Synthesis and luminescence enhancement of Cerium doped CdS nanoparticles

Abstract

Cerium doped cadmium sulfide nanoparticles (Ce:CdS) were synthesized by coprecipitation method with three different concentrations of cerium (1, 2 and 3 mol%). Powder X-ray diffraction pattern reveals the formation of cadmium sulfide nanoparticles with hexagonal (wurtzite) structure. It was observed that the presence of ceria does not alter the structure of CdS. Average particle size was measured to be ~ 3 nm. Reflectance spectra illustrate band-to-band absorption at 453, 500 and 507 nm respectively for 1, 2 and 3% Ce doped CdS nanoparticles. The presence of cerium was confirmed by EDX and ICP-OES analyses. The effect of dopant concentration on the photoluminescence (PL) intensity has also been studied. XRD and PL analyses demonstrate the Ce 3+ ions uniformly substitute Cd 2+ sites or interstitial sites in CdS lattice which influences the optical properties. Increase in the concentration of cerium slightly shifts the absorption and emission toward higher wavelength. Particle size and the crystallinity of Ce:CdS NPs were confirmed through HRTEM and SAED patterns.