The study, published today in the journal Nature Chemistry and led by Professor Jenny Clark, reveals that nature has been utilising a process called ‘singlet fission’ which is effectively a ‘two-for-one’ energy deal to optimise solar harvesting. The findings provide a new blueprint for green technology, particularly as engineers attempt to copy this exact mechanism to build next-generation solar panels and quantum technologies.
While scientists have long understood the basic rules of how plants and bacteria convert light into chemical fuel, the biological role of singlet fission has historically remained poorly understood.
Normally, photosynthesis operates on a one photon, one energy packet rule. When a pigment molecule absorbs a single particle of light (a photon), it generates a single packet of energy (an exciton) and sends it to the cell’s reaction centre.
This latest research follows laboratory experiments on purple photosynthetic bacteria showing that a novel hetero-fission process occurs within their light-harvesting complexes. When a high-energy pigment called a carotenoid absorbs sunlight, it does not just create one energy packet. Instead, it splits that energy into two lower-energy packets called 'triplets'. This latest research follows lab experiments on purple photosynthetic bacteria, which reveal a unique energy-splitting process happening inside their solar-collecting systems. When a high-energy pigment called a carotenoid absorbs sunlight, it doesn't just create a single packet of energy. Instead, it splits that solar energy into two lower-energy packets called "triplets." These triplets, which are born across neighbouring molecules, are locked into a protective quantum state that prevents their energy from bleeding off as waste heat. By partnering up, they act like a tiny, long-lasting biological battery. They safely store the energy for a fraction of a second before joining forces, allowing the power to be smoothly transferred into the rest of the cell.
To understand how this enhances efficiency, the researchers discovered that these triplets have an advantage: they are blocked from losing their energy rapidly. This allows them to act like a long-lasting biological battery, storing the energy safely until it's needed.
By creating this buffer, the mechanism temporarily staggers the delivery of energy. This ensures the biological system is never overwhelmed while simultaneously maximising the amount of solar energy successfully harvested.
We’ve discovered that nature has been using quantum mechanics to bypass standard efficiency limits for billions of years. By leveraging this 'two-for-one' energy deal, the bacteria can store power safely like a biological battery rather than losing it as waste heat.
If we can copy this natural blueprint, we can design next-generation quantum technologies that are uniquely stable, changing how we store and handle delicate quantum information at room temperature.
Professor Jenny Clark
Through exploring these quantum mechanisms, the study pinpointed exactly how the bacteria seamlessly integrate physics and biology to augment their energy output. The findings are intended to inform future quantum and advanced technology design, allowing engineers to mimic these natural genetic blueprints to keep quantum states stable and protected in human-made devices.