When an intrinsic semiconductor is doped with pentavalent impurity, the number of free lectrons increases. Will it result in any change in the number of holes already present?
The answer is YES.
When the semiconductor is doped with pentavalent impurity, the ne increases and will result in a decrease in nh according to the relation.
ni2 = ninh
This relationship is called the mass action law.
When the no. of free electrons increases, greater no. of holes already present get neutralised.