Publications

@article{,

title = {Self-Constructed Multiple Plasmonic Hotspots on an Individual Fractal to Amplify Broadband Hot Electron Generation},

author = {X Wang and C Liu and C Gao and K Yao and S S M Masouleh and R Bert\'{e} and H Ren and L D S Menezes and E Cort\'{e}s and I C Bicket and H Wang and N Li and Z Zhang and M Li and W Xie and Y Yu and Y Fang and S Zhang and H Xu and A Vomiero and Y Liu and G A Botton and S A Maier and H Liang},

url = {https://doi.org/10.1021/acsnano.1c03218},

doi = {10.1021/acsnano.1c03218},

issn = {1936-0851},

year  = {2021},

date = {2021-06-11},

journal = {ACS Nano},

abstract = {Plasmonic nanoparticles are ideal candidates for hot-electron-assisted applications, but their narrow resonance region and limited hotspot number hindered the energy utilization of broadband solar energy. Inspired by tree branches, we designed and chemically synthesized silver fractals, which enable self-constructed hotspots and multiple plasmonic resonances, extending the broadband generation of hot electrons for better matching with the solar radiation spectrum. We directly revealed the plasmonic origin, the spatial distribution, and the decay dynamics of hot electrons on the single-particle level by using ab initio simulation, dark-field spectroscopy, pump\textendashprobe measurements, and electron energy loss spectroscopy. Our results show that fractals with acute tips and narrow gaps can support broadband resonances (400\textendash1100 nm) and a large number of randomly distributed hotspots, which can provide unpolarized enhanced near field and promote hot electron generation. As a proof-of-concept, hot-electron-triggered dimerization of p-nitropthiophenol and hydrogen production are investigated under various irradiations, and the promoted hot electron generation on fractals was confirmed with significantly improved efficiency.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Manganese doping for enhanced magnetic brightening and circular polarization control of dark excitons in paramagnetic layered hybrid metal-halide perovskites},

author = {T Neumann and S Feldmann and P Moser and A Delhomme and J Zerhoch and T Van De Goor and S Wang and M Dyksik and T Winkler and J J Finley and P Plochocka and M S Brandt and C Faugeras and A V Stier and F Deschler},

url = {https://doi.org/10.1038/s41467-021-23602-1},

doi = {10.1038/s41467-021-23602-1},

issn = {2041-1723},

year  = {2021},

date = {2021-06-09},

journal = {Nature Communications},

volume = {12},

number = {1},

pages = {3489},

abstract = {Materials combining semiconductor functionalities with spin control are desired for the advancement of quantum technologies. Here, we study the magneto-optical properties of novel paramagnetic Ruddlesden-Popper hybrid perovskites Mn:(PEA)2PbI4 (PEA = phenethylammonium) and report magnetically brightened excitonic luminescence with strong circular polarization from the interaction with isolated Mn2+ ions. Using a combination of superconducting quantum interference device (SQUID) magnetometry, magneto-absorption and transient optical spectroscopy, we find that a dark exciton population is brightened by state mixing with the bright excitons in the presence of a magnetic field. Unexpectedly, the circular polarization of the dark exciton luminescence follows the Brillouin-shaped magnetization with a saturation polarization of 13% at 4 K and 6 T. From high-field transient magneto-luminescence we attribute our observations to spin-dependent exciton dynamics at early times after excitation, with first indications for a Mn-mediated spin-flip process. Our findings demonstrate manganese doping as a powerful approach to control excitonic spin physics in Ruddlesden-Popper perovskites, which will stimulate research on this highly tuneable material platform with promise for tailored interactions between magnetic moments and excitonic states.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Nanocellulose-Assisted Thermally Induced Growth of Silver Nanoparticles for Optical Applications},

author = {C J Brett and W Ohm and B Fricke and A E Alexakis and T Laarmann and V K\"{o}rstgens and P M\"{u}ller-Buschbaum and L D S\"{o}derberg and S V Roth},

url = {https://doi.org/10.1021/acsami.1c07544},

doi = {10.1021/acsami.1c07544},

issn = {1944-8244},

year  = {2021},

date = {2021-06-07},

journal = {ACS Applied Materials \& Interfaces},

volume = {13},

number = {23},

pages = {27696-27704},

abstract = {Optically responsive materials are present in everyday life, from screens to sensors. However, fabricating large-area, fossil-free materials for functional biocompatible applications is still a challenge today. Nanocelluloses from various sources, such as wood, can provide biocompatibility and are emerging candidates for templating organic optoelectronics. Silver (Ag) in its nanoscale form shows excellent optical properties. Herein, we combine both materials using thin-film large-area spray-coating to study the fabrication of optical response applications. We characterize the Ag nanoparticle formation by X-ray scattering and UV\textendashvis spectroscopy in situ during growth on the nanocellulose template. The morphology and optical properties of the nanocellulose film are compared to the rigid reference surface SiO2. Our results clearly show the potential to tailor the energy band gap of the resulting hybrid material.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Nano-Scale Complexions Facilitate Li Dendrite-Free Operation in LATP Solid-State Electrolyte},

author = {S Stegmaier and R Schierholz and I Povstugar and J Barthel and S P Rittmeyer and S Yu and S Wengert and S Rostami and H Kungl and K Reuter and R-A Eichel and C Scheurer},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202100707},

doi = {https://doi.org/10.1002/aenm.202100707},

issn = {1614-6832},

year  = {2021},

date = {2021-05-28},

journal = {Advanced Energy Materials},

volume = {n/a},

number = {n/a},

pages = {2100707},

abstract = {Abstract Dendrite formation and growth remains a major obstacle toward high-performance all solid-state batteries using Li metal anodes. The ceramic Li(1+x)Al(x)Ti(2−x)(PO4)3 (LATP) solid-state electrolyte shows a higher than expected stability against electrochemical decomposition despite a bulk electronic conductivity that exceeds a recently postulated threshold for dendrite-free operation. Here, transmission electron microscopy, atom probe tomography, and first-principles based simulations are combined to establish atomistic structural models of glass-amorphous LATP grain boundaries. These models reveal a nanometer-thin complexion layer that encapsulates the crystalline grains. The distinct composition of this complexion constitutes a sizable electronic impedance. Rather than fulfilling macroscopic bulk measures of ionic and electronic conduction, LATP might thus gain the capability to suppress dendrite nucleation by sufficient local separation of charge carriers at the nanoscale.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Fast and accurate determination of the electroactive surface area of MnOx},

author = {M H Aufa and S A Watzele and S Hou and R W Haid and R M Kluge and A S Bandarenka and B Garlyyev},

url = {https://www.sciencedirect.com/science/article/pii/S0013468621009828},

doi = {https://doi.org/10.1016/j.electacta.2021.138692},

issn = {0013-4686},

year  = {2021},

date = {2021-05-27},

journal = {Electrochimica Acta},

volume = {389},

pages = {138692},

abstract = {Manganese oxide (MnOx)-based materials are widely utilized in the field of electrocatalysis as bifunctional electrocatalysts for the oxygen reduction and evolution reactions. However, for an accurate assessment of their performance, the determination of their electrochemical active surface area (ECSA) is of paramount importance. So far, there is no fast and reproducible methodology. This article presents an easily applicable and affordable technique to determine the ECSA of MnOx accurately. The presented methodology makes use of the specific adsorption capacitance of reaction intermediates close to the onset potential of the oxygen evolution reaction. The electrochemical impedance spectroscopy is utilized to measure the specific adsorption capacitances at different potentials. Using MnOx thin-film electrodes, we determine the specific adsorption capacitances and present calibration values, which can be used for an accurate determination of the ECSA of different, for instance, nanostructured materials.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Understanding disorder and linker deficiency in porphyrinic zirconium-based metal\textendashorganic frameworks by resolving the Zr8O6 cluster conundrum in PCN-221},

