Preparation and characterization of Cu(In,Ga)Se2 thin films by selenization of Cu0.8Ga0.2 and In2Se 3 precursor films

Abstract

Se-containing precursor films with two different compositions were prepared by magnetron sputtering from Cu 0.8 Ga 0.2 and In 2 Se 3 targets, and then were selenized using Se vapor. The effects of precursor composition and selenization temperature on the film properties were investigated. The results show that Cu 2 - x Se phase plays a critical role in film growth and electrical properties of CIGS films. The Cu-rich films exhibit different surface morphology and better crystallinity, as compared to the Cu-poor films. All the CIGS films exhibit p-type conductivity. The resistivity of the Cu-rich films is about three orders of magnitude lower than that of the Cu-poor films, which is attributed to the presence of p-type highly conductive Cu 2 - x Se phase. © 2012 Jiang Liu et al.