Defect evolution of nanocrystalline SnO2 thin films induced by pulsed delivery during in situ annealing

Abstract The microstructural defects of nanocrystalline SnO 2 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 SnO 2 thin films could be significantly reduced by in situ annealing SnO 2 thin films at 300 °C for 2 h. High-resolution transmission electron microscopy showed that the stacking faults and twins were annihilated upon in situ annealing. In particular, the inside of the SnO 2 nanoparticles demonstrated perfect lattices free of defects after in situ annealing. Raman spectra also confirmed that the in situ annealed specimen was almost defect-free. By using in situ annealing, defect-free nanocrystalline SnO 2 thin films can be prepared in a simple and practical way, which holds the promise for applications as transparent electrodes and solid-state gas sensors.