gov (United States)

Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards

Benefits of Efficient Windows | Efficient Windows Collaborative

Science.gov (United States)

Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards

Assessing Window Replacement Options | Efficient Windows Collaborative

Science.gov (United States)

Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards

Windows for New Construction | Efficient Windows Collaborative

Science.gov (United States)

Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards

Flexible and stretchable electrodes for dielectric elastomer actuators

Science.gov (United States)

Rosset, Samuel; Shea, Herbert R.

2013-02-01

Dielectric elastomer actuators (DEAs) are flexible lightweight actuators that can generate strains of over 100 %. They are used in applications ranging from haptic feedback (mm-sized devices), to cm-scale soft robots, to meter-long blimps. DEAs consist of an electrode-elastomer-electrode stack, placed on a frame. Applying a voltage between the electrodes electrostatically compresses the elastomer, which deforms in-plane or out-of plane depending on design. Since the electrodes are bonded to the elastomer, they must reliably sustain repeated very large deformations while remaining conductive, and without significantly adding to the stiffness of the soft elastomer. The electrodes are required for electrostatic actuation, but also enable resistive and capacitive sensing of the strain, leading to self-sensing actuators. This review compares the different technologies used to make compliant electrodes for DEAs in terms of: impact on DEA device performance (speed, efficiency, maximum strain), manufacturability, miniaturization, the integration of self-sensing and self-switching, and compatibility with low-voltage operation. While graphite and carbon black have been the most widely used technique in research environments, alternative methods are emerging which combine compliance, conduction at over 100 % strain with better conductivity and/or ease of patternability, including microfabrication-based approaches for compliant metal thin-films, metal-polymer nano-composites, nanoparticle implantation, and reel-to-reel production of μm-scale patterned thin films on elastomers. Such electrodes are key to miniaturization, low-voltage operation, and widespread commercialization of DEAs.

On the Preparation and Testing of Fuel Cell Catalysts Using the Thin Film Rotating Disk Electrode Method.

Science.gov (United States)

Inaba, Masanori; Quinson, Jonathan; Bucher, Jan Rudolf; Arenz, Matthias

2018-03-16

We present a step-by-step tutorial to prepare proton exchange membrane fuel cell (PEMFC) catalysts, consisting of Pt nanoparticles (NPs) supported on a high surface area carbon, and to test their performance in thin film rotating disk electrode (TF-RDE) measurements. The TF-RDE methodology is widely used for catalyst screening; nevertheless, the measured performance sometimes considerably differs among research groups. These uncertainties impede the advancement of new catalyst materials and, consequently, several authors discussed possible best practice methods and the importance of benchmarking. The visual tutorial highlights possible pitfalls in the TF-RDE testing of Pt/C catalysts. A synthesis and testing protocol to assess standard Pt/C catalysts is introduced that can be used together with polycrystalline Pt disks as benchmark catalysts. In particular, this study highlights how the properties of the catalyst film on the glassy carbon (GC) electrode influence the measured performance in TF-RDE testing. To obtain thin, homogeneous catalyst films, not only the catalyst preparation, but also the ink deposition and drying procedures are essential. It is demonstrated that an adjustment of the ink's pH might be necessary, and how simple control measurements can be used to check film quality. Once reproducible TF-RDE measurements are obtained, determining the Pt loading on the catalyst support (expressed as Pt wt%) and the electrochemical surface area is necessary to normalize the determined reaction rates to either surface area or Pt mass. For the surface area determination, so-called CO stripping, or the determination of the hydrogen underpotential deposition (Hupd) charge, are standard. For the determination of the Pt loading, a straightforward and cheap procedure using digestion in aqua regia with subsequent conversion of Pt(IV) to Pt(II) and UV-vis measurements is introduced.

Stress evolution in elastic-plastic electrodes during electrochemical processes: A numerical method and its applications

Science.gov (United States)

Wen, Jici; Wei, Yujie; Cheng, Yang-Tse

2018-07-01

Monitoring in real time the stress state in high capacity electrodes during charge-discharge processes is pivotal to the performance assessment and structural optimization of advanced batteries. The wafer curvature measurement technique broadly employed in thin-film industry, together with stress analysis using the Stoney equation, has been successfully adopted to measure in situ the stress in thin film electrodes. How large plastic deformation or interfacial delamination during electrochemical cycles in such electrodes affects the applicability of Stoney equation remains unclear. Here we develop a robust electrochemical-mechanical coupled numerical procedure to investigate the influence of large plastic deformation and interfacial failure on the measured stress in thin film electrodes. We identify how the constitutive behavior of electrode materials and film-substrate interfacial properties affect the measured stress-capacity curves of electrodes, and hence establish the relationship of electrode material parameters with the characteristics of stress-capacity curves. Using Li-ions batteries as examples, we show that plastic deformation and interfacial delamination account for the asymmetric stress-capacity loops seen in in situ stress measurements. The methods used here, along with the finite-element code in the supplementary material, may be used to model the electrode behavior as a function of the state of charge.

12-inch x-ray image intensifier with thin metal input window

Energy Technology Data Exchange (ETDEWEB)

Obata, Yoshiharu; Anno, Hidero; Harao, Norio [Toshiba Corp., Kawasaki, Kanagawa (Japan)

1982-08-01

Borosilicate glass has been used for X-ray input window of image intensifiers (I.I.) up to now. Now two new types of 12-inch metal I.I., RT12301C and RT12302C, have been developed. They use convex 1-mm aluminum (instead of 5-mm borosilicate glass) for the input window. Adopting a high-performance penta-electronic lens and a new type of light guide CsI film, these intensifiers have greatly improved contrast, quantum detection efficiency (QDE) and resolution capability. In spite of low dosage, image quality equivalent to that in the conventional direct radiograph is obtained through combined use of the new-type 12-inch metal I.I. with 0.3-mm small-focal-spot X-ray tube. Great contribution to digital radiography is expected of this I.I.

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

KAUST Repository

Catrysse, Peter B.; Fan, Shanhui

2010-01-01

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

Ozone production by an atmospheric pulsed discharge with pre-ionization electrodes and partly covered electrode

International Nuclear Information System (INIS)

Kaneda, S.; Shimosaki, M.; Hayashi, N.; Ihara, S.; Satoh, S.; Yamabe, C.

2002-01-01

In this paper, results on ozone production by atmospheric pulsed discharge, are reported. In the research, two types of ozonizer (Type I and Type II) have been used to investigate improvements of ozone concentration and production efficiency. The ozonizer has plane-to-plane metal electrodes structure, and pre-ionization electrodes are placed on the high voltage electrodes (Type I). In Type II, the surface of grounded electrode with 20 mm of width is covered partly by dielectric (thin rubber) with 11 mm of width, while the geometry of both metal electrodes is same to Type I. In the case of Type I, maximum concentration of about 100 ppm and maximum yield of 70 g/kWh were obtained at input power of 0.3 W. On the other hands, in the case of Type II, 800 ppm and 100 g/kWh were obtained at input power of 1.5 W. It was found that the ozone concentration and production yield were improved by using electrode covered by dielectric. (author)

TiO 2 counter electrode for electrochromic devices

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science; Volume 38; Issue 2 ... The band gap energy decreases (g) from 3.45 eV for pristine CeO2 to 2.98–3.09 eV ... as counter electrode in electrochromic smart windows in which they are able to retain ...

Efficiency of Nb-Doped ZnO Nanoparticles Electrode for Dye-Sensitized Solar Cells Application

Science.gov (United States)

Anuntahirunrat, Jirapat; Sung, Youl-Moon; Pooyodying, Pattarapon

2017-09-01

The technological of Dye-sensitized solar cells (DSSCs) had been improved for several years. Due to its simplicity and low cost materials with belonging to the part of thin films solar cells. DSSCs have numerous advantages and benefits among the other types of solar cells. Many of the DSSC devices had use organic chemical that produce by specific method to use as thin film electrodes. The organic chemical that widely use to establish thin film electrodes are Zinc Oxide (ZnO), Titanium Dioxide (TiO2) and many other chemical substances. Zinc oxide (ZnO) nanoparticles had been used in DSSCs applications as thin film electrodes. Nanoparticles are a part of nanomaterials that are defined as a single particles 1-100 nm in diameter. From a few year ZnO widely used in DSSC applications because of its optical, electrical and many others properties. In particular, the unique properties and utility of ZnO structure. However the efficiency of ZnO nanoparticles based solar cells can be improved by doped various foreign impurity to change the structures and properties. Niobium (Nb) had been use as a dopant of metal oxide thin films. Using specification method to doped the ZnO nanoparticles thin film can improved the efficiencies of DSSCs. The efficiencies of Nb-doped ZnO can be compared by doping 0 at wt% to 5 at wt% in ZnO nanoparticles thin films that prepared by the spin coating method. The thin film electrodes doped with 3 at wt% represent a maximum efficiencies with the lowest resistivity of 8.95×10-4 Ω·cm.

Strain response of stretchable micro-electrodes: Controlling sensitivity with serpentine designs and encapsulation

International Nuclear Information System (INIS)

Gutruf, Philipp; Walia, Sumeet; Nur Ali, Md; Sriram, Sharath; Bhaskaran, Madhu

2014-01-01

The functionality of flexible electronics relies on stable performance of thin film micro-electrodes. This letter investigates the behavior of gold thin films on polyimide, a prevalent combination in flexible devices. The dynamic behavior of gold micro-electrodes has been studied by subjecting them to stress while monitoring their resistance in situ. The shape of the electrodes was systematically varied to examine resistive strain sensitivity, while an additional encapsulation was applied to characterize multilayer behavior. The realized designs show remarkable tolerance to repetitive strain, demonstrating that curvature and encapsulation are excellent approaches for minimizing resistive strain sensitivity to enable durable flexible electronics

pH sensing in aqueous solutions using a MnO{sub 2} thin film electrodeposited on a glassy carbon electrode

Energy Technology Data Exchange (ETDEWEB)

Cherchour, N. [Laboratoire de Technologie des Materiaux et Genie des Procedes (LTMGP), Departement de Genie des Procedes, Universite A. Mira, Route de Targa Ouzemmour, 06000 Bejaia (Algeria); CNRS, UPR 15, Laboratoire Interfaces et Systemes Electrochimiques (LISE, case courrier 133), 4 Place Jussieu, F-75005 Paris (France); UPMC Univ. Paris VI, UPR 15, Laboratoire Interfaces et Systemes Electrochimiques (LISE, case courrier 133), 4 Place Jussieu, F-75005 Paris (France); Deslouis, C. [CNRS, UPR 15, Laboratoire Interfaces et Systemes Electrochimiques (LISE, case courrier 133), 4 Place Jussieu, F-75005 Paris (France); UPMC Univ. Paris VI, UPR 15, Laboratoire Interfaces et Systemes Electrochimiques (LISE, case courrier 133), 4 Place Jussieu, F-75005 Paris (France); Messaoudi, B. [Laboratoire de Technologie des Materiaux et Genie des Procedes (LTMGP), Departement de Genie des Procedes, Universite A. Mira, Route de Targa Ouzemmour, 06000 Bejaia (Algeria); Pailleret, A., E-mail: alain.pailleret@upmc.fr [CNRS, UPR 15, Laboratoire Interfaces et Systemes Electrochimiques (LISE, case courrier 133), 4 Place Jussieu, F-75005 Paris (France); UPMC Univ. Paris VI, UPR 15, Laboratoire Interfaces et Systemes Electrochimiques (LISE, case courrier 133), 4 Place Jussieu, F-75005 Paris (France)

2011-11-30

An electrolysis technique at a constant potential was used to develop a highly reproducible and fast elaboration method of adherent manganese dioxide thin films on a glassy carbon electrode from aqueous solutions containing sulfuric acid and manganese sulfate. The resulting films were found to have a nanostructured character presumably due rather to birnessite ({delta}-MnO{sub 2}) than to {gamma}-MnO{sub 2}, as suggested by their Raman and XRD signatures. They lead to modified electrodes that present an obvious although complex pH dependent potentiometric response. This sensor indeed showed a single slope non-Nernstian linear behaviour over the 1.5-12 pH range for increasing pH direction ('trace'), whereas a Nernstian two slopes linear behaviour was observed for decreasing pH direction ('re-trace'). Preliminary EIS experiments carried out at a pH value of 1.8 seem to reveal a sensitivity mechanism based on proton insertion process at least at highly acidic pH values.

Optimization of a liquid hydrogen/deuterium target with extremely thin foil windows

International Nuclear Information System (INIS)

Nake, C.J.

1993-09-01

For external experiments at COSY a target of liquid hydrogen or deuterium has been developed, which is very small in order to take advantage of the excellent beam quality of COSY. Targets with thicknesses down to only mm's have been built and operate without bubbles. In order to make the effects of reactions in the windows much smaller than the target reactions, windows with a thickness of about 1.5 μm have been achieved. A novel system which stabilizes the pressure difference between the inside and the outside of the target cell to a small constant value under all target conditions is used. (orig.)

Preparation and characterization of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) composite thin films highly loaded with platinum nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Chang, Chao-Ching, E-mail: ccchang@tku.edu.tw [Department of Chemical and Materials Engineering, Tamkang University, No. 151, Yingzhuan Rd., Danshui Dist., New Taipei City 25137, Taiwan (China); Energy and Opto-Electronic Materials Research Center, Tamkang University, No. 151, Yingzhuan Rd., Danshui Dist., New Taipei City 25137, Taiwan (China); Jiang, Ming-Tai [Department of Chemical and Materials Engineering, Tamkang University, No. 151, Yingzhuan Rd., Danshui Dist., New Taipei City 25137, Taiwan (China); Chang, Chen-Liang; Lin, Cheng-Lan [Department of Chemical and Materials Engineering, Tamkang University, No. 151, Yingzhuan Rd., Danshui Dist., New Taipei City 25137, Taiwan (China); Energy and Opto-Electronic Materials Research Center, Tamkang University, No. 151, Yingzhuan Rd., Danshui Dist., New Taipei City 25137, Taiwan (China)

2011-06-15

Research highlights: {yields} Nano-sized and mono-dispersed Pt nanoparticles were synthesized by a polyol method. {yields} A thin film of PEDOT:PSS loaded with high concentration of Pt nanoparticles has been prepared. {yields} The PEDOT:PSS-Pt modified electrode has good potential to serve as a counter electrode in DSSC. - Abstract: In this work, we propose a simple and efficient, low-temperature ({approx}120 deg. C) process to prepare transparent thin films of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) loaded with high concentration (up to 22.5 wt%) of platinum (Pt) nanoparticles. Firstly, an improved polyol method was modified to synthesize nano-sized ({approx}5 nm) and mono-dispersed Pt particles. These nanoparticles were incorporated into the matrix of PEDOT:PSS thin films via a spin coating/drying procedure. The electrochemical activities of the PEDOT:PSS thin film modified electrodes with respect to the I{sup -}/I{sub 3}{sup -} redox reactions were investigated. It was found that the modified electrode of PEDOT:PSS thin film containing 22.5 wt% Pt exhibited the electrochemical activity comparable to the conventional Pt thin film electrode, suggesting that this electrode has good potential to serve as a counter electrode in dye-sensitized solar cells.

Effect of deposition temperature on the properties of Al-doped ZnO films prepared by pulsed DC magnetron sputtering for transparent electrodes in thin-film solar cells

Energy Technology Data Exchange (ETDEWEB)

Kim, Doo-Soo; Park, Ji-Hyeon; Shin, Beom-Ki; Moon, Kyeong-Ju [Information and Electronic Materials Research Laboratory, Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Son, Myoungwoo [Department of Nanobio Materials and Electronics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Ham, Moon-Ho [Department of Nanobio Materials and Electronics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Lee, Woong [School of Nano and Advanced Materials Engineering, Changwon National University, 9 Sarim-Dong, Changwon, Gyeongnam 641-773 (Korea, Republic of); Myoung, Jae-Min, E-mail: jmmyoung@yonsei.ac.kr [Information and Electronic Materials Research Laboratory, Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of)

2012-10-15

Highlights: Black-Right-Pointing-Pointer Surface-textured AZO films were achieved by combining PDMS method with wet etching. Black-Right-Pointing-Pointer The AZO film deposited at 230 Degree-Sign C by PDMS exhibited the best performance. Black-Right-Pointing-Pointer It is due to the higher plasma density supplied from PDMS system. Black-Right-Pointing-Pointer Wet etching of the films produces a crater-like rough surface morphology. - Abstract: A simple but scalable approach to the production of surface-textured Al-doped ZnO(AZO) films for low-cost transparent electrode applications in thin-film solar cells is introduced in this study by combining pulsed dc magnetron sputtering (PDMS) with wet etching in sequence. First, structural, electrical, and optical properties of the AZO films prepared by a PDMS were investigated as functions of deposition temperature to obtain transparent electrode films that can be used as indium-free alternative to ITO electrodes. Increase in the deposition temperature to 230 Degree-Sign C accompanied the improvement in crystalline quality and doping efficiency, which enabled the lowest electrical resistivity of 4.16 Multiplication-Sign 10{sup -4} {Omega} cm with the carrier concentration of 1.65 Multiplication-Sign 10{sup 21} cm{sup -3} and Hall mobility of 11.3 cm{sup 2}/V s. The wet etching of the films in a diluted HCl solution resulted in surface roughening via the formation of crater-like structures without significant degradation in the electrical properties, which is responsible for the enhanced light scattering capability required for anti-reflective electrodes in thin film solar cells.

A high-performance supercapacitor electrode based on N-doped porous graphene

Science.gov (United States)

Dai, Shuge; Liu, Zhen; Zhao, Bote; Zeng, Jianhuang; Hu, Hao; Zhang, Qiaobao; Chen, Dongchang; Qu, Chong; Dang, Dai; Liu, Meilin

2018-05-01

The development of high-performance supercapacitors (SCs) often faces some contradictory and competing requirements such as excellent rate capability, long cycling life, and high energy density. One effective strategy is to explore electrode materials of high capacitance, electrode architectures of fast charge and mass transfer, and electrolytes of wide voltage window. Here we report a facile and readily scalable strategy to produce high-performance N-doped graphene with a high specific capacitance (∼390 F g-1). A symmetric SC device with a wide voltage window of 3.5 V is also successfully fabricated based on the N-doped graphene electrode. More importantly, the as-assembled symmetric SC delivers a high energy density of 55 Wh kg-1 at a power density of 1800 W kg-1 while maintaining superior cycling life (retaining 96.6% of the initial capacitance after 20,000 cycles). Even at a power density as high as 8800 W kg-1, it still retains an energy density of 29 Wh kg-1, higher than those of previously reported graphene-based symmetric SCs.

