mam i am not getting the energy band theory to classify conductors semiconductor and insulator.please make it more simple and easy.

Asked by shreyamudgil_0209 | 14th Oct, 2010, 12:00: AM

Expert Answer:

Dear Student
Band theory is a way to to visualize the difference between conductors, insulators and semiconductors. for this  we plot the available energies for electrons in form of two bands: valence band and conduction band. For conduction, we need some electrons in the conduction band.
In insulators, there is no conduction. Hence the electrons in the valence band are separated by a large gap from the conduction band. In conductors, there is conduction, and hence the valence band overlaps the conduction band. In semiconductors there is a small enough gap between the valence and conduction bands that thermal or other excitations can bridge the gap and hence semi conductors start to conduct under these conditions. With such a small gap, the presence of a small percentage of a doping material can increase conductivity dramatically
Hope it helps you in understanding the concept better.

Answered by  | 15th Oct, 2010, 12:06: AM

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