South Korean researchers have developed a new catalytic process that improves the durability of conventional perovskite solar cells, maintaining 95% of their initial efficiency after 1,000 hours of extreme heat and humidity.
Perovskite solar cells pass the damp-heat test
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 that addresses one of the main weaknesses of conventional perovskite solar cell architecture: poor resistance to heat and humidity.
The breakthrough could open new commercial opportunities for conventional perovskite photovoltaics. The results are significant: during damp-heat testing, the cells retained almost all their initial power conversion efficiency after 1,000 hours of exposure to extreme heat and humidity.
For now, the innovation remains confined to KIER’s photovoltaic research laboratories. Nevertheless, it represents a major advance for the technology.
Since perovskites first emerged in energy research, their performance has improved at a remarkable pace. However, bringing single-junction perovskite solar cells to market remains a difficult prospect.
Although the power conversion efficiency of these materials has nearly matched that of silicon, they are approaching the theoretical Shockley-Queisser limit.
As a result, expectations are increasingly focused on multijunction technology, particularly tandem solar cells that combine perovskite with silicon or other perovskite materials.
To understand why the new South Korean research represents such an important development, it is necessary to examine the technology more closely.
Perovskite solar cells: standard versus inverted architecture
Perovskite solar cells (PSCs) are generally divided into two architectures, depending on the order in which their functional layers are arranged: standard (n-i-p), the original configuration, and inverted (p-i-n).
When compared, conventional architectures exhibit higher open-circuit voltage (Voc) and continue to lead in converting sunlight into electricity.
Inverted architectures, however, offer significantly greater operational stability. They are also better suited to the textured surface of silicon when used in tandem solar cells.
Beyond these compatibility challenges, the durability of conventional perovskite solar cells has remained a major obstacle. Researchers at the Korea Institute of Energy Research may now have found a solution by identifying the underlying problem and developing a way to address it.
During the manufacturing of standard perovskite solar cells, lithium salts and additives are introduced into the hole transport layer to improve charge transport efficiency.
However, under real operating conditions, these additives tend to evaporate, leaving gaps between the cell’s functional layers. These gaps compromise the cell’s lifespan.
The problem becomes more severe 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 difficult trade-off: maintaining high efficiency, which depends on lithium salts and additives, while extending the operational lifespan of the cells.
This is precisely the challenge addressed by the KIER research team.
How researchers improved perovskite solar cell durability
The scientists developed an innovative nickel oxide-based catalytic process, followed by a filtration step.
In this approach, lithium salts are used only to initiate the necessary chemical reactions. The lithium ions, together with the remaining salt, are then captured by nickel oxide, eliminating the need for additives.
Because nickel oxide particles are relatively large, the catalyst and the lithium ions bound to it can subsequently be filtered out and removed together.
The results were promising.
The researchers 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 cells demonstrated excellent durability under conditions of high temperature (85°C) and relative humidity (85%).
The devices retained 95% of their initial efficiency even after 1,000 hours of damp-heat testing.
According to the researchers, this breakthrough could play a decisive role 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).
