Publications

@article{nokey,

title = {Recent Advances in Cross-Couplings of Functionalized Organozinc Reagents},

author = {B Wei and P Knochel},

url = {https://www.thieme-connect.com/products/ejournals/abstract/10.1055/a-1589-0150},

doi = {10.1055/a-1589-0150},

issn = {0039-7881 DOI - 10.1055/a-1589-0150},

year  = {2021},

date = {2021-08-16},

journal = {Synthesis},

volume = {54},

number = {02},

pages = {246-254},

abstract = {Cross-couplings involving organozinc reagents usually require a Pd-catalyst (Negishi cross-coupling), however, uncatalyzed cross-couplings of zinc organometallics proceed well in the absence of transition-metal catalysts with reactive electrophiles such as benzal 1,1-diacetates, benzhydryl acetates, and iminium trifluoroacetates. Organozinc compounds also undergo C\textendashN bond formation with O-benzoylhydroxylamines or organic azides in the presence of cobalt- or iron-catalysts. Highly diastereoselective and enantioselective cross-couplings can be readily performed with room-temperature configurationally stable alkylzinc species, producing diastereoselectively and enantiomerically enriched products. Finally, highly regioselective magnesiations of functionalized arenes and heteroarenes undergo Negishi (after transmetalation with ZnCl2) or Cu-catalyzed cross-couplings.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Short Excited‐State Lifetimes Mediate Charge‐Recombination Losses in Organic Solar Cell Blends with Low Charge‐Transfer Driving Force},

author = {R Shivhare and G J Moore and A Hofacker and S Hutsch and Y Zhong and M Hambsch and T Erdmann and A Kiriy and S C Mannsfeld and F Ortmann},

issn = {0935-9648},

year  = {2021},

date = {2021-08-15},

journal = {Advanced Materials},

pages = {2101784},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Advanced Printed Semiconductors for Energy and Electronic Applications},

author = {T Ameri and L Ke and N Gasparini and R Soltani and M G\"{u}nther and A Buyruk and A A Amin},

url = {https://www.proceedings.iaamonline.org/image/article/1628028399Tayebeh-Ameri---Abstract.pdf},

doi = {https://www.proceedings.iaamonline.org/image/article/1628028399Tayebeh-Ameri---Abstract.pdf},

year  = {2021},

date = {2021-08-03},

urldate = {2021-08-03},

journal = {Video Proceedings of Advanced Materials},

volume = {2},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Electro-mediated PhotoRedox Catalysis for Selective C(sp3)-O Cleavages of Phosphinated Alcohols to Carbanions},

author = {X Tian and T A Karl and S Reiter and S Yakubov and R De Vivie-Riedle and B Koenig and J P Barham},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202105895},

doi = {https://doi.org/10.1002/anie.202105895},

issn = {1433-7851},

year  = {2021},

date = {2021-06-24},

urldate = {2021-06-24},

journal = {Angewandte Chemie International Edition},

volume = {n/a},

number = {n/a},

abstract = {We report a novel example of electro-mediated photoredox catalysis (e-PRC) in the reductive cleavage of C(sp 3 )-O bonds of phosphinated alcohols to alkyl carbanions. As well as deoxygenations, olefinations are reported which are E -selective and can be made Z -selective in a tandem reduction/photosensitization process where both steps are photoelectrochemically promoted. Spectroscopy, computation and catalyst structural variations reveal that our new naphthalene monoimide-type catalyst allows for a more intimate dispersive precomplexation of its radical anion form with the phosphinate substrate, facilitating a reactivity-determining C(sp 3 )-O cleavage. Surprisingly and in contrast to previously reported photoexcited radical anion chemistries, our conditions i) tolerate aryl chlorides/bromides and ii) do not give rise to Birch-type reductions.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {The Influence of the Blend Ratio, Solvent Additive, and Post-production Treatment on the Polymer Dynamics in PTB7:PCBM Blend Films},

author = {D M Schwaiger and W Lohstroh and P M\"{u}ller-Buschbaum},

url = {https://doi.org/10.1021/acs.macromol.1c00313},

doi = {10.1021/acs.macromol.1c00313},

issn = {0024-9297},

year  = {2021},

date = {2021-06-23},

urldate = {2021-06-23},

journal = {Macromolecules},

abstract = {The polymer dynamics inside a bulk heterojunction (BHJ), as used in organic solar cells, are investigated with quasielastic neutron scattering to study hydrogen motion in the polymer side chains. Different blend ratios of the polymer donor poly(4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl) (PTB7) and the small molecule acceptor [6,6]phenyl-C71-butyric acid methyl ester (PCBM) are investigated. In addition, the influence of performance-enhancing measures, such as the use of the solvent additive 1,8-diiodooctane (DIO) and the post-production treatment of the BHJ films with methanol, on the polymer dynamics is studied. The analysis of mean square displacements as well as relaxation times of diffusional motions of the hydrogen atoms, located mainly in the polymer side chains, shows a gradual stiffening of the PTB7 side chains for higher PCBM loading in the BHJ films. The presence of DIO significantly increases diffusive mobility inside the films, while the methanol treatment does not affect hydrogen motions.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Band gap engineering in blended organic semiconductor films based on dielectric interactions},

author = {K Ortstein and S Hutsch and M Hambsch and K Tvingstedt and B Wegner and J Benduhn and J Kublitski and M Schwarze and S Schellhammer and F Talnack and A Vogt and P B\"{a}uerle and N Koch and S C B Mannsfeld and H Kleemann and F Ortmann and K Leo},

url = {https://doi.org/10.1038/s41563-021-01025-z},

doi = {10.1038/s41563-021-01025-z},

issn = {1476-4660},

year  = {2021},

date = {2021-06-10},

urldate = {2021-06-10},

journal = {Nature Materials},

abstract = {Blending organic molecules to tune their energy levels is currently being investigated as an approach to engineer the bulk and interfacial optoelectronic properties of organic semiconductors. It has been proven that the ionization energy and electron affinity can be equally shifted in the same direction by electrostatic effects controlled by blending similar halogenated derivatives with different energetics. Here we show that the energy gap of organic semiconductors can also be tuned by blending. We use oligothiophenes with different numbers of thiophene rings as an example and investigate their structure and electronic properties. Photoelectron spectroscopy and inverse photoelectron spectroscopy show tunability of the single-particle gap, with the optical gaps showing similar, but smaller, effects. Theoretical analysis shows that this tuning is mainly caused by a change in the dielectric constant with blend ratio. Further studies will explore the practical impact of this energy-level engineering strategy for optoelectronic devices.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {In situ monitoring of mechanochemical covalent organic framework formation reveals templating effect of liquid additive},

author = {S T Emmerling and L S Germann and P A Julien and I Moudrakovski and M Etter and T Fri\v{s}\v{c}i\'{c} and R E Dinnebier and B V Lotsch},

url = {https://www.sciencedirect.com/science/article/pii/S2451929421002138},

doi = {https://doi.org/10.1016/j.chempr.2021.04.012},

issn = {2451-9294},

year  = {2021},

date = {2021-06-10},

journal = {Chem},

volume = {7},

number = {6},

pages = {1639-1652},

abstract = {Summary Covalent organic frameworks (COFs) have emerged as a new class of molecularly precise, porous functional materials characterized by broad structural and chemical versatility, with a diverse range of applications. Despite their increasing popularity, fundamental aspects of COF formation are poorly understood, lacking profound experimental insights into their assembly. Here, we use a combination of in situ X-ray powder diffraction and Raman spectroscopy to elucidate the reaction mechanism of mechanochemical synthesis of imine COFs, leading to the observation of key reaction intermediates that offer direct experimental evidence of framework templating through liquid additives. Moreover, the solid-state catalyst scandium triflate is instrumental in directing the reaction kinetics and mechanism, yielding COFs with crystallinity and porosity on par with solvothermal products. This work provides the first experimental evidence of solvent-based COF templating and is a significant advancement in mechanistic understanding of mechanochemistry as a green route for COF synthesis.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Dual Nanoresonators for Ultrasensitive Chiral Detection},

author = {E Mohammadi and A Tittl and K L Tsakmakidis and T V Raziman and A G Curto},

