Laser-dressed donor states in a CdS/SiO2 spherical nanodot under applied electric fields

Intense laser field effects on the impurity states in a CdS/SiO2 quantum dot under applied electric fields are studied within the effective mass approximation by using a finite difference method. We have followed the Floquet method to take into account the dressing effect on the confinement potential and on the electrostatic interaction between the electron and the impurity ion. A significant blue shift is obtained for the subband and impurity levels when an intense, non-resonant, laser field radiation is applied. We found that the variation of the donor energy versus the laser field parameter depends on the impurity position and can be adjusted by the external electric field. For on-center donors, a shift of the polarizability peak position toward the lower values of the electric field when the laser intensity increases is predicted.