Fermi level, \(E_{\text{F}}\)

https://doi.org/10.1351/goldbook.F02341
The chemical potential of electrons in a solid (metals, semiconductors or insulators) or in an electrolyte solution.
See: bandgap energy, conduction band, valence band
Source:
PAC, 1996, 68, 2223. 'Glossary of terms used in photochemistry (IUPAC Recommendations 1996)' on page 2242 (https://doi.org/10.1351/pac199668122223)