2014/01/13 by Yajing Li, Y. Li, P. Doak +7 · 74 citations
Chemistry · Engineering · Physics and Astronomy · #Atomic physics #Biasing #Chemical physics #Chemistry #Intramolecular force #Materials science #Molecular Junctions and Nanostructures #Molecular physics #Molecular vibration #Molecule #Optics #Physics #Quantum and electron transport phenomena #Raman spectroscopy #Spectroscopy and Quantum Chemical Studies #Voltage #cond-mat.mes-hall
paper · pdf · doi:10.1073/pnas.1320210111
published in Proceedings of the National Academy of Sciences 111(4), 1282-1287 (National Academy of Sciences) · 23 pages, 4 figures + 12 pages, 7 figures supporting material
openalex publication_date 2014/01/13 · arxiv created 2014/03/04 · arxiv updated 2014/03/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Vibrational modes of molecules are fundamental properties determined by intramolecular bonding, atomic masses, and molecular geometry, and often serve as important channels for dissipation in nanoscale processes. Although single-molecule junctions have been used to manipulate electronic structure and related functional properties of molecules, electrical control of vibrational mode energies has remained elusive. Here we use simultaneous transport and surface-enhanced Raman spectroscopy measurements to demonstrate large, reversible, voltage-driven shifts of vibrational mode energies of C60 molecules in gold junctions. C60 mode energies are found to vary approximately quadratically with bias, but in a manner inconsistent with a simple vibrational Stark effect. Our theoretical model instead suggests that the mode shifts are a signature of bias-driven addition of electronic charge to the molecule. These results imply that voltage-controlled tuning of vibrational modes is a general phenomenon at metal-molecule interfaces and is a means of achieving significant shifts in vibrational energies relative to a pure Stark effect.