title: Pressure-induced delocalization of photoexcited states in a semiconducting polymer.
abstract: We present broadband transient absorption spectroscopy on the fluorescent copolymer poly(9,9-dioctylfluorene-co-benzothiadiazole) under hydrostatic pressure of up to 75 kbar. We observe a strong reduction of the stimulated emission intensity under pressure, coupled with slower decay kinetics and reduced fluorescence intensity. These observations indicate increased delocalization of photogenerated singlet excitons, facilitated by an increased dielectric constant at high pressure. Spin triplet excitons, generated via an iridium complex-F8BT oligomer, show reduced lifetimes under pressure.
authors.affiliation: Cavendish Laboratory, Department of Physics, University of Cambridge, CB3 0HE, United Kingdom. sa468@cam.ac.uk
authors.forename: Sebastian
authors.initials: S
authors.lastname: Albert-Seifried
authors.forename: Justin M
authors.initials: JM
authors.lastname: Hodgkiss
authors.forename: Frédéric
authors.initials: F
authors.lastname: Laquai
authors.forename: Hugo A
authors.initials: HA
authors.lastname: Bronstein
authors.forename: Charlotte K
authors.initials: CK
authors.lastname: Williams
authors.forename: Richard H
authors.initials: RH
authors.lastname: Friend