Temperature Induced Structural and Photoluminescence Properties of Poly Ethylene Glycol (PEG) Capped/Uncapped Cadmium Oxide Nanoparticles (CdO NPs)

Uncapped and PEG capped CdO NPs were successfully synthesized by precipitation technique. XRD and TEM studies were used to investigate the particles structure, size and shape. As synthesized samples showed major hexagonal Cadmium Hydroxide [Cd (OH)2] phase and were completely transformed into cubic CdO crystalline phase above 400 °C annealing temperature. A good crystallinity was noticed in PEG capped CdO NPs. TEM images brought out the information about the synthesized nanoparticles (NPs) existed spherical in shape. The weight loss from thermogravimetric analysis (TGA) graphs depicted the formation of CdO NPs from Cd (OH)2. PEG on CdO NPs evidently increased the direct band gap emission intensity around 480 nm and while indirect band gap emission intensity of around 620 nm was increased in uncapped CdO NPs. Beside this, PL spectra revealed interesting changes with the effect of PEG, annealing temperature and excitation wavelengths. Hence PL spectra ascertained their possible use for optical and electronic applications.