Structural and optical characterization of wurtzite type ZnS

• ZnS nanofilms were deposited by RF magnetron sputtering on (100) GaAs substrates.
• It has investigated the substrate temperature effect on structure properties of ZnS.
• The ZnS grain size varied from 8.15 to 31.95 nm as a function of the grown temperature.
• ZnS nanofilms have good optical properties as was obtained by 300 K photoluminescence.

ZnS films 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), besides it allowed to find the residual impurities, mainly oxygen. The X-ray diffraction (XRD) analysis and Raman scattering reveal that ZnS deposited thin films showed hexagonal wurtzite crystalline phase. The films average crystallite size range was from 8.15 to 31.95 nm, which was determined using the Debye–Scherrer equation for the peak W(101). Besides an experimental study of first- and second-order Raman scattering of ZnS films is made. An energy level diagram involving oxygen traps and interstitial sulphur ions is used to explain the origin of the radiative transitions observed in the room temperature photoluminescence (PL) spectra.