Bound polaron in a wurtzite nitride semiconductor ellipsoidal quantum dot

The binding energy of a hydrogenic donor impurity in weakly oblate ellipsoidal quantum dot is investigated with a variational method by taking the electron couples with both branches of the mixing properties of the LO and TO polarizations (LO-like and TO-like phonons) due to the anisotropic effect into account. The interaction between impurity and phonons has also been considered to obtain the binding energy of bound polaron. The numerical computation has been performed for wurtzite nitride semiconductor GaN. The results show that the binding energy of bound polaron is reduced by the phonons effect on the impurity states. It indicates that the contribution of LO-like phonon to the binding energy is dominant, and the anisotropic angle and ellipticity influence on the binding energy are small. (C) 2009 Elsevier B.V. All rights reserved.