Veröffentlichungen
2019 |
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K. Bothe, S. Herlufsen, and J. D. Murphy Semiconductor Science and Technology 34 (3), 035030, (2019). Abstract | Links | BibTeX | Schlagwörter: luminescence @article{Bothe2019,
title = {Impact of iron on the room temperature luminescence efficiency of oxygen-containing precipitates in silicon}, author = {K Bothe and S Herlufsen and J D Murphy}, doi = {10.1088/1361-6641/ab0518}, year = {2019}, date = {2019-03-01}, journal = {Semiconductor Science and Technology}, volume = {34}, number = {3}, pages = {035030}, publisher = {IOP Publishing}, abstract = {Oxygen precipitation in silicon has been associated with a weak room temperature sub-bandgap luminescence emission at around 1600 nm. We show that the additional presence of iron impurities enhances this emission by an order of magnitude and results in a red shift of the peak luminescence by approximately 45 nm. We not only observe an increase in the luminescence emission with iron contamination level but also with the density and size of the oxide precipitates. Moreover, we provide evidence that the sub-bandgap luminescence emission increases proportionally with the concentration of iron segregated to oxide precipitates after high temperature (>700 °C) annealing and thus allows evaluation of the gettering efficiency of oxygen-containing precipitates. Annealing of iron-contaminated samples at low temperatures (550 °C) results in a considerable reduction in the interstitial iron concentration without changing the sub-bandgap luminescence, indicating that the sink to which iron diffuses depends upon temperature.}, keywords = {luminescence}, pubstate = {published}, tppubtype = {article} } Oxygen precipitation in silicon has been associated with a weak room temperature sub-bandgap luminescence emission at around 1600 nm. We show that the additional presence of iron impurities enhances this emission by an order of magnitude and results in a red shift of the peak luminescence by approximately 45 nm. We not only observe an increase in the luminescence emission with iron contamination level but also with the density and size of the oxide precipitates. Moreover, we provide evidence that the sub-bandgap luminescence emission increases proportionally with the concentration of iron segregated to oxide precipitates after high temperature (>700 °C) annealing and thus allows evaluation of the gettering efficiency of oxygen-containing precipitates. Annealing of iron-contaminated samples at low temperatures (550 °C) results in a considerable reduction in the interstitial iron concentration without changing the sub-bandgap luminescence, indicating that the sink to which iron diffuses depends upon temperature.
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2016 |
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O. Breitenstein, F. Frühauf, D. Hinken, and K. Bothe IEEE Journal of Photovoltaics 6 (5), 1243-1254, (2016). Abstract | Links | BibTeX | Schlagwörter: Current density, Effective diffusion length, electroluminescence imaging, Fuyuki approximation, Imaging, Limiting, luminescence, luminescence scaling factor, Nonhomogeneous media, Photovoltaic cells, saturation current density @article{Breitenstein2016,
title = {Effective diffusion length and bulk saturation current density imaging in solar cells by spectrally filtered luminescence imaging}, author = {O Breitenstein and F Frühauf and D Hinken and K Bothe}, doi = {10.1109/JPHOTOV.2016.2571621}, year = {2016}, date = {2016-09-01}, journal = {IEEE Journal of Photovoltaics}, volume = {6}, number = {5}, pages = {1243-1254}, abstract = {Most methods for interpreting electroluminescence (EL) or photoluminescence (PL) images of solar cells evaluate the local diode voltages but not the local luminescence intensity itself. One exception is the Fuyuki approximation, which assumes that the local value of the luminescence signal is proportional to the local effective diffusion length. This dependence has been derived for infinitely thick solar cells and neglects self-absorption of the luminescence photons. However, for real solar cells and imaging conditions, with increasing diffusion length, the luminescence signal approaches a limiting value; hence, the Fuyuki approximation no longer holds. In this paper, we compare EL and PL images of multicrystalline solar cells using different kinds of light filtering and find that gentle shortpass filtering is useful for avoiding optical artifacts. Based on earlier calculations, a