Dependence on MOCVD Growth Temperature of The Photoluminescence Properties of ZnSe, ZnTe, and ZnSe(1-x)Te(x) Alloys and ZnSe/ZnTe Superlattices

ABSTRACTIt has been recently shown that high quality ZnSe and ZnTc filns can be grown on GaAs using low temperature growth techniques such as Metal-Organic Chemical Vapor Deposition ( MOCVD). All samples: ZnSe, ZnTe, ZnSc(l−x)Tc(x) epilayers and ZnSe/ZnTc superlattices were grown using a novel zinc precursor, the Tri-Ethyl-Amine Di-Methyl-Zinc, while we used the classical precursors H2Se and Di-Isopropyl-Tellurium for selenium and tellurium. Investigation of the photoluminescence (PL) properties of ZnSc and ZnTe single layers enabled us to optimize the growth conditions of these compounds. The crystal growth conditions for mixed alloys and superlattices were determined by direct comparison to the aspect of low-temperature PL features. Strong PL spectra were obtained from these materials, suggesting us that tellurium has the ability to behave like an iso-clectronic center. At low concentration of tellurium in ZnSe, an interesting physical situation is observed, which we have interpreted in terms of extrinsic exciton “self-trapping” mechanism.