Electric field effects on D0 binding energies in a CdTe/ZnTe spherical quantum dot

The binding energy of a neutral (D0) hydrogenic impurity located at the center of a CdTe/ZnTe spherical quantum dot (QD) in an external electric field has been investigated. Calculations for the D0 case without field are performed under the effective mass approximation on the basis of exact solutions of the Schrodinger and Poisson equations. Eigenfunctions are expressed in terms of the Whittaker and Coulomb wave functions. The results for D0 impurity energies of ground 1s and excited 2p and 3d states depend strongly on CdTe/ZnTe QD size if the QD radius is less than one effective Bohr radius. Stark shift energy levels and their wave functions in an external electric field were determined based on the variational calculations scheme within the effective mass approximation. The results show the dependence of hydrogenic impurity binding energy on the dot radius and on the external electric field strength.