The
Fermi level is the total
chemical potential for electrons (or
electrochemical potential for electrons) and is usually denoted by
µ or
EF. The Fermi level of a body is a
thermodynamic quantity, and its significance is the
thermodynamic work required to add one electron to the body (not counting the work required to remove the electron from wherever it came from). A precise understanding of the Fermi level—how it relates to
electronic band structure in determining electronic properties, how it relates to the voltage and
flow of charge in an electronic circuit—is essential to an understanding of solid-state physics.