The Experts below are selected from a list of 14049 Experts worldwide ranked by ideXlab platform
Kensuke Nishioka - One of the best experts on this subject based on the ideXlab platform.
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Simulation of Temperature Characteristics of InGaP/InGaAs/Ge Triple-Junction Solar Cell under Concentrated Light
Japanese Journal of Applied Physics, 2011Co-Authors: Yuya Sakurada, Yasuyuki Ota, Kensuke NishiokaAbstract:Using an equivalent circuit model, the temperature characteristics of an InGaP/InGaAs/Ge triple-Junction Solar Cell under concentrated light conditions were analyzed in detail. The current–voltage (I–V) characteristics of the single-Junction Solar Cells (InGaP, InGaAs, and Ge Solar Cells) were measured at various temperatures. From the dark I–V characteristics of each single-Junction Solar Cell, the diode parameters and temperature exponents were extracted. The extracted diode parameters and temperature exponents were applied to the equivalent circuit model for the triple-Junction Solar Cell, and the Solar-Cell performance was calculated. There was good agreement between the measured and calculated I–V characteristics of the triple-Junction Solar Cell at various temperatures under concentrated light conditions.
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Temperature Characteristics Analysis of Triple‐Junction Solar Cell under Concentrated Conditions using Spice Diode Model
2011Co-Authors: Yuya Sakurada, Yasuyuki Ota, Kensuke NishiokaAbstract:Using spice diode model, the temperature characteristics of an InGaP/InGaAs/Ge triple‐Junction Solar Cell under concentrated light conditions were analyzed in detail. The current‐voltage (I‐V) characteristics of the single‐Junction Solar Cells (InGaP, InGaAs, and Ge Solar Cells) were measured at various temperatures. From dark I‐V characteristics of each single‐Junction Solar Cell, the diode parameters and temperature exponents were extracted. The extracted diode parameters and temperature exponents were applied to the equivalent circuit model for the triple‐Junction Solar Cell, and the Solar Cell performance was calculated with considering the temperature characteristics of series resistance. There was good agreement between the measured and calculated I‐V characteristics of the triple‐Junction Solar Cell at various temperatures under concentrated light conditions.
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detailed analysis of temperature characteristics of an ingap ingaas ge triple Junction Solar Cell
Journal of Electronic Materials, 2010Co-Authors: Kensuke Nishioka, Tsuyoshi Sueto, Masaki Uchida, Yasuyuki OtaAbstract:Temperature characteristics of an InGaP/InGaAs/Ge triple-Junction Solar Cell were analyzed in detail using an equivalent circuit calculation. The current–voltage (I–V) characteristics of single-Junction Solar Cells (InGaP, InGaAs, Ge Solar Cells) were measured at various temperatures. Fitting of I–V curves between measured and calculated data was carried out, and the diode parameters and temperature exponents of the single-Junction Solar Cells were extracted. The parameters for each single-Junction Solar Cell were used in the equivalent circuit model for the triple-Junction Solar Cell, and calculations of Solar Cell performance were carried out. Measured and calculated results of the I–V characteristics at various temperatures agreed well.
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Detailed Analysis of Temperature Characteristics of an InGaP/InGaAs/Ge Triple-Junction Solar Cell
Journal of Electronic Materials, 2010Co-Authors: Kensuke Nishioka, Tsuyoshi Sueto, Masaki Uchida, Yasuyuki OtaAbstract:Temperature characteristics of an InGaP/InGaAs/Ge triple-Junction Solar Cell were analyzed in detail using an equivalent circuit calculation. The current–voltage (I–V) characteristics of single-Junction Solar Cells (InGaP, InGaAs, Ge Solar Cells) were measured at various temperatures. Fitting of I–V curves between measured and calculated data was carried out, and the diode parameters and temperature exponents of the single-Junction Solar Cells were extracted. The parameters for each single-Junction Solar Cell were used in the equivalent circuit model for the triple-Junction Solar Cell, and calculations of Solar Cell performance were carried out. Measured and calculated results of the I–V characteristics at various temperatures agreed well.
