Question

The depletion layer of a $p-n$ junction

• A. is of constant width irrespective of the bias
• B. acts like an insulating zone under reverse bias
• C. has a width that increases with an increase in forward bias
• D. is depleted of ions

Answer 1

Answer: (B)

In semiconductor physics, the depletion region also called depletion layer or the space charge region is an insulating region within a conducting, doped semiconductor material where the charge carriers have been swept away through recombination. Under reverse bias of a $p-n$ junction, when $p-$ type is connected to negative terminal and $n-$ type to positive terminal, effectively increases. The potential barrier and width of depletion region grows larger with higher voltage, this stops the flow of charge carriers. Hence, it acts like an insulating zone under reverse bias.