This paper presents the results of experiments on the technology of obtaining and studying the mechanisms of current transport in a p+–p–p+ (p+–p–p+) structure based on zinc-compensated silicon in the dark and at different intensities of light illumination at temperatures of 300 and 100 K. Measurement the I-V characteristic of such a structure at T = 300 K in the dark and at T = 100 K at low light intensities showed that a complex dependence of I on U is observed. And at higher intensities, three characteristic regions are observed on the I-V characteristic: linear, almost quadratic, and a region with negative differential conductivity (NDC). In the regionof the I-V characteristic with NDC, quasi-sinusoidal infra-low-frequency self-oscillations of the photocurrent with a frequency of ~1 Hz were observed, the amplitude of which changes in a complex way. The physical nature of such self-oscillations of the photocurrent is still unclear. The obtained results are explained with the use of space charge limited current (SCLC) where the models with an ideal insulator and with an insulator in the volume of which there are two deep traps associated with ionized zinc atoms and three shallow attachment levels associated with zinc atoms, thermal defects and defects created by uncontrolled impurities located in the silicon volume are used.