Light-emitting diode
hideA light-emitting diode (LED) (pronounced /ˌɛliːˈdiː/, or just /lɛd/), is an electronic light source. The LED was first invented in Russia in the 1920s, and introduced in America as a practical electronic component in 1962. Oleg Vladimirovich Losev was a radio technician who noticed that diodes used in radio receivers emitted light when current was passed through them. In 1927, he published details in a Russian journal of the first ever LED.
All early devices emitted low-intensity red light, but modern LEDs are available across the visible, ultraviolet and infra red wavelengths, with very high brightness.
LEDs are based on the semiconductor diode. When the diode is forward biased (switched on), electrons are able to recombine with holes and energy is released in the form of light. This effect is called electroluminescence and the color of the light is determined by the energy gap of the semiconductor. The LED is usually small in area (less than 1 mm2) with integrated optical components to shape its radiation pattern and assist in reflection.
LEDs present many advantages over traditional light sources including lower energy consumption, longer lifetime, improved robustness, smaller size and faster switching. However, they are relatively expensive and require more precise current and heat management than traditional light sources.
Applications of LEDs are diverse. They are used as low-energy indicators but also for replacements for traditional light sources in general lighting and automotive lighting. The compact size of LEDs has allowed new text and video displays and sensors to be developed, while their high switching rates are useful in communications technology.
For more information about Light-emitting diode, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with light emitting diode
Lighter, cheaper, LED light bulbs are starting to enter the marketplace
Oct 22, 2009 |
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Just when you were finally warming up to the idea of swapping out your old light bulbs with compact fluorescent ones, you may soon find a new alternative at your local hardware store.
Super-thin flexible OLED from Sony
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Oct 07, 2009 |
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(PhysOrg.com) -- Sony is showing off prototypes incorporating its super-thin, flexible OLED technology at the CREATEC JAPAN 2009 IT and electronics trade show in Makuhari Messe (Chiba) in Japan.
Greenlighting a greener world (w/ Video)
Sep 02, 2009 |
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Just a few years ago, most conversations Christian Wetzel had about his research began with a quick explanation of LEDs.
LG to Launch 15-inch OLED TV
Electronics / Consumer & Gadgets
Sep 01, 2009 |
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(PhysOrg.com) -- The Korean company, LG Electronics, the second largest television manufacturer in the world, has announced it will launch a 15-inch organic display TV set in early September. The announcement, ...
Ultrathin light-emitting diodes create new classes of lighting and display systems
Aug 20, 2009 |
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(PhysOrg.com) -- A new process for creating ultrathin, ultrasmall inorganic light-emitting diodes (LEDs) and assembling them into large arrays offers new classes of lighting and display systems with interesting ...
New material for nanoscale computer chips
Nanotechnology / Nanomaterials
Aug 17, 2009 |
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Nanochemists from the Chinese Academy of Sciences and Nano-Science Center, Department of Chemistry at University of Copenhagen have developed nanoscale electric contacts out of organic and inorganic nanowires. ...
Liquid-OLED Offers More Light-Emitting Possibilities
Aug 14, 2009 |
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(PhysOrg.com) -- As organic light-emitting diodes (OLEDs) are poised to go mainstream in the near future, scientists continue to explore new twists on the technology. Recently, researchers have fabricated ...
LED light bulbs yield big savings in energy
Aug 13, 2009 |
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One way the United States could slash its electricity use, dependence on fossil fuels and emissions of heat-trapping gases is really quite simple: better light bulbs.
A bright idea: Philips lets flat lights out of lab
Jul 22, 2009 |
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(AP) -- Someday, our ceilings and walls might radiate light, illuminating indoor spaces as brightly and evenly as natural daylight.
Organic light-emitting diode screens ready to go mainstream
Jun 24, 2009 |
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It's not yet lights-out for LCD and plasma, but OLED displays are finally ready to begin pushing those technologies out of the limelight.
Transforming roofs from wasted space to energy source
Jun 04, 2009 |
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(PhysOrg.com) -- A transparent thin film barrier used to protect flat panel TVs from moisture could become the basis for flexible solar panels that would be installed on roofs like shingles.
LG claims world's thinnest LCD-TV panel
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May 19, 2009 |
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South Korea's LG Display said it has developed a liquid crystal display (LCD) television panel that is thinner than a pencil, describing it as the world's slimmest.
Diode lights offer bright future for low energy
May 13, 2009 |
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German scientists said Wednesday they had tweaked organic light-emitting diodes (OLEDs) -- the materials used in flat-screen TVs, laptop computer screens and mobile phone displays -- to become flexible, energy-efficient ...
Tiny particles make LED light more pleasing
Nanotechnology / Nanomaterials
May 05, 2009 |
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(AP) -- Light-emitting diodes are prime candidates for replacing inefficient incandescent bulbs, but have a few things working against them. They can provide a pleasing warm light or they can be energy-efficient, ...
Philips presents OLED-based interactive lighting concepts
Apr 23, 2009 |
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Royal Philips Electronics today premiered the world’s first OLED (Organic Light-Emitting Diodes) -based interactive lighting concepts, created for both consumer as well as professional use, during the Euroluce ...
