Solid State Electronic Devices, 7th Edition

5.2 Equilibrium Conditions

In this chapter we wish to develop both a useful mathematical description of the p-n junction and a strong qualitative understanding of its properties. There must be some compromise in these two goals, since a complete mathematical treatment would obscure the essentially simple physical features of junction operation, while a completely qualitative description would not be useful in making calculations. The approach, therefore, will be to describe the junction mathematically while neglecting small effects which add little to the basic solution. In Section 5.6 we shall include several deviations from the simple theory.

The mathematics of p-n junctions is greatly simplified for the case of the step junction, which has ...