Thin (001) tungsten trioxide films grown by laser deposition

Highly textured thin (0 0 1) tungsten trioxide (WO3) films have been deposited on (0 0 1) SiO2 substrates by XeCl excimer laser ablation of ceramic targets. The influence of the oxygen pressure and substrate temperature on the composition, crystallinity and optical properties of the films has been studied. The films were grown at pressures of 1–25 Pa and substrate temperatures from room temperature up to 670 °C. The best crystallinity was obtained for the films grown at 10 Pa and 500 °C as confirmed by XRD analyses and Raman spectroscopy. Optical transmission as high as 83% has been measured in the visible and near-infrared spectral regions. The ordinary index of refraction at wavelength of 633 nm increases with the growth temperature and reaches 1.97 at the optimum growth conditions.