Plasmon-Induced Hot-Carrier Generation differences in Gold and Silver Nanoclusters

Abstract

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 demand 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 have been carried out by using Time-Dependent Density Functional Tight-Binding (TD-DFTB) model. Optical absorption spectra of different icosahedral silver and gold nanoclusters of diameters between 1 and 4 nanometers has been simulated. Furthermore, the energy absorption process have 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 for the quantum confinement effects dominating in this size regime. Likewise, the plasmon-induced hot-carrier generation process under laser illuminations have 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 difference can be attributed to the existence of ultra-fast electronic dissipation channels in gold nanoclusters that are absented 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. <br>

Hot-Carrier Generation in Plasmonic Nanoparticles: The Importance of Atomic Structure

“…As the Coulomb energy contribution is carried mainly by nonresonant transitions ( Supplementary Figure S6 ), the occupation probabilities of the electron and hole states contributing to these nonresonant transitions oscillate analogously to the Coulomb energy. The oscillations are especially visible in the occupations of electron and hole states that form the plasmon, 35 that is, the states near the Fermi energy, often referred to as Drude carriers. 49 The oscillatory population and depopulation of these states indicate that they would not likely be individually separable while they are a part of the plasmon as the Coulomb interaction is an essential part of the excitation itself.…”

“… 4 , 5 , 20 − 26 Whereas atomic-scale effects in nanoplasmonics, in general, have been increasingly addressed in recent years, 27 − 32 atomic-scale modeling of plasmonic HC generation is only emerging. 33 − 35 In particular, detailed atomic-scale distributions of plasmon-generated HCs, to our knowledge, have not yet been scrutinized. In the context of photocatalysis detailed understanding of plasmonic HC generation at the atomic scale is, however, of paramount importance as chemical reactions take place at this size scale.…”

Plasmonic Metasensors Based on 2D Hybrid Atomically Thin Perovskite Nanomaterials

“…Single layer hBN is also known as white graphene. It has been well demonstrated that the silver substrate could provide a much narrower width of the resonance curves and also deeper resonance dips [ 49 , 50 ]. Two-dimensional perovskite is sandwiched between the hBN and graphene layers, where its optical property will not be affected due to oxidization and liquid contaminations [ 51 , 52 ].…”

Modeling of plasmonic properties of nanostructures for next generation solar cells and beyond

“…The use of DFTB promises significant computational cost savings and therefore ability to treat larger systems also with the real-time time-dependent approaches. RT TD-DFTB has been gaining use in plasmonics [87,88,176,177]. In RT TD-DFTB, the Liouville-von Neumann equation…”

“…While some more well-known approaches such as classical and TD-DFT were previously reviewed [82][83][84], the bulk of DFT-based literature deals with system sizes limited to a few nm, which is on the lower part of the range of particle sizes used in PV. We therefore specifically highlight emerging approaches which have the potential to significantly enhance modeling capabilities in the coming years, in particular, by allowing modeling at realistic length scales (of particles beyond 10 nm which are of most interest to plasmonic solar cells but remain problematic with Kohn-Sham DFT), such as timedependent orbital-free DFT [85,86], linear response and real-time time-dependent density functional tight binding [87][88][89][90] and machine learning-based approaches, and by allowing modeling beyond the single-particle based (DFT) picture with many-body perturbation theory [78][79][80][81]. The latter approach, while being computationally expensive, is also finding increasing use in the modeling of plasmonics as access to computing power expands, and is therefore explicitly included in this review.…”