T Grünleitner, A Henning, M Bissolo, A Kleibert, C F Vaz, A V Stier, J J Finley, I D Sharp
Electronically Tunable Transparent Conductive Thin Films for Scalable Integration of 2D Materials with Passive 2D–3D Interfaces Journal Article
In: Advanced Functional Materials, vol. n/a, no. n/a, pp. 2111343, 2022, ISSN: 1616-301X.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Electronically Tunable Transparent Conductive Thin Films for Scalable Integration of 2D Materials with Passive 2D\textendash3D Interfaces},
author = {T Gr\"{u}nleitner and A Henning and M Bissolo and A Kleibert and C F Vaz and A V Stier and J J Finley and I D Sharp},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202111343},
doi = {https://doi.org/10.1002/adfm.202111343},
issn = {1616-301X},
year = {2022},
date = {2022-01-22},
journal = {Advanced Functional Materials},
volume = {n/a},
number = {n/a},
pages = {2111343},
abstract = {Abstract A novel transparent conductive support structure for scalable integration of 2D materials is demonstrated, providing an electronically passive 2D\textendash3D interface while also enabling facile interfacial charge transport. This structure, which comprises an evaporated nanocrystalline carbon (nc-C) film beneath nanometer-thin atomic layer deposited AlOx, is thermally stable and allows direct chemical vapor deposition of 2D materials onto the surface. The combination of spatial uniformity, enhanced charge screening, and low interface defect concentrations yields a tenfold enhancement of MoS2 photoluminescence intensity compared to flakes on conventional Si/SiO2, while also retaining the strong optical contrast for monolayer flakes. Tunneling across the ultrathin AlOx enables facile interfacial charge injection, which is utilized for high-resolution scanning electron microscopy and photoemission electron microscopy with no detectable charging. Thus, this combination of scalable fabrication and electronic conductivity across a weakly interacting 2D\textendash3D interface opens up new opportunities for device integration and characterization of 2D materials.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
L Sigl, M Troue, M Katzer, M Selig, F Sigger, J Kiemle, M Brotons-Gisbert, K Watanabe, T Taniguchi, B D Gerardot, A Knorr, U Wurstbauer, A W Holleitner
Optical dipole orientation of interlayer excitons in MoSe2-WSe2 heterostacks Journal Article
In: Physical Review B, vol. 105, no. 3, pp. 035417, 2022.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Optical dipole orientation of interlayer excitons in MoSe2-WSe2 heterostacks},
author = {L Sigl and M Troue and M Katzer and M Selig and F Sigger and J Kiemle and M Brotons-Gisbert and K Watanabe and T Taniguchi and B D Gerardot and A Knorr and U Wurstbauer and A W Holleitner},
url = {https://link.aps.org/doi/10.1103/PhysRevB.105.035417},
doi = {10.1103/PhysRevB.105.035417},
year = {2022},
date = {2022-01-14},
urldate = {2022-01-14},
journal = {Physical Review B},
volume = {105},
number = {3},
pages = {035417},
abstract = {We report on the far-field photoluminescence intensity distribution of interlayer excitons in
MoSe2WSe2 heterostacks as measured by back focal plane imaging in the temperature range between 1.7 and 20 K. By comparing the data with an analytical model describing the dipolar emission pattern in a dielectric environment, we are able to obtain the relative contributions of the in- and out-of-plane transition dipole moments associated to the interlayer exciton photon emission. We determine the transition dipole moments for all observed interlayer exciton transitions to be (99±1)% in plane for R- and H-type stacking, independent of the excitation power and therefore the density of the exciton ensemble in the experimentally examined range. Finally, we discuss the limitations of the presented measurement technique to observe correlation effects in exciton ensembles.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
MoSe2WSe2 heterostacks as measured by back focal plane imaging in the temperature range between 1.7 and 20 K. By comparing the data with an analytical model describing the dipolar emission pattern in a dielectric environment, we are able to obtain the relative contributions of the in- and out-of-plane transition dipole moments associated to the interlayer exciton photon emission. We determine the transition dipole moments for all observed interlayer exciton transitions to be (99±1)% in plane for R- and H-type stacking, independent of the excitation power and therefore the density of the exciton ensemble in the experimentally examined range. Finally, we discuss the limitations of the presented measurement technique to observe correlation effects in exciton ensembles.
M Kuhl, A Henning, L Haller, L Wagner, C-M Jiang, V Streibel, I D Sharp, J Eichhorn
Designing multifunctional CoOx layers for efficient and stable electrochemical energy conversion Journal Article
In: Cambridge: Cambridge Open Engage, 2022.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Designing multifunctional CoOx layers for efficient and stable electrochemical energy conversion},
author = {M Kuhl and A Henning and L Haller and L Wagner and C-M Jiang and V Streibel and I D Sharp and J Eichhorn},
doi = {10.26434/chemrxiv-2022-23ck4},
year = {2022},
date = {2022-01-13},
urldate = {2022-01-13},
journal = {Cambridge: Cambridge Open Engage},
abstract = {Disordered and porous metal oxides are promising as earth-abundant and cost-effective alternatives to noble-metal electrocatalysts. Herein, we leverage non-saturated oxidation in plasma-enhanced atomic layer deposition to tune structural, mechanical, and optical properties of biphasic CoOx thin films, thereby tailoring their catalytic activities and chemical stabilities. To optimize the resulting film properties, we systematically vary the oxygen plasma power and exposure time in the deposition process. We find that short exposure times and low plasma powers incompletely oxidize the cobaltocene precursor to Co(OH)2 and result in the incorporation of carbon impurities. These Co(OH)2 films are highly porous and catalytically active, but their electrochemical stability is impacted by poor adhesion to the substrate. In contrast, long exposure times and high plasma powers completely oxidize the precursor to form Co3O4, reduce the carbon impurity incorporation, and improve the film crystallinity. While the resulting Co3O4 films are highly stable under electrochemical conditions, they are characterized by low oxygen evolution reaction activities. To overcome these competing properties, we applied the established relation between deposition parameters and functional film properties to design bilayer films exhibiting simultaneously improved electrochemical performance and chemical stability. The resulting biphasic films combine a highly active Co(OH)2 surface with a stable Co3O4 interface layer. In addition, these coatings exhibit minimal light absorption, thus rendering them well suited as protective catalytic layers on semiconductor light absorbers for application in photoelectrochemical devices.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
N Levin, J T Margraf, J Lengyel, K Reuter, M Tschurl, U Heiz
CO2-Activation by size-selected tantalum cluster cations (Ta1–16+): thermalization governing reaction selectivity Journal Article
In: Physical Chemistry Chemical Physics, vol. 24, no. 4, pp. 2623-2629, 2022, ISSN: 1463-9076.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {CO2-Activation by size-selected tantalum cluster cations (Ta1\textendash16+): thermalization governing reaction selectivity},
author = {N Levin and J T Margraf and J Lengyel and K Reuter and M Tschurl and U Heiz},
url = {http://dx.doi.org/10.1039/D1CP04469A},
doi = {10.1039/D1CP04469A},
issn = {1463-9076},
year = {2022},
date = {2022-01-06},
urldate = {2022-01-06},
journal = {Physical Chemistry Chemical Physics},
volume = {24},
number = {4},
pages = {2623-2629},
abstract = {The reactions of tantalum cluster cations of different sizes toward carbon dioxide are studied in an ion trap under multi-collisional conditions. For all sizes studied, consecutive reactions with several CO2 molecules are observed. This reveals two different pathways, namely oxide formation and the pickup of an entire molecule. Supported by calculations of the thermochemistry of TanO+ formation upon reaction with CO2, changes in the branching ratios at a particular cluster size are related to heat effects due to the vibrational heat capacity of the clusters and the exothermicity of the reaction.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
Y Zou, S Yuan, A Buyruk, J Eichhorn, S Yin, M A Reus, T Xiao, S Pratap, S Liang, C L Weindl, W Chen, C Mu, I D Sharp, T Ameri, M Schwartzkopf, S V Roth, P Müller-Buschbaum
The Influence of CsBr on Crystal Orientation and Optoelectronic Properties of MAPbI3-Based Solar Cells Journal Article
In: ACS Applied Materials & Interfaces, vol. 14, pp. 2958, 2022, ISSN: 1944-8244.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {The Influence of CsBr on Crystal Orientation and Optoelectronic Properties of MAPbI3-Based Solar Cells},
author = {Y Zou and S Yuan and A Buyruk and J Eichhorn and S Yin and M A Reus and T Xiao and S Pratap and S Liang and C L Weindl and W Chen and C Mu and I D Sharp and T Ameri and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},
url = {https://doi.org/10.1021/acsami.1c22184},
doi = {10.1021/acsami.1c22184},
issn = {1944-8244},
year = {2022},
date = {2022-01-06},
urldate = {2022-01-06},
journal = {ACS Applied Materials \& Interfaces},
volume = {14},
pages = {2958},
abstract = {Crystal orientations are closely related to the behavior of photogenerated charge carriers and are vital for controlling the optoelectronic properties of perovskite solar cells. Herein, we propose a facile approach to reveal the effect of lattice plane orientation distribution on the charge carrier kinetics via constructing CsBr-doped mixed cation perovskite phases. With grazing-incidence wide-angle X-ray scattering measurements, we investigate the crystallographic properties of mixed perovskite films at the microscopic scale and reveal the effect of the extrinsic CsBr doping on the stacking behavior of the lattice planes. Combined with transient photocurrent, transient photovoltage, and space-charge-limited current measurements, the transport dynamics and recombination of the photogenerated charge carriers are characterized. It is demonstrated that CsBr compositional engineering can significantly affect the perovskite crystal structure in terms of the orientation distribution of crystal planes and passivation of trap-state densities, as well as simultaneously facilitate the photogenerated charge carrier transport across the absorber and its interfaces. This strategy provides unique insight into the underlying relationship between the stacking pattern of crystal planes, photogenerated charge carrier transport, and optoelectronic properties of solar cells.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
S Yin, T Tian, C L Weindl, K S Wienhold, Q Ji, Y Cheng, Y Li, C M Papadakis, M Schwartzkopf, S V Roth, P Müller-Buschbaum
In Situ GISAXS Observation and Large Area Homogeneity Study of Slot-Die Printed PS-b-P4VP and PS-b-P4VP/FeCl3 Thin Films Journal Article
In: ACS Applied Materials & Interfaces, 2022, ISSN: 1944-8244.
