Tuning the structural, electrical and optical properties of Ti(III)-doped nanocrystalline TiO2 films by electrophoretic deposition time

Doped nanocrystalline TiO2 films were prepared by electrophoretic deposition of colloidal aqueous suspensions on optically transparent electrodes followed by annealing in air. Characterization experiments of the resulting films indicate that several properties can be tuned by electrophoresis time as a consequence of the electrochemically promoted insertion of Ti(III) atoms into the TiO2 lattice that takes place during the synthetic protocol. In this way, while structural parameters such as thickness, particle size, pore diameter, and electrical conductivity, were shown to change as a function of the electrophoresis time, the band edges of the films showed a constant red-shift due to the high doping density of the semiconductor material (∼ 1020 cm− 3).