C Lampe, I Kouroudis, M Harth, S Martin, A Gagliardi, A S Urban
Machine-Learning-Optimized Perovskite Nanoplatelet Synthesis Journal Article
In: arXiv preprint arXiv:2210.09783, 2022.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Machine-Learning-Optimized Perovskite Nanoplatelet Synthesis},
author = {C Lampe and I Kouroudis and M Harth and S Martin and A Gagliardi and A S Urban},
url = {https://arxiv.org/abs/2210.09783},
doi = {https://doi.org/10.48550/arXiv.2210.09783},
year = {2022},
date = {2022-10-18},
journal = {arXiv preprint arXiv:2210.09783},
abstract = {With the demand for renewable energy and efficient devices rapidly increasing, a need arises to find and optimize novel (nano)materials. This can be an extremely tedious process, often relying significantly on trial and error. Machine learning has emerged recently as a powerful alternative; however, most approaches require a substantial amount of data points, i.e., syntheses. Here, we merge three machine-learning models with Bayesian Optimization and are able to dramatically improve the quality of CsPbBr3 nanoplatelets (NPLs) using only approximately 200 total syntheses. The algorithm can predict the resulting PL emission maxima of the NPL dispersions based on the precursor ratios, which lead to previously unobtainable 7 and 8 ML NPLs. Aided by heuristic knowledge, the algorithm should be easily applicable to other nanocrystal syntheses and significantly help to identify interesting compositions and rapidly improve their quality.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
Q Wang, K Liu, K Hu, C Cai, H Li, H Li, M Herran, Y-R Lu, T-S Chan, C Ma, J Fu, S Zhang, Y Liang, E Cortés, M Liu
Attenuating metal-substrate conjugation in atomically dispersed nickel catalysts for electroreduction of CO2 to CO Journal Article
In: Nature Communications, vol. 13, no. 1, pp. 6082, 2022, ISSN: 2041-1723.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Attenuating metal-substrate conjugation in atomically dispersed nickel catalysts for electroreduction of CO2 to CO},
author = {Q Wang and K Liu and K Hu and C Cai and H Li and H Li and M Herran and Y-R Lu and T-S Chan and C Ma and J Fu and S Zhang and Y Liang and E Cort\'{e}s and M Liu},
url = {https://doi.org/10.1038/s41467-022-33692-0},
doi = {10.1038/s41467-022-33692-0},
issn = {2041-1723},
year = {2022},
date = {2022-10-14},
journal = {Nature Communications},
volume = {13},
number = {1},
pages = {6082},
abstract = {Atomically dispersed transition metals on carbon-based aromatic substrates are an emerging class of electrocatalysts for the electroreduction of CO2. However, electron delocalization of the metal site with the carbon support via d-π conjugation strongly hinders CO2 activation at the active metal centers. Herein, we introduce a strategy to attenuate the d-π conjugation at single Ni atomic sites by functionalizing the support with cyano moieties. In situ attenuated total reflection infrared spectroscopy and theoretical calculations demonstrate that this strategy increases the electron density around the metal centers and facilitates CO2 activation. As a result, for the electroreduction of CO2 to CO in aqueous KHCO3 electrolyte, the cyano-modified catalyst exhibits a turnover frequency of ~22,000 per hour at −1.178 V versus the reversible hydrogen electrode (RHE) and maintains a Faradaic efficiency (FE) above 90% even with a CO2 concentration of only 30% in an H-type cell. In a flow cell under pure CO2 at −0.93 V versus RHE the cyano-modified catalyst enables a current density of −300 mA/cm2 with a FE above 90%.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
L Kühner, F J Wendisch, A A Antonov, J Bürger, L Hüttenhofer, L D S Menezes, S A Maier, M V Gorkunov, Y Kivshar, A Tittl
Unlocking the out-of-plane dimension for photonic bound states in the continuum to achieve maximum optical chirality Journal Article
In: arXiv preprint arXiv:2210.05339, 2022.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Unlocking the out-of-plane dimension for photonic bound states in the continuum to achieve maximum optical chirality},
author = {L K\"{u}hner and F J Wendisch and A A Antonov and J B\"{u}rger and L H\"{u}ttenhofer and L D S Menezes and S A Maier and M V Gorkunov and Y Kivshar and A Tittl},
url = {https://arxiv.org/abs/2210.05339},
doi = {https://doi.org/10.48550/arXiv.2210.05339},
year = {2022},
date = {2022-10-11},
journal = {arXiv preprint arXiv:2210.05339},
abstract = {The realization of lossless metasurfaces with true chirality crucially requires the fabrication of three-dimensional structures, constraining their feasibility for experiments and hampering practical implementations. Even though the three-dimensional assembly of metallic nanostructures has been demonstrated previously, the resulting plasmonic resonances suffer from high intrinsic and radiative losses. The concept of photonic bound states in the continuum (BICs) is instrumental for tailoring radiative losses in diverse geometries, especially when implemented using lossless dielectrics, but applications have so far been limited to planar and intrinsically achiral structures. Here, we introduce a novel nanofabrication approach to unlock the height of generally flat all-dielectric metasurfaces as an accessible parameter for efficient resonance and functionality control. In particular, we realize out-of-plane symmetry breaking in quasi-BIC metasurfaces and leverage this design degree of freedom to demonstrate, for the first time, an optical all-dielectric quasi-BIC metasurface with maximum intrinsic chirality that responds selectively to light of a particular circular polarization depending on the structural handedness. Our experimental results not only open a new paradigm for all-dielectric BICs and chiral nanophotonics but also promise advances in the realization of efficient generation of optical angular momentum, holographic metasurfaces, and parity-time symmetry-broken optical systems.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
Y Lei, T Zhang, Y-C Lin, T Granzier-Nakajima, G Bepete, D A Kowalczyk, Z Lin, D Zhou, T F Schranghamer, A Dodda, A Sebastian, Y Chen, Y Liu, G Pourtois, T J Kempa, B Schuler, M T Edmonds, S Y Quek, U Wurstbauer, S M Wu, N R Glavin, S Das, S P Dash, J M Redwing, J A Robinson, M Terrones
Graphene and Beyond: Recent Advances in Two-Dimensional Materials Synthesis, Properties, and Devices Journal Article
In: ACS Nanoscience Au, 2022.
Abstract | Links | Tags: Solid-Solid
@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}
}
T Dinter, C Li, L Kühner, T Weber, A Tittl, S A Maier, J M Dawes, H Ren
Metasurface Measuring Twisted Light in Turbulence Journal Article
In: ACS Photonics, vol. 9, no. 9, pp. 3043-3051, 2022.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@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}
}
C Cai, B Liu, K Liu, P Li, J Fu, Y Wang, W Li, C Tian, Y Kang, A Stefancu, H Li, C-W Kao, T-S Chan, Z Lin, L Chai, E Cortés, M Liu
Heteroatoms Induce Localization of the Electric Field and Promote a Wide Potential-Window Selectivity Towards CO in the CO2 Electroreduction Journal Article
In: Angewandte Chemie International Edition, vol. 61, no. 44, pp. e202212640, 2022, ISSN: 1433-7851.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@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}
}
D Ruhstorfer, M Döblinger, H Riedl, J J Finley, G Koblmüller
Role of twin defects on growth dynamics and size distribution of undoped and Si-doped GaAs nanowires by selective area epitaxy Journal Article
In: Journal of Applied Physics, vol. 132, no. 20, pp. 204302, 2022.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@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}
}
S Tu, T Tian, A Lena Oechsle, S Yin, X Jiang, W Cao, N Li, M A Scheel, L K Reb, S Hou, A S Bandarenka, M Schwartzkopf, S V Roth, P Müller-Buschbaum
Improvement of the thermoelectric properties of PEDOT:PSS films via DMSO addition and DMSO/salt post-treatment resolved from a fundamental view Journal Article
In: Chemical Engineering Journal, vol. 429, pp. 132295, 2022, ISSN: 1385-8947.
