For more than a decade, perovskite cells have been the great promise—and great frustration—of clean energy. In the laboratory they already compete with silicon, but they always failed in the same way: they degraded too quickly. Now, a discovery breaks with what is established. The solution has not come from a complex industrial machine, but from a molecule that octopuses and squid have been using for millions of years to protect themselves from chemical damage.
The sabotage that comes from within. According to the study published in Advanced Energy Materialsthe problem is not just air or humidity, but a chemical reaction that is activated within the device itself.
When sunlight hits the perovskite, highly energetic electrons are generated. These electrons can react with residual oxygen trapped during manufacturing—a process typically performed in air—to form superoxide radicals (O₂·⁻), extremely reactive chemical species. These radicals attack the organic cations that keep the perovskite crystalline structure stable, initiating its decomposition.
The entry point. The damage does not begin on the visible surface of the panel, but in a key region known as the buried interface, the point of contact between the perovskite and the tin dioxide (SnO₂) layer, responsible for extracting the electrons generated by light.
As emphasized Nanowerknot even the best external encapsulation can stop this process: oxygen is already present inside the device from the first moment. To further complicate the problem, tin dioxide itself contains oxygen-rich defects that, under illumination and heat, migrate into the perovskite and accelerate its degradation from within.
Taurine to the rescue. Faced with this scenario, the team of researchers from the Daegu Gyeongbuk Institute of Science and Technology and the Korea Institute of Science and Technology opted for an unusual route in photovoltaic development: seeking inspiration in biology.
The answer came in the form of an ultrathin layer of taurine, a sulfur amino acid present in octopuses, squid and other marine organisms. According to Interesting Engineeringin nature taurine protects cells from oxidative damage, just the same type of threat that was degrading perovskites. Located at the interface between tin dioxide and perovskite, the molecule functions as a smart chemical shield.
A defense cycle that does not end. The study details, based on density functional theory (DFT) calculations and laboratory experiments, a two-step protection mechanism that is especially relevant. First, taurine intercepts superoxide radicals as they form. Its chemical structure, called zwitterionic—with positive and negative charges in different parts of the molecule—allows it to electrostatically attract these radicals and convert them into hydrogen peroxide, a much less aggressive species for perovskite.
Secondly, the process addresses an additional problem: the molecular iodine generated during the degradation of the material. This iodine tends to form compounds that further accelerate the collapse of the structure. Taurine reduces that iodine back to iodide ions, chemically stable and much less harmful. Most notable, as Nanowerk points outis that after completing these reactions, taurine is regenerated. It is not consumed or degraded in the process, but rather returns to its original state, creating a closed radical neutralization cycle that can be repeated throughout the operational life of the device.
From theory to real power. The benefits are not limited to durability. The presence of taurine also improves the electrical functioning of the cell. By chemically binding to both tin dioxide and perovskite, it acts as a molecular bridge that reduces defects at the interface, those small sinks where electrons are lost as heat.
In practice, this translates into fewer electronic defects, nearly doubled electron mobility in the tin dioxide layer, and charges that survive longer. The best device achieved efficiency 24.8%, with 1.18 volts in open circuit and a high fill factor. Figures very close to current records, but with an important difference: it lasts much longer.
In stability tests, taurine-treated cells retained 97% of their efficiency after 450 hours of continuous operation at 65°C. Under real ambient conditions, they maintained 80% of their performance for more than 130 hours, more than five times longer than conventional cells subjected to the same tests.
The story has some scientific irony. While industry refined increasingly complex solutions, biology had already been solving the same problem for millions of years. If this strategy can be scaled and adapted to industrial manufacturing, the future of solar energy could depend as much on engineering as it does on biology. Sometimes, to move towards the Sun, it is enough to look at the bottom of the sea.
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