Plasmon-induced hot-carrier generation differences in gold and silver nanoclusters

In the last thirty years, the study of plasmonic properties of noble metal nanostructures has become a very dynamic research area. The design and manipulation of matter in the nanometric scale demands a deep understanding of the underlying physico-chemical processes that operate in this size regimen...

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Bibliographic Details
Published in:Nanoscale 2019-04, Vol.11 (17), p.864-8615
Main Authors: Douglas-Gallardo, Oscar A, Berdakin, Matías, Frauenheim, Thomas, Sánchez, Cristián G
Format: Article
Language:English
Subjects:
Absorption cross sections
Absorption spectra
Chemical reactions
Computer simulation
Electron density
Energy absorption
Gold
Icosahedral phase
Nanoclusters
Noble metals
Organic chemistry
Quantum confinement
Silver
Single electrons
Time dependence
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Summary:In the last thirty years, the study of plasmonic properties of noble metal nanostructures has become a very dynamic research area. The design and manipulation of matter in the nanometric scale demands a deep understanding of the underlying physico-chemical processes that operate in this size regimen. Here, a fully atomistic study of the spectroscopic and photodynamic properties of different icosahedral silver and gold nanoclusters has been carried out by using a Time-Dependent Density Functional Tight-Binding (TD-DFTB) model. The optical absorption spectra of different icosahedral silver and gold nanoclusters of diameters between 1 and 4 nanometers have been simulated. Furthermore, the energy absorption process has been quantified by means of calculating a fully quantum absorption cross-section using the information contained in the reduced single-electron density matrix. This approach allows us take into account the quantum confinement effects dominating in this size regime. Likewise, the plasmon-induced hot-carrier generation process under laser illumination has been explored from a fully dynamical perspective. We have found noticeable differences in the energy absorption mechanisms and the plasmon-induced hot-carrier generation process in both metals which can be explained by their respective electronic structures. These differences can be attributed to the existence of ultra-fast electronic dissipation channels in gold nanoclusters that are absent in silver nanoclusters. To the best of our knowledge, this is the first report that addresses this topic from a real time fully atomistic time-dependent approach. In the last thirty years, the study of plasmonic properties of noble metal nanostructures has become a very dynamic research area.
ISSN:2040-3364
2040-3372
DOI:10.1039/c9nr01352k