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

url = {https://doi.org/10.1038/s41467-021-23348-w},

doi = {10.1038/s41467-021-23348-w},

issn = {2041-1723},

year  = {2021},

date = {2021-05-25},

journal = {Nature Communications},

volume = {12},

number = {1},

pages = {3099},

abstract = {Porphyrin-based metal\textendashorganic frameworks (MOFs), exemplified by MOF-525, PCN-221, and PCN-224, are promising 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, based on a comprehensive synthetic and structural analysis spanning local and long-range length scales, we show that PCN-221 consists of Zr6O4(OH)4 clusters in four distinct orientations within the unit cell, rather than Zr8O6 clusters as originally published, and linker vacancies at levels of around 50%, which may form in a locally correlated manner. 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\textendashlinker 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{nokey,

title = {Host\textendashGuest Interactions in a Metal\textendashOrganic Framework Isoreticular Series for Molecular Photocatalytic CO2 Reduction},

author = {P M Stanley and J Haimerl and C Thomas and A Urstoeger and M Schuster and N B Shustova and A Casini and B Rieger and J Warnan and R A Fischer},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202102729},

doi = {https://doi.org/10.1002/anie.202102729},

issn = {1433-7851},

year  = {2021},

date = {2021-05-20},

journal = {Angewandte Chemie International Edition},

volume = {60},

number = {33},

pages = {17854-17860},

abstract = {Abstract A strategy to improve homogeneous molecular catalyst stability, efficiency, and selectivity is the immobilization on supporting surfaces or within host matrices. Herein, we examine the co-immobilization of a CO2 reduction catalyst [ReBr(CO)3(4,4′-dcbpy)] and a photosensitizer [Ru(bpy)2(5,5′-dcbpy)]Cl2 using the isoreticular series of metal\textendashorganic frameworks (MOFs) UiO-66, -67, and -68. Specific host pore size choice enables distinct catalyst and photosensitizer spatial location\textemdasheither at the outer MOF particle surface or inside the MOF cavities\textemdashaffecting catalyst stability, electronic communication between reaction center and photosensitizer, and consequently the apparent catalytic rates. These results allow for a rational understanding of an optimized supramolecular layout of catalyst, photosensitizer, and host matrix.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Nanoscale Heterogeneities and Composition\textendashReactivity Relationships in Copper Vanadate Photoanodes},

author = {J Eichhorn and C-M Jiang and J K Cooper and I D Sharp and F M Toma},

url = {https://doi.org/10.1021/acsami.1c01848},

doi = {10.1021/acsami.1c01848},

issn = {1944-8244},

year  = {2021},

date = {2021-05-17},

urldate = {2021-05-17},

journal = {ACS Applied Materials \& Interfaces},

volume = {13},

number = {20},

pages = {23575-23583},

abstract = {The photoelectrochemical performance of thin film photoelectrodes can be impacted by deviations from the stoichiometric composition, both at the macroscale and at the nanoscale. This issue is especially pronounced for the class of ternary compounds that are currently investigated for simultaneously achieving the optoelectronic characteristics and chemical stability required for solar fuel generation. Here, we combine macroscopic photoelectrochemical testing with atomic force microscopy (AFM) and scanning transmission X-ray microscopy (STXM) to reveal relationships between photoelectrochemical activity, nanoscale morphology, and local chemical composition in copper vanadate (CVO) thin films as a model system. For films with varying Cu/(Cu + V) ratios around the ideal stoichiometry of stoiberite Cu5V2O10, AFM resolves submicrometer morphology variations, which correlate with variations of the Cu content resolved by STXM. Both stoichiometric and Cu-deficient films exhibit a clear photoresponse, which indicates electronic tolerance to reduced Cu content. While both films exhibit homogeneous O and V content, they are also characterized by local regions of Cu enrichment and depletion that extend beyond individual grains. By contrast, Cu-rich photoelectrodes exhibit a tendency toward CuO secondary phase formation and a significantly reduced photoelectrochemical activity, indicating a significantly poor electronic tolerance to Cu-enrichment. These findings highlight that the average film composition at the macroscale is insufficient for defining structure\textendashfunction relationships in complex ternary compounds. Rather, correlating microscopic variations in chemical composition to macroscopic photoelectrochemical performance provides insights into photocatalytic activity and stability that are otherwise not apparent from pure macroscopic characterization.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {The Significance of Polarons and Dynamic Disorder in Halide Perovskites},

author = {M J Schilcher and P J Robinson and D J Abramovitch and L Z Tan and A M Rappe and D R Reichman and D A Egger},

url = {https://doi.org/10.1021/acsenergylett.1c00506},

doi = {10.1021/acsenergylett.1c00506},

year  = {2021},

date = {2021-05-17},

journal = {ACS Energy Letters},

pages = {2162-2173},

abstract = {The development of halide perovskite semiconductors led to various technological breakthroughs in optoelectronics, in particular in the areas of photovoltaics and light-emitting diodes. Additionally, the study of their fundamental properties has uncovered intriguing puzzles that demand explanation. Polaronic effects associated with the coupling of electrons and holes to polar lattice vibrations are often invoked as a microscopic mechanism to explain various unusual experimental observations. While some form of polaronic behavior undoubtedly exists in these systems, several assumptions underlying standard models used to describe a polaron mechanism appear to be strongly violated in these materials. In this Perspective, we investigate the role of polaronic effects in halide perovskites and summarize signatures and failures of the polaron picture to explain physical characteristics of the materials. We highlight the importance of the complementary dynamic disorder concept that can rationalize various key properties of halide perovskites for which standard polaron and band-theory pictures of carrier transport fail.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Tuning the intermediate reaction barriers by a CuPd catalyst to improve the selectivity of CO2 electroreduction to C2 products},

author = {L Zhu and Y Lin and K Liu and E Cort\'{e}s and H Li and J Hu and A Yamaguchi and X Liu and M Miyauchi and J Fu and M Liu},

url = {https://www.sciencedirect.com/science/article/pii/S1872206720637548},

doi = {https://doi.org/10.1016/S1872-2067(20)63754-8},

issn = {1872-2067},

year  = {2021},

date = {2021-05-12},

urldate = {2021-05-12},

journal = {Chinese Journal of Catalysis},

volume = {42},

number = {9},

pages = {1500-1508},

abstract = {Electrochemical CO2 reduction is a promising strategy for the utilization of CO2 and intermittent excess electricity. Cu is the only single metal catalyst that can electrochemically convert CO2 into multicarbon products. However, Cu exhibits an unfavorable activity and selectivity for the generation of C2 products because of the insufficient amount of CO* provided for the C-C coupling. Based on the strong CO2 adsorption and ultrafast reaction kinetics of CO* formation on Pd, an intimate CuPd(100) interface was designed to lower the intermediate reaction barriers and improve the efficiency of C2 product formation. Density functional theory (DFT) calculations showed that the CuPd(100) interface enhanced the CO2 adsorption and decreased the CO2* hydrogenation energy barrier, which was beneficial for the C-C coupling. The potential-determining step (PDS) barrier of CO2 to C2 products on the CuPd(100) interface was 0.61 eV, which was lower than that on Cu(100) (0.72 eV). Encouraged by the DFT calculation results, the CuPd(100) interface catalyst was prepared by a facile chemical solution method and characterized by transmission electron microscopy. CO2 temperature-programmed desorption and gas sensor experiments further confirmed the enhancement of the CO2 adsorption and CO2* hydrogenation ability of the CuPd(100) interface catalyst. Specifically, the obtained CuPd(100) interface catalyst exhibited a C2 Faradaic efficiency of 50.3% ± 1.2% at −1.4 VRHE in 0.1 M KHCO3, which was 2.1 times higher than that of the Cu catalyst (23.6% ± 1.5%). This study provides the basis for the rational design of Cu-based electrocatalysts for the generation of multicarbon products by fine-tuning the intermediate reaction barriers.},

keywords = {Foundry Inorganic, Solid-Liquid},

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{,

title = {Characterization and Quantification of Depletion and Accumulation Layers in Solid-State Li+-Conducting Electrolytes Using In Situ Spectroscopic Ellipsometry},

author = {L Katzenmeier and L Carstensen and S J Schaper and P M\"{u}ller-Buschbaum and A S Bandarenka},

