Epitaxial growth and characterization of ZnTe thin films for terahertz devices

摘要

ZnTe layers were grown on sapphire substrates by metalorganic vapor phase epitaxy. The PL spectrum for the ZnTe grown at 420°C was dominated by a sharp excitonic emission at 2.375 eV associated with shallow acceptors while only Y line around 2.16 eV due to extended structural defects was observed for the ZnTe layer grown at 390°C. The surface roughness of the ZnTe layers increased linearly with layer thickness, which is ascribed to the three-dimensional growth mechanism.