Do we really need another PL study of CuInSe_2?

摘要

A detailed composition, intensity and temperature dependent photoluminescence (PL) study of CuInSe_2 has been performed to obtain data on defects, directly comparable to the defects in CuGaSe_2, prepared under the same conditions. Epitaxial films are grown by metal organic vapour phase epitaxy on GaAs. The PL study reveals three shallow defects, which are responsible for the doping behaviour in CuInSe_2: two acceptors, 40 and 60 meV deep, and a donor, approximately 12 meV deep. The shallower acceptor dominates for low or no Cu-excess, whereas the deeper one dominates material grown under high Cu-excess. These defects and their compositional dependence are the same as observed in CuGaSe_2. Thus no fundamental difference concerning the shallow defects exists between these two materials.