Characterization of Few-Layer 1T' MoTe₂ by Polarization-Resolved Second Harmonic Generation and Raman Scattering.

ABSTRACT: We study the crystal symmetry of few-layer 1T' MoTe₂ using the polarization dependence of the second harmonic generation (SHG) and Raman scattering. Bulk 1T' MoTe₂ 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' MoTe₂ 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 measure

SUBMITTER: Beams R 

PROVIDER: S-EPMC5542881 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature