Study on TiO2 thin films grown by advanced pulsed laser deposition on ITO

TiO₂ films were grown by an advanced pulsed laser deposition method (PLD) on ITO substrates to be used as functional electrodes in the manufacturing of solar cells. A pure titanium target (99.99%) was irradiated by a Nd:YAG laser (355 and 532 nm, 5 ns, 35 mJ, 3 J/cm²) in an oxygen atmosphere at different pressures (20-160 mTorr) and at room temperature. After deposition, the films were subjected to an annealing process at 350 °C. The film structure, surface morphology, thickness, roughness, and optical transmission were investigated. Regardless of the wavelength used, the films deposited at room temperature presented only Ti₂O and TiO peaks. After thermal treatment, the TiO₂ films became strongly crystalline, with a tetragonal structure and in the anatase phase; the threshold temperature value was 250 °C. The deposition rate was in the range of 0.035-0.250 nm/pulse, and the roughness was 135-305 nm. Optical transmission of the films in the visible range was between 40% and 60%.