url = {https://doi.org/10.1021/acsphotonics.1c00311},

doi = {10.1021/acsphotonics.1c00311},

year  = {2021},

date = {2021-05-28},

journal = {ACS Photonics},

abstract = {The discrimination of enantiomers is crucial in biochemistry. However, chiral sensing faces significant limitations due to inherently weak chiroptical signals. Nanophotonics is a promising solution to enhance sensitivity thanks to increased optical chirality maximized by strong electric and magnetic fields. Metallic and dielectric nanoparticles can separately provide electric and magnetic resonances. Here we propose their synergistic combination in hybrid metal\textendashdielectric nanostructures to exploit their dual character for superchiral fields beyond the limits of single particles. For optimal optical chirality, in addition to maximization of the resonance strength, the resonances must spectrally coincide. Simultaneously, their electric and magnetic fields must be parallel and π/2 out of phase and spatially overlap. We demonstrate that the interplay between the strength of the resonances and these optimal conditions constrains the attainable optical chirality in resonant systems. Starting from a simple symmetric nanodimer, we derive closed-form expressions elucidating its fundamental limits of optical chirality. Building on the trade-offs of different classes of dimers, we then suggest an asymmetric dual dimer based on realistic materials. These dual nanoresonators provide strong and decoupled electric and magnetic resonances together with optimal conditions for chiral fields. Finally, we introduce more complex dual building blocks for a metasurface with a record 300-fold enhancement of local optical chirality in nanoscale gaps, enabling circular dichroism enhancement by a factor of 20. By combining analytical insight and practical designs, our results put forward hybrid resonators to increase chiral sensitivity, particularly for small molecular quantities.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Loading linear arrays of Cu(II) inside aromatic amide helices},

author = {J Wang and B Wicher and A M\'{e}ndez-Ardoy and X Li and G Pecastaings and T Buffeteau and D M Bassani and V Maurizot and I Huc},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202104734},

doi = {https://doi.org/10.1002/anie.202104734},

issn = {1433-7851},

year  = {2021},

date = {2021-05-20},

journal = {Angewandte Chemie International Edition},

volume = {n/a},

number = {n/a},

abstract = {The very stable helices of 8-amino-2-quinolinecarboxylic acid oligoamides are shown to uptake Cu(II) ions in their cavity through deprotonation of their amide functions with minimal alteration of their shape, unlike most metallo-organic structures which generally much differ from their organic precursors. The outcome is the formation of intramolecular linear arrays of a defined number of Cu(II) centers (up to sixteen in this study) at a 3 r{A} distance, forming a molecular mimic of a metal wire completely surrounded by an organic sheath. The helices pack in the solid state so that the arrays of Cu(II) extend intermolecularly. Conductive-AFM and cyclic voltammetry suggest that electrons are transported throughout the metal-loaded helices in contrast with hole transport observed for analogous foldamers devoid of metal ions.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Electronic and Geometric Characterization of TICT Formation in Hemithioindigo Photoswitches by Picosecond Infrared Spectroscopy},

author = {K Stallhofer and M Nuber and F Sch\"{u}ppel and S Thumser and H Iglev and R De Vivie-Riedle and W Zinth and H Dube},

url = {https://doi.org/10.1021/acs.jpca.1c02646},

doi = {10.1021/acs.jpca.1c02646},

issn = {1089-5639},

year  = {2021},

date = {2021-05-14},

urldate = {2021-05-14},

journal = {The Journal of Physical Chemistry A},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Coherent vibrational dynamics reveals lattice anharmonicity in organic\textendashinorganic halide perovskite nanocrystals},

author = {T Debnath and D Sarker and H Huang and Z-K Han and A Dey and L Polavarapu and S V Levchenko and J Feldmann},

url = {https://doi.org/10.1038/s41467-021-22934-2},

doi = {10.1038/s41467-021-22934-2},

issn = {2041-1723},

year  = {2021},

date = {2021-05-11},

journal = {Nature Communications},

volume = {12},

number = {1},

pages = {2629},

abstract = {The halide ions of organic-inorganic hybrid perovskites can strongly influence the interaction between the central organic moiety and the inorganic metal halide octahedral units and thus their lattice vibrations. Here, we report the halide-ion-dependent vibrational coherences in formamidinium lead halide (FAPbX3, X = Br, I) perovskite nanocrystals (PNCs) via the combination of femtosecond pump\textendashprobe spectroscopy and density functional theory calculations. We find that the FAPbX3 PNCs generate halide-dependent coherent vibronic wave packets upon above-bandgap non-resonant excitation. More importantly, we observe several higher harmonics of the fundamental modes for FAPbI3 PNCs as compared to FAPbBr3 PNCs. This is likely due to the weaker interaction between the central FA moiety and the inorganic cage for FAPbI3 PNCs, and thus the PbI64− unit can vibrate more freely. This weakening reveals the intrinsic anharmonicity in the Pb-I framework, and thus facilitating the energy transfer into overtone and combination bands. These findings not only unveil the superior stability of Br\textendashbased PNCs over I\textendashbased PNCs but are also important for a better understanding of their electronic and polaronic properties.},

keywords = {Foundry Inorganic, Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Dehydrogenative 6π heterocyclization under visible light irradiation and mechanistic insights},

author = {Z Zhang and H Chen and N Keller and Q Xiong and L Liu and Y Lan and T Bein and J Li},

url = {http://dx.doi.org/10.1039/D1QO00356A},

doi = {10.1039/D1QO00356A},

year  = {2021},

date = {2021-05-07},

journal = {Organic Chemistry Frontiers},

volume = {8},

number = {14},

pages = {3788-3795},

abstract = {A visible-light-driven oxidative 6π heterocyclization for the synthesis of structurally diverse π-conjugated polycyclic 1-aminoisoquinolines has been developed. The reaction proceeds under visible-light or sunlight, obviates the need for photocatalysts and transition-metals, and features an unusually broad substrate scope and high efficacy. This synthetic pathway provided an easy access to highly fluorescent small molecules with high photoluminescence quantum yields. The N-heterocycles exhibit suitable optical properties for application as fluorescence quantum yield standards. DFT calculations were employed to gain insight into the mechanism and the results show that deprotonation is the rate-determining step, which can be promoted by a TFA additive.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {High-Performance Vertical Organic Transistors of Sub-5 nm Channel Length},

author = {J Lenz and A M Seiler and F R Geisenhof and F Winterer and K Watanabe and T Taniguchi and R T Weitz},

url = {https://doi.org/10.1021/acs.nanolett.1c01144},

doi = {10.1021/acs.nanolett.1c01144},

issn = {1530-6984},

year  = {2021},

date = {2021-05-06},

journal = {Nano Letters},

abstract = {Miniaturization of electronic circuits increases their overall performance. So far, electronics based on organic semiconductors has not played an important role in the miniaturization race. Here, we show the fabrication of liquid electrolyte gated vertical organic field effect transistors with channel lengths down to 2.4 nm. These ultrashort channel lengths are enabled by using insulating hexagonal boron nitride with atomically precise thickness and flatness as a spacer separating the vertically aligned source and drain electrodes. The transistors reveal promising electrical characteristics with output current densities of up to 2.95 MA cm\textendash2 at −0.4 V bias, on\textendashoff ratios of up to 106, a steep subthreshold swing of down to 65 mV dec\textendash1 and a transconductance of up to 714 S m\textendash1. Realizing channel lengths in the sub-5 nm regime and operation voltages down to 100 μV proves the potential of organic semiconductors for future highly integrated or low power electronics.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Graphene Energy Transfer for Single-Molecule Biophysics, Biosensing, and Super-Resolution Microscopy},

author = {I Kami\'{n}ska and J Bohlen and R Yaadav and P Sch\"{u}ler and M Raab and T Schr\"{o}der and J Z\"{a}hringer and K Zielonka and S Krause and P Tinnefeld},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202101099},

doi = {https://doi.org/10.1002/adma.202101099},

issn = {0935-9648},

year  = {2021},

date = {2021-05-03},

urldate = {2021-05-03},

journal = {Advanced Materials},

volume = {n/a},

number = {n/a},

pages = {2101099},

abstract = {Abstract Graphene is considered a game-changing material, especially for its mechanical and electrical properties. This work exploits that graphene is almost transparent but quenches fluorescence in a range up to ≈40 nm. Graphene as a broadband and unbleachable energy-transfer acceptor without labeling, is used to precisely determine the height of molecules with respect to graphene, to visualize the dynamics of DNA nanostructures, and to determine the orientation of F\"{o}rster-type resonance energy transfer (FRET) pairs. Using DNA origami nanopositioners, biosensing, single-molecule tracking, and DNA PAINT super-resolution with \<3 nm z-resolution are demonstrated. The range of examples shows the potential of graphene-on-glass coverslips as a versatile platform for single-molecule biophysics, biosensing, and super-resolution microscopy.},

keywords = {Foundry Inorganic, Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Photovoltaic Cells Based on Ternary P3HT:PCBM:Ruthenium(II) Complex Bearing 8-(diphenylphosphino)quinoline Active Layer},

author = {S Akel and M A Sharif and R Al-Esseili and M A Al-Wahish and H A Hodali and P M\"{u}ller-Buschbaum and L Schmidt-Mende and M Al-Hussein},

