Ab initio theory and calculations of many-body effects in photoemission from semiconductor surfaces: Cs3Sb as a case study

Understanding the momentum distribution of photoemitted electrons is important for developing next-generation photoinjectors for electron microscopes and particle accelerators, where the photoelectron beams are required to be highly focused. We will describe a recently developed ab initio theory to predict the momentum distribution of photoelectrons as a function of photon energy, including many-body effects as needed. We then present our most recent results for Cs₃Sb, which predict the (100) surface to provide highly focused photoelectron beams.