Аннотация:Modulated illumination was employed to find the amplitude and phase of the alternating photocurrent component as functions of electrode potential and modulation frequency. For the transient photoprocesses occurring at the interface, a model was considered which comprises recombination via two surface states and an electrochemical reaction involving photoexcited holes coming directly from the valence band. The expression obtained in terms of this model for the phase and frequency characteristics readily describes the experimental data over the frequency range between 30 and 830 Hz. Hence it is possible to find the kinetic parameters of the surface processes as functions of electrode potential.