Perturbation calculation of impurity states in spherical quantum dots with parabolic confinement

Abstract

An attempt is made to derive the impurity binding energies associated with the ground state and a few adjacent excited levels of a shallow hydrogenic impurity in spherical quantum dot (QD) with parabolic confinement, using the perturbation method. The binding energies are computed for GaAs QD as functions of the dot size and the donor position within the QD. The results show that the impurity binding energies decrease with the increase in dot size. The binding energy is also found to strongly depend on the location of the impurity. For s states, the donor binding energy is maximum for an on-centre impurity, while for 0p and 0d states, the binding energy maxima occur for an impurity located off the dot centre.