Localized and delocalized charge transfer during adsorption on semiconductors: Experiments and cluster calculations on the prototype surface ZnO(101̄0)
We present a combined experimental and theoretical study on chemisorption effects at an ionic semiconductor surface which exhibits negligible concentration of intrinsic surface states in the band gap. Chemisorption may be characterized by localized electronic charge redistribution in the valence-band range and by delocalized charge transfer between the adsorption complex and free electrons in the conduction-band range. Geometries, electronic structures, and total energies of adsorption complexes are discussed on the basis of results from sindo1 cluster calculations.