Plasmonic hot electrons for sensing, photodetection, and solar energy applications: A perspective

TLDR

Plasmonic metals generate energetic hot electrons and holes through non‑radiative Landau damping, and their properties can be tuned by material, size, shape, and dielectric environment, enabling nanostructures to act as plasmonic photosensitizers that absorb light and transfer energy to adjacent molecules or semiconductors. The article reviews mechanisms of hot‑electron transfer to adsorbates or semiconductors and outlines their use in photodetectors, photocatalysts, photoelectrochemical cells, photovoltaics, biosensors, and chemical sensors, while discussing design principles for plasmonic devices.

Abstract

In plasmonic metals, surface plasmon resonance decays and generates hot electrons and hot holes through non-radiative Landau damping. These hot carriers are highly energetic, which can be modulated by the plasmonic material, size, shape, and surrounding dielectric medium. A plasmonic metal nanostructure, which can absorb incident light in an extended spectral range and transfer the absorbed light energy to adjacent molecules or semiconductors, functions as a “plasmonic photosensitizer.” This article deals with the generation, emission, transfer, and energetics of plasmonic hot carriers. It also describes the mechanisms of hot electron transfer from the plasmonic metal to the surface adsorbates or to the adjacent semiconductors. In addition, this article highlights the applications of plasmonic hot electrons in photodetectors, photocatalysts, photoelectrochemical cells, photovoltaics, biosensors, and chemical sensors. It discusses the applications and the design principles of plasmonic materials and devices.