N- Type and P- Type :)

When pentavalent impurity is added to pure semiconductor, it is known as N-Type semiconductor. In N-type semiconductor electrons are majority carriers where as holes are minority carriers. impurities such as Arsenic, antimony are added.

When trivalent impurity is added to pure semiconductor, it is know as P-type semiconductor. In P-type semiconductor holes are majority carriers whereas electrons are minority carriers. Impurities such as indium, galium are added.

it would be a n-type semiconductor because phosphorus has more valence electrons than silicon does.

N is the type of semiconductor, MOS refers to Metal Oxide Semiconductor device.

band diagram of p type semiconductor