What's so Hot about Electrons in Metal Nanoparticles?

TL;DR

This paper reviews how metal nanoparticles generate hot electrons upon light absorption, exploring their dynamics, energy distribution, and implications for enhancing photocatalytic and solar energy conversion processes.

Contribution

It provides a comprehensive analysis of hot electron generation, coupling mechanisms, and the influence of nanoparticle material and shape, offering insights for improving plasmonic photocatalysis.

Findings

Material and shape influence hot electron generation

Spectroscopy reveals plasmon-molecular resonance coupling

Understanding many-body processes can enhance photocatalytic efficiency

Abstract

Metal nanoparticles are excellent light absorbers. The absorption processes create highly excited electron-hole pairs and recently there has been interest in harnessing these hot charge carriers for photocatalysis and solar energy conversion applications. The goal of this Perspectives article is to describe the dynamics and energy distribution of the charge carriers produced by photon absorption, and the implications for the photocatalysis mechanism. We will also discuss how spectroscopy can be used to provide insight into the coupling between plasmons and molecular resonances. In particular, the analysis shows that the choice of material and shape of the nanocrystal can play a crucial role in hot electron generation and coupling between plasmons and molecular transitions. The detection and even calculation of many-body hot-electron processes in the plasmonic systems with continuous spectra of electrons and short lifetimes are challenging, but at the same time very interesting from the point of view of both potential applications and fundamental physics. We propose that developing an understanding of these processes will provide a pathway for improving the efficiency of plasmon-induced photocatalysis.