Question

A p-type semiconductor is
A. Positively charged
B. Negatively charged
C. Uncharged
D. Uncharged at OK but charged at higher temperatures

Answer 1

The p- type semiconductors are one of the types of the semiconductors. When in pure semiconductors like silicon or germanium some trivalent impurities are added then the obtained type of the semiconductors is called p-type semiconductors.

Complete answer:
When the trivalent impurities like Boron (B), Gallium (Ga), Indium (In), Aluminium (Al) are added to the pure semiconductors like silicon and germanium then a large number of the holes are created.

But the p-type semiconductors are electrically neutral that is uncharged because when the trivalent impurities are doped into the tetravalent pure semiconductors like silicon and germanium then the fourth electron of the germanium needs to be bonded then the electron in the outermost shell of the silicon or germanium can jump into the vacancy and create hole on its own atom. So here the holes are the reason for this conduction to take place.

So, the holes are created for this condition to take place but the semiconductor is electrically neutral because the number of the electrons and holes are same in magnitude and opposite in sign.
Hence a p-type semiconductor is electrically neutral that is uncharged.

So, the correct answer is “Option C”.

Note:
Sometimes the p-type semiconductors are called as acceptors because of the presence of the excess holes. Since an acceptor donates excess holes, which are assumed to be positively charged, hence a semiconductor that has been doped with an acceptor is called a p-type semiconductor where “p” stands for the positive but the notice should be kept in mind that the p-type semiconductor materials remain neutral.