Electrical breakdown in nominally undoped n-Ge and p-Ge samples under interband photoexcitation

The results of studying low-temperature impurity-related electrical breakdown E thr in nominally undoped n-Ge and p-Ge samples subjected to intrinsic photoexcitation are reported. It was expected that, on the basis of the model of the recombination of free charge carriers via deep impurity centers, the value of E thr under these conditions would be bound to be the same for samples with different conductivity types and be independent of the degree of compensation in the samples. However, the experiments show that the breakdown field does not depend on the illumination intensity and is equal to its value in the absence of illumination. A qualitative explanation to the observed effect is suggested.