Inter-trap tunneling in vanadium doped TiO2 sol-gel films

Abstract

Multilayered anatase TiO2 films doped with 0.03 and 1.2 at.% vanadium, deposited on p-type Si substrates by the sol-gel layer-by-layer method are studied to reveal the influence of doping on the electrical properties of the films. Undoped TiO2 and doped TiO2:V films were incorporated in Metal-Insulator-Semiconductor structures and their current-voltage characteristics were measured and analyzed. The specific resistivity is in the order of 105 Ohm.cm, decreasing by increasing the electrical field, an evidence of the electron injection in these TiO2 and TiO2:V films. The current through the films is non-conduction band current limited with trap charge via deep levels with energy distribution in the TiO2bandgap. In the 77−300 K temperature range the current at high electric fields is carried out by the electron inter-trap tunneling in these TiO2 films.