Monday, October 29, 2007

Investor millions to turn 'black' to light

By Efrain Viscarolasaga

A Beverly company recently landed a multimillion-dollar investment to support its development of "black silicon," a new kind of silicon that may hold tremendous promise -- particularly in energy-producing photovoltaic solar cells.

SiOnyx Inc. closed an $11 million round of funding from investors including Harvard University, RedShift Ventures of Virginia, Harris & Harris Group of New York and Polaris Venture Partners of Waltham, according to documents filed with the U.S. Securities and Exchange Commission.

The company, which was spun out of Harvard in 2005, is operating quietly. CEO Stephen Saylor declined an invitation to speak about SiOnyx or its technology.

A 2006 release from repeat investor Harris & Harris revealed that this round adds to a first installment of $750,000. Published reports, including one from the Harvard University Gazette, indicate that black silicon was discovered accidentally in 1999 by researchers in Harvard's Division of Engineering and Applied Sciences. The team was led by Harvard professor Eric Mazur, who is listed as an investor in SiOnyx, as well as James Carey, who is the company's chief science officer.

Saylor, a former vice president at Adobe Systems Inc. and former president of Peterborough, N.H.-based FlashPoint Technology Inc., joined the company in 2006, according to his online resume.

"Black silicon" absorbs light at a greater rate than traditional silicon, mainly because of its surface, made of tiny spikes just hundreds of nanometers long. Black silicon's promise is that it turns normally gray silicon to a deep black that absorbs nearly all of the light to which it is exposed. That's an improvement when compared with cells made with polished silicon, which turn away approximately 40 percent of exposed light, according to Howard Branz, a principal scientist and head of the Silicon Materials and Devices section at the National Renewable Energy Laboratory (NREL) in Colorado.

Virtually all manufacturers now use anti-reflective coatings to boost the efficiency of solar cells, he said.

Black silicon has to improve on that, converting more light to energy, said Branz. "The (black silicon) effect is real," said Branz. "But (any company working with black silicon) will have to beat anti-reflective coatings in both efficiency and price."

And that's an expensive proposition, he said. The nanospikes of black silicon can be created in a variety of ways, and a handful of research labs are working hard to be the first to market.

Mazur's research group at Harvard indicates that SiOnyx is using tiny lasers in its development of black silicon. In Germany, researchers at the Technical University of Munich are working with gold nanoparticles to create the pitted effect of black silicon.