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Diffraction imaging of nanocrystalline structures in organic semiconductor molecular thin films


The properties of organic solids depend on their structure and morphology, yet direct imaging using conventional electron microscopy methods is hampered by the complex internal structure of these materials and their sensitivity to electron beams. Here, we manage to observe the nanocrystalline structure of two organic molecular thin-film systems using transmission electron microscopy by employing a scanning nanodiffraction method that allows for full access to reciprocal space over the size of a spatially localized probe (~2 nm). The morphologies revealed by this technique vary from grains with pronounced segmentation of the structure—characterized by sharp grain boundaries and overlapping domains—to liquid-crystal structures with crystalline orientations varying smoothly over all possible rotations that contain disclinations representing singularities in the director field. The results show how structure–property relationships can be visualized in organic systems using techniques previously only available for hard materials such as metals and ceramics.

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Fig. 1: Schematic of the diffraction imaging technique.
Fig. 2: Comparison of grain morphology between DIO samples.
Fig. 3: Comparison of grain morphology between PBTTT samples.
Fig. 4: Autocorrelation of the primary lattice vectors over distance Δr and relative orientation Δθ, for the films characterized in Figs. 2 and 3.

Data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request.


  1. Van Krevelen, D. W. & Te Nijenhuis, K. Properties of Polymers: Their Correlation with Chemical Structure; Their Numerical Estimation and Prediction from Additive Group Contributions (Elsevier, 2009).

  2. Wilmer, C. E. et al. Large-scale screening of hypothetical metal–organic frameworks. Nat. Chem. 4, 83–89 (2012).

    CAS  Article  Google Scholar 

  3. Fratini, S., Ciuchi, S., Mayou, D., de Laissardière, G. T. & Troisi, A. A map of high-mobility molecular semiconductors. Nat. Mater. 16, 998–1002 (2017).

    CAS  Article  Google Scholar 

  4. Ophus, C. Four dimensional scanning transmission electron microscopy: from scanning nanodiffraction to ptychography and beyond. Microsc. Microanal. 25, 563–582 (2019).

    CAS  Article  Google Scholar 

  5. Kim, J. H. et al. Optimization and analysis of conjugated polymer side chains for high‐performance organic photovoltaic cells. Adv. Funct. Mater. 26, 1517–1525 (2016).

    CAS  Article  Google Scholar 

  6. Li, G. et al. High-efficiency solution processable polymer photovoltaic cells by self-organization of polymer blends. Nat. Mater. 4, 864–868 (2005).

    CAS  Article  Google Scholar 

  7. Zhao, W. et al. Fullerene‐free polymer solar cells with over 11% efficiency and excellent thermal stability. Adv. Mater. 28, 4734–4739 (2016).

    CAS  Article  Google Scholar 

  8. Smits, E. C. P. et al. Bottom-up organic integrated circuits. Nature 455, 956–959 (2008).

    CAS  Article  Google Scholar 

  9. Di, D. et al. Efficient triplet exciton fusion in molecularly doped polymer light‐emitting diodes. Adv. Mater. 29, 1605987 (2017).

    Article  Google Scholar 

  10. Salaneck, W. R., Friend, R. H. & Brédas, J. L. Electronic structure of conjugated polymers: consequences of electron–lattice coupling. Phys. Rep. 319, 231–251 (1999).

    CAS  Article  Google Scholar 

  11. Collini, E. & Scholes, G. D. Coherent intrachain energy migration in a conjugated polymer at room temperature. Science 323, 369–373 (2009).

    CAS  Article  Google Scholar 

  12. Sirringhaus, H. et al. Two-dimensional charge transport in self-organized, high-mobility conjugated polymers. Nature 401, 685–688 (1999).

    CAS  Article  Google Scholar 

  13. Lemaur, V., Steel, M., Beljonne, D., Brédas, J.-L. & Cornil, J. Photoinduced charge generation and recombination dynamics in model donor/acceptor pairs for organic solar cell applications: a full quantum-chemical treatment. J. Am. Chem. Soc. 127, 6077–6086 (2005).

    CAS  Article  Google Scholar 

  14. Zhang, L. et al. Poly(3-butylthiophene) inducing crystallization of small molecule donor for enhanced photovoltaic performance. J. Phys. Chem. C 119, 23310–23318 (2015).

    CAS  Article  Google Scholar 

  15. McCulloch, I. et al. Liquid-crystalline semiconducting polymers with high charge-carrier mobility. Nat. Mater. 5, 328–333 (2006).

    Article  Google Scholar 

  16. Takacs, C. J. et al. Mapping orientational order in a bulk heterojunction solar cell with polarization-dependent photoconductive atomic force microscopy. ACS Nano 8, 8141–8151 (2014).

    CAS  Article  Google Scholar 

  17. Dennler, G., Scharber, M. C. & Brabec, C. J. Polymer‐fullerene bulk‐heterojunction solar cells. Adv. Mater. 21, 1323–1338 (2009).

    CAS  Article  Google Scholar 

  18. Zhao, W., Li, S., Zhang, S., Liu, X. & Hou, J. Ternary polymer solar cells based on two acceptors and one donor for achieving 12.2% efficiency. Adv. Mater. 29, 1604059 (2017).

    Article  Google Scholar 

  19. Maged, A. et al. Toward additive‐free small‐molecule organic solar cells: roles of the donor crystallization pathway and dynamics. Adv. Mater. 27, 7285–7292 (2015).

