Photoluminescence line shape of excitons in GaAs singlehyphen;quantum wells with and without heterointerface ordering

摘要

The photoluminescence line shape of excitons at low temperatures is investigated in GaAs singlehyphen;quantum wells grown by molecularhyphen;beam epitaxy with and without intentional heterointerface ordering. From the study of the excitation density dependence in the range between 1015and 1017cmminus;3, it is found that the inhomogeneous linewidth is significantly affected by bandhyphen;filling effects of intrinsic defect states spatially localized in the wider wells. In the sample with heterointerface ordering the bandhyphen;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.