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Sample records for transparent counter electrode

  1. Nitrogen-doped graphene as transparent counter electrode for efficient dye-sensitized solar cells

    SciTech Connect

    Wang, Guiqiang; Fang, Yanyan; Lin, Yuan; Xing, Wei; Zhuo, Shuping

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ? NG sheets are prepared through a hydrothermal reduction of graphite oxide. ? The transparent NG counter electrodes of DSCs are fabricated at room temperature. ? Transparent NG electrode exhibits excellent catalytic activity for the reduction of I{sub 3}{sup ?}. ? The DSC with NG electrode achieves a comparable efficiency to that of the Pt-based cell. ? The efficiency of rear illumination is about 85% that of front illumination. -- Abstract: Nitrogen-doped graphene sheets are prepared through a hydrothermal reduction of graphite oxide in the presence of ammonia and applied to fabricate the transparent counter electrode of dye-sensitized solar cells. The atomic percentage of nitrogen in doped graphene sample is about 2.5%, and the nitrogen bonds display pyridine and pyrrole-like configurations. Cyclic voltammetry studies demonstrate a much higher electrocatalytic activity toward I{sup ?}/I{sub 3}{sup ?} redox reaction for nitrogen-doped graphene, as compared with pristine graphene. The dye-sensitized solar cell with this transparent nitrogen-doped graphene counter electrode shows conversion efficiencies of 6.12% and 5.23% corresponding to front-side and rear-side illumination, respectively. Meanwhile, the cell with a Pt counter electrode shows a conversion efficiency of 6.97% under the same experimental condition. These promising results highlight the potential application of nitrogen-doped graphene in cost-effective, transparent dye-sensitized solar cells.

  2. Transparent metal selenide alloy counter electrodes for high-efficiency bifacial dye-sensitized solar cells.

    PubMed

    Duan, Yanyan; Tang, Qunwei; Liu, Juan; He, Benlin; Yu, Liangmin

    2014-12-22

    The exploration of cost-effective and transparent counter electrodes (CEs) is a persistent objective in the development of bifacial dye-sensitized solar cells (DSSCs). Transparent counter electrodes based on binary-alloy metal selenides (M-Se; M=Co, Ni, Cu, Fe, Ru) are now obtained by a mild, solution-based method and employed in efficient bifacial DSSCs. Owing to superior charge-transfer ability for the I(-) /I3 (-) redox couple, electrocatalytic activity toward I3 (-) reduction, and optical transparency, the bifacial DSSCs with CEs consisting of a metal selenide alloy yield front and rear efficiencies of 8.30?% and 4.63?% for Co0.85 Se, 7.85?% and 4.37?% for Ni0.85 Se, 6.43?% and 4.24?% for Cu0.50 Se, 7.64?% and 5.05?% for FeSe, and 9.22?% and 5.90?% for Ru0.33 Se in comparison with 6.18?% and 3.56?% for a cell with an electrode based on pristine platinum, respectively. Moreover, fast activity onset, high multiple start/stop capability, and relatively good stability demonstrate that these new electrodes should find applications in solar panels. PMID:25358619

  3. Cost-effective, transparent iron selenide nanoporous alloy counter electrode for bifacial dye-sensitized solar cell

    NASA Astrophysics Data System (ADS)

    Liu, Juan; Tang, Qunwei; He, Benlin; Yu, Liangmin

    2015-05-01

    Pursuit of cost-effective and efficient counter electrodes (CEs) is a persistent objective for dye-sensitized solar cells (DSSCs). We present here the design of transparent Fe-Se nanoporous alloy CEs for bifacial DSSC applications. Due to the superior charge-transfer ability for I-/I3- redox couples, electrocatalytic reduction toward I3- species, and optical transparency in visible-light region, the bifacial DSSC with FeSe alloy electrode yields maximum front and rear efficiencies of 9.16% and 5.38%, respectively. A fast start-up, high multiple start capability, and good stability of the FeSe alloy CE demonstrate the potential applications in driving solar panels. The impressive efficiency along with simple preparation of the cost-effective Fe-Se nanoporous alloy CEs highlights their potential application in robust bifacial DSSCs.

  4. Electrochromic counter electrode

    DOEpatents

    Lee, Se-Hee; Tracy, C. Edwin; Pitts, J. Roland; Jorgensen, Gary J.

    2005-02-22

    The present invention discloses an amorphous material comprising nickel oxide doped with tantalum that is an anodically coloring electrochromic material. The material of the present invention is prepared in the form of an electrode (200) having a thin film (202) of an electrochromic material of the present invention residing on a transparent conductive film (203). The material of the present invention is also incorporated into an electrochromic device (100) as a thin film (102) in conjunction with a cathodically coloring prior art electrochromic material layer (104) such that the devices contain both anodically coloring (102) and cathodically coloring (104) layers. The materials of the electrochromic layers in these devices exhibit broadband optical complimentary behavior, ionic species complimentary behavior, and coloration efficiency complimentary behavior in their operation.

  5. A facile synthesis of bimetallic AuPt nanoparticles as a new transparent counter electrode for quantum-dot-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Dao, Van-Duong; Choi, Youngwoo; Yong, Kijung; Larina, Liudmila L.; Shevaleevskiy, Oleg; Choi, Ho-Suk

    2015-01-01

    This study first reports the synthesis of AuPt bimetallic nanoparticles (AuPt-BNPs) on an FTO glass substrate using dry plasma reduction (DPR) and its application as an alternative transparent counter electrode (CE) for quantum-dot-sensitized solar cells (QDSCs) operated under bi-side illumination. DPR is an economically feasible and ecologically sustainable method. The formation of ultrafine crystalline AuPt-BNPs on an FTO substrate is confirmed through TEM, HRTEM with HAADF-STEM and HAADF-STEM-EDS analyses. The mechanism for controlling the size, mono-dispersity, and areal number density of nanoparticles on the substrate surface is suggested. The CE fabricated with AuPt-BNPs exhibits a high electro-catalytic activity without losing the optical transmittance of the FTO substrate. The QDSC employing the AuPt-BNP electrode reaches efficiencies of 2.4% under front-side illumination and 2.2% under back-side illumination. Bi-side illumination yields an efficiency of 3.4%, which is comparable to an efficiency of 3.7% obtained for the QDSC with the state-of-the-art CE.

  6. Fully solution-processed transparent conducting oxide-free counter electrodes for dye-sensitized solar cells: spray-coated single-wall carbon nanotube thin films loaded with chemically-reduced platinum nanoparticles.

    PubMed

    Kim, Sang Yong; Kim, Yesel; Lee, Kyung Moon; Yoon, Woo Sug; Lee, Ho Seok; Lee, Jong Tae; Kim, Seung-Joo; Ahn, Yeong Hwan; Park, Ji-Yong; Lee, Tai Kyu; Lee, Soonil

    2014-08-27

    We report fully solution-processed fabrication of transparent conducting oxide-free counter electrodes (CEs) for dye-sensitized solar cells (DSSCs) by combining spray-coating of single-wall carbon nanotubes (SWCNTs) and chemical reduction of chloroplatinic acid precursor to platinum nanoparticles (Pt NPs) with formic acid. The power conversion efficiency of a semitransparent DSSC with such SWCNT-based CE loaded with Pt NPs is comparable to that of a control device with a conventional CE. Quantification of Pt loading shows that network morphology of entangled SWCNTs is efficient in forming and retaining chemically reduced Pt NPs. Moreover, electron microscopy and electrochemical impedance spectroscopy results show that mainly Pt NPs, which are tens of nanometers in diameter and reside at the surface of SWCNT CEs, contribute to electrocatalytic activity for triiodide reduction, to which we attribute strong correlation between power conversion efficiency of DSSCs and time constant deduced from equivalent-circuit analysis of impedance spectra. PMID:25122074

  7. Performance dependence of Si quantum dot-sensitized solar cells on counter electrode

    NASA Astrophysics Data System (ADS)

    Seo, Hyunwoong; Ichida, Daiki; Uchida, Giichiro; Itagaki, Naho; Koga, Kazunori; Shiratani, Masaharu

    2014-01-01

    Au counter electrode is generally used with polysulfide electrolyte for quantum dot-sensitized solar cells (QDSCs) due to degradation of QD by iodine electrolyte and strong interaction between Pt counter electrode and S2- ions in polysulfide electrolyte. In this work, the effects of the thickness and morphology of Au counter electrode on the performance of Si QDSC were investigated. Au film thickness was linearly controlled from 5 to 500 nm by deposition time. Cyclic voltammetry and impedance analysis clarified the catalytic activity of counter electrode, surface resistance of transparent conductive oxide (TCO), and the charge transportation at the counter electrode. The increase of Au film thickness reduced the surface resistance of TCO with increased conductivity. No significant difference in the redox reaction from electrolyte to Si QDs was observed for Au film thickness from 20 to 500 nm. Catalytic reaction of counter electrode was activated with the increase of Au film thickness up to 200 nm. The impedance of charge transportation at the counter electrode was also decreased with Au deposition. Their surface resistance, catalytic activity and internal resistance were reflected in overall performance. Consequently, Si QDSC with 200-nm-thick Au counter electrode had the best performance.

  8. Graphene versus oxides for transparent electrode applications

    NASA Astrophysics Data System (ADS)

    Sandana, V. E.; Rogers, D. J.; Teherani, F. Hosseini; Bove, P.; Razeghi, M.

    2013-03-01

    Due to their combination of good electrical conductivity and optical transparency, Transparent Conducting Oxides (TCOs) are the most common choice as transparent electrodes for optoelectronics applications. In particular, devices, such as LEDs, LCDs, touch screens and solar cells typically employ indium tin oxide. However, indium has some significant drawbacks, including toxicity issues (which are hampering manufacturing), an increasing rarefication (due to a combination of relative scarcity and increasing demand [1]) and resulting price increases. Moreover, there is no satisfactory option at the moment for use as a p-type transparent contact. Thus alternative materials solutions are actively being sought. This review will compare the performance and perspectives of graphene with respect to TCOs for use in transparent conductor applications.

  9. Transparent electrode for optical switch

    DOEpatents

    Goldhar, J.; Henesian, M.A.

    1984-10-19

    The invention relates generally to optical switches and techniques for applying a voltage to an electro-optical crystal, and more particularly, to transparent electodes for an optical switch. System architectures for very large inertial confinement fusion (ICF) lasers require active optical elements with apertures on the order of one meter. Large aperture optical switches are needed for isolation of stages, switch-out from regenerative amplifier cavities and protection from target retroreflections.

  10. Transparent metallic fractal electrodes for semiconductor devices.

    PubMed

    Afshinmanesh, Farzaneh; Curto, Alberto G; Milaninia, Kaveh M; van Hulst, Niek F; Brongersma, Mark L

    2014-09-10

    Nanostructured metallic films have the potential to replace metal oxide films as transparent electrodes in optoelectronic devices. An ideal transparent electrode should possess a high, broadband, and polarization-independent transmittance. Conventional metallic gratings and grids with wavelength-scale periodicities, however, do not have all of these qualities. Furthermore, the transmission properties of a nanostructured electrode need to be assessed in the actual dielectric environment provided by a device, where a high-index semiconductor layer can reflect a substantial fraction of the incident light. Here we propose nanostructured aluminum electrodes with space-filling fractal geometries as alternatives to gratings and grids and experimentally demonstrate their superior optoelectronic performance through integration with Si photodetectors. As shown by polarization and spectrally resolved photocurrent measurements, devices with fractal electrodes exhibit both a broadband transmission and a flat polarization response that outperforms both square grids and linear gratings. Finally, we show the benefits of adding a thin silicon nitride film to the nanostructured electrodes to further reduce reflection. PMID:25140611

  11. Cu Mesh for Flexible Transparent Conductive Electrodes

    PubMed Central

    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

    2015-01-01

    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. PMID:26039977

  12. Copper Nanowires as Fully Transparent Conductive Electrodes

    PubMed Central

    Guo, Huizhang; Lin, Na; Chen, Yuanzhi; Wang, Zhenwei; Xie, Qingshui; Zheng, Tongchang; Gao, Na; Li, Shuping; Kang, Junyong; Cai, Duanjun; Peng, Dong-Liang

    2013-01-01

    In pondering of new promising transparent conductors to replace the cost rising tin-doped indium oxide (ITO), metal nanowires have been widely concerned. Herein, we demonstrate an approach for successful synthesis of long and fine Cu nanowires (NWs) through a novel catalytic scheme involving nickel ions. Such Cu NWs in high aspect ratio (diameter of 16.2 ± 2?nm and length up to 40??m) provide long distance for electron transport and, meanwhile, large space for light transmission. Transparent electrodes fabricated using the Cu NW ink achieve a low sheet resistance of 1.4?Ohm/sq at 14% transmittance and a high transparency of 93.1% at 51.5?Ohm/sq. The flexibility and stability were tested with 100-timebending by 180°and no resistance change occurred. Ohmic contact was achieved to the p- and n-GaN on blue light emitting diode chip and bright electroluminescence from the front face confirmed the excellent transparency. PMID:23900572

  13. Optically transparent multi-suction electrode arrays

    PubMed Central

    Nagarah, John M.; Stowasser, Annette; Parker, Rell L.; Asari, Hiroki; Wagenaar, Daniel A.

    2015-01-01

    Multielectrode arrays (MEAs) allow for acquisition of multisite electrophysiological activity with submillisecond temporal resolution from neural preparations. The signal to noise ratio from such arrays has recently been improved by substrate perforations that allow negative pressure to be applied to the tissue; however, such arrays are not optically transparent, limiting their potential to be combined with optical-based technologies. We present here multi-suction electrode arrays (MSEAs) in quartz that yield a substantial increase in the detected number of units and in signal to noise ratio from mouse cortico-hippocampal slices and mouse retina explants. This enables the visualization of stronger cross correlations between the firing rates of the various sources. Additionally, the MSEA's transparency allows us to record voltage sensitive dye activity from a leech ganglion with single neuron resolution using widefield microscopy simultaneously with the electrode array recordings. The combination of enhanced electrical signals and compatibility with optical-based technologies should make the MSEA a valuable tool for investigating neuronal circuits. PMID:26539078

  14. Bio-Inspired Chemical Fabrication of Stretchable Transparent Electrodes.

    PubMed

    Yu, You; Zhang, Yaokang; Li, Kan; Yan, Casey; Zheng, Zijian

    2015-07-01

    Stretchable and transparent electrodes are fabricated by chemical deposition of metal thin films on natural veins of leaves at ambient conditions. These vein-based transparent electrodes show excellent electro-optical property (0.9 ? sq(-1) at 83% T) even at 50% tensile strains, ideal for flexible and stretchable optoelectronic devices. PMID:25786920

  15. Graphene Transparent Conductive Electrodes for Next- Generation Microshutter Arrays

    NASA Technical Reports Server (NTRS)

    Li, Mary; Sultana, Mahmooda; Hess, Larry

    2012-01-01

    Graphene is a single atomic layer of graphite. It is optically transparent and has high electron mobility, and thus has great potential to make transparent conductive electrodes. This invention contributes towards the development of graphene transparent conductive electrodes for next-generation microshutter arrays. The original design for the electrodes of the next generation of microshutters uses indium-tin-oxide (ITO) as the electrode material. ITO is widely used in NASA flight missions. The optical transparency of ITO is limited, and the material is brittle. Also, ITO has been getting more expensive in recent years. The objective of the invention is to develop a graphene transparent conductive electrode that will replace ITO. An exfoliation procedure was developed to make graphene out of graphite crystals. In addition, large areas of single-layer graphene were produced using low-pressure chemical vapor deposition (LPCVD) with high optical transparency. A special graphene transport procedure was developed for transferring graphene from copper substrates to arbitrary substrates. The concept is to grow large-size graphene sheets using the LPCVD system through chemical reaction, transfer the graphene film to a substrate, dope graphene to reduce the sheet resistance, and pattern the film to the dimension of the electrodes in the microshutter array. Graphene transparent conductive electrodes are expected to have a transparency of 97.7%. This covers the electromagnetic spectrum from UV to IR. In comparison, ITO electrodes currently used in microshutter arrays have 85% transparency in mid-IR, and suffer from dramatic transparency drop at a wavelength of near-IR or shorter. Thus, graphene also has potential application as transparent conductive electrodes for Schottky photodiodes in the UV region.

  16. Solution-processed metal nanowire mesh transparent electrodes.

    PubMed

    Lee, Jung-Yong; Connor, Stephen T; Cui, Yi; Peumans, Peter

    2008-02-01

    Transparent conductive electrodes are important components of thin-film solar cells, light-emitting diodes, and many display technologies. Doped metal oxides are commonly used, but their optical transparency is limited for films with a low sheet resistance. Furthermore, they are prone to cracking when deposited on flexible substrates, are costly, and require a high-temperature step for the best performance. We demonstrate solution-processed transparent electrodes consisting of random meshes of metal nanowires that exhibit an optical transparency equivalent to or better than that of metal-oxide thin films for the same sheet resistance. Organic solar cells deposited on these electrodes show a performance equivalent to that of devices based on a conventional metal-oxide transparent electrode. PMID:18189445

  17. Improved photocurrent of a poly (3,4-ethylenedioxythiophene)-ClO??/TiO? thin film-modified counter electrode for dye-sensitized solar cells.

    PubMed

    Sakurai, Sho; Kawamata, Yuka; Takahashi, Masashi; Kobayashi, Koichi

    2011-01-01

    We prepared a poly(3,4-ethylenedioxythiophene) (PEDOT)-ClO??-supported TiO? thin-film electrode as a counter electrode on a transparent conductive oxide glass electrode for a dye-sensitized solar cell (DSSC) using a combination of sol-gel and electropolymerization methods. The photocurrent-voltage characteristics indicate that DSSCs with PEDOT-ClO??/TiO? thin-film counter electrodes had a high photovoltaic conversion efficiency similar to that of PEDOT-ClO??/TiO? particle composite-film electrodes. Furthermore, it was found that the photocurrent was increased by attaching a reflector to the opposite side of the transparent counter electrode. PMID:22123245

  18. Stretchable and transparent electrodes based on in-plane structures

    NASA Astrophysics Data System (ADS)

    Kim, Kukjoo; Kim, Joohee; Hyun, Byung Gwan; Ji, Sangyoon; Kim, So-Yun; Kim, Sungwon; An, Byeong Wan; Park, Jang-Ung

    2015-08-01

    Stretchable electronics has attracted great interest with compelling potential applications that require reliable operation under mechanical deformation. Achieving stretchability in devices, however, requires a deeper understanding of nanoscale materials and mechanics beyond the success of flexible electronics. In this regard, tremendous research efforts have been dedicated toward developing stretchable electrodes, which are one of the most important building blocks for stretchable electronics. Stretchable transparent thin-film electrodes, which retain their electrical conductivity and optical transparency under mechanical deformation, are particularly important for the favourable application of stretchable devices. This minireview summarizes recent advances in stretchable transparent thin-film electrodes, especially employing strategies based on in-plane structures. Various approaches using metal nanomaterials, carbon nanomaterials, and their hybrids are described in terms of preparation processes and their optoelectronic/mechanical properties. Some challenges and perspectives for further advances in stretchable transparent electrodes are also discussed.

  19. An Electrochemical Experiment Using an Optically Transparent Thin Layer Electrode

    ERIC Educational Resources Information Center

    DeAngelis, Thomas P.; Heineman, William R.

    1976-01-01

    Describes a unified experiment in which an optically transparent thin layer electrode is used to illustrate the techniques of thin layer electrochemistry, cyclic voltammetry, controlled potential coulometry, and spectroelectrochemistry. (MLH)

  20. A transparent electrode based on a metal nanotrough network

    NASA Astrophysics Data System (ADS)

    Wu, Hui; Kong, Desheng; Ruan, Zhichao; Hsu, Po-Chun; Wang, Shuang; Yu, Zongfu; Carney, Thomas J.; Hu, Liangbing; Fan, Shanhui; Cui, Yi

    2013-06-01

    Transparent conducting electrodes are essential components for numerous flexible optoelectronic devices, including touch screens and interactive electronics. Thin films of indium tin oxide--the prototypical transparent electrode material--demonstrate excellent electronic performances, but film brittleness, low infrared transmittance and low abundance limit suitability for certain industrial applications. Alternatives to indium tin oxide have recently been reported and include conducting polymers, carbon nanotubes and graphene. However, although flexibility is greatly improved, the optoelectronic performance of these carbon-based materials is limited by low conductivity. Other examples include metal nanowire-based electrodes, which can achieve sheet resistances of less than 10? ?-1 at 90% transmission because of the high conductivity of the metals. To achieve these performances, however, metal nanowires must be defect-free, have conductivities close to their values in bulk, be as long as possible to minimize the number of wire-to-wire junctions, and exhibit small junction resistance. Here, we present a facile fabrication process that allows us to satisfy all these requirements and fabricate a new kind of transparent conducting electrode that exhibits both superior optoelectronic performances (sheet resistance of ~2? ?-1 at 90% transmission) and remarkable mechanical flexibility under both stretching and bending stresses. The electrode is composed of a free-standing metallic nanotrough network and is produced with a process involving electrospinning and metal deposition. We demonstrate the practical suitability of our transparent conducting electrode by fabricating a flexible touch-screen device and a transparent conducting tape.

  1. CoS-Graphene Composite Counter Electrode for High Performance Dye-Sensitized Solar Cell.

    PubMed

    Wang, Fen; Wu, Congcong; Tan, Yuan; Jin, Tetsuro; Chi, Bo; Pu, Jian; Jian, Li

    2015-02-01

    CoS-graphene composite counter electrode for dye-sensitized solar cell (DSSC) was prepared by coating hydrothermal synthesized CoS with graphene onto the FTO conductive glass. SEM shows that CoS particles are uniformly dispersed in the graphene. The result confirms that the prepared composite counter electrode is of highly electrocatalytic activity towards iodine reduction, which is even better than Pt electrode. And cyclic voltammetry measurement also shows that the composite counter electrode has good stability after 100 scan cycles. DSSC with CoS-graphene as composite counter electrode achieves a maximum power conversion efficiency of 6.31%, which is better than Pt electrode. PMID:26353629

  2. Surface-Plasmon Enhanced Transparent Electrodes in Organic Photovoltaics

    SciTech Connect

    Reilly III, T. H.; van de Lagemaat, J.; Tenent, R. C.; Morfa, A. J.; Rowlen, K. L.

    2008-01-01

    Random silver nanohole films were created through colloidal lithography techniques and metal vapor deposition. The transparent electrodes were characterized by uv-visible spectroscopy and incorporated into an organic solar cell. The test cells were evaluated for solar power-conversion efficiency and incident photon-to-current conversion efficiency. The incident photon-to-current conversion efficiency spectra displayed evidence that a nanohole film with 92 nm diameter holes induces surface-plasmon-enhanced photoconversion. The nanohole silver films demonstrate a promising route to removing the indium tin oxide transparent electrode that is ubiquitous in organic optoelectronics.

  3. Polymer-metal hybrid transparent electrodes for flexible electronics

    NASA Astrophysics Data System (ADS)

    Kang, Hongkyu; Jung, Suhyun; Jeong, Soyeong; Kim, Geunjin; Lee, Kwanghee

    2015-03-01

    Despite nearly two decades of research, the absence of ideal flexible and transparent electrodes has been the largest obstacle in realizing flexible and printable electronics for future technologies. Here we report the fabrication of ‘polymer-metal hybrid electrodes’ with high-performance properties, including a bending radius <1?mm, a visible-range transmittance>95% and a sheet resistance <10???sq-1. These features arise from a surface modification of the plastic substrates using an amine-containing nonconjugated polyelectrolyte, which provides ideal metal-nucleation sites with a surface-density on the atomic scale, in combination with the successive deposition of a facile anti-reflective coating using a conducting polymer. The hybrid electrodes are fully functional as universal electrodes for high-end flexible electronic applications, such as polymer solar cells that exhibit a high power conversion efficiency of 10% and polymer light-emitting diodes that can outperform those based on transparent conducting oxides.

  4. Polymer-metal hybrid transparent electrodes for flexible electronics

    PubMed Central

    Kang, Hongkyu; Jung, Suhyun; Jeong, Soyeong; Kim, Geunjin; Lee, Kwanghee

    2015-01-01

    Despite nearly two decades of research, the absence of ideal flexible and transparent electrodes has been the largest obstacle in realizing flexible and printable electronics for future technologies. Here we report the fabrication of ‘polymer-metal hybrid electrodes’ with high-performance properties, including a bending radius <1?mm, a visible-range transmittance>95% and a sheet resistance <10???sq?1. These features arise from a surface modification of the plastic substrates using an amine-containing nonconjugated polyelectrolyte, which provides ideal metal-nucleation sites with a surface-density on the atomic scale, in combination with the successive deposition of a facile anti-reflective coating using a conducting polymer. The hybrid electrodes are fully functional as universal electrodes for high-end flexible electronic applications, such as polymer solar cells that exhibit a high power conversion efficiency of 10% and polymer light-emitting diodes that can outperform those based on transparent conducting oxides. PMID:25790133

  5. Improved thermal oxidation stability of solution-processable silver nanowire transparent electrode by reduced graphene oxide.

    PubMed

    Ahn, Yumi; Jeong, Youngjun; Lee, Youngu

    2012-12-01

    Solution-processable silver nanowire-reduced graphene oxide (AgNW-rGO) hybrid transparent electrode was prepared in order to replace conventional ITO transparent electrode. AgNW-rGO hybrid transparent electrode exhibited high optical transmittance and low sheet resistance, which is comparable to ITO transparent electrode. In addition, it was found that AgNW-rGO hybrid transparent electrode exhibited highly enhanced thermal oxidation and chemical stabilities due to excellent gas-barrier property of rGO passivation layer onto AgNW film. Furthermore, the organic solar cells with AgNW-rGO hybrid transparent electrode showed good photovoltaic behavior as much as solar cells with AgNW transparent electrode. It is expected that AgNW-rGO hybrid transparent electrode can be used as a key component in various optoelectronic application such as display panels, touch screen panels, and solar cells. PMID:23206541

  6. Foldable Transparent Substrates with Embedded Electrodes for Flexible Electronics.

    PubMed

    Kim, Jin-Hoon; Park, Jin-Woo

    2015-08-26

    We present highly flexible transparent electrodes composed of silver nanowire (AgNW) networks and silica aerogels embedded into UV-curable adhesive photopolymers (APPs). Because the aerogels have an extremely high surface-to-volume ratio, the enhanced van der Waals forces of the aerogel surfaces result in more AgNWs being uniformly coated onto a release substrate and embedded into the APP when mixed with an AgNW solution at a fixed concentration. The uniform distribution of the embedded composite electrodes of AgNWs and aerogels was verified by the Joule heating test. The APP with the composite electrodes has a lower sheet resistance (Rs) and a better mechanical stability compared with APP without aerogels. The APP with the embedded electrodes is a freestanding flexible substrate and can be used as an electrode coating on a polymer substrate, such as polydimethylsiloxane and polyethylene terephthalate. On the basis of the bending test results, the APPs with composite electrodes were sufficiently flexible to withstand a 1 mm bending radius (rb) and could be foldable with a slight change in Rs. Organic light emitting diodes were successfully fabricated on the APP with the composite electrodes, indicating the strong potential of the proposed flexible TEs for application as highly flexible transparent conductive substrates. PMID:26258906

  7. TCO/Ag/TCO transparent electrodes for solar cells application

    NASA Astrophysics Data System (ADS)

    Boscarino, S.; Crupi, I.; Mirabella, S.; Simone, F.; Terrasi, A.

    2014-09-01

    Among transparent electrodes, transparent conductive oxides (TCO)/metal/TCO structures can achieve optical and electrical performances comparable to, or better than, single TCO layers and very thin metallic films. In this work, we report on thin multilayers based on aluminum zinc oxide (AZO), indium tin oxide (ITO) and Ag deposited by RF magnetron sputtering on soda lime glass at room temperature. The TCO/Ag/TCO structures with thicknesses of about 50/10/50 nm were deposited with all combinations of AZO and ITO as top and bottom layers. While the electrical conductivity is dominated by the Ag intralayer irrespective of the TCO nature, the optical transmissions show a dependence on the nature of the top and bottom TCOs, mainly due to the change in the reflectivity of the multilayers. Structural, electrical and optical properties are studied to optimize the structure for very thin transparent electrodes suitable for photovoltaic applications.

  8. Transparent Electrodes Printed with Nanocrystal Inks for Flexible Smart Devices.

    PubMed

    Song, Jizhong; Zeng, Haibo

    2015-08-17

    Transparent electrodes (TEs) are crucial in a wide range of modern electronic and optoelectronic devices. However, traditional TEs cannot meet the requirements of smart devices under development in unique fields, such as electronic skins, wearable electronics, robotic skins, flexible and stretchable displays, and solar cells. Emerging TEs printed with nanocrystal (NC) inks are inexpensive and compatible with solution processes, and have huge potential in flexible, stretchable, and wearable devices. Every development in ink-based electrodes makes them more competitive for practical applications in various smart devices. Herein, we provide an overview of emergent ink-based electrodes, such as transparent conducting oxides, metal nanowires, graphene, and carbon nanotubes, and their application in solution-based flexible and stretchable devices. PMID:26223702

  9. Transparent composite electrode for high-efficiency polymer LEDs

    NASA Astrophysics Data System (ADS)

    Li, Lu; Yu, Zhibin; Liang, Jiajie; Chang, Chia-Hao; Hu, Weili; Pei, Qibing

    2012-09-01

    Polymer composite electrodes based on silver nanowires or carbon nanotubes have been prepared with transparency and surface conductivity approaching those of ITO/glass and better than ITO/PET. The conductive surface has an average roughness less than 10 nm, better than ITO/glass. Depending on the polymer matrix selected, the composite electrodes can be made rigid, flexible like polycarbonate, or stretchable like a rubber. Various polymer light emitting diodes,light emitting electrochemical cells and polymer solar cells have been fabricated using the composite electrode as anode, exhibiting electroluminescent efficiencies generally higher than control devices fabricated on ITO/glass. These polymer light emitting devices are all highly flexible and can be bent to less than 3 mm radius without loss of performance. With further modification of the composite electrodes, we have also demonstrated stretchable OLEDs wherein the emissive area can be elongated by as much as 50%.

  10. Silver nanowire transparent electrodes for liquid crystal-based smart windows

    E-print Network

    Goldthorpe, Irene

    Silver nanowire transparent electrodes for liquid crystal-based smart windows Hadi Hosseinzadeh history: Received 27 July 2014 Accepted 7 September 2014 Keywords: Silver nanowire Transparent electrode electrode. In this work, films of silver nanowires are proposed as an alternative electrode

  11. Angle-specific transparent conducting electrodes with metallic gratings

    SciTech Connect

    Rivolta, N. X. A. Maes, B.

    2014-08-07

    Transparent conducting electrodes, which are not made from indium tin oxide, and which display a strong angular dependence are useful for various technologies. Here, we introduce a tilted silver grating that combines a large conductance with a strong and angle-specific transmittance. When the light incidence angle matches the tilt angle of the grating, transmittance is close to the maximum along a very broadband range. We explain the behavior through simulations that show in detail the plasmonic and interference effects at play.

  12. Highly Robust Silver Nanowire Network for Transparent Electrode.

    PubMed

    Song, Tze-Bin; Rim, You Seung; Liu, Fengmin; Bob, Brion; Ye, Shenglin; Hsieh, Yao-Tsung; Yang, Yang

    2015-11-11

    Solution-processed silver nanowire networks are one of the promising candidates to replace a traditional indium tin oxide as next-generation transparent and flexible electrodes due to their ease of processing, moderate flexibility, high transparency, and low sheet resistance. To date, however, high stability of the nanowire networks remains a major challenge because the long-term usages of these electrodes are limited by their poor thermal and chemical stabilities. Existing methods for addressing this challenge mainly focus on protecting the nanowire network with additional layers that require vacuum processes, which can lead to an increment in manufacturing cost. Here, we report a straightforward strategy of a sol-gel processing as a fast and robust way to improve the stabilities of silver nanowires. Compared with reported nanoparticles embedded in nanowire networks, better thermal and chemical stabilities are achieved via sol-gel coating of TiO2 over the silver nanowire networks. The conformal surface coverage suppressed surface diffusion of silver atoms and prevented chemical corrosion from the environment. These results highlight the important role of the functional layer in providing better thermal and chemical stabilities along with improved electrical properties and mechanical robustness. The silver nanowire/TiO2 composite electrodes were applied as the source and drain electrodes for In2O3 thin-film transistors (TFTs) and the devices exhibited improved electrical performance annealed at 300 °C without the degradation of the electrodes. These key findings not only demonstrated a general and effective method to improve the thermal and chemical stabilities of metal nanowire networks but also provided a basic guideline toward rational design of highly efficient and robust composite electrodes. PMID:26488682

  13. Functionalized Graphene as a Catalytic Counter Electrode in Dye-Sensitized

    E-print Network

    Aksay, Ilhan A.

    Functionalized Graphene as a Catalytic Counter Electrode in Dye-Sensitized Solar Cells Joseph D reduction and is sufficiently corrosion-resistant to iodo species present in the electrolyte.6 9 How- ever materials for the counter electrode because they are low cost, corrosion resis- tant, and electrically

  14. Rational screening low-cost counter electrodes for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Hou, Yu; Wang, Dong; Yang, Xiao Hua; Fang, Wen Qi; Zhang, Bo; Wang, Hai Feng; Lu, Guan Zhong; Hu, P.; Zhao, Hui Jun; Yang, Hua Gui

    2013-03-01

    Dye-sensitized solar cells have attracted intense research attention owing to their ease of fabrication, cost-effectiveness and high efficiency in converting solar energy. Noble platinum is generally used as catalytic counter electrode for redox mediators in electrolyte solution. Unfortunately, platinum is expensive and non-sustainable for long-term applications. Therefore, researchers are facing with the challenge of developing low-cost and earth-abundant alternatives. So far, rational screening of non-platinum counter electrodes has been hamstrung by the lack of understanding about the electrocatalytic process of redox mediators on various counter electrodes. Here, using first-principle quantum chemical calculations, we studied the electrocatalytic process of redox mediators and predicted electrocatalytic activity of potential semiconductor counter electrodes. On the basis of theoretical predictions, we successfully used rust (?-Fe2O3) as a new counter electrode catalyst, which demonstrates promising electrocatalytic activity towards triiodide reduction at a rate comparable to platinum.

  15. Dye-sensitized solar cell counter electrodes based on carbon nanotubes.

    PubMed

    Hwang, Seunghwa; Batmunkh, Munkhbayar; Nine, Md J; Chung, Hanshik; Jeong, Hyomin

    2015-01-12

    Dye-sensitized solar cells (DSSCs) have received significant attention from the scientific community since their discovery in 1991. However, the high cost and scarcity of platinum has motivated researchers to seek other suitable materials for the counter electrode of DSSCs. Owing to their exceptional properties such as high conductivity, good electrochemical activity, and low cost, carbon nanotubes (CNTs) have been considered as promising alternatives to expensive platinum (Pt) in the counter electrode of DSSCs. Herein, we provide a Minireview of the CNTs use in the counter electrode of DSSCs. A brief overview of Pt-based counter electrodes is also discussed. Particular attention is given to the recent advances of counter electrodes with CNT-based composite structures. PMID:25367083

  16. Optically Transparent Carbon Nanotube Film Electrode for Thin Layer Spectroelectrochemistry.

    PubMed

    Wang, Tingting; Zhao, Daoli; Alvarez, Noe; Shanov, Vesselin N; Heineman, William R

    2015-10-01

    Carbon nanotube (CNT) film was evaluated as an optically transparent electrode (OTE) for thin layer spectroelectrochemistry. Chemically inert CNT arrays were synthesized by chemical vapor deposition (CVD) using thin films of Fe and Co as catalysts. Vertically aligned CNT arrays were drawn onto a quartz slide to form CNT films that constituted the OTE. Adequate conductivity and transparency make this material a good OTE for spectroelectrochemistry. These properties could be varied by the number of layers of CNTs used to form the OTE. Detection in the UV/near UV region down to 200 nm can be achieved using these transparent CNT films on quartz. The OTE was characterized by transmission electron microscopy, scanning electron microscopy, Raman spectroscopy, UV-visible spectroscopy, cyclic voltammetry, electrochemical impedance spectroscopy, and thin layer spectroelectrochemistry. Ferricyanide, tris(2,2'-bipyridine) ruthenium(II) chloride, and cytochrome c were used as representative redox probes for thin layer spectroelectrochemistry using the CNT film OTE, and the results correlated well with their known properties. Direct electron transfer of cytochrome c was achieved on the CNT film electrode. PMID:26291731

  17. Fatigue-free, superstretchable, transparent, and biocompatible metal electrodes.

    PubMed

    Guo, Chuan Fei; Liu, Qihan; Wang, Guohui; Wang, Yecheng; Shi, Zhengzheng; Suo, Zhigang; Chu, Ching-Wu; Ren, Zhifeng

    2015-10-01

    Next-generation flexible electronics require highly stretchable and transparent electrodes. Few electronic conductors are both transparent and stretchable, and even fewer can be cyclically stretched to a large strain without causing fatigue. Fatigue, which is often an issue of strained materials causing failure at low strain levels of cyclic loading, is detrimental to materials under repeated loads in practical applications. Here we show that optimizing topology and/or tuning adhesion of metal nanomeshes can significantly improve stretchability and eliminate strain fatigue. The ligaments in an Au nanomesh on a slippery substrate can locally shift to relax stress upon stretching and return to the original configuration when stress is removed. The Au nanomesh keeps a low sheet resistance and high transparency, comparable to those of strain-free indium tin oxide films, when the nanomesh is stretched to a strain of 300%, or shows no fatigue after 50,000 stretches to a strain up to 150%. Moreover, the Au nanomesh is biocompatible and penetrable to biomacromolecules in fluid. The superstretchable transparent conductors are highly desirable for stretchable photoelectronics, electronic skins, and implantable electronics. PMID:26392537

  18. Effects of counter electrodes on photovoltaic performance of all-solid-state TiO2-based dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Shang, Mingwei; Liu, Benjamin; Dong, Zhenhua; Dong, Zhenyu; Dong, Lifeng

    2015-03-01

    In order to analyse the effects of counter electrodes on photovoltaic performance of dye-sensitized solar cells (DSSCs), different electrodes were used as the counter electrodes for all-solid-state TiO2-based DSSCs. An inorganic solid-state electrolyte, CsSnI2.95F0.05, was selected to couple with N719 dye-sensitized TiO2 nanorod arrays to fabricate the DSSCs. Fluorine doped tin oxide transparent conducting glass (FTO), platinum coated FTO (Pt/FTO), graphite coated FTO (graphite/FTO), and graphite coated common glass (graphite/glass) were investigated as the counter electrodes, and the cells composed of the corresponding electrodes above have power-conversion efficiencies of 2.17%, 9.84%, 7.62%, and 3.45%, respectively. Our findings indicate that due to its unique catalytic and conducting properties, graphite can replace both Pt and FTO as a counter electrode to reduce the fabrication cost of all-solid-state TiO2-based DSSCs.

  19. Ultrasmooth, extremely deformable and shape recoverable Ag nanowire embedded transparent electrode

    NASA Astrophysics Data System (ADS)

    Nam, Sanggil; Song, Myungkwan; Kim, Dong-Ho; Cho, Byungjin; Lee, Hye Moon; Kwon, Jung-Dae; Park, Sung-Gyu; Nam, Kee-Seok; Jeong, Yongsoo; Kwon, Se-Hun; Park, Yun Chang; Jin, Sung-Ho; Kang, Jae-Wook; Jo, Sungjin; Kim, Chang Su

    2014-04-01

    Transparent electrodes have been widely used in electronic devices such as solar cells, displays, and touch screens. Highly flexible transparent electrodes are especially desired for the development of next generation flexible electronic devices. Although indium tin oxide (ITO) is the most commonly used material for the fabrication of transparent electrodes, its brittleness and growing cost limit its utility for flexible electronic devices. Therefore, the need for new transparent conductive materials with superior mechanical properties is clear and urgent. Ag nanowire (AgNW) has been attracting increasing attention because of its effective combination of electrical and optical properties. However, it still suffers from several drawbacks, including large surface roughness, instability against oxidation and moisture, and poor adhesion to substrates. These issues need to be addressed before wide spread use of metallic NW as transparent electrodes can be realized. In this study, we demonstrated the fabrication of a flexible transparent electrode with superior mechanical, electrical and optical properties by embedding a AgNW film into a transparent polymer matrix. This technique can produce electrodes with an ultrasmooth and extremely deformable transparent electrode that have sheet resistance and transmittance comparable to those of an ITO electrode.

  20. Ultrasmooth, extremely deformable and shape recoverable Ag nanowire embedded transparent electrode

    PubMed Central

    Nam, Sanggil; Song, Myungkwan; Kim, Dong-Ho; Cho, Byungjin; Lee, Hye Moon; Kwon, Jung-Dae; Park, Sung-Gyu; Nam, Kee-Seok; Jeong, Yongsoo; Kwon, Se-Hun; Park, Yun Chang; Jin, Sung-Ho; Kang, Jae-Wook; Jo, Sungjin; Kim, Chang Su

    2014-01-01

    Transparent electrodes have been widely used in electronic devices such as solar cells, displays, and touch screens. Highly flexible transparent electrodes are especially desired for the development of next generation flexible electronic devices. Although indium tin oxide (ITO) is the most commonly used material for the fabrication of transparent electrodes, its brittleness and growing cost limit its utility for flexible electronic devices. Therefore, the need for new transparent conductive materials with superior mechanical properties is clear and urgent. Ag nanowire (AgNW) has been attracting increasing attention because of its effective combination of electrical and optical properties. However, it still suffers from several drawbacks, including large surface roughness, instability against oxidation and moisture, and poor adhesion to substrates. These issues need to be addressed before wide spread use of metallic NW as transparent electrodes can be realized. In this study, we demonstrated the fabrication of a flexible transparent electrode with superior mechanical, electrical and optical properties by embedding a AgNW film into a transparent polymer matrix. This technique can produce electrodes with an ultrasmooth and extremely deformable transparent electrode that have sheet resistance and transmittance comparable to those of an ITO electrode. PMID:24763248

  1. Bilayered Oxide thin films for transparent electrode application

    NASA Astrophysics Data System (ADS)

    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.

  2. Highly stretchable and transparent electrodes of Au nanomeshes

    NASA Astrophysics Data System (ADS)

    Guo, Chuanfei

    2014-03-01

    Metallic nano-networks or nanomeshes may serve as the flexible transparent electrodes (FTEs) for bendable and foldable electronics. Here we present Au nanomeshes made by grain boundary lithography, showing good electrical conductance and transparency comparable to ITO film, but exceptionally high stretchability. The sheet resistance increases only ~ 3 times when stretched to an ultra-large strain of 160%. The Au nanomeshes also exhibit excellent performance under cyclic strain, and work well after exposing to high temperature of up to 500 °C. In addition, the low surface roughness enables good compatibility with device integration. The ultra-large stretchability of the Au nanomesh FTEs lies in a subtle balance between two roles played by the underlying elastomeric substrate. The vast difference in the elastic moduli of Au and the substrate allows the stretched Au mesh to deflect and twist out of the plane, while the elastomeric substrate stabilizes distributed rupture of Au ligaments. The Au nanomesh may be used as a FTE for bendable and foldable electronics.

  3. High-Performance Platinum-Free Dye-Sensitized Solar Cells with Molybdenum Disulfide Films as Counter Electrodes.

    PubMed

    Hussain, Sajjad; Shaikh, Shoyebmohamad F; Vikraman, Dhanasekaran; Mane, Rajaram S; Joo, Oh-Shim; Naushad, Mu; Jung, Jongwan

    2015-12-01

    By using a radio-frequency sputtering method, we synthesized large-area, uniform, and transparent molybdenum disulfide film electrodes (1, 3, 5, and 7?min) on transparent and conducting fluorine-doped tin oxide (FTO), as ecofriendly, cost-effective counter electrodes (CE) for dye-sensitized solar cells (DSSCs). These CEs were used in place of the routinely used expensive platinum CEs for the catalytic reduction of a triiodide electrolyte. The structure and morphology of the MoS2 was analyzed by using Raman spectroscopy, X-ray diffraction, and X-ray photoemission spectroscopy measurements and the DSSC characteristics were investigated. An unbroken film of MoS2 was identified on the FTO crystallites from field-emission scanning electron microscopy. Cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel curve measurements reveal the promise of MoS2 as a CE with a low charge-transfer resistance, high electrocatalytic activity, and fast reaction kinetics for the reduction of triiodide to iodide. Finally, an optimized transparent MoS2 CE, obtained after 5?min synthesis time, showed a high power-conversion efficiency of 6.0?%, which comparable to the performance obtained with a Pt CE (6.6?%) when used in TiO2 -based DSCCs, thus signifying the importance of sputtering time on DSSC performance. PMID:26472540

  4. Preparation and properties of low-cost graphene counter electrodes for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Wu, Qishuang; Shen, Yue; Wang, Qiandi; Gu, Feng; Cao, Meng; Wang, Linjun

    2013-12-01

    With the advantages of excellent electrical properties, high catalytic activity and low-cost preparation, Graphene is one of the most expected carbon materials to replace the expensive Pt as counter electrodes for dye-sensitized solar cells (DSSCs). In this paper, graphene counter electrodes were obtained by simple doctor-blade coating method on fluorine tin oxides (FTOs). The samples were investigated by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscope (SEM). Then the low-cost graphene electrodes were applied in typical sandwich-type DSSCs with TiO2 or ZnO as photoanodes, and their photoelectric conversion efficiency (?) were about 4.34% and 2.28%, respectively, which were a little lower than those of Pt electrodes but much higher than those of graphite electrodes. This law was consistent with the test results of electrochemical impedance spectroscopy (EIS). Low-cost graphene electrodes can be applied in DSSCs by process optimization.

  5. Polymer-assisted direct deposition of uniform carbon nanotube bundle networks for high performance transparent electrodes.

    PubMed

    Hellstrom, Sondra L; Lee, Hang Woo; Bao, Zhenan

    2009-06-23

    Flexible transparent electrodes are crucial for touch screen, flat panel display, and solar cell technologies. While carbon nanotube network electrodes show promise, characteristically poor dispersion properties have limited their practicality. We report that addition of small amounts of conjugated polymer to nanotube dispersions enables straightforward fabrication of uniform network electrodes by spin-coating and simultaneous tuning of parameters such as bundle size and density. After treatment in thionyl chloride, electrodes have sheet resistances competitive with other reported carbon nanotube based transparent electrodes to date. PMID:19422197

  6. Conducting polymers based counter electrodes for dye-sensitized solar cells

    SciTech Connect

    Veerender, P. E-mail: veeru1009@gmail.com; Saxena, Vibha E-mail: veeru1009@gmail.com; Gusain, Abhay E-mail: veeru1009@gmail.com; Jha, P. E-mail: veeru1009@gmail.com; Koiry, S. P. E-mail: veeru1009@gmail.com; Chauhan, A. K. E-mail: veeru1009@gmail.com; Aswal, D. K. E-mail: veeru1009@gmail.com; Gupta, S. K. E-mail: veeru1009@gmail.com

    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.

  7. Past achievements and future challenges in the development of optically transparent electrodes

    NASA Astrophysics Data System (ADS)

    Ellmer, Klaus

    2012-12-01

    Transparent conductive electrodes play important roles in information and energy technologies. These materials, particularly transparent conductive oxides, are widely used as transparent electrodes across technical fields such as low-emissivity coatings, flat-panel displays, thin-film solar cells and organic light-emitting diodes. This Review begins by summarizing the properties and applications of transparent conductive oxides such as In2O3, SnO2, ZnO and TiO2. Owing to the increasing demand for raw materials -- especially indium -- scientists are currently searching for alternatives to indium tin oxide. Carbon nanotube and metal nanowire networks, as well as regular metal grids, have been investigated for use as transparent conductive electrodes. This Review compares these materials and the recently 'rediscovered' graphene with today's established transparent conductive oxides.

  8. Highly conductive transparent organic electrodes with multilayer structures for rigid and flexible optoelectronics.

    PubMed

    Guo, Xiaoyang; Liu, Xingyuan; Lin, Fengyuan; Li, Hailing; Fan, Yi; Zhang, Nan

    2015-01-01

    Transparent electrodes are essential components for optoelectronic devices, such as touch panels, organic light-emitting diodes, and solar cells. Indium tin oxide (ITO) is widely used as transparent electrode in optoelectronic devices. ITO has high transparency and low resistance but contains expensive rare elements, and ITO-based devices have poor mechanical flexibility. Therefore, alternative transparent electrodes with excellent opto-electrical performance and mechanical flexibility will be greatly demanded. Here, organics are introduced into dielectric-metal-dielectric structures to construct the transparent electrodes on rigid and flexible substrates. We show that organic-metal-organic (OMO) electrodes have excellent opto-electrical properties (sheet resistance of below 10 ? sq(-1) at 85% transmission), mechanical flexibility, thermal and environmental stabilities. The OMO-based polymer photovoltaic cells show performance comparable to that of devices based on ITO electrodes. This OMO multilayer structure can therefore be used to produce transparent electrodes suitable for use in a wide range of optoelectronic devices. PMID:26014889

  9. Highly Conductive Transparent Organic Electrodes with Multilayer Structures for Rigid and Flexible Optoelectronics

    PubMed Central

    Guo, Xiaoyang; Liu, Xingyuan; Lin, Fengyuan; Li, Hailing; Fan, Yi; Zhang, Nan

    2015-01-01

    Transparent electrodes are essential components for optoelectronic devices, such as touch panels, organic light-emitting diodes, and solar cells. Indium tin oxide (ITO) is widely used as transparent electrode in optoelectronic devices. ITO has high transparency and low resistance but contains expensive rare elements, and ITO-based devices have poor mechanical flexibility. Therefore, alternative transparent electrodes with excellent opto-electrical performance and mechanical flexibility will be greatly demanded. Here, organics are introduced into dielectric–metal–dielectric structures to construct the transparent electrodes on rigid and flexible substrates. We show that organic-metal-organic (OMO) electrodes have excellent opto-electrical properties (sheet resistance of below 10?? sq?1 at 85% transmission), mechanical flexibility, thermal and environmental stabilities. The OMO-based polymer photovoltaic cells show performance comparable to that of devices based on ITO electrodes. This OMO multilayer structure can therefore be used to produce transparent electrodes suitable for use in a wide range of optoelectronic devices. PMID:26014889

  10. Rare-metal-free flexible counter electrodes for dye-sensitized solar-cells produced using wet processes only.

    PubMed

    Okada, Issei; Shiratori, Seimei

    2013-05-22

    Dye-sensitized solar-cells (DSCs) are cheap because they are produced using low-cost materials and simple manufacturing processes. However, the substrates of DSC counter electrodes are sputtered with a transparent conductive oxide and platinum. This involves vacuum manufacturing processes and high-cost (rare-metal) materials, and increases the costs of DSCs. In this study, we used non-rare-metal low-cost materials and simple wet processes, using combined poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) and Ag network (Ag NW) substrates. To solve the problem of Ag NW corrosion by the iodine electrolyte, we hot-pressed the Ag NW substrate and covered with a PEDOT/PSS layer as a barrier against iodine. The PEDOT/PSS layer acted as a catalyst and cells using an Ag NW covered with PEDOT/PSS generated electricity with illumination from both sides. The cell performance was improved by using a PEDOT/PSS layer containing 20 wt % TiO2 nanoparticles (NPs). The performance of the DSSC cell with an Ag NW substrate covered with a PEDOT/PSS layer containing TiO2 NPs (5.13%) was higher than that of a cell using an indium tin oxide substrate covered with the same layer (4.91%). These values are very similar to those of cells using a platinum counter electrode (5.36%). This research showed the possibility of replacing conventional high-cost counter electrodes with low-cost materials, and using only simple wet processes. PMID:23566351

  11. Electrochemically Reduced Graphene Oxide Multilayer Films as Efficient Counter Electrode for Dye-Sensitized Solar Cells

    PubMed Central

    Xu, Xiaobao; Huang, Dekang; Cao, Kun; Wang, Mingkui; Zakeeruddin, Shaik M.; Grätzel, Michael

    2013-01-01

    We report on a new counter electrode for dye-sensitized solar cells (DSCs), which is prepared using layer-by-layer assembly of negatively charged graphene oxide and positively charged poly (diallyldimethylammonium chloride) followed by an electrochemical reduction procedure. The DSC devises using the heteroleptic Ru complex C106TBA as sensitizer and this new counter electrode reach power conversion efficiencies of 9.5% and 7.6% in conjunction with low volatility and solvent free ionic liquid electrolytes, respectively. The new counter electrode exhibits good durability (60°C for 1000?h in a solar simulator, 100?mW cm?2) during the accelerated tests when used in combination with an ionic liquid electrolyte. This work identifies a new class of electro-catalysts with potential for low cost photovoltaic devices. PMID:23508212

  12. Ordered mesoporous tungsten suboxide counter electrode for highly efficient iodine-free electrolyte-based dye-sensitized solar cells.

    PubMed

    Jeong, Inyoung; Jo, Changshin; Anthonysamy, Arockiam; Kim, Jung-Min; Kang, Eunae; Hwang, Jongkook; Ramasamy, Easwaramoorthi; Rhee, Shi-Woo; Kim, Jin Kon; Ha, Kyoung-Su; Jun, Ki-Won; Lee, Jinwoo

    2013-02-01

    A disulfide/thiolate (T(2)/T(-)) redox-couple electrolyte, which is a promising iodine-free electrolyte owing to its transparent and noncorrosive properties, requires alternative counter-electrode materials because conventional Pt shows poor catalytic activity in such an electrolyte. Herein, ordered mesoporous tungsten suboxide (m-WO(3-x)), synthesized by using KIT-6 silica as a hard template followed by a partial reduction, is used as a catalyst for a counter electrode in T(2)/T(-)-electrolyte-based dye-sensitized solar cells (DSCs). The mesoporous tungsten suboxide, which possesses interconnected pores of 4 and 20 nm, provides a large surface area and efficient electrolyte penetration into the m-WO(3-x) pores. In addition to the advantages conferred by the mesoporous structure, partial reduction of tungsten oxide creates oxygen vacancies that can function as active catalytic sites, which causes a high electrical conductivity because of intervalence charge transfer between the W(5+) and W(6+) ions. m-WO(3-x) shows a superior photovoltaic performance (79 % improvement in the power conversion efficiency) over Pt in the T(2)/T(-) electrolyte. The superior catalytic activity of m-WO(3-x) is investigated by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel polarization curve analysis. PMID:23281317

  13. Can graphene outperform indium tin oxide as transparent electrode in organic solar cells?

    NASA Astrophysics Data System (ADS)

    Paletti, Paolo; Pawar, Ravinder; Ulisse, Giacomo; Brunetti, Francesca; Iannaccone, Giuseppe; Fiori, Gianluca

    2015-12-01

    Graphene holds promises as a transparent electrode in flexible solar cells due to its high mobility and transparency. However, the experimental power conversion efficiency of cells with graphene electrode is still small (<7%). In this paper, we evaluate possible engineering options to improve the power conversion efficiency, by means of multi-scale simulation approach including ab-initio simulations of graphene contacts to improve electrode workfunction and conductance, electromagnetic simulations to improve light management, and electrical simulations of complete cells. We find that the combined effect of using a transparent electrode of graphene with a few monolayers of MoO3 on top to optimize work function and resistivity, and of applying optimized grating to the graphene electrode, can increase power efficiency by up to 29%–47%, with respect to the ITO benchmark, depending on the material used for the hole transport layer (P3HT,PTB7, and Perovskite).

  14. Increase in the DSSC efficiency when using metal-coated carbon nanowall counter electrodes

    NASA Astrophysics Data System (ADS)

    Lee, Sangjoon; Choi, Won Seok; Lim, Dong-Gun; Choi, Eun Chang; Hong, Byungyou

    2014-08-01

    This research was conducted to improve the efficiency of dye-sensitized solar cells (DSSCs) using metal-layer-coated carbon nanowalls (CNWs) as counter electrodes. The CNWs were synthesized on a fluorine-doped tin-oxide (FTO) glass substrate in a microwave plasma-enhanced chemical vapor deposition (PECVD) system using methane (CH4), and the CNWS were sputter-coated with metal films several times by using an RF magnetron sputtering system and four-inch metal targets (Cu, W and Ni, separately). Then, the metal-layer-coated CNWs were used as counter electrodes for manufacturing the DSCCs. The vertical and the surface conditions of the metal-coated CNWs used as the DSCC electrodes were characterized by their electrical variations through field-emission scanning electron microscopy (FE-SEM) and Hall measurements. Their optical characteristics were analyzed using UV-Vis equipment, and the energy conversion efficiencies of the DSSCs manufactured using the metal-layer-coated CNWs as the counter electrodes were measured. The results confirmed that the efficiency improved when the W-coated CNW was used as the counter electrode.

  15. Metal-mesh based transparent electrode on a 3-D curved surface by electrohydrodynamic jet printing

    NASA Astrophysics Data System (ADS)

    Seong, Baekhoon; Yoo, Hyunwoong; Dat Nguyen, Vu; Jang, Yonghee; Ryu, Changkook; Byun, Doyoung

    2014-09-01

    Invisible Ag mesh transparent electrodes (TEs), with a width of 7??m, were prepared on a curved glass surface by electrohydrodynamic (EHD) jet printing. With a 100??m pitch, the EHD jet printed the Ag mesh on the convex glass which had a sheet resistance of 1.49??/?. The printing speed was 30?cm?s-1 using Ag ink, which had a 10?000 cPs viscosity and a 70?wt% Ag nanoparticle concentration. We further showed the performance of a 3-D transparent heater using the Ag mesh transparent electrode. The EHD jet printed an invisible Ag grid transparent electrode with good electrical and optical properties with promising applications on printed optoelectronic devices.

  16. Impact of transparent electrode on photoresponse of ZnO-based phototransistor

    SciTech Connect

    Lee, Seunghyup; Ahn, Seung-Eon Jeon, Yongwoo; Ahn, Ji-Hoon; Song, Ihun; Kim, Jungwoo; Choi, Hyung; Chung, U-in; Park, Jaechul; Jeon, Sanghun; Yun, Dong-Jin

    2013-12-16

    ZnO-based photo-thin film transistors with enhanced photoresponse were developed using transparent conductive oxide contacts. Changing the electrode from opaque Mo to transparent In-Zn-O increases the photocurrent by five orders of magnitude. By changing the opacity of each source and drain electrode, we could observe how the photoresponse is affected. We deduce that the photocurrent generation mechanism is based on an energy band change due to the photon irradiation. More importantly, we reveal that the photocurrent is determined by the energy barrier of injected electrons at the interface between the source electrode and the active layer.

  17. Transparent, Flexible, Low Noise Graphene Electrodes for Simultaneous Electrophysiology and Neuroimaging

    PubMed Central

    Kuzum, Duygu; Takano, Hajime; Shim, Euijae; Reed, Jason C; Juul, Halvor; Richardson, Andrew G.; de Vries, Julius; Bink, Hank; Dichter, Marc A.; Lucas, Timothy H.; Coulter, Douglas A.; Cubukcu, Ertugrul; Litt, Brian

    2014-01-01

    Calcium imaging is a versatile experimental approach capable of resolving single neurons with single-cell spatial resolution in the brain. Electrophysiological recordings provide high temporal, but limited spatial resolution, due to the geometrical inaccessibility of the brain. An approach that integrates the advantages of both techniques could provide new insights into functions of neural circuits. Here, we report a transparent, flexible neural electrode technology based on graphene, which enables simultaneous optical imaging and electrophysiological recording. We demonstrate that hippocampal slices can be imaged through transparent graphene electrodes by both confocal and two-photon microscopy without causing any light-induced artifacts in the electrical recordings. Graphene electrodes record high frequency bursting activity and slow synaptic potentials that are hard to resolve by multi-cellular calcium imaging. This transparent electrode technology may pave the way for high spatio-temporal resolution electrooptic mapping of the dynamic neuronal activity. PMID:25327632

  18. Solution processed transition metal sulfides: application as counter electrodes in dye sensitized solar cells (DSCs).

    PubMed

    Mulmudi, Hemant Kumar; Batabyal, Sudip Kumar; Rao, Manohar; Prabhakar, Rajiv Ramanujam; Mathews, Nripan; Lam, Yeng Ming; Mhaisalkar, Subodh Gautam

    2011-11-21

    A solution processed method for fabricating transition metal sulfides on fluorine doped tin oxide (FTO) as efficient counter electrodes in iodine/iodide based solar cells has been demonstrated. Conversion efficiencies of 7.01% and 6.50% were obtained for nickel and cobalt sulfides, respectively, comparable to the conventional thermally platinised FTO electrodes (7.32%). A comparable charge transfer resistance of Ni(3)S(2) and Co(8.4)S(8) to conventional Pt was found to be a key factor for such high efficiencies. Cyclic voltammetry, Kelvin probe microscopy, Electrochemical Impedance Spectroscopy, and Tafel polarization were performed to study the underlying reasons behind such efficient counter electrode performance. PMID:21964615

  19. Design and characterisation of a thin-film electrode array with shared reference/counter electrodes for electrochemical detection.

    PubMed

    Uludag, Yildiz; Olcer, Zehra; Sagiroglu, Mahmut Samil

    2014-07-15

    In the current study, a novel electrode array and integrated microfluidics have been designed and characterised in order to create a sensor chip which is not only easy, rapid and cheaper to produce but also have a smaller imprint and good electrochemical sensing properties. The current study includes the assessment of the effects of an Au quasi-reference electrode and the use of shared reference/counter electrodes for the array, in order to obtain a small array that can be produced using a fine metal mask. In the study, it is found that when Au is used as the quasi-reference electrode, the arrays with shared reference and counter electrodes result in faster electron transfer kinetics and prevent the potential change with respect to scan rate, and hence is advantageous with respect to conventional electrodes. In addition, the resulting novel electrode array has been shown to result in higher current density (10.52 µA/cm(2); HRP detection assay) and measured diffusion coefficient (14.40×10(-12) cm(2)/s; calculated from the data of cyclic voltammetry with 1mM potassium ferricyanide) with respect to conventional electrodes tested in the study. Using the new electrode arrays, the detection limits obtained from horse radish peroxidase (HRP) and bisphenol A assays were 12.5 ng/ml (2.84×10(-10) M ) and 10 ng/ml (44×10(-9) M), respectively. Performing the HRP detection assay in a flow injection system using array integrated microfluidics provided 25 times lower detection limit (11.36×10(-12) M), although Ti has been used as electrode material instead of Au. In short, incorporation of this new electrode array to lab-on-a-chip or MEMs (micro-electro mechanic systems) technologies may pave the way for easy to use automated biosensing devices that could be used for a variety of applications from diagnostics to environmental monitoring, and studies will continue to move forward in this direction. PMID:24561521

  20. Large-scale plasma patterning of transparent graphene electrode on flexible substrates.

    PubMed

    Kim, Ji Hye; Ko, Euna; Hwang, Joonki; Pham, Xuan-Hung; Lee, Joo Heon; Lee, Sung Hwan; Tran, Van-Khue; Kim, Jong-Ho; Park, Jin-Goo; Choo, Jaebum; Han, Kwi Nam; Seong, Gi Hun

    2015-03-10

    Graphene, a two-dimensional carbon material, has attracted significant interest for applications in flexible electronics as an alternative transparent electrode to indium tin oxide. However, it still remains a challenge to develop a simple, reproducible, and controllable fabrication technique for producing homogeneous large-scale graphene films and creating uniform patterns with desired shapes at defined positions. Here, we present a simple route to scalable fabrication of flexible transparent graphene electrodes using an oxygen plasma etching technique in a capacitively coupled plasma (CCP) system. Ascorbic acid-assisted chemical reduction enables the large-scale production of graphene with solution-based processability. Oxygen plasma in the CCP system facilitates the reproducible patterning of graphene electrodes, which allows controllable feature sizes and shapes on flexible plastic substrates. The resulting graphene electrode exhibits a high conductivity of 80 S cm(-1) and a transparency of 76% and retains excellent flexibility upon hard bending at an angle of ±175° and after repeated bending cycles. A simple LED circuit integrated on the patterned graphene film demonstrates the feasibility of graphene electrodes for use in flexible transparent electrodes. PMID:25692852

  1. Flexible, Highly Durable, and Thermally Stable SWCNT/Polyimide Transparent Electrodes.

    PubMed

    Kim, Seong-Ku; Liu, Tao; Wang, Xiaogong

    2015-09-23

    Flexible, transparent, and electrically conducting electrode materials are highly desired for flexible electronic applications. With a highly transparent polyimide (PI) as a substrate, a comprehensive and comparative study was performed to investigate four different fabrication schemes in producing transparent and electrically conducting SWCNT/PI electrodes. A very promising method that involves an in situ imidization process and nitric acid doping treatment was identified, which led to the fabrication of highly durable and thermally stable SWCNT/PI electrodes. The best performed electrode has a transmission of 77.6% at 550 nm and a sheet resistance (Rs) of 1169 ± 172 ?/?, which appeared no changes after repeating tests of bending, folding-unfolding, adhesive-tape-peeling-off, and wet tissue-paper scratching/wiping. The excellent thermal stability of such fabricated SWCNT/PI electrode is manifested by the very high glass transition temperature of 290.1 °C and low coefficient of thermal expansion (CTE) of 28.5 ppm °C(-1) in the temperature range from 75 to 200 °C. The new method expects to be able to pave the way in facile production of high-performance flexible, transparent, and conducting electrodes. PMID:26323087

  2. Atomic-Layer-Deposited Transparent Electrodes for Silicon Heterojunction Solar Cells

    SciTech Connect

    Demaurex, Benedicte; Seif, Johannes P.; Smit, Sjoerd; Macco, Bart; Kessels, W. M.; Geissbuhler, Jonas; De Wolf, Stefaan; Ballif, Christophe

    2014-11-01

    We examine damage-free transparent-electrode deposition to fabricate high-efficiency amorphous silicon/crystalline silicon heterojunction solar cells. Such solar cells usually feature sputtered transparent electrodes, the deposition of which may damage the layers underneath. Using atomic layer deposition, we insert thin protective films between the amorphous silicon layers and sputtered contacts and investigate their effect on device operation. We find that a 20-nm-thick protective layer suffices to preserve, unchanged, the amorphous silicon layers beneath. Insertion of such protective atomic-layer-deposited layers yields slightly higher internal voltages at low carrier injection levels. However, we identify the presence of a silicon oxide layer, formed during processing, between the amorphous silicon and the atomic-layer-deposited transparent electrode that acts as a barrier, impeding hole and electron collection.

