A Photoluminescence Study of MBE-Grown CuInSe2 Film with a Near-Stoichiometric Composition

Thin films of CuInSe₂ were grown on (001) GaAs by the molecular beam epitaxy technique without substrate rotation. A sample having a composition map covering both the Cu-rich and In-rich region was used for the photoluminescence (PL) study. We demonstrate that the PL property is consistently varied from the In-rich side to the Cu-rich side. An exciton peak was observed when the film composition was close to the stoichiometry.