http://www.technologyreview.com/read_article.aspx?id=17588&ch=energyResearchers at a Canadian startup say they've found a way to make low-cost, white-light LEDs that could one day end our addiction to inefficient incandescent bulbs. They claim to have cracked the cost barrier for solid-state lighting by replacing the expensive semiconductors compounds traditionally used in LEDs with low-cost silicon.
"Because it's a silicon-based system, we think
will be affordable," says Stephen Naor, chief executive officer of Ottawa-based Group IV Semiconductor (named after silicon's position in the periodic table). "That's critical, because if you don't have affordability, then nobody is going to buy it."
Roughly 60 percent of all lightbulbs in the world are still incandescent--and for good reason: most cost pennies to produce. However, 95 percent of the energy used by these bulbs is wasted as heat. Solid-state lighting is already widely used for specialty applications; LEDs on Christmas tree lights, for example, are based on gallium nitride semiconductors. And experts predict that this technology will be increasingly used for general lighting purposes (see "Turning on LEDs").
But making LEDs using semiconductors based on gallium nitride requires costly manufacturing processes. "The problem is you're using alloys, and there are always impurities. So you have to grow them using very sophisticated gear under ultrahigh vacuum equipment. It's a very costly process," says Sylvain Charbonneau, professor of physics at the University of Ottawa and director of applications technologies at the National Research Council of Canada. Charbonneau is also director of the Canadian Photonics Fabrication Centre, which Group IV will be using to design a prototype of its technology.
<more>
Printer-friendly format
Email this thread to a friend
Bookmark this thread
(1000+ posts)
Send PM |
Profile |
Ignore
