title: Role of nonemissive quenchers for the green emission in polyfluorene.
abstract: The stability of fluorene-based compounds and polymers, especially at the bridged C-9 position under photoirradiation and thermal treatment, has claimed much attention. The emission of fluorenone formed by degradation of the 9-site is regarded as the origin of the low emission band at 2.2-2.3 eV in polyfluorene-based conjugated materials. We have investigated the role of nonemissive quenchers such as alkyl ketones, which were also one of the products of polyfluorene degradation, for the low-energy emission in polyfluorenes. The spectral characteristics of a blend system of polyfluorene/nonemissive quencher/fluorenone are found to accord well with the kinetics of actual polyfluorene degradation. Our results indicate that strong green emission in degraded polyfluorene would be not caused only by fluorenone, but also by nonemissive quenchers for their effectively quenching bulk emission.
authors: Key Lab for Supramolecular Structure and Materials of Ministry of Education, Jilin University, Changchun 130012, People's Republic of China.
authors: Linlin
authors: L
authors: Liu
authors: Ping
authors: P
authors: Lu
authors: Zengqi
authors: Z
authors: Xie
authors: Huiping
authors: H
authors: Wang
authors: Shi
authors: S
authors: Tang
authors: Zhiming
authors: Z
authors: Wang
authors: Wu
authors: W
authors: Zhang
authors: Yuguang
authors: Y
authors: Ma