Synergetic defect passivation of high-quality 1.83 eV perovskite for efficient flexible perovskite/organic tandem photovoltaics

Abstract

Light-weight, flexible perovskite/organic tandem solar cells (TSCs) hold great potential for applications in wearable electronics, agricultural photovoltaics, building-integrated photovoltaics, car-integrated photovoltaics, and other emerging applications. However, matching current densities of near-infrared organic absorbers typically requires wide-bandgap (WBG, >1.80 eV) perovskites, which suffer from complex compositions, uncontrolled defect formation, and severe nonradiative recombination. Herein, we propose a rationally designed synergistic ionic additive, (R)-(+)-tetrahydro-3-furylamine p-toluenesulfonate salt, where both the cation and anion are engineered to deliver complementary defect passivation effects. Specifically, the p-toluenesulfonate anion and the (R)-(+)-tetrahydro-3-furylamine cation can form electrostatic interactions with various defects, while their functional groups can further enhance the passivation effect by strong interactions. The corresponding characterizations further reveal that this synergistic defect modulation strategy enables comprehensive defect passivation, residual stress relaxation, and mechanical robustness enhancement in WBG perovskite films. As a result, our WBG perovskite solar cells and perovskite/organic TSCs on flexible substrates achieve power conversion efficiencies of 18.13% and 22.44%, respectively, along with excellent mechanical bending stability.

Keywords

mechanical bending stability / perovskite/organic tandem solar cells / synergistic defect passivation / wide-bandgap perovskite

References

[1] Brinkmann KO, Wang P, Lang F, et al. Perovskite–organic tandem solar cells. Nat Rev Mater. 2024; 9(3): 202-217.

[2] Yi Z, Li X, Xiong Y, et al. Self-assembled monolayers (SAMs) in inverted perovskite solar cells and their tandem photovoltaics application. Interdiscip Mater. 2024; 3(2): 203-244.

[3] Xie G, Li H, Qiu L. Recent advances on monolithic perovskite–organic tandem solar cells. Interdiscip Mater. 2024; 3(1):e12142.

[4] Cui X, Xie G, Liu Y, et al. Boosting the efficiency of perovskite/organic tandem solar cells via enhanced near-infrared absorption and minimized energy losses. Adv Mater. 2024; 36(45):2408646.

[5] Wang Y, Wang Y, Gao F, Yang D. Efficient monolithic perovskite/silicon tandem photovoltaics. Energy Environ Mater. 2024; 7(3):e12639.

[6] Brinkmann KO, Becker T, Zimmermann F, et al. Perovskite–organic tandem solar cells with indium oxide interconnect. Nature. 2022; 604(7905): 280-286.

[7] Jost M, Kegelmann L, Korte L, Albrecht S. Monolithic perovskite tandem solar cells: a review of the present status and advanced characterization methods toward 30% efficiency. Adv Energy Mater. 2020; 10(26):1904102.

[8] Cao S, Luo S, Zheng T, et al. Hybrid self-assembled molecular interlayers for efficient and stable inverted perovskite solar cells. Adv Energy Mater. 2025; 15(23):2405367.

[9] Kim K, Moon T, Kim J. Wide bandgap perovskites: a comprehensive review of recent developments and innovations. Small. 2025; 21(19):2407007.

[10] Nie T, Fang ZM, Ren XD, Duan YW, Liu SZ. Recent advances in wide-bandgap organic–inorganic halide perovskite solar cells and tandem application. Nano Micro Lett. 2023; 15(1):70.

[11] Tao L, Qiu J, Sun B, et al. Stability of mixed-halide wide bandgap perovskite solar cells: strategies and progress. J Energy Chem. 2021; 61: 395-415.

[12] Chen B, Wang J, Ren N, et al. Conductive passivating contact for high fill factor monolithic perovskite/silicon tandem solar cells. Interdiscip Mater. 2023; 2(6): 855-865.

[13] Guo YX, Tan HR, Xu B. Deciphering halide ion migration and performance loss in wide-bandgap perovskite solar cells: connection, mechanism, and solutions. Energ Environ Sci. 2025; 18(19): 8744-8755.

