Science, Solar Energy.
Multi-junction solar cells work similarly. Say we have an InGaP/GaAs/Ge multi-junction photovoltaic cell. InGaP has the biggest band gap, eV 1.86. It’s like the biggest cookie cutter. Photons with eV 1.86 or higher can be used in this layer. The rest are passed onto GaAs, where photons with eV 1.4