The conduction band edge in the p material is not at the same level as the conduction band edge in the n material.

This statement is true. The conduction band edge in the p-type material is not at the same level as the conduction band edge in the n-type material in a semiconductor device.

Explanation:

1. Band Structure in Semiconductors:
In a semiconductor material, there are energy bands that electrons can occupy. The valence band is the highest energy band that is fully occupied by electrons at absolute zero temperature, while the conduction band is the next higher energy band that is empty or partially filled with electrons.

2. Difference in Energy Levels:
In a p-n junction, the p-type material has an excess of holes due to the presence of acceptor impurities, while the n-type material has an excess of electrons due to the presence of donor impurities. The conduction band edge in the p-type material is lower in energy compared to the conduction band edge in the n-type material.

3. Formation of Energy Barrier:
When the p-type and n-type materials are brought together to form a p-n junction, the energy levels of the conduction band in the two materials do not match. This creates an energy barrier at the interface between the p and n regions. The energy barrier prevents the majority carriers (electrons in n-type and holes in p-type) from easily crossing the junction and recombining with the opposite type of carriers.

4. Formation of Depletion Region:
Due to the energy barrier, a depletion region is formed at the interface of the p-n junction. The depletion region is depleted of majority carriers and consists of immobile charged ions. This region acts as a barrier to the flow of current in the reverse bias condition.

5. Formation of Built-in Potential:
The difference in energy levels between the conduction bands in the p and n materials results in the formation of a built-in potential across the p-n junction. This potential difference opposes the flow of majority carriers across the junction.

Conclusion:
In summary, the conduction band edge in the p material is not at the same level as the conduction band edge in the n material in a p-n junction. This difference in energy levels leads to the formation of an energy barrier, depletion region, and built-in potential, which are essential for the functioning of semiconductor devices.