url = {http://europepmc.org/abstract/MED/33955614 

https://doi.org/10.1002/adma.202100585},

doi = {10.1002/adma.202100585},

issn = {0935-9648},

year  = {2021},

date = {2021-05-06},

journal = {Advanced Materials},

pages = {e2100585},

abstract = {The future of mobility depends on the development of next-generation battery technologies, such as all-solid-state batteries. As the ionic conductivity of solid Li^{+} -conductors can, in some cases, approach that of liquid electrolytes, a significant remaining barrier faced by solid-state electrolytes (SSEs) is the interface formed at the anode and cathode materials, with chemical instability and physical resistances arising. The physical properties of space charge layers (SCLs), a widely discussed phenomenon in SSEs, are still unclear. In this work, spectroscopic ellipsometry is used to characterize the accumulation and depletion layers. An optical model is developed to quantify their thicknesses and corresponding concentration changes. It is shown that the Li^{+} -depleted layer (≈190 nm at 1 V) is thinner than the accumulation layer (≈320 nm at 1 V) in a glassy lithium-ion-conducting glass ceramic electrolyte (a trademark of Ohara Corporation). The in situ approach combining electrochemistry and optics resolves the ambiguities around SCL formation. It opens up a wide field of optical measurements on SSEs, allowing various experimental studies in the future.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Charge Traps in All‐Inorganic CsPbBr3 Perovskite Nanowire Field‐Effect Phototransistors},

author = {F Winterer and L S Walter and J Lenz and S Seebauer and Y Tong and L Polavarapu and R T Weitz},

issn = {2199-160X},

year  = {2021},

date = {2021-05-06},

journal = {Advanced Electronic Materials},

pages = {2100105},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Picosecond Charge Localization Dynamics in CH3NH3PbI3 Perovskite Probed by Infrared-Activated Vibrations},

author = {K Stallhofer and M Nuber and D Cortecchia and A Bruno and R Kienberger and F Deschler and C Soci and H Iglev},

url = {https://doi.org/10.1021/acs.jpclett.1c00935},

doi = {10.1021/acs.jpclett.1c00935},

year  = {2021},

date = {2021-05-05},

journal = {The Journal of Physical Chemistry Letters},

pages = {4428-4433},

abstract = {Hybrid metal halide perovskites exhibit well-defined semiconducting properties and efficient optoelectronic performance considering their soft crystal structure and low-energy lattice motions. The response of such a crystal lattice to light-induced charges is a fundamental question, for which experimental insight into ultrafast time scales is still sought. Here, we use infrared-activated vibrations (IRAV) of the organic components within the hybrid perovskite lattice as a sensitive probe for local structural reorganizations after photoexcitation, with femtosecond resolution. We find that the IRAV signal response shows a delayed rise of about 3 ps and subsequent decay of pronounced monomolecular character, distinguishing it from absorption associated with free carriers. We interpret our results as a two-step carrier localization process. Initially, carriers localize transiently in local energy minima formed by lattice fluctuations. A subpopulation of these can then fall into deeper trapped states over picoseconds, likely due to local reorganization of the organic molecules surrounding the carriers.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Carbonaceous Oxygen Evolution Reaction Catalysts: From Defect and Doping-Induced Activity over Hybrid Compounds to Ordered Framework Structures},

author = {F Zoller and S H\"{a}ringer and D B\"{o}hm and J Luxa and Z Sofer and D Fattakhova-Rohlfing},

doi = {10.1002/smll.202007484},

issn = {1613-6810},

year  = {2021},

date = {2021-05-04},

journal = {Small},

pages = {e2007484},

abstract = {Oxygen evolution reaction (OER) is expected to be of great importance for the future energy conversion and storage in form of hydrogen by water electrolysis. Besides the traditional noble-metal or transition metal oxide-based catalysts, carbonaceous electrocatalysts are of great interest due to their huge structural and compositional variety and unrestricted abundance. This review provides a summary of recent advances in the field of carbon-based OER catalysts ranging from "pure" or unintentionally doped carbon allotropes over heteroatom-doped carbonaceous materials and carbon/transition metal compounds to metal oxide composites where the role of carbon is mainly assigned to be a conductive support. Furthermore, the review discusses the recent developments in the field of ordered carbon framework structures (metal organic framework and covalent organic framework structures) that potentially allow a rational design of heteroatom-doped 3D porous structures with defined composition and spatial arrangement of doping atoms to deepen the understanding on the OER mechanism on carbonaceous structures in the future. Besides introducing the structural and compositional origin of electrochemical activity, the review discusses the mechanism of the catalytic activity of carbonaceous materials, their stability under OER conditions, and potential synergistic effects in combination with metal (or metal oxide) co-catalysts.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Review on physical impedance models in modern battery research},

author = {R R Gaddam and L Katzenmeier and X Lamprecht and A S Bandarenka},

url = {http://dx.doi.org/10.1039/D1CP00673H},

doi = {10.1039/D1CP00673H},

issn = {1463-9076},

year  = {2021},

date = {2021-05-04},

journal = {Physical Chemistry Chemical Physics},

volume = {23},

number = {23},

pages = {12926-12944},

abstract = {Electrochemical impedance spectroscopy (EIS) is a versatile tool to understand complex processes in batteries. This technique can investigate the effects of battery components like the electrode and electrolyte, electrochemical reactions, interfaces, and interphases forming in the electrochemical systems. The interpretation of the EIS data is typically made using models expressed in terms of the so-called electrical equivalent circuits (EECs) to fit the impedance spectra. Therefore, the EECs must unambiguously represent the electrochemistry of the system. EEC models with a physical significance are more relevant than the empirical ones with their inherent imperfect description of the ongoing processes. This review aims to present the readers with the importance of physical EEC modeling within the context of battery research. A general introduction to EIS and EEC models along with a brief description of the mathematical formalism is provided, followed by showcasing the importance of physical EEC models for EIS on selected examples from the research on traditional, aqueous, and newer all-solid-state battery systems.},

keywords = {Foundry Inorganic, 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{nokey,

title = {Conformational Control of Chemical Reactivity for Surface-Confined Ru-Porphyrins},

author = {P Knecht and J Reichert and P S Deimel and P Feulner and F Haag and F Allegretti and M Garnica and M Schwarz and W Auw\"{a}rter and P T P Ryan and T-L Lee and D A Duncan and A P Seitsonen and J V Barth and A C Papageorgiou},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202104075},

doi = {https://doi.org/10.1002/anie.202104075},

issn = {1433-7851},

year  = {2021},

date = {2021-05-03},

journal = {Angewandte Chemie International Edition},

volume = {60},

number = {30},

pages = {16561-16567},

abstract = {Abstract We assess the crucial role of tetrapyrrole flexibility in the CO ligation to distinct Ru-porphyrins supported on an atomistically well-defined Ag(111) substrate. Our systematic real-space visualisation and manipulation experiments with scanning tunnelling microscopy directly probe the ligation, while bond-resolving atomic force microscopy and X-ray standing-wave measurements characterise the geometry, X-ray and ultraviolet photoelectron spectroscopy the electronic structure, and temperature-programmed desorption the binding strength. Density-functional-theory calculations provide additional insight into the functional interface. We unambiguously demonstrate that the substituents regulate the interfacial conformational adaptability, either promoting or obstructing the uptake of axial CO adducts.},

keywords = {Foundry Inorganic, Solid-Solid},

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 = {33},

issue = {24},

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{nokey,

title = {Controlling exciton many-body states by the electric-field effect in monolayer $mathrmMoS_2$},

author = {J Klein and A H\"{o}tger and M Florian and A Steinhoff and A Delhomme and T Taniguchi and K Watanabe and F Jahnke and A W Holleitner and M Potemski and C Faugeras and J J Finley and A V Stier},

url = {https://link.aps.org/doi/10.1103/PhysRevResearch.3.L022009},

doi = {10.1103/PhysRevResearch.3.L022009},

year  = {2021},

date = {2021-04-30},

journal = {Physical Review Research},

volume = {3},

number = {2},

pages = {L022009},

abstract = {We report magneto-optical spectroscopy of gated monolayer 

MoS2 in high magnetic fields up to 28T and obtain new insights on the many-body interaction of neutral and charged excitons with the resident charges of distinct spin and valley texture. For neutral excitons at low electron doping, we observe a nonlinear valley Zeeman shift due to dipolar spin-interactions that depends sensitively on the local carrier concentration. As the Fermi energy increases to dominate over the other relevant energy scales in the system, the magneto-optical response depends on the occupation of the fully spin-polarized Landau levels (LL) in both K/K′ valleys. This manifests itself in a many-body state. Our experiments demonstrate that the exciton in monolayer semiconductors is only a single particle boson close to charge neutrality. We find that away from charge neutrality it smoothly transitions into polaronic states with a distinct spin-valley flavor that is defined by the LL quantized spin and valley texture.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Understanding entrapped molecular photosystem and metal\textendashorganic framework synergy for improved solar fuel production},

