Vanadium dioxide thin films deposited on TiO₂ buffer layer for smart thermochromic glazing of windows

Vanadium dioxide (VO₂) films were prepared on quartz glass and TiO₂-coated quartz glass substrates by reactive RF-magnetron sputtering. The VO₂ thin film with film thickness of 50 nm deposited on quartz glass substrates showed two kinds of regions with different color visible to the naked eye, i.e., the earth yellow region and the cyan region. Both XRD and Raman spectroscopy showed that the different color regions of the films had the different crystallinity quality and phase composition. Whereas, the VO₂ thin films with film thickness of 50 nm fabricated on TiO₂-coated quartz glass (with TiO₂ film thickness of 50 nm) had uniform color and exhibited a larger change in transmittance at near infrared region than the VO₂ thin films deposited on quartz glass did. A TiO₂ buffer layer improved the crystallinity and uniformity of the VO2 film. Such very thin VO₂ films with a TiO₂ buffer layer have high potential for practical application in smart thermal glazing of windows.