Question

Depletion width when voltage is larger than knee voltage

Answer 1

The depletion region reduces as the forward bias is increased. Does at any point it reach zero or negligible length? Knee voltage of a diode is defined as the minimum amount of forward bias required for the diode to show significant conduction. It denotes the potential barrier created across the depletion region via accumulation of charges, i.e. negative charges on P side, and positive on N side.