Free Online Dictionary
|Wikipedia English The Free Encyclopedia||Download this dictionary|
In physics, a charge carrier is a free (mobile, unbound) particle carrying an electric charge, especially the particles that carry electric currents in electrical conductors. Examples are electrons, ions and holes. In a conducting medium, an electric field can exert force on these free particles, causing a net motion of the particles through the medium; this is what constitutes an electric current. In different conducting media, different particles serve to carry charge:
- In metals, the charge carriers are electrons. One or two of the outer valence electrons from each atom is able to move about freely within the crystal lattice of the metal. The free electrons are referred to as conduction electrons, and the cloud of free electrons is called a Fermi gas.
- In ionic solutions, such as salt water, the charge carriers are ions, atoms or molecules that have gained or lost electrons so they are electrically charged. Atoms that have gained electrons so they are negatively charged are called anions, atoms that have lost electrons so they are positively charged are called cations. Cations and anions of the dissociated liquid also serve as charge carriers in melted ionic solids (see e.g. the Hall-Heroult process for an example of electrolysis of a melted ionic solid.
- In a plasma, an electrically charged gas which is found in electric arcs through air, neon signs, and the sun and stars, the electrons and cations of ionized gas act as charge carriers.
- In a vacuum, free electrons can act as charge carriers. These are sometimes called cathode rays. In a vacuum tube, the electrons are released by a heated metal cathode, by a process called thermionic emission.
- In semiconductors, the material used to make electronic components like transistors and integrated circuits (ICs), in addition to electrons, the travelling vacancies in the valence-band electron population, called "holes", act as mobile positive charges and are treated as charge carriers. Electrons and holes are the charge carriers in semiconductors.
|See more at Wikipedia.org...|
The following video provides you with the correct English pronunciation of the word "Minority Carrier", to help you become a better English speaker.
© This article uses material from Wikipedia® and is licensed under the GNU Free Documentation License and under the Creative Commons Attribution-ShareAlike License
|Integrated Circuit Dictionary||Download this dictionary|
the carrier type in the minority. For a doped semiconductor, one type of carrier either holes or electrons is present in much smaller concentrations than the other type of carrier, this is called a minority carrier.
Copyright © 2000 - 2006 IC Knowledge LLC. All rights reserved.
| Minority Carrier in French | Minority Carrier in Dutch | Minority Carrier in Portuguese | Minority Carrier in German | Minority Carrier in Russian | Minority Carrier in Turkish | Minority Carrier in Catalan | Minority Carrier in Croatian | Minority Carrier in Indonesian
You think you have ethics... Take the survey NOW!