Electrical Properties of Al, Ag, Cu, Ti and SS Thin Film for Electrode of Solar Cell

International Nuclear Information System (INIS)

Bambang Siswanto; Wirjoadi; Sudjatmoko; Tjipto Sujitno

2003-01-01

The Al, Ag, Cu, Ti and SS materials were deposited on the surface of glass substrate using plasma DC sputtering technique. The deposition process was done with the following plasma parameters : deposition time, gas pressure and substrate temperature with the aim to obtain a good conductance of thin films. Variation of substrate deposition time was 1 - 15 minutes, gas pressure was 5x10 -2 - 7x10 -2 torr and of temperature was 100 - 300 o C. The resistance measurement has been done by four points probes and the conductivity was calculated using mathematic formulation. It was obtained that the minimum resistance in the order of R = 0.07 Ω, was found at Ag materials and this was obtained at the following plasma parameters : deposition time 15 minutes, gas pressure 6x10 -2 torr and temperature 300 o C, while, the resistance of : Cu, Al, Ti and SS materials were R = 0.13 Ω, R = 450 Ω, R = 633 Ω, R = 911 Ω respectively, It could be concluded that the Ag thin film has a minimum resistance, high conductivity compared to the other materials Al, Cu, Ti and SS. Ag is therefore the suitable material for applying as electrode of solar cell. (author)

A thin film approach for SiC-derived graphene as an on-chip electrode for supercapacitors

Science.gov (United States)

Ahmed, Mohsin; Khawaja, Mohamad; Notarianni, Marco; Wang, Bei; Goding, Dayle; Gupta, Bharati; Boeckl, John J.; Takshi, Arash; Motta, Nunzio; Saddow, Stephen E.; Iacopi, Francesca

2015-10-01

We designed a nickel-assisted process to obtain graphene with sheet resistance as low as 80 Ω square-1 from silicon carbide films on Si wafers with highly enhanced surface area. The silicon carbide film acts as both a template and source of graphitic carbon, while, simultaneously, the nickel induces porosity on the surface of the film by forming silicides during the annealing process which are subsequently removed. As stand-alone electrodes in supercapacitors, these transfer-free graphene-on-chip samples show a typical double-layer supercapacitive behaviour with gravimetric capacitance of up to 65 F g-1. This work is the first attempt to produce graphene with high surface area from silicon carbide thin films for energy storage at the wafer-level and may open numerous opportunities for on-chip integrated energy storage applications.

Effect of heat treatments and window layer processing on the characteristics of CuInGaSe{sub 2} thin film solar cells

Energy Technology Data Exchange (ETDEWEB)

Ramanathan, K.; Contreras, M.A.; Tuttle, J.R. [National Renewable Energy Lab., Golden, CO (United States)] [and others

1996-05-01

Interaction between chemical bath deposited CdS and ZnO window layers are a focus of this paper. Low temperature anneals were used to follow the changes at the interface. Optical absorption spectra show that CdS and ZnO intermix upon annealing. When applied to ZnO/CdS/CuInGaSe{sub 2} thin film solar cells, changes in the short and long wavelength response were observed. The latter is attributed to an increase in the energy gap of the absorber by diffusion of S. The interdiffusion is shown to increase the short wavelength collection, and hence the current density of the devices. Photoluminescence data provides some indication of the quality of the interface.

Alkali metal-refractory metal biphase electrode for AMTEC

Science.gov (United States)

Williams, Roger M. (Inventor); Bankston, Clyde P. (Inventor); Cole, Terry (Inventor); Khanna, Satish K. (Inventor); Jeffries-Nakamura, Barbara (Inventor); Wheeler, Bob L. (Inventor)

1989-01-01

An electrode having increased output with slower degradation is formed of a film applied to a beta-alumina solid electrolyte (BASE). The film comprises a refractory first metal M.sup.1 such as a platinum group metal, suitably platinum or rhodium, capable of forming a liquid or a strong surface adsorption phase with sodium at the operating temperature of an alkali metal thermoelectric converter (AMTEC) and a second refractory metal insoluble in sodium or the NaM.sup.1 liquid phase such as a Group IVB, VB or VIB metal, suitably tungsten, molybdenum, tantalum or niobium. The liquid phase or surface film provides fast transport through the electrode while the insoluble refractory metal provides a structural matrix for the electrode during operation. A trilayer structure that is stable and not subject to deadhesion comprises a first, thin layer of tungsten, an intermediate co-deposited layer of tungsten-platinum and a thin surface layer of platinum.

Replacement Windows for Existing Homes Homes | Efficient Windows

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Collaborative Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring

Plasma etching treatment for surface modification of boron-doped diamond electrodes

Energy Technology Data Exchange (ETDEWEB)

Kondo, Takeshi [Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Ito, Hiroyuki [Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Kusakabe, Kazuhide [Department of Applied Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Ohkawa, Kazuhiro [Department of Applied Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Einaga, Yasuaki [Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522 (Japan); Fujishima, Akira [Kanagawa Academy of Science and Technology (KAST), 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa 213-0012 (Japan); Kawai, Takeshi [Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan)]. E-mail: kawai@ci.kagu.tus.ac.jp

2007-03-01

Boron-doped diamond (BDD) thin film surfaces were modified by brief plasma treatment using various source gases such as Cl{sub 2}, CF{sub 4}, Ar and CH{sub 4}, and the electrochemical properties of the surfaces were subsequently investigated. From X-ray photoelectron spectroscopy analysis, Cl and F atoms were detected on the BDD surfaces after 3 min of Cl{sub 2} and CF{sub 4} plasma treatments, respectively. From the results of cyclic voltammetry and electrochemical AC impedance measurements, the electron-transfer rate for Fe(CN){sub 6} {sup 3-/4-} and Fe{sup 2+/3+} at the BDD electrodes was found to decrease after Cl{sub 2} and CF{sub 4} plasma treatments. However, the electron-transfer rate for Ru(NH{sub 3}){sub 6} {sup 2+/3+} showed almost no change after these treatments. This may have been related to the specific interactions of surface halogen (C-Cl and C-F) moieties with the redox species because no electrical passivation was observed after the treatments. In addition, Raman spectroscopy showed that CH{sub 4} plasma treatment of diamond surfaces formed an insulating diamond-like carbon thin layer on the surfaces. Thus, by an appropriate choice of plasma source, short-duration plasma treatments can be an effective way to functionalize diamond surfaces in various ways while maintaining a wide potential window and a low background current.

Effects of the F₄TCNQ-Doped Pentacene Interlayers on Performance Improvement of Top-Contact Pentacene-Based Organic Thin-Film Transistors.

Science.gov (United States)

Fan, Ching-Lin; Lin, Wei-Chun; Chang, Hsiang-Sheng; Lin, Yu-Zuo; Huang, Bohr-Ran

2016-01-13

In this paper, the top-contact (TC) pentacene-based organic thin-film transistor (OTFT) with a tetrafluorotetracyanoquinodimethane (F₄TCNQ)-doped pentacene interlayer between the source/drain electrodes and the pentacene channel layer were fabricated using the co-evaporation method. Compared with a pentacene-based OTFT without an interlayer, OTFTs with an F₄TCNQ:pentacene ratio of 1:1 showed considerably improved electrical characteristics. In addition, the dependence of the OTFT performance on the thickness of the F₄TCNQ-doped pentacene interlayer is weaker than that on a Teflon interlayer. Therefore, a molecular doping-type F₄TCNQ-doped pentacene interlayer is a suitable carrier injection layer that can improve the TC-OTFT performance and facilitate obtaining a stable process window.

Mobility Enhancement in Amorphous In-Ga-Zn-O Thin-Film Transistor by Induced Metallic in Nanoparticles and Cu Electrodes

Directory of Open Access Journals (Sweden)

Shiben Hu

2018-03-01

Full Text Available In this work, we fabricated a high-mobility amorphous indium-gallium-zinc-oxide (a-IGZO thin-film transistor (TFT based on alumina oxide (Al 2 O 3 passivation layer (PVL and copper (Cu source/drain electrodes (S/D. The mechanism of the high mobility for a-IGZO TFT was proposed and experimentally demonstrated. The conductivity of the channel layer was significantly improved due to the formation of metallic In nanoparticles on the back channel during Al 2 O 3 PVL sputtering. In addition, Ar atmosphere annealing induced the Schottky contact formation between the Cu S/D and the channel layer caused by Cu diffusion. In conjunction with high conductivity channel and Schottky contact, the a-IGZO TFT based on Cu S/D and Al 2 O 3 PVL exhibited remarkable mobility of 33.5–220.1 cm 2 /Vs when channel length varies from 60 to 560 μ m. This work presents a feasible way to implement high mobility and Cu electrodes in a-IGZO TFT, simultaneously.

Design Guidance for New Windows | Efficient Windows Collaborative

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Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards

Selection Process for New Windows | Efficient Windows Collaborative

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Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards

Selection Process for Replacement Windows | Efficient Windows Collaborative

Science.gov (United States)

Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards

Design Guidance for Replacement Windows | Efficient Windows Collaborative

Science.gov (United States)

Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards

Proper Installation of New Windows | Efficient Windows Collaborative

Science.gov (United States)

Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards

Preparation of Pb(Zr0.52Ti0.48)O3 thin films on Pt/RuO2 double electrode by a new sol-gel route

International Nuclear Information System (INIS)

Kim, S.; Choi, Y.; Kim, C.; Oh, Y.

1997-01-01

Pb(Zr 0.52 Ti 0.48 )O 3 (PZT) thin film on Pt/RuO 2 double electrode was successfully prepared by using new alkoxide endash alkanolamine, sol-gel method. It was observed that the use of Pt/RuO 2 double electrode reduced leakage current, resulting in a marked improvement in the leakage characteristics and more reliable capacitors. Typical P-E hysteresis behavior was observed even at low applied voltage of 5 V, manifesting greatly improved remanance and coercivity. Fatigue and breakdown characteristic, measured at 5 V, showed stable behavior and no degradation in polarization was observed up to 10 11 cycles.copyright 1997 Materials Research Society

Rotational electrical impedance tomography using electrodes with limited surface coverage provides window for multimodal sensing

Science.gov (United States)

Lehti-Polojärvi, Mari; Koskela, Olli; Seppänen, Aku; Figueiras, Edite; Hyttinen, Jari

2018-02-01

Electrical impedance tomography (EIT) is an imaging method that could become a valuable tool in multimodal applications. One challenge in simultaneous multimodal imaging is that typically the EIT electrodes cover a large portion of the object surface. This paper investigates the feasibility of rotational EIT (rEIT) in applications where electrodes cover only a limited angle of the surface of the object. In the studied rEIT, the object is rotated a full 360° during a set of measurements to increase the information content of the data. We call this approach limited angle full revolution rEIT (LAFR-rEIT). We test LAFR-rEIT setups in two-dimensional geometries with computational and experimental data. We use up to 256 rotational measurement positions, which requires a new way to solve the forward and inverse problem of rEIT. For this, we provide a modification, available for EIDORS, in the supplementary material. The computational results demonstrate that LAFR-rEIT with eight electrodes produce the same image quality as conventional 16-electrode rEIT, when data from an adequate number of rotational measurement positions are used. Both computational and experimental results indicate that the novel LAFR-rEIT provides good EIT with setups with limited surface coverage and a small number of electrodes.

The water decomposition reactions on boron-doped diamond electrodes

International Nuclear Information System (INIS)

Suffredini, Hugo B.; Machado, Sergio A.S; Avaca, Luis A.

2004-01-01

The electrochemical processes occurring at both edges of the wide electrochemical window of the boron doped diamond (BDD) electrode were studied by polarization curves experiments to evaluate the apparent energy of activation for the rate determining step in each reaction. It was found that the hydrogen evolution reaction occurs by a Volmer-Heyrovsky mechanism with the first step being the RDS. Moreover, the apparent energy of activation calculated from the Tafel plots presented a value as high as 150 kJ mol -1 , indicating the formation of the M-H intermediate that is characteristic for the Volmer step. On the other hand, the apparent energy of activation for the oxygen evolution reaction was found to be 106 kJ mol -1 suggesting that the RDS in this mechanism is the initial adsorption step. In this way, it was demonstrated that the interaction between water molecules and the electrode surface is strongly inhibited on BDD thus justifying the extended potential window observed for this material. (author)

The water decomposition reactions on boron-doped diamond electrodes

Directory of Open Access Journals (Sweden)

Suffredini Hugo B

2004-01-01

Full Text Available The electrochemical processes occurring at both edges of the wide electrochemical window of the boron doped diamond (BDD electrode were studied by polarization curves experiments to evaluate the apparent energy of activation for the rate determining step in each reaction. It was found that the hydrogen evolution reaction occurs by a Volmer-Heyrovsky mechanism with the first step being the RDS. Moreover, the apparent energy of activation calculated from the Tafel plots presented a value as high as 150 kJ mol-1, indicating the formation of the M-H intermediate that is characteristic for the Volmer step. On the other hand, the apparent energy of activation for the oxygen evolution reaction was found to be 106 kJ mol-1 suggesting that the RDS in this mechanism is the initial adsorption step. In this way, it was demonstrated that the interaction between water molecules and the electrode surface is strongly inhibited on BDD thus justifying the extended potential window observed for this material.

Facile Synthesis of Ultralong and Thin Copper Nanowires and Its Application to High-Performance Flexible Transparent Conductive Electrodes

Science.gov (United States)

Wang, Yaxiong; Liu, Ping; Zeng, Baoqing; Liu, Liming; Yang, Jianjun

2018-03-01

A hydrothermal method for synthesizing ultralong and thin copper nanowires (CuNWs) with average diameter of 35 nm and average length of 100 μm is demonstrated in this paper. The concerning raw materials include copric (II) chloride dihydrate (CuCl2·2H2O), octadecylamine (ODA), and ascorbic acid, which are all very cheap and nontoxic. The effect of different reaction time and different molar ratios to the reaction products were researched. The CuNWs prepared by the hydrothermal method were applied to fabricate CuNW transparent conductive electrode (TCE), which exhibited excellent conductivity-transmittance performance with low sheet resistance of 26.23 Ω /\\square and high transparency at 550 nm of 89.06% (excluding Polyethylene terephthalate (PET) substrate). The electrode fabrication process was carried out at room temperature, and there was no need for post-treatment. In order to decrease roughness and protect CuNW TCEs against being oxidized, we fabricated CuNW/poly(methyl methacrylate) (PMMA) hybrid TCEs (HTCEs) using PMMA solution. The CuNW/PMMA HTCEs exhibited low surface roughness and chemical stability as compared with CuNW TCEs.

Large area window on vacuum chamber surface for neutron scattering instruments

International Nuclear Information System (INIS)

Itoh, Shinichi; Yokoo, Tetsuya; Ueno, Kenji; Suzuki, Junichi; Teraoku, Takuji; Tsuchiya, Masao

2012-01-01

The feasibility of a large area window using a thin aluminum plate on the surface of the vacuum chamber for neutron scattering instruments at a pulsed neutron source was investigated. In the prototype investigation for a window with an area of 1m×1.4m and a thickness of 1 mm, the measured pressure dependence of the displacement agreed well with a calculation using a nonlinear strain–stress curve up to the plastic deformation region. In addition, we confirmed the repetition test up to 2000 pressurization-and-release cycles, which is sufficient for the lifetime of the vacuum chamber for neutron scattering instruments. Based on these investigations, an actual model of the window to be mounted on the vacuum chamber of the High Resolution Chopper Spectrometer (HRC) at J-PARC was designed. By using a calculated stress distribution on the window, the clamping structure capable of balancing the tension in the window was determined. In a model with a structure identical to the actual window, we confirmed the repetition test over more than 7000 pressurization-and-release cycles, which shows a lifetime long enough for the actual usage of the vacuum chamber on the HRC.

Porous CrN thin films by selectively etching CrCuN for symmetric supercapacitors

KAUST Repository

Wei, Binbin

2018-03-18

Transition metal nitrides are regarded as a new class of excellent electrode materials for high-performance supercapacitors due to their superior chemical stability and excellent electrical conductivity. We synthesize successfully the porous CrN thin films for binder-free supercapacitor electrodes by reactive magnetron co-sputtering and selective chemical etching. The porous CrN thin film electrodes exhibit high-capacitance performance (31.3 mF cm−2 at 1.0 mA cm−2) and reasonable cycling stability (94% retention after 20000 cycles). Moreover, the specific capacitance is more than two-fold higher than that of the CrN thin film electrodes in previous work. In addition, a symmetric supercapacitor device with a maximum energy density of 14.4 mWh cm−3 and a maximum power density of 6.6 W cm−3 is achieved. These findings demonstrate that the porous CrN thin films will have potential applications in supercapacitors.

Porous CrN thin films by selectively etching CrCuN for symmetric supercapacitors

Science.gov (United States)

Wei, Binbin; Mei, Gui; Liang, Hanfeng; Qi, Zhengbing; Zhang, Dongfang; Shen, Hao; Wang, Zhoucheng

2018-05-01

Transition metal nitrides are regarded as a new class of excellent electrode materials for high-performance supercapacitors due to their superior chemical stability and excellent electrical conductivity. We synthesize successfully the porous CrN thin films for binder-free supercapacitor electrodes by reactive magnetron co-sputtering and selective chemical etching. The porous CrN thin film electrodes exhibit high-capacitance performance (31.3 mF cm-2 at 1.0 mA cm-2) and reasonable cycling stability (94% retention after 20000 cycles). Moreover, the specific capacitance is more than two-fold higher than that of the CrN thin film electrodes in previous work. In addition, a symmetric supercapacitor device with a maximum energy density of 14.4 mWh cm-3 and a maximum power density of 6.6 W cm-3 is achieved. These findings demonstrate that the porous CrN thin films will have potential applications in supercapacitors.

Organic Light-Emitting Diodes on Solution-Processed Graphene Transparent Electrodes

KAUST Repository

Wu, Junbo

2010-01-26

Theoretical estimates indicate that graphene thin films can be used as transparent electrodes for thin-film devices such as solar cells and organic light-emitting diodes, with an unmatched combination of sheet resistance and transparency. We demonstrate organic light-emitting diodes with solution-processed graphene thin film transparent conductive anodes. The graphene electrodes were deposited on quartz substrates by spincoating of an aqueous dispersion of functionalized graphene, followed by a vacuum anneal step to reduce the sheet resistance. Small molecular weight organic materials and a metal cathode were directly deposited on the graphene anodes, resulting in devices with a performance comparable to control devices on indium-tin-oxide transparent anodes. The outcoupling efficiency of devices on graphene and indium-tin-oxide is nearly identical, in agreement with model predictions. © 2010 American Chemical Society.

