Characterization of few-layer 1T′ MoTe 2 by polarization-resolved second harmonic generation and Raman scattering

Ryan Beams, Luiz Gustavo Cançado, Sergiy Krylyuk, Irina Kalish, Berç Kalanyan, Arunima K. Singh, Kamal Choudhary, Alina Bruma, Patrick M. Vora, Francesca Tavazza, Albert V. Davydov, Stephan J. Stranick

Research output: Contribution to journalArticle

46 Citations (Scopus)

Abstract

We study the crystal symmetry of few-layer 1T′ MoTe 2 using the polarization dependence of the second harmonic generation (SHG) and Raman scattering. Bulk 1T′ MoTe 2 is known to be inversion symmetric; however, we find that the inversion symmetry is broken for finite crystals with even numbers of layers, resulting in strong SHG comparable to other transition-metal dichalcogenides. Group theory analysis of the polarization dependence of the Raman signals allows for the definitive assignment of all the Raman modes in 1T′ MoTe 2 and clears up a discrepancy in the literature. The Raman results were also compared with density functional theory simulations and are in excellent agreement with the layer-dependent variations of the Raman modes. The experimental measurements also determine the relationship between the crystal axes and the polarization dependence of the SHG and Raman scattering, which now allows the anisotropy of polarized SHG or Raman signal to independently determine the crystal orientation.

Original languageEnglish (US)
Pages (from-to)9626-9636
Number of pages11
JournalACS nano
Volume10
Issue number10
DOIs
StatePublished - Oct 25 2016
Externally publishedYes

Fingerprint

Harmonic generation
Raman scattering
harmonic generations
Polarization
Raman spectra
Crystal symmetry
polarization
scattering
crystals
inversions
Group theory
Crystals
group theory
Crystal orientation
Transition metals
Density functional theory
broken symmetry
Anisotropy
transition metals
density functional theory

Keywords

  • crystal symmetry
  • optical spectroscopy
  • Raman scattering
  • second harmonic generation
  • two-dimensional material

ASJC Scopus subject areas

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

Cite this

Characterization of few-layer 1T′ MoTe 2 by polarization-resolved second harmonic generation and Raman scattering . / Beams, Ryan; Cançado, Luiz Gustavo; Krylyuk, Sergiy; Kalish, Irina; Kalanyan, Berç; Singh, Arunima K.; Choudhary, Kamal; Bruma, Alina; Vora, Patrick M.; Tavazza, Francesca; Davydov, Albert V.; Stranick, Stephan J.

In: ACS nano, Vol. 10, No. 10, 25.10.2016, p. 9626-9636.

Research output: Contribution to journalArticle

Beams, R, Cançado, LG, Krylyuk, S, Kalish, I, Kalanyan, B, Singh, AK, Choudhary, K, Bruma, A, Vora, PM, Tavazza, F, Davydov, AV & Stranick, SJ 2016, ' Characterization of few-layer 1T′ MoTe 2 by polarization-resolved second harmonic generation and Raman scattering ', ACS nano, vol. 10, no. 10, pp. 9626-9636. https://doi.org/10.1021/acsnano.6b05127
Beams, Ryan ; Cançado, Luiz Gustavo ; Krylyuk, Sergiy ; Kalish, Irina ; Kalanyan, Berç ; Singh, Arunima K. ; Choudhary, Kamal ; Bruma, Alina ; Vora, Patrick M. ; Tavazza, Francesca ; Davydov, Albert V. ; Stranick, Stephan J. / Characterization of few-layer 1T′ MoTe 2 by polarization-resolved second harmonic generation and Raman scattering In: ACS nano. 2016 ; Vol. 10, No. 10. pp. 9626-9636.
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