R Shafei, P J Strobel, P J Schmidt, D Maganas, W Schnick, F Neese
In: Physical Chemistry Chemical Physics, vol. 26, no. 7, pp. 6277-6291, 2024, ISSN: 1463-9076.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {A theoretical spectroscopy study of the photoluminescence properties of narrow band Eu2+-doped phosphors containing multiple candidate doping centers. Prediction of an unprecedented narrow band red phosphor},
author = {R Shafei and P J Strobel and P J Schmidt and D Maganas and W Schnick and F Neese},
url = {http://dx.doi.org/10.1039/D3CP06039J},
doi = {10.1039/D3CP06039J},
issn = {1463-9076},
year = {2024},
date = {2024-01-18},
journal = {Physical Chemistry Chemical Physics},
volume = {26},
number = {7},
pages = {6277-6291},
abstract = {We have previously presented a computational protocol that is based on an embedded cluster model and operates in the framework of TD-DFT in conjunction with the excited state dynamics (ESD) approach. The protocol is able to predict the experimental absorption and emission spectral shapes of Eu2+-doped phosphors. In this work, the applicability domain of the above protocol is expanded to Eu2+-doped phosphors bearing multiple candidate Eu doping centers. It will be demonstrated that this protocol provides full control of the parameter space that describes the emission process. The stability of Eu doping at various centers is explored through local energy decomposition (LED) analysis of DLPNO-CCSD(T) energies. This enables further development of the understanding of the electronic structure of the targeted phosphors, the diverse interactions between Eu and the local environment, and their impact on Eu doping probability, and control of the emission properties. Hence, it can be employed to systematically improve deficiencies of existing phosphor materials, defined by the presence of various intensity emission bands at undesired frequencies, towards classes of candidate Eu2+-doped phosphors with desired narrow band red emission. For this purpose, the chosen study set consists of three UCr4C4-based narrow-band phosphors, namely the known alkali lithosilicates RbNa[Li3SiO4]2:Eu2+ (RNLSO2), RbNa3[Li3SiO4]4:Eu2+ (RNLSO) and their isotypic nitridolithoaluminate phosphors consisting of CaBa[LiAl3N4]2:Eu2+ (CBLA2) and the proposed Ca3Ba[LiAl3N4]4:Eu2+ (CBLA), respectively. The theoretical analysis presented in this work led us to propose a modification of the CBLA2 phosphor that should have improved and unprecedented narrow band red emission properties. Finally, we believe that the analysis presented here is important for the future rational design of novel Eu2+-doped phosphor materials, with a wide range of applications in science and technology.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
S Schneider, S Klenk, S D Kloss, W Schnick
Please Mind the Gap: Highly Condensed P–N Networks in LiP4N7 and Li3−xP6N11−x(NH)x Journal Article
In: Chemistry – A European Journal, vol. 30, pp. e202303251, 2024, ISSN: 0947-6539.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Please Mind the Gap: Highly Condensed P\textendashN Networks in LiP4N7 and Li3−xP6N11−x(NH)x},
author = {S Schneider and S Klenk and S D Kloss and W Schnick},
url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.202303251},
doi = {https://doi.org/10.1002/chem.202303251},
issn = {0947-6539},
year = {2024},
date = {2024-01-04},
urldate = {2023-10-24},
journal = {Chemistry \textendash A European Journal},
volume = {30},
pages = {e202303251},
abstract = {Abstract Alkali nitridophosphates AP4N7 and A3P6N11 (A=Na, K, Rb, Cs) have been known for decades. However, their Li homologues have remained elusive. In this work, the highly condensed lithium (imido)nitridophosphates LiP4N7 and Li3−xP6N11−x(NH)x (x=1.66(3)) were synthesized from LiPN2 and P3N5 in the multianvil press at 10 GPa. They constitute the first lithium nitridophosphates with 3D networks exhibiting a degree of condensation larger than 0.5 and high thermal stability. LiP4N7 crystallizes in the orthorhombic space group P212121 with a=4.5846(6) r{A}},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
D Han, B Zhu, Z Cai, K B Spooner, S S Rudel, W Schnick, T Bein, D O Scanlon, H Ebert
