Zinc oxide layers having various Zn-contents were prepared in order to ascertain the role of Zn-interstitial defects, in the ultraviolet emission from ZnO, with the help of photoluminescence measurements. The typical photoluminescence spectrum obtained at room temperature exhibited a dominant ultra-violet line at 3.28eV and a visible line centered at 2.25eV. A detailed investigation revealed that the ultra-violet emission was due to a bound exciton transition-Zn-interstitial transition. The ultra-violet intensity due to Zn-rich samples was almost doubled, as compared to that of a sample with lower Zn content. The results obtained from the energy dispersive X-ray spectrum and Raman spectroscopy strengthened the photoluminescence results.

Role of Zn-Interstitial Defects in the Ultraviolet Emission from ZnO. Asghar, M., Mahmood, K., Ali, A., Hasan, M.A., Raja, M.Y.A., Hussain, I., Willander, M.: ECS Transactions, 2011, 35[6], 149-54