Kinetics of internal photoeffect in titanium dioxide films

The internal photoeffect in X-ray-amorphous titanium dioxide (TiO2) films deposited by reactive magnetron sputtering onto silica glass substrates has been studied. It is established that cyclic illumination of samples leads to a change in the photoinduced current kinetics, whereby the kinetic curves initially exhibit an extremum that subsequently decreases and eventually disappears. Using a system of equations that describes the kinetics of free electrons with allowance for their trapping on deep monoenergetic traps, it is shown that the observed behavior is related to a significant increase in the coefficient of interband recombination and a decrease in the concentration of vacant traps.