Discovery of multi-anion antiperovskites X6NFSn2 (X = Ca, Sr) as promising thermoelectric materials by computational screening Journal Article
In: Matter, vol. 7, iss. 1, pp. 158-174, 2024, ISSN: 2590-2385.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Discovery of multi-anion antiperovskites X6NFSn2 (X = Ca, Sr) as promising thermoelectric materials by computational screening},
author = {D Han and B Zhu and Z Cai and K B Spooner and S S Rudel and W Schnick and T Bein and D O Scanlon and H Ebert},
url = {https://www.sciencedirect.com/science/article/pii/S2590238523005234},
doi = {https://doi.org/10.1016/j.matt.2023.10.022},
issn = {2590-2385},
year = {2024},
date = {2024-01-03},
urldate = {2024-01-03},
journal = {Matter},
volume = {7},
issue = {1},
pages = {158-174},
abstract = {Summary The thermoelectric performance of existing perovskites lags far behind that of state-of-the-art thermoelectric materials such as SnSe. Despite halide perovskites showing promising thermoelectric properties, namely, high Seebeck coefficients and ultralow thermal conductivities, their thermoelectric performance is significantly restricted by low electrical conductivities. Here, we explore new multi-anion antiperovskites X6NFSn2 (X = Ca, Sr, and Ba) via B-site anion mutation in antiperovskite and global structure searches and demonstrate their phase stability by first-principles calculations. Ca6NFSn2 and Sr6NFSn2 exhibit decent Seebeck coefficients and ultralow lattice thermal conductivities (\<1 W m−1 K−1). Notably, Ca6NFSn2 and Sr6NFSn2 show remarkably larger electrical conductivities compared to the halide perovskite CsSnI3. The combined superior electrical and thermal properties of Ca6NFSn2 and Sr6NFSn2 lead to high thermoelectric figures of merit (ZTs) of ∼1.9 and ∼2.3 at high temperatures. Our exploration of multi-anion antiperovskites X6NFSn2 (X = Ca, Sr) realizes the “phonon-glass, electron-crystal” concept within the antiperovskite structure.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
S L Wandelt, A Mutschke, D Khalyavin, R Calaminus, J Steinadler, B V Lotsch, W Schnick
Combining Nitridoborates, Nitrides and Hydrides—Synthesis and Characterization of the Multianionic Sr6N[BN2]2H3 Journal Article
In: Angewandte Chemie International Edition, vol. 62, no. 50, pp. e202313564, 2023, ISSN: 1433-7851.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Combining Nitridoborates, Nitrides and Hydrides\textemdashSynthesis and Characterization of the Multianionic Sr6N[BN2]2H3},
author = {S L Wandelt and A Mutschke and D Khalyavin and R Calaminus and J Steinadler and B V Lotsch and W Schnick},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202313564},
doi = {https://doi.org/10.1002/anie.202313564},
issn = {1433-7851},
year = {2023},
date = {2023-10-31},
urldate = {2023-10-31},
journal = {Angewandte Chemie International Edition},
volume = {62},
number = {50},
pages = {e202313564},
abstract = {Abstract Multianionic metal hydrides, which exhibit a wide variety of physical properties and complex structures, have recently attracted growing interest. Here we present Sr6N[BN2]2H3, prepared in a solid-state ampoule reaction at 800 °C, as the first combination of nitridoborate, nitride and hydride anions within a single compound. The crystal structure was solved from single-crystal X-ray and neutron powder diffraction data in space group P21/c (no. 14), revealing a three-dimensional network of undulated layers of nitridoborate units, strontium atoms and hydride together with nitride anions. Magic angle spinning (MAS) NMR and vibrational spectroscopy in combination with quantum chemical calculations further confirm the structure model. Electrochemical measurements suggest the existence of hydride ion conductivity, allowing the hydrides to migrate along the layers.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
S Schneider, S T Kreiner, L G Balzat, B V Lotsch, W Schnick
Finding Order in Disorder: The Highly Disordered Lithium Oxonitridophosphate Double Salt Li8+xP3O10−xN1+x (x=1.4(5)) Journal Article
In: Chemistry – A European Journal, vol. 29, no. 55, pp. e202301986, 2023, ISSN: 0947-6539.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Finding Order in Disorder: The Highly Disordered Lithium Oxonitridophosphate Double Salt Li8+xP3O10−xN1+x (x=1.4(5))},
