SOLUTION

• The n-type semiconductors with a pentavalent (phosphorus) impurity where the “n” stands for negative because their conduction is due to a transfer of excess electrons.
• A pentavalent atom, the one that has five valence electrons is called a donor.
• Each donor produces one free electron in a silicon crystal. In an n-type semiconductor, the free electrons are the majority carriers, while the holes are the minority carriers because the free electrons outnumber the holes.