url = {https://www.sciencedirect.com/science/article/pii/S0927775721005549},

doi = {https://doi.org/10.1016/j.colsurfa.2021.126685},

issn = {0927-7757},

year  = {2021},

date = {2021-04-24},

urldate = {2021-04-24},

journal = {Colloids and Surfaces A: Physicochemical and Engineering Aspects},

pages = {126685},

abstract = {ABSTRACT Optical, morphological and photovoltaic properties are investigated for ternary solar cells containing a traditional poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl-C61-butyric-acid-methyl ester (P3HT:PCBM) bulkheterojunction (BHJ) active layer modified with different concentrations of a novel ruthenium complex [Ru(N-P)2(O-O)], where N-P abbreviates 8-(diphenylphosphino)quinolone and O-O = oxalate dianion. At a low concentration of the Ru-complex (2.5wt. %) the device efficiency is improved by 50% compared with the reference binary devices at ambient conditions. This substantial efficiency enhancement is attributed to the role of the Ru-complex in improving light absorption over a wavelength range of (295-800nm) in combination with a better matching of the energy levels of the ternary blend system. Moreover, at low concentration, the Ru-complex has a positive impact on the morphology of the active layer in the device. The inclusion of Ru-complex increases the P3HT crystallinity substantially with virtually no effect on the size and orientation of the crystalline lamellae. The enhancement in device efficiency becomes less pronounced with increasing the concentration of the Ru-complex due to the formation of several micron-size domains of [Ru(N-P)2(O-O)] in the ternary active layers. These large domains negatively affect the optical properties and morphology, thus inhibiting efficient charge generation and transport in the corresponding solar cells.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Increasing Photostability of Inverted Nonfullerene Organic Solar Cells by Using Fullerene Derivative Additives},

author = {M G\"{u}nther and D Bl\"{a}tte and A L Oechsle and S S Rivas and Yousefi A A Amin and P M\"{u}ller-Buschbaum and T Bein and T Ameri},

url = {https://doi.org/10.1021/acsami.1c00700},

doi = {10.1021/acsami.1c00700},

issn = {1944-8244},

year  = {2021},

date = {2021-04-16},

urldate = {2021-04-16},

journal = {ACS Applied Materials \& Interfaces},

abstract = {Organic solar cells (OSCs) recently achieved efficiencies of over 18% and are well on their way to practical applications, but still considerable stability issues need to be overcome. One major problem emerges from the electron transport material zinc oxide (ZnO), which is mainly used in the inverted device architecture and decomposes many high-performance nonfullerene acceptors due to its photocatalytic activity. In this work, we add three different fullerene derivatives\textemdashPC71BM, ICMA, and BisPCBM\textemdashto an inverted binary PBDB-TF:IT-4F system in order to suppress the photocatalytic degradation of IT-4F on ZnO via the radical scavenging abilities of the fullerenes. We demonstrate that the addition of 5% fullerene not only increases the performance of the binary PBDB-TF:IT-4F system but also significantly improves the device lifetime under UV illumination in an inert atmosphere. While the binary devices lose 20% of their initial efficiency after only 3 h, this time is increased fivefold for the most promising ternary devices with ICMA. We attribute this improvement to a reduced photocatalytic decomposition of IT-4F in the ternary system, which results in a decreased recombination. We propose that the added fullerenes protect the IT-4F by acting as a sacrificial reagent, thereby suppressing the trap state formation. Furthermore, we show that the protective effect of the most promising fullerene ICMA is transferable to two other binary systems PBDB-TF:BTP-4F and PTB7-Th:IT-4F. Importantly, this effect can also increase the air stability of PBDB-TF:IT-4F. This work demonstrates that the addition of fullerene derivatives is a transferable and straightforward strategy to improve the stability of OSCs.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Graphene-on-Glass Preparation and Cleaning Methods Characterized by Single-Molecule DNA Origami Fluorescent Probes and Raman Spectroscopy},

author = {S Krause and E Ploetz and J Bohlen and P Sch\"{u}ler and R Yaadav and F Selbach and F Steiner and I Kami\'{n}ska and P Tinnefeld},

url = {https://pubs.acs.org/doi/abs/10.1021/acsnano.0c08383},

doi = {10.1021/acsnano.0c08383},

issn = {1936-0851},

year  = {2021},

date = {2021-04-09},

urldate = {2021-04-09},

journal = {ACS Nano},

abstract = {Graphene exhibits outstanding fluorescence quenching properties that can become useful for biophysics and biosensing applications, but it remains challenging to harness these advantages due to the complex transfer procedure of chemical vapor deposition-grown graphene to glass coverslips and the low yield of usable samples. Here, we screen 10 graphene-on-glass preparation methods and present an optimized protocol. To obtain the required quality for single-molecule and super-resolution imaging on graphene, we introduce a graphene screening method that avoids consuming the investigated sample. We apply DNA origami nanostructures to place fluorescent probes at a defined distance on top of graphene-on-glass coverslips. Subsequent fluorescence lifetime imaging directly reports on the graphene quality, as deviations from the expected fluorescence lifetime indicate imperfections. We compare the DNA origami probes with conventional techniques for graphene characterization, including light microscopy, atomic force microscopy, and Raman spectroscopy. For the latter, we observe a discrepancy between the graphene quality implied by Raman spectra in comparison to the quality probed by fluorescence lifetime quenching measured at the same position. We attribute this discrepancy to the difference in the effective area that is probed by Raman spectroscopy and fluorescence quenching. Moreover, we demonstrate the applicability of already screened and positively evaluated graphene for studying single-molecule conformational dynamics on a second DNA origami structure. Our results constitute the basis for graphene-based biophysics and super-resolution microscopy.},

keywords = {Foundry Inorganic, Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Long- and short-ranged chiral interactions in DNA-assembled plasmonic chains},

author = {K Martens and F Binkowski and L Nguyen and L Hu and A O Govorov and S Burger and T Liedl},

url = {https://doi.org/10.1038/s41467-021-22289-8},

doi = {10.1038/s41467-021-22289-8},

issn = {2041-1723},

year  = {2021},

date = {2021-04-01},

journal = {Nature Communications},

volume = {12},

number = {1},

pages = {2025},

abstract = {Circular dichroism (CD) has long been used to trace chiral molecular states and changes of protein configurations. In recent years, chiral plasmonic nanostructures have shown potential for applications ranging from pathogen sensing to novel optical materials. The plasmonic coupling of the individual elements of such metallic structures is a crucial prerequisite to obtain sizeable CD signals. We here identify and implement various coupling entities\textemdashchiral and achiral\textemdashto demonstrate chiral transfer over distances close to 100 nm. The coupling is realized by an achiral nanosphere situated between a pair of gold nanorods that are arranged far apart but in a chiral fashion using DNA origami. The transmitter particle causes a strong enhancement of the CD response, the emergence of an additional chiral feature at the resonance frequency of the nanosphere, and a redshift of the longitudinal plasmonic resonance frequency of the nanorods. Matching numerical simulations elucidate the intricate chiral optical fields in complex architectures.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Biocompatible carbon nitride-based light-driven microswimmer propulsion in biological and ionic media with responsive on-demand drug delivery},

author = {V Sridhar and F Podjaski and Y Alapan and J Kr\"{o}ger and L Grunenberg and V Kishore and B V Lotsch and M Sitti},

url = {https://arxiv.org/abs/2103.17026},

doi = {arXiv:2103.17026v1},

year  = {2021},

date = {2021-03-31},

journal = {arXiv preprint arXiv:2103.17026},

abstract = {We propose two-dimensional organic poly(heptazine imide) (PHI) carbon nitride microparticles as light-driven microswimmers in various ionic and biological media. Their demonstrated high-speed (15-23 μm/s) swimming in multi-component ionic solutions with concentrations up to 1 M and without dedicated fuels is unprecedented, overcoming one of the bottlenecks of previous light-driven microswimmers. Such high ion tolerance is attributed to a favorable interplay between the particle's textural and structural nanoporosity and optoionic properties, facilitating ionic interactions in solutions with high salinity. Biocompatibility of the microswimmers is validated by cell viability tests with three different cell types and primary cells. The nanopores of the swimmers are loaded with a model cancer drug, doxorubicin (DOX), in high (185%) loading efficiency without passive release. Controlled drug release is reported in different pH conditions and can be triggered on-demand also by illumination. Light-triggered, boosted release of DOX and its active degradation products is demonstrated in oxygen-poor conditions using the intrinsic, environmentally sensitive and light-induced charge storage properties of PHI, which could enable future theranostic applications in oxygen-deprived tumor regions. These organic PHI microswimmers simultaneously solve the current light-driven microswimmer challenges of high ion tolerance, fuel-free high-speed propulsion in biological media, biocompatibility and controlled on-demand cargo release towards their biomedical, environmental and other potential future applications.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Single-molecule mechanics of synthetic aromatic amide helices: Ultrafast and robust non-dissipative winding},

author = {F Devaux and X Li and D Sluysmans and V Maurizot and E Bakalis and F Zerbetto and I Huc and A-S Duwez},

