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The Fe³⁺-TiO₂ thin films obtained through sol-gel method were characterized by x-ray diffraction, AFM and Raman spectroscopy. It was found that TiO₂ films consisted of nanometer particles. The experimental results shows that the nanometer TiO₂ thin films doped with Fe³⁺ were greatly improved in the activity aspect. This may be ascribed to change their structure and electrical properties after doping with Fe³⁺. The results were discussed theoretically in detail.

In this work, an attempt has been made to compare the physical properties of conductive films of Nb-doped TiO₂ deposited on Kapton polyimide, glass and silicon substrates. Thin films were deposited by radio frequency sputtering at room temperature and subsequently characterized using X-ray diffraction, X-ray photoelectron spectroscopy, UV-VIS-NIR spectroscopy and Hall Effect measurement. Structurally, the films grown on the flexible substrate exhibit more strain and had inferior crystallinity (crystallite size $\sim$13.8 nm) compared to the films deposited on glass and silicon substrates (crystallite size $\sim$27 nm). The film on glass had a resistivity value around $1.67\times 10^{-3}\mathrm{\Omega }\cdot \mathrm{\text{cm}}$ while the resistivity of the films grown on polyimide was found about five-fold higher. Furthermore, the films deposited on glass substrate showed optical transparency of $>$80% in the visible range (400–750 nm). The inferior electrical transport properties of the films grown on polyimide were correlated with the poor crystallinity and cracks induced during the annealing process. Furthermore, various possible routes have been discussed to improve crystallinity and control cracks in the films.

Titanium oxide thin films were prepared by sputtering technique onto glass substrates at room temperature (RT). The structure of the films was confirmed using X-ray diffraction (XRD) and revealed the stoichiometry with an O and Ti ratio of 2. The deposited films at RT were found to be amorphous and the films annealed at 300 and 400°C for 2 h were crystalline with orthorhombic structure. The lattice constants and grain size of the film are calculated. The electrical resistivity was found to depend on the film thickness and decreased with increasing the film thicknesses. The optical constants of the films such as the refractive index, extinction coefficient, and absorption coefficient were also determined using the optical transmittance measurements, and the results were discussed. The optical band gap varies from 3.2 to 3.5 eV as a function of oxygen/argon ratios.

The growth of the TiO₂ thin films coated on the polypropylene beads was analyzed experimentally in a rotating cylindrical plasma chemical vapor deposition (PCVD) reactor. The precursors for the thin films were generated by plasma reactions, and they deposited on the polypropylene beads to become the uniform thin films. The TiO₂ thin films grow more quickly on the polypropylene beads by increasing the mass flow rate of TTIP, or the rotation speed of the reactor. The smaller number of polypropylene beads in the reactor increases the growth rate of the thin films. The high-quality TiO₂ thin films can be coated on particles uniformly by using the rotating cylindrical PCVD process. The particles coated with high-quality TiO₂ thin films can be applied to the removal of air and water pollutants by a photodegradation reaction of TiO₂.

TiO₂ thin film was deposited by a DC reactive magnetron sputtering on ZnO/soda-lime glass substrate and single crystal SiO₂ below 200 °C. ZnO layer was used as a buffer layer. Deposition was performed at Ar + O₂ gas mixture with a pressure of 1.0 Pa and oxygen with a constant pressure of 0.2 Pa. The TiO₂ / ZnO thicknesses were approximately 1000 nm and 80 nm, respectively. As-deposited films were annealed at 400 °C. The structure and morphology of deposited layers were evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The transmittance of the films was measured using ultraviolet–visible light (UV–vis) spectrophotometer. Photocatalytic activities of the samples were evaluated by the degradation of 2-propanol. The microstructure of annealed films was anatase, having improved photocatalytic activity. The surface grain size of TiO₂ thin film after annealing was found about 25-35 nm and crystal size was approximately 8 nm. By using ZnO thin film as buffer layer, the photocatalytic property of TiO₂ films was improved.