Plants take advantage of quantum mechanics to harvest sunlight with near-perfect efficiency–though only roughly 2 percent of that capture sunlight ultimately gets stored as chemical energy. Now scientists are studying how this light-harvesting step of photosynthesis is optimized by nature to learn how to mimic it in engineered systems for use in solar cells or artificial leaves that produce fuels directly from the sun .

Plants rely on chromophores–molecules that absorb certain wavelengths of visible light while reflecting others — to harvest energy from the sun. When sunlight hits a plant, electrons in the topmost chromophores absorb energy from incoming photons and then transfer it from the newly energized molecule to another molecule at a lower energy state. That transfer repeats itself via a chain of molecules, a cascade of rapid energy pass-offs that ultimately separates an electron from the last chromophore in the chain, which provides energy that is stored by the plant as a carbohydrate.

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Scientific American - News