@article{BoldStolteShoyamaetal.2022,
  author    = {Bold, Kevin and Stolte, Matthias and Shoyama, Kazutaka and Holzapfel, Marco and Schmiedel, Alexander and Lambert, Christoph and W{\"u}rthner, Frank},
  title     = {Macrocyclic donor-acceptor dyads composed of a perylene bisimide dye surrounded by oligothiophene bridges},
  series = {Angewandte Chemie Internationale Edition},
  volume    = {61},
  journal   = {Angewandte Chemie Internationale Edition},
  number    = {1},
  doi       = {10.1002/anie.202113598},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256569},
  year      = {2022},
  abstract  = {Two macrocyclic architectures comprising oligothiophene strands that connect the imide positions of a perylene bisimide (PBI) dye have been synthesized via a platinum-mediated cross-coupling strategy. The crystal structure of the double bridged PBI reveals all syn-arranged thiophene units that completely enclose the planar PBI chromophore via a 12-membered macrocycle. The target structures were characterized by steady-state UV/Vis absorption, fluorescence and transient absorption spectroscopy, as well as cyclic and differential pulse voltammetry. Both donor-acceptor dyads show ultrafast F{\"o}rster Resonance Energy Transfer and photoinduced electron transfer, thereby leading to extremely low fluorescence quantum yields even in the lowest polarity cyclohexane solvent.},
  language  = {en}
}
@article{BoldStolteShoyamaetal.2022,
  author    = {Bold, Kevin and Stolte, Matthias and Shoyama, Kazutaka and Krause, Ana-Maria and Schmiedel, Alexander and Holzapfel, Marco and Lambert, Christoph and W{\"u}rthner, Frank},
  title     = {Macrocyclic Donor-Acceptor Dyads Composed of Oligothiophene Half-Cycles and Perylene Bisimides},
  series = {Chemistry - A European Journal},
  volume    = {28},
  journal   = {Chemistry - A European Journal},
  number    = {30},
  doi       = {10.1002/chem.202200355},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276435},
  year      = {2022},
  abstract  = {A series of donor-acceptor (D-A) macrocyclic dyads consisting of an electron-poor perylene bisimide (PBI) π-scaffold bridged with electron-rich α-oligothiophenes bearing four, five, six and seven thiophene units between the two phenyl-imide substituents has been synthesized and characterized by steady-state UV/Vis absorption and fluorescence spectroscopy, cyclic and differential pulse voltammetry as well as transient absorption spectroscopy. Tying the oligothiophene strands in a conformationally fixed macrocyclic arrangement leads to a more rigid π-scaffold with vibronic fine structure in the respective absorption spectra. Electrochemical analysis disclosed charged state properties in solution which are strongly dependent on the degree of rigidification within the individual macrocycle. Investigation of the excited state dynamics revealed an oligothiophene bridge size-dependent fast charge transfer process for the macrocyclic dyads upon PBI subunit excitation.},
  language  = {en}
}
@article{BrustNaglerShoyamaetal.2023,
  author    = {Brust, Felix and Nagler, Oliver and Shoyama, Kazutaka and Stolte, Matthias and W{\"u}rthner, Frank},
  title     = {Organic Light-Emitting Diodes Based on Silandiol-Bay-Bridged Perylene Bisimides},
  series = {Advanced Optical Materials},
  volume    = {11},
  journal   = {Advanced Optical Materials},
  number    = {5},
  doi       = {10.1002/adom.202202676},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312599},
  year      = {2023},
  abstract  = {Perylene bisimides (PBIs) are among the best fluorophores but have to be enwrapped for optoelectronic applications by large and heavy substituents to prevent their ππ-stacking, which is known to accelerate non-radiative decay processes in the solid state. Here, light-weight di-tert-butylsilyl groups are introduced to bridge 1,12-dihydroxy and 1,6,7,12-tetrahydroxy PBIs to afford sublimable dyes for vacuum-processed optoelectronic devices. For both new compounds, this substitution provides a twisted and shielded perylene π-core whose, via OSiObridges, rigid structure affords well-resolved absorption and emission spectra with strong fluorescence in solution, as well as in the solid state. The usefulness of these dyes for vacuum-processed optoelectronic devices is demonstrated in organic light-emitting diodes (OLEDs) that show monomer-like emission spectra and high maximum external quantum efficiency (EQEmax) values of up to 3.1\% for the doubly silicon-bridged PBI.},
  language  = {en}
}
@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{HechtLeowanawatGerlachetal.2020,
  author    = {Hecht, Markus and Leowanawat, Pawaret and Gerlach, Tabea and Stepanenko, Vladimir and Stolte, Matthias and Lehmann, Matthias and W{\"u}rthner, Frank},
  title     = {Self-Sorting Supramolecular Polymerization: Helical and Lamellar Aggregates of Tetra-Bay-Acyloxy Perylene Bisimide},