Abstract | Links | Tags: Foundry Organic, Solid-Solid
@article{nokey,
title = {In Situ GISAXS Observation and Large Area Homogeneity Study of Slot-Die Printed PS-b-P4VP and PS-b-P4VP/FeCl3 Thin Films},
author = {S Yin and T Tian and C L Weindl and K S Wienhold and Q Ji and Y Cheng and Y Li and C M Papadakis and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},
url = {https://doi.org/10.1021/acsami.1c19797},
doi = {10.1021/acsami.1c19797},
issn = {1944-8244},
year = {2022},
date = {2022-01-04},
urldate = {2022-01-04},
journal = {ACS Applied Materials \& Interfaces},
abstract = {Mesoporous hematite (α-Fe2O3) thin films with high surface-to-volume ratios show great potential as photoelectrodes or electrochemical electrodes in energy conversion and storage. In the present work, with the assistance of an up-scalable slot-die coating technique, locally highly ordered α-Fe2O3 thin films are successfully printed based on the amphiphilic diblock copolymer poly(styrene-b-4-vinylpyridine) (PS-b-P4VP) as a structure-directing agent. Pure PS-b-P4VP films are printed under the same conditions for comparison. The micellization of the diblock copolymer in solution, the film formation process of the printed thin films, the homogeneity of the dry films in the lateral and vertical direction as well as the morphological and compositional information on the calcined hybrid PS-b-P4VP/FeCl3 thin film are investigated. Because of convection during the solvent evaporation process, a similar dimple-type structure of vertically aligned cylindrical PS domains in a P4VP matrix developed for both printed PS-b-P4VP and hybrid PS-b-P4VP/FeCl3 thin films. The coordination effect between the Fe3+ ions and the vinylpyridine groups significantly affects the attachment ability of the P4VP chains to the silicon substrate. Accordingly, distinct feature sizes and homogeneity in the lateral direction, as well as the thicknesses in the perpendicular direction, are demonstrated in the two printed films. By removing the polymer template from the hybrid PS-b-P4VP/FeCl3 film at high temperature, a locally highly ordered mesoporous α-Fe2O3 film is obtained. Thus, a facile and up-scalable printing technique is presented for producing homogeneous mesoporous α-Fe2O3 thin films.},
keywords = {Foundry Organic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
M M Petrić, M Kremser, M Barbone, A Nolinder, A Lyamkina, A V Stier, M Kaniber, K Müller, J J Finley
Tuning the Optical Properties of a MoSe2 Monolayer Using Nanoscale Plasmonic Antennas Journal Article
In: Nano Letters, vol. 22, no. 2, pp. 561-569, 2022, ISSN: 1530-6984.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Tuning the Optical Properties of a MoSe2 Monolayer Using Nanoscale Plasmonic Antennas},
author = {M M Petri\'{c} and M Kremser and M Barbone and A Nolinder and A Lyamkina and A V Stier and M Kaniber and K M\"{u}ller and J J Finley},
url = {https://doi.org/10.1021/acs.nanolett.1c02676},
doi = {10.1021/acs.nanolett.1c02676},
issn = {1530-6984},
year = {2022},
date = {2022-01-03},
journal = {Nano Letters},
volume = {22},
number = {2},
pages = {561-569},
abstract = {Nanoplasmonic systems combined with optically active two-dimensional materials provide intriguing opportunities to explore and control light\textendashmatter interactions at extreme subwavelength length scales approaching the exciton Bohr radius. Here, we present room- and cryogenic-temperature investigations of a MoSe2 monolayer on individual gold dipole nanoantennas. By controlling nanoantenna size, the dipolar resonance is tuned relative to the exciton achieving a total tuning of ∼130 meV. Differential reflectance measurements performed on \>100 structures reveal an apparent avoided crossing between exciton and dipolar mode and an exciton\textendashplasmon coupling constant of g = 55 meV, representing g/(ℏωX) ≥ 3% of the transition energy. This places our hybrid system in the intermediate-coupling regime where spectra exhibit a characteristic Fano-like shape. We demonstrate active control by varying the polarization of the excitation light to programmably suppress coupling to the dipole mode. We further study the emerging optical signatures of the monolayer localized at dipole nanoantennas at 10 K.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
T Scholz, C Schneider, M W Terban, Z Deng, R Eger, M Etter, R E Dinnebier, P Canepa, B V Lotsch
Order-Disorder Transition driven Superionic Conduction in the New Plastic Polymorph of Na4P2S6 Journal Article
In: 2021.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Order-Disorder Transition driven Superionic Conduction in the New Plastic Polymorph of Na4P2S6},
author = {T Scholz and C Schneider and M W Terban and Z Deng and R Eger and M Etter and R E Dinnebier and P Canepa and B V Lotsch},
url = {https://chemrxiv.org/engage/chemrxiv/article-details/61b9af53f52bc46cf0c11492},
doi = {10.26434/chemrxiv-2021-7r31q},
year = {2021},
date = {2021-12-21},
abstract = {Sodium thiophophates are promising materials for large-scale energy storage applications benefiting from high ionic conductivities and the-political abundance of the elements. A representative of this class is Na4P2S6, which currently shows two known polymorphs\textendashα and β. This work describes a third polymorph of Na4P2S6, γ, that forms above 580◦C, exhibits fast ion conduction with low activation energy, and is mechanically soft. Based on high-temperature diffraction, pair distribution function analysis, thermal analysis, impedance spectroscopy, and ab initio molecular dynamic calculations, γ-Na4P2S6 is identified to be a plastic crystal, characterized by dynamic orientational disorder of the P2S64\textendash anions on a translationally fixed body centered cubic lattice. The prospect of stabilizing plastic crystals at operating temperatures of solid-state batteries and benefiting from their high ionic conductivities as well as mechanical properties could have a strong impact in the field of solid-state battery chemistry.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
T De Boer, J Häusler, P Strobel, T D Boyko, S S Rudel, W Schnick, A Moewes
Detecting a Hierarchy of Deep-Level Defects in the Model Semiconductor ZnSiN2 Journal Article
In: The Journal of Physical Chemistry C, 2021, ISSN: 1932-7447.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Detecting a Hierarchy of Deep-Level Defects in the Model Semiconductor ZnSiN2},
author = {T De Boer and J H\"{a}usler and P Strobel and T D Boyko and S S Rudel and W Schnick and A Moewes},
url = {https://doi.org/10.1021/acs.jpcc.1c08115},
doi = {10.1021/acs.jpcc.1c08115},
issn = {1932-7447},
year = {2021},
date = {2021-12-15},
journal = {The Journal of Physical Chemistry C},
abstract = {Recent developments in the materials synthesis of the Zn\textendashIV\textendashN2 system, including the alloy-free band gap tuning and synthesis of freestanding single crystals, reveal a system with potentially very broad applications. For that, important basic properties of these materials, such as the electronic band gap and the characteristics of defects, must be well understood, which has therefore become an urgent problem. In this work, X-ray absorption spectroscopy, X-ray emission spectroscopy, and density functional theory are utilized to characterize ZnSiN2. Excellent agreement between theory and experiment is obtained, with the band gap of ZnSiN2 determined to be 4.7 ± 0.3 eV. X-ray-excited optical luminescence spectroscopy is used to determine the presence of two deep-level defects, which are identified as due to the presence of nitrogen vacancies.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
N Cao, A Riss, E Corral-Rascon, A Meindl, W Auwärter, M O Senge, M Ebrahimi, J V Barth
Surface-confined formation of conjugated porphyrin-based nanostructures on Ag(111) Journal Article
In: Nanoscale, vol. 13, no. 47, pp. 19884-19889, 2021, ISSN: 2040-3364.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Surface-confined formation of conjugated porphyrin-based nanostructures on Ag(111)},
author = {N Cao and A Riss and E Corral-Rascon and A Meindl and W Auw\"{a}rter and M O Senge and M Ebrahimi and J V Barth},
url = {http://dx.doi.org/10.1039/D1NR06451G},
doi = {10.1039/D1NR06451G},
issn = {2040-3364},
year = {2021},
date = {2021-11-25},
journal = {Nanoscale},
volume = {13},
number = {47},
pages = {19884-19889},
abstract = {Porphyrin-based oligomers were synthesized from the condensation of adsorbed 4-benzaldehyde-substituted porphyrins through the formation of CC linkages, following a McMurry-type coupling scheme. Scanning tunneling microscopy, non-contact atomic force microscopy, and X-ray photoelectron spectroscopy data evidence both the dissociation of aldehyde groups and the formation of CC linkages. Our approach provides a path for the on-surface synthesis of porphyrin-based oligomers coupled by CC bridges \textendash as a means to create functional conjugated nanostructures.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
C G Staacke, H H Heenen, C Scheurer, G Csányi, K Reuter, J T Margraf
On the Role of Long-Range Electrostatics in Machine-Learned Interatomic Potentials for Complex Battery Materials Journal Article
In: ACS Applied Energy Materials, vol. 4, no. 11, pp. 12562-12569, 2021.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {On the Role of Long-Range Electrostatics in Machine-Learned Interatomic Potentials for Complex Battery Materials},
author = {C G Staacke and H H Heenen and C Scheurer and G Cs\'{a}nyi and K Reuter and J T Margraf},
url = {https://doi.org/10.1021/acsaem.1c02363},
doi = {10.1021/acsaem.1c02363},
year = {2021},
date = {2021-11-22},
journal = {ACS Applied Energy Materials},
volume = {4},
number = {11},
pages = {12562-12569},
abstract = {Modeling complex energy materials such as solid-state electrolytes (SSEs) realistically at the atomistic level strains the capabilities of state-of-the-art theoretical approaches. On one hand, the system sizes and simulation time scales required are prohibitive for first-principles methods such as the density functional theory. On the other hand, parameterizations for empirical potentials are often not available, and these potentials may ultimately lack the desired predictive accuracy. Fortunately, modern machine learning (ML) potentials are increasingly able to bridge this gap, promising first-principles accuracy at a much reduced computational cost. However, the local nature of these ML potentials typically means that long-range contributions arising, for example, from electrostatic interactions are neglected. Clearly, such interactions can be large in polar materials such as electrolytes, however. Herein, we investigate the effect that the locality assumption of ML potentials has on lithium mobility and defect formation energies in the SSE Li7P3S11. We find that neglecting long-range electrostatics is unproblematic for the description of lithium transport in the isotropic bulk. In contrast, (field-dependent) defect formation energies are only adequately captured by a hybrid potential combining ML and a physical model of electrostatic interactions. Broader implications for ML-based modeling of energy materials are discussed.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
J D Bartl, C Thomas, A Henning, M F Ober, G Savasci, B Yazdanshenas, P S Deimel, E Magnano, F Bondino, P Zeller, L Gregoratti, M Amati, C Paulus, F Allegretti, A Cattani-Scholz, J V Barth, C Ochsenfeld, B Nickel, I D Sharp, M Stutzmann, B Rieger
Modular Assembly of Vibrationally and Electronically Coupled Rhenium Bipyridine Carbonyl Complexes on Silicon Journal Article
In: Journal of the American Chemical Society, vol. 143, pp. 19505, 2021, ISSN: 0002-7863.
