Differentiate between n and p type semiconductors.

n - Type semiconductor:-

(i) If small amount of pentavalent impurity is added with, to a pure semiconductor giving a large number of free electrons in this, the extrinsic semiconductor therefore formed is termed as n- type semiconductor. The addition of pentavalent impurities as arsenic and antimony give a large no. of free electrons in the semiconductor crystal. These impurities, that produce n- type semiconductors, are termed as donor impurities since each atom of them donates individual free electron to the semiconductor crystal.       

(ii) The majority and minority carriers are electrons and holes correspondingly.

(iii) The impurity level is here below the bottom of conduction band.

p - Type semiconductor:-

(i) If small amount of trivalent impurity is added with to a pure semiconductor giving a large no. of holes in this, the extrinsic semiconductor therefore formed is termed as p- type semiconductor. This addition of trivalent impurities as gallium and indium give a large no. of holes in the semiconductor crystal. Theses impurities, that produce p- type semiconductors, are termed as acceptor impurities since each atom of them creates one hole that can accept one electron.

(ii) The majority and minority charge carriers are holes and electrons correspondingly.

(iii) The impurity level is here above the valence band.