Optical and Electrical Properties of Semiconducting ZnS Thin Film Prepared by Chemical Bath Deposition Technique

Abstract

The main purpose of this study is to synthesize and investigate the optical and electrical properties of zinc sulphide (ZnS) thin film which has some interesting optoelectronic properties. The films were grown by chemical bath deposition (CBD) technique on clean soda-lime substrates at room temperature (300k). The films were characterized using Fourier transform infrared spectroscopy (FTIR), Ultraviolet-Visible spectroscopy (UV-Vis), and Four point probe measurements. The FTIR spectrum of the film revealed the characteristic ZnS absorption bands below 800 cm-1.  The optical properties were studied in the spectra range of 300 to 1500 nm. The film revealed an average transmittance of above 80% in the visible and near infrared regions with a band gap of 3.30 eV. Optical constants of refractive index, extinction coefficient, electrical susceptibility, dielectric loss were estimated at λ = 800 nm. The values of ­­­­­­­­­­­­­­­­­­­­­­­­ 1.25 Ω. cm and 8.0 ×10-1 (Ω. cm)-1 were obtained as the electrical resistivity and conductivity respectively. The determined properties categorize ZnS thin film as a promising material for various optoelectronic devices.