Abstract | Links | Tags: Foundry Inorganic, Foundry Organic, Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Modular Assembly of Vibrationally and Electronically Coupled Rhenium Bipyridine Carbonyl Complexes on Silicon},
author = {J D Bartl and C Thomas and A Henning and M F Ober and G Savasci and B Yazdanshenas and P S Deimel and E Magnano and F Bondino and P Zeller and L Gregoratti and M Amati and C Paulus and F Allegretti and A Cattani-Scholz and J V Barth and C Ochsenfeld and B Nickel and I D Sharp and M Stutzmann and B Rieger},
url = {https://doi.org/10.1021/jacs.1c09061},
doi = {10.1021/jacs.1c09061},
issn = {0002-7863},
year = {2021},
date = {2021-11-12},
urldate = {2021-11-12},
journal = {Journal of the American Chemical Society},
volume = {143},
pages = {19505},
abstract = {Hybrid inorganic/organic heterointerfaces are promising systems for next-generation photocatalytic, photovoltaic, and chemical-sensing applications. Their performance relies strongly on the development of robust and reliable surface passivation and functionalization protocols with (sub)molecular control. The structure, stability, and chemistry of the semiconductor surface determine the functionality of the hybrid assembly. Generally, these modification schemes have to be laboriously developed to satisfy the specific chemical demands of the semiconductor surface. The implementation of a chemically independent, yet highly selective, standardized surface functionalization scheme, compatible with nanoelectronic device fabrication, is of utmost technological relevance. Here, we introduce a modular surface assembly (MSA) approach that allows the covalent anchoring of molecular transition-metal complexes with sub-nanometer precision on any solid material by combining atomic layer deposition (ALD) and selectively self-assembled monolayers of phosphonic acids. ALD, as an essential tool in semiconductor device fabrication, is used to grow conformal aluminum oxide activation coatings, down to sub-nanometer thicknesses, on silicon surfaces to enable a selective step-by-step layer assembly of rhenium(I) bipyridine tricarbonyl molecular complexes. The modular surface assembly of molecular complexes generates precisely structured spatial ensembles with strong intermolecular vibrational and electronic coupling, as demonstrated by infrared spectroscopy, photoluminescence, and X-ray photoelectron spectroscopy analysis. The structure of the MSA can be chosen to avoid electronic interactions with the semiconductor substrate to exclusively investigate the electronic interactions between the surface-immobilized molecular complexes.},
keywords = {Foundry Inorganic, Foundry Organic, Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
L Sigl, M Troue, M Katzer, M Selig, F Sigger, J Kiemle, M Brotons-Gisbert, K Watanabe, T Taniguchi, B D Gerardot
Optical dipole orientation of interlayer excitons in MoSe2-WSe2 heterostacks Journal Article
In: Cond-Mat. Mes-Hall, 2021.
Tags: Solid-Solid
@article{nokey,
title = {Optical dipole orientation of interlayer excitons in MoSe2-WSe2 heterostacks},
author = {L Sigl and M Troue and M Katzer and M Selig and F Sigger and J Kiemle and M Brotons-Gisbert and K Watanabe and T Taniguchi and B D Gerardot},
year = {2021},
date = {2021-11-02},
journal = {Cond-Mat. Mes-Hall},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
M Salman, C Bick, K Krischer
Bifurcations of Clusters and Collective Oscillations in Networks of Bistable Units Journal Article
In: arXiv preprint arXiv:2110.15004, 2021.
Abstract | Tags: Solid-Solid
@article{nokey,
title = {Bifurcations of Clusters and Collective Oscillations in Networks of Bistable Units},
author = {M Salman and C Bick and K Krischer},
year = {2021},
date = {2021-10-28},
journal = {arXiv preprint arXiv:2110.15004},
abstract = {We investigate dynamics and bifurcations in a mathematical model that captures electrochemical experiments on arrays of microelectrodes. In isolation, each individual microelectrode is described by a one-dimensional unit with a bistable current-potential response. When an array of such electrodes is coupled by controlling the total electric current, the common electric potential of all electrodes oscillates in some interval of the current. These coupling-induced collective oscillations of bistable one-dimensional units are captured by the model. Moreover, any equilibrium is contained in a cluster subspace, where the electrodes take at most three distinct states. We systematically analyze the dynamics and bifurcations of the model equations: We consider the dynamics on cluster subspaces of successively increasing dimension and analyze the bifurcations occurring therein. Most importantly, the system exhibits an equivariant transcritical bifurcation of limit cycles. From this bifurcation, several limit cycles branch, one of which is stable for arbitrarily many bistable units.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
L Hüttenhofer, M Golibrzuch, O Bienek, F J Wendisch, R Lin, M Becherer, I D Sharp, S A Maier, E Cortés
Metasurface Photoelectrodes for Enhanced Solar Fuel Generation Journal Article
In: Advanced Energy Materials, vol. 11, no. 46, pp. 2102877, 2021, ISSN: 1614-6832.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Metasurface Photoelectrodes for Enhanced Solar Fuel Generation},
author = {L H\"{u}ttenhofer and M Golibrzuch and O Bienek and F J Wendisch and R Lin and M Becherer and I D Sharp and S A Maier and E Cort\'{e}s},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202102877},
doi = {https://doi.org/10.1002/aenm.202102877},
issn = {1614-6832},
year = {2021},
date = {2021-10-27},
journal = {Advanced Energy Materials},
volume = {11},
number = {46},
pages = {2102877},
abstract = {Abstract Tailoring optical properties in photocatalysts by nanostructuring them can help increase solar light harvesting efficiencies in a wide range of materials. Whereas plasmon resonances are widely employed in metallic catalysts for this purpose, latest advances of nonradiative, dielectric nanophotonics also enable light confinement and enhanced visible light absorption in semiconductors. Here, a design procedure for large-scale nanofabrication of semiconductor photoelectrodes using imprint lithography is developed. Anapole excitations and metasurface lattice resonances are combined to enhance the absorption of the model material, amorphous gallium phosphide (a-GaP), over the visible spectrum. It is shown that cost-effective, high sample throughput is achieved while retaining the precise signature of the engineered photonic states. Photoelectrochemical measurements under hydrogen evolution reaction conditions and sunlight illumination reveal the contributions of the respective resonances and demonstrate an overall photocurrent enhancement of 5.7, compared to a planar film. These results are supported by optical and numerical analysis of single nanodisks and of the upscaled metasurface.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
F Haag, P S Deimel, P Knecht, L Niederegger, K Seufert, M G. Cuxart, Y Bao, A C Papageorgiou, M Muntwiler, W Auwärter, C R Hess, J V Barth, F Allegretti
The Flexible On-Surface Self-Assembly of a Low-Symmetry Mabiq Ligand: An Unconventional Metal-Assisted Phase Transformation on Ag(111) Journal Article
In: The Journal of Physical Chemistry C, vol. 125, no. 42, pp. 23178-23191, 2021, ISSN: 1932-7447.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {The Flexible On-Surface Self-Assembly of a Low-Symmetry Mabiq Ligand: An Unconventional Metal-Assisted Phase Transformation on Ag(111)},
author = {F Haag and P S Deimel and P Knecht and L Niederegger and K Seufert and M G. Cuxart and Y Bao and A C Papageorgiou and M Muntwiler and W Auw\"{a}rter and C R Hess and J V Barth and F Allegretti},
url = {https://doi.org/10.1021/acs.jpcc.1c07400},
doi = {10.1021/acs.jpcc.1c07400},
issn = {1932-7447},
year = {2021},
date = {2021-10-12},
journal = {The Journal of Physical Chemistry C},
volume = {125},
number = {42},
pages = {23178-23191},
abstract = {The self-assembly of metal\textendashorganic complexes and networks of increasing complexity on solid surfaces is important for their application in a variety of fields, such as catalysis, sensing, and molecular magnetism. Here, we have selected a low-symmetry, free-base macrocyclic biquinazoline ligand, H-Mabiq, which upon metalation has the potential to incorporate cations in two different coordination sites, affording multi-valency and multi-electron transfer capacity. We show that H-Mabiq molecules readily self-assemble onto the Ag(111) surface at room temperature, forming a well-ordered monolayer of closely packed molecules. Upon increasing the temperature, a new phase with a different long-range order and molecular packing is obtained. By means of scanning tunneling microscopy and photoelectron spectroscopy, we show that this new phase is characterized by a distinctive silver-bridged dimeric motif, entailing a Ag adatom accommodated at the peripheral coordination site of two opposing H-Mabiq molecules. Thus, the present work reveals the ability of the bio-inspired Mabiq ligands to form surface-confined two-dimensional assemblies incorporating metal adatoms. The results bode promise for the use of metal-containing Mabiq compounds to engineer regular bimetallic arrays with atomic precision.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
A Vogel, T Nilges
Ion Dynamics and Polymorphism in Cu20Te11Cl3 Journal Article
In: Inorganic Chemistry, vol. 60, no. 20, pp. 15233-15241, 2021, ISSN: 0020-1669.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Ion Dynamics and Polymorphism in Cu20Te11Cl3},
author = {A Vogel and T Nilges},
url = {https://doi.org/10.1021/acs.inorgchem.1c01764},
doi = {10.1021/acs.inorgchem.1c01764},
issn = {0020-1669},
year = {2021},
date = {2021-10-04},
journal = {Inorganic Chemistry},
volume = {60},
number = {20},
pages = {15233-15241},
abstract = {Coinage metal polychalcogenide halides are an intriguing class of materials, and many representatives are solid ion conductors and thermoelectric materials. The materials show high ion mobility, polymorphism, and various attractive interactions in the cation and anion substructures. Especially the latter feature leads to complex electronic structures and the occurrence of charge-density waves (CDWs) and, as a result, the first p\textendashn\textendashp switching materials. During our systematic investigations for new p\textendashn\textendashn switching materials in the Cu\textendashTe\textendashCl phase diagram, we were able to isolate polymorphic Cu20Te11Cl3, which we characterized structurally and with regard to its electronic and thermoelectric properties. Cu20Te11Cl3 is trimorphic, with phase transitions occurring at 288 and 450 K. The crystal structures of two polymorphs, the α phase, stable above 450 K, and the β polymorph (288\textendash450 K), are reported, and the complex structure chemistry featuring twinning upon a phase change is illustrated. We identified a dynamic cation substructure and a static anion substructure for all polymorphs, characterizing Cu20Te11Cl3 as a solid Cu-ion conductor. Temperature-dependent measurements of the Seebeck coefficient and total conductivity were performed and substantiated a linear response of the Seebeck coefficient, a lack of CDWs, and no p\textendashn\textendashp switching. Reasons for a lack of CDWs in Cu20Te11Cl3 are discussed and illustrated in the context of existing p\textendashn\textendashp switching materials.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
R Guo, D Han, W Chen, L Dai, K Ji, Q Xiong, S Li, L K Reb, M A Scheel, S Pratap, N Li, S Yin, T Xiao, S Liang, A L Oechsle, C L Weindl, M Schwartzkopf, H Ebert, P Gao, K Wang, M Yuan, N C Greenham, S D Stranks, S V Roth, R H Friend, P Müller-Buschbaum
Degradation mechanisms of perovskite solar cells under vacuum and one atmosphere of nitrogen Journal Article
In: Nature Energy, vol. 6, no. 10, pp. 977-986, 2021, ISSN: 2058-7546.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Degradation mechanisms of perovskite solar cells under vacuum and one atmosphere of nitrogen},
author = {R Guo and D Han and W Chen and L Dai and K Ji and Q Xiong and S Li and L K Reb and M A Scheel and S Pratap and N Li and S Yin and T Xiao and S Liang and A L Oechsle and C L Weindl and M Schwartzkopf and H Ebert and P Gao and K Wang and M Yuan and N C Greenham and S D Stranks and S V Roth and R H Friend and P M\"{u}ller-Buschbaum},
url = {https://doi.org/10.1038/s41560-021-00912-8},
doi = {10.1038/s41560-021-00912-8},
issn = {2058-7546},
year = {2021},
