University of California researchers led by Yang Yang, professor of materials science and engineering, have developed a polymer solar cell that achieves a 10.6 percent efficiency. The discovery comes at less than a year since the same research group reached an 8.6 percent efficiency, in July.
So far, polymer solar cells have been traditionally inefficient. Yang’s new efficient cell has been enabled by a new photovoltaic polymer developed by Sumitomo Chemical, a Japanese company. The researchers’ ultimate purpose is to fabricate polymer solar cells that are 15 percent efficient.
The new plastic solar cell combines two layers that work with different bands of light—a polymer that works with visible light and one that works with infrared light. “The solar spectrum is very broad, from the near infrared through the infrared to the ultraviolet, and one single solar-cell component can’t do it all,” says Yang.
However, the efficiency of solar cells drops by a third when they’re used in real life conditions, affected by the elements. To compete with multilayer inorganic (silicon) solar cells, Yang’s polymer version has to give a 15 percent in the lab. In that case, the cell used in real life conditions could yield a 10 percent efficiency.
This, combined with a low manufacturing price, could ultimately enable polymer solar cells to compete with their silicon siblings.