Question

When a semiconducting material is doped with an impurity, new acceptor levels are created. In a particular thermal collision, a valence electron receives an energy equal to 2kT and just reaches one of the acceptor levels. Assuming that the energy of the electron was at the top edge of the valence band and that the temperature T is equal to 300 K, find the energy of the acceptor levels above the valence band.

Answer 1

2 KT = Energy gap between acceptor hand and valency band

$\Rightarrow 2\times 1.38\times {10}^{-23}\times 300=E$

$\Rightarrow E=(2\times 1.38\times 3)\times {10}^{-21}J$

$=\left(\frac{6\times 1.38}{1.6}\right)\times \frac{{10}^{-21}}{{10}^{-19}}eV$

$=\left(\frac{6\times 1.38}{1.6}\right)\times {10}^{-2}eV$

$=5.175\times {10}^{-2}eV$

$=51.75meV$

$=50meV$