The Experts below are selected from a list of 36183 Experts worldwide ranked by ideXlab platform

L C Comandar - One of the best experts on this subject based on the ideXlab platform.

  • gigahertz gated ingaas inp single photon detector with detection Efficiency exceeding 55 at 1550 nm
    Journal of Applied Physics, 2015
    Co-Authors: L C Comandar, B Frohlich, J F Dynes, A W Sharpe, Marco Lucamarini, Z L Yuan, R V Penty, A J Shields
    Abstract:

    We report on a gated single-photon detector based on InGaAs/InP avalanche photodiodes (APDs) with a single-photon detection Efficiency exceeding 55% at 1550 nm. Our detector is gated at 1 GHz and employs the self-differencing technique for gate transient suppression. It can operate nearly dead time free, except for the one clock cycle dead time intrinsic to self-differencing, and we demonstrate a count rate of 500 Mcps. We present a careful analysis of the optimal driving conditions of the APD measured with a dead time free detector characterization setup. It is found that a shortened gate width of 360 ps together with an increased driving signal amplitude and operation at higher temperatures leads to improved performance of the detector. We achieve an afterpulse probability of 7% at 50% detection Efficiency with dead time free measurement and a Record Efficiency for InGaAs/InP APDs of 55% at an afterpulse probability of only 10.2% with a moderate dead time of 10 ns.

  • ghz gated ingaas inp single photon detector with detection Efficiency exceeding 55 at 1550 nm
    arXiv: Quantum Physics, 2014
    Co-Authors: L C Comandar, B Frohlich, J F Dynes, A W Sharpe, Marco Lucamarini, Z L Yuan, R V Penty, A J Shields
    Abstract:

    We report on a gated single-photon detector based on InGaAs/InP avalanche photodiodes (APDs) with a single-photon detection Efficiency exceeding 55% at 1550 nm. Our detector is gated at 1 GHz and employs the self-differencing technique for gate transient suppression. It can operate nearly dead time free, except for the one clock cycle dead time intrinsic to self-differencing, and we demonstrate a count rate of 500 Mcps. We present a careful analysis of the optimal driving conditions of the APD measured with a dead time free detector characterization setup. It is found that a shortened gate width of 360 ps together with an increased driving signal amplitude and operation at higher temperatures leads to improved performance of the detector. We achieve an afterpulse probability of 7% at 50% detection Efficiency with dead time free measurement and a Record Efficiency for InGaAs/InP APDs of 55% at an afterpulse probability of only 10.2% with a moderate dead time of 10 ns.

Michael Powalla - One of the best experts on this subject based on the ideXlab platform.

  • improved photocurrent in cu in ga se 2 solar cells from 20 8 to 21 7 Efficiency with cds buffer and 21 0 cd free
    IEEE Journal of Photovoltaics, 2015
    Co-Authors: Theresa Magorian Friedlmeier, Philip L Jackson, A Bauer, Dimitrios Hariskos, Oliver Kiowski, Roland Wuerz, Michael Powalla
    Abstract:

    New processing developments in the Cu(In,Ga)Se2 (CIGS)-based solar cell technology have enabled best cell efficiencies to exceed 21%. The key innovation involves the alkali post-deposition treatment (PDT) of the CIGS film. Furthermore, the range of optimal CIGS growth parameters and the minimal thickness of the CdS buffer layer is affected by the process modifications. In 2013, we reported a 20.8% Record device with PDT. Later optimizations, e.g., in the composition profile and CdS buffer layer thickness as discussed in this study, enabled us to increase the photocurrent density with only a slight loss in open-circuit voltage and unchanged fill factor, resulting in the current world Record of 21.7% Efficiency. Furthermore, a Record Efficiency of 21.0% could be achieved with a Cd-free Zn(O,S) buffer layer. This contribution presents measurements, simulations, and a discussion of the photocurrent increase.

