Question

Sn, C, Si and Ge are all group XIV elements . Yet , Sn is a conductor , C is an insulator while Si and Ge are semiconductors . Why?

Answer 1

Sn, C, Si, and Ge all belong to group XIV elements. But Sn is a conductor, C is an insulator while Si and Ge are semiconductors.

• This can be understood by the energy gap between the valence band and the conduction band of these elements. This energy gap is responsible for the conduction level of an element.

• The energy gap for Sn is 0 eV (i.e. energy gap between the valence band and conduction band is zero).

• In the case of C, it is 5.4 eV ( i.e energy gap between the valence band and conduction band is very large).

• For Si, it is 1.1 eV and for Ge, it is 0.7eV( i.e. energy gap between the valence band and conduction band is moderate).