Quantifying electronic band interactions in van der Waals materials using angle-resolved reflected-electron spectroscopy

• Published in: Nature communications Vol. 7; no. 1; p. 13621
• Main Authors: Jobst, Johannes, van der Torren, Alexander J. H., Krasovskii, Eugene E., Balgley, Jesse, Dean, Cory R., Tromp, Rudolf M., van der Molen, Sense Jan
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 29-11-2016; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/357/1018; 639/766/119/544; Boron; Boron nitride; Electron mobility; Electron spectroscopy; Electron states; Graphene; Heterostructures; Humanities and Social Sciences; Layered materials; Mobility; multidisciplinary; Organic chemistry; Science; Science (multidisciplinary); Silicones; Spectroscopy
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms13621

High electron mobility is one of graphene’s key properties, exploited for applications and fundamental research alike. Highest mobility values are found in heterostructures of graphene and hexagonal boron nitride, which consequently are widely used. However, surprisingly little is known about the interaction between the electronic states of these layered systems. Rather pragmatically, it is assumed that these do not couple significantly. Here we study the unoccupied band structure of graphite, boron nitride and their heterostructures using angle-resolved reflected-electron spectroscopy. We demonstrate that graphene and boron nitride bands do not interact over a wide energy range, despite their very similar dispersions. The method we use can be generally applied to study interactions in van der Waals systems, that is, artificial stacks of layered materials. With this we can quantitatively understand the ‘chemistry of layers’ by which novel materials are created via electronic coupling between the layers they are composed of.
Heterostructures of graphene and hexagonal boron nitride have great potential for high-mobility electronics, yet little is known about the electronic interaction between these two atomically thin materials. Here, the authors perform angle-resolved reflected-electron spectroscopy to unveil their interplay.