  series = {Angewandte Chemie International Edition},
  volume    = {59},
  journal   = {Angewandte Chemie International Edition},
  number    = {39},
  doi       = {10.1002/anie.202006744},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224586},
  pages     = {17084 -- 17090},
  year      = {2020},
  abstract  = {A new perylene bisimide (PBI), with a fluorescence quantum yield up to unity, self-assembles into two polymorphic supramolecular polymers. This PBI bears four solubilizing acyloxy substituents at the bay positions and is unsubstituted at the imide position, thereby allowing hydrogen-bond-directed self-assembly in nonpolar solvents. The formation of the polymorphs is controlled by the cooling rate of hot monomer solutions. They show distinctive absorption profiles and morphologies and can be isolated in different polymorphic liquid-crystalline states. The interchromophoric arrangement causing the spectral features was elucidated, revealing the formation of columnar and lamellar phases, which are formed by either homo- or heterochiral self-assembly, respectively, of the atropoenantiomeric PBIs. Kinetic studies reveal a narcissistic self-sorting process upon fast cooling, and that the transformation into the heterochiral (racemic) sheetlike self-assemblies proceeds by dissociation via the monomeric state.},
  language  = {en}
}
@article{KimLiessStolteetal.2021,
  author    = {Kim, Jin Hong and Liess, Andreas and Stolte, Matthias and Krause, Ana-Maria and Stepanenko, Vladimir and Zhong, Chuwei and Bialas, David and Spano, Frank and W{\"u}rthner, Frank},
  title     = {An Efficient Narrowband Near-Infrared at 1040 nm Organic Photodetector Realized by Intermolecular Charge Transfer Mediated Coupling Based on a Squaraine Dye},
  series = {Advanced Materials},
  volume    = {33},
  journal   = {Advanced Materials},
  number    = {26},
  doi       = {10.1002/adma.202100582},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256374},
  year      = {2021},
  abstract  = {A highly sensitive short-wave infrared (SWIR, λ > 1000 nm) organic photodiode (OPD) is described based on a well-organized nanocrystalline bulk-heterojunction (BHJ) active layer composed of a dicyanovinyl-functionalized squaraine dye (SQ-H) donor material in combination with PC\(_{61}\)BM. Through thermal annealing, dipolar SQ-H chromophores self-assemble in a nanoscale structure with intermolecular charge transfer mediated coupling, resulting in a redshifted and narrow absorption band at 1040 nm as well as enhanced charge carrier mobility. The optimized OPD exhibits an external quantum efficiency (EQE) of 12.3\% and a full-width at half-maximum of only 85 nm (815 cm\(^{-1}\)) at 1050 nm under 0 V, which is the first efficient SWIR OPD based on J-type aggregates. Photoplethysmography application for heart-rate monitoring is successfully demonstrated on flexible substrates without applying reverse bias, indicating the potential of OPDs based on short-range coupled dye aggregates for low-power operating wearable applications.},
  language  = {en}
}
@article{KimSchembriBialasetal.2022,
  author    = {Kim, Jin Hong and Schembri, Tim and Bialas, David and Stolte, Matthias and W{\"u}rthner, Frank},
  title     = {Slip-Stacked J-Aggregate Materials for Organic Solar Cells and Photodetectors},
  series = {Advanced Materials},
  volume    = {34},
  journal   = {Advanced Materials},
  number    = {22},
  doi       = {10.1002/adma.202104678},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276537},
  year      = {2022},
  abstract  = {Dye-dye interactions affect the optical and electronic properties in organic semiconductor films of light harvesting and detecting optoelectronic applications. This review elaborates how to tailor these properties of organic semiconductors for organic solar cells (OSCs) and organic photodiodes (OPDs). While these devices rely on similar materials, the demands for their optical properties are rather different, the former requiring a broad absorption spectrum spanning from the UV over visible up to the near-infrared region and the latter an ultra-narrow absorption spectrum at a specific, targeted wavelength. In order to design organic semiconductors satisfying these demands, fundamental insights on the relationship of optical properties are provided depending on molecular packing arrangement and the resultant electronic coupling thereof. Based on recent advancements in the theoretical understanding of intermolecular interactions between slip-stacked dyes, distinguishing classical J-aggregates with predominant long-range Coulomb coupling from charge transfer (CT)-mediated or -coupled J-aggregates, whose red-shifts are primarily governed by short-range orbital interactions, is suggested. Within this framework, the relationship between aggregate structure and functional properties of representative classes of dye aggregates is analyzed for the most advanced OSCs and wavelength-selective OPDs, providing important insights into the rational design of thin-film optoelectronic materials.},
