Plasma-enhanced chemical-vapor-deposited SiOx(Ny)/n-type polysilicon-on-oxide-passivating contacts in industrial back-contact Si solar cells

article
2024
authors
Mertens, V. and Dorn, S. and Langlois, J. and Stöhr, M. and Larionova, Y. and Veurman, W. and Brendel, R. and Ambrosius, N. and Vogt, A. and Pernau, T. and Haverkamp, H. and Dullweber, T.
journal
Solar RRL
doi:10.1002/solr.202300919

abstract

In this paper we investigate different in situ grown Plasma Enhanced Chemical Vapor Deposition (PECVD) grown interfacial oxides for n-type polysilicon passivating contacts. We apply SiOx(Ny)/n-type amorphous silicon stacks created from either N2O plasma or O2 plasma to POLO IBC solar cells using our structured deposition process through a glass mask to create the IBC layout. We determine experimentally the impact of plasma exposure time for interfacial oxide growth on solar cell efficiencies. The POLO IBC cell results show that the PECVD oxides SiOxNy and SiOx with optimized plasma exposure time give similar maximum efficiencies of 23.8 % and 23.7 %, respectively. These data demonstrate the feasibility to deposit a high-quality in situ PECVD interfacial SiOx(Ny) layers for surface passivation and current transport of passivated contacts at the same time. For the SiOx/n-type polysilicon stack we find that both, plasma exposure time for interfacial oxide growth or polysilicon anneal temperature variations, can lead to similar optimum of solar cell efficiencies. We analyze the current Voc losses due to metallization for our solar cells and calculate a realistic to achieve efficiency of 25.22 % for an optimized POLO IBC solar cells applying the Synergistic Efficiency Gain Analysis (SEGA) on Quokka3 simulations. This article is protected by copyright. All rights reserved.