Understanding the high p-type conductivity in Cu-excess CuAlS2: A first-principles study

Abstract The high p-type conductivity in Cu-excess CuAlS 2 reported from a recent experimental paper is not well understood as it is not supported by earlier theoretical studies. We found that Cu can be heavily doped at the Al site and can form compensated defect bands to shift up the valence band, leading to shallow acceptor levels under a Cu-excess condition. In particular, Zn doping at the Al site in Cu-excess CuAlS 2 has been suggested as a promising approach to improving the p-type conductivity in Cu-excess CuAlS 2 .