Stepwise dependence of the photoconductivity of Si/Ge structures with quantum dots on the interband illumination intensity

It was found that a stepwise increase in the interband light intensity causes an increase in the low-temperature lateral photoconductivity of a Si/Ge structure containing six layers of germanium quantum dots in a silicon host. As was previously observed in structures with a single layer of quantum dots, strengthening of the driving field results in the step positions shifting to lower light intensities. This effect was also found to take place under a dark driving field. The results are discussed in terms of the percolation theory of nonequilibrium electrons localized in the states between quantum dots.