    Article  Google Scholar 

  20. Arca, F., Loch, M. & Lugli, P. Enhancing efficiency of organic bulkheterojunction solar cells by using 1,8-diiodooctane as processing additive. IEEE J. Photovolt. 4, 1560–1565 (2014).

    Article  Google Scholar 

  21. Reichenberger, M. et al. Watching paint dry: the impact of diiodooctane on the kinetics of aggregate formation in thin films of poly(3-hexylthiophene). Macromolecules 49, 6420–6430 (2016).

    CAS  Article  Google Scholar 

  22. Herath, N. et al. Unraveling the fundamental mechanisms of solvent-additive-induced optimization of power conversion efficiencies in organic photovoltaic devices. ACS Appl. Mater. Interfaces 8, 20220–20229 (2016).

    CAS  Article  Google Scholar 

  23. Van Der Poll, T. S., Love, J. A., Nguyen, T. Q. & Bazan, G. C. Non‐basic high‐performance molecules for solution‐processed organic solar cells. Adv. Mater. 24, 3646–3649 (2012).

    Article  Google Scholar 

  24. Brown, S. J. et al. Enhancing organic semiconductor–surface plasmon polariton coupling with molecular orientation. Nano Lett. 17, 6151–6156 (2017).

    CAS  Article  Google Scholar 

  25. Panova, O. et al. Orientation mapping of semicrystalline polymers using scanning electron nanobeam diffraction. Micron 88, 30–36 (2016).

    CAS  Article  Google Scholar 

  26. Frank, F. C. I. Liquid crystals. On the theory of liquid crystals. Discuss. Faraday Soc. 25, 19–28 (1958).

    Article  Google Scholar 

  27. Meyer, R. B. On the existence of even indexed disclinations in nematic liquid crystals. Philos. Mag. 27, 405–424 (1973).

    CAS  Article  Google Scholar 

  28. Saupe, A. Disclinations and properties of the directorfield in nematic and cholesteric liquid crystals. Mol. Cryst. Liq. Cryst. 21, 211–238 (2007).

    Article  Google Scholar 

  29. Jimison, L. H., Toney, M. F., McCulloch, I., Heeney, M. & Salleo, A. Charge-transport anisotropy due to grain boundaries in directionally crystallized thin films of regioregular poly(3-hexylthiophene). Adv. Mater. 21, 1568–1572 (2009).

    CAS  Article  Google Scholar 

  30. Merzkirch, W. Flow Visualization (Elsevier, 2012).

  31. Wood, B. A. & Thomas, E. L. Are domains in liquid crystalline polymers arrays of disclinations? Nature 324, 655–657 (1986).

    CAS  Article  Google Scholar 

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

    CAS  Article  Google Scholar 

  33. Qian, L. et al. Effect of crystallinity of fullerene derivatives on doping density in the organic bulk heterojunction layer in polymer solar cells. Chin. Phys. Lett. 32, 056801 (2015).

    Article  Google Scholar 

  34. Yang, X. et al. Crystalline organization of a methanofullerene as used for plastic solar‐cell applications. Adv. Mater. 16, 802–806 (2004).

    CAS  Article  Google Scholar 

  35. Takacs, C. J. et al. Remarkable order of a high-performance polymer. Nano Lett. 13, 2522–2527 (2013).

    CAS  Article  Google Scholar 

  36. Rivnay, J., Mannsfeld, S. C. B., Miller, C. E., Salleo, A. & Toney, M. F. Quantitative determination of organic semiconductor microstructure from the molecular to device scale. Chem. Rev. 112, 5488–5519 (2012).

    CAS  Article  Google Scholar 

  37. Mollinger, S. A., Krajina, B. A., Noriega, R., Salleo, A. & Spakowitz, A. J. Percolation, tie-molecules, and the microstructural determinants of charge transport in semicrystalline conjugated polymers. ACS Macro Lett. 4, 708–712 (2015).

    CAS  Article  Google Scholar 

  38. Mohammadi, E. et al. Dynamic-template-directed multiscale assembly for large-area coating of highly-aligned conjugated polymer thin films. Nat. Commun. 8, 16070 (2017).

    CAS  Article  Google Scholar 

  39. Pekin, T. C., Gammer, C., Ciston, J., Minor, A. M. & Ophus, C. Optimizing disk registration algorithms for nanobeam electron diffraction strain mapping. Ultramicroscopy 176, 170–176 (2017).

    CAS  Article  Google Scholar 

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Primary funding for the work was provided by the Electron Microscopy of Soft Matter Program from the Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division of the US Department of Energy under contract no. DE-AC02-05CH11231. Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under contract no. DE-AC02-05CH11231. L.B. and A.S. acknowledge funding from the National Science Foundation DMR Award no. 1808401. The authors also thank H. Yan for providing materials and M. Toney for useful discussions.

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Authors and Affiliations



A.M.M. and N.B. conceived of the project. C.J.T., L.B. and O.P. prepared the samples. O.P. and K.C.B. designed the experiment and acquired the data. C.O., O.P., K.C.B., C.J.T., L.B., A.S. and A.M.M, analysed the data and all authors contributed to writing the manuscript.

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Correspondence to Andrew M. Minor.

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Panova, O., Ophus, C., Takacs, C.J. et al. Diffraction imaging of nanocrystalline structures in organic semiconductor molecular thin films. Nat. Mater. 18, 860–865 (2019).

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