Question

explain the formation of depletion layer of barrier in PN junction diode

Answer 1

When diode is in reverse bias condition ,charge carriers (holes and electrons) tends to move away from the pn-junction ,leaving behind immobile ions at the junction.This formation of junction is called depletion region as it has negligible charge carriers or is depleted of free charge carriers.

Answer 2

formation of depletion layer: 

as soon as the p-n junction is formed, electrons from n-type material diffuse into p-type material and fill some of the holes there . at the same time , holes from p-type material diffuse into the n-type material and are filled by electrons . this migration of charge carriers results in n-section acquiring positive charge and p-section negative charge. these two layers form the depletion region.

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