Light emitting diodes as a plant lighting source
- Wisconsin Center for Space Automation and Robotics, Madison, WI (United States)
- Univ. of Wisconsin, Madison, WI (United States)
Electroluminescence in solid materials is defined as the generation of light by the passage of an electric current through a body of solid material under an applied electric field. A specific type of electroluminescence, first noted by Lossew in 1923, involves the generation of photons when electrons are passed through a p-n junction of certain solid materials (junction of a n-type semiconductor, an electron donor, and a p-type semiconductor, an electron acceptor). Development efforts to translate these observations into visible light emitting devices, however, was not undertaken until the 1950s. The term, light emitting diode (LEDs), was first used in a report by Wolfe, et al., in 1955. The development of this light emitting semiconductor technology dates back less than 30 years. During this period of time, the LED has evolved from a rare and expensive light generating device to one of the most widely used electronic components. The most popular applications of the LED are as indicators or as optoelectronic switches. However, several recent advances in LED technology have made possible the utilization of LEDs for applications that require a high photon flux, such as for plant lighting in controlled environments. The new generation of LEDs based on a gallium aluminum arsenide (GaAlAS) semiconductor material fabricated as a double heterostructure on a transparent substrate has opened up many new applications for these LEDs.
- Research Organization:
- Univ. of Wisconsin, Madison, WI (United States)
- OSTI ID:
- 62383
- Report Number(s):
- CONF-9403214-; ON: DE95008170; TRN: 95:004109-0028
- Resource Relation:
- Conference: International lighting in controlled environments workshop, Madison, WI (United States), 27-30 Mar 1994; Other Information: PBD: [1994]; Related Information: Is Part Of International lighting in controlled environments workshop: Proceedings; PB: 393 p.
- Country of Publication:
- United States
- Language:
- English
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