author = {S Schneider and S T Kreiner and L G Balzat and B V Lotsch and W Schnick},
url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.202301986},
doi = {https://doi.org/10.1002/chem.202301986},
issn = {0947-6539},
year = {2023},
date = {2023-07-12},
journal = {Chemistry \textendash A European Journal},
volume = {29},
number = {55},
pages = {e202301986},
abstract = {Abstract The crystalline lithium oxonitridophosphate Li8+xP3O10−xN1+x, was obtained in an ampoule synthesis from P3N5 and Li2O. The compound crystallizes in the triclinic space group P with a=5.125(2)},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
C Harder, A E Alexakis, Y Bulut, S Xiong, B Sochor, G Pan, H Zhong, K Goordeyeva, M A Reus, V Körstgens, A Jeromin, T F Keller, L D Söderberg, E Malmström, P Müller-Buschbaum, S V Roth
Optical Properties of Slot-Die Coated Hybrid Colloid/Cellulose-Nanofibril Thin Films Journal Article
In: Advanced Optical Materials, vol. n/a, no. n/a, pp. 2203058, 2023, ISSN: 2195-1071.
Abstract | Links | Tags: Foundry Organic, Solid-Solid
@article{nokey,
title = {Optical Properties of Slot-Die Coated Hybrid Colloid/Cellulose-Nanofibril Thin Films},
author = {C Harder and A E Alexakis and Y Bulut and S Xiong and B Sochor and G Pan and H Zhong and K Goordeyeva and M A Reus and V K\"{o}rstgens and A Jeromin and T F Keller and L D S\"{o}derberg and E Malmstr\"{o}m and P M\"{u}ller-Buschbaum and S V Roth},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202203058},
doi = {https://doi.org/10.1002/adom.202203058},
issn = {2195-1071},
year = {2023},
date = {2023-04-05},
journal = {Advanced Optical Materials},
volume = {n/a},
number = {n/a},
pages = {2203058},
abstract = {Abstract Correlating nanostructure and optical properties of thin hybrid films is the crucial ingredient for designing sustainable applications ranging from structural colors in anticounterfeiting to sensors. Here, the tailoring of the refractive index of hybrid cellulose nanofibril/water-dispersed colloidal ink thin films is presented. The authors apply scalable, layer-by-layer slot-die coating for preparing the cellulose nanofibril and hybrid thin films. Making use of the mobility of the polymer chains in the colloids upon annealing, the influence of the different colloid sizes and their glass transition temperature on the refractive index of the hybrid material is shown. The complex refractive indices of the thin films are characterized by spectroscopic ellipsometry and correlated to the different nanostructures of the thin films. The authors find that post-deposition annealing changes the colloidal nanostructure from particulate to agglomerates. Depending on the size of the colloids, imbibition of the colloids into the cellulose nanofibril template is observed. This scalable approach offers new avenues in structural color functional biomaterial hybrid layers.},
keywords = {Foundry Organic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
S Wang, D Han, C Maheu, Z Xu, A Biewald, H Illner, R Hooijer, T Mayer, A Hartschuh, H Ebert, T Bein
Room-temperature synthesis of lead-free copper(I)-antimony(III)-based double perovskite nanocrystals Journal Article
In: APL Materials, vol. 11, no. 4, pp. 041110, 2023.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Room-temperature synthesis of lead-free copper(I)-antimony(III)-based double perovskite nanocrystals},
author = {S Wang and D Han and C Maheu and Z Xu and A Biewald and H Illner and R Hooijer and T Mayer and A Hartschuh and H Ebert and T Bein},
url = {https://aip.scitation.org/doi/abs/10.1063/5.0144708},
doi = {10.1063/5.0144708},
year = {2023},
date = {2023-04-05},
journal = {APL Materials},
volume = {11},
number = {4},
pages = {041110},