physically founded formula for the dependence of the gently shortpass-filtered luminescence signal on the bulk diffusion length, for a given rear surface recombination velocity, is presented. Since this formula only barely allows us to calculate the diffusion length from the luminescence signal, a simplified approximate formula is proposed, and its accuracy is checked. This method is tested on EL and Voc PL images of solar cells. We find that for a typical industrial multicrystalline Albackside solar cell, the obtained effective diffusion length images correlate well with such images obtained by spectral LBIC image evaluation. In addition, the saturation current density images correlate well with such images obtained by dark lock-in thermography, which show a much lower spatial resolution. The main limitation of the proposed method is that it is basically approximate and needs some fitting parameters.}, keywords = {Current density, Effective diffusion length, electroluminescence imaging, Fuyuki approximation, Imaging, Limiting, luminescence, luminescence scaling factor, Nonhomogeneous media, Photovoltaic cells, saturation current density}, pubstate = {published}, tppubtype = {article} } Most methods for interpreting electroluminescence (EL) or photoluminescence (PL) images of solar cells evaluate the local diode voltages but not the local luminescence intensity itself. One exception is the Fuyuki approximation, which assumes that the local value of the luminescence signal is proportional to the local effective diffusion length. This dependence has been derived for infinitely thick solar cells and neglects self-absorption of the luminescence photons. However, for real solar cells and imaging conditions, with increasing diffusion length, the luminescence signal approaches a limiting value; hence, the Fuyuki approximation no longer holds. In this paper, we compare EL and PL images of multicrystalline solar cells using different kinds of light filtering and find that gentle shortpass filtering is useful for avoiding optical artifacts. Based on earlier calculations, a physically founded formula for the dependence of the gently shortpass-filtered luminescence signal on the bulk diffusion length, for a given rear surface recombination velocity, is presented. Since this formula only barely allows us to calculate the diffusion length from the luminescence signal, a simplified approximate formula is proposed, and its accuracy is checked. This method is tested on EL and Voc PL images of solar cells. We find that for a typical industrial multicrystalline Albackside solar cell, the obtained effective diffusion length images correlate well with such images obtained by spectral LBIC image evaluation. In addition, the saturation current density images correlate well with such images obtained by dark lock-in thermography, which show a much lower spatial resolution. The main limitation of the proposed method is that it is basically approximate and needs some fitting parameters.
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2014 |
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J. C. Schlothauer, R. M. Ralaiarisoa, A. Morlier, M. Köntges, and B. Röder Journal of Polymer Research 21 (5), 457, (2014). Links | BibTeX | Schlagwörter: cross-linking, EVA, luminescence, photovoltaics, spectroscopy @article{Schlothauer2014,
title = {Determination of the cross-linking degree of commercial ethylene-vinyl-acetate polymer by luminescence spectroscopy}, author = {J C Schlothauer and R M Ralaiarisoa and A Morlier and M Köntges and B Röder}, doi = {10.1007/s10965-014-0457-9}, year = {2014}, date = {2014-05-01}, journal = {Journal of Polymer Research}, volume = {21}, number = {5}, pages = {457}, keywords = {cross-linking, EVA, luminescence, photovoltaics, spectroscopy}, pubstate = {published}, tppubtype = {article} } |
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C. Schinke, K. Bothe, P. C. Peest, J. Schmidt, and R. Brendel Applied Physics Letters 104 (8), 081915, (2014). Links | BibTeX | Schlagwörter: absorption coefficient, error analysis, luminescence, photoluminescence, visible spectra @article{Schinke2014,
title = {Uncertainty of the coefficient of band-to-band absorption of crystalline silicon at near-infrared wavelengths}, author = {C Schinke and K Bothe and P C Peest and J Schmidt and R Brendel}, doi = {10.1063/1.4866916}, year = {2014}, date = {2014-02-01}, journal = {Applied Physics Letters}, volume = {104}, number = {8}, pages = {081915}, keywords = {absorption coefficient, error analysis, luminescence, photoluminescence, visible spectra}, pubstate = {published}, tppubtype = {article} } |
