By Kari Williamson
Natcore and NREL will also enter a Cooperative Research and Development Agreement (CRADA) to develop commercial prototypes based on NREL’s black silicon inventions and patents.
“This technology will play an important role in moving forward the availability of solar technologies,” NREL Vice President for Commercialization & Technology Transfer William Farris says.
“It is one more step to help bolster the Department of Energy’s SunShot Initiative to make solar energy cost competitive with other forms of energy by the end of the decade.”
The Black Silicon Nanocatalytic Wet-Chemical Etch emerged from work by NREL solar PV researchers, who demonstrated that black silicon solar cells, which have been chemically etched to appear black, better absorb the sun’s energy.
The inexpensive, one-step method reduces light reflection from silicon wafers to less than 2%, and could reduce manufacturing production cost and capital expense.
The antireflection process turns silicon wafers black so they absorb 98% of solar radiation, compared to the typical 95% achieved by current solar PV cells.
The technology is still a few tenths of a percent less efficient than the best of the conventional cells. However, the black silicon prevents reflection of low-angle morning and afternoon sunlight far better, which means a jump in solar PV efficiency of at least 1 percentage point can be achieved.
NREL estimates that its method can reduce processing costs by 4-8%, resulting in overall savings in solar cell manufacturing of 1-3%, making black silicon particularly appealing.