In semiconductor production, doping intentionally introduces impurities into an extremely pure (also referred to as intrinsic) semiconductor for the purpose of modulating its electrical properties. The impurities are dependent upon the type of semiconductor. Lightly and moderately doped semiconductors are referred to as extrinsic. A semiconductor doped to such high levels that it acts more like a conductor than a semiconductor is referred to as degenerate. The most important factor that doping directly affects is the material’s carrier concentration. In an intrinsic semiconductor under thermal equilibrium, the concentration of electrons and holes is equivalent.
If we have a non-intrinsic semiconductor in thermal equilibrium there is a relation between the concentration of conducting electrons, the electron hole concentration and the material’s intrinsic carrier concentration. (Intrinsic carrier concentration varies between materials and is dependent on temperature).
|nj||The material's intrinsic carrier concentration (cm-1)|
|n0||The concentration of conducting electrons (cm-1)|
|p0||The electron hole concentration (cm-1)|