author = {P M Stanley and M Parkulab and B Rieger and J Warnan and R A Fischer},

url = {http://dx.doi.org/10.1039/D1FD00009H},

doi = {10.1039/D1FD00009H},

issn = {1359-6640},

year  = {2021},

date = {2021-04-27},

urldate = {2021-04-27},

journal = {Faraday Discussions},

volume = {231},

number = {0},

pages = {281-297},

abstract = {Artificial photosystems assembled from molecular complexes, such as the photocatalyst fac-ReBr(CO)3(4,4′-dcbpy) (dcbpy = dicarboxy-2,2′-bipyridine) and the photosensitiser Ru(bpy)2(5,5′-dcbpy)Cl2 (bpy = 2,2′-bipyridine), are a wide-spread approach for solar fuel production. Recently metal\textendashorganic framework (MOF) entrapping of such complexes was demonstrated as a promising concept for catalyst stabilisation and reaction environment optimisation in colloidal-based CO2 reduction. Building on this strategy, here we examined the influence of MIL-101-NH2(Al) MOF particle size, the electron donor source, and the presence of an organic base on the photocatalytic CO2-to-CO reduction performance, and the differences to homogeneous systems. A linear relation between smaller scaffold particle size and higher photocatalytic activity, longer system lifetimes for benign electron donors, and increased turnover numbers (TONs) with certain additive organic bases, were determined. This enabled understanding of key molecular catalysis phenomena and synergies in the nanoreactor-like host\textendashguest assembly, and yielded TONs of ∼4300 over 96 h of photocatalysis under optimised conditions, surpassing homogeneous TON values and lifetimes.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Anapole-Assisted Absorption Engineering in Arrays of Coupled Amorphous Gallium Phosphide Nanodisks},

author = {L H\"{u}ttenhofer and A Tittl and L K\"{u}hner and E Cort\'{e}s and S A Maier},

url = {https://doi.org/10.1021/acsphotonics.1c00238},

doi = {10.1021/acsphotonics.1c00238},

year  = {2021},

date = {2021-04-26},

journal = {ACS Photonics},

abstract = {Broadband solar light harvesting plays a crucial role for efficient energy conversion. Anapole excitations and associated absorption engineering in dielectric nanoresonators are a focus of nanophotonic research due to the intricate combination of nonradiating modes and strong electromagnetic field confinement in the underlying material. The arising high field strengths are used for enhanced second-harmonic generation and photocatalysis, where devices require large areas with closely spaced nanoresonators for sizable photonic yields. However, most anapole studies have so far been carried out at the single-particle level, neglecting the influence of anapole\textendashanapole interactions. Here, we present a systematic study of coupling mechanisms in rectangular arrays of amorphous GaP nanodisks that support anapole excitations at 600 nm, which is within the lossy spectral regime of the material. Our experimental findings show that maximum visible light extinction by the array and maximum absorption in the GaP are not achieved by the densest packing of resonators. Counterintuitively, increasing the array periodicities such that collective effects spectrally overlap with the anapole excitation of a single particle leads to an absorption enhancement of up to 300% compared to a single disk. An analysis of coupling in one- and two-dimensional arrays with polarization-dependent measurements and numerical simulations allows us to discriminate between coupling interactions parallel and perpendicular to the polarization axis and evaluate their strengths. Utilizing a multipolar decomposition of excitations in single nanodisks embedded in one-dimensional arrays, we can attribute the coupling to enhanced electric and toroidal dipoles under variation of the interparticle spacing. Our results provide a fundamental understanding of tailored light absorption in coupled anapole resonators and reveal important design guidelines for advanced metasurface approaches in a wide range of energy conversion applications.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Emerging Organic/Hybrid Photovoltaic Cells for Indoor Applications: Recent Advances and Perspectives},

author = {H Zheng and D Li and C Ran and Q Zhong and L Song and Y Chen and P M\"{u}ller-Buschbaum and W Huang},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/solr.202100042},

doi = {https://doi.org/10.1002/solr.202100042},

issn = {2367-198X},

year  = {2021},

date = {2021-04-23},

journal = {Solar RRL},

volume = {n/a},

number = {n/a},

pages = {2100042},

abstract = {Due to the continuous development and advances in the Internet of Things, wireless sensors, actuators for human−interactive machines, and indoor low-power devices require a continuous supply of energy. Photovoltaic cells working under indoor light are suitable candidates for charging these devices because of their high voltages (up to 5 V), low costs, and environmental friendliness. Herein, the research on organic photovoltaic, dye-sensitized, and perovskite cells in indoor photovoltaic applications with respect to the active layer, modified layer, and preparation process is summarized. The performance enhancement of indoor photovoltaic cells is outlined, including photoactive material selection, bandgap optimization, modification layer function, and device structure design, followed by the prospects and challenges of future developments in indoor photovoltaic cells. With this review an important perspective for the advancement of indoor photovoltaics is offered.},

keywords = {Foundry Inorganic},

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{,

title = {In-situ Detection of Active Sites for Carbon-Based Bifunctional Oxygen Reduction and Evolution Catalysis},

author = {R W Haid and R M Kluge and T O Schmidt and A S Bandarenka},

url = {https://www.sciencedirect.com/science/article/pii/S0013468621005752},

doi = {https://doi.org/10.1016/j.electacta.2021.138285},

issn = {0013-4686},

year  = {2021},

date = {2021-04-02},

urldate = {2021-04-02},

journal = {Electrochimica Acta},

volume = {382},

pages = {138285},

abstract = {Due to their availability and electrochemical versatility, carbon-based electrodes are becoming an increasingly popular option as electrocatalysts for fuel cells and metal-air batteries. Additionally, they show great potential as bifunctional catalysts for the oxygen reduction and evolution reaction (ORR/OER) in an alkaline medium. However, to compete with state-of-the-art catalysts, the nature of the active sites and the surface stability under reaction conditions need to be understood in depth. Here, we present a principle study on highly oriented pyrolytic graphite (HOPG), evaluating the surface behavior under both ORR and OER conditions in 0.1 M KOH. We use noise analysis in electrochemical scanning tunneling microscopy (n-EC-STM) to monitor and compare ORR and OER active sites with resolution down to the nanoscale. Furthermore, surface degradation can be evaluated during the operation. We find that close to the respective reaction onset, step sites and defects are active for both ORR and OER. Terraces sites are largely inactive and only become involved in the OER at higher potentials. This could imply corrosion of the carbon. However, since the observed surface structures remain unaltered before and after applying the OER in our experiments, we find no clear evidence of surface destruction. These fundamental insights could inspire further research concerning the active sites and stability of carbon-based catalysts as well as carbon support structures, to discover ways to tune the surface activity and stability to the dedicated purpose.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Open Framework Material Based Thin Films: Electrochemical Catalysis and State-of-the-art Technologies},

author = {W Li and S Mukerjee and B Ren and R Cao and R A Fischer},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202003499},

doi = {https://doi.org/10.1002/aenm.202003499},

issn = {1614-6832},

year  = {2021},

date = {2021-04-01},

journal = {Advanced Energy Materials},

volume = {n/a},

number = {n/a},

pages = {2003499},

abstract = {Abstract Open framework materials (OFMs), such as metal-organic frameworks and covalent organic frameworks have emerged as promising electrocatalysts to address the global energy crisis and environmental problems. Powdered non-film forms, that is, bulk OFMs exhibit excellent catalytic activities toward electrocatalytic carbon dioxide reduction, water splitting, and the oxygen reduction reaction. However, electrode preparation using bulk solids suffers from a range of oft-encountered difficulties, primarily limited by challenges in controlling their thickness, roughness, and particle sizes, despite early performance promises. Targeting energy sustainability, it is a matter of growing interest to directly integrate OFMs in the form of thin films onto conductive substrates. In essence, this leads to electrocatalysts with controlled features: thickness, roughness, and particle sizes. Thus far, there are only a handful of OFM thin films developed for electrocatalysis. Exploration of these understudied OFM thin films to serve electrocatalysis still lies at its infancy. This review will cover the key discoveries of OFM thin films as electrocatalysts and will critically examine the strengths, challenges, and future goals in exploring bespoke OFM thin films for electrocatalysis, under conditions that mimic real-world applications.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Assessment of active areas for the oxygen evolution reaction on an amorphous iridium oxide surface},

