EFFECT OF SPATIALLY DEPENDENT SCREENING ON THE BINDING-ENERGY OF SHALLOW IMPURITIES IN SPHERICAL GAAS-(GA,AL)AS QUANTUM DOTS

Within the effective-mass approximation and using a variational method the binding energies o hydrogenic impurities in spherical GaAs-(Ga,Al )As quantum dots are calculated considering the effect of a spatially dependent screening through an r-dependent dielectric response. It is found that the r-dependent dielectric response increases the binding e nergies when compared with those found using constant screening. The e ffect is more important for acceptors than for donors and must be take n into account in calculations that include the binding energies of ac ceptors impurities in GaAs-(Ga,Al)As quantum dots.