Key points: University of Cambridge researchers report that the organic semiconductor P3TTM can harvest light and produce extractable charges thanks to a single unpaired electron per molecule. Packed molecules show alternating spin alignment — a Mott–Hubbard signature previously seen mainly in inorganic oxides. In prototype tests a P3TTM film converted nearly all absorbed photons into electricity. If scalable and durable, single-material panels could be lighter, cheaper and help expand distributed clean energy.
Cambridge team discovers organic molecule P3TTM that could reshape solar panels: “This is the real magic”
Key points: University of Cambridge researchers report that the organic semiconductor P3TTM can harvest light and produce extractable charges thanks to a single unpaired electron per molecule. Packed molecules show alternating spin alignment — a Mott–Hubbard signature previously seen mainly in inorganic oxides. In prototype tests a P3TTM film converted nearly all absorbed photons into electricity. If scalable and durable, single-material panels could be lighter, cheaper and help expand distributed clean energy.
13:35, 03.11.2025Science
Cambridge researchers find organic semiconductor that generates extractable charges
Researchers at the University of Cambridge announced on October 1 that an organic semiconductor called P3TTM can absorb light and generate extractable electrical charges — a behaviour previously thought to be confined to inorganic materials such as metal oxides. The team says this finding “bridges a century of physics” because it reveals a mechanism for light harvesting in a simple organic material.
Measurements show that each P3TTM molecule hosts a single unpaired electron. When many P3TTM units pack closely, those unpaired electrons adopt an alternating up-and-down alignment (an antiferromagnetic arrangement). That pattern is a hallmark of Mott–Hubbard behaviour, a condensed-matter phenomenon largely associated with complex inorganic oxides until now.
“This is the real magic. Upon absorbing light, one of these electrons hops onto its nearest neighbor, creating positive and negative charges which can be extracted to give a photocurrent (electricity),” said lead researcher Biwen Li.
To probe practical potential, the researchers made a film of P3TTM and incorporated it into a simple prototype solar cell. In their experiments the device converted an exceptionally large fraction of absorbed photons into electrical current — the authors report that, in their tests, nearly every absorbed photon produced an extractable charge.
If this behaviour can be reproduced at scale and in durable devices, P3TTM or similar single-material systems could enable solar modules that are lighter and potentially cheaper than today's multi-layer cells. Lighter, lower-cost panels would reduce barriers to distributed rooftop and community solar installations and could accelerate clean-energy adoption, helping reduce emissions and associated health impacts in polluted areas.
The team cautions that further work is needed to demonstrate stability, manufacturability and long-term performance under real-world conditions. Scaling laboratory results into commercially viable modules typically requires solving challenges related to material processing, device architecture and environmental durability.
“We are not just improving old designs. We are writing a new chapter in the textbook, showing that organic materials are able to generate charges all by themselves,” said study co-author Professor Hugo Bronstein in the university press release.
While the discovery is promising, the timeline to market remains uncertain. The next steps will include refining device fabrication, testing longevity and exploring how P3TTM performs under sunlight, heat and humidity. If those hurdles can be overcome, organic single-material solar devices could become a practical complement to existing technologies.