Details

Autor(en) / Beteiligte

• Wang, W.
• Olovsson, W.
• Uhrberg, R. I. G.

Titel

Band structure of hydrogenated silicene on Ag(111): Evidence for half-silicane

Ist Teil von

• Physical review. B, 2016-02, Vol.93 (8), p.081406, Article 081406

Erscheinungsjahr

2016

Quelle

American Physical Society Journals

Beschreibungen/Notizen

• In the case of graphene, hydrogenation removes the conductivity due to the bands forming the Dirac cone by opening up a band gap. This type of chemical functionalization is of the utmost importance for electronic applications. As predicted by theoretical studies, a similar change in the band structure is expected for silicene, the closest analog to graphene. We here report a study of the atomic and electronic structures of hydrogenated silicene with hydrogen on one side, the so-called half-silicane. The ("2[radical]3 x 2[radical]3") phase of silicene on Ag(111) was used in this Rapid Communication since it can be formed homogeneously across the entire surface of the Ag substrate. Low-energy electron diffraction and scanning tunneling microscopy data clearly show that hydrogenation changes the structure of silicene on Ag(111) resulting in a (1 x 1) periodicity with respect to the silicene lattice. The hydrogenated silicene also exhibits a quasiregular (2[radical]3 x 2[radical]3)-like arrangement of vacancies. Angle-resolved photoelectron spectroscopy revealed two dispersive bands which can be unambiguously assigned to half-silicane. The common top of these bands is located at ~0.9 eV below the Fermi level. We find that the experimental bands are closely reproduced by the theoretical band structure of free-standing silicene with H adsorbed on the upper hexagonal sublattice.