Semiconductors Energy Level Classification

Description:

Material such as insulator, semi-conductors, metals/ conductors can be classified using energy level.

Insulator

In Insulator the valence band is fully occupied by electrons while the conduction band is vacant.

The energy gap in insulator is greater than 3eV. For a conduction of electricity, it is required to move the electrons from the valence band to the conduction band, to perform this action thermal energy greater than 3eV should be supplied to the insulator, which is not possible as the material will burn out due to such a large amount of heat.

Semiconductor

In semiconductor the valence band and the conduction band both are partially filled with electron.

Initially, all the electrons are in the valence band and semiconductor is unable to conduct electricity. The energy gap in semiconductor is less than 3eV. At room temperature, some electrons acquire enough energy to jump from valence band to the conduction band, hence allowing the semiconductor to conduct electricity.

Conductors/ metals

In conductor the conduction band and valence band overlap.

As both the bands overlap, electrons are always available for conduction of electricity. The energy gap in conductor is zero.