• The mineral perovskite is cheaper and more efficient at absorbing light than silicon solar cells, but it has a bit of durability problem when exposed to heat and moisture.
• Scientists at the University of Surrey embedded alumina nanoparticles into perovskites to trap unwanted iodine compounds that tend to supercharge perovskites’ oxidation process.
• The team successfully increased the lifespan of perovskite tenfold, but still have a long way to go to match the average 25-year lifespan of silicon solar cells.

As the world is desperately trying to end its century-long relationship with fossil fuels, solar power is looking like the most attractive alternative. In 2023, the U.S. produced roughly 238,121 gigawatt-hours (GWh) of electricity from solar—eight times more than what was generated in 2014. While these are hopeful numbers, a few things are keeping solar power from kickstarting an energy revolution, chief among them being the industry’s reliance on non-renewable silicon.

Luckily, there are other alternatives to silicon, including perovskites, which are more readily available than silicon and more efficient at absorbing light. However, there’s one big problem: their lifespan can be measured in just a matter of days, which simply won’t work for most commercial applications. Although lead-tin perovskites still have a long way to go to achieve this durability dream, researchers at the University of Surrey in the U.K. have developed a method for extending their lifespan by a factor of ten. The key is using alumina (Al_₂O_₃) nanoparticles to trap unwanted iodine compounds that form during oxidation. The results of the study were published in the journal EES Solar.

“A decade ago, the idea of perovskite solar cells lasting this long under real-world conditions seemed out of reach,” Hashini Perera, lead author of the study and postgraduate researcher, said in a press statement. “With these improvements, we’re breaking new ground in stability and performance, bringing perovskite technology closer to becoming a mainstream energy solution.”

More and more, tin-based perovskites are preferred to lead due to the latter element’s toxicity. As a 2021 study from Imperial College London and the University of Bath explains, tin is also toxic, but it’s more likely to oxidize into insoluble products. That said, this creates new problems.

“This tendency to easily oxidise is a double-edged sword,” Luis Lanzetta, lead author of the 2021 paper detailing how iodine leakage impacts tin perovskites, told Chemistry World. “Stability is the main problem of tin-based perovskites, mostly due to the oxidation reactions that take place when the materials are exposed to air and moisture […] we discovered that this species further triggers the oxidation of tin(II) into tin(IV) salts, feeding a vicious cycle that keeps decomposing the perovskite.”

In addition to trapping the iodine compounds, these alumina nanoparticles helped form a more uniform structure while also forming a protective 2D layer, according to the researchers. When tested under levels of extreme heat and humidity (like those that’d be experienced outside the lab), the perovskites lasted two months, or roughly 1,530 hours—nearly a tenfold increase from the 160 hours endured by perovskites that weren’t enhanced with alumina.

“What we’ve achieved here is a critical step toward developing high-performance solar cells that can withstand real-world conditions—bringing us closer to their commercial use at a global scale,” Imalka Jayawardena, a co-author of the study from the University of Surrey, said in a press statement.

Of course, two months is still a far cry from the 25-year lifespan of a typical silicon solar cell, but it’s a compelling piece of evidence that perovskites can be engineered beyond their inherent limitations.

Darren Orf

Contributing Editor

Darren lives in Portland, has a cat, and writes/edits about sci-fi and how our world works. You can find his previous stuff at Gizmodo and Paste if you look hard enough.