To become a mainstream energy source, solar panels need to become more efficient, and a recent breakthrough by researchers from Kyushu University and Johannes Gutenberg University Mainz may accelerate this progress. On March 25, 2026, they reported an experiment in which their technology generated more energy carriers than the number of photons absorbed.
Their system reached a quantum yield of about 130%, meaning one photon produced more than one usable excited state. The key innovation was developing a molecule that could capture these multiplied excitons, overcoming a long-standing obstacle. The innovation centers on a molybdenum-based metal complex that creates a “spin-flip” emitter. This molecule can accept energy from triplet states —a limitation found in commercially available solar cell panels.
Traditional solar cells use a single junction in a semiconductor, and unavoidable losses limit their efficiency to about 30%. This limit exists because sunlight contains photons of different energies. Low-energy photons can’t energize electrons, while high-energy ones lose excess energy as heat. As a result, solar panels must be large to make a real impact on electricity bills.
When light hits certain materials, it creates excitons—energy states shared between an electron and its “hole.” Singlet fission allows a high-energy exciton to split into two triplet excitons. If both are captured, a single photon can do more electrical work, boosting output.
Previous experiments achieved quantum efficiencies exceeding 100% via singlet fission. However, unwanted energy transfer between molecules often limited the benefits, reducing the number of useful charge carriers. This loss, known as Förster resonance energy transfer (FRET), occurs when energy moves between molecules without producing light. By matching energy levels, the researchers directed energy into triplet capture, minimizing losses and preserving more usable energy.
The experiments, done with tetracene molecules in liquid, allowed the team to closely observe energy movement. While a quantum yield above 100% sounds like free energy, it simply means more excitations per photon—not more total power.
Energy is still conserved, like breaking a large bill into smaller ones. In theory, this could reach 200% quantum yield, but real-world losses will keep actual devices lower. These results are just a proof of concept. The next step is making solid-state devices that last outdoors.
There are no 130% efficient panels yet, but this research shows that smarter light management could eventually make solar energy more effective and affordable.
