Indian Journal of Science and Technology

Abstract

Objectives: In this study, pure and cobalt doped ZnO nanoparticles are synthesized by simple solution method and ­doping effect of cobalt on the optical properties ZnO nanoparticles is studied at room temperature to enhance the optical ­properties by varying the electrons of appropriate concentration. Methods: Synthesis of ZnO nanoparticles was achieved by the simple and effective solution method using zinc nitrate tetra hydrate and cobalt nitrate tetra hydrate. The defects and impurities were investigated by Fourier transform infrared spectroscopy. Findings: The FTIR spectrum shows the characteristics peak of ZnO at 490 cm–1. In cobalt doping ZnO nanoparticles, the entire peak transmittance % got quenched. Together these results identified the impurities which exist near ZnO surface. No other peak was not observed in the ­spectra confirms that final products is ZnO nanoparticles. we measured the absorption spectra for pure and cobalt doped ZnO nanoparticles to study the effect of doping concentration of cobalt on the absorption of ZnO, After being doped with Co, the absorption peaks shifted towards longer wavelength region from 358 nm to 372nm. Band gap for Co doped ZnO nanoparticles are found to be between 3.28–3.05 eV range. This is due to the increase in particle size that results the less quantum confinement within the nanoparticles. Applications: Zinc Oxide semiconductor material is applied to many applications like solar cells, transparent electrode, transducer, and laser diodes due to its enhanced optical properties by doping transition materials.

Keywords: Band Gap and Absorption Spectra, Optical Property, Semiconductor, ZnO