Double resonance Raman modes in monolayer and few-layer MoTe2

Huaihong Guo, Teng Yang, Mahito Yamamoto, Lin Zhou, Ryo Ishikawa, Keiji Ueno, Kazuhito Tsukagoshi, Zhidong Zhang, Mildred S. Dresselhaus, Riichiro Saito

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63 Citations (Scopus)

Abstract

We study the second-order Raman process of mono- and few-layer MoTe2, by combining ab initio density functional perturbation calculations with experimental Raman spectroscopy using 532, 633, and 785 nm excitation lasers. The calculated electronic band structure and the density of states show that the resonance Raman process occurs at the M point in the Brillouin zone, where a strong optical absorption occurs due to a logarithmic Van Hove singularity of the electronic density of states. The double resonance Raman process with intervalley electron-phonon coupling connects two of the three inequivalent M points in the Brillouin zone, giving rise to second-order Raman peaks due to the M-point phonons. The calculated vibrational frequencies of the second-order Raman spectra agree with the observed laser-energy-dependent Raman shifts in the experiment.

Original languageEnglish
Article number205415
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume91
Issue number20
DOIs
Publication statusPublished - 2015 May 12

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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    Guo, H., Yang, T., Yamamoto, M., Zhou, L., Ishikawa, R., Ueno, K., Tsukagoshi, K., Zhang, Z., Dresselhaus, M. S., & Saito, R. (2015). Double resonance Raman modes in monolayer and few-layer MoTe2. Physical Review B - Condensed Matter and Materials Physics, 91(20), [205415]. https://doi.org/10.1103/PhysRevB.91.205415