Plasmonic nanoparticles are best known for their unique optical properties, however recent application of plasmon-generated hot electrons in nanoparticle catalysis, anisotropic nanoparticle growth, and photodetection, has resulted in the need for a fundamental description of the production and transfer of excited electrons in metal nanoparticles. We have investigated both the generation of hot electrons and their subsequent transfer to molecular-type acceptors with analysis of the homogeneous plasmon linewidth. The plasmon linewidth corresponds to a summation of the radiative and non-radiative damping pathways that contribute to relaxation of the surface plasmon. These channels can be described analytically and separated into four general subsets: bulk damping, radiative damping, electron surface scattering, and damping <i>via</i> charge interactions. We find that changes in the plasmon linewidth when metal nanoparticles are in contact with molecular-type acceptors, such as graphene, can be used to calculate the charge transfer rate, and provide insight into hot electron generation. We also examined electronic interactions between metal nanoparticles and thiol ligands, and determined that ligand-induced charge density changes alter the plasmon resonance energy. Our results are important for the future of metal nanoparticles in applications that rely on charge transfer such as light harvesting and plasmon-assisted chemical reactions.

Characterizing the generation of hot electrons by metal nanoparticles through their interaction with molecular-type electron acceptors

249th National Meeting (2015)

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