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


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.


  1. Li, G., Zhu, R. & Yang, Y. Polymer solar cells. Nat. Photon. 6, 153–161 (2012).

    Article  CAS  Google Scholar 

  2. Günes, S., Neugebauer, H. & Sariciftci, N. S. Conjugated polymer-based organic solar cells. Chem. Rev. 107, 1324–1338 (2007).

    Article  CAS  Google Scholar 

  3. Yuan, J. et al. Single-junction organic solar cell with over 15% efficiency using fused-ring acceptor with electron-deficient core. Joule 3, 1140–1151 (2019).

    Article  CAS  Google Scholar 

  4. Zhang, M. et al. Single-layered organic photovoltaics with double cascading charge transport pathways: 18% efficiencies. Nat. Commun. 12, 309 (2021).

    Article  CAS  Google Scholar 

  5. Yang, F. & Forrest, S. R. Photocurrent generation in nanostructured organic solar cells. ACS Nano 2, 1022–1032 (2008).

    Article  CAS  Google Scholar 

  6. Zhou, Z. et al. High-efficiency small-molecule ternary solar cells with a hierarchical morphology enabled by synergizing fullerene and non-fullerene acceptors. Nat. Energy 3, 952–959 (2018).

    Article  CAS  Google Scholar 

  7. Wang, Z. et al. The coupling and competition of crystallization and phase separation, correlating thermodynamics and kinetics in OPV morphology and performances. Nat. Commun. 12, 332 (2021).

    Article  CAS  Google Scholar 

  8. Zhu, L. et al. Progress and prospects of the morphology of non-fullerene acceptor based high-efficiency organic solar cells. Energy Environ. Sci. 14, 4341–4357 (2021).

    Article  CAS  Google Scholar 

  9. Lorch, C. et al. Controlling length-scales of the phase separation to optimize organic semiconductor blends. Appl. Phys. Lett. 107, 201903 (2015).

    Article  CAS  Google Scholar 

  10. Gasparini, N., Salleo, A., McCulloch, I. & Baran, D. The role of the third component in ternary organic solar cells. Nat. Rev. Mater. 4, 229–242 (2019).

    Article  Google Scholar 

  11. Lu, L., Kelly, M. A., You, W. & Yu, L. Status and prospects for ternary organic photovoltaics. Nat. Photon. 9, 491–500 (2015).

    Article  CAS  Google Scholar 

  12. Baran, D. et al. Reducing the efficiency–stability–cost gap of organic photovoltaics with highly efficient and stable small molecule acceptor ternary solar cells. Nat. Mater. 16, 363–369 (2017).

    Article  CAS  Google Scholar 

  13. Gasparini, N. et al. Designing ternary blend bulk heterojunction solar cells with reduced carrier recombination and a fill factor of 77%. Nat. Energy 1, 16118 (2016).

    Article  CAS  Google Scholar 

  14. Lu, L., Xu, T., Chen, W., Landry, E. S. & Yu, L. Ternary blend polymer solar cells with enhanced power conversion efficiency. Nat. Photon. 8, 716–722 (2014).

    Article  CAS  Google Scholar 

  15. Yang, Y. et al. High-performance multiple-donor bulk heterojunction solar cells. Nat. Photon. 9, 190–198 (2015).

    Article  CAS  Google Scholar 

  16. Kohn, P. et al. Crystallization-induced 10-nm structure formation in P3HT/PCBM blends. Macromolecules 46, 4002–4013 (2013).

    Article  CAS  Google Scholar 

  17. Sepe, A. et al. Structure formation in P3HT/F8TBT blends. Energy Environ. Sci. 7, 1725–1736 (2014).

    Article  CAS  Google Scholar 

  18. Kirchartz, T., Agostinelli, T., Campoy-Quiles, M., Gong, W. & Nelson, J. Understanding the thickness-dependent performance of organic bulk heterojunction solar cells: the influence of mobility, lifetime, and space charge. J. Phys. Chem. Lett. 3, 3470–3475 (2012).

    Article  CAS  Google Scholar 

  19. Kirchartz, T., Bisquert, J., Mora-Sero, I. & Garcia-Belmonte, G. Classification of solar cells according to mechanisms of charge separation and charge collection. Phys. Chem. Chem. Phys. 17, 4007–4014 (2015).

    Article  CAS  Google Scholar 

  20. Li, C. et al. Non-fullerene acceptors with branched side chains and improved molecular packing to exceed 18% efficiency in organic solar cells. Nat. Energy 6, 605–613 (2021).

    Article  CAS  Google Scholar 

  21. Zahn, D. R. T., Gavrila, G. N. & Gorgoi, M. The transport gap of organic semiconductors studied using the combination of direct and inverse photoemission. Chem. Phys. 325, 99–112 (2006).

    Article  CAS  Google Scholar 

  22. Zhang, M. et al. High-efficiency organic photovoltaics using eutectic acceptor fibrils to achieve current amplification. Adv. Mater. 33, 2007177 (2021).

    Article  CAS  Google Scholar 

  23. Song, J. et al. High-efficiency organic solar cells with low voltage loss induced by solvent additive strategy. Matter 4, 2542–2552 (2021).

