Lattice effect for enhanced hot-electron generation in nanoelectrodes

A stronger electric field in metal nanostructures can be realized by exciting nanoparticle plasmonic resonances to enhance hot electron generation. One can alter the nanoparticle shape, size, material, and/or the refractive index of the surrounding medium to achieve higher efficiency. Here, we report the nanostructure design that enhances the generation of plasmonic hot electrons from the periodically arranged gold nanoelectrodes. The periodic arrangement results in the excitation of collective lattice resonances in proximity to the Rayleigh anomalies (diffraction order transitions). We show how to select a lattice period that gives the highest field enhancement and the potential for the most efficient generation of plasmonic hot electrons, which are injected into the water environment from gold nanoelectrodes. Our study can serve as a general guideline in designing plasmonic nanostructures with nanoelectrodes injecting hot electrons into an aqueous environment.