Veröffentlichungen
2018 |
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M. Schnabel, M. Rienäcker, E. L. Warren, J. F. Geisz, R. Peibst, P. Stradins, and A. C. Tamboli Equivalent Performance in Three-Terminal and Four-Terminal Tandem Solar Cells Artikel IEEE Journal of Photovoltaics 8 (6), 1584-1589, (2018), ISSN: 2156-3381. Abstract | Links | BibTeX | Schlagwörter: Absorption, Computer architecture, Current measurement, Density measurement, III-V semiconductor materials, Microprocessors, Photovoltaic cells, Power system measurements, silicon @article{Schnabel2018b,
title = {Equivalent Performance in Three-Terminal and Four-Terminal Tandem Solar Cells}, author = {M Schnabel and M Rienäcker and E L Warren and J F Geisz and R Peibst and P Stradins and A C Tamboli}, doi = {10.1109/JPHOTOV.2018.2865175}, issn = {2156-3381}, year = {2018}, date = {2018-11-01}, journal = {IEEE Journal of Photovoltaics}, volume = {8}, number = {6}, pages = {1584-1589}, abstract = {Tandem or multijunction solar cells are a promising method to circumvent the efficiency limit of single-junction solar cells, but there is ongoing debate over how best to interconnect the subcells in a tandem cell. In addition to four-terminal and two-terminal tandem cell architectures, a new three-terminal tandem cell architecture has recently been demonstrated, which features a standard two-terminal (front-back) circuit as well as an interdigitated back contact (IBC) circuit connected to the bottom cell. It has no middle contacts, and thus, maintains some of the simplicity of a two-terminal tandem. In this study, we measure four-terminal GaInP//Si and GaInP/GaAs//Si tandem cells in four-terminal and three-terminal configurations by connecting wires to mimic a three-terminal architecture. We demonstrate that both modes allow the same efficiencies exceeding 30% to be attained. Furthermore, we show that the IBC circuit not only collects excess power from the bottom cell, but that it can inject power into the bottom cell if it is current limiting the front-back circuit, enabling four-terminal performance in monolithic structures, regardless of which cell delivers less current.}, keywords = {Absorption, Computer architecture, Current measurement, Density measurement, III-V semiconductor materials, Microprocessors, Photovoltaic cells, Power system measurements, silicon}, pubstate = {published}, tppubtype = {article} } Tandem or multijunction solar cells are a promising method to circumvent the efficiency limit of single-junction solar cells, but there is ongoing debate over how best to interconnect the subcells in a tandem cell. In addition to four-terminal and two-terminal tandem cell architectures, a new three-terminal tandem cell architecture has recently been demonstrated, which features a standard two-terminal (front-back) circuit as well as an interdigitated back contact (IBC) circuit connected to the bottom cell. It has no middle contacts, and thus, maintains some of the simplicity of a two-terminal tandem. In this study, we measure four-terminal GaInP//Si and GaInP/GaAs//Si tandem cells in four-terminal and three-terminal configurations by connecting wires to mimic a three-terminal architecture. We demonstrate that both modes allow the same efficiencies exceeding 30% to be attained. Furthermore, we show that the IBC circuit not only collects excess power from the bottom cell, but that it can inject power into the bottom cell if it is current limiting the front-back circuit, enabling four-terminal performance in monolithic structures, regardless of which cell delivers less current.