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

url = {https://www.sciencedirect.com/science/article/pii/S0021951721000531},

doi = {https://doi.org/10.1016/j.jcat.2021.02.007},

issn = {0021-9517},

year  = {2021},

date = {2021-04-01},

urldate = {2021-04-01},

journal = {Journal of Catalysis},

volume = {396},

pages = {14-22},

abstract = {Electrocatalytic “green” production of hydrogen from water for sustainable energy provision schemes is currently inefficient due to the sluggish kinetics of the oxygen evolution reaction (OER) at the anodes of the electrolysers. In the case of acidic polymer electrolyte membrane electrolysers, iridium (Ir) oxide catalysts pose a promising compromise between good OER activity and stability. However, the structure\textendashactivity relations for these materials remain largely unknown because the surface of a “real” oxide catalyst under reaction conditions becomes amorphous. In order to contribute to the understanding of these systems, we use electrochemical scanning tunnelling microscopy under reaction conditions (‘noise’ or n-EC-STM). With this technique, active areas can be detected by an increased noise level of the STM signal compared to inactive sites. The n-EC-STM measurements are applied to an amorphous iridium oxide surface, which is formed during electrochemical cycling of Ir(111). By doing so, we can monitor OER activity in-situ while simultaneously assessing the surface morphology. In order to elucidate the active areas, step and terrace sites were quantitatively compared to each other. The measurements reveal that terraces, step sites and concavities lead to a similar noise level increase in the STM signal. We, thus, conclude that the OER on the amorphous extended iridium oxide surface shows little structure-sensitivity. Subsequently, we suggest that in contrast to, e.g., metallic Pt for the oxygen electro-reduction, the shape of amorphous IrOx nanoparticles in an acidic medium should not significantly influence the OER turnover frequency.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Paired Ru‒O‒Mo ensemble for efficient and stable alkaline hydrogen evolution reaction},

author = {H Li and K Liu and J Fu and K Chen and K Yang and Y Lin and B Yang and Q Wang and H Pan and Z Cai and H Li and M Cao and J Hu and Y-R Lu and T-S Chan and E Cort\'{e}s and A Fratalocchi and M Liu},

url = {http://www.sciencedirect.com/science/article/pii/S2211285521000252},

doi = {https://doi.org/10.1016/j.nanoen.2021.105767},

issn = {2211-2855},

year  = {2021},

date = {2021-04-01},

urldate = {2021-04-01},

journal = {Nano Energy},

volume = {82},

pages = {105767},

abstract = {Electrocatalytic hydrogen evolution reaction (HER) in alkaline media is a promising electrochemical energy conversion strategy. Ruthenium (Ru) is an efficient catalyst with a desirable cost for HER, however, the sluggish H2O dissociation process, due to the low H2O adsorption on its surface, currently hampers the performances of this catalyst in alkaline HER. Herein, we demonstrate that the H2O adsorption improves significantly by the construction of Ru\textendashO\textendashMo sites. We prepared Ru/MoO2 catalysts with Ru\textendashO\textendashMo sites through a facile thermal treatment process and assessed the creation of Ru\textendashO\textendashMo interfaces by transmission electron microscope (TEM) and extended X-ray absorption fine structure (EXAFS). By using Fourier-transform infrared spectroscopy (FTIR) and H2O adsorption tests, we proved Ru\textendashO\textendashMo sites have tenfold stronger H2O adsorption ability than that of Ru catalyst. The catalysts with Ru\textendashO\textendashMo sites exhibited a state-of-the-art overpotential of 16 mV at 10 mA cm\textendash2 in 1 M KOH electrolyte, demonstrating a threefold reduction than the previous bests of Ru (59 mV) and commercial Pt (31 mV) catalysts. We proved the stability of these performances over 40 h without decline. These results could open a new path for designing efficient and stable catalysts.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {An electrically conducting three-dimensional iron-catecholate porous framework},

author = {A M\"{a}hringer and M D\"{o}blinger and M Hennemann and C Gruber and D Fehn and P I Scheurle and P Hosseini and I Santourian and A Schirmacher and J M Rotter and G Wittstock and K Meyer and T Clark and T Bein and D D Medina},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202102670},

doi = {https://doi.org/10.1002/anie.202102670},

issn = {1433-7851},

year  = {2021},

date = {2021-03-29},

journal = {Angewandte Chemie International Edition},

volume = {n/a},

number = {n/a},

abstract = {Here, we report the synthesis of a unique cubic metal-organic framework (MOF), the Fe-HHTP-MOF, comprising hexahydroxytriphenylene (HHTP) supertetrahedral units and FeIII ions, arranged in a diamond topology. The MOF is synthesized under solvothermal conditions, yielding a highly crystalline, deep black powder, with crystallites of 300-500 nm size and tetrahedral morphology. Nitrogen sorption analysis indicates a highly porous material with a surface area exceeding 1400 m2 g−1. Furthermore, Fe-HHTP-MOF shows broadband absorption from 475 nm up to 1900 nm with excellent absorption capability of 98.5% of the incoming light over the visible spectral region. Electrical conductivity measurements of pressed pellets reveal a high intrinsic electrical conductivity of up to 10−3 S cm−1. Quantum mechanical calculations predict Fe-HHTP-MOF to be an efficient electron conductor, exhibiting continuous charge-carrier pathways throughout the structure. This report expands the paradigm of intrinsically electroactive MOFs, serving as a solid basis for the development of highly porous, ordered frameworks with enhanced electrical conductivity.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Monitoring Active Sites for Hydrogen Evolution Reaction at Model Carbon Surfaces},

author = {R Kluge and R W Haid and I Stephens and F Calle-Vallejo and A S Bandarenka},

url = {http://dx.doi.org/10.1039/D1CP00434D},

doi = {10.1039/D1CP00434D},

issn = {1463-9076},

year  = {2021},

date = {2021-03-25},

urldate = {2021-03-25},

journal = {Physical Chemistry Chemical Physics},

volume = {23},

pages = {10051-10058},

abstract = {Carbon is ubiquitous as an electrode material in electrochemical energy conversion devices. If used as support material, the evolution of H2 is undesired on carbon. However, recently carbon-based materials are of high interest as economic and eco-conscious alternative to noble metal catalysts. The targeted design of improved carbon electrode materials requires atomic scale insight into the structure of the sites that catalyse H2 evolution. This work demonstrates that electrochemical scanning tunnelling microscopy under reaction conditions (n-EC-STM) can monitor active sites of highly oriented pyrolytic graphite for the hydrogen evolution reaction. With down to atomic resolution, the most active sites in acidic medium are pinpointed near edge sites and defects, whereas the basal planes remain inactive. Density functional theory calculations support these findings and reveal that only specific defects on graphite are active. Motivated by these results, the extensive usage of n-EC-STM on doped carbon-based materials is encouraged to locate their active sites and guide the synthesis of enhanced electrocatalysts.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Ultrafine TiO2 Nanoparticle Supported Nitrogen-Rich Graphitic Porous Carbon as an Efficient Anode Material for Potassium-Ion Batteries},

author = {D P Dubal and A Schneemann and V Ranc and \v{S} Kment and O Tomanec and M Petr and H Kmentova and M Otyepka and R Zbo\v{r}il and R A Fischer and K Jayaramulu},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aesr.202100042},

doi = {https://doi.org/10.1002/aesr.202100042},

issn = {2699-9412},

year  = {2021},

date = {2021-03-17},

journal = {Advanced Energy and Sustainability Research},

volume = {2},

number = {9},

pages = {2100042},

abstract = {Potassium-ion batteries (KIBs) have attracted enormous attention as a next-generation energy storage system due to their low cost, fast ionic conductivity within electrolytes, and high operating voltage. However, developing suitable electrode materials to guarantee high-energy output and structural stability to ensure long cycling performance remains a critical challenge. Herein, anatase TiO2 nanoparticles are encapsulated in nitrogen-rich graphitic carbon (TiO2@NGC) with hierarchical pores and high surface area (250 m2 g−1) using the Ti-based metal\textendashorganic framework NH2-MIL-125 (Ti8O8(OH)4(NH2-bdc)6 with NH2-bdc2− = 2-amino-1,4-benzenedicarboxylate) as a sacrificial template. Serving as the anode material in a K-ion half-cell, TiO2@NGC delivers a high capacity of 228 mA h g−1 with remarkable cycling performance (negligible loss over 2000 cycles with more than 98% Coulombic efficiency). The charge-storing mechanism is underpinned using ex situ characterization techniques such as ex situ X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. It is revealed that the original TiO2 phase gets transformed to the anorthic Ti7O13 and monoclinic K2Ti4O9 phase after the first charge/discharge cycle, which further initiates the charge storage process via the conversion reactions.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Phase formation through synthetic control: polymorphism in the sodium-ion solid electrolyte Na4P2S6},

