Conduction of electricity in semiconductors

[kartikwat]

When studying about semiconductos what are the valence band and conductivity band .what are its properties,where is it addressed.

 

[e.bar.goum]

It's all in the names! The conduction band is the range of energies required to free an electron from its atom, letting it move freely through the lattice, therefore conducting electricity. The valence band is then the highest range of energies of electrons which are bound to the atom. The energy gap between the valence band and the conduction band determines whether a material is a conductor, insulator or semiconductor.

Hyperphysics has rather a good writeup on the band theory of solids. http://hyperphysics.phy-astr.gsu.edu/hbase/solids/band.html