Single plasmon hot carrier generation in metallic nanoparticles

Lara Román Castellanos,Johannes Lischner,Ortwin Hess

doi:10.1038/s42005-019-0148-2

Lara Román Castellanos, Johannes Lischner + Show 1 more

Open Access

https://doi.org/10.1038/s42005-019-0148-2

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Abstract

Hot carriers produced from the decay of localized surface plasmons in metallic nanoparticles are intensely studied because of their optoelectronic, photovoltaic and photocatalytic applications. From a classical perspective, plasmons are coherent oscillations of the electrons in the nanoparticle, but their quantized nature comes to the fore in the novel field of quantum plasmonics. In this work, we introduce a quantum-mechanical material-specific approach for describing the decay of single quantized plasmons into hot electrons and holes. We find that hot carrier generation rates differ significantly from semiclassical predictions. We also investigate the decay of excitations without plasmonic character and show that their hot carrier rates are comparable to those from the decay of plasmonic excitations for small nanoparticles. Our study provides a rigorous and general foundation for further development of plasmonic hot carrier studies in the plasmonic regime required for the design of ultrasmall devices.

Highlights

Hot carriers produced from the decay of localized surface plasmons in metallic nanoparticles are intensely studied because of their optoelectronic, photovoltaic and photocatalytic applications
Localized surface plasmons (LSPs) in metallic nanoparticles facilitate drastic electric field enhancements and large light absorption cross-sections that can be harnessed in nanophotonic applications, such as plasmon-enhanced biosensing[1], surface-enhanced Raman scattering[2], data storage[3], or nanoheaters[4,5]
Calculating the Green’s function, for example via the GW method, is very challenging for metallic nanoparticles[34] and quasiparticle energies are often approximated using Kohn–Sham energies obtained from density-functional theory (DFT)[35]

Summary

Introduction

Hot carriers produced from the decay of localized surface plasmons in metallic nanoparticles are intensely studied because of their optoelectronic, photovoltaic and photocatalytic applications. Using semiclassical approaches, which combine a classical description of the LSP with a quantum-mechanical description of hot carriers, several groups analyzed the distribution of hot carriers resulting from the plasmon decay and studied its dependence on the nanoparticle size, material, and environment[14,15,16,17]. Gerchikov and coworkers[31] and Weick et al.[32] used a separation of centre-of-mass motion and relative motion of the electrons to derive a quantized electron–plasmon Hamiltonian Their approach cannot be used to study the decay of other neutral excitations, such as electron–hole pairs. We compare our quantum-mechanical results with semiclassical calculations and show that there is a significant discrepancy in the hot carriers rates for small nanoparticles

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