Journal Article

FZJ-2017-06642

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Direct Observation of the Band Gap Transition in Atomically Thin ReS2

Gehlmann, M.FZJ* ; Aguilera, I.FZJ* ; Bihlmayer, G.FZJ* ; Nemšák, S.FZJ* ; Nagler, P. ; Gospodarič, P.FZJ* ; Zamborlini, G.FZJ* ; Eschbach, M. ; Feyer, V.FZJ* ; Kronast, F. ; Młyńczak, E. ; Korn, T. ; Plucinski, L. (Corresponding author)FZJ* ; Schüller, C. ; Blügel, S.FZJ* ; Schneider, C. M.FZJ*

2017
ACS Publ. Washington, DC

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Please use a persistent id in citations: http://hdl.handle.net/2128/15912  doi:10.1021/acs.nanolett.7b00627

Abstract: 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.

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Contributing Institute(s):

1. Quanten-Theorie der Materialien (IAS-1)
2. Quanten-Theorie der Materialien (PGI-1)
3. JARA-FIT (JARA-FIT)
4. JARA - HPC (JARA-HPC)
5. Elektronische Eigenschaften (PGI-6)

Research Program(s):

1. 142 - Controlling Spin-Based Phenomena (POF3-142) (POF3-142)
2. 143 - Controlling Configuration-Based Phenomena (POF3-143) (POF3-143)

Appears in the scientific report 2017

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Database coverage:
; ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF >= 10 ; JCR ; NCBI Molecular Biology Database ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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