Publications

@article{nokey,

title = {Selective area growth of GaN nanowires and nanofins by molecular beam epitaxy on heteroepitaxial diamond (001) substrates},

author = {F Pantle and F Becker and M Kraut and S W\"{o}rle and T Hoffmann and S Artmeier and M Stutzmann},

url = {http://dx.doi.org/10.1039/D1NA00221J},

doi = {10.1039/D1NA00221J},

year  = {2021},

date = {2021-05-05},

journal = {Nanoscale Advances},

volume = {3},

number = {13},

pages = {3835-3845},

abstract = {GaN-on-diamond is a promising route towards reliable high-power transistor devices with outstanding performances due to better heat management, replacing common GaN-on-SiC technologies. Nevertheless, the implementation of GaN-on-diamond remains challenging. In this work, the selective area growth of GaN nanostructures on cost-efficient, large-scale available heteroepitaxial diamond (001) substrates by means of plasma-assisted molecular beam epitaxy is investigated. Additionally, we discuss the influence of an AlN buffer on the morphology of the GaN nanostructures. The nanowires and nanofins are characterized by a very high selectivity and controllable dimensions. Low temperature photoluminescence measurements are used to evaluate their structural quality. The growth of two GaN crystal domains, which are in-plane rotated against each other by 30°, is observed. The favoring of a certain domain is determined by the off-cut direction of the diamond substrates. By X-ray diffraction we show that the GaN nanostructures grow perpendicular to the diamond surface on off-cut diamond (001) substrates, which is in contrast to the growth on diamond (111), where the nanostructures are aligned with the substrate lattice. Polarity-selective wet chemical etching and Kelvin probe force microscopy reveal that the GaN nanostructures grow solely in the Ga-polar direction. This is a major advantage compared to the growth on diamond (111) and enables the application of GaN nanostructures on cost-efficient diamond for high-power/high-frequency applications.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Massively Parallel Arrays of Size-Controlled Metallic Nanogaps with Gap-Widths Down to the Sub-3-nm Level},

author = {S Luo and A Mancini and R Bert\'{e} and B H Hoff and S A Maier and J C De Mello},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202100491},

doi = {https://doi.org/10.1002/adma.202100491},

issn = {0935-9648},

year  = {2021},

date = {2021-05-03},

journal = {Advanced Materials},

volume = {33},

number = {20},

pages = {2100491},

abstract = {Abstract Metallic nanogaps (MNGs) are fundamental components of nanoscale photonic and electronic devices. However, the lack of reproducible, high-yield fabrication methods with nanometric control over the gap-size has hindered practical applications. A patterning technique based on molecular self-assembly and physical peeling is reported here that allows the gap-width to be tuned from more than 30 nm to less than 3 nm. The ability of the technique to define sub-3-nm gaps between dissimilar metals permits the easy fabrication of molecular rectifiers, in which conductive molecules bridge metals with differing work functions. A method is further described for fabricating massively parallel nanogap arrays containing hundreds of millions of ring-shaped nanogaps, in which nanometric size control is maintained over large patterning areas of up to a square centimeter. The arrays exhibit strong plasmonic resonances under visible light illumination and act as high-performance substrates for surface-enhanced Raman spectroscopy, with high enhancement factors of up to 3 × 108 relative to thin gold films. The methods described here extend the range of metallic nanostructures that can be fabricated over large areas, and are likely to find many applications in molecular electronics, plasmonics, and biosensing.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {The central role of the metal ion for photoactivity: Zn\textendash vs. Ni\textendashMabiq},

author = {R Lauenstein and S L Mader and H Derondeau and O Z Esezobor and M Block and A J R\"{o}mer and C Jandl and E Riedle and V R I Kaila and J Hauer and E Thyrhaug and C R Hess},

url = {http://dx.doi.org/10.1039/D0SC06096H},

doi = {10.1039/D0SC06096H},

issn = {2041-6520},

year  = {2021},

date = {2021-04-21},

journal = {Chemical Science},

abstract = {Photoredox catalysts are integral components of artificial photosystems, and have recently emerged as powerful tools for catalysing numerous organic reactions. However, the development of inexpensive and efficient earth-abundant photoredox catalysts remains a challenge. We here present the photochemical and photophysical properties of a Ni\textendashMabiq catalyst ([NiII(Mabiq)]OTf (1); Mabiq = 2-4:6-8-bis(3,3,4,4-tetramethyldihydropyrrolo)-10-15-(2,2-biquinazolino)-[15]-1,3,5,8,10,14-hexaene1,3,7,9,11,14-N6)\textemdashand of a Zn-containing analogue ([ZnII(Mabiq)OTf] (2))\textemdashusing steady state and time resolved optical spectroscopy, time-dependent density functional theory (TDDFT) calculations, and reactivity studies. The Ni and Zn complexes exhibit similar absorption spectra, but markedly different photochemical properties. These differences arise because the excited states of 2 are ligand-localized, whereas metal-centered states account for the photoactivity of 1. The distinct properties of the Ni and Zn complexes are manifest in their behavior in the photo-driven aza-Henry reaction and oxidative coupling of methoxybenzylamine.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

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 = {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{,

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 = {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{,

title = {Activation of 2-Cyclohexenone by BF3 Coordination: Mechanistic Insights from Theory and Experiment},

author = {M Peschel and P Kabacinski and D P Schwinger and E Thyrhaug and G Cerullo and T Bach and J Hauer and R De Vivie-Riedle

},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202016653},

doi = {https://doi.org/10.1002/anie.202016653},

issn = {1433-7851},

year  = {2021},

date = {2021-02-17},

urldate = {2021-02-17},

journal = {Angewandte Chemie International Edition},

volume = {n/a},

number = {n/a},

abstract = {Lewis acids have recently been recognized as catalysts enabling enantioselective photochemical transformations. Mechanistic studies on these systems are however rare, either due to their absorption at wavelengths shorter than 260 nm, or due to the limitations of theoretical dynamic studies for larger complexes. In this work, we overcome these challenges and employ sub-30-fs transient absorption in the UV, in combination with a highly accurate theoretical treatment on the XMS-CASPT2 level. We investigate 2-cyclohexenone and its complex to boron trifluoride and analyze the observed dynamics based on trajectory calculations including non-adiabatic coupling and intersystem crossing. This approach explains all ultrafast decay pathways observed in the complex. We show that the Lewis acid remains attached to the substrate in the triplet state, which in turn explains why chiral boron-based Lewis acids induce a high enantioselectivity in photocycloaddition reactions.},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Photocatalytic Hydrogen Evolution: Interfacial Engineering for Improved Photocatalysis in a Charge Storing 2D Carbon Nitride: Melamine Functionalized Poly(heptazine imide) (Adv. Energy Mater. 6/2021)},

author = {J Kr\"{o}ger and A Jim\'{e}nez-Solano and G Savasci and P Rov\'{o} and I Moudrakovski and K K\"{u}ster and H Schlomberg and H A Vignolo-Gonz\'{a}lez and V Duppel and L Grunenberg and C B Dayan and M Sitti and F Podjaski and C Ochsenfeld and B V Lotsch},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202170028},