  language  = {en}
}
@article{MenekseMahlAlbertetal.2023,
  author    = {Menekse, Kaan and Mahl, Magnus and Albert, Julius and Niyas, M. A. and Shoyama, Kazutaka and Stolte, Matthias and W{\"u}rthner, Frank},
  title     = {Supramolecularly Engineered Bulk-Heterojunction Solar Cells with Self-Assembled Non-Fullerene Nanographene Tetraimide Acceptors},
  series = {Solar RRL},
  volume    = {7},
  journal   = {Solar RRL},
  number    = {2},
  doi       = {10.1002/solr.202200895},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312099},
  year      = {2023},
  abstract  = {A series of novel imide-functionalized C\(_{64}\) nanographenes is investigated as acceptor components in organic solar cells (OSCs) in combination with donor polymer PM6. These electron-poor molecules either prevail as a monomer or self-assemble into dimers in the OSC active layer depending on the chosen imide substituents. This allows for the controlled stacking of electron-poor and electron-rich π-scaffolds to establish a novel class of non-fullerene acceptor materials to tailor the bulk-heterojunction morphology of the OSCs. The best performance is observed for derivatives that are able to self-assemble into dimers, reaching power conversion efficiencies of up to 7.1\%.},
  language  = {en}
}
@article{MenekseRennerMahlmeisteretal.2020,
  author    = {Menekse, Kaan and Renner, Rebecca and Mahlmeister, Bernhard and Stolte, Matthias and W{\"u}rthner, Frank},
  title     = {Bowl-shaped naphthalimide-annulated corannulene as nonfullerene acceptor in organic solar cells},
  series = {Organic Materials},
  volume    = {2},
  journal   = {Organic Materials},
  number    = {3},
  issn      = {2625-1825},
  doi       = {10.1055/s-0040-1714283},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299095},
  pages     = {229-234},
  year      = {2020},
  abstract  = {An electron-poor bowl-shaped naphthalimide-annulated corannulene with branched alkyl residues in the imide position was synthesized by a palladium-catalyzed cross-coupling annulation sequence. This dipolar compound exhibits strong absorption in the visible range along with a low-lying LUMO level at -3.85 eV, enabling n-type charge transport in organic thin-film transistors. Furthermore, we processed inverted bulk-heterojunction solar cells in combination with the two donor polymers PCE-10 and PM6 to achieve open-circuit voltages up to 1.04 V. By using a blend of the self-assembled naphthalimide-annulated corannulene and PCE-10, we were able to obtain a power conversion efficiency of up to 2.1\%, which is to the best of our knowledge the highest reported value for a corannulene-based organic solar cell to date.},
  language  = {en}
}
@article{RennerMahlmeisterAnhaltetal.2021,
  author    = {Renner, Rebecca and Mahlmeister, Bernhard and Anhalt, Olga and Stolte, Matthias and W{\"u}rthner, Frank},
  title     = {Chiral Perylene Bisimide Dyes by Interlocked Arene Substituents in the Bay Area},
  series = {Chemistry - A European Journal},
  volume    = {27},
  journal   = {Chemistry - A European Journal},
  number    = {46},
  doi       = {10.1002/chem.202101877},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-249070},
  pages     = {11997 -- 12006},
  year      = {2021},
  abstract  = {A series of perylene bisimide (PBI) dyes bearing various aryl substituents in 1,6,7,12 bay positions has been synthesized by Suzuki cross-coupling reaction. These molecules exhibit an exceptionally large and conformationally fixed twist angle of the PBI π-core due to the high steric congestion imparted by the aryl substituents in bay positions. Single crystal X-ray analyses of phenyl-, naphthyl- and pyrenyl-functionalized PBIs reveal interlocked π-π-stacking motifs, leading to conformational chirality and the possibility for the isolation of enantiopure atropoisomers by semipreparative HPLC. The interlocked arrangement endows these molecules with substantial racemization barriers of about 120 kJ mol\(^{-1}\) for the tetraphenyl- and tetra-2-naphthyl-substituted derivatives, which is among the highest racemization barriers for axially chiral PBIs. Variable temperature NMR studies reveal the presence of a multitude of up to fourteen conformational isomers in solution that are interconverted via smaller activation barriers of about 65 kJ mol\(^{-1}\). The redox and optical properties of these core-twisted PBIs have been characterized by cyclic voltammetry, UV/Vis/NIR and fluorescence spectroscopy and their respective atropo-enantiomers were further characterized by circular dichroism (CD) and circular polarized luminescence (CPL) spectroscopy.},
  language  = {en}
}