p-n Junction
An arrangement consisting a p-type semiconductor brought into a close contact with n-type semiconductor, is called a p-n junction.
The current in a p-n junction is given by k B = I o( e eV / k BT – 1)
where I o is reverse saturation current, V is potential difference across the diode,
and k B is the Boltzmann constant.
Terms Related to p-n Junction
( i) Depletion Layer At p-n. junction a region is created, where there is no charge carriers. This region is called depletion layer. The width of this
region is of the order of 10 6 m.
( ii) Potential Barrier The potential difference across the depletion layer is called potential barrier.
Barrier potential for Ge is 0.3 V and for Si is 0.7 V.
( iii) Forward Biasing In this biasing, the p-side is connected to positive terminal and n-side to negative terminal of a battery.