Photodielectric effect in Bi$_{12}$SiO$_{20}$ sillenite crystals

The results of studies of the effect of illumination on the frequency dependence of the electrical parameters of bismuth silicate Bi$_{12}$SiO$_{20}$ single crystals are presented. Illumination in the visible spectral region induces a change in the dielectric parameters (the photodielectric effect) and the manifestation of photoconductivity in the low-frequency region under study. The hopping character of conduction in the dark and upon excitation with light is established. The possible mechanisms of the photodielectric effect and charge transport in the crystals are discussed.