Hot-electron generation and energy transfer in plasmonic metastructures with hot spots: Quantum and Classical mechanisms

Generation of energetic (hot) electrons is an intrinsic property of any plasmonic nanostructure under illumination. Simultaneously, a striking advantage of metal nanocrystals over semiconductors lies in their very large absorption cross sections. Therefore, metal nanostructures with strong and tailored plasmonic resonances are very attractive for photocatalytic applications, which often involve excited electrons. However, the central questions in the problem of plasmonic hot electrons are quantifying the number of optically excited energetic electrons in a nanocrystal and finding out how to extract such electrons. Here we develop a theory describing the generation rates and the energy distributions of hot electrons in nanocrystals with various geometries. Hot-electron generation [1] together with non-radiative plasmonic transfer [2] represent efficient mechanisms to transport and localize optical and photo-chemical energies.

1. A.O. Govorov, H. Zhang, V. Demir, and Y. K. Gun’ko, Nano Today, 9, 85 (2014).
2. E.-M. Roller, L.V. Besteiro, C. Pupp, L. Khosravi Khorashad, A. O. Govorov, T.Liedl, Nature Physics, 13, 761-765 (2017).