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

International Nuclear Information System (INIS)

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

2001-01-01

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

Cochlear implantation in Mondini's deformity: could the straight electrode array with length of 31 mm be fully inserted?

Science.gov (United States)

Sun, Jia-Qiang; Sun, Jing-Wu; Hou, Xiao-Yan

2017-07-01

The straight electrode array with length of 31 mm can be fully inserted using round window insertion in cochlear implantation with Mondini's deformity. It is a safe and effective process, but also a challenging task of the full implantation in children with Mondini's deformity. The aim of this study is to discuss whether the straight electrode array with a length of 31 mm could be fully inserted in cochlear implantation with Mondini's deformity. A chart review of 30 patients undergoing cochlear implantation with Mondini's deformity using the electrode array with length of 31 mm was undertaken from January 2012 and December 2015 in Anhui Provincial Hospital. Full insertion of the straight electrode array with length of 31 mm were performed successfully in all patients with Mondini's deformity using round window insertion. Resistance was not encountered while introducing the electrodes. Ten of 30 patients had cerebrospinal fluid drainage during cochlear implantation. Cerebrospinal fluid drainage was controlled with small pieces of temporalis fascia packing round window in all patients. Intra-operative neural response telemetry was performed in all patients, and results were good. The result of X-ray showed proper placement of the cochlear implant electrode array. During surgery, no patients had experienced any immediate or delayed post-operative complications such as wound infection, intracranial complication, extrusion, or migration of the implant during an average follow-up period of 6-36 months.

Electrochemical behaviour of rhenium-graphite electrode

International Nuclear Information System (INIS)

Varypaev, V.N.; Krasikov, V.L.

1980-01-01

Electrochemical behaviour of combination electrode from graphite with electrodeposited thin coating of electrolytic rhenium is studied. Solution of 0.5 m NaCl+0.04 m AlCl 3 served as an electrolite. Polarization galvanostatic curves of hydrogen evolution upon electrodes with conditional rhenium thickness of 3.5 and 0.35 μm, 35 and 3.5 nm are obtained. Possibility of preparation of rhenium-graphite cathode with extremely low rhenium consume, electro-chemical properties of which are simu-lar to purely rhenium cathode is shown. Such electrode is characterized with stable in time low cathode potential of hydrogen evolution in chloride electrolyte and during cathode polarization it is not affected by corrosion

A MEMS platform for in situ, real-time monitoring of electrochemically induced mechanical changes in lithium-ion battery electrodes

International Nuclear Information System (INIS)

Pomerantseva, Ekaterina; Jung, Hyun; Gnerlich, Markus; Baron, Sergio; Gerasopoulos, Konstantinos; Ghodssi, Reza

2013-01-01

We report the first successful demonstration of an optical microelectromechanical systems (MEMS) sensing platform for the in situ characterization of electrochemically induced reversible mechanical changes in lithium-ion battery (LIB) electrodes. The platform consists of an array of flexible membranes with a reflective surface on one side and a thin-film LIB electrode on the other side. The membranes deflect due to the active battery material volume change caused by lithium intercalation (expansion) and extraction (contraction). This deflection is monitored using the Fabry–Perot optical interferometry principle. The active material volume change causes high internal stresses and mechanical degradation of the electrodes. The stress evolution observed in a silicon thin-film electrode incorporated into this MEMS platform follows a ‘first elastic, then plastic’ deformation scheme. Understanding of the internal stresses in battery electrodes during discharge/charge is important for improving the reliability and cycle lifetime of LIBs. The developed MEMS platform presents a new method for in situ diagnostics of thin-film LIB electrodes to aid the development of new materials, optimization of electrode performance, and prevention of battery failure. (paper)

Measurement of effective piezoelectric coefficients of PZT thin films for energy harvesting application with interdigitated electrodes.

Science.gov (United States)

Chidambaram, Nachiappan; Mazzalai, Andrea; Muralt, Paul

2012-08-01

Interdigitated electrode (IDE) systems with lead zirconate titanate (PZT) thin films play an increasingly important role for two reasons: first, such a configuration generates higher voltages than parallel plate capacitor-type electrode (PPE) structures, and second, the application of an electric field leads to a compressive stress component in addition to the overall stress state, unlike a PPE structure, which results in tensile stress component. Because ceramics tend to crack at relatively moderate tensile stresses, this means that IDEs have a lower risk of cracking than PPEs. For these reasons, IDE systems are ideal for energy harvesting of vibration energy, and for actuators. Systematic investigations of PZT films with IDE systems have not yet been undertaken. In this work, we present results on the evaluation of the in-plane piezoelectric coefficients with IDE systems. Additionally, we also propose a simple and measurable figure of merit (FOM) to analyze and evaluate the relevant piezoelectric parameter for harvesting efficiency without the need to fabricate the energy harvesting device. Idealized effective coefficients e(IDE) and h(IDE) are derived, showing its composite nature with about one-third contribution of the transverse effect, and about two-thirds contribution of the longitudinal effect in the case of a PZT film deposited on a (100)-oriented silicon wafer with the in-plane electric field along one of the Si directions. Randomly oriented 1-μm-thick PZT 53/47 film deposited by a sol-gel technique, was evaluated and yielded an effective coefficient e(IDE) of 15 C·m(-2). Our FOM is the product between effective e and h coefficient representing twice the electrical energy density stored in the piezoelectric film per unit strain deformation (both for IDE and PPE systems). Assuming homogeneous fields between the fingers, and neglecting the contribution from below the electrode fingers, the FOM for IDE structures with larger electrode gap is derived to be

Cell voltage versus electrode potential range in aqueous supercapacitors

Science.gov (United States)

Dai, Zengxin; Peng, Chuang; Chae, Jung Hoon; Ng, Kok Chiang; Chen, George Z.

2015-01-01

Supercapacitors with aqueous electrolytes and nanostructured composite electrodes are attractive because of their high charging-discharging speed, long cycle life, low environmental impact and wide commercial affordability. However, the energy capacity of aqueous supercapacitors is limited by the electrochemical window of water. In this paper, a recently reported engineering strategy is further developed and demonstrated to correlate the maximum charging voltage of a supercapacitor with the capacitive potential ranges and the capacitance ratio of the two electrodes. Beyond the maximum charging voltage, a supercapacitor may still operate, but at the expense of a reduced cycle life. In addition, it is shown that the supercapacitor performance is strongly affected by the initial and zero charge potentials of the electrodes. Further, the differences are highlighted and elaborated between freshly prepared, aged under open circuit conditions, and cycled electrodes of composites of conducting polymers and carbon nanotubes. The first voltammetric charging-discharging cycle has an electrode conditioning effect to change the electrodes from their initial potentials to the potential of zero voltage, and reduce the irreversibility. PMID:25897670

Fabrication and properties of SmFe2-PZT magnetoelectric thin films

KAUST Repository

Giouroudi, Ioanna

2013-05-17

Magnetoelectric (ME) thin film composites are attracting a continually increasing interest due to their unique features and potential applications in multifunctional microdevices and integrated units such as sensors, actuators and energy harvesting modules. By combining piezoelectric and highly magnetostrictive thin films, the potentialities of these materials increase. In this paper we report the fabrication of SmFe2 and PZT thin films and the investigation of their properties. First of all, a ~ 400 nm thin SmFe film was deposited on top of Si/SiO2 substrate by magnetron sputter deposition. Afterwards, a 140 nm Pt bottom electrode was sputtered on top of the SmFe film forming a bottom electrode. Spin coating was employed for the deposition of the 150 nm thin PZT layer. A PZT solution with 10 %Pb excess was utilized for this fabrication step. Finally, circular Pt top electrodes were sputtered as top electrodes. This paper focuses on the microstructure of the individual films characterized by X-Ray diffractometer (XRD) and scanning electron microscopy (SEM). A piezoelectric evaluation system, aixPES, with TF2000E analyzer component was used for the electric hysteresis measurements of PZT thin films and a vibrating sample magnetometer (VSM) was employed for the magnetic characterization of the SmFe. The developed thin films and the fabricated double layer SmFe-PZT exhibit both good ferromagnetic and piezoelectric responses which predict a promising ME composite structure. The quantitative chemical composition of the samples was confirmed by energy dispersive spectroscopy (EDX). © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Fabrication and properties of SmFe2-PZT magnetoelectric thin films

KAUST Repository

Giouroudi, Ioanna; Alnassar, Mohammed; Kosel, Jü rgen

2013-01-01

Magnetoelectric (ME) thin film composites are attracting a continually increasing interest due to their unique features and potential applications in multifunctional microdevices and integrated units such as sensors, actuators and energy harvesting modules. By combining piezoelectric and highly magnetostrictive thin films, the potentialities of these materials increase. In this paper we report the fabrication of SmFe2 and PZT thin films and the investigation of their properties. First of all, a ~ 400 nm thin SmFe film was deposited on top of Si/SiO2 substrate by magnetron sputter deposition. Afterwards, a 140 nm Pt bottom electrode was sputtered on top of the SmFe film forming a bottom electrode. Spin coating was employed for the deposition of the 150 nm thin PZT layer. A PZT solution with 10 %Pb excess was utilized for this fabrication step. Finally, circular Pt top electrodes were sputtered as top electrodes. This paper focuses on the microstructure of the individual films characterized by X-Ray diffractometer (XRD) and scanning electron microscopy (SEM). A piezoelectric evaluation system, aixPES, with TF2000E analyzer component was used for the electric hysteresis measurements of PZT thin films and a vibrating sample magnetometer (VSM) was employed for the magnetic characterization of the SmFe. The developed thin films and the fabricated double layer SmFe-PZT exhibit both good ferromagnetic and piezoelectric responses which predict a promising ME composite structure. The quantitative chemical composition of the samples was confirmed by energy dispersive spectroscopy (EDX). © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

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

Directory of Open Access Journals (Sweden)

Cui Yan

2014-01-01

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

Efficiency enhancement using a Zn1- x Ge x -O thin film as an n-type window layer in Cu2O-based heterojunction solar cells

Science.gov (United States)

Minami, Tadatsugu; Nishi, Yuki; Miyata, Toshihiro

2016-05-01

Efficiency enhancement was achieved in Cu2O-based heterojunction solar cells fabricated with a zinc-germanium-oxide (Zn1- x Ge x -O) thin film as the n-type window layer and a p-type Na-doped Cu2O (Cu2O:Na) sheet prepared by thermally oxidizing Cu sheets. The Ge content (x) dependence of the obtained photovoltaic properties of the heterojunction solar cells is mainly explained by the conduction band discontinuity that results from the electron affinity difference between Zn1- x Ge x -O and Cu2O:Na. The optimal value of x in Zn1- x Ge x -O thin films prepared by pulsed laser deposition was observed to be 0.62. An efficiency of 8.1% was obtained in a MgF2/Al-doped ZnO/Zn0.38Ge0.62-O/Cu2O:Na heterojunction solar cell.

Windows

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Heiselberg, Per; Svidt, Kjeld; Nielsen, Peter V.

In natural ventilation systems fresh air is often provided through opening of windows. However, the knowledge of the performance of windows is rather limited. Computation of natural ventilation air flow through windows is most commonly made using discharge coefficients, that are regarded as being...... constant. The reported results show that the discharge coefficient for a window opening cannot be regarded as a constant and that it varies considerably with the size of the opening area, the window type and the temperature difference. Therefore, the use of a constant value can lead to serious errors...

Printed optically transparent graphene cellulose electrodes

Science.gov (United States)

Sinar, Dogan; Knopf, George K.; Nikumb, Suwas; Andrushchenko, Anatoly

2016-02-01

Optically transparent electrodes are a key component in variety of products including bioelectronics, touch screens, flexible displays, low emissivity windows, and photovoltaic cells. Although highly conductive indium tin oxide (ITO) films are often used in these electrode applications, the raw material is very expensive and the electrodes often fracture when mechanically stressed. An alternative low-cost material for inkjet printing transparent electrodes on glass and flexible polymer substrates is described in this paper. The water based ink is created by using a hydrophilic cellulose derivative, carboxymethyl cellulose (CMC), to help suspend the naturally hydrophobic graphene (G) sheets in a solvent composed of 70% DI water and 30% 2-butoxyethanol. The CMC chain has hydrophobic and hydrophilic functional sites which allow adsorption on G sheets and, therefore, permit the graphene to be stabilized in water by electrostatic and steric forces. Once deposited on the functionalized substrate the electrical conductivity of the printed films can be "tuned" by decomposing the cellulose stabilizer using thermal reduction. The entire electrode can be thermally reduced in an oven or portions of the electrode thermally modified using a laser annealing process. The thermal process can reduce the sheet resistance of G-CMC films to < 100 Ω/sq. Experimental studies show that the optical transmittance and sheet resistance of the G-CMC conductive electrode is a dependent on the film thickness (ie. superimposed printed layers). The printed electrodes have also been doped with AuCl3 to increase electrical conductivity without significantly increasing film thickness and, thereby, maintain high optical transparency.

A thin film approach for SiC-derived graphene as an on-chip electrode for supercapacitors

International Nuclear Information System (INIS)

Ahmed, Mohsin; Wang, Bei; Goding, Dayle; Iacopi, Francesca; Khawaja, Mohamad; Notarianni, Marco; Takshi, Arash; Saddow, Stephen E; Gupta, Bharati; Motta, Nunzio; Boeckl, John J

2015-01-01

We designed a nickel-assisted process to obtain graphene with sheet resistance as low as 80 Ω square −1 from silicon carbide films on Si wafers with highly enhanced surface area. The silicon carbide film acts as both a template and source of graphitic carbon, while, simultaneously, the nickel induces porosity on the surface of the film by forming silicides during the annealing process which are subsequently removed. As stand-alone electrodes in supercapacitors, these transfer-free graphene-on-chip samples show a typical double-layer supercapacitive behaviour with gravimetric capacitance of up to 65 F g −1 . This work is the first attempt to produce graphene with high surface area from silicon carbide thin films for energy storage at the wafer-level and may open numerous opportunities for on-chip integrated energy storage applications. (paper)

A methodology to enlarge narrow stability windows

Energy Technology Data Exchange (ETDEWEB)

Araujo, Ewerton M.P.; Pastor, Jorge A.S.C.; Fontoura, Sergio A.B. [Pontificia Univ. Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil). Dept. de Engenharia Civil. Grupo de Tecnologia e Engenharia de Petroleo

2004-07-01

The stability window in a wellbore design is defined by the difference between fracture pressure and collapse pressure. Deep water environments typically present narrow stability windows, because rocks have low strength due to under-compaction process. Often also, horizontal wells are drilled to obtain a better development of reservoirs placed in thin layers of sandstone. In this scenario, several challenges are faced when drilling in deep water. The traditional approach for predicting instabilities is to determine collapses and fractures at borehole wall. However, the initiation of rupture does not indicate that the borehole fails to perform its function as a wellbore. Thus, a methodology in which the stability window may be enlarged is desirable. This paper presents one practical analytical methodology that consists in allowing wellbore pressures smaller than the conventional collapse pressure, i.e., based upon failure on the borehole wall. This means that a collapse region (shear failure) will be developed around the borehole wall. This collapse region is pre-defined and to estimate its size is used a failure criterion. The aforementioned methodology is implemented in a user-friendly software, which can perform analyses of stress, pore pressure, formation failure, mud weight and mud salinity design for drilling in shale formations. Simulations of a wellbore drilling in a narrow stability window environment are performed to demonstrate the improvements of using the methodology. (author)

Activated carbon/manganese dioxide hybrid electrodes for high performance thin film supercapacitors

Science.gov (United States)

Jang, Yunseok; Jo, Jeongdai; Jang, Hyunjung; Kim, Inyoung; Kang, Dongwoo; Kim, Kwang-Young

2014-06-01

We combine the activated carbon (AC) and the manganese dioxide (MnO2) in a AC/MnO2 hybrid electrode to overcome the low capacitance of activated carbon and MnO2 by exploiting the large surface area of AC and the fast reversible redox reaction of MnO2. An aqueous permanganate (MnO4 -) is converted to MnO2 on the surface of the AC electrode by dipping the AC electrode into an aqueous permanganate solution. The AC/MnO2 hybrid electrode is found to display superior specific capacitance of 290 F/g. This shows that supercapacitors classified as electric double layer capacitors and pseudocapacitors can be combined together.

Wet-Chemical Surface Texturing of Sputter-Deposited ZnO:Al Films as Front Electrode for Thin-Film Silicon Solar Cells

Directory of Open Access Journals (Sweden)

Xia Yan

2015-01-01

Full Text Available Transparent conductive oxides (TCOs play a major role as the front electrodes of thin-film silicon (Si solar cells, as they can provide optical scattering and hence improved photon absorption inside the devices. In this paper we report on the surface texturing of aluminium-doped zinc oxide (ZnO:Al or AZO films for improved light trapping in thin-film Si solar cells. The AZO films are deposited onto soda-lime glass sheets via pulsed DC magnetron sputtering. Several promising AZO texturing methods are investigated using diluted hydrochloric (HCl and hydrofluoric acid (HF, through a two-step etching process. The developed texturing procedure combines the advantages of the HCl-induced craters and the smaller and jagged—but laterally more uniform—features created by HF etching. In the two-step process, the second etching step further enhances the optical haze, while simultaneously improving the uniformity of the texture features created by the HCl etch. The resulting AZO films show large haze values of above 40%, good scattering into large angles, and a surface angle distribution that is centred at around 30°, which is known from the literature to provide efficient light trapping for thin-film Si solar cells.

