p-type semiconductor
Definition and meaning of p-type semiconductor in chemistry.
A p-type semiconductor is a semiconductor doped with acceptor impurities that create positively charged charge carriers called holes. Holes function as mobile positive charges that conduct electrical current through the crystal lattice.
In more detail
When acceptor elements such as boron or aluminum are introduced into a semiconductor host like silicon (Si), they accept electrons from the valence band, leaving behind holes that can move through the material. The motion of these holes constitutes electrical conduction. p-type semiconductors are essential complements to n-type semiconductors, which use donor impurities to create mobile electrons. Together, these two types form the basis of modern semiconductor technology, including diodes, transistors, integrated circuits, and photovoltaic cells.
Key facts
| Field | Physical Chemistry |
|---|---|
| Majority charge carriers | Holes (positive charges) |
| Common dopants | Boron, aluminum, gallium (Group IIIA elements) |
| Primary use | Semiconductor devices and integrated circuits |
Boron-doped silicon is a widely used p-type semiconductor in electronics. When boron atoms (from Group IIIA) substitute for silicon atoms in the crystal lattice, each boron atom accepts one electron from the valence band, creating a mobile hole that contributes to electrical conduction.
Frequently asked questions
Why is it called p-type?
The letter p stands for positive, referring to the positive charge of the majority carriers (holes) that move through the material.
How does current flow in a p-type semiconductor?
Holes move through the valence band in response to an applied electric field, transferring positive charge and thus conducting electrical current through the material.