How does an actor, comedian, son of a geer and a computer scientist…

Solar works by using the energy of photons to bump electrons from the valence bands up into the conductive band. These bands are separated by what is called the band gap. If the gap is 2 electron volts (eV) wide and the photon has 3 electron volts, the extra energy is “lost”. Photons with less than 2 eV don’t contribute anything. It’s possible to stack multiple layers with different band gaps to more efficiently capture a wider range of photons but there will still be losses due to interfacial physics that I don’t understand. Each layer adds to the cost of the cell as well