Energy gap of a Semiconducting diode- Experiment

It gives brief summary about how energy gap is found and their applications .The electron density is much greater than the hole density in the n-type semiconductor represented as ne >> nh whereas in the p-type semiconductor the hole density is much greater than the electron density: nh >> ne.In an n-type semiconductor the donor energy level is close to the conduction band and away from the valence band. While in the p-type semiconductor the acceptor energy level is close to the valence band and away from the conduction band.The impurity added in p-type semiconductor provides extra holes known as Acceptor atoms whereas in n-type semiconductor impurity provides extra electrons called Donor atoms.The Fermi level of the n-type semiconductor rests between the donor energy level and the conduction band while that of the p-type semiconductor is between the acceptor energy level and the valence band.In the p-type semiconductor majority carriers move from higher to lower potential in contrast to the n-type where the majority carriers move from lower to higher potential.