Carbon black nanoparticles film electrode prepared by using substrate-induced deposition approach

Energy Technology Data Exchange (ETDEWEB)

Svegl, Irena Grabec; Bele, Marjan [National Institute of Chemistry, P.O. Box 660, SI-1001 Ljubljana (Slovenia); Ogorevc, Bozidar [National Institute of Chemistry, P.O. Box 660, SI-1001 Ljubljana (Slovenia)], E-mail: bogorevc@ki.si

2008-11-03

A new type of carbon film electrode, composed of a thin layer of tightly packed carbon black (CB) nanoparticles deposited onto a gelatin-covered indium tin oxide/glass support using the surface-induced deposition (SID) approach, is presented. Some parameters of the novel SID method were optimized and the surface image and functionalization of the investigated carbon black film electrode (CBFE) was inspected by employing scanning electron microscopy and infrared spectroscopy. A cyclic voltammetry (CV) study was conducted in which the electron-transfer kinetics and CBFE interfacial characteristics were evaluated employing several selected reference redox systems, such as [Ru(NH{sub 3}){sub 6}]{sup 3+/2+}, [Fe(CN){sub 6}]{sup 3-/4-} and Fe{sup 3+/2+} in aqueous, and ferrocene/ferrocenium in acetonitrile media. CV recordings were also performed in order to compare the electrochemical behavior of the CBFE with that of some well-known and established bare carbon-based electrodes. In order to confirm the validity of the CB film preparation method, the electroanalytical performance of the proposed CBFE was examined by carrying out linear sweep voltammetry of ascorbic acid (AA), anodic stripping square-wave voltammetry of Cu(II) in acidic medium, and amperometric measurements of hydrogen peroxide under flow injection conditions. The sensing characteristics of the novel carbon film electrode, demonstrated in this preliminary study, comprise: (i) a wide working potential window ranging from +1.0 to -1.3 V (depending on the solution pH), (ii) a wide applicable pH range (at least from 2 to 12), (iii) low voltammetric background (<5 {mu}A cm{sup -2}), (iv) a satisfactory linear voltammetric and amperometric response (r{sup 2} > 0.99) to various analytes, (v) good reproducibility (for example, r.s.d. of 2% in amperometric detection of H{sub 2}O{sub 2} and r.s.d. of 8.5% for electrode-to-electrode CV runs), and (vi) stable and fast current response (at least 100 CV runs with

RF Magnetron Sputtering Deposited W/Ti Thin Film For Smart Window Applications

Science.gov (United States)

Oksuz, Lutfi; Kiristi, Melek; Bozduman, Ferhat; Uygun Oksuz, Aysegul

2014-10-01

Electrochromic (EC) devices can change reversible and persistent their optical properties in the visible region (400-800 nm) upon charge insertion/extraction according to the applied voltage. A complementary type EC is a device containing two electrochromic layers, one of which is anodically colored such as vanadium oxide (V2 O5) while the other cathodically colored such as tungsten oxide (WO3) which is separated by an ionic conduction layer (electrolyte). The use of a solid electrolyte such as Nafion eliminates the need for containment of the liquid electrolyte, which simplifies the cell design, as well as improves safety and durability. In this work, the EC device was fabricated on a ITO/glass slide. The WO3-TiO2 thin film was deposited by reactive RF magnetron sputtering using a 2-in W/Ti (9:1%wt) target with purity of 99.9% in a mixture gas of argon and oxygen. As a counter electrode layer, V2O5 film was deposited on an ITO/glass substrate using V2O3 target with the same conditions of reactive RF magnetron sputtering. Modified Nafion was used as an electrolyte to complete EC device. The transmittance spectra of the complementary EC device was measured by optical spectrophotometry when a voltage of +/-3 V was applied to the EC device by computer controlled system. The surface morphology of the films was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) (Fig. 2). The cyclic voltammetry (CV) for EC device was performed by sweeping the potential between +/-3 V at a scan rate of 50 mV/s.

Use of UV-protective windows and window films to aid in the prevention of skin cancer.

Science.gov (United States)

Edlich, Richard F; Winters, Kathryne L; Cox, Mary Jude; Becker, Daniel G; Horowitz, Jed H; Nichter, Larry S; Britt, L D; Long, William B; Edlic, Elizabeth C

2004-01-01

People are exposed to ambient solar ultraviolet (UV) radiation throughout their daily routine, intentionally and unintentionally. Cumulative and excessive exposure to UV radiation is the behavioral cause to skin cancers, skin damage, premature skin aging, and sun-related eye disorders. More than one million new cases of skin cancer were diagnosed in the United States this year. UV radiates directly and diffusely scattered by the various environmental and atmospheric conditions and has access to the skin from all directions. Because of this diffuse UV radiation, a person situated under a covering, such as the roof of a car or house, is not completely protected from the sun's rays. Because shade structures do not protect effectively against UV radiation, there have been major advances in photoprotection of glass by the development of specially designed photoprotective windows and films. It is the purpose of this collective review to highlight the photoprotective windows and films that should be incorporated into residential, commercial, and school glass windows to reduce sun exposure. Low-emittence (low-E) coatings are microscopically thin, virtually invisible, metal or metallic oxide layers deposited on a window or skylight glazing surface to reduce the U-factor by suppressing radiative heat flow as well as to limit UV radiation. The exclusive Thermaflect coating uses the most advanced, double-layer soft coat technology to continue to deliver top performance for UV protection as well as prevent heat loss in the home. This product blocks 87% of UV radiation and has an Energy Star certification in all climate zones. Tints and films have been another important advance in glass photoprotection, especially in automobiles. Quality widow film products are high-tech laminates of polyester and metallized coatings bonded by distortion-free adhesives. The International Window Film Association provides members with accreditation in solar control films, safety films, and

Thermochromic VO2 thin films deposited by magnetron sputtering for smart window applications

Science.gov (United States)

Fortier, Jean-Philippe

"Smart" windows are a perfect innovative example of technology that reduces our energy dependence and our impact on the environment while saving on the economical point of view. With the use of vanadium dioxide (VO2), a thermochromic compound, and this, as a thin coating, it would in fact be possible to control the sun's transmission of infrared light (heat) as a function of the surrounding environment temperature. In other words, its optical behavior would allow a more effective management of heat exchanges between a living venue and the outdoor environment. However, this type of window is still in a developmental stage. First, the oxide's deposition is not simple in nature. Based on a conventional deposition technique called magnetron sputtering mainly used in the fenestration industry, several factors such as the oxygen concentration and the substrate temperature during deposition can affect the coating's thermochromic behavior, and this, by changing its composition and crystallinity. Other control parameters such as the deposition rate, the pressure in the sputtering chamber and the choice of substrate may also modify the film microstructure, thereby varying its optical and electrical properties. In addition, several issues still persist as to its commercial application. For starters, the material's structural transition, related to the change of its optical properties, only occurs around 68°C. In addition, its low transparency and natural greenish colour are not visually appealing. Then, to this day, the deposition temperature required to crystallize and form the thermochromic oxide remains an obstacle for a possible large-scale application. Ultimately, although the material's change in temperature has been shown to be advantageous in situations of varying climate, the existing corrective solutions to these issues generate a deterioration of the thermochromic behavior. With no practical expertise on the material, this project was undertaken with certain

Study of the Carrier-Aided Thin Film Electrode Array Design for Cochlear Insertion

Directory of Open Access Journals (Sweden)

Yuchen Xu

2018-04-01

Full Text Available The micro-fabricated thin film electrode array (TFEA has been a promising design for cochlear implants (CIs because of its cost-effectiveness and fabrication precision. The latest polymer-based cochlear TFEAs have faced difficulties for cochlear insertion due to the lack of structural stiffness. To stiffen the TFEA, dissolvable stiffening materials, TFEAs with different structures, and TFEAs with commercial CIs as carriers have been invested. In this work, the concept of enhancing a Parylene TFEA with Kapton tape as a simpler carrier for cochlear insertion has been proved to be feasible. The bending stiffness of the Kapton-aided TFEA was characterized with an analytical model, a finite element model, and a cantilever bending experiment, respectively. While the Kapton tape increased the bending stiffness of the Parylene TFEA by 103 times, the 6-μm-thick TFEA with a similar Young’s modulus, as a polyimide, in turn significantly increased the bending stiffness of the 170-μm-thick Kapton carrier by 60%. This result indicated that even the TFEA is ultra-flexible and that its bending stiffness should not be neglected in the design or selection of its carrier.

Carbon nanotube network thin-film transistors on flexible/stretchable substrates

Science.gov (United States)

Takei, Kuniharu; Takahashi, Toshitake; Javey, Ali

2016-03-29

This disclosure provides systems, methods, and apparatus for flexible thin-film transistors. In one aspect, a device includes a polymer substrate, a gate electrode disposed on the polymer substrate, a dielectric layer disposed on the gate electrode and on exposed portions of the polymer substrate, a carbon nanotube network disposed on the dielectric layer, and a source electrode and a drain electrode disposed on the carbon nanotube network.

Carbon Nanofiber Electrode Array for Neurochemical Monitoring

Science.gov (United States)

Koehne, Jessica E.

2017-01-01

A sensor platform based on vertically aligned carbon nanofibers (CNFs) has been developed. Their inherent nanometer scale, high conductivity, wide potential window, good biocompatibility and well-defined surface chemistry make them ideal candidates as biosensor electrodes. Here, we report using vertically aligned CNF as neurotransmitter recording electrodes for application in a smart deep brain stimulation (DBS) device. Our approach combines a multiplexed CNF electrode chip, developed at NASA Ames Research Center, with the Wireless Instantaneous Neurotransmitter Concentration Sensor (WINCS) system, developed at the Mayo Clinic. Preliminary results indicate that the CNF nanoelectrode arrays are easily integrated with WINCS for neurotransmitter detection in a multiplexed array format. In the future, combining CNF based stimulating and recording electrodes with WINCS may lay the foundation for an implantable smart therapeutic system that utilizes neurochemical feedback control while likely resulting in increased DBS application in various neuropsychiatric disorders. In total, our goal is to take advantage of the nanostructure of CNF arrays for biosensing studies requiring ultrahigh sensitivity, high-degree of miniaturization, and selective biofunctionalization.

Noncovalent Pi-Pi Stacking at the Carbon-Electrolyte Interface: Controlling the Voltage Window of Electrochemical Supercapacitors.

Science.gov (United States)

Li, Mengya; Westover, Andrew S; Carter, Rachel; Oakes, Landon; Muralidharan, Nitin; Boire, Timothy C; Sung, Hak-Joon; Pint, Cary L

2016-08-03

A key parameter in the operation of an electrochemical double-layer capacitor is the voltage window, which dictates the device energy density and power density. Here we demonstrate experimental evidence that π-π stacking at a carbon-ionic liquid interface can modify the operation voltage of a supercapacitor device by up to 30%, and this can be recovered by steric hindrance at the electrode-electrolyte interface introduced by poly(ethylene oxide) polymer electrolyte additives. This observation is supported by Raman spectroscopy, electrochemical impedance spectroscopy, and differential scanning calorimetry that each independently elucidates the signature of π-π stacking between imidazole groups in the ionic liquid and the carbon surface and the role this plays to lower the energy barrier for charge transfer at the electrode-electrolyte interface. This effect is further observed universally across two separate ionic liquid electrolyte systems and is validated by control experiments showing an invariant electrochemical window in the absence of a carbon-ionic liquid electrode-electrolyte interface. As interfacial or noncovalent interactions are usually neglected in the mechanistic picture of double-layer capacitors, this work highlights the importance of understanding chemical properties at supercapacitor interfaces to engineer voltage and energy capability.

Insulated electrocardiographic electrodes. [without paste electrolyte

Science.gov (United States)

David, R. M.; Portnoy, W. A. (Inventor)

1975-01-01

An integrated system is disclosed including an insulated electrode and an impedance transformer which can be assembled in a small plastic housing and used for the acquisition of electrocardiographic data. The electrode may be employed without a paste electrolyte and may be attached to the body for extended usage without producing skin reaction. The electrode comprises a thin layer of suitable nontoxic dielectric material preferably deposited by radio frequency sputtering onto a conductive substrate. The impedance transformer preferably comprises an operational amplifier having an FET input stage connected in the unity gain configuration which provides a very low lower cut-off frequency, a high input impedance with a very small input bias current, a low output impedance, and a high signal-to-noise ratio.

Electrochemical, morphological and microstructural characterization of carbon film resistor electrodes for application in electrochemical sensors

International Nuclear Information System (INIS)

Gouveia-Caridade, Carla; Soares, David M.; Liess, Hans-Dieter; Brett, Christopher M.A.

2008-01-01

The electrochemical and microstructural properties of carbon film electrodes made from carbon film electrical resistors of 1.5, 15, 140 Ω and 2.0 kΩ nominal resistance have been investigated before and after electrochemical pre-treatment at +0.9 V vs SCE, in order to assess the potential use of these carbon film electrodes as electrochemical sensors and as substrates for sensors and biosensors. The results obtained are compared with those at electrodes made from previously investigated 2 Ω carbon film resistors. Cyclic voltammetry was performed in acetate buffer and phosphate buffer saline electrolytes and the kinetic parameters of the model redox system Fe(CN) 6 3-/4- obtained. The 1.5 Ω resistor electrodes show the best properties for sensor development with wide potential windows, similar electrochemical behaviour to those of 2 Ω and close-to-reversible kinetic parameters after electrochemical pre-treatment. The 15 and 140 Ω resistor electrodes show wide potential windows although with slower kinetics, whereas the 2.0 kΩ resistor electrodes show poor cyclic voltammetric profiles even after pre-treatment. Electrochemical impedance spectroscopy related these findings to the interfacial properties of the electrodes. Microstructural and morphological studies were carried out using contact mode Atomic Force Microscopy (AFM), Confocal Raman spectroscopy and X-ray diffraction. AFM showed more homogeneity of the films with lower nominal resistances, related to better electrochemical characteristics. X-ray diffraction and Confocal Raman spectroscopy indicate the existence of a graphitic structure in the carbon films

Assessment of Boron Doped Diamond Electrode Quality and Application to In Situ Modification of Local pH by Water Electrolysis.

Science.gov (United States)

Read, Tania L; Macpherson, Julie V

2016-01-06

Boron doped diamond (BDD) electrodes have shown considerable promise as an electrode material where many of their reported properties such as extended solvent window, low background currents, corrosion resistance, etc., arise from the catalytically inert nature of the surface. However, if during the growth process, non-diamond-carbon (NDC) becomes incorporated into the electrode matrix, the electrochemical properties will change as the surface becomes more catalytically active. As such it is important that the electrochemist is aware of the quality and resulting key electrochemical properties of the BDD electrode prior to use. This paper describes a series of characterization steps, including Raman microscopy, capacitance, solvent window and redox electrochemistry, to ascertain whether the BDD electrode contains negligible NDC i.e. negligible sp(2) carbon. One application is highlighted which takes advantage of the catalytically inert and corrosion resistant nature of an NDC-free surface i.e. stable and quantifiable local proton and hydroxide production due to water electrolysis at a BDD electrode. An approach to measuring the local pH change induced by water electrolysis using iridium oxide coated BDD electrodes is also described in detail.

Assessment of Boron Doped Diamond Electrode Quality and Application to In Situ Modification of Local pH by Water Electrolysis

Science.gov (United States)

Read, Tania L.; Macpherson, Julie V.

2016-01-01

Boron doped diamond (BDD) electrodes have shown considerable promise as an electrode material where many of their reported properties such as extended solvent window, low background currents, corrosion resistance, etc., arise from the catalytically inert nature of the surface. However, if during the growth process, non-diamond-carbon (NDC) becomes incorporated into the electrode matrix, the electrochemical properties will change as the surface becomes more catalytically active. As such it is important that the electrochemist is aware of the quality and resulting key electrochemical properties of the BDD electrode prior to use. This paper describes a series of characterization steps, including Raman microscopy, capacitance, solvent window and redox electrochemistry, to ascertain whether the BDD electrode contains negligible NDC i.e. negligible sp2 carbon. One application is highlighted which takes advantage of the catalytically inert and corrosion resistant nature of an NDC-free surface i.e. stable and quantifiable local proton and hydroxide production due to water electrolysis at a BDD electrode. An approach to measuring the local pH change induced by water electrolysis using iridium oxide coated BDD electrodes is also described in detail. PMID:26779959

Determination of the Resistance of Cone-Shaped Solid Electrodes

DEFF Research Database (Denmark)

Frandsen, Henrik Lund; Hendriksen, Peter Vang; Koch, Søren

2017-01-01

during processing can be avoided. Newman's formula for current constriction in the electrolyte is then used to deduce the active contact area based on the ohmic resistance of the cell, and from this the surface specific electro-catalytic activity. However, for electrode materials with low electrical......A cone-shaped electrode pressed into an electrolyte can with advantage be utilized to characterize the electro-catalytic properties of the electrode, because it is less dependent on the electrode microstructure than e.g. thin porous composite electrodes, and reactions with the electrolyte occurring...... conductivity (like Ce1-xPrxO2-δ), the resistance of the cell is significantly influenced by the ohmic resistance of the cone electrode, wherefore it must be included. In this work the ohmic resistance of a cone is modelled analytically based on simplified geometries. The two analytical models only differ...

Thin films of lithium manganese oxide spinel as cathode materials for secondary lithium batteries

International Nuclear Information System (INIS)

Shui, J.L.; Jiang, G.S.; Xie, S.; Chen, C.H.

2004-01-01

The miniaturization of rechargeable lithium-ion batteries requires high quality thin-film electrodes. Electrostatic spray deposition (ESD) technique was used to fabricate LiMn 2 O 4 thin-film electrodes with three different morphologies: sponge-like porous, fractal-like porous, and dense structures. X-ray diffraction (XRD) and scanning electron microscopy were used to analyze the structures of the electrodes. These electrodes were made into coin cells against metallic lithium for electrochemical characterization. Galvanostatic cycling of the cells revealed different rate capability for the cells with LiMn 2 O 4 electrodes of different morphologies. It is found that the cells with LiMn 2 O 4 electrodes of porous, especially the sponge-like porous, morphology better rate capability than those with dense LiMn 2 O 4 electrodes. Electrochemical impedance spectroscopy (EIS) study indicates that the large surface area of the porous electrodes should be attributed to the smaller interfacial resistance and better rate capability

Evaluation of the hybrid-L24 electrode using microcomputed tomography.

Science.gov (United States)

Driscoll, Colin L W; Carlson, Matthew L; Fama, Anthony F; Lane, John I

2011-07-01

To compare electrode array position, and depth of insertion of the Cochlear Hybrid-L24 electrode array following traditional cochleostomy and round window (RW) insertion. Prospective cadaveric temporal bone study. Ten cadaveric temporal bones were implanted with the Hybrid-L24 electrode array; half were introduced through a RW approach, whereas the other half were inserted through a traditional scala tympani cochleostomy. A micro-CT scanner was then used to evaluate electrode position, intracochlear trauma, and depth of insertion. All electrodes were inserted into the scala tympani without significant resistance. No electrodes demonstrated tip fold-over or through-fracturing of the osseous spiral lamina, basilar membrane, or spiral ligament. The average angular depth of insertion for all 10 electrodes was 252.4°. Compared to cochleostomy insertions, electrodes inserted through the RW more commonly acquired a proximal perimodiolar orientation, followed a more predictable course, and less commonly contacted critical soft tissue structures. The results of this study demonstrate that the Hybrid-L24 electrode can be successfully inserted using a RW or traditional cochleostomy technique with minimal intracochlear trauma. Our data also suggests that with this model, RW insertions may provide particular advantages with respect to hearing preservation over the traditional cochleostomy approach. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

Templated synthesis, characterization, and sensing application of macroscopic platinum nanowire network electrodes

DEFF Research Database (Denmark)

Wang, D. H.; Kou, R.; Gil, M. P.

