Explain n-type and p-type semiconductors with suitable examples.
Answers
This is a note on n
and p type semiconductor
Basically their are two types of semiconductors which are as follows:-
Intrinsic semiconductor:-When we have a semiconductor in pure form that is without doping then it is called as intrinsic semiconductor.
Extrinsic Semiconductor:- When a semiconductor is doped with some impurities then it is known as Extrinsic Semiconductor.
Now this Extrinsic Semiconductor has more two types
N- type :- When we use a pentavalent impurity for doping then we get a n-type semiconductor. Example of pentavalent impuritie are phosphorus or arsenic.
P-type :- When we use trivalent impurities for doping then we get a p-type semiconductor. Example of trivalent inpurities are aluminium or boron.
A semiconductor has 4 valance electrons in its outermost orbit. A pentavalent valent element has 5 electrons in thier outermost orbit and a trivalent element has 3 electrons in its outermost orbit. When a semiconductor is doped with a pentavalent impurity then 4 electrons of semiconductor form 4 covalent bonds with 4 electrons of the pentavalent impurity but 1 electron of impurity is left as it is. Due to which this doped semiconductor has 1 free electron so it is called n-type semiconductor. Same with trivalent impurity but difference is that one hole is created here since impurity has only 3 electrons so that type of semiconductor is called p-type semiconductor.
To sum up I would say that n-type semiconductor has electrons and p-type semiconductor has holes.