Blu-ray discs could be the key to improving solar panels

On paper, collecting the sun’s energy is a pretty great idea, but most solar panels suffer from relatively low photovoltaic efficiency. On average, most panels will collect less than 20-percent of the light that hits it. Can we do better? Absolutely: but we’ll need more Blu-ray discs. According to researchers at the Northwestern University of Evanston, Illinois, the microscopic hills an valleys found on a Blu-ray disc are surprisingly adapt at trapping light.

Using Blu-ray Discs to watch movies is so 2006. Now they can boost the efficiency of solar cells. Imprinting the discs’ data-storing etchings onto solar cells increases the cells’ absorption of sunlight, according to a study published November 25 in Nature Communications. Previous research has shown that making nanometer-sized etchings onto a solar cell’s surface helps trap more light, so Jiaxing Huang, a materials chemist at Northwestern University in Evanston, Ill., looked to Blu-ray Discs, which store data in the form of tiny bumps and pits. He and his team collected various movies and TV shows, and used a mold of the discs to imprint their patterns onto polymer solar cells. The patterned solar cells that Huang’s team tested absorbed nearly 22 percent more light than smooth cells. By coincidence, Huang says, the manufacturing process to compress data and prevent scratches from ruining discs creates etching patterns that help absorb light.