date = {2021-10-01},
urldate = {2021-10-01},
journal = {Nature Energy},
volume = {6},
number = {10},
pages = {977-986},
abstract = {Extensive studies have focused on improving the operational stability of perovskite solar cells, but few have surveyed the fundamental degradation mechanisms. One aspect overlooked in earlier works is the effect of the atmosphere on device performance during operation. Here we investigate the degradation mechanisms of perovskite solar cells operated under vacuum and under a nitrogen atmosphere using synchrotron radiation-based operando grazing-incidence X-ray scattering methods. Unlike the observations described in previous reports, we find that light-induced phase segregation, lattice shrinkage and morphology deformation occur under vacuum. Under nitrogen, only lattice shrinkage appears during the operation of solar cells, resulting in better device stability. The different behaviour under nitrogen is attributed to a larger energy barrier for lattice distortion and phase segregation. Finally, we find that the migration of excessive PbI2 to the interface between the perovskite and the hole transport layer degrades the performance of devices under vacuum or under nitrogen.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
O E Dagdeviren, D Glass, R Sapienza, E Cortés, S A Maier, I P Parkin, P Grütter, R Quesada-Cabrera
The Effect of Photoinduced Surface Oxygen Vacancies on the Charge Carrier Dynamics in TiO2 Films Journal Article
In: Nano Letters, vol. 21, no. 19, pp. 8348-8354, 2021, ISSN: 1530-6984.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {The Effect of Photoinduced Surface Oxygen Vacancies on the Charge Carrier Dynamics in TiO2 Films},
author = {O E Dagdeviren and D Glass and R Sapienza and E Cort\'{e}s and S A Maier and I P Parkin and P Gr\"{u}tter and R Quesada-Cabrera},
url = {https://doi.org/10.1021/acs.nanolett.1c02853},
doi = {10.1021/acs.nanolett.1c02853},
issn = {1530-6984},
year = {2021},
date = {2021-09-28},
journal = {Nano Letters},
volume = {21},
number = {19},
pages = {8348-8354},
abstract = {Metal-oxide semiconductors (MOS) are widely utilized for catalytic and photocatalytic applications in which the dynamics of charged carriers (e.g., electrons, holes) play important roles. Under operation conditions, photoinduced surface oxygen vacancies (PI-SOV) can greatly impact the dynamics of charge carriers. However, current knowledge regarding the effect of PI-SOV on the dynamics of hole migration in MOS films, such as titanium dioxide, is solely based upon volume-averaged measurements and/or vacuum conditions. This limits the basic understanding of hole-vacancy interactions, as they are not capable of revealing time-resolved variations during operation. Here, we measured the effect of PI-SOV on the dynamics of hole migration using time-resolved atomic force microscopy. Our findings demonstrate that the time constant associated with hole migration is strongly affected by PI-SOV, in a reversible manner. These results will nucleate an insightful understanding of the physics of hole dynamics and thus enable emerging technologies, facilitated by engineering hole-vacancy interactions.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
N Paul, J Huang, C Liu, T Lin, C Ouyang, Z Liu, C Chen, Z Chen, Z Weng, M Schwartzkopf, S V Roth, P Müller-Buschbaum, A Paul
Real-time observation of nucleation and growth of Au on CdSe quantum dot templates Journal Article
In: Scientific Reports, vol. 11, no. 1, pp. 18777, 2021, ISSN: 2045-2322.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Real-time observation of nucleation and growth of Au on CdSe quantum dot templates},
author = {N Paul and J Huang and C Liu and T Lin and C Ouyang and Z Liu and C Chen and Z Chen and Z Weng and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum and A Paul},
url = {https://doi.org/10.1038/s41598-021-97485-z},
doi = {10.1038/s41598-021-97485-z},
issn = {2045-2322},
year = {2021},
date = {2021-09-21},
journal = {Scientific Reports},
volume = {11},
number = {1},
pages = {18777},
abstract = {Semiconductor quantum dot (QD) arrays can be useful for optical devices such as lasers, solar cells and light-emitting diodes. As the size distribution influences the band-gap, it is worthwhile to investigate QDs prepared using different solvents because each of them could influence the overall morphology differently, depending on the ligand network around individual QDs. Here, we follow the nucleation and growth of gold (Au) on CdSe QD arrays to investigate the influence of surface ligands and thereby realized interparticle distance between QDs on Au growth behaviour. We particularly emphasize on the monolayer stage as the Au decoration on individual QDs is expected at this stage. Therefore, we sputter-deposit Au on each QD array to investigate the morphological evolution in real-time using time-resolved grazing-incidence small-angle X-ray scattering (GISAXS). The growth kinetics - independent of the template - signifies that the observed template-mediated nucleation is limited only to the very first few monolayers. Delicate changes in the Au growth morphology are seen in the immediate steps following the initial replicated decoration of the QD arrays. This is followed by a subsequent clustering and finally a complete Au coverage of the QD arrays.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
C Qian, V Villafañe, P Soubelet, A Hötger, T Taniguchi, K Watanabe, N P Wilson, A V Stier, A W Holleitner, J J Finley
Non-Local Exciton-Photon Interactions in Hybrid High-Q Nanocavities with Embedded hBN-Encapsulated MoS2 Monolayers Journal Article
In: arXiv preprint arXiv:2107.04387, 2021.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Non-Local Exciton-Photon Interactions in Hybrid High-Q Nanocavities with Embedded hBN-Encapsulated MoS2 Monolayers},
author = {C Qian and V Villafa\~{n}e and P Soubelet and A H\"{o}tger and T Taniguchi and K Watanabe and N P Wilson and A V Stier and A W Holleitner and J J Finley},
url = {https://arxiv.org/abs/2107.04387},
doi = {arXiv:2107.04387v2},
year = {2021},
date = {2021-09-20},
journal = {arXiv preprint arXiv:2107.04387},
abstract = {Atomically thin semiconductors can be readily integrated into a wide range of nanophotonic architectures for applications in quantum photonics and novel optoelectronic devices. We report the observation of non-local interactions of textitfree trions in pristine hBN/MoS2/hBN heterostructures coupled to single mode (Q \>104) quasi 0D nanocavities. The high excitonic and photonic quality of the interaction system stem from our integrated nanofabrication approach simultaneously with the hBN encapsulation and the maximized local cavity field amplitude within the MoS2 monolayer. We observe a non-monotonic temperature dependence of the cavity-trion interaction strength, consistent with the non-local light-matter interactions in which the free trion diffuse over lengthscales comparable to the cavity mode volume. Our approach can be generalized to other optically active 2D materials, opening the way towards harnessing novel light-matter interaction regimes for applications in quantum photonics.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
M Poblet, R Berté, H D Boggiano, Y Li, E Cortés, G Grinblat, S A Maier, A V Bragas
Acoustic Coupling between Plasmonic Nanoantennas: Detection and Directionality of Surface Acoustic Waves Journal Article
In: ACS Photonics, 2021.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Acoustic Coupling between Plasmonic Nanoantennas: Detection and Directionality of Surface Acoustic Waves},
author = {M Poblet and R Bert\'{e} and H D Boggiano and Y Li and E Cort\'{e}s and G Grinblat and S A Maier and A V Bragas},
url = {https://doi.org/10.1021/acsphotonics.1c00741},
doi = {10.1021/acsphotonics.1c00741},
year = {2021},
date = {2021-09-17},
urldate = {2021-09-17},
journal = {ACS Photonics},
abstract = {Hypersound waves can be efficient mediators between optical signals at the nanoscale. Having phase velocities several orders of magnitude lower than the speed of light, they propagate with much shorter wavelengths and can be controlled, directed, and even focused in a very small region of space. This work shows how two optical nanoantennas can be coupled through an acoustic wave that propagates with a certain directionality. An “emitter” antenna is first optically excited to generate acoustic coherent phonons that launch surface acoustic waves through the underlying substrate. These waves travel until they are mechanically detected by a “receiver” nanoantenna whose oscillation produces a detectable optical signal. Generation and detection are studied in detail, and new designs are proposed to improve the directionality of the hypersonic surface acoustic wave.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
Y Huang, T Xiao, Z Xie, J Zheng, Y Su, W Chen, K Liu, M Tang, J Zhu, P Müller-Buschbaum, L Li
Multistate Nonvolatile Metamirrors with Tunable Optical Chirality Journal Article
In: ACS Applied Materials & Interfaces, 2021, ISSN: 1944-8244.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Multistate Nonvolatile Metamirrors with Tunable Optical Chirality},
author = {Y Huang and T Xiao and Z Xie and J Zheng and Y Su and W Chen and K Liu and M Tang and J Zhu and P M\"{u}ller-Buschbaum and L Li},
url = {https://doi.org/10.1021/acsami.1c14204},
doi = {10.1021/acsami.1c14204},
issn = {1944-8244},
year = {2021},
date = {2021-09-14},
urldate = {2021-09-14},
journal = {ACS Applied Materials \& Interfaces},
abstract = {Compared with conventional mirrors that behave as isotropic electromagnetic (EM) reflectors, metamirrors composed of periodically aligned artificial meta-atoms exhibit increased degrees of freedom for EM manipulations. However, the functionality of most metamirrors is fixed by design, and how to achieve active EM control is still elusive. Here, we propose a multistate metamirror based on the nonvolatile phase change material Ge2Sb2Te5 (GST) with four distinct functionalities that can be realized in the infrared region by exploiting the temperature-activated phase transition. When varying the crystallinity of GST, the metamirror has the capability to perform as a right-handed circular polarization chiral mirror, a narrowband achiral mirror, a left-handed circular polarization chiral mirror, or a broadband achiral mirror, respectively. The inner physics is further explained by the construction or cancellation of extrinsic two-dimensional chirality. As a proof of concept, experimental verification is carried out and the measured results agree well with their simulated counterparts. Such a multifunctional tunable metamirror could address a wide range of applications from sensing and spectroscopy to analytical chemistry and imaging.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
J Klein, M Florian, A Hötger, A Steinhoff, A Delhomme, T Taniguchi, K Watanabe, F Jahnke, A W Holleitner, M Potemski
Trions in MoS2 are quantum superpositions of intra-and intervalley spin states Journal Article
In: arXiv preprint arXiv:2109.06281, 2021.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Trions in MoS2 are quantum superpositions of intra-and intervalley spin states},
author = {J Klein and M Florian and A H\"{o}tger and A Steinhoff and A Delhomme and T Taniguchi and K Watanabe and F Jahnke and A W Holleitner and M Potemski},
url = {https://arxiv.org/abs/2109.06281},
doi = {arXiv:2109.06281v1},
year = {2021},
date = {2021-09-13},
journal = {arXiv preprint arXiv:2109.06281},
abstract = {We report magneto-photoluminescence spectroscopy of gated MoS2 monolayers in high magnetic fields to 28 T. At B = 0T and electron density ns∼1012cm−2, we observe three trion resonances that cannot be explained within a single-particle picture. Employing ab initio calculations that take into account three-particle correlation effects as well as local and non-local electron-hole exchange interaction, we identify those features as quantum superpositions of inter- and intravalley spin states. We experimentally investigate the mixed character of the trion wave function via the filling factor dependent valley Zeeman shift in positive and negative magnetic fields. Our results highlight the importance of exchange interactions for exciton physics in monolayer MoS2 and provide new insights into the microscopic understanding of trion physics in 2D multi-valley semiconductors for low excess carrier densities.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
P Mao, C Liu, X Li, M Liu, Q Chen, M Han, S A Maier, E H Sargent, S Zhang
