How would you account for the following: impurity doped silicon is a semiconductor

CBSE Class 12
1

How would you account for the following: impurity doped silicon is a semiconductor.

2

Si is the member of group 14 ,when doped with the group 13 elements ,the holes will be created in the lattice since there is no fourth electron available for sharing.The holes will lead to electrical conductivity and the crystals thus formed are semiconductors.