  • properties of cu in ga se2 solar cells with new Record efficiencies up to 21 7
    Physica Status Solidi-rapid Research Letters, 2015
    Co-Authors: Philip Jackson, Theresa Magorian Friedlmeier, A Bauer, Dimitrios Hariskos, Oliver Kiowski, Roland Wuerz, Michael Powalla
    Abstract:

    We report on a new thin-film Cu(In,Ga)Se2 (CIGS) solar cell Record Efficiency of 21.7%. In order to better understand this newest development, we describe the specific solar cell data as obtained from I–V measurement and diode analysis, quantum Efficiency and secondary neutral mass spectrometry measurements. We hope that such a description will help to exploit the potential of this promising thin-film solar technology even further. (© 2015 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim)

  • new world Record Efficiency for cu in ga se2 thin film solar cells beyond 20
    Progress in Photovoltaics, 2011
    Co-Authors: Philip L Jackson, Dimitrios Hariskos, Roland Wuerz, Erwin Lotter, Stefan Paetel, Richard Menner, Wiltraud Wischmann, Michael Powalla
    Abstract:

    In this contribution, we present a new certified world Record Efficiency of 20.1 and 20.3% for Cu(In,Ga)Se2 thin-film solar cells. We analyse the characteristics of solar cells on such a performance level and demonstrate a high degree of reproducibility. Copyright © 2011 John Wiley & Sons, Ltd.

  • cadmium free buffer layers deposited by atomic later epitaxy for copper indium diselenide solar cells
    Thin Solid Films, 2000
    Co-Authors: El Bekkaye Yousfi, Michael Powalla, T Asikainen, V Pietu, P Cowache, Daniel Lincot
    Abstract:

    As a soft and highly controllable deposition technique, atomic layer epitaxy (ALE) is well suited to deposit buffer and window layers on CIS thin solar films with high interface quality. In this work we have investigated ALE buffer layers of zinc oxysulfide, indium sulfide and aluminum oxide deposited at low temperature (160°C). The most promising results have been obtained with using indium sulfide buffer layers, with a Record Efficiency of 13.5% (30.6 mA /cm2, 604 mV, FF=0.73 under 100 mW /cm2, without AR coating) achieved on a standard CIGS absorber. This opens a route for a dry cadmium-free buffer process fully compatible with the other vacuum deposition techniques (coevaporation, sputtering).

A J Shields - One of the best experts on this subject based on the ideXlab platform.

  • gigahertz gated ingaas inp single photon detector with detection Efficiency exceeding 55 at 1550 nm
    Journal of Applied Physics, 2015
    Co-Authors: L C Comandar, B Frohlich, J F Dynes, A W Sharpe, Marco Lucamarini, Z L Yuan, R V Penty, A J Shields
    Abstract:

    We report on a gated single-photon detector based on InGaAs/InP avalanche photodiodes (APDs) with a single-photon detection Efficiency exceeding 55% at 1550 nm. Our detector is gated at 1 GHz and employs the self-differencing technique for gate transient suppression. It can operate nearly dead time free, except for the one clock cycle dead time intrinsic to self-differencing, and we demonstrate a count rate of 500 Mcps. We present a careful analysis of the optimal driving conditions of the APD measured with a dead time free detector characterization setup. It is found that a shortened gate width of 360 ps together with an increased driving signal amplitude and operation at higher temperatures leads to improved performance of the detector. We achieve an afterpulse probability of 7% at 50% detection Efficiency with dead time free measurement and a Record Efficiency for InGaAs/InP APDs of 55% at an afterpulse probability of only 10.2% with a moderate dead time of 10 ns.

