Explain $n$-type and $p$-type semiconductors based on energy band theory.

(N/A) In an extrinsic semiconductor,due to the abundance of majority charge carriers,the minority carriers produced thermally have a higher probability of recombining with majority carriers,which indirectly reduces the intrinsic concentration of minority carriers.
The energy band structure of a semiconductor is modified by doping. In an extrinsic semiconductor,additional energy states due to donor impurities $(E_{D})$ and acceptor impurities $(E_{A})$ are introduced within the band gap.
In an $n$-type semiconductor,the donor energy level $E_{D}$ is located slightly below the bottom of the conduction band $(E_{C})$. Electrons from this level can move into the conduction band with a very small amount of thermal energy.
At room temperature,most donor atoms become ionized. Since the number of electrons provided by donor impurities is much larger than the number of thermally generated electron-hole pairs,the conduction band is dominated by electrons from the donor impurities,as shown in the figure.
For a $p$-type semiconductor,the acceptor energy level $E_{A}$ is located slightly above the top of the valence band $(E_{V})$. With a very small supply of thermal energy,an electron from the valence band can jump to the level $E_{A}$,leaving behind a hole in the valence band and ionizing the acceptor atom negatively.