Dynamical properties of atom-like emissions from single localized states in ZnCdS ternary mesa-shaped structures

Dynamical properties of exciton localization into spatially isolated localized states with atom-like density of states caused by alloy potential fluctuations were examined. Submicron-sized mesa-shaped structures were prepared to resolve the contribution of single localized states to the optical spectra, which makes it possible to observe atom-like emission lines and to discuss the dynamical properties of exciton energy relaxations by employing micro-time-resolved PL measurements. It will be shown that in the samples with high exciton energy transfer efficiency, photogenerated excitons can relax into the spatially isolated localized centers with strong zero-dimensional nature, which leads to the limited number of atom-like emission lines. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.