Aromatic-Substituted Carbazole Monolayers: Self-Assembly Optimization for Efficient Inverted Perovskite Solar Cells

Abstract

Self-assembled monolayers (SAMs) offer transformative potential as hole-transporting layers (HTLs) in inverted perovskite solar cells (IPSCs) through lossless contact engineering and suppressed interfacial recombination. To address persistent challenges of molecular aggregation, inadequate wettability, and limited durability, we pioneered a groundbreaking fluorine-substituted aromatic carbazole-based SAM molecule: (3-(3,6-bis(3-fluoro-4-methoxy-phenyl)-9H-carbazol-9-yl)-propyl)phosphonic acid (F-MeO-3PABCz). This design achieves three breakthroughs: (1) defect passivation via optimized perovskite crystallization and energy-level alignment, eliminating nonradiative recombination at the buried interface; (2) enhanced hole extraction/transport through directed molecular assembly; and (3) superior stability via fluorine-induced hydrophobicity and aggregation resistance. The result is an impressive-breaking champion power conversion efficiency (PCE) of 26.21% (certified 25.76%), surpassing commercial 4PACz-based devices (24.37%) by a significant margin. Accelerated aging tests confirm F-MeO-3PABCz's exceptional operational longevity, outperforming conventional HTLs under thermal and humidity stress. This work establishes a paradigm for SAM engineering by integrating fluorine substitution, aromatic rigidity, and phosphonic acid anchoring, paving the way for next-generation high-efficiency IPSCs with industrial-grade durability.

Keywords

inverted perovskite solar cells / self-assembled monolayers / suppressed aggregation

References

[1] C. Li, Y. Li, Y. Chen, et al., “Enhancing Efficiency of Industrially-Compatible Monolithic Perovskite/Silicon Tandem Solar Cells With Dually-Mixed Self-Assembled Monolayers,” Advanced Functional Materials 34 (2024): 2407805.

[2] S. Cao, S. Luo, T. Zheng, et al., “Hybrid Self-Assembled Molecular Interlayers for Efficient and Stable Inverted Perovskite Solar Cells,” Advanced Energy Materials 15 (2025): 2405367.

[3] Y. Duan, Y. Chen, Y. Wu, Z. Liu, S. Liu, and Q. Peng, “A Comprehensive Review of Organic Hole-Transporting Materials for Highly Efficient and Stable Inverted Perovskite Solar Cells,” Advanced Functional Materials 34 (2024): 2315604.

[4] Z. Li, X. Sun, X. Zheng, et al., “Stabilized Hole-Selective Layer for High-Performance Inverted p-i-n Perovskite Solar Cells,” Science 382 (2023): 284-289.

[5] Z. Xiong, Q. Zhang, K. Cai, et al., “Homogenized Chlorine Distribution for >27% Power Conversion Efficiency in Perovskite Solar Cells,” Science 390 (2025): 638-642.

[6] Z. Lin, Y. Wu, and X. Ouyang, “Modulated π-Bridge of Thioxothiazolidine Derivatives for Passivating Bilateral Interfaces and Grain Boundaries in n-i-p Perovskite Solar Cells,” Angewandte Chemie International Edition 64 (2025): e202424472.

[7] W. Shockley and H. J. Queisser, “Detailed Balance Limit of Efficiency of p-n Junction Solar Cells,” Journal of Applied Physics 32 (1961): 510-519.

[8] X. Zheng, Z. Li, Y. Zhang, et al., “Co-Deposition of Hole-Selective Contact and Absorber for Improving the Processability of Perovskite Solar Cells,” Nature Energy 8 (2023): 462-472.

[9] W. Wang, X. Liu, J. Wang, et al., “Versatile Self-Assembled Molecule Enables High-Efficiency Wide-Bandgap Perovskite Solar Cells and Organic Solar Cells,” Advanced Energy Materials 13 (2023): 2300694.

[10] H. Chen, A. Maxwell, C. Li, et al., “Regulating Surface Potential Maximizes Voltage in All-Perovskite Tandems,” Nature 613 (2023): 676-681.

