Which of the following statements are ture about semi-conductors ?

Options

A. Silicon doped with electron rich impurity is a p-type semi-conductor
B. Silicon doped with an electron rich impurity is an n-type semi-conductor
C. Delocalised electrons increase the conductivity of doped silicon
D. An electron vacancy increases the conductivity of a-type semi-conductor.

Answer

C

Explanation

(b,c) are corrcet statements.
(a) Silicon doped with electron rich impurity is an n-type semiconductor. Therefore, staement (a) is false. ltbRgt (b) The conductivity of n-type semi-conductors increases due to extraelectrons and not because of electron valency. Therefore statement (b) is false.