Researchers have developed a photovoltaic device that has an external quantum efficiency of 132 percent. This impossible-sounding feat was achieved using nanostructured black silicon, and could represent a major breakthrough for solar cells.
This new device is the first to not only reach 100-percent efficiency, but exceed it. At 132 percent, that means you get on average 1.32 electrons for every photon. It was made using black silicon as the active material, with nanostructures shaped like cones and columns, absorbing UV light.