[14] Mei JJ, Yan F. Recent advances in wide-bandgap perovskite solar cells. Adv Mater. 2025; 37(48):2418622.

[15] Wang C, Shao WL, Liang JW, et al. Suppressing phase segregation in wide bandgap perovskites for monolithic perovskite/organic tandem solar cells with reduced voltage loss. Small. 2022; 18(49):2204081.

[16] Guo X, Jia Z, Liu S, et al. Stabilizing efficient wide-bandgap perovskite in perovskite–organic tandem solar cells. Joule. 2024; 8(9): 2554-2569.

[17] Li X-Y, Wu Z, Yao Q, et al. Buried interface modification toward efficient CsPbI_2.2Br_0.8 based monolithic perovskite/organic tandem solar cells. Small. 2025; 21(3):2406824.

[18] Xie G, Li H, Fang J, et al. Crystallization thermodynamics regulation of 1.85 eV wide-bandgap perovskite for efficient and stable perovskite-organic tandem photovoltaics. Angew Chem Int ed. 2025; 64(17):e202501764.

[19] Tian RJ, Liu C, Meng YY, et al. Nucleation regulation and mesoscopic dielectric screening in α-FAPbI₃. Adv Mater. 2024; 36(13):2309998.

[20] Wang T, Li YK, Cao Q, et al. Deep defect passivation and shallow vacancy repair via an ionic silicone polymer toward highly stable inverted perovskite solar cells. Energ Environ Sci. 2022; 15(10): 4414-4424.

[21] Song Z, Wang J, Bao Y, et al. Optimization of crystallization dynamics in wide-bandgap bromine–iodine perovskite films for high-performance perovskite–organic tandem solar cells. Energ Environ Sci. 2025; 18(10): 4883-4892.

[22] Jiang X, Qin S, Meng L, et al. Isomeric diammonium passivation for perovskite–organic tandem solar cells. Nature. 2024; 635(8040): 860-866.

[23] Guo Q, Wang CY, Hayat T, Alsaedi A, Yao JX, Tan ZA. Recent advances in perovskite/organic integrated solar cells. Rare Met. 2021; 40(10): 2763-2777.

[24] Li D, Lian Q, Du T, et al. Co-adsorbed self-assembled monolayer enables high-performance perovskite and organic solar cells. Nat Commun. 2024; 15(1):7605.

[25] Wang RB, Han MDX, Wang Y, et al. Recent progress on efficient perovskite/organic tandem solar cells. J Energy Chem. 2023; 83: 158-172.

[26] Wu TH, Li X, Qi YB, Zhang YQ, Han LY. Defect passivation for perovskite solar cells: from molecule design to device performance. ChemSusChem. 2021; 14(20): 4354-4376.

[27] Yusoff AB, Vasilopoulou M, Georgiadou DG, Palilis LC, Abate A, Nazeeruddin MK. Passivation and process engineering approaches of halide perovskite films for high efficiency and stability perovskite solar cells. Energ Environ Sci. 2021; 14(5): 2906-2953.

[28] Ahmed R, Rehman S, Chen Z, Ye F, Ren X. Ligand assisted hydrogen bonding: a game-changer in lead passivation and stability in perovskite solar cells. Angew Chem Int ed. 2025; 64(2):e202418763.

[29] Chen W, Zhu YD, Xiu JW, et al. Monolithic perovskite/organic tandem solar cells with 23.6% efficiency enabled by reduced voltage losses and optimized interconnecting layer. Nat Energy. 2022; 7(3): 229-237.

[30] Wu SF, Yan YC, Yin J, et al. Redox mediator–stabilized wide-bandgap perovskites for monolithic perovskite–organic tandem solar cells. Nat Energy. 2024; 9(4): 411-421.

[31] Zhang ZC, Chen WJ, Jiang XX, et al. Suppression of phase segregation in wide-bandgap perovskites with thiocyanate ions for perovskite/organic tandems with 25.06% efficiency. Nat Energy. 2024; 9(5): 592-601.

[32] Guo Q, Dai Z, Dong CQ, et al. 17.3% efficiency CsPbI₂Br solar cells by integrating a near-infrared absorbed organic bulk-heterojunction layer. Chem Eng J. 2023; 461:2402143.

