Chemisorption-Site Geometry from Polarized Photoemission: Si(111)Cl and Ge(111)Cl

Abstract
The chemisorption-site geometries for chlorine on cleaved Si(111) 2×1 and Ge(111) 2×1 surfaces have been determined by comparing detailed pseudopotential calculations with energy distribution spectra and polarization selection rules of photoemission spectroscopy. Strong p-symmetry polarization effects observed in photoemission allow us to determine that on Si(111) the correct geometry is a onefold covalent site while on Ge(111) the Cl is in a threefold coordinated ionic site.