Theory of Impurity Levels

Abstract

The effective Hamiltonian for an electron trapped in a donor (acceptor) atom is derived from the Hamiltonian of the total system by taking account of the polarization effect of the medium on the basis of many-body treatment. As a result, an expression which enables us to calculate the impurity potential in the immediate vicinity of the impurity center is presented. One can also prove exactly by this expression that the impurity potential at a long distance from the impurity center is screened by the static dielectric constant of the host crystal for a uniform field.