2005-01-01

properties of the electrodes, such as electrochemical active area and methanol oxidation, have also been studied. Compared with conventional polycrystalline Pt electrodes, these novel nanowire network electrodes possess high electrochemical active areas and demonstrate higher current densities and a lower...... onset potential for methanol electro-oxidation. Enzymatic Pt nanowire-network-based sensors show higher sensitivity for glucose detection than that using conventional polycrystalline Pt electrode. Such macroscopic nanowire network electrodes provide ideal platforms for sensing and other device......Abstract: Novel platinum nanowire network electrodes have been fabricated through electrodeposition using mesoporous silica thin films as templates. These electrodes were characterized by X-ray diffraction, transmission electron microscope, and scanning electron microscope. The electrochemical...

Low-Temperature Solution Processable Electrodes for Piezoelectric Sensors Applications

Science.gov (United States)

Tuukkanen, Sampo; Julin, Tuomas; Rantanen, Ville; Zakrzewski, Mari; Moilanen, Pasi; Lupo, Donald

2013-05-01

Piezoelectric thin-film sensors are suitable for a wide range of applications from physiological measurements to industrial monitoring systems. The use of flexible materials in combination with high-throughput printing technologies enables cost-effective manufacturing of custom-designed, highly integratable piezoelectric sensors. This type of sensor can, for instance, improve industrial process control or enable the embedding of ubiquitous sensors in our living environment to improve quality of life. Here, we discuss the benefits, challenges and potential applications of piezoelectric thin-film sensors. The piezoelectric sensor elements are fabricated by printing electrodes on both sides of unmetallized poly(vinylidene fluoride) film. We show that materials which are solution processable in low temperatures, biocompatible and environmental friendly are suitable for use as electrode materials in piezoelectric sensors.

High Electrocatalytic Response of a Mechanically Enhanced NbC Nanocomposite Electrode Towards Hydrogen Evolution Reaction

KAUST Repository

Coy, Emerson; Yate, Luis; Valencia, Drochss P; Aperador, Willian; Siuzdak, Katarzyna; Torruella, Pau; Azanza, Eduardo; Estrade, Sonia; Iatsunskyi, Igor; Peiró , Francesca; Zhang, Xixiang; Tejada, Javier; Ziolo, Ronald F.

2017-01-01

Resistant and efficient electrocatalysts for hydrogen evolution reaction (HER) are desired to replace scarce and commercially expensive platinum electrodes. Thin film electrodes of metal-carbides are a promising alternative due to their reduced

Multi electrode semiconductors detectors

CERN Document Server

Amendolia, S R; Bertolucci, Ennio; Bosisio, L; Bradaschia, C; Budinich, M; Fidecaro, F; Foà, L; Focardi, E; Giazotto, A; Giorgi, M A; Marrocchesi, P S; Menzione, A; Ristori, L; Rolandi, Luigi; Scribano, A; Stefanini, A; Vincelli, M L

1981-01-01

Detectors with very high space resolution have been built in this laboratory and tested at CERN in order to investigate their possible use in high energy physics experiments. These detectors consist of thin layers of silicon crystals acting as ionization chambers. Thin electrodes, structured in strips or in more fancy shapes are applied to their surfaces by metal coating. The space resolution which could be reached is of the order of a few microns. An interesting feature of these solid state detectors is that they can work under very high or low external pressure or at very low temperature. The use of these detectors would strongly reduce the dimensions and the cost of high energy experiments. (3 refs).

Multi electrode semiconductor detectors

International Nuclear Information System (INIS)

Amendolia, S.R.; Batignani, G.; Bertolucci, E.; Bosisio, L.; Budinich, M.; Bradaschia, C.; Fidecaro, F.; Foa, L.; Focardi, E.; Giazotto, A.; Giorgi, M.A.; Marrocchesi, P.S.; Menzione, A.; Ristori, L.; Rolandi, L.; Scribano, A.; Stefanini, A.; Vincelli, M.L.

1981-01-01

Detectors with very high space resolution have been built in the laboratory and tested at CERN in order to investigate their possible use in high energy physics experiments. These detectors consist of thin layers of silicon crystals acting as ionization chambers. Thin electrodes, structured in strips or in more fancy shapes are applied to their surfaces by metal coating. The space resolution which could be reached is of the order of a few microns. An interesting feature of these solid state detectors is that they can work under very high or low external pressure or at very low temperature. The use of these detectors would strongly reduce the dimensions and the cost of high energy experiments. (Auth.)

Li4Ti5O12 thin-film electrodes by in-situ synthesis of lithium alkoxide for Li-ion microbatteries

International Nuclear Information System (INIS)

Mosa, J.; Aparicio, M.; Tadanaga, K.; Hayashi, A.; Tatsumisago, M.

2014-01-01

Rechargeable thin-film batteries have recently become the topic of widespread research for use as efficient energy storage devices. Spinel Li 4 Ti 5 O 12 has been considered as one of the most prospective anode materials for Li-ion batteries because of its excellent reversibility and long cycle life. We report here the sol–gel synthesis and coating preparation of spinel thin-film Li 4 Ti 5 O 12 electrodes for Li-ion microbatteries using lithium ethoxide produced in situ that reacts with titanium alkoxide to produce the precursor solution without particle precipitation. This synthesis procedure reduces the thermal treatment to obtain a pure phase at only 700 °C and 15 minutes. The physical and structural characterization of the 300 nm Li 4 Ti 5 O 12 coatings shows a very homogeneous distribution of elements and a pure spinel phase. Galvanostatic discharge-charge tests indicate maximum discharge capacities of 152 mA h g −1 when the material is treated at 700 °C for 15 minutes

Surgical implications of perimodiolar cochlear implant electrode design: avoiding intracochlear damage and scala vestibuli insertion.

Science.gov (United States)

Briggs, R J; Tykocinski, M; Saunders, E; Hellier, W; Dahm, M; Pyman, B; Clark, G M

2001-09-01

To review the mechanisms and nature of intracochlear damage associated with cochlear implant electrode array insertion, in particular, the various perimodiolar electrode designs. Make recommendations regarding surgical techniques for the Nucleus Contour electrode to ensure correct position and minimal insertion trauma. The potential advantages of increased modiolar proximity of intracochlear multichannel electrode arrays are a reduction in stimulation thresholds, an increase in dynamic range and more localized neural excitation. This may improve speech perception and reduce power consumption. These advantages may be negated if increased intracochlear damage results from the method used to position the electrodes close to the modiolus. A review of the University of Melbourne Department of Otolaryngology experience with temporal bone safety studies using the Nucleus standard straight electrode array and a variety of perimodiolar electrode array designs; comparison with temporal bone insertion studies from other centres and postmortem histopathology studies reported in the literature. Review of our initial clinical experience using the Nucleus Contour electrode array. The nature of intracochlear damage resulting from electrode insertion trauma ranges from minor, localized, spiral ligament tear to diffuse organ of Corti disruption and osseous spiral lamina fracture. The type of damage depends on the mechanical characteristics of the electrode array, the stiffness, curvature and size of the electrode in relation to the scala, and the surgical technique. The narrow, flexible, straight arrays are the least traumatic. Pre-curved or stiffer arrays are associated with an incidence of basilar membrane perforation. The cochleostomy must be correctly sited in relation to the round window to ensure scala tympani insertion. A cochleostomy anterior to the round window rather than inferior may lead to scala media or scala vestibuli insertion. Proximity of electrodes to the modiolus

Effects of the F4TCNQ-Doped Pentacene Interlayers on Performance Improvement of Top-Contact Pentacene-Based Organic Thin-Film Transistors

Directory of Open Access Journals (Sweden)

Ching-Lin Fan

2016-01-01

Full Text Available In this paper, the top-contact (TC pentacene-based organic thin-film transistor (OTFT with a tetrafluorotetracyanoquinodimethane (F4TCNQ-doped pentacene interlayer between the source/drain electrodes and the pentacene channel layer were fabricated using the co-evaporation method. Compared with a pentacene-based OTFT without an interlayer, OTFTs with an F4TCNQ:pentacene ratio of 1:1 showed considerably improved electrical characteristics. In addition, the dependence of the OTFT performance on the thickness of the F4TCNQ-doped pentacene interlayer is weaker than that on a Teflon interlayer. Therefore, a molecular doping-type F4TCNQ-doped pentacene interlayer is a suitable carrier injection layer that can improve the TC-OTFT performance and facilitate obtaining a stable process window.

Effects of the F4TCNQ-Doped Pentacene Interlayers on Performance Improvement of Top-Contact Pentacene-Based Organic Thin-Film Transistors

Science.gov (United States)

Fan, Ching-Lin; Lin, Wei-Chun; Chang, Hsiang-Sheng; Lin, Yu-Zuo; Huang, Bohr-Ran

2016-01-01

In this paper, the top-contact (TC) pentacene-based organic thin-film transistor (OTFT) with a tetrafluorotetracyanoquinodimethane (F4TCNQ)-doped pentacene interlayer between the source/drain electrodes and the pentacene channel layer were fabricated using the co-evaporation method. Compared with a pentacene-based OTFT without an interlayer, OTFTs with an F4TCNQ:pentacene ratio of 1:1 showed considerably improved electrical characteristics. In addition, the dependence of the OTFT performance on the thickness of the F4TCNQ-doped pentacene interlayer is weaker than that on a Teflon interlayer. Therefore, a molecular doping-type F4TCNQ-doped pentacene interlayer is a suitable carrier injection layer that can improve the TC-OTFT performance and facilitate obtaining a stable process window. PMID:28787845

Window and dome technologies and materials; Proceedings of the Meeting, Orlando, FL, Mar. 27-29, 1989

Science.gov (United States)

Klocek, Paul

1989-09-01

Papers on window and dome technologies and methodologies are presented, covering the processing and application of window and dome materials such as polycrystalline MgAl2O4 spinel, yttria and lanthana-doped yttria, transparent aluminum oxynitride, sapphire materials, fluoride glass, zinc sulfide, and germanium materials. Other topics include high modulus layers as protective coatings for window materials, ultrahard coatings for IR materials, IR applications of GeC thin filems, CVD diamond for IR applications, amorphic diamond films grown with a laser-ion source, dome cooling, microwave shielding effectiveness of electrically conductive coated optical windows, and the window evaluation program for an airborne FLIR system. In addition, papers are presented on modeling optical properties of window materials, lattice symmetries and thermal expansion, rain damage protection for IR materials, optical window materials for hypersonic flow, the IR emission due to aerodynamic heating of missile domes, a ZnS window for the IR instrumentation system, hypersonic aerooptical effects, optical and semiconductor properties of lead telluride coatings, boron phosphide for coating IR transparencies, and the measurement of high out-of-band filter rejection characteristics.

Electrode contacts on ferroelectric Pb(Zr x Ti1−x )O3 and SrBi2Ta2O9 thin films and their influence on fatigue properties

OpenAIRE

Lee, J. J.; Thio, C. L.; Desu, Seshu B.

1995-01-01

The degradation (fatigue) of dielectric properties of ferroelectric Pb(ZrxTi1-x)O-3 (PZT) and SrBi2Ta2O9 thin films during cycling was investigated. PZT and SrBi2Ta2O9 thin films were fabricated by metalorganic decomposition and pulsed laser deposition, respectively. Samples with electrodes of platinum (Pt) and ruthenium oxide (RuO2) were studied. The interfacial capacitance (if any) at the Pt/PZT, RuO2/PZT, and Pt/SrBi2Ta2O9 interfaces was determined from the thickness dependence of low-fiel...

F2-laser patterning of indium tin oxide (ITO) thin film on glass substrate

International Nuclear Information System (INIS)

Xu, M.Y.; Li, J.; Herman, P.R.; Lilge, L.D.

2006-01-01

This paper reports the controlled micromachining of 100 nm thick indium tin oxide (ITO) thin films on glass substrates with a vacuum-ultraviolet 157 nm F 2 laser. Partial to complete film removal was observed over a wide fluence window from 0.49 J/cm 2 to an optimized single pulse fluence of 4.5 J/cm 2 for complete film removal. Optical microscopy, atomic force microscopy, and energy dispersive X-ray analysis show little substrate or collateral damage by the laser pulse which conserved the stoichiometry, optical transparency and electrical conductivity of ITO coating adjacent to the trenches. At higher fluence, a parallel micron sized channel can be etched in the glass substrate. The high photon energy and top-hat beam homogenized optical system of the F 2 laser opens new means for direct structuring of electrodes and microchannels in biological microfluidic systems or in optoelectronics. (orig.)

Windows Azure

CERN Document Server

Johnson, Bruce; Chambers, James; Garber, Danny; Malik, Jamal; Fazio, Adam

2013-01-01

A collection of five must-have Azure titles, from some of the biggest names in the field Available individually, but at a discounted rate for the collection, this bundle of five e-books covers key developer and IT topics of Windows Azure, including ASP.NET, mobile services, web sites, data storage, and the hybrid cloud. A host of Microsoft employees and MPVs come together to cover the biggest challenges that professionals face when working with Windows Azure. The e-books included are as follows: Windows Azure and ASP.NET MVC MigrationWindows Azure Mobile ServicesWindows Azure Web SitesWindows

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.

Electrochemical reactivity at graphitic micro-domains on polycrystalline boron doped diamond thin-films electrodes

International Nuclear Information System (INIS)

Mahe, E.; Devilliers, D.; Comninellis, Ch.

2005-01-01

This paper deals with the electrochemical reactivity of boron doped diamond (BDD) electrodes. A comparative study has been carried out to show the influence of the presence of graphitic micro-domains upon the surface of these films. Those graphitic domains are sometimes present on as-grown boron doped diamond electrodes. The effect of doping a pure Csp 3 diamond electrode is established by highly oriented pyrolytic graphite (HOPG) abrasion onto the diamond surface. In order to establish the effect of doping on a pure Csp 3 diamond electrode, the amount of graphitic domains was increased by means of HOPG crystals grafted onto the BDD surface. Indeed that method allows the enrichment of the Csp 2 contribution of the electrode. The presence of graphitic domains can be correlatively associated with the presence of kinetically active redox sites. The electrochemical reactivity of boron doped diamond electrodes shows a distribution of kinetic constants on the whole surface of the electrode corresponding to different active sites. In this paper, we have studied by cyclic voltammetry and electrochemical impedance spectroscopy the kinetics parameters of the ferri/ferrocyanide redox couple in KCl electrolyte. A method is proposed to diagnose the presence of graphitic domains on diamond electrodes, and an electrochemical 'pulse cleaning' procedure is proposed to remove them

Learning Windows Azure Mobile Services for Windows 8 and Windows Phone 8

CERN Document Server

Webber-Cross, Geoff

2014-01-01

This book is based around a case study game which was written for the book. This means that the chapters progress in a logical way and build upon lessons learned as we go. Real-world examples are provided for each topic that are practical and not given out-of-context so they can be applied directly to other applications.If you are a developer who wishes to build Windows 8 and Phone 8 applications and integrate them with Windows Azure Mobile Services, this book is for you. Basic C# and JavaScript skills are advantageous, as well as some knowledge of building Windows 8 or Windows Phone 8 applica

Electrodeposition of CdTe thin film from acetate-based ionic liquid bath

Science.gov (United States)

Waldiya, Manmohansingh; Bhagat, Dharini; Mukhopadhyay, Indrajit

2018-05-01

CdTe being a direct band gap semiconductor, is mostly used in photovoltaics. Here we present, the synthesis of CdTe thin film on fluorine doped tin oxide (FTO) substrate potentiostatically using 1-butyl-3-methylimidazolium acetate ([Bmim][Ac]) ionic liquid (IL) bath at 90 °C. Major advantages of using electrodeposition involves process simplicity, large scalability & economic viability. Some of the benefits offered by IL electrolytic bath are low vapour pressure, wide electrochemical window, and good ionic mobility. Cd(CH3COO)2 (anhydrous) and TeO2 were used as the source precursors. The IL electrolytic bath temperature was kept at 90 °C for deposition, owing to the limited solubility of TeO2 in [Bmim][Ac] IL at room temperature. Cathodic electrodeposition was carried out using a three electrode cell setup at a constant potential of -1.20 V vs. platinum (Pt) wire. The CdTe/FTO thin film were annealed in argon (Ar) atmosphere. Optical study of nanostructured CdTe film were done using UV-Vis-IR and Raman spectroscopy. Raman analysis confirms the formation of CdTe having surface optics (SO) mode at 160.6 cm-1 and transverse optics (TO) mode at 140.5 cm-1. Elemental Te peaks at 123, 140.5 and 268 cm-1 were also observed. The optical band gap of Ar annealed CdTe thin film were found to be 1.47 eV (absorbance band edge ˜ 846 nm). The optimization of deposition parameters using acetate-based IL electrolytic bath to get nearly stoichiometric CdTe thin film is currently being explored.

Conducting polymers based counter electrodes for dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Veerender, P., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Saxena, Vibha, E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Gusain, Abhay, E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Jha, P., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Koiry, S. P., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Chauhan, A. K., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Aswal, D. K., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Gupta, S. K., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai - 400085 (India)

2014-04-24

Conducting polymer films were synthesized and employed as an alternative to expensive platinum counter electrodes for dye-sensitized solar cells. poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) thin films were spin-coated and polypyrrole films were electrochemically deposited via cyclic voltammetry method on ITO substrates. The morphology of the films were imaged by SEM and AFM. These films show good catalytic activity towards triiodide reduction as compared to Pt/FTO electrodes. Finally the photovoltaic performance of DSSC fabricated using N3 dye were compared with PT/FTO, PEDOT/ITO, and e-PPy counter electrodes.

