Observation and analysis of Fano-like lineshapes in the Raman spectra of molecules adsorbed at metal interfaces
| Autor: | Abraham Nitzan, Kate Rodriguez, Mayukh Banik, Shirshendu Dey, V. A. Apkarian, Eero Hulkko, Michael Galperin |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Raman scattering
surface-enhanced Raman scattering bipyridyl ethylene Materials science FOS: Physical sciences Nanotechnology 02 engineering and technology 010402 general chemistry 01 natural sciences Molecular physics Spectral line symbols.namesake Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Molecule Physics::Chemical Physics ta116 ta114 Condensed Matter - Mesoscale and Nanoscale Physics Scattering adsorbtion 021001 nanoscience & nanotechnology Ray 0104 chemical sciences 3. Good health X-ray Raman scattering Yield (chemistry) symbols 0210 nano-technology Raman spectroscopy metal surfaces |
| Zdroj: | Physical Review B. 93 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.93.035411 |
| Popis: | Surface enhanced Raman spectra from molecules (bipyridyl ethylene) adsorbed on gold dumbells are observed to become increasingly asymmetric (Fano-like) at higher incident light intensity. The electronic temperature (inferred from the anti-Stokes (AS) electronic Raman signal increases at the same time while no vibrational AS scattering is seen. These observations are analyzed by assuming that the molecule-metal coupling contains an intensity dependent contribution (resulting from light-induced charge transfer transitions as well as renormalization of the molecule metal tunneling barrier). We find that interference between vibrational and electronic inelastic scattering routes is possible in the presence of strong enough electron-vibrational coupling and can in principle lead to the observed Fano-like feature in the Raman scattering profile. However the best fit to the observed results, including the dependence on incident light intensity and the associated thermal response is obtained from a model that disregards this coupling and accounts for the structure of the continuous electronic component of the Raman scattering signal. The temperatures inferred from the Raman signal are argued to be only of qualitative value. 20 pages, 12 figures |
| Databáze: | OpenAIRE |
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