Single-step-fabricated disordered metasurfaces for enhanced light extraction from LEDs Journal Article
In: Light: Science & Applications, vol. 10, no. 1, pp. 180, 2021, ISSN: 2047-7538.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Single-step-fabricated disordered metasurfaces for enhanced light extraction from LEDs},
author = {P Mao and C Liu and X Li and M Liu and Q Chen and M Han and S A Maier and E H Sargent and S Zhang},
url = {https://doi.org/10.1038/s41377-021-00621-7},
doi = {10.1038/s41377-021-00621-7},
issn = {2047-7538},
year = {2021},
date = {2021-09-06},
journal = {Light: Science \& Applications},
volume = {10},
number = {1},
pages = {180},
abstract = {While total internal reflection (TIR) lays the foundation for many important applications, foremost fibre optics that revolutionised information technologies, it is undesirable in some other applications such as light-emitting diodes (LEDs), which are a backbone for energy-efficient light sources. In the case of LEDs, TIR prevents photons from escaping the constituent high-index materials. Advances in material science have led to good efficiencies in generating photons from electron\textendashhole pairs, making light extraction the bottleneck of the overall efficiency of LEDs. In recent years, the extraction efficiency has been improved, using nanostructures at the semiconductor/air interface that outcouple trapped photons to the outside continuum. However, the design of geometrical features for light extraction with sizes comparable to or smaller than the optical wavelength always requires sophisticated and time-consuming fabrication, which causes a gap between lab demonstration and industrial-level applications. Inspired by lightning bugs, we propose and realise a disordered metasurface for light extraction throughout the visible spectrum, achieved with single-step fabrication. By applying such a cost-effective light extraction layer, we improve the external quantum efficiency by a factor of 1.65 for commercialised GaN LEDs, demonstrating a substantial potential for global energy-saving and sustainability.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
A Thurn, J Bissinger, S Meinecke, P Schmiedeke, S S Oh, W W Chow, K Lüdge, G Koblmüller, J J Finley
Self-induced ultrafast electron-hole plasma temperature oscillations in nanowire lasers Journal Article
In: arXiv preprint arXiv:2108.11784, 2021.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Self-induced ultrafast electron-hole plasma temperature oscillations in nanowire lasers},
author = {A Thurn and J Bissinger and S Meinecke and P Schmiedeke and S S Oh and W W Chow and K L\"{u}dge and G Koblm\"{u}ller and J J Finley},
url = {https://arxiv.org/abs/2108.11784},
doi = {arXiv:2108.11784v2},
year = {2021},
date = {2021-09-06},
journal = {arXiv preprint arXiv:2108.11784},
abstract = {Nanowire lasers can be monolithically and site-selectively integrated onto silicon photonic circuits. To assess their full potential for ultrafast opto-electronic devices, a detailed understanding of their lasing dynamics is crucial. However, the roles played by their resonator geometry and the microscopic processes that mediate energy exchange between the photonic, electronic, and phononic systems are largely unexplored. Here, we apply femtosecond pump-probe spectroscopy to show that GaAs-AlGaAs core-shell nanowire lasers exhibit sustained intensity oscillations with frequencies ranging from 160 GHz to 260 GHz. These dynamics are intricately linked to the strong interaction between the lasing mode and the gain material arising from their wavelength-scale dimensions. Combined with dynamic competition between photoinduced carrier heating and cooling via phonon scattering, this enables self-induced electron-hole plasma temperature oscillations, which modulate the laser output. We anticipate that our results will lead to new approaches for ultrafast intensity and phase modulation of chip-integrated nanoscale semiconductor lasers.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
F Zoller, S Häringer, D Böhm, H Illner, M Döblinger, Z K Sofer, M Finsterbusch, T Bein, D Fattakhova-Rohlfing
Overcoming the Challenges of Freestanding Tin Oxide-Based Composite Anodes to Achieve High Capacity and Increased Cycling Stability Journal Article
In: Advanced Functional Materials, vol. 31, no. 43, pp. 2106373, 2021, ISSN: 1616-301X.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Overcoming the Challenges of Freestanding Tin Oxide-Based Composite Anodes to Achieve High Capacity and Increased Cycling Stability},
author = {F Zoller and S H\"{a}ringer and D B\"{o}hm and H Illner and M D\"{o}blinger and Z K Sofer and M Finsterbusch and T Bein and D Fattakhova-Rohlfing},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202106373},
doi = {https://doi.org/10.1002/adfm.202106373},
issn = {1616-301X},
year = {2021},
date = {2021-08-27},
journal = {Advanced Functional Materials},
volume = {31},
number = {43},
pages = {2106373},
abstract = {Abstract Freestanding electrodes are a promising way to increase the energy density of the batteries by decreasing the overall amount of electrochemically inactive materials. Freestanding antimony doped tin oxide (ATO)-based hybrid materials have not been reported so far, although this material has demonstrated excellent performance in conventionally designed electrodes. Two different strategies, namely electrospinning and freeze-casting, are explored for the fabrication of ATO-based hybrid materials. It is shown that the electrospinning of ATO/carbon based electrodes from polyvinyl pyrrolidone polymer (PVP) solutions was not successful, as the resulting electrode material suffers from rapid degradation. However, freestanding reduced graphene oxide (rGO) containing ATO/C/rGO nanocomposites prepared via a freeze-casting route demonstrates an impressive rate and cycling performance reaching 697 mAh g−1 at a high current density of 4 A g−1, which is 40 times higher as compared to SnO2/rGO and also exceeds the freestanding SnO2-based composites reported so far. Antimony doping of the nanosized tin oxide phase and carbon coating are thereby shown to be essential factors for appealing electrochemical performance. Finally, the freestanding ATO/C/rGO anodes are combined with freestanding LiFe0.2Mn0.8PO4/rGO cathodes to obtain a full freestanding cell operating without metal current collector foils showing nonetheless an excellent cycling stability.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
M Kraut, F Pantle, S Wörle, E Sirotti, A Zeidler, F Eckmann, M Stutzmann
Influence of environmental conditions and surface treatments on the photoluminescence properties of GaN nanowires and nanofins Journal Article
In: Nanotechnology, 2021, ISSN: 0957-4484.
Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Influence of environmental conditions and surface treatments on the photoluminescence properties of GaN nanowires and nanofins},
author = {M Kraut and F Pantle and S W\"{o}rle and E Sirotti and A Zeidler and F Eckmann and M Stutzmann},
issn = {0957-4484},
year = {2021},
date = {2021-08-16},
journal = {Nanotechnology},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
M Beetz, S Häringer, P Elsässer, J Kampmann, L Sauerland, F Wolf, M Günther, A Fischer, T Bein
Ultra‐Thin Protective Coatings for Sustained Photoelectrochemical Water Oxidation with Mo: BiVO4 Journal Article
In: Advanced Functional Materials, pp. 2011210, 2021, ISSN: 1616-301X.
Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Ultra‐Thin Protective Coatings for Sustained Photoelectrochemical Water Oxidation with Mo: BiVO4},
author = {M Beetz and S H\"{a}ringer and P Els\"{a}sser and J Kampmann and L Sauerland and F Wolf and M G\"{u}nther and A Fischer and T Bein},
url = {https://doi.org/10.1002/adfm.202011210},
issn = {1616-301X},
year = {2021},
date = {2021-08-12},
urldate = {2021-08-12},
journal = {Advanced Functional Materials},
pages = {2011210},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
M Kick, C Scheurer, H Oberhofer
Polaron-Assisted Charge Transport in Li-Ion Battery Anode Materials Journal Article
In: ACS Applied Energy Materials, 2021.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{,
title = {Polaron-Assisted Charge Transport in Li-Ion Battery Anode Materials},
author = {M Kick and C Scheurer and H Oberhofer},
url = {https://doi.org/10.1021/acsaem.1c01767},
doi = {10.1021/acsaem.1c01767},
year = {2021},
date = {2021-08-04},
journal = {ACS Applied Energy Materials},
abstract = {Lithium-ion batteries are without a doubt a key technology in the coming energy revolution. It is thus all the more surprising that one of the more prevalent Li battery anode materials, reduced lithium titanium oxide (LTO, Li4Ti5O12), is still poorly understood on a microscopic level. While recent theoretical and experimental evidence suggests that a polaron hopping mechanism is responsible for the increased electronic conductivity of reduced LTO, no such explanation exists for the concurrent improvements to the ionic mobility. In this computational study, we show that the presence of polaronic Ti3+ centers can indeed lead to a significant lowering of Li hopping barriers in both bulk and surface reduced LTO. For the latter, we find a reduced barrier height of roughly 40 meV compared to that of our pristine reference. This is in accordance with experimental findings showing that lithium-ion diffusion in reduced LTO is twice as high as that for pristine LTO. Finally, we show that\textemdashin accordance with experimental observations\textemdashpolaron formation upon lithiation of LTO leads to a similar behavior. Altogether, our analysis hints at a correlated movement of Li ions and polarons, highlighting LTO’s potential for rational defect engineering.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
D Han, C Feng, M-H Du, T Zhang, S Wang, G Tang, T Bein, H Ebert
Design of High-Performance Lead-Free Quaternary Antiperovskites for Photovoltaics via Ion Type Inversion and Anion Ordering Journal Article
In: Journal of the American Chemical Society, vol. 143, no. 31, pp. 12369-12379, 2021, ISSN: 0002-7863.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{,
title = {Design of High-Performance Lead-Free Quaternary Antiperovskites for Photovoltaics via Ion Type Inversion and Anion Ordering},
author = {D Han and C Feng and M-H Du and T Zhang and S Wang and G Tang and T Bein and H Ebert},
url = {https://doi.org/10.1021/jacs.1c06403},
doi = {10.1021/jacs.1c06403},
issn = {0002-7863},
year = {2021},
date = {2021-08-02},
urldate = {2021-08-02},
journal = {Journal of the American Chemical Society},
volume = {143},
number = {31},
pages = {12369-12379},
abstract = {The emergence of halide double perovskites significantly increases the compositional space for lead-free and air-stable photovoltaic absorbers compared to halide perovskites. Nevertheless, most halide double perovskites exhibit oversized band gaps (\>1.9 eV) or dipole-forbidden optical transition, which are unfavorable for efficient single-junction solar cell applications. The current device performance of halide double perovskite is still inferior to that of lead-based halide perovskites, such as CH3NH3PbI3 (MAPbI3). Here, by ion type inversion and anion ordering on perovskite lattice sites, two new classes of pnictogen-based quaternary antiperovskites with the formula of X6B2AA′ and X6BB′A2 are designed. Phase stability and tunable band gaps in these quaternary antiperovskites are demonstrated based on first-principles calculations. Further photovoltaic-functionality-directed screening of these materials leads to the discovery of 5 stable compounds (Ca6N2AsSb, Ca6N2PSb, Sr6N2AsSb, Sr6N2PSb, and Ca6NPSb2) with suitable direct band gaps, small carrier effective masses and low exciton binding energies, and dipole-allowed strong optical absorption, which are favorable properties for a photovoltaic absorber material. The calculated theoretical maximum solar cell efficiencies based on these five compounds are all larger than 29%, comparable to or even higher than that of the MAPbI3 based solar cell. Our work reveals the huge potential of quaternary antiperovskites in the optoelectronic field and provides a new strategy to design lead-free and air-stable perovskite-based photovoltaic absorber materials.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
S A Watzele, L Katzenmeier, J P Sabawa, B Garlyyev, A S Bandarenka
Temperature dependences of the double layer capacitance of some solid/liquid and solid/solid electrified interfaces. An experimental study Journal Article
In: Electrochimica Acta, vol. 391, pp. 138969, 2021, ISSN: 0013-4686.
