Electronic band structure of Two-Dimensional WS2/Graphene van der Waals Heterostructures

Abstract

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.

arXiv comment11 pages, 3 figures + SI 7 pages 8 figures

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• Nanoscale patterning of quasiparticle band alignment
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• Open-source automated chemical vapor deposition system for the production of two - dimensional nanomaterials
• The impact of valley profile on the mobility and Kerr rotation of transition metal dichalcogenides
• Unidirectional Rashba Spin Splitting in Single Layer WS${}_{2(1-x)}$Se${}_{2x}$ alloy
• Designable exciton mixing through layer alignment in WS${}_2$-graphene heterostructures
• Zero-field spin resonance in graphene with proximity-induced spin-orbit coupling