The In2O3, SnO2 and ZnO nanostructures were synthesized via the thermal evaporation method and their photoluminescence was investigated in order to explore the light emission mechanism. All of the three as-grown metallic oxide nanostructures had a strong blue or green photoluminescence at room temperature. However the blue or green light emission disappeared when the as-grown materials were oxidized in air at high temperature, and then reappeared again when the oxidized products were deoxidized in forming gas mixtures of argon and H2 at high temperatures. A common feature was that blue or green emission originated from the oxygen vacancies.

Correlation between Photoluminescence and Oxygen Vacancies in In2O3, SnO2 and ZnO Metal Oxide Nanostructures. Wu, P., Li, Q., Zou, X., Cheng, W., Zhang, D., Zhao, C., Chi, L., Xiao, T.: Journal of Physics - Conference Series, 2009, 188[1], 012054