author = {T Scholz and C Schneider and R Eger and V Duppel and I Moudrakovski and A Schulz and J Nuss and B V Lotsch},

url = {http://dx.doi.org/10.1039/D0TA11008F},

doi = {10.1039/D0TA11008F},

issn = {2050-7488},

year  = {2021},

date = {2021-03-10},

journal = {Journal of Materials Chemistry A},

volume = {9},

number = {13},

pages = {8692-8703},

abstract = {The development of all-solid-state sodium batteries for scalable energy storage solutions requires fast sodium conducting solid electrolytes. To fast-track their discovery, candidate materials need to be identified that are synthesized from abundant resources via cheap and green synthesis routes. Their ion conducting mechanism has to be understood and adapted to meet the stringent requirements for long-term operation in all-solid-state batteries. Here, structure and properties of the sodium hexathiohypodiphosphate Na4P2S6 obtained by two different synthesis methods are compared: a solid-state reaction and a precipitation route from aqueous solution. Combined investigations using powder X-ray diffraction (PXRD), precession electron diffraction (PED), differential scanning calorimetry (DSC), solid-state nuclear magnetic resonance spectroscopy (ssNMR), and Raman spectroscopy reveal that the solid-state synthesized material is characterized by a Na+ and vacancy disorder-driven enantiotropic phase transition at 160 °C (α- to β-Na4P2S6), which is accompanied by a symmetry change of the P2S64− anion. Precipitated Na4P2S6 already crystallizes in a β-like polymorph at room temperature, likely assisted by inter- and intralayer defects. Bond-valence and nudged elastic band (NEB) calculations were employed to identify a low energy, 2D conduction network in β-Na4P2S6, suggesting facile 2D long-range Na+ diffusion. Electrochemical impedance spectroscopy reveals a higher ionic conductivity at room temperature in precipitated β-like Na4P2S6 (2 × 10−6 S cm−1) compared to the solid-state α polymorph (7 × 10−7 S cm−1). The activation energy is around 0.4 eV for both materials. The findings highlight that even subtle structural changes can significantly impact the sodium-ion diffusion in solid electrolytes and at the same time reveal an intricate interplay between phase formation and synthetic control.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Investigation of degradation mechanisms in PEM fuel cells caused by low-temperature cycles},

author = {J P Sabawa and A S Bandarenka},

url = {https://www.sciencedirect.com/science/article/pii/S0360319921005917},

doi = {https://doi.org/10.1016/j.ijhydene.2021.02.088},

issn = {0360-3199},

year  = {2021},

date = {2021-03-05},

urldate = {2021-03-05},

journal = {International Journal of Hydrogen Energy},

volume = {46},

pages = {15951-15964},

abstract = {Environmental influences, especially temperatures below the freezing point, can affect the performance and long-term stability of PEMFCs. Within the scope of this research, a completely new test procedure was developed to characterize PEMFC single cells with respect to their long-term stability at temperature cycles between 80 °C and −10 °C. Using this procedure, the behavior of PEMFC single cells (active surface area of 43.6 cm2) with different cathode-ionomer-to-carbon (I/C) weight ratios (0.5/1.0/1.5) was evaluated. The generated in-situ measurement data clearly demonstrate that the performance of each PEMFC single cell changes individually as a function of the cathode I/C-ratio during the 120 stress cycles. While the MEA with an I/C ratio of 0.5 showed a power loss of ~1.49%, the MEAs with an I/C ratio of 1.0 and 1.5 showed a power loss of about ~7.75% and ~24.7%, respectively. The subsequent post-mortem ex-situ analyses clearly showed how the test procedure and the different I/C-ratios affected the changes in the catalyst layers (CL). The destructive mechanisms responsible for the changes can be divided into two categories: One part was driven by rapid enthalpy change leading to mechanical failure, and the other part, which led to the reduction of cathode CL thickness, was driven by rapid potential changes and potential shifts (overpotentials). This reduction in cathode CL thickness ultimately leads to an accumulation and excessive load of ionomer in the direction of GDL, resulting in a reduction in pore size, a shift in the core reaction area, and high O2 transport resistance.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {The Potential of Zero Charge and the Electrochemical Interface Structure of Cu(111) in Alkaline Solutions},

author = {A Auer and X Ding and A S Bandarenka and J Kunze-Liebh\"{a}user},

url = {https://doi.org/10.1021/acs.jpcc.0c09289},

doi = {10.1021/acs.jpcc.0c09289},

issn = {1932-7447},

year  = {2021},

date = {2021-03-01},

urldate = {2021-03-01},

journal = {The Journal of Physical Chemistry C},

volume = {125},

pages = {5020-5028},

abstract = {Copper (Cu) is a unique electrocatalyst, which is able to efficiently oxidize CO at very low overpotentials and reduce CO2 to valuable fuels with reasonable Faradaic efficiencies. Yet, knowledge of its electrochemical properties at the solid/liquid interface is still scarce. Here, we present the first two-stranded correlation of the potential of zero free charge (pzfc) of Cu(111) in alkaline electrolyte at different pH values through application of nanosecond laser pulses and the corresponding interfacial structure changes by in situ electrochemical scanning tunneling microscopy imaging. The pzfc of Cu(111) at pH 13 is identified at −0.73 VSHE in the apparent double layer region, prior to the onset of hydroxide adsorption. It shifts by (88 ± 4) mV to more positive potentials per decreasing pH unit. At the pzfc, Cu(111) shows structural dynamics at both pH 13 and pH 11, which can be understood as the onset of surface restructuring. At higher potentials, full reconstruction and electric field dependent OH adsorption occurs, which causes a remarkable decrease in the atomic density of the first Cu layer. The expansion of the Cu\textendashCu distance to 0.3 nm generates a hexagonal Moir\'{e} pattern, on which the adsorbed OH forms a commensurate (1 × 2) adlayer structure with a steady state coverage of 0.5 monolayers at pH 13. Our experimental findings shed light on the true charge distribution and its interrelation with the atomic structure of the electrochemical interface of Cu.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Role of cation-mediated recombination in perovskite solar cells},

author = {A Singh and W Kaiser and A Gagliardi},

url = {https://www.sciencedirect.com/science/article/pii/S0927024820305092},

doi = {https://doi.org/10.1016/j.solmat.2020.110912},

issn = {0927-0248},

year  = {2021},

date = {2021-03-01},

journal = {Solar Energy Materials and Solar Cells},

volume = {221},

pages = {110912},

abstract = {The origin of the hysteresis in the current\textendashvoltage (J\textendashV) characteristics in perovskite solar cells (PSCs) is one of the most debated topics of recent years. Hysteretic effects are connected with the slow redistribution of ionic defects during the voltage sweep. Existing literature focuses on the potential screening due to accumulated ions, solely, while neglecting the possibility of charge trapping and subsequent recombination via ions. We investigate the role of cation-mediated recombination of ions using time-dependent drift\textendashdiffusion simulations in MAPbI3 PSCs. Slow-moving cations are considered as traps for the electrons. Trapped electrons can subsequently recombine non-radiatively with holes. We analyze the role of the cation-mediated trapping and its parameters (capture coefficient, cation energy, ion mobility) as well as the scan rate on the device performance. For shallow cation energies, a decrease in open-circuit voltage and slight enhancement in hysteresis is observed. Deep cation energies lead to a substantial deterioration of device performance and large hysteresis enhancement. The presented study emphasizes the importance of considering the interaction of ions with charge carriers beyond the simple electrostatic models to improve our understanding of PSCs.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Highly Efficient Resolution-of-Identity Density Functional Theory Calculations on Central and Graphics Processing Units},

