Modifications in the optical and electronics characteristics of nano cadmium sulfide upon Ni-doping

Abstract

CdS and Cd0.9Ni0.1S samples were produced by the solid-state reaction method at low temperature and under a nitrogen atmosphere. The obtained phases in both samples were explored using x-ray diffraction technique. Rietveld refinement was applied to determine the cation occupancies in different crystallographic positions, lattice parameters and crystallite size. Utilizing scanning electron microscopy (SEM/EDS), the morphology and elemental composition of Cd0.9Ni0.1S sample were examined. Fourier-transform infrared spectroscopy and element energy dispersive spectroscopy techniques confirmed the inclusion of Ni ions in the CdS lattice. The determined energy bandgap for undoped and Ni-doped CdS is 2.26 and 1.98 eV, respectively. The effect of Ni doping on the photoluminescence intensity and emitted colors of host CdS was explored. Using density functional theory (VASP code), the effect of Ni substitutions on the structural properties of CdS lattice was investigated. Moreover, HSE06 hybrid functional was applied to determine the electronic properties of pure and Ni doped samples. Additionally, the optical properties including absorption coefficient, refractive index, and extinction coefficient were calculated using HSE06 functional.