CHARACTERIZATION OF ALLOY FORMATION AT THE ZNSE/CDSE QUANTUM-WELL INTERFACE BY PHOTOLUMINESCENCE SPECTROSCOPY

The interface of a binary single quantum-well (SQW) structure of ZnSe/CdSe, where CdSe of less than one monolayer is sandwiched between ZnSe layers (submonolayer SQW), is characterized by photoluminescence spectroscopy. The dependence of the energy, linewidth and intensity of excitonic emission from submonolayer SQWs on the well thickness of CdSe is extensively investigated. The characteristics of the excitonic emission are interpreted in terms of a heterostructure model in which 2 ML wide alloyed wells are taken into account. It is shown that the ZnCdSe alloy with layer thickness of about 2 ML forms at the interface in a ZnSe/CdSe quantum well heterostructure.