Lawrence Berkeley National Laboratory
Experimental and Ab Initio Ultrafast Carrier Dynamics in Plasmonic Nanoparticles
- Author(s): Brown, AM
- Sundararaman, R
- Narang, P
- Schwartzberg, AM
- Goddard, WA
- Atwater, HA
- et al.
Published Web Locationhttps://doi.org/10.1103/PhysRevLett.118.087401
© 2017 American Physical Society. Ultrafast pump-probe measurements of plasmonic nanostructures probe the nonequilibrium behavior of excited carriers, which involves several competing effects obscured in typical empirical analyses. Here we present pump-probe measurements of plasmonic nanoparticles along with a complete theoretical description based on first-principles calculations of carrier dynamics and optical response, free of any fitting parameters. We account for detailed electronic-structure effects in the density of states, excited carrier distributions, electron-phonon coupling, and dielectric functions that allow us to avoid effective electron temperature approximations. Using this calculation method, we obtain excellent quantitative agreement with spectral and temporal features in transient-absorption measurements. In both our experiments and calculations, we identify the two major contributions of the initial response with distinct signatures: short-lived highly nonthermal excited carriers and longer-lived thermalizing carriers.