If you have ever looked at your electric bill and thought, “Solar should be doing more by now,” you are not alone. Even the best panels still leave a lot of sunlight on the table, not because engineers are lazy, but because physics has been setting the rules for decades.
A research team led by Kyushu University, working with collaborators at Johannes Gutenberg University Mainz, now says it has found a clever way to grab some of that wasted energy.
In a new peer-reviewed study, the researchers report a roughly 130 percent quantum yield using a molybdenum-based “spin flip” metal complex that selectively harvests extra energy created by a quantum process called singlet fission.
The 130% number
To clear up the headline math first, because this is where confusion usually starts: the reported “about 130%” figure is a quantum yield result in a molecular system, not a claim that a rooftop panel is suddenly producing 130% more electricity than the sunlight hitting it.
In practical terms, the team showed that the system can create and harvest more energy carriers than the number of photons absorbed. Kyushu University describes it as “roughly 1.3 molybdenum-based metal complexes” excited per photon absorbed when paired with tetracene based materials in solution.
That sounds like it breaks the laws of physics, but it does not. The trick is that one higher energy photon can be split into two lower energy excitations, so you can get more carriers without creating energy from nothing.
Why panels waste light
Solar cells work when light excites electrons in a semiconductor and those moving charges become electricity. The catch is that sunlight is a messy mix of photons, and not all of them line up neatly with what a given material can use. (kyushu-u.ac.jp)
Lower energy infrared photons often do not have enough energy to move electrons the right way, while higher energy photons can dump their extra energy as heat. That wasted heat is one reason panels get hot in the sticky summer weather we all know, and why real world output can sag even when the sun looks perfect.
This fundamental bottleneck is closely related to what is commonly referred to as the Shockley-Queisser limit for single junction solar cells. Kyushu University summarizes the impact in plain language, saying solar cells can use “only about one third of the sunlight,” which is a useful mental model even if the exact number depends on the device.
Singlet fission in plain English
The research leans on singlet fission, a phenomenon where one absorbed photon produces one “singlet” exciton, which can then split into two “triplet” excitons. An exciton is basically a paired electron and “hole” that carries energy through a material, and it can be turned into electrical current if you do it right.
The promise is straightforward. If a single photon can reliably generate two usable excitons, the usual one photon to one exciton ceiling starts to look less absolute.
The problem, for years, has been the “if you do it right” part. Generating the extra triplet excitons is not the whole game, because you still have to capture them before they disappear into loss mechanisms.
The molybdenum catcher
This is where the molybdenum-based “spin flip” emitter comes in. The Kyushu team says it needed an energy acceptor that selectively captures the multiplied triplet excitons after fission, because otherwise the energy can be “stolen” before the multiplication pays off.
They point to a major culprit called Förster resonance energy transfer, or FRET, which can redirect energy in ways that undermine the singlet fission pathway. “The energy can be easily ‘stolen’ by a mechanism called Förster resonance energy transfer (FRET) before multiplication occurs,” associate professor Yoichi Sasaki said, explaining why a selective acceptor was essential.
Metal complexes are attractive here because chemists can tune their energy levels and behavior more flexibly than many conventional semiconductors. In this case, the “spin flip” behavior helps the complex accept triplet energy and emit in the near infrared, which is part of how the team tracks and harvests what would otherwise be hard to use.
Where this fits today
This result lands in an industry that is already squeezing out gains through more familiar routes like better silicon architectures and tandem designs.
On the National Renewable Energy Laboratory’s best research cell efficiency chart, record crystalline silicon research cells are shown in the high 20% range, while perovskite silicon tandems are shown at 35%, and multijunction devices under concentration go much higher.
On the product side, efficiency is not just a lab bragging right. When a module produces more power per square foot, that can reduce balance of system costs like racking, wiring, and labor, which is why companies chase incremental improvements so aggressively.
A concrete example came in early 2025, when Trina Solar announced a record conversion efficiency for an n-type heterojunction solar module at 25.44%, certified by Fraunhofer CalLab. That kind of progress is already reshaping commercial competition, even before more exotic quantum approaches mature.
The tough part
For now, this “spin flip” result is still a proof of concept. The Kyushu University release explicitly notes that the current experiments are not yet a working solar cell, and the next goal is integrating the materials in the solid state and eventually into devices.
PV Magazine’s reporting on the work makes the same point, quoting researcher Nobuo Kimizuka on the need to integrate singlet fission materials with spin flip emitters in solid-state systems and then evaluate performance. In other words, the chemistry is promising, but the engineering work is still ahead.
This is the moment when investors and product teams should stay curious but cautious. Turning a solution-based demonstration into a stable, manufacturable layer that survives heat, moisture, and years of outdoor use is a very different kind of challenge.
What to watch next
So what would count as a real milestone from here? Look for evidence that the same selective triplet harvesting works in solid films, then look for a device level demonstration where the extra carriers translate into measurable electrical output without sacrificing voltage or stability.
Also watch who partners with whom. This is a cross border collaboration that started, in part, through academic exchange and shared materials knowledge, and those networks often determine how quickly an idea finds its way into pilot scale hardware.
One last point is worth keeping in mind when you see “over 100 percent” headlines. The big story is not a miracle panel, it is a potential new tool for designers trying to turn more of the sun into usable charges, one careful energy handoff at a time.
The study was published in Journal of the American Chemical Society.
