Nonsteady-state photo-EMF in thin photoconductive layers

The nonsteady-state photo-EMF produced by vibrating interference fringes in thin photoconductive layers is considered. It is shown that the frequency transfer function of the average (over the layer thickness) current density is approximately of the high-pass filter type, with the maximum amplitude at high vibration frequency (ω≫ω₀) independent of the sample thickness d. The characteristic cutoff frequency ω₀ however, proves to be the dependent both on d and the spatial frequency of the pattern K: in the approximation of a thin layer (εKd/2≪1), it is (εKd/2)^-1 times lower than that for the bulk sample (εKd/2≪1)