From MIT's Technology Review:
Making LEDs microchip manufacturing methods could slash the cost of lighting.
A startup in California has developed a manufacturing technique that could substantially cut the cost of LED lightbulbs—a more energy-efficient type of lighting.
LEDs are conventionally made on a relatively costly substrate of silicon carbide or sapphire. Bridgelux has come up a new process takes advantage of existing fabrication machines used to make silicon computer chips, potentially cutting LED production costs by 75 percent, according to the company.
Despite their higher efficiencies and longer life, few homes and businesses use LED lighting—largely because of the initial cost. An LED chip makes up 30 to 60 percent of a commercial LED lightbulb. Electronic control circuits and heat management components take up the rest. So for a 60-watt equivalent bulb that costs $40, Bridgelux's technology could bring the cost down by $9 to $18. Integrating the light chip with the electronics might further reduce costs.
LEDs made with the new technique produce 135 lumens for each watt of power. The U.S. Department of Energy's Lighting Technology Roadmap calls for an efficiency of 150 lumens per watt by 2012. Some LED makers, such as Cree, in Durham, North Carolina, already sell LED lamps with efficiencies in that range. In contrast, incandescent bulbs emit around 15 lumens per watt, and fluorescent lightbulbs emit 50 to 100 lumens per watt....MORE