Pandey, V and Mishra, S and Maity, N and Paul, S and Abhijith M, B and Roy, AK and Glavin, NR and Watanabe, K and Taniguchi, T and Singh, AK and Kochat, V (2024) Probing Interlayer Interactions and Commensurate-Incommensurate Transition in Twisted Bilayer Graphene through Raman Spectroscopy. In: ACS Nano, 18 (6). pp. 4756-4764.
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Abstract
Twisted 2D layered materials have garnered much attention recently as a class of 2D materials whose interlayer interactions and electronic properties are dictated by the relative rotation/twist angle between the adjacent layers. In this work, we explore a prototype of such a twisted 2D system, artificially stacked twisted bilayer graphene (TBLG), where we probe, using Raman spectroscopy, the changes in the interlayer interactions and electron-phonon scattering pathways as the twist angle is varied from 0° to 30°. The long-range Moiré potential of the superlattice gives rise to additional intravalley and intervalley scattering of the electrons in TBLG, which has been investigated through their Raman signatures. Density functional theory (DFT) calculations of the electronic band structure of the TBLG superlattices were found to be in agreement with the resonant Raman excitations across the van Hove singularities in the valence and conduction bands predicted for TBLG due to hybridization of bands from the two layers. We also observe that the relative rotation between the graphene layers has a marked influence on the second order overtone and combination Raman modes signaling a commensurate-incommensurate transition in TBLG as the twist angle increases. This serves as a convenient and rapid characterization tool to determine the degree of commensurability in TBLG systems. © 2024 American Chemical Society.
| Item Type: | Journal Article |
|---|---|
| Publication: | ACS Nano |
| Publisher: | American Chemical Society |
| Additional Information: | The copyright for this article belongs to the Authors. |
| Keywords: | Density functional theory; Electronic properties; Graphene; Phonons, Bilayer Graphene; Combination modes; Commensurate-incommensurate transition; Density-functional-theory; Interlayer interactions; Layered material; Relative rotation; Twist angles; Twisted bilayer graphene; Twisted bilayers, Raman spectroscopy, graphene, article; bilayer membrane; controlled study; density functional theory; electron; hybridization; phonon; Raman spectrometry; rotation; signal transduction |
| Department/Centre: | Division of Chemical Sciences > Materials Research Centre |
| Date Deposited: | 09 Apr 2024 10:56 |
| Last Modified: | 09 Apr 2024 10:56 |
| URI: | https://eprints.iisc.ac.in/id/eprint/84687 |
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