photoelectron spectroscopy

Also contains definitions of: ESCA, XPS
https://doi.org/10.1351/goldbook.P04609
A spectroscopic technique which measures the @K03402@ of electrons emitted upon the @I03183@ of a substance by high energy monochromatic photons. A photoelectron spectrum is a plot of the number of electrons emitted versus their @K03402@. The spectrum consists of bands due to transitions from the @G02704@ of an atom or molecular entity to the ground and excited states of the corresponding @R05073@. Approximate interpretations are usually based on 'Koopmans theorem' and yield orbital energies. PES and UPS (UV photoelectron @S05848@) refer to the @S05848@ using vacuum @UT07492@ sources, while ESCA (electron @S05848@ for chemical analysis) and XPS use X-ray sources.
Sources:
Orange Book, 2nd ed., p. 246 [Terms]
PAC, 1976, 45, 221. (Nomenclature and Spectral Presentation in Electron Spectroscopy Resulting from Excitation by Photons) on page 223 [Terms] [Paper]
PAC, 1996, 68, 2223. (Glossary of terms used in photochemistry (IUPAC Recommendations 1996)) on page 2261 [Terms] [Paper]