Simultaneous measurements of electronic conduction and Raman response in molecular junctions

Abstract

Electronic conduction through single molecules is affected by the molecular electronic structure as well as by other information that is extremely difficult to assess, such as bonding geometry and chemical environment. The lack of an independent diagnostic technique has long hampered single-molecule conductance studies. We report simultaneous measurement of the conductance and the Raman spectra of nanoscale junctions used for single-molecule electronic experiments. Blinking and spectral diffusion in the Raman response of both para-mercaptoaniline and a fluorinated oligophenylyne ethynylene correlate in time with changes in the electronic conductance. Finite difference time domain calculations confirm that these correlations do not result from the conductance modifying the Raman enhancement. Therefore, these observations strongly imply that multimodal sensing of individual molecules is possible in these mass-producible nanostructures.

16 pages, 5 figures + supporting material of 15 pages, 10 figures

References in corpus (5)

• Single-Molecule Circuits with Well-Defined Molecular Conductance
• The Kondo effect in C${}_{60}$ single-molecule transistors
• Electromigrated nanoscale gaps for surface-enhanced Raman spectroscopy
• Controlling charge injection in organic field-effect transistors using self-assembled monolayers
• Kondo resonances and anomalous gate dependence of electronic conduction in single-molecule transistors

Cited by in corpus (3)

• Transport in molecular states language: Generalized quantum master equation approach
• Raman scattering in current carrying molecular junctions. A preliminary account
• Electronic and optical properties of electromigrated molecular junctions