STRUCTURAL CHARACTERISATION AND OPTICAL PROPERTIES OF ANNEALED ZnSSe THIN FILMS

ZnSSe thin films were thermally evaporated on unheated quartz substrates using ZnS/ZnSe thin film layers. The prepared films were subjected to post deposition pulsed laser annealing (PLA) at different powers of 15, 20 and 30W. XRD analysis indicates that all ZnS/ZnSe layers after annealing possess a single phase cubic structure with a strong preferred (111) orientation. The evaluated average crystallite size as deduced from the FWHM of the XRD layer peaks was varied from 26.5 nm for the as deposited sample to 34.80 nm for the sample annealed at PLA power of 30 W. The optical characteristics of the samples were studied by measuring the spectral transmittance and reflectance. The optical energy gap as well as refractive index were measured and then correlated with the PLA power.