Thinner Silicon Wafers Could Cut Solar Cell Costs in Half

A U.S. company has developed a new manufacturing technique that it says could cut the cost of producing solar cells in half by producing silicon wafers that are about one-tenth as thick as conventional wafers. Twin Creeks Technologies, a San Jose-based company, says it can produce crystalline silicon wafers that are only 20 microns thin — or about one-fifth the thickness of a layer of paint — compared with the 200-micron wafers commonly used in solar cells. While the conventional technologies use diamond saws to cut blocks of silicon — a process that wastes about half of the silicon — the new process essentially embeds protons at a desired depth within a block of silicon and heats the protons so that they occupy more space. Eventually the company is able to crack off the thin, 20-micron wafers, after which they are affixed to a thin metal backing that makes them durable enough to withstand the rest of the production process. The company has raised $93 million in venture capital, some of which will be used to build a solar factory in Mississippi.