Nobel prize-winning scientist Alan Heeger and his buddies have figured out a way to print more-efficient plastic solar cells, boosting their efficiency to 6.5%, a world record for these photovoltaic polymers. Heeger and his colleagues perform this trick by using two layers of different types of plastic, and whenever one layer doesn't turn light into electricity, the other one picks up the slack. Now the scientists are getting cocky, saying they can improve the tech even further.
They vow to "do significantly better than 6.5% in the near future." Other scientists agree, saying that 10% efficiency is likely very soon. Others say phooey. University of Denver scientist Sean Shaheen calls efficiency estimates "notoriously unreliable," accusing scientists of tweaking the solar spectrum to make their results look good. Others say that these dual-layer plastic solar cells will be trickier to manufacture than the single-layer plastic cells that are being prototyped today.
These guys have big plans for the technology, but before they bring this tandem cell to market, they'll first use those single-layer plastic solar cells in portable battery chargers that they hope to put on the market next year. But those will have only 5% efficiency. The holy grail is to place plastic solar cells on roofs, which they say will require at least 7% efficiency to be cost effective. That's where these tandem layer solar cells with upwards of 10% efficiency could prove to be a breakthrough.