Stacking-dependent interlayer phonons in 3R and 2H MoS2
We have investigated the interlayer shear and breathing phonon modes in MoS2 with pure 3R and 2H stacking order by using polarization-dependent ultralow-frequency Raman spectroscopy. We observe up to three shear branches and four breathing branches in MoS2 with thickness from 2 to 13 layers. The bre...
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sg-ntu-dr.10356-1435952023-07-14T15:47:01Z Stacking-dependent interlayer phonons in 3R and 2H MoS2 Van Baren, Jeremiah Ye, Gaihua Yan, Jia-An Ye, Zhipeng Rezaie, Pouyan Yu, Peng Liu, Zheng He, Rui Lui, Chun Hung School of Materials Science and Engineering Engineering::Materials 3R MoS2 2H MoS2 We have investigated the interlayer shear and breathing phonon modes in MoS2 with pure 3R and 2H stacking order by using polarization-dependent ultralow-frequency Raman spectroscopy. We observe up to three shear branches and four breathing branches in MoS2 with thickness from 2 to 13 layers. The breathing modes show the same Raman activity behavior for both polytypes, but the 2H breathing frequencies are consistently several wavenumbers higher than the 3R breathing frequencies, signifying that 2H MoS2 has slightly stronger interlayer lattice coupling than 3R MoS2. In contrast, the shear-mode Raman spectra are strikingly different for 2H and 3R MoS2. While the strongest shear mode corresponds to the highest-frequency branch in the 2H structure, it corresponds to the lowest-frequency branch in the 3R structure. Such distinct and complementary Raman spectra of the 3R and 2H polytypes allow us to survey a broad range of shear modes in MoS2, from the highest to lowest branch. By combining the linear chain model, group theory, effective bond polarizability model and first-principles calculations, we can account for all the major observations in our experiment. National Research Foundation (NRF) Accepted version Work at TTU (GY, ZY, RH) is supported by NSF CAREER Grant No. DMR-1760668. The DFT calculations of this work used the Extreme Science and Engineering Discovery Environment (XSEDE) Comet at the SDSC through allocation TG-DMR160101 and TG-DMR160088. JAY acknowledges support from the NSF grant DMR 1709781, the Fisher General Endowment, and SET grants from the Jess and Mildred Fisher College of Science and Mathematics at Towson University. PY and ZL acknowledge support from the Singapore National Research Foundation under NRF Award Nos. NRF-RF2013-08. 2020-09-14T01:32:29Z 2020-09-14T01:32:29Z 2019 Journal Article Van Baren, J., Ye, G., Yan, J.-A., Ye, Z., Rezaie, P., Yu, P., . . . Lui, C. H. (2019). Stacking-dependent interlayer phonons in 3R and 2H MoS2. 2D Materials, 6(2), 025022-. doi:10.1088/2053-1583/ab0196 2053-1583 https://hdl.handle.net/10356/143595 10.1088/2053-1583/ab0196 2 6 en 2D Materials © 2019 IOP Publishing Ltd. All rights reserved. This is an author-created, un-copyedited version of an article accepted for publication in 2D Materials. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher authenticated version is available online at https://doi.org/10.1088/2053-1583/ab0196 application/pdf |
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Engineering::Materials 3R MoS2 2H MoS2 Van Baren, Jeremiah Ye, Gaihua Yan, Jia-An Ye, Zhipeng Rezaie, Pouyan Yu, Peng Liu, Zheng He, Rui Lui, Chun Hung Stacking-dependent interlayer phonons in 3R and 2H MoS2 |
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We have investigated the interlayer shear and breathing phonon modes in MoS2 with pure 3R and 2H stacking order by using polarization-dependent ultralow-frequency Raman spectroscopy. We observe up to three shear branches and four breathing branches in MoS2 with thickness from 2 to 13 layers. The breathing modes show the same Raman activity behavior for both polytypes, but the 2H breathing frequencies are consistently several wavenumbers higher than the 3R breathing frequencies, signifying that 2H MoS2 has slightly stronger interlayer lattice coupling than 3R MoS2. In contrast, the shear-mode Raman spectra are strikingly different for 2H and 3R MoS2. While the strongest shear mode corresponds to the highest-frequency branch in the 2H structure, it corresponds to the lowest-frequency branch in the 3R structure. Such distinct and complementary Raman spectra of the 3R and 2H polytypes allow us to survey a broad range of shear modes in MoS2, from the highest to lowest branch. By combining the linear chain model, group theory, effective bond polarizability model and first-principles calculations, we can account for all the major observations in our experiment. |
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School of Materials Science and Engineering |
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School of Materials Science and Engineering Van Baren, Jeremiah Ye, Gaihua Yan, Jia-An Ye, Zhipeng Rezaie, Pouyan Yu, Peng Liu, Zheng He, Rui Lui, Chun Hung |
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Article |
author |
Van Baren, Jeremiah Ye, Gaihua Yan, Jia-An Ye, Zhipeng Rezaie, Pouyan Yu, Peng Liu, Zheng He, Rui Lui, Chun Hung |
author_sort |
Van Baren, Jeremiah |
title |
Stacking-dependent interlayer phonons in 3R and 2H MoS2 |
title_short |
Stacking-dependent interlayer phonons in 3R and 2H MoS2 |
title_full |
Stacking-dependent interlayer phonons in 3R and 2H MoS2 |
title_fullStr |
Stacking-dependent interlayer phonons in 3R and 2H MoS2 |
title_full_unstemmed |
Stacking-dependent interlayer phonons in 3R and 2H MoS2 |
title_sort |
stacking-dependent interlayer phonons in 3r and 2h mos2 |
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2020 |
url |
https://hdl.handle.net/10356/143595 |
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1772826314804297728 |