Virtual Plasmonic Dimers for Ultrasensitive Inspection of Cluster–Surface Coupling
| Autor: | Hannes Hartmann, Ingo Barke, Sylvia Speller, Jean Lermé, Karl-Heinz Meiwes-Broer, Marga-Martina Pohl, Kevin Oldenburg |
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| Přispěvatelé: | Institut für Physik [Rostock], Universität Rostock, Agrégats et nanostructures (AGNANO), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Leibniz-Institut für Katalyse (LIKAT Rostock), Universität Rostock-Leibniz Association |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Permittivity
Plasmons Materials science Resonance structures Mie scattering etal nanoparticles Physics::Optics 02 engineering and technology Electron Discrete dipole approximation 010402 general chemistry 01 natural sciences Molecular physics Resonance (particle physics) Physical and Theoretical Chemistry Plasmonic nanoparticles Plasmon [PHYS]Physics [physics] 021001 nanoscience & nanotechnology 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Dipole General Energy Nanoparticles 0210 nano-technology Multipole expansion |
| Zdroj: | Journal of Physical Chemistry C Journal of Physical Chemistry C, American Chemical Society, 2019, 123 (2), pp.1379-1388. ⟨10.1021/acs.jpcc.8b08928⟩ |
| ISSN: | 1932-7447 1932-7455 |
| Popis: | International audience; Plasmonic sensors owe their sensitivity to the susceptibility of collective electron modes to tiny changes of the local environment. Simple sensors are based on metal nanoparticles where spectral shifts of the resonance are frequently treated in view of an “effective” dielectric medium surrounding each particle. Using single-object spectroscopy probing a large number of silver particles on Si(111)-(7 × 7) in a photoemission electron microscope (PEEM), we show that this picture breaks down because of the formation of image dipoles in the substrate. Even at particle sizes as small as 10 nm, that is, small compared to the excitation wavelength, the dipole approximation is no longer valid because the system inherently creates higher order multipole modes. To validate this scenario, we compare plasmon energies, lifetimes, and their variability to the case of a surface with lower permittivity. Model calculations based on generalized Mie theory reveal that the formation of multipole modes is extremely sensitive to the local geometry on the scale of one ångström, in particular to the intradimer separation. Hence, such systems may enable novel ultrasensitive plasmonic detection schemes such as high-precision plasmonic rulers and probes for molecular interfaces or spacer layers. |
| Databáze: | OpenAIRE |
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