Old Blue Ray Disks May Drastically Improve Solar Cells

Blue-ray disks may be more useful than you might have thought. Scientists have discovered that Blue-ray disks may actually improve the performance of solar cells, which suggests a second use for unwanted disks.

"We had a hunch that Blue-ray disks might work for improving solar cells and, to our delight, we found the existing patterns are already very good," said Jiaxing Huang, one of the researchers, in a news release. "It's as if electrical engineers and computer scientists developing the Blue-ray technology have been subconsciously doing our jobs, too."

Blue-ray disks actually contain a higher density of data than either DVDs or CDs. This quasi-random pattern that's used for data storage can be transferred to the surface of solar cells. This, in turn, provides the right texture to improve the cells' light absorption and performance.

"We found a random pattern or texture does work better than no pattern, but a Blue-ray disk pattern is best of all," said Huang. "Then I wondered, why did it work? If you don't understand why, it's not good science."

In the end, the researchers found that the pattern on Blue-ray disks serves two major purposes: achieving as high a degree of compression as possible by converting the video signals into a seemingly random sequences of 1s and 0s and increasing error tolerance by adding controlled redundancy into the data sequence, which also limits the number of consecutive 1s and 0s. These two traits, it turns out, work quite well for light-trapping applications.

"It has been quite unexpected and truly thrilling to see new science coming out of the intersection of information theory, nanophotonics and materials science," said Huang.

The findings are published in the journal Nature Communications.