Green emission from ZnO–MgO nanocomposite due to Mg diffusion at the interface

摘要: Abstract The origin and electronic transitions responsible for green emission observed from ZnO–MgO nanocomposite are investigated. photoluminescence (PL) spectrum of annealed at 600 °C showed only a sharp intense UV peak centered 396 nm. As the annealing temperature increased to 1000 °C, positioned 503 nm is emerged its intensity enhanced gradually reached maximum value 900 °C then decreased 1000 °C. It that both intensities with variation atomic ratio (Zn/Mg=1.52, 0.50, 0.30, 0.21, 0.15). Our experiments confirmed enhancement due formation oxygen vacancies ( V o ) Mg doping interface ZnO MgO. This experimental observation in good agreement recent theoretical predictions which states lowers energies zinc interstitials (Zni) significantly. PL excitation spectra analysis reveals excited state emissions same lies 0.24 eV below conduction band ZnO. Hence, attributed transition an electron form shallow donor (defect level Zni) deep acceptor Vo).