doi = {https://doi.org/10.1002/aenm.202170028},

issn = {1614-6832},

year  = {2021},

date = {2021-02-11},

journal = {Advanced Energy Materials},

volume = {11},

number = {6},

pages = {2170028},

abstract = {In article number 2003016, Bettina V. Lotsch and co-workers demonstrate that covalent surface modifications of the 2D carbon nitride poly(heptazine imide) with melamine groups strongly influence its polarity and photo(electrochemical) properties. This potent tuning pathway also results in the boosting of photocatalytic hydrogen evolution due to increased donor interactions and enhanced hole extraction.},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Addressable nanoantennas with cleared hotspots for single-molecule detection on a portable smartphone microscope},

author = {K Trofymchuk and V Glembockyte and L Grabenhorst and F Steiner and C Vietz and C Close and M Pfeiffer and L Richter and M L Sch\"{u}tte and F Selbach and R Yaadav and J Z\"{a}hringer and Q Wei and A Ozcan and B Lalkens and G P Acuna and P Tinnefeld},

url = {https://doi.org/10.1038/s41467-021-21238-9},

doi = {10.1038/s41467-021-21238-9},

issn = {2041-1723},

year  = {2021},

date = {2021-02-11},

urldate = {2021-02-11},

journal = {Nature Communications},

volume = {12},

number = {1},

pages = {950},

abstract = {The advent of highly sensitive photodetectors and the development of photostabilization strategies made detecting the fluorescence of single molecules a routine task in many labs around the world. However, to this day, this process requires cost-intensive optical instruments due to the truly nanoscopic signal of a single emitter. Simplifying single-molecule detection would enable many exciting applications, e.g., in point-of-care diagnostic settings, where costly equipment would be prohibitive. Here, we introduce addressable NanoAntennas with Cleared HOtSpots (NACHOS) that are scaffolded by DNA origami nanostructures and can be specifically tailored for the incorporation of bioassays. Single emitters placed in NACHOS emit up to 461-fold (average of 89 ± 7-fold) brighter enabling their detection with a customary smartphone camera and an 8-US-dollar objective lens. To prove the applicability of our system, we built a portable, battery-powered smartphone microscope and successfully carried out an exemplary single-molecule detection assay for DNA specific to antibiotic-resistant Klebsiella pneumonia on the road.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Origin of Hole Transport in Small Molecule Dilute Donor Solar Cells},

author = {W Kaiser and L N S Murthy and C-L Chung and K-T Wong and J W P Hsu and A Gagliardi},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aesr.202000042},

doi = {https://doi.org/10.1002/aesr.202000042},

issn = {2699-9412},

year  = {2021},

date = {2021-02-01},

journal = {Advanced Energy and Sustainability Research},

volume = {2},

number = {3},

pages = {2000042},

abstract = {Dilute donor organic solar cells (OSCs) are a promising technology to circumvent the trade-off between open-circuit voltage (Voc) and short-circuit current density (Jsc). The origin of hole transport in OSCs with donor concentrations below the percolation threshold is diversely discussed in the community. Herein, both hole back transfer and long-range hopping (tunneling) are analyzed as possible mechanisms of photocurrent in small molecule dilute donor OSCs using kinetic Monte Carlo (kMC) simulations. In contrast to previous kMC studies, the driving force for exciton dissociation is accounted for. As a study system, nitrogen-bridged terthiophene (NBTT) molecules in a [6,6]-phenyl-C70-butyric acid methyl ester (PC71BM) matrix are investigated. The simulations show that hole back transfer from the small molecule donor to the fullerene matrix explains the measured concentration dependences of the photocurrents as well as the Jsc dependence on the light intensity for donor concentrations below 5 wt%. For 5 wt%, distances between NBTT molecules decrease to reasonable ranges that long-range hopping or tunneling cannot be discounted. Compared with polymer donors, larger hole localization is observed. The results emphasize that the barrier for hole back transfer is not only due to the highest occupied molecular orbital (HOMO) offset, but also by hole localization.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Entrapped Molecular Photocatalyst and Photosensitizer in Metal\textendashOrganic Framework Nanoreactors for Enhanced Solar CO2 Reduction},

author = {P M Stanley and C Thomas and E Thyrhaug and A Urstoeger and M Schuster and J Hauer and B Rieger and J Warnan and R A Fischer},

url = {https://doi.org/10.1021/acscatal.0c04673},

doi = {10.1021/acscatal.0c04673},

year  = {2021},

date = {2021-01-05},

urldate = {2021-01-05},

journal = {ACS Catalysis},

volume = {11},

number = {2},

pages = {871-882},

abstract = {Herein, we report on a molecular catalyst embedding metal\textendashorganic framework (MOF) that enables enhanced photocatalytic CO2 reduction activity. A benchmark photocatalyst fac-ReBr(CO)3(4,4′-dcbpy) (dcbpy = dicarboxy-2,2′-bipyridine) and photosensitizer Ru(bpy)2(5,5′-dcbpy)Cl2 (bpy = 2,2′-bipyridine) were synergistically entrapped inside the cages of the nontoxic and inexpensive MIL-101-NH2(Al) through noncovalent host\textendashguest interactions. The heterogeneous material improved Re catalyst stabilization under photocatalytic CO2 reduction conditions as selective CO evolution was prolonged from 1.5 to 40 h compared to the MOF-free photosystem upon reactivation with additional photosensitizer. By varying ratios of immobilized catalyst to photosensitizer, we demonstrated and evaluated the effect of reaction environment modulation in defined MOF cages acting as a nanoreactor. This illustrated the optimal efficiency for two photosensitizers and one catalyst per cage and further led to the determination of ad hoc relationships between molecular complex size, MOF pore windows, and number of hostable molecules per cage. Differing from typical homogeneous systems, photosensitizer\textemdashand not catalyst\textemdashdegradation was identified as a major performance-limiting factor, providing a future route to higher turnover numbers via a rational choice of parameters.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

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{nokey,

title = {Electrochemical top-down synthesis of C-supported Pt nano-particles with controllable shape and size: Mechanistic insights and application},

author = {B Garlyyev and S Watzele and J Fichtner and J Michali\v{c}ka and A Sch\"{o}kel and A Senyshyn and A Perego and D Pan and H A El-Sayed and J M Macak and P Atanassov and I V Zenyuk and A S Bandarenka},

url = {https://doi.org/10.1007/s12274-020-3281-z},

doi = {10.1007/s12274-020-3281-z},

issn = {1998-0000},

year  = {2020},

date = {2020-12-29},

journal = {Nano Research},

volume = {14},

number = {8},

pages = {2762-2769},

abstract = {In this work, we demonstrate the power of a simple top-down electrochemical erosion approach to obtain Pt nanoparticle with controlled shapes and sizes (in the range from ~ 2 to ~ 10 nm). Carbon supported nanoparticles with narrow size distributions have been synthesized by applying an alternating voltage to macroscopic bulk platinum structures, such as disks or wires. Without using any surfactants, the size and shape of the particles can be changed by adjusting simple parameters such as the applied potential, frequency and electrolyte composition. For instance, application of a sinusoidal AC voltage with lower frequencies results in cubic nanoparticles; whereas higher frequencies lead to predominantly spherical nanoparticles. On the other hand, the amplitude of the sinusoidal signal was found to affect the particle size; the lower the amplitude of the applied AC signal, the smaller the resulting particle size. Pt/C catalysts prepared by this approach showed 0.76 A/mg mass activity towards the oxygen reduction reaction which is ~ 2 times higher than the state-of-the-art commercial Pt/C catalyst (0.42 A/mg) from Tanaka. In addition to this, we discussed the mechanistic insights about the nanoparticle formation pathways.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Challenges in Plasmonic Catalysis},

