Intrensic Semiconductor

Intrensic Semiconductor :

These are semiconductor which are obtained in pure form without any impurity. These are the material of group IV of element of periodic table.

Example: Si , Ge.

Expression for Band gap Energy :

Here ,  Eg0= 0.785 ev for Germinium and 1.21 ev for Silicon

             α= 2.23 x10-4 ev/K for Germinium and  3.6x10-4 ev/K for Silicon.

From above  equation we can conclude that on increasing temperature the energy band gap of semiconductor  material decreases.

Carrier Concentration

In intrinsic semiconductor concentration of electron is equal to the concentration of holes.

i.e, n=p=ni

Variation of ni with Temperature

Where A is constant .

From above equation it is clear that 

It means on increasing the Temperature the intrinsic concentration of material increases.