Bridgelux says it will bring a lighting technology to market in two to three years that seemed outlandish only a short time ago.

If the company succeeds, this move could drastically drop the price of LED bulbs.

The breakthrough technology is a functional gallium nitride LED that emits 135 lumens per watt. The lights are 'grown' on inexpensive silicon wafers instead of more exotic materials. These GaN-on-silicon chips are lab samples and Bridgelux will have to fine-tune production processes, but Bridgelux CEO Bill Watkins says that the company could move into production in two to three years.

These silicon LEDs could cost 5 cents or less per unit, compared to 35 cents to 45 cents for a conventional chip, and could cut the price of LED bulbs by $7.50 or more.

"We are going to take the LED die down to pennies," he said. "There is no fundamental reason why it can't be done."

The breakthrough comes amid a push by Tea Party Republicans to repeal a law -- passed by George Bush -- that promotes LED bulbs and phases out inefficient incandescents. Today, Bridgelux makes its LEDs in the U.S., but the company has been actively recruited by foreign governments to set up overseas facilities. Europe, China and other nations have stronger lighting efficiency standards. 

LEDs are essentially finely tuned crystals of gallium nitride grown on top of wafers made of sapphire or silicon carbide. The epitaxial process of growing the gallium nitride is complex and the wafers aren't cheap. Most LED producers currently grow their LEDs on wafers measuring only two to four inches. Bridgelux, in fact, grows its LEDs on two-inch wafers. Large LED makers like Osram are only now in the midst of shifting to six-inch wafers. Sapphire wafers measuring eight inches across may never occur, Osram Opto CEO Aldo Kamper told us earlier this month.

“It is hard to imagine that sapphire gets that big,” Kamper said. 

Larger wafers, however, mean lower costs, because a manufacturer can make more chips simultaneously. Some researchers also believe that LEDs may only be capable of emitting 225 lumens per watt. Limits on wafer size and lumens per watt effectively put a ceiling -- one that is only a few years out -- on the ability of solid-state lighting manufacturers to cut costs. 

Silicon wafers are far cheaper than sapphire or silicon carbide. More importantly, there are literally thousands of fabrication facilities around the world that can produce eight-inch silicon wafers and that are currently running at half speed or producing fairly low-end components, according to Watkins. The semi industry already graduated to larger 12-inch wafers. Bridgelux's, in fact, were made in an old silicon fab in the Valley. 

"This is the holy grail. This is why all of the big semi guys like Samsung, LG and Toshiba are looking at LEDs," he said. "The problem for the semi guys is that they don't know how to do it yet."

Is it easy? No -- which makes actually pulling this off a big 'if.' Growing the layers on silicon is challenging. Another problem: silicon and gallium nitride heat up and cool off at different rates, and extreme temperatures are required in the growing process. This often results in cracking. Bridgelux has inserted thin films between the gallium nitride and silicon to buffer this.  

Watkins said he began to accelerate the silicon process when he became CEO a little over a year ago, but that the work has progressed faster than expected. (He told Greentech Media in December that the company was working on silicon LEDs.)

Others are working on the same goal. Osram has a silicon effort underway, and so do all of the major chip vendors. Bridgelux's goal is to beat them and then partner with a large semiconductor maker for mass manufacturing and commercialization.

"God made rules about the quantum effect and he said you cannot get above 225 lumens per watt," he joked. "But he didn't say anything about silicon. God said, 'It's OK, guys, but you're going to have to work hard.'"