Vacuum level

{
  "id": "MLC-T-CHM-012486",
  "term": "Vacuum level",
  "field": "Chemistry",
  "definition": "The energy level of an electron at rest just outside a solid surface, with zero kinetic energy relative to the sample surface, at a distance where image forces are negligible but the full surface dipole is felt. It depends on the surface, differing for example between the Si(001) and Si(111) planes. The work function is the energy needed to move an electron from the Fermi level to this level, and it is expressed in electronvolts.",
  "synonyms": [
    "local vacuum level"
  ],
  "subject": "Analytical Chemistry",
  "references": [
    "PAC, 2020, 92, 1781. 'Glossary of methods and terms used in surface chemical analysis (IUPAC Recommendations 2020)' on page 1818 (https://doi.org/10.1515/pac-2019-0404)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/vacuum-level/"
}