Tuning the structure and optical properties of nanostructured CdS by Cu doping

Abstract A simple and cost-effective route has been employed to synthesize pure and Cu doped (2 %, 4 % and 6 %) cadmium sulfide (CdS) nanoparticles. Structural, optical and morphological properties of pure and doped samples were analyzed using XRD, UV–vis spectrophotometry, SEM and FTIR spectroscopy. XRD results confirmed the formation of hexagonal crystal structure for doped and pure CdS nanoparticles with crystallite size varying from 11−17 nm. Moreover, significant reduced intensity of diffraction is also evident accompanied by slight peak-shifting towards higher angles. Agglomerated spherical morphology of the CdS nanoparticles with decreasing particle size upon Cu doping was observed by SEM. FTIR spectra was found to consist of stretching vibrations from Cd-S and other related groups with negligible changes in the vibrational modes upon doping. The UV–vis analysis demonstrates a significant increase in absorption intensity upon doping along with slight blue shift leading to an increased band gap for doped CdS. These finding represent a cost-effective way to prepare CdS and related materials with tunable optical band gap.