CARRIER CONCENTRATIONS

With an increase in temperature covalent bonds are broken in an intrinsic semiconductor and electron-hole pairs are generated.

As electrons and holes are charged particles, they are together are called charge carriers.

Carrier concentration is the number of electrons in the conduction band per unit volume ‘n’ and the number of holes in the valence band per unit volume ‘p’ of the material.

Carrier concentration is also known as the density of charge carriers.

Calculation of Electron Density

Let dn be the number of electrons whose energy lies in the energy interval E and E + dE in the conduction band.

Calculation of Hole Density

Let dp be the number of holes whose energy lies in the energy interval E and E + dE in the valence band.