The Effect of Thermal Annealing on the Structural and Optical Properties of CdS Thin Films Deposited by Vacuum Evaporation Method

Abstract

Cadmium Sulphide (CdS) thin films were grown on glass substrates by the vacuum evaporation technique. The effect of thermal annealing on the structural and optical properties of the as deposited samples was analyzed. Structure of these films was characterized by X-ray diffraction. CdS films deposited have polycrystalline structure cubic(zinc blende) and hexagonal (demand). The grain size increases with increasing annealing temperature. The optical properties of CdS films have highly transmittance in visible region of spectrum and reach to more than 84% . Band gap decreases from 2.55 to 2.33 eV with the increasing annealing temperature from 473K to 623 K.