A conduction band or conduction level is a semiconductor energy band where electrons can freely flow within a solid, resulting in a net transport of charge. When excited, electrons can move from the valence band into the band of electron orbitals known as the conduction band.
The electrons have sufficient energy in these orbitals to move freely throughout the substance. Electric current is produced by this movement of electrons. The outermost electron orbital that electrons really inhabit in an atom of any particular material is known as the valence band.
What is Band Gap?
The band gap, which is a measure of a material’s electrical conductivity, is the energy difference between the lowest unoccupied state of the conduction band and the lowest occupied energy level of the valence band.
It takes a lot of energy to excite valence electrons to the conduction band when the band gap is big. On the other hand, a material is said to be highly conductive if the valence band and conduction band overlap, as they do in metals.
Because insulators have a wide band gap, it takes an unreasonably high amount of energy to shift electrons into the band and create a current. The valence electrons in conductors are virtually free because the conduction and valence bands overlap in these materials.
Also Read: What is Charge Rate?
On the other hand, semiconductors have a narrow band gap that, at a certain energy level, enables a significant portion of the material’s valence electrons to flow into the conduction band.
They have a conductivity that falls between conductors and insulators as a result of this feature, which contributes to their suitability for electrical circuits because they won’t result in a short circuit like conductors.
This band gap also enables semiconductors to produce LEDs when formed into specific kinds of diodes and to turn light into power in solar cells. Both of these procedures rely on the energy that electrons transferring between the conduction and valence bands absorb or release.