surface states

https://doi.org/10.1351/goldbook.S06190
Energy levels localized in the @[email protected] of semiconductors, which do not bear any direct relation to the bulk energy distribution, but which can exchange electrons with the bulk. In such a case a @[email protected] may arise even when \(\sigma \) (the free @[email protected]) is zero, i.e. \(\sigma =\sigma _{\mathrm{sc}}+\sigma _{\mathrm{ss}}\), where \(\sigma _{\mathrm{sc}}\) is the space @[email protected] and \(\sigma _{\mathrm{ss}}\) is the @[email protected] associated with the surface states.
Source:
PAC, 1986, 58, 437. (Interphases in systems of conducting phases (Recommendations 1985)) on page 443 [Terms] [Paper]