[33] Masawa SM, Zhao CX, Liu J, Xu J, Yao JX. Fabrication and characterization of a lead-free cesium bismuth iodide perovskite through antisolvent-assisted crystallization. Nanomaterials. 2024; 14(7):626.

[34] Yang X, Song QH, Liu YZ, et al. A multifunctional additive for enhancing the performance of single-junction perovskite and perovskite/silicon tandem solar cells. J Mater Chem C. 2025; 13(18): 9285-9293.

[35] Chen B, Rudd PN, Yang S, Yuan YB, Huang JS. Imperfections and their passivation in halide perovskite solar cells. Chem Soc Rev. 2019; 48(14): 3842-3867.

[36] Li Z, Zhang J, Wu SF, et al. Minimized surface deficiency on wide-bandgap perovskite for efficient indoor photovoltaics. Nano Energy. 2020; 78:105377.

[37] Nie T, Jia LB, Feng JS, et al. Advances in single-halogen wide-bandgap perovskite solar cells. Adv Funct Mater. 2025; 35(9):2416264.

[38] Wang D, Guo HL, Wu X, et al. Interfacial engineering of wide-bandgap perovskites for efficient perovskite/CZTSSe tandem solar cells. Adv Funct Mater. 2022; 32(2):2107359.

[39] Fang ZM, Nie T, Liu SZ, Ding JN. Overcoming phase segregation in wide-bandgap perovskites: from progress to perspective. Adv Funct Mater. 2024; 34(42):2404402.

[40] Gao ZY, Zhu Y, Zhu JW, et al. Phase-stable wide-bandgap perovskites enabled by suppressed ion migration. J Energy Chem. 2024; 96: 120-128.

[41] Guo HD, Fang YY, Lei Y, et al. Mitigating ion migration with an ultrathin self-assembled ionic insulating layer affords efficient and stable wide-bandgap inverted perovskite solar cells. Small. 2023; 19(38):2302021.

[42] Hu M, Bi C, Yuan YB, Bai Y, Huang JS. Stabilized wide bandgap MAPbBr_xI_3-x perovskite by enhanced grain size and improved crystallinity. Adv Sci. 2016; 3(6):1500301.

[43] Wang ZW, Zeng LW, Zhu T, et al. Suppressed phase segregation for triple-junction perovskite solar cells. Nature. 2023; 618(7963): 74-79.

[44] Wen J, Zhao YC, Wu P, et al. Heterojunction formed via 3D-to-2D perovskite conversion for photostable wide-bandgap perovskite solar cells. Nat Commun. 2023; 14(1):7118.

[45] Yang L, Fang Z, Jin YB, et al. Suppressing halide segregation via pyridine-derivative isomers enables efficient 1.68 eV bandgap perovskite solar cells. Adv Mater. 2024; 36(21):2311923.

[46] Kim HJ, Han GS, Jung HS. Managing the lifecycle of perovskite solar cells: addressing stability and environmental concerns from utilization to end-of-life. eScience. 2024; 4(2):100243.

[47] Cao JL, Chen WJ, Zhao CL, et al. Realizing mechanical stable and efficient wide-bandgap flexible perovskite solar cells by toughening the buried interface. Sci China Mater. 2025; 68(5): 1415-1423.

[48] Chen ZY, Cheng QR, Chen HY, et al. Perovskite grain-boundary manipulation using room-temperature dynamic self-healing “ligaments” for developing highly stable flexible perovskite solar cells with 23.8% efficiency. Adv Mater. 2023; 35(18):2300513.

[49] Jin JJ, Zhu ZK, Ming YD, et al. Spontaneous bifacial capping of perovskite film for efficient and mechanically stable flexible solar cell. Nat Commun. 2025; 16(1):90.

[50] Wu YY, Xu GY, Xi JC, et al. In situ crosslinking-assisted perovskite grain growth for mechanically robust flexible perovskite solar cells with 23.4% efficiency. Joule. 2023; 7(2):19.

[51] Zhang WF, Liu J, Song W, et al. Chemical passivation and grain-boundary manipulation via in situ cross-linking strategy for scalable flexible perovskite solar cells. Sci Adv. 2025; 11(5):15.

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