Single molecule spectroscopy of polyfluorene chains reveals β-phase content and phase reversibility in organic solvents
Abstract
Conjugated polymers are an important class of organic semiconductors that can be deposited from solution to make optoelectronic devices. Among them, poly(9,9′-dioctylfluorene) (PFO) has distinctive optical properties arising from its ability to adopt an ordered planar conformation (β phase) from a disordered glassy phase (α phase). The β phase has attractive optical properties, but the precise mechanism of its formation in solution remains unknown. Here, we have combined specifically tailored polymer synthesis and surface-passivation strategies to provide the first spectroscopic characterization of single PFO chains in solution at room temperature. By anchoring PFO molecules at one end on an anti-adherent surface, we show that isolated chains can adopt the β-phase conformation in a solvent-dependent manner. Furthermore, we find that individual PFO chains can reversibly switch multiple times between phases in response to solvent-exchange events. The methodology presented here for polymer synthesis and immobilization is widely applicable to investigate other luminescent polymers.
Citation
Brenlla , A , Tenopala-Carmona , F , Kanibolotsky , A L , Skabara , P J , Samuel , I D W & Penedo-Esteiro , J C 2019 , ' Single molecule spectroscopy of polyfluorene chains reveals β-phase content and phase reversibility in organic solvents ' , Matter , vol. In press . https://doi.org/10.1016/j.matt.2019.07.020
Publication
Matter
Status
Peer reviewed
ISSN
2590-2385Type
Journal article
Rights
Copyright © 2019 Elsevier Inc. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the author created accepted manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1016/j.matt.2019.07.020
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