Development of highly transparent Pd-coated Ag nanowire electrode for display and catalysis applications

Energy Technology Data Exchange (ETDEWEB)

Canlier, Ali, E-mail: ali.canlier@agu.edu.tr [Department of Materials Science and Nanotechnology Engineering, Abdullah Gul University, P.O. Box 38080, Kayseri (Turkey); Ucak, Umit Volkan, E-mail: sirvolkan@gmail.com [Department of Materials Science and Nanotechnology Engineering, Abdullah Gul University, P.O. Box 38080, Kayseri (Turkey); Graduate School of Energy, Environment, Water, and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST), P.O. Box 305-701, Daejeon (Korea, Republic of); Usta, Hakan, E-mail: husta38@gmail.com [Department of Materials Science and Nanotechnology Engineering, Abdullah Gul University, P.O. Box 38080, Kayseri (Turkey); Cho, Changsoon, E-mail: cscho@kaist.ac.kr [Graduate School of Energy, Environment, Water, and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST), P.O. Box 305-701, Daejeon (Korea, Republic of); Lee, Jung-Yong, E-mail: jungyong.lee@kaist.ac.kr [Graduate School of Energy, Environment, Water, and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST), P.O. Box 305-701, Daejeon (Korea, Republic of); Sen, Unal, E-mail: senunal@gmail.com [Department of Mechanical Engineering, Abdullah Gul University, P.O. Box 38080, Kayseri (Turkey); Citir, Murat, E-mail: muratcitir@gmail.com [Department of Chemical Engineering, Abdullah Gul University, P.O. Box 38080, Kayseri (Turkey)

2015-09-30

Highlights: • Highly uniform thin-layer coating of Pd onto Ag nanowire surface was accomplished. • A transparent electrode of Pd-coated Ag nanowire was uniformly deposited on flexible substrate. • 95% of optical transmittance and 175 Ω/sq sheet resistance were obtained. • Extremely low haze of 1.9% and high oxidation stability proved an efficient transparent electrode. • This electrode can be used as Pd-catalyst for synthesis reactions and fuel cell electrode applications. - Abstract: Ag nanowire transparent electrode has excellent transmittance (90%) and sheet resistance (20 Ω/sq), yet there are slight drawbacks such as optical haze and chemical instability against aerial oxidation. Chemical stability of Ag nanowires needs to be improved in order for it to be suitable for electrode applications. In our recent article, we demonstrated that coating Ag nanowires with a thin layer of Au through galvanic exchange reactions enhances the chemical stability of Ag nanowire films highly and also helps to obtain lower haze. In this study, coating of a thin Pd layer has been applied successfully onto the surface of Ag nanowires. A mild Pd complex oxidant [Pd(en){sub 2}](NO{sub 3}){sub 2} was prepared in order to oxidize Ag atoms partially on the surface via galvanic displacement. The mild galvanic exchange allowed for a thin layer (1–2 nm) of Pd coating on the Ag nanowires with minimal truncation of the nanowire, where the average length and the diameter were 12.5 μm and 59 nm, respectively. The Pd-coated Ag nanowires were suspended in methanol and then electrostatically sprayed on flexible polycarbonate substrates. It has been revealed that average total transmittance remain around 95% within visible spectrum region (400–800 nm) whereas sheet resistance rises up to 175 Ω/sq. To the best of our knowledge, for the first time in the literature, Pd coating was employed on Ag nanowires in order to design transparent electrodes for high transparency and strong

Flexible transparent electrode

Science.gov (United States)

Demiryont, Hulya; Shannon, Kenneth C., III; Moorehead, David; Bratcher, Matthew

2011-06-01

This paper presents the properties of the EclipseTECTM transparent conductor. EclipseTECTM is a room temperature deposited nanostructured thin film coating system comprised of metal-oxide semiconductor elements. The system possesses metal-like conductivity and glass-like transparency in the visible region. These highly conductive TEC films exhibit high shielding efficiency (35dB at 1 to 100GHz). EclipseTECTM can be deposited on rigid or flexible substrates. For example, EclipseTECTM deposited on polyethylene terephthalate (PET) is extremely flexible that can be rolled around a 9mm diameter cylinder with little or no reduction in electrical conductivity and that can assume pre-extension states after an applied stress is relieved. The TEC is colorless and has been tailored to have high visible transmittance which matches the eye sensitivity curve and allows the viewing of true background colors through the coating. EclipseTECTM is flexible, durable and can be tailored at the interface for applications such as electron- or hole-injecting OLED electrodes as well as electrodes in flexible displays. Tunable work function and optical design flexibility also make EclipseTECTM well-suited as a candidate for grid electrode replacement in next-generation photovoltaic cells.

Morphology controllable time-dependent CoS nanoparticle thin films as efficient counter electrode for quantum dot-sensitized solar cells

Science.gov (United States)

Reddy, Araveeti Eswar; Rao, S. Srinivasa; Gopi, Chandu V. V. M.; Anitha, Tarugu; Thulasi-Varma, Chebrolu Venkata; Punnoose, Dinah; Kim, Hee-Je

2017-11-01

Cobalt sulfide (CoS) agglomerated nanoparticle thin films obtained by a facile chemical bath method at different deposition times. The CoS counter electrode (CE) deposited at 3 h deposition time (CC-3h) based quantum dot sensitized solar cells (QDSSCs) achieves higher power conversion efficiency (η) of 3.67% than those of CC-2h (1.83%), CC-4h (2.52%), and Pt (1.48%) CEs, under one sun illumination (100 mW cm-2, AM 1.5 G). The electrochemical analysis revealed that CC-3h CE shows a smaller charge transfer resistance (9.22 Ω) at the CE/electrolyte interface than the CC-2h (23.34 Ω), CC-4h (19.73 Ω) and Pt (139.92 Ω) CEs, respectively.

A Platform for Manufacturable Stretchable Micro-electrode Arrays

NARCIS (Netherlands)

Khoshfetrat Pakazad, S.; Savov, A.; Braam, S.R.; Dekker, R.

2012-01-01

A platform for the batch fabrication of pneumatically actuated Stretchable Micro-Electrode Arrays (SMEAs) by using state-of-the-art micro-fabrication techniques and materials is demonstrated. The proposed fabrication process avoids the problems normally associated with processing of thin film

Electrochemical reactivity at graphitic micro-domains on polycrystalline boron doped diamond thin-films electrodes

Energy Technology Data Exchange (ETDEWEB)

Mahe, E. [LI2C CNRS/UMR 7612, Laboratoire d' Electrochimie, Universite Pierre-et-Marie Curie - case courrier 51, 4, Place Jussieu, 75252 Paris Cedex 05 (France); Devilliers, D. [LI2C CNRS/UMR 7612, Laboratoire d' Electrochimie, Universite Pierre-et-Marie Curie - case courrier 51, 4, Place Jussieu, 75252 Paris Cedex 05 (France); Comninellis, Ch. [Unite de Genie Electrochimique, Institut de sciences des procedes chimiques et biologiques, Ecole Polytechnique Federale de Lausanne, 1015, Lausanne (Switzerland)

2005-04-01

This paper deals with the electrochemical reactivity of boron doped diamond (BDD) electrodes. A comparative study has been carried out to show the influence of the presence of graphitic micro-domains upon the surface of these films. Those graphitic domains are sometimes present on as-grown boron doped diamond electrodes. The effect of doping a pure Csp{sup 3} diamond electrode is established by highly oriented pyrolytic graphite (HOPG) abrasion onto the diamond surface. In order to establish the effect of doping on a pure Csp{sup 3} diamond electrode, the amount of graphitic domains was increased by means of HOPG crystals grafted onto the BDD surface. Indeed that method allows the enrichment of the Csp{sup 2} contribution of the electrode. The presence of graphitic domains can be correlatively associated with the presence of kinetically active redox sites. The electrochemical reactivity of boron doped diamond electrodes shows a distribution of kinetic constants on the whole surface of the electrode corresponding to different active sites. In this paper, we have studied by cyclic voltammetry and electrochemical impedance spectroscopy the kinetics parameters of the ferri/ferrocyanide redox couple in KCl electrolyte. A method is proposed to diagnose the presence of graphitic domains on diamond electrodes, and an electrochemical 'pulse cleaning' procedure is proposed to remove them.

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

International Nuclear Information System (INIS)

Leighton, Glenn J T; Huang, Zhaorong

2010-01-01

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

Numerical simulations for quantitative analysis of electrostatic interaction between atomic force microscopy probe and an embedded electrode within a thin dielectric: meshing optimization, sensitivity to potential distribution and impact of cantilever contribution

Science.gov (United States)

Azib, M.; Baudoin, F.; Binaud, N.; Villeneuve-Faure, C.; Bugarin, F.; Segonds, S.; Teyssedre, G.

2018-04-01

Recent experimental results demonstrated that an electrostatic force distance curve (EFDC) can be used for space charge probing in thin dielectric layers. A main advantage of the method is claimed to be its sensitivity to charge localization, which, however, needs to be substantiated by numerical simulations. In this paper, we have developed a model which permits us to compute an EFDC accurately by using the most sophisticated and accurate geometry for the atomic force microscopy probe. To avoid simplifications and in order to reproduce experimental conditions, the EFDC has been simulated for a system constituted of a polarized electrode embedded in a thin dielectric layer (SiN x ). The individual contributions of forces on the tip and on the cantilever have been analyzed separately to account for possible artefacts. The EFDC sensitivity to potential distribution is studied through the change in electrode shape, namely the width and the depth. Finally, the numerical results have been compared with experimental data.

Fabrication of Dye-Sensitized Solar Cells with a 3D Nanostructured Electrode

Directory of Open Access Journals (Sweden)

Guo-Yang Chen

2010-01-01

Full Text Available A novel Dye-Sensitized Solar Cell (DSSC scheme for better solar conversion efficiency is proposed. The distinctive characteristic of this novel scheme is that the conventional thin film electrode is replaced by a 3D nanostructured indium tin oxide (ITO electrode, which was fabricated using RF magnetron sputtering with an anodic aluminum oxide (AAO template. The template was prepared by immersing the barrier-layer side of an AAO film into a 30 wt% phosphoric acid solution to produce a contrasting surface. RF magnetron sputtering was then used to deposit a 3D nanostructured ITO thin film on the template. The crystallinity and conductivity of the 3D ITO films were further enhanced by annealing. Titanium dioxide nanoparticles were electrophoretically deposited on the 3D ITO film after which the proposed DSSC was formed by filling vacant spaces in the 3D nanostructured ITO electrode with dye. The measured solar conversion efficiency of the device was 0.125%. It presents a 5-fold improvement over that of conventional spin-coated TiO2 film electrode DSSCs.

Cu mesh for flexible transparent conductive electrodes.

Science.gov (United States)

Kim, Won-Kyung; Lee, Seunghun; Hee Lee, Duck; Hee Park, In; Seong Bae, Jong; Woo Lee, Tae; Kim, Ji-Young; Hun Park, Ji; Chan Cho, Yong; Ryong Cho, Chae; Jeong, Se-Young

2015-06-03

Copper electrodes with a micromesh/nanomesh structure were fabricated on a polyimide substrate using UV lithography and wet etching to produce flexible transparent conducting electrodes (TCEs). Well-defined mesh electrodes were realized through the use of high-quality Cu thin films. The films were fabricated using radio-frequency (RF) sputtering with a single-crystal Cu target--a simple but innovative approach that overcame the low oxidation resistance of ordinary Cu. Hybrid Cu mesh electrodes were fabricated by adding a capping layer of either ZnO or Al-doped ZnO. The sheet resistance and the transmittance of the electrode with an Al-doped ZnO capping layer were 6.197 ohm/sq and 90.657%, respectively, and the figure of merit was 60.502 × 10(-3)/ohm, which remained relatively unchanged after thermal annealing at 200 °C and 1,000 cycles of bending. This fabrication technique enables the mass production of large-area flexible TCEs, and the stability and high performance of Cu mesh hybrid electrodes in harsh environments suggests they have strong potential for application in smart displays and solar cells.

Crystallic silver amalgam--a novel electrode material.

Science.gov (United States)

Danhel, Ales; Mansfeldova, Vera; Janda, Pavel; Vyskocil, Vlastimil; Barek, Jiri

2011-09-21

A crystallic silver amalgam was found to be a suitable working electrode material for voltammetric determination of electrochemically reducible organic nitro-compounds. Optimum conditions for crystal growth were found, the crystal surface was investigated by atomic force microscopy in tapping mode and single crystals were used for the preparation of quasi-cylindrical single crystal silver amalgam electrode (CAgAE). An electrochemical behavior of this alternative electrode material was investigated in aqueous media by direct current voltammetry, cyclic voltammetry (CV), differential pulse voltammetry (DPV) and adsorptive stripping voltammetry (AdSV) using 4-nitrophenol as a model compound. Applicable potential windows of the CAgAE were found comparable with those obtained at a hanging mercury drop electrode, providing high hydrogen overpotential, and polished silver solid amalgam electrode. Thanks to the smooth single crystal electrode surface, the effect of the passivation is not too pronounced, direct DPV determination of 100 μmol l(-1) of 4-nitrophenol at CAgAEs in 0.2 mol l(-1) acetate buffer pH 4.8 provides a RSD around 1.5% (n = 15). DPV calibration curves of 4-nitrophenol are linear in the whole concentration range 1-100 μmol l(-1) with a limit of quantification of 1.5 μmol l(-1). The attempt to increase sensitivity by application of AdSV was not successful. The mechanism of 4-nitrophenol reduction at CAgAE was investigated by CV.

A numerical study of the effect of vent flow angle on the heat transfer rate from a cold window with a below-window hot-air vent

Energy Technology Data Exchange (ETDEWEB)

Oosthuizen, P.H. [Queen' s Univ., Kingston, ON (Canada). Dept. of Mechanical and Materials Engineering

2010-07-01

This study investigated the effects of the discharge angle on air leaving a hot air vent mounted below a window. The window was represented by a plane isothermal section recessed into a wall and was colder than air in the rest of the room. The vent was placed against the wall and had a uniform discharge velocity. Flow was assumed to be steady. Both laminar and turbulent flows were evaluated using a commercial computational fluid dynamics (CFD) simulation tool. A k-epsilon turbulence model was used to determine turbulent flow calculations. The study determined the Rayleigh number based on window height, the Reynolds number based on the vent discharge velocity, the angle of the vent discharge flow, the Prandtl number, and dimensionless vent discharge temperature differences. The study showed that a relatively thin layer of cold air adjacent to the floor is present at high Rayleigh numbers, where the downward natural convective flow over the window dominates the overall flow. At low Rayleigh numbers, the cold air flows upward towards the ceiling and temperatures in the room are nearly uniform. 47 refs., 11 figs.

Dynamics of space and polarization charges of ferroelectric thin films measured by atomic force microscopy

International Nuclear Information System (INIS)

Oh, Y.J.; Lee, J.H.; Jo, W.

2006-01-01

Retention behavior and local hysteresis characteristics in Pb(Zr 0.52 Ti 0.48 )O 3 (PZT) thin films on Pt electrodes have been investigated by electrostatic force microscopy (EFM). A sol-gel method is used to synthesize PZT thin films and drying conditions are carefully explored over a wide range of temperature. Decay and retention mechanisms of single-poled and reverse-poled regions of the ferroelectric thin films are explained by space charge redistribution. Trapping behavior of space charges is dependent on the nature of interface between ferroelectric thin films and bottom electrodes. Local measurement of polarization-electric field curves by EFM shows inhomogeneous space charge entrapment

Analysis of a grid window structure for RF cavities in a Muon cooling channel

International Nuclear Information System (INIS)

Ladran, A.; Li, D.; Moretti, A.; Rimmer, R.; Staples, J.; Virostek, S.; Zisman, M.

2003-01-01

We report on the electromagnetic and thermal analysis of a grid window structure for high gradient, low frequency RF cavities. Windows may be utilized to close the beam iris and increase shunt impedance of closed-cell RF cavities. This work complements previous work presented for windows made of solid beryllium foil. An electromagnetic and thermal analysis of the thin wall tubes in a grid pattern was conducted using both MAFIA4 and ANSYS finite element analyses. The results from both codes agreed well for a variety of grid configurations and spacing. The grid configuration where the crossing tubes touched was found to have acceptable E-Fields and H-Fields performance. The thermal profiles for the grid will also be shown to determine a viable cooling profile

Windows server cookbook for Windows server 2003 and Windows 2000

CERN Document Server

Allen, Robbie

2005-01-01

This practical reference guide offers hundreds of useful tasks for managing Windows 2000 and Windows Server 2003, Microsoft's latest server. These concise, on-the-job solutions to common problems are certain to save you many hours of time searching through Microsoft documentation. Topics include files, event logs, security, DHCP, DNS, backup/restore, and more

Investigation of resistive switching in barium strontium titanate thin films for memory applications

Energy Technology Data Exchange (ETDEWEB)

Shen, Wan

2010-11-17

Resistive random access memory (RRAM) has attracted much attention due to its low power consumption, high speed operation, non-readout disturbance and high density integration potential and is regarded as one of the most promising candidates for the next generation non-volatile memory. The resistive switching behavior of Mn-doped BaSrTiO{sub 3} (BST) thin films with different crystalline properties was investigated within this dissertation. The laser fluence dependence was checked in order to optimize the RRAM properties. Although the film epitaxial quality was improved by reducing the laser energy during deposition process, the yields fluctuated and only 3% RRAM devices with highest epitaxial quality of BST film shows resistive switching behavior instead of 67% for the samples with worse film quality. It gives a clue that the best thin film quality does not result in the best switching performance, and it is a clear evidence of the importance of the defects to obtain resistive switching phenomena. The bipolar resistive switching behavior was studied with epitaxial BST thin films on SRO/STO. Compared to Pt top electrode, the yield, endurance and reliability were strongly improved for the samples with W top electrode. Whereas the samples with Pt top electrode show a fast drop of the resistance for both high and low resistance states, the devices with W top electrode can be switched for 10{sup 4} times without any obvious degradation. The resistance degradation for devices with Pt top electrode may result from the diffusion of oxygen along the Pt grain boundaries during cycling whereas for W top electrode the reversible oxidation and reduction of a WO{sub x} layer, present at the interface between W top electrode and BST film, attributes to the improved switching property. The transition from bipolar to unipolar resistive switching in polycrystalline BST thin films was observed. A forming process which induces a metallic low resistance state is prerequisite for the

Investigation of resistive switching in barium strontium titanate thin films for memory applications

International Nuclear Information System (INIS)

Shen, Wan

2010-01-01

Resistive random access memory (RRAM) has attracted much attention due to its low power consumption, high speed operation, non-readout disturbance and high density integration potential and is regarded as one of the most promising candidates for the next generation non-volatile memory. The resistive switching behavior of Mn-doped BaSrTiO 3 (BST) thin films with different crystalline properties was investigated within this dissertation. The laser fluence dependence was checked in order to optimize the RRAM properties. Although the film epitaxial quality was improved by reducing the laser energy during deposition process, the yields fluctuated and only 3% RRAM devices with highest epitaxial quality of BST film shows resistive switching behavior instead of 67% for the samples with worse film quality. It gives a clue that the best thin film quality does not result in the best switching performance, and it is a clear evidence of the importance of the defects to obtain resistive switching phenomena. The bipolar resistive switching behavior was studied with epitaxial BST thin films on SRO/STO. Compared to Pt top electrode, the yield, endurance and reliability were strongly improved for the samples with W top electrode. Whereas the samples with Pt top electrode show a fast drop of the resistance for both high and low resistance states, the devices with W top electrode can be switched for 10 4 times without any obvious degradation. The resistance degradation for devices with Pt top electrode may result from the diffusion of oxygen along the Pt grain boundaries during cycling whereas for W top electrode the reversible oxidation and reduction of a WO x layer, present at the interface between W top electrode and BST film, attributes to the improved switching property. The transition from bipolar to unipolar resistive switching in polycrystalline BST thin films was observed. A forming process which induces a metallic low resistance state is prerequisite for the observation of

Sensing of volatile organic compounds by copper phthalocyanine thin films

Science.gov (United States)

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

2017-02-01

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

Enhanced efficiency of hybrid amorphous silicon solar cells based on single-walled carbon nanotubes/polymer composite thin film.

