1.
R Brendel; C Kruse; A Merkle; R Peibst
Screening Selective Contact Material Combinations for Novel Crystalline Si Cell Structures Proceedings Article
In: WIP, (Hrsg.): Proceedings of the 35th European Photovoltaic Solar Energy Conference and Exhibition, S. 39-46, Brussels, Belgium, 2018.
@inproceedings{Brendel2018,
title = {Screening Selective Contact Material Combinations for Novel Crystalline Si Cell Structures},
author = {R Brendel and C Kruse and A Merkle and R Peibst},
editor = {WIP},
doi = {10.4229/35thEUPVSEC20182018-1AO.2.6},
year = {2018},
date = {2018-09-24},
booktitle = {Proceedings of the 35th European Photovoltaic Solar Energy Conference and Exhibition},
pages = {39-46},
address = {Brussels, Belgium},
abstract = {High efficiency crystalline Si solar cells require contacts with high carrier selectivity. This is ensured for contacts having low recombination currents as well as low contact resistances. A large variety of material systems for electron- and hole-selective contacts were measured in the literature. We screen a subset of electron- and hole-selective contacts to find promising combinations in terms of efficiency potential on the one hand and in terms of practical processes on the other hand. We use modelling of ideal Si cells with non-ideal experimental contact properties to determine the maximum efficiency and the optimized areal contact fractions for many contact combinations. Cells using a-Si and/or poly-Si contacts have the highest contact-limited efficiencies. Such cells are, however, quite different from today’s PERC technology. We therefore also look for contact combinations that have one contact type equal to the current PERC technology and identify cell structures that combine a poly-Si(n) contact with a screen-printed Al-doped contacts (PAL cells) as an attractive upgrade for the PERC technology. We also report on experimental work on building blocks for various types of PAL cells.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
High efficiency crystalline Si solar cells require contacts with high carrier selectivity. This is ensured for contacts having low recombination currents as well as low contact resistances. A large variety of material systems for electron- and hole-selective contacts were measured in the literature. We screen a subset of electron- and hole-selective contacts to find promising combinations in terms of efficiency potential on the one hand and in terms of practical processes on the other hand. We use modelling of ideal Si cells with non-ideal experimental contact properties to determine the maximum efficiency and the optimized areal contact fractions for many contact combinations. Cells using a-Si and/or poly-Si contacts have the highest contact-limited efficiencies. Such cells are, however, quite different from today’s PERC technology. We therefore also look for contact combinations that have one contact type equal to the current PERC technology and identify cell structures that combine a poly-Si(n) contact with a screen-printed Al-doped contacts (PAL cells) as an attractive upgrade for the PERC technology. We also report on experimental work on building blocks for various types of PAL cells.
2.
H Schulte-Huxel; R Witteck; H Holst; M R Vogt; S Blankemeyer; D Hinken; T Brendemühl; T Dullweber; K Bothe; M Köntges; R Brendel
In: IEEE Journal of Photovoltaics, Bd. 7, Nr. 1, S. 25-31, 2017, ISSN: 2156-3381.
@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 = {},
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.
3.
R Brendel; T Dullweber; R Peibst; C Kranz; A Merkle; D Walter
Breakdown of the efficiency gap to 29% based on experimental input data and modelling Artikel
In: Progress in Photovoltaics: Research and Applications, Bd. 24, Nr. 12, S. 1475-1486, 2016.
