Synergy of Low- and High-Polarity Cations for Stabilizing 2D Perovskites

Xiao H, Tang L, Yang Y, Deng C, Xu Z, Luo P, Li Z, Lei T, Yang L, Li H, Song Y, Liu S, Gao L, Zhan Y, Lin T, Zhou W, Zhang J, Forberich K, Brabec CJ, Zhao Y (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Advanced Materials Wiley

DOI: 10.1002/adma.75134

Abstract

Perovskite solar cells (PSCs) employing three-dimensional/two-dimensional (3D/2D) heterostructures achieve high efficiencies but suffer from limited operational stability. Combining high-throughput experiments with first-principles simulations, we unveil that 2D perovskites are intrinsically susceptible to thermal degradation due to the deprotonation of spacer cations and subsequent escape of hydrogen iodide. Through artificial intelligence analysis of 278 distinct perovskites, we identify the surface electrostatic properties and molecular polarity of spacer cations as the key descriptors governing thermal resilience. Finally, we discover a bi-cationic 2D perovskite that integrates low-polarity phenylethylammonium with high-polarity pentafluorophenylethylammonium (5FBA), synergistically resolving phase segregation and thermal degradation beyond what either cation can achieve alone. The bi-cationic 3D/2D perovskite film stack shows suppressed ion migration owing to the robust interaction between 5FBA and 3D perovskite. Consequently, the resulting PSCs retain over 92% of their initial efficiency after 1500 h of thermal aging at 85°C and over 90% after 2000 h of continuous operation under 1-Sun illumination.

Authors with CRIS profile

Christoph Brabec

Involved external institutions

Forschungszentrum Jülich / Research Centre Jülich (FZJ) DE Germany (DE) University of Electronic Science and Technology of China (UESTC) / 电子科技大学 CN China (CN) Hunan Institute of Science and Technology CN China (CN) Xi'an University of Architecture and Technology (XAUAT) / 西安建筑科技大学 CN China (CN) Beihang University, Beijing University of Aeronautics and Astronautics (BUAA) / 北京航空航天大学 CN China (CN) PLA Army Engineering University / 中国人民解放军陆军工程大学 CN China (CN)

How to cite

APA:

Xiao, H., Tang, L., Yang, Y., Deng, C., Xu, Z., Luo, P.,... Zhao, Y. (2026). Synergy of Low- and High-Polarity Cations for Stabilizing 2D Perovskites. Advanced Materials. https://doi.org/10.1002/adma.75134

MLA:

Xiao, Hongbin, et al. "Synergy of Low- and High-Polarity Cations for Stabilizing 2D Perovskites." Advanced Materials (2026).

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