Intricate Resonant Raman Response in Anisotropic ReS2

Amber McCreary, Jeffrey R. Simpson, Yuanxi Wang, Daniel Rhodes, Kazunori Fujisawa, Luis Balicas, Madan Dubey, Vincent H. Crespi, Mauricio Terrones, Angela R. Hight Walker

Research output: Contribution to journalArticle

29 Scopus citations

Abstract

The strong in-plane anisotropy of rhenium disulfide (ReS2) offers an additional physical parameter that can be tuned for advanced applications such as logic circuits, thin-film polarizers, and polarization-sensitive photodetectors. ReS2 also presents advantages for optoelectronics, as it is both a direct-gap semiconductor for few-layer thicknesses (unlike MoS2 or WS2) and stable in air (unlike black phosphorus). Raman spectroscopy is one of the most powerful characterization techniques to nondestructively and sensitively probe the fundamental photophysics of a 2D material. Here, we perform a thorough study of the resonant Raman response of the 18 first-order phonons in ReS2 at various layer thicknesses and crystal orientations. Remarkably, we discover that, as opposed to a general increase in intensity of all of the Raman modes at excitonic transitions, each of the 18 modes behave differently relative to each other as a function of laser excitation, layer thickness, and orientation in a manner that highlights the importance of electron-phonon coupling in ReS2. In addition, we correct an unrecognized error in the calculation of the optical interference enhancement of the Raman signal of transition metal dichalcogenides on SiO2/Si substrates that has propagated through various reports. For ReS2, this correction is critical to properly assessing the resonant Raman behavior. We also implemented a perturbation approach to calculate frequency-dependent Raman intensities based on first-principles and demonstrate that, despite the neglect of excitonic effects, useful trends in the Raman intensities of monolayer and bulk ReS2 at different laser energies can be accurately captured. Finally, the phonon dispersion calculated from first-principles is used to address the possible origins of unexplained peaks observed in the Raman spectra, such as infrared-active modes, defects, and second-order processes.

Original languageEnglish (US)
Pages (from-to)5897-5907
Number of pages11
JournalNano letters
Volume17
Issue number10
DOIs
StatePublished - Oct 11 2017

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

Cite this

McCreary, A., Simpson, J. R., Wang, Y., Rhodes, D., Fujisawa, K., Balicas, L., Dubey, M., Crespi, V. H., Terrones, M., & Hight Walker, A. R. (2017). Intricate Resonant Raman Response in Anisotropic ReS2. Nano letters, 17(10), 5897-5907. https://doi.org/10.1021/acs.nanolett.7b01463