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F. Haase, S. Schäfer, C. Klamt, F. Kiefer, J. Krügener, R. Brendel, and R. Peibst IEEE Journal of Photovoltaics 8 (1), 23-29, (2018), ISSN: 2156-3381. Abstract | Links | BibTeX | Schlagwörter: Area measurement, charge carrier lifetime, Charge carrier lifetime analysis, Current measurement, Density measurement, Lighting, passivating contacts, perimeter recombination, Photovoltaic cells, Radiative recombination @article{Haase2018,
title = {Perimeter Recombination in 25%-Efficient IBC Solar Cells With Passivating POLO Contacts for Both Polarities}, author = {F Haase and S Schäfer and C Klamt and F Kiefer and J Krügener and R Brendel and R Peibst}, doi = {10.1109/JPHOTOV.2017.2762592}, issn = {2156-3381}, year = {2018}, date = {2018-01-01}, journal = {IEEE Journal of Photovoltaics}, volume = {8}, number = {1}, pages = {23-29}, abstract = {We introduce a method for the quantification of perimeter recombination in solar cells based on infrared lifetime measurements. We apply this method at a 25.0%-efficient interdigitated back contact (IBC) silicon solar cell with passivating contacts. The implied pseudo-efficiency determined by infrared lifetime mapping is 26.2% at an intermediate process step. The 1.2%abs loss is attributed to a process-related reduction in surface passivation quality, recombination in the perimeter area, and series resistance. The 2 × 2 cm2 -sized cell is processed on a 100 mm wafer. We determine the implied pseudo-efficiency with illuminated and with shaded perimeter area during infrared lifetime mapping. The difference between both implied pseudo-efficiencies yields the efficiency loss by perimeter recombination, which is determined to be 0.4%abs for a wafer resistivity of 1.3 Ω cm and even 0.9%abs for a wafer resistivity of 80 Ω cm.}, keywords = {Area measurement, charge carrier lifetime, Charge carrier lifetime analysis, Current measurement, Density measurement, Lighting, passivating contacts, perimeter recombination, Photovoltaic cells, Radiative recombination}, pubstate = {published}, tppubtype = {article} } We introduce a method for the quantification of perimeter recombination in solar cells based on infrared lifetime measurements. We apply this method at a 25.0%-efficient interdigitated back contact (IBC) silicon solar cell with passivating contacts. The implied pseudo-efficiency determined by infrared lifetime mapping is 26.2% at an intermediate process step. The 1.2%abs loss is attributed to a process-related reduction in surface passivation quality, recombination in the perimeter area, and series resistance. The 2 × 2 cm2 -sized cell is processed on a 100 mm wafer. We determine the implied pseudo-efficiency with illuminated and with shaded perimeter area during infrared lifetime mapping. The difference between both implied pseudo-efficiencies yields the efficiency loss by perimeter recombination, which is determined to be 0.4%abs for a wafer resistivity of 1.3 Ω cm and even 0.9%abs for a wafer resistivity of 80 Ω cm.
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2017 |
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C. N. Kruse, M. Wolf, C. Schinke, D. Hinken, R. Brendel, and K. Bothe IEEE Journal of Photovoltaics 7 (3), 747-754, (2017), ISSN: 2156-3381. Abstract | Links | BibTeX | Schlagwörter: Analytical models, Bars, Characterization of photovoltaics (PV), Current measurement, current–voltage characteristics, Electric potential, IEC standards, Numerical models, Photovoltaic cells, Probes @article{Kruse2017b,
title = {Impact of Contacting Geometries When Measuring Fill Factors of Solar Cell Current-Voltage Characteristics}, author = {C N Kruse and M Wolf and C Schinke and D Hinken and R Brendel and K Bothe}, doi = {10.1109/JPHOTOV.2017.2677084}, issn = {2156-3381}, year = {2017}, date = {2017-05-01}, journal = {IEEE Journal of Photovoltaics}, volume = {7}, number = {3}, pages = {747-754}, abstract = {We analyze the influence of a variety of different contacting geometries on the fill factor (FF) of solar cell I-V measurements. For this analysis, we compare a wide variety of modeled and measured FFs of Si solar cells. We consistently find large FF differences between individual contacting geometries. These differences amount to up to 3%abs for high busbar resistivities of up to 40 Ω/m. We analyze the contacting geometries for their sensitivity on uncontrolled variations of the contacting resistances. In this analysis, we find that using triplet rather than tandem configurations and using a larger number of test probes reduces the impact of varying contacting resistances to below 0.02%abs. We propose a contacting geometry that we consider to be suitable for calibrated I-V measurements. This contacting scheme is a configuration with a total of five triplets consisting of two current probes and one sense probe. The sense probe is positioned to measure the average busbar potential between the current probes. This is the optimal contacting geometry in terms of a low sensitivity to the busbar resistivity and variations of contacting resistances. In addition, this geometry does not impose unnecessarily large mechanical stress to the cell under measurement.