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@ARTICLE{DAvino:453855,
      author       = {D’Avino, Gabriele and Duhm, Steffen and Della Valle,
                      Raffaele Guido and Heimel, Georg and Oehzelt, Martin and
                      Kera, Satoshi and Ueno, Nobuo and Beljonne, David and
                      Salzmann, Ingo},
      title        = {{E}lectrostatic {I}nteractions {S}hape {M}olecular
                      {O}rganization and {E}lectronic {S}tructure of {O}rganic
                      {S}emiconductor {B}lends},
      journal      = {Chemistry of materials},
      volume       = {32},
      number       = {3},
      issn         = {1520-5002},
      address      = {Washington, DC},
      publisher    = {American Chemical Society},
      reportid     = {PUBDB-2021-00219},
      pages        = {1261 - 1271},
      year         = {2020},
      note         = {We thank Wolfgang Caliebe (HASYLAB, DESY) for experimental
                      support and Roland Resel (TU-Graz) for fruitful
                      discussions.},
      abstract     = {Halogenation of conjugated molecules represents a powerful
                      approach to tune the electronic structure of molecular thin
                      films through inductive effects and long-range
                      intermolecular electrostatic interactions. The mixing of
                      halogenated molecules with their pristine counterparts has
                      recently proven successful in altering the blend’s energy
                      levels to adjust the open-circuit voltage of organic solar
                      cells by the mixing ratio. Here, we show that the prevailing
                      rationale for this effect is not equally valid for different
                      molecular orientations. We provide a comprehensive
                      experimental and theoretical analysis of the prototypical
                      blend formed by pentacene and perfluoropentacene to relate
                      structure with electronic properties. We find a mixed-stack
                      structural motif in standing and lying orientations
                      depending on the substrate nature. In the standing
                      orientation, the ionization potential lies in between the
                      values of the pure components, in line with the established
                      picture of averaged molecular quadrupole moments. For the
                      lying orientation, however, we experimentally observe an
                      ionization potential lower than both pristine values, which
                      seems at odds with this simple rationale. Electrostatic
                      simulations based on the knowledge of the atomistic
                      structure of the films capture the complex experimental
                      scenario for both orientations. In particular, the ultralow
                      ionization potential of films formed by lying molecules is
                      identified as a signature of the monolayer structure, where
                      quadrupolar interactions are responsible for a difference of
                      ca. 0.4 eV in the highest occupied molecular orbital energy
                      as compared to thicker films with the same molecular
                      orientation.},
      cin          = {DOOR ; HAS-User},
      ddc          = {540},
      cid          = {I:(DE-H253)HAS-User-20120731},
      pnm          = {899 - ohne Topic (POF3-899)},
      pid          = {G:(DE-HGF)POF3-899},
      experiment   = {EXP:(DE-H253)D-W1-20150101},
      typ          = {PUB:(DE-HGF)16},
      UT           = {WOS:000513299400031},
      doi          = {10.1021/acs.chemmater.9b04763},
      url          = {https://bib-pubdb1.desy.de/record/453855},
}