Question

Why is there a band bending near the depletion region in a pn junction diode

Answer 1

Junctions, depletion regions, band bending, Fermi levels.  The combined region away from which electrons and holes have diffused is called the depletion region. The depletion region acquires a reverse potential because of the charge imbalance.

Answer 2

The combined region away from which electrons and holes have diffused is called the depletion region. The depletion region acquires a reverse potential because of the charge imbalance.