Fargan Asadov
This study investigates the effects of gamma irradiation and thermal annealing on the photoconductive properties of layered GaS and GaS crystals. The samples were exposed to gamma radiation at doses ranging from 50 to 200 krad and subsequently annealed at 473 K. The photoconductivity spectra revealed that the position of the main spectral maximum remained nearly unchanged, whereas the photosensitivity varied as a function of radiation dose, defect concentration, and the polarity of the applied electric field. Thermal annealing altered the radiation-induced defect structure and enhanced photoconductivity in the vicinity of the intrinsic absorption edge. In GaS crystals, Yb-related defect states are suggested to participate in trap-assisted recombination and charge-carrier transport, although their exact energetic positions require further investigation. These findings demonstrate that gamma irradiation combined with post-irradiation annealing provides an effective defect-engineering strategy for tailoring the optoelectronic properties of layered GaS-based semiconductors.