Microwave assisted synthesis of undoped and Cu doped CdS nanoparticles and their structural, morphological and optical characterization

Undoped and Cu (2%, 4%, and 6%) doped Cadmium Sulphide nanoparticles were synthesized in aqueous solution by microwave assisted method. In this study the doping effect of Cu on the structural and optical properties of CdS nanoparticles has also been discussed. For the synthesis of nanoparticles the chemicals used were cadmium acetate, thioacetamide, sodium sulphide and copper chloride. The as synthesized undoped and Cu doped CdS nanoparticles were found to be in crystalline phase. The crystalline phases have been characterized by X-ray diffraction (XRD). The average size of the nanocrystallites were calculated by the use of Debye-Scherrer formula and was found to be around 8 nm for undoped CdS and around 4.5 nm, 4.8 nm and 5.6nm for 2%, 4%, and 6% Cu doped CdS respectively. The morphology of the nanoparticles was studied by Scanning Electron Microscopy (SEM). The different functional groups present in the sample of nanoparticles were identified by FTIR study. The bandgap of the nanoparticles was calculated using UV-Visible absorption spectra. The result showed that the bandgap values were blue shifted from the bulk one. The observed shifts in both blue band and green band of photoluminescence spectra confirmed the substitution of Cu into Cd-S lattices.