Combining single-layer two-dimensional semiconducting transition metal dichalcogenides (TMDs) with graphene layer in van der Waals heterostructures offers an intriguing means of controlling the electronic properties through these heterostructures. Here, we report the electronic and structural properties of transferred single layer WS2 on epitaxial graphene using micro-Raman spectroscopy, angle-resolved photoemission spectroscopy measurements (ARPES) and Density Functional Theory (DFT) calculations. The results show good electronic properties as well as well-defined band arising from the strong splitting of the single layer WS2 valence band at K points, with a maximum splitting of 0.44 eV. By comparing our DFT results with local and hybrid functionals, we find the top valence band of the experimental heterostructure is close to the calculations for suspended single layer WS2. . Our results provide an important reference for future studies of electronic properties of WS2 and its applications in valleytronic devices.
@article{arxiv.1806.04851,
title = {Electronic band structure of Two-Dimensional WS2/Graphene van der Waals Heterostructures},
author = {Hugo Henck and Zeineb Ben Aziza and Debora Pierucci and Feriel Laourine and Francesco Reale and Pawel Palczynski and Julien Chaste and Mathieu G. Silly and François Bertran and Patrick Le Fevre and Emmanuel Lhuillier and Taro Wakamura and Cecilia Mattevi and Julien E. Rault and Matteo Calandra and Abdelkarim Ouerghi},
journal= {arXiv preprint arXiv:1806.04851},
year = {2018}
}