Pseudopotential Theory of Shallow-Donor Ground States

Abstract

The effective-mass theory of shallow impurity states is given a pseudopotential formulation. A first-principles pseudopotential is constructed accounting for orthogonalization to the impurity core states, spatial dependence of the dielectric constant, and the spatial dependence of the core shielding. Valley-orbit coupling is included, and a correction is made for the energy shift due to the deformation produced by the size difference of the host and impurity atoms. A variational calculation is done for the ground states of P, As, and Sb in Si, and good results are obtained for the lowest ground states ($A_1$) of P and Sb, poor results for As.