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evaluation of ingap ingaas ge triple Junction Solar Cell and optimization of Solar Cell s structure focusing on series resistance for high efficiency concentrator photovoltaic systems
Solar Energy Materials and Solar Cells, 2006Co-Authors: Kensuke Nishioka, Tatsuya Takamoto, Takaaki Agui, M Kaneiwa, Yukiharu Uraoka, Takashi FuyukiAbstract:The series resistance of an InGaP/InGaAs/Ge triple-Junction Solar Cell was evaluated in detail. Series resistance components such as electrode resistance, tunnel Junction resistance and lateral resistance between electrodes were estimated separately. The characteristics of the triple-Junction Solar Cell under concentrated light were evaluated by equivalent circuit calculation with a simulation program with integrated circuit emphasis (SPICE). By equivalent circuit calculation, the optimization of Cell designs was performed, focusing on series resistance and Cell current in order to realize high-efficiency concentrator Cells.
A W Bett - One of the best experts on this subject based on the ideXlab platform.
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Next Generation of Wafer-Bonded Multi-Junction Solar Cells
2014Co-Authors: A W Bett, Gerald Siefer, A Wekkeli, E Oliva, Michael Schachtner, D. Lackner, D. Reinwand, P. Fuss-kailuweit, F. Predan, Frank DimrothAbstract:The highest conversion efficiencies are reached by multi-Junction III-V Solar Cells. Wafer-bonding offers new possibilities to advance beyond the industrial standard triple-Junction Cells and its efficiency limitations. Here we present for the first time results of two novel 4-Junction device concepts based on direct wafer-bonding with a realistic efficiency potential of 50% under concentrated sunlight. In the first concept, an inverted grown GaInP/GaAs tandem Cell is bonded to a metamorphic GaInAs/Ge tandem Cell. Frist bonded 4-Junction Solar Cell on Ge shows an efficiency of 34.5% under one sun AM1.5d. In the latter concept a GaSb Cell will be bonded to an inverted metamorphic triple-Junction Solar Cell. The main challenge in this approach is a conductive direct wafer bond between the two Cell stacks. Here, bond characteristics between GaSb and Ga0.29In0.71P and another between GaSb and Ga0.79In0.21As are shown for the first time.
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current matched triple Junction Solar Cell reaching 41 1 conversion efficiency under concentrated sunlight
Applied Physics Letters, 2009Co-Authors: Wolfgang Guter, Marc Steiner, Gerald Siefer, S.p. Philipps, J Schone, A Wekkeli, E Welser, E Oliva, A W Bett, Frank DimrothAbstract:A metamorphic Ga0.35In0.65P/Ga0.83In0.17As/Ge triple-Junction Solar Cell is shown to provide current-matching of all three subCells and thus composes a device structure with virtually ideal band gap combination. We demonstrate that the key for the realization of this device is the improvement of material quality of the lattice-mismatched layers as well as the development of a highly relaxed Ga1−yInyAs buffer structure between the Ge substrate and the middle Cell. This allows the metamorphic growth with low dislocation densities below 106 cm−2. The performance of the approach has been demonstrated by a conversion efficiency of 41.1% at 454 suns (454 kW/m2, AM1.5d ASTM G173–03).
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numerical simulation of tunnel diodes and multi Junction Solar Cells
Photovoltaic Specialists Conference, 2008Co-Authors: Martin Hermle, S.p. Philipps, Gergö Letay, A W BettAbstract:In order to connect individual subCells in monolithically grown multi-Junction Solar Cells Esaki interband tunnel diodes are widely used. In this work, numerical simulations of an isolated III–V Esaki tunnel diode and of a dual-Junction Solar Cell are presented. With a tunnel model, which takes into account the full non-locality of the tunneling process, a good agreement between measured and simulated IV curve of a GaAs tunnel diode could be achieved. Using this model, the EQE and the IV curve of a complete dual-Junction Solar Cell including tunnel diode was simulated. The model is applied to calculate the current-matching condition of the dual-Junction Cell.
