Influence of strain on hydrogenic impurity states in a GaN/Al x Ga1−x N quantum dot

Abstract

Within the effective-mass approximation, we calculated the influence of strain on the binding energy of a hydrogenic donor impurity by a variational approach in a cylindrical wurtzite GaN/AlxGa1−xN strained quantum dot, including the strong builtin electric field effect due to the spontaneous and piezoelectric polarization. The results show that the binding energy of impurity decreases when the strain is considered. Then the built-in electric field becomes bigger with the Al content increasing and the binding energy of hydrogenic donor impurity decreases when the Al content is increasing. For dot height L < 2 nm, the change of the binding energy is very small with the Al content variety.