Question

Carbon is not a semiconductor in spite of its group being 14th group why

Answer 1

Because while carbon contain sand(silicon) particles in it, it works as semi conductor...

Answer 2

The conduction of electricity can be only conducted by charged particles which are called as ions. Moreover, the losing or gaining of the electron is known as ions. Since there is no generation of ions in carbon compounds as carbon creates covalent linkages by sharing electrons. Therefore it is a poor conductor of electricity  in spite of its group being 14th group because of its arrangement.