Now researchers claim that Blu-ray discs have one more advantage over DVDs: they also have the ability to help markedly improve the efficiency of solar cells, when their etched information patterns are repurposed for use as light concentrators.
According to new research from a team at Northwestern University, Illinois, it has been discovered that the scattering effect on light shone through the arrangement of data etched on a Blu-ray disc improves energy absorption across the spectrum of light used by solar cells.
"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 Associate Professor Jiaxing Huang, of the McCormick School of Engineering and Applied Science at Northwestern. "It's as if electrical engineers and computer scientists developing the Blu-ray technology have been subconsciously doing our jobs, too."
The quasi-random pattern applied to Blu-ray discs – formed as part of the development of their higher-density makeup – has proven to be of the right texture to significantly improve the scattering effect of light when applied to the surface of solar cells. That is, the arrangement of troughs and peaks (zeroes and ones) etched into the surface are sized at between 150 and 525 nanometers, making them ideal for improved light-trapping and concentration.