Computer Science & Engineering and EE : Notes Physics, Energy Bands in Solids

 

Energy Bands in Solids

 

Energy Band

The range of energies possessed by an electron in a solid is known as energy band. The energy bands in solid can be as a set of energy levels closely placed such that the energy band are considered to continuous ranges of permissible electron energy.

Valance Electrons

The electrons in the outermost shell of an atom are called Valence electrons.

Conduction Electrons

An electron in the conduction band of a solid, where it is free to move under the influence of an electric field is known as Conduction Electrons.

Energy Levels 

Energy levels are energy values that an electron in an atom can have or occupy. The lowest energy state or energy level is called the ground State. 

Energy Bands in Solids

The range of energies possessed by an electron in a solid is known as energy band. 

The electrons in an isolated atom have a well-defined set of energy levels. When two identical atoms are brought close together their electrons move under the influence of the combined electric fields of the two atoms and each previously single energy level splits into two levels, one higher and one lower than the corresponding level of the isolated atoms. When large numbers of atom are together, as in a crystal, the energy levels spread into bands. Such bands are called energy bands.

 

 

 

credit of image : ground state : https://en.wikipedia.org/wiki/Energy_level#/media/File:Energy_levels.svg