A research team led by Professor Park Nam-gyu of the Department of Chemical Engineering at Sungkyunkwan University said on the 2nd that it has developed a materials-control technology that can dramatically improve both the efficiency and long-term stability of perovskite solar cells.
The technology suppresses the formation of molecular dimers—responsible for performance degradation—in the electron transport layer, a core component of solar cells. As a result, it secured both an officially certified efficiency of 26.4% for a small-area cell and long-term stability exceeding 1,500 hours.
The team focused on the problem that the PCBM (phenyl-C61-butyric acid methyl ester) material, which is responsible for electron transport in conventional perovskite solar cells, undergoes "dimerization," clumping due to intermolecular bonding under high-temperature or light-stress conditions. This structural change lowers electron mobility and quickly degrades the efficiency of solar cells.
Accordingly, the team introduced a new molecule called 2,3,5,6-tetrafluoro-4-iodobenzoic acid (FIBA) to precisely control the packing of PCBM and developed a strategy to suppress molecular dimer formation. This substance induces the molecules to align vertically and form a stable stacked structure.
As a result, the team achieved an officially certified efficiency of 26.4% for a small-area device, 25.3% for a 1 ㎠ cell, and 21.3% for a large-area 30×30 ㎠ module (active area 764 ㎠). In a high-temperature light/voltage bias test at 85 degrees Celsius under International Summit on Organic and Hybrid Solar Cells Stability (ISOS-L2I) standard conditions, it also maintained 93% of the initial efficiency for more than 1,500 hours, demonstrating excellent long-term reliability.
Professor Park said, "This achievement is a breakthrough that can solve the stability issues hindering the commercialization of solar cells," adding, "In particular, by maintaining high efficiency even in large-area modules, it is expected to have very significant industrial impact."
Professor Park is a scholar who has been named a Highly Cited Researcher (HCR) for eight consecutive years since 2017, placing him in the top 1% globally. HCR is selected by the global scholarly information company Clarivate based on citation counts. He has received the Ho-Am Prize, the Korea Prime Minister's Award for Top Scientist and Engineer, and Italy's Eni Award, and was appointed a "Distinguished Chair Professor for Life," introduced by Sungkyunkwan University as the first in Korea to allow research without a mandatory retirement age.
This research was conducted jointly by Professor Park Nam-gyu's team at Sungkyunkwan University; the University of Science and Technology of China (USTC); Southern University of Science and Technology (SUSTech); Forschungszentrum Jülich in Germany; and the Hong Kong University of Science and Technology (Guangzhou). It was published online in the world-leading materials science journal "Nature Materials" on Sep. 30.
References
Nature Materials (2025), DOI: https://doi.org/10.1038/s41563-025-02368-7