MOTT-SCHOTTKY ANALYSIS OF NANOMETER-SCALE THIN-FILM ANATASE TIO2

Smooth nanometer-scale films of anatase TiO2 on indium-tin oxide subst rates (ITO) are obtained by electron-beam evaporation of reduced TiO2 powder. Mott-Schottky analysis shows an abrupt change in slope when th e depletion layer reaches the TiO2/ITO interface. An electrostatic mod el is derived, which gives a quantitative description of the observed change in slope. From the potential at which the slope changes, the di electric constant of anatase could be accurately determined. A value o f 55 is found, which is significantly lower than those reported for an atase TiO2.