Publications

@article{nokey,

title = {Contribution of multiple plasmon scattering in low-angle electron diffraction investigated by energy-filtered atomically resolved 4D-STEM},

author = {H L Robert and B Diederichs and K M\"{u}ller-Caspary},

url = {https://aip.scitation.org/doi/abs/10.1063/5.0129692},

doi = {10.1063/5.0129692},

year  = {2022},

date = {2022-10-06},

journal = {Applied Physics Letters},

volume = {121},

number = {21},

pages = {213502},

abstract = {We report the influence of multiple plasmon losses on the dynamical diffraction of high-energy electrons, in a scanning transmission electron microscopy (STEM) study. Using an experimental setup enabling energy-filtered momentum-resolved STEM, it is shown that the successive excitation of up to five plasmons within the imaged material results in a subsequent and significant redistribution of low-angle intensity in diffraction space. An empirical approach, based on the convolution with a Lorentzian kernel, is shown to reliably model this redistribution in dependence of the energy-loss. Our study demonstrates that both the significant impact of inelastic scattering in low-angle diffraction at elevated specimen thickness and a rather straightforward model can be applied to mimic multiple plasmon scattering, which otherwise is currently not within reach for multislice simulations due to computational complexity.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Emitter-Optomechanical Interaction in high-Q hBN Nanocavities},

author = {C Qian and V Villafa\~{n}e and M Schalk and G V Astakhov and U Kentsch and M Helm and A H\"{o}tger and P Soubelet and A W Holleitner and A V Stier},

url = {https://arxiv.org/abs/2210.00150},

doi = {https://doi.org/10.48550/arXiv.2210.00150},

year  = {2022},

date = {2022-10-01},

journal = {arXiv preprint arXiv:2210.00150},

abstract = {We investigate the interaction between optically excited charged boron vacancies V−B, localized photonic modes of ultra-high-Q (∼105) nanocavities and local vibronic modes. V−B is a color center for which phonon-induced processes generally dominate the emission. A pronounced asymmetry is observed in the emission spectrum for cavities in which V−B centers have been generated by N+ irradiation. Similar asymmetries are not observed for systems that do not contain V−B centers. To explain our findings, we model the system as phonon-induced light-matter coupling with multi-partite interplay between the electronic transition, cavity photons and local vibronic modes. Good agreement is obtained between experiment and theory. Our results indicate that the multi-partite interplay arises during the V−B emission process, illustrating that it is phonon-induced, rather than being caused by thermal population of vibronic modes. The multi-modal couplings between various photonic (V−B emission, cavity nanophotonic) and vibronic (V−B phonons, cavity nanomechanical) modes provide novel method to interface spin, photons and phonons in condensed matter systems.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Tuning Strong Metal\textendashSupport Interaction Kinetics on Pt-Loaded TiO2(110) by Choosing the Pressure: A Combined Ultrahigh Vacuum/Near-Ambient Pressure XPS Study},

author = {P Petzoldt and M Eder and S Mackewicz and M Blum and T Kratky and S G\"{u}nther and M Tschurl and U Heiz and B A J Lechner},

url = {https://doi.org/10.1021/acs.jpcc.2c03851},

doi = {10.1021/acs.jpcc.2c03851},

issn = {1932-7447},

year  = {2022},

date = {2022-09-29},

urldate = {2022-09-29},

journal = {The Journal of Physical Chemistry C},

volume = {126},

number = {38},

pages = {16127-16139},

abstract = {Pt catalyst particles on reducible oxide supports often change their activity significantly at elevated temperatures due to the strong metal\textendashsupport interaction (SMSI), which induces the formation of an encapsulation layer around the noble metal particles. However, the impact of oxidizing and reducing treatments at elevated pressures on this encapsulation layer remains controversial, partly due to the “pressure gap” between surface science studies and applied catalysis. In the present work, we employ synchrotron-based near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) to study the effect of O2 and H2 on the SMSI-state of well-defined Pt/TiO2(110) catalysts at pressures of up to 0.1 Torr. By tuning the O2 pressure, we can either selectively oxidize the TiO2 support or both the support and the Pt particles. Catalyzed by metallic Pt, the encapsulating oxide overlayer grows rapidly in 1 × 10\textendash5 Torr O2, but orders of magnitude less effectively at higher O2 pressures, where Pt is in an oxidic state. While the oxidation/reduction of Pt particles is reversible, they remain embedded in the support once encapsulation has occurred.},

keywords = {Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Graphene and Beyond: Recent Advances in Two-Dimensional Materials Synthesis, Properties, and Devices},

author = {Y Lei and T Zhang and Y-C Lin and T Granzier-Nakajima and G Bepete and D A Kowalczyk and Z Lin and D Zhou and T F Schranghamer and A Dodda and A Sebastian and Y Chen and Y Liu and G Pourtois and T J Kempa and B Schuler and M T Edmonds and S Y Quek and U Wurstbauer and S M Wu and N R Glavin and S Das and S P Dash and J M Redwing and J A Robinson and M Terrones},

url = {https://doi.org/10.1021/acsnanoscienceau.2c00017},

doi = {10.1021/acsnanoscienceau.2c00017},

year  = {2022},

date = {2022-09-16},

journal = {ACS Nanoscience Au},

abstract = {Since the isolation of graphene in 2004, two-dimensional (2D) materials research has rapidly evolved into an entire subdiscipline in the physical sciences with a wide range of emergent applications. The unique 2D structure offers an open canvas to tailor and functionalize 2D materials through layer number, defects, morphology, moir\'{e} pattern, strain, and other control knobs. Through this review, we aim to highlight the most recent discoveries in the following topics: theory-guided synthesis for enhanced control of 2D morphologies, quality, yield, as well as insights toward novel 2D materials; defect engineering to control and understand the role of various defects, including in situ and ex situ methods; and properties and applications that are related to moir\'{e} engineering, strain engineering, and artificial intelligence. Finally, we also provide our perspective on the challenges and opportunities in this fascinating field.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Tuning Strong Metal\textendashSupport Interaction Kinetics on Pt-Loaded TiO2(110) by Choosing the Pressure: A Combined Ultrahigh Vacuum/Near-Ambient Pressure XPS Study},

author = {P Petzoldt and M Eder and S Mackewicz and M Blum and T Kratky and S G\"{u}nther and M Tschurl and U Heiz and B A J Lechner},

url = {https://doi.org/10.1021/acs.jpcc.2c03851},

doi = {10.1021/acs.jpcc.2c03851},

issn = {1932-7447},

year  = {2022},

date = {2022-09-16},

urldate = {2022-09-16},

journal = {The Journal of Physical Chemistry C},

volume = {126},

number = {38},

pages = {16127-16139},

abstract = {Pt catalyst particles on reducible oxide supports often change their activity significantly at elevated temperatures due to the strong metal\textendashsupport interaction (SMSI), which induces the formation of an encapsulation layer around the noble metal particles. However, the impact of oxidizing and reducing treatments at elevated pressures on this encapsulation layer remains controversial, partly due to the “pressure gap” between surface science studies and applied catalysis. In the present work, we employ synchrotron-based near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) to study the effect of O2 and H2 on the SMSI-state of well-defined Pt/TiO2(110) catalysts at pressures of up to 0.1 Torr. By tuning the O2 pressure, we can either selectively oxidize the TiO2 support or both the support and the Pt particles. Catalyzed by metallic Pt, the encapsulating oxide overlayer grows rapidly in 1 × 10\textendash5 Torr O2, but orders of magnitude less effectively at higher O2 pressures, where Pt is in an oxidic state. While the oxidation/reduction of Pt particles is reversible, they remain embedded in the support once encapsulation has occurred.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Metasurface Measuring Twisted Light in Turbulence},

author = {T Dinter and C Li and L K\"{u}hner and T Weber and A Tittl and S A Maier and J M Dawes and H Ren},

url = {https://doi.org/10.1021/acsphotonics.2c00800},

doi = {10.1021/acsphotonics.2c00800},

year  = {2022},

date = {2022-09-09},

journal = {ACS Photonics},

volume = {9},

number = {9},

pages = {3043-3051},

abstract = {Orbital angular momentum (OAM) of light represents an independent degree of freedom using orthogonal helical modes for optical and quantum multiplexing, offering great potential to transform future ultrahigh-bandwidth information systems. Practical OAM communication systems suffer from turbulence-induced phase distortions to the propagating beams, decreasing the orthogonality of OAM modes through introduced modal crosstalk. To date, optical systems used for measuring OAM orthogonality breakdown in different turbulence conditions are too bulky and slow (e.g., one OAM mode at a time) for any practical use. Here, we demonstrate the use of an ultrathin OAM mode-sorting metasurface for characterizing the OAM orthogonality breakdown under different turbulence conditions. Our approach allows the measurement of the whole OAM spectrum at the same time. This metasurface exhibits strong OAM selectivity with an average modal crosstalk below −42.4 dB for OAM modes with topological charges ranging from −15 to +15. Our results suggest that higher-order OAM modes are as robust as lower-order modes in particular turbulence environments, paving the way for future practical free-space OAM communications harnessing high-dimensional OAM multiplexing. We demonstrated that a flat optical device with a small form factor can be integrated with practical communication systems for compact, fast, and efficient generation and detection of twisted light.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Heteroatoms Induce Localization of the Electric Field and Promote a Wide Potential-Window Selectivity Towards CO in the CO2 Electroreduction},

author = {C Cai and B Liu and K Liu and P Li and J Fu and Y Wang and W Li and C Tian and Y Kang and A Stefancu and H Li and C-W Kao and T-S Chan and Z Lin and L Chai and E Cort\'{e}s and M Liu},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202212640},

doi = {https://doi.org/10.1002/anie.202212640},

issn = {1433-7851},

year  = {2022},

date = {2022-09-08},

journal = {Angewandte Chemie International Edition},

volume = {61},

number = {44},

pages = {e202212640},

abstract = {Abstract Carbon dioxide electroreduction (CO2RR) is a sustainable way of producing carbon-neutral fuels. Product selectivity in CO2RR is regulated by the adsorption energy of reaction-intermediates. Here, we employ differential phase contrast-scanning transmission electron microscopy (DPC-STEM) to demonstrate that Sn heteroatoms on a Ag catalyst generate very strong and atomically localized electric fields. In situ attenuated total reflection infrared spectroscopy (ATR-IR) results verified that the localized electric field enhances the adsorption of *COOH, thus favoring the production of CO during CO2RR. The Ag/Sn catalyst exhibits an approximately 100 % CO selectivity at a very wide range of potentials (from −0.5 to −1.1 V, versus reversible hydrogen electrode), and with a remarkably high energy efficiency (EE) of 76.1 %.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Role of twin defects on growth dynamics and size distribution of undoped and Si-doped GaAs nanowires by selective area epitaxy},