  3. Atomic-Layer-Deposited Transparent Electrodes for Silicon Heterojunction Solar Cells

    DOE PAGESBeta

    Demaurex, Benedicte; Seif, Johannes P.; Smit, Sjoerd; Macco, Bart; Kessels, W. M.; Geissbuhler, Jonas; De Wolf, Stefaan; Ballif, Christophe

    2014-11-01

    We examine damage-free transparent-electrode deposition to fabricate high-efficiency amorphous silicon/crystalline silicon heterojunction solar cells. Such solar cells usually feature sputtered transparent electrodes, the deposition of which may damage the layers underneath. Using atomic layer deposition, we insert thin protective films between the amorphous silicon layers and sputtered contacts and investigate their effect on device operation. We find that a 20-nm-thick protective layer suffices to preserve, unchanged, the amorphous silicon layers beneath. Insertion of such protective atomic-layer-deposited layers yields slightly higher internal voltages at low carrier injection levels. However, we identify the presence of a silicon oxide layer, formed during processing,more »between the amorphous silicon and the atomic-layer-deposited transparent electrode that acts as a barrier, impeding hole and electron collection.« less

  4. High-performance NiO/Ag/NiO transparent electrodes for flexible organic photovoltaic cells.

    PubMed

    Xue, Zhichao; Liu, Xingyuan; Zhang, Nan; Chen, Hong; Zheng, Xuanming; Wang, Haiyu; Guo, Xiaoyang

    2014-09-24

    Transparent electrodes with a dielectric-metal-dielectric (DMD) structure can be implemented in a simple manufacturing process and have good optical and electrical properties. In this study, nickel oxide (NiO) is introduced into the DMD structure as a more appropriate dielectric material that has a high conduction band for electron blocking and a low valence band for efficient hole transport. The indium-free NiO/Ag/NiO (NAN) transparent electrode exhibits an adjustable high transmittance of ?82% combined with a low sheet resistance of ?7.6 ?·s·q(-1) and a work function of 5.3 eV after UVO treatment. The NAN electrode shows excellent surface morphology and good thermal, humidity, and environmental stabilities. Only a small change in sheet resistance can be found after NAN electrode is preserved in air for 1 year. The power conversion efficiencies of organic photovoltaic cells with NAN electrodes deposited on glass and polyethylene terephthalate (PET) substrates are 6.07 and 5.55%, respectively, which are competitive with those of indium tin oxide (ITO)-based devices. Good photoelectric properties, the low-cost material, and the room-temperature deposition process imply that NAN electrode is a striking candidate for low-cost and flexible transparent electrode for efficient flexible optoelectronic devices. PMID:25148532

  5. Electrode with transparent series resistance for uniform switching of optical modulation devices

    DOEpatents

    Tench, D. Morgan (Camarillo, CA); Cunningham, Michael A. (Thousand Oaks, CA); Kobrin, Paul H. (Newbury Park, CA)

    2008-01-08

    Switching uniformity of an optical modulation device for controlling the propagation of electromagnetic radiation is improved by use of an electrode comprising an electrically resistive layer that is transparent to the radiation. The resistive layer is preferably an innerlayer of a wide-bandgap oxide sandwiched between layers of indium tin oxide or another transparent conductor, and may be of uniform thickness, or may be graded so as to provide further improvement in the switching uniformity. The electrode may be used with electrochromic and reversible electrochemical mirror (REM) smart window devices, as well as display devices based on various technologies.

  6. ZnO:H indium-free transparent conductive electrodes for active-matrix display applications

    SciTech Connect

    Chen, Shuming Wang, Sisi

    2014-12-01

    Transparent conductive electrodes based on hydrogen (H)-doped zinc oxide (ZnO) have been proposed for active-matrix (AM) display applications. When fabricated with optimal H plasma power and optimal plasma treatment time, the resulting ZnO:H films exhibit low sheet resistance of 200 ?/? and high average transmission of 85% at a film thickness of 150?nm. The demonstrated transparent conductive ZnO:H films can potentially replace indium-tin-oxide and serve as pixel electrodes for organic light-emitting diodes as well as source/drain electrodes for ZnO-based thin-film transistors. Use of the proposed ZnO:H electrodes means that two photomask stages can be removed from the fabrication process flow for ZnO-based AM backplanes.

  7. Fully transparent organic transistors with junction-free metallic network electrodes

    NASA Astrophysics Data System (ADS)

    Pei, Ke; Wang, Zongrong; Ren, Xiaochen; Zhang, Zhichao; Peng, Boyu; Chan, Paddy K. L.

    2015-07-01

    We utilize highly transparent, junction-free metal network electrodes to fabricate fully transparent organic field effect transistors (OFETs). The patterned transparent Ag networks are developed by polymer crack template with adjustable line width and density. Sheet resistance of the network is 6.8 ?/sq and optical transparency in the whole visible range is higher than 80%. The bottom contact OFETs with DNTT active layer and parylene-C dielectric insulator show a maximum field-effect mobility of 0.13 cm2/V s (average mobility is 0.12 cm2/V s) and on/off ratio is higher than 107. The current OFETs show great potential for applications in the next generation of transparent and flexible electronics.

  8. Surface treatment effect of carbon fiber fabric counter electrode in dye sensitized solar cell.

    PubMed

    Pak, Hunkyun; Yoo, Young Ran

    2012-02-01

    Dye sensitized solar cells (DSSC) with surface modified carbon fiber fabric (CF) counter electrodes were prepared and tested. Four different type of CF were used; carbon fiber (CF); carbon fiber etched with NaOH (ECF); carbon fiber with thermally deposited platinum (CFPt); and carbon fiber etched with NaOH followed by thermal deposition of platinum (ECFPt). For comparison, DSSC with thermally Pt deposited fluorine doped tin oxide (FTO/Pt) glass counter electrode was also prepared and tested. Scanning electron microscope (SEM) proved that surface morphology of the carbon fiber was roughened by the etching process and platinum deposition process. The I-V curves of each DSSC were measured under simulated light (1 Sun, AM 1.5) to get open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF) and efficiency (eta). Electrochemical impedance spectroscopy of each cell was measured also. It was found that higher efficiency is obtained in order of using ECFPt > CFPt > FTO/Pt > ECF > CF counter electrode. PMID:22630028

  9. Incorporating hierarchical nanostructured carbon counter electrode into metal-free organic dye-sensitized solar cell.

    PubMed

    Fang, Baizeng; Fan, Sheng-Qiang; Kim, Jung Ho; Kim, Min-Sik; Kim, Minwoo; Chaudhari, Nitin K; Ko, Jaejung; Yu, Jong-Sung

    2010-07-01

    Hierarchical nanostructured carbon with a hollow macroporous core of ca. 60 nm in diameter in combination with mesoporous shell of ca. 30 nm in thickness has been explored as counter electrode in metal-free organic dye-sensitized solar cell. Compared with other porous carbon counterparts such as activated carbon and ordered mesoporous carbon CMK-3 and Pt counter electrode, the superior structural characteristics including large specific surface area and mesoporous volume and particularly the unique hierarchical core/shell nanostructure along with 3D large interconnected interstitial volume guarantee fast mass transport in hollow macroporous core/mesoporous shell carbon (HCMSC), and enable HCMSC to have highly enhanced catalytic activity toward the reduction of I(3)(-), and accordingly considerably improved photovoltaic performance. HCMSC exhibits a V(oc) of 0.74 V, which is 20 mV higher than that (i.e., 0.72 V) of Pt. In addition, it also demonstrates a fill factor of 0.67 and an energy conversion efficiency of 7.56%, which are markedly higher than those of its carbon counterparts and comparable to that of Pt (i.e., fill factor of 0.70 and conversion efficiency of 7.79%). Furthermore, HCMSC possesses excellent chemical stability in the liquid electrolyte containing I(-)/I(3)(-) redox couples, namely, after 60 days of aging, ca. 87% of its initial efficiency is still achieved by the solar cell based on HCMSC counter electrode. PMID:20334406

  10. Single-layer graphene as a stable and transparent electrode for nonaqueous radical annihilation electrogenerated chemiluminescence.

    PubMed

    Cristarella, Teresa C; Chinderle, Adam J; Hui, Jingshu; Rodríguez-López, Joaquín

    2015-04-01

    We explored the use of single-layer graphene (SLG) obtained by chemical vapor deposition, and transferred to a glass substrate, as a transparent electrode material for use in coupled electrochemical and spectroscopic experiments in nonaqueous media through electrogenerated chemiluminescence (ECL). SLG was used with classical ECL luminophores, rubrene and 9,10-diphenylanthracene, in an inert environment to generate stable electrochemical responses and measure light emission through it. As an electrode material, SLG displayed excellent stability during electrochemical potential stepping and voltammetry in a window that spanned at least from ca. -2.4 to +1.8 V versus SCE in acetonitrile and acetonitrile/benzene. Although the peak splitting between forward and reverse sweeps in voltammetry was larger in comparison to metal electrodes due to in-plane resistance, SLG displayed sufficiently facile electron transfer properties to yield stable voltammetric cycling and ECL. SLG electrodes patterned with poly tetrafluoroethylene permitted the stable generation of radical ions on an SLG microelectrode to be studied through scanning electrochemical microscopy in the generation/collection mode. SLG was able to stably collect radical ions produced by a 50 ?m gold tip with up to 96% collection efficiency. The transparency of graphene was used to obtain accurate spectral responses in ECL. While inner filter effects are known to cause a shift in peak emission wavelength of spectroelectrochemical studies, the use of SLG electrodes with detection through the graphene window reduced apparent peak shifts by up to 10 nm in peak wavelength. This work introduces SLG as a virtually transparent, electrochemically active, and chemically stable platform for studying ECL in the radical annihilation mode, where large electrode polarizations could compromise the chemical stability of other existing transparent electrodes. PMID:25780938

  11. Silver nanowire based flexible electrodes with improved properties: High conductivity, transparency, adhesion and low haze

    SciTech Connect

    Kiran Kumar, A.B.V.; Wan Bae, Chang; Piao, Longhai Kim, Sang-Ho

    2013-08-01

    Graphical abstract: This graphical abstract illustrates the schematic representation of the main drawbacks and rectifications for AgNWs based transparent electrodes. - Highlights: • Films exhibited low sheet resistance and optical properties with R{sub s} ? 30 ?/? and T ? 90%. • We decreased haze to 2% by controlling AgNWs length, diameter, and concentration. • We achieved good adhesion for AgNWs on PET film. • There is no significant change in resistance in the bending angle from 0° to 180°, and on twisting. - Abstract: Recent work has been focusing on solution processable transparent electrodes for various applications including solar cells and displays. As well as, the research aims majorly at silver nanowires (AgNWs) to replace ITO. We enhance the transparent electrode performance as a function of optical and mechanical properties with low sheet resistance, by controlling the AgNWs accept ratios, ink composition, and processing conditions. The nanowire network of transparent films agrees with the 2D percolation law. The film transmittance values at 550 nm are coping with a reference ITO film. Sheet resistance and haze values are suitable for flexible electronic applications. We fabricate transparent flexible film using a low-cost processing technique.

  12. Low-cost facile fabrication of flexible transparent copper electrodes by nanosecond laser ablation.

    PubMed

    Paeng, Dongwoo; Yoo, Jae-Hyuck; Yeo, Junyeob; Lee, Daeho; Kim, Eunpa; Ko, Seung Hwan; Grigoropoulos, Costas P

    2015-05-01

    Low-cost Cu flexible transparent conducting electrodes (FTCEs) are fabricated by facile nanosecond laser ablation. The fabricated Cu FTCEs show excellent opto-electrical properties (transmittance: 83%, sheet resistance: 17.48 ? sq(-1)) with outstanding mechanical durability. Successful demonstration of a touch-screen panel confirms the potential applicability of Cu FTCEs to the flexible optoelectronic devices. PMID:25821011

  13. Nanoparticles for Applications as Counter Electrodes of CdS Quantum Dot-Sensitized Solar Cells

    NASA Astrophysics Data System (ADS)

    Gu, Xiuquan; Zhang, Shuang; Qiang, Yinghuai; Zhao, Yulong; Zhu, Lei

    2014-07-01

    Cu2ZnSnS4 (CZTS) nanoparticles have been synthesized through a one-step solvothermal route, which exhibited a nearly single kesterite structure with a fundamental band gap of ˜1.54 eV. Quantum dots-sensitized solar cells were fabricated based on CZTS counter electrodes and CdS QD-sensitized TiO2 NRs photoelectrodes with various thicknesses of QD sensitization layers. The cells based on a CZTS electrode, compared with other single-layer DSSCs in this study, had the highest conversion efficiency of 0.27% (for CdS layer numbers of 9), which was obviously higher than Pt. The performance improvement was attributed to the better stability, sunlight sensitivity, and the resulting photoelectrocatalytic activity of the CZTS electrodes.

  14. Electrochemical sensor having suspended element counter electrode and deflection method for current sensing

    DOEpatents

    Thundat, Thomas G.; Brown, Gilbert M.

    2010-05-18

    An electrochemical suspended element-based sensor system includes a solution cell for holding an electrolyte comprising solution including at least one electrochemically reducible or oxidizable species. A working electrode (WE), reference electrode (RE) and a counter electrode (CE) are disposed in the solution. The CE includes an asymmetric suspended element, wherein one side of the suspended element includes a metal or a highly doped semiconductor surface. The suspended element bends when current associated with reduction or oxidation of the electrochemically reducible or oxidizable species at the WE passes through the suspended element. At least one measurement system measures the bending of the suspended element or a parameter which is a function of the bending.

  15. Light-trapping design of graphene transparent electrodes for efficient thin-film silicon solar cells.

    PubMed

    Zhao, Yongxiang; Chen, Fei; Shen, Qiang; Zhang, Lianmeng

    2012-09-01

    In this paper, the performance of solar cells with graphene transparent electrodes is compared with cells using conventional indium tin oxide (ITO) electrodes, and it is demonstrated the optical absorption of solar cells with bare graphene structure is worse than that of bare ITO structure because of the higher refractive index of graphene. To enhance the light trapping of graphene-based thin-film solar cells, a simple two-layer SiO(2)/SiC structure is proposed as antireflection coatings deposited on top of graphene transparent electrodes, and the thickness of each layer is optimized by differential evolution in order to enhance the optical absorption of a-Si:H thin-film solar cells to the greatest degree. The optimization results demonstrate the optimal SiO(2)/SiC/graphene structure can obtain 37.30% enhancement with respect to bare ITO structure, which has obviously exceeded the light-trapping enhancement of 34.15% for the optimal SiO(2)/SiC/ITO structure. Therefore, with the aid of the light-trapping structure, the graphene films are a very promising indium-free transparent electrode substitute for the conventional ITO electrode for use in cost-efficient thin-film silicon solar cells. PMID:22945173

  16. Graphene as a transparent electrode for amorphous silicon-based solar cells

    NASA Astrophysics Data System (ADS)

    Vaianella, F.; Rosolen, G.; Maes, B.

    2015-06-01

    The properties of graphene in terms of transparency and conductivity make it an ideal candidate to replace indium tin oxide (ITO) in a transparent conducting electrode. However, graphene is not always as good as ITO for some applications, due to a non-negligible absorption. For amorphous silicon photovoltaics, we have identified a useful case with a graphene-silica front electrode that improves upon ITO. For both electrode technologies, we simulate the weighted absorption in the active layer of planar amorphous silicon-based solar cells with a silver back-reflector. The graphene device shows a significantly increased absorbance compared to ITO-based cells for a large range of silicon thicknesses (34.4% versus 30.9% for a 300 nm thick silicon layer), and this result persists over a wide range of incidence angles.

  17. Nanocarbon-copper thin film as transparent electrode

    NASA Astrophysics Data System (ADS)

    Isaacs, R. A.; Zhu, H.; Preston, Colin; Mansour, A.; LeMieux, M.; Zavalij, P. Y.; Jaim, H. M. Iftekhar; Rabin, O.; Hu, L.; Salamanca-Riba, L. G.

    2015-05-01

    Researchers seeking to enhance the properties of metals have long pursued incorporating carbon in the metallic host lattice in order to combine the strongly bonded electrons in the metal lattice that yield high ampacity and the free electrons available in carbon nanostructures that give rise to high conductivity. The incorporation of carbon nanostructures into the copper lattice has the potential to improve the current density of copper to meet the ever-increasing demands of nanoelectronic devices. We report on the structure and properties of carbon incorporated in concentrations up to 5 wt. % (˜22 at. %) into the crystal structure of copper. Carbon nanoparticles of 5 nm-200 nm in diameter in an interconnecting carbon matrix are formed within the bulk Cu samples. The carbon does not phase separate after subsequent melting and re-solidification despite the absence of a predicted solid solution at such concentrations in the C-Cu binary phase diagram. This material, so-called, Cu covetic, makes deposition of Cu films containing carbon with similar microstructure to the metal possible. Copper covetic films exhibit greater transparency, higher conductivity, and resistance to oxidation than pure copper films of the same thickness, making them a suitable choice for transparent conductors.

  18. Nanocarbon-copper thin film as transparent electrode

    SciTech Connect

    Isaacs, R. A.; Zhu, H.; Preston, Colin; LeMieux, M.; Jaim, H. M. Iftekhar; Hu, L. Salamanca-Riba, L. G.; Mansour, A.; Zavalij, P. Y.; Rabin, O.

    2015-05-11

    Researchers seeking to enhance the properties of metals have long pursued incorporating carbon in the metallic host lattice in order to combine the strongly bonded electrons in the metal lattice that yield high ampacity and the free electrons available in carbon nanostructures that give rise to high conductivity. The incorporation of carbon nanostructures into the copper lattice has the potential to improve the current density of copper to meet the ever-increasing demands of nanoelectronic devices. We report on the structure and properties of carbon incorporated in concentrations up to 5?wt. % (?22 at. %) into the crystal structure of copper. Carbon nanoparticles of 5?nm–200?nm in diameter in an interconnecting carbon matrix are formed within the bulk Cu samples. The carbon does not phase separate after subsequent melting and re-solidification despite the absence of a predicted solid solution at such concentrations in the C-Cu binary phase diagram. This material, so-called, Cu covetic, makes deposition of Cu films containing carbon with similar microstructure to the metal possible. Copper covetic films exhibit greater transparency, higher conductivity, and resistance to oxidation than pure copper films of the same thickness, making them a suitable choice for transparent conductors.

  19. Co-Percolating Graphene-Wrapped Silver Nanowire Network for High Performance, Highly Stable, Transparent Conducting Electrodes

    SciTech Connect

    Chen, Ruiyi; Das, Suprem R; Jeong, Changwook; Khan, Mohammad Ryyan; Janes, David B; Alam, Muhammad A

    2013-04-25

    Transparent conducting electrodes (TCEs) require high transparency and low sheet resistance for applications in photovoltaics, photodetectors, flat panel displays, touch screen devices, and imagers. Indium tin oxide (ITO), or other transparent conductive oxides, have been used, and provide a baseline sheet resistance (RS) vs. transparency (T) relationship. Several alternative material systems have been investigated. The development of high-performance hybrid structures provides a route towards robust, scalable and low-cost approaches for realizing high-performance TCE.

  20. Hierarchical nanostructured spherical carbon with hollow core/mesoporous shell as a highly efficient counter electrode in CdSe quantum-dot-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Fan, Sheng-Qiang; Fang, Baizeng; Kim, Jung Ho; Kim, Jeum-Jong; Yu, Jong-Sung; Ko, Jaejung

    2010-02-01

    Hierarchical nanostructured spherical carbon with hollow core/mesoporous shell (HCMS) was explored as a counter electrode in CdSe quantum-dot-sensitized solar cells. Compared with conventional Pt electrodes and commercially available activated carbon, the HCMS carbon counter electrode exhibits a much larger fill factor due to the considerably decreased charge transfer resistance at the interface of the counter electrode/polysulfide electrolyte. Furthermore, a solar cell with the HCMS carbon counter electrode presents a high power conversion efficiency of up to 3.90% as well as an incident photon-to-current conversion efficiency peak of 80%.

  1. Electrochimica Acta 46 (2001) 20772084 Fe-containing CeVO4 films as Li intercalation transparent

    E-print Network

    Artuso, Florinda

    2001-01-01

    , the rare-earth orthovanadates matched the desired properties for transparent counter-electrodes [4-electrodes although many transition metal oxides have been proposed to work in tandem with WO3 in EC devices [2

  2. Direct tri-constituent co-assembly of highly ordered mesoporous carbon counter electrode for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Peng, Tao; Sun, Weiwei; Sun, Xiaohua; Huang, Niu; Liu, Yumin; Bu, Chenghao; Guo, Shishang; Zhao, Xing-Zhong

    2012-12-01

    Controlling over ordered porosity by self-assembly is challenging in the area of materials science. Materials with highly ordered aperture are favorable candidates in catalysis and energy conversion device. Here we describe a facile process to synthesize highly ordered mesoporous carbon (OMC) by direct tri-constituent co-assembly method, which uses resols as the carbon precursor, tri-block copolymer F127 as the soft template and tetraethoxysilane (TEOS) as the inorganic precursor. The obtained products are characterized by small-angle X-ray diffraction (SAXD), Brunauer-Emmett-Teller (BET) nitrogen sorption-desorption measurement and transmission electron microscope (TEM). The results indicate that the OMC possesses high surface areas of 1209 m2 g-1, homogeneous pore size of 4.6 nm and a large pore volume of 1.65 cm3 g-1. The advantages of high electrochemical active surface area and favorable accessible porosity of OMC benefit the catalysis of I3- to I-. As a result, the OMC counter electrode displays a remarkable property when it was applied in dye-sensitized solar cells (DSSCs). For comparison, carbon black (CB) counter electrode and Pt counter electrode have also been prepared. When these different counter electrodes were applied for dye-sensitized solar cells (DSSCs), the power-conversion efficiency (?) of the DSSCs with CB counter electrode are measured to be 5.10%, whereas the corresponding values is 6.39% for the DSSC with OMC counter electrode, which is comparable to 6.84% of the cell with Pt counter electrode under the same experimental conditions.

  3. Highly stretchable and transparent nanomesh electrodes made by grain boundary lithography.

    PubMed

    Guo, Chuan Fei; Sun, Tianyi; Liu, Qihan; Suo, Zhigang; Ren, Zhifeng

    2014-01-01

    Foldable photoelectronics and muscle-like transducers require highly stretchable and transparent electrical conductors. Some conducting oxides are transparent, but not stretchable. Carbon nanotube films, graphene sheets and metal-nanowire meshes can be both stretchable and transparent, but their electrical resistances increase steeply with strain <100%. Here we present highly stretchable and transparent Au nanomesh electrodes on elastomers made by grain boundary lithography. The change in sheet resistance of Au nanomeshes is modest with a one-time strain of ~160% (from ~21 ? per square to ~67 ? per square), or after 1,000 cycles at a strain of 50%. The good stretchability lies in two aspects: the stretched nanomesh undergoes instability and deflects out-of-plane, while the substrate stabilizes the rupture of Au wires, forming distributed slits. Larger ratio of mesh-size to wire-width also leads to better stretchability. The highly stretchable and transparent Au nanomesh electrodes are promising for applications in foldable photoelectronics and muscle-like transducers. PMID:24469072

  4. Highly stretchable and transparent nanomesh electrodes made by grain boundary lithography

    NASA Astrophysics Data System (ADS)

    Guo, Chuan Fei; Sun, Tianyi; Liu, Qihan; Suo, Zhigang; Ren, Zhifeng

    2014-01-01

    Foldable photoelectronics and muscle-like transducers require highly stretchable and transparent electrical conductors. Some conducting oxides are transparent, but not stretchable. Carbon nanotube films, graphene sheets and metal-nanowire meshes can be both stretchable and transparent, but their electrical resistances increase steeply with strain <100%. Here we present highly stretchable and transparent Au nanomesh electrodes on elastomers made by grain boundary lithography. The change in sheet resistance of Au nanomeshes is modest with a one-time strain of ~160% (from ~21?? per square to ~67?? per square), or after 1,000 cycles at a strain of 50%. The good stretchability lies in two aspects: the stretched nanomesh undergoes instability and deflects out-of-plane, while the substrate stabilizes the rupture of Au wires, forming distributed slits. Larger ratio of mesh-size to wire-width also leads to better stretchability. The highly stretchable and transparent Au nanomesh electrodes are promising for applications in foldable photoelectronics and muscle-like transducers.

  5. RF Sputtered Iridium (Ir) Film as a Counter Electrode for Dye-Sensitized Solar Cells

    NASA Astrophysics Data System (ADS)

    Mokurala, Krishnaiah; Kamble, Anvita; Bhargava, Parag; Mallick, Sudhanshu

    2015-11-01

    Iridium (Ir) films were deposited on fluorine-doped tin oxide substrate by radio-frequency sputtering at room temperature and the as-deposited films were used as counter electrodes (CE) for dye-sensitized solar cells (DSSC). The photo conversion efficiency (PCE) of DSSC fabricated with Ir-based CE was 7.2%. Electrocatalytic activity and electrochemical data for Ir-based CE were compared with those for conventional Pt-based CE. The results were indicative of potential use of Ir as an alternative CE material for DSSC.

  6. Planar silver nanowire, carbon nanotube and PEDOT:PSS nanocomposite transparent electrodes

    NASA Astrophysics Data System (ADS)

    Stapleton, Andrew J.; Yambem, Soniya D.; Johns, Ashley H.; Afre, Rakesh A.; Ellis, Amanda V.; Shapter, Joe G.; Andersson, Gunther G.; Quinton, Jamie S.; Burn, Paul L.; Meredith, Paul; Lewis, David A.

    2015-04-01

    Highly conductive, transparent and flexible planar electrodes were fabricated using interwoven silver nanowires and single-walled carbon nanotubes (AgNW:SWCNT) in a PEDOT:PSS matrix via an epoxy transfer method from a silicon template. The planar electrodes achieved a sheet resistance of 6.6 ± 0.0 ?/? and an average transmission of 86% between 400 and 800 nm. A high figure of merit of 367 ?-1 is reported for the electrodes, which is much higher than that measured for indium tin oxide and reported for other AgNW composites. The AgNW:SWCNT:PEDOT:PSS electrode was used to fabricate low temperature (annealing free) devices demonstrating their potential to function with a range of organic semiconducting polymer:fullerene bulk heterojunction blend systems.

  7. Inkjet printed silver nanowire network as top electrode for semi-transparent organic photovoltaic devices

    NASA Astrophysics Data System (ADS)

    Lu, Hui; Lin, Jian; Wu, Na; Nie, Shuhong; Luo, Qun; Ma, Chang-Qi; Cui, Zheng

    2015-03-01

    A method for direct inkjet printing of silver nanowire (Ag NW) to form transparent conductive network as the top electrode for inverted semi-transparent organic photovoltaic devices (OPV) was developed. The highest power conversion efficiency of the poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester (P3HT:PC61BM) based OPV was achieved to be 2.71% when the top electrode was formed by 7 times of printing. In general, devices with printed Ag NW top electrode had similar open-circuit voltage (VOC, around 0.60 V) but lower fill factor (FF, 0.33-0.54) than that of device with thermally deposited Ag opaque electrode (reference device). Both FF and short-circuit current density (JSC), however, were found to be increasing with the increase of printing times (3, 5, and 7), which could be partially attributed to the improved conductivity of Ag NW network electrodes. The solvent effect on device performances was studied carefully by comparing the current density-voltage (J-V) curves of different devices. The results revealed that solvent treatment on the anode buffer layer during printing led to a decrease of charge injection selectivity and an increase of charge recombination at the anode interface, which was considered to be the reason for the degrading of device performance.

  8. Capillary Printing of Highly Aligned Silver Nanowire Transparent Electrodes for High-Performance Optoelectronic Devices.

    PubMed

    Kang, Saewon; Kim, Taehyo; Cho, Seungse; Lee, Youngoh; Choe, Ayoung; Walker, Bright; Ko, Seo-Jin; Kim, Jin Young; Ko, Hyunhyub

    2015-12-01

    Percolation networks of silver nanowires (AgNWs) are commonly used as transparent conductive electrodes (TCEs) for a variety of optoelectronic applications, but there have been no attempts to precisely control the percolation networks of AgNWs that critically affect the performances of TCEs. Here, we introduce a capillary printing technique to precisely control the NW alignment and the percolation behavior of AgNW networks. Notably, partially aligned AgNW networks exhibit a greatly lower percolation threshold, which leads to the substantial improvement of optical transmittance (96.7%) at a similar sheet resistance (19.5 ? sq(-1)) as compared to random AgNW networks (92.9%, 20 ? sq(-1)). Polymer light-emitting diodes (PLEDs) using aligned AgNW electrodes show a 30% enhanced maximum luminance (33068 cd m(-2)) compared to that with random AgNWs and a high luminance efficiency (14.25 cd A(-1)), which is the highest value reported so far using indium-free transparent electrodes for fluorescent PLEDs. In addition, polymer solar cells (PSCs) using aligned AgNW electrodes exhibit a power conversion efficiency (PCE) of 8.57%, the highest value ever reported to date for PSCs using AgNW electrodes. PMID:26540011

  9. Broadband light absorption enhancement in polymer photovoltaics using metal nanowall gratings as transparent electrodes

    SciTech Connect

    Ye, Zhuo; Chaudhary, Sumit; Kuang, Ping; Ho, Kai-Ming

    2012-05-15

    The authors investigate light absorption in organic solar cells in which indium tin oxide (ITO) is replaced by a new metallic architecture (grating) as a transparent electrode. Different from typical metal nanowire gratings, our gratings consist of metal nanowalls with nanoscale footprint and (sub)microscale height [Adv. Mater. 23, 2469 (2011)], thus ensuring high optical transmittance and electrical conductivity. Simulations reveal that a broadband and polarization-insensitive light absorption enhancement is achieved via two mechanisms, when such silver nanowall gratings are employed in P3HT:PCBM based solar cells. Overall absorption enhanced by ~23% compared to a reference cell with ITO electrode.

  10. Graphene as transparent and current spreading electrode in silicon solar cell

    NASA Astrophysics Data System (ADS)

    Behura, Sanjay K.; Mahala, Pramila; Nayak, Sasmita; Jani, Omkar

    2014-11-01

    Fabricated bi-layer graphene (BLG) has been studied as transparent and current spreading electrode (TCSE) for silicon solar cell, using TCAD-Silvaco 2D simulation. We have carried out comparative study using both Ag grids and BLG as current spreading electrode (CSE) and TCSE, respectively. Our study reveals that BLG based solar cell shows better efficiency of 24.85% than Ag-based cell (21.44%), in all of the critical aspects, including generation rate, recombination rate, electric field, potential and quantum efficiency. Further BLG based cell exhibits pronounce rectifying behavior, low saturation current, and good turn-on voltage while studying in dark.

  11. Fabrication and characterization of cuprous oxide solar cell with net-shaped counter electrode

    NASA Astrophysics Data System (ADS)

    Basuki, Stefanus; Uranus, Henri P.; Pangaribuan, Julinda

    2015-01-01

    In this work, simple solar cells using cuprous oxide were fabricated and characterized. The solar cells in this experiment used cuprous oxide plate as detecting electrode and copper wires which were woven into a net-shape with a gap size of 2 x 2 cm as a counter electrode. Twenty samples of solar cells were fabricated with oxide layer which were thermally grown in temperature up to 550 oC. Samples with variations in oxidation time (15 minutes, 30 minutes, 40 minutes, and 45 minutes) and distance between electrodes (2 cm, 3 cm, and 4 cm) with an electrolyte solution of NaCl with molarity of 2.188 mol/l were produced. The samples were characterized by measuring their V-I curve. For this purpose, a simple, own-made solar simulator were fabricated and characterized. Using curve fitting technique, parameters such as FF (Fill Factor), efficiency, open circuit voltage, short circuit current, internal resistance, and performance degradation as a function of time of the cells were extracted. The result shows optimum efficiency of 4.573. 10-4%, while optimum oxidation time is 40 minutes and optimum distance between electrodes is 3 cm.

  12. Ag nanowire percolating network embedded in indium tin oxide nanoparticles for printable transparent conducting electrodes

    SciTech Connect

    Jeong, Jin-A; Kim, Han-Ki

    2014-02-17

    Solution-based printable transparent conducting electrodes consisting of Ag nanowire (NW) and indium tin oxide (ITO) nanoparticles (NPs) were fabricated by simple brush painting at room temperature under atmospheric ambient conditions. Effectively embedding the Ag NW percolating network into the ITO NPs provided a conduction path, led to a metallic conduction behavior of the ITO NPs/Ag NW/ITO NPs multilayer and supplied electrons into the ITO NPs. The optimized ITO NPs/Ag NW/ITO NPs multilayer showed a sheet resistance of 16.57??/sq and an optical transparency of 79.50% without post annealing. Based on high resolution transmission electron microscope analysis, we investigated the microstructure and interface structure of the ITO NPs/Ag NW/ITO NPs multilayer electrodes and suggested a possible mechanism to explain the low resistivity of the multilayers.

  13. Synthesis of Metal/Bimetal Nanowires and Their Applications as Flexible Transparent Electrodes.

    PubMed

    Wang, Xiao; Wang, Ranran; Shi, Liangjing; Sun, Jing

    2015-09-01

    As a potential alternative to indium oxide (ITO), metal nanowire transparent conductive electrodes (TCEs) have attracted more and more attention. Here, a facile method that can be applied to the synthesis of a variety of metal/bimetallic nanowires has been proposed. Metal/bimetallic nanowires synthesized through this method show high aspect ratios and great dispersibility, which makes them ideal building blocks for transparent electrodes. The synthesis mechanism is discussed in-depth to give a theoretical basis of morphology control of metal nanostructures in organic synthesizing systems. TCEs with high flexibility, excellent optical-electrical performance as well as outstanding anti-thermal and anti-moisture stability are constructed. To the best of our knowledge, this is the first work on synthesizing multiple metal/bimetallic nanowires through one method. PMID:26179912

  14. Improved efficiency of hybrid organic photovoltaics by pulsed laser sintering of silver nanowire network transparent electrode.

    PubMed

    Spechler, Joshua A; Nagamatsu, Ken A; Sturm, James C; Arnold, Craig B

    2015-05-20

    In this Research Article, we demonstrate pulsed laser processing of a silver nanowire network transparent conductor on top of an otherwise complete solar cell. The macroscopic pulsed laser irradiation serves to sinter nanowire-nanowire junctions on the nanoscale, leading to a much more conductive electrode. We fabricate hybrid silicon/organic heterojunction photovoltaic devices, which have ITO-free, solution processed, and laser processed transparent electrodes. Furthermore, devices which have high resistive losses show up to a 35% increase in power conversion efficiency after laser processing. We perform this study over a range of laser fluences, and a range of nanowire area coverage to investigate the sintering mechanism of nanowires inside of a device stack. The increase in device performance is modeled using a simple photovoltaic diode approach and compares favorably to the experimental data. PMID:25914946

  15. Nanopatterned conductive polymer films as a Pt, TCO-free counter electrode for low-cost dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Kwon, Jeong; Ganapathy, Veerappan; Kim, Young Hun; Song, Kyung-Deok; Park, Hong-Gyu; Jun, Yongseok; Yoo, Pil J.; Park, Jong Hyeok

    2013-08-01

    A low-cost nanopatterned highly conductive poly(3,4-ethylenedioxythiophene) (PEDOT) thin film was fabricated on a flexible plastic substrate via a chemical polymerization method combined with a nanoimprinting technique and used as a platinum (Pt), TCO-free counter electrode for dye-sensitized solar cells (DSSCs). The catalytic properties of the nanopatterned PEDOT as the counter electrode in DSSCs were studied using cyclic voltammetry, J-V measurements, impedance spectroscopy, and finite-difference time-domain (FDTD) simulations. The nanopatterned PEDOT counter electrodes exhibit better functionality as a counter electrode for tri-iodide reduction when compared to non-patterned PEDOT-based counter electrodes. The Pt and TCO-free DSSCs with a nanopatterned PEDOT-based counter electrode exhibited a power conversion efficiency of 7.1% under one sunlight illumination (100 mW cm-2), which is comparable to that of conventional DSSCs with standard platinum Pt/FTO paired counter electrodes. The ability to modulate catalytic functionality with changes in nanoscale morphology represents a promising route for developing new counter electrodes of Pt and TCO-free DSSCs.A low-cost nanopatterned highly conductive poly(3,4-ethylenedioxythiophene) (PEDOT) thin film was fabricated on a flexible plastic substrate via a chemical polymerization method combined with a nanoimprinting technique and used as a platinum (Pt), TCO-free counter electrode for dye-sensitized solar cells (DSSCs). The catalytic properties of the nanopatterned PEDOT as the counter electrode in DSSCs were studied using cyclic voltammetry, J-V measurements, impedance spectroscopy, and finite-difference time-domain (FDTD) simulations. The nanopatterned PEDOT counter electrodes exhibit better functionality as a counter electrode for tri-iodide reduction when compared to non-patterned PEDOT-based counter electrodes. The Pt and TCO-free DSSCs with a nanopatterned PEDOT-based counter electrode exhibited a power conversion efficiency of 7.1% under one sunlight illumination (100 mW cm-2), which is comparable to that of conventional DSSCs with standard platinum Pt/FTO paired counter electrodes. The ability to modulate catalytic functionality with changes in nanoscale morphology represents a promising route for developing new counter electrodes of Pt and TCO-free DSSCs. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr01294h

  16. Flexion bonding transfer of multilayered graphene as a top electrode in transparent organic light-emitting diodes.

    PubMed

    Tae Lim, Jong; Lee, Hyunkoo; Cho, Hyunsu; Kwon, Byoung-Hwa; Sung Cho, Nam; Kuk Lee, Bong; Park, Jonghyurk; Kim, Jaesu; Han, Jun-Han; Yang, Jong-Heon; Yu, Byoung-Gon; Hwang, Chi-Sun; Chu Lim, Seong; Lee, Jeong-Ik

    2015-01-01

    Graphene has attracted considerable attention as a next-generation transparent conducting electrode, because of its high electrical conductivity and optical transparency. Various optoelectronic devices comprising graphene as a bottom electrode, such as organic light-emitting diodes (OLEDs), organic photovoltaics, quantum-dot LEDs, and light-emitting electrochemical cells, have recently been reported. However, performance of optoelectronic devices using graphene as top electrodes is limited, because the lamination process through which graphene is positioned as the top layer of these conventional OLEDs is a lack of control in the surface roughness, the gapless contact, and the flexion bonding between graphene and organic layer of the device. Here, a multilayered graphene (MLG) as a top electrode is successfully implanted, via dry bonding, onto the top organic layer of transparent OLED (TOLED) with flexion patterns. The performance of the TOLED with MLG electrode is comparable to that of a conventional TOLED with a semi-transparent thin-Ag top electrode, because the MLG electrode makes a contact with the TOLED with no residue. In addition, we successfully fabricate a large-size transparent segment panel using the developed MLG electrode. Therefore, we believe that the flexion bonding technology presented in this work is applicable to various optoelectronic devices. PMID:26626439

  17. Flexion bonding transfer of multilayered graphene as a top electrode in transparent organic light-emitting diodes

    PubMed Central

    Tae Lim, Jong; Lee, Hyunkoo; Cho, Hyunsu; Kwon, Byoung-Hwa; Sung Cho, Nam; Kuk Lee, Bong; Park, Jonghyurk; Kim, Jaesu; Han, Jun-Han; Yang, Jong-Heon; Yu, Byoung-Gon; Hwang, Chi-Sun; Chu Lim, Seong; Lee, Jeong-Ik

    2015-01-01

    Graphene has attracted considerable attention as a next-generation transparent conducting electrode, because of its high electrical conductivity and optical transparency. Various optoelectronic devices comprising graphene as a bottom electrode, such as organic light-emitting diodes (OLEDs), organic photovoltaics, quantum-dot LEDs, and light-emitting electrochemical cells, have recently been reported. However, performance of optoelectronic devices using graphene as top electrodes is limited, because the lamination process through which graphene is positioned as the top layer of these conventional OLEDs is a lack of control in the surface roughness, the gapless contact, and the flexion bonding between graphene and organic layer of the device. Here, a multilayered graphene (MLG) as a top electrode is successfully implanted, via dry bonding, onto the top organic layer of transparent OLED (TOLED) with flexion patterns. The performance of the TOLED with MLG electrode is comparable to that of a conventional TOLED with a semi-transparent thin-Ag top electrode, because the MLG electrode makes a contact with the TOLED with no residue. In addition, we successfully fabricate a large-size transparent segment panel using the developed MLG electrode. Therefore, we believe that the flexion bonding technology presented in this work is applicable to various optoelectronic devices. PMID:26626439

  18. Enhanced performance of photonic crystal GaN light-emitting diodes with graphene transparent electrodes

    NASA Astrophysics Data System (ADS)

    Ge, Hai-Liang; Xu, Chen; Xu, Kun; Xun, Meng; Wang, Jun; Liu, Jie

    2015-03-01

    The two-dimensional (2D) triangle lattice air hole photonic crystal (PC) GaN-based light-emitting diodes (LED) with double-layer graphene transparent electrodes (DGTE) have been produced. The current spreading effect of the double-layer graphene (GR) on the surface of the PC structure of the LED has been researched. Specially, we found that the part of the graphene suspending over the air hole of the PC structure was of much higher conductivity, which reduced the average sheet resistance of the graphene transparent conducting electrode and improved the current spreading of the PC LED. Therefore, the work voltage of the DGTE-PC LED was obviously decreased, and the output power was greatly enhanced. The COMSOL software was used to simulate the current density distribution of the samples. The results show that the etching of PC structure results in the degradation of the current spreading and that the graphene transparent conducting electrode can offer an uniform current spreading in the DGTE-PC LED. PACS: 85.60.Jb; 68.65.Pq; 42.70.Qs

  19. Highly transparent Nb-doped indium oxide electrodes for organic solar cells

    SciTech Connect

    Kim, Jun Ho; Seong, Tae-Yeon; Na, Seok-In; Chung, Kwun-Bum; Lee, Hye-Min; Kim, Han-Ki

    2014-03-15

    The authors investigated the characteristics of Nb-doped In{sub 2}O{sub 3} (INbO) films prepared by co-sputtering of Nb{sub 2}O{sub 5} and In{sub 2}O{sub 3} for use in transparent anodes for organic solar cells (OSCs). To optimize the Nb dopant composition in the In{sub 2}O{sub 3} matrix, the effect of the Nb doping power on the resistivity and transparency of the INbO films were examined. The electronic structure and microstructure of the INbO films were also investigated using synchrotron x-ray absorption spectroscopy and x-ray diffraction examinations in detail. At the optimized Nb co-sputtering power of 30?W, the INbO film exhibited a sheet resistance of 15??/sq, and an optical transmittance of 86.04% at 550?nm, which are highly acceptable for the use as transparent electrodes in the fabrication of OSCs. More importantly, the comparable power conversion efficiency (3.34%) of the OSC with an INbO anode with that (3.31%) of an OSC with a commercial ITO anode indicates that INbO films are promising as a transparent electrode for high performance OSCs.

  20. Improvements in purification of silver nanowires by decantation and fabrication of flexible transparent electrodes. Application to capacitive touch sensors

    NASA Astrophysics Data System (ADS)

    Mayousse, Céline; Celle, Caroline; Moreau, Eléonore; Mainguet, Jean-François; Carella, Alexandre; Simonato, Jean-Pierre

    2013-05-01

    Transparent flexible electrodes made of metallic nanowires, and in particular silver nanowires (AgNWs), appear as an extremely promising alternative to transparent conductive oxides for future optoelectronic devices. Though significant progresses have been made the last few years, there is still some room for improvement regarding the synthesis of high quality silver nanowire solutions and fabrication process of high performance electrodes. We show that the commonly used purification process can be greatly simplified through decantation. Using this process it is possible to fabricate flexible electrodes by spray coating with sheet resistance lower than 25 ? sq-1 at 90% transparency in the visible spectrum. These electrodes were used to fabricate an operative transparent flexible touch screen. To our knowledge this is the first reported AgNW based touch sensor relying on capacitive technology.

  1. Highly efficient flexible optoelectronic devices using metal nanowire-conducting polymer composite transparent electrode

    NASA Astrophysics Data System (ADS)

    Jung, Eui Dae; Nam, Yun Seok; Seo, Houn; Lee, Bo Ram; Yu, Jae Choul; Lee, Sang Yun; Kim, Ju-Young; Park, Jang-Ung; Song, Myoung Hoon

    2015-09-01

    Here, we report a comprehensive analysis of the electrical, optical, mechanical, and surface morphological properties of composite nanostrutures based on silver nanowires (AgNW) and PEDOT:PSS conducting polymer for the use as flexible and transparent electrodes. Compared to ITO or the single material of AgNW or PEDOT:PSS, the AgNW/PEDOT:PSS composite electrode showed high electrical conductivity with a low sheet resistance of 26.8 ?/sq at 91% transmittance (at 550 nm), improves surface smoothness, and enhances mechanical properties assisted by an amphiphilic fluoro-surfactant. The polymeric light-emitting diodes (PLEDs) and organic solar cells (OSCs) using the AgNW/PEDOT:PSS composite electrode showed higher device performances than those with AgNW and PEDOT:PSS electrodes and excellent flexibility under bending test. These results indicates that the AgNW/PEDOT:PSS composite presented is a good candidate as next-generation transparent elelctrodes for applications into flexible optoelectronic devices. [Figure not available: see fulltext.

  2. Transparent aluminium nanowire electrodes with optical and electrical anisotropic response fabricated by defocused ion beam sputtering

    NASA Astrophysics Data System (ADS)

    Repetto, Diego; Giordano, Maria Caterina; Martella, Christian; Buatier de Mongeot, Francesco

    2015-02-01

    Self-organized Al nanowire (NW) electrodes have been obtained by defocused Ion Beam Sputtering (IBS) of polycrystalline Al films grown by sputter deposition. The electrical sheet resistance of the electrode has been acquired in situ during ion bombardment of the samples, evidencing an increase of the electronic transport anisotropy as a function of ion fluence between the two directions parallel and orthogonal to the NWs axis. Optical spectra in transmission also show a large dichroism between the two directions, suggesting the role of localized plasmons in the UV spectral range. The results show that Al NW electrodes, prepared under experimental conditions which are compatible with those of conventional industrial coaters and implanters, could represent a low cost alternative to the transparent conductive oxides employed in optoelectronic devices.

  3. Nano-honeycomb structured transparent electrode for enhanced light extraction from organic light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Shi, Xiao-Bo; Qian, Min; Wang, Zhao-Kui; Liao, Liang-Sheng

    2015-06-01

    A universal nano-sphere lithography method has been developed to fabricate nano-structured transparent electrode, such as indium tin oxide (ITO), for light extraction from organic light-emitting diodes (OLEDs). Perforated SiO2 film made from a monolayer colloidal crystal of polystyrene spheres and tetraethyl orthosilicate sol-gel is used as a template. Ordered nano-honeycomb pits on the ITO electrode surface are obtained by chemical etching. The proposed method can be utilized to form large-area nano-structured ITO electrode. More than two folds' enhancement in both current efficiency and power efficiency has been achieved in a red phosphorescent OLED which was fabricated on the nano-structured ITO substrate.

  4. Functionalized graphene sheets in dye-sensitized solar cell counter electrodes

    NASA Astrophysics Data System (ADS)

    Roy-Mayhew, Joseph Dominic

    The use of thermally exfoliated graphite oxide, commonly referred to as functionalized graphene sheets (FGSs), was investigated as a catalytic counter electrode material in dye-sensitized solar cells to substitute for platinum nanoparticles traditionally used in devices. A catalyst's activity depends both on the material's intrinsic activity as well as on its surface area accessible for reaction. Thus, this work aimed i) to determine the intrinsic activity of FGSs with various chemical compositions and structures, and ii) to create high surface area networks of FGSs to use as catalytic electrodes in dye-sensitized solar cells. Monolayers of FGSs were fabricated and electrochemically tested to determine the intrinsic catalytic activity for a common dye-sensitized solar cell redox mediator, cobalt bipyridine. It was found that lattice defect rich, oxygen-site poor FGSs catalyze the reduction of the cobalt complex as well as platinum does, exhibiting a rate constant of ~ 6 x 10-3 cm/s. This rate is an order of magnitude faster than exhibited with oxygen-site rich graphene oxide, and over two orders of magnitude faster than found with the basal plane of graphite (as a surrogate for pristine graphene). FGSs are less catalytic towards the iodide/triiodide redox mediator, thus larger surface areas must be used for effective catalysis. In this work, conductive, high surface area networks of FGSs were produced by first tape casting surfactant-stabilized aqueous suspensions of FGSs and then thermolyzing the surfactant materials. Iodide/triiodide mediated dye-sensitized solar cells using these FGS electrodes exhibited power conversion efficiencies within 10% of devices using platinum nanoparticles. Furthermore, to interpret the catalytic activity of FGSs towards the reduction of triiodide, a new electrochemical impedance spectroscopy equivalent circuit was proposed that matches the observed spectra features to the appropriate phenomena. Lastly, improved catalytic performance was achieved through better control of electrode morphology. By using ethyl cellulose as a sacrificial binder, and partially thermolyzing it, electrodes were created which exhibited lower effective charge transfer resistance (< 1 ?·cm 2) than the traditional platinum electrodes for the iodide/triiodide, the cobalt bipyridine, and a sulfur-based redox couple. Dye-sensitized solar cells using these FGS electrodes had power conversion efficiencies equal to or greater than those using platinum nanoparticles with each of the three major redox mediators.

  5. Modified conducting polymer films having high catalytic activity for use as counter electrodes in rigid and flexible dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Ke, Chun-Ren; Chang, Chih-Ching; Ting, Jyh-Ming

    2015-06-01

    We report replacing platinum based counter electrode (CE) in dye-sensitized solar cell (DSSC) with conducting polymer based CE. Conducting polymers are prepared through mixing poly-(3,4-ethylenedioxythio phene):poly-(styrene sulfonic acid) (PEDOT:PSS) with Triton. The polymer mixture is spin-coated on indium tin oxide (ITO)-coated glass substrate and ITO-coated polyethylene naphthalate plastic substrate to form a CE for use in both rigid and flexible DSSCs, respectively. The PEDOT:PSS-Triton polymer not only is transparent (up to 93%) and highly conductive but also exhibits better catalytic activity than the expensive platinum. The DSSC fabricated using the PEDOT:PSS-Triton conducting polymer CE shows better performance or higher power conversion efficiency than that using Pt-based CE, either rigid or flexible.

  6. Indium Tin Oxide-Free Transparent Conductive Electrode for GaN-Based Ultraviolet Light-Emitting Diodes.

    PubMed

    Kim, Ja-Yeon; Jeon, Jong-Hyun; Kwon, Min-Ki

    2015-04-22

    Transparent conducting electrodes are important components of highly efficient ultraviolet light-emitting diodes (UV LEDs). Indium tin oxide (ITO) is commonly used to form a current spreading layer, but its UV-range optical transparency is limited with a low sheet resistance. We demonstrate a simple solution-based coating technique to obtain large-area, highly uniform, and conductive silver-nanowire-based electrodes that exhibit UV-range optical transparency better than that of ITO for the same sheet resistance. The UV LEDs fabricated using this current spreading layer showed improved optical power emission as well as improvement in electrical properties. PMID:25830932

  7. Bifacial dye-sensitized solar cells: A strategy to enhance overall efficiency based on transparent polyaniline electrode

    NASA Astrophysics Data System (ADS)

    Wu, Jihuai; Li, Yan; Tang, Qunwei; Yue, Gentian; Lin, Jianming; Huang, Miaoliang; Meng, Lijian

    2014-02-01

    Dye-sensitized solar cell (DSSC) is a promising solution to global energy and environmental problems because of its clean, low-cost, high efficiency, good durability, and easy fabrication. However, enhancing the efficiency of the DSSC still is an important issue. Here we devise a bifacial DSSC based on a transparent polyaniline (PANI) counter electrode (CE). Owing to the sunlight irradiation simultaneously from the front and the rear sides, more dye molecules are excited and more carriers are generated, which results in the enhancement of short-circuit current density and therefore overall conversion efficiency. The photoelectric properties of PANI can be improved by modifying with 4-aminothiophenol (4-ATP). The bifacial DSSC with 4-ATP/PANI CE achieves a light-to-electric energy conversion efficiency of 8.35%, which is increased by ~24.6% compared to the DSSC irradiated from the front only. This new concept along with promising results provides a new approach for enhancing the photovoltaic performances of solar cells.

  8. Bifacial dye-sensitized solar cells: a strategy to enhance overall efficiency based on transparent polyaniline electrode.

    PubMed

    Wu, Jihuai; Li, Yan; Tang, Qunwei; Yue, Gentian; Lin, Jianming; Huang, Miaoliang; Meng, Lijian

    2014-01-01

    Dye-sensitized solar cell (DSSC) is a promising solution to global energy and environmental problems because of its clean, low-cost, high efficiency, good durability, and easy fabrication. However, enhancing the efficiency of the DSSC still is an important issue. Here we devise a bifacial DSSC based on a transparent polyaniline (PANI) counter electrode (CE). Owing to the sunlight irradiation simultaneously from the front and the rear sides, more dye molecules are excited and more carriers are generated, which results in the enhancement of short-circuit current density and therefore overall conversion efficiency. The photoelectric properties of PANI can be improved by modifying with 4-aminothiophenol (4-ATP). The bifacial DSSC with 4-ATP/PANI CE achieves a light-to-electric energy conversion efficiency of 8.35%, which is increased by ~24.6% compared to the DSSC irradiated from the front only. This new concept along with promising results provides a new approach for enhancing the photovoltaic performances of solar cells. PMID:24504117

  9. Bifacial dye-sensitized solar cells: A strategy to enhance overall efficiency based on transparent polyaniline electrode

    PubMed Central

    Wu, Jihuai; Li, Yan; Tang, Qunwei; Yue, Gentian; Lin, Jianming; Huang, Miaoliang; Meng, Lijian

    2014-01-01

    Dye-sensitized solar cell (DSSC) is a promising solution to global energy and environmental problems because of its clean, low-cost, high efficiency, good durability, and easy fabrication. However, enhancing the efficiency of the DSSC still is an important issue. Here we devise a bifacial DSSC based on a transparent polyaniline (PANI) counter electrode (CE). Owing to the sunlight irradiation simultaneously from the front and the rear sides, more dye molecules are excited and more carriers are generated, which results in the enhancement of short-circuit current density and therefore overall conversion efficiency. The photoelectric properties of PANI can be improved by modifying with 4-aminothiophenol (4-ATP). The bifacial DSSC with 4-ATP/PANI CE achieves a light-to-electric energy conversion efficiency of 8.35%, which is increased by ~24.6% compared to the DSSC irradiated from the front only. This new concept along with promising results provides a new approach for enhancing the photovoltaic performances of solar cells. PMID:24504117

  10. Ultrathin Nanotube/Nanowire Electrodes by Spin-Spray Layer-by-Layer Assembly: A Concept for Transparent Energy Storage.

    PubMed

    Gittleson, Forrest S; Hwang, Daniel; Ryu, Won-Hee; Hashmi, Sara M; Hwang, Jonathan; Goh, Tenghooi; Taylor, André D

    2015-10-27

    Fully integrated transparent devices require versatile architectures for energy storage, yet typical battery electrodes are thick (20-100 ?m) and composed of optically absorbent materials. Reducing the length scale of active materials, assembling them with a controllable method and minimizing electrode thickness should bring transparent batteries closer to reality. In this work, the rapid and controllable spin-spray layer-by-layer (SSLbL) method is used to generate high quality networks of 1D nanomaterials: single-walled carbon nanotubes (SWNT) and vanadium pentoxide (V2O5) nanowires for anode and cathode electrodes, respectively. These ultrathin films, deposited with ?2 nm/bilayer precision are transparent when deposited on a transparent substrate (>87% transmittance) and electrochemically active in Li-ion cells. SSLbL-assembled ultrathin SWNT anodes and V2O5 cathodes exhibit reversible lithiation capacities of 23 and 7 ?Ah/cm(2), respectively at a current density of 5 ?A/cm(2). When these electrodes are combined in a full cell, they retain ?5 ?Ah/cm(2) capacity over 100 cycles, equivalent to the prelithiation capacity of the limiting V2O5 cathode. The SSLbL technique employed here to generate functional thin films is uniquely suited to the generation of transparent electrodes and offers a compelling path to realize the potential of fully integrated transparent devices. PMID:26344174

  11. Recent advances in alternative counter electrode materials for Co-mediated dye-sensitized solar cells.

    PubMed

    Yun, Sining; Liu, Yanfang; Zhang, Taihong; Ahmad, Shahzada

    2015-07-28

    Recently, considerable attention has been paid to dye-sensitized solar cells (DSSCs) which are based on Co(2+)/Co(3+) redox shuttles, because of their unparalleled merits including higher redox potential, reduced corrosiveness towards metallic conductors, low costs and high power conversion efficiencies (PCE) (13%). The counter electrode (CE) is an essential component in DSSCs, and plays a crucial role in catalyzing Co(3+) ion reduction in Co-based DSSCs. In this mini-review, we review recent developments in CE materials for Co-mediated DSSCs including: noble metal platinum (Pt), carbon materials, transition metal compounds (TMCs), polymers, and their corresponding hybrids, highlighting important contributions worldwide that promise low cost, efficient, and robust Co-mediated DSSC systems. Additionally, the crucial challenges associated with employing these low-cost CE catalysts for Co-based redox couples in DSSCs are stressed. PMID:26132719

  12. Multistep electrochemical deposition of hierarchical platinum alloy counter electrodes for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Zhang, Junjun; Ma, Mingming; Tang, Qunwei; Yu, Liangmin

    2016-01-01

    The preferred platinum counter electrode (CE) has been a burden for commercialization of dye-sensitized solar cell (DSSC) due to high expense and chemical corrosion by liquid electrolyte. In the current study, we have successfully realized the multistep deposition of platinum alloy CEs including PtNi, PtFe, and PtCo for liquid-junction DSSC applications. The preliminary results demonstrate that the enhanced electrochemical activities are attributable to high charge-transfer ability and matching work functions of the PtM (M = Ni, Fe, Co) alloy CEs to redox potential of I-/I3- electrolyte. The resultant DSSCs yield impressive power conversion efficiencies of 8.65%, 7.48%, and 7.08% with PtNi, PtFe, and PtCo CEs, respectively. On behalf of the competitive reactions between transition metals with liquid electrolyte, the PtM alloy CEs display enhanced long-term stability.

  13. A flexible polypyrrole-coated fabric counter electrode for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Xu, Jie; Li, Meixia; Wu, Lei; Sun, Yongyuan; Zhu, Ligen; Gu, Shaojin; Liu, Li; Bai, Zikui; Fang, Dong; Xu, Weilin

    2014-07-01

    The current dye-sensitized solar cell (DSSC) technology is mostly based on fluorine doped tin oxide (FTO) coated glass substrate. The main problem with the FTO glass substrate is its rigidity, heavyweight and high cost. DSSCs with a fabric as substrate not only offer the advantages of flexibility, stretchability and light mass, but also provide the opportunities for easy implantation to wearable electronics. Herein, a novel fabric counter electrode (CE) for DSSCs has been reported employing a daily-used cotton fabric as substrate and polypyrrole (PPy) as catalytic material. Nickel (Ni) is deposited on the cotton fabric as metal contact by a simple electroless plating method to replace the expensive FTO. PPy is synthesized by in situ polymerization of pyrrole monomer on the Ni-coated fabric. The fabric CE shows sufficient catalytic activity towards the reduction of I3-. The DSSC fabricated using the fabric CE exhibits power conversion efficiency of ?3.30% under AM 1.5.

  14. Recent advances in alternative counter electrode materials for Co-mediated dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Yun, Sining; Liu, Yanfang; Zhang, Taihong; Ahmad, Shahzada

    2015-07-01

    Recently, considerable attention has been paid to dye-sensitized solar cells (DSSCs) which are based on Co2+/Co3+ redox shuttles, because of their unparalleled merits including higher redox potential, reduced corrosiveness towards metallic conductors, low costs and high power conversion efficiencies (PCE) (13%). The counter electrode (CE) is an essential component in DSSCs, and plays a crucial role in catalyzing Co3+ ion reduction in Co-based DSSCs. In this mini-review, we review recent developments in CE materials for Co-mediated DSSCs including: noble metal platinum (Pt), carbon materials, transition metal compounds (TMCs), polymers, and their corresponding hybrids, highlighting important contributions worldwide that promise low cost, efficient, and robust Co-mediated DSSC systems. Additionally, the crucial challenges associated with employing these low-cost CE catalysts for Co-based redox couples in DSSCs are stressed.

  15. Rapid atmospheric pressure plasma jet processed reduced graphene oxide counter electrodes for dye-sensitized solar cells.

    PubMed

    Liu, Hsiao-Wei; Liang, Sheng-Ping; Wu, Ting-Jui; Chang, Haoming; Kao, Peng-Kai; Hsu, Cheng-Che; Chen, Jian-Zhang; Chou, Pi-Tai; Cheng, I-Chun

    2014-09-10

    In this work, we present the use of reduced graphene oxide (rGO) as the counter electrode materials in dye-sensitized solar cells (DSSCs). rGO was first deposited on a fluorine-doped tin oxide glass substrate by screen-printing, followed by post-treatment to remove excessive organic additives. We investigated the effect of atmospheric pressure plasma jet (APPJ) treatment on the DSSC performance. A power conversion efficiency of 5.19% was reached when DSSCs with an rGO counter electrode were treated by APPJs in the ambient air for a few seconds. For comparison, it requires a conventional calcination process at 400 °C for 15 min to obtain comparable efficiency. Scanning electron micrographs show that the APPJ treatment modifies the rGO structure, which may reduce its conductivity in part but simultaneously greatly enhances its catalytic activity. Combined with the rapid removal of organic additives by the highly reactive APPJ, DSSCs with APPJ-treated rGO counter electrode show comparable efficiencies to furnace-calcined rGO counter electrodes with greatly reduced process time. This ultrashort process time renders an estimated energy consumption per unit area of 1.1 kJ/cm(2), which is only one-third of that consumed in a conventional furnace calcination process. This new methodology thus saves energy, cost, and time, which is greatly beneficial to future mass production. PMID:25127290

  16. Patternable PEDOT nanofilms with grid electrodes for transparent electrochromic devices targeting thermal camouflage

    NASA Astrophysics Data System (ADS)

    Kim, Bumsoo; Koh, Jong Kwan; Park, Junyong; Ahn, Changui; Ahn, Joonmo; Kim, Jong Hak; Jeon, Seokwoo

    2015-10-01

    This paper reports a new type of transmitting mode electrochromic device that uses the high-contrast electrochromism of poly(3,4-ethylenedioxythiophene) (PEDOT) and operates at long-wavelength infrared (8-12 ?m) . To maximize the transmittance contrast and transmittance contrast ratio of the device for thermal camouflage, we control the thickness of the thin PEDOT layer from 25 nm to 400 nm and develop a design of grid-type counter electrodes. The cyclability can be greatly improved by selective deposition of the PEDOT film on grid electrodes as an ion storage layer without any loss of overall transmittance. The device with optimized architectures shows a high transmittance contrast ratio of 83 % at a wavelength of 10 ?m with a response rate under 1.4 s when alternating voltage is applied. Captured images of an LED lamp behind the device prove the possibility of active, film-type camouflage against thermal detection.

  17. A novel hierarchical Pt- and FTO-free counter electrode for dye-sensitized solar cell

    PubMed Central

    2014-01-01

    A novel hierarchical Pt- and FTO-free counter electrode (CE) for the dye-sensitized solar cell (DSSC) was prepared by spin coating the mixture of TiO2 nanoparticles and poly(3,4-ethylenedioxy-thiophene):poly(styrenesulfonate) (PEDOT:PSS) solution onto the glass substrate. Compared with traditional Pt/FTO CE, the cost of the new CE is dramatically reduced by the application of bilayer TiO2-PEDOT:PSS/PEDOT:PSS film and the glass substrate. The sheet resistance of this composite film is 35 ? sq?1 and is low enough to be used as an electrode. The surface morphologies of TiO2-PEDOT:PSS layer and modified PEDOT:PSS layer were characterized by scanning electron microscope, which shows that the former had larger surface areas than the latter. Electrochemical impedance spectra and Tafel polarization curves prove that the catalytic activity of TiO2-PEDOT:PSS/PEDOT:PSS/glass CE is higher than that of PEDOT:PSS/FTO CE and is similar to Pt/FTO CE's. This new fabricated device with TiO2-PEDOT:PSS/PEDOT:PSS/glass CE achieves a high power conversion efficiency (PCE) of 4.67%, reaching 91.39% of DSSC with Pt/FTO CE (5.11%). PMID:24808802

  18. High efficiency organic-electrolyte DSSC based on hydrothermally deposited titanium carbide-carbon counter electrodes

    NASA Astrophysics Data System (ADS)

    Towannang, Madsakorn; Kumlangwan, Pantiwa; Maiaugree, Wasan; Ratchaphonsaenwong, Kunthaya; Harnchana, Viyada; Jarenboon, Wirat; Pimanpang, Samuk; Amornkitbamrung, Vittaya

    2015-07-01

    Pt-free TiC based electrodes were hydrothermally deposited onto FTO/glass substrates and used as dye-sensitized solar cell (DSSC) counter electrodes. A promising efficiency of 3.07% was obtained from the annealed hydrothermal TiC DSSCs based on a disulfide/thiolate electrolyte. A pronounced improvement in performance of 3.59% was achieved by compositing TiC with carbon, compared to that of a Pt DSSC, 3.84%. TEM analysis detected that the TiC particle surfaces were coated by thin carbon layer (7 nm). The SAED pattern and Raman spectrum of TiC-carbon films suggested that the carbon layer was composed of amorphous and graphite carbon. The formation of graphite on the TiC nanoparticles plays a crucial role in enhancing the film's reduction current to 10.12 mA/cm2 and in reducing the film impedance to 237.63 ?, resulting in a high efficiency of the TiC-carbon DSSC. [Figure not available: see fulltext.

  19. Pt-free counter electrode for dye-sensitized solar cells with high efficiency.

    PubMed

    Yun, Sining; Hagfeldt, Anders; Ma, Tingli

    2014-09-01

    Dye-sensitized solar cells (DSSCs) have attracted widespread attention in recent years as potential cost-effective alternatives to silicon-based and thin-film solar cells. Within typical DSSCs, the counter electrode (CE) is vital to collect electrons from the external circuit and catalyze the I3- reduction in the electrolyte. Careful design of the CEs can improve the catalytic activity and chemical stability associated with the liquid redox electrolyte used in most cells. In this Progress Report, advances made by our groups in the development of CEs for DSSCs are reviewed, highlighting important contributions that promise low-cost, efficient, and robust DSSC systems. Specifically, we focus on the design of novel Pt-free CE catalytic materials, including design ideas, fabrication approaches, characterization techniques, first-principle density functional theory (DFT) calculations, ab-initio Car-Parrinello molecular dynamics (CPMD) simulations, and stability evaluations, that serve as practical alternatives to conventional noble metal Pt electrodes. We stress the merits and demerits of well-designed Pt-free CEs, such as carbon materials, conductive polymers, transition metal compounds (TMCs) and their corresponding hybrids. Also, the prospects and challenges of alternative Pt catalysts for their applications in new-type DSSCs and other catalytic fields are discussed. PMID:25080873

  20. Highly flexible, hybrid-structured indium tin oxides for transparent electrodes on polymer substrates

    NASA Astrophysics Data System (ADS)

    Triambulo, Ross E.; Kim, Jung-Hoon; Na, Min-Young; Chang, Hye-Jung; Park, Jin-Woo

    2013-06-01

    We developed highly flexible, hybrid-structured crystalline indium tin oxide (ITO) for use as transparent electrodes on polymer substrates by embedding Ag nanoparticles (AgNPs) into the substrate. The hybrid ITO consists of domains in one orientation grown on the AgNPs and a matrix of the other orientation. The domains are stronger than the matrix and function as barriers to crack propagation. As a result, both the critical bending radius (rc) (under which the resistivity change (??) is less than a given value) and the change in ?? with decreasing r significantly decreased in the hybrid ITO compared with homogenous ITO.

  1. Highly flexible, hybrid-structured indium tin oxides for transparent electrodes on polymer substrates

    SciTech Connect

    Triambulo, Ross E.; Kim, Jung-Hoon; Park, Jin-Woo; Na, Min-Young; Chang, Hye-Jung

    2013-06-17

    We developed highly flexible, hybrid-structured crystalline indium tin oxide (ITO) for use as transparent electrodes on polymer substrates by embedding Ag nanoparticles (AgNPs) into the substrate. The hybrid ITO consists of domains in one orientation grown on the AgNPs and a matrix of the other orientation. The domains are stronger than the matrix and function as barriers to crack propagation. As a result, both the critical bending radius (r{sub c}) (under which the resistivity change ({Delta}{rho}) is less than a given value) and the change in {Delta}{rho} with decreasing r significantly decreased in the hybrid ITO compared with homogenous ITO.

