Science and Education Publishing Journal of Optoelectronics Engineering 2372-4781 4 1 2016 6 21 A Systematic Study of the Optical Properties of Co-, and Ni- Doped Colloidal Cadmium Sulphide Nanoparticles 11 16 EN P. Bhambhani Department of Physics, Banasthali University, Banasthali-304022, India P. A. Alvi JOE2016413 10.12691/joe-4-1-3 2016 1 15 2016 5 7 2016 6 19 Present research paper deals with the synthesis and characterization of CdS:Co and CdS:Ni nanoparticles. CdS:Co and CdS:Ni nanoparticles are synthesized with the different concentration of Co and Ni with the use of polyethylene glycol (PEG) as capping agent. Samples are characterized by Scanning Electron Microscopy (SEM), Ultraviolet-Visible (UV-VIS) and Photoluminescence (PL) spectroscopy. The size of synthesized nanoparticles is obtained ~50 nm approximately by SEM images. The effect of doping concentration on optical properties of CdS nanoparticles is studied by UV-VIS and PL spectroscopy. Band gap of Cd1-xCoxS and Cd1-xNixS nanomaterials decreases with doping concentration. The results demonstrate that the doping concentration play an important role in optical features of nanomaterials. On behalf of the outcomes, it can be reported that the nanoparticles can be utilized as a photodetectors operating in visible region of increasing wavelengths.