Localization-dependent thermalization of excitons inGaAs/AlxGa1xAsquantum wells

Abstract
Exciton temperatures in a series of molecular-beam-epitaxy-grown GaAs/AlxGa1xAs single quantum wells are derived from fits to 2-K photoluminescence spectra. The temperature of the free exciton is seen to vary directly with the degree of carrier confinement, and in wells larger than the exciton diameter unusually complete thermalization is observed. Excitonic lifetimes dependent on well width along with small interface recombination velocities explain the observations.