Abstract | Links | Tags: Foundry Inorganic, Solid-Liquid, Solid-Solid
@article{,
title = {Temperature dependences of the double layer capacitance of some solid/liquid and solid/solid electrified interfaces. An experimental study},
author = {S A Watzele and L Katzenmeier and J P Sabawa and B Garlyyev and A S Bandarenka},
url = {https://www.sciencedirect.com/science/article/pii/S0013468621012597},
doi = {https://doi.org/10.1016/j.electacta.2021.138969},
issn = {0013-4686},
year = {2021},
date = {2021-07-30},
journal = {Electrochimica Acta},
volume = {391},
pages = {138969},
abstract = {This study investigates the influence of the temperature on the electrical double layer capacitance (CDL) of various materials, which are essential for fuel cells and solid-state Li-ion batteries. Electrochemical impedance spectroscopy is utilized to measure the CDL of polycrystalline Pt/aqueous electrolytes interfaces, cathode catalyst layers of polymer electrolyte membrane fuel cells (PEMFC), and Au or Li electrodes in contact with a solid-state electrolyte (SSE), a prime example for solid-state ionics. Our results show that within the investigated temperature ranges, the CDL decreases with an increase in the temperature for Pt electrodes in an aqueous acidic electrolyte. However, for SSE and PEMFC cathode catalyst layers, the CDL increases with temperature. The CDL behavior with the temperature of herein presented systems is important for understanding and modeling of the interface processes for renewable energy conversion systems such as fuel cells, water electrolyzers, and batteries.},
keywords = {Foundry Inorganic, Solid-Liquid, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
D N Purschke, M R P Pielmeier, E Üzer, C Ott, C Jensen, A Degg, A Vogel, N Amer, T Nilges, F A Hegmann
Ultrafast Photoconductivity and Terahertz Vibrational Dynamics in Double-Helix SnIP Nanowires Journal Article
In: Advanced Materials, vol. n/a, no. n/a, pp. 2100978, 2021, ISSN: 0935-9648.
Abstract | Links | Tags: Solid-Solid
@article{,
title = {Ultrafast Photoconductivity and Terahertz Vibrational Dynamics in Double-Helix SnIP Nanowires},
author = {D N Purschke and M R P Pielmeier and E \"{U}zer and C Ott and C Jensen and A Degg and A Vogel and N Amer and T Nilges and F A Hegmann},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202100978},
doi = {https://doi.org/10.1002/adma.202100978},
issn = {0935-9648},
year = {2021},
date = {2021-07-19},
journal = {Advanced Materials},
volume = {n/a},
number = {n/a},
pages = {2100978},
abstract = {Abstract Tin iodide phosphide (SnIP), an inorganic double-helix material, is a quasi-1D van der Waals semiconductor that shows promise in photocatalysis and flexible electronics. However, the understanding of the fundamental photophysics and charge transport dynamics of this new material is limited. Here, time-resolved terahertz (THz) spectroscopy is used to probe the transient photoconductivity of SnIP nanowire films and measure the carrier mobility. With insight into the highly anisotropic electronic structure from quantum chemical calculations, an electron mobility as high as 280 cm2 V−1s−1 along the double-helix axis and a hole mobility of 238 cm2 V−1 s−1 perpendicular to the double-helix axis are detected. Additionally, infrared-active (IR-active) THz vibrational modes are measured, which shows excellent agreement with first-principles calculations, and an ultrafast photoexcitation-induced charge redistribution is observed that reduces the amplitude of a twisting mode of the outer SnI helix on picosecond timescales. Finally, it is shown that the carrier lifetime and mobility are limited by a trap density greater than 1018 cm−3. The results provide insight into the optical excitation and relaxation pathways of SnIP and demonstrate a remarkably high carrier mobility for such a soft and flexible material, suggesting that it could be ideally suited for flexible electronics applications.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
S Kaiser, F Maleki, K Zhang, W Harbich, U Heiz, S Tosoni, B A J Lechner, G Pacchioni, F Esch
Cluster Catalysis with Lattice Oxygen: Tracing Oxygen Transport from a Magnetite (001) Support onto Small Pt Clusters Journal Article
In: ACS Catalysis, vol. 11, no. 15, pp. 9519–9529, 2021.
Links | Tags: Foundry Inorganic, Molecularly-Functionalized, Solid-Solid
@article{,
title = {Cluster Catalysis with Lattice Oxygen: Tracing Oxygen Transport from a Magnetite (001) Support onto Small Pt Clusters},
author = {S Kaiser and F Maleki and K Zhang and W Harbich and U Heiz and S Tosoni and B A J Lechner and G Pacchioni and F Esch},
url = {https://pubs.acs.org/doi/10.1021/acscatal.1c01451},
year = {2021},
date = {2021-07-16},
urldate = {2021-07-16},
journal = {ACS Catalysis},
volume = {11},
number = {15},
pages = {9519\textendash9529},
keywords = {Foundry Inorganic, Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
T Götsch, H Tuerk, F-P Schmidt, I Vinke, De L B Haart, R Schlögl, K Reuter, R-A Eichel, A Knop-Gericke, C Scheurer
Visualizing the Atomic Structure Between YSZ and LSM: An Interface Stabilized by Complexions? Journal Article
In: ECS Transactions, vol. 103, no. 1, pp. 1331, 2021, ISSN: 1938-5862.
Tags: Solid-Solid
@article{,
title = {Visualizing the Atomic Structure Between YSZ and LSM: An Interface Stabilized by Complexions?},
author = {T G\"{o}tsch and H Tuerk and F-P Schmidt and I Vinke and De L B Haart and R Schl\"{o}gl and K Reuter and R-A Eichel and A Knop-Gericke and C Scheurer},
issn = {1938-5862},
year = {2021},
date = {2021-07-12},
urldate = {2021-07-12},
journal = {ECS Transactions},
volume = {103},
number = {1},
pages = {1331},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
A Buyruk, D Blätte, M Günther, M A Scheel, N F Hartmann, M Döblinger, A Weis, A Hartschuh, P Müller-Buschbaum, T Bein, T Ameri
1,10-Phenanthroline as an Efficient Bifunctional Passivating Agent for MAPbI3 Perovskite Solar Cells Journal Article
In: ACS Applied Materials & Interfaces, 2021, ISSN: 1944-8244.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{,
title = {1,10-Phenanthroline as an Efficient Bifunctional Passivating Agent for MAPbI3 Perovskite Solar Cells},
author = {A Buyruk and D Bl\"{a}tte and M G\"{u}nther and M A Scheel and N F Hartmann and M D\"{o}blinger and A Weis and A Hartschuh and P M\"{u}ller-Buschbaum and T Bein and T Ameri},
url = {https://doi.org/10.1021/acsami.1c05055},
doi = {10.1021/acsami.1c05055},
issn = {1944-8244},
year = {2021},
date = {2021-07-09},
urldate = {2021-07-09},
journal = {ACS Applied Materials \& Interfaces},
abstract = {Passivation is one of the most promising concepts to heal defects created at the surface and grain boundaries of polycrystalline perovskite thin films, which significantly deteriorate the photovoltaic performance and stability of corresponding devices. Here, 1,10-phenanthroline, known as a bidentate chelating ligand, is implemented between the methylammonium lead iodide (MAPbI3) film and the hole-transport layer for both passivating the lead-based surface defects (undercoordinated lead ions) and converting the excess/unreacted lead iodide (PbI2) buried at interfaces, which is problematic for the long-term stability, into “neutralized” and beneficial species (PbI2(1,10-phen)x},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
W Kaiser, V Janković, N Vukmirović, A Gagliardi
Nonequilibrium Thermodynamics of Charge Separation in Organic Solar Cells Journal Article
In: The Journal of Physical Chemistry Letters, vol. 12, no. 27, pp. 6389-6397, 2021.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Nonequilibrium Thermodynamics of Charge Separation in Organic Solar Cells},
author = {W Kaiser and V Jankovi\'{c} and N Vukmirovi\'{c} and A Gagliardi},
url = {https://doi.org/10.1021/acs.jpclett.1c01817},
doi = {10.1021/acs.jpclett.1c01817},
year = {2021},
date = {2021-07-07},
journal = {The Journal of Physical Chemistry Letters},
volume = {12},
number = {27},
pages = {6389-6397},
abstract = {This work presents a novel theoretical description of the nonequilibrium thermodynamics of charge separation in organic solar cells (OSCs). Using stochastic thermodynamics, we take realistic state populations derived from the phonon-assisted dynamics of electron\textendashhole pairs within photoexcited organic bilayers to connect the kinetics with the free energy profile of charge separation. Hereby, we quantify for the first time the difference between nonequilibrium and equilibrium free energy profile. We analyze the impact of energetic disorder and delocalization on free energy, average energy, and entropy. For a high disorder, the free energy profile is well-described as equilibrated. We observe significant deviations from equilibrium for delocalized electron\textendashhole pairs at a small disorder, implying that charge separation in efficient OSCs proceeds via a cold but nonequilibrated pathway. Both a large Gibbs entropy and large initial electron\textendashhole distance provide an efficient charge separation, while a decrease in the free energy barrier does not necessarily enhance charge separation.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
H Li, Y Liu, K Chen, J T Margraf, Y Li, K Reuter
Subgroup Discovery Points to the Prominent Role of Charge Transfer in Breaking Nitrogen Scaling Relations at Single-Atom Catalysts on VS2 Journal Article
In: ACS Catalysis, vol. 11, no. 13, pp. 7906-7914, 2021.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{,
title = {Subgroup Discovery Points to the Prominent Role of Charge Transfer in Breaking Nitrogen Scaling Relations at Single-Atom Catalysts on VS2},
author = {H Li and Y Liu and K Chen and J T Margraf and Y Li and K Reuter},
url = {https://doi.org/10.1021/acscatal.1c01324},
doi = {10.1021/acscatal.1c01324},
year = {2021},
date = {2021-07-02},
journal = {ACS Catalysis},
volume = {11},
number = {13},
pages = {7906-7914},
abstract = {The electrochemical nitrogen reduction reaction (NRR) is a much sought-after low-energy alternative to Haber\textendashBosch ammonia synthesis. Single-atom catalysts (SACs) promise to break scaling relations between adsorption energies of key NRR reaction intermediates that severely limit the performance of extended catalysts. Here, we perform a computational screening study of transition metal (TM) SACs supported on vanadium disulfide (VS2) and indeed obtain strongly broken scaling relations. A data-driven analysis by means of outlier detection and subgroup discovery reveals that this breaking is restricted to early TMs, while detailed electronic structure analysis rationalizes it in terms of strong charge transfer to the underlying support. This charge transfer selectively weakens *N and *NH adsorption and leads to promising NRR descriptors for SACs formed of earlier TMs like Ta that would conventionally not be associated with nitrogen reduction.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
C Qian, V Villafane, P Soubelet, A Hötger, T Taniguchi, K Watanabe, N P Wilson, A V Stier, A W Holleitner, J J Finley
Strong coupling and non-local interactions in MoS2 monolayers coupled to high-Q nanocavities Journal Article
In: Measurement, vol. 495, no. 445, pp. 105, 2021.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Strong coupling and non-local interactions in MoS2 monolayers coupled to high-Q nanocavities},
author = {C Qian and V Villafane and P Soubelet and A H\"{o}tger and T Taniguchi and K Watanabe and N P Wilson and A V Stier and A W Holleitner and J J Finley},
url = {https://ui.adsabs.harvard.edu/abs/2021arXiv210704387Q/abstract},
doi = {arXiv:2107.04387},
year = {2021},
date = {2021-07-02},
journal = {Measurement},
volume = {495},
number = {445},
pages = {105},
abstract = {Atomically thin semiconductors can be readily integrated into a wide range of nanophotonic architectures for applications in quantum photonics and novel optoelectronic devices. We report the observation of non-local interactions of textitfree trions in pristine hBN/MoS 2 /hBN heterostructures coupled to single mode (Q \>104 ) quasi 0D nanocavities. The high excitonic and photonic quality of the interaction system stem from our integrated nanofabrication approach simultaneously with the hBN encapsulation and the maximized local cavity field amplitude within the MoS 2 monolayer. We observe a non-monotonic temperature dependence of the cavity-trion interaction strength, consistent with the non-local light-matter interactions in which the free trion diffuse over lengthscales comparable to the cavity mode volume. Our approach can be generalized to other optically active 2D materials, opening the way towards harnessing novel light-matter interaction regimes for applications in quantum photonics.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
S Rieger, T Fürmann, J K Stolarczyk, J Feldmann
Optically Induced Coherent Phonons in Bismuth Oxyiodide (BiOI) Nanoplatelets Journal Article
In: Nano Letters, 2021, ISSN: 1530-6984.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{,
title = {Optically Induced Coherent Phonons in Bismuth Oxyiodide (BiOI) Nanoplatelets},
author = {S Rieger and T F\"{u}rmann and J K Stolarczyk and J Feldmann},
url = {https://doi.org/10.1021/acs.nanolett.1c00530},
doi = {10.1021/acs.nanolett.1c00530},
issn = {1530-6984},
year = {2021},
date = {2021-06-30},
journal = {Nano Letters},
abstract = {Bismuth oxyiodide (BiOI) is a promising material for photocatalysis combining intriguing optical and structural properties. We show that excitation by a femtosecond laser pulse creates coherent phonons inducing a time-variant oscillating modulation of the optical density. We find that the two underlying frequencies originate from lattice vibrations along the [001] crystallographic axis, the stacking direction of oppositely charged layers in BiOI. This is consistent with a subpicosecond charge separation driven by a built-in dipolar field. This partially screens the field, launching coherent phonons. Further, we determine the two major dephasing mechanisms that lead to the loss of vibronic coherence: (i) the anharmonic decay of an optical phonon into two acoustic phonons and (ii) phonon-carrier scattering. Our results provide a direct demonstration of the presence of an electric field in BiOI along the [001] axis and show its role in efficient charge separation that is crucial for photocatalytic applications of BiOI.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
D M Schwaiger, W Lohstroh, P Müller-Buschbaum
The Influence of the Blend Ratio, Solvent Additive, and Post-production Treatment on the Polymer Dynamics in PTB7:PCBM Blend Films Journal Article
In: Macromolecules, 2021, ISSN: 0024-9297.
