Injection and thermodepolarization currents in GaSe <Co> single crystals

The current-voltage characteristics (CVC) at different temperatures, the temperature dependence of electric conductivity σ(T)] and the currents of thermostimulated depolarization (TSD) have been studied in GaSe <0.05 at.% Co> on a combined basis.The location depth (E_t=0.57eV) and the concentration of traps (N_t=2.7x10¹²cm^?3) have been determined from the temperature dependence of the trapping factor. In the course of TSD investigations, levels with location depths of 0.28±0.02 and 0.57±0.03 eV have been revealed. It is noted that traps with the energy of 0.57±0.03 eV are found both with TSD measurements and on the basis of the temperature dependence of the electric conductivity and the trapping factor.It has been established that the hole centres above the valence band are responsible for the CVC, σ(T) and TSD. The location depths, concentrations and trapping cross-sections of these centres have been determined.