Veröffentlichungen
2019 |
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M. R. Vogt, R. Witteck, T. Gewohn, H. Schulte-Huxel, C. Schinke, M. Köntges, K. Bothe, and R. Brendel WIP (Hrsg.): Proceedings of the 36th European Photovoltaic Solar Energy Conference and Exhibition, 795-800, Marseille, France, (2019), ISBN: 3-936338-60-4. Abstract | Links | BibTeX | Schlagwörter: Antireflection Coating, module integration, Optical losses, PV Module, ray tracing, Simulation @inproceedings{Vogt2019c,
title = {Boosting PV Module Efficiency Beyond the Efficiency of Its Solar Cells – A Raytracing Study with Daidalos Now Available to the Scientific Community}, author = {M R Vogt and R Witteck and T Gewohn and H Schulte-Huxel and C Schinke and M Köntges and K Bothe and R Brendel}, editor = {WIP}, doi = {10.4229/EUPVSEC20192019-4BO.11.3}, isbn = {3-936338-60-4}, year = {2019}, date = {2019-10-23}, booktitle = {Proceedings of the 36th European Photovoltaic Solar Energy Conference and Exhibition}, pages = {795-800}, address = {Marseille, France}, abstract = {Today, the PV module energy conversion efficiency is below the efficiency of the cells prior to module integration. Using optical ray tracing simulations, we show how to increase module efficiencies beyond the efficiency of the solar cells. To achieve this we follow two basic principles: First, we minimize optical losses of the module components by minimizing the absorption in the glass and the encapsulation as well as by introducing multilayer glass ARC coatings that reduce the surface reflection. Second, we exploit the internal reflection at the glass-air interface by using light guiding structures in the cell gaps and as cell connects. This improves the light trapping by reducing the cell front side reflection losses. In our specific example presented in this work, the optimization leads to a module efficiency of 20.9%, which is a 0.1%abs above that of the non-encapsulated cells with an efficiency of 20.8%. }, keywords = {Antireflection Coating, module integration, Optical losses, PV Module, ray tracing, Simulation}, pubstate = {published}, tppubtype = {inproceedings} } Today, the PV module energy conversion efficiency is below the efficiency of the cells prior to module integration. Using optical ray tracing simulations, we show how to increase module efficiencies beyond the efficiency of the solar cells. To achieve this we follow two basic principles: First, we minimize optical losses of the module components by minimizing the absorption in the glass and the encapsulation as well as by introducing multilayer glass ARC coatings that reduce the surface reflection. Second, we exploit the internal reflection at the glass-air interface by using light guiding structures in the cell gaps and as cell connects. This improves the light trapping by reducing the cell front side reflection losses. In our specific example presented in this work, the optimization leads to a module efficiency of 20.9%, which is a 0.1%abs above that of the non-encapsulated cells with an efficiency of 20.8%.
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M. R. Vogt, R. Witteck, T. Gewohn, H. Schulte-Huxel, C. Schinke, M. Köntges, K. Bothe, and R. Brendel Boosting PV Module Efficiency Beyond the Efficiency of Its Solar Cells – A Raytracing Study with Daidalos Now Available to the Scientific Community Presentation/Poster Marseille, France, 10.09.2019, (36th European Photovoltaic Solar Energy Conference and Exhibition). Abstract | BibTeX | Schlagwörter: Antireflection Coating, module integration, Optical losses, PV Module, ray tracing, Simulation @misc{Vogt2019b,
title = {Boosting PV Module Efficiency Beyond the Efficiency of Its Solar Cells – A Raytracing Study with Daidalos Now Available to the Scientific Community}, author = {M R Vogt and R Witteck and T Gewohn and H Schulte-Huxel and C Schinke and M Köntges and K Bothe and R Brendel}, year = {2019}, date = {2019-09-10}, address = {Marseille, France}, abstract = {Today, the PV module energy conversion efficiency is below the efficiency of the cells prior to module integration. Using optical ray tracing simulations, we show how to increase module efficiencies beyond the efficiency of the solar cells. To achieve this we follow two basic principles: First, we minimize optical losses of the module components by minimizing the absorption in the glass and the encapsulation as well as by introducing multilayer glass ARC coatings that reduce the surface reflection. Second, we exploit the internal reflection at the glass-air interface by using light guiding structures in the cell gaps and as cell connects. This improves the light trapping by reducing the cell front side reflection losses. In our specific example presented in this work, the optimization leads to a module efficiency of 20.9%, which is a 0.1%abs above that of the non-encapsulated cells with an efficiency of 20.8%.}, note = {36th European Photovoltaic Solar Energy Conference and Exhibition}, keywords = {Antireflection Coating, module integration, Optical losses, PV Module, ray tracing, Simulation}, pubstate = {published}, tppubtype = {presentation} } Today, the PV module energy conversion efficiency is below the efficiency of the cells prior to module integration. Using optical ray tracing simulations, we show how to increase module efficiencies beyond the efficiency of the solar cells. To achieve this we follow two basic principles: First, we minimize optical losses of the module components by minimizing the absorption in the glass and the encapsulation as well as by introducing multilayer glass ARC coatings that reduce the surface reflection. Second, we exploit the internal reflection at the glass-air interface by using light guiding structures in the cell gaps and as cell connects. This improves the light trapping by reducing the cell front side reflection losses. In our specific example presented in this work, the optimization leads to a module efficiency of 20.9%, which is a 0.1%abs above that of the non-encapsulated cells with an efficiency of 20.8%.
