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.

Fano resonances result from the strong coupling and interference between a broad background state and a narrow, almost discrete state, leading to the emergence of asymmetric scattering spectral profiles. Under certain conditions, Fano resonances can experience a collapse of their width due to the destructive interference of strongly coupled modes, resulting in the formation of bound states in the continuum (BIC). In such cases, the modes are simultaneously localized in the nanostructure and coexist with radiating waves, leading to an increase in the quality factor, which is virtually unlimited. In this work, we report on the design of a layered hybrid plasmonic-dielectric metasurface that facilitates strong mode coupling and the formation of BIC, resulting in resonances with a high quality factor. We demonstrate the possibility of controlling Fano resonances and tuning Rabi splitting using the nanoantenna dimensions. We also experimentally demonstrate the generalized Kerker effect in a binary arrangement of silicon nanodisks, which allows for the tuning of the collective modes and creates new photonic functionalities and improved sensing capabilities. Our findings have promising implications for developing plasmonic sensors that leverage strong light-matter interactions in hybrid metasurfaces.

No abstract

No abstract

No abstract