Plasmonic Hot Electron Transport Driven Site-Specific Surface-Chemistry with Nanoscale Spatial Resolution

TL;DR

This study maps hot-electron-driven surface chemistry at 15 nm resolution on plasmonic nanostructures, revealing how hot carrier transport localizes reactive regions and advances nanoscale surface chemistry control.

Contribution

It provides the first spatially resolved mapping of hot-electron-driven reactions, combining experiments with first-principles calculations to understand hot carrier localization.

Findings

Hot-electron-driven reduction chemistry localized at 15 nm resolution.

Reactive regions determined by hot carrier transport from high-field areas.

Theoretical predictions align with experimental localization patterns.

Abstract

Nanoscale localization of electromagnetic fields near metallic nanostructures underpins the fundamentals and applications of plasmonics. The unavoidable energy loss from plasmon decay, initially seen as a detriment, has now expanded the scope of plasmonic applications to exploit the generated hot carriers. However, quantitative understanding of the spatial localization of these hot carriers, akin to electromagnetic near-field maps, has been elusive. Here we spatially map hot-electron-driven reduction chemistry with 15 nanometre resolution as a function of time and electromagnetic field polarization for different plasmonic nanostructures. We combine experiments employing a six-electron photo-recycling process that modify the terminal group of a self-assembled monolayer on plasmonic silver nanoantennas, with theoretical predictions from first-principles calculations of non-equilibrium hot-carrier transport in these systems. The resulting localization of reactive regions, determined by hot carrier transport from high-field regions, paves the way for hot-carrier extraction science and nanoscale regio-selective surface chemistry.