Characterization of Excitonic Nature in Raman Spectra Using Circularly Polarized Light

Yan Zhao, Shishu Zhang, Yuping Shi, Yanfeng Zhang, Riichiro Saito, Jin Zhang, Lianming Tong

Research output: Contribution to journalArticlepeer-review

Abstract

We propose a technique of Raman spectroscopy to characterize the excitonic nature and to evaluate the relative contribution of the two kinds of electron/exciton-phonon interactions that are observed in two-dimensional transition-metal dichalcogenides (TMDCs). In the TMDCs, the electron/exciton-phonon interactions mainly originate from the deformation potential (DP) or the Fröhlich interaction (FI) which give the mutually different Raman tensors. Using a circularly polarized light, the relative proportion of the DP and the FI can be defined by the ratio of helicity-polarized intensity that is observed by MoS2. By this analysis, we show that the excitonic FI interaction gradually increases with decreasing temperature, contributes equally to DP at ∼230 K, and dominates at lower temperatures. The excitonic effect in the Raman spectra is confirmed by modulating the dielectric environment for the exciton and by changing the laser power.

Original languageEnglish
Pages (from-to)10527-10535
Number of pages9
JournalACS Nano
Volume14
Issue number8
DOIs
Publication statusPublished - 2020 Aug 25

Keywords

  • Fröhlich interaction
  • MoS
  • Raman scattering
  • circularly polarized light
  • deformation potential
  • exciton-phonon coupling
  • helicity

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Characterization of Excitonic Nature in Raman Spectra Using Circularly Polarized Light'. Together they form a unique fingerprint.

Cite this