Identification of oxygen vacancy types from Raman spectra of SnO2 nanocrystals

Raman spectra acquired from spherical SnO2 nanocrystals prepared by pulsed laser ablation and hydrothermal synthesis exhibit three oxygen-vacancy-related Raman modes at 234, 573, and 618?cm-1. The peak location and intensity vary with annealing temperature under O2 finally approaching those of bulk materials. Density functional calculation discloses that the three Raman modes stem from subbridging, in-plane, and bridging oxygen vacancies, respectively. Raman spectra can thus be used to discern different types of oxygen vacancies in SnO2 nanocrystals. Copyright (c) 2012 John Wiley & Sons, Ltd.