South Korean researchers have developed a catalytic process that improves the durability of conventional perovskite solar cells, allowing them to retain 95% of their initial efficiency after 1,000 hours of exposure to extreme heat and humidity.
New perovskite solar cells capable of withstanding sauna-like conditions have emerged from South Korea. Researchers at the Korea Institute of Energy Research (KIER) have developed a catalytic process designed to address one of the main weaknesses of conventional perovskite technology: poor resistance to heat and humidity. The breakthrough could offer new commercial opportunities for solar cells based on the standard perovskite architecture. The results are significant: after undergoing a damp-heat test, the cells retained almost all their initial power conversion efficiency following 1,000 hours of exposure to extreme heat and humidity.
For now, the innovation remains confined to the laboratories of KIER’s photovoltaic research department, but it represents a considerable advance for the sector.
Since perovskites first appeared in energy research, they have achieved progress at a remarkable pace. Yet the prospect of bringing single-junction perovskite products to market still appears unlikely. Although the power conversion efficiency of these compounds has almost caught up with silicon, the Shockley-Queisser limit is now too close.
Today, expectations are largely focused on multijunction technology, particularly the combination of perovskite solar cells with silicon cells or other perovskite materials.
To understand how the new South Korean study could change the situation, however, it is necessary to examine the technology in greater detail.
Perovskite solar cells: standard versus inverted architectures
Two main architectures are used in the perovskite solar cell (PSC) sector, distinguished by the order in which their constituent layers are arranged: the standard (n-i-p) architecture, which was developed first, and the inverted (p-i-n) architecture.
When compared, conventional architectures exhibit a higher open-circuit voltage (Voc) and remain unmatched in terms of converting sunlight into electricity. Inverted architectures, on the other hand, offer significantly greater operational stability and are better suited to the textured silicon surfaces used in tandem configurations.
Leaving aside adhesion issues, the durability of conventional perovskite solar cells is a challenge that researchers at the Korea Institute of Energy Research may now have overcome. The team first identified the underlying problem before developing a solution.
During the manufacturing process for standard-architecture cells, lithium salts and additives are introduced into the hole transport layer to optimise charge transport efficiency.
The difficulty is that these additives tend to evaporate under real operating conditions, leaving gaps between the constituent layers that compromise the cells’ lifespan.
There is another problem. At high temperatures and humidity levels, lithium ions released from the salts diffuse uncontrollably through the cell, further reducing its durability.
Until now, researchers have faced a seemingly impossible compromise: maintaining high efficiency, for which lithium salts and additives are essential, while ensuring a longer operational lifespan.
This is precisely where KIER’s research comes into play.
How to improve the durability of perovskite solar cells
The scientists developed an innovative nickel oxide-based catalytic process followed by filtration. Lithium salts are used exclusively to initiate the necessary chemical reactions, after which the lithium ions and remaining salt are captured by the oxide.
The entire process eliminates the need for additives.
Taking advantage of the relatively large size of the nickel oxide particles, the researchers can then remove and dispose of the catalyst together with the lithium ions bound to it.
The results are notable. The team achieved a power conversion efficiency of 25.24%, exceeding the 25.21% obtained using conventional additive-based processes by 0.03 percentage points.
More importantly, the durability of the perovskite solar cells under high-temperature conditions (85°C) and high relative humidity (85% RH) proved excellent.
The cells retained 95% of their initial efficiency even after 1,000 hours of damp-heat testing.
According to the scientists, this breakthrough will be decisive in addressing the durability challenges of perovskite-based tandem solar cells, “paving the way for their commercialisation”.
The study, Redox-Active NiOx-Catalyzed Li+ Capture-Extraction Strategy for tBP-Free Spiro-OMeTAD Enables Exceptional Damp-Heat Stability in Perovskite Solar Cells, was published in Advanced Science (2026).
