Defect based violet-blue emission of Mg doped ZnO annealed at different temperatures

This paper describes structural and optical characterization of Mg doped ZnO nanoparticles. The system Zn1-xMgxO with x = 0.0, 0.01, 0.03, 0.05, 0.1 were prepared by a simple chemical method and annealing at different temperatures, T = 500, 700 and 900 degrees C. XRD spectra and the Rietveld refinement show that the crystalline phase of these samples belongs to the wurtzite hexagonal structure of space group P6(3)mc. The PL results show three main emission bands in the violet and blue emission regions. The presence of several emission bands are attributed to free excitation transitions, interstitial Zn, local zinc vacancy, single ionized oxygen vacancy, and deep level emissions. PL studies at 500 degrees C revealed that visible PL emission was enhanced with doping concentration (x). Mg doped ZnO structures have changed the optical properties significantly.