by Riko Seibo
Tokyo, Japan (SPX) Jan 01, 2026
Researchers at the Hefei Institutes of Physical Science of the Chinese Academy of Sciences have engineered an optimized electron transport layer for inverted perovskite solar cells that raises both power conversion efficiency and operational stability. The work, led by Prof. Pan Xu at the Institute of Solid State Physics, focuses on controlling the behavior of the fullerene derivative PCBM at the perovskite interface.
Perovskite solar cells have now reached power conversion efficiencies close to 27 percent, placing them among the leading candidates for next generation photovoltaic technologies. The Hefei team had previously reported a method to homogenize cation distribution within the perovskite absorber, improving that layer’s performance. In parallel with absorber optimization, they note that semiconductive charge transport layers are essential for efficient charge separation and extraction in complete devices.
PCBM, or -phenyl-C61-butyric acid methyl ester, is widely used as an electron transport material in inverted perovskite architectures but tends to form dimers when exposed to heat and light. This dimerization reduces charge carrier mobility, lowers device efficiency, and accelerates performance degradation, which poses a barrier to practical deployment. To understand and mitigate this effect, the researchers examined how PCBM molecules stack on different perovskite surface terminations and identified molecular orientation heterogeneity as a major factor that promotes dimer formation.
Building on this analysis, the team designed a PCBM precursor additive, 2,3,5,6-tetrafluoro-4-iodobenzoic acid (FIBA), to tune the molecular packing at the interface. FIBA interacts with PCBM at the perovskite surface and guides the molecules into a more ordered stacking arrangement, which homogenizes their orientation. This alignment changes the local topology so that the configuration needed for the cycloaddition reaction that produces PCBM dimers is suppressed, thereby inhibiting dimer formation at the transport layer.
Molecular dynamics simulations helped clarify how the additive modifies PCBM stacking and orientation at the microscopic level, linking molecular-scale organization with changes in macroscopic device behavior. The researchers then incorporated the optimized PCBM layer into inverted perovskite solar cells and systematically evaluated photovoltaic performance across different device sizes.
Using this approach, the group reported a power conversion efficiency of 26.6 percent for small-area devices with an active area of about 0.1 square centimeters. Single-cell devices with an area of 1 square centimeter reached 25.3 percent efficiency, while large-area modules covering 762 square centimeters achieved 21.3 percent efficiency. These results indicate that the interfacial strategy can be applied from laboratory-scale cells to larger modules.
The modified transport layer also improved device stability under combined environmental stresses. Optimized cells retained more than 85 percent of their initial efficiency after 2,000 hours of continuous operation under concurrent heat, humidity, and light exposure. The authors conclude that guiding PCBM stacking and suppressing dimerization offers a practical route to simultaneously enhance efficiency and stability in inverted perovskite solar cells and may be applicable to other perovskite-based device structures.
Research Report:Suppression of PCBM dimer formation in inverted perovskite solar cells
Related Links
Hefei Institutes of Physical Science Chinese Academy of Sciences
All About Solar Energy at SolarDaily.com
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 – Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled “by Staff Writers” include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report’s information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.
