Question

conductivity of silicon increses on doping it with phosphorus.​

Answer 1

Phosphorus atoms have 5 valence electrons which causes n-type doping. ... When numerous phosphorus atoms are substituted for silicon in crystal, many electrons are free which lead to increase in conductivity of silicon crysta

Answer 2

Yes, because silicon is tetravalent and when doped with pentavalent impurity like phosphorus then electron concentration increases and conductivity increases.

Also called n- type semiconductor.