Nanoparticle breakthrough could bring 'holy grail' of solar power within reach

Scientists have made a cheap and flexible solar cell that lasts nearly 10 times longer than others of its type, an advance that could one day help to revolutionize solar energy production.

Often referred to as the "holy grail" of solar power, perovskite cells offer a lightweight alternative to traditional silicon-based solar technology. Their flexible structure enables them to be applied to cars and phones in the form of a printable layer so they can charge on the go.

Sounds too good to be true? So far, you're right. Perovskites come with some major flaws. Notably, they degrade quickly due to chemical reactions with moisture in the air that make them leak iodine.

But now, a team of researchers has found a solution to this problem. By embedding nanoparticles within the perovskites, they produced a new cell that lasts for 1,530 hours, a near-tenfold increase on previous perovskite solar cell designs. The researchers published their findings Feb. 20 in the journal EES Solar.

"By addressing these common challenges we see with perovskite solar technology, our research blows the doors wide open for cheaper, more efficient and more widely accessible solar power," study co-author Imalka Jayawardena, an engineering researcher at the University of Surrey's Advanced Technology Institute in the U.K., said in a statement. "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."

Solar power surge

As the fastest-growing and cheapest form of renewable energy, solar power is key to cutting greenhouse gas emissions. But the technology's growth is hampered by its reliance on silicon, a finite and non-renewable resource that, in its purest form, is costly to produce.

To get around this bottleneck, scientists have looked to develop perovskite alternatives — synthetic versions of naturally occurring calcium titanium oxide crystals that can be made at a fraction of the cost. But unlike pure silicon cells, which can last for decades, solar cells made from perovskite only last for 100 or so hours, drastically limiting their utility.

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In the new study, the scientists looked for a way to trap the iodine that leaks from perovskites. Their solution was to embed tiny nanoparticles of aluminum oxide within the cells as they were manufactured. This not only prevented the iodine from leaking but also created a more uniform and electrically conductive structure.

After testing these cells under extreme heat and humidity, the researchers found that the modified cells maintained a high performance for more than two months (1,530 hours), a significant improvement on the 160-hour lifespan of unenhanced perovskite cells.

The researchers plan to continue investigating their new technique to see if these gains can be built upon further.

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