P and n type semiconductor get together and make p-n junction diode. when it is connected in reversed bias then avalanche breakdown occur. In reverse bias configuration depletion region increase when reverse bias voltage is increased and here current is due to the minority carriers. read more
Avalanche breakdown occurs in a pn junction diode which is moderately doped and has a thick junction (means its depletion layer width is high). Avalanche breakdown usuallyoccurs when we apply a high reverse voltage across the diode (obviously higher than the zener breakdown voltage,say Vz). read more
These diodes can indefinitely sustain a moderate level of current during breakdown. The voltage at which the breakdown occurs is called the breakdown voltage. There is a hysteresis effect; once avalanche breakdown has occurred, the material will continue to conduct even if the voltage across it drops below the breakdown voltage. read more
"Avalanche breakdown occurs in lightly-doped pn-junctions where the depletion region is comparatively long.ÝThe doping density controls the breakdown voltage.ÝThe temperature coefficient of the avalanche mechanism is positive.ÝThat is, as the temperature increases, so does the reverse breakdown voltage.ÝThe magnitude of the temperature coefficient also increases with increasing breakdown voltage. read more