Photoluminescence study of the effects of growth interruption on integer and fractional monolayer AlGaAs/GaAs quantum wells

Abstract

A set of quantum wells containing wells of integer n and integer plus half-monolayer n+1/2 thickness were grown. The photoluminescence of these samples contained distinct peaks for both the n and n+1/2 wells. The structure was regrown with growth interruption between layers. With sufficiently long interrupt times (∼60 s) the peaks due to the n+1/2 wells disappeared leaving only peaks from wells of integer monolayer thickness. This result can be interpreted in terms of structural changes at the interfaces such as island coalescence. The intensity of the peaks and shifts in their energy also provide a measure of contamination and microroughness.