[11] H.-L. Yip, S. K. Hau, N. S. Baek, H. Ma, and A. K.-Y. Jen, “Polymer Solar Cells That Use Self-Assembled-Monolayer-Modified ZnO/Metals as Cathodes,” Advanced Materials 20 (2008): 2376-2382.

[12] C. Li, Y. Chen, Y. Li, et al., “Achieving 32% Efficiency in Perovskite/Silicon Tandem Solar Cells With Bidentate-Anchored Superwetting Self-Assembled Molecular Layers,” Angewandte Chemie International Edition 64 (2025): e202502730.

[13] S. M. Park, M. Wei, N. Lempesis, et al., “Low-Loss Contacts on Textured Substrates for Inverted Perovskite Solar Cells,” Nature 624 (2023): 289-294.

[14] C. Li, Z. Zhang, H. Zhang, et al., “Fully Aromatic Self-Assembled Hole-Selective Layer Toward Efficient Inverted Wide-Bandgap Perovskite Solar Cells With Ultraviolet Resistance,” Angewandte Chemie International Edition 63 (2024): e202315281.

[15] M. Azam, T. Du, Z. Wan, et al., “Dual Functionality of Charge Extraction and Interface Passivation by Self-Assembled Monolayers in Perovskite Solar Cells,” Energy & Environmental Science 17 (2024): 6974-7016.

[16] H. Zhang, S. Zhang, X. Ji, et al., “Formamidinium Lead Iodide-Based Inverted Perovskite Solar Cells With Efficiency Over 25% Enabled by an Amphiphilic Molecular Hole-Transporter,” Angewandte Chemie International Edition 63 (2024): e202401260.

[17] A. Ullah, K. H. Park, H. D. Nguyen, et al., “Novel Phenothiazine-Based Self-Assembled Monolayer as a Hole Selective Contact for Highly Efficient and Stable p-i-n Perovskite Solar Cells,” Advanced Energy Materials 12 (2022): 2103175.

[18] Z. Yi, X. Li, Y. Xiong, et al., “Self-Assembled Monolayers (SAMs) in Inverted Perovskite Solar Cells and Their Tandem Photovoltaics Application,” Interdisciplinary Materials 3 (2024): 203-244.

[19] Y. Yang, H. Chen, C. Liu, et al., “Amidination of Ligands for Chemical and Field-Effect Passivation Stabilizes Perovskite Solar Cells,” Science 386 (2024): 898-902.

[20] S. Liu, J. Li, W. Xiao, et al., “Buried Interface Molecular Hybrid for Inverted Perovskite Solar Cells,” Nature 632 (2024): 536-542.

[21] X. Zhang, Y. Wang, K. Zhang, et al., “Reinforcing Coverage of Self-Assembled Monomolecular Layers for Inverted Perovskite Solar Cells With Efficiency of 25.70%,” Angewandte Chemie International Edition 64 (2025): e202423827.

[22] Z. Lin, J. Lin, Z. Zhu, et al., “Triad of Passivation Strategies for the Fabrication of Perovskite Solar Cells With Mitigated Defects and Enhanced Efficiency,” Advanced Functional Materials 35 (2025): 2502170.

[23] J. Zhou, Y. Luo, R. Li, et al., “Molecular Contacts With an Orthogonal π-Skeleton Induce Amorphization to Enhance Perovskite Solar Cell Performance,” Nature Chemistry 17 (2025): 564-570.

[24] G. Qu, S. Cai, Y. Qiao, et al., “Conjugated Linker-Boosted Self-Assembled Monolayer Molecule for Inverted Perovskite Solar Cells,” Joule 8 (2024): 2123-2134.

[25] C. Li, Y. Chen, Y. Li, et al., “Deciphering the Impact of Aromatic Linkers in Self-Assembled Monolayers on the Performance of Monolithic Perovskite/Si Tandem Photovoltaic,” Angewandte Chemie International Edition 64 (2025): e202420585.

[26] S. Gao, R. Peng, Y. Qiu, et al., “Conjugated Group Tuning of Self-Assembled Monolayer for Efficient Hole-Transport Layer in Organic Solar Cells,” Advanced Functional Materials 35 (2025): 2418223.

