TEMPERATURE-DEPENDENCE OF EXCITON LIFETIMES IN GAAS/ALGAAS QUANTUM-WELL STRUCTURES

The photoluminescence decay times in GaAdAlGaAs single quantum well structures with layer thickness between 20 d and 80 d have been investigated in the temperature range from 4 K up to room temperature. It is shown that the increase in the PL decay time usually ascribed to radiative free-excitons recombination is present even in conditions where other mechanisms such as recombination of localized excitons and free carriers, exciton ionization and thermal activation of nonradiative processes are effective. © 1990 IOP Publishing Ltd.