Abstract | Links | Tags: Foundry Organic, Solid-Solid
@article{,
title = {The Influence of the Blend Ratio, Solvent Additive, and Post-production Treatment on the Polymer Dynamics in PTB7:PCBM Blend Films},
author = {D M Schwaiger and W Lohstroh and P M\"{u}ller-Buschbaum},
url = {https://doi.org/10.1021/acs.macromol.1c00313},
doi = {10.1021/acs.macromol.1c00313},
issn = {0024-9297},
year = {2021},
date = {2021-06-23},
urldate = {2021-06-23},
journal = {Macromolecules},
abstract = {The polymer dynamics inside a bulk heterojunction (BHJ), as used in organic solar cells, are investigated with quasielastic neutron scattering to study hydrogen motion in the polymer side chains. Different blend ratios of the polymer donor poly(4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl) (PTB7) and the small molecule acceptor [6,6]phenyl-C71-butyric acid methyl ester (PCBM) are investigated. In addition, the influence of performance-enhancing measures, such as the use of the solvent additive 1,8-diiodooctane (DIO) and the post-production treatment of the BHJ films with methanol, on the polymer dynamics is studied. The analysis of mean square displacements as well as relaxation times of diffusional motions of the hydrogen atoms, located mainly in the polymer side chains, shows a gradual stiffening of the PTB7 side chains for higher PCBM loading in the BHJ films. The presence of DIO significantly increases diffusive mobility inside the films, while the methanol treatment does not affect hydrogen motions.},
keywords = {Foundry Organic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
J Klein, J Wierzbowski, P Soubelet, T Brumme, L Maschio, A Kuc, K Müller, A V Stier, J J Finley
Electrical control of orbital and vibrational interlayer coupling in bi-and trilayer 2H-MoS $ _2$ Journal Article
In: arXiv preprint arXiv:2106.11839, 2021.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Electrical control of orbital and vibrational interlayer coupling in bi-and trilayer 2H-MoS $ _2$},
author = {J Klein and J Wierzbowski and P Soubelet and T Brumme and L Maschio and A Kuc and K M\"{u}ller and A V Stier and J J Finley},
url = {https://arxiv.org/abs/2106.11839},
doi = {arXiv:2106.11839v1},
year = {2021},
date = {2021-06-22},
journal = {arXiv preprint arXiv:2106.11839},
abstract = {Manipulating electronic interlayer coupling in layered van der Waals (vdW) materials is essential for designing opto-electronic devices. Here, we control vibrational and electronic interlayer coupling in bi- and trilayer 2H-MoS2 using large external electric fields in a micro-capacitor device. The electric field lifts Raman selection rules and activates phonon modes in excellent agreement with ab-initio calculations. Through polarization resolved photoluminescence spectroscopy in the same device, we observe a strongly tunable valley dichroism with maximum circular polarization degree of ∼60% in bilayer and ∼35% in trilayer MoS2 that are fully consistent with a rate equation model which includes input from electronic band structure calculations. We identify the highly delocalized electron wave function between the layers close to the high symmetry Q points as the origin of the tunable circular dichroism. Our results demonstrate the possibility of electric field tunable interlayer coupling for controlling emergent spin-valley physics and hybridization driven effects in vdW materials and their heterostructures.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
L Katzenmeier, L Carstensen, S J Schaper, P Müller-Buschbaum, A S Bandarenka
In: Advanced Materials, vol. 33, no. 24, pp. 2100585, 2021, ISSN: 0935-9648.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Solid-State Electrolytes: Characterization and Quantification of Depletion and Accumulation Layers in Solid-State Li+-Conducting Electrolytes Using In Situ Spectroscopic Ellipsometry (Adv. Mater. 24/2021)},
author = {L Katzenmeier and L Carstensen and S J Schaper and P M\"{u}ller-Buschbaum and A S Bandarenka},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202170190},
doi = {https://doi.org/10.1002/adma.202170190},
issn = {0935-9648},
year = {2021},
date = {2021-06-18},
urldate = {2021-06-18},
journal = {Advanced Materials},
volume = {33},
number = {24},
pages = {2100585},
abstract = {Layers depleted of Li-ions in solid-state electrolytes have a substantial impact on the performance of all-solid-state batteries. In article number 2100585, Aliaksandr S. Bandarenka and co-workers develop a practical strategy to measure the thickness of such space charge layers and the corresponding concentration of Li-ions by applying spectroscopic ellipsometry to emerging battery materials.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
N Li, R Guo, W Chen, V Körstgens, J E Heger, S Liang, C J Brett, M A Hossain, J Zheng, P S Deimel, A Buyruk, F Allegretti, M Schwartzkopf, J G C Veinot, G Schmitz, J V Barth, T Ameri, S V Roth, P Müller-Buschbaum
In: Advanced Functional Materials, vol. n/a, no. n/a, pp. 2102105, 2021, ISSN: 1616-301X.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{,
title = {Tailoring Ordered Mesoporous Titania Films via Introducing Germanium Nanocrystals for Enhanced Electron Transfer Photoanodes for Photovoltaic Applications},
author = {N Li and R Guo and W Chen and V K\"{o}rstgens and J E Heger and S Liang and C J Brett and M A Hossain and J Zheng and P S Deimel and A Buyruk and F Allegretti and M Schwartzkopf and J G C Veinot and G Schmitz and J V Barth and T Ameri and S V Roth and P M\"{u}ller-Buschbaum},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202102105},
doi = {https://doi.org/10.1002/adfm.202102105},
issn = {1616-301X},
year = {2021},
date = {2021-06-17},
journal = {Advanced Functional Materials},
volume = {n/a},
number = {n/a},
pages = {2102105},
abstract = {Abstract Based on a diblock-copolymer templated sol\textendashgel synthesis, germanium nanocrystals (GeNCs) are introduced to tailor mesoporous titania (TiO2) films for obtaining more efficient anodes for photovoltaic applications. After thermal annealing in air, the hybrid films with different GeNC content are investigated and compared with films undergoing an argon atmosphere annealing. The surface and inner morphologies of the TiO2/GeOx nanocomposite films are probed via scanning electron microscopy and grazing-incidence small-angle X-ray scattering. The crystal phase, chemical composition, and optical properties of the nanocomposite films are examined with transmission electron microscopy, X-ray photoelectron spectroscopy, and ultraviolet\textendashvisible spectroscopy. Special focus is set on the air-annealed nanocomposite films since they hold greater promise for photovoltaics. Specifically, the charge\textendashcarrier dynamics of these air-annealed nanocomposite films are studied, and it is found that, compared with pristine TiO2 photoanodes, the GeNC addition enhances the electron transfer, yielding an increase in the short-circuit photocurrent density of exemplary perovskite solar cells and thus, an enhanced device efficiency as well as a significantly reduced hysteresis.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
A Dey, J Ye, A De, E Debroye, S K Ha, E Bladt, A S Kshirsagar, Z Wang, J Yin, Y Wang, L N Quan, F Yan, M Gao, X Li, J Shamsi, T Debnath, M Cao, M A Scheel, S Kumar, J A Steele, M Gerhard, L Chouhan, K Xu, X-G Wu, Y Li, Y Zhang, A Dutta, C Han, I Vincon, A L Rogach, A Nag, A Samanta, B A Korgel, C-J Shih, D R Gamelin, D H Son, H Zeng, H Zhong, H Sun, H V Demir, I G Scheblykin, I Mora-Seró, J K Stolarczyk, J Z Zhang, J Feldmann, J Hofkens, J M Luther, J Pérez-Prieto, L Li, L Manna, M I Bodnarchuk, M V Kovalenko, M B J Roeffaers, N Pradhan, O F Mohammed, O M Bakr, P Yang, P Müller-Buschbaum, P V Kamat, Q Bao, Q Zhang, R Krahne, R E Galian, S D Stranks, S Bals, V Biju, W A Tisdale, Y Yan, R L Z Hoye, L Polavarapu
State of the Art and Prospects for Halide Perovskite Nanocrystals Journal Article
In: ACS Nano, 2021, ISSN: 1936-0851.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{,
title = {State of the Art and Prospects for Halide Perovskite Nanocrystals},
author = {A Dey and J Ye and A De and E Debroye and S K Ha and E Bladt and A S Kshirsagar and Z Wang and J Yin and Y Wang and L N Quan and F Yan and M Gao and X Li and J Shamsi and T Debnath and M Cao and M A Scheel and S Kumar and J A Steele and M Gerhard and L Chouhan and K Xu and X-G Wu and Y Li and Y Zhang and A Dutta and C Han and I Vincon and A L Rogach and A Nag and A Samanta and B A Korgel and C-J Shih and D R Gamelin and D H Son and H Zeng and H Zhong and H Sun and H V Demir and I G Scheblykin and I Mora-Ser\'{o} and J K Stolarczyk and J Z Zhang and J Feldmann and J Hofkens and J M Luther and J P\'{e}rez-Prieto and L Li and L Manna and M I Bodnarchuk and M V Kovalenko and M B J Roeffaers and N Pradhan and O F Mohammed and O M Bakr and P Yang and P M\"{u}ller-Buschbaum and P V Kamat and Q Bao and Q Zhang and R Krahne and R E Galian and S D Stranks and S Bals and V Biju and W A Tisdale and Y Yan and R L Z Hoye and L Polavarapu},
url = {https://doi.org/10.1021/acsnano.0c08903},
doi = {10.1021/acsnano.0c08903},
issn = {1936-0851},
year = {2021},
date = {2021-06-17},
urldate = {2021-06-17},
journal = {ACS Nano},
abstract = {Metal-halide perovskites have rapidly emerged as one of the most promising materials of the 21st century, with many exciting properties and great potential for a broad range of applications, from photovoltaics to optoelectronics and photocatalysis. The ease with which metal-halide perovskites can be synthesized in the form of brightly luminescent colloidal nanocrystals, as well as their tunable and intriguing optical and electronic properties, has attracted researchers from different disciplines of science and technology. In the last few years, there has been a significant progress in the shape-controlled synthesis of perovskite nanocrystals and understanding of their properties and applications. In this comprehensive review, researchers having expertise in different fields (chemistry, physics, and device engineering) of metal-halide perovskite nanocrystals have joined together to provide a state of the art overview and future prospects of metal-halide perovskite nanocrystal research.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
S Yin, W Cao, Q Ji, Y Cheng, L Song, N Li, C L Weindl, M Schwartzkopf, S V Roth, P Müller-Buschbaum
