First-Principles Studies of the Vibrational Stark Effect in C60

ORAL

Abstract

C60 has played a central role in molecular and organic electronics, where coupling between charge and vibrational degrees of freedom is of paramount importance. Recent surface-enhanced Raman scattering (SERS) studies of C60-Au junctions have reported significant shifts in vibrational mode frequencies with applied bias. Here we compute the magnitude of the vibrational Stark effect in gas-phase C60 and seek to understand and simulate the shifts in Raman mode frequencies observed in these electromigration junction-SERS experiments. Using density functional theory and a finite-difference approach, we calculate trends in the vibrational Stark effect for different modes of gas-phase C60, comparing directly to experiment and assessing the role of substrate-induced charging and external electric fields. This work supported by DOE and computational resources provided by NERSC.

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Authors

  • Peter Doak

    Department of Chemistry, UC-Berkeley, Molecular Foundry, LBNL

  • Yajing Li

    Department of Physics and Astronomy, Rice University, Department of Physics and Astronomy, MS 61, Rice University

  • Douglas Natelson

    Department of Physics and Astronomy and Department of Computer and Electrical Engineering, Rice University, 6100 Main St, Houston, TX 77005, Department of Physics and Astronomy, Rice University, Department of Physics \& Astronomy, Rice University

  • Leeor Kronik

    Weizmann Institute of Science, Israel, Department of Materials and Interfaces, Weizmann Institute of Science

  • Jeffrey Neaton

    Molecular Foundry, LBNL, Lawrence Berkeley National Lab, Lawrence Berkeley National Laboratory