The highly polarizable pi-electron system of conjugated molecules forms the basis for their unique electronic and photophysical properties, which play an important role in numerous biological phenomena and make them important materials for technological applications. We present a theoretical investigation of the dynamics and relaxation of photoexcited states in conjugated polyfluorenes, which are promising materials for display applications. Our analysis shows that both fast (similar to20 fs) and slow (similar to1 ps) nuclear motions couple to the electronic degrees of freedom during the excited-state dynamics. Delocalized excitations dominate the absorption, whereas emission comes from localized (self-trapped) excitons. This localization is attributed to an inherent nonlinear coupling among vibronic degrees of freedom which leads to lattice and torsional distortions and results in specific signatures in spectroscopic observables. Computed vertical absorption and fluorescence frequencies as well as photoluminescence band shapes show good agreement with experiment. Finally, we demonstrate that dimerization such as spiro-linking does not affect the emission properties of molecules because the excitation becomes confined on a single chain of the composite molecule.
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Univ Calif Santa Barbara, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USAUniv Calif Santa Barbara, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USA
Gong, XO
Iyer, PK
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机构:Univ Calif Santa Barbara, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USA
Iyer, PK
Moses, D
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机构:Univ Calif Santa Barbara, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USA
Moses, D
Bazan, GC
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机构:Univ Calif Santa Barbara, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USA
Bazan, GC
Heeger, AJ
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机构:Univ Calif Santa Barbara, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USA
Heeger, AJ
Xiao, SS
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h-index: 0
机构:Univ Calif Santa Barbara, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USA
机构:
Univ Calif Santa Barbara, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USAUniv Calif Santa Barbara, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USA
Gong, XO
Iyer, PK
论文数: 0引用数: 0
h-index: 0
机构:Univ Calif Santa Barbara, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USA
Iyer, PK
Moses, D
论文数: 0引用数: 0
h-index: 0
机构:Univ Calif Santa Barbara, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USA
Moses, D
Bazan, GC
论文数: 0引用数: 0
h-index: 0
机构:Univ Calif Santa Barbara, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USA
Bazan, GC
Heeger, AJ
论文数: 0引用数: 0
h-index: 0
机构:Univ Calif Santa Barbara, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USA
Heeger, AJ
Xiao, SS
论文数: 0引用数: 0
h-index: 0
机构:Univ Calif Santa Barbara, Inst Polymers & Organ Solids, Santa Barbara, CA 93106 USA