  2. A study of TiO2/carbon black composition as counter electrode materials for dye-sensitized solar cells

    PubMed Central

    2013-01-01

    This study describes a systematic approach of TiO2/carbon black nanoparticles with respect to the loading amount in order to optimize the catalytic ability of triiodide reduction for dye-sensitized solar cells. In particular, the cell using an optimized TiO2 and carbon black electrode presents an energy conversion efficiency of 7.4% with a 5:1 ratio of a 40-nm TiO2 to carbon black. Based on the electrochemical analysis, the charge-transfer resistance of the carbon counter electrode changed based on the carbon black powder content. Electrochemical impedance spectroscopy and cyclic voltammetry study show lower resistance compared to the Pt counter electrode. The obtained nanostructures and photo electrochemical study were characterized. PMID:23672498

  3. Floating compression of Ag nanowire networks for effective strain release of stretchable transparent electrodes

    NASA Astrophysics Data System (ADS)

    Pyo, Jun Beom; Kim, Byoung Soo; Park, Hyunchul; Kim, Tae Ann; Koo, Chong Min; Lee, Jonghwi; Son, Jeong Gon; Lee, Sang-Soo; Park, Jong Hyuk

    2015-10-01

    Manipulation of the configuration of Ag nanowire (NW) networks has been pursued to enhance the performance of stretchable transparent electrodes. However, it has remained challenging due to the high Young's modulus and low yield strain of Ag NWs, which lead to their mechanical failure when subjected to structural deformation. We demonstrate that floating a Ag NW network on water and subsequent in-plane compression allows convenient development of a wavy configuration in the Ag NW network, which can release the applied strain. A greatly enhanced electromechanical stability of Ag NW networks can be achieved due to their wavy configuration, while the NW networks maintain the desirable optical and electrical properties. Moreover, the produced NW networks can be transferred to a variety of substrates, offering flexibility for device fabrication. The Ag NW networks with wavy configurations are used as compliant electrodes for dielectric elastomer actuators. The study demonstrates their promising potential to provide improved performance for soft electronic devices.Manipulation of the configuration of Ag nanowire (NW) networks has been pursued to enhance the performance of stretchable transparent electrodes. However, it has remained challenging due to the high Young's modulus and low yield strain of Ag NWs, which lead to their mechanical failure when subjected to structural deformation. We demonstrate that floating a Ag NW network on water and subsequent in-plane compression allows convenient development of a wavy configuration in the Ag NW network, which can release the applied strain. A greatly enhanced electromechanical stability of Ag NW networks can be achieved due to their wavy configuration, while the NW networks maintain the desirable optical and electrical properties. Moreover, the produced NW networks can be transferred to a variety of substrates, offering flexibility for device fabrication. The Ag NW networks with wavy configurations are used as compliant electrodes for dielectric elastomer actuators. The study demonstrates their promising potential to provide improved performance for soft electronic devices. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03814f

  4. Large-scale graphene-based composite films for flexible transparent electrodes fabricated by electrospray deposition

    NASA Astrophysics Data System (ADS)

    Kim, Woo Sik; Moon, Sook Young; Kim, Hui Jin; Park, Sungjin; Koyanagi, Jun; Huh, Hoon

    2014-12-01

    Large-scale transparent conducting electrodes were fabricated using the electrospray method on a glass wafer and polyethylene terephthalate film using chemically reduced graphene oxide and poly (3,4-ethylenedioxythiophene) (PEDOT). Graphene oxide (GO) is prepared by the modified Hummers method, and reduced GO (RG) is prepared at low temperature. By varying the concentration of RG and PEDOT of the composite material on the substrate, the electrical conductivity and transmittance of the electrode was controlled. The optical transmittance values of the graphene-based electrode at a wavelength of 550 nm were between 81 and 95% and had sheet resistances from 370 to 5400 ? sq-1. After 1000 cycles of a bending test, the sheet resistances of the graphene-based composite films were unchanged. Different types of graphene and graphene-based electrodes were characterized by field-emission scanning electron microscopy, high-resolution transmission electron microscopy, high-resolution Raman spectroscopy, x-ray photoelectron spectroscopy, x-ray diffraction, transmittance, and electrical conductivity measurements.

  5. Highly efficient and bendable organic solar cells using a three-dimensional transparent conducting electrode

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Bae, Tae-Sung; Park, Yeon Hyun; Kim, Dong Ho; Lee, Sunghun; Min, Guanghui; Lee, Gun-Hwan; Song, Myungkwan; Yun, Jungheum

    2014-05-01

    A three-dimensional (3D) transparent conducting electrode, consisting of a quasi-periodic array of discrete indium-tin-oxide (ITO) nanoparticles superimposed on a highly conducting oxide-metal-oxide multilayer using ITO and silver oxide (AgOx) as oxide and metal layers, respectively, is synthesized on a polymer substrate and used as an anode in highly flexible organic solar cells (OSCs). The 3D electrode is fabricated using vacuum sputtering sequences to achieve self-assembly of distinct ITO nanoparticles on a continuous ITO-AgOx-ITO multilayer at room-temperature without applying conventional high-temperature vapour-liquid-solid growth, solution-based nanoparticle coating, or complicated nanopatterning techniques. Since the 3D electrode enhances the hole-extraction rate in OSCs owing to its high surface area and low effective series resistance for hole transport, OSCs based on this 3D electrode exhibit a power conversion efficiency that is 11-22% higher than that achievable in OSCs by means of conventional planar ITO film-type electrodes. A record high efficiency of 6.74% can be achieved in a bendable OSC fabricated on a poly(ethylene terephthalate) substrate.A three-dimensional (3D) transparent conducting electrode, consisting of a quasi-periodic array of discrete indium-tin-oxide (ITO) nanoparticles superimposed on a highly conducting oxide-metal-oxide multilayer using ITO and silver oxide (AgOx) as oxide and metal layers, respectively, is synthesized on a polymer substrate and used as an anode in highly flexible organic solar cells (OSCs). The 3D electrode is fabricated using vacuum sputtering sequences to achieve self-assembly of distinct ITO nanoparticles on a continuous ITO-AgOx-ITO multilayer at room-temperature without applying conventional high-temperature vapour-liquid-solid growth, solution-based nanoparticle coating, or complicated nanopatterning techniques. Since the 3D electrode enhances the hole-extraction rate in OSCs owing to its high surface area and low effective series resistance for hole transport, OSCs based on this 3D electrode exhibit a power conversion efficiency that is 11-22% higher than that achievable in OSCs by means of conventional planar ITO film-type electrodes. A record high efficiency of 6.74% can be achieved in a bendable OSC fabricated on a poly(ethylene terephthalate) substrate. Electronic supplementary information (ESI) available: FE-SEM images of Ar plasma-treated PET surfaces, curve deconvolution of XPS Ag 3d5/2 spectra, refractive indices and extinction coefficients of the Ag and AgOx (O/Ag = 10 at%), changes in the specular reflections of the IAOI-NPA and IAI-NPA electrodes for different O/Ag atomic ratios and thicknesses of the AgOx layer, and comparisons between the Jsc values determined from simulated AM 1.5G illumination and IPCE spectra. See DOI: 10.1039/c3nr06755f

  6. Optimization of silver nanowire-based transparent electrodes: effects of density, size and thermal annealing.

    PubMed

    Lagrange, M; Langley, D P; Giusti, G; Jiménez, C; Bréchet, Y; Bellet, D

    2015-10-15

    Silver nanowire (AgNW) networks are efficient as flexible transparent electrodes, and are cheaper to fabricate than ITO (Indium Tin Oxide). Hence they are a serious competitor as an alternative to ITO in many applications such as solar cells, OLEDs, transparent heaters. Electrical and optical properties of AgNW networks deposited on glass are investigated in this study and an efficient method to optimize them is proposed. This paper relates network density, nanowire dimensions and thermal annealing directly to the physical properties of the nanowire networksusing original physical models. A fair agreement is found between experimental data and the proposed models. Moreover thermal stability of the nanowires is a key issue in thermal optimization of such networks and needs to be studied. In this work the impact of these four parameters on the networks physical properties are thoroughly investigated via in situ measurements and modelling, such a method being also applicable to other metallic nanowire networks. We demonstrate that this approach enables the optimization of both optical and electrical properties through modification of the junction resistance by thermal annealing, and a suitable choice of nanowire dimensions and network density. This work reports excellent optical and electrical properties of electrodes fabricated from AgNW networks with a transmittance T = 89.2% (at 550 nm) and a sheet resistance of Rs = 2.9 ? ?(-1), leading to the highest reported figure of merit. PMID:26437607

  7. Optimization of silver nanowire-based transparent electrodes: effects of density, size and thermal annealing

    NASA Astrophysics Data System (ADS)

    Lagrange, M.; Langley, D. P.; Giusti, G.; Jiménez, C.; Bréchet, Y.; Bellet, D.

    2015-10-01

    Silver nanowire (AgNW) networks are efficient as flexible transparent electrodes, and are cheaper to fabricate than ITO (Indium Tin Oxide). Hence they are a serious competitor as an alternative to ITO in many applications such as solar cells, OLEDs, transparent heaters. Electrical and optical properties of AgNW networks deposited on glass are investigated in this study and an efficient method to optimize them is proposed. This paper relates network density, nanowire dimensions and thermal annealing directly to the physical properties of the nanowire networksusing original physical models. A fair agreement is found between experimental data and the proposed models. Moreover thermal stability of the nanowires is a key issue in thermal optimization of such networks and needs to be studied. In this work the impact of these four parameters on the networks physical properties are thoroughly investigated via in situ measurements and modelling, such a method being also applicable to other metallic nanowire networks. We demonstrate that this approach enables the optimization of both optical and electrical properties through modification of the junction resistance by thermal annealing, and a suitable choice of nanowire dimensions and network density. This work reports excellent optical and electrical properties of electrodes fabricated from AgNW networks with a transmittance T = 89.2% (at 550 nm) and a sheet resistance of Rs = 2.9 ? ?-1, leading to the highest reported figure of merit.

  8. Fabrication of highly efficient transparent metal thin film electrodes using Direct Laser Interference Patterning

    NASA Astrophysics Data System (ADS)

    Eckhardt, S.; Müller-Meskamp, L.; Loeser, M.; Siebold, M.; Lasagni, A. F.

    2015-03-01

    The demand of highly efficient transparent electrodes without the use of rare earth materials such as indium requires a new generation of thin metallic films with both high transparency and electrical conductivity. For this purpose, Direct Laser interference Patterning was used to fabricate periodic hole-like surface patterns on thin metallic films in order to improve their optical transparency by selective laser ablation of the material and at the same time keeping the electrical properties at an acceptable level. Metallic films consisting of aluminum and copper with film thicknesses ranging between 5 and 40 nm were deposited on glass substrates and treated with nanosecond and picosecond pulse laser system. In order to analyze the processability of the films, the laser ablation threshold for each material as function of the layer thickness and pulse duration was firstly determined. After analyzing these initial experiments, the samples were structured with a 1.7 ?m spatial period hole-like-pattern using three beam direct laser interference patterning. The structural quality of the fabricated structures was analyzed as function laser energy density (laser fluence) using scanning electron microscopy (SEM), atom force microscopy (AFM). Finally, optical and electrical properties of the films were characterized using optical spectroscopy, as well as surface impedance measurements.

  9. Multilayer Transparent Top Electrode for Solution Processed Perovskite/Cu(In,Ga)(Se,S)2 Four Terminal Tandem Solar Cells.

    PubMed

    Yang, Yang Michael; Chen, Qi; Hsieh, Yao-Tsung; Song, Tze-Bin; Marco, Nicholas De; Zhou, Huanping; Yang, Yang

    2015-07-28

    Halide perovskites (PVSK) have attracted much attention in recent years due to their high potential as a next generation solar cell material. To further improve perovskites progress toward a state-of-the-art technology, it is desirable to create a tandem structure in which perovskite may be stacked with a current prevailing solar cell such as silicon (Si) or Cu(In,Ga)(Se,S)2 (CIGS). The transparent top electrode is one of the key components as well as challenges to realize such tandem structure. Herein, we develop a multilayer transparent top electrode for perovskite photovoltaic devices delivering an 11.5% efficiency in top illumination mode. The transparent electrode is based on a dielectric/metal/dielectric structure, featuring an ultrathin gold seeded silver layer. A four terminal tandem solar cell employing solution processed CIGS and perovskite cells is also demonstrated with over 15% efficiency. PMID:26098134

  10. Highly efficient dye-sensitized solar cell with GNS/MWCNT/PANI as a counter electrode

    SciTech Connect

    Al-bahrani, Majid Raissan; Xu, Xiaobao; Ahmad, Waqar; Ren, Xiaoliang; Su, Jun; Cheng, Ze; Gao, Yihua

    2014-11-15

    Highlights: • High-performance PANI/MWCNT-CE was incorporated in a Pt-CE in DSSCs. • GNS/MWCNT/PANI-CE exhibits a high power conversion efficiency (PCE) of 7.52%. • GNS/MWCNT/PANI composite has a high catalytic activity for the reduction of I{sub 3}{sup ?}. • GNS/MWCNT/PANI composite has a low R{sub CT} on the electrolyte/CE interface. - Abstract: A graphene-based nanosheet composite/multiwalled carbon nanotube/polyaniline (GNS/MWCNT/PANI) was synthesized via an in situ polymerization technique and applied by the spin-coating method as a counter electrode (CE) in dye-sensitized solar cells (DSSCs). The combination of the high catalytic activity of PANI and outstanding conductivity of GNS/MWCNT improved the photovoltaic performance of the hybrid CE. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) showed that the GNS/MWCNT/PANI composite has high catalytic activity for the reduction of triiodide to iodide and low charge-transfer resistance at the electrolyte/electrode interface. Transmission electron microscopy (TEM) images showed that the GNS/MWCNT/PANI-CE has a rough and porous structure and X-ray diffraction analysis confirmed the formation of PANI coating on the surface of the GNS/CNT. In particular, current–voltage measurements showed the superior power conversion efficiency (PCE) of 7.52% of the DSSC based on GNS/MWCNT/PANI-CE compared to the PCE of 6.69% of the DSSC based on Pt-CE.

  11. Transparent Electrodes for High E-Field Production Using A Buried ITO Layer

    E-print Network

    Gunton, Will; Semczuk, Mariusz; Madison, Kirk W

    2015-01-01

    We present a design and characterization of optically transparent electrodes suitable for atomic and molecular physics experiments where high optical access is required. The electrodes can be operated in air at standard atmospheric pressure and do not suffer electrical breakdown even for electric fields far exceeding the dielectric breakdown of air. This is achieved by putting an ITO coated dielectric substrate inside a stack of dielectric substrates, which prevents ion avalanche resulting from Townsend discharge. With this design, we observe no arcing for fields of up to 120 kV/cm. Using these plates, we directly verify the production of electric fields up to 18~kV/cm inside a quartz vacuum cell by a spectroscopic measurement of the dc Stark shift of the $5^2S_{1/2} \\rightarrow 5^2P_{3/2}$ transition for a cloud of laser cooled Rubidium atoms. We also report on the shielding of the electric field and residual electric fields that persist within the vacuum cell once the electrodes are discharged. In addition,...

  12. Highly Reliable Silver Nanowire Transparent Electrode Employing Selectively Patterned Barrier Shaped by Self-Masked Photolithography.

    PubMed

    Wang, Jun; Jiu, Jinting; Sugahara, Tohru; Nagao, Shijo; Nogi, Masaya; Koga, Hirotaka; He, Peng; Suganuma, Katsuaki; Uchida, Hiroshi

    2015-10-21

    The transparent electrode based on silver nanowire (AgNW) networks is one promising alternative of indium tin oxide film in particular for advanced flexible and printable electronics. However, the widespread application of AgNW electrode is hindered by its poor long-term reliability. Although the reliability can be improved by applying traditional overcoating layer or the core-shell structure, the transmittance or conductivity is inevitably undermined. In this paper, a novel patterned barrier of photoresist in situ assembled on the nanowire surface realized the reliability enhancement by simply employing AgNWs themselves as the mask in the photolithography process. The patterned barrier selectively covered the nanowires, while keeping the high transmittance and conductivity unchanged and improving the adhesion of AgNW networks on substrate. After 720 h storage in 85 °C/85% relative humidity (RH) environment, the resistance of electrode with patterned barrier only increased by 0.72 times. This study proposes a new way, i.e., the in situ patterned barrier containing light-sensitive substance, to selectively protect AgNW networks, which can be expanded to various metallic networks including nanowires, nanorods, nanocables, electrospun nanofibers, and so on. PMID:26419188

  13. Light energy conversion with pheophytin a monolayer at the SnO[sub 2] optically transparent electrode

    SciTech Connect

    Volkov, A.G. ); Markin, V.S. ); Leblanc R.M.; Gugeshashvili, M.I.; Zelent, B.; Munger, G. )

    1994-02-01

    The photoelectrochemical, absorption and fluorescence properties of pheophytin a mono- and multilayers, deposited on optically transparent tin oxide electrodes and quartz slides were investigated. Spectra of photocurrents coincided with the absorption spectra of photosynthetic pigment in monolayers at the SnO[sub 2]/solution interfaces. The anodic and cathodic photocurrents were measured at various electrode potentials. Effects of pH, electrode potentials, and concentration of redox reagents on the conversion of solar energy in monolayers on optically transparent electrodes are discussed. The absorption and fluorescence spectral characteristics, and fluorescence lifetime measurements of pheophytin a in monolayers and thin films are also discussed in view of the aggregation properties of the photosynthetic pigment. The thermodynamics of adsorption of large amphiphilic compounds at the interface between two immiscible liquids is considered. The adsorption behavior of pheophytin a dissolved in different solvents is investigated. The thermodynamic parameters of pheophytin a adsorption at octane/water and benzene/water interfaces were determined.

  14. Efficient Counter Electrode Manufactured from Ag2 S Nanocrystal Ink for Dye-Sensitized Solar Cells.

    PubMed

    He, Qingquan; Huang, Shoushuang; Zai, Jiantao; Tang, Nianqi; Li, Bo; Qiao, Qiquan; Qian, Xuefeng

    2015-10-19

    It is generally believed that silver or silver-based compounds are not suitable counter electrode (CE) materials for dye-sensitized solar cells (DSSCs) due to the corrosion of the I(-) /I3 (-) redox couple in electrolytes. However, Ag2 S has potential applications in DSSCs for catalyzing I3 (-) reduction reactions because of its high carrier concentration and tiny solubility product constant. In the present work, CE manufactured from Ag2 S nanocrystals ink exhibited efficient electrocatalytic activity in the reduction of I3 (-) to I(-) in DSSCs. The DSSC consisting of Ag2 S CE displayed a higher power conversion efficiency of 8.40?% than that of Pt CE (8.11?%). Moreover, the devices also showed the characteristics of fast activity onset, high multiple start/stop capability and good irradiated stability. The simple composition, easy preparation, stable chemical property, and good catalytic performance make the developed Ag2 S CE as a promising alternative to Pt CE in DSSCs. PMID:26338374

  15. Characterization of indium oxide for the use as a counter-electrode in an electrochromic device

    SciTech Connect

    Yu, P.C.; Haas, T.E. . Dept. of Chemistry); Goldner, R.B. . Electro-Optics Technology Center); Cogan, S.F. )

    1991-01-01

    Thin films of indium oxide, In{sub 2}O{sub 3} (4000 {Angstrom}), deposited on commercially available In{sub 2}O{sub 3}: Sn (ITO)/glass by rf sputtering, have been examined for potential application as a counter-electrode material in an electrochromic device, based on their chemical, structural, and optical properties. Cyclic voltammetry experiments showed that mobile lithium ions can be inserted (chemical reduction) and removed (chemical oxidation) from the host structure of indium oxide. Coulometric titrations showed that the films exhibited a hysteresis behavior for the injection and removal of lithium ions in Li{sub x}In{sub 2}O{sub 3} (x=0-0.23). Structural investigations of the indium oxide films, utilizing electron diffraction techniques, indicated that they were crystalline with a crystallite size of 175 {Angstrom}, in agreement with x-ray diffraction results. Differences in optical transmission between the lithiated and delithiated thin films were no more than 5% in the visible/near-infrared regions of the spectrum. 6 refs., 5 figs., 1 tab.

  16. Nano-branched transparent conducting oxides: beyond the brittleness limit for flexible electrode applications

    NASA Astrophysics Data System (ADS)

    Yu, Hak Ki; Kim, Sungjun; Koo, Bonhyeong; Jung, Gwan Ho; Lee, Bola; Ham, Juyoung; Lee, Jong-Lam

    2012-10-01

    Although the performance of transparent conducting oxides based on bixbyite In2O3 (Sn doped In2O3: ITO) and wurtzite ZnO (Al, In, and Ga doped ZnO) is sufficient in conventional optoelectronic devices, their flexibility remains insufficient for demands in mobile and foldable electronics generation. A lot of alternative materials such as metallic nanowires and carbon based nano-structures have been tried for transparent flexible electrodes, but poor thermal stability of metal nanowires and limits in conductivity of carbon based nano-structures are still waiting for permanent solutions. Here, we show that the cross-linked ITO nano-branches have superior mechanical flexibility compared to ITO bulk film without any cracks even with a bending radius of 0.1 cm. Moreover, for equivalent sheet resistivity, the ITO nano-branches exhibit optical transmittance comparable to that of commercial metallic nanowires (such as Ag and Cu in the visible spectrum) but show far superior thermal stability in conductivity without any degradation even at a temperature of 200 °C and a humidity of 90%.Although the performance of transparent conducting oxides based on bixbyite In2O3 (Sn doped In2O3: ITO) and wurtzite ZnO (Al, In, and Ga doped ZnO) is sufficient in conventional optoelectronic devices, their flexibility remains insufficient for demands in mobile and foldable electronics generation. A lot of alternative materials such as metallic nanowires and carbon based nano-structures have been tried for transparent flexible electrodes, but poor thermal stability of metal nanowires and limits in conductivity of carbon based nano-structures are still waiting for permanent solutions. Here, we show that the cross-linked ITO nano-branches have superior mechanical flexibility compared to ITO bulk film without any cracks even with a bending radius of 0.1 cm. Moreover, for equivalent sheet resistivity, the ITO nano-branches exhibit optical transmittance comparable to that of commercial metallic nanowires (such as Ag and Cu in the visible spectrum) but show far superior thermal stability in conductivity without any degradation even at a temperature of 200 °C and a humidity of 90%. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr32228e

  17. A dye sensitized solar cell using natural counter electrode and natural dye derived from mangosteen peel waste

    NASA Astrophysics Data System (ADS)

    Maiaugree, Wasan; Lowpa, Seksan; Towannang, Madsakorn; Rutphonsan, Phikun; Tangtrakarn, Apishok; Pimanpang, Samuk; Maiaugree, Prapen; Ratchapolthavisin, Nattawat; Sang-Aroon, Wichien; Jarernboon, Wirat; Amornkitbamrung, Vittaya

    2015-10-01

    Mangosteen peel is an inedible portion of a fruit. We are interested in using these residues as components of a dye sensitized solar cell (DSSC). Carbonized mangosteen peel was used with mangosteen peel dye as a natural counter electrode and a natural photosensitizer, respectively. A distinctive mesoporous honeycomb-like carbon structure with a rough nanoscale surface was found in carbonized mangosteen peels. The efficiency of a dye sensitized solar cell using carbonized mangosteen peel was compared to that of DSSCs with Pt and PEDOT-PSS counter electrodes. The highest solar conversion efficiency (2.63%) was obtained when using carbonized mangosteen peel and an organic disulfide/thiolate (T2/T-) electrolyte.

  18. NiO-NF/MWCNT nanocomposite catalyst as a counter electrode for high performance dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Raissan Al-bahrani, Majid; Liu, Linfeng; Ahmad, Waqar; Tao, Jiayou; Tu, Fanfan; Cheng, Ze; Gao, Yihua

    2015-03-01

    In this paper, we fabricated nickel oxide nanofilament/multiwall carbon nanotubes (NiO-NF/MWCNT) nanocomposite by a simple hydrothermal synthesis method as a counter- electrode (CE) in a dye-sensitized solar cell (DSSC). Transmission electron microscopy, scanning electron microscopy images and X-ray diffraction analysis clearly indicated the formation of NiO-NF/MWCNT nanocomposite. The electro-chemical properties of NiO-NF/MWCNT CE are studied by cyclic voltammetry and electrochemical impedance spectroscopy. In particular, current-voltage measurements indicated superior power conversion efficiency (PCE) of 7.63% of the NiO-NF/MWCNT CE compared to 6.72% for the platinum (Pt). The superior photovoltaic performance and low cost of the NiO-NF/MWCNT nanocomposite can be potentially exploited as a new counter-electrode in DSSCs.

  19. A dye sensitized solar cell using natural counter electrode and natural dye derived from mangosteen peel waste

    PubMed Central

    Maiaugree, Wasan; Lowpa, Seksan; Towannang, Madsakorn; Rutphonsan, Phikun; Tangtrakarn, Apishok; Pimanpang, Samuk; Maiaugree, Prapen; Ratchapolthavisin, Nattawat; Sang-aroon, Wichien; Jarernboon, Wirat; Amornkitbamrung, Vittaya

    2015-01-01

    Mangosteen peel is an inedible portion of a fruit. We are interested in using these residues as components of a dye sensitized solar cell (DSSC). Carbonized mangosteen peel was used with mangosteen peel dye as a natural counter electrode and a natural photosensitizer, respectively. A distinctive mesoporous honeycomb-like carbon structure with a rough nanoscale surface was found in carbonized mangosteen peels. The efficiency of a dye sensitized solar cell using carbonized mangosteen peel was compared to that of DSSCs with Pt and PEDOT-PSS counter electrodes. The highest solar conversion efficiency (2.63%) was obtained when using carbonized mangosteen peel and an organic disulfide/thiolate (T2/T?) electrolyte. PMID:26458745

  20. A dye sensitized solar cell using natural counter electrode and natural dye derived from mangosteen peel waste.

    PubMed

    Maiaugree, Wasan; Lowpa, Seksan; Towannang, Madsakorn; Rutphonsan, Phikun; Tangtrakarn, Apishok; Pimanpang, Samuk; Maiaugree, Prapen; Ratchapolthavisin, Nattawat; Sang-Aroon, Wichien; Jarernboon, Wirat; Amornkitbamrung, Vittaya

    2015-01-01

    Mangosteen peel is an inedible portion of a fruit. We are interested in using these residues as components of a dye sensitized solar cell (DSSC). Carbonized mangosteen peel was used with mangosteen peel dye as a natural counter electrode and a natural photosensitizer, respectively. A distinctive mesoporous honeycomb-like carbon structure with a rough nanoscale surface was found in carbonized mangosteen peels. The efficiency of a dye sensitized solar cell using carbonized mangosteen peel was compared to that of DSSCs with Pt and PEDOT-PSS counter electrodes. The highest solar conversion efficiency (2.63%) was obtained when using carbonized mangosteen peel and an organic disulfide/thiolate (T2/T(-)) electrolyte. PMID:26458745

  1. Pattern transfer of aligned metal nano/microwires as flexible transparent electrodes using an electrospun nanofiber template

    NASA Astrophysics Data System (ADS)

    Fuh, Yiin-Kuen; Lien, Li-Chih

    2013-02-01

    Due to the scarcity and high cost of indium, the predominant use of indium tin oxide (ITO) films as transparent electrodes has attracted great attention for finding a potential replacement, such as solution-processed networks of carbon nanotubes, graphene, or silver nanowires (NWs). More recently, the use of electrospun copper NWs as high-performance electrodes with a high aspect ratio of 100?000 and 90% transmittance at 50 ?/sq was experimentally achieved. However, the fabrication route of the Cu nanofiber (NF) web includes two high temperature processes (calcined 2 h in air at 500?°C and annealed 1 h in hydrogen at 300?°C). In this paper, we propose a new method to obtain metal nano/microwires to be used as flexible transparent electrodes by using electrospun NF templates and the dry pattern transfer process. Our proposed method is advantageous because we can easily tune the conductivity and transmittance (T) via sputtering time in minutes without the need for time-consuming high temperature thermal steps. Here, we comprehensively show the transferred high performance transparent electrodes with platinum (Pt)-coated NW electrodes with a facile and scalable electrospinning combined sputtering process. Pt-coated NWs have high aspect ratios of up to 5000 and, when sputtered with Pt, reduce junction resistance, which results in high T at low sheet resistance, e.g. 90% at 131 ?/sq. The Pt-coated NW electrodes also show great flexibility and stretchability, which easily surpass the brittleness of ITO films.

  2. Wurtzite copper-zinc-tin sulfide as a superior counter electrode material for dye-sensitized solar cells.

    PubMed

    Kong, Jun; Zhou, Zheng-Ji; Li, Mei; Zhou, Wen-Hui; Yuan, Sheng-Jie; Yao, Rong-Yue; Zhao, Yang; Wu, Si-Xin

    2013-01-01

    Wurtzite and kesterite Cu2ZnSnS4 (CZTS) nanocrystals were employed as counter electrode (CE) materials for dye-sensitized solar cells (DSSCs). Compared to kesterite CZTS, the wurtzite CZTS exhibited higher electrocatalytic activity for catalyzing reduction of iodide electrolyte and better conductivity. Accordingly, the DSSC with wurtzite CZTS CE generated higher power conversion efficiency (6.89%) than that of Pt (6.23%) and kesterite CZTS (4.89%) CEs. PMID:24191954

  3. Dye-sensitized solar cell with energy storage function through PVDF/ZnO nanocomposite counter electrode.

    PubMed

    Zhang, Xi; Huang, Xuezhen; Li, Chensha; Jiang, Hongrui

    2013-08-14

    Dye-sensitized solar cells with an energy storage function are demonstrated by modifying its counter electrode with a poly (vinylidene fluoride)/ZnO nanowire array composite. This simplex device could still function as an ordinary solar cell with a steady photocurrent output even after being fully charged. An energy storage density of 2.14 C g(-1) is achieved, while simultaneously a 3.70% photo-to-electric conversion efficiency is maintained. PMID:23740719

  4. Wurtzite copper-zinc-tin sulfide as a superior counter electrode material for dye-sensitized solar cells

    PubMed Central

    2013-01-01

    Wurtzite and kesterite Cu2ZnSnS4 (CZTS) nanocrystals were employed as counter electrode (CE) materials for dye-sensitized solar cells (DSSCs). Compared to kesterite CZTS, the wurtzite CZTS exhibited higher electrocatalytic activity for catalyzing reduction of iodide electrolyte and better conductivity. Accordingly, the DSSC with wurtzite CZTS CE generated higher power conversion efficiency (6.89%) than that of Pt (6.23%) and kesterite CZTS (4.89%) CEs. PMID:24191954

  5. Full printable processed mesoscopic CH?NH?PbI?/TiO? heterojunction solar cells with carbon counter electrode.

    PubMed

    Ku, Zhiliang; Rong, Yaoguang; Xu, Mi; Liu, Tongfa; Han, Hongwei

    2013-01-01

    A mesoscopic methylammonium lead iodide (CH?NH?PbI?) perovskite/TiO? heterojunction solar cell is developed with low-cost carbon counter electrode (CE) and full printable process. With carbon black/spheroidal graphite CE, this mesoscopic heterojunction solar cell presents high stability and power conversion efficiency of 6.64%, which is higher than that of the flaky graphite based device and comparable to the conventional Au version. PMID:24185501

  6. A simple route to making counter electrode for dye sensitized solar cells (DSSCs) using sucrose as carbon precursor.

    PubMed

    Kumar, Rahul; More, Venumadhav; Mohanty, Shyama Prasad; Nemala, Siva Sankar; Mallick, Sudhanshu; Bhargava, Parag

    2015-12-01

    Dye sensitized solar cells (DSSCs) have attracted much attention in recent years due to low cost fabrication as compared to silicon-based and thin film solar cells. Though, platinum is an excellent catalytic material for use in preparation of counter electrodes (CEs) for DSSCs it is expensive. Alternatives to replacement of platinum (Pt) that have been examined are carbon materials, conductive polymers and hybrids. In this work, counter electrode for DSSCs was fabricated using carbon material obtained from graphitization of sucrose at high temperature. A slurry of the carbon produced from sucrose graphitization was made with polyvinylpyrrolidone (PVP) as a surfactant and a coating was obtained by doctor blading the slurry over the FTO glass substrate. The current density (Jsc) and open circuit voltage (V(OC)) of fabricated cell (area 0.25 cm(2)) was 10.28 mAc m(-2) and 0.76 V respectively. The efficiency of the cell was 4.33% which was just slightly lower than that obtained for similar cells using platinum based counter electrode. PMID:26283098

  7. Solution processed metallic nanowire based transparent electrode capped with a multifunctional layer

    NASA Astrophysics Data System (ADS)

    Ghosh, D. S.; Chen, T. L.; Mkhitaryan, V.; Formica, N.; Pruneri, V.

    2013-06-01

    Solution processed metallic nanowires (NWs) have been attracting increasing attention because of the effective combination of electrical and optical properties. However, they still suffer from several drawbacks, including large surface roughness, instability against oxidation and moisture, and poor adhesion to the substrate. These factors need to be addressed for the wide-spread use of metallic NWs as transparent electrodes. In this work, we demonstrate that by using a solution processed zinc oxide (ZnO) capping layer, NW films show improved electro-optical properties, adhesion, and mechanical flexibility. In addition, the ZnO film reduces the surface roughness by more than half of its initial value, provides protection against oxidation, coalescence at high temperature, damp-heat conditions, and even extreme chemical environments.

  8. Ag@Ni core-shell nanowire network for robust transparent electrodes against oxidation and sulfurization.

    PubMed

    Eom, Hyeonjin; Lee, Jaemin; Pichitpajongkit, Aekachan; Amjadi, Morteza; Jeong, Jun-Ho; Lee, Eungsug; Lee, Jung-Yong; Park, Inkyu

    2014-10-29

    Silver nanowire (Ag NW) based transparent electrodes are inherently unstable to moist and chemically reactive environment. A remarkable stability improvement of the Ag NW network film against oxidizing and sulfurizing environment by local electrodeposition of Ni along Ag NWs is reported. The optical transmittance and electrical resistance of the Ni deposited Ag NW network film can be easily controlled by adjusting the morphology and thickness of the Ni shell layer. The electrical conductivity of the Ag NW network film is increased by the Ni coating via welding between Ag NWs as well as additional conductive area for the electron transport by electrodeposited Ni layer. Moreover, the chemical resistance of Ag NWs against oxidation and sulfurization can be dramatically enhanced by the Ni shell layer electrodeposited along the Ag NWs, which provides the physical barrier against chemical reaction and diffusion as well as the cathodic protection from galvanic corrosion. PMID:24961495

  9. Surface Modification of Silver Nanowires for Morphology and Processing Control in Composite Transparent Electrodes.

    PubMed

    Liang, Zhiming; Graham, Kenneth R

    2015-10-01

    Silver nanowires are attractive components for a number of materials and applications, including silver nanowire (AgNW)-polymer composites, electrically conductive coatings, and transparent electrodes. In this manuscript, the ability of thiols with hydrophobic to ionic end groups to bind to AgNW surfaces is investigated, followed by how the polarity of the surface modifying thiol influences the morphological and electrical properties of both AgNW/PEDOT:PSS blend films and pure AgNW networks. Utilizing surface modification of AgNWs with sodium 3-mercapto-1-propanesulfonate (MPS), morphologically homogeneous AgNW/PEDOT:PSS thin films with an order of magnitude lower sheet resistance at similar transmittance values than unmodified AgNWs are obtained with a one-step processing method. Brief optimization of MPS-AgNW/PEDOT:PSS blends yields a sheet resistance of 22.6 ?/? at 81.4% transmittance. PMID:26389535

  10. Atomic Physics Effects on Convergent, Child-Langmuir Ion Flow between Nearly Transparent Electrodes

    SciTech Connect

    Santarius, John F.; Emmert, Gilbert A.

    2013-11-07

    Research during this project at the University of Wisconsin Fusion Technology Institute (UW FTI) on ion and neutral flow through an arbitrary, monotonic potential difference created by nearly transparent electrodes accomplished the following: (1) developed and implemented an integral equation approach for atomic physics effects in helium plasmas; (2) extended the analysis to coupled integral equations that treat atomic and molecular deuterium ions and neutrals; (3) implemented the key deuterium and helium atomic and molecular cross sections; (4) added negative ion production and related cross sections; and (5) benchmarked the code against experimental results. The analysis and codes treat the species D0, D20, D+, D2+, D3+, D and, separately at present, He0 and He+. Extensions enhanced the analysis and related computer codes to include He++ ions plus planar and cylindrical geometries.

  11. Transparent Conducting Electrodes based on 1D and 2D Ag Nanogratings for Organic Photovoltaics

    E-print Network

    Zeng, Beibei; Bartoli, Filbert J

    2014-01-01

    The optical and electrical properties of optically-thin one-dimensional (1D) Ag nanogratings and two-dimensional (2D) Ag nanogrids are studied, and their use as transparent electrodes in organic photovoltaics are explored. A large broadband and polarization-insensitive optical absorption enhancement in the organic light-harvesting layers is theoretically and numerically demonstrated using either single-layer 2D Ag nanogrids or two perpendicular 1D Ag nanogratings, and is attributed to the excitation of surface plasmon resonances and plasmonic cavity modes. Total photon absorption enhancements of 150% and 200% are achieved for the optimized single-layer 2D Ag nanogrids and double (top and bottom) perpendicular 1D Ag nanogratings, respectively.

  12. Pt-free and efficient counter electrode with nanostructured CoNi2S4 for dye-sensitized solar cells

    PubMed Central

    Shi, Zhiwei; Deng, Kaimo; Li, Liang

    2015-01-01

    The counter electrode has a great influence on the performance of the dye-sensitized solar cells (DSSCs). The research and development of Pt-free counter electrode is becoming one of the hot areas in the field of DSSCs. Herein, we successfully synthesized a ternary metal sulfide (CoNi2S4) nanostructure on FTO substrate by hydrothermal method and investigated its application as counter electrode. The as-synthesized sample could exhibit better electrocatalystic property than that of Pt, and corresponding DSSCs have comparable conversion efficiency with typical Pt catalyzed cells. The easy synthesis, low cost and excellent electrocatalytic property may help the CoNi2S4 nanostructure stand out as an alternative counter electrode in DSSCs. PMID:25799125

  13. Effective indium-doped zinc oxide buffer layer on silver nanowires for electrically highly stable, flexible, transparent, and conductive composite electrodes.

    PubMed

    Lee, Hyun Jun; Hwang, Ju Hyun; Choi, Kyung Bok; Jung, Sun-Gyu; Kim, Kyu Nyun; Shim, Yong Sub; Park, Cheol Hwee; Park, Young Wook; Ju, Byeong-Kwon

    2013-11-13

    We demonstrate a flexible, transparent, and conductive composite electrode comprising silver nanowires (Ag NWs), and indium-doped zinc oxide (IZO) layers. IZO is sputtered onto an Ag NW layer, with the unique structural features of the resulting composite suitable as a flexible, transparent, conductive electrode. The IZO buffer layer prohibits surface oxidation of the Ag NW, and is thereby effective in preventing undesirable changes in electrical properties. The newly designed composite electrode is a promising alternative to conventional ITO films for the production of flexible and transparent electrodes to be applied in next-generation flexible electronic devices. PMID:24088674

  14. Bromination of graphene: a new route to making high performance transparent conducting electrodes with low optical losses (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Mansour, Ahmed E.; Amassian, Aram; Tanielian, Minas H.

    2015-09-01

    The high optical transmittance, electrical conductivity, flexibility and chemical stability of graphene have triggered great interest in its application as a transparent conducting electrode material and as a potential replacement for indium doped tin oxide. However, currently available large scale production methods such as chemical vapor deposition produce polycrystalline graphene, and require additional transfer process which further introduces defects and impurities resulting in a significant increase in its sheet resistance. Doping of graphene with foreign atoms has been a popular route for reducing its sheet resistance which typically comes at a significant loss in optical transmission. Herein, we report the successful bromine doping of graphene resulting in air-stable transparent conducting electrodes with up to 80% reduction of sheet resistance reaching ~180 ?/ at the cost of 2-3% loss of optical transmission in case of few layer graphene and 0.8% in case of single layer graphene. The remarkably low tradeoff in optical transparency leads to the highest enhancements in figure of merit reported thus far. Furthermore, our results show a controlled increase in the workfunction up to 0.3 eV with the bromine content. These results should help pave the way for further development of graphene as potentially a highly transparent substitute to other transparent conducting electrodes in optoelectronic devices.

  15. Chemical processing of three-dimensional graphene networks on transparent conducting electrodes for depleted-heterojunction quantum dot solar cells.

    PubMed

    Tavakoli, Mohammad Mahdi; Simchi, Abdolreza; Fan, Zhiyong; Aashuri, Hossein

    2016-01-01

    We present a novel chemical procedure to prepare three-dimensional graphene networks (3DGNs) as a transparent conductive film to enhance the photovoltaic performance of PbS quantum-dot (QD) solar cells. It is shown that 3DGN electrodes enhance electron extraction, yielding a 30% improvement in performance compared with the conventional device. PMID:26514615

  16. Electrospray deposition of carbon nanotube thin films for flexible transparent electrodes.

    PubMed

    Meng, Yinan; Xin, Guoqing; Nam, Jaewook; Cho, Sung Min; Chae, Heeyeop

    2013-09-01

    Flexible transparent carbon nanotube (CNT) electrodes were fabricated by electrospray deposition, a large-area scalable and cost-effective process. The carbon nanotubes were dispersed in N,N-dimethylformamide (DMF) and deposited on polyethylene terephthalate (PET) substrates by electrospray deposition process at room temperature and atmospheric pressure. Major process variables were characterized and optimized for the electrospray process development such as electric field between nozzle and substrates, CNT solution flowrate, gap between nozzle and substrates, solution concentration, solvent properties and surface temperature. The sheet resistance of the electrospray deposited CNT films were reduced by HNO3 doping process. 169 Omega/sq sheet resistance and 86% optical transmittance was achieved with low surface roughness of 1.2 nm. The films showed high flexibility and transparency, making them potential replacements of ITO or ZnO in such as solid state lighting, touch panels, and solar cells. Electrospray process is a scalable process and we believe that this process can be applied for large area carbon nanotube film formation. PMID:24205613

  17. Ag-Pd-Cu alloy inserted transparent indium tin oxide electrodes for organic solar cells

    SciTech Connect

    Kim, Hyo-Joong; Seo, Ki-Won; Kim, Han-Ki; Noh, Yong-Jin; Na, Seok-In

    2014-09-01

    The authors report on the characteristics of Ag-Pd-Cu (APC) alloy-inserted indium tin oxide (ITO) films sputtered on a glass substrate at room temperature for application as transparent anodes in organic solar cells (OSCs). The effect of the APC interlayer thickness on the electrical, optical, structural, and morphological properties of the ITO/APC/ITO multilayer were investigated and compared to those of ITO/Ag/ITO multilayer electrodes. At the optimized APC thickness of 8?nm, the ITO/APC/ITO multilayer exhibited a resistivity of 8.55?×?10{sup ?5} ? cm, an optical transmittance of 82.63%, and a figure-of-merit value of 13.54?×?10{sup ?3} ?{sup ?1}, comparable to those of the ITO/Ag/ITO multilayer. Unlike the ITO/Ag/ITO multilayer, agglomeration of the metal interlayer was effectively relieved with APC interlayer due to existence of Pd and Cu elements in the thin region of the APC interlayer. The OSCs fabricated on the ITO/APC/ITO multilayer showed higher power conversion efficiency than that of OSCs prepared on the ITO/Ag/ITO multilayer below 10?nm due to the flatness of the APC layer. The improved performance of the OSCs with ITO/APC/ITO multilayer electrodes indicates that the APC alloy interlayer prevents the agglomeration of the Ag-based metal interlayer and can decrease the thickness of the metal interlayer in the oxide-metal-oxide multilayer of high-performance OSCs.

  18. Silver Nanowire Transparent Conductive Electrodes for High-Efficiency III-Nitride Light-Emitting Diodes.

    PubMed

    Oh, Munsik; Jin, Won-Yong; Jeong, Hyeon Jun; Jeong, Mun Seok; Kang, Jae-Wook; Kim, Hyunsoo

    2015-01-01

    Silver nanowires (AgNWs) have been successfully demonstrated to function as next-generation transparent conductive electrodes (TCEs) in organic semiconductor devices owing to their figures of merit, including high optical transmittance, low sheet resistance, flexibility, and low-cost processing. In this article, high-quality, solution-processed AgNWs with an excellent optical transmittance of 96.5% at 450?nm and a low sheet resistance of 11.7??/sq were demonstrated as TCEs in inorganic III-nitride LEDs. The transmission line model applied to the AgNW contact to p-GaN showed that near ohmic contact with a specific contact resistance of ~10(-3)??cm(2) was obtained. The contact resistance had a strong bias-voltage (or current-density) dependence: namely, field-enhanced ohmic contact. LEDs fabricated with AgNW electrodes exhibited a 56% reduction in series resistance, 56.5% brighter output power, a 67.5% reduction in efficiency droop, and a approximately 30% longer current spreading length compared to LEDs fabricated with reference TCEs. In addition to the cost reduction, the observed improvements in device performance suggest that the AgNWs are promising for application as next-generation TCEs, to realise brighter, larger-area, cost-competitive inorganic III-nitride light emitters. PMID:26333768

  19. Silver Nanowire Transparent Conductive Electrodes for High-Efficiency III-Nitride Light-Emitting Diodes

    NASA Astrophysics Data System (ADS)

    Oh, Munsik; Jin, Won-Yong; Jun Jeong, Hyeon; Jeong, Mun Seok; Kang, Jae-Wook; Kim, Hyunsoo

    2015-09-01

    Silver nanowires (AgNWs) have been successfully demonstrated to function as next-generation transparent conductive electrodes (TCEs) in organic semiconductor devices owing to their figures of merit, including high optical transmittance, low sheet resistance, flexibility, and low-cost processing. In this article, high-quality, solution-processed AgNWs with an excellent optical transmittance of 96.5% at 450?nm and a low sheet resistance of 11.7??/sq were demonstrated as TCEs in inorganic III-nitride LEDs. The transmission line model applied to the AgNW contact to p-GaN showed that near ohmic contact with a specific contact resistance of ~10-3??cm2 was obtained. The contact resistance had a strong bias-voltage (or current-density) dependence: namely, field-enhanced ohmic contact. LEDs fabricated with AgNW electrodes exhibited a 56% reduction in series resistance, 56.5% brighter output power, a 67.5% reduction in efficiency droop, and a approximately 30% longer current spreading length compared to LEDs fabricated with reference TCEs. In addition to the cost reduction, the observed improvements in device performance suggest that the AgNWs are promising for application as next-generation TCEs, to realise brighter, larger-area, cost-competitive inorganic III-nitride light emitters.

  20. Silver Nanowire Transparent Conductive Electrodes for High-Efficiency III-Nitride Light-Emitting Diodes

    PubMed Central

    Oh, Munsik; Jin, Won-Yong; Jun Jeong, Hyeon; Jeong, Mun Seok; Kang, Jae-Wook; Kim, Hyunsoo

    2015-01-01

    Silver nanowires (AgNWs) have been successfully demonstrated to function as next-generation transparent conductive electrodes (TCEs) in organic semiconductor devices owing to their figures of merit, including high optical transmittance, low sheet resistance, flexibility, and low-cost processing. In this article, high-quality, solution-processed AgNWs with an excellent optical transmittance of 96.5% at 450?nm and a low sheet resistance of 11.7??/sq were demonstrated as TCEs in inorganic III-nitride LEDs. The transmission line model applied to the AgNW contact to p-GaN showed that near ohmic contact with a specific contact resistance of ~10?3??cm2 was obtained. The contact resistance had a strong bias-voltage (or current-density) dependence: namely, field-enhanced ohmic contact. LEDs fabricated with AgNW electrodes exhibited a 56% reduction in series resistance, 56.5% brighter output power, a 67.5% reduction in efficiency droop, and a approximately 30% longer current spreading length compared to LEDs fabricated with reference TCEs. In addition to the cost reduction, the observed improvements in device performance suggest that the AgNWs are promising for application as next-generation TCEs, to realise brighter, larger-area, cost-competitive inorganic III-nitride light emitters. PMID:26333768

  1. High-performance dye-sensitized solar cells with gel-coated binder-free carbon nanotube films as counter electrode

    NASA Astrophysics Data System (ADS)

    Mei, Xiaoguang; Cho, Swee Jen; Fan, Benhu; Ouyang, Jianyong

    2010-10-01

    High-performance dye-sensitized solar cells (DSCs) with binder-free films of carbon nanotubes (CNTs), including single-walled CNTs (SWCNTs) and multi-walled CNTs (MWCNTs), as the counter electrode are reported. The CNT films were fabricated by coating gels, which were prepared by dispersing CNTs in low-molecular-weight poly(ethylene glycol) (PEG) through mechanical grinding and subsequent ultrasonication, on fluorine tin oxide (FTO) glass. PEG was removed from the CNT films through heating. These binder-free CNT films were rough and exhibited good adhesion to substrates. They were used as the counter electrode of DSCs. The DSCs with SWCNT or MWCNT counter electrodes exhibited a light-to-electricity conversion efficiency comparable with that with the conventional platinum (Pt) counter electrode, when the devices were tested immediately after device fabrication. The DSCs with an SWCNT counter electrode exhibited good stability in photovoltaic performance. The efficiency did not decrease after four weeks. On the other hand, DSCs with the MWCNT or Pt counter electrode exhibited a remarkable decrease in the photovoltaic efficiency after four weeks. The high photovoltaic performance of these DSCs is related to the excellent electrochemical catalysis of CNTs on the redox of the iodide/triiodide pair, as revealed by the cyclic voltammetry and ac impedance spectroscopy.

  2. Simple method for manufacturing Pt counter electrodes on conductive plastic substrates for dye-sensitized solar cells.

    PubMed

    Gong, Yun; Li, Chunhui; Huang, Xiaoming; Luo, Yanhong; Li, Dongmei; Meng, Qingbo; Iversen, Bo Brummerstedt

    2013-02-01

    A novel, facile, and low-cost method was developed for manufacturing Pt counter electrodes (CEs) of dye-sensitized solar cells (DSCs) on the indium tin oxide-coated polyethylene terephthalate (ITO-PET). This press-transferring method reconciled the temperature conflict between the sintering process of thermal decomposition of H(2)PtCl(6) and plastic substrates. Cyclic voltammograms, electrochemical impedance spectroscopy, transmittance spectra and photovoltaic performance were characterized to investigate the transferred Pt CEs. It was found that the transferred Pt CEs on ITO-PET exhibited an excellent catalytic activity comparable with traditional electrodes on FTO glasses. On the front-side, an illuminated conversion efficiency of 7.21% was reached with more than 94% efficiency of conventional thermally deposited Pt CEs on FTO glasses, and on the back-side, the illuminated conversion efficiency was 4.86%, which was higher than that for conventional electrodes. PMID:23298312

  3. Technical requirements, manufacturing processes and cost efficiency for transparent electrodes based on silver nanowires and carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Ackermann, Thomas; Sahakalkan, Serhat; Kolaric, Ivica; Westkämper, Engelbert; Roth, Siegmar

    2015-08-01

    We outline the reasons why indium tin oxides is still not replaced in transparent electrodes although enormous research has been carried out in the past decade. We evaluate the advantages and drawbacks of possible alter- native materials with regard to material performance and cost-efficiency. As a result, we state that graphene is a very promising material but the production costs are very high. Without a technological breakthrough to- wards an energy- and material-efficient synthesis of graphene, this material will remain unfeasible for the use in industrially scaled production of transparent electrodes. Silver nanowires are easier to process but they exhibit high haze. Within our approach we produce ultra-transparent silver nanowire films and silver nanowire/carbon nanotube hybrid films with low haze. Our manufacturing technique is scalable on conventional smart phone glass and we present a conceptual production cell for the fabrication of ultra-transparent electrodes with optical transmission higher than 97 % and sheet resistance lower than 70 ?/sq. The optoelectrical performance of these films is superior to most of the recently published silver nanowire films. The theoretical material range for 1 g of AgNWs is 165 m

  4. Bromination of Graphene: A New Route to Making High Performance Transparent Conducting Electrodes with Low Optical Losses.

    PubMed

    Mansour, Ahmed E; Dey, Sukumar; Amassian, Aram; Tanielian, Minas H

    2015-08-19

    The unique optical and electrical properties of graphene have triggered great interest in its application as a transparent conducting electrode material and significant effort has been invested in achieving high conductivity while maintaining high transparency. Doping of graphene has been a popular route for reducing its sheet resistance, but this has typically come at a significant loss in optical transmittance. We demonstrate doping of few layers graphene (FLG) with bromine as a means of enhancing the conductivity via intercalation without major optical losses. Our results demonstrate the encapsulation of bromine within the FLG, leading to air-stable transparent conducting electrodes with 5-fold improvement of sheet resistance reaching ?180 ?/? at the cost of only 2-3% loss of optical transmittance. The remarkably low trade-off in optical transparency leads to the highest enhancements in the figure of merit reported thus far for FLG. Furthermore, we tune the work function by up to 0.3 eV by tuning the bromine content. These results should help pave the way for further development of graphene as a potential substitute to transparent conducting polymers and metal oxides used in optoelectronics, photovoltaics, and beyond. PMID:26200126

  5. Highly stretchable and mechanically stable transparent electrode based on composite of silver nanowires and polyurethane-urea.

    PubMed

    Kim, Dong-Hwan; Yu, Ki-Cheol; Kim, Youngmin; Kim, Jong-Woong

    2015-07-22

    Transparent electrodes based on conventional indium-tin oxide (ITO) can hardly meet the requirements of future generations of stretchable electronic devices, including artificial skins, stretchable displays, sensors, and actuators, because they cannot retain high conductivity under substantial stretching and bending deformation. Here we suggest a new approach for fabricating highly stretchable and transparent electrodes with good stability in environments where they would be stretched repeatedly. We designed polyurethane-urea (PUU), a urethane-based polymer, to enhance the adhesion between Ag nanowires (AgNWs) and poly(dimethylsiloxane) (PDMS). The adhesion could be further improved when irradiated by intense pulsed light (IPL). After delicate optimization of the layered AgNW/PUU/PDMS structure, we fabricated a stretchable transparent electrode that could withstand 100 cycles of 50% stretching-releasing, with exceptionally high stability and reversibility. This newly developed electrode is therefore expected to be directly applicable to a wide range of high-performance, low-cost, stretchable electronic devices. PMID:26135228

  6. Reactively sputtered nickel nitride as electrocatalytic counter electrode for dye- and quantum dot-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Soo Kang, Jin; Park, Min-Ah; Kim, Jae-Yup; Ha Park, Sun; Young Chung, Dong; Yu, Seung-Ho; Kim, Jin; Park, Jongwoo; Choi, Jung-Woo; Jae Lee, Kyung; Jeong, Juwon; Jae Ko, Min; Ahn, Kwang-Soon; Sung, Yung-Eun

    2015-05-01

    Nickel nitride electrodes were prepared by reactive sputtering of nickel under a N2 atmosphere at room temperature for application in mesoscopic dye- or quantum dot- sensitized solar cells. This facile and reliable method led to the formation of a Ni2N film with a cauliflower-like nanostructure and tetrahedral crystal lattice. The prepared nickel nitride electrodes exhibited an excellent chemical stability toward both iodide and polysulfide redox electrolytes. Compared to conventional Pt electrodes, the nickel nitride electrodes showed an inferior electrocatalytic activity for the iodide redox electrolyte; however, it displayed a considerably superior electrocatalytic activity for the polysulfide redox electrolyte. As a result, compared to dye-sensitized solar cells (DSCs), with a conversion efficiency (?)?=?7.62%, and CdSe-based quantum dot-sensitized solar cells (QDSCs, ??=?2.01%) employing Pt counter electrodes (CEs), the nickel nitride CEs exhibited a lower conversion efficiency (??=?3.75%) when applied to DSCs, but an enhanced conversion efficiency (??=?2.80%) when applied to CdSe-based QDSCs.

  7. Reactively sputtered nickel nitride as electrocatalytic counter electrode for dye- and quantum dot-sensitized solar cells.

    PubMed

    Soo Kang, Jin; Park, Min-Ah; Kim, Jae-Yup; Ha Park, Sun; Young Chung, Dong; Yu, Seung-Ho; Kim, Jin; Park, Jongwoo; Choi, Jung-Woo; Jae Lee, Kyung; Jeong, Juwon; Jae Ko, Min; Ahn, Kwang-Soon; Sung, Yung-Eun

    2015-01-01

    Nickel nitride electrodes were prepared by reactive sputtering of nickel under a N2 atmosphere at room temperature for application in mesoscopic dye- or quantum dot- sensitized solar cells. This facile and reliable method led to the formation of a Ni2N film with a cauliflower-like nanostructure and tetrahedral crystal lattice. The prepared nickel nitride electrodes exhibited an excellent chemical stability toward both iodide and polysulfide redox electrolytes. Compared to conventional Pt electrodes, the nickel nitride electrodes showed an inferior electrocatalytic activity for the iodide redox electrolyte; however, it displayed a considerably superior electrocatalytic activity for the polysulfide redox electrolyte. As a result, compared to dye-sensitized solar cells (DSCs), with a conversion efficiency (?)?= 7.62%, and CdSe-based quantum dot-sensitized solar cells (QDSCs, ? = 2.01%) employing Pt counter electrodes (CEs), the nickel nitride CEs exhibited a lower conversion efficiency (? = 3.75%) when applied to DSCs, but an enhanced conversion efficiency (? = 2.80%) when applied to CdSe-based QDSCs. PMID:25994801

  8. A new architecture as transparent electrodes for solar and IR applications based on photonic structures via soft lithography

    SciTech Connect

    Kuang, Ping

    2011-05-15

    Transparent conducting electrodes with the combination of high optical transmission and good electrical conductivity are essential for solar energy harvesting and electric lighting devices. Currently, indium tin oxide (ITO) is used because ITO offers relatively high transparency (>80%) to visible light and low sheet resistance (R{sub s} = 10 ohms/square ({Omega}#2;/?)) for electrical conduction. However, ITO is costly due to limited indium reserves, and it is brittle. These disadvantages have motivated the search for other conducting electrodes with similar or better properties. There has been research on a variety of electrode structures involving carbon nanotube networks, graphene films, nanowire and nanopatterned meshes and grids. Due to their novel characteristics in light manipulation and collection, photonic crystal structures show promise for further improvement. Here, we report on a new architecture consisting of nanoscale high aspect ratio metallic photonic structures as transparent electrodes fabricated via a combination of processes. For (Au) and silver (Ag) structures, the visible light transmission can reach as high as 80%, and the sheet resistance of the structure can be as low as 3.2{Omega}#2;/?. The optical transparency of the high aspect ratio metal structures at visible wavelength range is comparable to that of ITO glass, while their sheet resistance is more than 3 times lower, which indicates a much higher electrical conductivity of the metal structures. Furthermore, the high aspect ratio metal structures have very high infrared (IR) reflection (90%) for the transverse magnetic (TM) mode, which can lead to the development of fabrication of metallic structures as IR filters for heat control applications. Investigations of interdigitated structures based on the high aspect ratio metal electrodes are ongoing to study the feasibility in smart window applications in light transmission modulation.

  9. Flexible carbon nanotube/polypropylene composite plate decorated with poly(3,4-ethylenedioxythiophene) as efficient counter electrodes for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Lin, Jeng-Yu; Wang, Wei-Yen; Chou, Shu-Wei

    2015-05-01

    In this study, we fabricate an efficient, flexible and low-cost counter electrode (CE) composed of a plasma-etched carbon nanotubes/polypropylene (designated as ECP) composite plate decorated with poly(3,4-ethylene dioxythiophene) (PEDOT) for dye-sensitized solar cells (DSCs). The PEDOT-decorated monolithic ECP CEs are fabricated via series of processes including high-temperature refluxing, thermal compression, oxygen plasma etching, and electropolymerization. The bottom ECP plate is used to replace conventional transparent conducting oxide (TCO) as a conductive substrate, and the top PEDOT layer is employed as catalyst for I3- reduction. According to the extensive electrochemical measurements, the as-fabricated flexible PEDOT coated ECP CE demonstrates a Pt-like electrocatalytic for I3- reduction. The DSC based on the flexible PEDOT-decorated ECP CE yields impressive energy conversion efficiency of 6.82% (or 6.77% even after the bending test), which is comparable to that of the DSC using the Pt CE (7.20%) under similar device architecture conditions. Therefore, the PEDOT-decorated ECP based CEs show the possibility of serving as low-cost and flexible CEs for efficient DSCs.

  10. Ni3S2/Ni-P bilayer coated on polyimide as a Pt- and TCO-free flexible counter electrode for dye-sensitized solar cells.

    PubMed

    Lin, Jeng-Yu; Wang, Wei-Yan; Lin, Yi-Ting; Chou, Shu-Wei

    2014-03-12

    In this study, we reported an efficient, flexible, and low-cost (Pt-free and transparent conducting oxide (TCO)-free) counter electrode (CE) made of a polyimide (PI) substrate coated with a Ni3S2/Ni-P bilayer for dye-sensitized solar cells (DSCs). The bilayer Ni3S2/Ni-P hybrid film was deposited on a PI plastic substrate via a series of wet chemical/electrochemical processes. The bottom Ni-P layer was deposited on a PI to replace conventional TCO as a conductive layer, and the top Ni3S2 layer was employed as the electrocatalyst for I3(-) reduction. On the basis of the extensive electrochemical measurments, the as-prepared Ni3S2/Ni-P coated PI flexible CE demonstrated a Pt-like electrocatalytic for I3(-) reduction. As a result, the DSC assembled with the Ni3S2/Ni-P coated PI flexible CE exhibited an impressive photovoltaic conversion efficiency of 6.28% accompanied by a fill factor of 0.63 under 1 sun illumination (100 mW cm(-2), AM 1.5), which is comparative to that of the DSC based on the Pt coated indium tin oxide/polyethylene naphthalate (ITO/PEN) CE. PMID:24446929

  11. Enhanced efficiency of the dye-sensitized solar cells by excimer laser irradiated carbon nanotube network counter electrode

    SciTech Connect

    Chien, Yun-San Fu, Wei-En; Yang, Po-Yu; Lee, I-Che; Chu, Chih-Chieh; Chou, Chia-Hsin; Cheng, Huang-Chung

    2014-02-03

    The carbon nanotube network decorated with Pt nanoparticles (PtCNT) irradiated by excimer laser as counter electrode (CE) of dye-sensitized solar cells (DSSCs) has been systematically demonstrated. The conversion efficiency would be improved from 7.12% to 9.28% with respect to conventional Pt-film one. It was attributed to the enhanced catalytic surface from Pt nanoparticles and the improved conductivity due to the adjoining phenomenon of PtCNTs irradiated by laser. Moreover, the laser annealing could also promote the interface contact between CE and conductive glass. Therefore, such a simple laser-irradiated PtCNT network is promising for the future flexible DSSCs applications.

  12. A new in-situ preparation method to FeS counter electrode for quantum dots-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Quan, Linlin; Li, Weiping; Zhu, Liqun; Geng, Huifang; Chang, Xiaowen; Liu, Huicong

    2014-12-01

    FeS counter electrode (CE) with the structure of three-dimensional nanospheres for quantum dots-sensitized solar cells (QDSCs) is first fabricated by alternating current (AC) etching the A3 carbon steel and characterized with scanning electron microscope (SEM), Transmission electron microscope (TEM), current-voltage and impedance spectroscopy. The device applying FeS CE achieves a power conversion efficiency of 3.34%, which are much higher than that of using Pt (1.01%) and conventional Cu2S (1.54%). These results indicated that AC provides an efficient, simple and cost-effective method to fabricate CE for QDSCs.

  13. Highly reliable ag nanowire flexible transparent electrode with mechanically welded junctions.

    PubMed

    Hwang, Byungil; Shin, Hae-A-Seul; Kim, Taegeon; Joo, Young-Chang; Han, Seung Min

    2014-08-27

    Deformation behavior of the Ag nanowire flexible transparent electrode under bending strain is studied and results in a novel approach for highly reliable Ag nanowire network with mechanically welded junctions. Bending fatigue tests up to 500,000 cycles are used to evaluate the in situ resistance change while imposing fixed, uniform bending strain. In the initial stages of bending cycles, the thermally annealed Ag nanowire networks show a reduction in fractional resistance followed by a transient and steady-state increase at later stages of cycling. SEM analysis reveals that the initial reduction in resistance is caused by mechanical welding as a result of applied bending strain, and the increase in resistance at later stages of cycling is determined to be due to the failure at the thermally locked-in junctions. Based on the observations from this study, a new methodology for highly reliable Ag nanowire network is proposed: formation of Ag nanowire networks with no prior thermal annealing but localized junction formation through simple application of mechanical bending strain. The non-annealed, mechanically welded Ag nanowire network shows significantly enhanced cyclic reliability with essentially 0% increase in resistance due to effective formation of localized wire-to-wire contact. PMID:24789010

  14. Optimization of transparent and reflecting electrodes for amorphous silicon solar cells

    NASA Astrophysics Data System (ADS)

    Gordon, R. G.; Proscia, J.; Gustin, K.; Chapple-Sokol, J.; Strickler, D.; McCurdy, R.

    1988-06-01

    In this research, hydrogenated amorphous silicon (a-Si:H) films were deposited by an inexpensive, thermally induced, atmospheric-pressure chemical vapor deposition (CVD) process. High-quality films were grown at 300 A, more than two orders of magnitude faster than those produced by conventional glow discharge. Sources of uncontrolled oxygen, boron, phosphorus, and carbon contamination were identified and eliminated. The efficiency of a-Si solar cells can be increased by using rough, rather than smooth, tin oxide as the front-surface transparent electrode, because the rough tin oxide-silicon interface increases the absorption of red light (light trapping) and reduces the reflection loss of light across the whole spectrum. We produced, by CVD, rough tin oxide films from tetramethyltin. Cells grown on the rough films have higher efficiencies than those grown on smooth tin oxide. We also used a precursor tin compound (dimethyltin dichloride) that is less costly and less hazardous than others. Rough films can be grown from dimethyltin dichloride more than three times faster than from tetramethyltin. To combine the CVD processes we need a layer that prevents the tin oxide layer from being attacked by the silicon, such as a barrier layer of titanium oxide, which seems to be effective.

  15. Copper nanowire-graphene core-shell nanostructure for highly stable transparent conducting electrodes.

    PubMed

    Ahn, Yumi; Jeong, Youngjun; Lee, Donghwa; Lee, Youngu

    2015-03-24

    A copper nanowire-graphene (CuNW-G) core-shell nanostructure was successfully synthesized using a low-temperature plasma-enhanced chemical vapor deposition process at temperatures as low as 400 °C for the first time. The CuNW-G core-shell nanostructure was systematically characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman, and X-ray photoelectron spectroscopy measurements. A transparent conducting electrode (TCE) based on the CuNW-G core-shell nanostructure exhibited excellent optical and electrical properties compared to a conventional indium tin oxide TCE. Moreover, it showed remarkable thermal oxidation and chemical stability because of the tight encapsulation of the CuNW with gas-impermeable graphene shells. The potential suitability of CuNW-G TCE was demonstrated by fabricating bulk heterojunction polymer solar cells. We anticipate that the CuNW-G core-shell nanostructure can be used as an alternative to conventional TCE materials for emerging optoelectronic devices such as flexible solar cells, displays, and touch panels. PMID:25712446

  16. Application of Single Wall Carbon Nanotubes as Transparent Electrodes in Cu(In,Ga)Se2-Based Solar Cells: Preprint

    SciTech Connect

    Contreras, M.; Barnes, T.; van de Lagemaat, J.; Rumbles, G.; Coutts, T. J.; Weeks, C.; Glatkowski, P.; Levitsky, I.; Peltola, J.

    2006-05-01

    We present a new thin-film solar cell structure in which the traditional transparent conductive oxide electrode (ZnO) is replaced by a transparent conductive coating consisting of a network of bundled single-wall carbon nanotubes. Optical transmission properties of these coatings are presented in relation to their electrical properties (sheet resistance), along with preliminary solar cell results from devices made using CuIn1-xGaxSe2 thin-film absorber materials. Achieving an energy conversion efficiency of >12% and a quantum efficiency of {approx}80% demonstrate the feasibility of the concept. A discussion of the device structures will be presented considering the physical properties of the new electrodes comparing current-voltage results from the new solar cell structure and those from standard ZnO/CdS/Cu(In,Ga)Se2/Mo solar cells.

