Blu-ray discs could useful for more than just storing high-definition movies, new research suggests they could also help improve solar panels.
The pattern of information on Blu-ray discs was found to improve light absorption on the solar spectrum, no matter what film or T.V. show they held, Northwestern University reported. The method helped improve the absorption of solar cells by 21.8 percent.
"We had a hunch that Blu-ray discs might work for improving solar cells, and, to our delight, we found the existing patterns are already very good," said Jiaxing Huang, a materials chemist and an associate professor of materials science and engineering in the McCormick School of Engineering and Applied Science. "It's as if electrical engineers and computer scientists developing the Blu-ray technology have been subconsciously doing our jobs, too."
The researchers looked at a variety of content on Blu-ray discs including "action movies, dramas, documentaries, cartoons and black-and-white content" and found it didn't make a difference to their effect on light absorption.
Textures placed on the surface of solar cells help scatter light more effectively, aiding in absorption. For years researchers have been looking for the most successful and economical pattern to use for this application. The first movie the team tested out was the pattern found on the Blu-ray for Jackie Chan's "Supercop," which proved to make the solar cell more effective when replicated onto an active layer of a polymer solar cell.
"We found a random pattern or texture does work better than no pattern, but a Blu-ray disc pattern is best of all," Huang said. "Then I wondered, why did it work? If you don't understand why, it's not good science."
The team believes the method works because the patterns on the blue-ray discs are made up of a "quasi-random array of islands and pits" with feature sized between 150 and 525 nanometers, which is ideal for trapping light across all spectrums.
"In addition to improving polymer solar cells, our simulation suggests the Blu-ray patterns could be broadly applied for light trapping in other kinds of solar cells," said Cheng Sun, an associate professor of mechanical engineering at McCormick.
The findings were published Nov.25 in the journal Nature Communications.
