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 k_∥ and -k_∥ to the KRIPES cross sections.