issn = {2451-9294},

year  = {2021},

date = {2021-03-26},

journal = {Chem},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Molecular Oxygen Activation by Redox-Switchable Anthraquinone-Based Metal\textendashOrganic Frameworks},

author = {J G M De Carvalho and R A Fischer and A P\"{o}thig},

url = {https://doi.org/10.1021/acs.inorgchem.0c03629},

doi = {10.1021/acs.inorgchem.0c03629},

issn = {0020-1669},

year  = {2021},

date = {2021-03-25},

journal = {Inorganic Chemistry},

volume = {60},

number = {7},

pages = {4676-4682},

abstract = {A dipyridyl-substituted anthraquinone (2,6-di(pyridin-4-yl)-9,10-anthraquinone, DPAq) was incorporated as a redox-active linker molecule into crystalline coordination networks. The oxidation state of the organic linker can be selectively controlled prior to framework formation and furthermore be maintained in the solid state. Hydrogen bonding is identified to be a substantial stabilization factor. Additionally, it is shown that the anthraquinone\textendashanthrahydroquinone redox pair can be switched reversibly even after incorporation in the solid state by a thermal treatment/soaking procedure\textemdashgoing along with the formation of hydrogen peroxide from molecular oxygen (air) during the oxidation process.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Fast-Switching Vis\textendashIR Electrochromic Covalent Organic Frameworks},

author = {D Bessinger and K Muggli and M Beetz and F Auras and T Bein},

url = {https://doi.org/10.1021/jacs.0c12392},

doi = {10.1021/jacs.0c12392},

issn = {0002-7863},

year  = {2021},

date = {2021-03-16},

journal = {Journal of the American Chemical Society},

abstract = {Electrochromic coatings are promising for applications in smart windows or energy-efficient optical displays. However, classical inorganic electrochromic materials such as WO3 suffer from low coloration efficiency and slow switching speed. We have developed highly efficient and fast-switching electrochromic thin films based on fully organic, porous covalent organic frameworks (COFs). The low band gap COFs have strong vis\textendashNIR absorption bands in the neutral state, which shift significantly upon electrochemical oxidation. Fully reversible absorption changes by close to 3 OD can be triggered at low operating voltages and low charge per unit area. Our champion material reaches an electrochromic coloration efficiency of 858 cm2 C\textendash1 at 880 nm and retains \>95% of its electrochromic response over 100 oxidation/reduction cycles. Furthermore, the electrochromic switching is extremely fast with response times below 0.4 s for the oxidation and around 0.2 s for the reduction, outperforming previous COFs by at least an order of magnitude and rendering these materials some of the fastest-switching frameworks to date. This combination of high coloration efficiency and very fast switching reveals intriguing opportunities for applications of porous organic electrochromic materials.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Assembly and Manipulation of a Prototypical N-Heterocyclic Carbene with a Metalloporphyrin Pedestal on a Solid Surface},

author = {P Knecht and B Zhang and J Reichert and D A Duncan and M Schwarz and F Haag and P T P Ryan and T-L Lee and P S Deimel and P Feulner and F Allegretti and W Auw\"{a}rter and G M\'{e}dard and A P Seitsonen and J V Barth and A C Papageorgiou},

url = {https://doi.org/10.1021/jacs.1c01229},

doi = {10.1021/jacs.1c01229},

issn = {0002-7863},

year  = {2021},

date = {2021-03-11},

journal = {Journal of the American Chemical Society},

volume = {143},

number = {11},

pages = {4433-4439},

abstract = {The controlled arrangement of N-heterocyclic carbenes (NHCs) on solid surfaces is a current challenge of surface functionalization. We introduce a strategy of using Ru porphyrins in order to control both the orientation and lateral arrangement of NHCs on a planar surface. The coupling of the NHC to the Ru porphyrin is a facile process which takes place on the interface: we apply NHCs as functional, robust pillars on well-defined, preassembled Ru porphyrin monolayers on silver and characterize these interfaces with atomic precision via a battery of experimental techniques and theoretical considerations. The NHCs assemble at room temperature modularly and reversibly on the Ru porphyrin arrays. We demonstrate a selective and complete functionalization of the Ru centers. With its binding, the NHC modifies the interaction of the Ru porphyrin with the Ag surface, displacing the Ru atom by 1 r{A} away from the surface. This arrangement of NHCs allows us to address individual ligands by controlled manipulation with the tip of a scanning tunneling microscope, creating patterned structures on the nanometer scale.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Determining the In-Plane Orientation and Binding Mode of Single Fluorescent Dyes in DNA Origami Structures},

author = {K H\"{u}bner and H Joshi and A Aksimentiev and F D Stefani and P Tinnefeld and G P Acuna},

url = {https://doi.org/10.1021/acsnano.0c10259},

doi = {10.1021/acsnano.0c10259},

issn = {1936-0851},

year  = {2021},

date = {2021-03-04},

journal = {ACS Nano},

abstract = {We present a technique to determine the orientation of single fluorophores attached to DNA origami structures based on two measurements. First, the orientation of the absorption transition dipole of the molecule is determined through a polarization-resolved excitation measurement. Second, the orientation of the DNA origami structure is obtained from a DNA-PAINT nanoscopy measurement. Both measurements are performed consecutively on a fluorescence wide-field microscope. We employed this approach to study the orientation of single ATTO 647N, ATTO 643, and Cy5 fluorophores covalently attached to a 2D rectangular DNA origami structure with different nanoenvironments, achieved by changing both the fluorophores’ binding position and immediate vicinity. Our results show that when fluorophores are incorporated with additional space, for example, by omitting nucleotides in an elsewise double-stranded environment, they tend to stick to the DNA and to adopt a preferred orientation that depends more on the specific molecular environment than on the fluorophore type. With the aid of all-atom molecular dynamics simulations, we rationalized our observations and provide insight into the fluorophores’ probable binding modes. We believe this work constitutes an important step toward manipulating the orientation of single fluorophores in DNA origami structures, which is vital for the development of more efficient and reproducible self-assembled nanophotonic devices.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Picosecond time-resolved photon antibunching measures nanoscale exciton motion and the true number of chromophores},

author = {G J Hedley and T Schr\"{o}der and F Steiner and T Eder and F J Hofmann and S Bange and D Laux and S H\"{o}ger and P Tinnefeld and J M Lupton and J Vogelsang},

url = {https://doi.org/10.1038/s41467-021-21474-z},

doi = {10.1038/s41467-021-21474-z},

issn = {2041-1723},

year  = {2021},

date = {2021-02-26},

journal = {Nature Communications},

volume = {12},

number = {1},

pages = {1327},

abstract = {The particle-like nature of light becomes evident in the photon statistics of fluorescence from single quantum systems as photon antibunching. In multichromophoric systems, exciton diffusion and subsequent annihilation occurs. These processes also yield photon antibunching but cannot be interpreted reliably. Here we develop picosecond time-resolved antibunching to identify and decode such processes. We use this method to measure the true number of chromophores on well-defined multichromophoric DNA-origami structures, and precisely determine the distance-dependent rates of annihilation between excitons. Further, this allows us to measure exciton diffusion in mesoscopic H- and J-type conjugated-polymer aggregates. We distinguish between one-dimensional intra-chain and three-dimensional inter-chain exciton diffusion at different times after excitation and determine the disorder-dependent diffusion lengths. Our method provides a powerful lens through which excitons can be studied at the single-particle level, enabling the rational design of improved excitonic probes such as ultra-bright fluorescent nanoparticles and materials for optoelectronic devices.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Transition-Metal-Free Synthesis of Polyfunctional Triarylmethanes and 1,1-Diarylalkanes by Sequential Cross-Coupling of Benzal Diacetates with Organozinc Reagents},

author = {B Wei and Q Ren and T Bein and P Knochel},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202101682},

doi = {https://doi.org/10.1002/anie.202101682},

issn = {1433-7851},

year  = {2021},

date = {2021-02-24},

journal = {Angewandte Chemie International Edition},

volume = {60},

number = {18},

pages = {10409-10414},

abstract = {Abstract A variety of functionalized triarylmethane and 1,1-diarylalkane derivatives were prepared via a transition-metal-free, one-pot and two-step procedure, involving the reaction of various benzal diacetates with organozinc reagents. A sequential cross-coupling is enabled by changing the solvent from THF to toluene, and a two-step SN1-type mechanism was proposed and evidenced by experimental studies. The synthetic utility of the method is further demonstrated by the synthesis of several biologically relevant molecules, such as an anti-tuberculosis agent, an anti-breast cancer agent, a precursor of a sphingosine-1-phosphate (S1P) receptor modulator, and a FLAP inhibitor.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Amine-Linked Covalent Organic Frameworks as a Platform for Postsynthetic Structure Interconversion and Pore-Wall Modification},

