Inverse-photoemission spectroscopy of the unreconstructed, ideally H-terminated Si(111) surface

The chemically prepared H/Si(111)-(1×1) surface has been studied by k-resolved inverse-photoemission spectroscopy (KRIPES) along the two main directions (Γ¯ K¯ and Γ¯ M¯) of the surface Brillouin zone. Two conduction bands are evident at 2.6 and 4.0 eV at Γ¯ and display some dispersion. A marked asymmetry is observed in their dispersion along the M¯ ’Γ¯ M¯ direction. This asymmetry is a manifestation of the different contributions of the eigenstates associated with ${\mathbf{k}}_{\mathrm{\parallel }}$ and -${\mathbf{k}}_{\mathrm{\parallel }}$ to the KRIPES cross sections.