Influence of polarization and self-polarization charges on impurity binding energy in spherical quantum dot with parabolic confinement

TL;DR

This paper develops a theoretical model to calculate the impurity binding energy in spherical quantum dots, accounting for polarization and self-energy effects, revealing their contrasting impacts on binding energy.

Contribution

It introduces a comprehensive formulation considering polarization and self-energy in impurity binding energy calculations within spherical quantum dots.

Findings

Polarization charge increases binding energy.

Self energy decreases binding energy.

Small quantum dots show significant energy enhancement.

Abstract

We present a general formulation of the ground state binding energy of a shallow hydrogenic impurity in spherical quantum dot with parabolic confinement, considering the effects of polarization and self energy. The variational approach within the effective mass approximation is employed here. The binding energy of an on-center impurity is computed for a $\mathrm{GaAs}$/ $\mathrm{{Al}_{x}{Ga}_{1-x}As}$ quantum dot as a function of the dot size with the dot barrier as parameter. The influence of polarization and self energy are also treated separately. Results indicate that the binding energy increases due to the presence of polarization charge, while decreases due to the self energy of the carrier. An overall enhancement in impurity binding energy, especially for small dots is noted.