Blu-ray discs can improve solar cell performance
"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 at Northwestern University in Chicago said.
"It's as if electrical engineers and computer scientists developing the Blu-ray technology have been subconsciously doing our jobs, too."
Scientists already knew that placing texture on the surface of a solar cell scattered light more effectively, increasing a cell's efficiency. But they have been searching for a combination of the most effective texture that is also cost-efficient to manufacture. Blu-ray discs seem to fit the bill.
The discs contain a higher density of data than DVDs or CDs thanks to a quasi-random pattern. The disc's strings of binary code 0s and 1s, embedded as islands and pits are the near-optimal surface texture to improve absorption over the broad spectrum of sunlight, the Northwestern team found.
Huang and his team tested a wide range of movies and television shows stored on Blu-ray discs, including action movies, dramas, documentaries, cartoons and black-and-white content, and found the video content did not matter. All worked equally well.
"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.