EXCITONS IN HETEROEPITAXIAL CDSE CDS STRUCTURES/

X-ray diffractometry and low-temperature exciton spectroscopy are used to study heteroepitaxial CdSe/CdS layers grown at temperatures of 350 -485 degrees C by MOCVD, The high-temperature samples are found to dis play the exciton and x-ray diffraction spectra characteristic of hexag onal Wurtzite (W) structures, while the low-temperature samples displa y the features characteristic of the cubic structure of sphalerite (ZB ). A number of the samples have x-ray spectra characteristic of struct ures with stacking faults (SF), which represent a separate crystalline phase in the structures studied here. It is found that the individual crystalline phases are spatially separated. (C) 1998 American Institu te of Physics.