Graphical method to determine the Fermi level position
of the free surface of
an n-type semiconductor with a peaked distribution of surface
states (inset).
Plotted in
same figure are the space charge of the semiconductor
(BLUE) and the negative of the net
charge due to the surface states (RED).
The surface Fermi level position will be "pinned"
near the position of the surface state peak for
a wide range of semiconductor doping levels.