Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.
Nature Materials volume 23, pages 648–655 (2024 )Cite this article mixed strains
Understanding the structural and dynamic properties of disordered systems at the mesoscale is crucial. This is particularly important in organic mixed ionic–electronic conductors (OMIECs), which undergo significant and complex structural changes when operated in an electrolyte. In this study, we investigate the mesoscale strain, reversibility and dynamics of a model OMIEC material under external electrochemical potential using operando X-ray photon correlation spectroscopy. Our results reveal that strain and structural hysteresis depend on the sample’s cycling history, establishing a comprehensive kinetic sequence bridging the macroscopic and microscopic behaviours of OMIECs. Furthermore, we uncover the equilibrium and non-equilibrium dynamics of charge carriers and material-doping states, highlighting the unexpected coupling between charge carrier dynamics and mesoscale order. These findings advance our understanding of the structure–dynamics–function relationships in OMIECs, opening pathways for designing and engineering materials with improved performance and functionality in non-equilibrium states during device operation.
This is a preview of subscription content, access via your institution
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
Receive 12 print issues and online access
Prices may be subject to local taxes which are calculated during checkout
The original data underlying the figures in the main text are publicly available from the Northwestern University repository (Dryad) at https://doi.org/10.5061/dryad.4b8gthtkq. The datasets generated and/or analysed during this current study are available from the corresponding authors upon request. Source data are provided with this paper.
Both Python and MATLAB codes are publicly available via the Northwestern University repository (Dryad) at https://doi.org/10.5061/dryad.4b8gthtkq.
Moia, D. et al. Design and evaluation of conjugated polymers with polar side chains as electrode materials for electrochemical energy storage in aqueous electrolytes. Energy Environ. Sci. 12, 1349–1357 (2019).
Ji, X. D. et al. Mimicking associative learning using an ion-trapping non-volatile synaptic organic electrochemical transistor. Nat. Commun. 12, 2480 (2021).
Article CAS PubMed PubMed Central Google Scholar
Harikesh, P. C. et al. Organic electrochemical neurons and synapses with ion mediated spiking. Nat. Commun. 13, 901 (2022).
Article CAS PubMed PubMed Central Google Scholar
Shim, H. et al. An elastic and reconfigurable synaptic transistor based on a stretchable bilayer semiconductor. Nat. Electron. 5, 660–671 (2022).
Rashid , RB , Ji , XD & Rivnay , J. Organic electrochemical transistors in bioelectronic circuits . Biosensors. Bioelectron. Rev. 190, 113461 (2021).
Article CAS PubMed Google Scholar
Simon, D. T., Gabrielsson, E. O., Tybrandt, K. & Berggren, M. Organic bioelectronics: bridging the signaling gap between biology and technology. Chem. Rev. 116, 13009–13041 (2016).
Article CAS PubMed Google Scholar
Kukhta, N. A., Marks, A. & Luscombe, C. K. Molecular design strategies toward improvement of charge injection and ionic conduction in organic mixed ionic-electronic conductors for organic electrochemical transistors. Chem. Rev. 122, 4325–4355 (2022).
Article CAS PubMed Google Scholar
Wu, R. H., Matta, M., Paulsen, B. D. & Rivnay, J. Operando characterization of organic mixed ionic/electronic conducting materials. Chem. Rev. 122, 4493–4551 (2022).
Article CAS PubMed Google Scholar
Paulsen, B. D., Tybrandt, K., Stavrinidou, E. & Rivnay, J. Organic mixed ionic-electronic conductors. Nat. Mater. 19, 13–26 (2020).
Article CAS PubMed Google Scholar
Palumbiny, C. M. et al. The crystallization of PEDOT:PSS polymeric electrodes probed in situ during printing. Adv. Mater. 27, 3391–3397 (2015).
Article CAS PubMed Google Scholar
Manley, E. F. et al. In situ GIWAXS analysis of solvent and additive effects on PTB7 thin film microstructure evolution during spin coating. Adv. Mater. 29, 1703933 (2017).
Bischak, C. G. et al. A reversible structural phase transition by electrochemically-driven ion injection into a conjugated polymer. J. Am. Chem. Soc. 142, 7434–7442 (2020).
Article CAS PubMed Google Scholar
Paulsen, B. D. et al. Time-resolved structural kinetics of an organic mixed ionic-electronic conductor. Adv. Mater. 32, 2003404 (2020).
Richter, L. J., DeLongchamp, D. M. & Amassian, A. Morphology development in solution-processed functional organic blend films: an in situ viewpoint. Chem. Rev. 117, 6332–6366 (2017).
Article CAS PubMed Google Scholar
Paulsen, B. D. et al. Electrochemistry of thin films with in situ/operando grazing incidence X-ray scattering: bypassing electrolyte scattering for high fidelity time resolved studies. Small 17, 2103213 (2021).
Guo, J. J. et al. Hydration of a side-chain-free n-type semiconducting ladder polymer driven by electrochemical doping. J. Am. Chem. Soc. 145, 1866–1876 (2023).
