Exciton dynamics involving basal stacking faults in a-plane GaN studied by low-temperature time-resolved cathodoluminescence.

P. Corfdir (1) , J. Ristic (1) , Pierre Lefebvre (1, 2) , Amélie Dussaigne (1) , D. Martin (1) , Jean-Daniel Ganière (1) , N. Grandjean (1) , Benoit Deveaud-Plédran (1)

1 Institut de Photonique et d'Electronique Quantiques
2 GES - Groupe d'étude des semiconducteurs

Time-resolved cathodoluminescence at 27 K has been performed on a-plane GaN grown by epitaxial lateral overgrowth. We detail the relaxation and recombination mechanisms of excitons [free or bound to neutral donors, or bound to I1-type basal stacking faults (BSFs)] in relation to the local density in BSFs. We describe the slow exciton capture rate on isolated BSFs by a diffusion model involving donors via a hopping process. Where BSFs are organized into bundles, we relate the shorter rise time to intra-BSF localization processes and the multiexponential decay to the type-II band alignment of BSFs in wurtzite GaN.

Mots clés: Time-resolved cathodoluminescence; GaN; basal stacking fault; exciton; diffusion

Domaines: Autre [cond-mat.other]; Science des matériaux [cond-mat.mtrl-sci]; Micro et nanotechnologies/Microélectronique

P. Corfdir, J. Ristic, Pierre Lefebvre, Amélie Dussaigne, D. Martin, et al.. Exciton dynamics involving basal stacking faults in a-plane GaN studied by low-temperature time-resolved cathodoluminescence.. Applied Physics Letters, 2009, 94, pp.201115. ⟨10.1063/1.3142396⟩. ⟨hal-00391736⟩