Question

Distinguish between intrinsic and extrinsic semiconductors.

Answer 1

1. Intrinsic: 

• These are pure semiconducting tetravalent crystals.
• Their electrical conductivity is low. 
• There is no permitted energy state between valence and conduction band. 
• Their electrical conductivity depends on temperature.

2. Extrinsic:

• These are semiconducting tetravalent crystals doped with impurity atoms group III (or) V. 
• Their electrical conductivity is high. 
• There is no permitted energy state of the impurity atom between valence and conduction band. 
• Their electrical conductivity depends on temperature as well as dopant concentration.