In conventional silicon-based solar cells, each photon of light can only knock loose a single electron, creating electricity. That’s even if the photon carries more than enough energy to do so. One hammer, one nail. Now, for the first time researchers at MIT and Princeton University in the U.S. have got high-energy photons to strike silicon and kick out two electrons instead of one, opening the door for a new kind of solar cell with greater … [Read more...]