Abstract | Links | Tags: Foundry Organic, Solid-Solid
@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}
}
D Laniel, F Trybel, A Aslandukov, S Khandarkhaeva, T Fedotenko, Y Yin, F Tasnádi, A V Ponomareva, G Weck, F I Akbar
Synthesis of Ultra-Incompressible Carbon Nitrides Featuring Three-Dimensional Frameworks of CN4 Tetrahedra Recoverable at Ambient Conditions Journal Article
In: arXiv preprint arXiv:2209.01968, 2022.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@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}
}
T Weber, L Kühner, L Sortino, A B Mhenni, N P Wilson, J Kühne, J J Finley, S A Maier, A Tittl
Strong light-matter interaction with self-hybridized bound states in the continuum in monolithic van der Waals metasurfaces Journal Article
In: arXiv preprint arXiv:2209.01944, 2022.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@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}
}
J Bürger, V Schalles, J Kim, B Jang, M Zeisberger, J Gargiulo, L De S. Menezes, M A Schmidt, S A Maier
3D-Nanoprinted Antiresonant Hollow-Core Microgap Waveguide: An on-Chip Platform for Integrated Photonic Devices and Sensors Journal Article
In: ACS Photonics, vol. 9, no. 9, pp. 3012-3024, 2022.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@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}
}
S Wang, M Dyksik, C Lampe, M Gramlich, D K Maude, M Baranowski, A S Urban, P Plochocka, A Surrente
Thickness-Dependent Dark-Bright Exciton Splitting and Phonon Bottleneck in CsPbBr3-Based Nanoplatelets Revealed via Magneto-Optical Spectroscopy Journal Article
In: Nano Letters, vol. 22, no. 17, pp. 7011-7019, 2022, ISSN: 1530-6984.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@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}
}
L Frey, J F Pöhls, M Hennemann, A Mähringer, S Reuter, T Clark, R T Weitz, D D Medina
Oriented Thiophene-Extended Benzotrithiophene Covalent Organic Framework Thin Films: Directional Electrical Conductivity Journal Article
In: Advanced Functional Materials, vol. n/a, no. n/a, pp. 2205949, 2022, ISSN: 1616-301X.
Abstract | Links | Tags: Foundry Organic, Solid-Solid
@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}
}
D Laniel, F Trybel, A Néri, Y Yin, A Aslandukov, T Fedotenko, S Khandarkhaeva, F Tasnádi, S Chariton, C Giacobbe, E L Bright, M Hanfland, V Prakapenka, W Schnick, I A Abrikosov, L Dubrovinsky, N Dubrovinskaia
Revealing Phosphorus Nitrides up to the Megabar Regime: Synthesis of α′-P3N5, δ-P3N5 and PN2 Journal Article
In: Chemistry – A European Journal, vol. 28, iss. 62, pp. e202201998, 2022, ISSN: 0947-6539.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@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}
}
H Hu, T Weber, O Bienek, A Wester, L Hüttenhofer, I D Sharp, S A Maier, A Tittl, E Cortés
Catalytic Metasurfaces Empowered by Bound States in the Continuum Journal Article
In: ACS Nano, vol. 16, no. 8, pp. 13057-13068, 2022, ISSN: 1936-0851.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@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}
}
L S Walter, A Axt, J W Borchert, T Kammerbauer, F Winterer, J Lenz, S L Weber, R T Weitz
Revealing and Controlling Energy Barriers and Valleys at Grain Boundaries in Ultrathin Organic Films Journal Article
In: Small, vol. 18, no. 34, pp. 2200605, 2022, ISSN: 1613-6810.
Abstract | Links | Tags: Foundry Organic, Solid-Solid
@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}
}
S Liu, M W Heindl, N Fehn, S Caicedo-Dávila, L Eyre, S M Kronawitter, J Zerhoch, S Bodnar, A Shcherbakov, A Stadlbauer, G Kieslich, I D Sharp, D A Egger, A Kartouzian, F Deschler
Optically Induced Long-Lived Chirality Memory in the Color-Tunable Chiral Lead-Free Semiconductor (R)/(S)-CHEA4Bi2BrxI10–x (x = 0–10) Journal Article
In: Journal of the American Chemical Society, vol. 144, no. 31, pp. 14079-14089, 2022, ISSN: 0002-7863.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@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}
}
I Ozdemir, A W Holleitner, C Kastl, O Ü Aktürk
Thickness and defect dependent electronic, optical and thermoelectric features of WTe2 Journal Article
In: Scientific Reports, vol. 12, no. 1, pp. 12756, 2022, ISSN: 2045-2322.
Abstract | Links | Tags: Solid-Solid
@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}
}
H Türk, T Götsch, F-P Schmidt, A Hammud, D Ivanov, L G J De Haart, I Vinke, R-A Eichel, R Schlögl, K Reuter, A Knop-Gericke, T Lunkenbein, C Scheurer
Sr Surface Enrichment in Solid Oxide Cells - Approaching the Limits of EDX Analysis by Multivariate Statistical Analysis and Simulations Journal Article
In: ChemCatChem, vol. n/a, no. n/a, 2022, ISSN: 1867-3880.
Abstract | Links | Tags: Solid-Solid
@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}
}
E Gubanova, T O Schmidt, S Watzele, V Alexandrov, A S Bandarenka
Structure-Dependent Electrical Double-Layer Capacitances of the Basal Plane Pd(hkl) Electrodes in HClO4 Journal Article
In: The Journal of Physical Chemistry C, vol. 126, no. 27, pp. 11414-11420, 2022, ISSN: 1932-7447.
Abstract | Links | Tags: Solid-Solid
@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}
}
R Hooijer, A Weis, A Biewald, M T Sirtl, J Malburg, R Holfeuer, S Thamm, A Y Amin, M Righetto, A Hartschuh, L M Herz, T Bein
In: Advanced Optical Materials, vol. 10, no. 14, pp. 2200354, 2022, ISSN: 2195-1071.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@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}
}
I Abdelwahab, B Tilmann, Y Wu, D Giovanni, I Verzhbitskiy, M Zhu, R Berté, F Xuan, L D S Menezes, G Eda, T C Sum, S Y Quek, S A Maier, K P Loh
Giant second-harmonic generation in ferroelectric NbOI2 Journal Article
In: Nature Photonics, 2022, ISSN: 1749-4893.
