Within the formalism of the effective mass approximation, the Schrodinger equation is solved using a Hass variational method for a cubical GaAs/GaAlAs core/shell quantum dot. The impact actuated by the outside electric field, the hydrostatic pressure, the donor impurity off-center, and on-center effect, as well as the confinement geometric on the diamagnetic susceptibility, the polarizability, and the photoionization cross section (PCS), has been analyzed, taking into account the effect of the interaction electro–phonon (e–p). Our numerical results reveal that all of these principal parameters are very subject to the core and shell width. In addition, the impurity position and the electric field have a significant effect on the PCS without hydrostatic influence, especially when the impurity is situated at the center, and the situation becomes less significant in the boundaries of the system. On the other hand, it is found that the impact of both e–p interaction and hydrostatic influence causes a blueshift of the PCS. Interestingly, the polaronic effect is enhanced with the decreasing of the inner quantum dot width.
The binding energy and diamagnetic susceptibility of shallow hydrogenic impurity in cylindrical quantum dot is calculated using a variational approach within the effective mass approximation, as a function of dot size when the static pressure and the magnetic field are applied simultaneously. We describe the quantum confinement by an infinite deep potential; the numerical calculations are performed for HgS, which is a narrow gap, and GaAs, a large gap semiconductor. The results show that the diamagnetic susceptibility increases with the reduction in dot sizes and decreases when the hydrostatic pressure increases. We have shown that diamagnetic susceptibility strongly depends on size of the nanostructure and decreases with increasing size of the quantum dot and tends toward the limit of the bulk (−1, 1 a.u.) (increase in diamagnetic susceptibility in absolute value). We have found that the displacement of the impurity from the center of the quantum dot to the edge causes a decrease in the diamagnetic susceptibility. The absolute value of diamagnetic susceptibility of donors in GaAs is lower than in HgS.