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Nature Energy volume 10, pages 1251–1261 (2025)
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An Author Correction to this article was published on 30 October 2025
This article has been updated
The crystallization dynamics of non-fullerene acceptors influences the morphology and charge dynamics of the resulting organic solar cells, ultimately determining device performance. However, optimizing the molecular arrangement of donor and acceptor materials within the active layer remains challenging. Here we control the crystallization kinetics of non-fullerene acceptors with a crystallization-regulating agent, acenaphthene. Acenaphthene changes the self-organization of acceptor molecules by inducing a two-step crystallization: it first fixes the packing motif of the acceptor and then refines the crystallized framework, leading to highly oriented acceptors in the active layer. This forms several charge-transport pathways that improve the charge-transport properties of the device. As a result, efficiencies of 20.9% (20.4% certified) and 21% (20.5% certified) are achieved in D18/L8-BO and PM1/L8-BO-X binary organic solar cells, respectively, with a maximum fill factor of 83.2% (82.2% certified). The result is a step forward in the development of organic solar cells.
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The data that support the findings of this study are available within the Article and its Supplementary Information. Source data are provided with this paper.
A Correction to this paper has been published: https://doi.org/10.1038/s41560-025-01918-2
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G.L. thanks the Research Grants Council of Hong Kong (GRF Grant No. 15211320, CRF C4005-22Y and the RGC Senior Research Fellowship Scheme (SRFS2223-5S01)), Hong Kong Polytechnic University (the Sir Sze-yuen Chung Endowed Professorship Fund (8-8480), RISE (Q-CDBK), G-SAC5, PRI (1-CD7X)) and Guangdong-Hong Kong-Macao Joint Laboratory for Photonic-Thermal-Electrical Energy Materials and Devices (GDSTC No. 2019B121205001). H. Li thanks the Sichuan Science and Technology Programme (Grant No. 2023NSFSC0990). We thank Y. Chen (Beijing Synchrotron Radiation Facility) and L. Wang (Beijing Zhongke Wanyuan Technology) for the in situ spin-coating GIWAXS experiments. This work was carried out with the support of the SSRF, beamline BL02U2. We thank SSRF BL02U2 for the 2D GIWAXS measurements.
These authors contributed equally: Jiehao Fu, Hongxiang Li, Heng Liu.
Department of Electrical and Electronic Engineering, Research Institute for Smart Energy (RISE), Photonic Research Institute (PRI), The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
Jiehao Fu, Patrick W. K. Fong & Gang Li
College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, China
Hongxiang Li & Pei Cheng
Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
Heng Liu & Xinhui Lu
Thin-film Solar Cell Technology Research Center, Chongqing Institute of Green and Intelligent Technology, Chongqing School, University of Chinese Academy of Sciences (UCAS Chongqing), Chinese Academy of Sciences, Chongqing, China
Peihao Huang, Haiyan Chen & Zeyun Xiao
Advanced Materials Thrust, Function Hub, The Hong Kong University of Science and Technology, Guangzhou, China
Top Archie Dela Peña
Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
Mingjie Li
Zhejiang Key Laboratory for Island Green Energy and New Materials, School of Materials Science and Engineering, Taizhou University, Taizhou, China
Shirong Lu
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J.F. and G.L. conceived the study. J.F. fabricated the devices and performed most of the characterizations and analysis. H. Li and P.C. performed the in situ GIWAXS measurements and analysis. H. Liu and X.L. performed the ex situ GISAXS measurements and analysis. P.H. performed the density functional theory calculations. H.C., Z.X. and S.L. assisted with the NMR measurements and analysis. P.W.K.F. conducted the in situ UV–vis characterization. G.L. guided the study and supervised the execution. The paper was prepared, revised and finalized by J.F., H. Li, H. Liu and G.L. All authors discussed the results and commented on the paper.
Correspondence to Gang Li.
The authors declare no competing interests.
Nature Energy thanks the anonymous reviewers for their contribution to the peer review of this work.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary Notes 1 and 2, Figs. 1–34 and Tables 1–6.
Time-resolved GIWAXS patterns of the control sample during spin-coating.
Time-resolved GIWAXS patterns of the AP sample during spin-coating.
Time-resolved GIWAXS patterns of the control sample during thermal annealing.
Time-resolved GIWAXS patterns of the AP sample during thermal annealing.
Source data for supplementary figures and tables.
Statistical source data for Fig. 1.
Statistical source data for Fig. 6.
Statistical source data for Table 1.
Statistical source data for Table 2.
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Fu, J., Li, H., Liu, H. et al. Two-step crystallization modulated through acenaphthene enabling 21% binary organic solar cells and 83.2% fill factor. Nat Energy 10, 1251–1261 (2025). https://doi.org/10.1038/s41560-025-01862-1
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