ORIGIN OF THE Q = 11 MEV BOUND EXCITON IN GAN

The bound exciton line S with a localization energy of Q = 11.5 meV ha s been studied by power and temperature dependent photoluminescence (P L). High resistivity undoped and Mg doped wurtzite GaN samples grown b y MOCVD were analyzed. The experimental data provide strong evidence t hat line S is due to recombination of excitons bound to ionized shallo w donors which is consistent with theoretical expectations. A brief di scussion of the coupling strength of different excitons to LO phonons is given. (C) 1997 Elsevier Science S.A.