author = {E Cort\'{e}s and L V Besteiro and A Alabastri and A Baldi and G Tagliabue and A Demetriadou and P Narang},

url = {https://doi.org/10.1021/acsnano.0c08773},

doi = {10.1021/acsnano.0c08773},

issn = {1936-0851},

year  = {2020},

date = {2020-12-22},

urldate = {2020-12-22},

journal = {ACS Nano},

volume = {14},

number = {12},

pages = {16202-16219},

abstract = {The use of nanoplasmonics to control light and heat close to the thermodynamic limit enables exciting opportunities in the field of plasmonic catalysis. The decay of plasmonic excitations creates highly nonequilibrium distributions of hot carriers that can initiate or catalyze reactions through both thermal and nonthermal pathways. In this Perspective, we present the current understanding in the field of plasmonic catalysis, capturing vibrant debates in the literature, and discuss future avenues of exploration to overcome critical bottlenecks. Our Perspective spans first-principles theory and computation of correlated and far-from-equilibrium light\textendashmatter interactions, synthesis of new nanoplasmonic hybrids, and new steady-state and ultrafast spectroscopic probes of interactions in plasmonic catalysis, recognizing the key contributions of each discipline in realizing the promise of plasmonic catalysis. We conclude with our vision for fundamental and technological advances in the field of plasmon-driven chemical reactions in the coming years.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Optoelectronic processes in covalent organic frameworks},

author = {N Keller and T Bein},

url = {http://dx.doi.org/10.1039/D0CS00793E},

doi = {10.1039/D0CS00793E},

issn = {0306-0012},

year  = {2020},

date = {2020-12-17},

journal = {Chemical Society Reviews},

abstract = {Covalent organic frameworks (COFs) are crystalline porous materials constructed from molecular building blocks using diverse linkage chemistries. Their modular construction system allows not only for tailor-made design but also for an immense variety of building blocks, opening the door to numerous different functionalities and potential applications. As a consequence, a large number of building blocks that can act as light-harvesters, semiconductors, ligands, binding sites or redox centers have recently been integrated into the scaffolds of COFs. This unique combination of reticular chemistry with the molecular control of intrinsic properties paves the way towards the design of new semiconducting materials for (opto-)electronic applications such as sensors, photocatalysts or -electrodes, supercapacitor and battery materials, solar-harvesting devices or light emitting diodes. With new developments regarding the linkage motif, highly stable but still tunable COFs have been developed for applications even under harsh conditions. Further, the molecular stacking modes and distances in the COFs have been investigated as a powerful means to control optical and electrical characteristics of these self-assembled frameworks. Advanced understanding of optoelectronic processes in COFs has enabled their implementation in optoelectronic devices with promising potential for real-world applications. This review highlights the key developments of design concepts for the synthesis of electro- and photoactive COFs as well as our understanding of optoelectronic processes in these frameworks, hence establishing a new paradigm for the rational construction of well-defined novel optoelectronic materials and devices.},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Mode-Matching Enhancement of Second-Harmonic Generation with Plasmonic Nanopatch Antennas},

author = {A Noor and A R Damodaran and I-H Lee and S A Maier and S-H Oh and C Cirac\`{i}},

url = {https://doi.org/10.1021/acsphotonics.0c01545},

doi = {10.1021/acsphotonics.0c01545},

year  = {2020},

date = {2020-11-25},

journal = {ACS Photonics},

volume = {7},

number = {12},

pages = {3333-3340},

abstract = {Plasmonic enhancement of nonlinear optical processes confront severe limitations arising from the strong dispersion of metal susceptibilities and small interaction volumes that hamper the realization of desirable phase-matching-like conditions. Maximizing nonlinear interactions in nanoscale systems require simultaneous excitation of resonant modes that spatially and constructively overlap at all wavelengths involved in the process. Here, we present a hybrid rectangular patch antenna design for optimal second-harmonic generation (SHG) that is characterized by a non-centrosymmetric dielectric/ferroelectric material at the plasmonic hot spot. The optimization of the rectangular patch allows for the independent tuning of various modes of resonances that can be used to enhance the SHG process. We explore the angular dependence of SHG in these hybrid structures and highlight conditions necessary for the maximal SHG efficiency. Furthermore, we propose a novel configuration with a periodically poled ferroelectric layer for an orders-of-magnitude enhanced SHG at normal incidence. Such a platform may enable the development of integrated nanoscale light sources and on-chip frequency converters.},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Anharmonic Molecular Motion Drives Resonance Energy Transfer in peri-Arylene Dyads},

author = {V Sl\'{a}ma and V Perl\'{i}k and H Langhals and A Walter and T Man\v{c}al and J Hauer and F \v{S}anda},

url = {https://www.frontiersin.org/article/10.3389/fchem.2020.579166},

doi = {10.3389/fchem.2020.579166},

issn = {2296-2646},

year  = {2020},

date = {2020-11-23},

urldate = {2020-11-23},

journal = {Frontiers in Chemistry},

volume = {8},

abstract = {Spectral and dynamical properties of molecular donor-acceptor systems strongly depend on the steric arrangement of the constituents with exciton coupling J as a key control parameter. In the present work we study two peri-arylene based dyads with orthogonal and parallel transition dipoles for donor and acceptor moieties, respectively. We show that the anharmonic multi-well character of the orthogonal dyad's intramolecular potential explains findings from both stationary and time-resolved absorption experiments. While for a parallel dyad, standard quantum chemical estimates of J at 0 K are in good agreement with experimental observations, J becomes vanishingly small for the orthogonal dyad, in contrast to its ultrafast experimental transfer times. This discrepancy is not resolved even by accounting for harmonic fluctuations along normal coordinates. We resolve this problem by supplementing quantum chemical approaches with dynamical sampling of fluctuating geometries. In contrast to the moderate Gaussian fluctuations of J for the parallel dyad, fluctuations for the orthogonal dyad are found to follow non-Gaussian statistics leading to significantly higher effective J in good agreement with experimental observations. In effort to apply a unified framework for treating the dynamics of optical coherence and excitonic populations of both dyads, we employ a vibronic approach treating electronic and selected vibrational degrees on an equal footing. This vibronic model is used to model absorption and fluorescence spectra as well as donor-acceptor transport dynamics and covers the more traditional categories of F\"{o}rster and Redfield transport as limiting cases.},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Sodium Dodecylbenzene Sulfonate Interface Modification of Methylammonium Lead Iodide for Surface Passivation of Perovskite Solar Cells},

author = {Y Zou and R Guo and A Buyruk and W Chen and T Xiao and S Yin and X Jiang and L P Kreuzer and C Mu and T Ameri and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},

