Effect of annealing temperature on the structural and optical properties of SnO2 thin films elaborated by sol-gel technique

In this study, the influence of annealing temperature on the structural and optical properties of SnO2 thin films was investigated. SnO2 thin films were prepared by sol–gel deposition on glass substrates at room temperature and then annealed at different temperatures (300, 400 and 500°C) in air for two hours. The obtained films were characterized by Raman spectroscopy and UV–Vis spectrophotometry techniques. A single-phase rutile structure was revealed by Raman spectroscopy analysis. The optical measurements have shown that all the films have a high transparency (75-85%) in the visible spectral range, and the optical band gap increases from 3.68 to 3.89 eV with increasing annealing temperature.