Question

The depletion layer in the p-n junction region is caused by
A. Drift of holes
B. Diffusion of charge carriers
C. Migration of impurity ions
D. Drift of electrons

Answer 1

Hint:We know that when a p-n junction is formed when some free electrons diffuse to form negative ions and leave positive ions at the impurity sites. The depletion region or depletion layer is an insulating region within a conductive, doped semiconductor material where the mobile charge carriers have been diffused down.

Complete step by step solution:
We know that the depletion layer in the p-n junction region is caused by the movement of charge carriers along a concentration gradient, from an area of high concentration to an area of low attention. Therefore, the depletion layer in the p-n junction region is caused by the diffusion of charge carriers. Therefore, option(B) is correct.

Now, we know that the depletion region is independent of drift. Therefore, option(A) and (D) are incorrect. Also, diffusion is the movement of molecules along a concentration gradient, from an area of high concentration to an area of low concentration. The transport of a charged species under the influence of an electric field is known as migration. Therefore, option(C) is incorrect.

Hence, the correct answer is option B.

Note: Due to the large concentration of electrons on the N-side and holes in the P-side, they diffuse from their side to the other side when giving biasing. Hence the depletion region produces. The depletion layer of a p-n junction is also due to doping of the materials.