Science.gov (United States)

Rajanna, Pramod Mulbagal; Gilshteyn, Evgenia; Yagafarov, Timur; Alekseeva, Alena; Anisimov, Anton; Sergeev, Oleg; Neumueller, Alex; Bereznev, Sergei; Maricheva, Jelena; Nasibulin, Albert

2018-01-09

We report a simple approach to fabricate hybrid solar cells (HSCs) based on a single-walled carbon nanotube (SWCNT) film and a thin film hydrogenated amorphous silicon (a-Si:H). Randomly oriented high quality SWCNTs with an enhanced conductivity by means of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate are used as a window layer and a front electrode. A series of HSCs are fabricated in ambient conditions with different SWCNT film thicknesses. The polymethylmethacrylate layer drop-casted on fabricated HSCs reduces the reflection fourfold and enhances the short-circuit Jsc, open-circuit Voc, and efficiency by nearly 10%. A state-of-the-art J-V performance is shown for SWCNT/a-Si HSC with an open-circuit voltage of 900 mV and efficiency of 3.4% under simulated one-sun AM 1.5G direct illumination. © 2018 IOP Publishing Ltd.

Dye-sensitized solar cell with a pair of carbon-based electrodes

International Nuclear Information System (INIS)

Kyaw, Aung Ko Ko; Demir, Hilmi Volkan; Sun Xiaowei; Tantang, Hosea; Zhang Qichun; Wu Tao; Ke, Lin; Wei Jun

2012-01-01

We have fabricated a dye-sensitized solar cell (DSSC) with a pair of carbon-based electrodes using a transparent, conductive carbon nanotubes (CNTs) film modified with ultra-thin titanium-sub-oxide (TiO x ) as the working electrode and a bilayer of conductive CNTs and carbon black as the counter electrode. Without TiO x modification, the DSSC is almost nonfunctional whereas the power conversion efficiency (PCE) increases significantly when the working electrode is modified with TiO x . The performance of the cell could be further improved when the carbon black film was added on the counter electrode. The improved efficiency can be attributed to the inhibition of the mass recombination at the working electrode/electrolyte interface by TiO x and the acceleration of the electron transfer kinetics at the counter electrode by carbon black. The DSSC with a pair of carbon-based electrodes gives the PCE of 1.37%. (paper)

Effect of annealing over optoelectronic properties of graphene based transparent electrodes

Energy Technology Data Exchange (ETDEWEB)

Yadav, Shriniwas, E-mail: sniwas89@gmail.com; Kaur, Inderpreet, E-mail: inderpreety@yahoo.co.in [Academy of Scientific and Innovative Research- Central Scientific Instruments Organisation (AcSIR-CSIO), Sector-30C, Chandigarh (India); Council of Scientific and Industrial Research- Central Scientific Instruments Organisation (CSIR-CSIO), Sector-30C, Chandigarh (India)

2016-04-13

Graphene, an atom–thick two dimensional graphitic material have led various fundamental breakthroughs in the field of science and technology. Due to their exceptional optical, physical and electrical properties, graphene based transparent electrodes have shown several applications in organic light emitting diodes, solar cells and thin film transistors. Here, we are presenting effect of annealing over optoelectronic properties of graphene based transparent electrodes. Graphene based transparent electrodes have been prepared by wet chemical approach over glass substrates. After fabrication, these electrodes tested for optical transmittance in visible region. Sheet resistance was measured using four probe method. Effect of thermal annealing at 200 °C was studied over optical and electrical performance of these electrodes. Optoelectronic performance was judged from ratio of direct current conductivity to optical conductivity (σ{sub dc}/σ{sub opt}) as a figure of merit for transparent conductors. The fabricated electrodes display good optical and electrical properties. Such electrodes can be alternatives for doped metal oxide based transparent electrodes.

Effect of annealing over optoelectronic properties of graphene based transparent electrodes

Science.gov (United States)

Yadav, Shriniwas; Kaur, Inderpreet

2016-04-01

Graphene, an atom-thick two dimensional graphitic material have led various fundamental breakthroughs in the field of science and technology. Due to their exceptional optical, physical and electrical properties, graphene based transparent electrodes have shown several applications in organic light emitting diodes, solar cells and thin film transistors. Here, we are presenting effect of annealing over optoelectronic properties of graphene based transparent electrodes. Graphene based transparent electrodes have been prepared by wet chemical approach over glass substrates. After fabrication, these electrodes tested for optical transmittance in visible region. Sheet resistance was measured using four probe method. Effect of thermal annealing at 200 °C was studied over optical and electrical performance of these electrodes. Optoelectronic performance was judged from ratio of direct current conductivity to optical conductivity (σdc/σopt) as a figure of merit for transparent conductors. The fabricated electrodes display good optical and electrical properties. Such electrodes can be alternatives for doped metal oxide based transparent electrodes.

MS Windows domēna darbstaciju migrācija no MS Windows XP uz Windows Vista.

OpenAIRE

Tetere, Agate

2009-01-01

Kvalifikācijas darbā izpētīju darbstaciju migrācijas no Windows XP uz Windows Vista plusus un mīnusus. Darba gaitā tika veikti sekojoši uzdevumi: 1.Veikta Windows XP un Windows Vista darbstaciju instalācija, iestatījumu konfigurēšana un tika pārbaudīta sistēmas darbība 2.Veikta Windows Server 2003 un Windows Server 2008 instalācija, iestatījumu konfigurēšana un tika pārbaudīta sistēmas darbība 3.Izstrādāts migrācijas modelis 4.Veikta migrācijas optimizēšana 5.Veikta datu migrāc...

Materials And Devices In Electrochromic Window Development

Science.gov (United States)

Cogan, Stuart F.; Anderson, Elizabeth J.; Plante, Timothy D.; Rauh, R. David

1985-12-01

Windows with switchable electrochromic glazings are potentially useful for regulating solar input to building interiors. In this article, we describe the structure and operation of a proposed solid-state electrochromic glazing based on crystalline LixWO3 (c-LiXWO3) and a low coloration efficiency counter electrode material such as amorphous Nb2O5 (a-Nb2O5). The importance of reversibility in electrochromic glazing operation is emphasized, and optical switching experiments that demonstrate reversible lithium insertion/extraction in c-LixW03, a-LixWO3, and a-LixNb2O5 are described. Additional optical switching experiments in tandem electrochromic cells comprised of c-LixWO3/a-Nb2O5 and a-LixWO3/a-Nb2O5 demonstrated the proposed design, indicating reversible optical switching over 500 and 200 complete cycles, respectively, without degradation. Optical data on the evolution of reflective and absorp-tive modulation in c-LixWO3 are presented and solar attenuation results are used to demon-strate the advantage of using crystalline electrochromics to conserve daylighting during electrochromic window operation.

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

Science.gov (United States)

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

2018-04-01

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

Chemical Modification of Boron-Doped Diamond Electrodes for Applications to Biosensors and Biosensing.

Science.gov (United States)

Svítková, Jana; Ignat, Teodora; Švorc, Ľubomír; Labuda, Ján; Barek, Jiří

2016-05-03

Boron-doped diamond (BDD) is a prospective electrode material that possesses many exceptional properties including wide potential window, low noise, low and stable background current, chemical and mechanical stability, good biocompatibility, and last but not least exceptional resistance to passivation. These characteristics extend its usability in various areas of electrochemistry as evidenced by increasing number of published articles over the past two decades. The idea of chemically modifying BDD electrodes with molecular species attached to the surface for the purpose of creating a rational design has found promising applications in the past few years. BDD electrodes have appeared to be excellent substrate materials for various chemical modifications and subsequent application to biosensors and biosensing. Hence, this article presents modification strategies that have extended applications of BDD electrodes in electroanalytical chemistry. Different methods and steps of surface modification of this electrode material for biosensing and construction of biosensors are discussed.

Cell voltage versus electrode potential range in aqueous supercapacitors

OpenAIRE

Dai, Zengxin; Peng, Chuang; Chae, Jung Hoon; Ng, Kok Chiang; Chen, George Z.

2015-01-01

Supercapacitors with aqueous electrolytes and nanostructured composite electrodes are attractive because of their high charging-discharging speed, long cycle life, low environmental impact and wide commercial affordability. However, the energy capacity of aqueous supercapacitors is limited by the electrochemical window of water. In this paper, a recently reported engineering strategy is further developed and demonstrated to correlate the maximum charging voltage of a supercapacitor with the c...

Strategies for the fabrication of porous platinum electrodes

Energy Technology Data Exchange (ETDEWEB)

Kloke, Arne; Stetten, Felix von; Kerzenmacher, Sven [Laboratory for MEMS Applications, Department of Microsystems Engineering-IMTEK, University of Freiburg, Freiburg (Germany); Zengerle, Roland [Laboratory for MEMS Applications, Department of Microsystems Engineering-IMTEK, University of Freiburg, Freiburg (Germany); BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-Universitaet Freiburg (Germany)

2011-11-16

Porous platinum is of high technological importance due to its various applications in fuel cells, sensors, stimulation electrodes, mechanical actuators and catalysis in general. Based on a discussion of the general principles behind the reduction of platinum salts and corresponding deposition processes this article discusses techniques available for platinum electrode fabrication. The numerous, different strategies available to fabricate platinum electrodes are reviewed and discussed in the context of their tuning parameters, strengths and weaknesses. These strategies comprise bottom-up approaches as well as top-down approaches. In bottom-up approaches nanoparticles are synthesized in a first step by chemical, photochemical or sonochemical means followed by an electrode formation step by e.g. thin film technology or network formation to create a contiguous and conducting solid electrode structure. In top-down approaches fabrication starts with an already conductive electrode substrate. Corresponding strategies enable the fabrication of substrate-based electrodes by e.g. electrodeposition or the fabrication of self-supporting electrodes by dealloying. As a further top-down strategy, this review describes methods to decorate porous metals other than platinum with a surface layer of platinum. This way, fabrication methods not performable with platinum can be applied to the fabrication of platinum electrodes with the special benefit of low platinum consumption. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Culturing of primary rat neurons and glia on ultra-thin parylene-C

International Nuclear Information System (INIS)

Unsworth, C.P.; Delivopoulos, E.; Murray, A.F.

2010-01-01

Full text: In this article, we will describe how we have successfully cultured dissociated embryonic cortical neurons and glia from the postnatal rat hippocampus on extremely thin layers (up to 10 nm) of Parylene-C on a silicon dioxide substrate. Silicon wafers were oxidised, deposited with the biomaterial, Parylene-C, photo-lithographically patterned and plasma etched to produce chips that consisted of lines of Paryl ene-C with varying widths, thickness and lengths. The chips produced were then immersed in Horse Serum and plated with the cells. Ratios of Neurons; Glia; Cell Body were measured on, adjacent to and away from the Parylene-C. Our initial results show how these ratios remained roughly constant for ultra-thin Parylene-C thicknesses of 10 nm as compared to a benchmark thickness of 100 nm (where such cells are known to grow well). Thus, our findings demonstrate that it is possible to culture primary rat neurons and glia to practically cell membrane thicknesses of Parylene-C. Being able to culture cells on such ultra thin levels of Parylene-C will open up the possibility to develop Multi-Electrode Arrays (MEA) that can capacitively couple embedded electrodes through the parylene to the cells on its surface. Thus, providing a neat, insulated passive electrode. Only the ultra-thin thicknesses of Parylene demonstrated here would allow for the rea isation of such a technology. Hence, the outcome of this work, will be of great interest to the Neuroengineering and the Multi-Electrode Array (MEA) community, as an alternative material for the fabric tion of passive electrodes, used in capacitive coupling mode.

Grab Windows training opportunities; check CERN Windows roadmap!

CERN Multimedia

IT Department

2011-01-01

CERN Operating Systems and Information Services group (IT-OIS) actively monitors market trends to check how new software products correspond to CERN needs. In the Windows world, Windows 7 has been a big hit, with over 1500 Windows 7 PCs within less than a year since its support was introduced at CERN. No wonder: Windows XP is nearly 10 years old and is steadily approaching the end of its life-cycle. At CERN, support for Windows XP will stop at the end of December 2012. Compared to Vista, Windows 7 has the same basic hardware requirements, but offers higher performance, so the decision to upgrade is rather straightforward. CERN support for Vista will end in June 2011. In the world of Microsoft Office, version 2007 offers better integration with the central services than the older version 2003. Progressive upgrade from 2003 to 2007 is planned to finish in September 2011, but users are encouraged to pro-actively upgrade at their convenience. Please note that Office 2007 brings an important change in the area of ...

Preparation of Carbon Nanotube/TiO2 Mesoporous Hybrid Photoanode with Iron Pyrite (FeS2) Thin Films Counter Electrodes for Dye-Sensitized Solar Cell

OpenAIRE

Bayram Kilic; Sunay Turkdogan; Aykut Astam; Oguz Can Ozer; Mansur Asgin; Hulya Cebeci; Deniz Urk; Selin Pravadili Mucur

2016-01-01

Multi-walled carbon nanotube (MWCNT)/TiO2 mesoporous networks can be employed as a new alternative photoanode in dye-sensitized solar cells (DSSCs). By using the MWCNT/TiO2 mesoporous as photoanodes in DSSC, we demonstrate that the MWCNT/TiO2 mesoporous photoanode is promising alternative to standard FTO/TiO2 mesoporous based DSSC due to larger specific surface area and high electrochemical activity. We also show that iron pyrite (FeS2) thin films can be used as an efficient counter electrode...

Modified electrode voltammetric sensors for trace metals in environmental samples

Directory of Open Access Journals (Sweden)

Brett Christopher M.A.

2000-01-01

Full Text Available Nafion-modified mercury thin film electrodes have been investigated for the analysis of trace metals in environmental samples of waters and effluent by batch injection analysis with square wave anodic stripping voltammetry. The method, involving injection over the detector electrode of untreated samples of volume of the order of 50 microlitres has fast response, blocking and fouling of the electrode is minimum as shown by studies with surface-active components. Comparison is made between glassy carbon substrate electrodes and carbon fibre microelectrode array substrates, the latter leading to a small sensitivity enhancement. Application to analysis of river water and industrial effluent for labile zinc, cadmium, lead and copper ions is demonstrated in collected samples and after acid digestion.

White organic light-emitting diodes with 4 nm metal electrode

Science.gov (United States)

Lenk, Simone; Schwab, Tobias; Schubert, Sylvio; Müller-Meskamp, Lars; Leo, Karl; Gather, Malte C.; Reineke, Sebastian

2015-10-01

We investigate metal layers with a thickness of only a few nanometers as anode replacement for indium tin oxide (ITO) in white organic light-emitting diodes (OLEDs). The ultrathin metal electrodes prove to be an excellent alternative that can, with regard to the angular dependence and efficiency of the OLED devices, outperform the ITO reference. Furthermore, unlike ITO, the thin composite metal electrodes are readily compatible with demanding architectures (e.g., top-emission or transparent OLEDs, device unit stacking, etc.) and flexible substrates. Here, we compare the sheet resistance of both types of electrodes on polyethylene terephthalate for different bending radii. The electrical performance of ITO breaks down at a radius of 10 mm, while the metal electrode remains intact even at radii smaller than 1 mm.

Effect of hypotension and carbon dioxide changes in an improved genuine closed cranial window rat model

DEFF Research Database (Denmark)

Petersen, K A; Dyrby, Lone; Williamson, D

2005-01-01

The genuine closed cranial window model, in which the thinned parietal bone constitutes the covering of the preparation, has contributed to a better understanding of the pathophysiological mechanisms in migraine. In its present form, only measurements of the middle meningeal artery (MMA) are perf......The genuine closed cranial window model, in which the thinned parietal bone constitutes the covering of the preparation, has contributed to a better understanding of the pathophysiological mechanisms in migraine. In its present form, only measurements of the middle meningeal artery (MMA......) are performed. The aim of this study was, in addition, to measure pial artery/arteriole (PA) diameter and cortical cerebral blood flux in the same cranial window. The model was evaluated by studying the effects of hypotension and changes in arterial carbon dioxide pressure (PaCO2), because these parameters......-induced hypotension (-64+/-0.8 mmHg) caused an increase of MMA diameter of 11.8+/-8.4%, PA diameter of 61.2+/-7.7% and a decrease in LCBF(Flux) of -36.4+/-2.5%. The decrease in blood pressure did not significantly change the MMA (P=0.38); however, the PA diameter and the LCBF(Flux) were affected (P

Enhanced efficiency of hybrid amorphous silicon solar cells based on single-walled carbon nanotubes and polymer composite thin film

Science.gov (United States)

Rajanna, Pramod M.; Gilshteyn, Evgenia P.; Yagafarov, Timur; Aleekseeva, Alena K.; Anisimov, Anton S.; Neumüller, Alex; Sergeev, Oleg; Bereznev, Sergei; Maricheva, Jelena; Nasibulin, Albert G.

2018-03-01

We report a simple approach to fabricate hybrid solar cells (HSCs) based on a single-walled carbon nanotube (SWCNT) film and thin film hydrogenated amorphous silicon (a-Si:H). Randomly oriented high-quality SWCNTs with conductivity enhanced by means of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate are used as a window layer and a front electrode. A series of HSCs are fabricated in ambient conditions with varying SWCNT film thicknesses. The polymethylmethacrylate layer drop-casted on fabricated HSCs reduces the reflection fourfold and enhances the short-circuit J sc , open-circuit V oc , and efficiency by nearly 10%. A state-of-the-art J-V performance is shown for SWCNT/a-Si HSC with an open-circuit voltage of 900 mV and an efficiency of 3.4% under simulated one-sun AM 1.5 G direct illumination.