Abstract | Links | Tags: Solid-Solid
@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}
}
L Katzenmeier, M Gößwein, A Gagliardi, A S Bandarenka
Modeling of Space-Charge Layers in Solid-State Electrolytes: A Kinetic Monte Carlo Approach and Its Validation Journal Article
In: The Journal of Physical Chemistry C, vol. 126, no. 26, pp. 10900-10909, 2022, ISSN: 1932-7447.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@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}
}
T Ma, Y An, S Li, Y Zhao, H Wang, C Wang, S A Maier, X Li
Low Band Gap Perovskite Concentrator Solar Cells: Physics, Device Simulation, and Experiment Journal Article
In: ACS Applied Materials & Interfaces, vol. 14, no. 26, pp. 29856-29866, 2022, ISSN: 1944-8244.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@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}
}
T O Schmidt, A Ngoipala, R L Arevalo, S A Watzele, R Lipin, R M Kluge, S Hou, R W Haid, A Senyshyn, E L Gubanova, A S Bandarenka, M Vandichel
Elucidation of Structure–Activity Relations in Proton Electroreduction at Pd Surfaces: Theoretical and Experimental Study Journal Article
In: Small, vol. 18, no. 30, pp. 2202410, 2022, ISSN: 1613-6810.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@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}
}
M W Heindl, T Kodalle, N Fehn, L K Reb, S Liu, C Harder, M Abdelsamie, L Eyre, I D Sharp, S V Roth, P Müller-Buschbaum, A Kartouzian, C M Sutter-Fella, F Deschler
Strong Induced Circular Dichroism in a Hybrid Lead-Halide Semiconductor Using Chiral Amino Acids for Crystallite Surface Functionalization Journal Article
In: Advanced Optical Materials, vol. n/a, no. n/a, pp. 2200204, 2022, ISSN: 2195-1071.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@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}
}
N Li, R Guo, A L Oechsle, M A Reus, S Liang, L Song, K Wang, D Yang, F Allegretti, A Kumar, M Nuber, J Berger, S Bernstorff, H Iglev, J Hauer, R A Fischer, J V Barth, P Müller-Buschbaum
Operando Study of Structure Degradation in Solid-State Dye-Sensitized Solar Cells with a TiO2 Photoanode Having Ordered Mesopore Arrays Journal Article
In: Solar RRL, vol. n/a, no. n/a, pp. 2200373, 2022, ISSN: 2367-198X.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@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}
}
R D Allert, K D Briegel, D B Bucher
Advances in nano-and microscale NMR spectroscopy using diamond quantum sensors Journal Article
In: arXiv preprint arXiv:2205.12178, 2022.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@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}
}
W Zhang, R Dagar, P Rosenberger, A Sousa-Castillo, M Neuhaus, W Li, S A Khan, A S Alnaser, E Cortes, S A Maier, C Costa-Vera, M F Kling, B Bergues
All-optical nanoscopic spatial control of molecular reaction yields on nanoparticles Journal Article
In: Optica, vol. 9, no. 5, pp. 551-560, 2022.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {All-optical nanoscopic spatial control of molecular reaction yields on nanoparticles},
author = {W Zhang and R Dagar and P Rosenberger and A Sousa-Castillo and M Neuhaus and W Li and S A Khan and A S Alnaser and E Cortes and S A Maier and C Costa-Vera and M F Kling and B Bergues},
url = {http://opg.optica.org/optica/abstract.cfm?URI=optica-9-5-551},
doi = {10.1364/OPTICA.453915},
year = {2022},
date = {2022-05-20},
journal = {Optica},
volume = {9},
number = {5},
pages = {551-560},
abstract = {Molecular adsorbate reactions on nanoparticles play a fundamental role in areas such as nano-photocatalysis, atmospheric, and astrochemistry. They can be induced, enhanced, and controlled by field localization and enhancement on the nanoparticle surface. In particular, the ability to perform highly controlled near-field-mediated reactions is key to deepening our understanding of surface photoactivity on nanosystems. Here, using reaction nanoscopy, we experimentally demonstrate all-optical nanoscopic control of surface reaction yields by tailoring the near fields on nanoparticles with waveform-controlled linear and bicircular two-color laser pulses, respectively. We observe site-selective proton emission from the dissociative ionization of adsorbate molecules on SiO2 nanoparticles as a function of the polarization and relative phase of the two-color pulses. The angularly resolved close-to-uniform mapping between the surface reaction yields and the measured ion momentum enables the observation and spatial control of molecular reactions on the nanoparticle surface with nanoscopic resolution. The experimental results are modeled and reproduced qualitatively by classical trajectory Monte Carlo simulations. Our work paves the way toward reliable all-optical control of photocatalytic chemical reactions on nanoscale surfaces.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
C L Weindl, C E Fajman, M A Giebel, K S Wienhold, S Yin, T Tian, C Geiger, L P Kreuzer, M Schwartzkopf, S V Roth, T F Fässler, P Müller-Buschbaum
Effect of Solvent Vapor Annealing on Diblock Copolymer-Templated Mesoporous Si/Ge/C Thin Films: Implications for Li-Ion Batteries Journal Article
In: ACS Applied Nano Materials, vol. 5, no. 5, pp. 7278-7287, 2022.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Effect of Solvent Vapor Annealing on Diblock Copolymer-Templated Mesoporous Si/Ge/C Thin Films: Implications for Li-Ion Batteries},
author = {C L Weindl and C E Fajman and M A Giebel and K S Wienhold and S Yin and T Tian and C Geiger and L P Kreuzer and M Schwartzkopf and S V Roth and T F F\"{a}ssler and P M\"{u}ller-Buschbaum},
url = {https://doi.org/10.1021/acsanm.2c01191},
doi = {10.1021/acsanm.2c01191},
year = {2022},
date = {2022-05-17},
journal = {ACS Applied Nano Materials},
volume = {5},
number = {5},
pages = {7278-7287},
abstract = {Although amphiphilic diblock copolymer templating of inorganic materials such as TiO2 is already well investigated, sol\textendashgel synthesis routines for porous silicon and germanium are relatively rare. Therefore, especially in the field of Li-ion batteries, novel synthesis routines with the possibility to tune the silicon and germanium ratio and the morphology in the nanometer regime are of high interest. Here, we demonstrate a synthesis method that allows a change of morphology and elemental composition with minimal effort. We evidence a morphological transformation in the nanometer regime with real space (scanning electron microscopy) and complementary reciprocal space analysis methods (grazing-incidence small-angle X-ray scattering). Although energy-dispersive X-ray spectroscopy (EDS) reveals a considerable amount of oxygen in the thin film, crystalline Ge in the bulk is detected with powder X-ray diffraction (PXRD) and Raman spectroscopy. Due to the system’s simplicity, chemical mass production options such as roll-to-roll or slot-die printing can also be considered high-yield methods compared to standard synthesis routines.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
M P S Rodrigues, A H B Dourado, K Krischer, S I C Torresi
Gold–rhodium nanoflowers for the plasmon enhanced ethanol electrooxidation under visible light for tuning the activity and selectivity Journal Article
In: Electrochimica Acta, vol. 420, pp. 140439, 2022, ISSN: 0013-4686.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Gold\textendashrhodium nanoflowers for the plasmon enhanced ethanol electrooxidation under visible light for tuning the activity and selectivity},
author = {M P S Rodrigues and A H B Dourado and K Krischer and S I C Torresi},
url = {https://www.sciencedirect.com/science/article/pii/S0013468622006016},
doi = {https://doi.org/10.1016/j.electacta.2022.140439},
issn = {0013-4686},
year = {2022},
date = {2022-05-12},
journal = {Electrochimica Acta},
volume = {420},
pages = {140439},
