Question

What causes the depletion region?

Answer 1

1. A p-n junction diode's depletion area, also known as the depletion layer, is a space devoid of mobile charge carriers.
2. The depletion region is caused by the diffusion of charges. Because of the concentration gradient holes diffuse from p-side to the n-side across the junction while electrons diffuse from the n-side to the p-side.
3. The holes and the electrons diffusing towards each other combine near the junction.
4. When the diode is in the forward bias connection the width of the depletion region decreases.
5. When the diode is in the reverse bias connection the width of the depletion region increases.