}, keywords = {Analytical models, Bars, Characterization of photovoltaics (PV), Current measurement, current–voltage characteristics, Electric potential, IEC standards, Numerical models, Photovoltaic cells, Probes}, pubstate = {published}, tppubtype = {article} } We analyze the influence of a variety of different contacting geometries on the fill factor (FF) of solar cell I-V measurements. For this analysis, we compare a wide variety of modeled and measured FFs of Si solar cells. We consistently find large FF differences between individual contacting geometries. These differences amount to up to 3%abs for high busbar resistivities of up to 40 Ω/m. We analyze the contacting geometries for their sensitivity on uncontrolled variations of the contacting resistances. In this analysis, we find that using triplet rather than tandem configurations and using a larger number of test probes reduces the impact of varying contacting resistances to below 0.02%abs. We propose a contacting geometry that we consider to be suitable for calibrated I-V measurements. This contacting scheme is a configuration with a total of five triplets consisting of two current probes and one sense probe. The sense probe is positioned to measure the average busbar potential between the current probes. This is the optimal contacting geometry in terms of a low sensitivity to the busbar resistivity and variations of contacting resistances. In addition, this geometry does not impose unnecessarily large mechanical stress to the cell under measurement.
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H. Schulte-Huxel, R. Witteck, H. Holst, M. R. Vogt, S. Blankemeyer, D. Hinken, T. Brendemühl, T. Dullweber, K. Bothe, M. Köntges, and R. Brendel IEEE Journal of Photovoltaics 7 (1), 25-31, (2017), ISSN: 2156-3381. Abstract | Links | BibTeX | Schlagwörter: cell interconnection, Current measurement, loss analysis, Optical interconnections, Optical losses, passivated emitter and rear cell (PERC), photovoltaic (PV) module, Photovoltaic cells, Photovoltaic systems, ray tracing, Resistance, Silicon solar cell, Standards @article{Schulte-Huxel2016,
title = {High-efficiency modules with passivated emitter and rear solar cells an analysis of electrical and optical losses*}, author = {H Schulte-Huxel and R Witteck and H Holst and M R Vogt and S Blankemeyer and D Hinken and T Brendemühl and T Dullweber and K Bothe and M Köntges and R Brendel}, doi = {10.1109/JPHOTOV.2016.2614121}, issn = {2156-3381}, year = {2017}, date = {2017-01-01}, journal = {IEEE Journal of Photovoltaics}, volume = {7}, number = {1}, pages = {25-31}, abstract = {We process a photovoltaic (PV) module with 120 half passivated emitter and rear cells that exhibits an independently confirmed power of 303.2 W and a module efficiency of 20.2% (aperture area). The cells are optimized for operation within the module. We enhance light harvesting from the inactive spacing between the cells and the cell interconnect ribbons. Additionally, we reduce the inactive area to below 3% of the aperture module area. The impact of these measures is analyzed by ray-tracing simulations of the module. Using a numerical model, we analyze and predict the module performance based on the individual cell measurements and the optical simulations. We determine the power loss due to series interconnection of the solar cells to be 1.5%. This is compensated by a gain in current of 1.8% caused by the change of the optical environment of the cells in the module. We achieve a good agreement between simulations and experiments, both showing no cell-to-module power loss.}, keywords = {cell interconnection, Current measurement, loss analysis, Optical interconnections, Optical losses, passivated emitter and rear cell (PERC), photovoltaic (PV) module, Photovoltaic cells, Photovoltaic systems, ray tracing, Resistance, Silicon solar cell, Standards}, pubstate = {published}, tppubtype = {article} } We process a photovoltaic (PV) module with 120 half passivated emitter and rear cells that exhibits an independently confirmed power of 303.2 W and a module efficiency of 20.2% (aperture area). The cells are optimized for operation within the module. We enhance light harvesting from the inactive spacing between the cells and the cell interconnect ribbons. Additionally, we reduce the inactive area to below 3% of the aperture module area. The impact of these measures is analyzed by ray-tracing simulations of the module. Using a numerical model, we analyze and predict the module performance based on the individual cell measurements and the optical simulations. We determine the power loss due to series interconnection of the solar cells to be 1.5%. This is compensated by a gain in current of 1.8% caused by the change of the optical environment of the cells in the module. We achieve a good agreement between simulations and experiments, both showing no cell-to-module power loss.
