At a time when renewable energy is beginning to gain a lot of strength, achieving solar panels light, efficient and cheap It is undoubtedly the “Holy Grail” of current scientific research. Now some researchers from the University of Cambridge They just unlocked a quantum secret buried for more than a centurywith results capable of completely transforming how we capture and convert sunlight into electricity.
Unexpected. The advance arises from a observed quantum phenomenon in an organic material called P3TTM, a spin radical moleculethat is, it has a solitary and unpaired electron from the rest, which we can say is “antisocial.” This material is typically used in organic light-emitting technologies (such as LEDs) for its intense luminosity and chemical stability.
What is surprising in this case is that when many of these molecules are grouped together in a thin film, their unpaired electrons interact with each other in a very particular way. And instead of ignoring each other, they align in an alternating pattern (up-down), a quantum behavior known as that of a Mott-Hubbard insulatorsomething that until now was mainly associated with inorganic metal oxides.
Biwen Li, the principal investigator of the Cavendish Laboratory, describes it as “true magic.” Upon absorbing light, one of these electrons jumps to a neighboring molecule, instantly creating a positive and a negative charge. Those separate charges are, in essence, electricity ready to be harvested.
The revolution. Most of today’s organic solar panels work like a sandwich. They need two different materials: one that “gives” electrons when light hits it and another that “accepts” them. This union, or heterojunction, is essential, but it is also a source of inefficiency since it greatly complicates the manufacturing of the equipment.
The Cambridge discovery changes everything. The P3TTM performs the entire process itself. He doesn’t need a partner. Charge separation occurs between identical molecules, a process called “homojunction,” which opens the door to that efficiency that was the goal of much energy research.
How it works. If we look at the technical part, we can know that P3TTM films are manufactured using thermal evaporation techniques and are encapsulated for protection. Timed spectroscopic analyzes show two emitters: one at 645 nm due to the exciton of the radical, and another with late emission and red shifted (~800 nm), attributed to the recombination of separated charge pairs after the charge transfer process.
The collection efficiency under reverse polarization reaches 100%, indicating that practically every photon is converted into an electron usable to generate current, something never before achieved in organics.
The test. To test it, the team built a solar cell with a thin layer of P3TTM and, by illuminating it, achieved a charge collection efficiency close to 100%. This means that almost every photon of light that hit the material was converted into useful electrical current.
The story. The theory on which this discovery is based, which is the Mott-Hubbard theory of insulators, was developed by Sir Nevill Mott, a giant of condensed matter physics. Now this Cambridge work is published just on the 120th anniversary of Mott’s birth, paying tribute to the legacy of the man who laid the foundations for understanding the electronic phenomena in semiconductors that we will now be able to use.
The future. This is not just a small advance. It’s a paradigm shift. “We are not simply improving old designs,” says Professor Bronstein. “We are writing a new chapter in textbooks, demonstrating that organic materials can generate charges on their own,” he points out.
The implications we will see now could be enormous. We could be witnessing the birth of a new generation of solar technology: panels made of a single, low-cost, light and flexible material that could be integrated into any surface, from windows to clothing. There is still a way to go to reach a commercial product, but the quantum secret that they have revealed in Cambridge has just illuminated a much brighter and simpler energy future.
Images | American Public Power Dynamic Wang
GIPHY App Key not set. Please check settings