url = {https://doi.org/10.1021/acsami.0c14732},

doi = {10.1021/acsami.0c14732},

issn = {1944-8244},

year  = {2020},

date = {2020-11-15},

journal = {ACS Applied Materials \& Interfaces},

volume = {12},

number = {47},

pages = {52643-52651},

abstract = {Perovskite solar cells (PSCs) have been developed as a promising photovoltaic technology because of their excellent photovoltaic performance. However, interfacial recombination and charge carrier transport losses at the surface greatly limit the performance and stability of PSCs. In this work, the fabrication of high-quality PSCs based on methylammonium lead iodide with excellent ambient stability is reported. An anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), is introduced to simultaneously passivate the defect states and stabilize the cubic phase of the perovskite film. The SDBS located at grain boundaries and the surface of the active layer can effectively passivate under-coordinated lead ions and protect the perovskite components from water-induced degradation. As a result, a champion power conversion efficiency (PCE) of 19.42% is achieved with an open-circuit voltage (VOC) of 1.12 V, a short-circuit current (JSC) of 23.23 mA cm\textendash2, and a fill factor (FF) of 74% in combination with superior moisture stability. The SDBS-passivated devices retain 80% of their initial average PCE after 2112 h of storage under ambient conditions.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Improved Projection-Operator Diabatization Schemes for the Calculation of Electronic Coupling Values},

author = {S Ghan and C Kunkel and K Reuter and H Oberhofer},

url = {https://doi.org/10.1021/acs.jctc.0c00887},

doi = {10.1021/acs.jctc.0c00887},

issn = {1549-9618},

year  = {2020},

date = {2020-11-10},

urldate = {2020-11-10},

journal = {Journal of Chemical Theory and Computation},

volume = {16},

number = {12},

pages = {7431-7443},

abstract = {We address a long-standing ambiguity in the DFT-based projection-operator diabatization method for charge transfer couplings in donor\textendashacceptor systems. It has long been known that the original method yields diabats which are not strictly fragment-localized due to mixing arising from basis-set orthogonalization. We demonstrate that this can contribute to a severe underestimation of coupling strengths and a spurious dependence on the choice of the basis set. As a remedy, we reformulate the method within a simple tight-binding model to generate diabats with increased localization, yielding a proper basis set convergence and improved performance for the general Hab11 benchmark set. Orthogonality of diabats is ensured either through symmetric L\"{o}wdin or asymmetric Gram-Schmid procedures, the latter of which offers to extend these improvements to asymmetric systems such as adsorbates on surfaces.},

keywords = {Molecularly-Functionalized},

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 = {Nanoscale patterning at the Si/SiO2/graphene interface by focused He+ beam},

author = {A B\"{o}ttcher and R Schwaiger and T M Pazdera and D Exner and J Hauns and D Strelnikov and S Lebedkin and R Gr\"{o}ger and F Esch and B A J Lechner},

url = {https://iopscience.iop.org/article/10.1088/1361-6528/abb5cf/meta?casa_token=0ch84-BOwLoAAAAA:0ibNutoV58k0ONYDhRhhBtMaAbaDMOWEDghZKBvbCABbhx1dGH2gGSD1baUoc-Zosx5xyOGgxg},

doi = {10.1088/1361-6528/abb5cf},

issn = {0957-4484},

year  = {2020},

date = {2020-10-06},

urldate = {2020-10-06},

journal = {Nanotechnology},

volume = {31},

number = {50},

pages = {505302},

abstract = {We have studied the capability of He+ focused ion beam (He+-FIB) patterning to fabricate defect arrays on the Si/SiO2/Graphene interface using a combination of atomic force microscopy (AFM) and Raman imaging to probe damage zones. In general, an amorphized 'blister' region of cylindrical symmetry results upon exposing the surface to the stationary focused He+ beam. The topography of the amorphized region depends strongly on the ion dose, DS, (ranging from 103 to 107ions/spot) with craters and holes observed at higher doses. Furthermore, the surface morphology depends on the distance between adjacent irradiated spots, LS. Increasing the dose leads to (enhanced) subsurface amorphization and a local height increase relative to the unexposed regions. At the highest areal ion dose, the average height of a patterned area also increases as ∼1/LS. Correspondingly, in optical micrographs, the µm2-sized patterned surface regions change appearance. These phenomena can be explained by implantation of the He+ ions into the subsurface layers, formation of helium nanobubbles, expansion and modification of the dielectric constant of the patterned material. The corresponding modifications of the terminating graphene monolayer have been monitored by micro Raman imaging. At low ion doses, DS, the graphene becomes modified by carbon atom defects which perturb the 2D lattice (as indicated by increasing D/G Raman mode ratio). Additional x-ray photoionization spectroscopy (XPS) measurements allow us to infer that for moderate ion doses, scattering of He+ ions by the subsurface results in the oxidation of the graphene network. For largest doses and smallest LS values, the He+ beam activates extensive Si/SiO2/C bond rearrangement and a multicomponent material possibly comprising SiC and silicon oxycarbides, SiOC, is observed. We also infer parameter ranges for He+-FIB patterning defect arrays of potential use for pinning transition metal nanoparticles in model studies of heterogeneous catalysis.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {In Situ Quantification of the Local Electrocatalytic Activity via Electrochemical Scanning Tunneling Microscopy},

author = {R W Haid and R M Kluge and Y Liang and A S Bandarenka},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/smtd.202000710},

doi = {https://doi.org/10.1002/smtd.202000710},

issn = {2366-9608},

year  = {2020},

date = {2020-09-29},

journal = {Small Methods},

volume = {5},

number = {2},

pages = {2000710},

abstract = {Abstract Identification of catalytically active sites at solid/liquid interfaces under reaction conditions is an essential task to improve the catalyst design for sustainable energy devices. Electrochemical scanning tunneling microscopy (EC-STM) combines the control of the surface reactions with imaging on a nanoscale. When performing EC-STM under reaction conditions, the recorded analytical signal shows higher fluctuations (noise) at active sites compared to non-active sites (noise-EC-STM or n-EC-STM). In the past, this approach has been proven as a valid tool to identify the location of active sites. In this work, the authors show that this method can be extended to obtain quantitative information of the local activity. For the platinum(111) surface under oxygen reduction reaction conditions, a linear relationship between the STM noise level and a measure of reactivity, the turn-over frequency is found. Since it is known that the most active sites for this system are located at concave sites, the method has been applied to quantify the activity at steps. The obtained activity enhancement factors appeared to be in good agreement with the literature. Thus, n-EC-STM is a powerful method not only to in situ identify the location of active sites but also to determine and compare local reactivity.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

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 = {Carbon nitride-based light-driven microswimmers with intrinsic photocharging ability},

author = {V Sridhar and F Podjaski and J Kr\"{o}ger and A Jim\'{e}nez-Solano and B-W Park and B V Lotsch and M Sitti},

