LOCALIZED EXCITONIC EMISSIONS OF ZNCDSE ZNSE QUANTUM-WELLS GROWN AN AGAAS(110) CLEAVED SURFACE/

Anomalous optical properties of Zn1-xCdxSe/ZnSe strained-layer single quantum wells (SQWs) fabricated on cleaved GaAs(110) surfaces in ultra high vacuum by molecular beam epitaxy have been investigated. From the temperature-dependent photoluminescence measurement, the origins of l ocalized excitonic emissions of two kinds of SQW structures with diffe rent Cd compositions are suggested. Localization centers of SQWs with low Cd composition (14%) are mainly originated by the well thickness f luctuation. However, SQWs with high Cd composition (27%) showed locali zed excitonic emissions at low temperature due to the Cd composition F luctuations rather than the lack of thickness uniformity of the well l ayer. Estimated averaged depths of localization of excitons by model c alculations are 9 and 14 meV for the wells with 14% and 27% Cd composi tions, respectively. (C) 1998 American Institute of Physics. [S0003-69 51(98)03136-2].