  17. Optimization of transparent and reflecting electrodes for amorphous silicon solar cells. Annual subcontract report, April 1, 1994--March 31, 1995

    SciTech Connect

    Gordon, R.G.

    1995-10-01

    Transparent and reflecting electrodes are important parts of the structure of amorphous silicon solar cells. We report improved methods for depositing zinc oxide, deposition of tin nitride as a potential reflection-enhancing diffusion barrier between the a-Si and back metal electrodes. Highly conductive and transparent fluorine-doped zinc oxide was successfully produced on small areas by atmospheric pressure CVD from a less hazardous zinc precursor, zinc acetylacetonate. The optical properties measured for tin nitride showed that the back-reflection would be decreased if tin nitride were used instead of zinc oxide as a barrier layer over silver on aluminum. Niobium-doped titanium dioxide was produced with high enough electrical conductivity so that normal voltages and fill factors were obtained for a-Si cells made on it.

  18. Low-cost electrospun highly crystalline kesterite Cu2ZnSnS4 nanofiber counter electrodes for efficient dye-sensitized solar cells.

    PubMed

    Mali, Sawanta S; Patil, Pramod S; Hong, Chang Kook

    2014-02-12

    In the present investigation, kesterite Cu2ZnSnS4 (CZTS) nanofibers were obtained by electrospinning process using polyvinylpyrrolidone (PVP) and cellulose acetate (CA) solvent separately. The synthesized CZTS nanofibers were characterized using thermogravimetric analysis (TGA), optical absorption, X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FESEM), micro-Raman spectroscopy, high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). Our results showed that the PVP synthesized CZTS nanofibers are a single crystalline while CA assisted CZTS nanofibers are polycrystalline in nature. The optical properties demonstrated that the prepared nanofibers have strong absorption in 300-550 nm range with band gap energy of 1.5 eV. The X-ray and micro-Raman analysis revealed that synthesised nanofibers showing pure phase kesterite CZTS. Further the synthesized CZTS nanofibers were used as counter electrodes for dye-sensitized solar cells (DSSCs). Our results indicate that, PVP-CZTS and CA-CZTS counter electrode based DSSC shows 3.10% and 3.90% respectively. The detailed interfaces of these counter electrodes and DSSCs were analyzed by electrochemical impedance spectroscopic (EIS) measurements for analysis of such high power conversion efficiency. The present study will be helpful for alternative counter electrode for Pt counter electrodes in DSSCs application. We believe that our synthetic method will be helpful for low-cost and efficient thin film photovoltaic technology. PMID:24383575

  19. In-situ electrochemically deposited polypyrrole nanoparticles incorporated reduced graphene oxide as an efficient counter electrode for platinum-free dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Lim, Su Pei; Pandikumar, Alagarsamy; Lim, Yee Seng; Huang, Nay Ming; Lim, Hong Ngee

    2014-06-01

    This paper reports a rapid and in-situ electrochemical polymerization method for the fabrication of polypyrrole nanoparticles incorporated reduced graphene oxide (rGO@PPy) nanocomposites on a ITO conducting glass and its application as a counter electrode for platinum-free dye-sensitized solar cell (DSSC). The scanning electron microscopic images show the uniform distribution of PPy nanoparticles with diameter ranges between 20 and 30 nm on the rGO sheets. The electrochemical studies reveal that the rGO@PPy has smaller charge transfer resistance and similar electrocatalytic activity as that of the standard Pt counter electrode for the I3-/I- redox reaction. The overall solar to electrical energy conversion efficiency of the DSSC with the rGO@PPy counter electrode is 2.21%, which is merely equal to the efficiency of DSSC with sputtered Pt counter electrode (2.19%). The excellent photovoltaic performance, rapid and simple fabrication method and low-cost of the rGO@PPy can be potentially exploited as a alternative counter electrode to the expensive Pt in DSSCs.

  20. Optically transparent thin-film transistors based on 2D multilayer MoS2 and indium zinc oxide electrodes

    NASA Astrophysics Data System (ADS)

    Kwon, Junyeon; Hong, Young Ki; Kwon, Hyuk-Jun; Park, Yu Jin; Yoo, Byungwook; Kim, Jiwan; Grigoropoulos, Costas P.; Oh, Min Suk; Kim, Sunkook

    2015-01-01

    We report on optically transparent thin film transistors (TFTs) fabricated using multilayered molybdenum disulfide (MoS2) as the active channel, indium tin oxide (ITO) for the back-gated electrode and indium zinc oxide (IZO) for the source/drain electrodes, respectively, which showed more than 81% transmittance in the visible wavelength. In spite of a relatively large Schottky barrier between MoS2 and IZO, the n-type behavior with a field-effect mobility (?eff) of 1.4 cm2 V-1 s-1 was observed in as-fabricated transparent MoS2 TFT. In order to enhance the performances of transparent MoS2 TFTs, a picosecond pulsed laser was selectively irradiated onto the contact region of the IZO electrodes. Following laser annealing, ?eff increased to 4.5 cm2 V-1 s-1, and the on-off current ratio (Ion/Ioff) increased to 104, which were attributed to the reduction of the contact resistance between MoS2 and IZO.

  1. Optically transparent thin-film transistors based on 2D multilayer MoS? and indium zinc oxide electrodes.

    PubMed

    Kwon, Junyeon; Hong, Young Ki; Kwon, Hyuk-Jun; Park, Yu Jin; Yoo, Byungwook; Kim, Jiwan; Grigoropoulos, Costas P; Oh, Min Suk; Kim, Sunkook

    2015-01-21

    We report on optically transparent thin film transistors (TFTs) fabricated using multilayered molybdenum disulfide (MoS2) as the active channel, indium tin oxide (ITO) for the back-gated electrode and indium zinc oxide (IZO) for the source/drain electrodes, respectively, which showed more than 81% transmittance in the visible wavelength. In spite of a relatively large Schottky barrier between MoS2 and IZO, the n-type behavior with a field-effect mobility (?(eff)) of 1.4 cm(2) V(-1) s(-1) was observed in as-fabricated transparent MoS2 TFT. In order to enhance the performances of transparent MoS2 TFTs, a picosecond pulsed laser was selectively irradiated onto the contact region of the IZO electrodes. Following laser annealing, ?(eff) increased to 4.5 cm(2) V(-1) s(-1), and the on-off current ratio (I(on)/I(off)) increased to 10(4), which were attributed to the reduction of the contact resistance between MoS2 and IZO. PMID:25548952

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

    NASA Astrophysics Data System (ADS)

    Moulin, Etienne; Müller, Thomas Christian Mathias; Warzechac, Marek; Hoffmann, Andre; Paetzold, Ulrich Wilhelm; Aeberhard, Urs

    2015-03-01

    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-?m-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.

  3. Fabrication of Mesoporous CoS2 Nanotube Arrays as the Counter Electrodes of Dye-Sensitized Solar Cells.

    PubMed

    Tsai, Jung-Che; Hon, Min-Hsiung; Leu, Ing-Chi

    2015-09-01

    Mesoporous cobalt sulfide nanotube arrays on FTO-coated glass were synthesized by combining three simple technologies: the selective etching of ZnO sacrificial templates, mesoporous Co3 O4 formation from cobalt-chelated chitosan, and ion-exchange reaction (IER). The mesoporous Co3 O4 nanotubes composed of the Co3 O4 nanoparticles possess a high surface area and are taken advantage for further removal of templates and IER. The morphologies and crystal structures of the CoS2 nanotube arrays were characterized by SEM, TEM, and XRD analyses. Their electrocatalytic properties were determined by electrochemical analyses including cyclic voltammetry measurements and Tafel polarization. The DSSCs assembled with a CoS2 counter electrode achieved a power conversion efficiency of 6.13?%, which was comparable to that of the DSSC with the Pt counter electrode (6.04?%). This indicates that the mesoporous CoS2 nanotube array can be a low-cost and efficient alternative for the reduction of electrolytes in DSSCs. PMID:26154709

  4. A highly efficient flexible dye-sensitized solar cell based on nickel sulfide/platinum/titanium counter electrode

    NASA Astrophysics Data System (ADS)

    Yue, Gentian; Ma, Xingping; Zhang, Weifeng; Li, Fumin; Wu, Jihuai; Li, Guoqiang

    2015-01-01

    A composite film of nickel sulfide/platinum/titanium foil (NiS/Pt/Ti) with low cost and high electrocatalytic activity was synthesized by the use of an in situ electropolymerization route and proposed as a counter electrode (CE) catalyst for flexible dye-sensitized solar cells (FDSSCs). The FDSSC with the NiS/Pt/Ti CE exhibited a comparable power conversion efficiency of 7.20% to the FDSSC with the platinum/titanium (Pt/Ti) CE showing 6.07%. The surface morphology of the NiS/Pt/Ti CE with one-dimensional (1D) structure is characterized by using the scanning electron microscopy (SEM). The NiS/Pt/Ti CE also displayed multiple electrochemical functions of excellent conductivity, great electrocatalytic ability for iodine/triiodine, and low charge transfer resistance of 2.61 ± 0.02 ? cm2, which were characterized by using the cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel polarization plots. The photocurrent-photovoltage ( J-V) character curves were further used to calculate the theoretical optical light performance parameters of the FDSSCs. It may be said that the NiS/Pt/Ti counter electrode is a promising catalytic material to replace the expensive platinum in FDSSCs.

  5. A highly efficient flexible dye-sensitized solar cell based on nickel sulfide/platinum/titanium counter electrode.

    PubMed

    Yue, Gentian; Ma, Xingping; Zhang, Weifeng; Li, Fumin; Wu, Jihuai; Li, Guoqiang

    2015-01-01

    A composite film of nickel sulfide/platinum/titanium foil (NiS/Pt/Ti) with low cost and high electrocatalytic activity was synthesized by the use of an in situ electropolymerization route and proposed as a counter electrode (CE) catalyst for flexible dye-sensitized solar cells (FDSSCs). The FDSSC with the NiS/Pt/Ti CE exhibited a comparable power conversion efficiency of 7.20% to the FDSSC with the platinum/titanium (Pt/Ti) CE showing 6.07%. The surface morphology of the NiS/Pt/Ti CE with one-dimensional (1D) structure is characterized by using the scanning electron microscopy (SEM). The NiS/Pt/Ti CE also displayed multiple electrochemical functions of excellent conductivity, great electrocatalytic ability for iodine/triiodine, and low charge transfer resistance of 2.61?±?0.02 ? cm(2), which were characterized by using the cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel polarization plots. The photocurrent-photovoltage (J-V) character curves were further used to calculate the theoretical optical light performance parameters of the FDSSCs. It may be said that the NiS/Pt/Ti counter electrode is a promising catalytic material to replace the expensive platinum in FDSSCs. PMID:25977644

  6. Dye sensitized solar cell based on platinum decorated multiwall carbon nanotubes as catalytic layer on the counter electrode

    SciTech Connect

    Mathew, Ambily; Rao, G. Mohan; Munichandraiah, N.

    2011-11-15

    Graphical abstract: I-V characteristics of the DSSCs with Pt CE and Pt/MWCNT CE measured at 100 mW/cm{sup 2}. It shows relatively better performance with Pt/MWCNT counter electrodes. Highlights: {yields} Synthesis of multiwalled carbon nanotubes by pyrolysis. {yields} Synthesis of Pt/MWCNT composite by chemical reduction. {yields} Fabrication DSSC using Pt/MWCNT as catalytic layer on the counter electrode. {yields} Study of catalytic activity by Electrochemical Impedance Spectroscopy. -- Abstract: In this study we have employed multiwall carbon nanotubes (MWCNT), decorated with platinum as catalytic layer for the reduction of tri-iodide ions in dye sensitized solar cell (DSSC). MWCNTs have been prepared by a simple one step pyrolysis method using ferrocene as the catalyst and xylene as the carbon source. Platinum decorated MWCNTs have been prepared by chemical reduction method. The as prepared MWCNTs and Pt/MWCNTs have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In combination with a dye adsorbed TiO{sub 2} photoanode and an organic liquid electrolyte, Pt/MWCNT composite showed an enhanced short circuit current density of 16.12 mA/cm{sup 2} leading to a cell efficiency of 6.50% which is comparable to that of Platinum.

  7. Transparent organic thin film transistors with WO3/Ag/WO3 source-drain electrodes fabricated by thermal evaporation

    NASA Astrophysics Data System (ADS)

    Zhang, Nan; Hu, Yongsheng; Liu, Xingyuan

    2013-07-01

    High-performance transparent organic thin film transistors using a WO3/Ag/WO3 (WAW) multilayer as the source and drain electrodes have been developed without breaking the vacuum. The WAW electrodes were deposited by thermal evaporation at room temperature, leading to little damage to organic film. The optimized WAW electrode shows high transmittance (86.57%), low sheet resistance (11 ?/sq), and a high work function (5.0 eV). Consequently, we obtained high performance devices with mobility of 8.44 × 10-2 cm2/V . s, an on/off ratio of approximately 1.2 × 106, and an average visible range transmittance of 81.5%.

  8. Performance enhancement of metal nanowire-based transparent electrodes by electrically driven nanoscale nucleation of metal oxides

    NASA Astrophysics Data System (ADS)

    Shiau, Yu-Jeng; Chiang, Kai-Ming; Lin, Hao-Wu

    2015-07-01

    Solution-processed silver nanowire (AgNW) electrodes have been considered to be promising materials for next-generation flexible transparent conductive electrodes. Despite the fact that a single AgNW has extremely high conductivities, the high junction resistance between nanowires limits the performance of the AgNW matrix. Therefore, post-treatments are usually required to approach better NW-NW contact. Herein, we report a novel linking method that uses joule heating to accumulate sol-gel ZnO near nanowire junctions. The nanoscale ZnO nucleation successfully restrained the thermal instability of the AgNW under current injection and acted as an efficient tightening medium to realize good NW-NW contacts. A low process temperature (<50 °C), and thus low energy consumption, are required for ZnO nucleation. This made the use of substrates with very low operating temperatures, such as PET and PEN, feasible. The optimized AgNW transparent conductive electrodes (TCE) fabricated using this promising linking method exhibited a low sheet resistance (13 ? sq-1), a high transmission (92% at 550 nm), a high figure of merit (FOM; up to ?DC/?Op = 340) and can be applied to wide range of next-generation flexible optoelectronic devices.Solution-processed silver nanowire (AgNW) electrodes have been considered to be promising materials for next-generation flexible transparent conductive electrodes. Despite the fact that a single AgNW has extremely high conductivities, the high junction resistance between nanowires limits the performance of the AgNW matrix. Therefore, post-treatments are usually required to approach better NW-NW contact. Herein, we report a novel linking method that uses joule heating to accumulate sol-gel ZnO near nanowire junctions. The nanoscale ZnO nucleation successfully restrained the thermal instability of the AgNW under current injection and acted as an efficient tightening medium to realize good NW-NW contacts. A low process temperature (<50 °C), and thus low energy consumption, are required for ZnO nucleation. This made the use of substrates with very low operating temperatures, such as PET and PEN, feasible. The optimized AgNW transparent conductive electrodes (TCE) fabricated using this promising linking method exhibited a low sheet resistance (13 ? sq-1), a high transmission (92% at 550 nm), a high figure of merit (FOM; up to ?DC/?Op = 340) and can be applied to wide range of next-generation flexible optoelectronic devices. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr02780b

  9. Enhancement of Characteristics of Transparent Conductive Electrode on Flexible Substrate by Combination of Solution-Based Oxide and Metallic Layers.

    PubMed

    Hong, Sung-Jei; Kim, Yong-Hoon; Cha, Seung-Jae; Kim, Yong-Sung

    2015-10-01

    This study investigates solution-processed transparent conductors with hybrid structure consisting of silver nanowires (AgNWs) and indium-tin-oxide nanoparticles (ITO-NPs) layers fabricated on polymeric flexible polyethylene terephthalate (PET) substrate. The transparent conductors had stacked structures of AgNWs/ITO-NPs on 125-?m-thick PET and ITO-NPs/AgNWs/ITO-NPs on 125-?m-thick PET, 188-?m-thick PET, or 700-?m-thick glass substrate, respectively. Successful integrations were possible on the substrates without any deformation or distortion. Sheet resistance of the triple-layered transparent conductor samples exhibits low values ranging from 22.41 ?/square to 22.99 ?/squarer. Also, their optical transmittance exhibits high values ranging from 83.78 to 87.29% at 550 nm. The triple-layered transparent conductor showed a good thermal stability in terms of sheet resistance and optical transmittance against the high-temperature environment up to 250 °C. All the double and triple-layered transparent conductors fabricated on PET and glass substrates are so stable against the accelerated thermal aging from 110 °C to 130 °C, that ?R/R0 and ?T(550)/T0(550) values exhibit less than 0.068 and 0.049, respectively. Furthermore, the layers are so flexible that ?R/R0 of the layers on PET substrates is lower than 0.1 even at 4.0-mm bending. Especially, triple-layered transparent conductor on 125-?m-thick PET substrates exhibits ?R/R0 value of 0.042 even at 4.0 mm bending. Thus, it can be concluded that the hybrid structures have the advantage of both thermal stability and flexibility for electrical and optical properties of transparent conductive electrode; which makes them highly applicable in flexible electronics. PMID:26726453

  10. Optimization of transparent and reflecting electrodes for amorphous silicon solar cells. Final technical report

    SciTech Connect

    Gordon, R.G.; Kramer, K.; Liang, H.; Liu, X.; Pang, D.; Teff, D.

    1998-09-01

    Transparent conducting fluorine doped zinc oxide was deposited as thin films on soda lime glass substrates by atmospheric pressure chemical vapor deposition (CVD) at substrate temperatures of 460 to 500 degrees C. The precursors diethylzinc, tetramethylethylenediamine and benzoyl fluoride were dissolved in xylene. This solution was nebulized ultrasonically and then flash vaporized by a carrier gas of nitrogen preheated to 150 degrees C. Ethanol was vaporized separately, and these vapors were then mixed to form a homogeneous vapor mixture. Good reproducibility was achieved using this new CVD method. Uniform thicknesses were obtained by moving the heated glass substrates through the deposition zone. The best electrically and optical properties were obtained when the precursor solution was aged for more than a week before use. The films were polycrystalline and highly oriented with the c-axis perpendicular to the substrate. More than 90% of the incorporated fluorine atoms were electrically active as n-type dopants. The electrical resistivity of the films was as low as 5 x 10/sup -4/ Omega cm. The mobility was about 45 cm ²/Vs. The electron concentration was up to 3 x 10 %sup20;/cm³. The optical absorption of the films was about 3-4% at a sheet resistance of 7 ohms/square. The diffuse transmittance was about 10% at a wavelength of 650 nm. Amorphous ilicon solar cells were deposited using the textured fluorine doped zinc oxide films as a front electrode. The short circuit current was increased over similar cells made with fluorine doped tin oxide, but the open circuit voltages and fill factors were reduced. The voltage was restored by overcoating the fluorine-doped zinc oxide with a thin layer of fluorine-doped tin oxide.

  11. Synthesis of Cu2ZnSnS4 nanoparticles by solution based solid state reaction process and its application in dye sensitized solar cell as counter electrode

    NASA Astrophysics Data System (ADS)

    Mokurala, Krishnaiah; Bhargava, Parag; Mallick, Sudhanshu

    2014-04-01

    Cu2ZnSnS4 (CZTS) nanoparticles were synthesized by using solution based solid state reaction process and films were coated on FTO (Fluorine doped tin oxide) substrate using doctor blade technique. Phase identification, crystallinity of the synthesized nanoparticles was confirmed by XRD and Raman spectroscopy. Dye sensitized solar cells (DSSC) fabricated with CZTS as counter electrode showed photo conversion efficiency 2.57 % compared to Pt based counter electrode 3.17 % efficiency. The charge transport at CZTS/ electrolyte interface was studied by using electrochemical impedance spectroscopy.

  12. Ultra-thin and smooth transparent electrode for flexible and leakage-free organic light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Ok, Ki-Hun; Kim, Jiwan; Park, So-Ra; Kim, Youngmin; Lee, Chan-Jae; Hong, Sung-Jei; Kwak, Min-Gi; Kim, Namsu; Han, Chul Jong; Kim, Jong-Woong

    2015-03-01

    A smooth, ultra-flexible, and transparent electrode was developed from silver nanowires (AgNWs) embedded in a colorless polyimide (cPI) by utilizing an inverted film-processing method. The resulting AgNW-cPI composite electrode had a transparency of >80%, a low sheet resistance of 8 ?/?, and ultra-smooth surfaces comparable to glass. Leveraging the robust mechanical properties and flexibility of cPI, the thickness of the composite film was reduced to less than 10 ?m, which is conducive to extreme flexibility. This film exhibited mechanical durability, for both outward and inward bending tests, up to a bending radius of 30 ?m, while maintaining its electrical performance under cyclic bending (bending radius: 500 ?m) for 100,000 iterations. Phosphorescent, blue organic light-emitting diodes (OLEDs) were fabricated using these composites as bottom electrodes (anodes). Hole-injection was poor, because AgNWs were largely buried beneath the composite's surface. Thus, we used a simple plasma treatment to remove the thin cPI layer overlaying the nanowires without introducing other conductive materials. As a result, we were able to finely control the flexible OLEDs' electroluminescent properties using the enlarged conductive pathways. The fabricated flexible devices showed only slight performance reductions of <3% even after repeated foldings with a 30 ?m bending radius.

  13. Ultra-thin and smooth transparent electrode for flexible and leakage-free organic light-emitting diodes.

    PubMed

    Ok, Ki-Hun; Kim, Jiwan; Park, So-Ra; Kim, Youngmin; Lee, Chan-Jae; Hong, Sung-Jei; Kwak, Min-Gi; Kim, Namsu; Han, Chul Jong; Kim, Jong-Woong

    2015-01-01

    A smooth, ultra-flexible, and transparent electrode was developed from silver nanowires (AgNWs) embedded in a colorless polyimide (cPI) by utilizing an inverted film-processing method. The resulting AgNW-cPI composite electrode had a transparency of >80%, a low sheet resistance of 8 ?/?, and ultra-smooth surfaces comparable to glass. Leveraging the robust mechanical properties and flexibility of cPI, the thickness of the composite film was reduced to less than 10??m, which is conducive to extreme flexibility. This film exhibited mechanical durability, for both outward and inward bending tests, up to a bending radius of 30??m, while maintaining its electrical performance under cyclic bending (bending radius: 500??m) for 100,000 iterations. Phosphorescent, blue organic light-emitting diodes (OLEDs) were fabricated using these composites as bottom electrodes (anodes). Hole-injection was poor, because AgNWs were largely buried beneath the composite's surface. Thus, we used a simple plasma treatment to remove the thin cPI layer overlaying the nanowires without introducing other conductive materials. As a result, we were able to finely control the flexible OLEDs' electroluminescent properties using the enlarged conductive pathways. The fabricated flexible devices showed only slight performance reductions of <3% even after repeated foldings with a 30??m bending radius. PMID:25824143

  14. Performance enhancement of metal nanowire-based transparent electrodes by electrically driven nanoscale nucleation of metal oxides.

    PubMed

    Shiau, Yu-Jeng; Chiang, Kai-Ming; Lin, Hao-Wu

    2015-08-01

    Solution-processed silver nanowire (AgNW) electrodes have been considered to be promising materials for next-generation flexible transparent conductive electrodes. Despite the fact that a single AgNW has extremely high conductivities, the high junction resistance between nanowires limits the performance of the AgNW matrix. Therefore, post-treatments are usually required to approach better NW-NW contact. Herein, we report a novel linking method that uses joule heating to accumulate sol-gel ZnO near nanowire junctions. The nanoscale ZnO nucleation successfully restrained the thermal instability of the AgNW under current injection and acted as an efficient tightening medium to realize good NW-NW contacts. A low process temperature (<50 °C), and thus low energy consumption, are required for ZnO nucleation. This made the use of substrates with very low operating temperatures, such as PET and PEN, feasible. The optimized AgNW transparent conductive electrodes (TCE) fabricated using this promising linking method exhibited a low sheet resistance (13 ? sq(-1)), a high transmission (92% at 550 nm), a high figure of merit (FOM; up to ?DC/?Op = 340) and can be applied to wide range of next-generation flexible optoelectronic devices. PMID:26152810

  15. Ultra-thin and smooth transparent electrode for flexible and leakage-free organic light-emitting diodes

    PubMed Central

    Ok, Ki-Hun; Kim, Jiwan; Park, So-Ra; Kim, Youngmin; Lee, Chan-Jae; Hong, Sung-Jei; Kwak, Min-Gi; Kim, Namsu; Han, Chul Jong; Kim, Jong-Woong

    2015-01-01

    A smooth, ultra-flexible, and transparent electrode was developed from silver nanowires (AgNWs) embedded in a colorless polyimide (cPI) by utilizing an inverted film-processing method. The resulting AgNW-cPI composite electrode had a transparency of >80%, a low sheet resistance of 8 ?/?, and ultra-smooth surfaces comparable to glass. Leveraging the robust mechanical properties and flexibility of cPI, the thickness of the composite film was reduced to less than 10??m, which is conducive to extreme flexibility. This film exhibited mechanical durability, for both outward and inward bending tests, up to a bending radius of 30??m, while maintaining its electrical performance under cyclic bending (bending radius: 500??m) for 100,000 iterations. Phosphorescent, blue organic light-emitting diodes (OLEDs) were fabricated using these composites as bottom electrodes (anodes). Hole-injection was poor, because AgNWs were largely buried beneath the composite's surface. Thus, we used a simple plasma treatment to remove the thin cPI layer overlaying the nanowires without introducing other conductive materials. As a result, we were able to finely control the flexible OLEDs' electroluminescent properties using the enlarged conductive pathways. The fabricated flexible devices showed only slight performance reductions of <3% even after repeated foldings with a 30??m bending radius. PMID:25824143

  16. Efficient Dye-Sensitized Solar Cells Made from High Catalytic Ability of Polypyrrole@Platinum Counter Electrode

    NASA Astrophysics Data System (ADS)

    Ma, Xingping; Yue, Gentian; Wu, Jihuai; Lan, Zhang

    2015-08-01

    Polypyrrole@platinum (PPy@Pt) composite film was successfully synthesized by using a one-step electrochemical method and served as counter electrode (CE) for efficient dye-sensitized solar cells (DSSCs). The PPy@Pt CE with one-dimensional structure exhibited excellent electrocatalytic activity and superior charge transfer resistance for I-/I3 - electrolyte after being the cyclic voltammetry and electrochemical impedance spectroscopy tested. The photocurrent-photovoltage curves were further used to calculate the theoretical photoelectric performance parameters of the DSSCs. The DSSC based on the PPy@Pt CE achieved a remarkable power conversion efficiency of 7.35 %, higher about 19.9 % than that of conventional Pt CE (6.13 %). This strategy provides a new opportunity for fabricating low-cost and highly efficient DSSCs.

  17. Impacts of high-electroactive-surface-area buckypaper counter electrodes on the photovoltaic performance of dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Cheng, Cheng-En; Lin, Yu-Chang; Tsai, Shang-Yi; Lin, Zheng-Kun; Lee, Ping-Chen; Miao, Hsin-Yuan; Chang, Chen-Shiung; Shih-Sen Chien, Forest

    2015-09-01

    In this paper we study the photovoltaic performance of dye-sensitized solar cells (DSCs) with high-electroactive-surface-area buckypaper (BP) counter electrodes (CEs). BP is made of entangled multi-walled carbon nanotubes and has a high electroactive surface area, which is effectively 11.5 times higher than that of Pt. The high surface area of BP causes a high \\text{I}3- reduction rate at the CEs and suppresses the charge recombination at the anodes. Accordingly, the open-circuit voltage, the filling factor, and the power conversion efficiency of DSCs with BP CEs are enhanced, and these photovoltaic parameters exhibit a better trend with the increase of solar power compared with conventional DSCs with Pt CEs.

  18. Carbonaceous materials and their advances as a counter electrode in dye-sensitized solar cells: challenges and prospects.

    PubMed

    Kouhnavard, Mojgan; Ludin, Norasikin Ahmad; Ghaffari, Babak V; Sopian, Kamarozzaman; Ikeda, Shoichiro

    2015-05-11

    Dye-sensitized solar cells (DSSCs) serve as low-costing alternatives to silicon solar cells because of their low material and fabrication costs. Usually, they utilize Pt as the counter electrode (CE) to catalyze the iodine redox couple and to complete the electric circuit. Given that Pt is a rare and expensive metal, various carbon materials have been intensively investigated because of their low costs, high surface areas, excellent electrochemical stabilities, reasonable electrochemical activities, and high corrosion resistances. In this feature article, we provide an overview of recent studies on the electrochemical properties and photovoltaic performances of carbon-based CEs (e.g., activated carbon, nanosized carbon, carbon black, graphene, graphite, carbon nanotubes, and composite carbon). We focus on scientific challenges associated with each material and highlight recent advances achieved in overcoming these obstacles. Finally, we discuss possible future directions for this field of research aimed at obtaining highly efficient DSSCs. PMID:25925421

  19. Efficient Dye-Sensitized Solar Cells Made from High Catalytic Ability of Polypyrrole@Platinum Counter Electrode.

    PubMed

    Ma, Xingping; Yue, Gentian; Wu, Jihuai; Lan, Zhang

    2015-12-01

    Polypyrrole@platinum (PPy@Pt) composite film was successfully synthesized by using a one-step electrochemical method and served as counter electrode (CE) for efficient dye-sensitized solar cells (DSSCs). The PPy@Pt CE with one-dimensional structure exhibited excellent electrocatalytic activity and superior charge transfer resistance for I(-)/I3 (-) electrolyte after being the cyclic voltammetry and electrochemical impedance spectroscopy tested. The photocurrent-photovoltage curves were further used to calculate the theoretical photoelectric performance parameters of the DSSCs. The DSSC based on the PPy@Pt CE achieved a remarkable power conversion efficiency of 7.35 %, higher about 19.9 % than that of conventional Pt CE (6.13 %). This strategy provides a new opportunity for fabricating low-cost and highly efficient DSSCs. PMID:26272804

  20. Development of a Novel Bidimensional Spectroelectrochemistry Cell Using Transfer Single-Walled Carbon Nanotubes Films as Optically Transparent Electrodes.

    PubMed

    Garoz-Ruiz, Jesus; Heras, Aranzazu; Palmero, Susana; Colina, Alvaro

    2015-06-16

    A really easy method to transfer commercial single-walled carbon nanotubes (SWCNTs) to different substrates is proposed. In this paper, a homogeneous transference of SWCNTs films to nonconductor and transparent supports, such as polyethylene terephthalate, glass, and quartz, and to conductor supports, such as indium tin oxide, aluminum, highly ordered pyrolytic graphite, and glassy carbon, was achieved using a very fast, reproducible, and clean methodology. In order to test these transferences, SWCNTs films transferred on quartz were used as working optically UV-vis transparent electrodes due to their optimal electrical and optical properties. A new easy-to-use, homemade optical fiber based cell for bidimensional spectroelectrochemistry was developed, offering the possibility to measure in normal and parallel configuration. The cell was tested with ferrocenemethanol, a compound widely used in electrochemistry but scarcely studied by spectroelectrochemistry, covering the UV-vis spectral region. PMID:25989247

  1. GaN nanorod light emitting diodes with suspended graphene transparent electrodes grown by rapid chemical vapor deposition

    SciTech Connect

    Xu, Kun; Xu, Chen Deng, Jun; Zhu, Yanxu; Guo, Weiling; Mao, Mingming; Xun, Meng; Chen, Maoxing; Zheng, Lei; Xie, Yiyang; Sun, Jie; Mikroteknologi och Nanovetenskap, Chalmers Tekniska Högskola AB, Göteborg 41296

    2013-11-25

    Ordered and dense GaN light emitting nanorods are studied with polycrystalline graphene grown by rapid chemical vapor deposition as suspended transparent electrodes. As the substitute of indium tin oxide, the graphene avoids complex processing to fill up the gaps between nanorods and subsequent surface flattening and offers high conductivity to improve the carrier injection. The as-fabricated devices have 32% improvement in light output power compared to conventional planar GaN-graphene diodes. The suspended graphene remains electrically stable up to 300?°C in air. The graphene can be obtained at low cost and high efficiency, indicating its high potential in future applications.

  2. A composite catalyst of reduced black TiO2-x/CNT: a highly efficient counter electrode for ZnO-based dye-sensitized solar cells.

    PubMed

    Zhang, Chunyang; Xie, Yahong; Ma, Junhong; Hu, Jing; Zhang, Cancan

    2015-12-21

    A composite catalyst (reduced black TiO2-x/carbon nanotube) was synthesized through a simple sol-gel method and applied as a counter electrode (CE) in ZnO-based dye-sensitized solar cells (DSSCs). This material demonstrated notable electrocatalytic activity for I3(-) reduction, and the resultant DSSCs achieved a PCE of 5.71%. PMID:26473174

  3. Flexible transparent conducting composite films using a monolithically embedded AgNW electrode with robust performance stability.

    PubMed

    Im, Hyeon-Gyun; Jin, Jungho; Ko, Ji-Hoon; Lee, Jaemin; Lee, Jung-Yong; Bae, Byeong-Soo

    2014-01-21

    We report on the performance of an all-in-one flexible hybrid conducting film employing a monolithically embedded AgNW transparent electrode and a high-performance glass-fabric reinforced composite substrate (AgNW-GFRHybrimer film). Specifically, we perform in-depth investigations on the stability of the AgNW-GFRHybrimer film against heat, thermal oxidation, and wet chemicals to demonstrate the potential of the hybrid conducting film as a robust electrode platform for thin-film optoelectronic devices. With the ease of large-area processability, smooth surface topography, and robust performance stability, the AgNW-GFRHybrimer film can be a promising platform for high-performance optoelectronic devices. PMID:24284890

  4. Flexible transparent conducting composite films using a monolithically embedded AgNW electrode with robust performance stability

    NASA Astrophysics Data System (ADS)

    Im, Hyeon-Gyun; Jin, Jungho; Ko, Ji-Hoon; Lee, Jaemin; Lee, Jung-Yong; Bae, Byeong-Soo

    2013-12-01

    We report on the performance of an all-in-one flexible hybrid conducting film employing a monolithically embedded AgNW transparent electrode and a high-performance glass-fabric reinforced composite substrate (AgNW-GFRHybrimer film). Specifically, we perform in-depth investigations on the stability of the AgNW-GFRHybrimer film against heat, thermal oxidation, and wet chemicals to demonstrate the potential of the hybrid conducting film as a robust electrode platform for thin-film optoelectronic devices. With the ease of large-area processability, smooth surface topography, and robust performance stability, the AgNW-GFRHybrimer film can be a promising platform for high-performance optoelectronic devices.We report on the performance of an all-in-one flexible hybrid conducting film employing a monolithically embedded AgNW transparent electrode and a high-performance glass-fabric reinforced composite substrate (AgNW-GFRHybrimer film). Specifically, we perform in-depth investigations on the stability of the AgNW-GFRHybrimer film against heat, thermal oxidation, and wet chemicals to demonstrate the potential of the hybrid conducting film as a robust electrode platform for thin-film optoelectronic devices. With the ease of large-area processability, smooth surface topography, and robust performance stability, the AgNW-GFRHybrimer film can be a promising platform for high-performance optoelectronic devices. Electronic supplementary information (ESI) available: Further characteristics of AgNW-GFRHybrimer films and thermal oxidation of AgNW on glass. See DOI: 10.1039/c3nr05348b

  5. FeS/nickel foam as stable and efficient counter electrode material for quantum dot sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Geng, Huifang; Zhu, Liqun; Li, Weiping; Liu, Huicong; Quan, Linlin; Xi, Fanxing; Su, Xunwen

    2015-05-01

    A stable and efficient FeS/nickel foam (NF) counter electrode for quantum dots-sensitized solar cells (QDSCs) is first fabricated by electrochemistry deposition and characterized with scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), current voltage and impedance spectroscopy. The QDSC based on FeS/NF CE achieves a power conversion efficiency (PCE) of 4.39% attributing to the high fill factor (FF) of 0.58, and the PCE is much higher than that of based on FeS/FTO CE (2.76%) and other reported FeS CEs (1.76% and 3.34%). The phenomenon that the electrode can transform between FeS/NF (in the polysulfide electrolyte) and Fe2O3/NF (in the air) spontaneously is first reported. And the excellent stability in photoelectric performance of the CE is also demonstrated in the present work. Therefore, the FeS/NF is very promising as a stable and efficient CE for QDSCs.

  6. Transparent thin-film transistors with pentacene channel, AlOx gate, and NiOx electrodes

    NASA Astrophysics Data System (ADS)

    Choi, Jeong-M.; Hwang, D. K.; Kim, Jae Hoon; Im, Seongil

    2005-03-01

    We report on the fabrication of pentacene-based transparent thin-film transistors (TTFT) that consist of NiOx, AlOx, and indium-tin-oxide (ITO) for the source-drain (S/D) electrode, gate dielectric, and gate electrode, respectively. The NiOx S/D electrodes of which the work function is well matched to that of pentacene were deposited on a 50-nm-thick pentacene channel by thermal evaporation of NiO powder and showed a moderately low but still effective transmittance of ˜25% in the visible range along with a good sheet resistance of ˜60? /?. The maximum saturation current of our pentacene-based TTFT was about 15?A at a gate bias of -40V showing a high field effect mobility of 0.9cm2/Vs in the dark, and the on/off current ratio of our TTFT was about 5×105. It is concluded that jointly adopting NiOx for the S/D electrode and AlOx for gate dielectric realizes a high-quality pentacene-based TTFT.

  7. In situ synthesis of binary cobalt-ruthenium nanofiber alloy counter electrode for electrolyte-free cadmium sulfide quantum dot solar cells

    NASA Astrophysics Data System (ADS)

    Du, Nan; Ren, Lei; Sun, Weifu; Jin, Xiao; Zhao, Qing; Cheng, Yuanyuan; Wei, Taihuei; Li, Qinghua

    2015-06-01

    A facile, low-cost and low-temperature fabrication approach of counter electrode is essential for pursuing robust photovoltaic devices. Herein, we develop a hydrothermal in situ growth of Cobalt-Ruthenium (Co-Ru) alloy nanofiber electrode for quantum dot solar cell (QDSC) applications. Colloidal CdS QDs with tunable absorption band edge are synthesized and used as light absorber. After optimizing the QDs with the highest photoluminescence quantum yield accompanied by considerable solar light absorption ability, QDSC based on Co-Ru alloy electrode delivers a much higher power conversion efficiency than its counterparts, i.e., either pure Co or Ru metal electrodes. In detail, Co-Ru alloy electrode exhibits high specific area, excellent electrical behavior, intimate interface contact, and good stability, thus leading to notable improved device performances. The impressive robust function of Co-Ru alloy with simple manufacturing procedure highlights its potential applications in robust QDSCs.

  8. Effect of purity on the electro-optical properties of single wall nanotube-based transparent conductive electrodes

    SciTech Connect

    Garrett, Matthew P; Ivanov, Ilia N; Geohegan, David B; Hu, Bin

    2013-01-01

    We present a detailed assessment of centrifugation technique for purification of single wall carbon nanotubes (SWCNTs) for application as transparent conductive electrodes. As- grown and highly-purified SWCNTs were dispersed in surfactants by ultrasonication, and then centrifuged to selectively remove carbonaceous and metal impurities. The centrifuged supernatant suspensions were made into thin films by transferring filtrated nanotube coat- ings onto glass slides. The absorbance and resistance of nanotube coatings were measured, and their optical purity level estimated from a comparison of the area of the near-infrared S22 SWCNT optical absorption band relative to the area of the background. The single-step centrifugation process is shown to purify laser-vaporization grown SWCNTs from an initial optical purity of 0.10 to an averaged purity of 0.23, with an 8.8% yield, which is comparable to other purification techniques. The quality of transparent conductive electrodes esti- mated as a ratio of visible-spectrum absorbance to sheet conductivity is improved by a fac- tor of 12 upon purification.

  9. Fabrication of Oxidation-Resistant Metal Wire Network-Based Transparent Electrodes by a Spray-Roll Coating Process.

    PubMed

    Kiruthika, S; Gupta, Ritu; Anand, Aman; Kumar, Ankush; Kulkarni, G U

    2015-12-16

    Roll and spray coating methods have been employed for the fabrication of highly oxidation resistant transparent and conducting electrodes (TCEs) by a simple solution process using crackle lithography technique. We have spray-coated a crackle paint-based precursor to produce highly interconnected crackle network on PET roll mounted on a roll coater with web speed of 0.6 m/min. Ag TCE with a transmittance of 78% and sheet resistance of ?20 ?/? was derived by spraying Ag precursor ink over the crackle template followed by lift-off and annealing under ambient conditions. The Ag wire mesh was stable toward bending and sonication tests but prone to oxidation in air. When electrolessly coated with Pd, its robustness toward harsh oxidation conditions was enhanced. A low-cost transparent electrode has also been realized by using only small amounts of Ag as seed layer and growing Cu wire mesh by electroless method. Thus, made Ag/Cu meshes are found to be highly stable for more than a year even under ambient atmosphere. PMID:26580415

  10. Design and fabrication of nanometric TiO2/Ag/TiO2/Ag/TiO2 transparent conductive electrode for inverted organic photovoltaic cells application

    NASA Astrophysics Data System (ADS)

    Ghasemi Varnamkhasti, Mohsen; Shahriari, Esmaeil

    2014-05-01

    In this study, transparent conductive TiO2/Ag/TiO2/Ag/TiO2 (TATAT) nano-multilayer system is designed and optimum thickness of TiO2 and Ag layers are calculated. TATAT nano-multilayer films were deposited on glass substrates at room temperature by a thermal evaporation technique. We investigated some electrical, optical and structural properties of optimized TATAT multilayer such as sheet resistance, optical transmittance and the root-mean-square surface roughness. Here, we suggest a very low resistance transparent electrode (2.3 (?/?)) with a high transmittance (90%) for optoelectronics applications. Inverted organic photovoltaic cell was fabricated on the TATAT cathode. The fabricated cell with 12 nm of Ag layer shows higher power conversion efficiency (2.68%) compared to that fabricated on the ITO electrode (1.84%). The results show that the TATAT multilayer system is a suitable structure for use as transparent conductive electrode in optoelectronic devices.

  11. Time resolved optical emission images of an atmospheric pressure plasma jet with transparent electrodes

    SciTech Connect

    Puac, N.; Maletic, D.; Lazovic, S.; Malovic, G.; Petrovic, Z. Lj.; Dordevic, A.

    2012-07-09

    We study development of plasma packages in atmospheric pressure plasma jet from their formation as a discharge close to the instantaneous cathode, following their motion between and inside the electrodes up to their emergence at the edge of the glass tube and formation of a plasma bullet. Inside both electrodes, plasma is concentrated close to the walls and is bright, while outside it is located at the axis. This paper opens issues of the geometry of electrodes, fields, and atomic processes, allowing some predictions to be made about pertinent mechanisms.

  12. Light absorption mechanism in organic solar cells with hexagonal lattice nanohole aluminum transparent electrodes

    NASA Astrophysics Data System (ADS)

    Du, Qing Guo; Ren, Hengjiang; Wu, Lin; Bai, Ping; Eng Png, Ching; Sun, Xiao Wei; Hin Kam, Chan; de Sterke, C. Martijn

    2015-08-01

    We present the design of an organic solar cell (OSC), integrated with nanohole patterned aluminum electrode with hexagonal lattice and analyze the light absorption mechanism in detail. The periodic nanohole pattern in the electrode excites a resonant waveguide mode which localizes the electromagnetic fields into the active layer at the long wavelengths where the active material usually has a relatively low absorption coefficient. The calculated maximum achievable photocurrent density indicates that OSC integrated with nanohole patterned aluminum electrode shows slightly better performance compare to that of the conventional OSC integrated with an indium tin oxide electrode. Moreover, the waveguide mode can be tuned by varying the period of the nanohole array and the thickness of nanocrystalline zinc oxide for different kinds of cell structures. By combining with other strategies to enhance the absorption at the short wavelength, our finding provides a promising way to further improve the efficiency of the OSCs.

  13. A dye-sensitized solar cell based on natural photosensitizers and a PEDOT:PSS/TiO2 film as a counter electrode

    NASA Astrophysics Data System (ADS)

    Jafari, Fatemeh; Behjat, Abbas; Khoshroo, Ali R.; Ghoshani, Maral

    2015-02-01

    Poly(3, 4-ethylendioxythiophene)-poly(styrene sulfonate) mixed with TiO2 nanoparticles (PEDOT:PSS/TiO2) was used as a catalyst for tri-iodide reduction in dye-sensitized solar cells based on natural photosensitizers. A PEDOT:PSS/TiO2 film was coated on a conductive glass substrate by the spin coating method. The solar cells were fabricated, having the PEDOT:PSS/TiO2 film as a counter electrode and Pomegranate juice dye-sensitized TiO2 as an anode. The morphology of PEDOT:PSS/TiO2 films was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM) images. Cyclic voltammetry (CV) was employed to characterize the catalytic activity of the PEDOT:PSS/TiO2 film. Based on the analysis of CV, the enhancements for the electrochemical and photochemical performance of the PEDOT:PSS/TiO2 electrode are attributed to the fact that the dispersed TiO2 nanoparticles in the PEDOT:PSS matrix provide an improved catalytic activity and a facilitated diffusion for tri-iodide ions. The energy conversion efficiency is significantly improved after TiO2 nanoparticle incorporation. This improvement might be attributed to an increase in the counter electrode catalytic activity. The highest efficiency of 0.73% was obtained by using 100 nm TiO2 nanoparticles in the counter electrode.

  14. Direct synthesis of graphene 3D-coated Cu nanosilks network for antioxidant transparent conducting electrode

    NASA Astrophysics Data System (ADS)

    Xu, Hongmei; Wang, Huachun; Wu, Chenping; Lin, Na; Soomro, Abdul Majid; Guo, Huizhang; Liu, Chuan; Yang, Xiaodong; Wu, Yaping; Cai, Duanjun; Kang, Junyong

    2015-06-01

    Transparent conducting film occupies an important position in various optoelectronic devices. To replace the costly tin-doped indium oxide (ITO), promising materials, such as metal nanowires and graphene, have been widely studied. Moreover, a long-pursued goal is to consolidate these two materials together and express their outstanding properties simultaneously. We successfully achieved a direct 3D coating of a graphene layer on an interlacing Cu nanosilks network by the low pressure chemical vapor deposition method. High aspect ratio Cu nanosilks (13 nm diameter with 40 ?m length) were synthesized through the nickel ion catalytic process. Large-size, transparent conducting film was successfully fabricated with Cu nanosilks ink by the imprint method. A magnetic manipulator equipped with a copper capsule was used to produce high Cu vapor pressure on Cu nanosilks and realize the graphene 3D-coating. The coated Cu@graphene nanosilks network achieved high transparency, low sheet resistance (41 Ohm sq-1 at 95% transmittance) and robust antioxidant ability. With this technique, the transfer process of graphene is no longer needed, and a flexible, uniform and high-performance transparent conducting film could be fabricated in unlimited size.Transparent conducting film occupies an important position in various optoelectronic devices. To replace the costly tin-doped indium oxide (ITO), promising materials, such as metal nanowires and graphene, have been widely studied. Moreover, a long-pursued goal is to consolidate these two materials together and express their outstanding properties simultaneously. We successfully achieved a direct 3D coating of a graphene layer on an interlacing Cu nanosilks network by the low pressure chemical vapor deposition method. High aspect ratio Cu nanosilks (13 nm diameter with 40 ?m length) were synthesized through the nickel ion catalytic process. Large-size, transparent conducting film was successfully fabricated with Cu nanosilks ink by the imprint method. A magnetic manipulator equipped with a copper capsule was used to produce high Cu vapor pressure on Cu nanosilks and realize the graphene 3D-coating. The coated Cu@graphene nanosilks network achieved high transparency, low sheet resistance (41 Ohm sq-1 at 95% transmittance) and robust antioxidant ability. With this technique, the transfer process of graphene is no longer needed, and a flexible, uniform and high-performance transparent conducting film could be fabricated in unlimited size. Electronic supplementary information (ESI) available: Photographs, transmission spectra, Auger electron spectroscopy (AES) and transmission electron microscopy (TEM) images. See DOI: 10.1039/c5nr01711d

  15. Multiwalled carbon nanotube coated polyester fabric as textile based flexible counter electrode for dye sensitized solar cell.

    PubMed

    Arbab, Alvira Ayoub; Sun, Kyung Chul; Sahito, Iftikhar Ali; Qadir, Muhammad Bilal; Jeong, Sung Hoon

    2015-05-21

    Textile wearable electronics offers the combined advantages of both electronics and textile characteristics. The essential properties of these flexible electronics such as lightweight, stretchable, and wearable power sources are in strong demand. Here, we have developed a facile route to fabricate multi walled carbon nanotube (MWCNT) coated polyester fabric as a flexible counter electrode (CE) for dye sensitized solar cells (DSSCs). A variety of MWCNT and enzymes with different structures were used to generate individual enzyme-dispersed MWCNT (E-MWCNT) suspensions by non-covalent functionalization. A highly concentrated colloidal suspension of E-MWCNT was deposited on polyester fabric via a simple tape casting method using an air drying technique. In view of the E-MWCNT coating, the surface structure is represented by topologically randomly assembled tubular graphene units. This surface morphology has a high density of colloidal edge states and oxygen-containing surface groups which execute multiple catalytic sites for iodide reduction. A highly conductive E-MWCNT coated fabric electrode with a surface resistance of 15 ? sq(-1) demonstrated 5.69% power conversion efficiency (PCE) when used as a flexible CE for DSSCs. High photo voltaic performance of our suggested system of E-MWCNT fabric-based DSSCs is associated with high sheet conductivity, low charge transfer resistance (RCT), and excellent electro catalytic activity (ECA). Such a conductive fabric demonstrated stable conductivity against bending cycles and strong mechanical adhesion of E-MWCNT on polyester fabric. Moreover, the polyester fabric is hydrophobic and, therefore, has good sealing capacity and retains the polymer gel electrolyte without seepage. This facile E-MWCNT fabric CE configuration provides a concrete fundamental background towards the development of textile-integrated solar cells. PMID:25912056

  16. Improved Efficiency of Hybrid Organic Photovoltaics by Pulsed Laser Sintering of Silver Nanowire Network Transparent Electrode

    E-print Network

    Arnold, Craig B.

    Improved Efficiency of Hybrid Organic Photovoltaics by Pulsed Laser Sintering of Silver Nanowire: In this Research Article, we demonstrate pulsed laser processing of a silver nanowire network transparent conductor INTRODUCTION Percolating networks of silver nanowires (AgNW) efficiently conduct electricity while allowing

  17. Direct synthesis of graphene 3D-coated Cu nanosilks network for antioxidant transparent conducting electrode.

    PubMed

    Xu, Hongmei; Wang, Huachun; Wu, Chenping; Lin, Na; Soomro, Abdul Majid; Guo, Huizhang; Liu, Chuan; Yang, Xiaodong; Wu, Yaping; Cai, Duanjun; Kang, JunYong

    2015-06-28

    Transparent conducting film occupies an important position in various optoelectronic devices. To replace the costly tin-doped indium oxide (ITO), promising materials, such as metal nanowires and graphene, have been widely studied. Moreover, a long-pursued goal is to consolidate these two materials together and express their outstanding properties simultaneously. We successfully achieved a direct 3D coating of a graphene layer on an interlacing Cu nanosilks network by the low pressure chemical vapor deposition method. High aspect ratio Cu nanosilks (13 nm diameter with 40 ?m length) were synthesized through the nickel ion catalytic process. Large-size, transparent conducting film was successfully fabricated with Cu nanosilks ink by the imprint method. A magnetic manipulator equipped with a copper capsule was used to produce high Cu vapor pressure on Cu nanosilks and realize the graphene 3D-coating. The coated Cu@graphene nanosilks network achieved high transparency, low sheet resistance (41 Ohm sq(-1) at 95% transmittance) and robust antioxidant ability. With this technique, the transfer process of graphene is no longer needed, and a flexible, uniform and high-performance transparent conducting film could be fabricated in unlimited size. PMID:26018299

  18. Enhancement of the efficiency of dye-sensitized solar cell with multi-wall carbon nanotubes/polypyrrole composite counter electrodes prepared by electrophoresis/electrochemical polymerization

    SciTech Connect

    Luo, Jun; Niu, Hai-jun; Wen, Hai-lin; Wu, Wen-jun; Zhao, Ping; Wang, Cheng; Bai, Xu-duo; Wang, Wen

    2013-03-15

    Graphical abstract: The overall energy conversion efficiency of the DSSC employing the MWCNT/PPy CE reached 3.78%. Compared with a reference DSSC using single MWCNT film CE with efficiency of 2.68%, the energy conversion efficiency was increased by 41.04%. Highlights: ? MWCNT/PPy composite film prepared by electrodeposition layer by layer was used as counter electrode in DSSC. ? The overall energy conversion efficiency of the DSSC was 3.78% by employing the composite film. ? The energy conversion efficiency increased by 41.04% compared with efficiency of 2.68% by using the single MWCNT film. ? We analyzed the mechanism and influence factor of electron transfer in the composite electrode by EIS. - Abstract: For the purpose of replacing the precious Pt counter electrode in dye-sensitized solar cells (DSSCs) with higher energy conversion efficiency, multi-wall carbon nanotube (MWCNT)/polypyrrole (PPy) double layers film counter electrode (CE) was fabricated by electrophoresis and cyclic voltammetry (CV) layer by layer. Atom force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscope (TEM) demonstrated the morphologies of the composite electrode and Raman spectroscopy verified the PPy had come into being. The overall energy conversion efficiency of the DSSC employing the MWCNT/PPy CE reached 3.78%. Compared with a reference DSSC using single MWCNT film CE with efficiency of 2.68%, the energy conversion efficiency was increased by 41.04%. The result of impedance showed that the charge transfer resistance R{sub ct} of the MWCNT/PPy CE had the lowest value compared to that of MWCNT or PPy electrode. These results indicate that the composite film with high conductivity, high active surface area, and good catalytic properties for I{sub 3}{sup ?} reduction can potentially be used as the CE in a high-performance DSSC.

  19. Nanocarbon-copper thin film as transparent electrode R. A. Isaacs, H. Zhu, Colin Preston, A. Mansour, M. LeMieux, P. Y. Zavalij, H. M. Iftekhar Jaim, O. Rabin, L. Hu,

    E-print Network

    Anlage, Steven

    Nanocarbon-copper thin film as transparent electrode R. A. Isaacs, H. Zhu, Colin Preston, A: Thu, 14 May 2015 16:17:02 #12;Nanocarbon-copper thin film as transparent electrode R. A. Isaacs,1 H to high conductivity. The incorporation of carbon nanostructures into the copper lattice has the potential

  20. Dually functional, N-doped porous graphene foams as counter electrodes for dye-sensitized solar cells.

    PubMed

    Song, Long; Luo, Qiang; Zhao, Fei; Li, Yang; Lin, Hong; Qu, Liangti; Zhang, Zhipan

    2014-10-21

    A series of nitrogen-doped porous graphene foams (NPGFs) have been prepared by hydrothermally treating a mixed solution of graphite oxide (GO) and ammonia. The NPGFs are used as the counter electrode (CE) material for dye-sensitized solar cells (DSCs) in conjunction with the conventional iodide-based electrolyte and the recently developed sulfide-based electrolyte. Tafel-polarization tests and electrochemical impedance spectroscopic (EIS) measurements confirmed that the NPGFs work efficiently in both electrolyte systems, and under air mass (AM) 1.5G 100 mW cm(-2) light illumination, optimal efficiencies of 4.5% and 2.1% were obtained for the iodide-based electrolyte and sulfide-based electrolyte, respectively. To the best of our knowledge, this is the first study on N-doped graphene CEs in conjunction with sulfide-based electrolytes and therefore, the current results are deemed to provide new insights into developing novel low-cost and metal-free CEs for DSCs. PMID:25199841

  1. Enhanced Photovoltaic Performance in Polypyrrole Nanoparticles Counter Electrode Due to Incorporation of Multi-Walled Carbon Nanotubes.

    PubMed

    Baro, Mridula; Vijayan, C; Ramaprabhu, Sundara

    2015-07-01

    In this present work, Multi-walled carbon nanotubes (MWNTs) with different content by weight (10%, 20%, 30%, 50% and 70%) are introduced into Polypyrrole nanoparticles (PPy NP) matrix and fabricated as Pt free counter electrodes (CEs) for dye-sensitized solar cell (DSSC). For comparison DSSCs using pristine PPy NP, MWNTs and Platinum (Pt) were also fabricated. The incorporation of MWNTs acts as conductive channel and co-catalyst to the PPy NP CEs in the reduction of li to I-. The electrochemical catalytic activities of different CEs were analysed by Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) and photovoltaic performance was studied under standard AM 1.5 sunlight illumination. It was observed that incorporation of MWNTs in the PPy NP CE greatly enhanced the catalytic activity for I3 reduction and significantly reduced the charge transfer resistance in the PPy NP/MWNTs composite CE finally improving short-circuit photocurrent density, fill factor, open circuit voltage and power conversion efficiency of DSSC. DSSC fabricated from PPy NP/MWNTs composite CE with 50% MWNTs content reached the highest photoconversion efficiency of 5.80% which is 91% that of Pt CE based DSSC (6.37%). PMID:26373060

  2. Low-Temperature Thermally Reduced Molybdenum Disulfide as a Pt-Free Counter Electrode for Dye-Sensitized Solar Cells.

    PubMed

    Lin, Che-Hsien; Tsai, Chuen-Horng; Tseng, Fan-Gang; Yu, Yang-Yen; Wu, Hsuan-Chung; Hsieh, Chien-Kuo

    2015-12-01

    A two-dimensional nanostructure of molybdenum disulfide (MoS2) thin film exposed layered nanosheet was prepared by a low-temperature thermally reduced (TR) method on a fluorine-doped tin oxide (FTO) glass substrate as a platinum (Pt)-free and highly electrocatalytic counter electrode (CE) for dye-sensitized solar cells (DSSCs). Thermogravimetric analysis (TGA) results show that the MoS2 sulfidization temperature was approximately 300 °C. X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD) indicate that the stoichiometry and crystallization of MoS2 were more complete at higher temperatures; however, these temperatures reduce the number of edge-plane active sites in the short-range-order nanostructure. Accordingly, the DSSCs with 300 °C annealed TR-MoS2 CE exhibited an excellent photovoltaic conversion efficiency (PCE) of 6.351 %, up to 91.7 % of which is obtained using the conventional TD-Pt CE (PCE?=?6.929 %). The temperature of thermal reaction and the molar ratio of reaction precursors were found to significantly influence the resulting stoichiometry and crystallization of MoS2 nanosheets, thus affecting DSSCs' performance. PMID:26577390

  3. Counter electrode electrocatalysts from one-dimensional coaxial alloy nanowires for efficient dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Duan, Jialong; Tang, Qunwei; Zhang, Huihui; Meng, Yuanyuan; Yu, Liangmin; Yang, Peizhi

    2016-01-01

    Pursuit of cost-effective counter electrode (CE) electrocatalysts with no sacrifice of photovoltaic performances has been a persistent objective for advanced dye-sensitized solar cell (DSSC) platforms. Here we demonstrate the experimental realization of CE electrocatalysts from Cu@M@Pt (M = Fe, Co, Ni) coaxial alloy nanowires for efficient DSSCs. The reasonable electrocatalytic activity is attributed to work function matching of alloy CEs to potential of I- /I3- and redistribute the electronic structure on the Pt surface. In comparison with 8.48% for the Pt nanotube CE based DSSC, the solar cells yield power conversion efficiencies up to 8.21%, 7.85%, and 7.30% using Cu@Fe@Pt, Cu@Co@Pt, and Cu@Ni@Pt NWs, respectively. This work represents an important step forward, as it demonstrates how to make the CE catalyst active and to accelerate the electron transport from CE to electrolyte for high-efficiency but cost-effective DSSC platforms.

  4. Highly effective nickel sulfide counter electrode catalyst prepared by optimal hydrothermal treatment for quantum dot-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Gopi, Chandu V. V. M.; Srinivasa Rao, S.; Kim, Soo-Kyoung; Punnoose, Dinah; Kim, Hee-Je

    2015-02-01

    Nickel sulfide (NiS) thin film has been deposited on a fluorine-doped tin oxide substrate by a hydrothermal method using 3-mercaptopropionic acid and used as an efficient counter electrode (CE) for polysulfide redox reactions in quantum dot-sensitized solar cells (QDSSCs). NiS has low toxicity and environmental compatibility. In the present study, the size of the NiS nanoparticle increases with the hydrothermal deposition time. The performance of the QDSSCs is examined in detail using polysulfide electrolyte with the NiS CE. A TiO2/CdS/CdSe/ZnS-based QDSSC using the NiS CE shows enhanced photovoltaic performance with a power conversion efficiency (PCE) of 3.03%, which is superior to that of a cell with Pt CE (PCE 2.20%) under one sun illumination (AM 1.5, 100 mW cm-2). The improved photovoltaic performance of the NiS-based QDSSC may be attributed to a low charge transfer resistance (5.08 ?) for the reduction of polysulfide on the CE, indicating greater electrocatalytic activity of the NiS. Electrochemical impedance spectroscopy, cyclic voltammetry, and Tafel-polarization measurements were used to investigate the electrocatalytic activity of the NiS and Pt CEs.

  5. NH3-treated WO3 as low-cost and efficient counter electrode for dye-sensitized solar cells.

    PubMed

    Song, Dandan; Chen, Zhao; Cui, Peng; Li, Meicheng; Zhao, Xing; Li, Yaoyao; Chu, Lihua

    2015-01-01

    A novel low-cost and efficient counter electrode (CE) was obtained by treating catalytic inert tungsten trioxide (WO3) nanomaterial in NH3 atmosphere at elevated temperatures. The formation of tungsten oxynitride from WO3 after NH3 treatment, as evidenced by X-ray photoelectron spectroscopy and X-ray diffraction, increases the catalytic activity of the CE. Correspondingly, the power conversion efficiency (PCE) of the DSC is significantly increased from 0.9% for pristine WO3 CE to 5.9% for NH3-treated WO3 CE. The photovoltaic performance of DSC using NH3-treated WO3 CE is comparable to that of DSC using standard Pt CE (with a PCE of 6.0%). In addition, it is also shown that NH3 treatment is more efficient than H2 or N2 treatment in enhancing the catalytic performance of WO3 CE. This work highlights the potential of NH3-treated WO3 for the application in DSCs and provides a facile method to get highly efficient and low-cost CEs from catalytic inert metal oxides. PMID:25852314

  6. Polymer-facilitated low temperature fusing of spray-coated silver nanowire networks as transparent top and bottom electrodes in small molecule organic photovoltaics (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Selzer, Franz; Weiß, Nelli; Kneppe, David; Bormann, Ludwig; Sachse, Christoph; Gaponik, Nikolai; Eychmüller, Alexander; Leo, Karl; Müller-Meskamp, Lars

    2015-10-01

    Networks of silver nanowires (AgNWs) are promising candidates for transparent conducting electrodes in organic photovoltaics (OPV), as they achieve similar performance as the commonly used indium tin oxide (ITO) at lower cost and increased flexibility. The initial sheet resistance (Rs) of AgNW electrodes typically needs to be reduced by a post-annealing step (90 min@200 °C), being detrimental for processing on polymeric substrates. We present novel low temperature-based methods to integrate AgNWs in organic small molecule-based photovoltaics, either as transparent and highly conductive bottom-electrode or, for the first time, as spray-coated AgNW top-electrode. The bottom-electrodes are prepared by organic matrix assisted low-temperature fusing. Here, selected polymers are coated below the AgNWs to increase the interaction between NWs and substrate. In comparison to networks without these polymeric sublayers, the Rs is reduced by two orders of magnitude. AgNW top-electrodes are realized by dispersing modified high-quality AgNWs in inert solvents, which do not damage small molecule layers. Accordingly, our AgNW dispersion can be spray-coated onto all kind of OPV devices. Both bottom- and top-electrodes show a Rs of <11 ?/ at >87 % transparency directly after spray-coating at very low substrate temperatures of <80 °C. We also demonstrate the implementation of our AgNW electrodes in organic solar cells. The corresponding devices show almost identical performance compared to organic solar cells exploiting ITO as bottom or thermally evaporated thin-metal as top-electrode.

  7. Optical characterization of highly conductive single-wall carbon-nanotube transparent electrodes

    NASA Astrophysics Data System (ADS)

    Barnes, T. M.; van de Lagemaat, J.; Levi, D.; Rumbles, G.; Coutts, T. J.; Weeks, C. L.; Britz, D. A.; Levitsky, I.; Peltola, J.; Glatkowski, P.

    2007-06-01

    We report on a complete characterization of the optical dispersion properties of conducting thin films of single-wall carbon nanotubes (SWCNTs). The films studied exhibit sheet resistances between 50 and 1000?/sq and optical transparencies between 65% and 95% on glass and quartz substrates. These films have the potential to replace transparent conducting oxides in applications such as photovoltaics and flat-panel displays; however, their optical properties are not sufficiently well understood. The SWCNT films are shown to be hole conductors, potentially enabling their use as hole-selective contacts and allowing alternative device designs. The fundamental optical, morphological, and electrical characteristics of the films are presented here, and a phenomenological optical model that accurately describes the optical behavior of the films is introduced. Particular attention is paid to ellipsometry measurements and thorough evaluation of the reflection and absorption spectra of the films.

  8. Large-area functionalized CVD graphene for work function matched transparent electrodes

    NASA Astrophysics Data System (ADS)

    Bointon, Thomas H.; Jones, Gareth F.; de Sanctis, Adolfo; Hill-Pearce, Ruth; Craciun, Monica F.; Russo, Saverio

    2015-11-01

    The efficiency of flexible photovoltaic and organic light emitting devices is heavily dependent on the availability of flexible and transparent conductors with at least a similar workfunction to that of Indium Tin Oxide. Here we present the first study of the work function of large area (up to 9?cm2) FeCl3 intercalated graphene grown by chemical vapour deposition on Nickel, and demonstrate values as large as 5.1?eV. Upon intercalation, a charge density per graphene layer of 5???1013?±?5???1012?cm?2 is attained, making this material an attractive platform for the study of plasmonic excitations in the infrared wavelength spectrum of interest to the telecommunication industry. Finally, we demonstrate the potential of this material for flexible electronics in a transparent circuit on a polyethylene naphthalate substrate.

  9. Large-area functionalized CVD graphene for work function matched transparent electrodes.

    PubMed

    Bointon, Thomas H; Jones, Gareth F; De Sanctis, Adolfo; Hill-Pearce, Ruth; Craciun, Monica F; Russo, Saverio

    2015-01-01

    The efficiency of flexible photovoltaic and organic light emitting devices is heavily dependent on the availability of flexible and transparent conductors with at least a similar workfunction to that of Indium Tin Oxide. Here we present the first study of the work function of large area (up to 9?cm(2)) FeCl3 intercalated graphene grown by chemical vapour deposition on Nickel, and demonstrate values as large as 5.1?eV. Upon intercalation, a charge density per graphene layer of 5???10(13)?±?5???10(12)?cm(-2) is attained, making this material an attractive platform for the study of plasmonic excitations in the infrared wavelength spectrum of interest to the telecommunication industry. Finally, we demonstrate the potential of this material for flexible electronics in a transparent circuit on a polyethylene naphthalate substrate. PMID:26548711

  10. Full Printable Processed Mesoscopic CH3NH3PbI3/TiO2 Heterojunction Solar Cells with Carbon Counter Electrode

    PubMed Central

    Ku, Zhiliang; Rong, Yaoguang; Xu, Mi; Liu, Tongfa; Han, Hongwei

    2013-01-01

    A mesoscopic methylammonium lead iodide (CH3NH3PbI3) perovskite/TiO2 heterojunction solar cell is developed with low-cost carbon counter electrode (CE) and full printable process. With carbon black/spheroidal graphite CE, this mesoscopic heterojunction solar cell presents high stability and power conversion efficiency of 6.64%, which is higher than that of the flaky graphite based device and comparable to the conventional Au version. PMID:24185501

  11. Excellent optical and interfacial performance of a PEDOT-b-PEG block copolymer counter electrode for polymer electrolyte-based solid-state dye-sensitized solar cells.

