Effect of Mg Doping on the Structural and Optical Properties of CdS Nanoparticles Synthesized by co-Precipitation Method

Cd1 - xMgxS (x = 0.00, 0.05, 0.10, 0.15 and 0.20) nanoparticles were synthesized by co-precipitation method for the first time. Compositional, morphological, structural and optical studies of the as prepared samples were carried out by X-ray diffraction (XRD), Energy dispersive analysis of X-rays (EDAX), Scanning electron microscopy (SEM), Diffuse reflectance spectroscopy (DRS) and Photoluminescence (PL) techniques. XRD studies revealed the structural phase transition from cubic to hexagonal and increase in the average grain size of the nanoparticles (lie in the range 1.4 nm to 2.8 nm) with increasing Mg content. EDAX spectra rules out the existence of impurities in the samples. Bandgap widening was observed in all the samples compared to bulk CdS (2.42 eV). Decrease in bandgap (3.02 eV to 2.54 eV), luminescence quenching and red shift of luminescence peak position were observed with increasing Mg in Cd1 - xMgxS.