abstract = {In the field of perovskite solar cells, explorations of new lead-free all-inorganic perovskite materials are of great interest to address the instability and toxicity issues of lead-based hybrid perovskites. Recently, copper-antimony-based double perovskite materials have been reported with ideal band gaps, which possess great potential as absorbers for photovoltaic applications. Here, we synthesize Cs2CuSbCl6 double perovskite nanocrystals (DPNCs) at ambient conditions by a facile and fast synthesis method, namely, a modified ligand-assisted reprecipitation method. We choose methanol as a solvent for precursor salts as it is less toxic and easily removed in contrast to widely used dimethylformamide. Our computational structure search shows that the Cs2CuSbCl6 structure containing alternating [CuCl6]5− and [SbCl6]3− octahedral units is a metastable phase that is 30 meV/atom higher in energy compared to the ground state structure with [CuCl3]2− and [SbCl6]3− polyhedra. However, this metastable Cs2CuSbCl6 double perovskite structure can be stabilized through solution-based nanocrystal synthesis. Using an anion-exchange method, Cs2CuSbBr6 DPNCs are obtained for the first time, featuring a narrow bandgap of 0.9 eV. Finally, taking advantage of the solution processability of DPNCs, smooth and dense Cs2CuSbCl6 and Cs2CuSbBr6 DPNC films are successfully fabricated.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
M Armer, P Dörflinger, A Weis, C Büchner, A Gottscholl, J Höcker, K Frank, L Nusser, M T Sirtl, B Nickel, T Bein, V Dyakonov
Low Temperature Optical Properties of Novel Lead-Free Cs2NaFeCl6 Perovskite Single Crystals Journal Article
In: Advanced Photonics Research, vol. n/a, no. n/a, pp. 2300017, 2023, ISSN: 2699-9293.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Low Temperature Optical Properties of Novel Lead-Free Cs2NaFeCl6 Perovskite Single Crystals},
author = {M Armer and P D\"{o}rflinger and A Weis and C B\"{u}chner and A Gottscholl and J H\"{o}cker and K Frank and L Nusser and M T Sirtl and B Nickel and T Bein and V Dyakonov},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adpr.202300017},
doi = {https://doi.org/10.1002/adpr.202300017},
issn = {2699-9293},
year = {2023},
date = {2023-04-02},
journal = {Advanced Photonics Research},
volume = {n/a},
number = {n/a},
pages = {2300017},
abstract = {Lead-free double perovskites have attracted much attention as possible alternatives to lead halide based perovskites in photovoltaic applications. However, to date only few double perovskites have been successfully employed in optoelectronic device prototypes. Therefore, the search for stable and lead-free materials is ongoing. Here, we present the successful growth of high-quality Cs2NaFeCl6 single crystals and their temperature-dependent structural and optical properties. By combining electron paramagnetic resonance (EPR), crystal structure analysis and density functional theory (DFT) we could determine a cubic crystal structure with a spin of 5/2 for this material, showing strongly spin polarized character. Furthermore, combining photoluminescence (PL) and optical absorption measurements we find a bandgap of approximately 2.1 eV at room temperature as well as the presence of excitonic states. Using Elliot's formula, we are able to extract the temperature-dependent behavior of the bandgap as well as an estimated exciton binding energy of only 20 meV at 80 K.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
L Nan, J Giráldez-Martínez, A Stefancu, L Zhu, M Liu, A O Govorov, L V Besteiro, E Cortés
Investigating Plasmonic Catalysis Kinetics on Hot-Spot Engineered Nanoantennae Journal Article
In: Nano Letters, 2023, ISSN: 1530-6984.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Investigating Plasmonic Catalysis Kinetics on Hot-Spot Engineered Nanoantennae},
author = {L Nan and J Gir\'{a}ldez-Mart\'{i}nez and A Stefancu and L Zhu and M Liu and A O Govorov and L V Besteiro and E Cort\'{e}s},
url = {https://doi.org/10.1021/acs.nanolett.3c00219},
doi = {10.1021/acs.nanolett.3c00219},
issn = {1530-6984},
year = {2023},
date = {2023-03-31},
journal = {Nano Letters},