    PubMed

    Kim, Tea-Yon; Wei, Wei; Cho, Woohyung; Lee, Sungjin; Won, Jongok; Kang, Yong Soo

    2015-12-01

    A poly(3,4-ethylenedioxythiophene)-b-poly(ethylene glycol) (PEDOT-b-PEG) block copolymer doped with perchlorate on FTO shows excellent optical and interfacial performance as a counter electrode (CE), such as low charge transfer resistance and low reflectivity for polymer electrolyte-based solid-state dye-sensitized solar cells (DSCs), resulting in 8.45% energy conversion efficiency, greater than the common Pt CE, via a facile room-temperature process. PMID:26435266

  12. Amplified spontaneous emission under optical pumping from an organic semiconductor laser structure equipped with transparent carrier injection electrodes

    NASA Astrophysics Data System (ADS)

    Yamamoto, Hidetoshi; Oyamada, Takahito; Sasabe, Hiroyuki; Adachi, Chihaya

    2004-02-01

    We succeeded in observing amplified spontaneous emissions (ASEs) from an organic semiconductor laser structure equipped with transparent carrier injection electrodes under optical pumping. We employed a transparent indium-tin-oxide (ITO) anode and cathode, which significantly minimized light propagation loss compared with that in conventional metal electrodes. In particular, we incorporated an ultrathin MgAg layer between the organic electron transport layer and ITO cathode to enhance electron injection efficiency, while maintaining low light propagation loss, and also to protect the organic layer from plasma damage when forming the ITO. By optically pumping the ITO [30 nm]/4,4'-bis[N(1-naphthyl)-N-phenyl-amino]biphenyl (?-NPD) [20 nm]/ 4,4'-di(N-carbazolyl)biphenyl (CBP) doped with 1,4-dimethoxy-2,5-bis[p-{N-phenyl-N(m-tolyl)amino}styryl]benzene (BSB) [70 nm]/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) [20 nm]/tris-(8-hydroxy-quinoline)aluminum (Alq3) [20 nm]/MgAg [2.5 nm]/ITO [20 nm] device, a low ASE threshold of Eth=5.1±1.0 ?J/cm2 with a full width at half maximum of 11 nm was obtained under optical excitation. We also evaluated electrical pumping with this device. Although we observed high efficiency electroluminescence at an external quantum efficiency (?ext) of 3.6% at a low current density of J=0.1 mA/cm2, a rapid decrease in ?ext was observed with an increase in current density, suggesting the presence of large exciton-polaron annihilation.

  13. Indium-free Cu/fluorine doped ZnO composite transparent conductive electrodes with stretchable and flexible performance on poly(ethylene terephthalate) substrate

    NASA Astrophysics Data System (ADS)

    Han, Jun; Gong, Haibo; Yang, Xiaopeng; Qiu, Zhiwen; Zi, Min; Qiu, Xiaofeng; Wang, Hongqiang; Cao, Bingqiang

    2015-03-01

    Material-abundant ZnO and metal thin film have been proposed as potential alternatives for the most widely commercial indium tin oxide (ITO) transparent and conductive electrode. Yet the deterioration of optical transparency and conductivity for these materials makes them difficult to compete with ITO. In this work, a double-layer structured film-composed of FZO and Cu film is presented at room temperature, which combines the high transparency of FZO and high conductivity of Cu film. We first studied the effect of oxygen pressure on the transparency and conductivity of free-standing FZO layer deposited on poly(ethylene terephthalate) (PET) by PLD method. Also the structural, electrical, and optical properties of bilayers electrode dependence on the Cu layer thickness were optimized in detail. As the Cu layer thickness increases, the resistivity decreases. The lowest resistivity of 6.6 × 10-5 ? cm with a carrier concentration of 1.11 × 1022 cm-3 and mobility of 8.52 cm2 V-1 s-1 was obtained at the optimum Cu (12 nm) layer thickness. We find that FZO layer have anti-reflection effect for Cu/FZO (250 nm) bilayer in the wavelength range of 650-1000 nm compared with single Cu layer. And we firstly study the stretchable performance for Cu film-based composite electrodes with stretching ratio changing from 0 to 5%. Furthermore, we study excellent mechanical flexibility and stability of composite electrodes by bending test.

  14. Fast fabrication of copper nanowire transparent electrodes by a high intensity pulsed light sintering technique in air.

    PubMed

    Ding, Su; Jiu, Jinting; Tian, Yanhong; Sugahara, Tohru; Nagao, Shijo; Suganuma, Katsuaki

    2015-11-18

    Copper nanowire transparent electrodes have received increasing interest due to the low price and nearly equal electrical conductivity compared with other TEs based on silver nanowires and indium tin oxide (ITO). However, a post-treatment at high temperature in an inert atmosphere or a vacuum environment was necessary to improve the conductivity of Cu NW TEs due to the easy oxidation of copper in air atmosphere, which greatly cancelled out the low price advantage of Cu NWs. Here, a high intensity pulsed light technique was introduced to sinter and simultaneously deoxygenate these Cu NWs into a highly conductive network at room temperature in air. The strong light absorption capacity of Cu NWs enabled the welding of the nanowires at contact spots, as well as the removal of the thin layer of residual organic compounds, oxides and hydroxide of copper even in air. The Cu NW TE with a sheet resistance of 22.9 Ohm sq(-1) and a transparency of 81.8% at 550 nm has been successfully fabricated within only 6 milliseconds exposure treatment, which is superior to other films treated at high temperature in a hydrogen atmosphere. The HIPL process was simple, convenient and fast to fabricate easily oxidized Cu NW TEs in large scale in an air atmosphere, which will largely extend the application of cheap Cu NW TEs. PMID:26536570

  15. Indium-zinc oxide transparent electrode for nitride-based light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Mizutani, S.; Nakashima, S.; Iwaya, M.; Takeuchi, T.; Kamiyama, S.; Akasaki, I.; Kondo, T.; Teramae, F.; Suzuki, A.; Kitano, T.; Mori, M.; Matsubara, M.

    2013-03-01

    The basic properties of indium-zinc oxide (IZO) were investigated from the view point of the potential of light-emitting diodes (LEDs) for nanostructured transparent contact. The resistivity and contact resistance to p-GaN were obtained to be 2.5×10-4 ?cm and 9.4×10-4 ?cm2, respectively, which are comparable to those of indium-tin oxide (ITO). The light output of the LED with the moth-eye IZO was 10 % and 40 % higher than that of the LED with the moth-eye ITO and that of the LED without the moth-eye structure, respectively.

  16. Laser direct imaging of transparent indium tin oxide electrodes using high speed stitching techniques

    NASA Astrophysics Data System (ADS)

    Cheng, Pi-Ying; Hsiao, Wen-Tse; Chung, Chien-Kai; Tseng, Shih-Feng; Liao, Ien-Chang

    2014-09-01

    To accomplish an electrode patterning in large area, we present a high speed stitching technique used in an ultraviolet laser processing system and investigate the interaction between laser beams and indium tin oxide (ITO) thin films deposited on glass substrates. After optimizing the process parameters of the laser direct imaging (LDI) for the large-area electrode patterning, the ablated lines looked like regularly fish-scale marks of about a 40 ?m diameter and a 120 nm depth around the processing path. The parameters includes the laser power of 1W, the scanning speed of galvanometers of 800 mm/s, and the laser pulse repetition frequency of 50 kHz. Moreover, the resistance value of the ablated ITO thin film is larger than 200M? that is electrically insulated from the other regions of electrode structure. LDI technology with UV laser beam has great potential applications in patterning on wafer or sapphire substrates and patterning a conductive layer deposited on the touch panels for semiconductor and optoelectric industries, respectively.

  17. Laser synthesized super-hydrophobic conducting carbon with broccoli-type morphology as a counter-electrode for dye sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Gokhale, Rohan; Agarkar, Shruti; Debgupta, Joyashish; Shinde, Deodatta; Lefez, Benoit; Banerjee, Abhik; Jog, Jyoti; More, Mahendra; Hannoyer, Beatrice; Ogale, Satishchandra

    2012-10-01

    A laser photochemical process is introduced to realize superhydrophobic conducting carbon coatings with broccoli-type hierarchical morphology for use as a metal-free counter electrode in a dye sensitized solar cell. The process involves pulsed excimer laser irradiation of a thin layer of liquid haloaromatic organic solvent o-dichlorobenzene (DCB). The coating reflects a carbon nanoparticle-self assembled and process-controlled morphology that yields solar to electric power conversion efficiency of 5.1% as opposed to 6.2% obtained with the conventional Pt-based electrode.A laser photochemical process is introduced to realize superhydrophobic conducting carbon coatings with broccoli-type hierarchical morphology for use as a metal-free counter electrode in a dye sensitized solar cell. The process involves pulsed excimer laser irradiation of a thin layer of liquid haloaromatic organic solvent o-dichlorobenzene (DCB). The coating reflects a carbon nanoparticle-self assembled and process-controlled morphology that yields solar to electric power conversion efficiency of 5.1% as opposed to 6.2% obtained with the conventional Pt-based electrode. Electronic supplementary information (ESI) available: Materials and equipment details, solar cell fabrication protocol, electrolyte spreading time measurement details, XPS spectra, electronic study, film adhesion test detailed analysis and field emission results. See DOI: 10.1039/c2nr32082g

  18. Low-cost solution processed nano millet like structure CoS2 film superior to pt as counter electrode for quantum dot sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Rao, S. Srinivasa; Punnosse, Dinah; Kim, Soo-Kyoung; Kim, Hee-Je

    2015-05-01

    Cobalt Sulfide (CoS2) counter electrodes (CE) with uniform size distribution were obtained on fluorine-doped tin oxide (FTO) substrate as counter electrodes for polysulfide redox electrolyte in CdS/CdSe/ ZnS quantum dot-sensitized solar cells (QDSSCs) by chemical bath deposition (CBD) technique. In this study, we optimized the cobalt source, deposition temperature and time in the preparation of CoS2 thin film to achieve greater conversion efficiency with strong adhesion on FTO. Relative to the platinum (Pt) electrodes, the CoS2 electrode shows a higher catalytic activity, faster electron transport and lower chargetransfer resistance, which can play a role in rendering higher power conversion efficiency. As a result, QDSSCs with the optimized CoS2 CE achieved a higher short-circuit current density of 13.08 mA cm-2, open-circuit voltage of 0.47 V, fill factor of 0.34 and overall photovoltaic conversion efficiency of 2.17% obtained under one sun illumination (100 mW cm-2). Therefore, CoS2 CE can be used as a promising CE in QDSSCs with efficiency exceeding that of high-cost Pt-based cells (1.64%). [Figure not available: see fulltext.

  19. Enhanced Electrochemical Catalytic Efficiencies of Electrochemically Deposited Platinum Nanocubes as a Counter Electrode for Dye-Sensitized Solar Cells.

    PubMed

    Wei, Yu-Hsuan; Tsai, Ming-Chi; Ma, Chen-Chi M; Wu, Hsuan-Chung; Tseng, Fan-Gang; Tsai, Chuen-Horng; Hsieh, Chien-Kuo

    2015-12-01

    Platinum nanocubes (PtNCs) were deposited onto a fluorine-doped tin oxide glass by electrochemical deposition (ECD) method and utilized as a counter electrode (CE) for dye-sensitized solar cells (DSSCs). In this study, we controlled the growth of the crystalline plane to synthesize the single-crystal PtNCs at room temperature. The morphologies and crystalline nanostructure of the ECD PtNCs were examined by field emission scanning electron microscopy and high-resolution transmission electron microscopy. The surface roughness of the ECD PtNCs was examined by atomic force microscopy. The electrochemical properties of the ECD PtNCs were analyzed by cyclic voltammetry, Tafel polarization, and electrochemical impedance spectra. The Pt loading was examined by inductively coupled plasma mass spectrometry. The DSSCs were assembled via an N719 dye-sensitized titanium dioxide working electrode, an iodine-based electrolyte, and a CE. The photoelectric conversion efficiency (PCE) of the DSSCs with the ECD PtNC CE was examined under the illumination of AM 1.5 (100 mWcm(-2)). The PtNCs in this study presented a single-crystal nanostructure that can raise the electron mobility to let up the charge-transfer impedance and promote the charge-transfer rate. In this work, the electrocatalytic mass activity (MA) of the Pt film and PtNCs was 1.508 and 4.088 mAmg(-1), respectively, and the MA of PtNCs was 2.71 times than that of the Pt film. The DSSCs with the pulse-ECD PtNC CE showed a PCE of 6.48 %, which is higher than the cell using the conventional Pt film CE (a PCE of 6.18 %). In contrast to the conventional Pt film CE which is fabricated by electron beam evaporation method, our pulse-ECD PtNCs maximized the Pt catalytic properties as a CE in DSSCs. The results demonstrated that the PtNCs played a good catalyst for iodide/triiodide redox couple reactions in the DSSCs and provided a potential strategy for electrochemical catalytic applications. PMID:26625891

  20. Incorporation of C in Cu for the Fabrication of Transparent Electrodes

    NASA Astrophysics Data System (ADS)

    Isaacs, Romaine; Zhu, Hongli; Preston, Colin; Zavali, Peter; Mansour, Azzam; Lemieux, Melbs; Hu, Liangbing; Salamanca-Riba, Lourdes

    2015-03-01

    The incorporation of carbon nanostructures into the copper lattice has the potential to improve the current density of copper to meet the ever-increasing demands of nanoelectronic devices. We report on the structure and properties of a new material formed by the incorporation of carbon in concentrations up to 10 wt% into the crystal structure of copper that we refer to as ``Cu covetic''. The carbon does not phase separate after subsequent melting and re-solidification despite the absence of a predicted solid solution at such concentrations in the binary phase diagram. Bulk samples, as well as thin films grown at room temperature and high temperature are investigated. X-ray photoelectron spectroscopy (XPS) confirmed that C incorporates in the bulk of the Cu. Transmission Electron Microscopy (TEM) shows that C forms a modulated structure in the crystal lattice, and Electron Energy Loss Spectroscopy (EELS) indicates that C-K edge has graphitic nature with sp2 bonding. Copper covetic films exhibit greater transparency, higher conductivity, and resistance to oxidation than pure copper films of the same thickness, making them a suitable choice for transparent conductors. Supported by DARPA/ARL under Grant No. W911NF-13-1-0058 and ONR under Grant N000141410042.

  1. Indium-free, highly transparent, flexible Cu2O/Cu/Cu2O mesh electrodes for flexible touch screen panels

    PubMed Central

    Kim, Dong-Ju; Kim, Hyo-Joong; Seo, Ki-Won; Kim, Ki-Hyun; Kim, Tae-Wong; Kim, Han-Ki

    2015-01-01

    We report on an indium-free and cost-effective Cu2O/Cu/Cu2O multilayer mesh electrode grown by room temperature roll-to-roll sputtering as a viable alternative to ITO electrodes for the cost-effective production of large-area flexible touch screen panels (TSPs). By using a low resistivity metallic Cu interlayer and a patterned mesh structure, we obtained Cu2O/Cu/Cu2O multilayer mesh electrodes with a low sheet resistance of 15.1?Ohm/square and high optical transmittance of 89% as well as good mechanical flexibility. Outer/inner bending test results showed that the Cu2O/Cu/Cu2O mesh electrode had a mechanical flexibility superior to that of conventional ITO films. Using the diamond-patterned Cu2O/Cu/Cu2O multilayer mesh electrodes, we successfully demonstrated TSPS of the flexible film-film type and rigid glass-film-film type TSPs. The TSPs with Cu2O/Cu/Cu2O mesh electrode were used to perform zoom in/out functions and multi-touch writing, indicating that these electrodes are promising cost-efficient transparent electrodes to substitute for conventional ITO electrodes in large-area flexible TSPs. PMID:26582471

  2. Indium-free, highly transparent, flexible Cu2O/Cu/Cu2O mesh electrodes for flexible touch screen panels

    NASA Astrophysics Data System (ADS)

    Kim, Dong-Ju; Kim, Hyo-Joong; Seo, Ki-Won; Kim, Ki-Hyun; Kim, Tae-Wong; Kim, Han-Ki

    2015-11-01

    We report on an indium-free and cost-effective Cu2O/Cu/Cu2O multilayer mesh electrode grown by room temperature roll-to-roll sputtering as a viable alternative to ITO electrodes for the cost-effective production of large-area flexible touch screen panels (TSPs). By using a low resistivity metallic Cu interlayer and a patterned mesh structure, we obtained Cu2O/Cu/Cu2O multilayer mesh electrodes with a low sheet resistance of 15.1?Ohm/square and high optical transmittance of 89% as well as good mechanical flexibility. Outer/inner bending test results showed that the Cu2O/Cu/Cu2O mesh electrode had a mechanical flexibility superior to that of conventional ITO films. Using the diamond-patterned Cu2O/Cu/Cu2O multilayer mesh electrodes, we successfully demonstrated TSPS of the flexible film-film type and rigid glass-film-film type TSPs. The TSPs with Cu2O/Cu/Cu2O mesh electrode were used to perform zoom in/out functions and multi-touch writing, indicating that these electrodes are promising cost-efficient transparent electrodes to substitute for conventional ITO electrodes in large-area flexible TSPs.

  3. Indium-free, highly transparent, flexible Cu2O/Cu/Cu2O mesh electrodes for flexible touch screen panels.

    PubMed

    Kim, Dong-Ju; Kim, Hyo-Joong; Seo, Ki-Won; Kim, Ki-Hyun; Kim, Tae-Wong; Kim, Han-Ki

    2015-01-01

    We report on an indium-free and cost-effective Cu2O/Cu/Cu2O multilayer mesh electrode grown by room temperature roll-to-roll sputtering as a viable alternative to ITO electrodes for the cost-effective production of large-area flexible touch screen panels (TSPs). By using a low resistivity metallic Cu interlayer and a patterned mesh structure, we obtained Cu2O/Cu/Cu2O multilayer mesh electrodes with a low sheet resistance of 15.1?Ohm/square and high optical transmittance of 89% as well as good mechanical flexibility. Outer/inner bending test results showed that the Cu2O/Cu/Cu2O mesh electrode had a mechanical flexibility superior to that of conventional ITO films. Using the diamond-patterned Cu2O/Cu/Cu2O multilayer mesh electrodes, we successfully demonstrated TSPS of the flexible film-film type and rigid glass-film-film type TSPs. The TSPs with Cu2O/Cu/Cu2O mesh electrode were used to perform zoom in/out functions and multi-touch writing, indicating that these electrodes are promising cost-efficient transparent electrodes to substitute for conventional ITO electrodes in large-area flexible TSPs. PMID:26582471

  4. Composite films of carbon black nanoparticles and sulfonated-polythiophene as flexible counter electrodes for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Li, Chun-Ting; Lee, Chi-Ta; Li, Sie-Rong; Lee, Chuan-Pei; Chiu, I.-Ting; Vittal, R.; Wu, Nae-Lih; Sun, Shih-Sheng; Ho, Kuo-Chuan

    2016-01-01

    A composite film based on carbon black nanoparticles and sulfonated-poly(thiophene-3-[2-(2-methoxyethoxy)ethoxy]-2,5-diyl) (CB-NPs/s-PT) is formed on a flexible titanium foil for the use as the electro-catalytic counter electrode (CE) of dye-sensitized solar cells (DSSCs). The CB-NPs provide the large amount of electro-catalytic active sites for the composite film, and the s-PT polymer serves as a conductive binder to enhance the inter-particle linkage among CB-NPs and to improve the adhesion between the composite film and the flexible substrate. The flexible CB-NPs/s-PT composite film is designed to possess good electro-catalytic ability for I-/I3- redox couple by providing large active sites and rapid reduction kinetic rate constant of I3- . The cell with a CB-NPs/s-PT CE exhibits a good cell efficiency (?) of 9.02 ± 0.01% at 100 mW cm-2, while the cell with a platinum CE shows an ? of only 8.36 ± 0.02% under the same conditions. At weak light illuminations (20-80 mW cm-2), a DSSC with CB-NPs/s-PT CE still exhibits ?'s of 7.20 ± 0.04-9.08 ± 0.02%. The low-cost CB-NPs/s-PT CE not only renders high cell efficiency to its DSSC but also shows a great potential to replace the expensive platinum; moreover it is suitable for large-scale production or for indoor applications.

  5. Transparent and conducting electrodes for organic electronics from reduced graphene oxide

    NASA Astrophysics Data System (ADS)

    Eda, Goki; Lin, Yun-Yue; Miller, Steve; Chen, Chun-Wei; Su, Wei-Fang; Chhowalla, Manish

    2008-06-01

    The deposition and optoelectronic properties of reduced graphene oxide thin films are described. Thin films with thicknesses ranging from 1-10nm have been deposited by the vacuum filtration method. The conductivity of the thin films can be varied over six orders of magnitude by varying the filtration volume of the graphene oxide aqueous suspension while maintaining the transmittance between 60%-95%. In addition, enhancement in the conductance through Cl doping is demonstrated. The combination of the reduction and Cl treatments make the reduced graphene oxide thin films sufficiently conducting to incorporate them as the hole collecting electrode in proof of concept organic photovoltaic devices.

  6. Transparent electrodes in silicon heterojunction solar cells: Influence on contact passivation

    DOE PAGESBeta

    Tomasi, Andrea; Sahli, Florent; Seif, Johannes Peter; Fanni, Lorenzo; de Nicolas Agut, Silvia Martin; Geissbuhler, Jonas; Paviet-Salomon, Bertrand; Nicolay, Sylvain; Barraud, Loris; Niesen, Bjoern; et al

    2015-10-26

    Charge carrier collection in silicon heterojunction solar cells occurs via intrinsic/doped hydrogenated amorphous silicon layer stacks deposited on the crystalline silicon wafer surfaces. Usually, both the electron and hole collecting stacks are externally capped by an n-type transparent conductive oxide, which is primarily needed for carrier extraction. Earlier, it has been demonstrated that the mere presence of such oxides can affect the carrier recombination in the crystalline silicon absorber. Here, we present a detailed investigation of the impact of this phenomenon on both the electron and hole collecting sides, including its consequences for the operating voltages of silicon heterojunction solarmore »cells. As a result, we define guiding principles for improved passivating contact design for high-efficiency silicon solar cells.« less

  7. Transparent electrodes in silicon heterojunction solar cells: Influence on contact passivation

    SciTech Connect

    Tomasi, Andrea; Sahli, Florent; Seif, Johannes Peter; Fanni, Lorenzo; de Nicolas Agut, Silvia Martin; Geissbuhler, Jonas; Paviet-Salomon, Bertrand; Nicolay, Sylvain; Barraud, Loris; Niesen, Bjoern; De Wolf, Stefaan; Ballif, Christophe

    2015-10-26

    Charge carrier collection in silicon heterojunction solar cells occurs via intrinsic/doped hydrogenated amorphous silicon layer stacks deposited on the crystalline silicon wafer surfaces. Usually, both the electron and hole collecting stacks are externally capped by an n-type transparent conductive oxide, which is primarily needed for carrier extraction. Earlier, it has been demonstrated that the mere presence of such oxides can affect the carrier recombination in the crystalline silicon absorber. Here, we present a detailed investigation of the impact of this phenomenon on both the electron and hole collecting sides, including its consequences for the operating voltages of silicon heterojunction solar cells. As a result, we define guiding principles for improved passivating contact design for high-efficiency silicon solar cells.

  8. Blown Bubble Assembly of Graphene Oxide Patches for Transparent Electrodes in Carbon-Silicon Solar Cells.

    PubMed

    Wu, Shiting; Yang, Yanbing; Li, Yitan; Wang, Chunhui; Xu, Wenjing; Shi, Enzheng; Zou, Mingchu; Yang, Liusi; Yang, Xiangdong; Li, Yan; Cao, Anyuan

    2015-12-30

    Graphene oxide (GO) sheets have a strong tendency to aggregate, and their interfaces can impose limitations on the electrical conductivity, which would hinder practical applications. Here, we present a blown bubble film method to assemble GO sheets with a uniform distribution over a large area and further interconnect individual GO sheets by transforming the bubble film into graphitized carbon. A conventional polymer was used to facilitate the bubble blowing process and disperse GO sheets in the bubble. Then, the bubble film was annealed on a Cu substrate, resulting in a highly transparent reduced GO (RGO)-carbon hybrid structure consisting of RGO patches well adhered to the carbon film. We fabricated RGO-carbon/Si solar cells with power conversion efficiencies up to 6.42%, and the assembled RGO patches hybridized with carbon film can form an effective junction with Si, indicating potential applications in thin film electronic devices and photovoltaics. PMID:26641030

  9. Study on Ag mesh/conductive oxide hybrid transparent electrode for film heaters.

    PubMed

    Kwon, Namyong; Kim, Kyohyeok; Heo, Jinhee; Yi, Insook; Chung, Ilsub

    2014-07-01

    Ag mesh-indium tin oxide (ITO) hybrid transparent conductive films were fabricated and evaluated for use in film heaters. PS monolayer templates were prepared using highly mono-dispersed PS spheres (11.2 ?m) obtained by a filtering process with micro-sieves. At first, three Ag meshes with different sheet resistances (20, 100, and 300 ? sq(-1)) and transmittances (70, 73, and 76%) were evaluated for film heaters in terms of voltage and long-term stability. Subsequently, in an effort to obtain better transmittance, Ag mesh-ITO hybrid heaters were fabricated utilizing finite ITO depositions. At the optimised ITO thickness (15 nm), the sheet resistance and the transmittance were 300 ? sq(-1) and 88%, respectively, which indicates that this material is a good potential candidate for an efficient defroster in vehicles. PMID:24916322

  10. Environmental stability of high-mobility indium-oxide based transparent electrodes

    NASA Astrophysics Data System (ADS)

    Tohsophon, Thanaporn; Dabirian, Ali; De Wolf, Stefaan; Morales-Masis, Monica; Ballif, Christophe

    2015-11-01

    Large-scale deployment of a wide range of optoelectronic devices, including solar cells, critically depends on the long-term stability of their front electrodes. Here, we investigate the performance of Sn-doped In2O3 (ITO), H-doped In2O3 (IO:H), and Zn-doped In2O3 (IZO) electrodes under damp heat (DH) conditions (85 °C, 85% relative humidity). ITO, IO:H capped with ITO, and IZO show high stability with only 3%, 9%, and 13% sheet resistance (Rs) degradation after 1000 h of DH, respectively. For uncapped IO:H, we find a 75% Rs degradation, due to losses in electron Hall mobility (?Hall). We propose that this degradation results from chemisorbed OH- or H2O-related species in the film, which is confirmed by thermal desorption spectroscopy and x-ray photoelectron spectroscopy. While ?Hall strongly degrades during DH, the optical mobility (?optical) remains unchanged, indicating that the degradation mainly occurs at grain boundaries.

  11. Improved open-circuit voltage in Cu(In,Ga)Se2 solar cells with high work function transparent electrodes

    NASA Astrophysics Data System (ADS)

    Jäger, Timo; Romanyuk, Yaroslav E.; Bissig, Benjamin; Pianezzi, Fabian; Nishiwaki, Shiro; Reinhard, Patrick; Steinhauser, Jérôme; Schwenk, Johannes; Tiwari, Ayodhya N.

    2015-06-01

    Hydrogenated indium oxide (IOH) is implemented as transparent front contact in Cu(In,Ga)Se2 (CIGS) solar cells, leading to an open circuit voltage VOC enhanced by ˜20 mV as compared to reference devices with ZnO:Al (AZO) electrodes. This effect is reproducible in a wide range of contact sheet resistances corresponding to various IOH thicknesses. We present the detailed electrical characterization of glass/Mo/CIGS/CdS/intrinsic ZnO (i-ZnO)/transparent conductive oxide (TCO) with different IOH/AZO ratios in the front TCO contact in order to identify possible reasons for the enhanced VOC. Temperature and illumination intensity-dependent current-voltage measurements indicate that the dominant recombination path does not change when AZO is replaced by IOH, and it is mainly limited to recombination in the space charge region and at the junction interface of the solar cell. The main finding is that the introduction of even a 5 nm-thin IOH layer at the i-ZnO/TCO interface already results in a step-like increase in VOC. Two possible explanations are proposed and verified by one-dimensional simulations using the SCAPS software. First, a higher work function of IOH as compared to AZO is simulated to yield an VOC increase by 21 mV. Second, a lower defect density in the i-ZnO layer as a result of the reduced sputter damage during milder sputter-deposition of IOH can also add to a maximum enhanced VOC of 25 mV. Our results demonstrate that the proper choice of the front TCO contact can reduce the parasitic recombination and boost the efficiency of CIGS cells with improved corrosion stability.

  12. Development of bifacial inverted polymer solar cells using a conductivity-controlled transparent PEDOT:PSS and a striped Au electrode on the hole collection side

    NASA Astrophysics Data System (ADS)

    Kuwabara, Takayuki; Katori, Shinji; Arima, Kazuhiro; Omura, Yoshihiro; Yamaguchi, Takahiro; Taima, Tetsuya; Takahashi, Kohshin

    2014-02-01

    An inverted bifacial polymer solar cell was developed using a conductivity-controlled transparent poly(3,4-ethylenedioxylenethiophene):poly(4-styrene sulfonic acid) (PEDOT:PSS) as a hole collection layer and a striped Au electrode with a large open aperture ratio (Rap) as a hole collection electrode. We investigated the performance of the device by varying the interelectrode distance of the striped Au electrode and the sheet resistance of the PEDOT:PSS film. The device using untreated Clevios P (PEDOT:PSS) showed a maximum electric output (Pw) in the Rap range of 50 to 65%. When alcohol-treated Clevios P (Clevios P+) with a lower electrical resistance was used, the maximum Pw increased by 40% compared with that of the device using Clevios P. The maximum Pw was obtained in the Rap range of 84% as the hole collection efficiency of the striped Au electrode improved with the decreased sheet resistance of the PEDOT:PSS.

  13. Silver nanowires for transparent conductive electrode to GaN-based light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Jeong, Gyu-Jae; Lee, Jae-Hwan; Han, Sang-Hyun; Jin, Won-Yong; Kang, Jae-Wook; Lee, Sung-Nam

    2015-01-01

    Transparent, conductive, and uniform Ag nanowires (NWs) were introduced to improve the optical performance of GaN-based light-emitting diodes (LEDs) by a spin-coating technique. The Ag NWs acted as a current spreading layer, exhibiting high transmittance and low sheet resistance, and ultimately leading to high performance GaN-based LEDs with an ultra large size of 5 × 5 mm2. Compared to the transmittance of conventional LEDs without Ag NWs, the relative transmittance of LEDs with Ag NWs was approximately 90% of the overall wavelength region. However, the electroluminescence (EL) intensity of LED with Ag NWs was much higher than that of conventional LEDs without Ag NWs for injection current above 45 mA. In addition, the EL full width at half maximum of LEDs with Ag NWs was much lower than that of conventional LEDs without Ag NWs. Based on these results, we believe that the enhanced optical performance of ultra large LEDs was due to an increase in the current spreading effect.

  14. Silver nanowires for transparent conductive electrode to GaN-based light-emitting diodes

    SciTech Connect

    Jeong, Gyu-Jae; Lee, Jae-Hwan; Han, Sang-Hyun; Lee, Sung-Nam; Jin, Won-Yong; Kang, Jae-Wook

    2015-01-19

    Transparent, conductive, and uniform Ag nanowires (NWs) were introduced to improve the optical performance of GaN-based light-emitting diodes (LEDs) by a spin-coating technique. The Ag NWs acted as a current spreading layer, exhibiting high transmittance and low sheet resistance, and ultimately leading to high performance GaN-based LEDs with an ultra large size of 5?×?5?mm{sup 2}. Compared to the transmittance of conventional LEDs without Ag NWs, the relative transmittance of LEDs with Ag NWs was approximately 90% of the overall wavelength region. However, the electroluminescence (EL) intensity of LED with Ag NWs was much higher than that of conventional LEDs without Ag NWs for injection current above 45?mA. In addition, the EL full width at half maximum of LEDs with Ag NWs was much lower than that of conventional LEDs without Ag NWs. Based on these results, we believe that the enhanced optical performance of ultra large LEDs was due to an increase in the current spreading effect.

  15. Optimization of transparent and reflecting electrodes for amorphous silicon solar cells

    SciTech Connect

    Gordon, R.G. . Dept. of Chemistry)

    1993-04-01

    This report describes work to improve the performance of solar cells by improving the electrical and optical properties of their transparent conducting oxides (TCO) layers. Boron-doped zinc-oxide films were deposited by atmospheric pressure chemical vapor deposition in a laminar-flow reactor from diethyl zinc, tert-butanol, and diborane in the temperature range between 300[degrees]C and 420[degrees]C. When the deposition temperature was above 320[degrees]C, both doped and undoped films have highly oriented crystallites with their c-axes perpendicular to the substrate plane. Films deposited from 0.07% diethyl zinc and 2.4% tert-butanol have electron densities between 3.5 [times] 10[sup 20] cm[sup [minus]3] and 5.5 [times] 10[sup 20] cm[sup [minus]3], conductivities between 250 [Omega][sup [minus]1] and 2500 [Omega][sup [minus]1] and mobilities between 2.5 cm[sup 2]/V-s and 35.0 cm[sup 2]/V-s, depending on dopant concentration, film thickness, and deposition temperature. Optical measurements show that the maximum infrared reflectance of the doped films is close to 90%, compared to about 20% for undoped films. Film visible absorption and film conductivity were found to increase with film thickness. The ratio of conductivity to visible absorption coefficient for doped films was between 0.1 [Omega] and 1.1 [Omega][sup [minus]1]. The band gap of the film changes from 3.3 eV to 3.7 eV when the film is doped with 0.012% diborane.

  16. Mesoporous Bi2S3 nanorods with graphene-assistance as low-cost counter-electrode materials in dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Guo, Sheng-Qi; Jing, Tian-Zeng; Zhang, Xiao; Yang, Xiao-Bing; Yuan, Zhi-Hao; Hu, Fang-Zhong

    2014-11-01

    In this work, we report the synthesis of mesoporous Bi2S3 nanorods under hydrothermal conditions without additives, and investigated their catalytic activities as the CE in DSCs by I-V curves and tested conversion efficiency. To further improve their power conversion efficiency, we added different amounts of reduced graphene by simple physical mixing. With the addition of 9 wt% reduced graphene (rGO), the short-circuit current density, open-circuit voltage and fill factor were Jsc = 15.33 mA cm-2, Voc = 0.74 V and FF = 0.609. More importantly, the conversion efficiency reached 6.91%, which is slightly inferior to the commercial Pt counter electrode (7.44%). Compared to the conventional Pt counter electrodes of solar cells, this new material has the advantages of low-cost, facile synthesis and high efficiency with graphene assistance. To the best of our knowledge, this Bi2S3 + 9 wt% rGO system has the best performance ever recorded in all Bi2S3-based CEs in the DSCs system.In this work, we report the synthesis of mesoporous Bi2S3 nanorods under hydrothermal conditions without additives, and investigated their catalytic activities as the CE in DSCs by I-V curves and tested conversion efficiency. To further improve their power conversion efficiency, we added different amounts of reduced graphene by simple physical mixing. With the addition of 9 wt% reduced graphene (rGO), the short-circuit current density, open-circuit voltage and fill factor were Jsc = 15.33 mA cm-2, Voc = 0.74 V and FF = 0.609. More importantly, the conversion efficiency reached 6.91%, which is slightly inferior to the commercial Pt counter electrode (7.44%). Compared to the conventional Pt counter electrodes of solar cells, this new material has the advantages of low-cost, facile synthesis and high efficiency with graphene assistance. To the best of our knowledge, this Bi2S3 + 9 wt% rGO system has the best performance ever recorded in all Bi2S3-based CEs in the DSCs system. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr04274c

  17. Solution-Processable Transparent Conductive Hole Injection Electrode for OLED SSL

    SciTech Connect

    2012-07-15

    An interconnected network of silver nanowires has been used as transparent anode in OLED devices. This layer was deposited by spin-coating and slot-die coating from an aqueous nanowire suspension. The sheet resistance of the film was 10ohms/sq with a transmission (including the glass substrate) of higher than 85%. The first phase of the project focused on the implementation of this nanowire layer with a hole-injection-layer (HIL) which has been developed at Plextronics and has been shown to provide good stability and efficiency in conventional OLED devices. We modified the HIL solution such that it coated reasonably well with suitable surface morphology so that actual devices can be manufactured. During the second phase we investigated the hole-injection and stability of hole-onlydevices. We determined that the use of the nanowire network as anode does not introduce an additional degradation mechanism since the observed device characteristics did not differ from those made with ITO anode. We then proceeded to make actual OLED devices with this nanowire / HIL stack and achieved device characteristics similar state-of-the-art OLED devices with a single junction. In order to gain traction with potential OLED manufacturers, we decided to contract Novaled to prepare large-area demonstrators for us. For these devices, we used an allevaporated stack, i.e. we did use Novaledâ??s HIL material instead of Plextronicsâ??. We successfully fabricated demonstrators with an area of 25cm2 with a double or triple junction stack. Minor stack optimizations were necessary to achieve efficacies and lifetime equivalent with ITO devices made with the same devices stack. Due to the reduced microcavity effect, the color of the emitted light is significantly more stable with respect to the viewing angle compared to ITO devices. This fact in conjunction with the promise of lower production cost due to the elimination of the ITO sputtering process and the direct patterning of the anode layer are the obvious advantages of this technology. The project has shown that this nanowire technology is a viable option to achieve OLED devices with good lifetime and efficiency and we are currently working with manufacturers to utilize this technology in a production setting.

  18. Enhancing light out-coupling of organic light-emitting devices using indium tin oxide-free low-index transparent electrodes

    SciTech Connect

    Huang, Yi-Hsiang; Lu, Chun-Yang; Tsai, Shang-Ta; Tsai, Yu-Tang; Chen, Chien-Yu; Tsai, Wei-Lung; Lin, Chun-Yu; Chang, Hong-Wei; Lee, Wei-Kai; Jiao, Min; Wu, Chung-Chih

    2014-05-05

    With its increasing and sufficient conductivity, the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been capable of replacing the widely used but less cost-effective indium tin oxides (ITOs) as alternative transparent electrodes for organic light-emitting devices (OLEDs). Intriguingly, PEDOT:PSS also possesses an optical refractive index significantly lower than those of ITO and typical organic layers in OLEDs and well matching those of typical OLED substrates. Optical simulation reveals that by replacing ITO with such a low-index transparent electrode, the guided modes trapped within the organic/ITO layers in conventional OLEDs can be substantially suppressed, leading to more light coupled into the substrate than the conventional ITO device. By applying light out-coupling structures onto outer surfaces of substrates to effectively extract radiation into substrates, OLEDs using such low-index transparent electrodes achieve enhanced optical out-coupling and external quantum efficiencies in comparison with conventional OLEDs using ITO.

  19. Platinum-Free Counter Electrode Comprised of Metal-Organic-Framework (MOF)-Derived Cobalt Sulfide Nanoparticles for Efficient Dye-Sensitized Solar Cells (DSSCs)

    PubMed Central

    Hsu, Shao-Hui; Li, Chun-Ting; Chien, Heng-Ta; Salunkhe, Rahul R.; Suzuki, Norihiro; Yamauchi, Yusuke; Ho, Kuo-Chuan; Wu, Kevin C.-W.

    2014-01-01

    We fabricated a highly efficient (with a solar-to-electricity conversion efficiency (?) of 8.1%) Pt-free dye-sensitized solar cell (DSSC). The counter electrode was made of cobalt sulfide (CoS) nanoparticles synthesized via surfactant-assisted preparation of a metal organic framework, ZIF-67, with controllable particle sizes (50 to 320?nm) and subsequent oxidation and sulfide conversion. In contrast to conventional Pt counter electrodes, the synthesized CoS nanoparticles exhibited higher external surface areas and roughness factors, as evidenced by X-ray diffraction (XRD), scanning electron microscopy (SEM) element mapping, and electrochemical analysis. Incident photon-to-current conversion efficiency (IPCE) results showed an increase in the open circuit voltage (VOC) and a decrease in the short-circuit photocurrent density (Jsc) for CoS-based DSSCs compared to Pt-based DSSCs, resulting in a similar power conversion efficiency. The CoS-based DSSC fabricated in the study show great potential for economically friendly production of Pt-free DSSCs. PMID:25382139

  20. Mesoporous Bi?S? nanorods with graphene-assistance as low-cost counter-electrode materials in dye-sensitized solar cells.

    PubMed

    Guo, Sheng-qi; Jing, Tian-zeng; Zhang, Xiao; Yang, Xiao-bing; Yuan, Zhi-hao; Hu, Fang-zhong

    2014-11-01

    In this work, we report the synthesis of mesoporous Bi?S? nanorods under hydrothermal conditions without additives, and investigated their catalytic activities as the CE in DSCs by I-V curves and tested conversion efficiency. To further improve their power conversion efficiency, we added different amounts of reduced graphene by simple physical mixing. With the addition of 9 wt% reduced graphene (rGO), the short-circuit current density, open-circuit voltage and fill factor were Jsc = 15.33 mA cm(-2), Voc = 0.74 V and FF = 0.609. More importantly, the conversion efficiency reached 6.91%, which is slightly inferior to the commercial Pt counter electrode (7.44%). Compared to the conventional Pt counter electrodes of solar cells, this new material has the advantages of low-cost, facile synthesis and high efficiency with graphene assistance. To the best of our knowledge, this Bi?S? + 9 wt% rGO system has the best performance ever recorded in all Bi?S?-based CEs in the DSCs system. PMID:25341187

  1. Highly transparent conductive electrode with ultra-low HAZE by grain boundary modification of aqueous solution fabricated alumina-doped zinc oxide nanocrystals

    SciTech Connect

    Nian, Qiong; Cheng, Gary J.; Callahan, Michael; Bailey, John; Look, David; Efstathiadis, Harry

    2015-06-01

    Commercial production of transparent conducting oxide (TCO) polycrystalline films requires high electrical conductivity with minimal degradation in optical transparency. Aqueous solution deposited TCO films would reduce production costs of TCO films but suffer from low electrical mobility, which severely degrades both electrical conductivity and optical transparency in the visible spectrum. Here, we demonstrated that grain boundary modification by ultra-violet laser crystallization (UVLC) of solution deposited aluminium-doped zinc oxide (AZO) nanocrystals results in high Hall mobility, with a corresponding dramatic improvement in AZO electrical conductance. The AZO films after laser irradiation exhibit electrical mobility up to 18.1 cm{sup 2} V{sup ?1} s{sup ?1} with corresponding electrical resistivity and sheet resistances as low as 1 × 10{sup ?3} ? cm and 75 ?/sq, respectively. The high mobility also enabled a high transmittance (T) of 88%-96% at 550 nm for the UVLC films. In addition, HAZE measurement shows AZO film scattering transmittance as low as 1.8%, which is superior over most other solution deposited transparent electrode alternatives such as silver nanowires. Thus, AZO films produced by the UVLC technique have a combined figure of merit for electrical conductivity, optical transparency, and optical HAZE higher than other solution based deposition techniques and comparable to vacuumed based deposition methods.

  2. Development of an electric field application system with transparent electrodes towards the electron EDM measurement with laser-cooled Fr atoms

    NASA Astrophysics Data System (ADS)

    Ishikawa, Taisuke; Ando, Shun; Aoki, Takahiro; Arikawa, Hiroshi; Harada, Ken-Ichi; Hayamizu, Tomohiro; Inoue, Takeshi; Itoh, Masatoshi; Kawamura, Hirokazu; Kato, Ko; Sakamoto, Kosuke; Uchiyama, Aiko; Sakemi, Yasuhiro

    2014-09-01

    The permanent electric dipole moment (EDM) of elementary particles is a good probe for new physics beyond the standard model. Since the francium (Fr) atom has a large enhancement factor of the electron EDM and laser-cooled atoms can have long coherence times, we plan to utilize laser-cooled Fr atoms for the electron EDM search experiment. Besides, a strong electric field is one of key issues for the EDM experiment. Recently, we have embarked on a development of the electric field application system with transparent electrodes coated by tin-doped indium oxide (ITO). The ITO electrodes break the difficulty in the coexistence of electrodes with several cooling laser lights. The actual electric field applied to the atom is evaluated by measuring the dc Stark shift for the laser-cooled rubidium atoms. In this presentation, the present status of the electric field application system will be reported. The permanent electric dipole moment (EDM) of elementary particles is a good probe for new physics beyond the standard model. Since the francium (Fr) atom has a large enhancement factor of the electron EDM and laser-cooled atoms can have long coherence times, we plan to utilize laser-cooled Fr atoms for the electron EDM search experiment. Besides, a strong electric field is one of key issues for the EDM experiment. Recently, we have embarked on a development of the electric field application system with transparent electrodes coated by tin-doped indium oxide (ITO). The ITO electrodes break the difficulty in the coexistence of electrodes with several cooling laser lights. The actual electric field applied to the atom is evaluated by measuring the dc Stark shift for the laser-cooled rubidium atoms. In this presentation, the present status of the electric field application system will be reported. This work is supported by Grants-in-Aid for Scientific Research (No. 26220705) and Tohoku University's Focused Research Project.

  3. Part I. Carbon and mercury-carbon optically transparent electrodes. Part II. Investigation of redox properties of technetium by cyclic voltammetry and thin layer spectroelectrochemistry

    SciTech Connect

    Hurst, R.W.

    1980-01-01

    A carbon optically transparent electrode (C OTE) has been prepared by vapor-deposithing a thin carbon film (150 to 310 A thick) on glass and quartz. Optical transparency is good throughout the ultraviolet-visible region. Electrochemical and spectroelectrochemical measurements were made with ferricyanide and o-tolidine respectively. The C OTE serves as a good substrate for deposition of a thin mercury film to form a mercury film transparent electrode (Hg-C OTE). The Hg-C OTE exhibits electrochemical properties of conventional mercury film electrodes as evidenced by Pb/sup 2 +/ cyclic voltammograms. The Hg-C OTE exhibits electrochemical properties of conventional mercury film electrodes as evidenced by Pb/sup 2 -/ cyclic VOHammograms. The Hg-C OTE enabled the spectrochemical characterization of cysteine oxidation, which was shown to involve the oxidation of mercury to form mercurous cysteinate. An 8080 based microcomputer has been interfaced with a Harrick oscillating mirror rapid scanning uv-visible spectrophotometer. Two different approaches are compared for controlling the galvanometer. The first utilizes the digital hardware on the Harrick processing module to derive the mirror drive waveform, while the second creates the waveform under direct software control. A potentiostat is also interfaced and the system is demonstrated by the spectroelectrochemical determination of the redox potential of o-tolidine. Redox potentials are also determined for a series of technetium complexes by the spectropotentiostatic technique. These include hexahalogens, ditertiary arsine, and 1,2-bis(diphenylphosphino) ethane complexes of technetium. Transient hexavalent technetium is produced, detected, and characterized in aqueous alkaline media by pulse radiolysis and very fast scan cyclic voltammetry. The lifetime is of the order of milliseconds. This species is potentially useful in the preparation of technetium radiopharmaceuticals.

  4. Cherenkov Counters

    SciTech Connect

    Barbero, Marlon

    2012-04-19

    When a charged particle passes through an optically transparent medium with a velocity greater than the phase velocity of light in that medium, it emits prompt photons, called Cherenkov radiation, at a characteristic polar angle that depends on the particle velocity. Cherenkov counters are particle detectors that make use of this radiation. Uses include prompt particle counting, the detection of fast particles, the measurement of particle masses, and the tracking or localization of events in very large, natural radiators such as the atmosphere, or natural ice fields, like those at the South Pole in Antarctica. Cherenkov counters are used in a number of different fields, including high energy and nuclear physics detectors at particle accelerators, in nuclear reactors, cosmic ray detectors, particle astrophysics detectors and neutrino astronomy, and in biomedicine for labeling certain biological molecules.

  5. Graphene-NiO nanohybrid prepared by dry plasma reduction as a low-cost counter electrode material for dye-sensitized solar cells.

    PubMed

    Dao, Van-Duong; Larina, Liudmila L; Jung, Kwang-Deog; Lee, Joong-Kee; Choi, Ho-Suk

    2014-01-01

    NiO nanoparticles (NPs) were hybridized on the surface of reduced graphene oxide (RGO) by dry plasma reduction (DPR) at atmospheric pressure without any toxic chemicals and at a low temperature. NiO-NPs of 0.5-3 nm size, with a typical size of 1.5 nm, were uniformly hybridized on the surface of RGO. An XPS analysis and the Raman spectra also revealed the repair of some structural damage on the basal plane of the graphene. The material when applied to the counter electrode (CE) of dye-sensitized solar cells (DSCs) exhibited a power conversion efficiency of 7.42% (± 0.10%), which is comparable to a conventional Pt-sputtered CE (8.18% (± 0.08%)). This material outperformed CEs produced using NiO-NPs (1.53% (± 0.15%)), GO (4.48% (± 0.12%)) and RGO (5.18% (± 0.11)) due to its high electrochemical catalytic activity and high conductivity. The charge transfer resistance for NiO-NP-RGO was as low as 1.93 ? cm(2), while those of a NiO-NP-immobilized electrode and a GO-coated electrode were 44.39 ? cm(2) and 12.19 ? cm(2), respectively, due to a synergistic effect. PMID:24217311

  6. Healable capacitive touch screen sensors based on transparent composite electrodes comprising silver nanowires and a furan/maleimide diels-alder cycloaddition polymer.

    PubMed

    Li, Junpeng; Liang, Jiajie; Li, Lu; Ren, Fengbo; Hu, Wei; Li, Juan; Qi, Shuhua; Pei, Qibing

    2014-12-23

    A healable transparent capacitive touch screen sensor has been fabricated based on a healable silver nanowire-polymer composite electrode. The composite electrode features a layer of silver nanowire percolation network embedded into the surface layer of a polymer substrate comprising an ultrathin soldering polymer layer to confine the nanowires to the surface of a healable Diels-Alder cycloaddition copolymer and to attain low contact resistance between the nanowires. The composite electrode has a figure-of-merit sheet resistance of 18 ?/sq with 80% transmittance at 550 nm. A surface crack cut on the conductive surface with 18 ? is healed by heating at 100 °C, and the sheet resistance recovers to 21 ? in 6 min. A healable touch screen sensor with an array of 8×8 capacitive sensing points is prepared by stacking two composite films patterned with 8 rows and 8 columns of coupling electrodes at 90° angle. After deliberate damage, the coupling electrodes recover touch sensing function upon heating at 80 °C for 30 s. A capacitive touch screen based on Arduino is demonstrated capable of performing quick recovery from malfunction caused by a razor blade cutting. After four cycles of cutting and healing, the sensor array remains functional. PMID:25486240

  7. Light Induced Water Oxidation on Cobalt-Phosphate (Co-Pi) Catalyst Modified Semi-Transparent, Porous SiO2-BiVO4 Electrodes

    SciTech Connect

    Pilli, S. K.; Deutsch, T. G.; Furtak, T. E.; Turner, J. A.; Brown, L. D.; Herring, A. M.

    2012-04-21

    A facile and simple procedure for the synthesis of semi-transparent and porous SiO{sub 2}-BiVO{sub 4} electrodes is reported. The method involves a surfactant assisted metal-organic decomposition at 500 C. An earth abundant oxygen evolution catalyst (OEC), cobalt phosphate (Co-Pi), has been used to modify the SiO{sub 2}-BiVO{sub 4} electrode by electrodeposition (ED) and photoassisted electrodeposition (PED) methods. Modified electrodes by these two methods have been examined for light induced water oxidation and compared to the unmodified SiO{sub 2}-BiVO{sub 4} electrodes by various photoelectrochemical techniques. The PED method was a more effective method of OEC preparation than the ED method as evidenced by an increased photocurrent magnitude during photocurrent-potential (I-V) characterizations. Electrode surfaces catalyzed by PED exhibited a very large cathodic shift (420 mV) in the onset potential for water oxidation. The chopped-light I-V measurements performed at different intervals over 24-hour extended testing under illumination and applied bias conditions show a fair photostability for PED Co-Pi modified SiO{sub 2}-BiVO{sub 4}.

  8. Laser welding of nanoparticulate TiO2 and transparent conducting oxide electrodes for highly efficient dye-sensitized solar cell.

    PubMed

    Kim, Jinsoo; Kim, Jonghyun; Lee, Myeongkyu

    2010-08-27

    Poor interfacial contact is often encountered in nanoparticulate film-based devices. The dye-sensitized solar cell (DSSC) is a representative case in which a nanoporous TiO(2) electrode needs to be prepared on the transparent conducting oxide (TCO)-coated glass substrate. In this study, we demonstrate that the inter-electrode contact resistance accounts for a considerable portion of the total resistance of a DSSC and its efficiency can be greatly enhanced by welding the interface with a laser. TiO(2) films formed on the TCO-coated glass substrate were irradiated with a pulsed ultraviolet laser beam at 355 nm; this transmits through the TCO and glass but is strongly absorbed by TiO(2). Electron microscopy analysis and impedance measurements showed that a thin continuous TiO(2) layer is formed at the interface as a result of the local melting of TiO(2) nanoparticles and this layer completely bridges the gap between the two electrodes, improving the current flow with a reduced contact resistance. We were able to improve the efficiency by 35-65% with this process. DSSCs fabricated using a homemade TiO(2) paste revealed an efficiency improvement from eta = 3.3% to 5.4%, and an increase from 8.2% to 11.2% was achieved with the TiO(2) electrodes made from a commercial paste. PMID:20671364

  9. Near-infrared transparent electrodes for precision TengMan electro-optic measurements: In2O3 thin-film electrodes with tunable

    E-print Network

    Ho, Seng-Tiong

    .4,6 Re- cently, Michelotti et al. reported that, compared to ITO, Al- doped ZnO exhibits improved conducting oxide TCO thin films are usually used as top electrodes in Teng­Man measurements because they can

  10. A spray-coating process for highly conductive silver nanowire networks as the transparent top-electrode for small molecule organic photovoltaics

    NASA Astrophysics Data System (ADS)

    Selzer, Franz; Weiß, Nelli; Kneppe, David; Bormann, Ludwig; Sachse, Christoph; Gaponik, Nikolai; Eychmüller, Alexander; Leo, Karl; Müller-Meskamp, Lars

    2015-01-01

    We present a novel top-electrode spray-coating process for the solution-based deposition of silver nanowires (AgNWs) onto vacuum-processed small molecule organic electronic solar cells. The process is compatible with organic light emitting diodes (OLEDs) and organic light emitting thin film transistors (OLETs) as well. By modifying commonly synthesized AgNWs with a perfluorinated methacrylate, we are able to disperse these wires in a highly fluorinated solvent. This solvent does not dissolve most organic materials, enabling a top spray-coating process for sensitive small molecule and polymer-based devices. The optimized preparation of the novel AgNW dispersion and spray-coating at only 30 °C leads to high performance electrodes directly after the deposition, exhibiting a sheet resistance of 10.0 ? ?-1 at 87.4% transparency (80.0% with substrate). By spraying our novel AgNW dispersion in air onto the vacuum-processed organic p-i-n type solar cells, we obtain working solar cells with a power conversion efficiency (PCE) of 1.23%, compared to the air exposed reference devices employing thermally evaporated thin metal layers as the top-electrode.We present a novel top-electrode spray-coating process for the solution-based deposition of silver nanowires (AgNWs) onto vacuum-processed small molecule organic electronic solar cells. The process is compatible with organic light emitting diodes (OLEDs) and organic light emitting thin film transistors (OLETs) as well. By modifying commonly synthesized AgNWs with a perfluorinated methacrylate, we are able to disperse these wires in a highly fluorinated solvent. This solvent does not dissolve most organic materials, enabling a top spray-coating process for sensitive small molecule and polymer-based devices. The optimized preparation of the novel AgNW dispersion and spray-coating at only 30 °C leads to high performance electrodes directly after the deposition, exhibiting a sheet resistance of 10.0 ? ?-1 at 87.4% transparency (80.0% with substrate). By spraying our novel AgNW dispersion in air onto the vacuum-processed organic p-i-n type solar cells, we obtain working solar cells with a power conversion efficiency (PCE) of 1.23%, compared to the air exposed reference devices employing thermally evaporated thin metal layers as the top-electrode. Electronic supplementary information (ESI) available: XPS and SEM data clarifying the crucial role of the amount of stabilizer on sheet resistance; j-V-data of the annealed air cell enabling a deeper understanding of the influence of air exposure. See DOI: 10.1039/c4nr06502f.

  11. Optimization of TiO2/Cu/TiO2 multilayers as a transparent composite electrode deposited by electron-beam evaporation at room temperature

    NASA Astrophysics Data System (ADS)

    Sun, Hong-Tao; Wang, Xiao-Ping; Kou, Zhi-Qi; Wang, Li-Jun; Wang, Jin-Ye; Sun, Yi-Qing

    2015-04-01

    Highly transparent indium-free composite electrodes of TiO2/Cu/TiO2 are deposited by electron-beam evaporation at room temperature. The effects of Cu thickness and annealing temperature on the electrical and optical properties of the multilayer film are investigated. The critical thickness of Cu mid-layer to form a continuous conducting layer is found to be 11 nm. The multilayer with a mid-Cu thickness of 11 nm is optimized to obtain a resistivity of 7.4×10-5 ?·cm and an average optical transmittance of 86% in the visible spectral range. The figure of merit of the TiO2/Cu(11 nm)/TiO2 multilayer annealed at 150 °C reaches a minimum resistivity of 5.9×10-5 ?·cm and an average optical transmittance of 88% in the visible spectral range. The experimental results indicate that TiO2/Cu/TiO2 multilayers can be used as a transparent electrode for solar cell and other display applications. Project supported by the Research Innovation Key Project of Education Committee of Shanghai, China (Grant No. 14ZZ137) and the National Cultivation Fund from University of Shanghai for Science and Technology (Grant No. 14XPM04).

  12. Photoresist-Free Patterning by Mechanical Abrasion of Water-Soluble Lift-Off Resists and Bare Substrates: Toward Green Fabrication of Transparent Electrodes

    PubMed Central

    Printz, Adam D.; Chan, Esther; Liong, Celine; Martinez, René S.; Lipomi, Darren J.

    2013-01-01

    This paper describes the fabrication of transparent electrodes based on grids of copper microwires using a non-photolithographic process. The process—“abrasion lithography”—takes two forms. In the first implementation (Method I), a water-soluble commodity polymer film is abraded with a sharp tool, coated with a conductive film, and developed by immersion in water. Water dissolves the polymer film and lifts off the conductive film in the unabraded areas. In the second implementation (Method II), the substrate is abraded directly by scratching with a sharp tool (i.e., no polymer film necessary). The abraded regions of the substrate are recessed and roughened. Following deposition of a conductive film, the lower profile and roughened topography in the abraded regions prevents mechanical exfoliation of the conductive film using adhesive tape, and thus the conductive film remains only where the substrate is scratched. As an application, conductive grids exhibit average sheet resistances of 17 ? sq–1 and transparencies of 86% are fabricated and used as the anode in organic photovoltaic cells in concert with the conductive polymer, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). Compared to devices in which PEDOT:PSS alone serves as an anode, devices comprising grids of copper/nickel microwires and PEDOT:PSS exhibit lowered series resistance, which manifests in greater fill factor and power conversion efficiency. This simple method of forming micropatterns could find use in applications where cost and environmental impact should be minimized, especially as a potential replacement for the transparent electrode indium tin oxide (ITO) in thin-film electronics over large areas (i.e., solar cells) or as a method of rapid prototyping for laboratory-scale devices. PMID:24358321

  13. Rapid synthesis of ultra-long silver nanowires for tailor-made transparent conductive electrodes: proof of concept in organic solar cells

    NASA Astrophysics Data System (ADS)

    José Andrés, Luis; Menéndez, María Fe; Gómez, David; Martínez, Ana Luisa; Bristow, Noel; Kettle, Jeffrey Paul; Menéndez, Armando; Ruiz, Bernardino

    2015-07-01

    Rapid synthesis of ultralong silver nanowires (AgNWs) has been obtained using a one-pot polyol-mediated synthetic procedure. The AgNWs have been prepared from the base materials in less than one hour with nanowire lengths reaching 195 ?m, which represents the quickest synthesis and one of the highest reported aspect ratios to date. These results have been achieved through a joint analysis of all reaction parameters, which represents a clear progress beyond the state of the art. Dispersions of the AgNWs have been used to prepare thin, flexible, transparent and conducting films using spray coating. Due to the higher aspect ratio, an improved electrical percolation network is observed. This allows a low sheet resistance (RS = 20.2 ?/sq), whilst maintaining high optical film transparency (T = 94.7%), driving to the highest reported figure-of-merit (FoM = 338). Owing to the light-scattering influence of the AgNWs, the density of the AgNW network can also be varied to enable controllability of the optical haze through the sample. Based on the identification of the optimal haze value, organic photovoltaics (OPVs) have been fabricated using the AgNWs as the transparent electrode and have been benchmarked against indium tin oxide (ITO) electrodes. Overall, the performance of OPVs made using AgNWs sees a small decrease in power conversion efficiency (PCE), primarily due to a fall in open-circuit voltage (50 mV). This work indicates that AgNWs can provide a low cost, rapid and roll-to-roll compatible alternative to ITO in OPVs, with only a small compromise in PCE needed.

  14. Rapid synthesis of ultra-long silver nanowires for tailor-made transparent conductive electrodes: proof of concept in organic solar cells.

    PubMed

    José Andrés, Luis; Fe Menéndez, María; Gómez, David; Luisa Martínez, Ana; Bristow, Noel; Paul Kettle, Jeffrey; Menéndez, Armando; Ruiz, Bernardino

    2015-07-01

    Rapid synthesis of ultralong silver nanowires (AgNWs) has been obtained using a one-pot polyol-mediated synthetic procedure. The AgNWs have been prepared from the base materials in less than one hour with nanowire lengths reaching 195 ?m, which represents the quickest synthesis and one of the highest reported aspect ratios to date. These results have been achieved through a joint analysis of all reaction parameters, which represents a clear progress beyond the state of the art. Dispersions of the AgNWs have been used to prepare thin, flexible, transparent and conducting films using spray coating. Due to the higher aspect ratio, an improved electrical percolation network is observed. This allows a low sheet resistance (RS = 20.2 ?/sq), whilst maintaining high optical film transparency (T = 94.7%), driving to the highest reported figure-of-merit (FoM = 338). Owing to the light-scattering influence of the AgNWs, the density of the AgNW network can also be varied to enable controllability of the optical haze through the sample. Based on the identification of the optimal haze value, organic photovoltaics (OPVs) have been fabricated using the AgNWs as the transparent electrode and have been benchmarked against indium tin oxide (ITO) electrodes. Overall, the performance of OPVs made using AgNWs sees a small decrease in power conversion efficiency (PCE), primarily due to a fall in open-circuit voltage (50 mV). This work indicates that AgNWs can provide a low cost, rapid and roll-to-roll compatible alternative to ITO in OPVs, with only a small compromise in PCE needed. PMID:26056864

  15. Direct Assembly of Graphene Oxide on Flexible Substrates for Highly Transparent Electrodes via the Langmuir-Blodgett Technique.

    PubMed

    Han, Tae Hee

    2015-02-01

    The surface activity of graphene oxide (GO) offers an ideal building block upon which to construct two-dimensional (2D) nanostructures via side-by-side assembly strategies. In this work, we demonstrate the Langmuir-Blodgett assembly of GO into a 2D film with a carbon monolayer thickness on a PET substrate over a large area. After the reduction of the GO films at a low temperature, transparent flexible conducting films were realized. Our straightforward route for preparing graphene-based transparent films provides a controlled strategy to coat graphene monolayers on flexible substrates. PMID:26353631

  16. Development of Carbon Based optically Transparent Electrodes from Pyrolyzed Photoresist for the Investigation of Phenomena at Electrified Carbon-Solution Interfaces

    SciTech Connect

    Sebastian Donner

    2007-12-01

    The work presented herein describes a fundamental investigations of carbon as electrode material by using the pyrolysis of photoresist to create an optically transparent material. The development of these carbon-based optically transparent electrodes (C-OTEs) enables investigations of molecular interactions within the electrical double layer, processes that are central to a wide range of important phenomena, including the impact of changes in the surface charge density on adsorption. The electrochemical importance of carbon cannot be understated, having relevance to separations and detection by providing a wide potential window and low background current in addition to being low cost and light weight. The interactions that govern the processes at the carbon electrode surface has been studied extensively. A variety of publications from the laboratories of McCreery and Kinoshita provide in depth summaries about carbon and its many applications in electrochemistry. These studies reveal that defects, impurities, oxidation, and a variety of functional groups create adsorption sites on carbon surfaces with different characteristics. The interest in C-OTEs was sparked by the desire to study and understand the behavior of individual molecules at electrified interfaces. It draws on the earlier development of Electrochemically Modulated Liquid Chromatography (EMLC), which uses carbon as the stationary phase. EMLC takes advantage of changing the applied potential to the carbon electrode to influence the retention behavior of analytes. However, perspectives gained from, for example, chromatographic measurements reflect the integrated response of a large ensemble of potentially diverse interactions between the adsorbates and the carbon electrode. Considering the chemically and physically heterogeneous surface of electrode materials such as glassy carbon, the integrated response provides little insight into the interactions at a single molecule level. To investigate individual processes, they have developed C-OTEs in order to couple electrochemistry with single molecule spectroscopy (SMS). Like EMLC, the novel merger of SMS with electrochemistry is a prime example of how a hybrid method can open new and intriguing avenues that are of both fundamental and technological importance. They show that by taking the benefits of total internal reflection fluorescence microscopy (TIRFM) and incorporating carbon as electrode material observations central to the interactions between single DNA molecules and an electrified carbon surface can be delineated. Using TIRFM while applying a positive potential to the electrode, individual molecules can be observed as they reversibly and irreversibly adsorb to the carbon surface. The positive potential attracts the negatively charged DNA molecules to the electrode surface. Dye labels on the DNA within the evanescent wave are excited and their fluorescence is captured by an intensified charge coupled device (ICCD) camera. Results are therefore presented regarding the interactions of {lambda}-DNA, 48,502 base pairs (48.5 kbp), HPV-16, 7.9 kbp, and 1 kbp fraction of pBR322 DNA. In addition to the influence of molecular size on adsorption, the fabrication, characterization, and more conventional spectroelectrochemical applications of these novel C-OTEs are presented.

  17. Impurity-doped ZnO Thin Films Prepared by Physical Deposition Methods Appropriate for Transparent Electrode Applications in Thin-film Solar Cells

    NASA Astrophysics Data System (ADS)

    Minami, Tadatsugu; Miyata, Toshihiro; Nomoto, Jun-ichi

    2012-04-01

    This paper describes the development of transparent conducting impurity-doped ZnO thin films that would be appropriate for applications as transparent electrodes in thin-film solar cells. Transparent conducting Al-, B- and Ga-doped ZnO (AZO, BZO and GZO) thin films were prepared in a thickness range from 500 to 2000 nm on glass substrates at 200°C using various physical deposition methods: BZO films with vacuum arc plasma evaporation, AZO and GZO films with different types of magnetron sputtering depositions (MSDs) and all films with pulsed laser deposition (PLD). The suitability and stability of the electrical properties and, in addition, the suitability of the light scattering characteristics and surface texture formation were investigated in the prepared thin films. In particular, the suitability and stability evaluation was focused on the use of AZO, BZO and GZO thin films prepared by doping each impurity at an appropriate content to attain the lowest resistivity. The higher Hall mobility obtained in impurity-doped ZnO thin films with a resistivity on the order of 10-4 ?cm was related more to the content, i.e., the obtained carrier concentration, rather than the kind of impurity doped into the films. The stability of resistivity of the BZO thin films in long-term moisture-resistance tests (in air at 85% relative humidity and 85°C) was found to be lower than that of the AZO and GZO thin films. The surface texture formation was carried out by wet-chemical etching (in a 0.1% HCl solution at 25°C) conducted either before or after being heat-treated either with rapid thermal annealing (RTA) or without RTA. The suitability of the light scattering characteristics and the surface texture formation obtainable by wet-chemical etching (for use in transparent electrode applications) was considerably dependent on the deposition method used as well as whether the wet-chemical etching was conducted with or without RTA. A significant improvement of both transmittance and haze value at wavelengths up to about 1200 nm in the near-infrared region was attained in surface-textured AZO films that were prepared by r.f. power superimposed d.c. MSD as well as etched after being heat treated with RTA at 500°C for 5 min in air. The obtained suitability and stability in impurity-doped ZnO thin films were related more to the content rather than the kind of impurity doped into the films as well as to the deposition method used.