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internal voltages in gainp gainas ge multiJunction Solar Cells determined by electroluminescence measurements
Applied Physics Letters, 2008Co-Authors: Thomas Kirchartz, Martin Hermle, A W Bett, Uwe Rau, Anke Helbig, J H WernerAbstract:We analyze electroluminescence spectra of a GaInP∕GaInAs∕Ge triple-Junction Solar Cell at different injection currents. Using the reciprocity theorem between electroluminescent emission and external quantum efficiency of Solar Cells allows us to derive the current/voltage curves and the diode quality factors of all individual subCells.
Frank Dimroth - One of the best experts on this subject based on the ideXlab platform.
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CPV module design optimization for advanced multi-Junction Solar Cell concepts
2015Co-Authors: Marc Steiner, Peter Kiefel, Gerald Siefer, Maike Wiesenfarth, Frank Dimroth, Rainer Krause, Andreas Gombert, Andreas W. BettAbstract:A network model for multi-Junction Solar Cells has been combined with ray tracing and finite element simulations of a Fresnel lens in order to interpret experimentally derived measurement results. This combined model reveals a good agreement between simulation and measurement for advanced four-Junction Solar Cells under a Fresnel lens when the Cell-to-lens distance was varied. Thus, the effect of fill factor drop caused by distributed series resistance losses due to chromatic aberration is well described by this model. Eventually, this model is used to calculate I-V characteristics of a four-Junction Cell, as well as of a upright metamorphic and lattice-matched triple-Junction Solar Cell under the illumination profile of a Fresnel lens. A significant fill factor drop at distinct Cell-to-lens distances was found for all three investigated Solar Cell types. In this work we discuss how this fill factor drop can be avoided. It is shown that already a halving of the sheet resistance within one of the lateral c...
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Next Generation of Wafer-Bonded Multi-Junction Solar Cells
2014Co-Authors: A W Bett, Gerald Siefer, A Wekkeli, E Oliva, Michael Schachtner, D. Lackner, D. Reinwand, P. Fuss-kailuweit, F. Predan, Frank DimrothAbstract:The highest conversion efficiencies are reached by multi-Junction III-V Solar Cells. Wafer-bonding offers new possibilities to advance beyond the industrial standard triple-Junction Cells and its efficiency limitations. Here we present for the first time results of two novel 4-Junction device concepts based on direct wafer-bonding with a realistic efficiency potential of 50% under concentrated sunlight. In the first concept, an inverted grown GaInP/GaAs tandem Cell is bonded to a metamorphic GaInAs/Ge tandem Cell. Frist bonded 4-Junction Solar Cell on Ge shows an efficiency of 34.5% under one sun AM1.5d. In the latter concept a GaSb Cell will be bonded to an inverted metamorphic triple-Junction Solar Cell. The main challenge in this approach is a conductive direct wafer bond between the two Cell stacks. Here, bond characteristics between GaSb and Ga0.29In0.71P and another between GaSb and Ga0.79In0.21As are shown for the first time.
