Hot Electron Generation through Near-Field Excitation of Plasmonic Nanoresonators

We theoretically study hot electron generation through the emission of a dipole source coupled to a nano-resonator on a metal surface. In our hybrid approach, we solve the time-harmonic Maxwell's equations numerically and apply a quantum model to predict the efficiency of hot electron generation. Strongly confined electromagnetic fields and the strong enhancement of hot electron generation at the metal surface are predicted and are further interpreted with the theory of quasinormal modes. In the investigated nanoresonator setup, both the emitting source and the acceptor resonator are localized in the same volume, and this configuration looks promising to achieve high efficiencies of hot electron generation. By comparing with the efficiency calculated in the absence of the plasmonic nanoresonator, that is, the dipole source is located near a flat, unstructured metal surface, we show that the effective excitation of the modes of the nanoresonator boosts the generation efficiency of energetic charge carriers. The proposed scheme can be used in tip-based spectroscopies and other optoelectronic applications.

Automated summary

This theoretical study investigates the generation of hot electrons through the coupling of a dipole source with a nano-resonator on a metal surface. Numerical solutions of the time-harmonic Maxwell's equations and a quantum model are used to predict the efficiency of hot electron generation. Strongly confined electromagnetic fields and enhanced hot electron generation at the metal surface are observed, with the proposed nano-resonator setup showing potential for achieving high efficiencies of hot electron generation. By exciting the modes of the nano-resonator, the generation efficiency of energetic charge carriers is significantly boosted, demonstrating potential applications in tip-based spectroscopies and optoelectronics.