The electronic structure of epitaxial single-layer MoS2 on Au(111) is investigated by angle-resolved photoemission spectroscopy, scanning tunnelling spectroscopy, and first principles calculations. While the band dispersion of the supported single-layer is close to a free-standing layer in the vicinity of the valence band maximum at Kˉ and the calculated electronic band gap on Au(111) is similar to that calculated for the free-standing layer, significant modifications to the band structure are observed at other points of the two-dimensional Brillouin zone: At Γˉ, the valence band maximum has a significantly higher binding energy than in the free MoS2 layer and the expected spin-degeneracy of the uppermost valence band at the Mˉ point cannot be observed. These band structure changes are reproduced by the calculations and can be explained by the detailed interaction of the out-of-plane MoS2 orbitals with the substrate.
@article{arxiv.1601.00095,
title = {Single-layer MoS$_2$ on Au(111): band gap renormalization and substrate interaction},
author = {Albert Bruix and Jill A. Miwa and Nadine Hauptmann and Daniel Wegner and Søren Ulstrup and Signe S. Grønborg and Charlotte E. Sanders and Maciej Dendzik and Antonija Grubišić Čabo and Marco Bianchi and Jeppe V. Lauritsen and Alexander A. Khajetoorians and Bjørk Hammer and Philip Hofmann},
journal= {arXiv preprint arXiv:1601.00095},
year = {2016}
}