title: Quantifying highly efficient incoherent energy transfer in perylene-based multichromophore arrays.
abstract: Multichromophore perylene arrays were designed and synthesized to have extremely efficient resonance energy transfer. Using broadband ultrafast photoluminescence and transient absorption spectroscopies, transfer timescales of approximately 1 picosecond were resolved, corresponding to efficiencies of up to 99.98%. The broadband measurements also revealed spectra corresponding to incoherent transfer between localized states. Polarization resolved spectroscopy was used to measure the dipolar angles between donor and acceptor chromophores, thereby enabling geometric factors to be fixed when assessing the validity of Förster theory in this regime. Förster theory was found to predict the correct magnitude of transfer rates, with measured ∼2-fold deviations consistent with the breakdown of the point-dipole approximation at close approach. The materials presented, along with the novel methods for quantifying ultrahigh energy transfer efficiencies, will be valuable for applications demanding extremely efficient energy transfer, including fluorescent solar concentrators, optical gain, and photonic logic devices.
authors.affiliation: School of Chemistry, The Australian Centre for Nanomedicine and the ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, The University of New South Wales, NSW 2052, Australia. p.thordarson@unsw.edu.au.
authors.forename: James E A
authors.initials: JE
authors.lastname: Webb
authors.forename: Kai
authors.initials: K
authors.lastname: Chen
authors.forename: Shyamal K K
authors.initials: SK
authors.lastname: Prasad
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Wojciechowski
authors.forename: Alexander
authors.initials: A
authors.lastname: Falber
authors.forename: Pall
authors.initials: P
authors.lastname: Thordarson
authors.forename: Justin M
authors.initials: JM
authors.lastname: Hodgkiss