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Single-junction organic solar cells with over 19% efficiency enabled by a refined double-fibril network morphology

Abstract

In organic photovoltaics, morphological control of donor and acceptor domains on the nanoscale is the key for enabling efficient exciton diffusion and dissociation, carrier transport and suppression of recombination losses. To realize this, here, we demonstrated a double-fibril network based on a ternary donor–acceptor morphology with multi-length scales constructed by combining ancillary conjugated polymer crystallizers and a non-fullerene acceptor filament assembly. Using this approach, we achieved an average power conversion efficiency of 19.3% (certified 19.2%). The success lies in the good match between the photoelectric parameters and the morphological characteristic lengths, which utilizes the excitons and free charges efficiently. This strategy leads to an enhanced exciton diffusion length and a reduced recombination rate, hence minimizing photon-to-electron losses in the ternary devices as compared to their binary counterparts. The double-fibril network morphology strategy minimizes losses and maximizes the power output, offering the possibility of 20% power conversion efficiencies in single-junction organic photovoltaics.

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Fig. 1: Materials and device performance.
Fig. 2: Morphology of thin films.
Fig. 3: Device physics characterization.
Fig. 4: Single-crystal structure of L8-BO.
Fig. 5: Exciton diffusion length and device parameters.

Data availability

Source data are provided with this paper. The remaining data are available from the corresponding authors upon request.

Code availability

The codes or algorithms used to analyse the data reported in this study are available from the corresponding authors upon request.

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Acknowledgements

This work was financially supported by the National Natural Science Foundation of China (grant nos 51973110, 21734009, 21905102, 51825301, 21734001 and 22109094), the National Key R&D Program of China (grant nos 2020YFB1505500 and 2020YFB1505502), the Program of Shanghai Science and Technology Commission’s Science and Technology Innovation Action Plan (grant nos 20ZR1426200, 20511103800, 20511103802 and 20511103803), the Natural Science Foundation of Shandong Province (grant no. ZR2019LFG005), the Key Research Project of Shandong Province (grant no. 2020CXGC010403) and the Center of Hydrogen Science, Shanghai Jiao Tong University, China. J.N. and J.Y. thank the European Research Council for support under the European Union’s Horizon 2020 research and innovation programme (grant nos 742708 and 648901). We thank C. Wang and C. Zhu from the Advanced Light Source for providing X-ray scattering tests, which were carried out at beamlines 7.3.3 and 11.0.1.2 at the Advanced Light Source, Molecular Foundry, Lawrence Berkeley National Laboratory, supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences.

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Authors

Contributions

F.L. and Y.S. conceived and directed this project. L.Z. fabricated and characterized the organic photovoltaic devices. L.Z. and M.Z. conducted the certification. J.X. processed and analysed the single-crystal data. C.L. synthesized L8-BO. M.Z. and T.H. carried out the transient photovoltage, transient photocurrent and impedance characterizations and analysed the data. G.Z. and H.Z. provided the transient absorption spectroscopy results and corresponding analysis. W.Z. carried out the GIXD and RSoXS measurements and assisted with data analysis. J.S. conducted the AFM measurements. J.Y., R.C.I.M. and J.N. conducted the drift diffusion simulation and analysis. Y. Zou conducted the TEM measurements. Y. Zhang, X.X., Z.Z. and R.Z. contributed to the fruitful discussions of this project. L.Z. and M.Z. wrote the manuscript, and C.-C.C., J.Y., R.C.I.M., J.N., Y.S. and F.L. contributed to revisions of the manuscript. This manuscript was mainly prepared by F.L., Y.S., L.Z., M.Z. and J.X., and all authors participated in the manuscript preparation and commented on the manuscript.

Corresponding authors

Correspondence to Jun Yan, Yanming Sun or Feng Liu.

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Supplementary Figs. 1–49, Tables 1–21, Notes 1–11, Materials and Methods, and references.

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Supplementary Data 1

Statistical source data for Supplementary Tables 15–17.

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Zhu, L., Zhang, M., Xu, J. et al. Single-junction organic solar cells with over 19% efficiency enabled by a refined double-fibril network morphology. Nat. Mater. 21, 656–663 (2022). https://doi.org/10.1038/s41563-022-01244-y

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