    Article  CAS  Google Scholar 

  24. Cui, Y. et al. Single-junction organic photovoltaic cell with 19% efficiency. Adv. Mater. 33, 2102420 (2021).

    Article  CAS  Google Scholar 

  25. Chong, K. et al. Realizing 19.05% efficiency polymer solar cells by progressively improving charge extraction and suppressing charge recombination. Adv. Mater. 34, 2109516 (2022).

    Article  CAS  Google Scholar 

  26. Liu, Q. et al. 18% efficiency organic solar cells. Sci. Bull. 65, 272–275 (2020).

    Article  CAS  Google Scholar 

  27. Song, J. et al. Morphology characterization of bulk heterojunction solar cells. Small Methods 2, 1700229 (2018).

    Article  CAS  Google Scholar 

  28. Sangroniz, L., Cavallo, D. & Müller, A. J. Self-nucleation effects on polymer crystallization. Macromolecules 53, 4581–4604 (2020).

    Article  CAS  Google Scholar 

  29. Oh, J. Y. et al. Self-seeded growth of poly(3-hexylthiophene) (P3HT) nanofibrils by a cycle of cooling and heating in solutions. Macromolecules 45, 7504–7513 (2012).

    Article  CAS  Google Scholar 

  30. Liu, F., Brady, M. A. & Wang, C. Resonant soft X-ray scattering for polymer materials. Eur. Polym. J. 81, 555–568 (2016).

    Article  CAS  Google Scholar 

  31. Wang, C. et al. Defining the nanostructured morphology of triblock copolymers using resonant soft X-ray scattering. Nano Lett. 11, 3906–3911 (2011).

    Article  CAS  Google Scholar 

  32. Su, G. M., Patel, S. N., Pemmaraju, C. D., Prendergast, D. & Chabinyc, M. L. First-principles predictions of near-edge X-ray absorption fine structure spectra of semiconducting polymers. J. Phys. Chem. C 121, 9142–9152 (2017).

    Article  CAS  Google Scholar 

  33. Watts, B., Swaraj, S., Nordlund, D., Lüning, J. & Ade, H. Calibrated NEXAFS spectra of common conjugated polymers. J. Chem. Phys. 134, 024702 (2011).

    Article  CAS  Google Scholar 

  34. Zhong, W. et al. Decoupling complex multi-length-scale morphology in non-fullerene photovoltaics with nitrogen K-edge resonant soft X-ray scattering. Adv. Mater. 34, 2107316 (2021).

    Article  CAS  Google Scholar 

  35. Collins, B. A. et al. Polarized X-ray scattering reveals non-crystalline orientational ordering in organic films. Nat. Mater. 11, 536–543 (2012).

    Article  CAS  Google Scholar 

  36. Liu, F. et al. Relating chemical structure to device performance via morphology control in diketopyrrolopyrrole-based low band gap polymers. J. Am. Chem. Soc. 135, 19248–19259 (2013).

    Article  CAS  Google Scholar 

  37. Bakulin, A. A. et al. The role of driving energy and delocalized states for charge separation in organic semiconductors. Science 335, 1340–1344 (2012).

    Article  CAS  Google Scholar 

  38. Rao, A. et al. The role of spin in the kinetic control of recombination in organic photovoltaics. Nature 500, 435–439 (2013).

    Article  CAS  Google Scholar 

  39. Yu, Z. M. et al. Molecular helices as electron acceptors in high-performance bulk heterojunction solar cells. Nat. Commun. 6, 8242 (2015).

    Article  CAS  Google Scholar 

  40. Sandberg, O. J., Tvingstedt, K., Meredith, P. & Armin, A. Theoretical perspective on transient photovoltage and charge extraction techniques. J. Phys. Chem. C 123, 14261–14271 (2019).

    Article  CAS  Google Scholar 

  41. MacKenzie, R. C. I., Shuttle, C. G., Chabinyc, M. L. & Nelson, J. Extracting microscopic device parameters from transient photocurrent measurements of P3HT:PCBM solar cells. Adv. Energy Mater. 2, 662–669 (2012).

    Article  CAS  Google Scholar 

  42. Xiao, B. et al. Relationship between fill factor and light intensity in solar cells based on organic disordered semiconductors: the role of tail states. Phys. Rev. Appl. 14, 024034 (2020).

    Article  CAS  Google Scholar 

  43. MacKenzie, R. C. I. General-Purpose Photovoltaic Device Model (gpvdm) (2011).

  44. Wang, C., Dong, H., Jiang, L. & Hu, W. Organic semiconductor crystals. Chem. Soc. Rev. 47, 422–500 (2018).

    Article  CAS  Google Scholar 

  45. Lai, H. & He, F. Crystal engineering in organic photovoltaic acceptors: a 3D network approach. Adv. Energy Mater. 10, 2002678 (2020).

    Article  CAS  Google Scholar 

  46. Zhu, L. et al. Efficient organic solar cell with 16.88% efficiency enabled by refined acceptor crystallization and morphology with improved charge transfer and transport properties. Adv. Energy Mater. 10, 1904234 (2020).

    Article  CAS  Google Scholar 

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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 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 and Affiliations



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.

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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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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).

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