Effect of irradiation with gamma-ray photons on the charge-transport mechanism in n-CdS/p-CdTe heterostructures

摘要

Effect of irradiation with gamma-ray photons on the mechanism of charge transport in an n-CdS/p-CdTe heterostructure is considered. It is shown that the forward current-voltage characteristic of an n-CdS/p-CdTe heterostructure before and after irradiation is described by two exponential dependences: I = I (01)exp(qV/C (01) kT) and I = I (02)exp(qV/C (02) kT). It is found that, in the first portion of the current-voltage characteristic, the current is limited by thermoelectronic emission while, in the second portion, the current is limited by recombination of nonequilibrium charge carriers in the electrically neutral portion of a CdTe1 - x S (x) alloy at the n-CdS/p-CdTe heteroboundary. Anomalous dose dependences of parameters of the n-CdS/p-CdTe heterosystem are attributed to a variation in the degree of compensation of local centers at the CdS-CdTe1 - x S (x) interface and in the CdTe1 - x S (x) layers in relation to the dose of irradiation with gamma-ray photons.