On the structural and optical characteristics of zinc telluride thin films

Zinc telluride (ZnTe) thin films were prepared by vacuum evaporation of polycrystalline ZnTe onto glass substrates at 300-450K. The films were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM).The crystalline structure was found to be cubic (zinc blende). The film crystallites are preferentially oriented with (111) planes parallel to the substrates XRD patterns and AFM images have been used to determine the microstructural parameters (crystallite size, lattice parameter) of investigated films.The optical bandgap (Eg=1.95 eV-2.40 eV) determined from absorption spectra indicates direct band-to-band transitions. The effect of the deposition conditions and post-deposition heat treatment on the structural and optical properties has been studied.