Details

Autor(en) / Beteiligte

• Gehlmann, Mathias
• Aguilera, Irene
• Bihlmayer, Gustav
• Nemšák, Slavomír
• Nagler, Philipp
• Gospodarič, Pika
• Zamborlini, Giovanni
• Eschbach, Markus
• Feyer, Vitaliy
• Kronast, Florian
• Młyńczak, Ewa
• Korn, Tobias
• Plucinski, Lukasz
• Schüller, Christian
• Blügel, Stefan
• Schneider, Claus M

Titel

Direct Observation of the Band Gap Transition in Atomically Thin ReS2

Ist Teil von

• Nano letters, 2017-09, Vol.17 (9), p.5187-5192

Ort / Verlag

American Chemical Society

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• ReS2 is considered as a promising candidate for novel electronic and sensor applications. The low crystal symmetry of this van der Waals compound leads to a highly anisotropic optical, vibrational, and transport behavior. However, the details of the electronic band structure of this fascinating material are still largely unexplored. We present a momentum-resolved study of the electronic structure of monolayer, bilayer, and bulk ReS2 using k-space photoemission microscopy in combination with first-principles calculations. We demonstrate that the valence electrons in bulk ReS2 arecontrary to assumptions in recent literaturesignificantly delocalized across the van der Waals gap. Furthermore, we directly observe the evolution of the valence band dispersion as a function of the number of layers, revealing the transition from an indirect band gap in bulk ReS2 to a direct gap in the bilayer and the monolayer. We also find a significantly increased effective hole mass in single-layer crystals. Our results establish bilayer ReS2 as an advantageous building block for two-dimensional devices and van der Waals heterostructures.