EELS studies of the tuning and robustness of plasmonic response in high aspect ratio gold nanostructures
| Autor: | Arenal, Raúl, Peláez-Fernández, Mario, Majérus, Bruno, Dufour, Romain, Funes-Hernando, Daniel, Duvail, Jean-Luc |
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| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Popis: | Resumen del trabajo presentado al MRS Fall Meeting & Exhibit, celebrado en Boston, Massachusetts (USA) del 27 de noviembre al 2 de diciembre de 2022. For the past couple of decades, plasmonics has been on the spotlight of research, mainly for its varied applications. Within this field, the study and tuning of localized surface plasmon resonances (LSPRs) in metallic nanowires has been of importance due to their application versatility; ranging from photonics to electronics, sensors, or even chemical analysis through surface-enhanced light spectroscopies. Additionally, recent works have shown it is possible modify the morphology of these nanowires by means of laser irradiation, hence providing a new realm of high aspect-ratio nanostructures with potential new properties. Low-loss electron energy loss spectroscopy (EELS) is a very fitting technique regarding the study of plasmonic resonances in these novel nanostructures, combining a nanometric spatial resolution and a very accurate spectral resolution. In this way, the monochromated EELS studies shown in this work, combined with state-of-the-art discrete dipole approximation (DDA) modelling, show how the plasmonic response of high aspect ratio gold 1D nanostructures can be tuned by means of coupled and non-coupled nanoparticles attached to the tips of gold nanowires, as well as a proof of concept as to how this technique can be used to understand coupling in these nanostructures. Specifically, these studies have been carried out on gold nanowires and nanostructures consisting of nanoparticles of various sizes joint to them, producing high aspect-ratio half-dumbbells and dumbbells. The investigation of the surface plasmon resonances has been developed through a non-negative matrix (NMF) decomposition of EELS spectrum images. This high aspect-ratio gold nanostructures sustain Fabry-Perot-like surface plasmon responses from infrared to visible. We show that these resonances can be tuned by means of laser irradiation, where low energy modes stay unperturbed. All these analyses serve as experimental proof of the selective tuning (or robustness) of the plasmonic modes in a specific spectral range, which is of critical interest regarding applications for sensing devices and nano-sources, as well as optical remote control. |
| Databáze: | OpenAIRE |
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