Charge-carrier density

As the charge carrier density is referred to in physics, the number of charge carriers that are present in a given volume ( unit M-3). It is an important parameter for describing the electrical conductivity and all related processes. They should not be confused with the charge density, which indicates the magnitude of the charge per unit volume ( in Coulombs · m -3).

The carrier density is a particle, i.e., they may be any density such as location-dependent:

And the integration over a volume returns the number of charge carriers of this volume:

Is the charge carrier density anywhere:

Simplifying the above formula to