author = {L Grunenberg and G Savasci and M W Terban and V Duppel and I Moudrakovski and M Etter and R E Dinnebier and C Ochsenfeld and B V Lotsch},

url = {https://doi.org/10.1021/jacs.0c12249},

doi = {10.1021/jacs.0c12249},

issn = {0002-7863},

year  = {2021},

date = {2021-02-24},

urldate = {2021-02-24},

journal = {Journal of the American Chemical Society},

volume = {143},

number = {9},

pages = {3430-3438},

abstract = {Covalent organic frameworks have emerged as a powerful synthetic platform for installing and interconverting dedicated molecular functions on a crystalline polymeric backbone with atomic precision. Here, we present a novel strategy to directly access amine-linked covalent organic frameworks, which serve as a scaffold enabling pore-wall modification and linkage-interconversion by new synthetic methods based on Leuckart\textendashWallach reduction with formic acid and ammonium formate. Frameworks connected entirely by secondary amine linkages, mixed amine/imine bonds, and partially formylated amine linkages are obtained in a single step from imine-linked frameworks or directly from corresponding linkers in a one-pot crystallization-reduction approach. The new, 2D amine-linked covalent organic frameworks, rPI-3-COF, rTTI-COF, and rPy1P-COF, are obtained with high crystallinity and large surface areas. Secondary amines, installed as reactive sites on the pore wall, enable further postsynthetic functionalization to access tailored covalent organic frameworks, with increased hydrolytic stability, as potential heterogeneous catalysts.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Super-resolution Imaging of Energy Transfer by Intensity-Based STED-FRET},

author = {A M Molszalai and B Siarry and J Lukin and S Giusti and N Unsain and A C\'{a}ceres and F Steiner and P Tinnefeld and D Refojo and T M Jovin and F D Stefani},

url = {https://doi.org/10.1021/acs.nanolett.1c00158},

doi = {10.1021/acs.nanolett.1c00158},

issn = {1530-6984},

year  = {2021},

date = {2021-02-23},

journal = {Nano Letters},

abstract = {F\"{o}rster resonance energy transfer (FRET) imaging methods provide unique insight into the spatial distribution of energy transfer and (bio)molecular interaction events, though they deliver average information for an ensemble of events included in a diffraction-limited volume. Coupling super-resolution fluorescence microscopy and FRET has been a challenging and elusive task. Here, we present STED-FRET, a method of general applicability to obtain super-resolved energy transfer images. In addition to higher spatial resolution, STED-FRET provides a more accurate quantification of interaction and has the capacity of suppressing contributions of noninteracting partners, which are otherwise masked by averaging in conventional imaging. The method capabilities were first demonstrated on DNA-origami model systems, verified on uniformly double-labeled microtubules, and then utilized to image biomolecular interactions in the membrane-associated periodic skeleton (MPS) of neurons.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Sensing a binding event through charge transport variations using an aromatic oligoamide capsule},

author = {P Mateus and A Jacquet and A M\'{e}ndez-Ardoy and A Boulloy and B Kauffmann and G Pecastaings and T Buffeteau and Y Ferrand and D M Bassani and I Huc},

url = {http://dx.doi.org/10.1039/D0SC06060G},

doi = {10.1039/D0SC06060G},

issn = {2041-6520},

year  = {2021},

date = {2021-01-22},

journal = {Chemical Science},

volume = {12},

number = {10},

pages = {3743-3750},

abstract = {The selective binding properties of a 13-mer oligoamide foldamer capsule composed of 4 different aromatic subunits are reported. The capsule was designed to recognize dicarboxylic acids through multiple-point interactions owing to a combination of protonation/deprotonation events, H-bonding, and geometrical constraints imparted by the rigidity of the foldamer backbone. Compared to tartaric acid, binding of 2,2-difluorosuccinic acid or 2,2,3,3-tetrafluorosuccinic acid resulted in symmetry breaking due to deprotonation of only one of the two carboxylic acid groups of the encapsulated species as shown by NMR studies in solution and by single-crystal X-ray diffraction in the solid state. An analogous 14-mer foldamer capsule terminated with a thiol anchoring group was used to probe the complexation event in self-assembled monolayers on Au substrates. Ellipsometry and polarization-modulation infrared absorption-reflection spectroscopy studies were consistent with the formation of a single molecule layer of the foldamer capsule oriented vertically with respect to the surface. The latter underwent smooth complexation of 2,2-difluorosuccinic acid with deprotonation of one of the two carboxylic acid groups. A significant (80-fold) difference in the charge transport properties of the monolayer upon encapsulation of the dicarboxylic acid was evidenced from conducting-AFM measurements (S = 1.1 × 10−9vs. 1.4 × 10−11 ohm−1 for the empty and complexed capsule, respectively). The modulation in conductivity was assigned to protonation of the aromatic foldamer backbone.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Synergistic Interplay between Asymmetric Backbone Conformation, Molecular Aggregation, and Charge-Carrier Dynamics in Fused-Ring Electron Acceptor-Based Bulk Heterojunction Solar Cells},

author = {X Song and L Hou and R Guo and Q Wei and L Yang and X Jiang and S Tu and A Zhang and Z Kan and W Tang and G Xing and P M\"{u}ller-Buschbaum},

url = {https://doi.org/10.1021/acsami.0c19700},

doi = {10.1021/acsami.0c19700},

issn = {1944-8244},

year  = {2021},

date = {2021-01-20},

urldate = {2021-01-20},

journal = {ACS Applied Materials \& Interfaces},

volume = {13},

number = {2},

pages = {2961-2970},

abstract = {Asymmetric fused-ring electron acceptors (a-FREAs) have proved to be a promising type of electron acceptor for high-performance organic solar cells (OSCs). However, the relationship among molecular structures of a-FREAs and their nanoscale morphology, charge-carrier dynamics, and device performance remains unclear. In this contribution, two FREAs differing in conjugated backbone geometry with an asymmetric conformation (IPT-2F) or symmetric one (INPIC-2F) are selected to systematically explore the superiorities of the asymmetric conformation. Despite the frailer extinction coefficient and weaker crystallinity, IPT-2F shows stronger dipole interactions in the asymmetrical backbone, which would induce a closer lamellar packing than that of the symmetrical counterpart. Using PBDB-T as the electron donor, the IPT-2F-based OSCs achieve the best power conversion efficiency of 14.0%, which is ca. 67% improvement compared to the INPIC-2F-based ones (8.37%), resulting from a simultaneously increased short-circuited current density (Jsc) and fill factor. Systematical investigations on optoelectronic and morphological properties show that the asymmetric conformation-structured IPT-2F exhibits better miscibility with the polymer donor to induce a favorable blend ordering with small domain sizes and suitable phase separation compared to the INPIC-2F symmetric molecule. This facilitates an efficient charge generation and transport, inhibits charge-carrier recombination, and promotes valid charge extraction in IPT-2F-based devices.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Pulsed Interleaved MINFLUX},

author = {L A Masullo and F Steiner and J Z\"{a}hringer and L F Lopez and J Bohlen and L Richter and F Cole and P Tinnefeld and F D Stefani},

url = {https://doi.org/10.1021/acs.nanolett.0c04600},

doi = {10.1021/acs.nanolett.0c04600},

issn = {1530-6984},

year  = {2021},

date = {2021-01-13},

urldate = {2021-01-13},

journal = {Nano Letters},

volume = {21},

number = {1},

pages = {840-846},

abstract = {We introduce p-MINFLUX, a new implementation of the highly photon-efficient single-molecule localization method with a simplified experimental setup and additional fluorescence lifetime information. In contrast to the original MINFLUX implementation, p-MINFLUX uses interleaved laser pulses to deliver the doughnut-shaped excitation foci at a maximum repetition rate. Using both static and dynamic DNA origami model systems, we demonstrate the performance of p-MINFLUX for single-molecule localization nanoscopy and tracking, respectively. p-MINFLUX delivers 1\textendash2 nm localization precision with 2000\textendash1000 photon counts. In addition, p-MINFLUX gives access to the fluorescence lifetime enabling multiplexing and super-resolved lifetime imaging. p-MINFLUX should help to unlock the full potential of innovative single-molecule localization schemes.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {DNA origami based superconducting nanowires},

author = {L Shani and P Tinnefeld and Y Fleger and A Sharoni and B Y Shapiro and A Shaulov and O Gang and Y Yeshurun},

url = {https://doi.org/10.1063/5.0029781},

doi = {10.1063/5.0029781},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {AIP Advances},

volume = {11},

number = {1},

pages = {015130},

keywords = {Foundry Inorganic, Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {A Solution-Processable Polymer-Based Thin-Film Thermoelectric Generator},

author = {R M Kluge and N Saxena and P M\"{u}ller-Buschbaum},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aesr.202000060},

doi = {https://doi.org/10.1002/aesr.202000060},

issn = {2699-9412},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Advanced Energy and Sustainability Research},

