Optical characteristics of Al-doped ZnS thin film using pulsed laser deposition technique: the effect of aluminum concentration

Abstract

"An efficient pulsed laser deposition (PLD) method was used to create un-doped and aluminum (Al) doped zinc sulfide (ZnS) nanomaterial. The effect of Al concentration on optical properties was investigated using two different techniques; namely, Ultra-violate visible light (UV-Vis) and Photoluminescence (PL) spectroscopies. Specifically, the optical analysis revealed a decrease in the optical bandgap values from 3.5 to 3.28 eV upon the addition of 8% of Al as dopant. While, the PL spectra of all samples showed a broad emission band in the 300-500 nm range. ZnS emission bands with Gaussian fitting are located at 396 and 459 nm. Despite from the pure ZnS peaks, three additional peaks at 345, 369, and 386 nm are observed for Al doped ZnS nanomaterial. Additionally, increasing the Al content up to 6% resulted in enhanced photoluminescence, but above this level, photoluminescence quenching was observed."