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LED Lighting As Cheap As CFLs Invented
mcgrew writes "New Scientist reports that a British team has overcome the obstacles to cheap LED lighting, and that LED lamps as cheap as CFLs will be on the market in five years. Quoting: 'Gallium nitride cannot be grown on silicon like other solid-state electronic components because it shrinks at twice the rate of silicon as it cools. Crystals of GaN must be grown at 1000C, so by the time a new LED made on silicon has cooled, it has already cracked, rendering the devices unusable. One solution is to grow the LEDs on sapphire, which shrinks and cools at much the same rate as GaN. But the expense is too great to be commercially competitive. Now Colin Humphreys's team at the University of Cambridge has discovered a simple solution to the shrinkage problem. They included layers of aluminium gallium nitride in their LED design... These LEDs can be grown on silicon as so many other electronics components are. ... A 15-centimetre silicon wafer costs just $15 and can accommodate 150,000 LEDs making the cost per unit tiny.'"
These are going to be awesome in an office environment. Especially since the ceilings are so high and nobody likes changing the lights. But I have yet to find truly warm non-tungsten/halogen/mercury/fire/quartz/evil light for home use. I could not picture LEDs (which are basically antennas radiating a frequency that we happen to see) overtaking the other lights (heat sources that coincidentally give off visible light) in terms of color richness.
I'm all for getting away from CFLs, as their production alone is NOT environmentally friendly (most of the mercury in the world is mined in China, where HALF of it is "lost" to the environment during production, which means "polluted"), not to mention the ratio thrown out.
But what about the LEDs? How toxic (or not) are the materials they're talking about? And what about the production of such? And heck, back on the pollution thing, WHERE they are produced makes a big difference, since if it's in China, forget any environmental disposal of chemicals used, whereas if it's in a developed country, it'll probably be OK.
Not insurmountable problems, but I do want to know how those things will work out.
I'm not sure everyone is completely aware of how big an advance this is. I'm going to buy Philips' stock as soon as I can. I'm sorry people have been screwed by some misleading marketing, but LEDs are the future of lighting... and the big green movement.
And yes, they're really easy to dim, either by converting to DC and modulating current, or by using a PWM - I'm not sure which is more efficient/cheaper.
I can't wait for CFLs to go away. Eventually you'll see commercially available, color-selectable LED bulbs.
Anyone know if the process was patented/sold to a specific company? Pretty obvious why...