abstract = {Strong hot-spots can facilitate photocatalytic reactions potentially providing effective solar-to-chemical energy conversion pathways. Although it is well-known that the local electromagnetic field in plasmonic nanocavities increases as the cavity size reduces, the influence of hot-spots on photocatalytic reactions remains elusive. Herein, we explored hot-spot dependent catalytic behaviors on a highly controlled platform with varying interparticle distances. Plasmon-meditated dehalogenation of 4-iodothiophenol was employed to observe time-resolved catalytic behaviors via in situ surface-enhanced Raman spectroscopy on dimers with 5, 10, 20, and 30 nm interparticle distances. As a result, we show that by reducing the gap from 20 to 10 nm, the reaction rate can be sped up more than 2 times. Further reduction in the interparticle distance did not improve reaction rate significantly although the maximum local-field was ∼2.3-fold stronger. Our combined experimental and theoretical study provides valuable insights in designing novel plasmonic photocatalytic platforms.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
A V Bragas, S A Maier, H D Boggiano, G Grinblat, R Berté, L D S Menezes, E Cortés
Nanomechanics with plasmonic nanoantennas: ultrafast and local exchange between electromagnetic and mechanical energy Journal Article
In: J. Opt. Soc. Am. B, 2023.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Nanomechanics with plasmonic nanoantennas: ultrafast and local exchange between electromagnetic and mechanical energy},
author = {A V Bragas and S A Maier and H D Boggiano and G Grinblat and R Bert\'{e} and L D S Menezes and E Cort\'{e}s},
url = {https://opg.optica.org/josab/abstract.cfm?doi=10.1364/JOSAB.482384},
doi = {https://doi.org/10.1364/JOSAB.482384},
year = {2023},
date = {2023-03-10},
journal = {J. Opt. Soc. Am. B},
abstract = {Converted into mechanical nanoresonators after optical pulsed excitation and electron decay into coherent acoustic phonons, plasmonic nanoantennas produce a periodic modulation of their optical properties, allowing, in turn, an optical reading of these extremely small movements. In this work we review the physics of these nanoresonators and their acoustic vibrations, whose frequencies are in the range of a few to tens of GHz. The accurate determination of their oscillation frequencies allows them to act as mechanical nanoprobes, measure local mechanical moduli of the environment, and perform high-resolution imaging using phononic reconstruction. Furthermore, the internal and external damping mechanisms which affect the quality factor of the nanoresonator and, in particular, the role of the substrate when the nanoantennas are integrated into platforms and probed individually are also reviewed. Finally, we discuss the all-optical generation of hypersonic surface acoustic waves with nanoantennas and the importance of their manipulation for potential acousto-plasmonic devices operating in the GHz range and the nanoscale.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
C Cai, K Liu, L Zhang, F Li, Y Tan, P Li, Y Wang, M Wang, Z Feng, D Motta Meira, W Qu, A Stefancu, W Li, H Li, J Fu, H Wang, D Zhang, E Cortés, M Liu
Atomically Local Electric Field Induced Interface Water Reorientation for Alkaline Hydrogen Evolution Reaction Journal Article
In: Angewandte Chemie International Edition, vol. n/a, no. n/a, pp. e202300873, 2023, ISSN: 1433-7851.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Atomically Local Electric Field Induced Interface Water Reorientation for Alkaline Hydrogen Evolution Reaction},
author = {C Cai and K Liu and L Zhang and F Li and Y Tan and P Li and Y Wang and M Wang and Z Feng and D Motta Meira and W Qu and A Stefancu and W Li and H Li and J Fu and H Wang and D Zhang and E Cort\'{e}s and M Liu},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202300873},
doi = {https://doi.org/10.1002/anie.202300873},
issn = {1433-7851},
year = {2023},
date = {2023-03-08},
journal = {Angewandte Chemie International Edition},
volume = {n/a},
number = {n/a},
pages = {e202300873},
abstract = {Abstract The slow water dissociation process in alkaline electrolyte severely limits the kinetics of HER. The orientation of H2O is well known to affect the dissociation process, but H2O orientation is hard to control because of its random distribution. Herein, an atomically asymmetric local electric field was designed by IrRu dizygotic single-atom sites (IrRu DSACs) to tune the H2O adsorption configuration and orientation, thus optimizing its dissociation process. The electric field intensity of IrRu DSACs is over 4.00×1010 N/C. The ab initio molecular dynamics simulations combined with in situ Raman spectroscopy analysis on the adsorption behavior of H2O show that the M−H bond length (M=active site) is shortened at the interface due to the strong local electric field gradient and the optimized water orientation promotes the dissociation process of interfacial water. This work provides a new way to explore the role of single atomic sites in alkaline hydrogen evolution reaction.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
