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A materials physics perspective on structure–processing–function relations in blends of organic semiconductors

Nature Reviews Materials volume 8, pages 439–455 (2023)Cite this article

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Abstract

During the past 30 years of research in organic electronics, the development of mechanistic understanding of important structure–processing–performance interrelationships has been slowly but steadily growing. Nevertheless, especially if blends are used in the active device layer, the development of new materials and device fabrication still predominantly relies on time-consuming trial-and-error procedures. In this Review, we demonstrate that well-established models, rooted in classical materials science and the thermodynamics of mixtures, can provide quantitative frameworks to guide material and process design. We provide, from a materials physics perspective, a concise and accessible overview on the relation between fundamental thermodynamic and kinetic principles relevant to (solution) processing, active layer morphology and stability of organic electronic devices based on blends by means of illustrative examples from organic photovoltaics. We aim to address a wide audience, including synthetic chemists, materials scientists, device engineers and beyond.

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Fig. 1: Processing, morphology and molecular structure.
Fig. 2: Measurement and prediction of thermodynamic parameters.
Fig. 3: Phase diagram and structure formation in ternary blends comprising a donor, an acceptor and a solvent.
Fig. 4: OPV device processing informed by ϕ–χ phase diagrams.
Fig. 5: Relation between χ and device stability.
Fig. 6: Binary phase diagrams for systems in which one or both components can crystallize.

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Acknowledgements

J.J.M. acknowledges the financial support from the Max-Planck Institute for Polymer Research (Mainz, Germany). N.S. thanks the National Science Foundation (DMR 1729737). Z.P. and H.A. gratefully acknowledge support from the U.S. Office of Naval Research (N000141712204 and N000142012155). The authors are indebted to many colleagues and collaborators for discussions and in particular to L. Ye for contributions to the initial draft of the manuscript and its figures.

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  1. Department of Physics and Organic and Carbon Electronics Laboratories (ORaCEL), North Carolina State University, Raleigh, NC, USA

    Zhengxing Peng & Harald Ade

  2. School of Materials Science and Engineering and School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA

    Natalie Stingelin

  3. Department of Molecular Electronics, Max-Planck Institute for Polymer Research, Mainz, Germany

    Jasper J. Michels

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All authors researched data for the article. J.J.M., N.S. and H.A. contributed substantially to discussion of the content. J.J.M., N.S. and H.A. wrote the article. All authors reviewed and/or edited the manuscript before submission.

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Peng, Z., Stingelin, N., Ade, H. et al. A materials physics perspective on structure–processing–function relations in blends of organic semiconductors. Nat Rev Mater 8, 439–455 (2023). https://doi.org/10.1038/s41578-023-00541-5

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