Question

What are N-type semiconductors? How they are formed?

Answer 1

Pentavalent elements are those elements which have five electrons in their outer shell. When pentavalent impurities like phosphorus or arsenic are added into semiconductor, four electrons form bonds with the surrounding silicon atoms leaving one electron free.

Answer 2

N type of semiconductors can be prepared by adding pentavalent impurities like Phosphorous, antimony,arsenic. These are added to semicoductors so as to increase the rate of conduction. In this case electrons acts as majority carriers and not the holes. This is because at every time there one more electron which is not involved in bonding