Binding energy and optical properties of core/shell triaxial ellipsoidal quantum dots under electric field

Abstract We have studied the binding energy and optical properties of a donor impurity, including optical absorption coefficients (ACs), refractive index changes (RICs), and photoionization cross section (PCS) in a triaxial core/shell ellipsoidal quantum dot (QD) under an electric field. The results show that, the influence of the QD shape on the binding energy is dependent on the impurity position, the shape anisotropy can decrease or increases the binding energy. The influence of electric field on the binding energy is dependent on its direction due to the shape anisotropy. The influence of QD shape on the ACs and RICs is strongly dependent on the impurity position and becomes largest for on-center impurity. By contrast, the influence of QD shape on the peak position of PCS becomes largest when the impurity is located at the boundary of the QD, while its influence on the peak intensity is more complex. In addition, due to the shape anisotropy, the effect of electric field on the optical properties of QD is dependent on its direction.