Dynamics of anti-Stokes photoluminescence in type-II AlxGa1−xAs−GaInP2 heterostructures: The important role of long-lived carriers near the interface

Abstract

We have studied the anti-Stokes photoluminescence (ASPL) of a type-II ${\mathrm{Al}}_x{\mathrm{Ga}}_{1-x}{\mathrm{A}\mathrm{s}-\mathrm{G}\mathrm{a}\mathrm{I}\mathrm{n}\mathrm{P}}_2$ heterojunction. We have found that the ASPL can appear in both layers adjacent to the heterojunction when the excitation photon energy is higher than the energy of below-band-gap (BBG) luminescence. The intensity of ${\mathrm{GaInP}}_2$-related ASPL shows an almost linear dependence on the excitation intensity. Time-resolved photoluminescence experiments reveal that the ASPL can be sustained as long as the BBG luminescence remains. Our results suggest that the energy up conversion for the ASPL is via a two-step two-photon absorption process involving localized, long-lived carriers near the type-II interface.