SOURCE OF THE YELLOW LUMINESCENCE BAND IN GAN GROWN BY GAS-SOURCE MOLECULAR-BEAM EPITAXY AND THE GREEN LUMINESCENCE BAND IN SINGLE-CRYSTAL ZNO

In this paper we show that the origin of the yellow luminescence band in GaN and the green luminescence band in ZnO is best explained by a t ransition between a shallow donor and a deep level. High resolution ph otoluminescence spectroscopy measurements on GaN (0 0 0 1) films grown by gas-source molecular beam epitaxy are compared with theoretical pr edictions. These comparisons show that the makeup of the deep level in GaN is most likely a complex consisting of a gallium vacancy, V-Ga an d a nearest neighbor donor consisting of an oxygen atom on a nitrogen site, O-N, or V-Ga-O-N. By analogy, the makeup of the deep level in Zn O is most likely a complex consisting of a zinc vacancy, V-Zn and a ne arest neighbor donor consisting of a chlorine atom on an oxygen site V -Zn-Cl-O. Chlorine is suggested since it is a dominant donor in ZnO an d is known to be present in the ZnO growth process. (C) 1998 Elsevier Science Ltd. All rights reserved.