GaAs/AIAs superlattices under pressure: steady-state and subpicosecond time-resolved measurements

Abstract

Low-temperature photoluminescence measurements under hydrostatic pressure were performed on 100]-, 311]-and 111]-grown GaAs/AlAs superlattices. The indirect optical transitions for all three growth directions were identified by their characteristic pressure dependences as originating from the X point of the AlAs conduction band. Subpicosecond-time-resolved measurements on a GaAs/AIAs superlattice show a decrease of electron transfer times from the GaAs layer into the A1As layer with pressure from 400 fs to 5Ofs and an intensity dependence of the pressure-induced crossover from type I to type II.