author = {J Kussmann and H Laqua and C Ochsenfeld},

url = {https://doi.org/10.1021/acs.jctc.0c01252},

doi = {10.1021/acs.jctc.0c01252},

issn = {1549-9618},

year  = {2021},

date = {2021-02-22},

journal = {Journal of Chemical Theory and Computation},

abstract = {We present an efficient method to evaluate Coulomb potential matrices using the resolution of identity approximation and semilocal exchange-correlation potentials on central (CPU) and graphics processing units (GPU). The new GPU-based RI-algorithm shows a high performance and ensures the favorable scaling with increasing basis set size as the conventional CPU-based method. Furthermore, our method is based on the J-engine algorithm [White; , Head-Gordon, J. Chem. Phys. 1996, 7, 2620], which allows for further optimizations that also provide a significant improvement of the corresponding CPU-based algorithm. Due to the increased performance for the Coulomb evaluation, the calculation of the exchange-correlation potential of density functional theory on CPUs quickly becomes a bottleneck to the overall computational time. Hence, we also present a GPU-based algorithm to evaluate the exchange-correlation terms, which results in an overall high-performance method for density functional calculations. The algorithms to evaluate the potential and nuclear derivative terms are discussed, and their performance on CPUs and GPUs is demonstrated for illustrative calculations.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Transfer of 1D Photonic Crystals via Spatially Resolved Hydrophobization},

author = {M D\"{a}ntl and S Guderley and K Szendrei-Temesi and D Chatzitheodoridou and P Ganter and A Jim\'{e}nez-Solano and B V Lotsch},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/smll.202007864},

doi = {https://doi.org/10.1002/smll.202007864},

issn = {1613-6810},

year  = {2021},

date = {2021-02-15},

journal = {Small},

volume = {17},

number = {12},

pages = {2007864},

abstract = {Abstract 1D photonic crystals (1DPCs) are well known from a variety of applications ranging from medical diagnostics to optical fibers and optoelectronics. However, large-scale application is still limited due to complex fabrication processes and bottlenecks in transferring 1DPCs to arbitrary substrates and pattern creation. These challenges were addressed by demonstrating the transfer of millimeter- to centimeter-scale 1DPC sensors comprised of alternating layers of H3Sb3P2O14 nanosheets and TiO2 nanoparticles based on a non-invasive chemical approach. By depositing the 1DPC on a sacrificial layer of lithium tin sulfide nanosheets and hydrophobizing only the 1DPC by intercalation of n-octylamine via the vapor phase the 1DPC can be detached from the substrate by immersing the sample in water. Upon exfoliation of the hydrophilic sacrificial layer, the freestanding 1DPC remains at the water\textendashair interface. In a second step, it can be transferred to arbitrary surfaces such as curved glass. In addition, the transfer of patterned 1DPCs is demonstrated by combining the sacrificial layer approach with area-resolved intercalation and etching. The fact that the sensing capability of the 1DPC is not impaired and can be modified after transfer renders this method a generic platform for the fabrication of photonic devices.},

keywords = {Foundry Inorganic},

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{,

title = {Perovskite Nanocrystals: Synthesis, Stability, and Optoelectronic Applications},

author = {S Wang and Yousefi A A Amin and L Wu and M Cao and Q Zhang and T Ameri},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/sstr.202000124},

doi = {https://doi.org/10.1002/sstr.202000124},

issn = {2688-4062},

year  = {2021},

date = {2021-02-07},

journal = {Small Structures},

volume = {n/a},

number = {n/a},

pages = {2000124},

abstract = {Metal halide perovskite (MHP) materials, named as the game changers, have attracted researchers’ attention worldwide for over a decade. Among them, nanometer-scale perovskite nanocrystals (PNCs) have exhibited attractive photophysical properties, such as tunable bandgaps, narrow emission, strong light-absorption coefficients, and high defect tolerance, because they combined the excellent optoelectronic properties of bulk perovskite materials with strong quantum confinement effects of the nanoscale. These materials possess a great potential to be applied in the optoelectronic devices. For commercial applications in devices like solar cells (SCs), light-emitting diodes (LEDs), and photodetectors (PDs), the stability of PNCs against ambient atmosphere like oxygen and moisture, as well as light and high temperature is crucial. Herein, the synthetic methods and stability issues of the PNCs are introduced first, followed by the introduction of the strategies for improving their stability by encapsulation. The applications of PNCs in various optoelectronic devices are then briefly presented. Finally, the remained challenges in improving the stability of PNCs toward the PNC-based optoelectronics with high performance and great durability are addressed.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Electronic properties of semiconducting Zn(Si, Ge, Sn)N2 alloys},

author = {M Ogura and D Han and M M Pointner and L S Junkers and S S Rudel and W Schnick and H Ebert},

url = {https://link.aps.org/doi/10.1103/PhysRevMaterials.5.024601},

doi = {10.1103/PhysRevMaterials.5.024601},

year  = {2021},

date = {2021-02-02},

urldate = {2021-02-02},

journal = {Physical Review Materials},

volume = {5},

number = {2},

pages = {024601},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Formation Mechanisms for Phosphorene and SnIP},

author = {M R P Pielmeier and T Nilges},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202016257},

doi = {https://doi.org/10.1002/anie.202016257},

issn = {1433-7851},

year  = {2021},

date = {2021-01-29},

journal = {Angewandte Chemie International Edition},

volume = {n/a},

number = {n/a},

abstract = {Abstract Phosphorene\textemdashthe monolayered material of the element allotrope black phosphorus (Pblack)\textemdashand SnIP are 2D and 1D semiconductors with intriguing physical properties. Pblack and SnIP have in common that they can be synthesized via short way transport or mineralization using tin, tin(IV) iodide and amorphous red phosphorus. This top-down approach is the most important access route to phosphorene. The two preparation routes are closely connected and differ mainly in reaction temperature and molar ratios of starting materials. Many speculative intermediates or activator side phases have been postulated especially for top-down Pblack/phosphorene synthesis, such as Hittorf's phosphorus or Sn24P19.3I8 clathrate. The importance of phosphorus-based 2D and 1D materials for energy conversion, storage, and catalysis inspired us to elucidate the formation mechanisms of these two compounds. Herein, we report on the reaction mechanisms of Pblack/phosphorene and SnIP from P4 and SnI2 via direct gas phase formation.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Identification of Potential Optoelectronic Applications for Metal Thiophosphates},

author = {D Han and H Ebert},

url = {https://doi.org/10.1021/acsami.0c17818},

doi = {10.1021/acsami.0c17818},

issn = {1944-8244},

year  = {2021},

date = {2021-01-27},

urldate = {2021-01-27},

journal = {ACS Applied Materials \& Interfaces},

volume = {13},

number = {3},

pages = {3836-3844},

abstract = {Metal thiophosphates are a large family of compounds that received far less attention than conventional chalcogenides. Recently, however, metal thiophosphates arouse research interest in regard of energy harvesting and conversion due to their structural and chemical diversity. Nevertheless, there remain many unexplored metal thiophosphates. Here, we performed a comprehensive investigation on the electronic and optoelectronic properties of a series of metal thiophosphates using first-principles calculations and identified several highly promising compounds as p-type transparent conductors, photovoltaic absorbers, and single visible-light-driven photocatalysts for water splitting. Our investigation reveals the intrinsic features of a series of typical metal thiophosphates, identifies their new optoelectronic applications, and validates that metal thiophosphates are promising materials deserving exploration.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Relaxed Current Matching Requirements in Highly Luminescent Perovskite Tandem Solar Cells and Their Fundamental Efficiency Limits},

author = {A R Bowman and F Lang and Y-H Chiang and A Jim\'{e}nez-Solano and K Frohna and G E Eperon and E Ruggeri and M Abdi-Jalebi and M Anaya and B V Lotsch and S D Stranks},

url = {https://doi.org/10.1021/acsenergylett.0c02481},

doi = {10.1021/acsenergylett.0c02481},

year  = {2021},

date = {2021-01-22},

journal = {ACS Energy Letters},

volume = {6},

number = {2},

pages = {612-620},

abstract = {Perovskite-based tandem solar cells are of increasing interest as they approach commercialization. Here we use experimental parameters from optical spectroscopy measurements to calculate the limiting efficiency of perovskite\textendashsilicon and all-perovskite two-terminal tandems, employing currently available bandgap materials, as 42.0% and 40.8%, respectively. We show luminescence coupling between subcells (the optical transfer of photons from the high-bandgap to low-bandgap subcell) relaxes current matching when the high-bandgap subcell is a luminescent perovskite. We calculate that luminescence coupling becomes important at charge trapping rates (≤106 s\textendash1) already being achieved in relevant halide perovskites. Luminescence coupling increases flexibility in subcell thicknesses and tolerance to different spectral conditions. For maximal benefit, the high-bandgap subcell should have the higher short-circuit current under average spectral conditions. This can be achieved by reducing the bandgap of the high-bandgap subcell, allowing wider, unstable bandgap compositions to be avoided. Lastly, we visualize luminescence coupling in an all-perovskite tandem through cross-section luminescence imaging.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {3D Deep Learning Enables Accurate Layer Mapping of 2D Materials},

