What is the main difference between n-type and p-type semiconductors?

In semiconductors, the main difference between n-type and p-type materials lies in the type of charge carriers that dominate their electrical conduction.

N-type semiconductors are created by doping a pure semiconductor (like silicon) with elements that have more electrons in their outer shell than silicon—these are typically from group V of the periodic table, such as phosphorus or arsenic. The additional electrons from these dopants become the majority charge carriers, and since electrons carry a negative charge, n-type semiconductors have negative carriers.

On the other hand, p-type semiconductors are produced by doping with elements that have fewer electrons in their outer shell, often from group III, like boron or aluminum. This doping process creates "holes," which are essentially the absence of electrons and can be thought of as positive charge carriers, since when an electron moves to fill a hole, it allows for the transportation of electrical charge. Thus, p-type semiconductors have positive carriers.

This understanding of charge carriers is critical in the operation of various electronic devices, such as diodes and transistors, which depend on the interaction between n-type and p-type materials to create p-n junctions that allow for controlled electron flow.