  18. Zinc Oxide and Iron Phthalocyanine(FePc) based Hybrid Inorganic-Organic p-n Junction Diode Using Heavily Doped Zinc Oxide Transparent Conducting Electrode

    NASA Astrophysics Data System (ADS)

    Singh, Budhi; Ghosh, Subhasis

    2011-07-01

    We report on the fabrication of FePc/ZnO hybrid p-n junction device using Aluminum doped zinc oxide (AZO) as the transparent conducting electrode. The structure of such devices consist of ZnO and an organic molecular semiconductors, in which ZnO and Organic thin films served as n and p-type component respectively. We have obtained a rectification factor greater than ˜102 and current density of 0.3mA/cm2 at 2V.The capacitance-voltage characterization of the device further validates the formation of a one sided abrupt p-n junction at the ZnO/FePc interface.

  19. Synergistically enhanced stability of highly flexible silver nanowire/carbon nanotube hybrid transparent electrodes by plasmonic welding.

    PubMed

    Lee, Jongsoo; Woo, Ju Yeon; Kim, Ju Tae; Lee, Byung Yang; Han, Chang-Soo

    2014-07-23

    Here, we report highly transparent and flexible AgNW/SWCNT hybrid networks on PET substrates combined with plasmonic welding for securing ultrahigh stability in mechanical and electrical properties under severe bending. Plasmonic welding produces local heating and welding at the junction of AgNWs and leads strong adhesion between AgNW and SWCNT as well as between hybrid structure and substrate. The initial sheet resistance of plasmon treated AgNW/SWCNT hybrid film was 26 ? sq(-1), with >90% optical transmittance over the wavelength range 400-2700 nm. Following 200 cycles of convex/concave bending with a bending radius of 5 mm, the sheet resistance changed from 26 to 29 ? sq(-1). This hybrid structure combined with the plasmonic welding process provided excellent stability, low resistance, and high transparency, and is suitable for highly flexible electronics applications, including touch panels, solar cells, and OLEDs. PMID:24972024

  20. Hole-Conductor-Free Mesoscopic TiO2/CH3NH3PbI3 Heterojunction Solar Cells Based on Anatase Nanosheets and Carbon Counter Electrodes.

    PubMed

    Rong, Yaoguang; Ku, Zhiliang; Mei, Anyi; Liu, Tongfa; Xu, Mi; Ko, Songguk; Li, Xiong; Han, Hongwei

    2014-06-19

    A hole-conductor-free fully printable mesoscopic TiO2/CH3NH3PbI3 heterojunction solar cell was developed with TiO2 nanosheets containing high levels of exposed (001) facets. The solar cell embodiment employed a double layer of mesoporous TiO2 and ZrO2 as a scaffold infiltrated by perovskite as a light harvester. No hole conductor or Au reflector was employed. Instead, the back contact was simply a printable carbon layer. The perovskite was infiltrated from solution through the porous carbon layer. The high reactivity of (001) facets in TiO2 nanosheets improved the interfacial properties between the perovskite and the electron collector. As a result, photoelectric conversion efficiency of up to 10.64% was obtained with the hole-conductor-free fully printable mesoscopic TiO2/CH3NH3PbI3 heterojunction solar cell. The advantages of fully printable technology and the use of low-cost carbon-materials-based counter electrode and hole-conductor-free structure provide this design a promising prospect to approach low-cost photovoltaic devices. PMID:26270509

  1. A room-temperature process for fabricating a nano-Pt counter electrode on a plastic substrate for efficient dye-sensitized cells

    NASA Astrophysics Data System (ADS)

    Hsieh, Tsung-Yu; Wei, Tzu-Chien; Zhai, Peng; Feng, Shien-Ping; Ikegami, Masashi; Miyasaka, Tsutomu

    2015-06-01

    We present a method for depositing polyvinylpyrrolidone-capped platinum nanoparticles (PVP-nPt) on a plastic substrate as the counter electrode (CE) for dye-sensitized cells. This method was implemented using a modified two-step dip-coating process performed under ambient conditions. In particular, a short UV-ozone exposure period was adopted to replace conventional annealing, rendering the whole process feasible for plastic substrates. The surfactant required for deposition was confirmed by analyzing a Fourier transform infrared spectroscopy spectrum; however, we discovered that the surfactant jeopardized charge transfer between the PVP-nPt CE and the substrate. Furthermore, the UV-ozone treatment efficiently decomposed the surfactant, and the electrochemical-catalytic property improved considerably. When the CE was combined with a dye-sensitized photoanode fabricated on a plastic substrate, the power conversion efficiency (PCE) reached 6.24%. To further prove that the PCE is limited by the plastic photoanode instead of the proposed plastic PVP-nPt CE, a photoanode fabricated on FTO glass and the proposed plastic PVP-nPt CE with a PCE of 8.80% was demonstrated. Finally, thermal aging (conducted at 60 °C, 1000 h) test on this device indicated excellent durability, and the PCE was only 1% lower than its initial value.

  2. Spray deposited copper zinc tin sulphide (Cu2ZnSnS4) film as a counter electrode in dye sensitized solar cells.

    PubMed

    Swami, Sanjay Kumar; Chaturvedi, Neha; Kumar, Anuj; Chander, Nikhil; Dutta, Viresh; Kumar, D Kishore; Ivaturi, A; Senthilarasu, S; Upadhyaya, Hari M

    2014-11-21

    Stoichiometric thin films of Cu2ZnSnS4 (CZTS) were deposited by the spray technique on a FTO coated glass substrate, with post-annealing in a H2S environment to improve the film properties. CZTS films were used as a counter electrode (CE) in Dye-Sensitized Solar Cells (DSCs) with N719 dye and an iodine electrolyte. The DSC of 0.25 cm(2) area using a CE of CZTS film annealed in a H2S environment under AM 1.5G illumination (100 mW cm(-2)) exhibited a short circuit current density (JSC) = 18.63 mA cm(-2), an open circuit voltage (VOC) = 0.65 V and a fill factor (FF) = 0.53, resulting in an overall power conversion efficiency (PCE) = 6.4%. While the DSC using as deposited CZTS film as a CE showed the PCE = 3.7% with JSC = 13.38 mA cm(-2), VOC = 0.57 V and FF = 0.48. Thus, the spray deposited CZTS films can play an important role as a CE in the large area DSC fabrication. PMID:25286339

  3. In situ synthesis of binded, thick and porous carbon nanoparticle dye sensitized solar cell counter electrode with nickel gel as catalyst source

    NASA Astrophysics Data System (ADS)

    Zeng, Wei; Fang, Guojia; Han, Tianyang; Li, Borui; Liu, Nishuang; Zhao, Dongshan; Liu, Zhiqiang; Wang, Dianyuan; Zhao, Xingzhong; Zou, Dechun

    2014-01-01

    A TiO2-embedded NiCl2 gel is prepared and used as growth catalyst to in situ synthesize binded, thick and porous carbon nanoparticles (CNPs) on Ti foil substrate with a simple flame synthesis method for dye sensitized solar cell (DSSC) counter electrode (CE) applications. The viscous gel catalyst can hold sufficient NiCl2 coated on substrate to make CNP layer thick. The embedded TiO2 can effectively separate the abundant NiCl2 components to active the Ni catalyst for CNP growth and then make CNP layer become porous. In addition, the TiO2 components can bind the porous CNP products to make them conductive. With an optimized TiO2 fraction, the CE shows high catalytic ability and electrical conductivity. By applying this CNP CE for DSSC, a photovoltaic conversion efficiency of 6.6% is achieved, which exceeds 6.5% of a reference cell using costly platinum as CE. Furthermore, the CNP structure is demonstrated beneficial to carrier transport by a mass transfer model. This easy and effective preparation method may have a potential application in general nanomaterial preparation.

  4. Performances of some low-cost counter electrode materials in CdS and CdSe quantum dot-sensitized solar cells

    PubMed Central

    2014-01-01

    Different counter electrode (CE) materials based on carbon and Cu2S were prepared for the application in CdS and CdSe quantum dot-sensitized solar cells (QDSSCs). The CEs were prepared using low-cost and facile methods. Platinum was used as the reference CE material to compare the performances of the other materials. While carbon-based materials produced the best solar cell performance in CdS QDSSCs, platinum and Cu2S were superior in CdSe QDSSCs. Different CE materials have different performance in the two types of QDSSCs employed due to the different type of sensitizers and composition of polysulfide electrolytes used. The poor performance of QDSSCs with some CE materials is largely due to the lower photocurrent density and open-circuit voltage. The electrochemical impedance spectroscopy performed on the cells showed that the poor-performing QDSSCs had higher charge-transfer resistances and CPE values at their CE/electrolyte interfaces. PMID:24512605

  5. Effect of crystallization of Cu?ZnSnSxSe?-x counter electrode on the performance for efficient dye-sensitized solar cells.

    PubMed

    Chen, Hongli; Kou, Dongxing; Chang, Zhixian; Zhou, Wenhui; Zhou, Zhengji; Wu, Sixin

    2014-12-10

    Cu2ZnSnSxSe4-x (CZTSSe) counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) are commonly developed with porous structures, but their high surface area could also retard electron transport processes owing to the abundant grain boundaries. Herein, we employed a convenient solution method and a rapid heating process to prepare well crystalline CZTSSe CEs in DSSCs. The influence of crystallization of CZTSSe film on DSSCs performances was discussed in depth. The thermogravimetric analysis, phase morphology, conductivity, and electrochemical characteristics of CZTSSe films were performed. It is found that the rapid heating process is beneficial to the formation of well crystalline film with large grains. As the porosity and grain boundaries in the bulk film are dramatically reduced with the enhanced crystallization, the charge transport process is gradually improved. Using cyclic voltammogram and electrochemical impedance spectroscopy measurements, we propose that the accelerating charge transport is of great importance to the photovoltaic performances of DSSCs due to their superior electrocatalytic activities. As the highest cell efficiency was achieved, well crystalline CZTSSe is an efficient CE catalytic material. PMID:25382857

  6. Iron pyrite thin film counter electrodes for dye-sensitized solar cells: high efficiency for iodine and cobalt redox electrolyte cells.

    PubMed

    Shukla, Sudhanshu; Loc, Nguyen Huu; Boix, Pablo P; Koh, Teck Ming; Prabhakar, Rajiv Ramanujam; Mulmudi, Hemant K; Zhang, Jun; Chen, Shi; Ng, Chin Fan; Huan, Cheng Hon Alfred; Mathews, Nripan; Sritharan, Thirumany; Xiong, Qihua

    2014-10-28

    Iron pyrite has been the material of interest in the solar community due to its optical properties and abundance. However, the progress is marred due to the lack of control on the surface and intrinsic chemistry of pyrite. In this report, we show iron pyrite as an efficient counter electrode (CE) material alternative to the conventional Pt and poly(3,4-ethylenedioxythiophene (PEDOT) CEs in dye-sensitized solar cells (DSSCs). Pyrite film CEs prepared by spray pyrolysis are utilized in I3(-)/I(-) and Co(III)/Co(II) electrolyte-mediated DSSCs. From cyclic voltammetry and impedance spectroscopy studies, the catalytic activity is found to be comparable with that of Pt and PEDOT in I3(-)/I(-) and Co(III)/Co(II) electrolyte, respectively. With the I3(-)/I(-) electrolyte, photoconversion efficiency is found to be 8.0% for the pyrite CE and 7.5% for Pt, whereas with Co(III)/Co(II) redox DSSCs, efficiency is found to be the same for both pyrite and PEDOT (6.3%). The excellent performance of the pyrite CE in both the systems makes it a distinctive choice among the various CE materials studied. PMID:25241831

  7. Boosting the Open Circuit Voltage and Fill Factor of QDSSCs Using Hierarchically Assembled ITO@Cu2S Nanowire Array Counter Electrodes.

    PubMed

    Jiang, Yan; Yu, Bin-Bin; Liu, Jie; Li, Zhi-Hua; Sun, Jian-Kun; Zhong, Xin-Hua; Hu, Jin-Song; Song, Wei-Guo; Wan, Li-Jun

    2015-05-13

    The key challenges in enhancing the power conversion efficiency (PCE) of a quantum dot-sensitized solar cell (QDSSC) are efficiently achieving charge separation at the photoanode and improving the charge transfer, which is limited by the interface between the electrolyte and the counter electrode (CE). Here, hierarchically assembled ITO@Cu2S nanowire arrays with conductive single-crystalline ITO cores and Cu2S nanocrystal shells were designed as efficient QDSSCs CEs. These arrays not only provided an efficient three-dimensional charge transport network but also allowed for the effective deposition of more Cu2S nanocrystals as active sites to catalyze the electrolyte reaction. This design considerably reduced the sheet and charge transfer resistance of the CE, thus decreasing the series resistance and increasing the shunt resistance of the QDSSC. As a result, QDSSCs with this CE exhibited an unprecedentedly high Voc of 0.688 V, a fill factor of 58.39%, and a PCE of 6.12%, which is 21.2% higher than that of the conventional brass/Cu2S CE. PMID:25929671

  8. In situ growth of hierarchical NiS2 hollow microspheres as efficient counter electrode for dye-sensitized solar cell

    NASA Astrophysics Data System (ADS)

    Wan, Zhongquan; Jia, Chunyang; Wang, Yan

    2015-07-01

    Hierarchical NiS2 hollow microspheres (HM-NiS2) were successfully in situ grown on FTO by a one-step hydrothermal method, and then tested as the counter electrode (CE) for dye-sensitized solar cell (DSSC) for the first time. The SEM images reveal that the hierarchical NiS2 microspheres were successfully grown on FTO substrate. It is worth noting that some of the shells are partially broken, which is advantageous for providing more electrolyte adsorptions and electrocatalytic active sites. The electrocatalytic ability and electrochemical properties of the HM-NiS2 were studied by cyclic voltammetry, electrochemical impedance spectroscopy and Tafel polarization. The power conversion efficiency of 7.84% is achieved for the DSSC based on HM-NiS2 CE, which is close to that of the DSSC using Pt CE (7.89%). The results indicate that the in situ fabricated HM-NiS2 CE may be a good candidate for high efficiency and low-cost DSSCs.

  9. Photovoltaic performances of Cu2-xTe sensitizer based on undoped and indium(3+)-doped TiO2 photoelectrodes and assembled counter electrodes.

    PubMed

    Srathongluan, Pornpimol; Kuhamaneechot, Rattanakorn; Sukthao, Prapatsawan; Vailikhit, Veeramol; Choopun, Supab; Tubtimtae, Auttasit

    2016-02-01

    Novel binary Cu2-xTe nanoparticles based on undoped and indium-doped TiO2 photoelectrodes were synthesized using a successive ionic layer adsorption and reaction (SILAR) technique as a sensitizer for liquid-junction solar cells. A larger diameter of TiO2 promoted a narrower energy band gap after indium doping, attributing to yield a broader absorption range of nanoparticle sensitizer due to the increasing amount of Cu2-xTe NPs on TiO2 surface. The atomic percentages showed the stoichiometric formation of Cu2Te incorporated in a Cu2-xTe structure. The best photovoltaic performance with the lower SILAR cycle, i.e., n=13 was performed after indium doping in both of carbon and Cu2S CEs and revealed that the efficiency of 0.73% under the radiant 100mW/cm(2) (AM 1.5G). The electrochemical impedance spectroscopy (EIS) was used to investigate the electrical properties via effect of material doping and counter electrodes with a lower charge-transfer resistance (Rct) and it was also found that the electron lifetime was improved after the sample doped with indium and assembled with carbon CE. PMID:26524258

  10. Roll-to-Roll Encapsulation of Metal Nanowires between Graphene and Plastic Substrate for High-Performance Flexible Transparent Electrodes.

    PubMed

    Deng, Bing; Hsu, Po-Chun; Chen, Guanchu; Chandrashekar, B N; Liao, Lei; Ayitimuda, Zhawulie; Wu, Jinxiong; Guo, Yunfan; Lin, Li; Zhou, Yu; Aisijiang, Mahaya; Xie, Qin; Cui, Yi; Liu, Zhongfan; Peng, Hailin

    2015-06-10

    Transparent conductive film on plastic substrate is a critical component in low-cost, flexible, and lightweight optoelectronics. Industrial-scale manufacturing of high-performance transparent conductive flexible plastic is needed to enable wide-ranging applications. Here, we demonstrate a continuous roll-to-roll (R2R) production of transparent conductive flexible plastic based on a metal nanowire network fully encapsulated between graphene monolayer and plastic substrate. Large-area graphene film grown on Cu foil via a R2R chemical vapor deposition process was hot-laminated onto nanowires precoated EVA/PET film, followed by a R2R electrochemical delamination that preserves the Cu foil for reuse. The encapsulated structure minimized the resistance of both wire-to-wire junctions and graphene grain boundaries and strengthened adhesion of nanowires and graphene to plastic substrate, resulting in superior optoelectronic properties (sheet resistance of ?8 ? sq(-1) at 94% transmittance), remarkable corrosion resistance, and excellent mechanical flexibility. With these advantages, long-cycle life flexible electrochromic devices are demonstrated, showing up to 10000 cycles. PMID:26020567

  11. Facile, substrate-scale growth of mono- and few-layer homogeneous MoS2 films on Mo foils with enhanced catalytic activity as counter electrodes in DSSCs.

    PubMed

    Antonelou, Aspasia; Syrrokostas, George; Sygellou, Lamprini; Leftheriotis, George; Dracopoulos, Vassileios; Yannopoulos, Spyros N

    2016-01-29

    The growth of MoS2 films by sulfurization of Mo foils at atmospheric pressure is reported. The growth procedure provides, in a controlled way, mono- and few-layer thick MoS2 films with substrate-scale uniformity across square-centimeter area on commercial foils without any pre- or post-treatment. The prepared few-layer MoS2 films are investigated as counter electrodes for dye-sensitized solar cells (DSSCs) by assessing their ability to catalyse the reduction of I3 (-) to I(-) in triiodide redox shuttles. The dependence of the MoS2 catalytic activity on the number of monolayers is explored down to the bilayer thickness, showing performance similar to that of, and stability against corrosion better than, Pt-based nanostructured film. The DSSC with the MoS2-Mo counter electrode yields a photovoltaic energy conversion efficiency of 8.4%, very close to that of the Pt-FTO-based DSSC, i.e. 8.7%. The current results disclose a facile, cost-effective and green method for the fabrication of mechanically robust and chemically stable, few-layer MoS2 on flexible Mo substrates and further demonstrate that efficient counter electrodes for DSSCs can be prepared at thicknesses down to the 1-2 nm scale. PMID:26657923

  12. Zinc oxide modified with benzylphosphonic acids as transparent electrodes in regular and inverted organic solar cell structures

    SciTech Connect

    Lange, Ilja; Reiter, Sina; Kniepert, Juliane; Piersimoni, Fortunato; Brenner, Thomas; Neher, Dieter; Pätzel, Michael; Hildebrandt, Jana; Hecht, Stefan

    2015-03-16

    An approach is presented to modify the work function of solution-processed sol-gel derived zinc oxide (ZnO) over an exceptionally wide range of more than 2.3?eV. This approach relies on the formation of dense and homogeneous self-assembled monolayers based on phosphonic acids with different dipole moments. This allows us to apply ZnO as charge selective bottom electrodes in either regular or inverted solar cell structures, using poly(3-hexylthiophene):phenyl-C71-butyric acid methyl ester as the active layer. These devices compete with or even surpass the performance of the reference on indium tin oxide/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate. Our findings highlight the potential of properly modified ZnO as electron or hole extracting electrodes in hybrid optoelectronic devices.

  13. Zinc Oxide Modified with Benzylphosphonic Acids as Transparent Electrodes in Regular and Inverted Organic Solar Cell Structures

    E-print Network

    Ilja Lange; Sina Reiter; Juliane Kniepert; Fortunato Piersimoni; Michael Paetzel; Jana Hildebrandt; Thomas Brenner; Stefan Hecht; Dieter Neher

    2015-02-05

    An approach is presented to modify the WF of solution-processed sol-gel derived ZnOover an exceptionally wide range of more than 2.3 eV. This approach relies on the formation of dense and homogeneous self-assembled monolayers based on phosphonic acids with different dipole moments. This allows us to apply ZnO as charge selective bottom electrodes in either regular or inverted solar cell structures, using P3HT:PCBM as the active layer. These devices compete with or even exceed the performance of the reference cell on ITO/PEDOT:PSS. Our finding challenges the current view that bottom electrodes in inverted solar cells need to be electron-blocking for good device performance.

  14. Large Scale Laser Crystallization of Solution-based Alumina-doped Zinc Oxide (AZO) Nanoinks for Highly Transparent Conductive Electrode.

    PubMed

    Nian, Qiong; Callahan, Michael; Saei, Mojib; Look, David; Efstathiadis, Harry; Bailey, John; Cheng, Gary J

    2015-01-01

    A new method combining aqueous solution printing with UV Laser crystallization (UVLC) and post annealing is developed to deposit highly transparent and conductive Aluminum doped Zinc Oxide (AZO) films. This technique is able to rapidly produce large area AZO films with better structural and optoelectronic properties than most high vacuum deposition, suggesting a potential large-scale manufacturing technique. The optoelectronic performance improvement attributes to UVLC and forming gas annealing (FMG) induced grain boundary density decrease and electron traps passivation at grain boundaries. The physical model and computational simulation developed in this work could be applied to thermal treatment of many other metal oxide films. PMID:26515670

  15. Large Scale Laser Crystallization of Solution-based Alumina-doped Zinc Oxide (AZO) Nanoinks for Highly Transparent Conductive Electrode

    NASA Astrophysics Data System (ADS)

    Nian, Qiong; Callahan, Michael; Saei, Mojib; Look, David; Efstathiadis, Harry; Bailey, John; Cheng, Gary J.

    2015-10-01

    A new method combining aqueous solution printing with UV Laser crystallization (UVLC) and post annealing is developed to deposit highly transparent and conductive Aluminum doped Zinc Oxide (AZO) films. This technique is able to rapidly produce large area AZO films with better structural and optoelectronic properties than most high vacuum deposition, suggesting a potential large-scale manufacturing technique. The optoelectronic performance improvement attributes to UVLC and forming gas annealing (FMG) induced grain boundary density decrease and electron traps passivation at grain boundaries. The physical model and computational simulation developed in this work could be applied to thermal treatment of many other metal oxide films.

  16. Large Scale Laser Crystallization of Solution-based Alumina-doped Zinc Oxide (AZO) Nanoinks for Highly Transparent Conductive Electrode

    PubMed Central

    Nian, Qiong; Callahan, Michael; Saei, Mojib; Look, David; Efstathiadis, Harry; Bailey, John; Cheng, Gary J.

    2015-01-01

    A new method combining aqueous solution printing with UV Laser crystallization (UVLC) and post annealing is developed to deposit highly transparent and conductive Aluminum doped Zinc Oxide (AZO) films. This technique is able to rapidly produce large area AZO films with better structural and optoelectronic properties than most high vacuum deposition, suggesting a potential large-scale manufacturing technique. The optoelectronic performance improvement attributes to UVLC and forming gas annealing (FMG) induced grain boundary density decrease and electron traps passivation at grain boundaries. The physical model and computational simulation developed in this work could be applied to thermal treatment of many other metal oxide films. PMID:26515670

  17. Efficient p-type dye-sensitized solar cells with all-nano-electrodes: NiCo2S4 mesoporous nanosheet counter electrodes directly converted from NiCo2O4 photocathodes

    PubMed Central

    2014-01-01

    We report the successful growth of NiCo2S4 nanosheet films converted from NiCo2O4 nanosheet films on fluorine-doped tin oxide substrates by a low-temperature solution process. Low-cost NiCo2S4 and NiCo2O4 nanosheet films were directly used for replacing conventional Pt and NiO as counter electrodes and photocathodes, respectively, to construct all-nano p-type dye-sensitized solar cells (p-DSSCs) with high performance. Compared to Pt, NiCo2S4 showed higher catalytic activity towards the I-/I3- redox in electrolyte, resulting in an improved photocurrent density up to 2.989 mA/cm2, which is the highest value in reported p-DSSCs. Present p-DSSCs demonstrated a cell efficiency of 0.248 % that is also comparable with typical NiO-based p-DSSCs. PMID:25489277

  18. Engineering the interfaces of ITO@Cu2S nanowire arrays toward efficient and stable counter electrodes for quantum-dot-sensitized solar cells.

    PubMed

    Jiang, Yan; Zhang, Xing; Ge, Qian-Qing; Yu, Bin-Bin; Zou, Yu-Gang; Jiang, Wen-Jie; Hu, Jin-Song; Song, Wei-Guo; Wan, Li-Jun

    2014-09-10

    Among the issues that restrict the power conversion efficiency (PCE) of quantum-dot-sensitized solar cells (QDSSCs), insufficient catalytic activity and stability of counter electrodes (CEs) are critical but challenging ones. The state-of-the-art Cu/Cu2S CEs still suffer from mechanical instability and uncertainty due to the reaction of copper and electrolyte. Herein, ITO@Cu2S core-shell nanowire arrays were developed to fabricate CEs for QDSSCs, which have no such issues in Cu/Cu2S CEs. These nanowire arrays exhibited small charge transfer resistance and sheet resistance, and provided more active catalytic sites and easy accessibility for electrolyte due to the three-dimensional structure upon use as CEs. More interestingly, it was found that the interface of ITO/Cu2S significantly affected the performance of ITO@Cu2S nanowire array CEs. By varying synthetic methods, a series of ITO@Cu2S nanowire arrays were prepared to investigate the influence of ITO/Cu2S interface on their performance. The results showed that ITO@Cu2S nanowire array CEs with a continuous Cu2S nanocrystal shell fabricated via an improved cation exchange route exhibited excellent and thickness-dependent performance. The PCE of corresponding QDSSCs increased by 11.6 and 16.5% compared to that with the discrete Cu2S nanocrystal and the classic Cu/Cu2S CE, respectively, indicating its promising potential as a new type of CE for QDSSCs. PMID:25137502

  19. ZnSnO/Ag/indium tin oxide multilayer films as a flexible and transparent electrode for photonic devices

    NASA Astrophysics Data System (ADS)

    Kim, Dae-Hyun; Lee, Han-Kyeol; Na, Jin-Young; Kim, Sun-Kyung; Yoo, Young-Zo; Seong, Tae-Yeon

    2015-07-01

    To replace thick ITO single layer electrodes, ZnSnO (ZTO)/Ag/indium tin oxide (ITO) multilayer films were investigated as a function of Ag layer thickness. The ZTO/Ag/ITO films showed maximum transmittance in the range of 79.4-89.2%, depending on the Ag layer thickness. The relationship between transmittance and Ag thickness was simulated using the scattering matrix method to understand the high transmittance. As the Ag thickness increases from 6 to 14 nm, the carrier concentration increases from 4.12 × 1021 to 1.11 × 1022 cm-3 and the mobility increases from 8.14 to 17.4 cm2/V s. The ZTO (20 nm)/Ag (10 nm)/ITO (30 nm) multilayer films had a sheet resistance of 9 ?/sq. The ZTO/Ag/ITO multilayer had Haacke's figure of merit of 28.3 × 10-3 ?-1. The ZTO/Ag/ITO films deposited on PET substrates showed dramatically improved mechanical flexibility when subjected to bending test compared to 60 nm-thick ITO single layer electrodes.

  20. Improved open-circuit voltage in Cu(In,Ga)Se{sub 2} solar cells with high work function transparent electrodes

    SciTech Connect

    Jäger, Timo Romanyuk, Yaroslav E.; Bissig, Benjamin; Pianezzi, Fabian; Nishiwaki, Shiro; Reinhard, Patrick; Steinhauser, Jérôme; Tiwari, Ayodhya N.; Schwenk, Johannes

    2015-06-14

    Hydrogenated indium oxide (IOH) is implemented as transparent front contact in Cu(In,Ga)Se{sub 2} (CIGS) solar cells, leading to an open circuit voltage V{sub OC} enhanced by ?20?mV as compared to reference devices with ZnO:Al (AZO) electrodes. This effect is reproducible in a wide range of contact sheet resistances corresponding to various IOH thicknesses. We present the detailed electrical characterization of glass/Mo/CIGS/CdS/intrinsic ZnO (i-ZnO)/transparent conductive oxide (TCO) with different IOH/AZO ratios in the front TCO contact in order to identify possible reasons for the enhanced V{sub OC}. Temperature and illumination intensity-dependent current-voltage measurements indicate that the dominant recombination path does not change when AZO is replaced by IOH, and it is mainly limited to recombination in the space charge region and at the junction interface of the solar cell. The main finding is that the introduction of even a 5?nm-thin IOH layer at the i-ZnO/TCO interface already results in a step-like increase in V{sub OC}. Two possible explanations are proposed and verified by one-dimensional simulations using the SCAPS software. First, a higher work function of IOH as compared to AZO is simulated to yield an V{sub OC} increase by 21?mV. Second, a lower defect density in the i-ZnO layer as a result of the reduced sputter damage during milder sputter-deposition of IOH can also add to a maximum enhanced V{sub OC} of 25?mV. Our results demonstrate that the proper choice of the front TCO contact can reduce the parasitic recombination and boost the efficiency of CIGS cells with improved corrosion stability.

  1. Liquid-phase exfoliation of chemical vapor deposition-grown single layer graphene and its application in solution-processed transparent electrodes for flexible organic light-emitting devices

    SciTech Connect

    Wu, Chaoxing; Li, Fushan E-mail: gtl-fzu@hotmail.com; Wu, Wei; Chen, Wei; Guo, Tailiang E-mail: gtl-fzu@hotmail.com

    2014-12-15

    Efficient and low-cost methods for obtaining high performance flexible transparent electrodes based on chemical vapor deposition (CVD)-grown graphene are highly desirable. In this work, the graphene grown on copper foil was exfoliated into micron-size sheets through controllable ultrasonication. We developed a clean technique by blending the exfoliated single layer graphene sheets with conducting polymer to form graphene-based composite solution, which can be spin-coated on flexible substrate, forming flexible transparent conducting film with high conductivity (?8 ?/?), high transmittance (?81% at 550?nm), and excellent mechanical robustness. In addition, CVD-grown-graphene-based polymer light emitting diodes with excellent bendable performances were demonstrated.

  2. Liquid-phase exfoliation of chemical vapor deposition-grown single layer graphene and its application in solution-processed transparent electrodes for flexible organic light-emitting devices

    NASA Astrophysics Data System (ADS)

    Wu, Chaoxing; Li, Fushan; Wu, Wei; Chen, Wei; Guo, Tailiang

    2014-12-01

    Efficient and low-cost methods for obtaining high performance flexible transparent electrodes based on chemical vapor deposition (CVD)-grown graphene are highly desirable. In this work, the graphene grown on copper foil was exfoliated into micron-size sheets through controllable ultrasonication. We developed a clean technique by blending the exfoliated single layer graphene sheets with conducting polymer to form graphene-based composite solution, which can be spin-coated on flexible substrate, forming flexible transparent conducting film with high conductivity (˜8 ?/?), high transmittance (˜81% at 550 nm), and excellent mechanical robustness. In addition, CVD-grown-graphene-based polymer light emitting diodes with excellent bendable performances were demonstrated.

  3. Highly efficient inverted top emitting organic light emitting diodes using a transparent top electrode with color stability on viewing angle

    SciTech Connect

    Kim, Jung-Bum; Lee, Jeong-Hwan; Moon, Chang-Ki; Kim, Jang-Joo

    2014-02-17

    We report a highly efficient phosphorescent green inverted top emitting organic light emitting diode with excellent color stability by using the 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile/indium zinc oxide top electrode and bis(2-phenylpyridine)iridium(III) acetylacetonate as the emitter in an exciplex forming co-host system. The device shows a high external quantum efficiency of 23.4% at 1000?cd/m{sup 2} corresponding to a current efficiency of 110?cd/A, low efficiency roll-off with 21% at 10?000?cd/m{sup 2} and low turn on voltage of 2.4?V. Especially, the device showed very small color change with the variation of ?x?=?0.02, ?y?=?0.02 in the CIE 1931 coordinates as the viewing angle changes from 0° to 60°. The performance of the device is superior to that of the metal/metal cavity structured device.

  4. Transparent and conductive electrodes combining AZO and ATO thin films for enhanced light scattering and electrical performance

    NASA Astrophysics Data System (ADS)

    Guillén, C.; Montero, J.; Herrero, J.

    2013-01-01

    Al:ZnO (AZO) and Sb:SnO2 (ATO) thin films have been deposited by DC sputtering on soda lime glass (SLG) substrates. The preparation conditions were adjusted to obtain transparent films with high conductivity for AZO and high texture for ATO. Then, the combination of AZO and ATO thin films has been tested to enhance the optical scattering and the electrical performance. The structure, morphology, optical, and electrical properties have been analyzed for SLG/AZO, SLG/ATO and SLG/ATO/AZO samples. The surface texture has been characterized optically by the haze parameters for transmittance and reflectance (HT and HR), which have been related to the root mean square roughness for each sample. Some increase of the electrical resistance is obtained for the AZO films deposited on rough ATO underlayers as compared with analogous AZO grown directly on the smooth SLG substrate. Nevertheless, ATO/AZO bilayers have allowed to achieve better electrical conductivity than ATO and greater optical scattering than isolated ATO or AZO films. In this way, average haze values of HT = 30% and HR = 72%, together with sheet resistance of 20 ?/sq. have been obtained by combining 150 nm-thick ATO and 800 nm-thick AZO films.

  5. The Preparation and Properties of Al-Doped ZnO Thin Films as Transparent Electrodes for Solar Cell

    NASA Astrophysics Data System (ADS)

    Ding, J. N.; Tan, C. B.; Yuan, N. Y.; Feng, X. W.; Chang, X. Y.; Ye, F.

    Transparent conductive oxides based on ZnO are promising materials for application in thin-film solar photovoltaic cells. Al-doped ZnO thin films with a large area of 1 m × 1.5 m were prepared by magnetic sputtering on glass substrate using a ceramic target (98 wt. % ZnO, 2 wt. % Al2O3) in different Ar+H2 ambient at different substrate temperature. SiO2 layer with a thickness of 20 nm was deposited as a resistant layer. To investigate the influence of H2-flow on the properties of AZO films, H2-flow rate was changed during the growth process with a fixed Ar-flow rate. The effect of the substrate temperature and the H2-flow rate on the structure, electrical and optical properties was studied. In order to enhance light scattering and absorption inside the cell, suitable surface texture is needed. The influence of wet chemical etching on surface roughness and haze of AZO were also investigated.

  6. Composite Transparent Electrode of Graphene Nanowalls and Silver Nanowires on Micropyramidal Si for High-Efficiency Schottky Junction Solar Cells.

    PubMed

    Jiao, Tianpeng; Liu, Jian; Wei, Dapeng; Feng, Yanhui; Song, Xuefen; Shi, Haofei; Jia, Shuming; Sun, Wentao; Du, Chunlei

    2015-09-16

    The conventional graphene-silicon Schottky junction solar cell inevitably involves the graphene growth and transfer process, which results in complicated technology, loss of quality of the graphene, extra cost, and environmental unfriendliness. Moreover, the conventional transfer method is not well suited to conformationally coat graphene on a three-dimensional (3D) silicon surface. Thus, worse interfacial conditions are inevitable. In this work, we directly grow graphene nanowalls (GNWs) onto the micropyramidal silicon (MP) by the plasma-enhanced chemical vapor deposition method. By controlling growth time, the cell exhibits optimal pristine photovoltaic performance of 3.8%. Furthermore, we improve the conductivity of the GNW electrode by introducing the silver nanowire (AgNW) network, which could achieve lower sheet resistance. An efficiency of 6.6% has been obtained for the AgNWs-GNWs-MP solar cell without any chemical doping. Meanwhile, the cell exhibits excellent stability exposed to air. Our studies show a promising way to develop simple-technology, low-cost, high-efficiency, and stable Schottky junction solar cells. PMID:26308388

  7. High response Schottky ultraviolet photodetector formed by PEDOT:PSS transparent electrode contacts to Mg0.1Zn0.9O

    NASA Astrophysics Data System (ADS)

    Hu, Zuo-Fu; Wu, Huai-Hao; Lv, Yan-Wu; Zhang, Xi-Qing

    2015-10-01

    In this paper, we report a Schottky ultraviolet photodetector based on poly (3,4-ethylenedioxy-thiophene) poly(styrenesulfonate) (PEDOT:PSS) transparent electrode contacts to Mg0.1Zn0.9O. The I-V characteristic curves of the device are measured in the dark condition and under the illumination of a 340-nm UV light. The device shows a typical rectifying behavior with a current rectification ratio of 103 at ±2 V, which exhibits a good Schottky behavior. The photo-to-dark current ratio is high, which is 1×103 at -4 V. A peak response of 0.156 A/W at 340 nm is observed. The device also exhibits a wide response from 250 nm to 340 nm, with a response larger than 0.1 A/W. It covers the UV-B region (280 nm-320 nm), which makes the device very suitable for the detection of UV-B light. Project supported by the National Natural Science Foundation of China (Grant No. 50972007), the National Basic Research Program of China (Grant No. 2011CB932703), the National Natural Science Foundation for Distinguished Young Scholars of China (Grant No. 60825407), and the Opened Fund of the State Key Laboratory on Integrated Optoelectronics.

  8. Optical-to-optical interface device. [consisting of two transparent electrodes on glass substrates that enclose thin film photoconductor and thin layer of nematic liquid crystal

    NASA Technical Reports Server (NTRS)

    Jacobson, A. D.

    1973-01-01

    Studies were conducted on the performance of a photoactivated dc liquid crystal light valve. The dc light valve is a thin film device that consists of two transparent electrodes, deposited on glass substrates, that enclose a thin film photoconductor (cadmium sulfide) and a thin layer of a nematic liquid crystal that operates in the dynamic scattering mode. The work was directed toward application of the light valve to high resolution non-coherent light to coherent light image conversion. The goal of these studies was to improve the performance and quality of the already existing dc light valve device and to evaluate quantitatively the properties and performance of the device as they relate to the coherent optical data processing application. As a result of these efforts, device sensitivity was improved by a factor of ten, device resolution was improved by a factor of three, device lifetime was improved by two-orders of magnitude, undesirable secondary liquid crystal scattering effects were eliminated, the scattering characteristics of the liquid crystal were thoroughly documented, the cosmetic quality of the devices was dramatically improved, and the performance of the device was fully documented.

  9. Outcoupling-Enhanced Flexible Organic Light-Emitting Diodes on Ameliorated Plastic Substrate with Built-in Indium-Tin-Oxide-Free Transparent Electrode.

    PubMed

    Xiang, Heng-Yang; Li, Yan-Qing; Zhou, Lei; Xie, Hao-Jun; Li, Chi; Ou, Qing-Dong; Chen, Lin-Sen; Lee, Chun-Sing; Lee, Shuit-Tong; Tang, Jian-Xin

    2015-07-28

    Enhancing light outcoupling in flexible organic light-emitting diodes (FOLEDs) is an important task for increasing their efficiencies for display and lighting applications. Here, a strategy for an angularly and spectrally independent boost in light outcoupling of FOLEDs is demonstrated by using plastic substrates with a low refractive index, consisting of a bioinspired optical coupling layer and a transparent conductive electrode composed of a silver network. The good transmittance to full-color emission (>94% over the whole visible wavelength range), ultralow sheet resistance to carrier injection (<5 ? sq(-1)), and high tolerance to mechanical bending of the ameliorated plastic substrates synergistically optimize the device performance of FOLEDs. The maximum power efficiencies reach 47, 93, 56, and 52 lm W(-1) for red, green, blue, and white emissions, which are competitive with similarly structured OLEDs fabricated on traditional indium-tin-oxide (ITO) glass. This paradigm for light outcoupling enhancement in ITO-free FOLEDs offers additional features and design freedoms for highly efficient flexible optoelectronics in large-scale and low-cost manufacturing without the need for a high-refractive-index plastic substrate. PMID:26143652

  10. Design and fabrication of nanometric ZnS/Ag/MoO3 transparent conductive electrode and investigating the effect of annealing process on its characteristics

    NASA Astrophysics Data System (ADS)

    Kermani, Hamideh; Fallah, Hamid Reza; Hajimahmoodzadeh, Morteza

    2013-01-01

    In this paper, a ZnS/Ag/MoO3 (ZAM) nano-multilayer structure is designed theoretically and optimum thicknesses of each layer are calculated. ZnS/Ag/MoO3 multilayer films with optimized thicknesses have also been fabricated on glass substrates by thermal evaporation method at room temperature. The structural, electrical and optical properties of ZnS/Ag/MoO3 multilayer are investigated with respect to the variation of annealing temperature. X-ray diffraction patterns show that increase in annealing temperature increases the crystallinity of the structures. High-quality multilayer films with the sheet resistance of 4.5 ?/sq and the maximum optical transmittance of 85% at 100 °C annealing temperature are obtained. The allowed direct band gap for annealing at different temperatures is estimated to be in the range of 3.37-3.79 eV. The performance of the ZAM multilayer films are evaluated using a predefined figure of merit. These multilayer films can be used as transparent conductive electrodes in optoelectronic devices such as solar cells and organic light emitting diodes.

  11. Transparent lithium-ion batteries , Sangmoo Jeongb

    E-print Network

    Cui, Yi

    Transparent lithium-ion batteries Yuan Yanga , Sangmoo Jeongb , Liangbing Hua , Hui Wua , Seok Woo, and solar cells; however, transparent batteries, a key component in fully integrated transparent devices, have not yet been reported. As battery electrode materials are not transpar- ent and have to be thick

  12. Transparent lithium-ion batteries

    PubMed Central

    Yang, Yuan; Jeong, Sangmoo; Hu, Liangbing; Wu, Hui; Lee, Seok Woo; Cui, Yi

    2011-01-01

    Transparent devices have recently attracted substantial attention. Various applications have been demonstrated, including displays, touch screens, and solar cells; however, transparent batteries, a key component in fully integrated transparent devices, have not yet been reported. As battery electrode materials are not transparent and have to be thick enough to store energy, the traditional approach of using thin films for transparent devices is not suitable. Here we demonstrate a grid-structured electrode to solve this dilemma, which is fabricated by a microfluidics-assisted method. The feature dimension in the electrode is below the resolution limit of human eyes, and, thus, the electrode appears transparent. Moreover, by aligning multiple electrodes together, the amount of energy stored increases readily without sacrificing the transparency. This results in a battery with energy density of 10 Wh/L at a transparency of 60%. The device is also flexible, further broadening their potential applications. The transparent device configuration also allows in situ Raman study of fundamental electrochemical reactions in batteries. PMID:21788483

  13. Nutrition Counter

    MedlinePLUS

    ... Counter: A Reference For The Kidney Patient AAKP Nutrition Counter: A Reference For The Kidney Patient Buy ... Harum RD, CSR, LD Certified Specialist in Renal Nutrition, Miami, Florida Reviewed by: 2005 – Maria Karalis, MBA, ...

  14. A solution-processed molybdenum oxide treated silver nanowire network: a highly conductive transparent conducting electrode with superior mechanical and hole injection properties

    NASA Astrophysics Data System (ADS)

    Chang, Jung-Hao; Chiang, Kai-Ming; Kang, Hao-Wei; Chi, Wei-Jung; Chang, Jung-Hung; Wu, Chih-I.; Lin, Hao-Wu

    2015-02-01

    We demonstrate the fabrication of solution-processed MoOx-treated (s-MoOx) silver nanowire (AgNW) transparent conductive electrodes (TCEs) utilizing low-temperature (sub-100 °C) processes. The s-MoOx aggregates around the AgNW and forms gauze-like MoOx thin films between the mesh, which can effectively lower the sheet resistance by more than two orders of magnitude. Notably, these s-MoOx-treated AgNW TCEs exhibit a combination of several promising characteristics, such as a high and broad transmittance across a wavelength range of 400 to 1000 nm, transmission of up to 96.8%, a low sheet resistance of 29.8 ohm sq-1, a low haze value of 0.90%, better mechanical properties against bending and adhesion tests, and preferable gap states for efficient hole injection in optoelectronic applications. By utilizing these s-MoOx-treated AgNW TCEs as the anode in ITO-free organic light emitting diodes, promising performance of 29.2 lm W-1 and 10.3% external quantum efficiency are demonstrated. The versatile, multi-functional s-MoOx treatment presented here paves the way for the use of low-temperature, solution-processed MoOx as both a nanowire linker and a hole injection interfacial layer for future flexible optoelectronic devices.We demonstrate the fabrication of solution-processed MoOx-treated (s-MoOx) silver nanowire (AgNW) transparent conductive electrodes (TCEs) utilizing low-temperature (sub-100 °C) processes. The s-MoOx aggregates around the AgNW and forms gauze-like MoOx thin films between the mesh, which can effectively lower the sheet resistance by more than two orders of magnitude. Notably, these s-MoOx-treated AgNW TCEs exhibit a combination of several promising characteristics, such as a high and broad transmittance across a wavelength range of 400 to 1000 nm, transmission of up to 96.8%, a low sheet resistance of 29.8 ohm sq-1, a low haze value of 0.90%, better mechanical properties against bending and adhesion tests, and preferable gap states for efficient hole injection in optoelectronic applications. By utilizing these s-MoOx-treated AgNW TCEs as the anode in ITO-free organic light emitting diodes, promising performance of 29.2 lm W-1 and 10.3% external quantum efficiency are demonstrated. The versatile, multi-functional s-MoOx treatment presented here paves the way for the use of low-temperature, solution-processed MoOx as both a nanowire linker and a hole injection interfacial layer for future flexible optoelectronic devices. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr06805j

  15. Transparent conductive graphene textile fibers

    NASA Astrophysics Data System (ADS)

    Neves, A. I. S.; Bointon, T. H.; Melo, L. V.; Russo, S.; de Schrijver, I.; Craciun, M. F.; Alves, H.

    2015-05-01

    Transparent and flexible electrodes are widely used on a variety of substrates such as plastics and glass. Yet, to date, transparent electrodes on a textile substrate have not been explored. The exceptional electrical, mechanical and optical properties of monolayer graphene make it highly attractive as a transparent electrode for applications in wearable electronics. Here, we report the transfer of monolayer graphene, grown by chemical vapor deposition on copper foil, to fibers commonly used by the textile industry. The graphene-coated fibers have a sheet resistance as low as ~1?k? per square, an equivalent value to the one obtained by the same transfer process onto a Si substrate, with a reduction of only 2.3 per cent in optical transparency while keeping high stability under mechanical stress. With this approach, we successfully achieved the first example of a textile electrode, flexible and truly embedded in a yarn.

  16. Transparent conductive graphene textile fibers

    PubMed Central

    Neves, A. I. S.; Bointon, T. H.; Melo, L. V.; Russo, S.; de Schrijver, I.; Craciun, M. F.; Alves, H.

    2015-01-01

    Transparent and flexible electrodes are widely used on a variety of substrates such as plastics and glass. Yet, to date, transparent electrodes on a textile substrate have not been explored. The exceptional electrical, mechanical and optical properties of monolayer graphene make it highly attractive as a transparent electrode for applications in wearable electronics. Here, we report the transfer of monolayer graphene, grown by chemical vapor deposition on copper foil, to fibers commonly used by the textile industry. The graphene-coated fibers have a sheet resistance as low as ~1?k? per square, an equivalent value to the one obtained by the same transfer process onto a Si substrate, with a reduction of only 2.3 per cent in optical transparency while keeping high stability under mechanical stress. With this approach, we successfully achieved the first example of a textile electrode, flexible and truly embedded in a yarn. PMID:25952133

  17. Transparent conductive graphene textile fibers.

    PubMed

    Neves, A I S; Bointon, T H; Melo, L V; Russo, S; de Schrijver, I; Craciun, M F; Alves, H

    2015-01-01

    Transparent and flexible electrodes are widely used on a variety of substrates such as plastics and glass. Yet, to date, transparent electrodes on a textile substrate have not been explored. The exceptional electrical, mechanical and optical properties of monolayer graphene make it highly attractive as a transparent electrode for applications in wearable electronics. Here, we report the transfer of monolayer graphene, grown by chemical vapor deposition on copper foil, to fibers commonly used by the textile industry. The graphene-coated fibers have a sheet resistance as low as ~1?k? per square, an equivalent value to the one obtained by the same transfer process onto a Si substrate, with a reduction of only 2.3 per cent in optical transparency while keeping high stability under mechanical stress. With this approach, we successfully achieved the first example of a textile electrode, flexible and truly embedded in a yarn. PMID:25952133

  18. VOLTAMMETRIC MEMBRANE CHLORINE DIOXIDE ELECTRODE

    EPA Science Inventory

    A voltammetric membrane electrode system has been modified and applied to the in situ measurement of chlorine dioxide. The electrode system consisted of a gold cathode, a silver/silver chloride reference electrode, and a gold counter electrode. Different membrane materials were t...

  19. Room-temperature synthesis of Cu(2-x)E (E = S, Se) nanotubes with hierarchical architecture as high-performance counter electrodes of quantum-dot-sensitized solar cells.

    PubMed

    Chen, Xin Qi; Li, Zhen; Bai, Yang; Sun, Qiao; Wang, Lian Zhou; Dou, Shi Xue

    2015-01-12

    Copper chalcogenide nanostructures (e.g. one-dimensional nanotubes) have been the focus of interest because of their unique properties and great potential in various applications. Their current fabrications mainly rely on high-temperature or complicated processes. Here, with the assistance of theoretical prediction, we prepared Cu(2-x)E (E = S, Se) micro-/nanotubes (NTs) with a hierarchical architecture by using copper nanowires (Cu NWs), stable sulfur and selenium powder as precursors at room temperature. The influence of reaction parameters (e.g. precursor ratio, ligands, ligand ratio, and reaction time) on the formation of nanotubes was comprehensively investigated. The resultant Cu(2-x)E (E = S, Se) NTs were used as counter electrodes (CE) of quantum-dot-sensitized solar cells (QDSSCs) to achieve a conversion efficiency (?) of 5.02 and 6.25%, respectively, much higher than that of QDSSCs made with Au CE (? = 2.94%). PMID:25400022

  20. Facile water-based spray pyrolysis of earth-abundant Cu2FeSnS4 thin films as an efficient counter electrode in dye-sensitized solar cells.

    PubMed

    Prabhakar, Rajiv Ramanujam; Huu Loc, Nguyen; Kumar, Mulmudi Hemant; Boix, Pablo P; Juan, Sun; John, Rohit Abraham; Batabyal, Sudip K; Wong, Lydia Helena

    2014-10-22

    A novel approach to produce earth-abundant Cu2FeSnS4 (CFTS) thin film using spray pyrolysis of nontoxic aqueous precursors followed by sulfurization is reported. The CFTS phase formation was confirmed by both Raman spectroscopy and X-ray diffraction techniques. Hall measurements of these films reveal p-type conductivity with good charge carrier density and mobilities appropriate for solar harvesting devices. To the best of our knowledge, this is the first report on the electrical properties of solution-processed Cu2FeSnS4 thin films estimated using Hall measurements. Dye-sensitized solar cells (DSSC) fabricated with CFTS thin film as a photocathode in iodine/iodide electrolyte exhibit good power conversion efficiency, 8.03%, indicating that CFTS would be a promising cheaper alternative to replace Pt as a counter electrode in DSSCs. PMID:25255739

  1. Calorie Counter

    MedlinePLUS

    ... window. My Saved Articles » My ACS » + - Text Size American Cancer Society Calorie Counter Being at a healthy weight has ... Health On The Net National Health Council © 2015 American Cancer Society, Inc. All rights reserved. The American Cancer Society ...

  2. “Brick-like” N-doped graphene/carbon nanotube structure forming three-dimensional films as high performance metal-free counter electrodes in dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Ma, Jie; Li, Cheng; Yu, Fei; Chen, Junhong

    2015-01-01

    The "brick-like" N-doped graphene-carbon nanotube (NGC) composites are designed by mechanically grinding the filtration films, which are fabricated to form a three-dimensional structure film as a counter electrode (CE). The N-doped graphene/carbon nanotube films with a three-dimensional "brick-like" structure can provide numerous vertical active edge sites. The excellent electrochemical catalytic activities of CE can be obtained by adjusting the different ratio of graphene to CNTs to control the size and N-doping content of breaking particles. NGC17 CE based dye-sensitized solar cells (DSSC) have reached a high efficiency (6.74%) close to platinum-based cells (6.89%). The excellent efficiency may be attributed to the following factors: a) the ?EP of NGC17 (304 mV) is lower than that of the Pt electrode (389 mV); b) the charge transfer resistance (Rct) at the NGC17-CE/electrolyte interface was 1.78 ? cm-2, which is lower than that of a Pt-CE/electrolyte interface (8.97 ? cm-2).

  3. Li4Ti5O12 and LiMn2O4 thin-film electrodes on transparent conducting oxides for all-solid-state and electrochromic applications

    NASA Astrophysics Data System (ADS)

    Roeder, Manuel; Beleke, Alexis B.; Guntow, Uwe; Buensow, Johanna; Guerfi, Abdelbast; Posset, Uwe; Lorrmann, Henning; Zaghib, Karim; Sextl, Gerhard

    2016-01-01

    Transparent Li4Ti5O12 and LiMn2O4 thin films were prepared on transparent conducting oxide substrates via sol-gel dip coating technique. The resulting films were highly uniform and transparent after annealing at 600 °C and 400 °C for Li4Ti5O12 and LiMn2O4, respectively. Different film thicknesses ranging from 50 nm to about 800 nm were attained and the films were characterized by scanning electron microscopy (SEM) for surface morphology and X-ray diffraction (XRD) for evaluating the crystallization of the active materials. Ellipsometric porosimetry was used to measure the porosity of the anode material. Furthermore, electrochemical techniques such as cyclovoltametry and galvanostatic charging/discharging confirm the successful synthesis of electrochemically active LiMn2O4 and Li4Ti5O12 films. Single-layer electrodes show stable capacities at discharge rates up to 100C indicating the high rate capability and therefore and therefore are classified as materials for power. Furthermore, the electrochromic effects were observed for both thin-film systems and evaluated in preliminary tests.

  4. A novel system of electrodes transparent to ultrasound for simultaneous detection of myoelectric activity and B-mode ultrasound images of skeletal muscles

    PubMed Central

    Vieira, T. M. M.; Loram, I. D.; Merletti, R.; Hodson-Tole, E. F.

    2013-01-01

    Application of two-dimensional surface electrode arrays can provide a means of mapping motor unit action potentials on the skin surface above a muscle. The resulting muscle tissue displacement can be quantified, in a single plane, using ultrasound (US) imaging. Currently, however, it is not possible to simultaneously map spatio-temporal propagation of activation and resulting tissue strain. In this paper, we developed and tested a material that will enable concurrent measurement of two-dimensional surface electromyograms (EMGs) with US images. Specific protocols were designed to test the compatibility of this new electrode material, both with EMG recording and with US analysis. Key results indicate that, for this new electrode material, 1) the electrode-skin impedance is similar to that of arrays of electrodes reported in literature; 2) the reflection of US at the electrode-skin interface is negligible; 3) the likelihood of observing missing contacts, short-circuits, and artifacts in EMGs is not affected by the US probe; 4) movement of tissues sampled by US can be tracked accurately. We, therefore, conclude this approach will facilitate multimodal imaging of muscle to provide new spatio-temporal information regarding electromechanical function of muscle. This is relevant to basic physiology-biomechanics of active and passive force transmission through and between muscles, of motor unit spatio-temporal activity patterns, of their variation with architecture and task-related function, and of their adaptation with aging, training-exercise-disuse, neurological disease, and injury. PMID:23908313

  5. Effect of Gold Thickness and Annealing on Optical and Electrical Properties of TiO2/Au/TiO2 Multilayers as Transparent Composite Electrode on Flexible Substrate

    NASA Astrophysics Data System (ADS)

    Dhar, Aritra; Zhao, Zhao; Alford, T. L.

    2015-04-01

    Multilayer structures of TiO2/Au/TiO2 have been deposited onto flexible substrates by room temperature sputtering to develop indium-free transparent composite electrodes (TCEs). The effect of Au thicknesses on optical, electrical properties and the mechanism of conduction have been discussed. The electrical conductivity of the TCEs is solely contributed by the middle metal layer. The critical thickness ( t c) of the Au mid-layer to form a continuous conducting layer is 10 nm, and the multilayer has been optimized to obtain a sheet resistance of 12.2 ?/sq and an average optical transmittance of 86% at 590 nm. The Haacke figure of merit (FOM) for t c has one of the highest FOM with 18 × 10-3 ?-1. The samples were annealed in various environments for 24 h up to 150°C.

  6. Direct transparent electrode patterning on layered GaN substrate by screen printing of indium tin oxide nanoparticle ink for Eu-doped GaN red light-emitting diode

    SciTech Connect

    Kashiwagi, Y. Yamamoto, M.; Saitoh, M.; Takahashi, M.; Ohno, T.; Nakamoto, M.; Koizumi, A.; Fujiwara, Y.; Takemura, Y.; Murahashi, K.; Ohtsuka, K.; Furuta, S.

    2014-12-01

    Transparent electrodes were formed on Eu-doped GaN-based red-light-emitting diode (GaN:Eu LED) substrates by the screen printing of indium tin oxide nanoparticle (ITO np) inks as a wet process. The ITO nps with a mean diameter of 25?nm were synthesized by the controlled thermolysis of a mixture of indium complexes and tin complexes. After the direct screen printing of ITO np inks on GaN:Eu LED substrates and sintering at 850?°C for 10?min under atmospheric conditions, the resistivity of the ITO film was 5.2?m??cm. The fabricated LED up to 3?mm square surface emitted red light when the on-voltage was exceeded.

  7. Transparent organic light emitting devices

    NASA Astrophysics Data System (ADS)

    Gu, G.; Bulovi?, V.; Burrows, P. E.; Forrest, S. R.; Thompson, M. E.

    1996-05-01

    We report the demonstration of transparent organic light emitting devices (OLEDs) which are ˜70% transparent throughout the visible spectrum when switched off, and emit light from both sides with a total external quantum efficiency of ˜0.1% when turned on. The devices are Alq3-based single heterostructure OLEDs grown on an ITO-coated glass substrate with a top electrode composed of a very thin layer of Mg-Ag and an overlaying ITO film. The top electrode is both electron injecting and transparent. The transparent OLEDs are expected to be useful in high-resolution full-color displays, as well as for helmet-mounted, windshield-mounted, or other ``head-up'' display applications.

  8. Conductive and transparent multilayer films for low-temperature TiO2/Ag/SiO2 electrodes by E-beam evaporation with IAD

    PubMed Central

    2014-01-01

    Conductive and transparent multilayer thin films consisting of three alternating layers (TiO2/Ag/SiO2, TAS) have been fabricated for applications as transparent conducting oxides. Metal oxide and metal layers were prepared by electron-beam evaporation with ion-assisted deposition, and the optical and electrical properties of the resulting films as well as their energy bounding characteristics and microstructures were carefully investigated. The optical properties of the obtained TAS material were compared with those of well-known transparent metal oxide glasses such as ZnO/Ag/ZnO, TiO2/Ag/TiO2, ZnO/Cu/ZnO, and ZnO/Al/ZnO. The weathering resistance of the TAS film was improved by using a protective SiO2 film as the uppermost layer. The transmittance spectra and sheet resistance of the material were carefully measured and analyzed as a function of the layer thickness. By properly adjusting the thickness of the metal and dielectric films, a low sheet resistance of 6.5 ohm/sq and a high average transmittance of over 89% in the 400 to 700 nm wavelength regions were achieved. We found that the Ag layer played a significant role in determining the optical and electrical properties of this film. PMID:24433437

  9. Optical Impedance Transformer for Transparent Conducting Ken Xingze Wang,,

    E-print Network

    Fan, Shanhui

    Optical Impedance Transformer for Transparent Conducting Electrodes Ken Xingze Wang,, Jessica R develop the concept of optical impedance transformation, and use this concept to design nanophotonic conducting electrode, without compromising its electrical performance. KEYWORDS: Optical impedance

  10. Stacked Cu1.8S nanoplatelets as Counter Electrode for Quantum Dot-Sensitized Solar Cell

    SciTech Connect

    Savariraj, Dennyson A.; Rajendrakumar, G.; Selvam, Samayanan; Karthick, S. N.; Balamuralitharan, B.; Kim, Hee-Je; Viswanathan, Kodakkal K.; Vijayakumar, M.; Prabakar, Kandasamy

    2015-11-09

    It is found that electrocatalytic activity of Cu2-xS thin films used in quantum dots sensitized solar cells (QDSSC) as countner electrode (CE) for the reduction of polysulfide electrolyte depends on the the surface active sulfur species and defficiency of Cu. The preferential bonding between Cu2+ and S2- leading to the selective formation of Cu1.8S stacked platelets like morphology is determined by Cetyl Trimethyl Ammonium Bromide surfactant with temperature and crab like Cu-S coordination bond formed dictates the surface area to volume ratio of the Cu1.8S thin films and the electrocatalytic activity. The Cu deficiency enhances the conductivity of the Cu1.8S thin films and exhibits near- infrared localized surface plasmon resonanc due to free carrier intraband absorption and UV-VIS absorption spectra shows excitonic effect due to quantum size effect. When these Cu1.8S thin films were employed as CE in QDSSC, robust photoconversion efficiency of 5.2 % is yielded by the film deposited at 60°C by a sinlge step chemical bath deposition method.

  11. One-step synthesis of carbon nanosheets converted from a polycyclic compound and their direct use as transparent electrodes of ITO-free organic solar cells.

    PubMed

    Son, Su-Young; Noh, Yong-Jin; Bok, Changsuk; Lee, Sungho; Kim, Byoung Gak; Na, Seok-In; Joh, Han-Ik

    2014-01-21

    Through a catalyst- and transfer-free process, we fabricated indium tin oxide (ITO)-free organic solar cells (OSCs) using a carbon nanosheet (CNS) with properties similar to graphene. The morphological and electrical properties of the CNS derived from a polymer of intrinsic microporosity-1 (PIM-1), which is mainly composed of several aromatic hydrocarbons and cycloalkanes, can be easily controlled by adjusting the polymer concentration. The CNSs, which are prepared by simple spin-coating and heat-treatment on a quartz substrate, are directly used as the electrodes of ITO-free OSCs, showing a high efficiency of approximately 1.922% under 100 mW cm(-2) illumination and air mass 1.5 G conditions. This catalyst- and transfer-free approach is highly desirable for electrodes in organic electronics. PMID:24162657

  12. Metal substrate based electrodes for flexible dye-sensitized solar cells: fabrication methods, progress and challenges.

    PubMed

    Balasingam, Suresh Kannan; Kang, Man Gu; Jun, Yongseok

    2013-12-21

    A step towards commercialization of dye-sensitized solar cells (DSSCs) requires more attention to engineering aspects, such as flexibility, the roll to roll fabrication process, the use of cost effective materials, etc. In this aspect, advantages of flexible DSSCs attracted many researchers to contemplate the transparent conducting oxide coated flexible plastic substrates and the thin metallic foils. In this feature article, the pros and cons of these two kinds of substrates are compared. The flexible dye-sensitized solar cells fabricated using metal substrates are briefly discussed. The working electrodes of DSSCs fabricated on various metal substrates, their fabrication methods, the effect of high temperature calcination and drawbacks of back illumination are reviewed in detail. A few reports on the flexible metal substrate based counter electrodes that could be combined with the plastic substrate based working electrodes are also covered at the end. PMID:24196211

  13. Color Transparency

    E-print Network

    Gerald A. Miller

    2012-08-17

    Color transparency is the vanishing of nuclear initial or final state interactions involving specific reactions. The reasons for believing that color transparency might be a natural consequence of QCD are reviewed. The main impetus for this talk is recent experimental progress, and this is reviewed briefly.

  14. Enhanced photovoltaic performance and time varied controllable growth of a CuS nanoplatelet structured thin film and its application as an efficient counter electrode for quantum dot-sensitized solar cells via a cost-effective chemical bath deposition.

    PubMed

    Venkata Thulasi-Varma, Chebrolu; Rao, S Srinivasa; Kumar, Challa Shesha Sai Pavan; Gopi, Chandu V V M; Durga, I Kanaka; Kim, Soo-Kyoung; Punnoose, Dinah; Kim, Hee-Je

    2015-11-28

    For the first time we report a simple synthetic strategy to prepare copper sulfide counter electrodes on fluorine-doped tin oxide (FTO) substrates using the inexpensive chemical bath deposition method in the presence of hydrochloric acid (HCl) at different deposition times. CuS nanoplatelet structures were uniformly grown on the FTO substrate with a good dispersion and optimized conditions. The growth process of the CuS nanoplatelets can be controlled by changing the deposition time in the presence of HCl. HCl acts as a complexing agent as well as improving S(2-) concentration against S atoms in this one-step preparation. The photovoltaic performance was significantly improved in terms of the power conversion efficiency (PCE), short-circuit density (Jsc), open-circuit voltage (Voc), and the fill factor (FF). The optimized deposition time of CuS 60 min resulted in a higher PCE of 4.06%, Jsc of 12.92 mA cm(-2), Voc of 0.60 V, and a FF of 0.52 compared to CuS 50 min, CuS 70 min, and a Pt CE. The superior performance of the 60 min sample is due to the greater electrocatalytic activity and low charge transfer resistance at the interface of the CE and the polysulfide electrolyte. The concentration of Cu/S also had an important role in the formation of the CuS nanoplatelet structures. The optical bandgaps for the CuS with different morphologies were measured to be in the range of 1.98-2.28 eV. This improved photovoltaic performance is mainly attributed to the greater number of active reaction sites created by the CuS layer on the FTO substrate, which results large specific surface, superior electrical conductivity, low charge transfer resistance, and faster electron transport in the presence of HCl. Cyclic voltammetry, electrochemical impedance spectroscopy and Tafel-polarization measurements were used to investigate the electrocatalytic activity of the CuS and Pt CEs. This synthetic procedure not only provides high electrocatalytic activity for QDSSCs but could also be a cost-effective way to fabricate flexible electrodes in dye-sensitized solar cells or supercapacitor applications. PMID:26497705

  15. Temperature-stable and optically transparent thin-film zinc oxide aerogel electrodes as model systems for 3D interpenetrating organic-inorganic heterojunction solar cells.

    PubMed

    Krumm, Michael; Pawlitzek, Fabian; Weickert, Jonas; Schmidt-Mende, Lukas; Polarz, Sebastian

    2012-12-01

    Novel, nanostructured electrode materials comprising porous ZnO films with aerogel morphology are presented. Almost any substrate including polymers, metals, or ceramics can be coated using a method that is suitable for mass production. The thin, porous films can be prepared from the wet gels via conventional drying, supercritical drying is not necessary. The filigree ZnO network is thermally very stable and exhibits sufficient electrical conductivity for advanced electronic applications. The latter was tested by realizing a highly desired architecture of organic-inorganic hybrid solar cells. After sensitizing of the ZnO with a purely organic squarine dye (SQ2), a nanostructured, interpenetrating 3D network of the inorganic semiconductor (ZnO) and organic semiconductor (P3HT) was prepared. The solar cell device was tested under illumination with AM 1.5G solar light (100 mW/cm(2)) and exhibited an energy conversion efficiency (?(eff)) of 0.69%. PMID:23194020

  16. Optimization of transparent and reflecting electrodes for amorphous silicon solar cells. Annual subcontract report, 1 May 1991--30 April 1992

    SciTech Connect

    Gordon, R.G.

