LONG-PERSISTENT RELAXATION AND FROZEN CONDUCTIVITY IN ZNSE WITH RADIATION-INDUCED DEFECTS

In n-ZnSe crystals which have been preliminarily annealed in liquid Zn and then exposed to radiation by a flow of electrons with an energy of E = 1.3 MeV and a dose of irradiation from 2.73 x 10(16) to 5.19 x 10(17) electrons/cm(2) phenomena of a long-persistent conductivity relaxation (LP) and frozen conduction (FC) at 77 K are brought out and examined. It is shown that the character of the relaxation processes at small doses of irradiation is satisfactorily explained by the two-barrier model of an inhomogeneous semiconductor which represents a low-resistance matrix with high-resistance inclusions (clusters). As the dose of irradiation grows the overlapping of space charge regions which surround the high-resistance inclusions increases and the considered model of high-resistance inclusions passes at D = 3 x 10(17) electrons/cm(2) into a model of a random potential relief. The temperature quenching of FC is explained assuming that with temperature growth the drift and recombination barriers decrease simultaneously as a result of the variation of the size of the space charge regions which surround the clusters.