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Temperature Dependent Electroluminescence and Voltages of Multi-Junction Solar Cells
2013Co-Authors: Andreas W. Bett, Frank Dimroth, Michael Schachtner, Henning Helmers, Christian KarcherAbstract:Christian Karcher, Henning Helmers, Michael Schachtner, Frank Dimroth and Andreas W. Bett Fraunhofer Institute for Solar Energy Systems ISE Heidenhofstr. 2, 79110 Freiburg, Germany Telephone: +49(0)761/4588-5073, Fax: +49(0)761/4588 9250, Email: christian.karcher@ise.fraunhofer.de ABSTRACT: The spectral electroluminescene (EL) of a monolithic triple-Junction Solar Cell reveals the sub Cell open circuit voltages under variation of temperature and carrier concentration. We present an EL-setup which is able to acquire a full spectrum in less than 10 seconds and give insight into the voltage-extraction process. The sum of the sub Cell voltages is in exCellent agreement to open circuit voltages acquired under concentrated illumination. The temperature induced voltage losses are investigated and explained by a bandgap dependent increase in intrinsic carrier concentration. Finally, the accurate extraction of the sub Cell bandgaps helps to identify a temperature rise with increasing current density. Keywords: III-V Semiconductors, MultiJunction Solar Cell, Electroluminescence, Characterisation, Concentrator Cells 1 INTRODUCTION Multi-Junction Solar Cell devices comprising III-V compound semiconductors are nowadays widely applied as photovoltaic converters. These converters are used terrestrially in concentrator systems to maximize their power-to-cost ratio. Additionally, extraterrestrial applications are of great importance. Here highly efficient Solar Cells are required. Both fields of application span a broad range of operation parameters such as a variance in temperature and irradiance conditions. In order to tap the full potential of these Cells with regard to current matching and power extraction under different conditions of operation, a full set of parameters under temperature and irradiance variation is of great interest. In this paper we present a sophisticated study of a triple-Junction Solar Cell typically applied in state-of-the-art concentrator systems. In particular, this structure is a lattice-matched triple-Junction Solar Cell (tripLM) made of Ga
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Promises of advanced multi-Junction Solar Cells for the use in CPV systems
2010 35th IEEE Photovoltaic Specialists Conference, 2010Co-Authors: Frank Dimroth, Marc Steiner, S.p. Philipps, E Welser, E Oliva, Gerhard Peharz, Rene Kellenbenz, Tobias Roesener, V. Klinger, Matthias MeuselAbstract:III–V multi-Junction concentrator Solar Cells today are optimized for maximum conversion efficiency under AM1.5d standard test conditions at 25 °C Cell temperature. But, a higher efficiency for a multi-Junction Solar Cell under these artificial conditions does not necessarily lead to more energy generation in a real photovoltaic concentrator system. The variation of the spectrum during the day and year is crucial to the amount of energy which can be produced. In this paper we calculate the energy which can be harvested on the basis of more than 4000 realistic spectra generated for each daytime hour of the year. Calculations are performed for three typical CPV locations in Colorado, Spain and Israel. A detailed balance approach is used to predict the energy harvesting efficiency for each bandgap combination in a specific multi-Junction Solar Cell. It turns out that all advanced concepts have advantages compared to the state-of-the-art Ga 0.5 In 0.5 P/Ga 0.99 In 0.01 As/Ge triple-Junction Solar Cell used today. For example, a monolithic 4-Junction device with an ideal combination of bandgap energies could boost the power generation of a CPV system by up to 19 %. Material availability, quality and manufacturing complexity will finally determine the most successful approaches for achieving optimum performance.
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current matched triple Junction Solar Cell reaching 41 1 conversion efficiency under concentrated sunlight
Applied Physics Letters, 2009Co-Authors: Wolfgang Guter, Marc Steiner, Gerald Siefer, S.p. Philipps, J Schone, A Wekkeli, E Welser, E Oliva, A W Bett, Frank DimrothAbstract:A metamorphic Ga0.35In0.65P/Ga0.83In0.17As/Ge triple-Junction Solar Cell is shown to provide current-matching of all three subCells and thus composes a device structure with virtually ideal band gap combination. We demonstrate that the key for the realization of this device is the improvement of material quality of the lattice-mismatched layers as well as the development of a highly relaxed Ga1−yInyAs buffer structure between the Ge substrate and the middle Cell. This allows the metamorphic growth with low dislocation densities below 106 cm−2. The performance of the approach has been demonstrated by a conversion efficiency of 41.1% at 454 suns (454 kW/m2, AM1.5d ASTM G173–03).
Takashi Fuyuki - One of the best experts on this subject based on the ideXlab platform.
