Veröffentlichungen
2018 |
J. A. Tsanakas, U. Jahn, M. Herz, M. Köntges, D. Parlevliet, M. Paggi, J. S. Stein, K. A. Berger, B. Kubicek, S. Ranta, R. French, M. Richter, and T. Tanahashi Infrared and Electroluminescence Imaging for PV Field Applications: An Overview of the Latest Report by IEA PVPS Task 13 Inproceedings WIP (Hrsg.): Proceedings of the 35th European Photovoltaic Solar Energy Conference and Exhibition, 1440-1447, Brussels, Belgium, (2018). Abstract | Links | BibTeX | Schlagwörter: EL, electroluminescence imaging, infrared imaging, Operation, Performance, reliability @inproceedings{Tsanakas2018,
title = {Infrared and Electroluminescence Imaging for PV Field Applications: An Overview of the Latest Report by IEA PVPS Task 13}, author = {J A Tsanakas and U Jahn and M Herz and M Köntges and D Parlevliet and M Paggi and J S Stein and K A Berger and B Kubicek and S Ranta and R French and M Richter and T Tanahashi}, editor = {WIP}, doi = {10.4229/35thEUPVSEC20182018-6DP.2.4}, year = {2018}, date = {2018-09-24}, booktitle = {Proceedings of the 35th European Photovoltaic Solar Energy Conference and Exhibition}, pages = {1440-1447}, address = {Brussels, Belgium}, abstract = {This paper presents an overview of the latest research and technical reporting activity of TASK13 participants, within the Subtask 3.3 (“Characterization of PV Module Condition in the Field”); and particularly, key findings of the new “Review on Infrared (IR) and Electroluminescence (EL) Imaging for PV Field Applications” TASK13 Report. Goal of the latter is to provide guidelines and recommendations for using IR and EL imaging, in order to identify and assess specific failure modes of PV modules and systems in field applications. As such, the paper provides first a discussion on the relevant state-of-the-art and particularly the new IEC standards, Technical Specifications (TS) and guidelines. It also describes current practices for IR and EL imaging of PV modules and systems, looking at environmental and device requirements and the interpretation of sample patterns with abnormalities. In addition, examples of typical inspection results are given, showing characteristic IR/thermal and EL signatures of different failure modes occurring in fielded PV modules and arrays.}, keywords = {EL, electroluminescence imaging, infrared imaging, Operation, Performance, reliability}, pubstate = {published}, tppubtype = {inproceedings} } This paper presents an overview of the latest research and technical reporting activity of TASK13 participants, within the Subtask 3.3 (“Characterization of PV Module Condition in the Field”); and particularly, key findings of the new “Review on Infrared (IR) and Electroluminescence (EL) Imaging for PV Field Applications” TASK13 Report. Goal of the latter is to provide guidelines and recommendations for using IR and EL imaging, in order to identify and assess specific failure modes of PV modules and systems in field applications. As such, the paper provides first a discussion on the relevant state-of-the-art and particularly the new IEC standards, Technical Specifications (TS) and guidelines. It also describes current practices for IR and EL imaging of PV modules and systems, looking at environmental and device requirements and the interpretation of sample patterns with abnormalities. In addition, examples of typical inspection results are given, showing characteristic IR/thermal and EL signatures of different failure modes occurring in fielded PV modules and arrays.
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2016 |
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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2011 |
C. Schinke, D. Hinken, K. Bothe, C. Ulzhöfer, A. Milsted, J. Schmidt, and R. Brendel Determination of the Collection Diffusion Length by Electroluminescence Imaging Artikel Energy Procedia 8 , 147-152, (2011), ISSN: 1876-6102, (Proceedings of the SiliconPV 2011 Conference (1st International Conference on Crystalline Silicon Photovoltaics)). Links | BibTeX | Schlagwörter: collection diffusion length, electroluminescence imaging @article{Schinke2011b,
title = {Determination of the Collection Diffusion Length by Electroluminescence Imaging}, author = {C Schinke and D Hinken and K Bothe and C Ulzhöfer and A Milsted and J Schmidt and R Brendel}, doi = {10.1016/j.egypro.2011.06.116}, issn = {1876-6102}, year = {2011}, date = {2011-08-01}, journal = {Energy Procedia}, volume = {8}, pages = {147-152}, note = {Proceedings of the SiliconPV 2011 Conference (1st International Conference on Crystalline Silicon Photovoltaics)}, keywords = {collection diffusion length, electroluminescence imaging}, pubstate = {published}, tppubtype = {article} } |