Article CAS PubMed Google Scholar
Quill, T. J. et al. An ordered, self-assembled nanocomposite with efficient electronic and ionic transport. Nat. Mater. 22, 362–368 (2023).
Article CAS PubMed Google Scholar
Savva, A., Wustoni, S. & Inal, S. Ionic-to-electronic coupling efficiency in PEDOT:PSS films operated in aqueous electrolytes. J. Mater. Chem. C 6, 12023–12030 (2018).
Wu, R. H., Paulsen, B. D., Ma, Q. & Rivnay, J. Mass and charge transport kinetics in an organic mixed ionic-electronic conductor. Chem. Mater. 34, 9699–9710 (2022).
Tropp, J. et al. Revealing the impact of molecular weight on mixed conduction in glycolated polythiophenes through electrolyte choice. ACS Mater. Lett. 5, 1367–1375 (2023).
Ouyang, L. Q., Musumeci, C., Jafari, M. J., Ederth, T. & Inganas, O. Imaging the phase separation between PEDOT and polyelectrolytes during processing of highly conductive PEDOT:PSS films. ACS Appl. Mater. Interfaces 7, 19764–19773 (2015).
Article CAS PubMed Google Scholar
Rivnay, J. et al. Structural control of mixed ionic and electronic transport in conducting polymers. Nat. Commun. 7, 11287 (2016).
Article PubMed PubMed Central Google Scholar
Kim, N. et al. Highly conductive PEDOT:PSS nanofibrils induced by solution-processed crystallization. Adv. Mater. 26, 2268–2272 (2014).
Article CAS PubMed Google Scholar
Yeon, C., Yun, S. J., Kim, J. & Lim, J. W. PEDOT:PSS films with greatly enhanced conductivity via nitric acid treatment at room temperature and their application as Pt/TCO-free counter electrodes in dye-sensitized solar cells. Adv. Electron. Mater. 1, 1500121 (2015).
Kim, T., Park, S., Seo, J., Lee, C. W. & Kim, J. M. Highly conductive PEDOT:PSS with enhanced chemical stability. Org. Electron. 74, 77–81 (2019).
Jiang, N. S., Endoh, M. K. & Koga, T. ‘Marker’ grazing-incidence X-ray photon correlation spectroscopy: a new tool to peer into the interfaces of nanoconfined polymer thin films. Polym. J. 45, 26–33 (2013).
Sinha, S. K., Jiang, Z. & Lurio, L. B. X-ray photon correlation spectroscopy studies of surfaces and thin films. Adv. Mater. 26, 7764–7785 (2014).
Article CAS PubMed Google Scholar
Desai, R. C. & Kapral, R. Dynamics of Self-Organized and Self-Assembled Structures 38–49 (Cambridge Univ. Press, 2009).
Shpyrko, O. G. X-ray photon correlation spectroscopy. J. Synchrotron Radiat. 21, 1057–1064 (2014).
Article CAS PubMed Google Scholar
Malik, A. et al. Coherent X-ray study of fluctuations during domain coarsening. Phys. Rev. Lett. 81, 5832–5835 (1998).
Madsen, A., Leheny, R. L., Guo, H. Y., Sprung, M. & Czakkel, O. Beyond simple exponential correlation functions and equilibrium dynamics in X-ray photon correlation spectroscopy. New J. Phys. 12, 055001 (2010).
Steinruck, H. G. et al. Concentration and velocity profiles in a polymeric lithium-ion battery electrolyte. Energy Environ. Sci. 13, 4312–4321 (2020).
Ju, G. X. et al. Coherent X-ray spectroscopy reveals the persistence of island arrangements during layer-by-layer growth. Nat. Phys. 15, 589–594 (2019).
Lal, J. et al. Universal dynamics of coarsening during polymer-polymer thin-film spinodal dewetting kinetics. Phys. Rev. E 102, 032802 (2020).
Article CAS PubMed Google Scholar
Yavitt, B. M. et al. Structural dynamics in UV curable resins resolved by in situ 3D printing X-ray photon correlation spectroscopy. ACS Appl. Polym. Mater. 2, 4096–4108 (2020).
Johnson, K. J. et al. In operando monitoring of dynamic recovery in 3D-printed thermoset nanocomposites by XPCS. Langmuir 35, 8758–8768 (2019).
Article CAS PubMed Google Scholar
Amadei, F. et al. Ion-mediated cross-linking of biopolymers confined at lquid/liquid interfaces probed by in situ high-energy grazing incidence X-ray photon correlation spectroscopy. J. Phys. Chem. B 124, 8937–8942 (2020).
Article CAS PubMed Google Scholar
Song, J. et al. Microscopic dynamics underlying the stress relaxation of arrested soft materials. Proc. Natl Acad. Sci. USA 119, 2201566119 (2022).
Donley, G. J. et al. Investigation of the yielding transition in concentrated colloidal systems via rheo-XPCS. Proc. Natl Acad. Sci. USA 120, 2215517120 (2023).
Sutton, M., Lhermitte, J. R. M., Ehrburger-Dolle, F. & Livet, F. High resolution strain measurements in highly disordered materials. Phys. Rev. Res. 3, 013119 (2021).
