A simple and effective route to annihilate defects in nanocrystalline SnO2 thin films prepared by pulsed laser deposition

The microstructural defects of nanocrystalline SnO₂ thin films prepared by pulsed laser deposition have been investigated using transmission electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy. Defects inside nanocrystalline SnO₂ thin films could be significantly reduced by annealing the SnO₂ thin films at 300°C for 2 h. High-resolution transmission electron microscopy showed that stacking faults and twins were annihilated upon annealing. In particular, the edges of the SnO₂ nanoparticles demonstrated perfect lattices free of defects after annealing. Raman spectra also confirmed that annealing the specimen was almost defect-free. By using thermal annealing, defect-free nanocrystalline SnO₂ thin films can be prepared in a simple and practical way, which holds promise for applications as transparent electrodes and solid-state gas sensors. © 2008 Materials Research Society.