Ascertaining Plasmonic Hot Electrons Generation from Plasmon Decay in Hybrid Plasmonic Modes

In the propagating process along metal surface, surface plasmon polaritons (SPPs) mainly decay into thermal loss or release into photons, while a part of them were converted into electrons with high energy termed as hot electrons, which have great significance in photonics and electronics. In this work, the generation of plasmonic hot electrons was ascertained in the nanoparticle-film system through plasmon-driven surface catalysis (PDSC) reactions. The surface-enhanced Raman scattering (SERS) spectra of p,p'-dimercaptoazobenzene (DMAB) catalyzed by 4-nitrobenzenethiol (4NBT) experimentally demonstrated the essential catalysis electrons were generated in this hybrid plasmon mode. The results pointed out the priority of plasmonic hot electron generation in the dimer-film gap compared to the monomer-film gap which was analyzed by the surface electric and charge distribution. Furthermore, the SERS spectra of 4NBT in the metal nanoparticle-dielectric film system confirmed the necessity of hybrid plasmon mode in the generation of plasmonic hot electrons in the nanoparticle-film system. Because of the simple configuration and convenient fabrication of nanoparticle-film system, the work on this hybrid plasmon mode has a significant role in promoting the application of plasmonic hot electrons.