Negative luminescence

Negative luminescence

Negative luminescence is a physical phenomenon by which an electronic device emits less thermal radiation when an electric current is passed through it than it does in thermal equilibrium (current off). When viewed by a thermal camera, an operating negative luminescent device looks colder than its environment.

Contents

Physics

Negative luminescence is most readily observed in semiconductors. Incoming infrared radiation is absorbed in the material by the creation of an electron–hole pair. An electric field is used to remove the electrons and holes from the region before they have a chance to recombine and re-emit thermal radiation. This effect occurs most efficiently in regions of low charge carrier density.

Negative luminescence has also been observed in semiconductors in orthogonal electric and magnetic fields. In this case, the junction of a diode is not necessary and the effect can be observed in bulk material. A term that has been applied to this type of negative luminescence is galvanomagnetic luminescence.

Negative luminescence might appear to be a violation of Kirchhoff's law of thermal radiation. This is not true, as the law only applies in thermal equilibrium.

Another term that has been used to describe negative luminescent devices is "Emissivity switch", as an electric current changes the effective emissivity.

History

This effect was first seen by Russian physicists in the 1960s in A.F.Ioffe Physicotechnical Institute, Leningrad, Russia. Subsequently it was studied in semiconductors such as indium antimonide (InSb), germanium (Ge) and indium arsenide (InAs) by workers in West Germany, Ukraine (Institute of Semiconductor Physics, Kiev), Japan (Chiba University) and the USA. It was first observed in the mid-infrared (3-5 µm wavelength) in the more convenient diode structures in InSb heterostructure diodes by workers at the Defence Research Agency, Great Malvern, UK (now QinetiQ). These British workers later demonstrated LWIR band (8-12 µm) negative luminescence using mercury cadmium telluride diodes.

Later the Naval Research Laboratory, Washington DC, started work on negative luminescence in mercury cadmium telluride (HgCdTe). The phenomenon has since been observed by several university groups around the world.

References

  • Applications of negative luminescence, T. Ashley, C. T. Elliott, N. T. Gordon, T. J. Phillips and R. S. Hall, Infrared Physics & Technology, Vol. 38, Iss. 3 Pages 145-151 (1997) doi:10.1016/S1350-4495(96)00038-2
  • Negative luminescence and its applications, C. T. Elliott, Philosophical Transactions: Mathematical, Physical and Engineering Sciences, Vol. 359 (1780) pp. 567-579 (2001) doi:10.1098/rsta.2000.0743
  • Galvanomagnetic luminescence of indium antimonide, P. Berdahl and L. Shaffer, Applied Physics Letters vol. 47, Iss. 12, pp. 1330-1332 (1985) doi:10.1063/1.96270
  • Negative luminescence of semiconductors, P. Berdahl, V. Malyutenko, and T. Morimoto, Infrared Physics (ISSN 0020-0891), vol. 29, 1989, p. 667-672 (1989) doi:10.1016/0020-0891(89)90107-3

Patent

External links


Wikimedia Foundation. 2010.

Нужен реферат?

Look at other dictionaries:

  • luminescence — luminescent, adj. /looh meuh nes euhns/, n. 1. the emission of light not caused by incandescence and occurring at a temperature below that of incandescent bodies. 2. the light produced by such an emission. [1885 90; < L lumin (see LUMEN) +… …   Universalium

  • C. Thomas Elliott — Charles Thomas Elliott (known as Tom Elliott), FRS, CBE, is a leading scientist in the fields of narrow gap semiconductor and infrared detector research. Hailing from county Durham, after gaining his Ph.D., he worked at the University of… …   Wikipedia

  • Kirchhoff's law of thermal radiation — See also Kirchhoff s laws for other laws named after Kirchhoff .In thermodynamics, Kirchhoff s law of thermal radiation, or Kirchhoff s law for short, is a general statement equating emission and absorption in heated objects, proposed by Gustav… …   Wikipedia

  • analysis — /euh nal euh sis/, n., pl. analyses / seez /. 1. the separating of any material or abstract entity into its constituent elements (opposed to synthesis). 2. this process as a method of studying the nature of something or of determining its… …   Universalium

  • radiation — radiational, adj. /ray dee ay sheuhn/, n. 1. Physics. a. the process in which energy is emitted as particles or waves. b. the complete process in which energy is emitted by one body, transmitted through an intervening medium or space, and… …   Universalium

  • Nitrogen-vacancy center — The nitrogen vacancy center (N V center) is one of numerous point defects in diamond. Its most explored and useful property is photoluminescence, which can be easily detected from an individual N V center. Electron spins at N V centers, localized …   Wikipedia

  • radiation measurement — ▪ technology Introduction       technique for detecting the intensity and characteristics of ionizing radiation, such as alpha, beta, and gamma rays or neutrons, for the purpose of measurement.       The term ionizing radiation refers to those… …   Universalium

  • atom — /at euhm/, n. 1. Physics. a. the smallest component of an element having the chemical properties of the element, consisting of a nucleus containing combinations of neutrons and protons and one or more electrons bound to the nucleus by electrical… …   Universalium

  • Anggun — Infobox musical artist Name = Anggun Background = solo singer Birth name = Anggun Cipta Sasmi Alias = Born = birth date and age|1974|04|29 Jakarta, Indonesia Died = Origin = Instrument = Vocals, Piano Genre = Pop French pop Pop/Rock Adult… …   Wikipedia

  • Crystallographic defects in diamond — Synthetic diamonds of various colors grown by the high pressure high temperature technique, the diamond size is 2 mm …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”