Question

How is the band gap formed?

Answer 1

Explanation:

Band gap: The distance between the conduction band and the valence band of electrons is known as a band gap.

1. Science's quantum revolution provided part of the knowledge that went into the development of band theory. Felix Bloch came up with the concept of using the quantum theory to explain solids in $1928$. Bands, which are relatively tightly spaced orbitals with little variation in energy, were discovered by Walter Heitler and Fritz London in $1927$.
2. The minimal energy needed to excite an electron up to a condition in the conduction band where it can engage in conduction is essentially represented by the band gap.
3. The valence band is the lower energy level; therefore, if there is a gap between it and the higher energy conduction band, energy must be added for electrons to become free. This band gap's magnitude and existence make it possible to distinguish between conductors, semiconductors, and insulators. The following band diagrams can be used to visualize these distances: