Cu(In, Ga)Se2 absorbers prepared by one-step sputtering process with Cu-rich quaternary target

Cu-rich quaternary target has long stability, good reliability and reproducibility. We fabricated CIGS thin film solar cell by using one-step sputtering with quaternary target, and conversion efficiency has achieved over 10%. In this study, we investigated the characteristics of Cu-rich CIGS absorbers prepared by the one-step sputtering. We observed that Cu2-xSe phase segregated on the CIGS top surface, and KCN treatment could effectively remove the second phase from EPMA mapping analysis. Cu-rich CIGS absorber layer has large, facet grains, and wide process window for sputtering fabrication, it`s a potential candidate to replace the Cu-rich stage in 3-stage process.