Efficiency of Silicon Solar Cells Climbs

In research published recently in Nature Energy, researchers at Kaneka Corp., a resin and plastics manufacturer based in Osaka, describe the first silicon solar cell to achieve a record-breaking 26.3 percent efficiency—a 0.7 percent increase over the previous record. That may not seem like a lot, but it’s really a big step when you consider that silicon solar cells’ theoretical maximum efficiency is just 29 percent.

In producing its new 180.43-square-centimeter monocrystalline silicon prototype cell, Kaneka further developed and improved on several of the technologies promoted by New Energy and industrial Technology Development Organization (NEDO). Chief among them is Kaneka’s proprietary heterojunction technology. It reduces recombination, or resistive loss, where instead of exiting the device to produce electricity, positive and negative charges in the solar cell combine and produce heat.

In addition, the company improved the energy-collection efficiency of the solar cell’s interdigitated electrodes. But even more important, Kaneka moved the grid of electrodes from the front of the cell—the light-receiving area—to the back, boosting the amount of sunlight entering the cell, thereby reducing losses in the optics.

Read more at IEEE Spectrum

Image Credit: Kunta Yoshikawa/Kaneka/Nature Energy

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