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

url = {https://aip.scitation.org/doi/abs/10.1063/5.0124808},

doi = {10.1063/5.0124808},

year  = {2022},

date = {2022-09-08},

journal = {Journal of Applied Physics},

volume = {132},

number = {20},

pages = {204302},

abstract = {We report the effects of Si doping on the growth dynamics and size distribution of entirely catalyst-free GaAs nanowire (NW) arrays grown by selective area molecular beam epitaxy on SiO2-masked Si (111) substrates. Surprising improvements in the NW-array uniformity are found with increasing Si doping, while the growth of undoped NWs appears in a metastable regime, evidenced by large size and shape distributions, and the simultaneous presence of crystallites with tetrahedral termination. Correlating scanning electron microscopy and transmission electron microscopy investigations, we propose that the size and shape distributions are strongly linked to the underlying twin defect formation probabilities that govern the growth. Under the present growth conditions, Si-doping of GaAs NWs leads to a very high twin defect formation probability (∼0.4), while undoped NWs exhibit a nearly threefold decreased probability (∼0.15). By adopting a model for facet-mediated growth, we describe how the altered twin formation probabilities impact the competing growth of the relevant low-index NW facets, and hence, NW size and shape. Our model is further supported by a generic Monte Carlo simulation approach to highlight the role of twin defects in reproducing the experimentally observed size distributions.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Improvement of the thermoelectric properties of PEDOT:PSS films via DMSO addition and DMSO/salt post-treatment resolved from a fundamental view},

author = {S Tu and T Tian and A Lena Oechsle and S Yin and X Jiang and W Cao and N Li and M A Scheel and L K Reb and S Hou and A S Bandarenka and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},

url = {https://www.sciencedirect.com/science/article/pii/S1385894721038742},

doi = {https://doi.org/10.1016/j.cej.2021.132295},

issn = {1385-8947},

year  = {2022},

date = {2022-09-06},

urldate = {2022-09-06},

journal = {Chemical Engineering Journal},

volume = {429},

pages = {132295},

abstract = {The combination of dimethyl sulfoxide (DMSO)-solvent doping and physical\textendashchemical DMSO/salt de-doping in a sequence has been used to improve the thermoelectric (TE) properties of poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) films. A high power factor of ca.105.2 µW m−1 K−2 has been achieved for the PEDOT:PSS film after post-treatment with 10 % sodium sulfite (Na2SO3) in the DMSO/salt mixture (v/v), outperforming sodium bicarbonate (NaHCO3). The initial DMSO-doping treatment induces a distinct phase separation by facilitating the aggregation of the PEDOT molecules. At the same time, the subsequent DMSO/salt de-doping post-treatment strengthens the selective removal of the surplus non-conductive PSS chains. Substantial alterations in the oxidation level, chain conformations, PEDOT crystallites and their preferential orientation are observed upon treatment on the molecular level. At the mesoscale level, the purification and densification of PEDOT-rich domains enable the realization of inter-grain coupling by the formation of the electronically well-percolated network. Thereby, both electrical conductivity and Seebeck coefficient are optimized.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Synthesis of Ultra-Incompressible Carbon Nitrides Featuring Three-Dimensional Frameworks of CN4 Tetrahedra Recoverable at Ambient Conditions},

author = {D Laniel and F Trybel and A Aslandukov and S Khandarkhaeva and T Fedotenko and Y Yin and F Tasn\'{a}di and A V Ponomareva and G Weck and F I Akbar},

url = {https://arxiv.org/abs/2209.01968},

doi = {https://doi.org/10.48550/arXiv.2209.01968},

year  = {2022},

date = {2022-09-05},

journal = {arXiv preprint arXiv:2209.01968},

abstract = {More than thirty years ago, carbon nitrides featuring 3D frameworks of tetrahedral CN4 units were identified as one of the great aspirations of materials science, expected to have a hardness greater than or comparable to diamond. Since then, no unambiguous experimental evidence of their existence has been delivered. Here, we report the high-pressure high-temperature synthesis of the long-sought-after covalent carbon nitrides, tI14-C3N4, hP126-C3N4, and tI24-CN2, in laser-heated diamond anvil cells. Their structures were solved and refined using synchrotron single-crystal X-ray diffraction. In these solids, carbon atoms, all sp3-hybridized, and nitrogen atoms are fully saturated, forming four and three covalent bonds, respectively, leading to three-dimensional arrangements of corner-sharing CN4 tetrahedra. These carbon nitrides are ultra-incompressible, with hP126-C3N4 and tI24-CN2 even rivalling diamond's incompressibility, and superhard. These novel compounds are recoverable to ambient conditions in crystalline form and chemically stable in air. Being wide-band gap semiconductors with intriguing features in their electronic structure, they are expected to exhibit multiple exceptional functionalities besides their mechanical properties, opening new perspectives for materials science.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Strong light-matter interaction with self-hybridized bound states in the continuum in monolithic van der Waals metasurfaces},

author = {T Weber and L K\"{u}hner and L Sortino and A B Mhenni and N P Wilson and J K\"{u}hne and J J Finley and S A Maier and A Tittl},

url = {https://arxiv.org/abs/2209.01944},

doi = {https://doi.org/10.48550/arXiv.2209.01944},

year  = {2022},

date = {2022-09-05},

journal = {arXiv preprint arXiv:2209.01944},

abstract = {Photonic bound states in the continuum (BICs) are a standout nanophotonic platform for strong light-matter coupling with transition metal dichalcogenides (TMDCs), but have so far mostly been employed as all-dielectric metasurfaces with adjacent TMDC layers, incurring limitations related to strain, mode overlap, and material integration. In this work, we experimentally demonstrate for the first time asymmetry-dependent BIC resonances in 2D arrays of monolithic metasurfaces composed solely of the nanostructured bulk TMDC WS2 with BIC modes exhibiting sharp and tailored linewidths, ideal for selectively enhancing light-matter interactions. Geometrical variation enables the tuning of the BIC resonances across the exciton resonance in bulk WS2, revealing the strong-coupling regime with an anti-crossing pattern and a Rabi splitting of 116 meV. The precise control over the radiative loss channel provided by the BIC concept is harnessed to tailor the Rabi splitting via a geometrical asymmetry parameter of the metasurface. Crucially, the coupling strength itself can be controlled and is shown to be independent of material-intrinsic losses. Our BIC-driven monolithic metasurface platform can readily incorporate other TMDCs or excitonic materials to deliver previously unavailable fundamental insights and practical device concepts for polaritonic applications.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {The Puzzling Question about the Origin of the Second Electron in the Molecular Photocatalytic Reduction of CO2},

author = {C Thomas and M Wittig and B Rieger},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/cctc.202200841},

doi = {https://doi.org/10.1002/cctc.202200841},

issn = {1867-3880},

year  = {2022},

date = {2022-09-04},

journal = {ChemCatChem},

volume = {14},

number = {21},

pages = {e202200841},

abstract = {Abstract Herein, a new supramolecular photocatalyst RuRe3 containing three Re(dmb)CO3Cl (dmb=4,4‘-dimethyl-2,2‘-bipyridine) (Re) building blocks connected through an ethylene bridge to one [Ru(dmb)3]2+-unit (Ru) is presented. We investigated the photophysical properties of this novel tetranuclear complex and compared these to compounds with one (RuRe) and two (RuRe2) catalytic units. Under irradiation, all three photocatalysts exhibit high activity and photostability for the reduction of CO2 to CO, with RuRe3 achieving the highest turnover number (11800) reported to date for a Re(I)/Ru(II)-containing homogeneous catalyst. This tetranuclear complex is especially superior at small catalyst concentrations, which is attributed to an efficient second electron transfer via an intramolecular mechanism. Intermolecular electron transfer from small and mobile Re to RuRe motifs are found to also increase the catalytic performance of the system to a similar level (turnover number=12100). These synergistic effects are attributed to an improved catalytic cycle, stabilizing the bi- and tetrametallic complexes by providing the electrons quickly and effectively. Since the second electron provision is not finally clarified for molecular systems until today, our photocatalytic studies present important insights into this crucial step. Further, these investigations should be considered for the design and synthesis of new and efficient supramolecular CO2-reducing photocatalysts.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {3D-Nanoprinted Antiresonant Hollow-Core Microgap Waveguide: An on-Chip Platform for Integrated Photonic Devices and Sensors},

author = {J B\"{u}rger and V Schalles and J Kim and B Jang and M Zeisberger and J Gargiulo and L De S. Menezes and M A Schmidt and S A Maier},

url = {https://doi.org/10.1021/acsphotonics.2c00725},

doi = {10.1021/acsphotonics.2c00725},

year  = {2022},

date = {2022-09-02},

journal = {ACS Photonics},

volume = {9},

number = {9},

pages = {3012-3024},

abstract = {Due to their unique capabilities, hollow-core waveguides are playing an increasingly important role, especially in meeting the growing demand for integrated and low-cost photonic devices and sensors. Here, we present the antiresonant hollow-core microgap waveguide as a platform for the on-chip investigation of light-gas interaction over centimeter-long distances. The design consists of hollow-core segments separated by gaps that allow external access to the core region, while samples with lengths up to 5 cm were realized on silicon chips through 3D-nanoprinting using two-photon absorption based direct laser writing. The agreement of mathematical models, numerical simulations and experiments illustrates the importance of the antiresonance effect in that context. Our study shows the modal loss, the effect of gap size and the spectral tuning potential, with highlights including extremely broadband transmission windows (\>200 nm), very high contrast resonance (\>60 dB), exceptionally high structural openness factor (18%) and spectral control by nanoprinting (control over dimensions with step sizes (i.e., increments) of 60 nm). The application potential was demonstrated in the context of laser scanning absorption spectroscopy of ammonia, showing diffusion speeds comparable to bulk diffusion and a low detection limit. Due to these unique properties, application of this platform can be anticipated in a variety of spectroscopy-related fields, including bioanalytics, environmental sciences, and life sciences.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Thickness-Dependent Dark-Bright Exciton Splitting and Phonon Bottleneck in CsPbBr3-Based Nanoplatelets Revealed via Magneto-Optical Spectroscopy},

