Structural and Optical Characterization of Tin (Sn) Doped Zinc Sulfide (ZnS) Thin Film

Zinc Sulfide (ZnS) thin film was deposited on glass substrate using chemical bath deposition technique and Tin (Sn) doping was performed by adding Tin Chloride (SnCl 2 ) solution as Sn source. These films were further characterized by X-ray diffractometer (XRD) and UV-VIS-NIR spectrophotometer. ZnS thin film had single phase hexagonal structure and Sn doping replaces Zn atom without altering shape. Deposition temperature fixed at 70°C for 30 minutes and annealed for 15 minutes at 100°C. XRD intensity increase as the percentage of Sn doping increases, Optical properties like transmittance, dielectric constant, energy bandgap and absorbance had promising results. Transmittance in near-infrared region was greater than 83%, relatively stable absorbance of (5–11) %, energy bandgap from 3.60 eV to 3.84 eV, small fluctuation in dielectric constant and reduced refractive index. Optical bandgap and dielectric constant of ZnS thin film both have proportional relation with percentage of Tin doping.