Binding energy of a hydrogenic donor impurity in an ellipsoidal finite-potential quantum dot

In this article, the binding energy of a hydrogenic donor impurity in weakly oblate Ellipsoidal Quantum Dot (EQD), using the perturbation theory within the framework of effective mass approximation, is investigated. In this regard, the binding energies of 1S, 2S and 2P(0) states for GaAs/AlxGa1-xAs structures, as functions of the dot radius and ellipticity constant, are calculated. Results show that variations of binding energies of a hydrogenic impurity with respect to the dot dimension are similar to the case of Spherical Quantum Dot (SQD). In addition, it is found that the binding energy is inversely proportional to the ellipticity constant. This behavior is more profound for 2P(0) state, where, depending on the dot's dimensionality and ellipticity, the binding energy may become negative. (c) 2007 WILE-VCH Verlag GmbH & Co. KGaA, Weinheim.