author = {S Wang and M Dyksik and C Lampe and M Gramlich and D K Maude and M Baranowski and A S Urban and P Plochocka and A Surrente},

url = {https://doi.org/10.1021/acs.nanolett.2c01826},

doi = {10.1021/acs.nanolett.2c01826},

issn = {1530-6984},

year  = {2022},

date = {2022-08-29},

journal = {Nano Letters},

volume = {22},

number = {17},

pages = {7011-7019},

abstract = {The optimized exploitation of perovskite nanocrystals and nanoplatelets as highly efficient light sources requires a detailed understanding of the energy spacing within the exciton manifold. Dark exciton states are particularly relevant because they represent a channel that reduces radiative efficiency. Here, we apply large in-plane magnetic fields to brighten optically inactive states of CsPbBr3-based nanoplatelets for the first time. This approach allows us to access the dark states and directly determine the dark-bright splitting, which reaches 22 meV for the thinnest nanoplatelets. The splitting is significantly less for thicker nanoplatelets due to reduced exciton confinement. Additionally, the form of the magneto-PL spectrum suggests that dark and bright state populations are nonthermalized, which is indicative of a phonon bottleneck in the exciton relaxation process.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {High-performance and Large-area Inverted Perovskite Solar Cells based on NiOx Films Enabled with A Novel Microstructure-Control Technology},

author = {G Shen and X Li and Y Zou and H Dong and D Zhu and Y Jiang and X R Ng and F Lin and P M\"{u}ller-Buschbaum and C Mu},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/eem2.12504},

doi = {https://doi.org/10.1002/eem2.12504},

year  = {2022},

date = {2022-08-26},

journal = {ENERGY \& ENVIRONMENTAL MATERIALS},

volume = {n/a},

number = {n/a},

pages = {e12504},

abstract = {Abstract The improvement in the efficiency of inverted perovskite solar cells (PSCs) is significantly limited by undesirable contact at the NiOX/perovskite interface. In this study, a novel microstructure-control technology is proposed for the fabrication of porous NiOX films using Pluronic P123 as the structure-directing agent and acetylacetone (AcAc) as the coordination agent. The synthesized porous NiOX films enhanced the hole extraction efficiency and reduced recombination defects at the NiOX/perovskite interface. Consequently, without any modification, the power conversion efficiency (PCE) of the PSC with MAPbI3 as the absorber layer improved from 16.50 to 19.08 %. Moreover, the PCE of the device composed of perovskite Cs0.05(MA0.15FA0.85)0.95Pb(I0.85Br0.15)3 improved from 17.49 to 21.42 %. Furthermore, the application of the fabricated porous NiOX on fluorine-doped tin oxide (FTO) substrates enabled the fabrication of large-area PSCs (1.2 cm2) with a PCE of 19.63 %. This study provides a novel strategy for improving the contact at the NiOX/perovskite interface for the fabrication of high-performance large-area perovskite solar cells.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Oriented Thiophene-Extended Benzotrithiophene Covalent Organic Framework Thin Films: Directional Electrical Conductivity},

author = {L Frey and J F P\"{o}hls and M Hennemann and A M\"{a}hringer and S Reuter and T Clark and R T Weitz and D D Medina},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202205949},

doi = {https://doi.org/10.1002/adfm.202205949},

issn = {1616-301X},

year  = {2022},

date = {2022-08-24},

journal = {Advanced Functional Materials},

volume = {n/a},

number = {n/a},

pages = {2205949},

abstract = {Abstract The synthesis of covalent organic frameworks (COFs) based on a novel thiophene-extended benzotrithiophene (BTT) building block is described, which in combination with triazine-based amines (1,3,5-triazine-2,4,6-triyl)trianiline (TTA) or (1,3,5-triazine-2,4,6-triyl)tris(([1,1´-biphenyl]-4-amine)) (TTTBA)) affords crystalline, and porous imine-linked COFs, BTT TTA and BTT TTTBA, with surface areas as high as 932 and 1200 m2 g−1, respectively. Oriented thin films are grown successfully on different substrates, as indicated by grazing incidence diffraction (GID). Room-temperature in-plane electrical conductivity of up to 10−4 S m−1 is measured for both COFs. Temperature-dependent electrical conductivity measurements indicate activation energies of ≈123.3 meV for BTT TTA and ≈137.5 meV for BTT TTTBA and trap-dominated charge transport via a hopping mechanism for both COFs. Moreover, conductive atomic force microscopy reveals directional and defect-dominated charge transport in the oriented BTT COF films with a strong preference for the in-plane direction within the molecular 2D-planes. Quantum mechanical calculations predict BTT TTTBA to conduct holes and electrons effectively in both in-plane and out-of-plane directions. In-plane, charge carrier transport is of hopping character where the triazine cores represent the barrier. Out-of-plane, a continuous charge-carrier pathway is calculated that is hampered by an imposed structural defect simulated by a rotated molecular COF layer.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Revealing Phosphorus Nitrides up to the Megabar Regime: Synthesis of α′-P3N5, δ-P3N5 and PN2},

author = {D Laniel and F Trybel and A N\'{e}ri and Y Yin and A Aslandukov and T Fedotenko and S Khandarkhaeva and F Tasn\'{a}di and S Chariton and C Giacobbe and E L Bright and M Hanfland and V Prakapenka and W Schnick and I A Abrikosov and L Dubrovinsky and N Dubrovinskaia},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.202201998},

doi = {https://doi.org/10.1002/chem.202201998},

issn = {0947-6539},

year  = {2022},

date = {2022-08-23},

urldate = {2022-08-23},

journal = {Chemistry \textendash A European Journal},

volume = {28},

issue = {62},

pages = {e202201998},

abstract = {Non-metal nitrides are an exciting field of chemistry, featuring a significant number of compounds that can possess outstanding materials properties. This characteristic relies on maximizing the number of strong covalent bonds, with crosslinked XN 6 octahedra frameworks being particularly intriguing. In this study, the phosphorus-nitrogen system was studied up to 137 GPa in laser-heated diamond anvil cells and three previously unobserved phases were synthesized and characterized by single-crystal X-ray diffraction, Raman spectroscopy measurements and density functional theory calculations. δ-P 3 N 5 and PN 2 were found to form at 72 and 134 GPa, respectively, and both feature dense 3D networks of the so far elusive PN 6 units. The two are ultra-incompressible, having a bulk modulus of K 0 = 322 GPa for δ-P 3 N 5 and of K 0 = 339 GPa for PN 2 . Upon decompression below 7 GPa, δ-P 3 N 5 undergoes a transformation into a novel α′-P 3 N 5 solid, stable at ambient conditions, that has a unique structure type based on PN 4 tetrahedra. The formation of α′-P 3 N 5 underlines that a phase space otherwise inaccessible can be explored through high-pressure formed phases.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Introducing a Symmetry-Breaking Coupler into a Dielectric Metasurface Enables Robust High-Q Quasi-BICs},

author = {G Q Moretti and A Tittl and E Cort\'{e}s and S A Maier and A V Bragas and G Grinblat},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adpr.202200111},

doi = {https://doi.org/10.1002/adpr.202200111},

issn = {2699-9293},

year  = {2022},

date = {2022-08-21},

journal = {Advanced Photonics Research},

volume = {n/a},

number = {n/a},

pages = {2200111},

abstract = {Dielectric metasurfaces supporting quasibound states in the continuum (quasi-BICs) exhibit very high-quality factor resonances and electric field confinement. However, accessing the high-Q end of the quasi-BIC regime usually requires marginally distorting the metasurface design from a BIC condition, pushing the needed nanoscale fabrication precision to the limit. This work introduces a novel concept for generating high-Q quasi-BICs, which strongly relaxes this requirement by incorporating a relatively large perturbative element close to high-symmetry points of an undistorted BIC metasurface, acting as a coupler to the radiation continuum. This approach is validated by adding a ≈100 nm diameter cylinder between two reflection-symmetry points separated by a 300 nm gap in an elliptical disk metasurface unit cell, using gallium phosphide as the dielectric. It is found that high-Q resonances emerge when the cylindrical coupler is placed at any position between such symmetry points. This metasurface's second harmonic generation capability in the optical range is further explored. Displacing the coupler as much as a full diameter from a BIC condition produces record-breaking normalized conversion efficiencies \>102 W−1. The strategy of enclosing a disruptive element between multiple high-symmetry points in a BIC metasurface can be applied to construct robust high-Q quasi-BICs in many geometrical designs.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Strong Polarization Dependent Nonlinear Excitation of a Perovskite Nanocrystal Monolayer on a Chiral Dielectric Nanoantenna Array},

author = {I Vin\c{c}on and F J Wendisch and D De Gregorio and S D Pritzl and Q A Akkerman and H Ren and L De S. Menezes and S A Maier and J Feldmann},

url = {https://doi.org/10.1021/acsphotonics.2c00159},

doi = {10.1021/acsphotonics.2c00159},

year  = {2022},

date = {2022-08-17},

journal = {ACS Photonics},

abstract = {With their unique optoelectronic properties, perovskite nanocrystals are highly advantageous semiconductor materials for tailored light applications including an interaction with circularly polarized light. Although chiral perovskite nanocrystals have been obtained by the adsorption of chiral molecules, their chiroptical response is still intrinsically weak. Alternatively, perovskites have been combined with artificial chiral surfaces demonstrating enhanced chiroptical responses. However, bulk perovskite films of considerable thickness were required, mitigating the perovskite’s photoluminescence efficiency and processability. Here we developed a hybrid system of a dielectric chiral nanoantenna array that was coated with a monolayer of cubic all-inorganic lead halide perovskite nanocrystals. By tuning the thickness of the perovskite film down to one monolayer of nanocrystals, we restricted the interactions exclusively to the near-field regime. The chiral surface built of z-shaped Si nanoantennas features pronounced chiral resonances in the visible to IR region. We demonstrate that the two-photon excited photoluminescence emission of the nanocrystals can be enhanced by up to one order of magnitude in this configuration. This emission increase is controllable by the choice of the excitation wavelength and polarization with an asymmetry in emission of up to 25% upon left and right circularly polarized illumination. Altogether, our findings demonstrate a pathway to an all-optical control and modulation of perovskite light emission via strong polarization sensitive light\textendashmatter interactions in the near-field, rendering this hybrid system interesting for sensing and display technologies.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Catalytic Metasurfaces Empowered by Bound States in the Continuum},