url = {http://www.pnas.org/content/117/40/24748.abstract},

doi = {10.1073/pnas.2007362117},

year  = {2020},

date = {2020-09-21},

journal = {Proceedings of the National Academy of Sciences},

volume = {117},

number = {40},

pages = {24748},

abstract = {Light-driven microswimmers offer prospects for autonomous microsystems. Understanding their surface catalytic processes responsible for propulsion is essential in tailoring them for specific applications. So far, photocatalytic microswimmers have been limited by the requirement of continuous illumination. Here, we report light-driven 2D carbon nitride-based Janus microswimmers, which show efficient propulsion in aqueous media not only during but also after illumination for about 30 min after 30 s prior illumination, due to so-called solar battery swimming. Contrary to the mainstream reports, we reveal oxygen reduction rather than hydrogen evolution being responsible for propulsion with alcohol fuels. Balancing reaction conditions, we report the realization of light-induced intrinsic charging of a microswimmer, enabling sustained ballistic propulsion in the dark through discharge of accumulated energy.Controlling autonomous propulsion of microswimmers is essential for targeted drug delivery and applications of micro/nanomachines in environmental remediation and beyond. Herein, we report two-dimensional (2D) carbon nitride-based Janus particles as highly efficient, light-driven microswimmers in aqueous media. Due to the superior photocatalytic properties of poly(heptazine imide) (PHI), the microswimmers are activated by both visible and ultraviolet (UV) light in conjunction with different capping materials (Au, Pt, and SiO2) and fuels (H2O2 and alcohols). Assisted by photoelectrochemical analysis of the PHI surface photoreactions, we elucidate the dominantly diffusiophoretic propulsion mechanism and establish the oxygen reduction reaction (ORR) as the major surface reaction in ambient conditions on metal-capped PHI and even with TiO2-based systems, rather than the hydrogen evolution reaction (HER), which is generally invoked as the source of propulsion under ambient conditions with alcohols as fuels. Making use of the intrinsic solar energy storage ability of PHI, we establish the concept of photocapacitive Janus microswimmers that can be charged by solar energy, thus enabling persistent light-induced propulsion even in the absence of illumination\textemdasha process we call “solar battery swimming”\textemdashlasting half an hour and possibly beyond. We anticipate that this propulsion scheme significantly extends the capabilities in targeted cargo/drug delivery, environmental remediation, and other potential applications of micro/nanomachines, where the use of versatile earth-abundant materials is a key prerequisite.All data, materials, and associated protocols that support the findings of this study are shown in Materials and Methods and SI Appendix.},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Annihilation Dynamics of Molecular Excitons Measured at a Single Perturbative Excitation Energy},

author = {C Heshmatpour and P Malevich and F Plasser and M Menger and C Lambert and F \v{S}anda and J Hauer},

url = {https://doi.org/10.1021/acs.jpclett.0c02141},

doi = {10.1021/acs.jpclett.0c02141},

year  = {2020},

date = {2020-09-17},

journal = {The Journal of Physical Chemistry Letters},

volume = {11},

number = {18},

pages = {7776-7781},

abstract = {Exciton\textendashexciton annihilation (EEA) is a ubiquitous phenomenon, which may limit the efficiency of photovoltaic devices. Conventional methods of determining EEA time scales rely on measuring the intensity dependence of third-order signals. In this work, we directly extract the annihilation rate of molecular excitons in a covalently joined molecular trimer without the need to perform and analyze intensity dependent data by employing fifth-order coherent optical spectroscopy signals emitted into ±2k⃗1 ∓ 2k⃗2 + k⃗3 phase matching directions. Measured two-dimensional line shapes and their time traces are analyzed in the framework of the many-body version of the Frenkel exciton model, extended to incorporate annihilation dynamics. Combining double-sided Feynman diagrams with explicit simulations of the fifth-order response, we identify a single peak as a direct reporter of EEA. We retrieve an annihilation time of 30 fs for the investigated squaraine trimer.},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {In Situ Photothermal Response of Single Gold Nanoparticles through Hyperspectral Imaging Anti-Stokes Thermometry},

author = {M Barella and I L Violi and J Gargiulo and L P Martinez and F Goschin and V Guglielmotti and D Pallarola and S Schl\"{u}cker and M Pilo-Pais and G P Acuna and S A Maier and E Cort\'{e}s and F D Stefani},

url = {https://doi.org/10.1021/acsnano.0c06185},

doi = {10.1021/acsnano.0c06185},

issn = {1936-0851},

year  = {2020},

date = {2020-09-17},

journal = {ACS Nano},

volume = {15},

number = {2},

pages = {2458-2467},

abstract = {Several fields of applications require a reliable characterization of the photothermal response and heat dissipation of nanoscopic systems, which remains a challenging task for both modeling and experimental measurements. Here, we present an implementation of anti-Stokes thermometry that enables the in situ photothermal characterization of individual nanoparticles (NPs) from a single hyperspectral photoluminescence confocal image. The method is label-free, potentially applicable to any NP with detectable anti-Stokes emission, and does not require any prior information about the NP itself or the surrounding media. With it, we first studied the photothermal response of spherical gold NPs of different sizes on glass substrates, immersed in water, and found that heat dissipation is mainly dominated by the water for NPs larger than 50 nm. Then, the role of the substrate was studied by comparing the photothermal response of 80 nm gold NPs on glass with sapphire and graphene, two materials with high thermal conductivity. For a given irradiance level, the NPs reach temperatures 18% lower on sapphire and 24% higher on graphene than on bare glass. The fact that the presence of a highly conductive material such as graphene leads to a poorer thermal dissipation demonstrates that interfacial thermal resistances play a very significant role in nanoscopic systems and emphasize the need for in situ experimental thermometry techniques. The developed method will allow addressing several open questions about the role of temperature in plasmon-assisted applications, especially ones where NPs of arbitrary shapes are present in complex matrixes and environments.},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {A Fermi smearing variant of the Tamm\textendashDancoff approximation for nonadiabatic dynamics involving S1\textendashS0 transitions: Validation and application to azobenzene},

author = {L D M Peters and J Kussmann and C Ochsenfeld},

url = {https://aip.scitation.org/doi/abs/10.1063/5.0016487},

doi = {10.1063/5.0016487},

year  = {2020},

date = {2020-09-02},

journal = {The Journal of Chemical Physics},

volume = {153},

number = {9},

pages = {094104},

abstract = {The main shortcoming of time-dependent density functional theory (TDDFT) regarding its use for nonadiabatic molecular dynamics (NAMD) is its incapability to describe conical intersections involving the ground state. To overcome this problem, we combine Fermi smearing (FS) DFT with a fractional-occupation variant of the Tamm\textendashDancoff approximation (TDA) of TDDFT in the generalized gradient approximation. The resulting method (which we denote as FS-TDA) gives access to ground- and excited-state energies, gradients, and nonadiabatic coupling vectors, which are physically correct even in the vicinity of S1\textendashS0 conical intersections. This is shown for azobenzene, a widely used photoswitch, via single point calculations and NAMD simulations of its cis\textendashtrans photoisomerization. We conclude that FS-TDA may be used as an efficient alternative to investigate these processes.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Disorder and Linker Deficiency in Porphyrinic Zr-MOFs: Resolving the Zr8O6 Cluster Conundrum in PCN-221},

author = {C Koschnick and R St\"{a}glich and T Scholz and M Terban and A V Mankowski and G Savasci and F Binder and A Sch\"{o}kel and M Etter and J Nuss and R Siegel and L Germann and C Ochsenfeld and R Dinnebier and J Senker and B V Lotsch},

url = {http://europepmc.org/abstract/PPR/PPR210987 

https://doi.org/10.26434/chemrxiv.12918968.v1},

doi = {10.26434/chemrxiv.12918968.v1},

year  = {2020},

date = {2020-09-01},

urldate = {2020-09-01},

publisher = {ChemRxiv},

abstract = {Porphyrin-based metal-organic frameworks (MOFs), exemplified by the prototypical representatives MOF-525, PCN-221, and PCN-224 are among the most promising MOF systems for catalysis, optoelectronics, and solar energy conversion. However, subtle differences between synthetic protocols for these three MOFs give rise to vast discrepancies in purported product outcomes and description of framework topologies. Here, we reveal the type and disorder of the Zr-clusters based on a comprehensive synthetic and structural analysis spanning local and long-range length scales. Our analysis on PCN-221 reveals Zr6O4(OH)4 clusters in four distinct orientations within the unit cell, rather than Zr8O6 clusters as originally published, accompanied by random linker vacancies around 50%. We propose disordered PCN-224 (dPCN-224) as a unified model to understand PCN-221, MOF-525, and PCN-224 by varying the degree of orientational cluster disorder, linker conformation and vacancies, and cluster\textemdashlinker binding. Our work thus introduces a new perspective on network topology and disorder in Zr-MOFs and pinpoints the structural variables that direct their functional properties.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

