Аннотация:Modulated light was used to measure the amplitude and phase of the alternating photocurrent component as functions of electrode potential and modulation frequency. A model of transient photoprocesses at the interface was discussed which comprises the capture of a photoexcited electron by an acceptor in the solution and formation of an intermediate which is further reduced by electrons from the valence band. The theoretical expressions obtained in terms of this model provide a good description of the experimental data over the range of modulation frequencies of the light intensity from 30 to 500 Hz when the transition of the photoexcited electron to the acceptor in the solution is the rate-determining step of the photoprocess.