- Chinese Academy of Sciences researchers used Prussian Blue nanoparticles to push perovskite solar cells to 26.9% efficiency, in a study published in Science.
- The same treatment dramatically improved durability: minimodules kept over 90% of output after 2,500 hours at 85°C and 85% humidity.
- A 30×30 cm submodule hit a certified 22.9%, and a five-month outdoor test showed no decline versus a commercial silicon reference.
Perovskite solar efficiency has a new milestone — and this time it comes with the durability data the technology has always lacked. Researchers from the Chinese Academy of Sciences (CAS) have used Prussian Blue nanoparticles as structural templates to control perovskite crystallization, reaching 26.9% power conversion efficiency in inverted cells while sharply improving stability, according to a study recently published in the journal Science.
pv magazine’s reporting details the advance: the Prussian Blue (PB) nanoparticles guided the crystallization of formamidinium lead iodide (FAPbI3) films, suppressing unwanted intermediate phases, favoring the photoactive α-phase, improving crystal alignment, and reducing lattice strain. Inverted (p-i-n) cells reached 26.9% efficiency — independently certified at 26.2% — up from 26.0% for untreated devices, while conventional (n-i-p) devices improved from 24.2% to 26.1%. pv magazine Australia confirmed the same results.
Perovskite solar efficiency is nice; stability is the real story
Perovskite solar cells have been breaking efficiency records for a decade — the technology already rivals silicon in the lab. What has held it back is durability: perovskites degrade under heat, humidity and light, suffering from defect formation and ion migration that erode performance. A record efficiency without stability is a curiosity, not a product.
That’s what makes the Prussian blue solar cell results genuinely significant. The nanoparticles increased the activation energy for ion migration from 0.89 eV to 1.25 eV — in plain terms, they made it much harder for the ions inside the material to wander out of place, which is a key degradation pathway. Conventional minimodules retained over 90% of their initial efficiency after 2,500 hours at 85°C and 85% relative humidity — brutal accelerated-aging conditions — and over 80% after 2,200 hours of continuous operation. Accelerated aging projects a T80 lifetime (the point where output falls to 80% of initial) of about seven years at 35°C, though the researchers note that figure is extrapolated, not demonstrated.
From lab cells to real modules
Another reason to take this result seriously: it scales. The team built a 30 cm × 30 cm inverted submodule with a 756 cm² aperture area that achieved a certified 22.9% efficiency — still excellent at that size, where perovskites typically lose performance. And in a five-month outdoor test in Zhuhai, China, the devices showed no discernible performance decline versus a commercial silicon reference device.
Outdoor testing is the credibility check the perovskite field has needed. Lab aging protocols can be gamed, intentionally or not; five months under real sun, rain and heat in subtropical China is much harder to dismiss. Corresponding author Chong Liu said the structurally compatible PB framework “guides perovskite crystallization, mediates the conversion of abnormal lead and iodine species, and restricts A-site cation redistribution” — the materials science behind the performance.
Where perovskites go from here
The broader context is a technology approaching an inflection point. Perovskite-silicon tandems — which stack a perovskite layer on conventional silicon — have already pushed past 30% in the lab, and manufacturers are racing to commercialize. The remaining barrier has always been the same: proving a perovskite device can survive 25 years on a rooftop or in a solar farm. Nobody is claiming this paper solves that — seven projected years is not twenty-five — but it attacks the problem at its root, in the crystal structure itself, rather than papering over it with better encapsulation.
There are still open questions. Lead content remains a concern for regulators and some markets, though encapsulation and recycling research is advancing in parallel. Manufacturing the nanoparticle treatment at scale, uniformly, and cheaply is unproven. And independent replication by other groups — the gold standard in materials science — will take months.
Why it matters for solar’s next decade
Step back from the lab and the stakes become clear. Silicon solar is a mature, extraordinary technology — but it is approaching its practical efficiency limits, and further cost reductions increasingly come from scale rather than science. Perovskites offer something silicon cannot: a fundamentally different material that can be processed at low temperatures, printed on flexible substrates, and stacked on top of silicon to harvest parts of the spectrum silicon misses.
That is why every major solar manufacturer and a flock of startups are invested in the technology’s success. The prize is a step-change in panel efficiency without a step-change in manufacturing cost — cheaper electricity from the same sunlight. Breakthroughs like the Prussian Blue treatment don’t deliver that prize by themselves, but each one that simultaneously lifts efficiency and durability shortens the road. The perovskite story has been “five years away” for a decade; results like this are how “five years away” eventually becomes “shipping.”
What’s next
Watch for two things: replication studies from other labs, and whether any manufacturer licenses the approach for pilot production. A perovskite solar cell record that arrives with harsh-environment stability data, certified submodule results, and outdoor testing is the strongest signal yet that the technology’s defining weakness — durability — is yielding to materials engineering. If the trajectory holds, the solar panels of the 2030s may owe their performance to a pigment first synthesized in 18th-century Berlin.
