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Roles of silver nanoclusters in surface-enhanced Raman spectroscopy
| Title: | Roles of silver nanoclusters in surface-enhanced Raman spectroscopy |
| Authors: | Tsuneda, Takao Browse this author | | Iwasa, Takeshi Browse this author | | Taketsugu, Tetsuya Browse this author →KAKEN DB |
| Issue Date: | 7-Sep-2019 |
| Publisher: | American Institute of Physics (AIP) |
| Journal Title: | Journal of chemical physics |
| Volume: | 151 |
| Issue: | 9 |
| Start Page: | 094102 |
| Publisher DOI: | 10.1063/1.5111944 |
| Abstract: | The cause for the huge enhancement factors of surface-enhanced Raman spectroscopy (SERS) by the addition of small silver nanoclusters is theoretically investigated by focusing on the difference between resonance Raman activity and surface plasmon effects. First, the resonance and off-resonance Raman spectra are calculated using the incident light wavenumbers of the low-lying charge transfer excitations for the surface (S) and vertex (V) complexes of the pyridine molecule attaching to three small silver nanoclusters: Ag-5, Ag-10, and Ag-20. As a result, it is found that the incident radiation dramatically increases the resonance Raman activities with the enhancement factors up to 10(12). This indicates that the resonance Raman effects are dominant in the enhancement factors of SERS, at least when to use small silver clusters. It is also found that the resonance Raman spectra significantly depend on the adsorption sites given in S or V complexes, and on the inclusion or exclusion of the long-range correction for density functional theory, irrespective of the size of the silver clusters. The electromagnetic field enhancement effects called surface plasmon effects are also examined for the Ag-20 cluster to confirm this conclusion. Consequently, the enhancement in the electric field is roughly evaluated as less than one for the static polarizability of this small cluster. It is, therefore, concluded that the resonance Raman activity effect is dominant in the huge SERS enhancement factors for, at least, small silver nanoclusters. |
| Rights: | The following article has been submitted to/accepted by Journal of Chemical Physics. After it is published, it will be found at https://aip.scitation.org/journal/jcp. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/76053 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 武次 徹也
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