Simultaneous measurements of electronic conduction and Raman response in molecular junctions.
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 p-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.
Ward
Daniel R
DR
Department of Physics and Astronomy, Rice Quantum Institute, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
Halas
Naomi J
NJ
Ciszek
Jacob W
JW
Tour
James M
JM
Wu
Yanpeng
Y
Nordlander
Peter
P
Natelson
Douglas
D