Features of the dark conductivity of zinc selenide

The experimentally obtained I–V dependences of the dark conductivity of zinc-selenide single crystals have a nonlinear character. The contact phenomena, injection currents, and the Poole–Frenkel effect are considered among the possible causes of such behavior of the I–V characteristics. As a result of investigation, the following is established: (i) the contact between the $n$-ZnSe single crystal and metallic In is ohmic; (ii) in low fields, the I–V characteristic obeys Ohm’s law; (iii) in strong fields, the dark conductivity of the investigated samples is determined by the Poole–Frenkel effect. Also Poole–Frenkel theory is supplemented for different potentials of interaction of the local center with the charge carrier.