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 = {Regulating Photochemical Selectivity with Temperature: Isobutanol on TiO2(110)},

author = {C Courtois and C A Walenta and M Tschurl and U Heiz and C M Friend},

url = {\<Go to ISI\>://WOS:000557854400021},

doi = {10.1021/jacs.0c04411},

issn = {0002-7863},

year  = {2020},

date = {2020-07-29},

urldate = {2020-07-29},

journal = {Journal of the American Chemical Society},

volume = {142},

number = {30},

pages = {13072-13080},

abstract = {Selective photocatalytic transformations of chemicals derived from biomass, such as isobutanol, have been long envisioned for a sustainable chemical production. A strong temperature dependence in the reaction selectivity is found for isobutanol photo-oxidation on rutile TiO2(110). The strong temperature dependence is attributed to competition between thermal desorption of the primary photoproduct and secondary photochemical steps. The aldehyde, isobutanal, is the primary photoproduct of isobutanol. At room temperature, isobutanal is obtained selectively from photo-oxidation because of rapid thermal desorption. In contrast, secondary photo-oxidation of isobutanal to propane dominates at lower temperature (240 K) due to the persistence of isobutanal on the surface after it is formed. The byproduct of isobutanal photo-oxidation is CO, which is evolved at higher temperature as a consequence of thermal decomposition of an intermediate, such as formate. The photo-oxidation to isobutanal proceeds after thermally induced isobutoxy formation. These results have strong implications for controlling the selectivity of photochemical processes more generally, in that, selectivity is governed by competition of desorption vs secondary photoreaction of products. This competition can be exploited to design photocatalytic processes to favor specific chemical transformations of organic molecules.},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Origin of Poisoning in Methanol Photoreforming on TiO2(110): The Importance of Thermal Back-Reaction Steps in Photocatalysis},

author = {C Courtois and M Eder and S L Kollmannsberger and M Tschurl and C A Walenta and U Heiz},

url = {\<Go to ISI\>://WOS:000551549800025},

doi = {10.1021/acscatal.0c01615},

issn = {2155-5435},

year  = {2020},

date = {2020-07-17},

urldate = {2020-07-17},

journal = {Acs Catalysis},

volume = {10},

number = {14},

pages = {7747-7752},

abstract = {Alcohol photoreforming on titania represents a perfect model system for elucidating fundamental processes in the heterogeneous photocatalysis of semiconductors. One important but open question is the origin of poisoning during the photoreaction of primary alcohols on a bare, reduced rutile TiO2(110) crystal under ultrahigh vacuum conditions. By comparing the photocatalytic properties of methanol and 2-methyl-2-pentanol, it is demonstrated that the fading activity in methanol photoreforming does not originate from the often-assigned increase of trap states for photon-generated charge carriers. Instead, we attribute the apparent catalyst poisoning to an increased rate of thermal back reactions, particularly to that of the photochemical oxidation step. While overall back reactions are generally considered in photocatalysis, back reactions of individual steps are largely neglected so far. Our work shows that their inclusion in the reaction scheme is inevitable for the comprehensive modeling of photocatalytic processes.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {In Situ Printing: Insights into the Morphology Formation and Optical Property Evolution of Slot-Die-Coated Active Layers Containing Low Bandgap Polymer Donor and Nonfullerene Small Molecule Acceptor},

author = {K S Wienhold and V Korstgens and S Grott and X Y Jiang and M Schwartzkopf and S V Roth and P Muller-Buschbaum},

url = {\<Go to ISI\>://WOS:000527841700001},

doi = {10.1002/solr.202000086},

issn = {2367-198X},

year  = {2020},

date = {2020-07-01},

journal = {Solar Rrl},

volume = {4},

number = {7},

abstract = {Printing of active layers for high-efficiency organic solar cells with the slot-die coating technique can overcome the challenge of upscaling, which will be needed for organic photovoltaics on its way to marketability. The morphology of a bulk-heterojunction organic solar cell has a very high impact on its power conversion efficiency. Therefore, it is of particular importance to understand the mechanisms of structure formation during printing of active layers to enable further optimization of the solar cell performance and upscaling of the production process. Meniscus-guided slot-die coating of the blend of a low bandgap conjugated polymer donor with benzodithiophene units PBDB-T-SF and the nonfullerene small molecule acceptor IT-4F is studied in situ with optical microscopy, Ultraviolet-visible spectroscopy, and grazing incidence small angle X-ray scattering. The structure formation is followed from the liquid to the final dry film state. Thereby, five regimes of morphology formation are determined. The morphological evolution in the printed active layer is correlated to changing optical properties of the thin film. In the final dry film, polymer domains of several tens of nanometers are observed, which will be favorable for application in high-efficiency organic solar cells.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {In Operando GISAXS and GIWAXS Stability Study of Organic Solar Cells Based on PffBT4T-2OD:PC71BM with and without Solvent Additive},

author = {D Yang and F C Lohrer and V Korstgens and A Schreiber and B Cao and S Bernstorff and P Muller-Buschbaum},

url = {\<Go to ISI\>://WOS:000544597000001},

doi = {10.1002/advs.202001117},

year  = {2020},

date = {2020-07-01},

urldate = {2020-07-01},

journal = {Advanced Science},

abstract = {Solvent additives are known to modify the morphology of bulk heterojunction active layers to achieve high efficiency organic solar cells. However, the knowledge about the influence of solvent additives on the morphology degradation is limited. Hence, in operando grazing-incidence small and wide angle X-ray scattering (GISAXS and GIWAXS) measurements are applied on a series of PffBT4T-2OD:PC71BM-based solar cells prepared without and with solvent additives. The solar cells fabricated without a solvent additive, with 1,8-diiodoctane (DIO), and witho-chlorobenzaldehyde (CBA) additive show differences in the device degradation and changes in the morphology and crystallinity of the active layers. The mesoscale morphology changes are correlated with the decay of the short-circuit currentJ(sc)and the evolution of crystalline grain sizes is codependent with the decay of open-circuit voltageV(oc). Without additive, the loss inJ(sc)dominates the degradation, whereas with solvent additive (DIO and CBA) the loss inV(oc)rules the degradation. CBA addition increases the overall device stability as compared to DIO or absence of additive.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Chiral Assembly of Gold-Silver Core-Shell Plasmonic Nanorods on DNA Origami with Strong Optical Activity},

author = {L Nguyen and M Dass and M F Ober and L V Besteiro and Z M M Wang and B Nickel and A O Govorov and T Liedl and A Heuer-Jungemann},

