Efficiency Enhancement of Cu(In,Ga)(S,Se) Solar Cells by Indium-Doped CdS Buffer Layers.

Author(s) Cheng, T.M.; Cai, C.H.; Huang, W.C.; Xu, W.L.; Tu, L.H.; Lai, C.H.
Journal ACS Appl Mater Interfaces
Date Published 2020 Apr 01

Improving power conversion efficiency of photovoltaic devices has been widely investigated; however, most research studies mainly focus on the modification of the absorber layer. Here, we present an approach to enhance the efficiency of Cu(In,Ga)(S,Se) (CIGSSe) thin-film solar cells simply by tuning the CdS buffer layer. The CdS buffer layer was deposited by chemical bath deposition. Indium doping was done during the growth process by adding InCl into the growing aqueous solution. We show that the solar cell efficiency is increased by proper indium doping. Based on the characteristics of the single CdS (with or without In-doping) layer and of the CIGSSe/CdS interface, we conclude that the efficiency enhancement is attributed to the interface-defect passivation of heterojunction, which significantly improves both open circuit voltage and fill factor. The results were supported by SCAPS simulations, which suggest that our approach can also be applied to other buffer systems.

DOI 10.1021/acsami.0c02416
ISSN 1944-8252
Citation ACS Appl Mater Interfaces. 2020.