Natcore has an exclusive patent license from the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) to develop and commercialize a line of black silicon products—including equipment, chemicals, and solar cells—based on NREL patents.
“Black silicon” refers to the apparent color of the surface of a silicon wafer after it has been etched with nano-scale pores. The etching takes place in a matter of a few minutes in a liquid solution at room temperature; the black color results from the absence of reflected light from the porous wafer surface.
The reflectivity of a polished silicon wafer surface approaches 40%, giving the wafer its shiny appearance. Adding the typical solar cell industry antireflective coating reduces the average reflectivity to approximately 6% and gives the cells their distinctive dark blue color. The black silicon process has been shown by Natcore scientists and researchers at NREL to further reduce the average reflectivity to less than 1.5%.
NREL is the U.S. Department of Energy’s primary national laboratory for renewable energy and energy efficiency research and development. NREL is operated for DOE by the Alliance for Sustainable Energy LLC.