VFB = 1/q (G- S)

- - -

VFB= - Vbi

(the amount of “band bending”)

(position of the Fermi level)

(includes semiconductorand oxide components)

Degenerate Semiconductors

As the doping conc. increases more, EF rises above EC

EV

EC (intrinsic)available impurity band states EFEg

EC (degenerate) ~ EDfilled impurity band states

apparent band gap narrowing:Eg* (is optically measured)

-

Eg* is the apparent band gap: an electron must gain energy Eg* = EF-EV

Quantum Effectson Threshold Voltage