  • ghz gated ingaas inp single photon detector with detection Efficiency exceeding 55 at 1550 nm
    arXiv: Quantum Physics, 2014
    Co-Authors: L C Comandar, B Frohlich, J F Dynes, A W Sharpe, Marco Lucamarini, Z L Yuan, R V Penty, A J Shields
    Abstract:

    We report on a gated single-photon detector based on InGaAs/InP avalanche photodiodes (APDs) with a single-photon detection Efficiency exceeding 55% at 1550 nm. Our detector is gated at 1 GHz and employs the self-differencing technique for gate transient suppression. It can operate nearly dead time free, except for the one clock cycle dead time intrinsic to self-differencing, and we demonstrate a count rate of 500 Mcps. We present a careful analysis of the optimal driving conditions of the APD measured with a dead time free detector characterization setup. It is found that a shortened gate width of 360 ps together with an increased driving signal amplitude and operation at higher temperatures leads to improved performance of the detector. We achieve an afterpulse probability of 7% at 50% detection Efficiency with dead time free measurement and a Record Efficiency for InGaAs/InP APDs of 55% at an afterpulse probability of only 10.2% with a moderate dead time of 10 ns.

Lars Stolt - One of the best experts on this subject based on the ideXlab platform.

  • world Record cu in ga se2 based thin film sub module with 17 4 Efficiency
    Progress in Photovoltaics, 2012
    Co-Authors: Erik Wallin, Ulf Malm, Tobias Jarmar, Edoff Olle Lundberg Marika, Lars Stolt
    Abstract:

    We report a new certified world-Record Efficiency for thin-film Cu(In,Ga)Se2-based photovoltaic sub-modules of 17.4%(aperture area). The Record Efficiency of the 16 cm2, monolithically integrated, sub-module has been independently confirmedby Fraunhofer ISE. The Record device is the result of extensive co-optimization of all processing steps. Duringthe optimization process, strong focus has been put on the scalability of processes to cost-effective mass production, asreflected, for example, in Cu(In,Ga)Se2 deposition time and substrate temperature. Device manufacturing as well as resultsof electrical and material characterization is discussed.

  • world Record cu in ga se2 based thin film sub module with 17 4 Efficiency
    Progress in Photovoltaics, 2012
    Co-Authors: Erik Wallin, Ulf Malm, Tobias Jarmar, Edoff Olle Lundberg Marika, Lars Stolt
    Abstract:

    We report a new certified world-Record Efficiency for thin-film Cu(In,Ga)Se2-based photovoltaic sub-modules of 17.4%(aperture area). The Record Efficiency of the 16 cm2, monolithically integrated, sub-module has been independently confirmedby Fraunhofer ISE. The Record device is the result of extensive co-optimization of all processing steps. Duringthe optimization process, strong focus has been put on the scalability of processes to cost-effective mass production, asreflected, for example, in Cu(In,Ga)Se2 deposition time and substrate temperature. Device manufacturing as well as resultsof electrical and material characterization is discussed.

Hiroki Sugimoto - One of the best experts on this subject based on the ideXlab platform.

  • cd free cu in ga se s 2 thin film solar cell with Record Efficiency of 23 35
    IEEE Journal of Photovoltaics, 2019
    Co-Authors: Motoshi Nakamura, Takuya Kato, Koji Yamaguchi, Yoshinori Kimoto, Yusuke Yasaki, Hiroki Sugimoto
    Abstract:

    In this article, the excellent properties of state-of-the-art Cd-free Cu(In,Ga)(Se,S)2 (CIGSSe) solar cells with Zn(O,S,OH) x /Zn0.8Mg0.2O double buffer layers, deposited by a combination of chemical bath deposition and atomic layer deposition techniques, are presented. By the replacement of conventional CdS buffer layers with this double buffer layer, the open-circuit voltage ( V oc) deficit of the devices could be significantly reduced, and V oc increased by approximately 15 mV. In addition, the fill factor and short-circuit current were also improved, increasing the device Efficiency by approximately 0.5 absolute percent compared with devices with CdS buffers. The Cd-free double buffer layer improved the device Efficiency regardless of the bandgap of the CIGSSe absorber. The minority carrier lifetime ( τ ) measured via time-resolved photoluminescence became longer, indicating that carrier recombination is mitigated using the double buffer layer. Based on the device parameters extracted by fitting the Suns– V oc characteristics to the double-diode model, the longer τ could be attributed to the decreased recombination rate in the space-charge region, rather than in the bulk and at the interface. The best performing cell was evaluated by a reliable third party, the National Institute of Advanced Industrial Science and Technology; this cell achieved a new world Record Efficiency of 23.35% for 1-cm2-sized thin-film polycrystalline solar cells. The device parameters of this cell are also discussed in this article.

