Work function

The work function is the minimum energy (usually measured in electron volts) needed to remove an electron from the Fermi level in a metal to a point at infinite distance away outside the surface. The work function is generally about half the ionization energy of a free atom of the metal. For example, Caesium has ionization energy 3.9 eV and work function 1.9 eV.

Related Topics:
Energy - Electron volt - Electron - Fermi level - Metal - Ionization energy - Caesium

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W = -E_{tot}(N+1) + {E_{tot}(N) + V(infty) } = - {partial E_{tot} over {partial N} } + V(infty) = - mu + V(infty)

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E_{tot}(N+1) - E_{tot}(N) = {partial E_{tot} over {partial N} } = mu

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epsilon_F = , mu

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Here V is vacuum level and F is Fermi level.

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