The influence of MOCVD process scheme on the optical properties of GaN layers

The GaN layers were grown on sapphire substrates using atmospheric pressure MOCVD system. The new process scheme was developed to improve the quality of epitaxial layers. Additional buffer layers, grown with increasing temper ature and increasing V/III ratio, were inserted between the low temperature buffer layer and the high temperature GaN overlayer grown on it. The influ ence of growth conditions on luminescence properties of GaN layers, especia lly the yellow emission, was investigated. (C) 1999 Elsevier Science S.A. A ll rights reserved.