Question

Question no.1

1. The potential barrier existing across an unbiased p-n junction is 0.2 volt. What minimum kinetic energy a hole should have to diffuse from p-side to the n-side if -

(a) The junction is unbiased (b) The junction is forward biased at 0.1 volt
(c) The junction is reverse-biased at 0.1 volt.

Answer 1

Potential barrier = 0.2 Volt

a) K.E. = (Potential difference) x e = 0.2 eV (in unbiased condn)

b) In forward biasing

KE + Ve = 0.2e

=> KE = 0.2e – 0.1e = 0.1e.

c) In reverse biasing

KE – Ve = 0.2 e

=> KE = 0.2e + 0.1e = 0.3e.