[27] G. Qu, L. Zhang, Y. Qiao, et al., “Self-Assembled Materials With an Ordered Hydrophilic Bilayer for High Performance Inverted Perovskite Solar Cells,” Nature Communications 16 (2025): 86.

[28] G. Wang, J. Zheng, W. Duan, et al., “Molecular Engineering of Hole-Selective Layer for High Band Gap Perovskites for Highly Efficient and Stable Perovskite-Silicon Tandem Solar Cells,” Joule 7 (2023): 2583-2594.

[29] H. Bi, J. Liu, Z. Zhang, et al., “All-Perovskite Tandem Solar Cells Approach 26.5% Efficiency by Employing Wide Bandgap Lead Perovskite Solar Cells With New Monomolecular Hole Transport Layer,” ACS Energy Letters 8 (2023): 3852-3859.

[30] C. Guo, H.-Q. Du, Y.-C. Wang, et al., “Bifacially Reinforced Self-Assembled Monolayer Interfaces for Minimized Recombination Loss and Enhanced Stability in Perovskite/Silicon Tandem Solar Cells,” Advanced Materials 37 (2025): 2504520.

[31] D. W. Bruce, “Employing Fluorine for Supramolecular Control in Self-Assembled and Self-Organised Molecular Systems,” Chemical Science 16 (2025): 22213-22230.

[32] Z. Chen, X. Li, S. Qin, et al., “Asymmetric Self-Assembled Monolayer as Hole Transport Layer Enables Binary Organic Solar Cells Based on PM6: Y6 With Over 19% Efficiency,” CCS Chemistry 7 (2025): 507-518.

[33] Z. Min, C. Guo, J. Guo, et al., “Homogeneously Contacted Co-Self-Assembled Monolayer Enables Over 26% Inverted Perovskite Solar Cells,” Advanced Functional Materials 36 (2026): e28728.

[34] Y. Chen, J. Chen, X. Wang, P. Deng, Y. Shen, and X. Wang, “Fluorinated Graphene Quantum Dots-Induced Defect Passivation of Perovskite Film Toward Stable and Efficient Perovskite Solar Cell,” International Journal of Hydrogen Energy 137 (2025): 107-113.

[35] C.-H. Chen, G.-W. Liu, X. Chen, et al., “Methylthio Substituent in SAM Constructing Regulatory Bridge With Photovoltaic Perovskites,” Angewandte Chemie International Edition 64 (2025): e202419375.

[36] I. Wenzl, C. Yam, and T. Lee, “Structure and Wettability of Methoxy-Terminated Self-Assembled Monolayers on Gold,” Langmuir 19 (2003): 10217-10224.

[37] Z. Chen, X. Li, S. Qin, et al., “Asymmetric Self-Assembled Monolayer as Hole Transport Layer Enables Binary Organic Solar Cells Based on PM6: Y6 With Over 19% Efficiency,” CCS Chemistry 7 (2025): 507-518.

[38] I. Ali, M. F. U. Din, D. T. Cuzzupè, et al., “Ti₃C₂T_x-Modified PEDOT:PSS Hole-Transport Layer for Inverted Perovskite Solar Cells,” Molecules 27 (2022): 7452.

[39] Z. Nie, W. Meng, S. Peng, et al., “Molecular Hybrid Bridging for Efficient and Stable Inverted Perovskite Solar Cells Without a Pre-Deposited Hole Transporting Layer,” Advanced Materials 37 (2025): e10685.

[40] T. Geng, J. Ding, Z. Zhang, et al., “Rationally Tailored Passivation Molecules to Minimize Interfacial Energy Loss for Efficient Perovskite Solar Cells,” Moore and More 2 (2025): 9.

[41] Y. Xing, Z. Li, Y. Li, et al., “Simultaneous Interfacial Defect Passivation and Free-Volume Reduction by Fluorinated Hole Transport Materials for High-Performance Perovskite Solar Cells,” Advanced Materials 38 (2026): e13884.

