Observation of forbidden phonons, Fano resonance and dark excitons by resonance Raman scattering in few-layer WS2

The optical properties of the two-dimensional (2D) crystals are dominated by tightly bound electron–hole pairs (excitons) and lattice vibration modes (phonons). The exciton-phonon interaction is fundamentally important to understand the optical properties of 2D materials and thus helps to develop em...

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Main Authors: Tan, Qing-Hai, Sun, Yu-Jia, Liu, Xue-Lu, Zhao, Yanyuan, Xiong, Qihua, Tan, Ping-Heng, Zhang, Jun
Other Authors: School of Physical and Mathematical Sciences
Format: Article
Language:English
Published: 2020
Subjects:
WS2
Online Access:https://hdl.handle.net/10356/140432
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1404322023-02-28T19:26:51Z Observation of forbidden phonons, Fano resonance and dark excitons by resonance Raman scattering in few-layer WS2 Tan, Qing-Hai Sun, Yu-Jia Liu, Xue-Lu Zhao, Yanyuan Xiong, Qihua Tan, Ping-Heng Zhang, Jun School of Physical and Mathematical Sciences Science::Physics Resonant Raman Scattering WS2 The optical properties of the two-dimensional (2D) crystals are dominated by tightly bound electron–hole pairs (excitons) and lattice vibration modes (phonons). The exciton-phonon interaction is fundamentally important to understand the optical properties of 2D materials and thus helps to develop emerging 2D crystal based optoelectronic devices. Here, we presented the excitonic resonant Raman scattering (RRS) spectra of few-layer WS2 excited by 11 lasers lines covered all of A, B and C exciton transition energies at different sample temperatures from 4 to 300 K. As a result, we are not only able to probe the forbidden phonon modes unobserved in ordinary Raman scattering, but also can determine the bright and dark state fine structures of 1s A exciton. In particular, we also observed the quantum interference between low-energy discrete phonon and exciton continuum under resonant excitation. Our works pave a way to understand the exciton-phonon coupling and many-body effects in 2D materials. NRF (Natl Research Foundation, S’pore) MOE (Min. of Education, S’pore) Accepted version 2020-05-29T02:04:32Z 2020-05-29T02:04:32Z 2017 Journal Article Tan, Q.-H., Sun, Y.-J., Liu, X.-L., Zhao, Y., Xiong, Q., Tan, P.-H., & Zhang, J. (2017). Observation of forbidden phonons, Fano resonance and dark excitons by resonance Raman scattering in few-layer WS2. 2D Materials, 4(3), 031007-. doi:10.1088/2053-1583/aa79bb 2053-1583 https://hdl.handle.net/10356/140432 10.1088/2053-1583/aa79bb 2-s2.0-85029182551 3 4 en 2D Materials © 2017 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/aa79bb application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Science::Physics
Resonant Raman Scattering
WS2
spellingShingle Science::Physics
Resonant Raman Scattering
WS2
Tan, Qing-Hai
Sun, Yu-Jia
Liu, Xue-Lu
Zhao, Yanyuan
Xiong, Qihua
Tan, Ping-Heng
Zhang, Jun
Observation of forbidden phonons, Fano resonance and dark excitons by resonance Raman scattering in few-layer WS2
description The optical properties of the two-dimensional (2D) crystals are dominated by tightly bound electron–hole pairs (excitons) and lattice vibration modes (phonons). The exciton-phonon interaction is fundamentally important to understand the optical properties of 2D materials and thus helps to develop emerging 2D crystal based optoelectronic devices. Here, we presented the excitonic resonant Raman scattering (RRS) spectra of few-layer WS2 excited by 11 lasers lines covered all of A, B and C exciton transition energies at different sample temperatures from 4 to 300 K. As a result, we are not only able to probe the forbidden phonon modes unobserved in ordinary Raman scattering, but also can determine the bright and dark state fine structures of 1s A exciton. In particular, we also observed the quantum interference between low-energy discrete phonon and exciton continuum under resonant excitation. Our works pave a way to understand the exciton-phonon coupling and many-body effects in 2D materials.
author2 School of Physical and Mathematical Sciences
author_facet School of Physical and Mathematical Sciences
Tan, Qing-Hai
Sun, Yu-Jia
Liu, Xue-Lu
Zhao, Yanyuan
Xiong, Qihua
Tan, Ping-Heng
Zhang, Jun
format Article
author Tan, Qing-Hai
Sun, Yu-Jia
Liu, Xue-Lu
Zhao, Yanyuan
Xiong, Qihua
Tan, Ping-Heng
Zhang, Jun
author_sort Tan, Qing-Hai
title Observation of forbidden phonons, Fano resonance and dark excitons by resonance Raman scattering in few-layer WS2
title_short Observation of forbidden phonons, Fano resonance and dark excitons by resonance Raman scattering in few-layer WS2
title_full Observation of forbidden phonons, Fano resonance and dark excitons by resonance Raman scattering in few-layer WS2
title_fullStr Observation of forbidden phonons, Fano resonance and dark excitons by resonance Raman scattering in few-layer WS2
title_full_unstemmed Observation of forbidden phonons, Fano resonance and dark excitons by resonance Raman scattering in few-layer WS2
title_sort observation of forbidden phonons, fano resonance and dark excitons by resonance raman scattering in few-layer ws2
publishDate 2020
url https://hdl.handle.net/10356/140432
_version_ 1759856436098105344