    1993-04-01

    This report describes work to improve the performance of solar cells by improving the electrical and optical properties of their transparent conducting oxides (TCO) layers. Boron-doped zinc-oxide films were deposited by atmospheric pressure chemical vapor deposition in a laminar-flow reactor from diethyl zinc, tert-butanol, and diborane in the temperature range between 300{degrees}C and 420{degrees}C. When the deposition temperature was above 320{degrees}C, both doped and undoped films have highly oriented crystallites with their c-axes perpendicular to the substrate plane. Films deposited from 0.07% diethyl zinc and 2.4% tert-butanol have electron densities between 3.5 {times} 10{sup 20} cm{sup {minus}3} and 5.5 {times} 10{sup 20} cm{sup {minus}3}, conductivities between 250 {Omega}{sup {minus}1} and 2500 {Omega}{sup {minus}1} and mobilities between 2.5 cm{sup 2}/V-s and 35.0 cm{sup 2}/V-s, depending on dopant concentration, film thickness, and deposition temperature. Optical measurements show that the maximum infrared reflectance of the doped films is close to 90%, compared to about 20% for undoped films. Film visible absorption and film conductivity were found to increase with film thickness. The ratio of conductivity to visible absorption coefficient for doped films was between 0.1 {Omega} and 1.1 {Omega}{sup {minus}1}. The band gap of the film changes from 3.3 eV to 3.7 eV when the film is doped with 0.012% diborane.

  17. High-Performance Fully Nanostructured Photodetector with Single-Crystalline CdS Nanotubes as Active Layer and Very Long Ag Nanowires as Transparent Electrodes.

    PubMed

    An, Qinwei; Meng, Xianquan; Sun, Pan

    2015-10-21

    Long and single-crystalline CdS nanotubes (NTs) have been prepared via a physical evaporation process. A metal-semiconductor-metal full-nanostructured photodetector with CdS NTs as active layer and Ag nanowires (NWs) of low resistivity and high transmissivity as electrodes has been fabricated and characterized. The CdS NTs-based photodetectors exhibit high performance, such as lowest dark currents (0.19 nA) and high photoresponse ratio (Ilight/Idark ? 4016) (among CdS nanostructure network photodetectors and NTs netwok photodetectors reported so far) and very low operation voltages (0.5 V). The photoconduction mechanism, including the formation of a Schottky barrier at the interface of Ag NW and CdS NTs and the effect of oxygen adsorption process on the Schottky barrier has also been provided in detail based on the studies of CdS NTs photodetector in air and vacuum. Furthermore, CdS NTs photodetector exhibits an enhanced photosensitivity as compared with CdS NWs photodetector. The enhancement in performance is dependent on the larger surface area of NTs adsorbing more oxygen in air and the microcavity structure of NTs with higher light absorption efficiency and external quantum efficiency. It is believed that CdS NTs can potentially be useful in the designs of 1D CdS-based optoelectronic devices and solar cells. PMID:26457660

  18. Semitransparent inverted polymer solar cells employing a sol-gel-derived TiO2 electron-selective layer on FTO and MoO3/Ag/MoO3 transparent electrode.

    PubMed

    Li, Fumin; Chen, Chong; Tan, Furui; Li, Chunxi; Yue, Gentian; Shen, Liang; Zhang, Weifeng

    2014-01-01

    We report a new semitransparent inverted polymer solar cell (PSC) with a structure of glass/FTO/nc-TiO2/P3HT:PCBM/MoO3/Ag/MoO3. Because high-temperature annealing which decreased the conductivity of indium tin oxide (ITO) must be handled in the process of preparation of nanocrystalline titanium oxide (nc-TiO2), we replace glass/ITO with a glass/fluorine-doped tin oxide (FTO) substrate to improve the device performance. The experimental results show that the replacing FTO substrate enhances light transmittance between 400 and 600 nm and does not change sheet resistance after annealing treatment. The dependence of device performances on resistivity, light transmittance, and thickness of the MoO3/Ag/MoO3 film was investigated. High power conversion efficiency (PCE) was achieved for FTO substrate inverted PSCs, which showed about 75% increase compared to our previously reported ITO substrate device at different thicknesses of the MoO3/Ag/MoO3 transparent electrode films illuminated from the FTO side (bottom side) and about 150% increase illuminated from the MoO3/Ag/MoO3 side (top side). PMID:25332693

  19. Electrodynamic Arrays Having Nanomaterial Electrodes

    NASA Technical Reports Server (NTRS)

    Trigwell, Steven (Inventor); Biris, Alexandru S. (Inventor); Calle, Carlos I. (Inventor)

    2013-01-01

    An electrodynamic array of conductive nanomaterial electrodes and a method of making such an electrodynamic array. In one embodiment, a liquid solution containing nanomaterials is deposited as an array of conductive electrodes on a substrate, including rigid or flexible substrates such as fabrics, and opaque or transparent substrates. The nanomaterial electrodes may also be grown in situ. The nanomaterials may include carbon nanomaterials, other organic or inorganic nanomaterials or mixtures.

  20. Distributed performance counters

    DOEpatents

    Davis, Kristan D; Evans, Kahn C; Gara, Alan; Satterfield, David L

    2013-11-26

    A plurality of first performance counter modules is coupled to a plurality of processing cores. The plurality of first performance counter modules is operable to collect performance data associated with the plurality of processing cores respectively. A plurality of second performance counter modules are coupled to a plurality of L2 cache units, and the plurality of second performance counter modules are operable to collect performance data associated with the plurality of L2 cache units respectively. A central performance counter module may be operable to coordinate counter data from the plurality of first performance counter modules and the plurality of second performance modules, the a central performance counter module, the plurality of first performance counter modules, and the plurality of second performance counter modules connected by a daisy chain connection.

  1. Nanoimprint-assisted fabrication of high haze metal mesh electrode for solar cells

    NASA Astrophysics Data System (ADS)

    Iwahashi, Takashi; Yang, Rong; Okabe, Noriaki; Sakurai, Junpei; Lin, Jun; Matsunaga, Daisuke

    2014-12-01

    We propose a concept of transparent electrode for solar cells surpassing conventional transparent conductive oxide. Transparent electrode requires low electrical resistivity, high optical transparency, and high optical haze. Although transparent conductive oxide by chemical vapor deposition is widely used as a transparent electrode for solar cells, a breakthrough of the trade-off between electrical and optical properties is required for further improvement of solar cell efficiency. We demonstrate solution-processed electrode fabrication by using nanoimprint technology and metal nanoparticle ink. Silver mesh electrode is self-aligned on nanoimprinted texture with concave pattern as a template for mesh grid. Our electrode concept can realize desired high optical haze by nanoimprinted texture, as well as low electrical resistivity and high optical transparency by metal mesh electrode simultaneously, which boosts solar cell efficiency.

  2. Transparent and conformal 'piezoionic' touch sensor

    NASA Astrophysics Data System (ADS)

    us Sarwar, Mirza S.; Dobashi, Yuta; Scabeni Glitz, Ettore F.; Farajollahi, Meisam; Mirabbasi, Shahriar; Naficy, Sina; Spinks, Geoffrey M.; Madden, John D. W.

    2015-04-01

    A polyurethane hydrogel based touch sensor with high transparency and conformability is demonstrated. Polyurethane hydrogels swollen with various electrolytes were compressed at a pressure of 30 kPa, simulating a fingertap on a conventional touch screen device. Unlike ionic polymer metal composite and conducting polymer trilayer sensors, where electrodes render the sensors opaque and relatively rigid, the electrodes used in this work are metal wires or strips, separated from each other by regions of transparent film, enabling transparency and compliance. The voltages and currents observed when the perturbation is above one electrode are on the order of 10-2 V and 10-7 A, relative to a second electrode that is approximately 1 cm away. The sign of voltage and current signals detected from perturbations made between electrodes is determined by relative proximity to each electrode, and the magnitude appears to decrease with increasing distance from the electrodes. These observations suggest that it may be possible to discriminate the location of touch based on signals transmitted to the edges of an ionically conductive film. A model to describe the inhomogeneous ionic distribution and predict the resultant voltage and current is presented to qualitatively explain the sensing, based on the Donnan potential.

  3. SMART COUNTER The smart counter can

    E-print Network

    Chu, Hao-hua

    SMART COUNTER The smart counter can detect countertop cooking actions. We assume that all food ingredients are stored in RFID-tagged containers. Using the weight change of each container, we can inference how a user mixes food ingredients and the nutrition information of the resulting mixtures. SMART STOVE

  4. Silver nanowires embedded gel electrodes

    NASA Astrophysics Data System (ADS)

    Abe, Yuta; Gong, Jin; Furukawa, Hidemitsu

    2013-04-01

    The polyelectrolyte of high-strength gels was made to improve the mechanical properties in our previous study. In the field of electronic devices, the demand of polymer electrodes, which have high conductivity, high flexibility and transparence, is increasing. In this study, we attempt to make a transparent polymer electrode by laminating polymer thin film and silver nanowire (AgNW). High transparenct poly(methyl methacrylate) (PMMA) film, which is produced by using solvent cast method is used. AgNW is prepared by reacting Silver chloride (AgCl) with Silver nitrate (AgNO3) based on previous study. The AgNWs taking on different shapes were obtained. Fibrous AgNWs are formed by using high molecular weight polyvinylpyrrolidone (PVP). These results showed a possibility of developing the polymer electrode with high conductivity, high flexibility and transparence.

  5. Fabrication of tantalum and nitrogen codoped ZnO (Ta, N-ZnO) thin films using the electrospay: twin applications as an excellent transparent electrode and a field emitter.

    PubMed

    Mahmood, Khalid; Park, Seung Bin; Sung, Hyung Jin

    2013-05-01

    The realization of stable p-type nitrogen-doped ZnO thin films with durable and controlled growth is important for the fabrication of nanoscale electronic and optoelectronic devices. ZnO thin films codoped with tantalum and nitrogen (Ta, N-ZnO) were fabricated by using the electrospraying method at an atmospheric pressure. X-ray diffraction (XRD) studies demonstrated that all the prepared films were polycrystalline in nature with hexagonal wurtzite structure. In addition, a shift in the XRD patterns was observed, and the crystal orientation was changed at a certain amount of nitrogen (>6 at.%) in the starting solution. Analysis of X-ray diffraction patterns and X-ray photoelectron spectra revealed that nitrogen which was combined with the zinc atom (N-Zn) was successfully doped into the ZnO crystal lattice. It was also observed that 2 at.% tantalum and 6 at.% nitrogen (2 at.% Ta and 6 at.% N) were the optimal dopant amounts to achieve the minimum resistivity of about 9.70 × 10(-5) ? cm and the maximum transmittance of 98% in the visible region. Consequently, the field-emission characteristics of such a Ta, N-ZnO emitter can exhibit the higher current density of 1.33 mA cm(-2), larger field-enhancement factor (?) of 4706, lower turn-on field of 2.6 V ?m(-1), and lower threshold field of 3.5 V ?m(-1) attributed to the enhanced conductivity and better crystallinity of films. Moreover, the obtained values of resistivity were closest to the lowest resistivity values among the doped ZnO films as well as to the indium tin oxide (ITO) resistivity values that were previously studied. We confirmed that the tantalum and nitrogen atoms substitution in the ZnO lattice induced positive effects in terms of enhancing the free carrier concentration which will further improve the electrical, optical, and field-emission properties. The proposed electrospraying method was well suitable for the fabrication of Ta, N-ZnO thin films at optimum conditions with superior electrical, optical, and field-emission characteristics, implying the potential applications as both a transparent electrode and field-emission (FE) devices. PMID:23547983

  6. Optically transparent piezoelectric transducer for ultrasonic particle manipulation.

    PubMed

    Brodie, Graham W J; Qiu, Yongqiang; Cochran, Sandy; Spalding, Gabriel C; MacDonald, Michael P

    2014-03-01

    We report an optically transparent ultrasonic device, consisting of indium-tin-oxide-coated lithium niobate (LNO), for use in particle manipulation. This device shows good transparency in the visible and near-infrared wavelengths and, acoustically, compares favorably with conventional prototype devices with silver electrodes. PMID:24569243

  7. Deformable Transparent All-Carbon-Nanotube Transistors

    E-print Network

    Maruyama, Shigeo

    to remove residual resist (lift-off), rinsed with isopropyl alcohol (IPA), and dried using a nitrogen gun diminishes the optical transparency, whereas brittle ITO limits the mechanical flexibility of the device.21-12 for all electrodes (source, drain, and gate) have recently been reported. These metal-free devices can

  8. An Inexpensive Radiation Counter.

    ERIC Educational Resources Information Center

    Holton, Brian; Balla, Zsolt

    1985-01-01

    Describes a radiation counter comparable to commercial units which costs less than $100. It consists of six sections: Geiger-Mueller tube and holder; high voltage supply; low voltage supply; pulse shaping circuit; "start/stop counts" gating circuit; and counter/display. List of materials needed and schematic diagrams are included. (JN)

  9. Manufacturability of lab-on-chip devices : dimensional variation analysis of electrode foils using visual technology

    E-print Network

    Namvari, Kasra

    2011-01-01

    Electrodes are necessary components for measuring changes in electrical properties in many microfluidic devices. Daktari CD4 Cell Counter system utilizes an interdigitated electrode foil in order to measure the concentration ...

  10. Samus Counter Lifting Fixture

    SciTech Connect

    Stredde, H.; /Fermilab

    1998-05-27

    A lifting fixture has been designed to handle the Samus counters. These counters are being removed from the D-zero area and will be transported off site for further use at another facility. This fixture is designed specifically for this particular application and will be transferred along with the counters. The future use of these counters may entail installation at a facility without access to a crane and therefore a lift fixture suitable for both crane and/or fork lift usage has been created The counters weigh approximately 3000 lbs. and have threaded rods extended through the counter at the top comers for lifting. When these counters were first handled/installed these rods were used in conjunction with appropriate slings and handled by crane. The rods are secured with nuts tightened against the face of the counter. The rod thread is M16 x 2({approx}.625-inch dia.) and extends 2-inch (on average) from the face of the counter. It is this cantilevered rod that the lift fixture engages with 'C' style plates at the four top comers. The strongback portion of the lift fixture is a steel rectangular tube 8-inch (vertical) x 4-inch x .25-inch wall, 130-inch long. 1.5-inch square bars are welded perpendicular to the long axis of the rectangular tube at the appropriate lift points and the 'C' plates are fastened to these bars with 3/4-10 high strength bolts -grade 8. Two short channel sections are positioned-welded-to the bottom of the rectangular tube on 40 feet centers, which are used as locators for fork lift tines. On the top are lifting eyes for sling/crane usage and are rated at 3500 lbs. safe working load each - vertical lift only.

  11. Portable multiplicity counter

    DOEpatents

    Newell, Matthew R. (Los Alamos, NM); Jones, David Carl (Los Alamos, NM)

    2009-09-01

    A portable multiplicity counter has signal input circuitry, processing circuitry and a user/computer interface disposed in a housing. The processing circuitry, which can comprise a microcontroller integrated circuit operably coupled to shift register circuitry implemented in a field programmable gate array, is configured to be operable via the user/computer interface to count input signal pluses receivable at said signal input circuitry and record time correlations thereof in a total counting mode, coincidence counting mode and/or a multiplicity counting mode. The user/computer interface can be for example an LCD display/keypad and/or a USB interface. The counter can include a battery pack for powering the counter and low/high voltage power supplies for biasing external detectors so that the counter can be configured as a hand-held device for counting neutron events.

  12. Transparent self-cleaning dust shield

    DOEpatents

    Mazumder, Malay K.; Sims, Robert A.; Wilson, James D.

    2005-06-28

    A transparent electromagnetic shield to protect solar panels and the like from dust deposition. The shield is a panel of clear non-conducting (dielectric) material with embedded parallel electrodes. The panel is coated with a semiconducting film. Desirably the electrodes are transparent. The electrodes are connected to a single-phase AC signal or to a multi-phase AC signal that produces a travelling electromagnetic wave. The electromagnetic field produced by the electrodes lifts dust particles away from the shield and repels charged particles. Deposited dust particles are removed when the electrodes are activated, regardless of the resistivity of the dust. Electrostatic charges on the panel are discharged by the semiconducting film. When used in conjunction with photovoltaic cells, the power for the device may be obtained from the cells themselves. For other surfaces, such as windshields, optical windows and the like, the power must be derived from an external source. One embodiment of the invention employs monitoring and detection devices to determine when the level of obscuration of the screen by dust has reached a threshold level requiring activation of the dust removal feature.

  13. Electrode compositions

    DOEpatents

    Block, J.; Fan, X.

    1998-10-27

    An electrode composition is described for use as an electrode in a non-aqueous battery system. The electrode composition contains an electrically active powder in a solid polymer and, as a dispersant, a C{sub 8}-C{sub 15} alkyl capped oligomer of a hexanoic acid that is electrochemically inert at 2.5--4.5 volts.

  14. Electrode compositions

    DOEpatents

    Block, Jacob (Rockville, MD); Fan, Xiyun (Orange, TX)

    1998-01-01

    An electrode composition for use as an electrode in a non-aqueous battery system. The electrode composition contains an electrically active powder in a solid polymer and, as a dispersant, a C.sub.8 -C.sub.15 alkyl capped oligomer of a hexanoic acid that is electrochemically inert at 2.5-4.5 volts.

  15. Soils. Transparency Masters.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    This document is a collection of 43 overhead transparency masters to be used as teaching aids in a course of study involving soils such as geology, agronomy, hydrology, earth science, or land use study. Some transparencies are in color. Selected titles of transparencies may give the reader a better understanding of the graphic content. Titles are:…

  16. Stretchable, Transparent, Ionic Conductors

    E-print Network

    Suo, Zhigang

    Stretchable, Transparent, Ionic Conductors Christoph Keplinger,1,2,3 * Jeong-Yun Sun,1,2 * Choon, transparent conductors are mostly electronic conductors. They limit the performance of interconnects, sensors by ionic conductors that are highly stretchable, fully transparent to light of all colors, and capable

  17. All-solution processed transparent organic light emitting diodes.

    PubMed

    Zhang, Min; Höfle, Stefan; Czolk, Jens; Mertens, Adrian; Colsmann, Alexander

    2015-12-21

    In this work, we report on indium tin oxide-free, all-solution processed transparent organic light emitting diodes (OLEDs) with inverted device architecture. Conductive polymer layers are employed as both transparent cathodes and transparent anodes, with the top anodes having enhanced conductivities from a supporting stochastic silver nanowire mesh. Both electrodes exhibit transmittances of 80-90% in the visible spectral regime. Upon the incorporation of either yellow- or blue-light emitting fluorescent polymers, the OLEDs show low onset voltages, demonstrating excellent charge carrier injection from the polymer electrodes into the emission layers. Overall luminances and current efficiencies equal the performance of opaque reference OLEDs with indium tin oxide and aluminium electrodes, proving excellent charge carrier-to-light conversion within the device. PMID:26566172

  18. The art of transparency

    PubMed Central

    Sayim, Bilge; Cavanagh, Patrick

    2011-01-01

    Artists throughout the ages have discovered a number of techniques to depict transparency. With only a few exceptions, these techniques follow closely the properties of physical transparency. The two best known properties are X-junctions and the luminance relations described by Metelli. X-junctions are seen where the contours of a transparent material cross contours of the surface behind; Metelli's constraints on the luminance relations between the direct and filtered portions of the surface specify a range of luminance values that are consistent with transparency. These principles have been used by artists since the time of ancient Egypt. However, artists also discovered that stimuli can be seen as transparent even when these physical constraints are not met. Ancient Greek artists, for example, were able to depict transparent materials in simple black-and-white line drawings. Artists also learned how to represent transparency in cases where neither X-junctions nor Metelli's constraints could apply: for example, where no portions of the objects behind the transparent material extend beyond it. Many painters convincingly portrayed transparency in these cases by depicting the effects the transparent medium would have on material or object properties. Here, we show how artists employed these and other techniques revealing their anticipation of current formalizations of perceived transparency, and we suggest new, as-yet-untested principles. PMID:23145252

  19. Compressor surge counter

    DOEpatents

    Castleberry, Kimberly N. (Harriman, TN)

    1983-01-01

    A surge counter for a rotating compressor is provided which detects surging by monitoring the vibration signal from an accelerometer mounted on the shaft bearing of the compressor. The circuit detects a rapid increase in the amplitude envelope of the vibration signal, e.g., 4 dB or greater in less than one second, which is associated with a surge onset and increments a counter. The circuit is rendered non-responsive for a period of about 5 seconds following the detection which corresponds to the duration of the surge condition. This prevents multiple registration of counts during the surge period due to rapid swings in vibration amplitude during the period.

  20. Fully transparent and rollable electronics.

    PubMed

    Mativenga, Mallory; Geng, Di; Kim, Byungsoon; Jang, Jin

    2015-01-28

    Major obstacles toward the manufacture of transparent and flexible display screens include the difficulty of finding transparent and flexible semiconductors and electrodes, temperature restrictions of flexible plastic substrates, and bulging or warping of the flexible electronics during processing. Here we report the fabrication and performance of fully transparent and rollable thin-film transistor (TFT) circuits for display applications. The TFTs employ an amorphous indium-gallium-zinc oxide semiconductor (with optical band gap of 3.1 eV) and amorphous indium-zinc oxide transparent conductive electrodes, and are built on 15-?m-thick solution-processed colorless polyimide (CPI), resulting in optical transmittance >70% in the visible range. As the CPI supports processing temperatures >300 °C, TFT performance on plastic is similar to that on glass, with typical field-effect mobility, turn-on voltage, and subthreshold voltage swing of 12.7 ± 0.5 cm(2)/V·s, -1.7 ± 0.2 V, and 160 ± 29 mV/dec, respectively. There is no significant degradation after rolling the TFTs 100 times on a cylinder with a radius of 4 mm or when shift registers, each consisting of 40 TFTs, are operated while bent to a radius of 2 mm. For handling purposes, carrier glass is used during fabrication, together with a very thin (?1 nm) solution-processed carbon nanotube (CNT)/graphene oxide (GO) backbone that is first spin-coated on the glass to decrease adhesion of the CPI to the glass; peel strength of the CPI from glass decreases from 0.43 to 0.10 N/cm, which eases the process of detachment performed after device fabrication. Given that the CNT/GO remains embedded under the CPI after detachment, it minimizes wrinkling and decreases the substrate's tensile elongation from 8.0% to 4.6%. Device performance is also stable under electrostatic discharge exposures up to 10 kV, as electrostatic charge can be released via the conducting CNTs. PMID:25526282

  1. Magnetron cathodes in plasma electrode Pockels cells

    DOEpatents

    Rhodes, M.A.

    1995-04-25

    Magnetron cathodes, which produce high current discharges, form greatly improved plasma electrodes on each side of an electro-optic crystal. The plasma electrode has a low pressure gas region on both sides of the crystal. When the gas is ionized, e.g., by a glow discharge in the low pressure gas, the plasma formed is a good conductor. The gas electrode acts as a highly uniform conducting electrode. Since the plasma is transparent to a high energy laser beam passing through the crystal, the plasma is transparent. A crystal exposed from two sides to such a plasma can be charged up uniformly to any desired voltage. A typical configuration utilizes helium at 50 millitorr operating pressure and 2 kA discharge current. The magnetron cathode produces a more uniform plasma and allows a reduced operating pressure which leads to lower plasma resistivity and a more uniform charge on the crystal. 5 figs.

  2. Magnetron cathodes in plasma electrode pockels cells

    DOEpatents

    Rhodes, Mark A. (Pleasanton, CA)

    1995-01-01

    Magnetron cathodes, which produce high current discharges, form greatly improved plasma electrodes on each side of an electro-optic crystal. The plasma electrode has a low pressure gas region on both sides of the crystal. When the gas is ionized, e.g., by a glow discharge in the low pressure gas, the plasma formed is a good conductor. The gas electrode acts as a highly uniform conducting electrode. Since the plasma is transparent to a high energy laser beam passing through the crystal, the plasma is transparent. A crystal exposed from two sides to such a plasma can be charged up uniformly to any desired voltage. A typical configuration utilizes helium at 50 millitorr operating. pressure and 2 kA discharge current. The magnetron cathode produces a more uniform plasma and allows a reduced operating pressure which leads to lower plasma resistivity and a more uniform charge on the crystal.

  3. Liquid electrode

    DOEpatents

    Ekechukwu, Amy A. (Augusta, GA)

    1994-01-01

    A dropping electrolyte electrode for use in electrochemical analysis of non-polar sample solutions, such as benzene or cyclohexane. The liquid electrode, preferably an aqueous salt solution immiscible in the sample solution, is introduced into the solution in dropwise fashion from a capillary. The electrolyte is introduced at a known rate, thus, the droplets each have the same volume and surface area. The electrode is used in making standard electrochemical measurements in order to determine properties of non-polar sample solutions.

  4. Extreme optomechanically induced transparency

    E-print Network

    Bodiya, Timothy Paul

    2015-01-01

    This thesis describes the theory and experimental implementation optomechanically induced transparency utilizing ultra low loss mechanical oscillators and high laser power to achieve extremely strong optical induced ...

  5. Ion-selective electrodes in medicinal drug determination

    NASA Astrophysics Data System (ADS)

    Kharitonov, Sergei V.

    2007-04-01

    Data published in the past 10 years on the use of ion-selective electrodes in direct potentiometry and potentiometric titration for the determination of organic medicinal drugs are analysed. In the vast majority of cases, ion-sensitive membranes contain associates of drug cations or anions with appropriate counter-ions. The theoretical approaches to optimisation of the characteristics of ion-selective electrodes are discussed. The mechanism of electrode response generation for neutral and charged carriers of organic ions is considered.

  6. Transparent conducting silver nanowire networks

    E-print Network

    van de Groep, Jorik; Polman, Albert; 10.1021/nl301045a

    2013-01-01

    We present a transparent conducting electrode composed of a periodic two-dimensional network of silver nanowires. Networks of Ag nanowires are made with wire diameters of 45-110 nm and pitch of 500, 700 and 1000 nm. Anomalous optical transmission is observed, with an averaged transmission up to 91% for the best transmitting network and sheet resistances as low as 6.5 {\\Omega}/sq for the best conducting network. Our most dilute networks show lower sheet resistance and higher optical transmittance than an 80 nm thick layer of ITO sputtered on glass. By comparing measurements and simulations we identify four distinct physical phenomena that govern the transmission of light through the networks: all related to the excitation of localized surface plasmons and surface plasmon polaritons on the wires. The insights given in this paper provide the key guidelines for designing high-transmittance and low-resistance nanowire electrodes for optoelectronic devices, including thin-film solar cells. For these latter, we disc...

  7. Semi-transparent perovskite solar cells for tandems with silicon and CIGS

    E-print Network

    McGehee, Michael

    Semi-transparent perovskite solar cells for tandems with silicon and CIGS Colin D. Bailie,a M on top to make a tandem solar cell. We use a transparent silver nanowire electrode on perovskite solar in efficiency over the bottom cell alone. This work paves the way for integrating perovskites into a low

  8. Transparencies and Reflections.

    ERIC Educational Resources Information Center

    Hubbard, Guy

    1999-01-01

    Discusses the use of perspective, or showing things as the human eye sees them, when creating reflections and transparencies in works of art. Provides examples of artwork using transparency, reflection, and refraction by M. C. Escher, Richard Estes, and Janet Fish to give students an opportunity to learn about these three art techniques. (CMK)

  9. Pionic Color Transparency

    E-print Network

    Arnold Larson; Gerald A. Miller; M. Strikman

    2006-04-11

    We use a semi-classical approximation to investigate the effects of color transparency on pion electroproduction reactions. The resulting reduced nuclear interactions produce significant, but not dominating, differences with the results of conventional distorted-wave, Glauber-type treatments at kinematics accessible to Jefferson Laboratory. Nuclear effects that could mimic the influence of color transparency are also discussed.

  10. Vibrational spectroscopy at electrolyte/electrode interfaces with graphene gratings

    NASA Astrophysics Data System (ADS)

    Bie, Ya-Qing; Horng, Jason; Shi, Zhiwen; Ju, Long; Zhou, Qin; Zettl, Alex; Yu, Dapeng; Wang, Feng

    2015-06-01

    Microscopic understanding of physical and electrochemical processes at electrolyte/electrode interfaces is critical for applications ranging from batteries, fuel cells to electrocatalysis. However, probing such buried interfacial processes is experimentally challenging. Infrared spectroscopy is sensitive to molecule vibrational signatures, yet to approach the interface three stringent requirements have to be met: interface specificity, sub-monolayer molecular detection sensitivity, and electrochemically stable and infrared transparent electrodes. Here we show that transparent graphene gratings electrode provide an attractive platform for vibrational spectroscopy at the electrolyte/electrode interfaces: infrared diffraction from graphene gratings offers enhanced detection sensitivity and interface specificity. We demonstrate the vibrational spectroscopy of methylene group of adsorbed sub-monolayer cetrimonium bromide molecules and reveal a reversible field-induced electrochemical deposition of cetrimonium bromide on the electrode controlled by the bias voltage. Such vibrational spectroscopy with graphene gratings is promising for real time and in situ monitoring of different chemical species at the electrolyte/electrode interfaces.

  11. Vibrational spectroscopy at electrolyte/electrode interfaces with graphene gratings

    PubMed Central

    Bie, Ya-Qing; Horng, Jason; Shi, Zhiwen; Ju, Long; Zhou, Qin; Zettl, Alex; Yu, Dapeng; Wang, Feng

    2015-01-01

    Microscopic understanding of physical and electrochemical processes at electrolyte/electrode interfaces is critical for applications ranging from batteries, fuel cells to electrocatalysis. However, probing such buried interfacial processes is experimentally challenging. Infrared spectroscopy is sensitive to molecule vibrational signatures, yet to approach the interface three stringent requirements have to be met: interface specificity, sub-monolayer molecular detection sensitivity, and electrochemically stable and infrared transparent electrodes. Here we show that transparent graphene gratings electrode provide an attractive platform for vibrational spectroscopy at the electrolyte/electrode interfaces: infrared diffraction from graphene gratings offers enhanced detection sensitivity and interface specificity. We demonstrate the vibrational spectroscopy of methylene group of adsorbed sub-monolayer cetrimonium bromide molecules and reveal a reversible field-induced electrochemical deposition of cetrimonium bromide on the electrode controlled by the bias voltage. Such vibrational spectroscopy with graphene gratings is promising for real time and in situ monitoring of different chemical species at the electrolyte/electrode interfaces. PMID:26123807

  12. Liquid electrode

    DOEpatents

    Ekechukwu, A.A.

    1994-07-05

    A dropping electrolyte electrode is described for use in electrochemical analysis of non-polar sample solutions, such as benzene or cyclohexane. The liquid electrode, preferably an aqueous salt solution immiscible in the sample solution, is introduced into the solution in dropwise fashion from a capillary. The electrolyte is introduced at a known rate, thus, the droplets each have the same volume and surface area. The electrode is used in making standard electrochemical measurements in order to determine properties of non-polar sample solutions. 2 figures.

  13. Electrolessly Deposited Electrospun Metal Nanowire Transparent Po-Chun Hsu,

    E-print Network

    Cui, Yi

    to synthesize inter- connected, ultralong MNW networks. For both silver and copper nanowire networks, the Rs are reported to have Rs and T values of 9 /sq and 89%, respectively, for silver nanowires (AgNWs)9b and 40 /sqElectrolessly Deposited Electrospun Metal Nanowire Transparent Electrodes Po-Chun Hsu, Desheng Kong

  14. Scalable Coating and Properties of Transparent, Flexible, Silver Nanowire

    E-print Network

    Cui, Yi

    , there is an increasing need for low-cost trans- parent electrodes. Various types of transpar- ent and conductive oxides for CNT networks on plas- tic is 200 1000 ohms/sq with an optical transmittance of 80 90%. For voltage driven devices, such as capacitive touch screens, electrowetting displays, and liquid crystal displays

  15. Silver Nanowires (AgNWs) Embedded Electrodes for Gel Actuator

    NASA Astrophysics Data System (ADS)

    Abe, Yuta; Gong, Jin; Hasnat Kabir, M.; Makino, Masato; Furukawa, Hidemitsu

    In the field of electronic devices, the demand of polymer electrodes, which have high conductivity, high flexibility and transparence, is increasing. The polyelectrolyte of high-strength gels was made to improve the mechanical properties in our previous study [1]. In this study, we attempt to make a transparent polymer electrode by laminating polymer thin film and silver nanowires (AgNWs). High transparence poly(methyl methacrylate) (PMMA) film, which is produced by using solvent cast method. AgNWs are prepared by reacting Silver chloride (AgCl) with Silver nitrate (AgNO3) based on previous study[2]. The AgNWs taking on different shapes are obtained. Particle and fibrous AgNWs are formed by using low and high molecular weight polyvinylpyrrolidone (PVP), respectively (Fig. 1). The possibility of developing the polymer electrode with high conductivity, high flexibility and transparence is shown from these results.

  16. Countering antivaccination attitudes.

    PubMed

    Horne, Zachary; Powell, Derek; Hummel, John E; Holyoak, Keith J

    2015-08-18

    Three times as many cases of measles were reported in the United States in 2014 as in 2013. The reemergence of measles has been linked to a dangerous trend: parents refusing vaccinations for their children. Efforts have been made to counter people's antivaccination attitudes by providing scientific evidence refuting vaccination myths, but these interventions have proven ineffective. This study shows that highlighting factual information about the dangers of communicable diseases can positively impact people's attitudes to vaccination. This method outperformed alternative interventions aimed at undercutting vaccination myths. PMID:26240325

  17. Low latency counter event indication

    DOEpatents

    Gara, Alan G. (Mount Kisco, NY); Salapura, Valentina (Chappaqua, NY)

    2008-09-16

    A hybrid counter array device for counting events with interrupt indication includes a first counter portion comprising N counter devices, each for counting signals representing event occurrences and providing a first count value representing lower order bits. An overflow bit device associated with each respective counter device is additionally set in response to an overflow condition. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits. An operatively coupled control device monitors each associated overflow bit device and initiates incrementing a second count value stored at a corresponding memory location in response to a respective overflow bit being set. The incremented second count value is compared to an interrupt threshold value stored in a threshold register, and, when the second counter value is equal to the interrupt threshold value, a corresponding "interrupt arm" bit is set to enable a fast interrupt indication. On a subsequent roll-over of the lower bits of that counter, the interrupt will be fired.

  18. Low latency counter event indication

    DOEpatents

    Gara, Alan G. (Mount Kisco, NY); Salapura, Valentina (Chappaqua, NY)

    2010-08-24

    A hybrid counter array device for counting events with interrupt indication includes a first counter portion comprising N counter devices, each for counting signals representing event occurrences and providing a first count value representing lower order bits. An overflow bit device associated with each respective counter device is additionally set in response to an overflow condition. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits. An operatively coupled control device monitors each associated overflow bit device and initiates incrementing a second count value stored at a corresponding memory location in response to a respective overflow bit being set. The incremented second count value is compared to an interrupt threshold value stored in a threshold register, and, when the second counter value is equal to the interrupt threshold value, a corresponding "interrupt arm" bit is set to enable a fast interrupt indication. On a subsequent roll-over of the lower bits of that counter, the interrupt will be fired.

  19. A Dictionary for Transparency

    SciTech Connect

    Kouzes, Richard T.

    2001-11-15

    There are many terms that are used in association with the U.S. Defense Threat Reduction Agency (DTRA) Transparency Project associated with the Mayak Fissile Materials Storage Facility. This is a collection of proposed definitions of these terms.

  20. Transparency and imaginary colors

    E-print Network

    Koenderink, Jan J.

    Unlike the Metelli monochrome transparencies, when overlays and their backgrounds have chromatic content, the inferred surface colors may not always be physically realizable, and are in some sense “imaginary.” In these ...

  1. Semi-transparent inverted organic solar cells

    NASA Astrophysics Data System (ADS)

    Schmidt, H.; Winkler, T.; Tilgner, M.; Flügge, H.; Schmale, S.; Bülow, T.; Meyer, J.; Johannes, H.-H.; Riedl, T.; Kowalsky, W.

    2009-08-01

    We will present efficient semi-transparent bulk-heterojunction [regioregular of poly(3-hexylthiophene): (6,6)-phenyl C61 butyric acid methyl ester] solar cells with an inverted device architecture. Highly transparent ZnO and TiO2 films prepared by Atomic Layer Deposition are used as cathode interlayers on top of ITO. The topanode consists of a RF-sputtered ITO layer. To avoid damage due to the plasma deposition of this layer, a sputtering buffer layer of MoO3 is used as protection. This concept allows for devices with a transmissivity higher than 60 % for wavelengths 650 nm. The thickness of the MoO3 buffer has been varied in order to study its effect on the electrical properties of the solar cell and its ability to prevent possible damage to the organic active layers upon ITO deposition. Without this buffer or for thin buffers it has been found that device performance is very poor concerning the leakage current, the fill factor, the short circuit current and the power conversion efficiencies. As a reference inverted solar cells with a metal electrode (Al) instead of the ITO-top contact are used. The variation between the PCE of top versus conventional illumination of the semi-transparent cells was also examined and will be interpreted in view of the results of the optical simulation of the dielectric device stack with and without reflection top electrode. Power conversion efficiencies of 2-3 % for the opaque inverted solar cells and 1.5-2.5 % for the semi-transparent devices were obtained under an AM1.5G illumination.

  2. Calibration-Free Fusion of Step Counter and Wireless Fingerprints for Indoor Localization

    E-print Network

    Chan, Shueng-Han Gary

    the accuracy of fingerprint-based localiza- tion, one may fuse step counter measurement with location es other works need a calibration process for RSSI measurement consistency if different devices are used-free, and works transparently for hetero- geneous devices and users. It is based on a novel formulation embedded

  3. Fabrication and Characterization of Porous DSC Counter Electrodes

    E-print Network

    Psaltis, Demetri

    plots of symmetric cells with Pt CEs on FTO and NTO substrates with different RF. NTO substrates.3. PMMA, RF=13.3. PMMA, RF=17.2. PMMA, RF=17.2. TiO2 , RF=39. TiO2 , RF=39. Figure 4. Photoelectric (I illumination; dash: dark current. The photoelectric characteristics of DSCs based on FTO and NTO substrates

  4. Effect of the Mesh Transparency on the Electrical Characteristics of DC Pseudo Discharge

    NASA Astrophysics Data System (ADS)

    A. Abd Al-Halim, M.; Abu-Hashem, A.; I. Moubarak, D.

    2015-06-01

    A DC pseudo discharge for air has been studied. Air pressure is used in the range between 0.7 Torr and 12 Torr. The breakdown occurs between a plane cathode and a mesh anode at transparencies of 19%, 46%, and 65%. The current-voltage characteristic curves of the discharge, which are measured at different pressures, distances, and mesh transparences, take effect in the region of abnormal glow. The discharge voltage decreases as the air pressure increases, while more voltage is needed to maintain the discharge when either the mesh transparency or the inter-electrode distance is increased. An increment of mesh transparency causes high negative potential behind the mesh due to the high concentration of electrons, which accumulate and collide with neutral atoms. Paschen curves deviate from the expected regular one. The left side of Paschen curves appears at inter-electrode distance of 1 mm, whereas the right side appears at inter-electrode distance of 5 mm. The intermediate region is observed only at 3 mm distance between the two electrodes. For the transparency range used in this work, it is found that the decrement of the breakdown voltage, on the right side, depends on the mesh transparency. For different electrode separations, the measured Paschen curves are coincident and deviate from the standard ones of Paschen's law.

  5. Supersymmetric transparent optical intersections

    NASA Astrophysics Data System (ADS)

    Longhi, Stefano

    2015-02-01

    Supersymmetric (SUSY) optical structures provide a versatile platform to manipulate the scattering and localization properties of light, with potential applications to mode conversion, spatial multiplexing and invisible devices. Here we show that SUSY can be exploited to realize broadband transparent intersections between guiding structures in optical networks for both continuous and discretized light. These include transparent crossing of high-contrast-index waveguides and directional couplers, as well as crossing of guiding channels in coupled resonator lattices.

  6. Nanostructured Transparent Conducting Oxides via Blockcopolymer Patterning

    E-print Network

    Kim, Joung Youn Ellie

    2014-05-27

    as other scientific insights. I am grateful to Dr. K.K. Banger for the help with conductivity measurements as well as the collaborative work on the amorphous TCO. His insights on sol-gel chemistry as well as TCO’s in general have been invaluable for my... , Springer [2] Ellmer, K., (2012) Past achievements and future challenges in the development of optically transparent electrodes, Nature Photonics, 6 (12), 809-817 v Thesis Overview The aim of this thesis was to develop a new class of TCO material in thin...

  7. Space and power efficient hybrid counters array

    DOEpatents

    Gara, Alan G. (Mount Kisco, NY); Salapura, Valentina (Chappaqua, NY)

    2009-05-12

    A hybrid counter array device for counting events. The hybrid counter array includes a first counter portion comprising N counter devices, each counter device for receiving signals representing occurrences of events from an event source and providing a first count value corresponding to a lower order bits of the hybrid counter array. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits of the hybrid counter array. A control device monitors each of the N counter devices of the first counter portion and initiates updating a value of a corresponding second count value stored at the corresponding addressable memory location in the second counter portion. Thus, a combination of the first and second count values provide an instantaneous measure of number of events received.

  8. Space and power efficient hybrid counters array

    DOEpatents

    Gara, Alan G. (Mount Kisco, NY); Salapura, Valentina (Chappaqua, NY)

    2010-03-30

    A hybrid counter array device for counting events. The hybrid counter array includes a first counter portion comprising N counter devices, each counter device for receiving signals representing occurrences of events from an event source and providing a first count value corresponding to a lower order bits of the hybrid counter array. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits of the hybrid counter array. A control device monitors each of the N counter devices of the first counter portion and initiates updating a value of a corresponding second count value stored at the corresponding addressable memory location in the second counter portion. Thus, a combination of the first and second count values provide an instantaneous measure of number of events received.

  9. Cermet electrode

    DOEpatents

    Maskalick, Nicholas J. (Pittsburgh, PA)

    1988-08-30

    Disclosed is a cermet electrode consisting of metal particles of nickel, cobalt, iron, or alloys or mixtures thereof immobilized by zirconia stabilized in cubic form which contains discrete deposits of about 0.1 to about 5% by weight of praseodymium, dysprosium, terbium, or a mixture thereof. The solid oxide electrode can be made by covering a substrate with particles of nickel, cobalt, iron, or mixtures thereof, growing a stabilized zirconia solid oxide skeleton around the particles thereby immobilizing them, contacting the skeleton with a compound of praseodymium, dysprosium, terbium, or a mixture thereof, and heating the skeleton to a temperature of at least 500.degree. C. The electrode can also be made by preparing a slurry of nickel, cobalt, iron, or mixture and a compound of praseodymium, dysprosium, terbium, or a mixture thereof, depositing the slurry on a substrate, heating the slurry to dryness, and growing a stabilized zirconia skeleton around the metal particles.

  10. Photoelectrochemical electrodes

    NASA Technical Reports Server (NTRS)

    Williams, R. M.; Rembaum, A. (inventors)

    1983-01-01

    The surface of a moderate band gap semiconductor such as p-type molybdenum sulfide is modified to contain an adherent film of charge mediating ionene polymer containing an electroactive unit such as bipyridimium. Electron transport between the electrode and the mediator film is favorable and photocorrosion and recombination processes are suppressed. Incorporation of particles of catalyst such as platinum within the film provides a reduction in overvoltage. The polymer film is readily deposited on the electrode surface and can be rendered stable by ionic or addition crosslinking. Catalyst can be predispersed in the polymer film or a salt can be impregnated into the film and reduced therein.

  11. Over-the-Counter Medicines

    MedlinePLUS

    Over-the-counter (OTC) medicines are drugs you can buy without a prescription. Some OTC medicines relieve aches, pains and itches. Some prevent or cure ... the Food and Drug Administration decides whether a medicine is safe enough to sell over-the-counter. ...

  12. Multi-layer electrode for high contrast electrochromic devices

    DOEpatents

    Schwendeman, Irina G. (Wexford, PA); Finley, James J. (Pittsburgh, PA); Polcyn, Adam D. (Pittsburgh, PA); Boykin, Cheri M. (Wexford, PA)

    2011-11-01

    An electrochromic device includes a first substrate spaced from a second substrate. A first transparent conductive electrode is formed over at least a portion of the first substrate. A polymeric anode is formed over at least a portion of the first conductive electrode. A second transparent conductive electrode is formed over at least a portion of the second substrate. In one aspect of the invention, a multi-layer polymeric cathode is formed over at least a portion of the second conductive electrode. In one non-limiting embodiment, the multi-layer cathode includes a first cathodically coloring polymer formed over at least a portion of the second conductive electrode and a second cathodically coloring polymer formed over at least a portion of the first cathodically coloring polymer. An ionic liquid is positioned between the anode and the cathode.

  13. Plasmonic electrodes for bulk-heterojunction organic photovoltaics: a review

    NASA Astrophysics Data System (ADS)

    Petoukhoff, Christopher E.; Shen, Zeqing; Jain, Manika; Chang, AiMei; O'Carroll, Deirdre M.

    2015-01-01

    Here, we review recent progress on the integration of plasmonic electrodes into bulk-heterojunction organic photovoltaic devices. Plasmonic electrodes, consisting of thin films of metallic nanostructures, can exhibit a number of optical, electrical, and morphological effects that can be exploited to improve performance parameters of ultrathin photovoltaic active layers. We review the various types of plasmonic electrodes that have been incorporated into organic photovoltaics such as nanohole, nanowire, and nanoparticle arrays and grating electrodes and their impact on various device performance parameters. The use of plasmonic back electrodes can impact device performance in a number of ways because the mechanisms of performance improvements are often a complex combination of optical, electrical, and structural effects. Inverted bulk heterojunction device architectures have been shown to benefit from the multifunctionality of plasmonic back electrodes as they can minimize space-charge effects and reduce hole carrier collection lengths in addition to providing improved light localization in the active layer. The use of semi-transparent plasmonic electrodes can also be beneficial for organic photovoltaics as they can exhibit a variety of optical properties such as light scattering, light localization, extraordinary transmission of light, and absorption-induced transparency, in addition to providing an alternative to metal oxide-based transparent electrodes.

  14. High performance, transparent a-IGZO TFTs on a flexible thin glass substrate

    NASA Astrophysics Data System (ADS)

    Lee, Gwang Jun; Kim, Joonwoo; Kim, Jung-Hye; Jeong, Soon Moon; Jang, Jae Eun; Jeong, Jaewook

    2014-03-01

    We investigated electrical properties of transparent amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) with amorphous indium zinc oxide (a-IZO) transparent electrodes on a flexble thin glass substrate. The TFTs show a high field-effect mobility, a good subthreshold slope and a high on/off ratio owing to the high temperature thermal annealing process which cannot be applied to typical transparent polymer-based flexible substrates. Bias stress instability tests applying tensile stress concurrently with the bending radius of up to 40 mm indicated that mechanically and electrically stable a-IGZO TFTs can be fabricated on the transparent thin glass substrate.

  15. Bifunctional air electrode for metal-air batteries

    NASA Astrophysics Data System (ADS)

    Carlsson, L.; Ojefors, L.

    1980-03-01

    In order to fulfill volume and cost requirements on metal-air batteries it is necessary to use bifunctional air electrodes which also serve as counter-electrodes during charge. This twofold duty puts a very high demand on the electrode, especially the structure and catalyst. In the iron-air battery program of SNDC a 0.6 mm porous Ni-electrode with Ag catalyst has been developed for this purpose with a life of more than 1000 charge/discharge cycles. In this paper design, performance, structural changes, mode of failure etc. are discussed.

  16. Permanently calibrated interpolating time counter

    NASA Astrophysics Data System (ADS)

    Jachna, Z.; Szplet, R.; Kwiatkowski, P.; Ró?yc, K.

    2015-01-01

    We propose a new architecture of an integrated time interval counter that provides its permanent calibration in the background. Time interval measurement and the calibration procedure are based on the use of a two-stage interpolation method and parallel processing of measurement and calibration data. The parallel processing is achieved by a doubling of two-stage interpolators in measurement channels of the counter, and by an appropriate extension of control logic. Such modification allows the updating of transfer characteristics of interpolators without the need to break a theoretically infinite measurement session. We describe the principle of permanent calibration, its implementation and influence on the quality of the counter. The precision of the presented counter is kept at a constant level (below 20?ps) despite significant changes in the ambient temperature (from -10 to 60?°C), which can cause a sevenfold decrease in the precision of the counter with a traditional calibration procedure.

  17. Synthesizing a Healable Stretchable Transparent Conductor.

    PubMed

    Li, Junpeng; Qi, Shuhua; Liang, Jiajie; Li, Lu; Xiong, Yan; Hu, Wei; Pei, Qibing

    2015-07-01

    We report the first demonstration of a healable stretchable transparent electrode comprising a silver nanowire (AgNW) network and poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT) hybrid layer in the surface of a Diels-Alder elastomer substrate. The thin PEDOT layer solders the silver nanowires and confines the nanowire network in the substrate surface. The bonding between the nanowires and PEDOT is tuned via ethanol-water wetting, which allows for large-strain prestretching of the AgNW network. The composite electrode prepared via such a wetting and prestretching treatment has a figure-of-merit sheet resistance of 15 ohm/sq with 78% transmittance at 550 nm and can be stretched by 100% strain. Damages caused by razor blade cutting on the conductive surface could be healed, and the damaging-healing could be repeated for three times at the same location. The healed electrode exhibits similar resistance-strain response as the fresh electrode because of the PEDOT layer being capable of circumventing broken nanowire sites. Fatigue-induced damages after 100 cycles of 60% strain can also be healed by simple heating. PMID:26062004

  18. Wearable solar cells by stacking textile electrodes.

    PubMed

    Pan, Shaowu; Yang, Zhibin; Chen, Peining; Deng, Jue; Li, Houpu; Peng, Huisheng

    2014-06-10

    A new and general method to produce flexible, wearable dye-sensitized solar cell (DSC) textiles by the stacking of two textile electrodes has been developed. A metal-textile electrode that was made from micrometer-sized metal wires was used as a working electrode, while the textile counter electrode was woven from highly aligned carbon nanotube fibers with high mechanical strengths and electrical conductivities. The resulting DSC textile exhibited a high energy conversion efficiency that was well maintained under bending. Compared with the woven DSC textiles that are based on wire-shaped devices, this stacked DSC textile unexpectedly exhibited a unique deformation from a rectangle to a parallelogram, which is highly desired in portable electronics. This lightweight and wearable stacked DSC textile is superior to conventional planar DSCs because the energy conversion efficiency of the stacked DSC textile was independent of the angle of incident light. PMID:24789065

  19. Zinc oxyfluoride transparent conductor

    DOEpatents

    Gordon, Roy G. (Cambridge, MA)

    1991-02-05

    Transparent, electrically conductive and infrared-reflective films of zinc oxyfluoride are produced by chemical vapor deposition from vapor mixtures of zinc, oxygen and fluorine-containing compounds. The substitution of fluorine for some of the oxygen in zinc oxide results in dramatic increases in the electrical conductivity. For example, diethyl zinc, ethyl alcohol and hexafluoropropene vapors are reacted over a glass surface at 400.degree. C. to form a visibly transparent, electrically conductive, infrared reflective and ultraviolet absorptive film of zinc oxyfluoride. Such films are useful in liquid crystal display devices, solar cells, electrochromic absorbers and reflectors, energy-conserving heat mirrors, and antistatic coatings.

  20. Multiple channel programmable coincidence counter

    DOEpatents

    Arnone, Gaetano J. (Los Alamos, NM)

    1990-01-01

    A programmable digital coincidence counter having multiple channels and featuring minimal dead time. Neutron detectors supply electrical pulses to a synchronizing circuit which in turn inputs derandomized pulses to an adding circuit. A random access memory circuit connected as a programmable length shift register receives and shifts the sum of the pulses, and outputs to a serializer. A counter is input by the adding circuit and downcounted by the seralizer, one pulse at a time. The decoded contents of the counter after each decrement is output to scalers.

  1. Counter-driver shock tube

    NASA Astrophysics Data System (ADS)

    Tamba, T.; Nguyen, T. M.; Takeya, K.; Harasaki, T.; Iwakawa, A.; Sasoh, A.

    2015-11-01

    A "counter-driver" shock tube was developed. In this device, two counter drivers are actuated with an appropriate delay time to generate the interaction between a shock wave and a flow in the opposite direction which is induced by another shock wave. The conditions for the counter drivers can be set independently. Each driver is activated by a separate electrically controlled diaphragm rupture device, in which a pneumatic piston drives a rupture needle with a temporal jitter of better than 1.1 ms. Operation demonstrations were conducted to evaluate the practical performance.

  2. Electrode structures

    SciTech Connect

    Brennan, M.P.

    1981-01-06

    In a sodium sulphur cell, a cathode electrode of annular form comprising a plurality of segments, each of trapezoidal form in cross-section and joined by webs along a longer edge of each segment so that the assembly is foldable to form a substantially annular structure. This electrode may be made by compressing a blanket or sheet of carbon or graphite felt or fibres in a heated mould, which is shaped to produce the segments joined by thin webs, the material being impregnated with sulphur or sodium polysulphide before or after insertion in the mould, and the material being cooled before removal from the mould. Alternatively, the segments may be formed from the blanket or sheet by using shaped rolls, the material being cooled, E.G. By water or air, as it leaves the rolls.

  3. Prospects of graphene electrodes in photovoltaics Yasin Khatami, Wei Liu, Jiahao Kang, and Kaustav Banerjee*

    E-print Network

    vapor deposition (CVD) (which is the only way of producing large area graphene transferrable to any of the deposition process make ITO less favorable in transparent electrode applications. Graphene has been under

  4. How Transparent Are Central Banks?

    E-print Network

    Eijffinger, Sylvester C. W.; Geraats, Petra M.

    2004-06-16

    Central bank transparency has become the topic of a lively public and academic debate on monetary policy. Unfortunately, it has been complicated by the fact that transparency is a qualitative concept that is hard to measure. This paper proposes a...

  5. Nanostructured Solid Oxide Fuel Cell Electrodes

    SciTech Connect

    Sholklapper, Tal Zvi

    2007-12-15

    The ability of Solid Oxide Fuel Cells (SOFC) to directly and efficiently convert the chemical energy in hydrocarbon fuels to electricity places the technology in a unique and exciting position to play a significant role in the clean energy revolution. In order to make SOFC technology cost competitive with existing technologies, the operating temperatures have been decreased to the range where costly ceramic components may be substituted with inexpensive metal components within the cell and stack design. However, a number of issues have arisen due to this decrease in temperature: decreased electrolyte ionic conductivity, cathode reaction rate limitations, and a decrease in anode contaminant tolerance. While the decrease in electrolyte ionic conductivities has been countered by decreasing the electrolyte thickness, the electrode limitations have remained a more difficult problem. Nanostructuring SOFC electrodes addresses the major electrode issues. The infiltration method used in this dissertation to produce nanostructure SOFC electrodes creates a connected network of nanoparticles; since the method allows for the incorporation of the nanoparticles after electrode backbone formation, previously incompatible advanced electrocatalysts can be infiltrated providing electronic conductivity and electrocatalysis within well-formed electrolyte backbones. Furthermore, the method is used to significantly enhance the conventional electrode design by adding secondary electrocatalysts. Performance enhancement and improved anode contamination tolerance are demonstrated in each of the electrodes. Additionally, cell processing and the infiltration method developed in conjunction with this dissertation are reviewed.

  6. EDITORIAL: On display with transparent conducting films On display with transparent conducting films

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2012-03-01

    Transparent conducting films were already featuring in scientific literature over one hundred years ago. In 1894 Aryton and Mather described a conducting varnish for coating the screens of electric apparatus so they would not charge when accidentally brushed by a coat sleeve or other material [1]. Their method began with a similar approach to that used to make savoury jellies; by dissolving gelatine in vinegar, after which less palatable ingredients were incorporated including sulphuric acid and an antisulphuric enamel. While the search for transparent conducting films continued to attract other researchers, the same problem remained: the transparency would be compromised if the film was too thick, and the conductivity would be compromised if the film was too thin. In the early 1950s Gillham and Preston reported that thin gold films sputtered on bismuth oxide and heated resulted in a material that successfully combined the previously mutually exclusive properties of transparency and conductivity [2]. Other oxide films were also found to favourably combine these properties, including tin oxide, as reported by Ishiguro and colleagues in Japan in 1958 [3]. Today tin oxide doped with indium (ITO) has become the industry standard for transparent conducting films in a range of applications including photovoltaic technology and displays. It is perhaps the mounting ubiquity of electronic displays as a result of the increasingly digitised and computerised environment of the modern day world that has begun to underline the main drawback of ITO: expense. In this issue, a collaboration of researchers in Korea present an overview of graphene as a transparent conducting material with the potential to replace ITO in a range of electronic and optoelectronic applications [4]. One of the first innovations in optical microscopy was the use of dyes. This principle first came into practice with the use of ultraviolet light to reveal previously indistinguishable features. As explained by a researcher in the early 1930s, 'It is obvious that if the dyes used for selective staining in ordinary microscopical work are supplemented by substances which cause a particular detail of the structure to fluoresce with a specific colour in ultraviolet light, then many strings will be added to the bow of the practical microscopist' [3]. More recently, emphasis on the role of plasmons—collective oscillations of electrons in nanoscale metal structures—has received considerable research attention. Plasmons enhance the local electromagnetic field and can lead to increased fluorescence rates from nearby fluorophores depending on the efficiency of the counteracting process, non-radiative transfer [4]. Flat ITO films have been used extensively in photovoltaic studies as transparent electrodes [5]. Over the past few years, nanowire structures have recently been used to increase the surface area of the interface between dye and oxide in dye-sensitized solar cells [6]. A collaboration of researchers in China and Australia has recently extended the innovation of the nanowire structure to the ITO electrode [7]. Using cyclic voltammetry the researchers confirmed that using a 3D ITO-nanowire electrode significantly enhanced the reaction current. Despite its attractive properties, alternatives to ITO are now in high demand. The rise in devices requiring flat electronic displays has begun to overwhelm the legitimacy of using such a rare element as indium for transparent conducting films. ITO is also brittle, causing problems for flexible displays. Films of carbon nanotubes have been proposed for transparent conducting films but improvements to the sheet resistance are needed before they can compete with the performance of ITO. The effects of HNO3 treatment on the resistivity of carbon nanotube films has attracted some debate in the community, and stimulated the work of Ji-Beom Yoo and colleagues in Korea [8]. Their results suggest that p-type doping has a larger effect on the sheet resistance of HNO3 treated carbon-nanotube films than the removal of residual N-methylpy

  7. Transparent Polycrystalline Historical Developments and

    E-print Network

    Van Stryland, Eric

    density. Translucent (left) and transparent (right) Al2O3 (Apetz et al. J. Am. Ceram. Soc., 2003) PLZT of Ceramic #12;#12;Birefringence Prevents Transparency · Toward normal if n1n2Transparent Polycrystalline Materials: Historical Developments and Next Generation Applications

  8. Highly efficient fully transparent inverted OLEDs

    NASA Astrophysics Data System (ADS)

    Meyer, J.; Winkler, T.; Hamwi, S.; Schmale, S.; Kröger, M.; Görrn, P.; Johannes, H.-H.; Riedl, T.; Lang, E.; Becker, D.; Dobbertin, T.; Kowalsky, W.

    2007-09-01

    One of the unique selling propositions of OLEDs is their potential to realize highly transparent devices over the visible spectrum. This is because organic semiconductors provide a large Stokes-Shift and low intrinsic absorption losses. Hence, new areas of applications for displays and ambient lighting become accessible, for instance, the integration of OLEDs into the windshield or the ceiling of automobiles. The main challenge in the realization of fully transparent devices is the deposition of the top electrode. ITO is commonly used as transparent bottom anode in a conventional OLED. To obtain uniform light emission over the entire viewing angle and a low series resistance, a TCO such as ITO is desirable as top contact as well. However, sputter deposition of ITO on top of organic layers causes damage induced by high energetic particles and UV radiation. We have found an efficient process to protect the organic layers against the ITO rf magnetron deposition process of ITO for an inverted OLED (IOLED). The inverted structure allows the integration of OLEDs in more powerful n-channel transistors used in active matrix backplanes. Employing the green electrophosphorescent material Ir(ppy) 3 lead to IOLED with a current efficiency of 50 cd/A and power efficiency of 24 lm/W at 100 cd/m2. The average transmittance exceeds 80 % in the visible region. The on-set voltage for light emission is lower than 3 V. In addition, by vertical stacking we achieved a very high current efficiency of more than 70 cd/A for transparent IOLED.

  9. Nanopatterned Metallic Films for Use As Transparent Conductive Electrodes in

    E-print Network

    Fan, Shanhui

    tall and narrow wires. Our design principles remain valid for oblique incidence and readily carry over metallic films have been shown numerically to possess superior optical trans- mittance and electrical sheet

  10. Electrospun Metal Nanofiber Webs as High-Performance Transparent Electrode

    E-print Network

    McGehee, Michael

    and solar cells with increasingly large industry demands. Sheet resistance (Rs) and optical transmittance (T much effort both in industry and in academia to find a replacement for ITO.6 Emerging candidates costly lithography steps and are difficult to be scaled up. In solution processed silver nano- wire

  11. Single-walled carbon nanotube transparent conductive films fabricated by reductive dissolution and spray coating for organic photovoltaics

    SciTech Connect

    Ostfeld, Aminy E.; Arias, Ana Claudia; Catheline, Amélie; Ligsay, Kathleen; Kim, Kee-Chan; Fogden, Siân; Chen, Zhihua; Facchetti, Antonio

    2014-12-22

    Solutions of unbundled and unbroken single-walled carbon nanotubes have been prepared using a reductive dissolution process. Transparent conductive films spray-coated from these solutions show a nearly twofold improvement in the ratio of electrical conductivity to optical absorptivity versus those deposited from conventional aqueous dispersions, due to substantial de-aggregation and sizable nanotube lengths. These transparent electrodes have been utilized to fabricate P3HT-PCBM organic solar cells achieving power conversion efficiencies up to 2.3%, comparable to those of solar cells using indium tin oxide transparent electrodes.

  12. Solution-processed transparent blue organic light-emitting diodes with graphene as the top cathode

    PubMed Central

    Chang, Jung-Hung; Lin, Wei-Hsiang; Wang, Po-Chuan; Taur, Jieh-I; Ku, Ting-An; Chen, Wei-Ting; Yan, Shiang-Jiuan; Wu, Chih-I

    2015-01-01

    Graphene thin films have great potential to function as transparent electrodes in organic electronic devices, due to their excellent conductivity and high transparency. Recently, organic light-emitting diodes (OLEDs)have been successfully demonstrated to possess high luminous efficiencies with p-doped graphene anodes. However, reliable methods to fabricate n-doped graphene cathodes have been lacking, which would limit the application of graphene in flexible electronics. In this paper, we demonstrate fully solution-processed OLEDs with n-type doped multilayer graphene as the top electrode. The work function and sheet resistance of graphene are modified by an aqueous process which can also transfer graphene on organic devices as the top electrodes. With n-doped graphene layers used as the top cathode, all-solution processed transparent OLEDs can be fabricated without any vacuum process. PMID:25892370

  13. Solution-processed transparent blue organic light-emitting diodes with graphene as the top cathode

    NASA Astrophysics Data System (ADS)

    Chang, Jung-Hung; Lin, Wei-Hsiang; Wang, Po-Chuan; Taur, Jieh-I.; Ku, Ting-An; Chen, Wei-Ting; Yan, Shiang-Jiuan; Wu, Chih-I.

    2015-04-01

    Graphene thin films have great potential to function as transparent electrodes in organic electronic devices, due to their excellent conductivity and high transparency. Recently, organic light-emitting diodes (OLEDs)have been successfully demonstrated to possess high luminous efficiencies with p-doped graphene anodes. However, reliable methods to fabricate n-doped graphene cathodes have been lacking, which would limit the application of graphene in flexible electronics. In this paper, we demonstrate fully solution-processed OLEDs with n-type doped multilayer graphene as the top electrode. The work function and sheet resistance of graphene are modified by an aqueous process which can also transfer graphene on organic devices as the top electrodes. With n-doped graphene layers used as the top cathode, all-solution processed transparent OLEDs can be fabricated without any vacuum process.

  14. Low-Work-Function, ITO-Free Transparent Cathodes for Inverted Polymer Solar Cells.

    PubMed

    Xue, Zhichao; Liu, Xingyuan; Lv, Ying; Zhang, Nan; Guo, Xiaoyang

    2015-09-16

    A low-work-function, indium tin oxide (ITO)-free transparent cathode having a tin oxide (SnOX)/Ag/SnOX/bismuth oxide (Bi2O3) (SASB) structure is developed without using annealing treatment. This represents the first time that Bi2O3 has been introduced to lower the work function of transparent electrodes. The SASB transparent cathode exhibits excellent photoelectric properties with a maximum transmittance of ?88%, a low sheet resistance of ?9.0 ?·sq(-1), and a suitable work function of 4.22 eV that matches the lowest unoccupied molecular orbital level of the acceptor for exacting electrons efficiently. The power conversion efficiency of the polymer solar cell with the SASB electrode is 6.21%, which is comparable to that of ITO-based devices. The results indicate that SASB is a good alternative to ITO as transparent cathodes in optoelectronic devices. PMID:26323711

  15. ENGINEERED ELECTRODES AND ELECTRODE-ORGANIC INTERFACES FOR HIGH-EFFICIENCY ORGANIC PHOTOVOLTAICS

    SciTech Connect

    Tobin J. Marks; R.P.H. Chang; Tom Mason; Ken Poeppelmeier; Arthur J. Freeman

    2008-11-13

    Organic photovoltaic (OPV) cells offer the ultimate promise of low cost, readily manufacturable, and durable solar power. While recent advances have led to cells with impressive performance levels, OPV cells have yet to break the double-digit efficiency barrier. Further gains in efficiency and durability, to that competitive with high-performance inorganic photovoltaics will require breakthroughs in transparent electrode and interfacial materials science and engineering. This project involved an integrated basic research effort carried out by an experienced and highly collaborative interdisciplinary team to address in unconventional ways, critical electrode-interfacial issues underlying OPV performance--controlling band offsets between transparent electrodes and organics, addressing current loss/leakage problems at interfaces, enhancing adhesion, interfacial stability, and device durability while minimizing cost. It synergistically combined materials and interfacial reagent synthesis, nanostructural and photovoltaic characterization, and high level quantum theory. The research foci were: 1) understanding of/development of superior transparent electrode materials and materials morphologies--i.e., better matched electronically and chemically to organic active layers, 2) understanding-based development of inorganic interfacial current-collecting/charge-blocking layers, and 3) understanding-based development of self-assembled adhesion/current-collecting/charge-blocking/cross-linking layers for high-efficiency OPV interfaces. Pursing the goal of developing the fundamental scientific understanding needed to design, fabricate, prototype and ultimately test high-efficiency OPV cells incorporating these new concepts, we achieved a record power conversion efficiency of 5.2% for an organic bulk-heterjunction solar cell.

