Reference : Raman imaging of twist angle variations in twisted bilayer graphene at intermediate angles
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Physics
Physics and Materials Science
http://hdl.handle.net/10993/52822
Raman imaging of twist angle variations in twisted bilayer graphene at intermediate angles
English
Schäpers, A. [Rheinisch - Westfälische Technische Hochschule Aachen - RWTH]
Sonntag, J. [Rheinisch - Westfälische Technische Hochschule Aachen - RWTH]
Valerius, L. [Rheinisch - Westfälische Technische Hochschule Aachen - RWTH]
Pestka, B. [Rheinisch - Westfälische Technische Hochschule Aachen - RWTH]
Strasdas, J. [Rheinisch - Westfälische Technische Hochschule Aachen - RWTH]
Watanabe, K. [Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan]
Taniguchi, T. [International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan]
Wirtz, Ludger mailto [University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Physics and Materials Science (DPHYMS)]
Morgenstern, M. [Rheinisch - Westfälische Technische Hochschule Aachen - RWTH]
Beschoten, B. [Rheinisch - Westfälische Technische Hochschule Aachen - RWTH]
Dolleman, R. J. [Rheinisch - Westfälische Technische Hochschule Aachen - RWTH]
Stampfer, C. [Rheinisch - Westfälische Technische Hochschule Aachen - RWTH]
2022
2D Mater.
IOP Publishing
9
4
045009
Yes
International
2053-1583
[en] twisted bilayer graphene ; Raman spectroscopy ; electronic structure
[en] Van der Waals layered materials with well-defined twist angles between the crystal lattices of individual layers have attracted increasing attention due to the emergence of unexpected material properties. As many properties critically depend on the exact twist angle and its spatial homogeneity, there is a need for a fast and non-invasive characterization technique of the local twist angle, to be applied preferably right after stacking. We demonstrate that confocal Raman spectroscopy can be utilized to spatially map the twist angle in stacked bilayer graphene for angles between 6.5 and 8 degree when using a green excitation laser. The twist angles can directly be extracted from the moiré superlattice-activated Raman scattering process of the transverse acoustic (TA) phonon mode. Furthermore, we show that the width of the TA Raman peak contains valuable information on spatial twist angle variations on length scales below the laser spot size of ∼500 nm.
Researchers ; Professionals ; Students
http://hdl.handle.net/10993/52822
10.1088/2053-1583/ac7e59
FnR ; FNR13376969 > Ludger Wirtz > ACCEPT > Anharmonic And Exchange Interactions In Phonon Spectra > 01/01/2020 > 30/06/2024 > 2018

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