2013 |
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K. Bothe, and D. Hinken Quantitative Luminescence Characterization of Crystalline Silicon Solar Cells Buchkapitel G. P. Willeke, and E. R. Weber (Hrsg.): Semiconductors and Semimetals (Advances in Photovoltaics: Part 2), 89 , Kapitel 5, 259-339, Elsevier, (2013), ISSN: 0080-8784. Links | BibTeX | Schlagwörter: luminescence, Series Resistance, Solar Cells @inbook{Bothe2013b,
title = {Quantitative Luminescence Characterization of Crystalline Silicon Solar Cells}, author = {K Bothe and D Hinken}, editor = {G P Willeke and E R Weber}, doi = {10.1016/B978-0-12-381343-5.00005-7}, issn = {0080-8784}, year = {2013}, date = {2013-10-01}, booktitle = {Semiconductors and Semimetals (Advances in Photovoltaics: Part 2)}, volume = {89}, pages = {259-339}, publisher = {Elsevier}, chapter = {5}, series = {Semiconductors and Semimetals}, keywords = {luminescence, Series Resistance, Solar Cells}, pubstate = {published}, tppubtype = {inbook} } |
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R. Krain, S. Beljakova, S. Herlufsen, M. Krieger, and J. Schmidt Energy Procedia 38 , 101-107, (2013), ISSN: 1876-6102, (Proceedings of the 3rd International Conference on Crystalline Silicon Photovoltaics (SiliconPV 2013)). Links | BibTeX | Schlagwörter: defects, DLTS, FeB, luminescence, Multicrystalline silicon, ZnB @article{KRAIN2013101,
title = {Classification of Defective Regions in p-type Multicrystalline Silicon by Comparing Luminescence Images Measured under Different Conditions}, author = {R Krain and S Beljakova and S Herlufsen and M Krieger and J Schmidt}, doi = {10.1016/j.egypro.2013.07.255}, issn = {1876-6102}, year = {2013}, date = {2013-09-05}, journal = {Energy Procedia}, volume = {38}, pages = {101-107}, note = {Proceedings of the 3rd International Conference on Crystalline Silicon Photovoltaics (SiliconPV 2013)}, keywords = {defects, DLTS, FeB, luminescence, Multicrystalline silicon, ZnB}, pubstate = {published}, tppubtype = {article} } |
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C. Schinke, D. Hinken, J. Schmidt, K. Bothe, and R. Brendel Modelling the spectral luminescence emission of silicon solar cells and wafers Artikel IEEE Journal of Photovoltaics 3 (3), 1038-1052, (2013). Links | BibTeX | Schlagwörter: Charge carrier distribution, luminescence, Photon escape probability @article{Schinke2013b,
title = {Modelling the spectral luminescence emission of silicon solar cells and wafers}, author = {C Schinke and D Hinken and J Schmidt and K Bothe and R Brendel}, doi = {10.1109/JPHOTOV.2013.2263985}, year = {2013}, date = {2013-07-01}, journal = {IEEE Journal of Photovoltaics}, volume = {3}, number = {3}, pages = {1038-1052}, keywords = {Charge carrier distribution, luminescence, Photon escape probability}, pubstate = {published}, tppubtype = {article} } |
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C. Schinke, D. Hinken, J. Schmidt, R. Brendel, and K. Bothe Analyzing the spectral luminescence emission of silicon solar cells and wafers Inproceedings IEEE (Hrsg.): 2013 IEEE 39th Photovoltaic Specialists Conference (PVSC) , 0203-0208, Tampa, FL, USA, (2013), ISBN: 978-1-4799-3299-3. Links | BibTeX | Schlagwörter: Absorption, Charge carrier distribution, luminescence, Photon escape probability, Photonics, Photovoltaic cells, Semiconductor device modeling, Surface waves, Wavelength measurement @inproceedings{Schinke2013,
title = {Analyzing the spectral luminescence emission of silicon solar cells and wafers}, author = {C Schinke and D Hinken and J Schmidt and R Brendel and K Bothe}, editor = {IEEE}, doi = {10.1109/PVSC.2013.6744131}, isbn = {978-1-4799-3299-3}, year = {2013}, date = {2013-06-16}, booktitle = {2013 IEEE 39th Photovoltaic Specialists Conference (PVSC) }, journal = {Proceedings of the 39th IEEE Photovoltaic Specialists Conference}, pages = {0203-0208}, address = {Tampa, FL, USA}, keywords = {Absorption, Charge carrier distribution, luminescence, Photon escape probability, Photonics, Photovoltaic cells, Semiconductor device modeling, Surface waves, Wavelength measurement}, pubstate = {published}, tppubtype = {inproceedings} } |
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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D. Hinken, C. Schinke, S. Herlufsen, A. Schmidt, K. Bothe, and R. Brendel Review of Scientific Instruments 82 (3), 033706, (2011). Links | BibTeX | Schlagwörter: Cameras, III-V semiconductors, luminescence, silicon, Solar Cells @article{Hinken2011,
