Question

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 the p-side to the n-side if (a) the junction is unbiased, (b) the junction is forward-biased at 0.1 volt and (c) the junction is reverse- biased at 0.1 volt ?

Answer 1

Potential barrier = 0.2 Volt

(a) K.E. = (Potential difference) $\times e$

= 0.2 e V

(In unbiased condition.)

(b) In forward biasing

$KE+Ve=0.2e$

$\Rightarrow KE=0.2e-0.1e=0.1e$

(c) In reverse biasing

$KE-Ve=0.2e$

$\Rightarrow KE=0.2e+0.1e=0.3e.$