Size-Dependent Electron-Phonon Coupling in Monocrystalline Gold Nanoparticles

The absorption of light very effectively generates hot electrons in plasmonic nanoparticles. These hot electrons can be used to photocatalyze chemical reactions. Relaxation of the hot electrons takes place via thermalization with the lattice. In our recent study, we investigated this so-called electron-phonon coupling in gold nanoparticles (AuNPs). Size dependency of the electron-phonon coupling has been controversially discussed in literature. By comparing mono- to polycrystalline AuNPs, we could show that electron-surface scattering contributes substantially to electron-phonon coupling, giving rise to size-dependent electron-phonon coupling in monocrystalline AuNPs, while blurring the size dependency in polycrystalline AuNPs.[1] We investigated further aspects of the hot electron dynamics in plasmonic nanoparticles such as its temperature dependency or the excitation mechanism of breathing oscillations.<br/><br/>[1]: ACS Photonics 2021, 8, 752−757