What is Zener diode

Zener diode a type of semiconductor diode, consisting of a p-n junction with high doping concentrations on either side of the junction. It acts as a rectifier until the applied reverse voltage reaches a certain value, the zener breakdown voltage, when the device becomes conducting. This effect occurs as a result of electrons being excited directly from the valence band into the conduction band (see ENERGY BANDS). Zener diodes are used in voltage-limiting circuits; they are named after the us physicist clarence melvin zener (1905-93).