ABSTRACT
This chapter presents the physics and characteristics of the p-n junction. The difference in electrostatic potential between solid substances of different properties, when they are brought into contact with each other, is called the contact potential. The contact potential between the p-type and n-type regions of a p-n junction is called the built-in potential. A depletion layer with few carriers is formed around the p-n junction interface, and it has an associated depletion capacitance. The p-n junction diode has a rectifying effect. Properties of the one-sided junction are determined by the lowly doped side. The dc current-voltage characteristics and the reverse saturation current of the abrupt junction can be derived analytically under several assumptions. The physics of p-n junctions can be understood to a large extent from energy band diagrams with the quasi Fermi levels.
