Anatase TiO 2 films obtained by cathodic arc deposition

Abstract

TiO 2 thin films were prepared on glass substrates at different temperatures employing an unfiltered cathodic arc device. The temperature values were varied from room temperature to 400 °C. The crystalline structure of the films was determined by X-ray diffraction. The surface morphology was studied by scanning electron microscopy and atomic force microscopy. Transmittance in UV–visible region was also measured. All films deposited at temperatures lower than 300 °C were amorphous, whereas films obtained at higher temperatures grew in crystalline anatase phase. Phase transition amorphous-to-anatase was observed after post-annealing at 400 °C. The average transmittance value for all films was higher than 80%, a comparison among the films obtained at different temperatures showed a transmittance value slightly higher for films obtained at highest temperatures. Grain size for as-deposited crystalline films was determined approximately in 20 nm, with a surface roughness of about 2 nm.