Fermi energy and work function
Posted: Sat Apr 14, 2007 4:52 pm
Dear All,
Work function is defined as: \Phi=E(vacuum)-E(Fermi); in VASP calculations, E(Fermi) is set at the top of the valence band, which can be found in OUTCAR.
For metals, it is straightforward to calculate \Phi using E(Fermi) from OUTCAR.
My question is: in semiconductors, how do we define E(Fermi) for the work function? should we instead take it at the middle of the band gap?
Thanks.
Work function is defined as: \Phi=E(vacuum)-E(Fermi); in VASP calculations, E(Fermi) is set at the top of the valence band, which can be found in OUTCAR.
For metals, it is straightforward to calculate \Phi using E(Fermi) from OUTCAR.
My question is: in semiconductors, how do we define E(Fermi) for the work function? should we instead take it at the middle of the band gap?
Thanks.