Photoluminescence line shape of excitons in GaAs single-quantum wells with and without heterointerface ordering

Abstract

The photoluminescence line shape of excitons at low temperatures is investigated in GaAs single‐quantum wells grown by molecular‐beam epitaxy with and without intentional heterointerface ordering. From the study of the excitation density dependence in the range between 10¹⁵ and 10¹⁷ cm⁻³, it is found that the inhomogeneous linewidth is significantly affected by band‐filling effects of intrinsic defect states spatially localized in the wider wells. In the sample with heterointerface ordering the band‐filling effects are directly identified by observation of saturation of the localized excitonic emissions, which are split as a result of increased spatial coherence of the excitonic states.