LUMINESCENCE OF GAN GAAS(111)B GROWN BY MOLECULAR-BEAM EPITAXY WITH HYDRAZINE/

Hexagonal GaN layers were grown on (111)B GaAs substrates by gas-sourc e molecular beam epitaxy using hydrazine as a source of nitrogen. A sm ooth and abrupt AlN/GaAs interface was prepared by nitridation of an A lAs buffer layer grown on clean GaAs(lll)B surface. This buffer layer is stable at growth temperatures above 700 degrees C. The AlN layer pr epared on this buffer exhibits two-dimensional growth. The subsequent GaN and GaInN layers show a quasi-two-dimensional growth. The photo-an d cathodoluminescence spectra of these samples show a narrow (similar to 160 meV) band-edge emission and the absence of the ''yellow'' defec t band. Further narrowing (similar to 20 meV) of the edge emission in unintentionally In-doped GaN is ascribed to the presence of confined d omains of Ga1-xInxN. (C) 1998 American Vacuum Society.