@article{HeStolteBurschkaetal.2015,
  author    = {He, Tao and Stolte, Matthias and Burschka, Christian and Hansen, Nis Hauke and Musiol, Thomas and K{\"a}lblein, Daniel and Pflaum, Jens and Tao, Xutang and Brill, Jochen and W{\"u}rthner, Frank},
  title     = {Single-crystal field-effect transistors of new Cl\(_{2}\)-NDI polymorph processed by sublimation in air},
  series = {Nature Communications},
  volume    = {6},
  journal   = {Nature Communications},
  number    = {5954},
  doi       = {10.1038/ncomms6954},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149255},
  year      = {2015},
  abstract  = {Physical properties of active materials built up from small molecules are dictated by their molecular packing in the solid state. Here we demonstrate for the first time the growth of n-channel single-crystal field-effect transistors and organic thin-film transistors by sublimation of 2,6-dichloro-naphthalene diimide in air. Under these conditions, a new polymorph with two-dimensional brick-wall packing mode (\(\beta\)-phase) is obtained that is distinguished from the previously reported herringbone packing motif obtained from solution (\(\alpha\)-phase). We are able to fabricate single-crystal field-effect transistors with electron mobilities in air of up to 8.6 cm\(^{2}\)V\(^{-1}\)s\(^{-1}\) (\(\alpha\)-phase) and up to 3.5 cm\(^{2}\)V\(^{-1}\)s\(^{-1}\) (\(\beta\)-phase) on n-octadecyltriethoxysilane-modified substrates. On silicon dioxide, thin-film devices based on \(\beta\)-phase can be manufactured in air giving rise to electron mobilities of 0.37 cm\(^{2}\)V\(^{-1}\)s\(^{-1}\). The simple crystal and thin-film growth procedures by sublimation under ambient conditions avoid elaborate substrate modifications and costly vacuum equipment-based fabrication steps.},
  language  = {en}
}
@article{GoerlZhangStepanenkoetal.2015,
  author    = {G{\"o}rl, Daniel and Zhang, Xin and Stepanenko, Vladimir and W{\"u}rthner, Frank},
  title     = {Supramolecular block copolymers by kinetically controlled co-self-assembly of planar and core-twisted perylene bisimides},
  series = {Nature Communications},
  volume    = {6},
  journal   = {Nature Communications},
  number    = {7009},
  doi       = {10.1038/ncomms8009},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-148657},
  year      = {2015},
  abstract  = {New synthetic methodologies for the formation of block copolymers have revolutionized polymer science within the last two decades. However, the formation of supramolecular block copolymers composed of alternating sequences of larger block segments has not been realized yet. Here we show by transmission electron microscopy (TEM), 2D NMR and optical spectroscopy that two different perylene bisimide dyes bearing either a flat (A) or a twisted (B) core self-assemble in water into supramolecular block copolymers with an alternating sequence of (A\(_{m}\)BB)\(_{n}\). The highly defined ultralong nanowire structure of these supramolecular copolymers is entirely different from those formed upon self-assembly of the individual counterparts, that is, stiff nanorods (A) and irregular nanoworms (B), respectively. Our studies further reveal that the as-formed supramolecular block copolymer constitutes a kinetic self-assembly product that transforms into thermodynamically more stable self-sorted homopolymers upon heating.},
  language  = {en}
}
@article{SungKimFimmeletal.2015,
  author    = {Sung, Jooyoung and Kim, Pyosang and Fimmel, Benjamin and W{\"u}rthner, Frank and Kim, Dongho},
  title     = {Direct observation of ultrafast coherent exciton dynamics in helical π-stacks of self-assembled perylene bisimides},
  series = {Nature Communications},
  volume    = {6},
  journal   = {Nature Communications},
  number    = {8646},
  doi       = {10.1038/ncomms9646},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-148157},
  year      = {2015},
  abstract  = {Ever since the discovery of dye self-assemblies in nature, there have been tremendous efforts to exploit biomimetic supramolecular assemblies for tailored artificial photon processing materials. This feature necessarily has resulted in an increasing demand for understanding exciton dynamics in the dye self-assemblies. In a sharp contrast with pi-type aggregates, however, the detailed observation of exciton dynamics in H-type aggregates has remained challenging. In this study, as we succeed in measuring transient fluorescence from Frenkel state of π-stacked perylene tetracarboxylic acid bisimide dimer and oligomer aggregates, we present an experimental demonstration on Frenkel exciton dynamics of archetypal columnar π-π stacks of dyes. The analysis of the vibronic peak ratio of the transient fluorescence spectra reveals that unlike the simple π-stacked dimer, the photoexcitation energy in the columnar π-stacked oligomer aggregates is initially delocalized over at least three molecular units and moves coherently along the chain in tens of femtoseconds, preceding excimer formation process.},
  language  = {en}
}