Environmental Engineering Reference
In-Depth Information
This charge denotes a non-linear charge-voltage characteristic of the
device, modeled by a non-linear capacitor called a junction capacitance.
For small changes in the applied voltage around a bias value,
the
capacitor can be viewed as a small-signal capacitance,
whose expression
is found by differentiating
1
(1.12) with respect to
where
is a capacitance per unit of area and depends only on the doping
concentration.
1.2.2
Graded Junctions
All the above equations are valid in the case of abrupt junctions. For
graded junctions, that is where the doping concentration changes smoothly
1
All the derivatives are evaluated at the quiescent operating point.
