Defects and defect identification in group III-nitrides

In this paper the shallow donors oxygen and silicon in GaN and AlGaN and th e problem of DX formation are reviewed. New experimental results obtained b y optically detected magnetic resonance are presented which clarify the beh avior of Mg accepters in GaN. The properties of the violet, yellow and red luminescence bands in GaN are also briefly commented on. Transition metal i ons which are residual contaminants give rise to sharp zero-phonon limes in the near infrared followed by phonon sidebands. Their charge and spin stat es as well as the chemical identity are in part revealed by electron parama gnetic resonance and detailed magneto-luminescence experiments. (C) 2000 Pu blished by Elsevier Science S.A. All rights reserved.