First-Principles Investigations of the Atomic and Electronic Structure of Pb, Sn and Ge Adsorbed on the ${\rm Ge}(111)\mbox{-}(\sqrt{3}\times\sqrt{3})$ Surface

Abstract

Submonolayer adsorption of group-IV elements (Ge, Sn, Pb) on the Ge(111) surface has been investigated using first-principles pseudopotential total-energy and force calculations. The most prominent adsorption geometries, namely T4 and H3, are compared with respect to their atomic and electronic structure. As the most striking result, our calculations favor adsorption of adatoms in thresfold-symmetric T4 sites for all three different adatom species in agreement with earlier predictions and experiment.