X-ray photoelectron spectroscopy (XPS, also called electron spectroscopy
for chemical analysis, ESCA) is a electron spectroscopic
method that uses X-rays to eject electrons from inner-shell orbitals. The
kinetic energy, Ek, of these photoelectrons is determined by
the energy of the X-ray radiation, h![]() Ek = h n - Eb The experimentally measured energies of the photoelectrons are given by: Ek = h n - Eb − Ew where Ew is the work function of the spectrometer. |
Energy-level diagram for XPS
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The electron binding energies are dependent on the chemical environment
of the atom, making XPS useful to identify the oxidation state and ligands
of an atom.