A method for deposition of tungsten trioxide (WO3)

Thin films of tungsten oxide (WO3) have been grown by hot-filament metal oxide deposition (HFMOD) technique under atmospheric pressure and an oxygen atmosphere on glass substrates. The thin film of WO3 has been extensively studied as an electrochromic material and has numerous applications in electrochromic devices. In order to explore the possibility of using WO3 in electrochromic devices, a preliminary and thorough study of the structural and optical properties of the host material is an important step. By the X-ray diffraction analysis the single phase natures, monoclinic and orthorhombic structure of the films have been confirmed. The IR spectra were constituted of many broad peaks in the 1400-3500 cm-1 region That are assigned to ν(OH) and δ(OH) modes of adsorbed water. The corresponding WO3 vibrations are in infrared regions of 1453-400 cm-1 and 3454 cm-1, which correspond to W-O stretching, bending and lattice modes. By Transmittance measures determines that the optical bandgap is around 2.92 eV. We have observed that the good quality WO3 thin films can be satisfactorily grown by this technique.