Effects of an electric field on the binding energy of shallow hydrogenic impurities in GaAs-(Ga,Al)As quantum boxes

The binding energies of shallow hydrogenic donor impurities in GaAs-(Ga,Al) As quantum boxes are calculated as a function of the size of the structure and as a function of the intensity of an applied electric field. The calcul ations are performed within the effective-mass approximation and using a va riational method. We have found that when the size of the quantum box is re duced, both the energy of the ground state and the binding energy increase. Likewise we found that when the electric field intensity is increased, bot h the energy of the ground state and the binding energy decrease.