Features of the edge photoconductivity of gamma-irradiated layered crystals GaS and GaS:Yb under the strong electric field

The influence of the surface electric field on the edge photoconductivity (PC) in undoped and ytterbium-doped (N[Formula: see text][Formula: see text] 10[Formula: see text] cm[Formula: see text]) layered GaS crystals at T = 77 K irradiated with gamma quanta was investigated. It was found that the PC of layered crystals in the absorption edge region due to charge exchange of surface levels is formed as a result of electric smoothing of fluctuations in the potential of surface energy bands. The degree of smoothing of the surface bending of the zones depends on the dose of [Formula: see text]-irradiation, the concentration of impurity atoms and also on the magnitude and direction of the transverse electric field.