Single-Order, Subwavelength Resonant Nanograting as a Uniformly Hot Substrate for Surface-Enhanced Raman Spectroscopy
| Autor: | Bob Koefer, Sheng Liu, Gary B. Braun, Xuegong Deng, Martin Moskovits, Paul Sciortino, Thomas Tombler |
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| Rok vydání: | 2010 |
| Předmět: |
Materials science
Macromolecular Substances Surface Properties Molecular Conformation Nanowire Bioengineering Grating Spectrum Analysis Raman symbols.namesake Optics Electric field Materials Testing Nanotechnology General Materials Science Particle Size business.industry Mechanical Engineering Radiant energy Equipment Design General Chemistry Surface-enhanced Raman spectroscopy Condensed Matter Physics Cladding (fiber optics) Polarization (waves) Nanostructures Equipment Failure Analysis Refractometry symbols Optoelectronics Gold Crystallization business Raman spectroscopy |
| Zdroj: | Nano Letters. 10:1780-1786 |
| ISSN: | 1530-6992 1530-6984 |
| DOI: | 10.1021/nl1003587 |
| Popis: | The surface-enhanced Raman spectroscopy (SERS) activity and the optical reflectance of a subwavelength gold nanograting fabricated entirely using top down technologies on silicon wafers are presented. The grating consists of 120 nm gold cladding on top of parallel silica nanowires constituting the grating's lines, with gaps between nanowires10 nm wide at their narrowest point. The grating produces inordinately intense SERS and shows very strong polarization dependence. Reflectance measurements for the optimized grating indicate that (when p-polarization is used and at least one of the incident electric field components lies across the grating lines) the reflectance drops to1% at resonance, indicating that essentially all of the radiant energy falling on the surface is coupled into the grating. The SERS intensity and the reflectance at resonance anticorrelate predicatively, suggesting that reflectance measurements can provide a nondestructive, wafer-level test of SERS efficacy. The SERS performance of the gratings is very uniform and reproducible. Extensive measurements on samples cut from both the same wafer and from different wafers, produce a SERS intensity distribution function that is similar to that obtained for ordinary Raman measurements carried out at multiple locations on a polished (100) silicon wafer. |
| Databáze: | OpenAIRE |
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