abstract = {Direct ethanol fuel cells (DEFCs) are a promising power source, but the low selectivity to ethanol complete oxidation is still challenging. The localized surface plasmon resonance (LSPR) excitation has been reported to accelerate and drive several chemical reactions, including the ethanol oxidation reaction (EOR), coming as a strategy to improve catalysts performance. Nonetheless, metallic nanoparticles (NPs) that present the LSPR excitation in the visible range are known for leading to the incomplete oxidation of ethanol. Thus, we report here the application of gold-rhodium nanoflowers (Au@Rh NFs) towards the plasmon-enhanced EOR. These hybrid materials consist of a Au spherical nucleus covered by Rh branches shell, combining plasmonic and catalytic properties. Firstly, the Au@Rh NFs metallic ratio was investigated in dark conditions to obtain an optimal catalyst. Experiments were also performed under light irradiation. Our data demonstrated an improvement of 352% in current density and 36% in selectivity to complete ethanol oxidation under 533 nm laser incidence. Moreover, the current density showed a linear increase with the laser power density, indicating a photochemical effect and thus enhancement due to the LSPR properties.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
A Bangun, O Melnyk, B März, B Diederichs, A Clausen, D Weber, F Filbir, K Müller-Caspary
Inverse Multislice Ptychography by Layer-wise Optimisation and Sparse Matrix Decomposition Journal Article
In: arXiv preprint arXiv:2205.03902, 2022.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Inverse Multislice Ptychography by Layer-wise Optimisation and Sparse Matrix Decomposition},
author = {A Bangun and O Melnyk and B M\"{a}rz and B Diederichs and A Clausen and D Weber and F Filbir and K M\"{u}ller-Caspary},
url = {https://arxiv.org/abs/2205.03902},
doi = {https://doi.org/10.48550/arXiv.2205.03902},
year = {2022},
date = {2022-05-08},
journal = {arXiv preprint arXiv:2205.03902},
abstract = {We propose algorithms based on an optimisation method for inverse multislice ptychography in, e.g. electron microscopy. The multislice method is widely used to model the interaction between relativistic electrons and thick specimens. Since only the intensity of diffraction patterns can be recorded, the challenge in applying inverse multislice ptychography is to uniquely reconstruct the electrostatic potential in each slice up to some ambiguities. In this conceptual study, we show that a unique separation of atomic layers for simulated data is possible when considering a low acceleration voltage. We also introduce an adaptation for estimating the illuminating probe. For the sake of practical application, we finally present slice reconstructions using experimental 4D scanning transmission electron microscopy (STEM) data.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
R Shafei, D Maganas, P J Strobel, P J Schmidt, W Schnick, F Neese
In: Journal of the American Chemical Society, vol. 144, no. 18, pp. 8038-8053, 2022, ISSN: 0002-7863.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Electronic and Optical Properties of Eu2+-Activated Narrow-Band Phosphors for Phosphor-Converted Light-Emitting Diode Applications: Insights from a Theoretical Spectroscopy Perspective},
author = {R Shafei and D Maganas and P J Strobel and P J Schmidt and W Schnick and F Neese},
url = {https://doi.org/10.1021/jacs.2c00218},
doi = {10.1021/jacs.2c00218},
issn = {0002-7863},
year = {2022},
date = {2022-04-26},
journal = {Journal of the American Chemical Society},
volume = {144},
number = {18},
pages = {8038-8053},
abstract = {In this work, we present a computational protocol that is able to predict the experimental absorption and emission spectral shapes of Eu2+-doped phosphors. The protocol is based on time-dependent density functional theory and operates in conjunction with an excited-state dynamics approach. It is demonstrated that across the study set consisting of representative examples of nitride, oxo-nitride, and oxide Eu2+-doped phosphors, the energy distribution and the band shape of the emission spectrum are related to the nature of the 4f\textendash5d transitions that are probed in the absorption process. Since the 4f orbitals are very nearly nonbonding, the decisive quantity is the covalency of the 5d acceptor orbitals that become populated in the electronically excited state that leads to emission. The stronger the (anti) bonding interaction between the lanthanide and the ligands is in the excited state, the larger will be the excited state distortion. Consequently, the corresponding emission will get broader due to the vibronic progression that is induced by the structural distortion. In addition, the energy separation of the absorption bands that are dominated by states with valence 4f\textendash5d and a metal to ligand charge transfer character defines a measure for the thermal quenching of the studied Eu2+-doped phosphors. Based on this analysis, simple descriptors are identified that show a strong correlation with the energy position and bandwidth of the experimental emission bands without the need for elaborate calculations. Overall, we believe that this study serves as an important reference for designing new Eu2+-doped phosphors with desired photoluminescence properties.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
V F Kunzelmann, C-M Jiang, I Ihrke, E Sirotti, T Rieth, A Henning, J Eichhorn, I D Sharp
Solution-based synthesis of wafer-scale epitaxial BiVO4 thin films exhibiting high structural and optoelectronic quality Journal Article
In: Journal of Materials Chemistry A, 2022, ISSN: 2050-7488.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Solution-based synthesis of wafer-scale epitaxial BiVO4 thin films exhibiting high structural and optoelectronic quality},
author = {V F Kunzelmann and C-M Jiang and I Ihrke and E Sirotti and T Rieth and A Henning and J Eichhorn and I D Sharp},
url = {http://dx.doi.org/10.1039/D1TA10732A},
doi = {10.1039/D1TA10732A},
issn = {2050-7488},
year = {2022},
date = {2022-04-22},
journal = {Journal of Materials Chemistry A},
abstract = {We demonstrate a facile approach to solution-based synthesis of wafer-scale epitaxial bismuth vanadate (BiVO4) thin films by spin-coating on yttria-stabilized zirconia. Epitaxial growth proceeds via solid-state transformation of initially formed polycrystalline films, driven by interface energy minimization. The (010)-oriented BiVO4 films are smooth and compact, possessing remarkably high structural quality across complete 2′′ wafers. Optical absorption is characterized by a sharp onset with a low sub-band gap response, confirming that the structural order of the films results in correspondingly high optoelectronic quality. This combination of structural and optoelectronic quality enables measurements that reveal a strong optical anisotropy of BiVO4, which leads to significantly increased in-plane optical constants near the fundamental band edge that are of particular importance for maximizing light harvesting in semiconductor photoanodes. Temperature-dependent transport measurements confirm a thermally activated hopping barrier of ∼570 meV, consistent with small electron polaron conduction. This simple approach for synthesis of high-quality epitaxial BiVO4, without the need for complex deposition equipment, enables a broadly accessible materials base to accelerate research aimed at understanding and optimizing photoelectrochemical energy conversion mechanisms.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
L Katzenmeier, L Carstensen, A S Bandarenka
Li+ Conductivity of Space Charge Layers Formed at Electrified Interfaces Between a Model Solid-State Electrolyte and Blocking Au-Electrodes Journal Article
In: ACS Applied Materials & Interfaces, vol. 14, no. 13, pp. 15811-15817, 2022, ISSN: 1944-8244.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Li+ Conductivity of Space Charge Layers Formed at Electrified Interfaces Between a Model Solid-State Electrolyte and Blocking Au-Electrodes},
author = {L Katzenmeier and L Carstensen and A S Bandarenka},
url = {https://doi.org/10.1021/acsami.2c00650},
doi = {10.1021/acsami.2c00650},
issn = {1944-8244},
year = {2022},
date = {2022-04-06},
journal = {ACS Applied Materials \& Interfaces},
volume = {14},
number = {13},
pages = {15811-15817},