title = {Experimental setup for camera-based measurements of electrically and optically stimulated luminescence of silicon solar cells and wafers}, author = {D Hinken and C Schinke and S Herlufsen and A Schmidt and K Bothe and R Brendel}, doi = {10.1063/1.3541766}, year = {2011}, date = {2011-03-01}, journal = {Review of Scientific Instruments}, volume = {82}, number = {3}, pages = {033706}, keywords = {Cameras, III-V semiconductors, luminescence, silicon, Solar Cells}, pubstate = {published}, tppubtype = {article} } |
2009 |
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K. Bothe, K. Ramspeck, D. Hinken, C. Schinke, J. Schmidt, S. Herlufsen, R. Brendel, J. Bauer, J. -M. Wagner, N. Zakharov, and O. Breitenstein Luminescence emission from forward- and reverse-biased multicrystalline silicon solar cells Artikel Journal of Applied Physics 106 (10), 104510, (2009). Links | BibTeX | Schlagwörter: crystal defects, dislocations, luminescence, silicon, Solar Cells @article{Bothe2009b,
title = {Luminescence emission from forward- and reverse-biased multicrystalline silicon solar cells}, author = {K Bothe and K Ramspeck and D Hinken and C Schinke and J Schmidt and S Herlufsen and R Brendel and J Bauer and J -M Wagner and N Zakharov and O Breitenstein}, doi = {10.1063/1.3256199}, year = {2009}, date = {2009-11-01}, journal = {Journal of Applied Physics}, volume = {106}, number = {10}, pages = {104510}, keywords = {crystal defects, dislocations, luminescence, silicon, Solar Cells}, pubstate = {published}, tppubtype = {article} } |
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D. Hinken, K. Bothe, K. Ramspeck, S. Herlufsen, and R. Brendel WIP (Hrsg.): 24th European Photovoltaic Solar Energy Conference, 1082-1085, Hamburg, Germany, (2009), ISBN: 3-936338-25-6. Links | BibTeX | Schlagwörter: Characterisation, Characterization, luminescence, solar cell @inproceedings{Hinken2009,
title = {Determination of the Emitter Saturation Current Density of Silicon Solar Cells Using Photoluminescence and Quantum Efficiency Analysis}, author = {D Hinken and K Bothe and K Ramspeck and S Herlufsen and R Brendel}, editor = {WIP}, doi = {10.4229/24thEUPVSEC2009-2CO.3.5}, isbn = {3-936338-25-6}, year = {2009}, date = {2009-09-01}, booktitle = {24th European Photovoltaic Solar Energy Conference}, pages = {1082-1085}, address = {Hamburg, Germany}, keywords = {Characterisation, Characterization, luminescence, solar cell}, pubstate = {published}, tppubtype = {inproceedings} } |
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K. Bothe, D. Hinken, K. Ramspeck, S. Herlufsen, J. Schmidt, R. Brendel, J. Bauer, J. -M. Wagner, N. Zakharov, and O. Breitenstein Imaging and Analysis of Pre-Breakdown Sites in Multicrystalline Silicon Solar Cells Inproceedings WIP (Hrsg.): 24th European Photovoltaic Solar Energy Conference, 918-924, Hamburg, Germany, (2009), ISBN: 3-936338-25-6. Links | BibTeX | Schlagwörter: Imaging, luminescence, Multicrystalline, silicon, Thermography @inproceedings{Bothe2009,
title = {Imaging and Analysis of Pre-Breakdown Sites in Multicrystalline Silicon Solar Cells}, author = {K Bothe and D Hinken and K Ramspeck and S Herlufsen and J Schmidt and R Brendel and J Bauer and J -M Wagner and N Zakharov and O Breitenstein}, editor = {WIP}, doi = {10.4229/24thEUPVSEC2009-2AO.1.4}, isbn = {3-936338-25-6}, year = {2009}, date = {2009-09-01}, booktitle = {24th European Photovoltaic Solar Energy Conference}, pages = {918-924}, address = {Hamburg, Germany}, keywords = {Imaging, luminescence, Multicrystalline, silicon, Thermography}, pubstate = {published}, tppubtype = {inproceedings} } |
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D. Hinken, K. Bothe, K. Ramspeck, S. Herlufsen, and R. Brendel Determination of the effective diffusion length of silicon solar cells from photoluminescence Artikel Journal of Applied Physics 105 (10), 104516, (2009). Links | BibTeX | Schlagwörter: diffusion, luminescence, photoluminescence, photons, Solar Cells @article{Hinken2009b,
title = {Determination of the effective diffusion length of silicon solar cells from photoluminescence}, author = {D Hinken and K Bothe and K Ramspeck and S Herlufsen and R Brendel}, doi = {10.1063/1.3130408}, year = {2009}, date = {2009-05-01}, journal = {Journal of Applied Physics}, volume = {105}, number = {10}, pages = {104516}, keywords = {diffusion, luminescence, photoluminescence, photons, Solar Cells}, pubstate = {published}, tppubtype = {article} } |