Potassium-induced charge redistribution on Si(111) surfaces studied by core-level photoemission spectroscopy

High-resolution core-level photoemission spectra of the K/Si(111)(7×{}7) surface system are presented. The Si 2p results show that potassium adsorption induces a Si 2p core level to shift to o/Ihighero/P binding energy, i.e., to the opposite direction than that expected from the Si-K electronegativity differences. This result is compared with that of the K/Si(111)({}3 ×{} {}3 )R30^∘{}-B system and is interpreted in terms of the K-induced charge redistribution between the Si-adatom--rest-atom pair.