author = {H Hu and T Weber and O Bienek and A Wester and L H\"{u}ttenhofer and I D Sharp and S A Maier and A Tittl and E Cort\'{e}s},

url = {https://doi.org/10.1021/acsnano.2c05680},

doi = {10.1021/acsnano.2c05680},

issn = {1936-0851},

year  = {2022},

date = {2022-08-11},

journal = {ACS Nano},

volume = {16},

number = {8},

pages = {13057-13068},

abstract = {Photocatalytic platforms based on ultrathin reactive materials facilitate carrier transport and extraction but are typically restricted to a narrow set of materials and spectral operating ranges due to limited absorption and poor energy-tuning possibilities. Metasurfaces, a class of 2D artificial materials based on the electromagnetic design of nanophotonic resonators, allow optical absorption engineering for a wide range of materials. Moreover, tailored resonances in nanostructured materials enable strong absorption enhancement and thus carrier multiplication. Here, we develop an ultrathin catalytic metasurface platform that leverages the combination of loss-engineered substoichiometric titanium oxide (TiO2\textendashx) and the emerging physical concept of optical bound states in the continuum (BICs) to boost photocatalytic activity and provide broad spectral tunability. We demonstrate that our platform reaches the condition of critical light coupling in a TiO2\textendashx BIC metasurface, thus providing a general framework for maximizing light\textendashmatter interactions in diverse photocatalytic materials. This approach can avoid the long-standing drawbacks of many naturally occurring semiconductor-based ultrathin films applied in photocatalysis, such as poor spectral tunability and limited absorption manipulation. Our results are broadly applicable to fields beyond photocatalysis, including photovoltaics and photodetectors.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Energy Transfer in Stability-Optimized Perovskite Nanocrystals},

author = {M G Greiner and A Singldinger and N A Henke and C Lampe and U Leo and M Gramlich and A S Urban},

url = {https://doi.org/10.1021/acs.nanolett.2c02108},

doi = {10.1021/acs.nanolett.2c02108},

issn = {1530-6984},

year  = {2022},

date = {2022-08-08},

journal = {Nano Letters},

volume = {22},

number = {16},

pages = {6709-6715},

abstract = {Outstanding optoelectronic properties and a facile synthesis render halide perovskite nanocrystals (NCs) a promising material for nanostructure-based devices. However, the commercialization is hindered mainly by the lack of NC stability under ambient conditions and inefficient charge carrier injection. Here, we investigate solutions to both problems, employing methylammonium lead bromide (MAPbBr3) NCs encapsulated in diblock copolymer core\textendashshell micelles of tunable size. We confirm that the shell does not prohibit energy transfer, as FRET efficiencies between these NCs and 2D CsPbBr3 nanoplatelets (NPLs) reach 73.6%. This value strongly correlates to the micelle size, with thicker shells displaying significantly reduced FRET efficiencies. Those high efficiencies come with a price, as the thinnest shells protect the encapsulated NCs less from environmentally induced degradation. Finding the sweet spot between efficiency and protection could lead to the realization of tailored energy funnels with enhanced carrier densities for high-power perovskite NC-based optoelectronic applications.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Identification of the Highly Active Co\textendashN4 Coordination Motif for Selective Oxygen Reduction to Hydrogen Peroxide},

author = {S Chen and T Luo and X Li and K Chen and J Fu and K Liu and C Cai and Q Wang and H Li and Y Chen and C Ma and L Zhu and Y-R Lu and T-S Chan and M Zhu and E Cort\'{e}s and M Liu},

url = {https://doi.org/10.1021/jacs.2c01194},

doi = {10.1021/jacs.2c01194},

issn = {0002-7863},

year  = {2022},

date = {2022-08-03},

journal = {Journal of the American Chemical Society},

volume = {144},

number = {32},

pages = {14505-14516},

abstract = {Electrosynthesis of hydrogen peroxide (H2O2) through oxygen reduction reaction (ORR) is an environment-friendly and sustainable route for obtaining a fundamental product in the chemical industry. Co\textendashN4 single-atom catalysts (SAC) have sparkled attention for being highly active in both 2e\textendash ORR, leading to H2O2 and 4e\textendash ORR, in which H2O is the main product. However, there is still a lack of fundamental insights into the structure\textendashfunction relationship between CoN4 and the ORR mechanism over this family of catalysts. Here, by combining theoretical simulation and experiments, we unveil that pyrrole-type CoN4 (Co\textendashN SACDp) is mainly responsible for the 2e\textendash ORR, while pyridine-type CoN4 catalyzes the 4e\textendash ORR. Indeed, Co\textendashN SACDp exhibits a remarkable H2O2 selectivity of 94% and a superb H2O2 yield of 2032 mg for 90 h in a flow cell, outperforming most reported catalysts in acid media. Theoretical analysis and experimental investigations confirm that Co\textendashN SACDp─with weakening O2/HOO* interaction─boosts the H2O2 production.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Ordered Ag Nanoneedle Arrays with Enhanced Electrocatalytic CO2 Reduction via Structure-Induced Inhibition of Hydrogen Evolution},

author = {Q Chen and K Liu and Y Zhou and X Wang and K Wu and H Li and E Pensa and J Fu and M Miyauchi and E Cort\'{e}s and M Liu},

url = {https://doi.org/10.1021/acs.nanolett.2c01853},

doi = {10.1021/acs.nanolett.2c01853},

issn = {1530-6984},

year  = {2022},

date = {2022-08-01},

journal = {Nano Letters},

volume = {22},

number = {15},

pages = {6276-6284},

abstract = {Silver is an attractive catalyst for converting CO2 into CO. However, the high CO2 activation barrier and the hydrogen evolution side reaction seriously limit its practical application and industrial perspective. Here, an ordered Ag nanoneedle array (Ag-NNAs) was prepared by template-assisted vacuum thermal-evaporation for CO2 electroreduction into CO. The nanoneedle array structure induces a strong local electric field at the tips, which not only reduces the activation barrier for CO2 electroreduction but also increases the energy barrier for the hydrogen evolution reaction (HER). Moreover, the array structure endows a high surface hydrophobicity, which can regulate the adsorption of water molecules at the interface and thus dynamically inhibit the competitive HER. As a result, the optimal Ag-NNAs exhibits 91.4% Faradaic efficiency (FE) of CO for over 700 min at −1.0 V vs RHE. This work provides a new concept for the application of nanoneedle array structures in electrocatalytic CO2 reduction reactions.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Revealing and Controlling Energy Barriers and Valleys at Grain Boundaries in Ultrathin Organic Films},

author = {L S Walter and A Axt and J W Borchert and T Kammerbauer and F Winterer and J Lenz and S L Weber and R T Weitz},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/smll.202200605},

doi = {https://doi.org/10.1002/smll.202200605},

issn = {1613-6810},

year  = {2022},

date = {2022-07-29},

journal = {Small},

volume = {18},

number = {34},

pages = {2200605},

abstract = {Abstract In organic electronics, local crystalline order is of critical importance for the charge transport. Grain boundaries between molecularly ordered domains are generally known to hamper or completely suppress charge transfer and detailed knowledge of the local electronic nature is critical for future minimization of such malicious defects. However, grain boundaries are typically hidden within the bulk film and consequently escape observation or investigation. Here, a minimal model system in form of monolayer-thin films with sub-nm roughness of a prototypical n-type organic semiconductor is presented. Since these films consist of large crystalline areas, the detailed energy landscape at single grain boundaries can be studied using Kelvin probe force microscopy. By controlling the charge-carrier density in the films electrostatically, the impact of the grain boundaries on charge transport in organic devices is modeled. First, two distinct types of grain boundaries are identified, namely energetic barriers and valleys, which can coexist within the same thin film. Their absolute height is found to be especially pronounced at charge-carrier densities below 1012 cm\textendash2\textemdashthe regime at which organic solar cells and light emitting diodes typically operate. Finally, processing conditions by which the type or energetic height of grain boundaries can be controlled are identified.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Mechanistic Insights into OC\textendashCOH Coupling in CO2 Electroreduction on Fragmented Copper},

author = {K Yao and J Li and H Wang and R Lu and X Yang and M Luo and N Wang and Z Wang and C Liu and T Jing and S Chen and E Cort\'{e}s and S A Maier and S Zhang and T Li and Y Yu and Y Liu and X Kang and H Liang},

url = {https://doi.org/10.1021/jacs.2c01044},

doi = {10.1021/jacs.2c01044},

issn = {0002-7863},

year  = {2022},

date = {2022-07-29},

journal = {Journal of the American Chemical Society},

volume = {144},

number = {31},

pages = {14005-14011},

abstract = {The carbon\textendashcarbon (C\textendashC) bond formation is essential for the electroconversion of CO2 into high-energy-density C2+ products, and the precise coupling pathways remain controversial. Although recent computational investigations have proposed that the OC\textendashCOH coupling pathway is more favorable in specific reaction conditions than the well-known CO dimerization pathway, the experimental evidence is still lacking, partly due to the separated catalyst design and mechanistic/spectroscopic exploration. Here, we employ density functional theory calculations to show that on low-coordinated copper sites, the *CO bindings are strengthened, and the adsorbed *CO coupling with their hydrogenation species, *COH, receives precedence over CO dimerization. Experimentally, we construct a fragmented Cu catalyst with abundant low-coordinated sites, exhibiting a 77.8% Faradaic efficiency for C2+ products at 300 mA cm\textendash2. With a suite of in situ spectroscopic studies, we capture an *OCCOH intermediate on the fragmented Cu surfaces, providing direct evidence to support the OC\textendashCOH coupling pathway. The mechanistic insights of this research elucidate how to design materials in favor of OC\textendashCOH coupling toward efficient C2+ production from CO2 reduction.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Optically Induced Long-Lived Chirality Memory in the Color-Tunable Chiral Lead-Free Semiconductor (R)/(S)-CHEA4Bi2BrxI10\textendashx (x = 0\textendash10)},

author = {S Liu and M W Heindl and N Fehn and S Caicedo-D\'{a}vila and L Eyre and S M Kronawitter and J Zerhoch and S Bodnar and A Shcherbakov and A Stadlbauer and G Kieslich and I D Sharp and D A Egger and A Kartouzian and F Deschler},

