PROPERTIES OF CUBIC GAN GROWN BY MBE

We review our investigation of cubic GaN films on (001) GaAs, focusing on the structural, optical, and electrical properties of these films. Cubic GaN films grown epitaxially on GaAs suffer from the large latti ce mismatch between these two materials in that they contain extremely high densities of structural defects. Surprisingly, the optical quali ty of these films does not seem much affected by the presence of defec ts, as intense photoluminescence is detected a? room temperature and a bove. Finally, the rather high background electron concentrations in o ur films is shown to be a consequence of contamination with O and not to be an intrinsic property of cubic phase GaN. (C) 1997 Elsevier Scie nce S.A.