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evaluation of ingap ingaas ge triple Junction Solar Cell and optimization of Solar Cell s structure focusing on series resistance for high efficiency concentrator photovoltaic systems
Solar Energy Materials and Solar Cells, 2006Co-Authors: Kensuke Nishioka, Tatsuya Takamoto, Takaaki Agui, M Kaneiwa, Yukiharu Uraoka, Takashi FuyukiAbstract:The series resistance of an InGaP/InGaAs/Ge triple-Junction Solar Cell was evaluated in detail. Series resistance components such as electrode resistance, tunnel Junction resistance and lateral resistance between electrodes were estimated separately. The characteristics of the triple-Junction Solar Cell under concentrated light were evaluated by equivalent circuit calculation with a simulation program with integrated circuit emphasis (SPICE). By equivalent circuit calculation, the optimization of Cell designs was performed, focusing on series resistance and Cell current in order to realize high-efficiency concentrator Cells.
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evaluation of ingap ingaas ge triple Junction Solar Cell and optimization of Solar Cell s structure focusing on series resistance for high efficiency concentrator photovoltaic systems
Solar Energy Materials and Solar Cells, 2006Co-Authors: Kensuke Nishioka, Tatsuya Takamoto, Takaaki Agui, M Kaneiwa, Yukiharu Uraoka, Takashi FuyukiAbstract:The series resistance of an InGaP/InGaAs/Ge triple-Junction Solar Cell was evaluated in detail. Series resistance components such as electrode resistance, tunnel Junction resistance and lateral resistance between electrodes were estimated separately. The characteristics of the triple-Junction Solar Cell under concentrated light were evaluated by equivalent circuit calculation with a simulation program with integrated circuit emphasis (SPICE). By equivalent circuit calculation, the optimization of Cell designs was performed, focusing on series resistance and Cell current in order to realize high-efficiency concentrator Cells.
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evaluation of ingap ingaas ge triple Junction Solar Cell under concentrated light by simulation program with integrated circuit emphasis
Japanese Journal of Applied Physics, 2004Co-Authors: Kensuke Nishioka, Tatsuya Takamoto, Takaaki Agui, M Kaneiwa, Yukiharu Uraoka, Takashi FuyukiAbstract:The characteristics of a multi-Junction Solar Cell under concentrated light were evaluated by Simulation Program with Integrated Circuit Emphasis (SPICE). We developed the multi-unit model and analyzed the affects of the chromatic aberration and intensity distribution for the multi-Junction Cells. In the multi-unit model, the same numbers of units as grid numbers are installed for every electrode, and the units were connected to each other via lateral resistances. In order to obtain the generation current from each diode, we measured the intensity of concentrated light through the pinhole using single-Junction Solar Cells consisting of InGaP, GaAs and Ge as detectors. By using the multi-unit model, we could successfully calculate the electrical Cell performances taking the chromatic aberration and intensity distribution into account, and the calculated value agreed well with the experimental value. The multi-unit model will be very useful for Cell designs and performance analysis of the concentrator Cells.
Andreas W. Bett - One of the best experts on this subject based on the ideXlab platform.
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CPV module design optimization for advanced multi-Junction Solar Cell concepts
2015Co-Authors: Marc Steiner, Peter Kiefel, Gerald Siefer, Maike Wiesenfarth, Frank Dimroth, Rainer Krause, Andreas Gombert, Andreas W. BettAbstract:A network model for multi-Junction Solar Cells has been combined with ray tracing and finite element simulations of a Fresnel lens in order to interpret experimentally derived measurement results. This combined model reveals a good agreement between simulation and measurement for advanced four-Junction Solar Cells under a Fresnel lens when the Cell-to-lens distance was varied. Thus, the effect of fill factor drop caused by distributed series resistance losses due to chromatic aberration is well described by this model. Eventually, this model is used to calculate I-V characteristics of a four-Junction Cell, as well as of a upright metamorphic and lattice-matched triple-Junction Solar Cell under the illumination profile of a Fresnel lens. A significant fill factor drop at distinct Cell-to-lens distances was found for all three investigated Solar Cell types. In this work we discuss how this fill factor drop can be avoided. It is shown that already a halving of the sheet resistance within one of the lateral c...
