ECN publication
Title:
All-side SiNx passivated mc-Si solar cells evaluated with respect to parasitic shunting
 
Author(s):
Cesar, I.; Bende, E.E.; Galbiati, G.; Jansen, L.; Weeber, A.W.; Bultman, J.H.
 
Published by: Publication date:
ECN Solar Energy 9-6-2009
 
ECN report number: Document type:
ECN-M--09-075 Conference Paper
 
Number of pages: Full text:
6 Download PDF  

Presented at: 34th IEEE Photovoltaic Specialists Conference, Philadelphia, USA, 7-12 juni 2009.

Abstract:
In search of solar cell concepts that allow processing thinner wafers (<150 micron), the conventional full Al rear side is replaced by an open rear metallization combined with a dielectric passivation layer. We show a gain of 2.1% (relative) in the product of Jsc×Voc, when we apply a passivated SiNx dielectric layer and local Al contacts on the rear of ptype mc-Si solar cells instead of a full Al-BSF. To achieve this gain, metallization designs of H-patterns and point-contacts were used with a rear coverage less than 8%. The gain in Jsc×Voc is an improvement over our previously reported results for open rear side cells with rear coverage of 14%. In addition, we propose a new method to quantify parasitic shunting to evaluate the efficiency potential of this cell concept. Experimental evidence shows that the parasitic shunting is one of the main limiting factors and the new method predicts a gain in Jsc and Voc in absence of this phenomenon. Omitting additional resistive losses of the open rear side cell compared to its full-coverage counterpart, we predict a gain in efficiency of about 0.6% absolute if parasitic shunting could be eliminated


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