Electric field effect on the electronic states in a GaAs spherical quantum dot

摘要

Using a variational procedure, we have calculated the energy levels in a GaAs spherical quantum dot under the action of an external electric field, assuming an infinite confinement potentia. Our results show that the electronic states depend strongly not only the applied electric field, but also on the quantum confinement. Because the field-induced spatial separation of conduction and valence electron is in GaAs quantum dot decreases the overlap between their associated wave functions, in the presence of the electric field it is expected a reduction of the luminescence. We obtained the dependence of the recombination rate between conduction and valence electrons as a function of the applied field for different dot radii. We have found that large polarizations are expected for GaAs quantum dot with a radius R $GREQ 100 angstrom. These aspects must be taken into account in the interpretation of optical phenomena related to shallow impurities in which the effect of an applied electric field competes with the quantum confinement.