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2015 |
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S. Essig, J. F. Geisz, M. A. Steiner, A. Merkle, R. Peibst, J. Schmidt, R. Brendel, S. Ward, D. J. Friedman, P. Stradins, and D. L. Young Development of highly-efficient GaInP/Si Tandem Solar Cells Inproceedings IEEE (Hrsg.): 2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC), New Orleans, LA, USA, (2015), ISBN: 978-1-4799-7944-8. Links | BibTeX | Schlagwörter: Current measurement, Gain measurement, III–V semiconductor materials, Indexes, Multijunction solar cells, Performance evaluation, Photonics, silicon @inproceedings{Essig2015,
title = {Development of highly-efficient GaInP/Si Tandem Solar Cells}, author = {S Essig and J F Geisz and M A Steiner and A Merkle and R Peibst and J Schmidt and R Brendel and S Ward and D J Friedman and P Stradins and D L Young}, editor = {IEEE}, doi = {10.1109/PVSC.2015.7355602}, isbn = {978-1-4799-7944-8}, year = {2015}, date = {2015-06-14}, booktitle = {2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC)}, journal = {Proceedings of the 42nd IEEE Photovoltaic Specialists Conference}, address = {New Orleans, LA, USA}, keywords = {Current measurement, Gain measurement, III–V semiconductor materials, Indexes, Multijunction solar cells, Performance evaluation, Photonics, silicon}, pubstate = {published}, tppubtype = {inproceedings} } |
2012 |
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C. Schinke, F. Kiefer, M. Offer, D. Hinken, A. Schmidt, N. P. Harder, R. Bock, T. Brendemühl, J. Schmidt, K. Bothe, and R. Brendel IEEE Journal of Photovoltaics 2 (3), 247-255, (2012). Links | BibTeX | Schlagwörter: Current measurement, current–voltage characteristics, Electrical resistance measurement, Fill Factor, Integrated circuit modeling, interdigitated back-contact (IBC) solar cell, Photovoltaic cells, Pins, Resistance, Voltage measurement @article{Schinke2012,
title = {Contacting interdigitated back-contact solar cells with four busbars for precise current-voltage measurements under standard testing conditions}, author = {C Schinke and F Kiefer and M Offer and D Hinken and A Schmidt and N P Harder and R Bock and T Brendemühl and J Schmidt and K Bothe and R Brendel}, doi = {10.1109/JPHOTOV.2012.2195637}, year = {2012}, date = {2012-07-01}, journal = {IEEE Journal of Photovoltaics}, volume = {2}, number = {3}, pages = {247-255}, keywords = {Current measurement, current–voltage characteristics, Electrical resistance measurement, Fill Factor, Integrated circuit modeling, interdigitated back-contact (IBC) solar cell, Photovoltaic cells, Pins, Resistance, Voltage measurement}, pubstate = {published}, tppubtype = {article} } |
2011 |
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O. Breitenstein, J. Bauer, K. Bothe, D. Hinken, J. Müller, W. Kwapil, M. C. Schubert, and W. Warta Can Luminescence Imaging Replace Lock-in Thermography on Solar Cells? Artikel IEEE Journal of Photovoltaics 1 (2), 159-167, (2011), ISSN: 2156-3381. Links | BibTeX | Schlagwörter: Current measurement, Electroluminescence, infrared imaging, Lock-in thermography, luminescence, photoluminescence, Photovoltaic cells, Resistance, Spatial resolution, thermal analysis @article{Breitenstein2011,
