Energy band and energy gap
According to Niels Bohr's atomic model, electrons in the atoms do not have a continuous energy. Electrons can only have a certain set of energy. This is why the orbits of electrons in the atomic model are represented by lines.
If there is only one atomic nucleus, it will be explained, but if the nuclei are densely attached like solids, the electron orbits of the atoms become thicker as they overlap each other.
As a result, the energy level becomes a band of constant width not a single line.
The energy band is the thickened energy level. The electron's energy between the band and the band, the line and the band, can not exist and are called an energy gap.
Importance of energy bands
Energy bands are a very important concept in metal and semiconductor engineering.
In the case of metal, it is a conductor because electrons can move around freely through the energy band. Many non-metals are non-conductive because there is no energy band.
Semiconductors use energy bands and energy gaps well. Semiconductors can control the current flow according to the surrounding physical conditions. This property can be used instead of a physical switch. The remarkable development of computers and many other electronic devices is based on this property.