Effect of Ce-doping on the structural, optical and photoluminescence characteristics of nano Zn0.75Cd0.25S

Abstract

Nano Zn0.75CexCd0.25S samples with different doping amounts of cerium (x = 0.0, 0.02, 0.04, 0.06) were synthesized using the thermolysis approach. The possibility of Ce ion incorporation into the ZnS0.75Cd0.25S lattice either substitutionally for Zn/Cd or interstitially into the voids of the lattice was examined using Rietveld refinement analysis based on X-ray diffraction (XRD) data. The lattice parameters, crystallite size and microstrain of the formed samples were computed. Particles with homogeneous spherical morphology can be seen using TEM technique with nano size of 2–4 nm, approving the values obtained from XRD. The optical properties of the prepared samples were examined by the diffuse reflectance spectroscopy technique. The optical energy gap value of Zn0.75Cd0.25S is 2.79 eV. As the Ce content rose, this value decreased until it reached 2.68 eV. The refractive index (n) values derived from numerous models, along with the average n values for all samples were calculated. The incorporation of Ce doping into nano Zn0.75-xCexCd0.25S samples results in an increase in their dielectric constants, suggesting their potential role for energy storage applications. With a rise in Ce doping, the non-linear optical parameters of Zn0.75-xCexCd0.25S were improved. Gaussian function fitting was used to decompose the photoluminescence (PL) emission of different samples. Upon doping with Ce, a noticeable reduction in the PL intensity was observed. The sample without any doping showed a cyan color, whereas the doped samples exhibited a cyan-green color.