When a semiconducting material is doped with an impurity, new acceptor levels are created. In a particular thermal collision, a valence electron revives an energy equal to 2kT and just reaches one of the acceptor levels. Assuming that the energy of the electron was at the topo 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.
Given:
Indirectly in the problem we are given the acceptor level 
.
This is because the electron was at the top of the edge of valance band and reaches acceptor level on receiving the energy given.
∴ energy of the acceptor level must 
Answer is 51.72meV
1