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2017 |
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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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2016 |
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S. Schäfer, C. Gemmel, S. Kajari-Schröder, and R. Brendel Light trapping and surface passivation of micron-scaled macroporous blind holes Artikel IEEE Journal of Photovoltaics 6 (2), 397-403, (2016). Abstract | Links | BibTeX | Schlagwörter: Absorption, charge carrier lifetime, Current density, Etching, Optical losses, optical reflectivity, Optical variables measurement, silicon, Surface texture @article{Schäfer2016,
title = {Light trapping and surface passivation of micron-scaled macroporous blind holes}, author = {S Schäfer and C Gemmel and S Kajari-Schröder and R Brendel}, doi = {10.1109/JPHOTOV.2015.2505179}, year = {2016}, date = {2016-03-01}, journal = {IEEE Journal of Photovoltaics}, volume = {6}, number = {2}, pages = {397-403}, abstract = {We fabricate a blind hole surface texture by anodic etching of macroporous Si. The blind holes, i.e., pores that do not penetrate the wafer completely, have an average diameter of 2.7 μm, a distance of 4 μm, and a depth of 9 μm. This texture is capable of reducing the AM1.5G photon flux-weighted front reflectance to 1.5% without depositing an antireflection coating. The μm-feature size makes it a less fragile alternative to common nm-sized black silicon structures. We passivate the blind holes by atomic layer deposited AlOx. The blind hole texture allows for a carrier lifetime of (2.2 ± 0.25) ms corresponding to an effective surface recombination velocity of (8 ± 1.5) cm/s with respect to the macroscopic front surface. A direct comparison of the optical performance and the surface passivation quality with a standard SiNx-coated random pyramid surface shows that blind holes allow for a relative efficiency gain of (3 ± 0.2)% when applied, e.g., in an otherwise perfect back-contacted solar cell.}, keywords = {Absorption, charge carrier lifetime, Current density, Etching, Optical losses, optical reflectivity, Optical variables measurement, silicon, Surface texture}, pubstate = {published}, tppubtype = {article} } We fabricate a blind hole surface texture by anodic etching of macroporous Si. The blind holes, i.e., pores that do not penetrate the wafer completely, have an average diameter of 2.7 μm, a distance of 4 μm, and a depth of 9 μm. This texture is capable of reducing the AM1.5G photon flux-weighted front reflectance to 1.5% without depositing an antireflection coating. The μm-feature size makes it a less fragile alternative to common nm-sized black silicon structures. We passivate the blind holes by atomic layer deposited AlOx. The blind hole texture allows for a carrier lifetime of (2.2 ± 0.25) ms corresponding to an effective surface recombination velocity of (8 ± 1.5) cm/s with respect to the macroscopic front surface. A direct comparison of the optical performance and the surface passivation quality with a standard SiNx-coated random pyramid surface shows that blind holes allow for a relative efficiency gain of (3 ± 0.2)% when applied, e.g., in an otherwise perfect back-contacted solar cell.
