Abstract
Active layers in organic electronic devices often contain extensive glassy (non-crystalline) regions whose roles remain largely uncharted compared to their crystalline counterparts. Here, we demonstrate that the thermodynamic state of these glassy phases constitutes a powerful lever for tuning the optoelectronic properties of polymer semiconductors. Using poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PFO) as a model system, we show that controlled vitrification kinetics and formation from distinct liquid precursors—including isotropic and liquid-crystalline mesophases—yield glassy PFO films with markedly different microstructures and photoluminescence characteristics. These results uncover direct correlations between glass formation pathways and functional electronic behavior, establishing the glassy state as an active design parameter rather than a passive structural byproduct. Our findings thus introduce a paradigm shift in the processing-structure-property relationships of polymer semiconductors and open new avenues for glass-phase engineering toward enhanced efficiency and stability in next-generation optoelectronic devices.
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The datasets generated during and/or analyzed during the current study have been deposited at the OSF database at the following link: https://osf.io/mx89w/overview. All data are available from the corresponding authors upon request.
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Acknowledgements
We thank De Mello’s group for kindly providing the PFO material. J.M. thanks financial support from the MICIU (Grant Agreement PID2021-126243NB-I00), the European Research Council (Grant 101086805) and Xunta de Galicia through the Convenio-ERC program. M.C.Q. acknowledge financial support from MCIN/ AEI /10.13039/501100011033/ and the European Union (FEDER) through grants PID2021-128924OB-I00 and CEX2023-001263-S in the framework of the Spanish Severo Ochoa Center of Excellence. D.C. thanks the financial support from Eusko Jaurlaritza (Basque Government) through the grant IT-1566-22.
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N.R.: data curation, investigation, methodology, writing - review & editing. J.A.: data curation, investigation, methodology. V.D.: data curation, investigation, methodology, writing - review & editing. M.C.Q.: data curation, investigation, writing - review & editing. J.M.: writing - review & editing, supervision, funding acquisition, conceptualization. D.C.: writing - review & editing, supervision, funding acquisition, conceptualization.
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Ramos, N., Asatryan, J., Di Lisio, V. et al. Tailoring the glassy phase in polymer semiconductors tunes their optical properties. Nat Commun (2026). https://doi.org/10.1038/s41467-026-70115-w
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DOI: https://doi.org/10.1038/s41467-026-70115-w
