C N Kruse; M Wolf; C Schinke; D Hinken; R Brendel; K Bothe
In: IEEE Journal of Photovoltaics, Bd. 7, Nr. 3, S. 747-754, 2017, ISSN: 2156-3381.
@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 = {},
pubstate = {published},
tppubtype = {article}
}
C Kranz; B Wolpensinger; R Brendel; T Dullweber
Analysis of local aluminum rear contacts of bifacial PERC+ solar cells Artikel
In: IEEE Journal of Photovoltaics, Bd. 6, Nr. 4, S. 830, 2016.
@article{Kranz2016b,
title = {Analysis of local aluminum rear contacts of bifacial PERC+ solar cells},
author = {C Kranz and B Wolpensinger and R Brendel and T Dullweber},
doi = {10.1109/JPHOTOV.2016.2551465},
year = {2016},
date = {2016-07-01},
journal = {IEEE Journal of Photovoltaics},
volume = {6},
number = {4},
pages = {830},
abstract = {A recently published industrial passivated emitter rear contact (PERC) solar cell concept called PERC+ enables bifacial applications by printing an aluminum (Al) finger grid instead of the full-area Al layer aligned to the laser contact openings on the rear side. We demonstrate that the rear contacts of these PERC+ solar cells exhibit back-surface field (BSF) depths of around 6 μm over a large range of contact linewidths, whereas PERC cells with full-area Al rear layer show a reduction of the Al-BSF depths for narrower contact lines. Using an existing analytical model for the local contact formation, we show that the measured Al-BSF depths are well described solely by the different volume of Al paste printed on the rear side. Consequently, the open-circuit voltage of PERC+ solar cells improves by up to 5 mV when reducing the contact linewidth only. In contrast, for PERC cells with full-area Al layer, the Voc slightly decreases with narrower contact linewidths due to the thinner Al-BSF depths. We observe a strongly reduced number of voids in the Al-Si eutectic layer for PERC+ cells, compared with PERC. As physical root cause for void formation, we propose the minimization of surface energy of the Al-Si melt.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
M Müller; P P Altermatt; H Wagner; G Fischer
In: IEEE Journal of Photovoltaics, Bd. 4, Nr. 1, S. 107-113, 2014, ISSN: 2156-3381.
@article{Müller2014b,
title = {Sensitivity Analysis of Industrial Multicrystalline PERC Silicon Solar Cells by Means of 3-D Device Simulation and Metamodeling},
author = {M Müller and P P Altermatt and H Wagner and G Fischer},
doi = {10.1109/JPHOTOV.2013.2287753},
issn = {2156-3381},
year = {2014},
date = {2014-01-01},
journal = {IEEE Journal of Photovoltaics},
volume = {4},
number = {1},
pages = {107-113},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
J Müller; S Gatz; K Bothe; R Brendel
Optimizing the geometry of local aluminum-alloyed contacts to fully screen-printed silicon solar cells Proceedings Article
In: IEEE, (Hrsg.): 2012 38th IEEE Photovoltaic Specialists Conference, S. 002223-002228, Austin, TX, USA, 2012, ISBN: 978-1-4673-0064-3.
@inproceedings{Müller2012,
title = {Optimizing the geometry of local aluminum-alloyed contacts to fully screen-printed silicon solar cells},
author = {J Müller and S Gatz and K Bothe and R Brendel},
editor = {IEEE},
doi = {10.1109/PVSC.2012.6318038},
isbn = {978-1-4673-0064-3},
year = {2012},
date = {2012-06-01},
booktitle = {2012 38th IEEE Photovoltaic Specialists Conference},
pages = {002223-002228},
address = {Austin, TX, USA},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}