  Plasmonic hot carrier devices extract excited carriers from metal
nanostructures before equilibration, and have the potential to surpass
semiconductor light absorbers. However their efficiencies have so far remained
well below theoretical limits, which necessitates quantitative prediction of
carrier transport and energy loss in plasmonic structures to identify and
overcome bottlenecks in carrier harvesting. Here, we present a theoretical and
computational framework, Non-Equilibrium Scattering in Space and Energy
(NESSE), to predict the spatial evolution of carrier energy distributions that
combines the best features of phase-space (Boltzmann) and particle-based (Monte
Carlo) methods. Within the NESSE framework, we bridge first-principles
electronic structure predictions of plasmon decay and carrier collision
integrals at the atomic scale, with electromagnetic field simulations at the
nano- to mesoscale. Finally, we apply NESSE to predict spatially-resolved
energy distributions of photo-excited carriers that impact the surface of
experimentally realizable plasmonic nanostructures at length scales ranging
from tens to several hundreds of nanometers, enabling first-principles design
of hot carrier devices.
