Hunter, Lloyd P. Department of Electrical Engineering, University of Rochester, Rochester, New York.
Last reviewed:January 2020
- Alloy-junction transistors
- Grown-junction transistors
- Planar diffused epitaxial transistors
- Mesa transistors
- Power transistors
- Unijunction transistor
- Related Primary Literature
- Additional Reading
A transistor in which emitter and collector barriers are formed by pn junctions between semiconductor regions of opposite conductivity type. These junctions are separated by a distance considerably less than a minority-carrier diffusion length, so that minority carriers injected at the emitter junction will not recombine before reaching the collector barrier and therefore be effective in modulating the collector-barrier impedance. Junction transistors are widely used both as discrete devices and in integrated circuits. The discrete devices are found in the high-power and high-frequency applications. Junction transistors range in power rating from a few milliwatts to about 300 W, in characteristic frequency from 0.5 to 2000 MHz, and in gain from 10 to 50 dB. Silicon is the most widely used semiconductor material, although germanium is still used for some applications. Junction transistors are applicable to any electronic amplification, detection, or switching problem not requiring operation above 200°C (392°F), 700 V, or 2000 MHz. Not all these limits can be achieved in one device, however. Junction transistors are classified by the number and order of their regions of different conductivity type, by the method of fabricating and structure, and sometimes by the principle of operation. Most modern transistors are fabricated by the silicon self-masked planar double-diffusion technique. The alloy technique and the grown-junction technique are primarily of historical importance. For a general description and definition of terms used here and a description of the mechanism of operation. See also: Transistor
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 10,000 highly qualified scientists and 46 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information