(Left) Cross section of the Nanoshell surface. (Right) How light, in red, propogates through the shells. (via Stanford University)
A paper published by a team of engineers at Stanford reveals a new way to capture energy from the sun employing nanotechnology. They made this possible by creating thin solar panels out of hollowed out nanoshells. The nanoshells themselves are made out of photovoltaic nanocrystalline-silicon that are hollowed out at the center. The nanoshells capture light and due to their concave geometry. The surface of the material acts like a wave guide, forcing the light to circulate inside the shells. The team likened the idea to how sound propagates through a whispering-gallary. As a result, the light is better absorbed by the material due to the increase in time duration of light within the material. With a three layer structure, up to 75% of critical spectrums of light are absorbed.
Post-doctoral researcher on the project, Yan Yao, explained the benefit, "A micron-thick flat film of solid nanocrystalline-silicon can take a few hours to deposit, while nanoshells achieving similar light absorption take just minutes.... This is a new approach to broadband light absorption. The use of whispering-gallery resonant modes inside nanoshells is very exciting. It not only can lead to better solar cells, but it can be applied in other areas where efficient light absorption is important, such as solar fuels and photodetectors.”
Additionally, the construction of the nanoshells allows for quick production and many new possible applications. The material is highly efficient even under heat. The thin construction allows for flexibility which is currently not possible with solar panels. This technology brings a lot of potential for future applications in high-efficiency sun collection industry. So many players in the solar game, if they would only work together.