Interface modification by In-S soaking process on CIGS solar cells with CBD-ZNS buffer layer

ZnS is a promising candidate for replacing the CdS buffer layer on Cu(In,Ga)Se₂ (CIGS) solar cells. In this study, CIGS was soaked into InCl₃ (0.005 M)- CH₃CSNH₂ (0.1 M) aqueous solution at room temperature for several seconds before the chemical bath deposition of ZnS buffer layer. The performance of In-S soaked device was strongly enhanced from 0.24% to 7.31% along with increasing in Jsc, Voc, FF, and carrier life time. The enhancement may be attributed to an appropriate interface modification, deduced from Photoluminescence (PL), Time-Resolved Photoluminescence (TR-PL), and Current-Voltage measurement respectively.