Optical characterization of CuInSe/sub 2/ grown by molecular beam epitaxy

CuInSe/sub 2/ epitaxial films with near stoichiometric compositions have been grown on GaAs (001) by molecular beam epitaxy, and radiative recombination processes in these films have been characterized by means of low temperature photoluminescence (PL) spectroscopy. Temperature dependent PL measurements on such epitaxial films have made possible the identification of conduction band to acceptor and donor-acceptor pair transitions. Well-defined emission lines were present near the bandgap, and the emissions at 1.0386 eV and at 1.0311 eV were found to be due to the ground-state free exciton and the excitons bound to neutral acceptors, respectively. The bandgap of CuInSe/sub 2/ is also determined to be E/sub g/=1.0462 eV at 2 K.