url = {https://doi.org/10.1021/jacs.2c01994},

doi = {10.1021/jacs.2c01994},

issn = {0002-7863},

year  = {2022},

date = {2022-07-27},

journal = {Journal of the American Chemical Society},

volume = {144},

number = {31},

pages = {14079-14089},

abstract = {Hybrid organic\textendashinorganic networks that incorporate chiral molecules have attracted great attention due to their potential in semiconductor lighting applications and optical communication. Here, we introduce a chiral organic molecule (R)/(S)-1-cyclohexylethylamine (CHEA) into bismuth-based lead-free structures with an edge-sharing octahedral motif, to synthesize chiral lead-free (R)/(S)-CHEA4Bi2BrxI10\textendashx crystals and thin films. Using single-crystal X-ray diffraction measurements and density functional theory calculations, we identify crystal and electronic band structures. We investigate the materials’ optical properties and find circular dichroism, which we tune by the bromide\textendashiodide ratio over a wide wavelength range, from 300 to 500 nm. We further employ transient absorption spectroscopy and time-correlated single photon counting to investigate charge carrier dynamics, which show long-lived excitations with optically induced chirality memory up to tens of nanosecond timescales. Our demonstration of chirality memory in a color-tunable chiral lead-free semiconductor opens a new avenue for the discovery of high-performance, lead-free spintronic materials with chiroptical functionalities.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Size and Coverage Effects of Ni and Pt Co-Catalysts in the Photocatalytic Hydrogen Evolution from Methanol on TiO2(110)},

author = {M Eder and C Courtois and P Petzoldt and S Mackewicz and M Tschurl and U Heiz},

url = {https://doi.org/10.1021/acscatal.2c02230},

doi = {10.1021/acscatal.2c02230},

year  = {2022},

date = {2022-07-21},

journal = {ACS Catalysis},

pages = {9579-9588},

abstract = {In the past decade, hydrogen evolution from photocatalytic alcohol oxidation on metal-loaded TiO2 has emerged as an active research field. While the presence of a metal cluster co-catalyst is crucial as a H2 recombination center, size and coverage effects on the catalyst performance are not yet comprehensively understood. To some extent, this is due to the fact that common deposition methods do not allow for an independent change in size and coverage, which can be overcome by the use of cluster sources and the deposition of size-selected clusters. This study compares size-selected Ni and Pt clusters as co-catalysts on a TiO2(110) single crystal and the resulting size- and coverage-dependent effects in the photocatalytic hydrogen evolution from alcohols in ultrahigh vacuum (UHV). Larger clusters and higher coverages of Ni enhance the product formation rate, although deactivation over time occurs. In contrast, Pt co-catalysts exhibit a stable and higher activity and size-specific effects have to be taken into account. While H2 evolution is improved by a higher concentration of Pt clusters, an increase in the metal content by the deposition of larger particles can even be detrimental to the performance of the photocatalyst. The acquired overall mechanistic picture is corroborated by H2 formation kinetics from mass spectrometric data. Consequently, for some metals, size effects are relevant for improving the catalytic performance, while for other co-catalyst materials, merely the coverage is decisive. The elucidation of different size and coverage dependencies represents an important step toward a rational catalyst design for photocatalytic hydrogen evolution.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Thickness and defect dependent electronic, optical and thermoelectric features of WTe2},

author = {I Ozdemir and A W Holleitner and C Kastl and O \"{U} Akt\"{u}rk},

url = {https://doi.org/10.1038/s41598-022-16899-5},

doi = {10.1038/s41598-022-16899-5},

issn = {2045-2322},

year  = {2022},

date = {2022-07-18},

journal = {Scientific Reports},

volume = {12},

number = {1},

pages = {12756},

abstract = {Transition metal dichalcogenides (TMDs) receive significant attention due to their outstanding electronic and optical properties. In this study, we investigate the electronic, optical, and thermoelectric properties of single and few layer $$hbox WTe_2$$in detail utilizing first-principles methods based on the density functional theory (DFT). Within the scope of both PBE and HSE06 including spin orbit coupling (SOC), the simulations predict the electronic band gap values to decrease as the number of layers increases. Moreover, spin-polarized DFT calculations combined with the semi-classical Boltzmann transport theory are applied to estimate the anisotropic thermoelectric power factor (Seebeck coefficient, S) for $$hbox WTe_2$$in both the monolayer and multilayer limit, and S is obtained below the optimal value for practical applications. The optical absorbance of $$hbox WTe_2$$monolayer is obtained to be slightly less than the values reported in literature for 2H TMD monolayers of $$hbox MoS_2$$, $$hbox MoSe_2$$, and $$hbox WS_2$$. Furthermore, we simulate the impact of defects, such as vacancy, antisite and substitution defects, on the electronic, optical and thermoelectric properties of monolayer $$hbox WTe_2$$. Particularly, the Te-$$hbox O_2$$substitution defect in parallel orientation yields negative formation energy, indicating that the relevant defect may form spontaneously under relevant experimental conditions. We reveal that the electronic band structure of $$hbox WTe_2$$monolayer is significantly influenced by the presence of the considered defects. According to the calculated band gap values, a lowering of the conduction band minimum gives rise to metallic characteristics to the structure for the single Te(1) vacancy, a diagonal Te line defect, and the Te(1)-$$hbox O_2$$substitution, while the other investigated defects cause an opening of a small positive band gap at the Fermi level. Consequently, the real ($$varepsilon _1(\omega )$$) and imaginary ($$varepsilon _2(\omega )$$) parts of the dielectric constant at low frequencies are very sensitive to the applied defects, whereas we find that the absorbance (A) at optical frequencies is less significantly affected. We also predict that certain point defects can enhance the otherwise moderate value of S in pristine $$hbox WTe_2$$to values relevant for thermoelectric applications. The described $$hbox WTe_2$$monolayers, as functionalized with the considered defects, offer the possibility to be applied in optical, electronic, and thermoelectric devices.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Statistically optimal analysis of the extended-system adaptive biasing force (eABF) method},

author = {A Hulm and J C B Dietschreit and C Ochsenfeld},

url = {https://aip.scitation.org/doi/abs/10.1063/5.0095554},

doi = {10.1063/5.0095554},

year  = {2022},

date = {2022-07-13},

journal = {The Journal of Chemical Physics},

volume = {157},

number = {2},

pages = {024110},

abstract = {The extended-system adaptive biasing force (eABF) method and its newer variants offer rapid exploration of the configuration space of chemical systems. Instead of directly applying the ABF bias to collective variables, they are harmonically coupled to fictitious particles, which separates the problem of enhanced sampling from that of free energy estimation. The prevalent analysis method to obtain the potential of mean force (PMF) from eABF is thermodynamic integration. However, besides the PMF, most information is lost as the unbiased probability of visited configurations is never recovered. In this contribution, we show how statistical weights of individual frames can be computed using the Multistate Bennett’s Acceptance Ratio (MBAR), putting the post-processing of eABF on one level with other frequently used sampling methods. In addition, we apply this formalism to the prediction of nuclear magnetic resonance shieldings, which are very sensitive to molecular geometries and often require extensive sampling. The results show that the combination of enhanced sampling by means of extended-system dynamics with the MBAR estimator is a highly useful tool for the calculation of ensemble properties. Furthermore, the extension of the presented scheme to the recently published Gaussian-accelerated molecular dynamics eABF hybrid is straightforward and approximation free.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Sr Surface Enrichment in Solid Oxide Cells - Approaching the Limits of EDX Analysis by Multivariate Statistical Analysis and Simulations},

author = {H T\"{u}rk and T G\"{o}tsch and F-P Schmidt and A Hammud and D Ivanov and L G J De Haart and I Vinke and R-A Eichel and R Schl\"{o}gl and K Reuter and A Knop-Gericke and T Lunkenbein and C Scheurer},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/cctc.202200300},

doi = {https://doi.org/10.1002/cctc.202200300},

issn = {1867-3880},

year  = {2022},

date = {2022-07-08},

journal = {ChemCatChem},

volume = {n/a},

number = {n/a},

abstract = {In solid oxide cells, Sr segregation has been correlated with degradation. Yet, the atomistic mechanism remains unknown. Here we begin to localize the origin of Sr surface nucleation by combining force field based simulations, energy dispersive X-ray spectroscopy (EDX) and multi-variate statistical analysis. We find increased ion mobility in the complexion between yttria-stabilized zirconia and strontium-doped lanthanum manganite. Furthermore, we developed a robust and automated routine to detect localized nucleation seeds of Sr at the complexion/vacuum interface. This hints at a mechanism originating at the complexion and requires in-depths studies at the atomistic level, where the developed routine can be beneficial for analysing large hyperspectral EDX datasets.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Structure-Dependent Electrical Double-Layer Capacitances of the Basal Plane Pd(hkl) Electrodes in HClO4},

author = {E Gubanova and T O Schmidt and S Watzele and V Alexandrov and A S Bandarenka},

url = {https://doi.org/10.1021/acs.jpcc.2c03117},

doi = {10.1021/acs.jpcc.2c03117},

issn = {1932-7447},

year  = {2022},

date = {2022-07-05},

journal = {The Journal of Physical Chemistry C},

volume = {126},

number = {27},

pages = {11414-11420},

abstract = {Electrical double-layer capacitance (CDL) measurements are among the key experiments in physical electrochemistry aimed to understand the properties of electrified solid/liquid interfaces. CDL serves as a critical parameter for developing physical models of electrochemical interfaces. Palladium (Pd) electrodes are among the most widely used functional materials in many applications, including (electro)catalysis. In this work, we report on double-layer capacitances of the basal plane Pd(111), Pd(100), and Pd(110) electrodes in aqueous HClO4 electrolytes measured using electrochemical impedance spectroscopy. Importantly, we find that the CDL values estimated at the minima of the capacitance vs electrode potential curves can be correlated with the density-functional-theory (DFT)-calculated adsorption energies for water molecules and the coordination of electrode surface atoms. Our results thus suggest that it might be possible to find simple descriptors of the electrical double layer (EDL) analogous to those used for functional electrode materials. Taken together, such descriptors could be employed for efficient high-throughput screening of various electrode/electrolyte interfaces, such as in supercapacitor and electrocatalytic systems.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Silver-Bismuth Based 2D Double Perovskites (4FPEA)4AgBiX8 (X = Cl, Br, I): Highly Oriented Thin Films with Large Domain Sizes and Ultrafast Charge-Carrier Localization},

