Effect of substrate temperature on the structural and the optical properties of CdTe (100) epitaxial films grown on GaAs (100) substrates

CdTe thin films were grown on GaAs(100) substrates by using molecular beam epitaxy at various temperatures. The results of the X-ray diffraction (XRD) patterns showed that the orientation of the grown CdTe thin films was the (100) orientation. XRD patterns, atomic force microscopy images, high-resolution transmission electron microscopy (HRTEM) images, and photoluminescence spectra showed that the crystallinity of CdTe(100) epilayers grown on GaAs(100) substrates was improved by increasing the substrate temperature. HRTEM images showed that misfit dislocations existed at the CdTe/GaAs heterointerface. These results can help improve understanding of the substrate temperature effect on the structural and the optical properties of CdTe(100)/GaAs(100) heterostructures.