title = {Can Luminescence Imaging Replace Lock-in Thermography on Solar Cells?}, author = {O Breitenstein and J Bauer and K Bothe and D Hinken and J Müller and W Kwapil and M C Schubert and W Warta}, doi = {10.1109/JPHOTOV.2011.2169394}, issn = {2156-3381}, year = {2011}, date = {2011-10-01}, journal = {IEEE Journal of Photovoltaics}, volume = {1}, number = {2}, pages = {159-167}, keywords = {Current measurement, Electroluminescence, infrared imaging, Lock-in thermography, luminescence, photoluminescence, Photovoltaic cells, Resistance, Spatial resolution, thermal analysis}, pubstate = {published}, tppubtype = {article} } |
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N. Mingirulli, J. Haschke, R. Gogolin, R. Ferré, T. F. Schulze, J. Düsterhöft, N. P. Harder, and L. Korte Interdigitated back-contacted silicon heterojunction solar cells with improved fill-factor and efficiency Inproceedings IEEE (Hrsg.): 2011 37th IEEE Photovoltaic Specialists Conference, 003338, Seattle, WA, USA, (2011), ISSN: 0160-8371. Links | BibTeX | Schlagwörter: Amorphous silicon, Buffer layers, Computer architecture, Current measurement, heterojunctions, Microprocessors, Photovoltaic cells @inproceedings{Mingirulli2011b,
title = {Interdigitated back-contacted silicon heterojunction solar cells with improved fill-factor and efficiency}, author = {N Mingirulli and J Haschke and R Gogolin and R Ferré and T F Schulze and J Düsterhöft and N P Harder and L Korte}, editor = {IEEE}, doi = {10.1109/PVSC.2011.6186658}, issn = {0160-8371}, year = {2011}, date = {2011-06-01}, booktitle = {2011 37th IEEE Photovoltaic Specialists Conference}, pages = {003338}, address = {Seattle, WA, USA}, keywords = {Amorphous silicon, Buffer layers, Computer architecture, Current measurement, heterojunctions, Microprocessors, Photovoltaic cells}, pubstate = {published}, tppubtype = {inproceedings} } |
2010 |
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D. Hinken, A. Milsted, R. Bock, B. Fischer, K. Bothe, M. Schutze, J. Isenberg, A. Schulze, and M. Wagner Determination of the Base-Dopant Concentration of Large-Area Crystalline Silicon Solar Cells Artikel IEEE Transactions on Electron Devices 57 (11), 2831-2837, (2010), ISSN: 0018-9383. Links | BibTeX | Schlagwörter: Capacitance, Capacitance–voltage characteristics, Current measurement, Junctions, Photovoltaic cells, silicon, Surface texture, Surface treatment @article{Hinken2010,
title = {Determination of the Base-Dopant Concentration of Large-Area Crystalline Silicon Solar Cells}, author = {D Hinken and A Milsted and R Bock and B Fischer and K Bothe and M Schutze and J Isenberg and A Schulze and M Wagner}, doi = {10.1109/TED.2010.2064777}, issn = {0018-9383}, year = {2010}, date = {2010-11-01}, journal = {IEEE Transactions on Electron Devices}, volume = {57}, number = {11}, pages = {2831-2837}, keywords = {Capacitance, Capacitance–voltage characteristics, Current measurement, Junctions, Photovoltaic cells, silicon, Surface texture, Surface treatment}, pubstate = {published}, tppubtype = {article} } |