OPTICAL-TRANSITIONS IN CUBIC GAN GROWN ON GAAS(100) SUBSTRATES BY METALORGANIC VAPOR-PHASE EPITAXY

We investigated the optical transitions in cubic GaN films grown on Ga As(1 0 0) substrates by metalorganic vapor-phase epitaxy. The cubic Ga N films show good optical quality. From temperature and excitation int ensity dependence, the emission lines at 3.274 and 3.178 eV were assig ned to the excitonic transition and the donor-acceptor pair transition , respectively. We also suggested an additional acceptor level (E-A' a pproximate to 212 meV) to explain the origin of the emission lines at 3.088 and 3.056 eV, on the basis of the excitation intensity dependenc e. (C) 1998 Elsevier Science B.V. All rights reserved.