author = {R Hooijer and A Weis and A Biewald and M T Sirtl and J Malburg and R Holfeuer and S Thamm and A Y Amin and M Righetto and A Hartschuh and L M Herz and T Bein},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202200354},

doi = {https://doi.org/10.1002/adom.202200354},

issn = {2195-1071},

year  = {2022},

date = {2022-07-03},

journal = {Advanced Optical Materials},

volume = {10},

number = {14},

pages = {2200354},

abstract = {Abstract Two-dimensional (2D) hybrid double perovskites are a promising emerging class of materials featuring superior intrinsic and extrinsic stability over their 3D parent structures, while enabling additional structural diversity and tunability. Here, we expand the Ag\textendashBi-based double perovskite system, comparing structures obtained with the halides chloride, bromide, and iodide and the organic spacer cation 4-fluorophenethylammonium (4FPEA) to form the n = 1 Ruddlesden\textendashPopper (RP) phases (4FPEA)4AgBiX8 (X = Cl, Br, I). We demonstrate access to the iodide RP-phase through a simple organic spacer, analyze the different properties as a result of halide substitution and incorporate the materials into photodetectors. Highly oriented thin films with very large domain sizes are fabricated and investigated with grazing incidence wide angle X-ray scattering, revealing a strong dependence of morphology on substrate choice and synthesis parameters. First-principles calculations confirm a direct band gap and show type Ib and IIb band alignment between organic and inorganic quantum wells. Optical characterization, temperature-dependent photoluminescence, and optical-pump terahertz-probe spectroscopy give insights into the absorption and emissive behavior of the materials as well as their charge-carrier dynamics. Overall, we further elucidate the possible reasons for the electronic and emissive properties of these intriguing materials, dominated by phonon-coupled and defect-mediated polaronic states.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Maximizing the Accessibility in DNA Origami Nanoantenna Plasmonic Hotspots},

author = {C Close and K Trofymchuk and L Grabenhorst and B Lalkens and V Glembockyte and P Tinnefeld},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/admi.202200255},

doi = {https://doi.org/10.1002/admi.202200255},

issn = {2196-7350},

year  = {2022},

date = {2022-07-01},

journal = {Advanced Materials Interfaces},

volume = {n/a},

number = {n/a},

pages = {2200255},

abstract = {Abstract DNA nanotechnology has conquered the challenge of positioning quantum emitters in the hotspot of optical antenna structures for fluorescence enhancement. Therefore, DNA origami serves as the scaffold to arrange nanoparticles and emitters, such as fluorescent dyes. For the next challenge of optimizing the applicability of plasmonic hotspots for molecular assays, a Trident DNA origami structure that increases the accessibility of the hotspot is introduced, thereby improving the kinetics of target molecule binding. This Trident NanoAntenna with Cleared HOtSpot (NACHOS) is compared with previous DNA origami nanoantennas and improved hotspot accessibility is demonstrated without compromising fluorescence enhancement. The approach taps into the potential of Trident NACHOS for single-molecule-based plasmonic biosensing.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Giant second-harmonic generation in ferroelectric NbOI2},

author = {I Abdelwahab and B Tilmann and Y Wu and D Giovanni and I Verzhbitskiy and M Zhu and R Bert\'{e} and F Xuan and L D S Menezes and G Eda and T C Sum and S Y Quek and S A Maier and K P Loh},

url = {https://doi.org/10.1038/s41566-022-01021-y},

doi = {10.1038/s41566-022-01021-y},

issn = {1749-4893},

year  = {2022},

date = {2022-06-30},

journal = {Nature Photonics},

abstract = {Implementing nonlinear optical components in nanoscale photonic devices is challenged by phase-matching conditions requiring thicknesses in the order of hundreds of wavelengths, and is disadvantaged by the short optical interaction depth of nanometre-scale materials and weak photon\textendashphoton interactions. Here we report that ferroelectric NbOI2 nanosheets exhibit giant second-harmonic generation with conversion efficiencies that are orders of magnitude higher than commonly reported nonlinear crystals. The nonlinear response scales with layer thickness and is strain- and electrical-tunable; a record \>0.2% absolute SHG conversion efficiency and an effective nonlinear susceptibility $$chi _mathrmeff^(2)$$in the order of 10−9 m V−1 are demonstrated at an average pump intensity of 8 kW cm\textendash2. Due to the interplay between anisotropic polarization and excitonic resonance in NbOI2, the spatial profile of the polarized SHG response can be tuned by the excitation wavelength. Our results represent a new paradigm for ultrathin, efficient nonlinear optical components.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {In Situ Observation of Morphological and Oxidation Level Degradation Processes within Ionic Liquid Post-treated PEDOT:PSS Thin Films upon Operation at High Temperatures},

author = {A L Oechsle and J E Heger and N Li and S Yin and S Bernstorff and P M\"{u}ller-Buschbaum},

url = {https://doi.org/10.1021/acsami.2c05745},

doi = {10.1021/acsami.2c05745},

issn = {1944-8244},

year  = {2022},

date = {2022-06-27},

journal = {ACS Applied Materials \& Interfaces},

volume = {14},

number = {27},

pages = {30802-30811},

abstract = {Organic thermoelectric thin films are investigated in terms of their stability at elevated operating temperatures. Therefore, the electrical conductivity of ethyl-3-methylimidazolium dicyanamide (EMIM DCA) post-treated poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) thin films is measured over 4.5 h of heating at 50 or 100 °C for different EMIM DCA concentrations. The changes in the electrical performance are correlated with changes in the film morphology, as evidenced with in situ grazing-incidence small-angle X-ray scattering (GISAXS). Due to the overall increased PEDOT domain distances, the resulting impairment of the interdomain charge carrier transport directly correlates with the observed electrical conductivity decay. With in situ ultraviolet−visible (UV\textendashVis) measurements, a simultaneously occurring reduction of the PEDOT oxidation level is found to have an additional electrical conductivity lowering contribution due to the decrease of the charge carrier density. Finally, the observed morphology and oxidation level degradation is associated with the deterioration of the thermoelectric properties and hence a favorable operating temperature range is suggested for EMIM DCA post-treated PEDOT:PSS-based thermoelectrics.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Imaging elliptically polarized infrared near-fields on nanoparticles by strong-field dissociation of functional surface groups},

author = {P Rosenberger and R Dagar and W Zhang and A Sousa-Castillo and M Neuhaus and E Cortes and S A Maier and C Costa-Vera and M F Kling and B Bergues},

url = {https://doi.org/10.1140/epjd/s10053-022-00430-6},

doi = {10.1140/epjd/s10053-022-00430-6},

issn = {1434-6079},

year  = {2022},

date = {2022-06-27},

journal = {The European Physical Journal D},

volume = {76},

number = {6},

pages = {109},

abstract = {We investigate the strong-field ion emission from the surface of isolated silica nanoparticles aerosolized from an alcoholic solution, and demonstrate the applicability of the recently reported near-field imaging at 720 nm [Rupp et al., Nat. Comm., 10(1):4655, 2019] to longer wavelength (2 $$mu $$m) and polarizations with arbitrary ellipticity. Based on the experimental observations, we discuss the validity of a previously introduced semi-classical model, which is based on near-field driven charge generation by a Monte-Carlo approach and classical propagation. We furthermore clarify the role of the solvent in the surface composition of the nanoparticles in the interaction region. We find that upon injection of the nanoparticles into the vacuum, the alcoholic solvent evaporates on millisecond time scales, and that the generated ions originate predominantly from covalent bonds with the silica surface rather than from physisorbed solvent molecules. These findings have important implications for the development of future theoretical models of the strong-field ion emission from silica nanoparticles, and the application of near-field imaging and reaction dynamics of functional groups on isolated nanoparticles.},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Elucidating the Role of Antisolvents on the Surface Chemistry and Optoelectronic Properties of CsPbBrxI3-x Perovskite Nanocrystals},

author = {J Ye and Z Li and D J Kubicki and Y Zhang and L Dai and C Otero-Mart\'{i}nez and M A Reus and R Arul and K R Dudipala and Z Andaji-Garmaroudi and Y-T Huang and Z Li and Z Chen and P M\"{u}ller-Buschbaum and H-L Yip and S D Stranks and C P Grey and J J Baumberg and N C Greenham and L Polavarapu and A Rao and R L Z Hoye},

url = {https://doi.org/10.1021/jacs.2c02631},

doi = {10.1021/jacs.2c02631},

issn = {0002-7863},

year  = {2022},

date = {2022-06-27},

journal = {Journal of the American Chemical Society},

volume = {144},

number = {27},

pages = {12102-12115},

abstract = {Colloidal lead-halide perovskite nanocrystals (LHP NCs) have emerged over the past decade as leading candidates for efficient next-generation optoelectronic devices, but their properties and performance critically depend on how they are purified. While antisolvents are widely used for purification, a detailed understanding of how the polarity of the antisolvent influences the surface chemistry and composition of the NCs is missing in the field. Here, we fill this knowledge gap by studying the surface chemistry of purified CsPbBrxI3-x NCs as the model system, which in itself is considered a promising candidate for pure-red light-emitting diodes and top-cells for tandem photovoltaics. Interestingly, we find that as the polarity of the antisolvent increases (from methyl acetate to acetone to butanol), there is a blueshift in the photoluminescence (PL) peak of the NCs along with a decrease in PL quantum yield (PLQY). Through transmission electron microscopy and X-ray photoemission spectroscopy measurements, we find that these changes in PL properties arise from antisolvent-induced iodide removal, which leads to a change in halide composition and, thus, the bandgap. Using detailed nuclear magnetic resonance (NMR) and Fourier-transform infrared spectroscopy (FTIR) measurements along with density functional theory calculations, we propose that more polar antisolvents favor the detachment of the oleic acid and oleylamine ligands, which undergo amide condensation reactions, leading to the removal of iodide anions from the NC surface bound to these ligands. This work shows that careful selection of low-polarity antisolvents is a critical part of designing the synthesis of NCs to achieve high PLQYs with minimal defect-mediated phase segregation.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Designing Multifunctional Cobalt Oxide Layers for Efficient and Stable Electrochemical Oxygen Evolution},

author = {M Kuhl and A Henning and L Haller and L I Wagner and C-M Jiang and V Streibel and I D Sharp and J Eichhorn},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/admi.202200582},

