Emissions from single localized states observed in ZnCdS ternary alloy mesa structures

Sharp and discrete emission lines from single localized states in ZnCdS ternary alloys were clearly observed from selectively grown mesa structures. This is a demonstration that compound semiconductor alloy systems, which usually show broad emission spectra due to alloy fluctuations, are able to exhibit emissions from discrete energy levels with quasi-zero-dimensional density of states in limited mesa areas where limited number of deeper localized states will contribute. Introduction of ZnCdS/MgS short-period superlattices is found to play a significant role for the exciton migration enhancement from shallower to deeper localized states, which makes the observation of the emission lines from the single localized states possible in the ZnCdS alloy layers. (C) 2003 American Institute of Physics.