Asymmetric Stark shift in an impurity doped dome-shaped quantum dot with wetting layer

Abstract

The effects of vertical electric field and donor impurity on the electronic properties of the dome-shaped InAs/GaAs quantum dot coupled to its wetting layer were investigated. The dependence of the electron density, energy and Stark shift of the S-, P- and WL-states on the applied electric field was studied with and without impurity. The S- and P-states have no significant qualitative changes in the shape of the wave functions with increasing the electric field, except that they become slightly shifted due to the competition between the field action and the quantum confinement. The wave function of the WL-state is strongly modified in polarized structures. Our results reveal that the Stark shift of electron energies can be fitted with a quadratic dependence on the electric field, the linear and quadratic terms corresponding to the dipole moment and static electron polarizability. Their estimated values reasonable agree with those calculated.