News tagged with led
LED's efficiency exceeds 100%
(PhysOrg.com) -- For the first time, researchers have demonstrated that an LED can emit more optical power than the electrical power it consumes. Although scientifically intriguing, the results won’t ...
Mar 05, 2012 |
4.4 / 5 (65) |
60
|
White LEDs with super-high luminous efficacy could satisfy all general lighting needs
(PhysOrg.com) -- Researchers from the Nichia Corporation in Tokushima, Japan, have set an ambitious goal: to develop a white LED that can replace every interior and exterior light bulb currently used in homes ...
Aug 31, 2010 |
4.8 / 5 (50) |
34
|
OLED Tunes its Colors for Sunlight-Style Illumination
(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 ...
Jul 16, 2009 |
5 / 5 (39) |
15
Low-cost LEDs to slash household electric bills
A new way of making LEDs could see household lighting bills reduced by up to 75% within five years.
Jan 29, 2009 |
4.5 / 5 (33) |
30
Quantum-dot LED screens may soon rival OLEDs and LCDs
(PhysOrg.com) -- A partnership has been formed between US, South Korean and Belgian companies to develop quantum-dot light emitting diode (QLED) displays to rival the organic light emitting diode (OLED) markets ...
Technology / Hi Tech & Innovation
Dec 13, 2010 |
4.8 / 5 (30) |
28
|
Soraa LED light may dim 50-watt halogen rivals
(PhysOrg.com) -- Soraa, a Fremont, California company founded in 2008, this week launched its first product, a light that uses LEDS (light emitting diodes). The "Soraa LED MR16 lamp" is the "perfect" replacement ...
Feb 09, 2012 |
4.4 / 5 (27) |
24
|
Smart Lighting: New LED Drops the 'Droop'
(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.
Jan 12, 2009 |
4.8 / 5 (24) |
14
Dean Kamen's LED Island Goes Off the Grid
(PhysOrg.com) -- Dean Kamen, best known as the inventor of the Segway scooter and a thought-controlled prosthetic arm, has taken a personal interest in reducing energy consumption.
Technology / Energy & Green Tech
Dec 08, 2008 |
4.3 / 5 (25) |
4
LED efficiency puzzle solved by theorists
Researchers at the University of California, Santa Barbara, say they've figured out the cause of a problem that's made light-emitting diodes (LEDs) impractical for general lighting purposes. Their work will help engineers ...
Apr 19, 2011 |
4.6 / 5 (21) |
16
|
LED light bulbs yield big savings in energy
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.
Technology / Energy & Green Tech
Aug 13, 2009 |
4.8 / 5 (20) |
42
Flexible LEDs for implanting under the skin
(PhysOrg.com) -- Researchers in the US, China, Korea and Singapore have collaborated to develop flexible ultra-thin sheets of inorganic light emitting diodes (LEDs) and photodetectors for implantation under ...
Oct 18, 2010 |
4.8 / 5 (19) |
12
|
Nano-LEDs emit full visible spectrum of light
(PhysOrg.com) -- Physicists from Taiwan have designed and fabricated nano-sized light-emitting diodes (LEDs) that emit light spanning the entire visible spectrum. Although the tiny full-color LEDs aren't intended ...
Jun 17, 2011 |
4.9 / 5 (18) |
2
|
Solar-powered LED light made of bottles
(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 ...
Electronics / Consumer & Gadgets
Jan 20, 2009 |
3.3 / 5 (26) |
7
Solar Cells with LEDs Provide Inexpensive Lighting
(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 ...
Technology / Energy & Green Tech
Nov 09, 2009 |
4.3 / 5 (18) |
2
LED there be light
Q: How many LED engineers does it take to change a light bulb?
Technology / Hi Tech & Innovation
Jun 22, 2009 |
4.2 / 5 (18) |
3
Light-emitting diode
A 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.
