Electronic structure of the Ag/Si interface: Angle-resolved, energy-dependent, photoemission study

The photoionization cross section ({σ}) and the photoelectron asymmetry parameter ({β}) for the Ag/Si interface [prepared by depositing 0.3 ML of Ag atoms onto a Si(111)7×{}7 substrate at room temperature] in the photon-energy range h{ν}=70--200 eV are compared with the atomic results. Near the Cooper minimum, the h{ν} dependence of {σ} and {β} from the Ag/Si interface are very close to the experimental values for atomic Ag and to the theoretical predictions in the relativistic random-phase approximation (RRPA) for atomic Pd. This set of experimental data strongly suggests that Ag atoms on the surface of Si do not nucleate into clusters sufficiently large to exhibit valence-band characteristics of bulk Ag and that the Ag/Si system is representative of nonreactive Schottky-barrier formation.