Stark effect in a multilayer system of coupled InAs/GaAs quantum dots

Abstract

Electron emission in a system of vertically coupled quantum dots (VCQDs) in InAs/GaAs p-n-heterostructures obtained by molecular beam epitaxy has been studied by means of deep-level transient spectroscopy (DLTS) as a function of the number of quantum dot (QD) rows and the reverse bias voltage. For a GaAs spacer thickness of d GaAs = 40 A, the system occurs in a molecular state, irrespective of the number of QD rows. An increase in this number leads to a decrease in the Stark shift, which is probably related to a decrease in the lattice strain potential in the vicinity of VCQDs.