Optical transitions in cubic GaN grown on GaAs(1 0 0) substrates by metalorganic vapor-phase epitaxy

Abstract

We investigated the optical transitions in cubic GaN films grown on GaAs(100) substrates by metalorganic vapor-phase epitaxy. The cubic GaN films show good optical quality. From temperature and excitation intensity dependence, the emission lines at 3.274 and 3.178eV were assigned to the excitonic transition and the donor–acceptor pair transition, respectively. We also suggested an additional acceptor level (EA′≈212meV) to explain the origin of the emission lines at 3.088 and 3.056eV, on the basis of the excitation intensity dependence.