author = {X Dong and H Li and Z Jiang and T Gr\"{u}nleitner and \.{I} G\"{u}ler and J Dong and K Wang and M H K\"{o}hler and M Jakobi and B H Menze and A K Yetisen and I D Sharp and A V Stier and J J Finley and A W Koch},

url = {https://doi.org/10.1021/acsnano.0c09685},

doi = {10.1021/acsnano.0c09685},

issn = {1936-0851},

year  = {2021},

date = {2021-01-19},

journal = {ACS Nano},

volume = {15},

number = {2},

pages = {3139-3151},

abstract = {Layered, two-dimensional (2D) materials are promising for next-generation photonics devices. Typically, the thickness of mechanically cleaved flakes and chemical vapor deposited thin films is distributed randomly over a large area, where accurate identification of atomic layer numbers is time-consuming. Hyperspectral imaging microscopy yields spectral information that can be used to distinguish the spectral differences of varying thickness specimens. However, its spatial resolution is relatively low due to the spectral imaging nature. In this work, we present a 3D deep learning solution called DALM (deep-learning-enabled atomic layer mapping) to merge hyperspectral reflection images (high spectral resolution) and RGB images (high spatial resolution) for the identification and segmentation of MoS2 flakes with mono-, bi-, tri-, and multilayer thicknesses. DALM is trained on a small set of labeled images, automatically predicts layer distributions and segments individual layers with high accuracy, and shows robustness to illumination and contrast variations. Further, we show its advantageous performance over the state-of-the-art model that is solely based on RGB microscope images. This AI-supported technique with high speed, spatial resolution, and accuracy allows for reliable computer-aided identification of atomically thin materials.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Raman spectrum of Janus transition metal dichalcogenide monolayers WSSe and MoSSe},

author = {M M Petri\'{c} and M Kremser and M Barbone and Y Qin and Y Sayyad and Y Shen and S Tongay and J J Finley and A R Botello-M\'{e}ndez and K M\"{u}ller},

url = {https://link.aps.org/doi/10.1103/PhysRevB.103.035414},

doi = {10.1103/PhysRevB.103.035414},

year  = {2021},

date = {2021-01-15},

journal = {Physical Review B},

volume = {103},

number = {3},

pages = {035414},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Pure non-local machine-learned density functional theory for electron correlation},

author = {J T Margraf and K Reuter},

url = {https://doi.org/10.1038/s41467-020-20471-y},

doi = {10.1038/s41467-020-20471-y},

issn = {2041-1723},

year  = {2021},

date = {2021-01-12},

urldate = {2021-01-12},

journal = {Nature Communications},

volume = {12},

number = {1},

pages = {344},

abstract = {Density-functional theory (DFT) is a rigorous and (in principle) exact framework for the description of the ground state properties of atoms, molecules and solids based on their electron density. While computationally efficient density-functional approximations (DFAs) have become essential tools in computational chemistry, their (semi-)local treatment of electron correlation has a number of well-known pathologies, e.g. related to electron self-interaction. Here, we present a type of machine-learning (ML) based DFA (termed Kernel Density Functional Approximation, KDFA) that is pure, non-local and transferable, and can be efficiently trained with fully quantitative reference methods. The functionals retain the mean-field computational cost of common DFAs and are shown to be applicable to non-covalent, ionic and covalent interactions, as well as across different system sizes. We demonstrate their remarkable possibilities by computing the free energy surface for the protonated water dimer at hitherto unfeasible gold-standard coupled cluster quality on a single commodity workstation.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Charged Exciton Kinetics in Monolayer MoSe2 near Ferroelectric Domain Walls in Periodically Poled LiNbO3},

author = {P Soubelet and J Klein and J Wierzbowski and R Silvioli and F Sigger and A V Stier and K Gallo and J J Finley},

url = {https://doi.org/10.1021/acs.nanolett.0c03810},

doi = {10.1021/acs.nanolett.0c03810},

issn = {1530-6984},

year  = {2021},

date = {2021-01-11},

journal = {Nano Letters},

volume = {21},

number = {2},

pages = {959-966},

abstract = {Monolayer semiconducting transition metal dichalcogenides are a strongly emergent platform for exploring quantum phenomena in condensed matter, building novel optoelectronic devices with enhanced functionalities. Because of their atomic thickness, their excitonic optical response is highly sensitive to their dielectric environment. In this work, we explore the optical properties of monolayer thick MoSe2 straddling domain wall boundaries in periodically poled LiNbO3. Spatially resolved photoluminescence experiments reveal spatial sorting of charge and photogenerated neutral and charged excitons across the boundary. Our results reveal evidence for extremely large in-plane electric fields of ≃4000 kV/cm at the domain wall whose effect is manifested in exciton dissociation and routing of free charges and trions toward oppositely poled domains and a nonintuitive spatial intensity dependence. By modeling our result using drift-diffusion and continuity equations, we obtain excellent qualitative agreement with our observations and have explained the observed spatial luminescence modulation using realistic material parameters.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Layer-by-Layer Spray-Coating of Cellulose Nanofibrils and Silver Nanoparticles for Hydrophilic Interfaces},

author = {Q Chen and C J Brett and A Chumakov and M Gensch and M Schwartzkopf and V K\"{o}rstgens and L D S\"{o}derberg and A Plech and P Zhang and P M\"{u}ller-Buschbaum and S V Roth},

url = {https://doi.org/10.1021/acsanm.0c02819},

doi = {10.1021/acsanm.0c02819},

year  = {2021},

date = {2021-01-05},

urldate = {2021-01-05},

journal = {ACS Applied Nano Materials},

volume = {4},

number = {1},

pages = {503-513},

abstract = {Silver nanoparticles (AgNPs) and AgNP-based composite materials have attracted growing interest due to their structure-dependent optical, electrical, catalytic, and stimuli-responsive properties. For practical applications, polymeric materials are often combined with AgNPs to provide flexibility and offer a scaffold for homogenous distribution of the AgNPs. However, the control over the assembly process of AgNPs on polymeric substrates remains a big challenge. Herein, we report the fabrication of AgNP/cellulose nanofibril (CNF) thin films via layer-by-layer (LBL) spray-coating. The morphology and self-assembly of AgNPs with increasing number of spray cycles are characterized by atomic force microscopy (AFM), grazing-incidence small-angle X-ray scattering (GISAXS), and grazing-incidence wide-angle X-ray scattering (GIWAXS). We deduce that an individual AgNP (radius = 15 ± 3 nm) is composed of multiple nanocrystallites (diameter = 2.4 ± 0.9 nm). Our results suggest that AgNPs are assembled into large agglomerates on SiO2 substrates during spray-coating, which is disadvantageous for AgNP functionalization. However, the incorporation of CNF substrates contributes to a more uniform distribution of AgNP agglomerates and individual AgNPs by its network structure and by absorbing the partially dissolved AgNP agglomerates. Furthermore, we demonstrate that the spray-coating of the AgNP/CNF mixture results in similar topography and agglomeration patterns of AgNPs compared to depositing AgNPs onto a precoated CNF thin film. Contact-angle measurements and UV/vis spectroscopy suggest that the deposition of AgNPs onto or within CNFs could increase the hydrophilicity of AgNP-containing surfaces and the localized surface plasmon resonance (LSPR) intensity of AgNP compared to AgNPs sprayed on SiO2 substrates, suggesting their potential applications in antifouling coatings or label-free biosensors. Thereby, our approach provides a platform for a facile and scalable production of AgNP/CNF films with a low agglomeration rate by two different methods as follows: (1) multistep layer-by-layer (LBL) spray-coating and (2) direct spray-coating of the AgNP/CNF mixture. We also demonstrate the ability of CNFs as a flexible framework for directing the uniform assembly of AgNPs with tailorable wettability and plasmonic properties.},

keywords = {Foundry Inorganic, 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}

}