Intrinsic and extrinsic semiconductors differ in their conduction mechanisms and origin of defects. Intrinsic semiconductors have conduction between the valence and conduction bands, while extrinsic semiconductors are doped with other elements to create acceptor or donor levels near the bands leading to p-type or n-type conductivity respectively between the bands and these defect levels. The document discusses the electronic structure and defects in intrinsic and extrinsic semiconductors.

1. Intrinsic and extrinsic semiconductors
Dr. Mithil Fal Desai
Shree Mallikarjun and Shri Chetan Manju
Desai College Canacona Goa

2. Type of semiconductors
Conduction
mechanism
Origin of defect
Conductivity in-
between
Conductors and
Insulators
Semiconductors
Extrinsic
n-type p-type
Intrinsic

3. Intrinsic semiconductor
Conduction band
Valence band
Eg
Energy
Fermi level
Si- 1s2, 2s2, 2p6, 3s2, 3p2

4. Extrinsic semiconductor (p-type)
Conduction band
Valence band
Energy
Si- 1s2, 2s2, 2p6, 3s2, 3p2
Ga- 1s2, 2s2, 2p6, 3s2, 3p6, 4s2,3d10, 4p1
Acceptor
level

5. Extrinsic semiconductor(n-type)
Conduction band
Valence band
Energy
Si- 1s2, 2s2, 2p6, 3s2, 3p2
As- 1s2, 2s2, 2p6, 3s2, 3p6, 4s2,3d10, 4p3
Donor
level