CBSE NOTES CLASS 12 PHYSICS
CHAPTER 14 SEMICONDUCTORS
Conductivity of an extrinsic semiconductor
The crystal as a whole is neutral.
In a doped semiconductor
where ne and nh are the number density of electrons and holes and ni is number density of intrinsic carriers, i.e., electrons or holes.
Electrical conductivity of extrinsic semiconductor is given by
Where ρ is resistivity, μe and μh are mobility of electrons and holes respectively.