abstract = {The formation of space charge layers in solid-state ion conductors has been investigated as early as the 1980s. With the advent of all-solid-state batteries as an alternative to traditional Li-ion batteries, possibly improving performance and safety, the phenomenon of space charge formation caught the attention of researchers as a possible origin for the observed high interfacial resistance. Following classical space charge theory, such high resistances result from the formation of the depletion layers. These layers of up to hundreds of nanometers in thickness are almost free of mobile cations. With the prediction of a Debye-like screening effect, the thickness of the depletion layer is expected to scale with the square root of the absolute temperature. In this work, we studied the temperature dependence of the depletion layer properties in model solid Ohara LICGC Li+ conducting electrolytes using electrochemical impedance spectroscopy. We show that the activation energy inside the depletion layer increases to ca 0.42 eV compared to ca 0.39 eV in the bulk electrolyte. Moreover, the proportionality between temperature and depletion layer thickness, correlating to the Debye length, is tested and validated.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
M A Reus, L K Reb, A F Weinzierl, C L Weindl, R Guo, T Xiao, M Schwartzkopf, A Chumakov, S V Roth, P Müller-Buschbaum
Time-Resolved Orientation and Phase Analysis of Lead Halide Perovskite Film Annealing Probed by In Situ GIWAXS Journal Article
In: Advanced Optical Materials, vol. n/a, no. n/a, pp. 2102722, 2022, ISSN: 2195-1071.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Time-Resolved Orientation and Phase Analysis of Lead Halide Perovskite Film Annealing Probed by In Situ GIWAXS},
author = {M A Reus and L K Reb and A F Weinzierl and C L Weindl and R Guo and T Xiao and M Schwartzkopf and A Chumakov and S V Roth and P M\"{u}ller-Buschbaum},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202102722},
doi = {https://doi.org/10.1002/adom.202102722},
issn = {2195-1071},
year = {2022},
date = {2022-04-03},
journal = {Advanced Optical Materials},
volume = {n/a},
number = {n/a},
pages = {2102722},
abstract = {Abstract Scalable thin-film deposition methods are increasingly important for hybrid lead halide perovskite thin films. Understanding the structure evolution during non-equilibrium processes helps to find suitable materials and processing parameters to produce films with well-performing optoelectronic properties. Here, spin-cast and slot-die coated bilayers of lead iodide (PbI2) and methylammonium iodide (MAI) are investigated by in situ grazing-incidence wide-angle X-ray scattering during the thermal annealing process, which converts the bilayer into methylammonium lead iodide (MAPI). Photoluminescence (PL) and UV/Vis measurements show increasing crystallinity during the annealing process and a slight PL red-shift of the spin-cast film, attributed to crystallite coalescence that is not prominent for the slot-die coated film. The disintegration of the solvent-precursor complex (MA)2(Pb3I8) ⋅ 2 DMSO and conversion into perovskite are followed in situ and differences in the morphology and time evolution are observed. In both, spin-cast and slot-die coated thin-films, the isotropic orientation is dominant, however, in the slot-die coated films, the perovskite crystallites have an additional face-on orientation ((110) parallel to substrate) that is not detected in spin-cast films. An Avrami model is applied for the perovskite crystal growth that indicates reduced dimensionality of the growth for the printed thin films.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
T De Boer, M F A Fattah, M R Amin, S J Ambach, S Vogel, W Schnick, A Moewes
Band gap and electronic structure of defects in the ternary nitride BP3N6: experiment and theory Journal Article
In: Journal of Materials Chemistry C, vol. 10, pp. 6429-6434, 2022, ISSN: 2050-7526.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Band gap and electronic structure of defects in the ternary nitride BP3N6: experiment and theory},
author = {T De Boer and M F A Fattah and M R Amin and S J Ambach and S Vogel and W Schnick and A Moewes},
url = {https://doi.org/10.1039/D1TC06009K},
doi = {10.1039/D1TC06009K},
issn = {2050-7526},
year = {2022},
date = {2022-03-28},
urldate = {2022-03-28},
journal = {Journal of Materials Chemistry C},
volume = {10},
pages = {6429-6434},
abstract = {Recent advances in methods to access nitride systems by a high-pressure high-temperature approach have made possible the one-step synthesis of mixed ternary non-metal nitrides. As a prerequisite to use in a practical device, it is important to understand important bulk electronic properties, such as the band gap, as well as characterizing the presence and effect of defects that are present. In this work, the novel ternary nitride BP3N6 is studied using techniques sensitive to the partial electronic density of states, specifically X-ray absorption spectroscopy and X-ray emission spectroscopy. Complementary full-potential all-electron density functional theory (DFT) calculations allow important bulk electronic parameters, such as the band gap, to be elucidated. The band gap of BP3N6 has been determined to be 3.9 ± 0.2 eV and 4.1 ± 0.4 eV at the B K- and N K-edges, respectively. This is close to a theoretical value of 4.3 eV predicted by the PBEsol exchange\textendashcorrelation functional and considerably less than a value of 5.8 eV predicted by the modified Becke\textendashJohnson exchange\textendashcorrelation functional. X-Ray excited optical luminescence (XEOL) measurements are performed to interrogate the presence of point defects in this system. Together with DFT calculations, these measurements reveal the presence of nitrogen vacancies which lead to multiple mid-gap trap states.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
D Han, S S Rudel, W Schnick, H Ebert
Self-doping behavior and cation disorder in MgSnN2 Journal Article
In: Physical Review B, vol. 105, no. 12, pp. 125202, 2022.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Self-doping behavior and cation disorder in MgSnN2},
author = {D Han and S S Rudel and W Schnick and H Ebert},
url = {https://link.aps.org/doi/10.1103/PhysRevB.105.125202},
doi = {10.1103/PhysRevB.105.125202},
year = {2022},
date = {2022-03-28},
urldate = {2022-03-28},
journal = {Physical Review B},
volume = {105},
number = {12},
pages = {125202},
abstract = {Investigations on II−Sn−N2(II=Mg, Ca) have been started very recently compared to the intense research of Zn−IV−N2 (IV=Si, Ge, Sn). In this work, we study the phase stability of MgSnN2 and ZnSnN2 in wurtzite and rocksalt phases by first principles calculations. The calculated phase diagram agrees with the experimental observation; i.e., MgSnN2 can form in the wurtzite and rocksalt phases while ZnSnN2 only crystallizes in the wurtzite phase. Due to the higher ionicity of Mg-N bonds compared to Sn-N bonds and Zn-N bonds, wurtzite-type
MgSnN2 appears under Mg-rich conditions. The defect properties and doping behavior of MgSnN2 in the wurtzite phase are further investigated. We find that MgSnN2 exhibits self-doped n-type conductivity, and donor-type antisite defect SnMg is the primary source of free electrons. The high possibility of forming the stoichiometry-preserving MgSn+SnMg defect complex leads to our study of cation disorder in MgSnN2 by using the cluster expansion method with first principles calculations. It is found that cation disorder in MgSnN2 induces a band-gap reduction because of a violation of the octet rule. The local disorder, namely, forming (4,0) or (0,4) tetrahedra, leads to an appreciable band-gap reduction and hinders the enhancement of the optical absorption.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
MgSnN2 appears under Mg-rich conditions. The defect properties and doping behavior of MgSnN2 in the wurtzite phase are further investigated. We find that MgSnN2 exhibits self-doped n-type conductivity, and donor-type antisite defect SnMg is the primary source of free electrons. The high possibility of forming the stoichiometry-preserving MgSn+SnMg defect complex leads to our study of cation disorder in MgSnN2 by using the cluster expansion method with first principles calculations. It is found that cation disorder in MgSnN2 induces a band-gap reduction because of a violation of the octet rule. The local disorder, namely, forming (4,0) or (0,4) tetrahedra, leads to an appreciable band-gap reduction and hinders the enhancement of the optical absorption.
X Song, K Zhang, R Guo, K Sun, Z Zhou, S Huang, L Huber, M Reus, J Zhou, M Schwartzkopf, S V Roth, W Liu, Y Liu, W Zhu, P Müller-Buschbaum
Process-aid solid engineering triggers delicately modulation of Y-series non-fullerene acceptor for efficient organic solar cells Journal Article
In: Advanced Materials, vol. n/a, no. n/a, pp. 2200907, 2022, ISSN: 0935-9648.