doi = {https://doi.org/10.1002/admi.202200582},

issn = {2196-7350},

year  = {2022},

date = {2022-06-24},

journal = {Advanced Materials Interfaces},

volume = {9},

number = {21},

pages = {2200582},

abstract = {Abstract Disordered and porous metal oxides are promising earth-abundant and cost-effective alternatives to noble-metal electrocatalysts. Herein, nonsaturated oxidation in plasma-enhanced atomic layer deposition is leveraged to tune the structural, mechanical, and optical properties of biphasic cobalt hydroxide films, thereby tailoring their catalytic activities and chemical stabilities. Short oxygen plasma exposure times and low plasma powers incompletely oxidize the cobaltocene precursor to Co(OH)2 and result in carbon impurity incorporation. These Co(OH)2 films are highly porous and catalytically active, but their electrochemical stability is impacted by poor substrate adhesion. In contrast, long exposure times and high powers completely oxidize the precursor to Co3O4, reduce the carbon incorporation, and improve the crystallinity. While the Co3O4 films have high electrochemical stability, they are characterized by low oxygen evolution reaction activity. To overcome these competing properties, the established relation between deposition parameters and functional film properties is applied to design bilayer films exhibiting simultaneously improved electrochemical performance and chemical stability. The bilayer films combine a highly active Co(OH)2 surface with a stable Co3O4 interface layer. These coatings exhibit minimal light absorption, thus making them suitable as protective catalytic layers on semiconductor light absorbers for application in photoelectrochemical devices.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Modeling of Space-Charge Layers in Solid-State Electrolytes: A Kinetic Monte Carlo Approach and Its Validation},

author = {L Katzenmeier and M G\"{o}\sswein and A Gagliardi and A S Bandarenka},

url = {https://doi.org/10.1021/acs.jpcc.2c02481},

doi = {10.1021/acs.jpcc.2c02481},

issn = {1932-7447},

year  = {2022},

date = {2022-06-23},

journal = {The Journal of Physical Chemistry C},

volume = {126},

number = {26},

pages = {10900-10909},

abstract = {The space-charge layer (SCL) phenomenon in Li+-ion-conducting solid-state electrolytes (SSEs) is gaining much interest in different fields of solid-state ionics. Not only do SCLs influence charge-transfer resistance in all-solid-state batteries but also are analogous to their electronic counterpart in semiconductors; they could be used for Li+-ionic devices. However, the rather “elusive” nature of these layers, which occur on the nanometer scale and with only small changes in concentrations, makes them hard to fully characterize experimentally. Theoretical considerations based on either electrochemical or thermodynamic models are limited due to missing physical, chemical, and electrochemical parameters. In this work, we use kinetic Monte Carlo (kMC) simulations with a small set of input parameters to model the spatial extent of the SCLs. The predictive power of the kMC model is demonstrated by finding a critical range for each parameter in which the space-charge layer growth is significant and must be considered in electrochemical and ionic devices. The time evolution of the charge redistribution is investigated, showing that the SCLs form within 500 ms after applying a bias potential.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Macromolecular Rhenium\textendashRuthenium Complexes for Photocatalytic CO2 Conversion: From Catalytic Lewis Pair Polymerization to Well-Defined Poly(vinyl bipyridine)\textendashMetal Complexes},

author = {A S Maier and C Thomas and M Kr\"{a}nzlein and T M Pehl and B Rieger},

url = {https://doi.org/10.1021/acs.macromol.2c00440},

doi = {10.1021/acs.macromol.2c00440},

issn = {0024-9297},

year  = {2022},

date = {2022-06-23},

journal = {Macromolecules},

abstract = {Herein, the first catalytical polymerization of 4-vinyl-4′-methyl-2,2′-bipyridine (VBpy) via Lewis pair-mediated group-transfer polymerization using different combinations of Lewis acidic trialkyl aluminum compounds and Lewis basic phosphines is reported. In this context, a broad screening of different Lewis pairs is conducted, demonstrating the necessity of an adjustment of the steric and electronic properties of the Lewis pair to the demands of the monomer. Further, end-group analysis of short-chain oligomers via electrospray ionization mass spectrometry (ESI-MS) for the experimentally determined optimum combination Al(i-Bu)3/PMe3 ({D} = 1.31\textendash1.36},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Low Band Gap Perovskite Concentrator Solar Cells: Physics, Device Simulation, and Experiment},

author = {T Ma and Y An and S Li and Y Zhao and H Wang and C Wang and S A Maier and X Li},

url = {https://doi.org/10.1021/acsami.2c06393},

doi = {10.1021/acsami.2c06393},

issn = {1944-8244},

year  = {2022},

date = {2022-06-22},

journal = {ACS Applied Materials \& Interfaces},

volume = {14},

number = {26},

pages = {29856-29866},

abstract = {Perovskite solar cells (PSCs) own rapidly increasing power conversion efficiencies (PCEs), but their concentrated counterparts (i.e., PCSCs) show a much lower performance. A deeper understanding of PCSCs relies on a thorough study of the intensive energy losses of the device along with increasing the illumination intensity. Taking the low band gap Sn\textendashPb PCSC as an example, we realize a device-level optoelectronic simulation to thoroughly disclose the internal photovoltaic physics and mechanisms by addressing the fundamental electromagnetic and carrier-transport processes within PCSCs under various concentration conditions. We find that the primary factor limiting the performance improvement of PCSCs is the significantly increased bulk recombination under the increased light concentration, which is attributed mostly to the inferior transport/collection ability of holes determined by the hole transport layer (HTL). We perform further electrical manipulation on the perovskite layer and the HTL so that the carrier-transport capability is significantly improved. Under the optoelectronic design, we fabricate low band gap PCSCs, which exhibit particularly high PCEs of up to 22.36% at 4.17 sun.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Elucidation of Structure\textendashActivity Relations in Proton Electroreduction at Pd Surfaces: Theoretical and Experimental Study},

author = {T O Schmidt and A Ngoipala and R L Arevalo and S A Watzele and R Lipin and R M Kluge and S Hou and R W Haid and A Senyshyn and E L Gubanova and A S Bandarenka and M Vandichel},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/smll.202202410},

doi = {https://doi.org/10.1002/smll.202202410},

issn = {1613-6810},

year  = {2022},

date = {2022-06-20},

journal = {Small},

volume = {18},

number = {30},

pages = {2202410},

abstract = {Abstract The structure\textendashactivity relationship is a cornerstone topic in catalysis, which lays the foundation for the design and functionalization of catalytic materials. Of particular interest is the catalysis of the hydrogen evolution reaction (HER) by palladium (Pd), which is envisioned to play a major role in realizing a hydrogen-based economy. Interestingly, experimentalists observed excess heat generation in such systems, which became known as the debated “cold fusion” phenomenon. Despite the considerable attention on this report, more fundamental knowledge, such as the impact of the formation of bulk Pd hydrides on the nature of active sites and the HER activity, remains largely unexplored. In this work, classical electrochemical experiments performed on model Pd(hkl) surfaces, “noise” electrochemical scanning tunneling microscopy (n-EC-STM), and density functional theory are combined to elucidate the nature of active sites for the HER. Results reveal an activity trend following Pd(111) \> Pd(110) \> Pd(100) and that the formation of subsurface hydride layers causes morphological changes and strain, which affect the HER activity and the nature of active sites. These findings provide significant insights into the role of subsurface hydride formation on the structure\textendashactivity relations toward the design of efficient Pd-based nanocatalysts for the HER.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Strong Induced Circular Dichroism in a Hybrid Lead-Halide Semiconductor Using Chiral Amino Acids for Crystallite Surface Functionalization},

author = {M W Heindl and T Kodalle and N Fehn and L K Reb and S Liu and C Harder and M Abdelsamie and L Eyre and I D Sharp and S V Roth and P M\"{u}ller-Buschbaum and A Kartouzian and C M Sutter-Fella and F Deschler},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202200204},

doi = {https://doi.org/10.1002/adom.202200204},

issn = {2195-1071},

year  = {2022},

date = {2022-06-17},

journal = {Advanced Optical Materials},

volume = {n/a},

number = {n/a},

pages = {2200204},

abstract = {Abstract Chirality is a desired property in functional semiconductors for optoelectronic, catalytic, and spintronic applications. Here, introducing enantiomerically-pure 3-aminobutyric acid (3-ABA) into thin films of the 1D semiconductor dimethylammonium lead iodide (DMAPbI3) is found to result in strong circular dichroism (CD) in the optical absorption. X-ray diffraction and grazing incidence small angle X-ray scattering (GISAXS) are applied to gain molecular-scale insights into the chirality transfer mechanism, which is attributed to a chiral surface modification of DMAPbI3 crystallites. This study demonstrates that the CD signal strength can be controlled by the amino-acid content relative to the crystallite surface area. The CD intensity is tuned by the composition of the precursor solution and the spin-coating time, thereby achieving anisotropy factors (gabs) as high as 1.75 × 10\textendash2. Grazing incidence wide angle scattering reveals strong preferential ordering that can be suppressed via tailored synthesis conditions. Different contributions to the chiroptical properties are resolved by a detailed analysis of the CD signal utilizing an approach based on the Mueller matrix model. This report of a novel class of chiral hybrid semiconductors with precise control over their optical activity presents a promising approach for the design of circularly polarized light detectors and emitters.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Covalent Organic Framework Nanoplates Enable Solution-Processed Crystalline Nanofilms for Photoelectrochemical Hydrogen Evolution},

author = {L Yao and A Rodr\'{i}guez-Camargo and M Xia and D M\"{u}cke and R Guntermann and Y Liu and L Grunenberg and A Jim\'{e}nez-Solano and S T Emmerling and V Duppel and K Sivula and T Bein and H Qi and U Kaiser and M Gr\"{a}tzel and B V Lotsch},

