Fermi level

      a measure of the energy of the least tightly held electrons within a solid, named for Enrico Fermi (Fermi, Enrico), the physicist who first proposed it. It is important in determining the electrical and thermal properties of solids. The value of the Fermi level at absolute zero (−273.15 °C) is called the Fermi energy and is a constant for each solid. The Fermi level changes as the solid is warmed and as electrons are added to or withdrawn from the solid. Each of the many distinct energies with which an electron can be held within a solid is called an energy level. According to the laws of quantum mechanics, each energy level can accommodate only a limited number of electrons. The Fermi level is any energy level having the probability that it is exactly half filled with electrons. Levels of lower energy than the Fermi level tend to be entirely filled with electrons, whereas energy levels higher than the Fermi tend to be empty.

      When materials with different individual Fermi levels are placed in contact, some electrons flow from the material with the higher Fermi level into the other material. This transfer of electrons raises the lower Fermi level and lowers the higher Fermi level. When the transfer is complete, the Fermi levels of the two materials are equal. This behaviour is important in electronic devices that juxtapose different materials.

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Universalium. 2010.

Look at other dictionaries:

  • Fermi Level —  Fermi Level  Уровень Ферми   Некоторый условный уровень энергии системы фермионов, в частности электронов твердого тела, соответствующий энергии Ферми …   Толковый англо-русский словарь по нанотехнологии. - М.

  • Fermi level — Fermio lygmuo statusas T sritis radioelektronika atitikmenys: angl. Fermi level vok. Fermi Niveau, n rus. уровень Ферми, m pranc. niveau de Fermi, m …   Radioelektronikos terminų žodynas

  • Fermi level — Fermio lygmuo statusas T sritis chemija apibrėžtis Elektronų cheminis potencialas kristale. atitikmenys: angl. Fermi level rus. уровень Ферми; фермиевский уровень …   Chemijos terminų aiškinamasis žodynas

  • fermi level — noun Usage: usually capitalized F : the energy level of an atom in a solid at a given temperature for which there is a 50 percent probability of occupation of any available state of that energy by an electron …   Useful english dictionary

  • Fermi level energy — Fermio lygmens energija statusas T sritis Standartizacija ir metrologija apibrėžtis Didžiausioji galima fermionų sistemos užpildytosios būsenos energijos vertė absoliučiojo nulio temperatūroje. atitikmenys: angl. Fermi energy; Fermi level energy… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • Fermi level energy — Fermio lygmens energija statusas T sritis fizika atitikmenys: angl. Fermi energy; Fermi level energy vok. Fermi Niveau Energie, f rus. уровень Ферми, m; фермиевская энергия, f pranc. énergie du niveau de Fermi, f …   Fizikos terminų žodynas

  • Fermi level position — Fermio lygmens padėtis statusas T sritis fizika atitikmenys: angl. Fermi level position vok. Lage des Fermi Niveaus, f rus. положение уровня Ферми, n pranc. position du niveau de Fermi, f …   Fizikos terminų žodynas

  • Quasi Fermi level — A Quasi Fermi level is a term used in quantum mechanics and especially in solid state physics to describe the change in charge carrier energy caused by the application of an external electric potential for instance in a semiconductor.When a… …   Wikipedia

  • hole quasi-Fermi level — skylių Fermio kvazilygmuo statusas T sritis radioelektronika atitikmenys: angl. hole quasi Fermi level vok. Defektelektronen Quasi Fermi Niveau, n rus. дырочный квазиуровень Ферми, m pranc. quasi niveau Fermi des trous, m …   Radioelektronikos terminų žodynas

  • electron quasi-Fermi level — elektronų Fermio kvazilygmuo statusas T sritis radioelektronika atitikmenys: angl. electron quasi Fermi level vok. Elektronen Quasi Fermi Niveau, n rus. электронный квазиуровень Ферми, m pranc. quasi niveau Fermi des électrons, m …   Radioelektronikos terminų žodynas

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