Structural and photoluminescence properties of Mg substituted ZnO nanoparticles

This paper reports on structural and optical properties of Mg doped ZnO nanoparticles prepared through sol-gel method using polyvinyl alcohol as chelating agent. X-ray diffractometer (XRD), Field Emission Scanning Electron Microscope (FE-SEM), UV-Vis (UV-Vis), Fourier Transform Infrared (FTIR) and Photoluminescence (PL) spectrophotometers were employed to study the structural and optical properties. XRD and FE-SEM results demonstrated that particle size of ZnO decreased with increase in Mg concentrations. It was observed that the absorption spectrum of ZnO blue shifted as the Mg concentration enhanced from 1 mol.% to 5 mol.%, presumably due to reduction in particle size. It was found that MgO secondary phase was not formed even above the solid solubility limit of Mg in ZnO. ZnO nanoparticles exhibited an intense and strong UV emission peak at 396 nm and this peak is attributed to the electron transition from the localized level slightly below conduction band to the valence band. The position of this emission peak remained same for all concentrations of Mg in ZnO.