Hh. Weitering et al., ELECTRON CORRELATION, METALLIZATION, AND FERMI-LEVEL PINNING AT ULTRATHIN K SI(111) INTERFACES/, Physical review. B, Condensed matter, 48(11), 1993, pp. 8119-8135
In this paper we present a detailed photoemission study of the K/Si(11
1)7X7 and K/Si(111)(square-root 3 X square-root 3)R 30-degrees-B inter
faces. Angle-resolved valence-band spectroscopy reveals the presence o
f an almost dispersionless interface state below E(F). Both interfaces
are clearly nonmetallic at room-temperature saturation coverage. We c
ritically address the issues of charge transfer and Fermi-level pinnin
g by a detailed analysis of the K 3p and Si 2p core-level spectra. We
conclude that, up to saturation coverage, correlation effects determin
e the electronic properties of these interfaces. Metallization occurs
during the development of the second layer at cryogenic temperatures.