Photoemission Spectroscopy

• An x-ray photon is incident on sample, and ejects either a core or valence electron
• If we measure the kinetic energy of the emitted electrons we can determine the electron binding energy
• In angle resolved photoemission spectroscopy (ARPES), we measure the momentum of emitted valence band electrons, and this gives valence band dispersion and Fermi surfaces
• In angle integrated photoemission, we integrate over the momentum of the emitted valence band electrons, and get the valence band density of states
• Finally, in x-ray photoemission spectroscopy (XPS), we measure the kinetic energy of the emitted core electrons, and determine core level binding energies