Multidimensional Morphology Control for PS-b-P4VP Templated Mesoporous Iron (III) Oxide Thin Films Journal Article
In: Advanced Materials Interfaces, vol. n/a, no. n/a, pp. 2100141, 2021, ISSN: 2196-7350.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{,
title = {Multidimensional Morphology Control for PS-b-P4VP Templated Mesoporous Iron (III) Oxide Thin Films},
author = {S Yin and W Cao and Q Ji and Y Cheng and L Song and N Li 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/admi.202100141},
doi = {https://doi.org/10.1002/admi.202100141},
issn = {2196-7350},
year = {2021},
date = {2021-06-12},
journal = {Advanced Materials Interfaces},
volume = {n/a},
number = {n/a},
pages = {2100141},
abstract = {Abstract Mesoporous α-Fe2O3 thin films with large area homogeneity demonstrate tremendous potential in multiple applications. In the present work, the synthesis of morphology-controlled α-Fe2O3 thin films is realized with polystyrene-block-poly(4-vinyl pyridine) (PS-b-P4VP) diblock copolymer assisted sol-gel chemistry. The solvent category (DMF and 1,4-dioxane) and polymer-to-FeCl3 ratio used for the solution preparation are systematically varied to tune the morphology of the thin films. For both solvents, DMF and 1,4-dioxane, nanocluster structures are obtained with low PS-b-P4VP concentration. When the concentration of PS-b-P4VP reaches the critical micelle concentration, spherical and wormlike porous structures are specifically formed in the DMF and 1,4-dioxane solvent system, respectively. Further increasing the polymer-to-FeCl3 ratios leads to the enlargement of the spherical pore sizes in the DMF system, whereas the center-to-center distances of the wormlike structures in the 1,4-dioxane system decrease. Moreover, DMF/1,4-dioxane solvent mixtures with different volume ratios are applied for the sol\textendashgel solution preparation to gain more insight into how the solvent selectivity affects the thin film morphology. By adjusting the preferential affinity of the solvent mixture to the polymer blocks, a spherical to wormlike pore shape transition is observed with a critical Δχ value of around 0.77.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
E Mohammadi, A Tittl, K L Tsakmakidis, T V Raziman, A G Curto
Dual Nanoresonators for Ultrasensitive Chiral Detection Journal Article
In: ACS Photonics, 2021.
Abstract | Links | Tags: Foundry Organic, Solid-Solid
@article{,
title = {Dual Nanoresonators for Ultrasensitive Chiral Detection},
author = {E Mohammadi and A Tittl and K L Tsakmakidis and T V Raziman and A G Curto},
url = {https://doi.org/10.1021/acsphotonics.1c00311},
doi = {10.1021/acsphotonics.1c00311},
year = {2021},
date = {2021-05-28},
journal = {ACS Photonics},
abstract = {The discrimination of enantiomers is crucial in biochemistry. However, chiral sensing faces significant limitations due to inherently weak chiroptical signals. Nanophotonics is a promising solution to enhance sensitivity thanks to increased optical chirality maximized by strong electric and magnetic fields. Metallic and dielectric nanoparticles can separately provide electric and magnetic resonances. Here we propose their synergistic combination in hybrid metal\textendashdielectric nanostructures to exploit their dual character for superchiral fields beyond the limits of single particles. For optimal optical chirality, in addition to maximization of the resonance strength, the resonances must spectrally coincide. Simultaneously, their electric and magnetic fields must be parallel and π/2 out of phase and spatially overlap. We demonstrate that the interplay between the strength of the resonances and these optimal conditions constrains the attainable optical chirality in resonant systems. Starting from a simple symmetric nanodimer, we derive closed-form expressions elucidating its fundamental limits of optical chirality. Building on the trade-offs of different classes of dimers, we then suggest an asymmetric dual dimer based on realistic materials. These dual nanoresonators provide strong and decoupled electric and magnetic resonances together with optimal conditions for chiral fields. Finally, we introduce more complex dual building blocks for a metasurface with a record 300-fold enhancement of local optical chirality in nanoscale gaps, enabling circular dichroism enhancement by a factor of 20. By combining analytical insight and practical designs, our results put forward hybrid resonators to increase chiral sensitivity, particularly for small molecular quantities.},
keywords = {Foundry Organic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
S Stegmaier, R Schierholz, I Povstugar, J Barthel, S P Rittmeyer, S Yu, S Wengert, S Rostami, H Kungl, K Reuter, R-A Eichel, C Scheurer
Nano-Scale Complexions Facilitate Li Dendrite-Free Operation in LATP Solid-State Electrolyte Journal Article
In: Advanced Energy Materials, vol. n/a, no. n/a, pp. 2100707, 2021, ISSN: 1614-6832.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{,
title = {Nano-Scale Complexions Facilitate Li Dendrite-Free Operation in LATP Solid-State Electrolyte},
author = {S Stegmaier and R Schierholz and I Povstugar and J Barthel and S P Rittmeyer and S Yu and S Wengert and S Rostami and H Kungl and K Reuter and R-A Eichel and C Scheurer},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202100707},
doi = {https://doi.org/10.1002/aenm.202100707},
issn = {1614-6832},
year = {2021},
date = {2021-05-28},
journal = {Advanced Energy Materials},
volume = {n/a},
number = {n/a},
pages = {2100707},
abstract = {Abstract Dendrite formation and growth remains a major obstacle toward high-performance all solid-state batteries using Li metal anodes. The ceramic Li(1+x)Al(x)Ti(2−x)(PO4)3 (LATP) solid-state electrolyte shows a higher than expected stability against electrochemical decomposition despite a bulk electronic conductivity that exceeds a recently postulated threshold for dendrite-free operation. Here, transmission electron microscopy, atom probe tomography, and first-principles based simulations are combined to establish atomistic structural models of glass-amorphous LATP grain boundaries. These models reveal a nanometer-thin complexion layer that encapsulates the crystalline grains. The distinct composition of this complexion constitutes a sizable electronic impedance. Rather than fulfilling macroscopic bulk measures of ionic and electronic conduction, LATP might thus gain the capability to suppress dendrite nucleation by sufficient local separation of charge carriers at the nanoscale.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
M H Aufa, S A Watzele, S Hou, R W Haid, R M Kluge, A S Bandarenka, B Garlyyev
Fast and accurate determination of the electroactive surface area of MnOx Journal Article
In: Electrochimica Acta, vol. 389, pp. 138692, 2021, ISSN: 0013-4686.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{,
title = {Fast and accurate determination of the electroactive surface area of MnOx},
author = {M H Aufa and S A Watzele and S Hou and R W Haid and R M Kluge and A S Bandarenka and B Garlyyev},
url = {https://www.sciencedirect.com/science/article/pii/S0013468621009828},
doi = {https://doi.org/10.1016/j.electacta.2021.138692},
issn = {0013-4686},
year = {2021},
date = {2021-05-27},
journal = {Electrochimica Acta},
volume = {389},
pages = {138692},
abstract = {Manganese oxide (MnOx)-based materials are widely utilized in the field of electrocatalysis as bifunctional electrocatalysts for the oxygen reduction and evolution reactions. However, for an accurate assessment of their performance, the determination of their electrochemical active surface area (ECSA) is of paramount importance. So far, there is no fast and reproducible methodology. This article presents an easily applicable and affordable technique to determine the ECSA of MnOx accurately. The presented methodology makes use of the specific adsorption capacitance of reaction intermediates close to the onset potential of the oxygen evolution reaction. The electrochemical impedance spectroscopy is utilized to measure the specific adsorption capacitances at different potentials. Using MnOx thin-film electrodes, we determine the specific adsorption capacitances and present calibration values, which can be used for an accurate determination of the ECSA of different, for instance, nanostructured materials.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
L Katzenmeier, L Carstensen, S J Schaper, P Müller-Buschbaum, A S Bandarenka
In: Advanced Materials, pp. e2100585, 2021, ISSN: 0935-9648.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{,
title = {Characterization and Quantification of Depletion and Accumulation Layers in Solid-State Li+-Conducting Electrolytes Using In Situ Spectroscopic Ellipsometry},
author = {L Katzenmeier and L Carstensen and S J Schaper and P M\"{u}ller-Buschbaum and A S Bandarenka},
url = {http://europepmc.org/abstract/MED/33955614
https://doi.org/10.1002/adma.202100585},
doi = {10.1002/adma.202100585},
issn = {0935-9648},
year = {2021},
date = {2021-05-06},
journal = {Advanced Materials},
pages = {e2100585},
abstract = {The future of mobility depends on the development of next-generation battery technologies, such as all-solid-state batteries. As the ionic conductivity of solid Li^{+} -conductors can, in some cases, approach that of liquid electrolytes, a significant remaining barrier faced by solid-state electrolytes (SSEs) is the interface formed at the anode and cathode materials, with chemical instability and physical resistances arising. The physical properties of space charge layers (SCLs), a widely discussed phenomenon in SSEs, are still unclear. In this work, spectroscopic ellipsometry is used to characterize the accumulation and depletion layers. An optical model is developed to quantify their thicknesses and corresponding concentration changes. It is shown that the Li^{+} -depleted layer (≈190 nm at 1 V) is thinner than the accumulation layer (≈320 nm at 1 V) in a glassy lithium-ion-conducting glass ceramic electrolyte (a trademark of Ohara Corporation). The in situ approach combining electrochemistry and optics resolves the ambiguities around SCL formation. It opens up a wide field of optical measurements on SSEs, allowing various experimental studies in the future.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}