The hunt for the third acceptor in CuInSe and Cu(In,Ga)Se absorber layers.

The model for intrinsic defects in Cu(In,Ga)Se semiconductor layers is still under debate for the full range between CuInSe and CuGaSe. It is commonly agreed by theory and experiment, that there are at least one shallow donor and two shallow acceptors. Spatially resolved photoluminescence on CuGaSe previously revealed a third acceptor.