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

Step-by-step solution

The potential barrier across the p - n junction is given as V = 0.2 V . The n -side of the junction is at a higher potential than the p -side by 0.2 V . For a hole (charge q = +e ) to diffuse from the p -side to the n -side, it must overcome this potential barrier. The minimum kinetic energy required by the hole is equal to the potential energy barrier it needs to cross. K_ min = qV K_ min = e 0.2 V = 0.2 eV