Photo-electron spectroscopy (PES)

Photo-electron spectroscopy (PES) is a technique for the investigation of the electronic and chemical properties of solids. In a PES experiment, monochromatic photons are absorbed by a solid, and the excited electrons, which leave the surface, are analyzed with respect to their kinetic energy. In this way, the electron-energy distribution can be recorded, yielding the binding energies of the electrons in the solid. Because of the limited mean-free path of the electrons below 10 Å, PES is very surface sensitive. With angle-resolved photoemission spectroscopy (ARPES) also information on the momentum of the electrons can be derived, allowing to determine the energy dispersion of the electronic bands.