volume = {2},

number = {1},

pages = {2000060},

abstract = {Thermoelectric modules are capable of transforming thermal energy into electrical power. Implementing earth-abundant and cost-effective organic materials, they can contribute to an eco-friendly way of energy production out of low-grade waste heat and natural heat sources via the Seebeck effect. Moreover, the flexibility of organic materials can allow for adaption to curved surfaces such as the human skin and wearable electronics. Herein, a solution-processable thermoelectric generator (TEG) using exclusively polymers as active materials is presented. The high-mobility n-type polymer poly[[N,N-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5-(2,2-bithiophene)] (P(NDI2OD-T2)) and the widely studied p-type polymer blend poly(3,4-ethylene-dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) are combined into a thin-film TEG. The presented device design is not limited to this system but is applicable to any pair of organic materials processable from solution and can be easily upscaled to fully flexible devices via, e.g., printing and roll-to-roll processing.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Covalent Graphene-MOF Hybrids for High-Performance Asymmetric Supercapacitors},

author = {K Jayaramulu and M Horn and A Schneemann and H Saini and A Bakandritsos and V Ranc and M Petr and V Stavila and C Narayana and B Scheibe and \v{S} Kment and M Otyepka and N Motta and D Dubal and R Zbo\v{r}il and R A Fischer},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202004560},

doi = {https://doi.org/10.1002/adma.202004560},

issn = {0935-9648},

year  = {2020},

date = {2020-12-04},

journal = {Advanced Materials},

volume = {33},

number = {4},

pages = {2004560},

abstract = {Abstract In this work, the covalent attachment of an amine functionalized metal-organic framework (UiO-66-NH2 = Zr6O4(OH)4(bdc-NH2)6; bdc-NH2 = 2-amino-1,4-benzenedicarboxylate) (UiO-Universitetet i Oslo) to the basal-plane of carboxylate functionalized graphene (graphene acid = GA) via amide bonds is reported. The resultant GA@UiO-66-NH2 hybrid displayed a large specific surface area, hierarchical pores and an interconnected conductive network. The electrochemical characterizations demonstrated that the hybrid GA@UiO-66-NH2 acts as an effective charge storing material with a capacitance of up to 651 F g−1, significantly higher than traditional graphene-based materials. The results suggest that the amide linkage plays a key role in the formation of a π-conjugated structure, which facilitates charge transfer and consequently offers good capacitance and cycling stability. Furthermore, to realize the practical feasibility, an asymmetric supercapacitor using a GA@UiO-66-NH2 positive electrode with Ti3C2TX MXene as the opposing electrode has been constructed. The cell is able to deliver a power density of up to 16 kW kg−1 and an energy density of up to 73 Wh kg−1, which are comparable to several commercial devices such as Pb-acid and Ni/MH batteries. Under an intermediate level of loading, the device retained 88% of its initial capacitance after 10 000 cycles.},

keywords = {Foundry Inorganic, Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Self-Regeneration and Self-Healing in DNA Origami Nanostructures},

author = {J M Scheckenbach and P Tinnefeld and V Glembockyte and T Schubert and C Forthmann},

url = {https://doi.org/10.1002/anie.202012986},

doi = {https://doi.org/10.1002/anie.202012986},

issn = {1433-7851},

year  = {2020},

date = {2020-11-23},

journal = {Angewandte Chemie International Edition},

volume = {n/a},

number = {n/a},

abstract = {DNA nanotechnology and advances in the DNA origami technique have enabled facile design and synthesis of complex and functional nanostructures. Molecular devices are, however, prone to rapid functional and structural degradation due to the high proportion of surface atoms at the nanoscale and due to complex working environments. Besides stabilizing mechanisms, approach for the self-repair of functional molecular devices are desirable. Here we exploit the self-assembly and reconfigurability of DNA origami nanostructures to induce the self-repair of defects of photoinduced and enzymatic damage. With different examples of repair in DNA nanostructures, we distinguish between unspecific self-regeneration and damage specific self-healing mechanisms. Using DNA origami nanorulers studied by atomic force and superresolution DNA PAINT microscopy, quantitative preservation of fluorescence properties is demonstrated with direct potential for improving nanoscale calibration samples.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Solving the COF trilemma: towards crystalline, stable and functional covalent organic frameworks},

author = {F Haase and B V Lotsch},

url = {http://dx.doi.org/10.1039/D0CS01027H},

doi = {10.1039/D0CS01027H},

issn = {0306-0012},

year  = {2020},

date = {2020-11-06},

journal = {Chemical Society Reviews},

abstract = {Covalent organic frameworks (COFs) have entered the stage as a new generation of porous polymers which stand out by virtue of their crystallinity, diverse framework topologies and accessible pore systems. An important \textendash but still underdeveloped \textendash feature of COFs is their potentially superior stability in comparison to other porous materials. Achieving COFs which are simultaneously crystalline, stable, and functional is still challenging as reversible bond formation is one of the prime prerequisites for the crystallization of COFs. However, as the COF field matures new strategies have surfaced that bypass this crystallinity \textendash stability dichotomy. Three major approaches for obtaining both stable and crystalline COFs have taken form in recent years: Tweaking the reaction conditions for reversible linkages, separating the order inducing step and the stability inducing step, and controlling the structural degrees of freedom during assembly and in the final COF. This review discusses rational approaches to stability and crystallinity engineering in COFs, which are apt at overcoming current challenges in COF design and open up new avenues to new real-world applications of COFs.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Polymer photocatalysts for solar-to-chemical energy conversion},

author = {T Banerjee and F Podjaski and J Kr\"{o}ger and B P Biswal and B V Lotsch},

url = {https://doi.org/10.1038/s41578-020-00254-z},

doi = {10.1038/s41578-020-00254-z},

issn = {2058-8437},

year  = {2020},

date = {2020-11-05},

journal = {Nature Reviews Materials},

abstract = {Solar-to-chemical energy conversion for the generation of high-energy chemicals is one of the most viable solutions to the quest for sustainable energy resources. Although long dominated by inorganic semiconductors, organic polymeric photocatalysts offer the advantage of a broad, molecular-level design space of their optoelectronic and surface catalytic properties, owing to their molecularly precise backbone. In this Review, we discuss the fundamental concepts of polymeric photocatalysis and examine different polymeric photocatalysts, including carbon nitrides, conjugated polymers, covalent triazine frameworks and covalent organic frameworks. We analyse the photophysical and physico-chemical concepts that govern the photocatalytic performance of these materials, and derive design principles and possible future research directions in this emerging field of ‘soft photocatalysis’.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {DNA origami nanorulers and emerging reference structures},

author = {M Scheckenbach and J Bauer and J Z\"{a}hringer and F Selbach and P Tinnefeld},

url = {https://doi.org/10.1063/5.0022885},

doi = {10.1063/5.0022885},

year  = {2020},

date = {2020-11-01},

journal = {APL Materials},

volume = {8},

number = {11},

pages = {110902},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Deep Learning Total Energies and Orbital Energies of Large Organic Molecules Using Hybridization of Molecular Fingerprints},

author = {O Rahaman and A Gagliardi},

url = {https://doi.org/10.1021/acs.jcim.0c00687},

doi = {10.1021/acs.jcim.0c00687},

issn = {1549-9596},

year  = {2020},

date = {2020-10-29},

journal = {Journal of Chemical Information and Modeling},

volume = {60},

number = {12},

pages = {5971-5983},

abstract = {The ability to predict material properties without the need for resource-consuming experimental efforts can immensely accelerate material and drug discovery. Although ab initio methods can be reliable and accurate in making such predictions, they are computationally too expensive on a large scale. The recent advancements in artificial intelligence and machine learning as well as the availability of large quantum mechanics derived datasets enable us to train models on these datasets as a benchmark and to make fast predictions on much larger datasets. The success of these machine learning models highly depends on the machine-readable fingerprints of the molecules that capture their chemical properties as well as topological information. In this work, we propose a common deep learning-based framework to combine different types of molecular fingerprints to enhance prediction accuracy. A graph neural network (GNN), many-body tensor representation (MBTR), and a set of simple molecular descriptors (MD) were used to predict the total energies, highest occupied molecular orbital (HOMO) energies, and lowest unoccupied molecular orbital (LUMO) energies of a dataset containing ∼62k large organic molecules with complex aromatic rings and remarkably diverse functional groups. The results demonstrate that a combination of best performing molecular fingerprints can produce better results than the individual ones. The simple and flexible deep learning framework developed in this work can be easily adapted to incorporate other types of molecular fingerprints.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Highly conducting Wurster-type twisted covalent organic frameworks},

author = {J M Rotter and R Guntermann and M Auth and A M\"{a}hringer and A Sperlich and V Dyakonov and D D Medina and T Bein},

