Question

The potential barrier at p-n junction is due to
A. Fixed acceptor and donor ions on the other side of the junction
B. Minority carriers on either side of junction
C. Majority carriers on either side of junction
D. Both majority and minority carriers on either side of junction

Answer 1

Hint: The potential barrier created throughout the P-N junction is due to the diffusion of electrons and holes, and this potential barrier normally does not allow charging flow through the junction.

Complete step-by-step answer:
Actually, when an N-type material is joined to a P-type material, a p-n junction is formed and a semiconductor diode thus produced.

The potential barrier in the p-n junction is a type of barrier which does not allow the normal flow of charge across the junction and this resistance to the flow of charge is known as barrier potential.

So basically what happens in a p-njunction is that, a large density of concentration difference of charge carriers exists which results that some of the free electrons begin to migrate from the donor impurity atoms across the newly formed junction in order to fill up the holes in the P-type material and producing negative ions, it produces a potential barrier through the collection of electric charges of opposite polarities hence the charge density of the P-type along the junction is filled with negatively charged acceptor ions and the charge density of the N-type along the junction becomes positive and this charge transition of electrons and holes across the PN junction is called diffusion.

Therefore this potential barrier in the junction which opposes further diffusion is due to the fixed acceptor and donor ions on either side of the junction.

Hence the correct option is A.

Note: As there is existence of potential barrier that's why no free charge carriers can rest so that the regions on either side of the junction are completely depleted from any more free carriers compared to the materials of the N and P type further away from the junction and this area around the p-n junction is now called the depletion layer.