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Enhanced Raman scattering from exciton coupling in 2D TMD-molecular heterostructures

ORAL

Abstract

Excitons in 2D transition metal dichalcogenide (TMD) semiconductors have large oscillator strength, while molecular excitons exhibit highly tunable emission. A molecular-2D material heterojunction offers a platform to combine the properties of the excitons in the disparate materials. In our study, we investigate the coupling of the WSe2 B exciton with the 0-0 exciton of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA). We observe evidence of a hybrid exciton with the strong absorption character of the WSe2 B exciton leading to enhanced (20-fold) Raman scattering of the PTCDA modes. The interaction is modeled using a coupled oscillator model, which is supported by excitation energy dependent Raman measurements. We also find that the Raman enhancement decreases with increasing WSe2 thickness due to the increased reflectivity of the heterostructure. Our findings elucidate the effects of nearly degenerate exciton coupling in 2D TMD-molecule systems and how they may lead to novel optical processes.

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Presenters

  • Christine Muccianti

    Physics, University of Arizona

Authors

  • Christine Muccianti

    Physics, University of Arizona

  • Sara L Zachritz

    Chemistry & Biochemistry, University of Arizona

  • Angel Garlant

    Physics, University of Arizona

  • Calley Eads

    Chemistry & Biochemistry, University of Arizona

  • Bekele Badada

    Physics, University of Arizona

  • Adam Alfrey

    Physics, University of Arizona

  • Michael R Koehler

    JIAM Diffraction Facility, Joint Institue for Advanced Materials, University of Tennessee, Joint Institute for Advanced Materials Diffraction Facility, University of Tennessee, The University of Tennessee

  • David George Mandrus

    Materials Science and Technology Division, Oak Ridge National Labratory, Materials Science and Engineering, University of Tennessee, Department of Materials Science and Engineering, University of Tennessee, University of Tennessee, Department of Materials Science and Engineering, University of Tennessee Knoxville, Department of Materials Science & Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA, Oakridge National Laboratory, Materials Science and Engineering, University of Tennessee, Knoxville, Oak Ridge National Laboratory, University of Tennessee - Knoxville, Materials Science and Technology Division, Oak Ridge National Laboratory, Department of Physics, University of Tennessee Knoxville, Materials Science and Technology, Oak Ridge National Laboratory, Oak Ridge National Laboratory, Materials Science and Technology Division, Department of Materials Science, The University of Tennessee, University of Tennessee, Knoxville

  • Rudolf H Binder

    James C. Wyant College of Optical Sciences, University of Arizona

  • Brian J LeRoy

    Physics, University of Arizona, Department of Physics, University of Arizona, Physics, University of Arizona, Tucson AZ, University of Arizona

  • Oliver L.A. Monti

    Chemistry & Biochemistry, University of Arizona, University of Arizona

  • John Schaibley

    Department of Physics, University of Arizona, Physics, University of Arizona, University of Arizona