url = {http://dx.doi.org/10.1039/D0SC03909H},

doi = {10.1039/D0SC03909H},

issn = {2041-6520},

year  = {2020},

date = {2020-10-27},

urldate = {2020-10-27},

journal = {Chemical Science},

volume = {11},

number = {47},

pages = {12843-12853},

abstract = {Covalent organic frameworks (COFs) define a versatile structural paradigm combining attractive properties such as crystallinity, porosity, and chemical and structural modularity which are valuable for various applications. For the incorporation of COFs into optoelectronic devices, efficient charge carrier transport and intrinsic conductivity are often essential. Here, we report the synthesis of two imine-linked two-dimensional COFs, WTA and WBDT, featuring a redox-active Wurster-type motif based on the twisted tetragonal N,N,N′,N′-tetraphenyl-1,4-phenylenediamine node. By condensing this unit with either terephthalaldehyde (TA) or benzodithiophene dialdehyde (BDT), COFs featuring a dual-pore kagome-type structure were obtained as highly crystalline materials with large specific surface areas and mesoporosity. In addition, the experimentally determined high conduction band energies of both COFs render them suitable candidates for oxidative doping. The incorporation of a benzodithiophene linear building block into the COF allows for high intrinsic macroscopic conductivity. Both anisotropic and average isotropic electrical conductivities were determined with van der Pauw measurements using oriented films and pressed pellets, respectively. Furthermore, the impact of different dopants such as F4TCNQ, antimony pentachloride and iodine on the conductivities of the resulting doped COFs was studied. By using the strong organic acceptor F4TCNQ, a massive increase of the radical cation density (up to 0.5 radicals per unit cell) and long-term stable electrical conductivity as high as 3.67 S m−1 were achieved for the anisotropic transport in an oriented film, one of the highest for any doped COF to date. Interestingly, no significant differences between isotropic and anisotropic charge transport were found in films and pressed pellets. This work expands the list of possible building nodes for electrically conducting COFs from planar systems to twisted geometries. The achievement of high and stable electrical conductivity paves the way for possible applications of new COFs in organic (opto)electronics.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Multiscale Conformational Sampling Reveals Excited-State Locality in DNA Self-Repair Mechanism},

author = {V Piccinni and S Reiter and D Keefer and R De Vivie-Riedle},

url = {https://doi.org/10.1021/acs.jpca.0c07207},

doi = {10.1021/acs.jpca.0c07207},

issn = {1089-5639},

year  = {2020},

date = {2020-10-22},

urldate = {2020-10-22},

journal = {The Journal of Physical Chemistry A},

volume = {124},

number = {44},

pages = {9133-9140},

abstract = {Ultraviolet (UV) irradiation is known to be responsible for DNA damage. However, experimental studies in DNA oligonucleotides have shown that UV light can also induce sequence-specific self-repair. Following charge transfer from a guanine adenine sequence adjacent to a cyclobutane pyrimidine dimer (CPD), the covalent bond between the two thymines could be cleaved, recovering the intact base sequence. Mechanistic details promoting the self-repair remained unclear, however. In our theoretical study, we investigated whether optical excitation could directly lead to a charge-transfer state, thereby initiating the repair, or whether the initial excited state remains localized on a single nucleobase. We performed conformational sampling of 200 geometries of the damaged DNA double strand solvated in water and used a hybrid quantum and molecular mechanics approach to compute excited states at the complete active space perturbation level of theory. Analysis of the conformational data set clearly revealed that the excited-state properties are uniformly distributed across the fluctuations of the nucleotide in its natural environment. From the electronic wavefunction, we learned that the electronic transitions remained predominantly local on either adenine or guanine, and no direct charge transfer occurred in the experimentally accessed energy range. The investigated base sequence is not only specific to the CPD repair mechanism but ubiquitously occurs in nucleic acids. Our results therefore give a very general insight into the charge locality of UV-excited DNA, a property that is regarded to have determining relevance in the structural consequences following absorption of UV photons.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Internal nanoscale architecture and charge carrier dynamics of wide bandgap non-fullerene bulk heterojunction active layers in organic solar cells},

author = {X Jiang and H Kim and P S Deimel and W Chen and W Cao and D Yang and S Yin and R Schaffrinna and F Allegretti and J V Barth and M Schwager and H Tang and K Wang and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},

url = {http://dx.doi.org/10.1039/D0TA09671G},

doi = {10.1039/D0TA09671G},

issn = {2050-7488},

year  = {2020},

date = {2020-10-19},

journal = {Journal of Materials Chemistry A},

volume = {8},

number = {44},

pages = {23628-23636},

abstract = {Bulk heterojunction (BHJ) organic solar cells have gained increasing attention in the past few years. In this work, active layers of a wide-bandgap polymer donor with benzodithiophene units PBDB-T-2F and a non-fullerene small molecule acceptor IT-M are assembled into photovoltaic devices with different amounts of solvent additive 1,8-diiodooctane (DIO). The influence of DIO on the nanoscale film morphology and crystalline structure as well as the charge carrier dynamics of the active layers are investigated by combining grazing-incidence small-angle X-ray scattering (GISAXS), grazing-incidence wide-angle X-ray scattering (GIWAXS), X-ray reflectivity (XRR), UV-visible (UV-vis) absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), time-resolved photoluminescence (TRPL) and space charge limited current measurements, which are correlated with the corresponding performance of the solar cells. At 0.5 vol% DIO addition, the wide-bandgap non-fullerene organic solar cells show the best performance due to high open-circuit voltage and short-circuit current resulting from an improved charge carrier management due to the optimal inner nanoscale morphology of the active layers in terms of surface enrichment, crystallinity and crystalline orientation.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Alternative electron pathways in photosynthesis: strength in numbers},

author = {D Leister},

url = {https://nph.onlinelibrary.wiley.com/doi/abs/10.1111/nph.16911},

doi = {https://doi.org/10.1111/nph.16911},

issn = {0028-646X},

year  = {2020},

date = {2020-09-26},

urldate = {2020-09-26},

journal = {New Phytologist},

volume = {228},

number = {4},

pages = {1166-1168},

abstract = {This article is a Commentary on Storti et al. (2020), 228: 1316\textendash1326.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Ionothermal Synthesis of Imide-Linked Covalent Organic Frameworks},

author = {J Maschita and T Banerjee and G Savasci and F Haase and C Ochsenfeld and B V Lotsch},

url = {https://doi.org/10.1002/anie.202007372},

doi = {https://doi.org/10.1002/anie.202007372},

issn = {1433-7851},

year  = {2020},

date = {2020-09-01},

journal = {Angewandte Chemie International Edition},

volume = {59},

number = {36},

pages = {15750-15758},

abstract = {Abstract Covalent organic frameworks (COFs) are an extensively studied class of porous materials, which distinguish themselves from other porous polymers in their crystallinity and high degree of modularity, enabling a wide range of applications. COFs are most commonly synthesized solvothermally, which is often a time-consuming process and restricted to well-soluble precursor molecules. Synthesis of polyimide-linked COFs (PI-COFs) is further complicated by the poor reversibility of the ring-closing reaction under solvothermal conditions. Herein, we report the ionothermal synthesis of crystalline and porous PI-COFs in zinc chloride and eutectic salt mixtures. This synthesis does not require soluble precursors and the reaction time is significantly reduced as compared to standard solvothermal synthesis methods. In addition to applying the synthesis to previously reported imide COFs, a new perylene-based COF was also synthesized, which could not be obtained by the classical solvothermal route. In situ high-temperature XRPD analysis hints to the formation of precursor?salt adducts as crystalline intermediates, which then react with each other to form the COF.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Light-Induced and Oxygen-Mediated Degradation Processes in Photoactive Layers Based on PTB7-Th},

author = {F C L\"{o}hrer and C Senfter and C J Schaffer and J Schlipf and D Mosegu\'{i} Gonz\'{a}lez and P Zhang and S V Roth and P M\"{u}ller-Buschbaum},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adpr.202000047},

doi = {https://doi.org/10.1002/adpr.202000047},

issn = {2699-9293},

year  = {2020},

date = {2020-08-26},

urldate = {2020-08-26},

journal = {Advanced Photonics Research},

volume = {1},

number = {1},

pages = {2000047},

abstract = {Low-bandgap polymers are sensitive to various degradation processes, which strongly decrease their lifetime. The chemical and physical changes occurring in the low-bandgap polymer with benzodithiophene units poly[4,8-bis(5-(2-ethylhexyl)thiophene-2-yl)benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-2-carboxylate] (PTB7-Th) and its blend with the fullerene derivative [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) are followed during irradiation-induced aging by combination of various characterization methods. The active layer morphology is investigated using atomic force microscopy (AFM) as well as in-operando grazing incidence small angle X-ray scattering (GISAXS), indicating morphological alterations and material loss due to chemical modifications. Optical spectroscopy gives insights into these chemical processes which lead to significant absorption losses under ambient conditions. Independent of the energy of the absorbed photons, but only in combination with oxygen, the excitation of the polymer leads to a fatal increase in oxidation probability. Fourier transform infrared (FTIR) data highlight the sensitivity of the conjugated polymer backbone to oxidation, a result of lost conjugation and therefore absorption capability. With combined AFM height and infrared (IR) mapping, the chemical degradation and material loss is confirmed on a nanoscale. Although the chemical structure is seriously damaged, the blend morphology is not undergoing major changes.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Hot Hydrocarbon-Solvent Slot-Die Coating Enables High-Efficiency Organic Solar Cells with Temperature-Dependent Aggregation Behavior},

