Optical and electrochromic properties of sol-gel made anti-reflective WO₃-TiO₂ films

The study is an analysis of the optical and electrochromic properties of antireflective WO₃-TiO₂ thin films prepared by sol-gel method. TiO₂ (1, 5, 10 and 15 mol%)-mixed WO₃ thin films were deposited on ITO-coated glass and Corning glass substrates by spin process. The titanium content of the layers was determined by X-ray photoelectron spectroscopy (XPS). Effects of annealing temperature and titanium content on the electrochromic and optical properties of the WO₃-TiO₂ films were investigated by cyclic voltammograms with in situ monochromatic transmittance measurements. Sol-gel derived WO₃-TiO₂ anti-reflection coatings on glass substrates are successfully developed. Scanning electron microscope (SEM) pictures of pure WO₃ and WO ₃-TiO₂ films indicate that even small titania contents can lead to significant structural changes of tungsten oxide films.