21.2 Metal-Semiconductor Contacts
521
Fig. 21.4 Band diagrams of metal-semiconductor junctions for a, b, c an n-type semiconductor and d, e, f a p-type
semiconductor (here F Bp > 0). (b, e) in thermodynamic equilibrium, (a, d) with forward bias (V > 0), (c, f) with reverse
bias (V < 0)
F Bp = E g − (W m − χ sc ) .
(21.4)
Between the surface of the metal and the bulk part of the semiconductor there is a potential drop
V bi =
F Bn
e
+ V n =
W m − χ sc
e
+ V n ,
(21.5)
which is termed the built-in potential (or diffusion voltage). The exact form of the voltage drop, the
so-called band bending, will be discussed in Sect. 21.2.2.
521
Fig. 21.4 Band diagrams of metal-semiconductor junctions for a, b, c an n-type semiconductor and d, e, f a p-type
semiconductor (here F Bp > 0). (b, e) in thermodynamic equilibrium, (a, d) with forward bias (V > 0), (c, f) with reverse
bias (V < 0)
F Bp = E g − (W m − χ sc ) .
(21.4)
Between the surface of the metal and the bulk part of the semiconductor there is a potential drop
V bi =
F Bn
e
+ V n =
W m − χ sc
e
+ V n ,
(21.5)
which is termed the built-in potential (or diffusion voltage). The exact form of the voltage drop, the
so-called band bending, will be discussed in Sect. 21.2.2.