Question

Answer the question number xxv
Q.(xxv) Why does pure silicon which is an insulator behave as semiconductor on heating?

Answer 1

At absolute zero (0K), an intrinsic semiconductor will act like a perfect insulator. At this temperature, the electrons in the valence band will remain there. The heat energy required to excite the electrons from the valence band to the conduction band is insufficient at 0K. When the temperature increases, some of the electrons from the valence band got excited and moves to the conduction band. This will give rise to the conductivity of the semiconductor.