Permanent Dipole Moments Enhance Electronic Coupling and Singlet Fission in Pentacene

• DOI: 10.1021/acs.jpclett.1c01805
• Publication Date: 2021-08-02T16:16:29Z
• Authors: Clemens Zeiser; Luca Moretti; Thomas Geiger; Lukas Kalix; Ana M. Valencia; Margherita Maiuri; Caterina Cocchi; Holger F. Bettinger; Giulio Cerullo; Katharina Broch
• Keywords: Pentacene; Singlet fission; Chromophore; Organic semiconductor

Singlet fission (SF), the photophysical process in which one singlet exciton is transformed into two triplets, depends inter alia on coupling of electronic states. Here, we use fluorination and resulting changes partial charge distribution across chromophore backbone as a particularly powerful tool to control this parameter pentacene. We find that introduction permanent dipole moment leads an enhanced Frenkel transfer states increased SF rate probed using ultrafast transient absorption spectroscopy. These findings are contrasted with H-aggregate formation significantly reduced triplet-pair state lifetime fluorinated pentacene for different negligible moment.