Low-temperature time-resolved cathodoluminescence study of exciton dynamics involving basal stacking faults in a-plane GaN
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.
Keywords: cathodoluminescence ; diffusion ; excitons ; gallium compounds ; III-V semiconductors ; semiconductor epitaxial layers ; stacking faults ; time resolved spectra ; wide band gap semiconductors
Record created on 2009-05-23, modified on 2016-08-08