Transparent thin films of pure anatase Titania nanoparticles with low surface roughness prepared by electron beam deposition method

Abstract

In this research, electron beam deposition method was used to synthesize Titanium dioxide (TiO2, Titania) thin films on quartz substrates at different oxygen partial pressures followed by thermal annealing. The samples were characterized by x-ray diffraction (XRD), UV-visible spectrophotometry, four-point probe and atomic force microscopy (AFM) techniques. A detailed study on the effects of deposition conditions on structural, optical, electrical and morphological properties of TiO2 films was systematically considered. The results reveal that all films possessed the anatase structure after heat treatment. The thermal annealing resulted in a gradual increase in crystallite size and optical transmittance while the corresponding refractive index decreased. The optical band gap, Eg, of TiO2 films increased from 3.76 eV to 3.83 eV. It is also found that electrical resistivity, ρ, decreased from 3.45 × 105 Ω cm to 1.25 × 104 Ω cm. Furthermore, the AFM micrographs revealed that the annealed film deposited at lower oxygen partial pressure produce a fine surface roughness suitable for many practical applications such as hydrophilic properties of thin films, for instance.