Impact of preparation temperature on the structure, optical and electronic characteristics of Zn<inf>0.9</inf>V<inf>0.1</inf>S nanoparticles with Williamson-Hall model mechanistic view

Abstract

In this work, the impact of preparation temperature on the structural, optical, and electronic characteristics of vanadium doped ZnS nanoparticles has been explored. Nanoparticles of Zn0.9V0.1S samples were formed by molten salt solid state reaction procedure at different temperatures (200, 300, 400, 500 °C). Rietveld refinement and Williamson-Hall analysis were applied to trace the changes in the cell parameters, crystallite size and lattice microstrain related with lattice defects, such as Zn- and S-vacancies, and S-interstitial. The chemical composition of samples was investigated by Fourier-transform infrared spectroscopy technique. The UV–Vis spectra revealed the reduction of the direct optical band gap energy from 3.91 to 3.27 eV as the temperature is increased. Photoluminescence measurements revealed the dependence of emitted colors and intensity on temperature with a blue shift caused by strong quantum confinement in the particles. The electronic characteristics for ZnS, V-doped ZnS (V:ZnS), and V/O-doped ZnS (V:ZnS:O) were performed for comparison using density functional calculation (DFT) calculation. DFT calculation demonstrated that ZnS sample exhibited a semiconductor nature while V:ZnS and V:ZnS:O samples revealed half metallic and metallic characteristics, respectively. ZnS has a non-magnetic characteristics whilst V:ZnS and V:ZnS:O samples exhibit a magnetic feature.