What are conductors,insulators and semiconductors?

Conductors: The materials which permits the flow of charge carriers with higher conductivity are called conductors. In conductor, the valance band and conduction band overlaps with out any energy gap(EG). The conductivity of a conductor is normally greater than 103. The examples of conductors are gold, silver, copper etc.

Insulators: The materials which blocks the flow of electrons or which offers higher resistivity to the flow of electrons are called insulators. The energy gap between valency and conduction bad in the insulators is greater than 1eV. The conductivity of insulator is less than 10-7 and the examples of insulators are rubber, glass, Teflon, mica etc.

Semiconductors: The materials which are partially conductive and whose conductivity can be controlled are called semiconductors. These are most useful materials in electronic circuits. The energy gap Eg between valency and conduction bad of semiconductors are almost equal to 1eV. Silicon and Germanium are the best examples of semiconductors.