Photoinduced charge carrier dynamics in germanium

The light-induced injection of charge carriers from the valence to the conduction band of a solid, and their subsequent thermalization and relaxation, are fundamental physical processes. They allow dynamically altering the conductivity of a semiconductor, controlling its electro-optical properties with light fields. In this paper, we discuss the elusive photoinjection mechanism occurring during light-matter interaction, to then focus on the charge thermalization and relaxation processes in germanium.