The U.S. Department of Energy’s National Renewable Energy Lab (NREL) has announced it will release an exclusive patent license to its black silicon solar cell technology to Natcore Technology Inc.
Natcore says it plans to retail its own commercial line of black silicon products, including equipment, chemicals and solar cells.
The company has also signed a Cooperative Research and Development Agreement with the NREL to develop commercial prototypes based on NREL’s black silicon inventions and patents.
The NREL’s “Black Silicon Nanocatalytic Wet-Chemical Etch” technology won a 2010 R&D 100 Award. The technique works by boring up to one trillion tiny holes into the surface of a standard silver silicon wafer the size of a compact disc. As the holes get deeper, light is absorbed until a point where the wafer appears to be black.”
Normal industry antireflective coating gives some solar panels their familiar blue appearance, but according to Natcore, modules made up of black silicon cells will generate more electricity than standard solar panels. This is due to their enhanced light-trapping properties, but also because porous black silicon has lower angular dependence – meaning it absorbs more sunlight in overcast conditions early in the morning and late afternoon, maximising the efficiency of the panels.
Prior to the license agreement, Natcore and NREL worked together to bring the technology to the point of commercialisation; overcoming a number of hurdles in the process.
While punching holes over the surface of the solar cell may help absorb light, it also decreases power output by creating imperfections that can interrupt electric charges moving towards the solar contact points. These areas must be treated, or “passivated,” to allow the smooth flow of current across the surface of the solar cell.
The NREL had previously sent unfinished black silicon wafers to Natcore for special coating and “passivation” treatment before sending them back to NREL labs for completion.
“Natcore has the ability to passivate black silicon cells using their liquid phase deposition (LPD) technology. That has been the missing piece. It’s what will enable black silicon to reach its potential,” says Dr. Dennis Flood, Natcore’s Chief Technology Officer.
Although precise financial details have not been released, it is under stood the license contains technical and market milestones for Natcore, including solar cell efficiency goals, some of which are to be met by August of 2012, along with a royalty structure.