Moth Eyes May Hold Secret to Better Solar Panels

Science & Technology (alternative energy)

Moth Eyes

We've always been fascinated with what engineers and scientists are working on to make solar power more efficient. From solar balloons to nanotech "hairy" panels, there are lots of promising developments out there.

Today, lets look at a new approach. It's kind of similar to the "hairy" solar panel mentioned above, but this time the inspiration comes from the natural world (aka biomimicry), more specifically from the eyes of moths.

Silicon is reflective, so a lot of light that could be turned into electricity is bounced back and lost. Anti-reflective coating is used, but its effectiveness is limited and it has downsides too. So while looking for a solution, researchers noticed that moths have very non-reflective eyes ("most likely an evolutionary defense against nocturnal predators").

Peng Jiang from the University of Florida:

Moth eyes have orderly bumps on their corneas. Jiang refers to these bumps as “nipples.” The nipples are in an array that creates a situation in which almost no reflection exists. [...]
Jiang says that a method of spin coating is used to create the effect. Nanoparticles in a liquid suspension are placed on a silicon wafer, similar to those used in solar cells. As the wafer is spun, the force created distributes the nanoparticles in the liquid. A sort of mask is created that can be used as a template. Etching is used to transfer the nanoparticle structure onto the silicon wafer beneath.

But most important: in addition to being technologically easy, the process is also inexpensive. The exact opposite of the current anti-reflective coating.

The moth-eye process creates panels that reflect less than 2% of light. That's a vast improvement over the "35 to 40 percent reflection rate seen without the anti-reflection coating layers."

::Moth eyes may hold key to more efficient solar cells

Photo credit: Peng Jiang

Update: If you are interested in solar power, also check out 15 Photovoltaics Solar Power Innovations You Must See.