A semiconducting organic molecule discovered by a team at the University of Cambridge could completely transform the way we we capture sunlight. The finding promises lighter, more affordable solar panels made from a single component, thanks to near 100% efficiency in electricity generation.
Organic molecule behaves as a Mott-Hubbard insulator
The protagonist of the study is an organic radical called P3TTM. This molecule contains an unpaired electron, a feature that gives it unusual electronic behavior. When many of these molecules are arranged in a thin film, the electrons begin to align alternately between neighboring molecules, as in materials known as Mott-Hubbard insulators.
This phenomenon, more typical of complex inorganic systems, is manifested here in a purely organic structure. What is most relevant is that when light falls on this film, electrons jump between molecules generating positive and negative charges that can be collected to produce electric current, without the need for double layer structures.
A leap in efficiency for organic solar energy
Conversion efficiency measured in the laboratory is close to 100%, a radical improvement over conventional designs based on electron donors and acceptors. Instead of relying on two different materials, P3TTM allows a single component to absorb light and generate the charges needed to produce electricity.
This simplification can result in devices that are cheaper and easier to manufacture. In addition, the use of organic molecules opens the door to flexible, adaptable and lightweight.
Connection between quantum physics and energy sustainability
The discovery is not only a technical breakthrough, but also a tribute to the history of physics. Professor Sir Richard Friend, one of the authors of the study, began his career influenced by the ideas of physicist Sir Nevill Mott, whose theoretical work now manifests itself in this new type of material. In the 120th anniversary year of Mott’s birth, his legacy is given new life in green technologies.
This breakthrough was made possible by a collaboration between chemists and physicists from the Yusuf Hamied Department of Chemistry and the Cavendish Laboratory at the University of Cambridge, in a study published in the journal Nature with support from the European Research Council.
The future of photovoltaics with customized molecules
The possibility of tuning the behavior of these molecules by chemical synthesis opens up a new field for solar materials engineering. Structures such as P3TTM can be optimized to maximize their electronic interaction and their response to different wavelengths of light, which could lead to more versatile and higher-performing and higher-performance solar panels.
With such advances, solar energy based on organic molecules is no longer a distant promise but a real and competitive option in the global energy transition.
Source: University of Cambridge
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