Question

Distinguish between 'intrinsic' and 'extrinsic' semiconductors.

Answer 1

Intrinsic Semiconductor -

1. It is pure, natural semiconductor, such as pure Ge and pure Si .
   
2. In it the concentrations of electrons and holes are equal.
   
3. Its electrical conductivity is very low.
   
4. Its conductivity cannot controlled.
   
5. Its conductivity increases exponentially with temperature
   

Extrinsic Semiconductor-

1. It is prepared by adding a small quantity of impurity to a pure semiconductor, such as n-and p-type semiconductors.
   
2. In it the two concentrations are unequal. There is an excess of electrons in n-type semiconductors and an excess of holes in p-type semiconductors.
   
3. Its electrical conductivity is significantly high.
   
4. Its conductivity can be controlled by adjusting the quantity of the impurity added.
   
5. Its conductivity also increases with temperature, but not exponentially.