Abstract | Links | Tags: Foundry Organic, Solid-Solid
@article{nokey,
title = {Process-aid solid engineering triggers delicately modulation of Y-series non-fullerene acceptor for efficient organic solar cells},
author = {X Song and K Zhang and R Guo and K Sun and Z Zhou and S Huang and L Huber and M Reus and J Zhou and M Schwartzkopf and S V Roth and W Liu and Y Liu and W Zhu and P M\"{u}ller-Buschbaum},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202200907},
doi = {https://doi.org/10.1002/adma.202200907},
issn = {0935-9648},
year = {2022},
date = {2022-03-22},
journal = {Advanced Materials},
volume = {n/a},
number = {n/a},
pages = {2200907},
abstract = {Abstract Volatile solids with symmetric π-backbone have been intensively implemented on manipulating the nanomorphology for improving the operability and stability of organic solar cells. However, due to the isotropic stacking, the announced solids with symmetric geometry cannot modify the microscopic phase separation and component distribution collaboratively, which would constrain the promotion of exciton splitting and charge collection efficiency. Inspired by the superiorities of asymmetric configuration, a novel process-aid solid (PAS) engineering is proposed. By coupling with BTP core unit in Y-series molecule, an asymmetric, volatile 1, 3-dibromo-5-chlorobenzene (DBCl) solid can induce the anisotropic dipole direction, elevated dipole moment, and interlaminar interaction spontaneously. Due to the synergetic effects on the favorable phase separation and desired component distribution, the PAS treated devices feature the evident improvement of exciton splitting, charge transport, and collection, accompanied by the suppressed trap-assisted recombination. Consequently, we achieve an impressive fill factor of 80.2% with maximum power conversion efficiency (PCE) of 18.5% in the PAS treated device. More strikingly, the PAS treated devices demonstrate a promising thickness-tolerance character, where a record PCE of 17.0% is yielded in PAS devices with a 300 nm thickness photoactive layer, which represents the highest PCE for thick-film OSCs. This article is protected by copyright. All rights reserved},
keywords = {Foundry Organic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
E Khorshidi, B Rezaei, D Blätte, A Buyruk, M A Reus, J Hanisch, B Böller, P Müller-Buschbaum, T Ameri
Hydrophobic Graphene Quantum Dots for Defect Passivation and Enhanced Moisture Stability of CH3NH3PbI3 Perovskite Solar Cells Journal Article
In: Solar RRL, vol. n/a, no. n/a, pp. 2200023, 2022, ISSN: 2367-198X.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Hydrophobic Graphene Quantum Dots for Defect Passivation and Enhanced Moisture Stability of CH3NH3PbI3 Perovskite Solar Cells},
author = {E Khorshidi and B Rezaei and D Bl\"{a}tte and A Buyruk and M A Reus and J Hanisch and B B\"{o}ller and P M\"{u}ller-Buschbaum and T Ameri},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/solr.202200023},
doi = {https://doi.org/10.1002/solr.202200023},
issn = {2367-198X},
year = {2022},
date = {2022-03-19},
journal = {Solar RRL},
volume = {n/a},
number = {n/a},
pages = {2200023},
abstract = {Passivating the defects and grain boundaries (GBs) of perovskite films at the interface by interface engineering is a promising route to achieve efficient and stable perovskite solar cells (PSCs). Herein, a new type of graphene, that is, hydrophobic graphene quantum dots (HGQDs) containing amide linkages, which consist of carbonyl and dodecyl amine groups, is successfully used as a bifunctional interface modifier to engineer the interface of the perovskite/hole transport layer. A comprehensive characterization including X-ray photoelectron spectroscopy, Fourier-transform photocurrent spectroscopy, Raman spectroscopy, photoluminescence spectroscopy, and space-charge-limited current measurements is performed to identify the underlying passivation mechanisms. It can be demonstrated that the HGQDs, due to the bifunctional groups containing N and O atoms, effectively passivate the uncoordinated Pb2+ ions at the perovskite film surface and GBs and consequently induce a lower trap state density. Moreover, HGQDs enhance the quality of the perovskite film which reduces the charge recombination at the interface. Therefore, the power conversion efficiency of PSCs treated with HGQDs is significantly increased from 16.00% to 18.30%, mainly based on the improved open-circuit voltage and fill factor. Importantly, the HGQDs featuring hydrophobicity due to alkyl chains significantly enhance moisture stability.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
M F Lichtenegger, J Drewniok, A Bornschlegl, C Lampe, A Singldinger, N A Henke, A S Urban
Electron–Hole Binding Governs Carrier Transport in Halide Perovskite Nanocrystal Thin Films Journal Article
In: ACS Nano, 2022, ISSN: 1936-0851.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Electron\textendashHole Binding Governs Carrier Transport in Halide Perovskite Nanocrystal Thin Films},
author = {M F Lichtenegger and J Drewniok and A Bornschlegl and C Lampe and A Singldinger and N A Henke and A S Urban},
url = {https://doi.org/10.1021/acsnano.2c00369},
doi = {10.1021/acsnano.2c00369},
issn = {1936-0851},
year = {2022},
date = {2022-03-18},
journal = {ACS Nano},
abstract = {Two-dimensional halide perovskite nanoplatelets (NPLs) have exceptional light-emitting properties, including wide spectral tunability, ultrafast radiative decays, high quantum yields (QY), and oriented emission. Due to the high binding energies of electron\textendashhole pairs, excitons are generally considered the dominant species responsible for carrier transfer in NPL films. To realize efficient devices, it is imperative to understand how exciton transport progresses therein. We employ spatially and temporally resolved optical microscopy to map exciton diffusion in perovskite nanocrystal (NC) thin films between 15 °C and 55 °C. At room temperature (RT), we find the diffusion length to be inversely correlated to the thickness of the nanocrystals (NCs). With increasing temperatures, exciton diffusion declines for all NC films, but at different rates. This leads to specific temperature turnover points, at which thinner NPLs exhibit higher diffusion lengths. We attribute this anomalous diffusion behavior to the coexistence of excitons and free electron hole-pairs inside the individual NCs within our temperature range. The organic ligand shell surrounding the NCs prevents charge transfer. Accordingly, any time an electron\textendashhole pair spends in the unbound state reduces the FRET-mediated inter-NC transfer rates and, consequently, the overall diffusion. These results clarify how exciton diffusion progresses in strongly confined halide perovskite NC films, emphasizing critical considerations for optoelectronic devices.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
T M Brenner, M Grumet, P Till, M Asher, W G Zeier, D A Egger, O Yaffe
Anharmonic Lattice Dynamics in Sodium Ion Conductors Journal Article
In: arXiv preprint arXiv:2203.07955, 2022.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Anharmonic Lattice Dynamics in Sodium Ion Conductors},
author = {T M Brenner and M Grumet and P Till and M Asher and W G Zeier and D A Egger and O Yaffe},
url = {https://arxiv.org/abs/2203.07955},
doi = {https://doi.org/10.48550/arXiv.2203.07955},
year = {2022},
date = {2022-03-15},
journal = {arXiv preprint arXiv:2203.07955},
abstract = {We employ THz-range temperature-dependent Raman spectroscopy and first-principles lattice-dynamical calculations to show that the undoped sodium ion conductors Na3PS4 and isostructural Na3PSe4 both exhibit anharmonic lattice dynamics. The anharmonic effects in the compounds involve coupled host lattice -- Na+ ion dynamics that drive the tetragonal-to-cubic phase transition in both cases, but with a qualitative difference in the anharmonic character of the transition. Na3PSe4 shows almost purely displacive character with the soft modes disappearing in the cubic phase as the change of symmetry shifts these modes to the Raman-inactive Brillouin zone boundary. Na3PS4 instead shows order-disorder character in the cubic phase, with the soft modes persisting through the phase transition and remaining active in Raman in the cubic phase, violating Raman selection rules for that phase. Our findings highlight the important role of coupled host lattice -- mobile ion dynamics in vibrational instabilities that are coincident with the exceptional conductivity in these Na+ ion conductors.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
M Golibrzuch, T L Maier, M J Feil, K Krischer, M Becherer
Tuning the feature size of nanoimprinting stamps: A method to enhance the flexibility of nanoimprint lithography Journal Article
In: Journal of Applied Physics, vol. 131, no. 12, pp. 124301, 2022.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Tuning the feature size of nanoimprinting stamps: A method to enhance the flexibility of nanoimprint lithography},
author = {M Golibrzuch and T L Maier and M J Feil and K Krischer and M Becherer},
url = {https://aip.scitation.org/doi/abs/10.1063/5.0079282},
doi = {10.1063/5.0079282},
year = {2022},
date = {2022-03-09},
journal = {Journal of Applied Physics},
volume = {131},
number = {12},
pages = {124301},
abstract = {In the field of nanoimprinting lithography, fabricating large-area imprinting stamps is often the most time- and resource-consuming step. Specifically in research, it is often not reasonable to produce a new imprinting stamp for each new experimental configuration. Therefore, the lack of flexibility in feature sizes makes prototyping and tailoring the feature sizes according to their application challenging. To overcome these restrictions, we developed an imprinting stamp reproduction and tuning method which enables the size of the features of existing imprinting stamps to be tuned within nanometer precision. For replication, we first fabricate a chromium nanoisland array on silicon dioxide using the to-be tuned imprinting stamp. Then, the silicon dioxide is anisotropically etched in a reactive ion etching process with chromium as a hard mask. The formed replica of the imprinting stamp is subsequently tuned in an isotropic etching step with hydrofluoric acid. The method enables us to tune the size of the features of our nanoimprinting stamps within nanometer precision without influencing their shape with a yield above 96%. The tuned stamps are then used to fabricate metal nanoisland arrays with the respective tuned sizes. To evaluate the influence of the feature sizes, we exemplarily study the plasmonic resonance of gold nanoisland arrays fabricated using stamps with different feature diameters. Here, we see a good agreement between measured and simulated plasmonic resonance wavelengths of the samples. Hence, with the tuning method, we can tailor specific size-dependent properties of our nanoisland arrays according to individual experiments and applications.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
X Jiang, P Chotard, K Luo, F Eckmann, S Tu, M A Reus, S Yin, J Reitenbach, C L Weindl, M Schwartzkopf, S V Roth, P Müller-Buschbaum
In: Advanced Energy Materials, vol. n/a, no. n/a, pp. 2103977, 2022, ISSN: 1614-6832.