url = {https://doi.org/10.1021/jacs.2c01433},

doi = {10.1021/jacs.2c01433},

issn = {0002-7863},

year  = {2022},

date = {2022-06-15},

journal = {Journal of the American Chemical Society},

volume = {144},

number = {23},

pages = {10291-10300},

abstract = {As covalent organic frameworks (COFs) are coming of age, the lack of effective approaches to achieve crystalline and centimeter-scale-homogeneous COF films remains a significant bottleneck toward advancing the application of COFs in optoelectronic devices. Here, we present the synthesis of colloidal COF nanoplates, with lateral sizes of ∼200 nm and average heights of 35 nm, and their utilization as photocathodes for solar hydrogen evolution. The resulting COF nanoplate colloid exhibits a unimodal particle-size distribution and an exceptional colloidal stability without showing agglomeration after storage for 10 months and enables smooth, homogeneous, and thickness-tunable COF nanofilms via spin coating. Photoelectrodes comprising COF nanofilms were fabricated for photoelectrochemical (PEC) solar-to-hydrogen conversion. By rationally designing multicomponent photoelectrode architectures including a polymer donor/COF heterojunction and a hole-transport layer, charge recombination in COFs is mitigated, resulting in a significantly increased photocurrent density and an extremely positive onset potential for PEC hydrogen evolution (over +1 V against the reversible hydrogen electrode), among the best of classical semiconductor-based photocathodes. This work thus paves the way toward fabricating solution-processed large-scale COF nanofilms and heterojunction architectures and their use in solar-energy-conversion devices.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Radial bound states in the continuum for polarization-invariant nanophotonics},

author = {L K\"{u}hner and L Sortino and R Bert\'{e} and J Wang and H Ren and S A Maier and Y S Kivshar and A Tittl},

url = {https://arxiv.org/abs/2206.05206},

doi = {https://doi.org/10.48550/arXiv.2206.05206},

year  = {2022},

date = {2022-06-10},

journal = {arXiv preprint arXiv:2206.05206},

abstract = {All-dielectric nanophotonics underpinned by bound states in the continuum (BICs) have demonstrated breakthrough applications in nanoscale light manipulation, frequency conversion and optical sensing. Leading BIC implementations range from isolated nanoantennas with localized electromagnetic fields to symmetry-protected metasurfaces with controllable resonance quality (Q) factors. However, they either require structured light illumination with complex beamshaping optics or large, fabrication-intense arrays of polarization-sensitive unit cells, hindering tailored nanophotonic applications and on-chip integration. Here, we introduce radial quasi bound states in the continuum (rBICs) as a new class of radially distributed electromagnetic modes controlled by structural asymmetry in a ring of dielectric rod pair resonators. The rBIC platform provides polarization-invariant and tunable high-Q resonances with strongly enhanced near-fields in an ultracompact footprint as low as 2 μm2. We demonstrate rBIC realizations in the visible for sensitive biomolecular detection and enhanced second-harmonic generation from monolayers of transition metal dichalcogenides, opening new perspectives for compact, spectrally selective, and polarization-invariant metadevices for multi-functional light-matter coupling, multiplexed sensing, and high-density on-chip photonics.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {From Free-Energy Profiles to Activation Free Energies},

author = {J C Dietschreit and D J Diestler and A Hulm and C Ochsenfeld and R G\'{o}mez-Bombarelli},

url = {https://arxiv.org/abs/2206.02893},

doi = {https://doi.org/10.48550/arXiv.2206.02893},

year  = {2022},

date = {2022-06-06},

journal = {arXiv preprint arXiv:2206.02893},

abstract = {Given a chemical reaction going from reactant (R) to the product (P) on a potential energy surface (PES) and a collective variable (CV) that discriminates between R and P, one can define a free-energy profile (FEP) as the logarithm of the marginal Boltzmann distribution of the CV. The FEP is not a true free energy, however, it is common to treat the FEP as the free-energy analog of the minimum energy path on the PES and to take the activation free energy, ΔF‡RP, as the difference between the maximum of the FEP at the transition state and the minimum at R. We show that this approximation can result in large errors. Since the FEP depends on the CV, it is therefore not unique, and different, discriminating CVs can yield different activation free energies for the same reaction. We derive an exact expression for the activation free energy that avoids this ambiguity with respect to the choice of CV. We find ΔF‡RP to be a combination of the probability of the system being in the reactant state, the probability density at the transition state surface, and the thermal de~Broglie wavelength associated with the transition from R to P. We then evaluate the activation free energies based on our formalism for simple analytic models and realistic chemical systems. The analytic models show that the widespread FEP-based approximation applies only at low temperatures for CVs for which the effective mass of the associated pseudo-particle is small. Most chemical reactions of practical interest involve polyatomic molecules with complex, high-dimensional PES that cannot be treated analytically and pose the added challenge of choosing a good CV, typically through heuristics. We study the influence of the choice of CV and find that, while the reaction free energy is largely unaffected, ΔF‡RP is quite sensitive.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Light-driven molecular motors embedded in covalent organic frameworks},

author = {C St\"{a}hler and L Grunenberg and M W Terban and W R Browne and D Doellerer and M Kathan and M Etter and B V Lotsch and B L Feringa and S Krause},

url = {http://dx.doi.org/10.1039/D2SC02282F},

doi = {10.1039/D2SC02282F},

issn = {2041-6520},

year  = {2022},

date = {2022-06-02},

journal = {Chemical Science},

abstract = {The incorporation of molecular machines into the backbone of porous framework structures will facilitate nano actuation, enhanced molecular transport, and other out-of-equilibrium host\textendashguest phenomena in well-defined 3D solid materials. In this work, we detail the synthesis of a diamine-based light-driven molecular motor and its incorporation into a series of imine-based polymers and covalent organic frameworks (COF). We study structural and dynamic properties of the molecular building blocks and derived self-assembled solids with a series of spectroscopic, diffraction, and theoretical methods. Using an acid-catalyzed synthesis approach, we are able to obtain the first crystalline 2D COF with stacked hexagonal layers that contains 20 mol% molecular motors. The COF features a specific pore volume and surface area of up to 0.45 cm3 g−1 and 604 m2 g−1, respectively. Given the molecular structure and bulkiness of the diamine motor, we study the supramolecular assembly of the COF layers and detail stacking disorders between adjacent layers. We finally probe the motor dynamics with in situ spectroscopic techniques revealing current limitations in the analysis of these new materials and derive important analysis and design criteria as well as synthetic access to new generations of motorized porous framework materials.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Metasurface-Enhanced Infrared Spectroscopy: An Abundance of Materials and Functionalities},

author = {A John-Herpin and A Tittl and L K\"{u}hner and F Richter and S H Huang and G Shvets and S-H Oh and H Altug},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202110163},

doi = {https://doi.org/10.1002/adma.202110163},

issn = {0935-9648},

year  = {2022},

date = {2022-05-31},

journal = {Advanced Materials},

volume = {n/a},

number = {n/a},

pages = {2110163},

abstract = {Abstract Infrared (IR) spectroscopy provides unique information on the composition and dynamics of biochemical systems by resolving the characteristic absorption fingerprints of their constituent molecules. Based on this inherent chemical specificity and the capability for label-free, non-invasive, and real-time detection, IR spectroscopy approaches have unlocked a plethora of breakthrough application perspectives for fields ranging from environmental monitoring and defense to chemical analysis and medical diagnostics. Nanophotonics has played a crucial role for pushing the sensitivity limits of traditional far-field spectroscopy by using resonant nanostructures to focus the incident light into nanoscale hot-spots of the electromagnetic field, greatly enhancing light-matter interaction. Metasurfaces composed of regular arrangements of such resonators further increase the design space for tailoring this nanoscale light control both spectrally and spatially, which has established them as an invaluable toolkit for surface-enhanced spectroscopy. Starting from the fundamental concepts of metasurface-enhanced IR spectroscopy, we showcase a broad palette of resonator geometries, materials and arrangements for realizing highly sensitive metadevices, with a special focus on emerging systems such as phononic and 2D van der Waals materials, and integration with waveguides for lab-on-a-chip devices. Furthermore, we will highlight some advanced sensor functionalities of metasurface-based IR spectroscopy, including multiresonance, tunability, dielectrophoresis, live cell sensing, and machine-learning-aided analysis. This article is protected by copyright. All rights reserved},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Operando Study of Structure Degradation in Solid-State Dye-Sensitized Solar Cells with a TiO2 Photoanode Having Ordered Mesopore Arrays},

author = {N Li and R Guo and A L Oechsle and M A Reus and S Liang and L Song and K Wang and D Yang and F Allegretti and A Kumar and M Nuber and J Berger and S Bernstorff and H Iglev and J Hauer and R A Fischer and J V Barth and P M\"{u}ller-Buschbaum},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/solr.202200373},

doi = {https://doi.org/10.1002/solr.202200373},

issn = {2367-198X},

year  = {2022},

date = {2022-05-31},

journal = {Solar RRL},

volume = {n/a},

number = {n/a},

pages = {2200373},

abstract = {Via operando grazing-incidence small-angle X-ray scattering, the degradation mechanisms of solid-state dye-sensitized solar cells (ssDSSCs) using two types of ordered mesoporous TiO2 scaffolds with different pore sizes, and an exemplary dye D205, are investigated. The temporal evolution of the inner morphology shows a strong impact on device performance. The photoinduced dye aggregation on the TiO2 surface leads to an increase in the domain radius but a decreased spatial order of the photoactive layer during the burn-in stage. This dye aggregation on the TiO2 surface causes the short-circuit current density loss, which plays a major role in the power conversion efficiency decay. Finally, it is found that a larger surface area in the small-pore sample yields a faster short-circuit current density decay as compared with the big-pore sample. Therefore, a control of dye aggregation and the pore size of TiO2 photoelectrodes is crucial for the stability of TiO2-based ssDSSCs.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Advances in nano-and microscale NMR spectroscopy using diamond quantum sensors},

author = {R D Allert and K D Briegel and D B Bucher},

url = {https://arxiv.org/abs/2205.12178},

doi = {https://doi.org/10.48550/arXiv.2205.12178},

year  = {2022},

date = {2022-05-24},

journal = {arXiv preprint arXiv:2205.12178},

abstract = {Quantum technologies have seen a rapid developmental surge over the last couple of years. Though often overshadowed by quantum computation, quantum sensors show tremendous potential for widespread applications in chemistry and biology. One system stands out in particular: the nitrogen-vacancy (NV) center in diamond, an atomic-sized sensor allowing the detection of nuclear magnetic resonance (NMR) signals at unprecedented length scales down to a single proton. In this article, we review the fundamentals of NV center-based quantum sensing and its distinct impact on nano- to microscale NMR spectroscopy. Furthermore, we highlight and discuss possible future applications of this novel technology ranging from energy research, material science, or single-cell biology, but also associated challenges of these rapidly developing NMR sensors.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}