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Title: Observation of forbidden phonons, Fano resonance and dark excitons by resonance Raman scattering in few-layer WS2
Authors: Tan, Qing-Hai
Sun, Yu-Jia
Liu, Xue-Lu
Zhao, Yanyuan
Xiong, Qihua
Tan, Ping-Heng
Zhang, Jun
Keywords: Science::Physics
Issue Date: 2017
Source: 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
Journal: 2D Materials
Abstract: 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.
ISSN: 2053-1583
DOI: 10.1088/2053-1583/aa79bb
Rights: © 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
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:SPMS Journal Articles

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