Abstract | Links | Tags: Foundry Organic, Solid-Solid
@article{nokey,
title = {Revealing Donor\textendashAcceptor Interaction on the Printed Active Layer Morphology and the Formation Kinetics for Nonfullerene Organic Solar Cells at Ambient Conditions},
author = {X Jiang and P Chotard and K Luo and F Eckmann and S Tu and M A Reus and S Yin and J Reitenbach and C L Weindl and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202103977},
doi = {https://doi.org/10.1002/aenm.202103977},
issn = {1614-6832},
year = {2022},
date = {2022-02-27},
journal = {Advanced Energy Materials},
volume = {n/a},
number = {n/a},
pages = {2103977},
abstract = {Abstract Slot-die coating is a powerful method for upscaling the production of organic solar cells (OSCs) with low energy consumption print processes at ambient conditions. Herein, chlorobenzene (CB) and chloroform (CF) are compared as host solvents for printing films of the neat novel fused-ring unit based wide-bandgap donor polymer (PDTBT2T-FTBDT), the small molecule nonfullerene acceptor based on a fused ring with a benzothiadiazole core (BTP-4F) as well as the respective PDTBT2T-FTBDT:BTP-4F blend films at room temperature in air. Using CF printing of the PDTBT2T-FTBDT:BTP-4F active layer, OSCs with a high power conversion efficiency of up to 13.2% are reached in ambient conditions. In comparison to CB printed blend films, the active layer printed out of CF has a superior morphology, a smoother film surface and a more pronounced face-on orientation of the crystallites, which altogether result in an enhanced exciton dissociation, a superior charge transport, and suppressed nonradiative charge carrier recombination. Based on in situ studies of the slot-die coating process of PDTBT2T-FTBDT, BTP-4F, and PDTBT2T-FTBDT:BTP-4F films, the details of the film formation kinetics are clarified, which cause the superior behavior for CF compared to CB printing due to balancing the aggregation and crystallization of donor and acceptor.},
keywords = {Foundry Organic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
B M Stühmeier, R J Schuster, L Hartmann, S Selve, H A El-Sayed, H A Gasteiger
In: Journal of The Electrochemical Society, 2022, ISSN: 1945-7111.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Modification of the Electrochemical Surface Oxide Formation and the Hydrogen Oxidation Activity of Ruthenium by Strong Metal Support Interactions},
author = {B M St\"{u}hmeier and R J Schuster and L Hartmann and S Selve and H A El-Sayed and H A Gasteiger },
url = {http://iopscience.iop.org/article/10.1149/1945-7111/ac58c9},
doi = {https://doi.org/10.1149/1945-7111/ac58c9},
issn = {1945-7111},
year = {2022},
date = {2022-02-25},
urldate = {2022-02-25},
journal = {Journal of The Electrochemical Society},
abstract = {A major hurdle for the wide spread commercialization of proton exchange membrane based fuel cells (PEMFCs) and water electrolyzers are the durability and high cost of noble metal catalysts. Here, alternative support materials might offer advantages, as they can alter the properties of a catalyst by means of a strong metal support interaction (SMSI) that has been shown to prevent platinum oxidation and suppress the oxygen reduction reaction on titanium oxide supported platinum nanoparticles deposited on a carbon support (Pt/TiOx/C). Herein, we report a novel Ru/TiOx/C catalyst that according to tomographic transmission electron microscopy analysis consists of partially encapsulated Ru particles in a Ru/TiOx-composite matrix supported on a carbon support. It is shown by cyclic voltammetry and X-ray photoelectron spectroscopy that ruthenium oxidation is mitigated by an SMSI between Ru and TiOx after reductive heat-treatment (Ru/TiOx/C400°C,H2 ). As a result, the catalyst is capable of oxidizing hydrogen up to the onset of oxygen evolution reaction, in stark contrast to a Ru/C reference catalyst. PEMFC-based hydrogen pump measurements confirmed the stabilization of the hydrogen oxidation reaction (HOR) activity on Ru/TiOx/C400°C,H2 and showed a ≈3 fold higher HOR activity compared to Ru/C, albeit roughly two orders of magnitude less active than Pt/C.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
L Eisenburger, V Weippert, C Paulmann, D Johrendt, O Oeckler, W Schnick
Discovery of Two Polymorphs of TiP4N8 Synthesized from Binary Nitrides Journal Article
In: Angewandte Chemie International Edition, vol. 61, iss. 19, pp. e202202014, 2022, ISSN: 1433-7851.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Discovery of Two Polymorphs of TiP4N8 Synthesized from Binary Nitrides},
author = {L Eisenburger and V Weippert and C Paulmann and D Johrendt and O Oeckler and W Schnick},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202202014},
doi = {https://doi.org/10.1002/anie.202202014},
issn = {1433-7851},
year = {2022},
date = {2022-02-18},
urldate = {2022-02-18},
journal = {Angewandte Chemie International Edition},
volume = {61},
issue = {19},
pages = {e202202014},
abstract = {Abstract TiP4N8 was obtained from the binary nitrides TiN and P3N5 upon addition of NH4F as a mineralizer at 8 GPa and 1400 °C. An intricate interplay of disorder and polymorphism was elucidated by in situ temperature-dependent single-crystal X-ray diffraction, STEM-HAADF, and the investigation of annealed samples. This revealed two polymorphs, which consist of dense networks of PN4 tetrahedra (degree of condensation κ=0.5) and either augmented triangular TiN7 prisms or triangular TiN6 prisms for α- and β-TiP4N8, respectively. The structures of TiP4N8 exhibit body-centered tetragonal (bct) framework topology. DFT calculations confirm the measured band gaps of α- and β-TiP4N8 (1.6\textendash1.8 eV) and predict the thermochemistry of the polymorphs in agreement with the experiments.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
Y Zhou, Y Liang, J Fu, K Liu, Q Chen, X Wang, H Li, L Zhu, J Hu, H Pan, M Miyauchi, L Jiang, E Cortés, M Liu
Vertical Cu Nanoneedle Arrays Enhance the Local Electric Field Promoting C2 Hydrocarbons in the CO2 Electroreduction Journal Article
In: Nano Letters, 2022, ISSN: 1530-6984.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Vertical Cu Nanoneedle Arrays Enhance the Local Electric Field Promoting C2 Hydrocarbons in the CO2 Electroreduction},
author = {Y Zhou and Y Liang and J Fu and K Liu and Q Chen and X Wang and H Li and L Zhu and J Hu and H Pan and M Miyauchi and L Jiang and E Cort\'{e}s and M Liu},
url = {https://doi.org/10.1021/acs.nanolett.1c04653},
doi = {10.1021/acs.nanolett.1c04653},
issn = {1530-6984},
year = {2022},
date = {2022-02-15},
journal = {Nano Letters},
abstract = {Electrocatalytic reduction of CO2 to multicarbon products is a potential strategy to solve the energy crisis while achieving carbon neutrality. To improve the efficiency of multicarbon products in Cu-based catalysts, optimizing the *CO adsorption and reducing the energy barrier for carbon\textendashcarbon (C\textendashC) coupling are essential features. In this work, a strong local electric field is obtained by regulating the arrangement of Cu nanoneedle arrays (CuNNAs). CO2 reduction performance tests indicate that an ordered nanoneedle array reaches a 59% Faraday efficiency for multicarbon products (FEC2) at −1.2 V (vs RHE), compared to a FEC2 of 20% for a disordered nanoneedle array (CuNNs). As such, the very high and local electric fields achieved by an ordered Cu nanoneedle array leads to the accumulation of K+ ions, which benefit both *CO adsorption and C\textendashC coupling. Our results contribute to the design of highly efficient catalysts for multicarbon products.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
