Question

When you have a P-N junction and you connect it to a DC voltage, this will lead

• A. The electrons near to the gap between the P-N junction from the N type material to move to the P side
• B. The lack of electrons in the N type side will lead to have a holes
• C. The holes near to the gap between the P-N junction from the P type material to move to the N side
• D. Both A and C

Answer 1

The correct option is D Both A and C

When you have a $p-n$ junction and we connect it to a DC voltage, this will lead to:

1. When the $N-$type semiconductor and $p-$type semiconductor materials are first joined together a very large density gradient exits between both sides of the $P-N$ junction.

2. The results is that some of the electrons from the donar impurities atoms begin to migrate across this newly formed junction to fill up the holes in the $P-$type materials producing negative ions.

3. Since this electrons have moved across the $P-N$ junction from $n-$type to $p-$type, they leave behind positively charged donar ions on the negative across the junction in the opposite direction into the region where there are large number of free electrons.

4. As a result, the charged density of the $P-$type along the junction is filled with negatively charged acceptors ions, and the charges density of the $N-$type along the junction becomes positive.