A Breakthrough in LED Lights from Silicon

Light-emitting diodes, otherwise known as the humble LED, have a host of impressive green credentials. They use far less energy than incandescent light, and now that science has gotten to a place where LEDs can offer similar brightness to some standard light bulbs – as much as 300 lumens – the LED's applications are much wider, and they are no longer limited to tiny flashlight bulbs or electronic indicator lights.

 One problem remains, though, in that more powerful LEDs are expensive. Most LEDs are fabricated on substrates of expensive raw materials such as sapphire or silicon carbide, a process that results in LED light bulbs that can cost upwards of $40 each. A number of companies are currently engaged in research to use less expensive materials in an effort to drive costs down.

The Wall Street Journal today profiled a Livermore, Calif., company called Bridgelux (News - Alert) that has claimed a breakthrough in using silicon to fabricate LEDs. Besides the cost advantage of the material, the approach could theoretically make use of the many older semiconductor factories that are inexpensive to operate, writes the Wall Street Journal.

Bridgelux's CEO, Bill Watkins (formerly of Seagate Technology (News - Alert)) says the problem is that silicon is much more difficult to work with for LED applications. The effort typically requires depositing the material gallium nitride on silicon wafers, and the results usually fall far short of the performance of LEDs made with conventional materials.

On Tuesday, however, Bridgelux said it has managed to use eight-inch silicon wafers to make components that achieved 135 lumens per watt -- essentially reaching commercial-grade performance with the material for the first time. It will take two or three years to improve production yields to make the process commercially viable, but Watkins sees no barriers to using the approach to reduce production costs by 75 percent, reports the Journal.

“This is a game-changer around the whole cost structure,” said Watkins. “We think we can get to $5 bulbs.”