Bilaterally Microstructured Thin Polydimethylsiloxane Film Production

DEFF Research Database (Denmark)

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

2015-01-01

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

Flexible electroluminescent device with inkjet-printed carbon nanotube electrodes

Science.gov (United States)

Azoubel, Suzanna; Shemesh, Shay; Magdassi, Shlomo

2012-08-01

Carbon nanotube (CNTs) inks may provide an effective route for producing flexible electronic devices by digital printing. In this paper we report on the formulation of highly concentrated aqueous CNT inks and demonstrate the fabrication of flexible electroluminescent (EL) devices by inkjet printing combined with wet coating. We also report, for the first time, on the formation of flexible EL devices in which all the electrodes are formed by inkjet printing of low-cost multi-walled carbon nanotubes (MWCNTs). Several flexible EL devices were fabricated by using different materials for the production of back and counter electrodes: ITO/MWCNT and MWCNT/MWCNT. Transparent electrodes were obtained either by coating a thin layer of the CNTs or by inkjet printing a grid which is composed of empty cells surrounded by MWCNTs. It was found that the conductivity and transparency of the electrodes are mainly controlled by the MWCNT film thickness, and that the dominant factor in the luminance intensity is the transparency of the electrode.

Graphene-based integrated electrodes for flexible lithium ion batteries

International Nuclear Information System (INIS)

Shi, Ying; Wen, Lei; Zhou, Guangmin; Chen, Jing; Pei, Songfeng; Huang, Kun; Cheng, Hui-Ming; Li, Feng

2015-01-01

We have prepared flexible free-standing electrodes with anode and cathode active materials deposited on a highly conductive graphene membrane by a two-step filtration method. Compared with conventional electrodes using metal as current collectors, these electrodes have displayed stronger adhesion, superior electrochemical performance, higher energy density, and better flexibility. A full lithium ion battery assembled by adopting these graphene-based electrodes has showed high rate capability and long cyclic life. We have also assembled a thin, lightweight, and flexible lithium ion battery with poly-(dimethyl siloxane) sheets as packaging material to light a red light-emitting diode. This flexible battery can be easily bent without structural failure or performance loss and operated well under a bent state. The fabrication process of these graphene-based integrated electrodes only has two filtration steps; thus it is easy to scale up. These results suggest great potential for these graphene-based flexible batteries in lightweight, bendable, and wearable electronic devices. (paper)

New Hypothesis for SOFC Ceramic Oxygen Electrode Mechanisms

DEFF Research Database (Denmark)

Mogensen, Mogens Bjerg; Chatzichristodoulou, Christodoulos; Graves, Christopher R.

2016-01-01

A new hypothesis for the electrochemical reaction mechanism in solid oxide cell ceramic oxygen electrodes is proposed based on literature including our own results. The hypothesis postulates that the observed thin layers of SrO-La2O3 on top of ceramic perovskite and other Ruddlesden-Popper...

Characterization of RuO sub 2 electrodes for ferroelectric thin films prepared by metal-organic chemical-vapor deposition using Ru(C sub 1 sub 1 H sub 1 sub 9 O sub 2) sub 3

CERN Document Server

Lee, J M; Shin, J C; Hwang, C S; Kim, H J; Suk, C G

1999-01-01

Pure and conducting RuO sub 2 thin films were deposited on Si substrates at 250 approx 450 .deg. C using Ru(C sub 1 sub 1 H sub 1 sub 9 O sub 2) sub 3 as a precursor by low-pressure metal-organic chemical-vapor deposition (LP-MOCVD). At a lower deposition temperature,smoother and denser RuO sub 2 thin films were deposited. The RuO sub 2 thin films, which were crack free, adhered well onto the substrates and showed very low resistivities around 45 approx 60 mu OMEGA cm. RuO sub 2 thin films on (Ba, Sr)/TiO sub 3 /Pt/SiO sub 2 /Si showed good properties, indicating that MOCVD RuO sub 2 thin films from Ru(C sub 1 sub 1 H sub 1 sub 9 O sub 2) sub 3 can be applied as electrodes of high-dielectric thin films for capacitors in ultra-large-scale DRAMs.

Silver nanowire/polyaniline composite transparent electrode with improved surface properties

International Nuclear Information System (INIS)

Kumar, A.B.V. Kiran; Jiang, Jianwei; Bae, Chang Wan; Seo, Dong Min; Piao, Longhai; Kim, Sang-Ho

2014-01-01

Highlights: • AgNWs/PANI transparent electrode was prepared by layer-by-layer coating method. • The surface roughness of the electrode reached to 6.5 nm (root mean square). • The electrode had reasonable sheet resistance (25 Ω/□) and transmittance (83.5%). - Abstract: Silver nanowires (AgNWs) are as potential candidates to replace indium tin oxide (ITO) in transparent electrodes because of their preferred conducting and optical properties. However, their rough surface properties are not favorable for the fabrication of optoelectronic devices, such as displays and thin-film solar cells. In the present investigation, AgNWs/polyaniline composite transparent electrodes with better surface properties were successfully prepared. AgNWs were incorporated into polyaniline:polystyrene sulfonate (PANI:PSS) by layer-by-layer coating and mechanical pressing. PANI:PSS decreased the surface roughness of the AgNWs electrode by filling the gap of the random AgNWs network. The transparent composite electrode had decreased surface roughness (root mean square 6.5 nm) with reasonable sheet resistance (25 Ω/□) and transmittance (83.5%)

Polishing large NaCl windows on a continuous polisher

International Nuclear Information System (INIS)

Williamson, R.

1979-01-01

The Helios and Antares CO 2 fusion laser systems incorporate numerous large sodium chloride windows. These must be refinished periodically, making necessary a consistent and predictable polishing capability. A continuous polisher (or annular lap) which might at Kirtland's Developmental Optical Facility. Large NaCl windows had not been polished on this type of machine. The machine has proven itself capable of producing lambda/16 figures at 633 nm (HeNe) with extremely smooth surfaces on glass. Since then, we have been working exclusively on NaCl optics. Due to different polishing parameters between NaCl and glass, and the slight solubility of the pitch in the slurry, this phase presents new problems. The work on glass will be reviewed. Results on NaCl to date will be reported. The potential of this type of machine relative to prisms, thin and irregularly shaped optics will be discussed

Tailored ion energy distributions on plasma electrodes

International Nuclear Information System (INIS)

Economou, Demetre J.

2013-01-01

As microelectronic device features continue to shrink approaching atomic dimensions, control of the ion energy distribution on the substrate during plasma etching and deposition becomes increasingly critical. The ion energy should be high enough to drive ion-assisted etching, but not too high to cause substrate damage or loss of selectivity. In many cases, a nearly monoenergetic ion energy distribution (IED) is desired to achieve highly selective etching. In this work, the author briefly reviews: (1) the fundamentals of development of the ion energy distribution in the sheath and (2) methods to control the IED on plasma electrodes. Such methods include the application of “tailored” voltage waveforms on an electrode in continuous wave plasmas, or the application of synchronous bias on a “boundary electrode” during a specified time window in the afterglow of pulsed plasmas

Window Stories

DEFF Research Database (Denmark)

Hauge, Bettina

This research project has investigated 17 households in Germany (cities and rural areas). The main aim was to learn about the significance of the window to these people: What they think of their windows, how, when and why they use them in their everyday life, if they have a favorite window and wh...

Windows 10 simplified

CERN Document Server

McFedries, Paul

2015-01-01

Learn Windows 10 quickly and painlessly with this beginner's guide Windows 10 Simplified is your absolute beginner's guide to the ins and outs of Windows. Fully updated to cover Windows 10, this highly visual guide covers all the new features in addition to the basics, giving you a one-stop resource for complete Windows 10 mastery. Every page features step-by-step screen shots and plain-English instructions that walk you through everything you need to know, no matter how new you are to Windows. You'll master the basics as you learn how to navigate the user interface, work with files, create

Windows and doors

Energy Technology Data Exchange (ETDEWEB)

1988-01-01

A complete manual is presented on windows and doors for the housing contractor. In order to understand the role of windows and doors in a house's energy performance, an introduction explains the house as a system of components that can have effects on each other. Further chapters explain in detail the parts of a window, window types and RSI values; window servicing and repair; window replacement; parts of a door, door types and RSI values; door service and repair, including weatherstripping; door replacement; and how to ensure quality, service, and customer satisfaction. A glossary of terms is included. 61 figs., 3 tabs.

The rational for a mid-scala electrode array.

Science.gov (United States)

Boyle, P J

2016-06-01

Today increasing numbers of cochlear implant candidates have residual hearing that can be aided and hence is worth trying to preserve. This means that surgical technique and electrode array design must be adapted to minimize trauma. Wide opening of the round window is often preferred to reduce drill related trauma and to avoid pressure spikes during electrode array insertion. A recent meta-analysis suggested that there is no significant correlation between hearing preservation and either insertion depth or scala position. However, a slow insertion speed of at least 30seconds was associated with better hearing preservation. An electrode design is proposed that targets the middle of the scala tympani. This minimizes frictional forces from either lateral or medial wall during insertion and imposes less static pressure on cochlear structures following insertion. The flexibility to insert via the round window requires a 0.7-mm maximum dimension at the proximal end of the array. Micro-anatomical analysis by micro-CT indicated that a 420-degree insertion depth was optimal between cochlear coverage and available space within the scala tympani. Physical measurements showed that mean insertion forces remained below 10mN during insertion. A series of 20 human temporal bone insertions found a mean insertion depth of 400 degrees with no scala dislocations. Six clinical series, in total 94 cases, found postoperative hearing in 81% of cases with a mean loss of 12dB compared to preoperative levels. Speech understanding out to one year post-fitting trended better for a mid-scala design group than for a straight electrode array group; although the differences were not statistically significant. A mid-scala array design appears able to be inserted with minimal trauma, to return a predictable insertion depth across various sizes of cochleae and to support reasonable levels of speech understanding without relying on residual hearing. Copyright © 2016. Published by Elsevier Masson

Hearing Preservation Outcomes With a Mid-Scala Electrode in Cochlear Implantation.

Science.gov (United States)

Hunter, Jacob B; Gifford, René H; Wanna, George B; Labadie, Robert F; Bennett, Marc L; Haynes, David S; Rivas, Alejandro

2016-03-01

To evaluate hearing preservation (HP) outcomes in adult cochlear implant recipients with a mid-scala electrode. Tertiary academic center. Adult patients implanted with a mid-scala electrode between May 2013 and July 2015. Cochlear implantation. Age, sex, surgical approach, residual hearing changes post cochlear implantation, HP rates using different published classifications, and speech perception scores. Fifty ears for 47 patients (mean age, 58.2 yr; range, 23-86) were implanted with the electrode. Recognizing that not all patients were true HP candidates and/or underwent generally accepted HP surgical techniques, 39 ears had preoperative low-frequency hearing (audiometric threshold ≤ 85dB HL at 250Hz), 24 preserved acoustic hearing postoperatively (75.0%). Patients who had preserved acoustic hearing were implanted via round window (N = 18), extended round window (N = 4), or via cochleostomy (N = 2) approaches. Mean threshold elevation for low-frequency pure-tone average (125, 250, and 500  Hz) was 20.2  dB after surgery. 43.8% of patients had aidable low-frequency hearing at activation, 30.0% at 6-months postoperatively, and 30.8% 1-year postopera tively. Using a formula outlined by Skarzynski and colleagues, at 6-months postoperatively, 15.0% of patients had complete HP, whereas 40.0% had partial HP. At 1-year, these percentages decreased to 0% and 38.5%, respectively. Age, type of approach, and perioperative steroid use were not correlated with HP outcomes at activation and 6-months postoperatively (p > 0.05). The mid-scala electrode evaluated allows preservation of low-frequency hearing in patients undergoing cochlear implantation at rates and degrees of preservation close to other reports in the cochlear implant literature.

Electrode/Dielectric Strip For High-Energy-Density Capacitor

Science.gov (United States)

Yen, Shiao-Ping S.

1994-01-01

Improved unitary electrode/dielectric strip serves as winding in high-energy-density capacitor in pulsed power supply. Offers combination of qualities essential for high energy density: high permittivity of dielectric layers, thinness, and high resistance to breakdown of dielectric at high electric fields. Capacitors with strip material not impregnated with liquid.

A comparative study of the adsorption and oxidation of L-alanine and L-serine on Au(1 0 0), Au(1 1 1) and gold thin film electrodes in acid media

International Nuclear Information System (INIS)

Sandoval, Andrea P.; Orts, José Manuel; Rodes, Antonio; Feliu, Juan M.

2013-01-01

The adsorption and oxidation of L-alanine and L-serine at Au(1 1 1) and Au(1 0 0) single crystal and evaporated thin-film electrodes with preferential (1 1 1) orientation was studied in perchloric acid solutions. For this purpose, cyclic voltammetry experiments were combined with external reflection infrared spectroscopy (gold single crystals) and surface-enhanced infrared reflection–absorption spectroscopy under attenuated total reflection conditions (ATR-SEIRAS) (gold thin films). In addition, theoretical harmonic vibrational frequencies, obtained from B3LYP/LANL2DZ, 6-31+G(d) calculations for the zwitterionic species adsorbed on Au clusters with (1 1 1) orientation, were used to interpret the experimental spectra. The optimized geometry obtained from DFT calculations for the corresponding zwitterion plus a water molecule, under the application of an external electric field of 0.01 a.u. corresponds to a bidentate asymmetrical bridge adsorption configuration. The absence of an adsorbate band for the asymmetric OCO stretching in the experimental infrared spectra confirms the bidentate bonding of the adsorbed zwitterion through the oxygen atoms of the carboxylate group irrespective of the crystallographic orientation of the electrode surface, the adsorbate coverage and the electrode potential. In addition to typical interfacial water bands associated to perchlorate anions, which are co-adsorbed in order to compensate the positive charge of the ammonium group, the ATR-SEIRA spectra also show bands around 2950 cm −1 that can be related to the formation of hydrogen bonds between interfacial water and the ammonium group of the adsorbed zwitterion. The voltammetric experiments have shown that, as in the case of platinum electrodes, L-serine oxidizes at lower potentials than L-alanine. Under these conditions, the in situ infrared experiments show the formation of carbon dioxide and adsorbed cyanide as oxidation products of L-serine. In the case of L-alanine, only

Asymmetric electrochemical supercapacitor, based on polypyrrole coated carbon nanotube electrodes

International Nuclear Information System (INIS)

Su, Y.; Zhitomirsky, I.

2015-01-01

Highlights: • Polypyrrole (PPy) coated multiwalled carbon nanotubes (MWCNT) were prepared. • New method is based on the use of new electrochemically active dopants for PPy. • The dopans provided dispersion of MWCNT and promoted PPy coating formation. • Symmetric PPy–MWCNT supercapacitors showed high capacitance and low resistance. • Asymmetric PPy–MWCNT/VN–MWCNT devices and modules allowed larger voltage window. - Abstract: Conductive polypyrrole (PPy) polymer – multiwalled carbon nanotubes (MWCNT) composites were synthesized using sulfanilic acid azochromotrop (SPADNS) and sulfonazo III sodium salt (CHR-BS) as anionic dopants for chemical polymerization of PPy. The composites were tested for application in electrodes of electrochemical supercapacitors (ES). Sedimentation tests, electrophoretic deposition experiments and Fourier transform infrared spectroscopy (FTIR) investigations showed that strong adsorption of anionic CHR-BS on MWCNT provided MWCNT dispersion. The analysis of scanning and transmission electron microscopy data demonstrated that the use of CHR-BS allowed the formation of PPy coatings on MWCNT. As a result, the composites, prepared using CHR-BS, showed higher capacitance, compared to the composites, prepared using SPADNS. The electrodes, containing MWCNT, coated with PPy showed a capacitance of 179 F g −1 for active mass loading of 10 mg cm −2 , good capacitance retention at scan rates in the range of 2–100 mV s −1 and excellent cyclic stability. Asymmetric ES devices, containing positive PPy–MWCNT electrodes and negative vanadium nitride (VN)–MWCNT electrodes showed significant improvement in energy storage performance, compared to the symmetric ES due to the larger voltage window. The low impedance and high capacitance of the individual cells paved the way to the development of modules with higher voltage, which showed good electrochemical performance

MS Windows domēna darbstacijas migrācijas iespējas no MS Windows XP uz MS Windows 7.

OpenAIRE

Zariņš, Valdis

2009-01-01

Kvalifikācijas darbā tiek aprakstītas MS Windows domēna darbstacijas migrācijas iespējas no MS Windows XP uz MS Windows 7, kā servera operētājsistēmas izmantojot tādus Microsoft produktus, kā Microsoft Windows Server 2003 un Microsoft Windows Server 2008. Kvalifikācijas darba teorētiskaja daļā tiek apskatīti Microsoft Windows 7 priekšrocības un uzlabojumus gan no darbstacijas lietotāja , gan no darbstacijas administratora puses. Ir aprakstītas Microsoft Windows Server 2008 jauninājumu ie...

Simple fabrication of active electrodes using direct laser transference

International Nuclear Information System (INIS)

Cavallo, P.; Coneo Rodriguez, R.; Broglia, M.; Acevedo, D.F.; Barbero, C.A.

2014-01-01

Highlights: •Electroactive materials can be transferred using a single pulse of laser light. •The transfer is made in air using a 6 ns pulse of Nd-YAG laser (532 or 1064 nm). •Conducting polymers films can be transferred maintaining the electroactivity. •Conducting polymer multilayers can be deposited using successive pulses. •Metallic (Au, Pt) transferred micro/nanoparticles are electrocatalytic. -- Abstract: Direct laser transference (DLT) method is applied to obtain electrodes modified with thin films of conducting polymers (CPs) or catalytic metals. A short (6–10 ns) pulse of laser light (second harmonic of Nd-YAG Laser, λ = 532 nm) is shined on the backside of a thin (<200 nm) film of the material to be transferred, which is deposited on a transparent substrate. The illuminated region heats up and the material (conducting polymer or metal) is thermally transferred to a solid target placed at short distance in air. In that ways, CPs are transferred onto polypropylene, glass, indium doped tin oxide (ITO), glassy carbon and gold films. In the same manner, electrocatalytic metals (platinum or gold) are transferred onto conductive substrates (glassy carbon or ITO films on glass). The films have been characterized by scanning electron microscopy, cyclic voltammetry, atomic force microscopy, UV-visible and Fourier Transform Infrared spectroscopies. The chemical, electrical and redox properties of the polymeric materials transferred remain unaltered after the transfer. Moreover, CP multilayers can be built applying DLT several times onto the same substrate. Besides polyaniline, it is shown that it is also possible to transfer functionalized polyanilines. The electrode modified with transferred Pt shows electrocatalytic activity toward methanol oxidation while ferricyanide shows a quasireversible behavior on electrodes modified with transferred Au. The method is simple and fast, works in air without complex environmental conditions and can produce active

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Preparation and optical characterization of DNA-riboflavin thin films

Science.gov (United States)

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

2016-09-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-08-31

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

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.