Synthesis of Nickel-Doped TiO₂ Thin Films and Their Structural and Optical Properties at Different Annealing Temperatures

Titanium oxide (TiO₂) and nickel-doped TiO₂ thin films were deposited onto glass substrates by reactive DC magnetron sputtering technique at different oxygen contents. Then, prepared films were annealed at temperatures of 300 and 500°C. Influence of O₂/Ar ratio, nickel doping and annealing temperature on structural, morphological and optical properties of TiO₂ thin films were studied and discussed. The XRD analysis results have confirmed the amorphous nature of the films. The results show that increase of annealing temperature and oxygen content in argon-oxygen gas mixture have lead to an increase of films transparency. By doping the TiO₂ with nickel the optical band gap energy has slightly decreased. AFM analysis results have shown that the surface morphology of films is effectively influenced by annealing temperature.