  16. Transparent conducting oxide nanotubes.

    PubMed

    Alivov, Yahya; Singh, Vivek; Ding, Yuchen; Nagpal, Prashant

    2014-09-26

    Thin film or porous membranes made of hollow, transparent, conducting oxide (TCO) nanotubes, with high chemical stability, functionalized surfaces and large surface areas, can provide an excellent platform for a wide variety of nanostructured photovoltaic, photodetector, photoelectrochemical and photocatalytic devices. While large-bandgap oxide semiconductors offer transparency for incident light (below their nominal bandgap), their low carrier concentration and poor conductivity makes them unsuitable for charge conduction. Moreover, materials with high conductivity have nominally low bandgaps and hence poor light transmittance. Here, we demonstrate thin films and membranes made from TiO2 nanotubes heavily-doped with shallow Niobium (Nb) donors (up to 10%, without phase segregation), using a modified electrochemical anodization process, to fabricate transparent conducting hollow nanotubes. Temperature dependent current-voltage characteristics revealed that TiO2 TCO nanotubes, doped with 10% Nb, show metal-like behavior with resistivity decreasing from 6.5 × 10(-4) ?cm at T = 300 K (compared to 6.5 × 10(-1) ?cm for nominally undoped nanotubes) to 2.2 × 10(-4) ?cm at T = 20 K. Optical properties, studied by reflectance measurements, showed light transmittance up to 90%, within wavelength range 400 nm-1000 nm. Nb doping also improves the field emission properties of TCO nanotubes demonstrating an order of magnitude increase in field-emitter current, compared to undoped samples. PMID:25180635

  17. Impedance spectroscopy on dye-sensitized solar cells with a poly(ethylenedioxythiophene):poly(styrenesulfonate) counter electrolyte

    NASA Astrophysics Data System (ADS)

    Kim, Young-Keun; Park, Sung-Hae; Hwang, Won-Pill; Seo, Min-Hye; Park, Hyun-Woo; Jang, Young-Wook; Kim, Mi-Ra; Lee, Jin-Kook

    2012-06-01

    We have successfully fabricated the dye-sensitized solar cell (DSSC) devices using ruthenium complex dye, polymer electrolytes, and poly(ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT: PSS) as a counter electrode. The overall power conversion efficiencies of the devices using polyethylene oxide (PEO), polyethylene glycol (PEG), polymethylmethacrylate (PMMA), and polyvinyl acetate (PVAc) as polymer electrolytes were 4.08%, 3.87%, 0.49%, and 0.20%, respectively, while the efficiencies of DSSC devices using Pt counter electrodes showed similar values of 5.7 ± 0.1%. The differences in the efficiencies and the charge transfer resistances (R CT ) of the DSSCs with various polymer electrolytes and counter electrodes were measured by using an electrochemical impedance analyzer (EIS) and are discussed.

  18. Modiolus-hugging intracochlear electrode array with shape memory alloy.

    PubMed

    Min, Kyou Sik; Jun, Sang Beom; Lim, Yoon Seob; Park, Se-Ik; Kim, Sung June

    2013-01-01

    In the cochlear implant system, the distance between spiral ganglia and the electrodes within the volume of the scala tympani cavity significantly affects the efficiency of the electrical stimulation in terms of the threshold current level and spatial selectivity. Because the spiral ganglia are situated inside the modiolus, the central axis of the cochlea, it is desirable that the electrode array hugs the modiolus to minimize the distance between the electrodes and the ganglia. In the present study, we propose a shape-memory-alloy-(SMA-) embedded intracochlear electrode which gives a straight electrode a curved modiolus-hugging shape using the restoration force of the SMA as triggered by resistive heating after insertion into the cochlea. An eight-channel ball-type electrode array is fabricated with an embedded titanium-nickel SMA backbone wire. It is demonstrated that the electrode array changes its shape in a transparent plastic human cochlear model. To verify the safe insertion of the electrode array into the human cochlea, the contact pressures during insertion at the electrode tip and the contact pressures over the electrode length after insertion were calculated using a 3D finite element analysis. The results indicate that the SMA-embedded electrode is functionally and mechanically feasible for clinical applications. PMID:23762181

  19. Access resistance of stimulation electrodes as a function of electrode proximity to the retina

    NASA Astrophysics Data System (ADS)

    Majdi, Joseph A.; Minnikanti, Saugandhika; Peixoto, Nathalia; Agrawal, Anant; Cohen, Ethan D.

    2015-02-01

    Objective. Epiretinal prostheses seek to effectively stimulate the retina by positioning electrode arrays close to its surface so current pulses generate narrow retinal electric fields. Our objective was to evaluate the use of the electrical impedance of insulated platinum electrodes as a measure of the proximity of insulated platinum electrodes to the inner surface of the retina. Approach. We examined the impedance of platinum disk electrodes, 0.25 mm in diameter, insulated with two widths (0.8 and 1.6 mm outer diameter) of transparent fluoropolymer in a rabbit retinal eyecup preparation. Optical coherence tomography measured the electrode’s proximity to the retinal surface which was correlated with changes in the voltage waveform at the electrode. Electrode impedance changes during retinal deformation were also studied. Main results. When the 1.6 mm diameter insulated electrodes advanced towards the retinal surface from 1000 ?m, their voltage step at current pulse onset increased, reflecting an access resistance increase of 3880 ± 630 ?, with the 50% midpoint averaging 30 ?m, while thin 0.8 mm insulated electrode advancement showed an access resistance increase 50% midpoint averaging 16 ?m. Using impedance spectroscopy, electrode-retina proximity differences were seen in the 1.6 mm insulated electrode impedance modulus between 1 and 100 kHz and the waveform phase angle at 0.3-10 kHz, while thin 0.8 mm insulated electrode advancement produced smaller impedance modulus changes with retinal proximity between 3 and 100 kHz. These impedance changes with retinal proximity may reflect different sized zones of eye wall being coupled in series with the insulated platinum electrode. Significance. The proximity of stimulus electrodes to neural tissue in fluid-filled spaces can be estimated from access resistance changes in the stimulus pulse waveform. Because many prosthetic devices allow back telemetry communication of the stimulus electrode waveform, it is possible these series resistance increases observed with retinal proximity could be used as a metric of stimulus electrode placement.

  20. Perceptual transparency from image deformation

    PubMed Central

    Kawabe, Takahiro; Maruya, Kazushi; Nishida, Shin’ya

    2015-01-01

    Human vision has a remarkable ability to perceive two layers at the same retinal locations, a transparent layer in front of a background surface. Critical image cues to perceptual transparency, studied extensively in the past, are changes in luminance or color that could be caused by light absorptions and reflections by the front layer, but such image changes may not be clearly visible when the front layer consists of a pure transparent material such as water. Our daily experiences with transparent materials of this kind suggest that an alternative potential cue of visual transparency is image deformations of a background pattern caused by light refraction. Although previous studies have indicated that these image deformations, at least static ones, play little role in perceptual transparency, here we show that dynamic image deformations of the background pattern, which could be produced by light refraction on a moving liquid’s surface, can produce a vivid impression of a transparent liquid layer without the aid of any other visual cues as to the presence of a transparent layer. Furthermore, a transparent liquid layer perceptually emerges even from a randomly generated dynamic image deformation as long as it is similar to real liquid deformations in its spatiotemporal frequency profile. Our findings indicate that the brain can perceptually infer the presence of “invisible” transparent liquids by analyzing the spatiotemporal structure of dynamic image deformation, for which it uses a relatively simple computation that does not require high-level knowledge about the detailed physics of liquid deformation. PMID:26240313

  1. Perceptual transparency from image deformation.

    PubMed

    Kawabe, Takahiro; Maruya, Kazushi; Nishida, Shin'ya

    2015-08-18

    Human vision has a remarkable ability to perceive two layers at the same retinal locations, a transparent layer in front of a background surface. Critical image cues to perceptual transparency, studied extensively in the past, are changes in luminance or color that could be caused by light absorptions and reflections by the front layer, but such image changes may not be clearly visible when the front layer consists of a pure transparent material such as water. Our daily experiences with transparent materials of this kind suggest that an alternative potential cue of visual transparency is image deformations of a background pattern caused by light refraction. Although previous studies have indicated that these image deformations, at least static ones, play little role in perceptual transparency, here we show that dynamic image deformations of the background pattern, which could be produced by light refraction on a moving liquid's surface, can produce a vivid impression of a transparent liquid layer without the aid of any other visual cues as to the presence of a transparent layer. Furthermore, a transparent liquid layer perceptually emerges even from a randomly generated dynamic image deformation as long as it is similar to real liquid deformations in its spatiotemporal frequency profile. Our findings indicate that the brain can perceptually infer the presence of "invisible" transparent liquids by analyzing the spatiotemporal structure of dynamic image deformation, for which it uses a relatively simple computation that does not require high-level knowledge about the detailed physics of liquid deformation. PMID:26240313

  2. Transparent Organic Photodetector using a Near-Infrared Absorbing Cyanine Dye

    PubMed Central

    Zhang, Hui; Jenatsch, Sandra; De Jonghe, Jelissa; Nüesch, Frank; Steim, Roland; Véron, Anna C.; Hany, Roland

    2015-01-01

    Organic photodetectors are interesting for low cost, large area optical sensing applications. Combining organic semiconductors with discrete absorption bands outside the visible wavelength range with transparent and conductive electrodes allows for the fabrication of visibly transparent photodetectors. Visibly transparent photodetectors can have far reaching impact in a number of areas including smart displays, window-integrated electronic circuits and sensors. Here, we demonstrate a near-infrared sensitive, visibly transparent organic photodetector with a very high average visible transmittance of 68.9%. The transmitted light of the photodetector under solar irradiation exhibits excellent transparency colour perception and rendering capabilities. At a wavelength of 850?nm and at ?1?V bias, the photoconversion efficiency is 17% and the specific detectivity is 1012 Jones. Large area photodetectors with an area of 1.6?cm2 are demonstrated. PMID:25803320

  3. Transparent organic photodetector using a near-infrared absorbing cyanine dye.

    PubMed

    Zhang, Hui; Jenatsch, Sandra; De Jonghe, Jelissa; Nüesch, Frank; Steim, Roland; Véron, Anna C; Hany, Roland

    2015-01-01

    Organic photodetectors are interesting for low cost, large area optical sensing applications. Combining organic semiconductors with discrete absorption bands outside the visible wavelength range with transparent and conductive electrodes allows for the fabrication of visibly transparent photodetectors. Visibly transparent photodetectors can have far reaching impact in a number of areas including smart displays, window-integrated electronic circuits and sensors. Here, we demonstrate a near-infrared sensitive, visibly transparent organic photodetector with a very high average visible transmittance of 68.9%. The transmitted light of the photodetector under solar irradiation exhibits excellent transparency colour perception and rendering capabilities. At a wavelength of 850?nm and at -1?V bias, the photoconversion efficiency is 17% and the specific detectivity is 10(12) Jones. Large area photodetectors with an area of 1.6?cm(2) are demonstrated. PMID:25803320

  4. Trapping atoms on a transparent permanent-magnet atom chip

    E-print Network

    A. Shevchenko; M. Heilio; T. Lindvall; A. Jaakkola; I. Tittonen; M. Kaivola; T. Pfau

    2006-04-21

    We describe experiments on trapping of atoms in microscopic magneto-optical traps on an optically transparent permanent-magnet atom chip. The chip is made of magnetically hard ferrite-garnet material deposited on a dielectric substrate. The confining magnetic fields are produced by miniature magnetized patterns recorded in the film by magneto-optical techniques. We trap Rb atoms on these structures by applying three crossed pairs of counter-propagating laser beams in the conventional magneto-optical trapping (MOT) geometry. We demonstrate the flexibility of the concept in creation and in-situ modification of the trapping geometries through several experiments.

  5. High resolution time interval counter

    DOEpatents

    Condreva, Kenneth J. (Livermore, CA)

    1994-01-01

    A high resolution counter circuit measures the time interval between the occurrence of an initial and a subsequent electrical pulse to two nanoseconds resolution using an eight megahertz clock. The circuit includes a main counter for receiving electrical pulses and generating a binary word--a measure of the number of eight megahertz clock pulses occurring between the signals. A pair of first and second pulse stretchers receive the signal and generate a pair of output signals whose widths are approximately sixty-four times the time between the receipt of the signals by the respective pulse stretchers and the receipt by the respective pulse stretchers of a second subsequent clock pulse. Output signals are thereafter supplied to a pair of start and stop counters operable to generate a pair of binary output words representative of the measure of the width of the pulses to a resolution of two nanoseconds. Errors associated with the pulse stretchers are corrected by providing calibration data to both stretcher circuits, and recording start and stop counter values. Stretched initial and subsequent signals are combined with autocalibration data and supplied to an arithmetic logic unit to determine the time interval in nanoseconds between the pair of electrical pulses being measured.

  6. High resolution time interval counter

    DOEpatents

    Condreva, K.J.

    1994-07-26

    A high resolution counter circuit measures the time interval between the occurrence of an initial and a subsequent electrical pulse to two nanoseconds resolution using an eight megahertz clock. The circuit includes a main counter for receiving electrical pulses and generating a binary word--a measure of the number of eight megahertz clock pulses occurring between the signals. A pair of first and second pulse stretchers receive the signal and generate a pair of output signals whose widths are approximately sixty-four times the time between the receipt of the signals by the respective pulse stretchers and the receipt by the respective pulse stretchers of a second subsequent clock pulse. Output signals are thereafter supplied to a pair of start and stop counters operable to generate a pair of binary output words representative of the measure of the width of the pulses to a resolution of two nanoseconds. Errors associated with the pulse stretchers are corrected by providing calibration data to both stretcher circuits, and recording start and stop counter values. Stretched initial and subsequent signals are combined with autocalibration data and supplied to an arithmetic logic unit to determine the time interval in nanoseconds between the pair of electrical pulses being measured. 3 figs.

  7. Hybrid electrode based on carbon nanotube and graphene for ultraviolet light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Seo, Tae Hoon; Lee, Gun Hee; Park, Sungchan; Chandramohan, S.; Park, Ah Hyun; Cho, Hyunjin; Park, Min; Jong Kim, Myung; Suh, Eun-Kyung

    2015-10-01

    We report on a transparent current-spreading electrode that combines carbon nanotubes (CNTs) and graphene for UV-LEDs. We compared the device performance and long-term stability of this CNT-graphene hybrid electrode (CGE) with those of the silver nanowire-graphene electrode (SGE) reported previously. Both types of electrode offered excellent UV transmittance and reduced sheet resistance through the bridging effect for grain boundaries and defects in graphene by nanotubes or nanowires. UV-LEDs using such electrodes offered reduced forward voltage and enhanced electroluminescence intensity, but the device with the CGE showed excellent stability whereas the SGE degraded with time.

  8. High Temperature Transparent Furnace Development

    NASA Technical Reports Server (NTRS)

    Bates, Stephen C.

    1997-01-01

    This report describes the use of novel techniques for heat containment that could be used to build a high temperature transparent furnace. The primary objective of the work was to experimentally demonstrate transparent furnace operation at 1200 C. Secondary objectives were to understand furnace operation and furnace component specification to enable the design and construction of a low power prototype furnace for delivery to NASA in a follow-up project. The basic approach of the research was to couple high temperature component design with simple concept demonstration experiments that modify a commercially available transparent furnace rated at lower temperature. A detailed energy balance of the operating transparent furnace was performed, calculating heat losses through the furnace components as a result of conduction, radiation, and convection. The transparent furnace shells and furnace components were redesigned to permit furnace operation at at least 1200 C. Techniques were developed that are expected to lead to significantly improved heat containment compared with current transparent furnaces. The design of a thermal profile in a multizone high temperature transparent furnace design was also addressed. Experiments were performed to verify the energy balance analysis, to demonstrate some of the major furnace improvement techniques developed, and to demonstrate the overall feasibility of a high temperature transparent furnace. The important objective of the research was achieved: to demonstrate the feasibility of operating a transparent furnace at 1200 C.

  9. Colorless, Transparent, Aromatic Polyimide Films

    NASA Technical Reports Server (NTRS)

    St. Clair, A. K.; St. Clair, T. L.; Ezzell, K. S.; Ely, R. M.

    1986-01-01

    New process yields aromatic condensation polyimide films essentially colorless. Films between 90- and 100-percent transparent at visible wavelength of 500 nm. Optically transparent polyimide films made from variety of aromatic condensation polyimides. Range from very pale in color to colorless, compared to bright yellow color of conventional/ commercial aromatic polyimide film. Increased transparency achieved at no sacrifice in thermal stability, flexibility, toughness, or mechanical properties. These features extremely attractive as films or coating materials for aerospace applications or for any other applications where high optical transparency or thermal stability is required.

  10. Corneal structure and transparency

    PubMed Central

    Meek, Keith M.; Knupp, Carlo

    2015-01-01

    The corneal stroma plays several pivotal roles within the eye. Optically, it is the main refracting lens and thus has to combine almost perfect transmission of visible light with precise shape, in order to focus incoming light. Furthermore, mechanically it has to be extremely tough to protect the inner contents of the eye. These functions are governed by its structure at all hierarchical levels. The basic principles of corneal structure and transparency have been known for some time, but in recent years X-ray scattering and other methods have revealed that the details of this structure are far more complex than previously thought and that the intricacy of the arrangement of the collagenous lamellae provides the shape and the mechanical properties of the tissue. At the molecular level, modern technologies and theoretical modelling have started to explain exactly how the collagen fibrils are arranged within the stromal lamellae and how proteoglycans maintain this ultrastructure. In this review we describe the current state of knowledge about the three-dimensional stromal architecture at the microscopic level, and about the control mechanisms at the nanoscopic level that lead to optical transparency. PMID:26145225

  11. The transparency trap.

    PubMed

    Bernstein, Ethan

    2014-10-01

    To promote accountability, productivity, and shared learning, many organizations create open work environments and gather reams of data on how individuals spend their time. A few years ago, HBS professor Ethan Bernstein set out to find empirical evidence that such approaches improve organizational performance. What he discovered is that this kind of transparency often has an unintended consequence: It can leave employees feeling vulnerable and exposed. When that happens, they conceal any conduct that deviates from the norm so that they won't have to explain it. Unrehearsed, experimental behaviors sometimes stop altogether. But Bernstein also discovered organizations that had established zones of privacy within open environments by setting four types of boundaries: around teams, between feedback and evaluation, between decision rights and improvement rights, and around periods of experimentation. Moreover, across several studies, the companies that had done all this were the ones that consistently got the most creative, efficient, and thoughtful work from their employees. Bernstein's conclusion? By balancing transparency and privacy, organizations can capture the benefits of both, and encourage just the right amount of "positive deviance" needed to increase innovation and productivity. PMID:25509576

  12. Transparent dressing for rhytidectomy.

    PubMed

    Basile, A R; Basile, F V

    2001-01-01

    Several dressings have been proposed for rhytidectomy. At present, the type most frequently used consists of flat cotton strips soaked in mineral oil placed on the incisions and along the mandibular line. Gauze sponges are then placed on the cheeks and an elastic net is wrapped around the head and left open anteriorly to expose the face and eyes. Despite its widespread use, this technique presents problems. It is uncomfortable for the patient, it is tight and confining, it obstructs hearing, complicates hygiene, attracts unnecessary attention, and, most importantly, does not permit visualization of the surgical site or of the complications that might arise, such as hematomas. Thus, we propose a more efficient dressing made of sterilized, transparent PVC film of the type used to protect food in the refrigerator (Saran Wrap-like). This dressing has proved to be more comfortable for the patient, is not tight or confining, does not cause changes in hearing, facilitates local hygiene, does not attract unnecessary attention on the part of the patient himself or of third parties and, most importantly, it is transparent and adheres to all points of the skin flap, permitting early visualization of complications, such as hematomas. PMID:11731853

  13. Corneal structure and transparency.

    PubMed

    Meek, Keith M; Knupp, Carlo

    2015-11-01

    The corneal stroma plays several pivotal roles within the eye. Optically, it is the main refracting lens and thus has to combine almost perfect transmission of visible light with precise shape, in order to focus incoming light. Furthermore, mechanically it has to be extremely tough to protect the inner contents of the eye. These functions are governed by its structure at all hierarchical levels. The basic principles of corneal structure and transparency have been known for some time, but in recent years X-ray scattering and other methods have revealed that the details of this structure are far more complex than previously thought and that the intricacy of the arrangement of the collagenous lamellae provides the shape and the mechanical properties of the tissue. At the molecular level, modern technologies and theoretical modelling have started to explain exactly how the collagen fibrils are arranged within the stromal lamellae and how proteoglycans maintain this ultrastructure. In this review we describe the current state of knowledge about the three-dimensional stromal architecture at the microscopic level, and about the control mechanisms at the nanoscopic level that lead to optical transparency. PMID:26145225

  14. High-performance and stable organic transistors and circuits with patterned polypyrrole electrodes.

    PubMed

    Li, Liqiang; Jiang, Lin; Wang, Wenchong; Du, Chuan; Fuchs, Harald; Hu, Wenping; Chi, Lifeng

    2012-04-24

    High performance p-/n-type transistors and complementary inverter circuits are demonstrated using patterned polypyrrole (PPY) as pure electrodes. Strikingly, these devices show good stability under continuous operation and long-term storage conditions. Furthermore, PPY electrodes also exhibit good applicability in solution-processed and flexible devices. All these results indicate the great potential of PPY electrodes in solution-processed, all-organic, flexible, transparent, and low-power electronics. PMID:22431264

  15. Basic Research Needs for Countering Terrorism

    SciTech Connect

    Stevens, W.; Michalske, T.; Trewhella, J.; Makowski, L.; Swanson, B.; Colson, S.; Hazen, T.; Roberto, F.; Franz, D.; Resnick, G.; Jacobson, S.; Valdez, J.; Gourley, P.; Tadros, M.; Sigman, M.; Sailor, M.; Ramsey, M.; Smith, B.; Shea, K.; Hrbek, J.; Rodacy, P.; Tevault, D.; Edelstein, N.; Beitz, J.; Burns, C.; Choppin, G.; Clark, S.; Dietz, M.; Rogers, R.; Traina, S.; Baldwin, D.; Thurnauer, M.; Hall, G.; Newman, L.; Miller, D.; Kung, H.; Parkin, D.; Shuh, D.; Shaw, H.; Terminello, L.; Meisel, D.; Blake, D.; Buchanan, M.; Roberto, J.; Colson, S.; Carling, R.; Samara, G.; Sasaki, D.; Pianetta, P.; Faison, B.; Thomassen, D.; Fryberger, T.; Kiernan, G.; Kreisler, M.; Morgan, L.; Hicks, J.; Dehmer, J.; Kerr, L.; Smith, B.; Mays, J.; Clark, S.

    2002-03-01

    To identify connections between technology needs for countering terrorism and underlying science issues and to recommend investment strategies to increase the impact of basic research on efforts to counter terrorism.

  16. Fabrication of fully transparent nanowire transistors for transparent and

    E-print Network

    Zhou, Chongwu

    ) are of particular interest for future display devices because of their high carrier mobilities compared with bulk compatible with plastic substrates, as well as their optical transparency and inherent mechanical flexibility. Here we report fully transparent In2O3 and ZnO NWTs fabricated on both glass and flexible plastic

  17. Engineering of contact resistance between transparent single-walled carbon nanotube films and a-Si:H single junction solar cells by gold nanodots.

    PubMed

    Kim, Jeehwan; Hong, Augustin J; Chandra, Bhupesh; Tulevski, George S; Sadana, Devendra K

    2012-04-10

    The viability of single-walled carbon nanotubes (SWCNTs) as a transparent conducting electrode on a-Si:H based single junction solar cells was explored. A Schottky barrier formed at a SWCNT/a-Si:H interface was removed by introducing high work function gold nanodots at the SWCNT/a-Si:H interface. This allows comparable device performance from SWCNT-electrode-based a-Si:H solar cells to that obtained by using conventional transparent conducting oxides. PMID:22388916

  18. Chemical Modification of Electrodes.

    ERIC Educational Resources Information Center

    Bard, Allen J.

    1983-01-01

    Methods of preparing and characterizing modified electrodes are outlined and several applications are described. Topics include how electrodes are modified, characterization of such electrodes, and why it is necessary to modify electrodes. Reasons include use in electrocatalysis and display devices and in analytical/photoelectrochemical…

  19. Fundamental electrode kinetics

    NASA Technical Reports Server (NTRS)

    Elder, J. P.

    1968-01-01

    Report presents the fundamentals of electrode kinetics and the methods used in evaluating the characteristic parameters of rapid-charge transfer processes at electrode-electrolyte interfaces. The concept of electrode kinetics is outlined, followed by the principles underlying the experimental techniques for the investigation of electrode kinetics.

  20. Ion-Selective Electrodes.

    ERIC Educational Resources Information Center

    Arnold, Mark A.; Meyerhoff, Mark E.

    1984-01-01

    Literature on ion-selective electrodes (ISEs) is reviewed in seven sections: books, conferences, reviews; potentiometric membrane electrodes; glass and solid-state membrane electrodes; liquid and polymer membrane ISEs; coated wire electrodes, ion-selective field effect transistors, and microelectrodes; gas sensors and selective bioelectrode…

  1. High-Speed Multipass Coulter Counter with Ultrahigh Resolution.

    PubMed

    Edwards, Martin A; German, Sean R; Dick, Jeffrey E; Bard, Allen J; White, Henry S

    2015-12-22

    Coulter counters measure the size of particles in solution by passing them through an orifice and measuring a resistive pulse, i.e., a drop in the ionic current flowing between two electrodes placed on either side of the orifice. The magnitude of the pulse gives information on the size of the particle; however, resolution is limited by variability in the path of the translocation, due to the Brownian motion of the particle. We present a simple yet powerful modified Coulter counter that uses programmable data acquisition hardware to switch the voltage after sensing the resistive pulse of a nanoparticle passing through the orifice of a nanopipet. Switching the voltage reverses the direction of the driving force on the particle and, when this detect-switch cycle is repeated, allows us to pass an individual nanoparticle through the orifice thousands of times. By measuring individual particles more than 100 times per second we rapidly determine the distribution of the resistive pulses for each particle, which allows us to accurately determine the mean pulse amplitude and deliver considerably improved size resolution over a conventional Coulter counter. We show that single polystyrene nanoparticles can be shuttled back and forth and monitored for minutes, leading to a precisely determined mean blocking current equating to sub-angstrom size resolution. PMID:26549738

  2. Science Experimenter: Experimenting with a Geiger Counter.

    ERIC Educational Resources Information Center

    Mims, Forrest M., III

    1992-01-01

    Describes the use of geiger counters for scientific investigations and experiments. Presents information about background radiation, its sources and detection. Describes how geiger counters work and other methods of radiation detection. Provides purchasing information for geiger counters, related computer software and equipment. (MCO)

  3. HSPES membrane electrode assembly

    NASA Technical Reports Server (NTRS)

    Kindler, Andrew (Inventor); Yen, Shiao-Ping (Inventor)

    2000-01-01

    An improved fuel cell electrode, as well as fuel cells and membrane electrode assemblies that include such an electrode, in which the electrode includes a backing layer having a sintered layer thereon, and a non-sintered free-catalyst layer. The invention also features a method of forming the electrode by sintering a backing material with a catalyst material and then applying a free-catalyst layer.

  4. Transparency in Cooperative Online Education

    ERIC Educational Resources Information Center

    Dalsgaard, Christian; Paulsen, Morten Flate

    2009-01-01

    The purpose of this article is to discuss the following question: What is the potential of social networking within cooperative online education? Social networking does not necessarily involve communication, dialogue, or collaboration. Instead, the authors argue that "transparency" is a unique feature of social networking services. Transparency

  5. Science role in countering terrorism

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Geoscience expertise figures as a component of a new report on harnessing the U.S. science and technology community in the fight against terrorism.The National Research Council report, "Making the Nation Safer: The Role of Science and Technology in Countering Terrorism," proposes research agendas in a number of areas perceived to be vulnerable to terrorism. These areas include nuclear and radiological threats, toxic chemicals and explosive materials, information technology, energy systems, and cities and fixed infrastructure.

  6. Science role in countering terrorism

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Geoscience expertise figures as a component of a new report on harnessing the U.S. science and technology community in the fight against terrorism.The National Research Council report, “Making the Nation Safer: The Role of Science and Technology in Countering Terrorism,” proposes research agendas in a number of areas perceived to be vulnerable to terrorism. These areas include nuclear and radiological threats, toxic chemicals and explosive materials, information technology, energy systems, and cities and fixed infrastructure.

  7. Boron-10 Lined Proportional Counter Wall Effects

    SciTech Connect

    Siciliano, Edward R.; Kouzes, Richard T.

    2012-05-01

    The Department of Energy Office of Nuclear Safeguards (NA-241) is supporting the project 'Coincidence Counting With Boron-Based Alternative Neutron Detection Technology' at Pacific Northwest National Laboratory (PNNL) for development of an alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a boron-lined proportional tube based system in the configuration of a coincidence counter. This report provides information about how variations in proportional counter radius and gas pressure in a typical coincident counter design might affect the observed signal from boron-lined tubes. A discussion comparing tubes to parallel plate counters is also included.

  8. Transparent Conducting Silver Nanowire Networks Jorik van de Groep,* Pierpaolo Spinelli, and Albert Polman

    E-print Network

    Polman, Albert

    Transparent Conducting Silver Nanowire Networks Jorik van de Groep,* Pierpaolo Spinelli, and Albert-dimensional network of silver nanowires. Networks of Ag nanowires are made with wire diameters of 45-110 nm-resistance nanowire electrodes for optoelectronic devices, including thin-film solar cells. For the latter, we discuss

  9. Controlled porosity in electrodes

    DOEpatents

    Chiang, Yet-Ming; Bae, Chang-Jun; Halloran, John William; Fu, Qiang; Tomsia, Antoni P.; Erdonmez, Can K.

    2015-06-23

    Porous electrodes in which the porosity has a low tortuosity are generally provided. In some embodiments, the porous electrodes can be designed to be filled with electrolyte and used in batteries, and can include low tortuosity in the primary direction of ion transport during charge and discharge of the battery. In some embodiments, the electrodes can have a high volume fraction of electrode active material (i.e., low porosity). The attributes outlined above can allow the electrodes to be fabricated with a higher energy density, higher capacity per unit area of electrode (mAh/cm.sup.2), and greater thickness than comparable electrodes while still providing high utilization of the active material in the battery during use. Accordingly, the electrodes can be used to produce batteries with high energy densities, high power, or both compared to batteries using electrodes of conventional design with relatively highly tortuous pores.

  10. High frequency reference electrode

    DOEpatents

    Kronberg, J.W.

    1994-05-31

    A high frequency reference electrode for electrochemical experiments comprises a mercury-calomel or silver-silver chloride reference electrode with a layer of platinum around it and a layer of a chemically and electrically resistant material such as TEFLON around the platinum covering all but a small ring or halo' at the tip of the reference electrode, adjacent to the active portion of the reference electrode. The voltage output of the platinum layer, which serves as a redox electrode, and that of the reference electrode are coupled by a capacitor or a set of capacitors and the coupled output transmitted to a standard laboratory potentiostat. The platinum may be applied by thermal decomposition to the surface of the reference electrode. The electrode provides superior high-frequency response over conventional electrodes. 4 figs.

  11. Flexible retinal electrode array

    DOEpatents

    Okandan, Murat (Albuquerque, NM); Wessendorf, Kurt O. (Albuquerque, NM); Christenson, Todd R. (Albuquerque, NM)

    2006-10-24

    An electrode array which has applications for neural stimulation and sensing. The electrode array can include a large number of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. The electrode array can be formed from a combination of bulk and surface micromachining, with electrode tips that can include an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis where the electrodes can be tailored to provide a uniform gentle contact pressure with optional sensing of this contact pressure at one or more of the electrodes.

  12. Micromachined electrode array

    DOEpatents

    Okandan, Murat (Edgewood, NM); Wessendorf, Kurt O. (Albuquerque, NM)

    2007-12-11

    An electrode array is disclosed which has applications for neural stimulation and sensing. The electrode array, in certain embodiments, can include a plurality of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. In other embodiments of the electrode array, the electrodes can be fixed to the substrate. The electrode array can be formed from a combination of bulk and surface micromachining, and can include electrode tips having an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis.

  13. High frequency reference electrode

    DOEpatents

    Kronberg, James W. (Aiken, SC)

    1994-01-01

    A high frequency reference electrode for electrochemical experiments comprises a mercury-calomel or silver-silver chloride reference electrode with a layer of platinum around it and a layer of a chemically and electrically resistant material such as TEFLON around the platinum covering all but a small ring or "halo" at the tip of the reference electrode, adjacent to the active portion of the reference electrode. The voltage output of the platinum layer, which serves as a redox electrode, and that of the reference electrode are coupled by a capacitor or a set of capacitors and the coupled output transmitted to a standard laboratory potentiostat. The platinum may be applied by thermal decomposition to the surface of the reference electrode. The electrode provides superior high-frequency response over conventional electrodes.

  14. A high transmittance color liquid crystal display mode with controllable color gamut and transparency.

    PubMed

    Mun, Byung-June; Kang, Wan Seok; Lee, Joun Ho; Choi, Hyun Chul; Kim, Byeong Koo; Kang, Bongsoon; Lim, Young Jin; Lee, Seung Hee; Lee, Gi-Dong

    2014-05-19

    In this paper, we propose a color transparent liquid crystal (LC) mode that can control the properties of the color gamut and transparency in a single panel. To achieve high transmittance in the transparent LC mode, a reactive mesogen (RM) with embedded color dichroic dyes was applied instead of a color filter. Basically, the LC mode applied a 3-terminal electrode structure to switch between the transparent LC mode and the conventional color LC mode. Depending on the direction of the applied voltage, we can operate both the color mode and the transparent mode in a single panel, and modulate the transparency and color purity of the cell through appropriate voltage control. In the experiments, we confirmed that the transmittance and the color gamut of the cell were 39.4% and 2% in the transparent LC mode and 14.9% and 34% in the color LC mode, respectively. Modulation of the color gamut and transparency between each LC mode are also demonstrated in the paper. PMID:24921368

  15. Laminating solution-processed silver nanowire mesh electrodes onto solid-state dye-sensitized solar cells

    E-print Network

    McGehee, Michael

    Laminating solution-processed silver nanowire mesh electrodes onto solid-state dye-sensitized solar Counter electrode Optoelectronics Solution processed a b s t r a c t Solution processed silver nanowire that can be performed at room temperature. It has recently been shown that films of Ag nanowires can

  16. Laminated ultrathin chemical vapor deposition graphene films based stretchable and transparent high-rate supercapacitor.

    PubMed

    Xu, Ping; Kang, Junmo; Choi, Jae-Boong; Suhr, Jonghwan; Yu, Jianyong; Li, Faxue; Byun, Joon-Hyung; Kim, Byung-Sun; Chou, Tsu-Wei

    2014-09-23

    Due to their exceptional flexibility and transparency, CVD graphene films have been regarded as an ideal replacement of indium tin oxide for transparent electrodes, especially in applications where electronic devices may be subjected to large tensile strain. However, the search for a desirable combination of stretchability and electrochemical performance of such devices remains a huge challenge. Here, we demonstrate the implementation of a laminated ultrathin CVD graphene film as a stretchable and transparent electrode for supercapacitors. Transferred and buckled on PDMS substrates by a prestraininig-then-buckling strategy, the four-layer graphene film maintained its outstanding quality, as evidenced by Raman spectra. Optical transmittance of up to 72.9% at a wavelength of 550 nm and stretchability of 40% were achieved. As the tensile strain increased up to 40%, the specific capacitance showed no degradation and even increased slightly. Furthermore, the supercapacitor demonstrated excellent frequency capability with small time constants under stretching. PMID:25144124

  17. High performance cermet electrodes

    DOEpatents

    Isenberg, Arnold O. (Forest Hills Boro, PA); Zymboly, Gregory E. (Penn Hills, PA)

    1986-01-01

    Disclosed is a method of increasing the operating cell voltage of a solid oxide electrochemical cell having metal electrode particles in contact with an oxygen-transporting ceramic electrolyte. The metal electrode is heated with the cell, and oxygen is passed through the oxygen-transporting ceramic electrolyte to the surface of the metal electrode particles so that the metal electrode particles are oxidized to form a metal oxide layer between the metal electrode particles and the electrolyte. The metal oxide layer is then reduced to form porous metal between the metal electrode particles and the ceramic electrolyte.

  18. Transparent conductors composed of nanomaterials

    NASA Astrophysics Data System (ADS)

    Layani, Michael; Kamyshny, Alexander; Magdassi, Shlomo

    2014-05-01

    This is a review on recent developments in the field of transparent conductive coatings (TCCs) for ITO replacement. The review describes the basic properties of conductive nanomaterials suitable for fabrication of such TCCs (metallic nanoparticles and nanowires, carbon nanotubes and graphene sheets), various methods of patterning the metal nanoparticles with formation of conductive transparent metallic grids, honeycomb structures and 2D arrays of interconnected rings as well as fabrication of TCCs based on graphene and carbon nanotubes. Applications of TCCs in electronic and optoelectronic devices, such as solar cells, electroluminescent and electrochromic devices, touch screens and displays, and transparent EMI shielders, are discussed.

  19. Highly Transparent and Conductive Carbon Nanotube Thin Film Assemblies

    NASA Astrophysics Data System (ADS)

    Gamboa, Daniel; Park, Yong Tae; Ham, Aaron; Grunlan, Jaime

    2010-03-01

    Layer-by-layer (LbL) assembly was used to generate transparent, highly conductive thin films containing carbon nanotubes. Purified single-walled carbon nanotubes (SWNT), stabilized with negatively-charged deoxycholate, were alternately deposited with poly(diallyldimethylammonium chloride) [PDDA] from water onto a PET substrate. These assemblies exhibit visible light transmission > 70% (measured at 700 nm) and electrical conductivity of ˜ 100 S/cm (˜ 50 nm thick with a sheet resistance of ˜ 2 k?/sq) after 20-bilayers of deposition. After heating for just two minutes at 350^oC (on a glass substrate), transparency is increased and conductivity approaches 400 S/cm. With just two bilayers of SWNT/PDDA, these films have an electrical conductivity of 30 S/cm (12 nm thick with a sheet resistance of 70 k?/sq) and transmission greater than 95% at 700nm. This study demonstrates the ability of the LbL technique to produce highly transparent and conductive nanotube-based thin films. These types of films are potentially useful for anti-static films with few bilayers or transparent electrodes with tens of bilayers. Flexible displays, smart windows and solar cells could all benefit from this technology platform.

  20. Vector Color Transparency

    E-print Network

    W. R. Greenberg; G. A. Miller

    1993-09-20

    Color transparency (CT) in high momentum transfer $(e,e' \\vec p)$ reactions is explored. The spin of the proton and photon are treated explicitly, hence the name ``Vector CT". The Dirac distorted wave impulse approximation is used as a starting point; then CT effects are embedded. A hadronic basis is used to describe the struck proton as a wavepacket of physical baryon resonances. The effects of the wavepacket expansion on the normal component of the ejectile polarization, which vanishes in the limit of full CT, are investigated. This formalism is also applied to study CT effects in total cross sections, individual separated nuclear response functions, Fermi motion of the initial nucleon, non-zero size of the initial wavepacket and the effects of relativistic lower components. We show that including CT reduces the violations of current conservation (CC), a typical problem in calculations of this kind. The energy dependence of the normal polarization in $(e,e' \\vec p)$ reactions is found to be slow. However, a measurement of the normal transverse response in a heavy nucleus, such as $^{208}Pb$ seems to afford the opportunity to see CT at quite low momentum transfers. The effects of Fermi motion are investigated, and choosing the momentum of the struck nucleon to be large leads to significant violations of CC.

  1. Transparent volume imaging

    NASA Astrophysics Data System (ADS)

    Wixson, Steve E.

    1990-07-01

    Transparent Volume Imaging began with the stereo xray in 1895 and ended for most investigators when radiation safety concerns eliminated the second view. Today, similiar images can be generated by the computer without safety hazards providing improved perception and new means of image quantification. A volumetric workstation is under development based on an operational prototype. The workstation consists of multiple symbolic and numeric processors, binocular stereo color display generator with large image memory and liquid crystal shutter, voice input and output, a 3D pointer that uses projection lenses so that structures in 3 space can be touched directly, 3D hard copy using vectograph and lenticular printing, and presentation facilities using stereo 35mm slide and stereo video tape projection. Volumetric software includes a volume window manager, Mayo Clinic's Analyze program and our Digital Stereo Microscope (DSM) algorithms. The DSM uses stereo xray-like projections, rapidly oscillating motion and focal depth cues such that detail can be studied in the spatial context of the entire set of data. Focal depth cues are generated with a lens and apeture algorithm that generates a plane of sharp focus, and multiple stereo pairs each with a different plane of sharp focus are generated and stored in the large memory for interactive selection using a physical or symbolic depth selector. More recent work is studying non-linear focussing. Psychophysical studies are underway to understand how people perce ive images on a volumetric display and how accurately 3 dimensional structures can be quantitated from these displays.

  2. Air transparent soundproof window

    NASA Astrophysics Data System (ADS)

    Kim, Sang-Hoon; Lee, Seong-Hyun

    2014-11-01

    A soundproof window or wall which is transparent to airflow is presented. The design is based on two wave theories: the theory of diffraction and the theory of acoustic metamaterials. It consists of a three-dimensional array of strong diffraction-type resonators with many holes centered on each individual resonator. The negative effective bulk modulus of the resonators produces evanescent wave, and at the same time the air holes with subwavelength diameter existed on the surfaces of the window for macroscopic air ventilation. The acoustic performance levels of two soundproof windows with air holes of 20mm and 50mm diameters were measured. The sound level was reduced by about 30 - 35dB in the frequency range of 400 - 5,000Hz with the 20mm window, and by about 20 - 35dB in the frequency range of 700 - 2,200Hz with the 50mm window. Multi stop-band was created by the multi-layers of the window. The attenuation length or the thickness of the window was limited by background noise. The effectiveness of the soundproof window with airflow was demonstrated by a real installation.

  3. Selectively reflective transparent sheets

    NASA Astrophysics Data System (ADS)

    Waché, Rémi; Florescu, Marian; Sweeney, Stephen J.; Clowes, Steven K.

    2015-08-01

    We investigate the possibility to selectively reflect certain wavelengths while maintaining the optical properties on other spectral ranges. This is of particular interest for transparent materials, which for specific applications may require high reflectivity at pre-determined frequencies. Although there exist currently techniques such as coatings to produce selective reflection, this work focuses on new approaches for mass production of polyethylene sheets which incorporate either additives or surface patterning for selective reflection between 8 to 13 ? m. Typical additives used to produce a greenhouse effect in plastics include particles such as clays, silica or hydroxide materials. However, the absorption of thermal radiation is less efficient than the decrease of emissivity as it can be compared with the inclusion of Lambertian materials. Photonic band gap engineering by the periodic structuring of metamaterials is known in nature for producing the vivid bright colors in certain organisms via strong wavelength-selective reflection. Research to artificially engineer such structures has mainly focused on wavelengths in the visible and near infrared. However few studies to date have been carried out to investigate the properties of metastructures in the mid infrared range even though the patterning of microstructure is easier to achieve. We present preliminary results on the diffuse reflectivity using FDTD simulations and analyze the technical feasibility of these approaches.

  4. PTFOS: Flexible and Absorbable Intracranial Electrodes for Magnetic Resonance Imaging

    PubMed Central

    Bonmassar, Giorgio; Fujimoto, Kyoko; Golby, Alexandra J.

    2012-01-01

    Intracranial electrocortical recording and stimulation can provide unique knowledge about functional brain anatomy in patients undergoing brain surgery. This approach is commonly used in the treatment of medically refractory epilepsy. However, it can be very difficult to integrate the results of cortical recordings with other brain mapping modalities, particularly functional magnetic resonance imaging (fMRI). The ability to integrate imaging and electrophysiological information with simultaneous subdural electrocortical recording/stimulation and fMRI could offer significant insight for cognitive and systems neuroscience as well as for clinical neurology, particularly for patients with epilepsy or functional disorders. However, standard subdural electrodes cause significant artifact in MRI images, and concerns about risks such as cortical heating have generally precluded obtaining MRI in patients with implanted electrodes. We propose an electrode set based on polymer thick film organic substrate (PTFOS), an organic absorbable, flexible and stretchable electrode grid for intracranial use. These new types of MRI transparent intracranial electrodes are based on nano-particle ink technology that builds on our earlier development of an EEG/fMRI electrode set for scalp recording. The development of MRI-compatible recording/stimulation electrodes with a very thin profile could allow functional mapping at the individual subject level of the underlying feedback and feed forward networks. The thin flexible substrate would allow the electrodes to optimally contact the convoluted brain surface. Performance properties of the PTFOS were assessed by MRI measurements, finite difference time domain (FDTD) simulations, micro-volt recording, and injecting currents using standard electrocortical stimulation in phantoms. In contrast to the large artifacts exhibited with standard electrode sets, the PTFOS exhibited no artifact due to the reduced amount of metal and conductivity of the electrode/trace ink and had similar electrical properties to a standard subdural electrode set. The enhanced image quality could enable routine MRI exams of patients with intracranial electrode implantation and could also lead to chronic implantation solutions. PMID:22984396

  5. Improved biomedical electrode

    NASA Technical Reports Server (NTRS)

    Frost, J. D., Jr.

    1972-01-01

    Newly designed electrode is prefilled, disposable, electrolyte-saturated spong. New design permits longe periods of storage without deterioration, and readiness in matter of seconds. Electrodes supply signals for electroencephalogram, electro-oculogram, and electrocardiogram.

  6. Intrinsic Transparent Conductors without Doping

    NASA Astrophysics Data System (ADS)

    Zhang, Xiuwen; Zhang, Lijun; Perkins, John D.; Zunger, Alex

    2015-10-01

    Transparent conductors (TCs) combine the usually contraindicated properties of electrical conductivity with optical transparency and are generally made by starting with a transparent insulator and making it conductive via heavy doping, an approach that generally faces severe "doping bottlenecks." We propose a different idea for TC design—starting with a metallic conductor and designing transparency by control of intrinsic interband transitions and intraband plasmonic frequency. We identify the specific design principles for three such prototypical intrinsic TC classes and then search computationally for materials that satisfy them. Remarkably, one of the intrinsic TC, Ag3Al22O34 , is predicted also to be a prototype 3D compounds that manifest natural 2D electron gas regions with very high electron density and conductivity.

  7. Color Transparency at COMPASS energies

    E-print Network

    Gerald A. Miller; Mark Strikman

    2010-05-05

    Pionic quasielastic knockout of protons from nuclei at 200 GeV show very large effects of color transparency as -t increases from 0 to several GeV^2. Similar effects are expected for quasielastic photoproduction of vector mesons.

  8. Intrinsic Transparent Conductors without Doping.

    PubMed

    Zhang, Xiuwen; Zhang, Lijun; Perkins, John D; Zunger, Alex

    2015-10-23

    Transparent conductors (TCs) combine the usually contraindicated properties of electrical conductivity with optical transparency and are generally made by starting with a transparent insulator and making it conductive via heavy doping, an approach that generally faces severe "doping bottlenecks." We propose a different idea for TC design-starting with a metallic conductor and designing transparency by control of intrinsic interband transitions and intraband plasmonic frequency. We identify the specific design principles for three such prototypical intrinsic TC classes and then search computationally for materials that satisfy them. Remarkably, one of the intrinsic TC, Ag_{3}Al_{22}O_{34}, is predicted also to be a prototype 3D compounds that manifest natural 2D electron gas regions with very high electron density and conductivity. PMID:26551133

  9. Insulated ECG electrodes

    NASA Technical Reports Server (NTRS)

    Portnoy, W. M.; David, R. M.

    1973-01-01

    Insulated, capacitively coupled electrode does not require electrolyte paste for attachment. Other features of electrode include wide range of nontoxic material that may be employed for dielectric because of sputtering technique used. Also, electrode size is reduced because there is no need for external compensating networks with FET operational amplifier.

  10. Electrically conductive diamond electrodes

    DOEpatents

    Swain, Greg (East Lansing, MI); Fischer, Anne (Arlington, VA),; Bennett, Jason (Lansing, MI); Lowe, Michael (Holt, MI)

    2009-05-19

    An electrically conductive diamond electrode and process for preparation thereof is described. The electrode comprises diamond particles coated with electrically conductive doped diamond preferably by chemical vapor deposition which are held together with a binder. The electrodes are useful for oxidation reduction in gas, such as hydrogen generation by electrolysis.

  11. Longitudinal discharge laser electrodes

    DOEpatents

    Warner, B.E.; Miller, J.L.; Ault, E.R.

    1994-08-23

    The improved longitudinal discharge laser electrode with IR baffle includes an electrode made up of washers spaced along the laser axis in order to form inter-washer spaces for hollow cathode discharge to take place and for IR radiation to be trapped. Additional IR baffles can be placed between the electrode ann the window. 2 figs.

  12. Longitudinal discharge laser electrodes

    DOEpatents

    Warner, Bruce E. (Livermore, CA); Miller, John L. (Dublin, CA); Ault, Earl R. (Dublin, CA)

    1994-01-01

    The improved longitudinal discharge laser electrode with IR baffle includes an electrode made up of washers spaced along the laser axis in order to form inter-washer spaces for hollow cathode discharge to take place and for IR radiation to be trapped. Additional IR baffles can be placed between the electrode ann the window.

  13. A Simple Hydrogen Electrode

    ERIC Educational Resources Information Center

    Eggen, Per-Odd

    2009-01-01

    This article describes the construction of an inexpensive, robust, and simple hydrogen electrode, as well as the use of this electrode to measure "standard" potentials. In the experiment described here the students can measure the reduction potentials of metal-metal ion pairs directly, without using a secondary reference electrode. Measurements…

  14. Near-electrode imager

    DOEpatents

    Rathke, Jerome W. (Lockport, IL); Klingler, Robert J. (Westmont, IL); Woelk, Klaus (Wachtberg, DE); Gerald, II, Rex E. (Brookfield, IL)

    2000-01-01

    An apparatus, near-electrode imager, for employing nuclear magnetic resonance imaging to provide in situ measurements of electrochemical properties of a sample as a function of distance from a working electrode. The near-electrode imager uses the radio frequency field gradient within a cylindrical toroid cavity resonator to provide high-resolution nuclear magnetic resonance spectral information on electrolyte materials.

  15. Fuel cell electrodes

    DOEpatents

    Strmcnik, Dusan; Cuesta, Angel; Stamenkovic, Vojislav; Markovic, Nenad

    2015-06-23

    A process includes patterning a surface of a platinum group metal-based electrode by contacting the electrode with an adsorbate to form a patterned platinum group metal-based electrode including platinum group metal sites blocked with adsorbate molecules and platinum group metal sites which are not blocked.

  16. Transparency at the level of safeguards implementation

    SciTech Connect

    Petit, A.

    1994-07-01

    Safeguards approaches that include higher degrees of transparency at the level of facilities and at the level of the state also need a higher degree of transparency at the level of IAEA safeguards implementation. Here the author gives a brief discussion of: (1) confidentiality or transparency in the present approach; and (2) transparency in the alternative safeguards approach.

  17. Transparent Humidity Sensor Using Cross-Linked Polyelectrolyte Membrane

    SciTech Connect

    Zhang, Q.; Smith, James R.; Saraf, Laxmikant V.; Hua, Feng

    2009-07-02

    This paper describes the fabrication of a porous cross-linked polyelectrolyte membrane and the characterization of its humidity sensitivity performance. Electrostatic self-assembly, combined with acid treatment, and post-deposition annealing produced the membrane. The fabrication process offers the ability to control the thickness of the membrane, as well as enabling the engineering of the humidity sensitivity properties. A transparent humidity sensor was fabricated by integrating the membrane between two parallel electrodes. In order to improve the moisture absorption and diffusion, both the polyelectrolyte layer and the electrode were made porous. The membrane was cross-linked to enhance the durability in high humid environments. Such a polyelectrolyte membrane showed high sensitivity to relative humidity variation over a range of 25%–99%. The see-through property of the structure adds extra features and benefits to the sensor.

  18. Quantization error in precision time counters

    NASA Astrophysics Data System (ADS)

    Szymanowski, R.; Szplet, R.; Kwiatkowski, P.

    2015-07-01

    The quantization error in interpolating time counters is analyzed for three models of interpolator and for correlated and uncorrelated input events representing the start and end of the measured time interval. The analysis is related to the currently most common two-stage time interpolation method and based on data from several up-to-date integrated time counters. The main aim of this discussion is to find a general and accurate method for presentation and calculation of the quantization error in real, non-ideal time counters. We propose a novel graphical representation of the error, which may be useful for analysis of time counters with any interpolation method used.

  19. Transparent conductive thin-film encapsulation layers (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Behrendt, Andreas; Gahlmann, Tobias; Trost, Sara; Polywka, Andreas; Görrn, Patrick; Riedl, Thomas

    2015-10-01

    Gas diffusion barriers (GDB) are inevitable to protect sensitive organic materials or devices against ambient gases. Typically, thin-film gas diffusion barriers are insulators, e.g. Al2O3 or multilayers of Al2O3/ZrO2, etc.. A wide range of applications would require GDB which are at the same time transparent and electrically conductive. They could serve as electrode and moisture barrier simultaneously, thereby simplifying production. As of yet, work on transparent conductive GDB (TCGDBs) is very limited. TCGDBs based on ZnO prepared by atomic layer deposition (ALD) have been reported. Due to the chemical instability of ZnO, it turns out that their electrical conductivity severely deteriorates by orders of magnitude upon exposure to damp heat conditions after very short time. We will show that these issues can be overcome by the use of tin oxide (SnO2). Conductivities of up to 300 S/cm and extremely low water vapor transmission rates (WVTR) on the order of 10-6 g/(m2 day) can been achieved in SnOx layers prepared by ALD at low temperatures (<150°C). A sandwich of SnOx/Ag/SnOx is shown to provide an average transmittance of 82% and a low sheet resistance of 9 Ohm/sq. At the same time the resulting electrodes are extremely robust. E.g., while unprotected Cu and Ag electrodes degrade within a few minutes at 85°C/85%rH (e.g. Cu lost 7 orders of magnitude in electrical conductivity), sandwich structures of SnOx/(Cu or Ag)/SnOx remain virtually unchanged even after 100 h. The SnOx in this work will also provide corrosion protection for the metal in case of harsh processing steps on top these electodes (e.g. acidic). We demonstrate the application of these TCGDBs as electrodes for organic solar cells and OLEDs.

  20. Sensor Noise Camera Identification: Countering Counter-Forensics Miroslav Goljan, Jessica Fridrich, and Mo Chen

    E-print Network

    Fridrich, Jessica

    Sensor Noise Camera Identification: Countering Counter-Forensics Miroslav Goljan, Jessica Fridrich. In this paper, we develop methods to reveal counter-forensic activities in which an attacker estimates. Keywords: Camera identification, digital forensics, photo-response non-uniformity, sensor fingerprint

  1. Compact fission counter for DANCE

    SciTech Connect

    Wu, C Y; Chyzh, A; Kwan, E; Henderson, R; Gostic, J; Carter, D; Bredeweg, T; Couture, A; Jandel, M; Ullmann, J

    2010-11-06

    The Detector for Advanced Neutron Capture Experiments (DANCE) consists of 160 BF{sub 2} crystals with equal solid-angle coverage. DANCE is a 4{pi} {gamma}-ray calorimeter and designed to study the neutron-capture reactions on small quantities of radioactive and rare stable nuclei. These reactions are important for the radiochemistry applications and modeling the element production in stars. The recognition of capture event is made by the summed {gamma}-ray energy which is equivalent of the reaction Q-value and unique for a given capture reaction. For a selective group of actinides, where the neutron-induced fission reaction competes favorably with the neutron capture reaction, additional signature is needed to distinguish between fission and capture {gamma} rays for the DANCE measurement. This can be accomplished by introducing a detector system to tag fission fragments and thus establish a unique signature for the fission event. Once this system is implemented, one has the opportunity to study not only the capture but also fission reactions. A parallel-plate avalanche counter (PPAC) has many advantages for the detection of heavy charged particles such as fission fragments. These include fast timing, resistance to radiation damage, and tolerance of high counting rate. A PPAC also can be tuned to be insensitive to {alpha} particles, which is important for experiments with {alpha}-emitting actinides. Therefore, a PPAC is an ideal detector for experiments requiring a fast and clean trigger for fission. A PPAC with an ingenious design was fabricated in 2006 by integrating amplifiers into the target assembly. However, this counter was proved to be unsuitable for this application because of issues related to the stability of amplifiers and the ability to separate fission fragments from {alpha}'s. Therefore, a new design is needed. A LLNL proposal to develop a new PPAC for DANCE was funded by NA22 in FY09. The design goal is to minimize the mass for the proposed counter and still be able to maintain a stable operation under extreme radioactivity and the ability to separate fission fragments from {alpha}'s. In the following sections, the description is given for the design and performance of this new compact PPAC, for studying the neutron-induced reactions on actinides using DANCE at LANL.

  2. Hybrid dielectric layer for low operating voltages of transparent and flexible organic complementary inverter

    NASA Astrophysics Data System (ADS)

    Go, Mu Seok; Song, Ji-Min; Kim, Chaewon; Lee, Jaegab; Kim, Jiyoung; Lee, Mi Jung

    2015-03-01

    Although flexibility and transparency are considered advantages of organic electronic devices along with low processing cost and the possibility of large-area production, high operating voltages and metallic contacts are obstacles to their application in real electronic products. In this work, flexible and transparent organic complementary inverters that can be operated with low voltage were fabricated on a plastic substrate. Two different air-stable organic semiconductors, fluorinated copper phthalocyanine and pentacene, are used for n-type and p-type transistors, respectively. An ITO gate electrode was deposited by sputtering, and a hybrid dielectric layer with a thin Al2O3 layer and self-assembled monolayers (SAMs) was fabricated to reduce the operation voltage. To confirm the properties of the hybrid dielectric layer, the capacitance and gate leakage current were measured. Then, source and drain electrodes were formed from gold or ITO specifically for fully transparent devices. For the ITO electrodes, a MoO3 interlayer was incorporated between the pentacene and ITO to reduce the contact resistance caused by mismatch of workfunction. Finally, we evaluated the low-voltage operation of the flexible organic inverters and the fully transparent device through transmittance measurement. [Figure not available: see fulltext.

  3. Low-temperature-processed efficient semi-transparent planar perovskite solar cells for bifacial and tandem applications.

    PubMed

    Fu, Fan; Feurer, Thomas; Jäger, Timo; Avancini, Enrico; Bissig, Benjamin; Yoon, Songhak; Buecheler, Stephan; Tiwari, Ayodhya N

    2015-01-01

    Semi-transparent perovskite solar cells are highly attractive for a wide range of applications, such as bifacial and tandem solar cells; however, the power conversion efficiency of semi-transparent devices still lags behind due to missing suitable transparent rear electrode or deposition process. Here we report a low-temperature process for efficient semi-transparent planar perovskite solar cells. A hybrid thermal evaporation-spin coating technique is developed to allow the introduction of PCBM in regular device configuration, which facilitates the growth of high-quality absorber, resulting in hysteresis-free devices. We employ high-mobility hydrogenated indium oxide as transparent rear electrode by room-temperature radio-frequency magnetron sputtering, yielding a semi-transparent solar cell with steady-state efficiency of 14.2% along with 72% average transmittance in the near-infrared region. With such semi-transparent devices, we show a substantial power enhancement when operating as bifacial solar cell, and in combination with low-bandgap copper indium gallium diselenide we further demonstrate 20.5% efficiency in four-terminal tandem configuration. PMID:26576667

  4. Low-temperature-processed efficient semi-transparent planar perovskite solar cells for bifacial and tandem applications

    NASA Astrophysics Data System (ADS)

    Fu, Fan; Feurer, Thomas; Jäger, Timo; Avancini, Enrico; Bissig, Benjamin; Yoon, Songhak; Buecheler, Stephan; Tiwari, Ayodhya N.

    2015-11-01

    Semi-transparent perovskite solar cells are highly attractive for a wide range of applications, such as bifacial and tandem solar cells; however, the power conversion efficiency of semi-transparent devices still lags behind due to missing suitable transparent rear electrode or deposition process. Here we report a low-temperature process for efficient semi-transparent planar perovskite solar cells. A hybrid thermal evaporation-spin coating technique is developed to allow the introduction of PCBM in regular device configuration, which facilitates the growth of high-quality absorber, resulting in hysteresis-free devices. We employ high-mobility hydrogenated indium oxide as transparent rear electrode by room-temperature radio-frequency magnetron sputtering, yielding a semi-transparent solar cell with steady-state efficiency of 14.2% along with 72% average transmittance in the near-infrared region. With such semi-transparent devices, we show a substantial power enhancement when operating as bifacial solar cell, and in combination with low-bandgap copper indium gallium diselenide we further demonstrate 20.5% efficiency in four-terminal tandem configuration.

  5. 76 FR 1180 - FDA Transparency Initiative: Improving Transparency to Regulated Industry

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-07

    ...SERVICES Food and Drug Administration [Docket No. FDA-2009-N-0247] FDA Transparency Initiative: Improving Transparency to...Transparency Initiative, the Food and Drug Administration (FDA) is announcing the availability of a report...

  6. On generating counter-rotating streamwise vortices

    NASA Astrophysics Data System (ADS)

    Winoto, S. H.; Mitsudharmadi, H.; Budiman, A. C.; Hasheminejad, S. M.; Nadesan, T.; Tandiono; Low, H. T.; Lee, T. S.

    2015-09-01

    Counter-rotating streamwise vortices are known to enhance the heat transfer rate from a surface and also to improve the aerodynamic performance of an aerofoil. In this paper, some methods to generate such counter-rotating vortices using different methods or physical conditions will be briefly considered and discussed.

  7. Transparent stereoscopic display and application

    NASA Astrophysics Data System (ADS)

    Ranieri, Nicola; Seifert, Hagen; Gross, Markus

    2014-03-01

    Augmented reality has become important to our society as it can enrich the actual world with virtual information. Transparent screens offer one possibility to overlay rendered scenes with the environment, acting both as display and window. In this work, we review existing transparent back-projection screens for the use with active and passive stereo. Advantages and limitations are described and, based on these insights, a passive stereoscopic system using an anisotropic back-projection foil is proposed. To increase realism, we adapt rendered content to the viewer's position using a Kinect tracking system, which adds motion parallax to the binocular cues. A technique well known in control engineering is used to decrease latency and increase frequency of the tracker. Our transparent stereoscopic display prototype provides immersive viewing experience and is suitable for many augmented reality applications.

  8. Over-the-counter Acne Treatments

    PubMed Central

    Graber, Emmy M.

    2012-01-01

    Acne is a common dermatological disorder that most frequently affects adolescents; however, individuals may be affected at all ages. Many people who suffer from acne seek treatment from both prescription and over-the-counter acne medications. Due to convenience, lower cost, and difficulty getting an appointment with a dermatologist, the use of over-the-counter acne treatments is on the rise. As the plethora of over-the-counter acne treatment options can be overwhelming, it is important that dermatologists are well-versed on this subject to provide appropriate information about treatment regimens and potential drug interactions and that their patients see them as well-informed. This article reviews the efficacy of various over-the-counter acne treatments based on the current literature. A thorough literature review revealed there are many types of over-the-counter acne treatments and each are designed to target at least one of the pathogenic pathways that are reported to be involved in the development of acne lesions. Many of the key over-the-counter ingredients are incorporated in different formulations to broaden the spectrum and consumer appeal of available products. Unfortunately, many over-the-counter products are not well-supported by clinical studies, with a conspicuous absence of double-blind or investigator-blind, randomized, vehicle-controlled studies. Most studies that do exist on over-the-counter acne products are often funded by the manufacturer. Use of over-the-counter acne treatments is a mainstay in our society and it is important that dermatologists are knowledgeable about the different options, including potential benefits and limitations. Overall, over-the-counter acne therapies can be classified into the following five major groups: cleansers, leave-on products, mechanical treatments, essential oils, and vitamins. PMID:22808307

  9. The Omega Counter, a Frequency Counter Based on the Linear Regression

    E-print Network

    Rubiola, E; Bourgeois, P -Y; Vernotte, F

    2015-01-01

    This article introduces the {\\Omega} counter, a frequency counter -- or a frequency-to-digital converter, in a different jargon -- based on the Linear Regression (LR) algorithm on time stamps. We discuss the noise of the electronics. We derive the statistical properties of the {\\Omega} counter on rigorous mathematical basis, including the weighted measure and the frequency response. We describe an implementation based on a SoC, under test in our laboratory, and we compare the {\\Omega} counter to the traditional {\\Pi} and {\\Lambda} counters. The LR exhibits optimum rejection of white phase noise, superior to that of the {\\Pi} and {\\Lambda} counters. White noise is the major practical problem of wideband digital electronics, both in the instrument internal circuits and in the fast processes which we may want to measure. The {\\Omega} counter finds a natural application in the measurement of the Parabolic Variance, described in the companion article arXiv:1506.00687 [physics.data-an].

  10. Three-terminal resistive switching memory in a transparent vertical-configuration device

    SciTech Connect

    Ungureanu, Mariana; Llopis, Roger; Casanova, Fèlix; Hueso, Luis E.; Ikerbasque, Basque Foundation for Science, Bilbao

    2014-01-06

    The resistive switching phenomenon has attracted much attention recently for memory applications. It describes the reversible change in the resistance of a dielectric between two non-volatile states by the application of electrical pulses. Typical resistive switching memories are two-terminal devices formed by an oxide layer placed between two metal electrodes. Here, we report on the fabrication and operation of a three-terminal resistive switching memory that works as a reconfigurable logic component and offers an increased logic density on chip. The three-terminal memory device we present is transparent and could be further incorporated in transparent computing electronic technologies.

  11. Transparent, flexible, ultrathin sound source devices using Indium Tin oxide films

    NASA Astrophysics Data System (ADS)

    Tian, He; Xie, Dan; Yang, Yi; Ren, Tian-Ling; Wang, Yu-Feng; Zhou, Chang-Jian; Peng, Ping-Gang; Wang, Li-Gang; Liu, Li-Tian

    2011-07-01

    Thermoacoustic effects were observed in 100-nm indium tin oxide (ITO) films. The sound emission from the ITO films was measured as a function of power, distance, and frequency. Significant flat and wide frequency responses occurred between 20 and 50 kHz. The sound pressure and efficiency were in good agreement with theoretical results. This indicates that a thermoacoustic effect exists in metal-oxide materials and that a large family of transparent electrode materials may exhibit similar properties. Using the ultrathin, transparent, and flexible characteristics, we showed promising applications of ITO sound source devices that were integrated with liquid crystal display screens.

  12. Transparently insulated astronaut training centre

    SciTech Connect

    Kerschberger, A. )

    1994-03-01

    Transparent insulation is a promising way of reducing the heating energy consumption of buildings. Until recently, TI-systems were mainly used in dwellings and office buildings with typical room temperatures of 20-22[degrees]C. Buildings with higher room temperatures offer a greater potential for profitable use of solar energy. The German Research Institute for Aeronautics and Space Flight (DLR) has built such a building, the Crew Training Complex (CTC) for the training of European astronauts at Cologne-Porz. The architectural quality of the training complex shows that transparent insulation does not just bring high energy savings, but also asthetic benefits.

  13. 21 CFR 864.5220 - Automated differential cell counter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Automated differential cell counter. 864.5220 Section 864... § 864.5220 Automated differential cell counter. (a) Identification. An automated differential cell counter is a device used to...

  14. 21 CFR 864.5200 - Automated cell counter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Automated cell counter. 864.5200 Section 864.5200...Hematology Devices § 864.5200 Automated cell counter. (a) Identification. An automated cell counter is a fully-automated or...

  15. 21 CFR 864.5200 - Automated cell counter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Automated cell counter. 864.5200 Section 864.5200...Hematology Devices § 864.5200 Automated cell counter. (a) Identification. An automated cell counter is a fully-automated or...

  16. 21 CFR 864.5200 - Automated cell counter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Automated cell counter. 864.5200 Section 864.5200...Hematology Devices § 864.5200 Automated cell counter. (a) Identification. An automated cell counter is a fully-automated or...

  17. 21 CFR 864.5200 - Automated cell counter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Automated cell counter. 864.5200 Section 864.5200...Hematology Devices § 864.5200 Automated cell counter. (a) Identification. An automated cell counter is a fully-automated or...

  18. 21 CFR 864.5220 - Automated differential cell counter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Automated differential cell counter. 864.5220 Section 864... § 864.5220 Automated differential cell counter. (a) Identification. An automated differential cell counter is a device used to...

  19. 21 CFR 864.5220 - Automated differential cell counter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Automated differential cell counter. 864.5220 Section 864... § 864.5220 Automated differential cell counter. (a) Identification. An automated differential cell counter is a device used to...

  20. 21 CFR 864.5220 - Automated differential cell counter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Automated differential cell counter. 864.5220 Section 864... § 864.5220 Automated differential cell counter. (a) Identification. An automated differential cell counter is a device used to...