Twin Creek Technologies, of San Jose, CA, is developing a solar cell manufacturing technology which utilizes a high-energy ion accelerator to slice silicon wafers that are ten times thinner than typical layers.
In today’s typical wafer sawing process, half the silicon is lost to “sawdust”. But Twin Creek ditches the saw altogether. They use injected hydrogen atoms to thermo-chemically shear off 20 micro thick wafers with no waste.
This is a valuable breakthrough, because the cost of the silicon wafer accounts for almost half the total cost of solar panels.
Manufacturing a standard cell today requires 6.5 grams of silicon per watt of capacity, worth about 40 cents; the new system will use just 600 milligrams and cost 10 cents per cell, he said. The finished product can be wrapped in plastic instead of being covered with a special grade of low-iron glass on a hard backing. [via nytimes.com]
This innovation reduces the cost of the silicon required for a given power output, and it also reduces the amount of other supporting materials required, like low-iron glass. The company also claims that–surprisingly, since this process required the design of an ion accelerator 10 times more powerful than any commercially available today–this process has lower capital costs than existing methods. That goes to show how much manufacturers are paying today to Applied Materials for the cutting and finishing machines.
Watch a video on the company’s website describing the process here.
This is all very cool, but Twin Creek isn’t the only firm that is innovating to reduce the amount of silicon required for a PV cell.
Ampulse Corporation is leveraging technology developed at Oak Ridge National Laboratory (ORNL) and the National Renewable Energy Laboratory (NREL) to grow silicon crystals directly on an inexpensive foil substrate using chemical vapor deposition. This process claims to grow a silicon layer as thin as only 10 microns.
The Ampulse process “goes straight from pure silicon-containing gas to high-quality crystal silicon film,” said Brent Nelson, who runs the PDIL at NREL. “The advantage is you can make the wafer just as thin as you need it — 10 microns or less.” [via renewableenergyworld.com]
Other thin silicon startups worth watching: