MECHANISMS OF PHOTOLUMINESCENCE UP-CONVERSION AT THE GAAS (ORDERED) GAINP2 INTERFACE/

F.A.J.M. Driessen [Appl. Phys. Lett. 67, 1995, 2813] recently reported emission from GaAs/(partially ordered) GaInP2 quantum wells grown on GaAs when the excitation photon energy was above the band gap of GaAs. We found that such upconverted emission could be excited from partial ly ordered GaInP2 grown on GaAs even when the photon energy was below the band gap of GaAs. Auger processes are found to be inadequate in ex plaining our results. Instead we propose a two-step two-photon excitat ion mechanism together with a model in which the GaAs and GaInP2 condu ction bands are almost degenerate. Copyright (C) 1996 Elsevier Science Ltd