Photoluminescence Analysis of CdS/CIGS Interfaces in CIGS Solar Cells

Abstract

In this study, the element diffusion behavior and defect states at the CdS/CIGS interface and their effect on solar cell performance were investigated after post-annealing treatment in an air environment at 150°C and 200°C, respectively. The results showed that the defect states (VSe and VCu) were passivated by the elements of O, S, and Cd forming a new compound CIGSSe, which led to an increase in the band-gap on the CIGS surface and a high carrier concentration at the p-n junction. There was an improvement in the photovoltaic performance of the solar cells from 3.71% to 7.25% through post-annealing treatment at 200°C for 30 min.