A quantum chemical semiempirical investigation of electron-vibrational dynamics of photoexcited conjugated polyfluorenes shows that delocalized electronic excitations dominate the absorption, whereas chemical defects (if present) dramatically impact the emission by trapping the photogenerated exciton into a localized state and acting as guest emitters at recombination. These results offer theoretical insight into the effect of non-quenching defect sites in conjugated polymers and explain the origin of a controversial low energy emission band frequently observed in bulk polyfluorene samples. (C) 2003 Elsevier Science B.V. All rights reserved.
机构:
Univ Calif Santa Barbara, Dept Phys, Dept Mat, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USAUniv Calif Santa Barbara, Dept Phys, Dept Mat, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USA
机构:
Univ Calif Santa Barbara, Dept Phys, Dept Mat, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USAUniv Calif Santa Barbara, Dept Phys, Dept Mat, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USA