Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Efficiency Potential Analysis of p- and n-Type Epitaxially Grown Si Wafers

: Rittmann, C.; Dalke, J.; Drießen, M.; Weiss, C.; Schindler, F.; Sorgenfrei, R.; Schubert, M.C.; Janz, S.

Fulltext urn:nbn:de:0011-n-6407808 (1.1 MByte PDF)
MD5 Fingerprint: 7ac73315f43f78ce2db51277121c12a9
Created on: 6.10.2021

38th European Photovoltaic Solar Energy Conference and Exhibition, EU PVSEC 2021 : Lissabon, Portugal, 06.09.2021-10.09.2021
München: WIP, 2021
ISBN: 3-936338-78-7
European Photovoltaic Solar Energy Conference and Exhibition (EU PVSEC) <38, 2021, Online>
Conference Paper, Electronic Publication
Fraunhofer ISE ()
Photovoltaik; Silicium-Photovoltaik; feedstock; Kristallisation; wafering; Epitaxie; Si-Folien und SiC-Abscheidungen; Charakterisierung von Prozess- und Silicium-Materialien

In this paper, we investigate the quality of epitaxially grown, 110 μm thick, n- and p-type silicon (Si) layers deposited in a CVD batch reactor of microelectronic standard. Two types of wafers are characterized: ‘EpiRef’ grown on chemically and mechanically polished reference substrates and ‘EpiWafer’ grown on substrates with a porous silicon detachment layer. EpiRef wafers exhibit excellent minority carrier lifetimes of 2.5 ms for n-type and 1.3 ms for p-type. EpiWafers show reduced, but still promising lifetimes of 0.5 ms (in local areas up to 1 ms) for n-type and 40 μs for p-type. For EpiWafers, we found that quality limitations are due to stacking faults as well as interstitial iron contamination for p-type. An efficiency limiting bulk recombination analysis (ELBA), allows for an assessment of the corresponding efficiency potential assuming a TOPCon cell model with a cell limit of 25.9 % for n-type and a TOPCoRE cell model with a cell limit of 26.5 % for p-type. In selected 1 cm² areas, potential efficiencies of EpiRef wafers are only -0.4 %abs below the theoretical cell limit for n-type and -1.3 %abs for p-type whereas EpiWafers feature losses of -1.2 %abs for n-type and even -5.4 %abs for p-type.