Transient electron energy distribution in supported Ag nanoparticles

Abstract

The electron relaxation in Ag nanoparticles supported on graphite is investigated by time-resolved multiphoton photoemission spectroscopy. The photoemission spectra map the transient electron energy distribution in the nanoparticles and reveal the internal thermalization and cooling of the electron gas. The excess energy stored in the electron gas is calculated using the free-electron model. In contrast to the behaviour of isolated nanoparticles the energy loss rate from the electron gas increases with the pump fluence. This indicates that the electron gas equilibration in Ag nanoparticles on graphite is modified by excited electron transport.