Localized exciton luminescence in nitrogen-incorporated SnO2 thin films

The photoluminescence properties of nitrogen-incorporated SnO2 thin films on Si (100) substrates deposited by reactive magnetron sputtering have been studied. A strong photoluminescence band centered at 3.696 eV with full width at half maximum of 0.2 eV has been observed at room temperature. The peak position of the emission shifts to higher energy with increasing excitation intensity or decreasing temperature. The emission is considered due to the localized exciton recombination, and the observed exciton localization and band-tail states are believed to originate from the potential fluctuation induced by spatial distribution fluctuations of nitrogen concentration and/or grain boundary defects in the nanocrystalline film. (c) 2006 American Institute of Physics.