Semiconductor-metal transition of the single-domain K/Si(100)-(2×1) interface by Fermi-surface determination

Abstract

The semiconductor-metal electronic transition of the K/Si(100)-(2×1) interface is studied by exploring the Fermi surface with photoemission spectroscopy. Once metallized at a critical coverage the surface remains metallic up to saturation. The experimentally determined Fermi surface consists of hole pockets centered around the Γ + ̄ points of the surface Brillouin zone. These results are fairly well reproduced by calculations based on a 2D Mott-Hubbard model. The metallization process is related to the overlap of Si-confined electron clouds surrounding the K atoms rather than to changes in the surface atomic structure. © 1998 The American Physical Society