Effects of Intrinsic Fano Interference on Surface Enhanced Raman Spectroscopy: Comparison between Platinum and Gold
| Autor: | Qingzhen Hao, Lasse Jensen, Bei Wang, Yuebing Zheng, Peter C. Eklund, Vincent H. Crespi, Tony Jun Huang, Bala Krishna Juluri, I-Kao Chiang |
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| Rok vydání: | 2010 |
| Předmět: |
Chemistry
Analytical chemistry Physics::Optics Electron Discrete dipole approximation Surface-enhanced Raman spectroscopy Molecular physics Surfaces Coatings and Films Electronic Optical and Magnetic Materials Wavelength symbols.namesake General Energy Electric field symbols Physical and Theoretical Chemistry Raman spectroscopy Excitation Plasmon |
| Zdroj: | The Journal of Physical Chemistry C. 114:18059-18066 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/jp105276w |
| Popis: | Using pyridine as a probe molecule, we performed surface enhanced Raman spectroscopy (SERS) studies on platinum and gold nanodisk arrays at both plasmon resonant and off-plasmon resonant excitation wavelengths. A large Raman cross-section enhancement factor (EF) of ∼106 was obtained with plasmon resonant excitation on the Au array, and the EF decreases with off-resonant excitations. However, for Pt nanodisks the experimental EF is much smaller (∼102) and not sensitive to excitation wavelength. Electric field intensities calculated in Au and Pt nanoparticles using the discrete dipole approximation (DDA) with a dielectric function including or excluding interband transitions allowed us to explain the SERS EF differences at different excitation wavelengths. The observed SERS insensitivity to excitation wavelength in Pt was explained using Fano interference between the free plasmon electrons and continuum interband transitions. The importance of Fano interference was explored analytically in the electrostatic... |
| Databáze: | OpenAIRE |
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