SOLUTION

In the depletion region of a PN junction, there is a shortage of Holes and electrons.

Detailed Explanation

⇒ Consider the p-n junction at room temperature (say 300°K).

⇒ When an electron diffuses to the p-side, it leaves behind a positively charged donor ion on the n-side.

⇒ When a hole diffuses to the n-side, it leaves behind a negatively charged acceptor ion on the p-side, which is immobile.

⇒ As the holes continue to diffuse, a layer of negative charge is developed on the p-side of the junction.

⇒ Thus, due to the diffusion of electrons and holes across the junction, a thin layer around the junction becomes devoid of free charge carriers.

⇒ Consequently, a region that consists of the uncovered acceptor and donor ions is developed in the junction area. This region is called the depletion region.

⇒ As the depletion region consists of immobile positive and negative ions, it is called a space-charge region. Its thickness is of the order of one-tenth of a micron.

⇒ Thus in depletion region is a shortage of holes and electrons since it consists of donor and acceptor ions.