@article{Brendel2016c,
title = {Breakdown of the efficiency gap to 29% based on experimental input data and modelling},
author = {R Brendel and T Dullweber and R Peibst and C Kranz and A Merkle and D Walter},
doi = {10.1002/pip.2696},
year = {2016},
date = {2016-12-01},
journal = {Progress in Photovoltaics: Research and Applications},
volume = {24},
number = {12},
pages = {1475-1486},
abstract = {We demonstrate a procedure for quantifying efficiency gains that treats resistive, recombinative, and optical losses on an equal footing. For this, we apply our conductive boundary model as implemented in the Quokka cell simulator. The generation profile is calculated with a novel analytical light‐trapping model. This model parameterizes the measured reflection spectra and is capable of turning the experimental case gradually into an ideal Lambertian scheme. Simulated and measured short‐circuit current densities agree for our 21.2%‐efficient screen‐printed passivated emitter and rear cell and for our 23.4%‐efficient ion‐implanted laser‐processed interdigitated back‐contacted cell. For the loss analysis of these two cells, we set all experimentally accessible control parameters (e.g., saturation current densities, sheet resistances, and carrier lifetimes) one at a time to ideal values. The efficiency gap to the ultimate limit of 29% is thereby fully explained in terms of both individual improvements and their respective synergistic effects. This approach allows comparing loss structures of different types of solar cells, for example, passivated emitter and rear cell and interdigitated back‐contacted cells.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We demonstrate a procedure for quantifying efficiency gains that treats resistive, recombinative, and optical losses on an equal footing. For this, we apply our conductive boundary model as implemented in the Quokka cell simulator. The generation profile is calculated with a novel analytical light‐trapping model. This model parameterizes the measured reflection spectra and is capable of turning the experimental case gradually into an ideal Lambertian scheme. Simulated and measured short‐circuit current densities agree for our 21.2%‐efficient screen‐printed passivated emitter and rear cell and for our 23.4%‐efficient ion‐implanted laser‐processed interdigitated back‐contacted cell. For the loss analysis of these two cells, we set all experimentally accessible control parameters (e.g., saturation current densities, sheet resistances, and carrier lifetimes) one at a time to ideal values. The efficiency gap to the ultimate limit of 29% is thereby fully explained in terms of both individual improvements and their respective synergistic effects. This approach allows comparing loss structures of different types of solar cells, for example, passivated emitter and rear cell and interdigitated back‐contacted cells.
4.
R Brendel; M Rienaecker; R Peibst
A quantitative measure for the carrier selectivity of contacts to solar cells Proceedings Article
In: WIP, (Hrsg.): Proceedings of the 32nd European Photovoltaic Solar Energy Conference, S. 447-451, Munich, Germany, 2016, ISBN: 3-936338-41-8.
@inproceedings{Brendel2016,
title = {A quantitative measure for the carrier selectivity of contacts to solar cells},
author = {R Brendel and M Rienaecker and R Peibst},
editor = {WIP},
doi = {10.4229/EUPVSEC20162016-2CO.4.1},
isbn = {3-936338-41-8},
year = {2016},
date = {2016-09-01},
booktitle = {Proceedings of the 32nd European Photovoltaic Solar Energy Conference},
journal = {Proceedings of the 32nd European Photovoltaic Solar Energy Conference},
pages = {447-451},
address = {Munich, Germany},
abstract = {We discuss a physically motivated definition for a quantitative measure of the selectivity of electron and hole contacts. We define the selectivity S10 = log10(Vth /(c ×Jc)) to depend on the contact resistance c, the recombination current density Jc of the contact, and the thermal voltage Vth. A high selectivity relies on a highly asymmetric equilibrium carrier concentration of majority and minority carriers in the contact. The maximum efficiency max increases with the selectivity S10. This increase is linear until the efficiency starts to be limited by radiative recombination. We give analytic equations for calculating the maximum efficiency max(S10) of a crystalline Si cell that is ideal except for either one or two contacts. Achieving the maximum efficiency max requires optimized areal fractions fe,max and fh,max for the electron and the hole contacts, respectively . We give analytic equations for these contact fractions.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
We discuss a physically motivated definition for a quantitative measure of the selectivity of electron and hole contacts. We define the selectivity S10 = log10(Vth /(c ×Jc)) to depend on the contact resistance c, the recombination current density Jc of the contact, and the thermal voltage Vth. A high selectivity relies on a highly asymmetric equilibrium carrier concentration of majority and minority carriers in the contact. The maximum efficiency max increases with the selectivity S10. This increase is linear until the efficiency starts to be limited by radiative recombination. We give analytic equations for calculating the maximum efficiency max(S10) of a crystalline Si cell that is ideal except for either one or two contacts. Achieving the maximum efficiency max requires optimized areal fractions fe,max and fh,max for the electron and the hole contacts, respectively . We give analytic equations for these contact fractions.
