Time-resolved cathodoluminescence studies at 27K were made of a-plane GaN, grown by epitaxial lateral overgrowth. The relaxation and recombination mechanisms of excitons (free or bound to neutral donors, or bound to I1-type basal stacking faults) were studied in relation to the local density of basal stacking faults. The slow exciton capture rate on isolated basal stacking faults was described by means of a diffusion model which involved donors via a hopping process. Where basal stacking faults were organized into bundles, the shorter rise-time was related to intra-basal stacking fault localization processes and the multi-exponential decay was related to the type-II band alignment of basal stacking faults in wurtzite GaN.

Low-Temperature Time-Resolved Cathodoluminescence Study of Exciton Dynamics Involving Basal Stacking Faults in a-Plane GaN. P.Corfdir, J.Ristić, P.Lefebvre, T.Zhu, D.Martin, A.Dussaigne, J.D.Ganière, N.Grandjean, B.Deveaud-Plédran: Applied Physics Letters, 2009, 94[20], 201115