Related topics: light , light emitting diode
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 led
OLED Tunes its Colors for Sunlight-Style Illumination
Jul 16, 2009 |
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(PhysOrg.com) -- Scientists have developed a lighting device that can change its color temperature throughout the day, matching the natural daylight chromaticities produced by the sun. Currently, no other ...
Scientists Fabricate Organic Transistor with Improved Performance
Apr 24, 2009 |
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(PhysOrg.com) -- Organic semiconductors are promising building blocks for many devices, from LEDs to transistors, offering potential advantages such as cost-effectiveness, flexibility, and high performance. ...
Solar Cells with LEDs Provide Inexpensive Lighting
Nov 09, 2009 |
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(PhysOrg.com) -- Of the 1.5 billion people in developing countries who do not have electricity, many rely on kerosene lamps for light after the sun goes down. But now, researchers from Denmark have designed ...
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.
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 ...
LG claims world's thinnest LCD-TV panel
Electronics / Consumer & Gadgets
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.
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, ...
Solar-powered LED light made of bottles
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Jan 20, 2009 |
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(PhysOrg.com) -- The Solarbulb, a new lighting gadget from miniWIZ, doesn't exactly come with all parts included: you have to add your own water or soda bottle. The LED Solarbulb screws onto just about any ...
Smart Lighting: New LED Drops the 'Droop'
Jan 12, 2009 |
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(PhysOrg.com) -- Researchers at Rensselaer Polytechnic Institute have developed and demonstrated a new type of light emitting diode (LED) with significantly improved lighting performance and energy efficiency.
Toward Plastic Spin Transistors
Aug 17, 2008 |
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(PhysOrg.com) -- University of Utah physicists successfully controlled an electrical current using the "spin" within electrons – a step toward building an organic "spin transistor": a plastic semiconductor ...
Sony optimistic on 3-D TVs, in-house display
Nov 26, 2009 |
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(AP) -- A third to a half of the Sony Corp. TV sets sold annually will be packed with 3-D features by the year ending March 2013, a senior executive said Thursday.
LED light bulbs yield big savings in energy
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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.
LED closes the yellow gap: Full conversion of blue into amber light by new nitride phosphor
Jul 23, 2009 |
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(PhysOrg.com) -- Monochromatic light-emitting diodes cover a large part of the visible spectrum with high effi-ciency. For blue light, nitride diodes achieve external quantum efficiencies in excess of 65%, ...
LED there be light
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Q: How many LED engineers does it take to change a light bulb?
Low-cost LEDs to slash household electric bills
Jan 29, 2009 |
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A new way of making LEDs could see household lighting bills reduced by up to 75% within five years.
