Low-cost LED lights?
July 21, 2008 | Source: KurzweilAI
Purdue University researchers have developed a new fabrication process that promises to make LEDs cost-competitive with compact fluorescent lights, which are four times more efficient than conventional incandescent lights, but contain harmful mercury.
They replaced the expensive sapphire-based substrate with low-cost, metal-coated silicon wafers using a built-in reflective layer of zirconium nitride, while solving its chemical instability problems.
Another advantage of silicon is that it dissipates heat better than sapphire, reducing damage caused by heating, which is likely to improve reliability and increase the lifetime of LED lighting.
LEDs also are expected to be far longer lasting than conventional lighting, lasting perhaps as long as 15 years before burning out.
Incandescent bulbs are about 10 percent efficient; white LEDs range from 47 percent to 64 percent efficient, but LED lights on the market cost about $100.
The researchers expect affordable LED lights to be on the market within two years.
