Scientists at the University of Cambridge have discovered a surprising new way to turn sunlight into electricity, and it could transform the way we design solar panels.
For the first time, they have seen a phenomenon—previously thought possible only in inorganic materials—happen in a glowing organic semiconductor molecule.
This opens the door to cheaper, lighter, and simpler solar cells made from just one type of material.
The breakthrough centers on a special molecule called P3TTM, which belongs to a class of organic semiconductors.
What makes P3TTM different is that it carries a single unpaired electron at its core.
This lone electron gives the molecule unusual electronic and magnetic properties.
Researchers had already been studying these molecules for their ability to glow brightly, making them useful in devices like organic LEDs.
But this new study revealed an unexpected ability: the molecules can also act like a type of material known as a Mott-Hubbard insulator, something usually seen only in complex inorganic crystals.
When P3TTM molecules are packed closely together, their unpaired electrons begin to interact. Instead of staying isolated, the electrons align with their neighbors in a repeating pattern—up, down, up, down.
When light shines on the molecules, one electron can hop from its home to a neighboring molecule, leaving behind a positive charge. Together, these moving charges can be collected as an electrical current.
The researchers built a solar cell using a thin film of P3TTM, and the results were remarkable. Almost every photon of light that entered the film was converted into an electrical charge.
This efficiency is striking because traditional organic solar cells require at least two different materials working together—one to give away electrons and the other to accept them. That design creates inefficiencies.
In contrast, the new material doesn’t need a partner. Each molecule can handle the process of generating charges on its own, making the design simpler and potentially much cheaper.
The team also found that they could adjust the way the molecules touch each other to fine-tune the effect. By carefully designing the molecular structure, they balanced the energy needed to move electrons around. This tuning is crucial for making the process efficient enough for real-world solar panels.
The discovery also carries a historical echo. Professor Sir Richard Friend, one of the leaders of the project, once worked with Sir Nevill Mott, the Nobel Prize–winning physicist who first explained how electrons behave in these kinds of systems. This year marks the 120th anniversary of Mott’s birth, making the discovery a fitting tribute to his legacy.
By showing that organic molecules can generate electricity by themselves, the researchers believe they are opening a new chapter in solar technology.
The future may see solar panels made from lightweight, flexible, and inexpensive materials, bringing clean energy within reach for more people around the world.
