WO3 thin films for optical gas sensing

Thin films of WO3 were deposited on quartz substrates by the RF magnetron sputtering. Different annealing temperatures of 423, 473, 573 and 773 K were used for different films. The films were annealed under the ambient conditions. The influence of the annealing temperature on the structure and optical properties of the WO3 was studied. The surface morphology of the thin films was investigated by atomic force microscopy, which showed that the annealing temperature increases the surface crystallinity. Spectrometric measurements of transmittance were carried out in the wavelength range 190–3300 nm and the energy gap, Eg, has been evaluated.