Surface electronic transport on silicon: donor- and acceptor-type adsorbates on Si 111/-63=63-Ag substrate

Adsorptions of monovalent atoms noble and alkali metals.of submonolayer coverages 0.1–0.2 ML. on the Si 111.-63 =63-Ag surface commonly induced similar 621=621 superstructures, all of which exhibited high electrical conductances. Common processes seem to work among these adsorbates in such phenomena; the valence electrons of the adsorbates are transferred to the substrate surface-state bands carrier doping.. On the contrary, adsorption of C60 molecules on the 63=63-Ag surface reduced the conductance, presumably because conduction electrons in the surface-state band of the substrate are transferred to the molecules due to their strong electronegativity acceptor-type adsorbates.. q2000 Elsevier Science B.V. All rights reserved