What is the Difference Between Valence Band and Conduction Band?

The main difference between the valence band and the conduction band lies in the energy level and the location of the electrons within the atomic structure. Here are the key differences between the two:

1. Energy Level: The valence band is a lower energy state, while the conduction band is at a higher energy level.
2. Location in Energy Band Diagram: The valence band is located below the Fermi level (forbidden energy gap) in the energy band diagram, while the conduction band is located above the Fermi level.
3. Electron Density: The electron density in the valence band is high because it has more electrons per unit volume, whereas the electron density in the conduction band is low.
4. Electron Behavior: Electrons in the valence band experience strong force by the nucleus, while the nucleus exhibits very weak or almost negligible force on the electrons in the conduction band.
5. Conditions: In metals, the valence band and conduction band overlap, resulting in a high conductivity. In semiconductors, there is a small gap between the valence and conduction bands, allowing for some conductivity, while in insulators, the gap is very large, making it difficult for electrons to move between the bands.

In summary, the valence band consists of electrons that are tightly bound to the atomic nucleus and require a significant amount of energy to be excited, while the conduction band consists of electrons that are less tightly bound and can be excited with less energy. The energy difference between the highest occupied state of the valence band and the lowest unoccupied state of the conduction band determines the electrical conductivity of a material.

Comparative Table: Valence Band vs Conduction Band

The valence band and conduction band are two different energy levels in a material, separated by a certain amount of energy. The main difference between them is that the valence band specifies the energy levels of electrons that are bound to the nucleus, while the conduction band holds electrons responsible for conduction. Here is a comparison table highlighting the differences between the valence band and conduction band:

In insulators and semiconductors, electrons can be excited from the valence band to the conduction band, which is responsible for electrical conductivity. The energy difference between the highest occupied energy state of the valence band and the lowest unoccupied energy state of the conduction band is called the band gap. The band gap is indicative of the electrical conductivity of a material.