Image courtesy Indiana Distributed Energy Advocates
On Tuesday, December 20, the National Renewable Energy Laboratory (NREL) transferred licensing technology for black silicon to solar development-stage firm Natcore Technology Inc.
The NREL is one of a
dozen laboratories operating under the auspices of the U.S. Department of Energy and
engaged in renewable energy and energy efficiency technologies, many of which are later transferred to the marketplace via technology startups like Natcore.
Natcore, founded in 2009 via the acquisition of a company of the same name, is a producer and seller of thin- and thick-film silicon dioxide and/or mixed silicons. Its technology is aimed at reducing silicon usage in the manufacturing process and promoting the mass production of highly efficient (tandem) solar cells.
Tuesday’s announcement advances an arrangement whereby NREL originally sent unfinished black silicon solar cells to Natcore, which then coated them with silicon dioxide (SiO
2) and sealed, or “passivated” them to make them
nonreflective via its liquid phase deposition (LPD) technology, which has been shown to reduce reflectivity to less than 1.5 percent compared to an industry average of about 6 percent. Reduced reflectivity helps insure that sunlight doesn’t bounce off a solar cell, but instead is
captured to generate electricity.
Once NREL had completed electrical connections and tested the resultant samples in their labs in Golden, Colorado, they entered into a Cooperative Research and Development Agreement (
CRADA) with Natcore to commercialize the technology, potentially
sometime next year.
The ultimate aim, via a series of technical and market waypoints which incorporate a royalty structure, is to produce solar energy which achieves grid parity by matching, over a large representative sample, the retail cost of electricity from traditional sources like coal, oil, gas and nuclear.
The black silicon technology
emerged from NREL etching processes in 2010 which rendered silicon wafers so close to black they essentially absorbed nearly all the light from the solar, or
Frauenhofer, spectrum – an adsorption range which can be achieved in an inexpensive, one-step process in three minutes or less.
Subsequent to NREL’s report, its team won the 2010 R&D Magazine “R&D100” awards for the process, formally known as “Black Silicon Nanocatalytic Wet-Chemical Etch”.
At a 98-percent absorption rate (as compared to 95 percent for most solar cells today), the black silicon cells achieve excellent efficiency, though they still miss the mark (by tenths of a percent) compared to super-efficient conventional silicon solar cells.
Production costs, however, are sufficiently reduced to offer solar cell manufacturers a savings of between one and three percent, and this, as much as efficiency, is the best path to increasing solar energy uptake and making it both ubiquitous and affordable.
For more information on solar technologies, please visit Energy Boom’s
learning pages.
