Low-temperature buffer layer effects on the quality of ZnTe epilayers grown on sapphire substrates

Abstract

The effects of a low-temperature ZnTe buffer layer on the structural, optical properties and surface morphology of ZnTe epilayers grown on (0001) sapphire substrates by metalorganic vapor phase epitaxy are investigated. X-ray diffraction, x-ray rocking curves, photoluminescence spectra, Raman spectra, and atomic force microscopy analysis reveal that the crystal quality, optical properties, and surface roughness of ZnTe epilayers can be improved by introducing a low-temperature ZnTe buffer layer between ZnTe epilayer and sapphire substrate, and that the thickness of the low-temperature ZnTe buffer layer is critical for obtaining a high quality ZnTe epilayer.