Question

In a p-n junction, the depletion region is 400 nm wide and an electric field of 5 x 10⁵ V/m exists in it. (a) Find the height of the potential barrier, (b) What should be the minimum kinetic energy of a conduction electron which can diffuse from the n-side to the p-side ?

Answer 1

Depletion region ‘d’ = 400 nm = 4 x10^–7 m

Electric field E = 5 x10⁵ V/m

a) Potential barrier V = E x d = 0.2 V

b) Kinetic energy required = Potential barrier x e = 0.2 eV [Where e = Charge of electron]