Interface disorder in GaAs/AlGaAs quantum wells grown by molecular beam epitaxy at high substrate temperature

Abstract

The interface disorder of quantum wells grown by molecular beam epitaxy at high substrate temperature is investigated by low-temperature photoluminescence. The excitonic emission from a single quantum well is a single sharp peak, and the well width precisely determined from the emission peak energy does not equal to integral multiples of one-monolayer width in almost all samples. These results indicate that the lateral size of growth islands with a one-monolayer height is much smaller than the exciton diameter and a one-monolayer interface acts as a layer with smaller AlAs mole fraction than the barrier layer.