It's only true for a single junction. https://en.wikipedia.org/wiki/Shockley%E2%80%93Queisser_limit https://en.wikipedia.org/wiki/Shockley%E2%80%93Queisser_lim

It's only true for a single junction. https://en.wikipedia.org/wiki/Shockley%E2%80%93Queisser_limit https://en.wikipedia.org/wiki/Shockley%E2%80%93Queisser_limi... Multi-junction cells beat that limit, but they're still horribly expensive to manufacture which confines them to niche uses like spacecraft.