Charge Transfer in Single Chains of a Donor–Acceptor Conjugated Tri-Block Copolymer
Hooley, Emma N
Jones, David J
Journal of Physical Chemistry B
American Chemical Society
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Hooley, E. N., Jones, D. J., & Greenham, N. C. (2014). Charge Transfer in Single Chains of a Donor–Acceptor Conjugated Tri-Block Copolymer. Journal of Physical Chemistry B, 119 7266-7274. https://doi.org/10.1021/jp510769p
The photophysics of a conjugated tri-block copolymer comprising poly(9,9-dioctylfluorene-co-bis- N,N’-(4-methylphenyl)-bis-N,N’-phenyl-1,4-phenylenediamine (PFM) electron donor and poly-(4-(9,9- dioctyl-9H-fluoren-2-yl)benzo[c][1,2,5]-thiadiazole) (F8BT) electron acceptor blocks has been studied in solution, in films and as single chains. While an additional long-wavelength emission apparent in neat films of the copolymer is attributed to inter-chain exciplex formation, no such long-wavelength emission is apparent in solution or from single molecules. However, in these cases, time-resolved fluorescence measurements indicate the presence of a delayed fluorescence. The kinetics of the delayed emission can be interpreted in terms of an equilibrium between a locally-excited and a charge-transfer state at the interface of the copolymer block components. Rate constants and thermodynamic quantities associated with these processes have been evaluated. The single molecule results allow the assignment of an intramolecular charge-transfer state in an isolated conjugated block copolymer chain.
Conjugated polymer, block copolymer, single molecule fluorescence, charge transfer, delayed fluorescence, exciplex
We thank the Australian Research Council (ARC) for financial support of this research through grants DP0986166, LE100100131 and LE110100161. ENH acknowledges an Australian Postgraduate Award. We acknowledge Sam Ashworth for technical assistance with data collection. NCG is grateful to the School of Chemistry, The University of Melbourne for a Wilsmore Fellowship, and to Queen’s College, Melbourne for a Sugden Fellowship.
External DOI: https://doi.org/10.1021/jp510769p
This record's URL: https://www.repository.cam.ac.uk/handle/1810/246745