Coulomb-interaction effects on the excited states of double acceptors in germanium and silicon.

Abstract

Infrared spectra of double-acceptor impurities in Si and Ge show small splittings. This fine structure cannot be explained by a split ground-state manifold only. An analysis of the Coulomb hole-hole splitting of the excited states, an estimate of the parameters involved, and dipole transition probabilities between the various ground-state symmetries and the excited states are presented. The spacing of accessible states may be large enough to be experimentally resolved.