Spin-dependent processes and Mg-acceptors in GaN single quantum well diodes and p-type GaN films

Electrically detected magnetic resonance (EDMR) measurements at 34 GHz were performed to obtain more information about the rate limiting transport pro cesses in blue and green InGaN single quantum well light emitting diodes. W ith respect to g-factor and linewidth, two centers in both diodes were reso lved, which could not be separated in earlier 9 GHz experiments. The positi on of an enhancing signal at g approximate to 2.008 (Delta B approximate to 15 mT) is found to shift to g approximate to 2.010 with increasing forward bias. Comparative EDMR and EPR (electron paramagnetic resonance) measureme nts on p-type GaN:Mg and Al0.3Ga0.7N:Mg films show that this feature is cau sed by spin-dependent hopping in the acceptor band of the p-type Al0.3Ga0.7 N cladding layers in the diodes. In addition, a quenching line at g approxi mate to 2.002 (Delta B approximate to 18 mT) was observed at high forward b iases as well as under reverse breakthrough conditions.