author = {H Zhao and H B Naveed and B Lin and X Zhou and J Yuan and K Zhou and H Wu and R Guo and M A Scheel and A Chumakov and S V Roth and Z Tang and P M\"{u}ller-Buschbaum and W Ma},

doi = {10.1002/adma.202002302},

issn = {0935-9648},

year  = {2020},

date = {2020-08-18},

urldate = {2020-08-18},

journal = {Adv Mater},

volume = {32},

number = {39},

pages = {e2002302},

abstract = {Organic solar cells (OSCs) have made rapid progress in terms of their development as a sustainable energy source. However, record-breaking devices have not shown compatibility with large-scale production via solution processing in particular due to the use of halogenated environment-threatening solvents. Here, slot-die fabrication with processing involving hydrocarbon-based solvents is used to realize highly efficient and environmentally friendly OSCs. Highly compatible slot-die coating with roll-to-roll processing using halogenated (chlorobenzene (CB)) and hydrocarbon solvents (1,2,4-trimethylbenzene (TMB) and ortho-xylene (o-XY)) is used to fabricate photoactive films. Controlled solution and substrate temperatures enable similar aggregation states in the solution and similar kinetics processes during film formation. The optimized blend film nanostructures for different solvents in the highly efficient PM6:Y6 blend is adopted to show a similar morphology, which results in device efficiencies of 15.2%, 15.4%, and 15.6% for CB, TMB, and o-XY solvents. This approach is successfully extended to other donor-acceptor combinations to demonstrate the excellent universality of this method. The results combine a method to optimize the aggregation state and film formation kinetics with the fabrication of OSCs with environmentally friendly solvents by slot-die coating, which is a critical finding for the future development of OSCs in terms of their scalable production and high-performance.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Near-atomic-scale observation of grain boundaries in a layer-stacked two-dimensional polymer},

author = {H Y Qi and H Sahabudeen and B K Liang and M Polozij and M A Addicoat and T E Gorelik and M Hambsch and M Mundszinger and S Park and B V Lotsch and S C B Mannsfeld and Z K Zheng and R H Dong and T Heine and X L Feng and U Kaiser},

url = {\<Go to ISI\>://WOS:000560465800030},

doi = {10.1126/sciadv.abb5976},

issn = {2375-2548},

year  = {2020},

date = {2020-08-14},

journal = {Science Advances},

volume = {6},

number = {33},

abstract = {Two-dimensional (2D) polymers, hold great promise in the rational materials design tailored for next-generation applications. However, little is known about the grain boundaries in 2D polymers, not to mention their formation mechanisms and potential influences on the material's functionalities. Using aberration-corrected high-resolution transmission electron microscopy, we present a direct observation of the grain boundaries in a layer-stacked 2D polyimine with a resolution of 2.3 angstrom, shedding light on their formation mechanisms. We found that the polyimine growth followed a "birth-and-spread" mechanism. Antiphase boundaries implemented a self-correction to the missing-linker and missing-node defects, and tilt boundaries were formed via grain coalescence. Notably, we identified grain boundary reconstructions featuring closed rings at tilt boundaries. Quantum mechanical calculations revealed that boundary reconstruction is energetically allowed and can be generalized into different 2D polymer systems. We envisage that these results may open up the opportunity for future investigations on defect-property correlations in 2D polymers.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {In Situ Studies of Solvent Additive Effects on the Morphology Development during Printing of Bulk Heterojunction Films for Organic Solar Cells},

author = {D Yang and S Grott and X Jiang and K S Wienhold and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/smtd.202000418},

doi = {https://doi.org/10.1002/smtd.202000418},

issn = {2366-9608},

year  = {2020},

date = {2020-08-09},

urldate = {2020-08-09},

journal = {Small Methods},

volume = {4},

number = {9},

pages = {2000418},

abstract = {Abstract The development of polymer morphology and crystallinity of printed bulk heterojunction (BHJ) films doped with the different solvent additives 1,8-diiodooctane (DIO) or diphenyl ether (DPE) is investigated with in situ grazing-incidence small/wide-angle X-ray scattering. The solvent additives, having different boiling points, lead to a different film drying behavior and morphology growth states in the BHJ films of the benzothiadiazole-based polymer (PPDT2FBT) and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM). The phase demixing in the printed films is changing over time along with solvent evaporation. Polymer domains start aggregating to form larger domains in the liquid\textendashliquid phase, while phase separation mainly occurs in the liquid\textendashsolid phase. The present work provides a profound insight into the morphology development of printed BHJ films doped with different solvent additives, which is particularly important for the large-scale fabrication of organic photovoltaics.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Following In Situ the Evolution of Morphology and Optical Properties during Printing of Thin Films for Application in Non-Fullerene Acceptor Based Organic Solar Cells},

author = {K S Wienhold and C L Weindl and S Yin and T Tian and M Schwartzkopf and A Rothkirch and S V Roth and P M\"{u}ller-Buschbaum},

url = {https://doi.org/10.1021/acsami.0c12390},

doi = {10.1021/acsami.0c12390},

issn = {1944-8244},

year  = {2020},

date = {2020-08-07},

urldate = {2020-08-07},

journal = {ACS Applied Materials \& Interfaces},

volume = {12},

number = {36},

pages = {40381-40392},

abstract = {In situ printing gives insight into the evolution of morphology and optical properties during slot-die coating of active layers for application in organic solar cells and enables an upscaling and optimization of the thin film deposition process and the photovoltaic performance. Active layers based on the conjugated polymer donor with benzodithiophene units PBDB-T-2Cl and the non-fullerene small-molecule acceptor IT-4F are printed with a slot-die coating technique and probed in situ with grazing incidence small-angle X-ray scattering, grazing incidence wide-angle X-ray scattering, and ultraviolet/visible light spectroscopy. The formation of the morphology is followed from the liquid state to the final dry film for different printing conditions (at 25 and 35 °C), and five regimes of film formation are determined. The morphological changes are correlated to changing optical properties. During the film formation, crystallization of the non-fullerene small-molecule acceptor takes place and polymer domains with sizes of some tens of nanometers emerge. A red shift of the optical band gap and a broadening of the absorbance spectrum occurs, which allow for exploiting the sun spectrum more efficiently and are expected to have a favorable effect on the solar cell performance.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Investigation of Molecular Dynamics of a PTB7:PCBM Polymer Blend with Quasi-Elastic Neutron Scattering},

author = {D Schwaiger and W Lohstroh and P M\"{u}ller-Buschbaum},

url = {https://doi.org/10.1021/acsapm.0c00455},

doi = {10.1021/acsapm.0c00455},

year  = {2020},

date = {2020-08-03},

urldate = {2020-08-03},

journal = {ACS Applied Polymer Materials},

volume = {2},

number = {9},

pages = {3797-3804},

abstract = {In organic photovoltaics, bulk heterojunctions (BHJs) of organic semiconductor substances such as conjugated polymers and fullerenes are frequently used as active layers in which light is transformed into free charge carriers. The performance of the respective solar cells is critically influenced by the inner morphology of the active layer. Besides structural, also dynamical properties are important but by far less frequently investigated. In this study, we probe the polymer dynamics of an active layer composed of a low band gap polymer and a fullerene derivate. The acceptor [6,6]-phenyl-C61-butyric-acid-methyl-ester (PCBM) and the donor poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7), as well as their 1:1 blend, are probed with time-of-flight quasi-elastic neutron scattering. Our observable timescale window of motions covers a range from 1 ps to approximately 50 ps. We probe a temperature range from 150 to 400 K, which covers the reported maximum power conversion efficiency of the respective BHJ solar cells. Within this temperature range, PCBM does not show any dynamics on the observable timescale. Blending with PCBM (wt. ratio 1:1) causes frustration of the PTB7 side-chain dynamics, which manifests in increased relaxation times and decreased diffusion coefficients. Important for solar cell applications, temperature variations do have a major impact on the polymer dynamics, which in some circumstances are far more pronounced than the influence of blending with PCBM. Furthermore, we show that this temperature dependence follows an Arrhenius-type behavior.},

keywords = {Foundry Organic},

pubstate = {published},

tppubtype = {article}

}