Empty- and Filled-Electronic States of the Si(111)\sqrt3×\sqrt3-Sn, \sqrt3×\sqrt3-In and 2\sqrt3×2\sqrt3-Sn Surfaces

Abstract

Momentum-resolved inverse photoemission spectra have been measured for Si(111) \sqrt3×\sqrt3-Sn and -In surfaces. An empty part of the metallic surface-state band for \sqrt3×\sqrt3-Sn is observed. It is noted that the metallic band (including the empty and filled parts) for the \sqrt3×\sqrt3-Sn surface disperses in the same manner as the empty band for the \sqrt3×\sqrt3-In surface. This is consistent with the previous proposal that the atomic arrangements of the \sqrt3×\sqrt3-Sn and \sqrt3×\sqrt3-column III surfaces are identical to each other. For the Si(111)2\sqrt3×2\sqrt3-Sn surface, momentum-resolved inverse photoemission spectra and coverage-dependent angle-resolved photoemission spectra have been measured. It has been found that the 2\sqrt3×2\sqrt3-Sn surface is semiconducting and at least two filled- and one empty-surface-state bands exist in the bulk band gap.