Hot electron photoemission from plasmonic nanoparticles: Role of transient absorption in surface mechanism

We analyze and compare surface- and volume-based internal photoelectric effects from spherical nanoparticles, obtaining analytical expressions for the photoemission rate in both cases. Similar to results for a flat metal surface, one can show that the surface mechanism prevails, since it is unaffected by detrimental hot electron collisions. Transient absorption results from dielectric permittivity discontinuity at the nanoparticle boundary and leads to a substantial (by ∼5 times) increase of the photoelectron emission rate.