Fermi Level definition of Fermi Level in the Free Online Encyclopedia.

Fermi level [′fer·mē ‚lev·əl]

(statistical mechanics)

The energy level at which the Fermi-Dirac distribution function of an assembly of fermions is equal to one-half. Also known as Fermi energy.

Fermi Level

the energy level below which all energy states of the particles of a degenerate gas that obey Fermi-Dirac statistics are occupied at a temperature of absolute zero (seeSTATISTICAL MECHANICS). Particles of a degenerate gas that obey Fermi-Dirac statistics are called fermions. The existence of the Fermi level is a consequence of the Pauli exclusion principle, according to which not more than (2s + 1) particles, where s is the spin of a particle, may occupy a state with a specified momentum p. The Fermi level coincides with the values of the chemical potential of a fermion gas at T = 0°K.

The Fermi level ℰ_F can be expressed in terms of the number n of gas particles per unit volume: ℰ_F = [(2πℏ)²/2m] [3n/4π(2s + 1)]^⅔, where m is the particle mass. The quantity is called the Fermi momentum. At T = 0°K, the particles occupy all states with momenta p < p_F; all states with p > p_F are empty. In other words, at T = 0°K, fermions occupy states in momentum space that lie within a sphere p² = 2mℰ_F of radius p_F; this sphere is called the Fermi sphere. Upon heating, some particles move from a state with p < p_F to a state with p > p_F. Vacant sites, called holes, occur within the Fermi sphere. The quantity is called the Fermi velocity and specifies the upper limit to the velocities of fermions at T = 0°K.

A degenerate gas consisting of conduction electrons in a solid at T = 0°K occupies surfaces of more complex shape in momentum space (see).

REFERENCE

Landau, L. D., and E. M. Lifshits. Statisticheskaia fizika, 2nd ed. Moscow, 1964. (Teoreticheskaia fizika, vol. 5.)

M. I. KAGANOV

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No references found	Among specific topics are defects in solids, the decline of Old Quantum Theory, characteristics of Fermi level, intrinsic semiconductors, the variation of photoconductivity with illumination, the origin of magnetization, and a classification of superconductors by their magnetic field behavior. Solid state engineering physics by SciTech Book News places the Fermi level closer to the occupied density of states and could create a hole carrier concentration as well as lead to defect state trapping and hopping conductivity to the P3HT. Identification of the possible defect states in ... by Feng, D.-Q.; Caruso, A.N.; Losovyj, Y.B.; Shulz, D.L.; Dowben, P.A. / Polymer Engineering and Science Interfacial charge injection is dictated by chemical bonding and the resulting band lineup between the Fermi level of the contact and transport levels (HOMO and LUMO) of the molecule. One- and two-photon photoelectron spectroscopy used to study ... by Journal of Research of the National Institute of Standards and Technology	ferme ornee ferme ornée ferment ferment oil Fermentation fermentation accelerator Fermentation of Fodder fermentation tube fermented milk fermenter Fermenting Vat Fermentnaia I Spirtovaia Promyshlennost Ferments fermi Fermi age Fermi age equation Fermi age model Fermi beta-decay theory Fermi constant Fermi derivative Fermi distribution Fermi energy Fermi Gas Fermi hole Fermi interaction Fermi Level Fermi liquid Fermi National Accelerator Laboratory Fermi plot Fermi resonance Fermi selection rules Fermi sphere Fermi Surface Fermi temperature Fermi transition Fermi's golden rules Fermi, Enrico Fermi-Dirac distribution function Fermi-Dirac gas Fermi-Dirac Statistics Fermi-propagated Fermion fermion field fermionic condensate Fermium Fermo Fermor Fermor, Villim Fermor, Villim Villimovich fermorite fern	fermentors fermentors ferments ferments ferments ferments Fermerere Fermet's Last Theorem Fermet's Last Theorem Fermeture Fermi Fermi Fermi Fermi age Fermi age equation Fermi age model Fermi Award Fermi ball Fermi ball Fermi beta-decay theory Fermi constant Fermi derivative Fermi distribution Fermi energy Fermi energy Fermi Enrico Fermi gas Fermi hole Fermi Hyper-Netted Chain Method Fermi interaction Fermi Level Fermi liquid Fermi liquid theory Fermi momentum Fermi momentum Fermi National Accelerator Laboratory Fermi National Accelerator Laboratory Fermi plot Fermi Prize Fermi Research Alliance, LLC Fermi resonance Fermi sea Fermi sea Fermi selection rules Fermi sphere Fermi surface Fermi temperature Fermi temperature Fermi transition Fermi velocity Fermi velocity Fermi's golden rules Fermi's interaction Fermi, Enrico Fermi, Enrico Fermi-Bose Hubbard Model Fermi-Dirac distribution function Fermi-Dirac gas Fermi-Dirac statistics Fermi-Dirac statistics Fermi-Liquid Drop Model

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No references found

Among specific topics are defects in solids, the decline of Old Quantum Theory, characteristics of Fermi level, intrinsic semiconductors, the variation of photoconductivity with illumination, the origin of magnetization, and a classification of superconductors by their magnetic field behavior.

Solid state engineering physics by SciTech Book News

places the Fermi level closer to the occupied density of states and could create a hole carrier concentration as well as lead to defect state trapping and hopping conductivity to the P3HT.

Identification of the possible defect states in ... by Feng, D.-Q.; Caruso, A.N.; Losovyj, Y.B.; Shulz, D.L.; Dowben, P.A. / Polymer Engineering and Science

Interfacial charge injection is dictated by chemical bonding and the resulting band lineup between the Fermi level of the contact and transport levels (HOMO and LUMO) of the molecule.

One- and two-photon photoelectron spectroscopy used to study ... by Journal of Research of the National Institute of Standards and Technology

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