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Temperature Dependent Electroluminescence and Voltages of Multi-Junction Solar Cells
2013Co-Authors: Andreas W. Bett, Frank Dimroth, Michael Schachtner, Henning Helmers, Christian KarcherAbstract:Christian Karcher, Henning Helmers, Michael Schachtner, Frank Dimroth and Andreas W. Bett Fraunhofer Institute for Solar Energy Systems ISE Heidenhofstr. 2, 79110 Freiburg, Germany Telephone: +49(0)761/4588-5073, Fax: +49(0)761/4588 9250, Email: christian.karcher@ise.fraunhofer.de ABSTRACT: The spectral electroluminescene (EL) of a monolithic triple-Junction Solar Cell reveals the sub Cell open circuit voltages under variation of temperature and carrier concentration. We present an EL-setup which is able to acquire a full spectrum in less than 10 seconds and give insight into the voltage-extraction process. The sum of the sub Cell voltages is in exCellent agreement to open circuit voltages acquired under concentrated illumination. The temperature induced voltage losses are investigated and explained by a bandgap dependent increase in intrinsic carrier concentration. Finally, the accurate extraction of the sub Cell bandgaps helps to identify a temperature rise with increasing current density. Keywords: III-V Semiconductors, MultiJunction Solar Cell, Electroluminescence, Characterisation, Concentrator Cells 1 INTRODUCTION Multi-Junction Solar Cell devices comprising III-V compound semiconductors are nowadays widely applied as photovoltaic converters. These converters are used terrestrially in concentrator systems to maximize their power-to-cost ratio. Additionally, extraterrestrial applications are of great importance. Here highly efficient Solar Cells are required. Both fields of application span a broad range of operation parameters such as a variance in temperature and irradiance conditions. In order to tap the full potential of these Cells with regard to current matching and power extraction under different conditions of operation, a full set of parameters under temperature and irradiance variation is of great interest. In this paper we present a sophisticated study of a triple-Junction Solar Cell typically applied in state-of-the-art concentrator systems. In particular, this structure is a lattice-matched triple-Junction Solar Cell (tripLM) made of Ga
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Calibrated numerical model of a GaInP–GaAs dual‐Junction Solar Cell
physica status solidi (RRL) - Rapid Research Letters, 2008Co-Authors: S.p. Philipps, Frank Dimroth, Martin Hermle, Gergö Letay, B. M. George, Andreas W. BettAbstract:In this letter a calibrated numerical model of a III–V dual-Junction Solar Cell including tunnel diode and Bragg reflector is presented. The quantum efficiencies of the subCells are computed by using the principle of current-limitation in monolithic multi-Junction Solar Cells. A special procedure with bias-illumination and bias-voltage was implemented. Numerical simulations are used to study the influence of the top Cell thickness on the Cells' quantum efficiency and on the current-matching condition. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
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Numerical simulation of tunnel diodes and multi-Junction Solar Cells
2008 33rd IEEE Photovolatic Specialists Conference, 2008Co-Authors: Martin Hermle, S.p. Philipps, Gergö Letay, Andreas W. BettAbstract:In order to connect individual subCells in monolithically grown multi-Junction Solar Cells Esaki interband tunnel diodes are widely used. In this work, numerical simulations of an isolated III–V Esaki tunnel diode and of a dual-Junction Solar Cell are presented. With a tunnel model, which takes into account the full non-locality of the tunneling process, a good agreement between measured and simulated IV curve of a GaAs tunnel diode could be achieved. Using this model, the EQE and the IV curve of a complete dual-Junction Solar Cell including tunnel diode was simulated. The model is applied to calculate the current-matching condition of the dual-Junction Cell.
