Raman Enhancement of a Dipolar Molecule on Graphene
| Autor: | Myungwoong Kim, Changshui Huang, Padma Gopalan, Bryan M. Wong, Nathaniel S. Safron, Michael S. Arnold |
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| Rok vydání: | 2014 |
| Předmět: |
Materials science
Graphene Analytical chemistry Substrate (electronics) Chromophore Molecular physics Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention symbols.namesake General Energy law Polarizability symbols Molecule Physical and Theoretical Chemistry Raman spectroscopy Saturation (magnetic) Excitation |
| Zdroj: | The Journal of Physical Chemistry C. 118:2077-2084 |
| ISSN: | 1932-7455 1932-7447 |
| Popis: | We show a large enhancement in the Raman signal from a highly polarizable molecule attached to single layer graphene. Through spatial mapping of the Raman signal and wavelength-dependent Raman measurements from a dipolar chromophore latched to a graphene/SiO2 substrate and to a bare SiO2 substrate, we show that strong electronic coupling in the hybrid structure contributes to the enhancement. The dipolar molecule is a pyrene tethered Disperse Red 1 (DR1P) that noncovalently binds to graphene. Upon comparison of the Raman signal of DR1P on single layer graphene with that on a bare SiO2/Si substrate, we found that the enhancement factor is in the range 29–69 at 532 nm excitation. As the surface coverage of DR1P on graphene increases, Raman intensity also increases and saturates at a certain concentration. The saturation of the Raman signal intensity at higher DR1P concentrations were accompanied by shifts in the G band and the 2D band of graphene due to p-doping. We further show that the Raman enhancement t... |
| Databáze: | OpenAIRE |
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