Growth and characterization of ZnS nanofilms grown by RF magnetron sputtering on GaAs

Zinc sulphide (ZnS) is one of the most important II-VI group semiconductors, with a wide direct band gap of 3.8 eV has been extensively investigated and used in electroluminescent devices, flat panel displays, infrared windows, sensors, and lasers. To explore the possibility of using it in electroluminescent devices, a study of the structural and optical properties of the host material is an important step. Based on the above criterion, the structural and optical properties of ZnS nanofilms have been studied in the present work. ZnS nanofilms were grown on (001) GaAs substrates at different temperatures by RF magnetron sputtering. The ZnS chemical stoichiometry was determined by Energy-dispersive X-ray spectroscopy (EDS). The XRD analysis and Raman scattering reveal that ZnS deposited nanofilms showed hexagonal wurtzite crystalline phase. The average crystallite size range of the film was from 8.15 to 32.95 nm, which was determined using the Scherrer equation. Besides an experimental study on first- and second-order Raman scattering of ZnS films is made. An energy level diagram involving oxygen traps and interstitial sulphur ions used to explain the origin of the observed emission peaks in the room temperature photoluminescence spectra.