Giridharagopal, R. et al. Electrochemical strain microscopy probes morphology-induced variations in ion uptake and performance in organic electrochemical transistors. Nat. Mater. 16, 737–742 (2017).
Article CAS PubMed Google Scholar
Yeung, C. & Jasnow, D. Two-time correlations, self-averaging, and an analytically solvable model of phase-ordering dynamics. Phys. Rev. B 42, 10523–10535 (1990).
Brown, G., Rikvold, P. A., Sutton, M. & Grant, M. Speckle from phase-ordering systems. Phys. Rev. E 56, 6601–6612 (1997).
Fluerasu, A., Sutton, M. & Dufresne, E. M. X-ray intensity fluctuation spectroscopy studies on phase-ordering systems. Phys. Rev. Lett. 94, 055501 (2005).
Ersman, P. A. et al. Screen printed digital circuits based on vertical organic electrochemical transistors. Flex. Print. Electron. 2, 045008 (2017).
Guo, J. et al. Why accumulation mode organic electrochemical transistors turn off much faster than they turn on. Preprint at https://arxiv.org/abs/2305.01179 (2023).
Cavassin, P. et al. Electrochemical doping in ordered and disordered domains of organic mixed ionic-electronic conductors. Adv. Mater. 35, e2300308 (2023).
Bazant, M. Z. Theory of chemical kinetics and charge transfer based on nonequilibrium thermodynamics. Acc. Chem. Res. 46, 1144–1160 (2013).
Article CAS PubMed Google Scholar
J.R. gratefully acknowledges funding support from the Alfred P. Sloan Foundation (award no. FG-2019-12046). R.W., B.D.P. and J.R. acknowledge support from the National Science Foundation (grant no. NSF DMR-1751308). This work is also funded by Northwestern’s MRSEC program (NSF DMR-2308691). This work utilized the SPID facility of Northwestern University’s NUANCE Center, which is partially supported by the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205), the Materials Research Science and Engineering Center (NSF DMR-2308691), the State of Illinois and Northwestern University. This research used resources of the Advanced Photon Source operated by the Argonne National Laboratory supported by the US Department of Energy (DOE), Office of Science (contract no. DE-AC02-06CH11357). Use of the Stanford Synchrotron Radiation Lightsource at SLAC National Accelerator Laboratory is supported by the US DOE, Office of Science, Office of Basic Energy Sciences (contract no. DE-AC02-76SF00515). We extend our special thanks to G. S. Shekhawat, H. Choi and L. J. Lauhon (Northwestern) for the attempt of in situ atomic force microscopy and related discussions. J.S. and Q.Z. acknowledge expert technical assistance of R. Ziegler (Argonne) and thank E. Dufrense (Argonne) and M. Sutton (Mcgill) for insightful and fruitful discussion.
Department of Chemistry, Northwestern University, Evanston, IL, USA
Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA
Dilara Meli & Jonathan Rivnay
X-ray Science Division, Argonne National Laboratory, Lemont, IL, USA
Joseph Strzalka, Suresh Narayanan & Qingteng Zhang
Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
Bryan D. Paulsen & Jonathan Rivnay
Hard X-ray Material Science Division, Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
You can also search for this author in PubMed Google Scholar
You can also search for this author in PubMed Google Scholar
You can also search for this author in PubMed Google Scholar
You can also search for this author in PubMed Google Scholar
You can also search for this author in PubMed Google Scholar
You can also search for this author in PubMed Google Scholar
You can also search for this author in PubMed Google Scholar
You can also search for this author in PubMed Google Scholar
R.W., D.M. and C.J.T. designed and tested the operando cell and conducted the experiments. J.S., S.N. and Q.Z. supported the operando GIXPCS measurements at the Advanced Photon Source. C.J.T., J.R. and B.D.P. conceived and directed the study. R.W. analysed the data and conducted the model simulation under the supervision of C.J.T. R.W., J.R. and C.J.T. wrote the manuscript with discussion and input from all authors.
Correspondence to Jonathan Rivnay or Christopher J. Takacs.
The authors declare no competing interests.
Nature Materials 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 1–5, Figs. 1–25 and Table 1.
Example XPCS patterns before strain alignment.
Example XPCS patterns after the first strain alignment.
Example XPCS patterns aligned after two iterations.
Example XPCS patterns aligned after 40 iterations.
Operando GIXPCS to monitor chemical-potential-induced strain and scattering intensity in adiabatic and non-adiabatic processes.
Sequence of strain, phase contrast and charge kinetics.
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
Wu, R., Meli, D., Strzalka, J. et al. Bridging length scales in organic mixed ionic–electronic conductors through internal strain and mesoscale dynamics. Nat. Mater. 23, 648–655 (2024). https://doi.org/10.1038/s41563-024-01813-3
DOI: https://doi.org/10.1038/s41563-024-01813-3
Anyone you share the following link with will be able to read this content:
Sorry, a shareable link is not currently available for this article.
Provided by the Springer Nature SharedIt content-sharing initiative
Nature Materials (Nat. Mater.) ISSN 1476-4660 (online) ISSN 1476-1122 (print)
others nutritional supplements Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.