Electronic properties of TiO2 thin films under UV light irradiation

TiO₂ has photocatalysis. When UV light irradiated, electron-hole pairs are generated in TiO₂. The source of photocatalysis is oxidation and reduction reactions due to electrons and holes at the surface. In this paper, we tried to obtain the electronic properties such as resistivity, carrier density and mobility in anatase TiO₂ thin films under UV light irradiation. The resistivity decreased with UV light intensity. Without UV light irradiation, the resistivity was over the measuring range. The measured values of the Hall voltage were not stable. We consider contributions to the Hall voltage of electrons and holes are canceled each other as an intrinsic semiconductor. It is also suggested that mobilities of electrons and holes have unstable behavior under the combination of magnetic field and UV light irradiation.