Secondary-electron emission from first principles

Multi-length and time-scale relaxation processes connect non-equilibrium excited electrons in a target material after ion or electron irradiation with characteristic properties when they are emitted as secondary electrons. The focus will be on graphene as a prototypical two-dimensional material for which I will discuss the regimes of high electron and lattice temperatures. Our simulations show that lattice temperature significantly increases secondary electron emission, whereas electron temperature has a negligible effect. I will discuss the early stages, in which secondary electrons emitted within a few femto-seconds after ion impact can be of use as high-resolution thermalization probes. The classical and quantum mechanical regime of projectile electrons will be derived from real-time time-dependent density functional theory simulations.