IONIZED DONOR BOUND EXCITONS IN GAN

The temperature and excitation power dependence of a bound exciton pho toluminescence line S with a localization energy Q = 11.5 meV has been studied in undoped and moderately Mg-doped wurtzite GaN of high resis tivity. The data provide strong evidence that line S is due to recombi nation of excitons bound to ionized shallow donors. The consistency of this assignment with theoretical predictions is demonstrated. (C) 199 7 American Institute of Physics.