In a p-n junction,a potential barrier of 250 mev exsists across the junction.A hole with a kimetic energy of 300 meV approaches the junction. Find the kinetic energy of the hole when it crosses the junction if the hole approached the junction (a)from the p-side and (b)from the n-side.

Explanation

Potential barrier `'d' = 250`
Initial of hole `= 330meV`
We know `KE` of the hole decerease when the juncetion is forward biased and increases when reverse biased in the given `pn` diode.
So
(a)Final KE = (300-250)meV
` = 50me V`
(b) `Intial KE = (300+250)meV`
` = 550meV`