url = {\<Go to ISI\>://WOS:000543744100103},

doi = {10.1021/acsnano.0c03127},

issn = {1936-0851},

year  = {2020},

date = {2020-06-23},

journal = {Acs Nano},

volume = {14},

number = {6},

pages = {7454-7461},

abstract = {The spatial organization of metal nanoparticles has become an important tool for manipulating light in nanophotonic applications. Silver nanoparticles, particularly silver nanorods, have excellent plasmonic properties but are prone to oxidation and are therefore inherently unstable in aqueous solutions and salt-containing buffers. Consequently, gold nanoparticles have often been favored, despite their inferior optical performance. Bimetallic, i.e., gold-silver core-shell nanoparticles, can resolve this issue. We present a method for synthesizing highly stable gold-silver core-shell NRs that are instantaneously functionalized with DNA, enabling chiral self-assembly on DNA origami. The silver shell gives rise to an enhancement of plasmonic properties, reflected here in strongly increased circular dichroism, as compared to pristine gold nanorods. Gold-silver nanorods are ideal candidates for plasmonic sensing with increased sensitivity as needed in pathogen RNA or antibody testing for nonlinear optics and light-funneling applications in surface enhanced Raman spectroscopy. Furthermore, the control of interparticle orientation enables the study of plasmonic phenomena, in particular, synergistic effects arising from plasmonic coupling of such bimetallic systems.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Following in Operando the Structure Evolution-Induced Degradation in Printed Organic Solar Cells with Nonfullerene Small Molecule Acceptor},

author = {K S Wienhold and W Chen and S S Yin and R J Guo and M Schwartzkopf and S V Roth and P Muller-Buschbaum},

url = {\<Go to ISI\>://WOS:000538529300001},

doi = {10.1002/solr.202000251},

issn = {2367-198X},

year  = {2020},

date = {2020-06-01},

urldate = {2020-06-01},

journal = {Solar Rrl},

abstract = {Understanding the degradation mechanisms of printed bulk-heterojunction (BHJ) organic solar cells during operation is essential to achieve long-term stability and realize real-world applications of organic photovoltaics. Herein, the degradation of printed organic solar cells based on the conjugated benzodithiophene polymer PBDB-T-SF and the nonfullerene small molecule acceptor IT-4F with 0.25 vol% 1,8-diiodooctane (DIO) solvent additive is studied in operando for two different donor:acceptor ratios. The inner nano-morphology is analyzed with grazing incidence small angle X-ray scattering (GISAXS), and current-voltage (I-V) characteristics are probed simultaneously. Irrespective of the mixing ratio, degradation occurs by the same degradation mechanism. A decrease in the short-circuit current density (J(SC)) is identified to be the determining factor for the decline of the power conversion efficiency. The decrease in J(SC) is induced by a reduction of the relative interface area between the conjugated polymer and the small molecule acceptor in the BHJ structure, resembling the morphological degradation of the active layer.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Transfer of Direct to Indirect Bound Excitons by Electron Intervalley Scattering in Cs2AgBiBr6 Double Perovskite Nanocrystals},

author = {A Dey and A F Richter and T Debnath and H Huang and L Polavarapu and J Feldmann},

url = {https://doi.org/10.1021/acsnano.0c00997},

doi = {10.1021/acsnano.0c00997},

issn = {1936-0851},

year  = {2020},

date = {2020-04-16},

journal = {ACS Nano},

volume = {14},

number = {5},

pages = {5855-5861},

abstract = {Lead-free halide double perovskites have emerged as a nontoxic alternative to the heavily researched lead-based halide perovskites. However, their optical properties and the initial charge carrier relaxation processes are under debate. In this study, we apply time-resolved photoluminescence and differential transmission spectroscopy to investigate the photoexcited charge carrier dynamics within the indirect band structure of Cs2AgBiBr6 nanocrystals. Interestingly, we observe a high energetic emission stemming from the direct band gap, besides the previously reported emission from the indirect band gap transition. We attribute this emission to the radiative recombination of direct bound excitons. This emission maximum redshifts nearly 1 eV within 10 ps due to electron intervalley scattering, which leads to a transfer of direct to indirect bound excitons. We conclude that these direct bound excitons possess a giant oscillator strength causing not only a pronounced absorption peak at the optical band gap energy but also luminescence to occur at the direct band gap transition in spite of the prevailing intervalley scattering process. These results expand the understanding of the optical properties and the charge carrier relaxation in double perovskites, thus, facilitating the further development of optoelectronic devices harnessing lead-free perovskites.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Addressable Nanoantennas with Cleared Hotspots for Single-Molecule Detection on a Portable Smartphone Microscope},

author = {K Trofymchuk and V Glembockyte and L Grabenhorst and F Steiner and C Vietz and C Close and M Pfeiffer and L Richter and M L Sch\"{u}tte and F Selbach and R Yaadav and J Z\"{a}hringer and Q Wei and A Ozcan and B Lalkens and G P Acuna and P Tinnefeld},

url = {http://biorxiv.org/content/early/2020/04/09/2020.04.09.032037.abstract},

doi = {10.1101/2020.04.09.032037},

year  = {2020},

date = {2020-04-09},

urldate = {2020-04-09},

journal = {bioRxiv},

pages = {2020.04.09.032037},

abstract = {The advent of highly sensitive photodetectors1,2 and the development of photostabilization strategies3 made detecting the fluorescence of a single molecule a routine task in many labs around the world. However, to this day, this process requires cost-intensive optical instruments due to the truly nanoscopic signal of a single emitter. Simplifying single-molecule detection would enable many exciting applications, e.g. in point-of-care diagnostic settings, where costly equipment would be prohibitive.4 Here, we introduce addressable NanoAntennas with Cleared HOtSpots (NACHOS) that are scaffolded by DNA origami nanostructures and can be specifically tailored for the incorporation of bioassays. Single emitters placed in the NACHOS emit up to 461-fold brighter enabling their detection with a customary smartphone camera and an 8-US-dollar objective lens. To prove the applicability of our system, we built a portable, battery-powered smartphone microscope and successfully carried out an exemplary single-molecule detection assay for DNA specific to antibiotic-resistant Klebsiella pneumonia "on the road “.Competing Interest StatementPT and GPA are inventors on a patent of the described Bottom-up method for fluorescence enhancement in molecular assays, EP1260316.1, 2012, US20130252825 A1.},

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

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Surface Species in Photocatalytic Methanol Reforming on Pt/TiO2(110): Learning from Surface Science Experiments for Catalytically Relevant Conditions},

author = {C A Walenta and C Courtois and S L Kollmannsberger and M Eder and M Tschurl and U Heiz},

url = {\<Go to ISI\>://WOS:000526395000011},

doi = {10.1021/acscatal.0c00260},

issn = {2155-5435},

year  = {2020},

date = {2020-04-03},

urldate = {2020-04-03},

journal = {Acs Catalysis},

volume = {10},

number = {7},

pages = {4080-4091},

abstract = {Photocatalytic hydrogen evolution from methanol is a standard test reaction for photocatalyst materials. Surprisingly, the exact chemical mechanism is still widely discussed in the literature. In order to disentangle photochemical from thermal reaction steps and gain insights on the atomic level, we use a Pt cluster-loaded TiO2(110) photocatalyst in very well-defined environments. Using Auger electron spectroscopy, temperature-programmed desorption/reaction, isotopic labeling, and isothermal photoreactions, it is possible to identify the surface species present on the catalyst under photocatalytic conditions. Furthermore, an initial conditioning of the photocatalyst is observed and attributed to thermal dehydrogenation of methanol to CO species on the cluster. The analysis of the isothermal photoreactions reveals that the photo-oxidation kinetics are not significantly affected by cocatalyst loading. The observed conversion and product distribution of formaldehyde and methyl formate can be rationalized with kinetic parameters gained from the bare TiO2(110) crystal. The work leads to a detailed mechanistic understanding of the surface species and paves the way for an educated microkinetic modeling approach, which may be extended to a variety of noble metal cocatalysts and other TiO2 modifications.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Quantum biology revisited},