[42] X. Deng, F. Qi, F. Li, et al., “Co-Assembled Monolayers as Hole-Selective Contact for High-Performance Inverted Perovskite Solar Cells With Optimized Recombination Loss and Long-Term Stability,” Angewandte Chemie International Edition 61 (2022): e202203088.

[43] S. Zhang, R. Wu, C. Mu, et al., “Conjugated Self-Assembled Monolayer as Stable Hole-Selective Contact for Inverted Perovskite Solar Cells,” ACS Energy Letters 4 (2022): 1976-1983.

[44] H. Liu, Y. Xin, Z. Suo, et al., “Dipole Moments Regulation of Biphosphonic Acid Molecules for Self-Assembled Monolayers Boosts the Efficiency of Organic Solar Cells Exceeding 19.7%,” Journal of the American Chemical Society 146 (2024): 14287-14296.

[45] M. A. Truong, T. Funasaki, L. Ueberricke, et al., “Tripodal Triazatruxene Derivative as a Face-On Oriented Hole-Collecting Monolayer for Efficient and Stable Inverted Perovskite Solar Cells,” Journal of the American Chemical Society 145 (2023): 7528-7539.

[46] Z. Wei, Q. Zhou, X. Niu, et al., “Surpassing 90% Shockley-Queisser VOC Limit in 1.79 eV Wide-Bandgap Perovskite Solar Cells Using Bromine-Substituted Self-Assembled Monolayers,” Energy & Environmental Science 18 (2025): 1847-1855.

[47] C. Luo, Q. Zhou, K. Wang, et al., “Engineering Bonding Sites Enables Uniform and Robust Self-Assembled Monolayer for Stable Perovskite Solar Cells,” Nature Materials 24 (2025): 1265-1272.

[48] X. Sun, H. Fan, X. Xu, et al., “A Fluorination Strategy and Low-Acidity Anchoring Group in Self-Assembled Molecules for Efficient and Stable Inverted Perovskite Solar Cells,” Chemistry - A European Journal 30 (2024): e202400629.

[49] W. Yu, S. Ahmad, H. Zhang, et al., “Multiple Methoxy-Substituted Hole Transporter for Inverted Perovskite Solar Cells,” Journal of Energy Chemistry 56 (2021): 127-131.

[50] B. He, T. Liu, C. Wang, et al., “Improving Crystallinity and Out-Of-Plane Orientation in Quasi-2D Ruddlesden-Popper Perovskite by Fluorinated Organic Salt for Light-Emitting Diodes,” Small 19 (2023): 2303255.

[51] L. M. Svirskaite, E. Kasparavičius, M. Steponaitis, et al., “Fluorene- and Fluorenone-Based Molecules as Electron-Transporting SAMs for Photovoltaic Devices,” RSC Advances 14 (2024): 14973-14981.

[52] L. Jia, S. Xia, J. Li, et al., “Efficient Perovskite/Silicon Tandem With Asymmetric Self-Assembly Molecule,” Nature 644 (2025): 912-919.

[53] B. Jiao, L. Tan, Y. Ye, et al., “One-Stone-Two-Birds: Over 26% Efficiency in Perovskite Solar Cells via Synergistic Crystallization & Interface Regulation,” Energy & Environmental Science 18 (2025): 5437-5447.

[54] Y. Feng, Y. Wang, H. Yang, et al., “Homogenized Self-Assembled Molecules for Inverted Perovskite Solar Cells,” Angewandte Chemie International Edition 64 (2025): e202505876.

[55] W. Wang, H. Liang, Y. Ding, et al., “Super -Hydrophilic SAMs via Chlorine Substituted All-Hydrophilic Molecule Modification for Monolithic Perovskite-Silicon Tandem Solar Cells,” Advanced Energy Materials 15 (2025): e02222.

[56] T. Zhao, R. He, T. Liu, et al., “Mitigating the Efficiency Deficit in Single-Crystal Perovskite Solar Cells by Precise Control of the Growth Processes,” ACS Nano 19 (2025): 3282-3292.

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2026 The Author(s). Aggregate published by SCUT, AIEI, and John Wiley & Sons Australia, Ltd.