Electrodeposition-based synthesis and characterization of ZnS nanostructure thin films for optoelectronics devices

Abstract

Zinc sulphide (ZnS) nanostructure thin films were effectively deposited on ITO substrate in the current investigation using the electrodeposition method. The structural and geometric properties of the developed thin films were analysed using XRD and SEM. XRD investigation revealed a wurtzite hexagonal crystal structure, and the estimated crystal size for the favoured orientation was around 63 nm. The visual characteristics were ascertained by analyzing UV-visible spectra, and the direct bandgap of ZnS is calculated to be ~ 3.93 eV using Tauc's plot. Since the developed nanostructure thin film comprises defect states, the band gap energy is lower than bulk material. The current-voltage aspects of the developed thin film were measured in the dark and the presence of 20 W LED light and 100 W tungsten filament light, respectively. Compared to dark mode, there was a discernible difference in the current for both LED and conventional light. These findings suggest that low-cost ZnS may be used as a substitute for solar cells, which are environment-friendly and Cd-free window layers for optoelectronic devices.