n-type semiconductor
Definition and meaning of n-type semiconductor in chemistry.
N-type semiconductors are extrinsic semiconductor materials that have been doped with specific donor impurities to increase the number of free electrons, which serve as the primary charge carriers for electrical conduction. The letter n stands for negative, reflecting the negative charge of these abundant electron carriers.
In more detail
To create an n-type semiconductor, a pure element like silicon or germanium is doped with trace amounts of a Group 15 element, such as phosphorus or arsenic. When the dopant atoms integrate into the crystal lattice, four of their valence electrons form covalent bonds with the surrounding silicon atoms. The fifth electron remains weakly bound and can be easily excited into the conduction band at room temperature. This significantly increases the electrical conductivity of the material by providing a large population of mobile negative charges.
Key facts
| Field | Physical Chemistry |
|---|---|
| Base material | Silicon or Germanium |
| Majority carriers | Electrons |
Adding a small amount of phosphorus to a pure silicon crystal produces an n-type semiconductor that is essential for building modern computer transistors.
Frequently asked questions
What does the n stand for?
It stands for negative, referring to the charge of the majority carriers.
How is it different from a p-type semiconductor?
A p-type uses electron holes as positive charge carriers instead of free electrons.