BINDING-ENERGY OF A DOUBLE DONOR IN A PARABOLIC QUANTUM-WELL

We have calculated the binding energies of the ground state of a double donor associated with the first subband in a parabolic quantum well. Taking into account the nonparabolicity of the conduction band, we have considered the two cases of positive donor center and neutral donor center. The results have been obtained as a function of the parabolicity parameter by using a variational approach. It is found that the nonparabolicity causes an increase in the binding energy; also, this energy increases with the increasing of the parabolicity parameter alpha.