BINDING-ENERGIES AND REFERENCE LEVELS IN PHOTOELECTRON-SPECTROSCOPY

Measurements on solids enable the Fermi level to be positioned relative to the spectrometer vacuum level; those on gases should in turn allow placement of the latter with respect to the vacuum level at infinity. A combination of the two would therefore position the Fermi energy on an absolute scale. The separation between EF and V∞ corresponds to the spectrometer electrochemical potential. This is the quantity which must be added to binding energies measured relative to EF to reference them to V∞,ie B∞ = BF + \ ̄gmsp. The requirements for performing this alignment are discussed, and \ ̄gmsp is measured on the present spectrometer. The value of 4.1 eV which is obtained should supplant the use of sample work functions in the alignment procedure. © 1990.