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Updated: Jun 13, 2025
Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells
Published on: March 19, 2017
Cation and Octahedral Synergistic Regulation for Stable FAPbI3 Perovskite Solar Cells
Guangcai Hu1, Ziyue Zhao2, Yang Shen2
1State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, and Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, Zhejiang, 310027, P. R. China.
Abstract:
Formamidinium lead iodide (FAPbI3) perovskite, one of the most promising light-absorbing materials, faces substantial stability issues, including FA+ organic component volatilization and undesirable phase transition between corner-sharing and face-sharing [PbI6]4 ̶ octahedra. Especially, the asymmetric hydrogen bonding, arising from oriented and irregularly spinning FA+ cation, accelerates these transformations, compromising both the efficiency and long-term stability of FAPbI3 PSCs. Herein, a robust strategy is reported to stabilize FAPbI3 perovskite by using tricyclohexylphosphine trifluoromethanesulfonate (Cy3PH+SO3CF3 -) to strengthen hydrogen bonds within FA+ and alleviate octahedral deformation. The hydrogen-bonding capacity of Cy3PH+ effectively constrains and stabilizes orientated FA+ through strong hydrogen bonds (F─H, N─H), while the strong electronegative SO3CF3 - ion modifies [PbI6]4 - octahedral deformation by diversified covalent bonds (Pb─F, Pb─O) and releases the internal stress of the lattice. As such, the resulting FAPbI3 demonstrates mitigated organic volatilization and suppressed phase transition, significantly enhancing phase stability under thermal/humidity stress conditions. Moreover, because of co-regulated FA+ cation and octahedral lattice, FAPbI3 perovskite exhibits improved carrier dynamics and better matched energy-level alignment with carrier transport layers. The optimized FAPbI3-based PSCs deliver an impressive efficiency of 25.93% and exhibit exceptional stability, retaining 97% of initial efficiency after over 1500 h maximum power point tracking.
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