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M. R. Vogt, H. Hahn, H. Holst, M. Winter, C. Schinke, M. Köntges, R. Brendel, and P. P. Altermatt IEEE Journal of Photovoltaics 6 (1), 111-118, (2016). Abstract | Links | BibTeX | Schlagwörter: Ellipsometry, Extraterrestrial measurements, Glass, Iron, Iron content, Optical losses, ray tracing, soda-lime glass, solar cell module, Uncertainty, Wavelength measurement @article{Vogt2015b,
title = {Measurement of the optical constants of soda-lime glasses in dependence of iron content, and modeling of iron-related power losses in crystalline Si solar cell modules}, author = {M R Vogt and H Hahn and H Holst and M Winter and C Schinke and M Köntges and R Brendel and P P Altermatt}, doi = {10.1109/JPHOTOV.2015.2498043}, year = {2016}, date = {2016-01-01}, journal = {IEEE Journal of Photovoltaics}, volume = {6}, number = {1}, pages = {111-118}, abstract = {It is well known that the absorbance of soda-lime glass is very sensitive to the amount of iron contamination; therefore, it strongly affects the power output of mass-produced crystalline silicon solar cell modules. We use a combination of ellipsometry and transmission measurements to determine the optical constants, at wavelengths between 300 and 1690 nm, of soda-lime-silica glasses containing an iron content between 1 0/00. and 0.01 0/00., measured with inductive coupled plasma optical emission spectroscopy. We derive two different semiempirical models for the extinction coefficient of soda-lime-silica glass as a function of its iron content: one model for iron alone and the other model for iron including other typical remaining coloring agents. Furthermore, we use ray tracing and spice simulations to predict the power losses in standard modules as a function of iron content in their cover glass sheet. Considering a module with 3.2-mm glass thickness, our results predict a decline in module output power due to iron content in the glass of 1.1% (3 W) for Fe2 O3 = 0.1 0/00. and 9.8% (28 W) for Fe2 O3 = 1 0/00.}, keywords = {Ellipsometry, Extraterrestrial measurements, Glass, Iron, Iron content, Optical losses, ray tracing, soda-lime glass, solar cell module, Uncertainty, Wavelength measurement}, pubstate = {published}, tppubtype = {article} } It is well known that the absorbance of soda-lime glass is very sensitive to the amount of iron contamination; therefore, it strongly affects the power output of mass-produced crystalline silicon solar cell modules. We use a combination of ellipsometry and transmission measurements to determine the optical constants, at wavelengths between 300 and 1690 nm, of soda-lime-silica glasses containing an iron content between 1 0/00. and 0.01 0/00., measured with inductive coupled plasma optical emission spectroscopy. We derive two different semiempirical models for the extinction coefficient of soda-lime-silica glass as a function of its iron content: one model for iron alone and the other model for iron including other typical remaining coloring agents. Furthermore, we use ray tracing and spice simulations to predict the power losses in standard modules as a function of iron content in their cover glass sheet. Considering a module with 3.2-mm glass thickness, our results predict a decline in module output power due to iron content in the glass of 1.1% (3 W) for Fe2 O3 = 0.1 0/00. and 9.8% (28 W) for Fe2 O3 = 1 0/00.
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2015 |
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M. Winter, M. Vogt, P. P. Altermatt, and H. Holst Impact of realistic illumination on optical losses in Si solar cell modules compared to standard testing conditions Inproceedings WIP (Hrsg.): Proceedings of the 31st European Photovoltaic Solar Energy Conference, 1877-1882, Hamburg, Germany, (2015), ISBN: 3-936338-39-6. Links | BibTeX | Schlagwörter: module, Optical losses, ray tracing, Solar Radiation @inproceedings{Winter2015,
title = {Impact of realistic illumination on optical losses in Si solar cell modules compared to standard testing conditions}, author = {M Winter and M Vogt and P P Altermatt and H Holst}, editor = {WIP}, doi = {10.4229/EUPVSEC20152015-5DO.11.3}, 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 = {1877-1882}, address = {Hamburg, Germany}, keywords = {module, Optical losses, ray tracing, Solar Radiation}, pubstate = {published}, tppubtype = {inproceedings} } |
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M. Winter, M. Vogt, H. Holst, P, and Altermatt Optical and Quantum Electronics 47 , 1373-1379, (2015). Links | BibTeX | Schlagwörter: Optical losses, photovoltaic, ray tracing, solar cell module @article{Winter2015b,
title = {Combining structures on different length scales in ray tracing: analysis of optical losses in solar cell modules}, author = {M Winter and M Vogt and H Holst and P and Altermatt}, doi = {10.1007/s11082-014-0078-x}, year = {2015}, date = {2015-06-01}, journal = {Optical and Quantum Electronics}, volume = {47}, pages = {1373-1379}, keywords = {Optical losses, photovoltaic, ray tracing, solar cell module}, pubstate = {published}, tppubtype = {article} } |
2014 |
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M. Winter, M. R. Vogt, H. Holst, and P. P. Altermatt Combining structures on different length scales in ray tracing: Analysis of optical losses in solar cell modules Inproceedings Numerical Simulation of Optoelectronic Devices, 2014, 167-168, (2014), ISSN: 2158-3234. Links | BibTeX | Schlagwörter: Absorption, Adaptive optics, Glass, Optical losses, Photovoltaic cells, ray tracing, Standards @inproceedings{6935409,
title = {Combining structures on different length scales in ray tracing: Analysis of optical losses in solar cell modules}, author = {M Winter and M R Vogt and H Holst and P P Altermatt}, doi = {10.1109/NUSOD.2014.6935409}, issn = {2158-3234}, year = {2014}, date = {2014-09-01}, booktitle = {Numerical Simulation of Optoelectronic Devices, 2014}, pages = {167-168}, keywords = {Absorption, Adaptive optics, Glass, Optical losses, Photovoltaic cells, ray tracing, Standards}, pubstate = {published}, tppubtype = {inproceedings} } |