Transport and recombination of photo-carriers under potential fluctuation in TiOx films prepared by rf magnetron sputtering method

Residual long-term decays of photocurrent after stopping the irradiation of UV light have been reported in titanium oxide films. Excited electrons recombine with holes through the various routs. The photocurrent decay exhibits a stretched exponential form. It is shown in the case of argon environment that the recombination is dominated by the dispersive diffusion process of electrons. In the mixture of argon and oxygen gas environment, oxygens reacting with electrons near the surface dominate recombination processes. Origin of stretched-exponential dynamics is discussed (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)