Creating the perfect solar cell (i.e. a cell that’s both efficient and cheaply produced) is certainly a work in progress. Researchers across the world have attempted to create cells from silicon, plastic and even human hair! Now, researchers at Cornell University came up with another concept: crafting solar cells from carbon nanotubes. Though still in the very early stages of development, if perfected, carbon nanotube-based cells could provide a more efficient method of converting light to electricity.
Led by professor Paul McEuen, researchers at Cornell recently tested a simple solar cell (called a photodiode) crafted from a single carbon nanotube. In this case, a carbon nanotube is basically a rolled up sheet of graphene the size of a DNA molecule. The nanotube was wired between two electrical contacts, one negatively and one positively charged. As electrons moved through the nanotube, they became excited and released excess energy, which then created even more electrons flowing through the tube. Researchers discovered that more light shined on the nanotube created even more electricity, a huge difference from today’s silicon solar cells where excess energy is lost in the form of heat rather than used to create more electricity.
While the device is certainly in its earliest stages of development, the discovery does show that carbon nanotubes can efficiently convert light to electricity. Now, researchers need to figure out a way to scale up the device while still keeping it efficient and relatively inexpensive.
Whether carbon nanotube-based solar cells will come online in the near future (or ever, for that matter) remains to be seen. But the fact that so many scientists are putting so much energy into creating cheap and efficient solar cells is very encouraging.