author = {J Cao and R J Cogdell and D F Coker and H-G Duan and J Hauer and U Kleinekath\"{o}fer and T L C Jansen and T Man\v{c}al and R J D Miller and J P Ogilvie and V I Prokhorenko and T Renger and H-S Tan and R Tempelaar and M Thorwart and E Thyrhaug and S Westenhoff and D Zigmantas},

url = {http://advances.sciencemag.org/content/6/14/eaaz4888.abstract},

doi = {10.1126/sciadv.aaz4888},

year  = {2020},

date = {2020-04-01},

journal = {Science Advances},

volume = {6},

number = {14},

pages = {eaaz4888},

abstract = {Photosynthesis is a highly optimized process from which valuable lessons can be learned about the operating principles in nature. Its primary steps involve energy transport operating near theoretical quantum limits in efficiency. Recently, extensive research was motivated by the hypothesis that nature used quantum coherences to direct energy transfer. This body of work, a cornerstone for the field of quantum biology, rests on the interpretation of small-amplitude oscillations in two-dimensional electronic spectra of photosynthetic complexes. This Review discusses recent work reexamining these claims and demonstrates that interexciton coherences are too short lived to have any functional significance in photosynthetic energy transfer. Instead, the observed long-lived coherences originate from impulsively excited vibrations, generally observed in femtosecond spectroscopy. These efforts, collectively, lead to a more detailed understanding of the quantum aspects of dissipation. Nature, rather than trying to avoid dissipation, exploits it via engineering of exciton-bath interaction to create efficient energy flow.},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Validation of the inverted adsorption structure for free-base tetraphenyl porphyrin on Cu(111)},

author = {P T P Ryan and P L Lalaguna and F Haag and M M Braim and P Ding and D J Payne and J V Barth and T L Lee and D P Woodruff and F Allegretti and D A Duncan},

url = {\<Go to ISI\>://WOS:000526692700019},

doi = {10.1039/c9cc09638h},

issn = {1359-7345},

year  = {2020},

date = {2020-03-28},

journal = {Chemical Communications},

volume = {56},

number = {25},

pages = {3681-3684},

abstract = {Utilising normal incidence X-ray standing waves we rigourously scrutinise the "inverted model" as the adsorption structure of free-base tetraphenyl porphyrin on Cu(111). We demonstrate that the iminic N atoms are anchored at near-bridge adsorption sites on the surface displaced laterally by 1.1 +/- 0.2 angstrom in excellent agreement with previously published calculations.},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Organic solar cells probed with advanced neutron scattering techniques},

author = {K S Wienhold and X Y Jiang and P Muller-Buschbaum},

url = {\<Go to ISI\>://WOS:000522430600001},

doi = {10.1063/5.0003997},

issn = {0003-6951},

year  = {2020},

date = {2020-03-23},

journal = {Applied Physics Letters},

volume = {116},

number = {12},

abstract = {Neutron scattering techniques provide unique insights into the active layer morphology of organic solar cells. The nanoscale morphology, the thin film vertical composition, and the intermixing on a molecular level, which all strongly have an impact on the performance of organic solar cells, can be probed with neutrons. In addition to the static structure, also fast dynamics occurring in the active material is accessible with neutrons. This perspective letter highlights the power of grazing incidence small angle neutron scattering and quasi-elastic neutron scattering experiments after shortly introducing into the working principle of organic solar cells.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Tailoring Morphology Compatibility and Device Stability by Adding PBDTTPD-COOH as Third Component to Fullerene-Based Polymer Solar Cells},

author = {D Yang and B Cao and V Korstgens and N Saxena and N Li and C Bilko and S Grott and W Chen and X Y Jiang and J E Heger and S Bernstorff and P Muller-Buschbaum},

url = {\<Go to ISI\>://WOS:000526598300061},

doi = {10.1021/acsaem.9b02290},

issn = {2574-0962},

year  = {2020},

date = {2020-03-23},

journal = {Acs Applied Energy Materials},

volume = {3},

number = {3},

pages = {2604-2613},

abstract = {The crystallinity and morphology of polymer and fullerene have a profound influence on the performance of bulk heterojunction (BHJ) organic photovoltaic devices. The poor compatibility of donor and acceptor molecules in the BHJs hinders the further improvement of the device performance and stability in organic solar cells. In this work, the conjugated polymer PBDTTPD-COOH is introduced as a third component into BHJ films of PTB7-Th:PC71BM and PffBT4T-2OD:PC71BM to improve the crystallinity and morphology. The crystallinity of both donor polymers is enhanced and more face-on orientated crystals are observed in the corresponding films, which is correlated with the improvement of the current density of the related solar cells. Also, the improved BHJ morphology leads to an increased fill factor. Furthermore, the device stability significantly increases by the addition of the third component PBDTTPD-COOH. The T80 lifetime value is enhanced 10 times in the doped devices as compared with the binary solar cells in the case of the PTB7-Th:PC71BM series.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Fluorophore photostability and saturation in the hotspot of DNA origami nanoantennas},

author = {L Grabenhorst and K Trofymchuk and F Steiner and V Glembockyte and P Tinnefeld},

url = {http://dx.doi.org/10.1088/2050-6120/ab6ac8},

doi = {10.1088/2050-6120/ab6ac8},

issn = {2050-6120},

year  = {2020},

date = {2020-02-05},

urldate = {2020-02-05},

journal = {Methods and Applications in Fluorescence},

volume = {8},

number = {2},

pages = {024003},

abstract = {Fluorescent dyes used for single-molecule spectroscopy can undergo millions of excitation-emission cycles before photobleaching. Due to the upconcentration of light in a plasmonic hotspot, the conditions for fluorescent dyes are even more demanding in DNA origami nanoantennas. Here, we briefly review the current state of fluorophore stabilization for single-molecule imaging and reveal additional factors relevant in the context of plasmonic fluorescence enhancement. We show that despite the improved photostability of single-molecule fluorophores by DNA origami nanoantennas, their performance in the intense electric fields in plasmonic hotspots is still limited by the underlying photophysical processes, such as formation of dim states and photoisomerization. These photophysical processes limit the photon count rates, increase heterogeneity and aggravate quantification of fluorescence enhancement factors. These factors also reduce the time resolution that can be achieved in biophysical single-molecule experiments. Finally, we show how the photophysics of a DNA hairpin assay with a fluorophore-quencher pair can be influenced by plasmonic DNA origami nanoantennas leading to implications for their use in fluorescence-based diagnostic assays. Especially, we show that such assays can produce false positive results by premature photobleaching of the dark quencher.},

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

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Demonstration of n-type behavior in catalyst-free Si-doped GaAs nanowires grown by molecular beam epitaxy},

author = {D Ruhstorfer and S Mejia and M Ramsteiner and M D\"{o}blinger and H Riedl and J J Finley and G Koblm\"{u}ller},

url = {https://aip.scitation.org/doi/abs/10.1063/1.5134687},

doi = {10.1063/1.5134687},

year  = {2020},

date = {2020-02-04},

journal = {Applied Physics Letters},

volume = {116},

number = {5},

pages = {052101},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}