Plasmonic Properties of Metallic Nanoparticles : Beyond the Dipolar Resonance
- Authors
- Publication Date
- Dec 14, 2018
- Source
- HAL-Descartes
- Keywords
- Language
- English
- License
- Unknown
- External links
Abstract
Last decades the interest in metallic nanoparticles increased enormously due to their optical tremendous properties. These properties refer to the localized surface plasmon resonances, which are characteristic for metallic nanoparticles of smaller sizes than the illumination wavelength. These resonances are directly linked to the oscillation of the conduction electrons of the metal and lead to a strong electromagnetic near-field localized at the nanoparticle surface. The plasmonic nanoparticles are successfully used in various application such as bio-chemical sensing, lasing, color generation, surface enhanced spectroscopies, photo-thermal therapy of cancer and etc.. Mostly, the applications are based on a single plasmonic resonance (mode) called dipolar. These modes are sensitive to many internal and external factors. In this thesis, we deeply study the factors, which may act on the spectral position of these modes. Moreover, we introduce the experimental set-ups influence on the recorded optical spectra. Besides the dipolar mode, a plasmonic nanostructure may exhibit many other modes which can be potentially used in applications. We investigate the excitation and the revealing mechanisms of so-called “hidden” plasmonic modes. In the final stage of the study we used the multi-resonant properties of a gold nanocylinder to demonstrate the enhancement of the quantum dots fluorescence by a doubly resonant plasmonic effect. This approach has a strong potential to be used in the solar energy applications.
