Strain-induced localization of electrons in layers of the second-type Ge/Si quantum dots

Electronic states in multilayer Ge/Si heterostructures with different periods of the arrangement of layers of Ge quantum dots have been studied by the photocurrent spectroscopy method. It has been found that the binding energy of electrons increases with a decrease in the thickness of a silicon spacer and with the extension of Si layers near the vortices of Ge nanoclusters. The results constitute experimental evidence of the deformation mechanism of the formation of localized electronic states in Ge/Si heterostructures with second-type quantum dots.