Localized exciton emission from ZnO nanocrystalline films

ZnO nanocrystalline films were grown using In2O3 nanostructure as template by pulsed laser deposition. A strong emission at 3.372 eV dominates the low temperature photoluminescence (PL) spectra. Combined with annealing and surface passivation process, it is indicated from temperature-dependent PL results that the emission could be attributed to recombination of localized excitons. The low probability that localized excitons decay through nonradiative recombination centers may contribute to the efficient luminescence at low temperature. It was suggested that disorder introduced by grain boundaries is responsible for the exciton localization. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3310804]