title: Charge Transfer in Single Chains of a Donor-Acceptor Conjugated Tri-Block Copolymer.
abstract: The photophysics of a conjugated triblock 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 interchain 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.
authors.affiliation: †School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Emma N
authors.initials: EN
authors.lastname: Hooley
authors.affiliation: †School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: David J
authors.initials: DJ
authors.lastname: Jones
authors.affiliation: ‡Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 OHE, United Kingdom.
authors.forename: Neil C
authors.initials: NC
authors.lastname: Greenham
authors.affiliation: †School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Kenneth P
authors.initials: KP
authors.lastname: Ghiggino
authors.affiliation: §School of Chemistry, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Toby D M
authors.initials: TD
authors.lastname: Bell