In X-ray photoelectron spectroscopy, measurement of the
charging potential of a particular sample from a comparison of the experimentally measured
\(\ce{C 1s}\) binding energy, arising from adsorbed hydrocarbons on the sample, with a standard binding energy value.
Notes: - A nominal value of \(\pu{285.0 eV}\) is often used for the binding energy of the relevant \(\ce{C 1s}\) peak, although some analysts prefer specific values in the range \(\pu{284.6 eV}\) to \(\pu{285.2 eV}\), depending on the nature of the substrate. This method does not determine the true charging potential, since the true binding energy of the adsorbed hydrocarbons is not known.
- Different sample charging potentials can occur on different areas on the surface, or at different depths, arising, for example, from sample inhomogeneities or non-uniform intensity of the incident-radiation flux.
See also: Fermi level referencing
Source:
PAC, 2020, 92, 1781. 'Glossary of methods and terms used in surface chemical analysis (IUPAC Recommendations 2020)' on page 1819 (https://doi.org/10.1515/pac-2019-0404)