Electrical properties of TiO2 thin films

The electrical properties of n-type titanium dioxide thin films deposited by magnetron-sputtering method have been investigated by temperature-dependent conductivity. We observed that the temperature dependence of the electrical conductivity of titanium dioxide films exhibits a crossover from T−1/4 to T−1/2 dependence in the temperature range between 80 and 110 K. Characteristic parameters describing conductivity, such as the characteristic temperature (T0), hopping distance (Rhop), average hopping energy (Δhop), Coulomb gap (ΔC), localization length (ξ) and density of states (N(EF)), were determined, and their values were discussed within the models describing conductivity in TiO2 thin films.