5.
R Brendel; T Dullweber; R Peibst; C Kranz; A Merkle; D Walter
Breakdown of the efficiency gap to 29% based on experimental input data and modelling Proceedings Article
In: WIP, (Hrsg.): Proceedings of the 31st European Photovoltaic Solar Energy Conference, S. 264-272, Hamburg, Germany, 2015, ISBN: 3-936338-39-6.
@inproceedings{Brendel2015,
title = {Breakdown of the efficiency gap to 29% based on experimental input data and modelling},
author = {R Brendel and T Dullweber and R Peibst and C Kranz and A Merkle and D Walter},
editor = {WIP},
doi = {10.4229/EUPVSEC20152015-2BP.1.2},
isbn = {3-936338-39-6},
year = {2015},
date = {2015-09-14},
booktitle = {Proceedings of the 31st European Photovoltaic Solar Energy Conference},
journal = {Proceedings of the 31st European Photovoltaic Solar Energy Conference},
pages = {264-272},
address = {Hamburg, Germany},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
6.
C Mader; J Müller; S Eidelloth; R Brendel
Local rear contacts to silicon solar cells by in-line high-rate evaporation of aluminum Artikel
In: Solar Energy Materials and Solar Cells, Bd. 107, S. 272-282, 2012.
@article{Mader2012,
title = {Local rear contacts to silicon solar cells by in-line high-rate evaporation of aluminum},
author = {C Mader and J Müller and S Eidelloth and R Brendel},
doi = {10.1016/j.solmat.2012.06.047},
year = {2012},
date = {2012-12-01},
journal = {Solar Energy Materials and Solar Cells},
volume = {107},
pages = {272-282},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
7.
J H Petermann; T Ohrdes; P P Altermatt; S Eidelloth; R Brendel
In: IEEE Transactions on Electron Devices, Bd. 59, Nr. 4, S. 909-917, 2012.
@article{Petermann2012,
title = {19% efficient thin-film crystalline silicon solar cells from layer transfer using porous silicon: a loss analysis by means of three-dimensional simulations},
author = {J H Petermann and T Ohrdes and P P Altermatt and S Eidelloth and R Brendel},
doi = {10.1109/TED.2012.2183001},
year = {2012},
date = {2012-04-01},
journal = {IEEE Transactions on Electron Devices},
volume = {59},
number = {4},
pages = {909-917},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
8.
S Steingrube; H Wagner; H Hannebauer; S Gatz; R Chen; S T Dunham; T Dullweber; P P Altermatt; R Brendel
In: Energy Procedia, Bd. 8, S. 263-268, 2011, ISSN: 1876-6102, (Proceedings of the SiliconPV 2011 Conference (1st International Conference on Crystalline Silicon Photovoltaics)).
@article{Steingrube2011c,
title = {Loss analysis and improvements of industrially fabricated Cz-Si solar cells by means of process and device simulations},
author = {S Steingrube and H Wagner and H Hannebauer and S Gatz and R Chen and S T Dunham and T Dullweber and P P Altermatt and R Brendel},
doi = {10.1016/j.egypro.2011.06.134},
issn = {1876-6102},
year = {2011},
date = {2011-08-01},
journal = {Energy Procedia},
volume = {8},
pages = {263-268},
note = {Proceedings of the SiliconPV 2011 Conference (1st International Conference on Crystalline Silicon Photovoltaics)},
keywords = {},
pubstate = {published},
tppubtype = {article}
}