Improve solar cell light absorption efficiency

Carve the movie on a solar panel? This seemingly irrational and even a bit crazy idea, but let a few scientists studying solar cells tasted the sweetness. A few days ago, a research team from Northwestern University in the United States said that inspired by Blu-ray movie compression and recording technology, they have developed a solar cell with better light-absorbing properties. Even more interesting is that they also found that the technology is not sensitive to the contents of the recording, whether it is Jackie Chan's "Super Police" or Pixar produced "Toy Story", can be a good solar cell light absorption capacity . Related papers were published in the November 25 issue of Nature Communications.

Huang Jiaxing, an associate professor of materials and engineering at Northwestern University who led the study, said: “We had a hunch before that. Blu-ray discs may be helpful for improving the efficiency of solar cells. It is gratifying that subsequent experiments. It really confirms this."

In the field of solar cells, it is known that if a special texture or pattern is added to the surface of a solar cell, light can be effectively dispersed, thereby improving light-absorbing efficiency. For this reason, scientists have long sought a balance between cost and effectiveness, hoping to find a texture that is most easily realized and effective. The new discovery of Northwestern University is achieved through this channel.

Whether CD, DVD or Blu-ray Disc is a kind of data compression and storage technology, the difference is that Blu-ray Disc has higher data density and more data storage. Blu-ray discs use a blue laser beam with a wavelength of 405 nanometers for reading and writing. DVDs and CDs use red lasers with a wavelength of 650 nanometers and 780 nanometers. The laser burns these binary codes, consisting of 0s and 1s, on plastic discs to form individual protrusions or depressions. These bulges and depressions are forming the "pattern" that Huang Jiaxing's team needs. The reason for the final choice of blue light is that after analyzing various algorithms, Huang Jiaxing's team found that higher compression ratio algorithms and quasi-random data storage modes make the carved patterns more in line with the requirements of solar cells for light absorption. The blue laser produces more bumps in the wavelength range of 150 to 525 nanometers, and it turns out that this pattern is ideal for capturing light in all spectral ranges.

The Physicist Organization Network reported on November 26 (Beijing time) that in the experiment, Huang Jiaxing's team used the Blu-ray version of “Super Police” as an object of etching, and copied the pattern on the entire disc to a polymer solar cell. As a result, it was found that, in terms of light absorption and energy absorption, the use of a random pattern of solar cells is superior to a normal solar cell without a pattern, and “Super Police” solar cells are better than random patterns. It has been determined that the multi-frequency absorption capability of light using a Blu-ray film solar cell reaches 21.8%.

In addition, the researchers also tested Blu-ray Discs, which included a variety of content including action movies, TV shows, documentaries, cartoons, and black-and-white images, and found that the content was not important. All finished Blu-ray discs can equally well enhance solar cell light absorption.

Huang Jiaxing said: "In addition to improving the performance of polymer solar cells, the new technology also applies to other solar cells. This is quite surprising, but most exciting is that this study made us feel the nanophotonics The great charm of this cross subject with material science.” (Reporter Wang Xiaolong)