Effects of built-in internal fields and Al alloy content on donor binding energy of a hydrogenic impurity in a wurtzite GaN/AlGaN quantum dot

Abstract

Built-in internal field induced donor hydrogenic binding energy of an impurity in a wurtzite GaN/AlGaN quantum dot is investigated. The built-in internal electric field has the contribution from spontaneous and piezo-electric polarisation. The computations are carried out with the inclusion of conduction band non-parabolicity through the energy dependent effective mass. It is calculated with a variational approach within the framework of single band effective-mass approximation. A two-parametric trial wave function is employed in order to improve the results. The effects of quantum confinement and the strength of internal electric fields on the donor binding energy are discussed. The results show that the strength of the internal field is of the order MV/cm and it has more influence on the geometrical confinement and the composition of Al alloy content in the GaN/AlxGa1-xN quantum dot. These results are in good agreement with the other investigators.