Effect of Firing Temperature on the Structural, Optical, and Electrical Properties of VO<sub>2</sub> Thin Films Deposited by Chemical Solution Deposition.
Characteristics of VO2 films prepared on alkali-free glass substrates by chemical solution deposition (CSD) using vanadyl oxalate nhydrate as the raw material are investigated. Diffraction peaks corresponding to VO2 are observed in the samples obtained at firing temperatures of 350 to 550°C. However, diffraction peaks of the samples obtained at 500 and 550°C show a mixture of VO2 and V6O13 phases. Regarding the surface and cross-section morphology of the films, the crystal grain size and porosity of the films steadily increase with firing temperature. The samples show an abrupt change in resistivity around 70°C. The change in resistivity caused by the metal-insulator transition are about three orders of magnitude. The sample transmittance in the near-infrared region decreases sharply with the phase transition. The maximum reduction in transmittance at 2000nm is 55.4%.