1. Sunlight passes through a multifaceted lens known as a Fresnel. The lens focuses direct sunlight, delivering the power equivalent of 297 suns to the solar cell below.
2. The first subcell, made from gallium indium phosphide, captures photons from the shortest wavelengths of light. The subcells beneath it contain elements capable of capturing progressively longer wavelengths.
3. Each subcell consists of several semiconductor layers, which create an electric field. As photons enter, they excite electrons, freeing them from the subcell.
4. Once the freed electrons reach the top of the stack, a metal contact funnels them toward an output terminal as a direct current.