Ultrafast Hot Carrier Dynamics in Materials from Ab Initio Calculations

!!!!!How does an excited electron lose its energy? This problem is central in fields ranging from condensed matter physics to electrical engineering and energy. We developed and applied calculations to study the dynamics of out-of-equilibrium charge carriers – also known as hot carriers (HCs) – in semiconductors and metals [1–3]. We present ab initio calculations of electron-phonon, electron-electron, and electron-defect scattering rates that can predict the relaxation times and mean free paths of HCs in materials. We apply this framework to: 1) HC thermalization in the first picosecond after sunlight absorption in silicon. 2) HCs in GaAs, for which our results contribute to resolve experimental controversies and challenge the tenet that optical lattice vibrations are mainly responsible for HC energy loss. 3) HCs generated by surface plasmons in noble metals, a process of relevance in optoelectronics, photocatalysis and photovoltaics, for which we predict optimal conditions for HC generation and extraction, and compute plasmonic losses ab