S Michaelis De Vasconcellos, D Wigger, U Wurstbauer, A W Holleitner, R Bratschitsch, T Kuhn
Single-photon emitters in layered van der Waals materials Journal Article
In: physica status solidi (b), vol. n/a, no. n/a, 2022, ISSN: 0370-1972.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Single-photon emitters in layered van der Waals materials},
author = {S Michaelis De Vasconcellos and D Wigger and U Wurstbauer and A W Holleitner and R Bratschitsch and T Kuhn},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/pssb.202100566},
doi = {https://doi.org/10.1002/pssb.202100566},
issn = {0370-1972},
year = {2022},
date = {2022-01-28},
journal = {physica status solidi (b)},
volume = {n/a},
number = {n/a},
abstract = {Single-photon emitters have recently been discovered in various atomically thin materials. Their properties, controllability, and the possibility of their monolithic integration in electronic and photonic device structures makes them attractive candidates for a wide range of applications in quantum information and communication, and also in other fields of physics and technology. In this review article an overview of single-photon emitters in layered van der Waals materials and their physical properties is given, theoretical concepts for the modeling of their level structure and their coupling to phonons are presented, and techniques for the creation and localization of these emitters in the host material are described. Perspectives for their application in various fields, such as their coupling to photonic resonators and waveguides, their control by external electric fields or strain, and their integration in optomechanical devices are discussed. Finally, functionalities relying on properties beyond single-photon emission are briefly addressed. This article is protected by copyright. All rights reserved.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
K S Liu, A Henning, M W Heindl, R D Allert, J D Bartl, I D Sharp, R Rizzato, D B Bucher
Surface NMR using quantum sensors in diamond Journal Article
In: Proceedings of the National Academy of Sciences, vol. 119, no. 5, pp. e2111607119, 2022.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Surface NMR using quantum sensors in diamond},
author = {K S Liu and A Henning and M W Heindl and R D Allert and J D Bartl and I D Sharp and R Rizzato and D B Bucher},
url = {https://www.pnas.org/doi/abs/10.1073/pnas.2111607119 %X Many of the functions and applications of materials in catalysis, energy conversion, drug delivery, bioanalysis, and electronics are based on their interfacial properties and structures. The characterization of their molecular properties under ambient or chemically reactive conditions is a fundamental scientific challenge. Here, we develop a surface-sensitive magnetic resonance technique that combines the nanoscale-sensing capabilities of defects in diamond with a high precision and versatile protocol for diamond surface modification. We demonstrate the functionality of this method for probing the molecular properties and kinetics at surfaces and interfaces under ambient conditions. NMR is a noninvasive, molecular-level spectroscopic technique widely used for chemical characterization. However, it lacks the sensitivity to probe the small number of spins at surfaces and interfaces. Here, we use nitrogen vacancy (NV) centers in diamond as quantum sensors to optically detect NMR signals from chemically modified thin films. To demonstrate the method’s capabilities, aluminum oxide layers, common supports in catalysis and materials science, are prepared by atomic layer deposition and are subsequently functionalized by phosphonate chemistry to form self-assembled monolayers. The surface NV-NMR technique detects spatially resolved NMR signals from the monolayer, indicates chemical binding, and quantifies molecular coverage. In addition, it can monitor in real time the formation kinetics at the solid\textendashliquid interface. With our approach, we show that NV quantum sensors are a surface-sensitive NMR tool with femtomole sensitivity for in situ analysis in catalysis, materials, and biological research.},
doi = {doi:10.1073/pnas.2111607119},
year = {2022},
date = {2022-01-26},
journal = {Proceedings of the National Academy of Sciences},
volume = {119},
number = {5},
pages = {e2111607119},
abstract = {NMR is a noninvasive, molecular-level spectroscopic technique widely used for chemical characterization. However, it lacks the sensitivity to probe the small number of spins at surfaces and interfaces. Here, we use nitrogen vacancy (NV) centers in diamond as quantum sensors to optically detect NMR signals from chemically modified thin films. To demonstrate the method’s capabilities, aluminum oxide layers, common supports in catalysis and materials science, are prepared by atomic layer deposition and are subsequently functionalized by phosphonate chemistry to form self-assembled monolayers. The surface NV-NMR technique detects spatially resolved NMR signals from the monolayer, indicates chemical binding, and quantifies molecular coverage. In addition, it can monitor in real time the formation kinetics at the solid\textendashliquid interface. With our approach, we show that NV quantum sensors are a surface-sensitive NMR tool with femtomole sensitivity for in situ analysis in catalysis, materials, and biological research.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
W Ran, A Walz, K Stoiber, P Knecht, H Xu, A C Papageorgiou, A Huettig, D Cortizo-Lacalle, J P Mora-Fuentes, A Mateo-Alonso, H Schlichting, J Reichert, J V Barth
In: Angewandte Chemie International Edition, vol. n/a, no. n/a, 2022, ISSN: 1433-7851.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Depositing Molecular Graphene Nanoribbons on Ag(111) by Electrospray - Controlled Ion Beam Deposition: Self-assembly and On-Surface Transformations},
author = {W Ran and A Walz and K Stoiber and P Knecht and H Xu and A C Papageorgiou and A Huettig and D Cortizo-Lacalle and J P Mora-Fuentes and A Mateo-Alonso and H Schlichting and J Reichert and J V Barth},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202111816},
doi = {https://doi.org/10.1002/anie.202111816},
issn = {1433-7851},
year = {2022},
date = {2022-01-25},
journal = {Angewandte Chemie International Edition},
volume = {n/a},
number = {n/a},
abstract = {The chemical processing of low dimensional carbon nanostructures is crucial for their integration in future devices. Here we apply a new methodology in atomically precise engineering by combining multistep solution synthesis of N-doped molecular graphene nanoribbons (GNRs) with mass-selected ultra-high vacuum electrospray - controlled ion beam deposition on surfaces and real space visualisation by scanning tunnelling microscopy. We demonstrate how this method yields solely a controllable amount of single, otherwise unsublimable, GNRs of 2.9 nm length on a planar Ag(111) surface. This methodology allows for further processing by employing on-surface synthesis protocols and exploiting the reactivity of the substrate. Following multiple chemical transformations, the GNRs provide reactive building blocks to form extended, metal-organic coordination polymers.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}