LEDs are just an application of solid state physics and are not that new to us. We have seen these lights in radios, cell phones etc already. Only the improvisation to use these as dedicated light sources to replace incandescent bulbs is revolutionary and rather new.
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Efficient, useful blue-light LED draws Nobel Prize in physics
Three researchers received the 2014 Nobel Prize in physics on Tuesday for the invention of this blue light-emitting diode (LED), a technology now used in high-speed networking, data storage, smartphones, water purification, and efficient home illumination.
The winners are
Isamu Akasaki, a Japanese citizen and professor at Meijo University and Nagoya University;
Hiroshi Amano, a Japanese citizen and professor at Nagoya University; and
Shuji Nakamura, an American citizen and professor at the University of California in Santa Barbara.
The key advantage of their invention 20 years ago is the production of light with far less waste of electrical energy than with preceding technologies like incandescent and fluorescent lights, the Royal Swedish Academy of Sciences said in awarding the prize.
"A quarter of energy consumption goes to illumination," said Per Delsing, a physics professor at the Chalmers University of Technology in Sweden, during a press conference announcing the award. As a result, any increase in efficiency and consequent saving of energy "is really going to have a big impact on modern civilization," he said.
Nobel Prizes in physics often go to fundamental discoveries such as the Higgs Boson. But when the committee makes an award for an invention, "we really emphasize the usefulness of the invention," said Anne L'Huillier, an atomic physics professor at Lund University in Sweden, also speaking at the press conference. And the blue LED is nothing if not useful.
Recent Nobel prizes have been awarded for concepts that are very far from day-to-day human experiences -- giant magnetoresistance, Bose-Einstein condensates, superconductors and superfluids, and the accelerating expansion of the universe, for example. The blue LED -- something you can buy at the local home-improvement store -- seems downright mundane by comparison.
But it's anything but ordinary, said H. Frederick Dylla, chief executive officer of the American Institute of Physics, who called the work a "tour de force" because it required a combination of materials science, physics, and chemistry. Indeed, the invention of the blue LED was on a short list of his institute's candidates for the prize, he said.
"It's a very expensive technology requiring atomic-layer epitaxy, where layers are put down atomic layer by atomic layer at a very high vacuum," Dylla said. It's vastly more complicated than incandescent lights, he added. "Compare that to drawing tungsten wire and putting it into a blob of glass and blowing out the air with some argon, and you have a light bulb for a few cents."
The frosted bulbs on today's LEDs aren't just there for softer light -- they also hide the unsightly hardware inside. But what if you're a fan of the exposed bulb aesthetic, and looking for a worthy replacement for those translucent incandescents lining your bathroom mirror?
Philips thinks it has just the thing with its new Clear LED, a 40W replacement bulb which the Dutch company promises will mimic the "elegant shape and sparkling light" of traditional incandescents. With its A60 shape, clear glass bulb, and inconspicuous heat sinks, this LED is designed to strike a more familiar tone with consumers than its often irregular-looking competition.
With LED prices continuing to fall, we're seeing more and more bulbs selling for $10 or less. One of the latest options is the Osram 60W Replacement Ultra LED, which rings in just a few cents shy of that 10-buck benchmark. Thankfully, this lower price plateau doesn't represent a dip in quality, at least not with Osram. With well over 800 lumens of light output from a power draw of just 8.5 watts, it's one of the most efficient 60W replacement LEDs we've tested, and it performed well during our dimming tests, too. That makes it an easy bulb to recommend, even among an increasingly crowded field of worthwhile competitors.
Rising efficiency standards spelled the end of the 100W incandescent light bulb. Thankfully, your options have been steadily expanding ever since, with a full crop of new LEDs promising that same level of brightness from a substantially smaller power draw. Of these new bulbs, the GE 100W Replacement LED is one of the best. The bulb's most impressive spec is that it only consumes 16 watts of electricity, efficient enough to put out 100 lumens per watt. That ties it with Utilitech's bulb, making the two of them the most efficient 100W replacements we tested. Nothing else was able to get above 90 lumens per watt. GE backs its longevity claims up with a 10-year warranty, the same warranty that Cree offers for its bulbs. That's as long a warranty as you'll find on a brand-name light bulb, and an exceptional deal for skeptics who aren't sold on LED value just yet.