Empty- and Filled-Electronic States of the Si(111)\(\sqrt{3}\times \sqrt{3}\)-Sn, \(\sqrt{3}\times \sqrt{3}\)-In and \(2\sqrt{3}\times 2\sqrt{3}\)-Sn Surfaces

Momentum-resolved inverse photoemission spectra have been measured for Si(111) \(\sqrt{3}\times \sqrt{3}\)-Sn and -In surfaces. An empty part of the metallic surface-state band for \(\sqrt{3}\times \sqrt{3}\)-Sn is observed. It is noted that the metallic band (including the empty and filled parts) for the \(\sqrt{3}\times \sqrt{3}\)-Sn surface disperses in the same manner as the empty band for the \(\sqrt{3}\times \sqrt{3}\)-In surface. This is consistent with the previous proposal that the atomic arrangements of the \(\sqrt{3}\times \sqrt{3}\)-Sn and \(\sqrt{3}\times \sqrt{3}\)-column III surfaces are identical to each other. For the Si(111)\(2\sqrt{3}\times 2\sqrt{3}\)-Sn surface, momentum-resolved inverse photoemission spectra and coverage-dependent angle-resolved photoemission spectra have been measured. It has been found that the \(2\sqrt{3}\times 2\sqrt{3}\)-Sn surface is semiconducting and at least two filled- and one empty-surface-state bands exist in the bulk band gap.