  • Record Efficiency for thin film polycrystalline solar cells up to 22 9 achieved by cs treated cu in ga se s 2
    IEEE Journal of Photovoltaics, 2019
    Co-Authors: Takuya Kato, Yoshiaki Hirai, Hiroki Sugimoto, Veronica Bermudez
    Abstract:

    An Efficiency of 22.9% for 1-cm2-sized Cu(In,Ga)(Se,S)2 solar cells has been independently verified, establishing a Record device Efficiency for thin-film polycrystalline solar cells. The main improvement in the solar cell device is due to a reduction in the deficit of the open-circuit voltage ( V oc), which is notably suppressed by modifying the absorber formation. This is presumably due to reduced defect density, as suggested by the enhanced photoluminescence performance. Such improvement in the absorber quality allowed for an opportunity to benefit from the effects of a wider absorber bandgap. The reverse saturation current density and V oc were significantly improved. Meanwhile, heavier alkali treatment on the absorber surface using cesium was adopted to further boost the device performance. As a result, the significant enhancements in V oc and fill factor led to the achievement of this Record-breaking Efficiency. These findings have been systematically reproduced and will be leveraged to improve the module performance of Solar Frontier's production in the near future.

  • new world Record cu in ga se s 2 thin film solar cell Efficiency beyond 22
    Photovoltaic Specialists Conference, 2016
    Co-Authors: Rui Kamada, Takuya Kato, Takeshi Yagioka, Shunsuke Adachi, Atsushi Handa, Hiroki Sugimoto
    Abstract:

    World Record Efficiency of 22.3% Cu(In, Ga)(Se, S) 2 (CIGS) thin film solar cell has been achieved in Solar Frontier K.K. and certified independently by Fraunhofer Institute fur Solare Energiesysteme (ISE). The device parameters are as follows, J SC : 39.4 mA cm−2, V OC : 721.9 mV and FF: 0.782. Compared to our previous champion with 20.9% Efficiency, a major improvement in V OC (+36.1 mV) was observed due to KF post deposition treatment that improve the absorber layer and the use of CdS buffer. As we thrive to achieve the utmost ecological advantages, Cd-free buffer was also developed by replacing the ZnO/CdS buffer with optimized (Zn, Mg)O/Zn(O, S, OH) buffer layers. As a result, an in-house conversion Efficiency of 22.8% was achieved. This demonstrated that Cd-free CIGS solar cell still possesses huge potential and we will continue to explore new pathways to achieve higher Efficiency CIGS solar cells.

  • new world Record Efficiency for pure sulfide cu in ga s 2 thin film solar cell with cd free buffer layer via kcn free process
    IEEE Journal of Photovoltaics, 2016
    Co-Authors: Homare Hiroi, Hiroki Sugimoto, Shunsuke Adachi, Yasuaki Iwata, Akira Yamada
    Abstract:

    World-Record conversion Efficiency of 15.5%, which is a number independently certified by an external accredited laboratory, was achieved on a pure-sulfide Cu(In,Ga)S2 (CIGS) thin-film solar cell fabricated by metal sputtering and H2S gas sulfurization. This is the highest conversion Efficiency reported for pure-sulfide CIGS thin-film solar cells. We exceeded the limit of 15% Efficiency thanks to the buffer layer optimization. The buffer layer consists of Cd-free materials, and the absorber was fabricated via a KCN-free process.