Studies on sulfur diffusion into Cu(In,Ga)Se-2 thin films

A systematic study was carried out to investigate the distribution of sulfu r (S) in CuInSe2 (CIS) and Cu(In,Ga)Se-2 (CIGS) absorbers which were expose d to an H2S atmosphere at elevated temperature. Results demonstrated that S diffusion into CIS layers was a strong function of the original stoichiome try of the absorber before sulfurization. Sulfur inclusion into Cu-rich CIS films was much more favorable compared to S diffusion in Cu-poor layers. T he sulfur distribution profile was also strongly influenced by the micro-st ructure of the original CIS and CIGS layers, with sections of the films wit h smaller grains accommodating more S. Copyright (C) 2000 John Wiley & Sons , Ltd.