Y Li, Y Li, J E Heger, J Zhou, T Guan, C R Everett, W Wei, Z Hong, Y Wu, X Jiang, S Yin, X Yang, D Li, C Jiang, B Sun, P Müller-Buschbaum
Revealing Surface and Interface Evolution of Molybdenum Nitride as Carrier-Selective Contacts for Crystalline Silicon Solar Cells Journal Article
In: ACS Applied Materials & Interfaces, vol. 15, no. 10, pp. 13753-13760, 2023, ISSN: 1944-8244.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Revealing Surface and Interface Evolution of Molybdenum Nitride as Carrier-Selective Contacts for Crystalline Silicon Solar Cells},
author = {Y Li and Y Li and J E Heger and J Zhou and T Guan and C R Everett and W Wei and Z Hong and Y Wu and X Jiang and S Yin and X Yang and D Li and C Jiang and B Sun and P M\"{u}ller-Buschbaum},
url = {https://doi.org/10.1021/acsami.2c22781},
doi = {10.1021/acsami.2c22781},
issn = {1944-8244},
year = {2023},
date = {2023-03-06},
journal = {ACS Applied Materials \& Interfaces},
volume = {15},
number = {10},
pages = {13753-13760},
abstract = {Molybdenum nitride (MoNx) was perceived as carrier-selective contacts (CSCs) for crystalline silicon (c-Si) solar cells due to having proper work functions and excellent conductivities. However, the poor passivation and non-Ohmic contact at the c-Si/MoNx interface endow an inferior hole selectivity. Here, the surface, interface, and bulk structures of MoNx films are systematically investigated by X-ray scattering, surface spectroscopy, and electron microscope analysis to reveal the carrier-selective features. Surface layers with the composition of MoO2.51N0.21 form upon air exposure, which induces the overestimated work function and explains the origin of inferior hole selectivities. The c-Si/MoNx interface is confirmed to adopt long-term stability, providing guidance for designing stable CSCs. A detailed evolution of the scattering length density, domain sizes, and crystallinity in the bulk phase is presented to elucidate its superior conductivity. These multiscale structural investigations offer a clear structure\textendashfunction correlation of MoNx films, providing key inspiration for developing excellent CSCs for c-Si solar cells.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
B M Stühmeier, A M Damjanović, K Rodewald, H A Gasteiger
Selective anode catalyst for the mitigation of start-up/shut-down induced cathode degradation in proton exchange membrane fuel cells Journal Article
In: Journal of Power Sources, vol. 558, pp. 232572, 2023, ISSN: 0378-7753.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Selective anode catalyst for the mitigation of start-up/shut-down induced cathode degradation in proton exchange membrane fuel cells},
author = {B M St\"{u}hmeier and A M Damjanovi\'{c} and K Rodewald and H A Gasteiger},
url = {https://www.sciencedirect.com/science/article/pii/S037877532201549X},
doi = {https://doi.org/10.1016/j.jpowsour.2022.232572},
issn = {0378-7753},
year = {2023},
date = {2023-02-28},
journal = {Journal of Power Sources},
volume = {558},
pages = {232572},
abstract = {Reducing cathode degradation during start-up and shut-down (SUSD) events is one of the remaining challenges for the widespread application of proton exchange membrane fuel cells (PEMFC). An anode catalyst that is selective for the hydrogen oxidation reaction (HOR) while its activity for the oxygen reduction reaction (ORR) is severely reduced, could substantially prolong the SUSD lifetime of the cathode. Herein, we report on single-cell measurements with a Pt/TiOx/C (x ≤ 2) catalyst that has been shown to be HOR selective by rotating disk electrode (RDE) measurements. The HOR activity of the catalyst was compared to conventional Pt/C by H2-pump measurements at ultra-low loadings. The ORR activity of Pt/TiOx/C was compared to Pt/C anodes with high and low Pt loadings, showing a diminished selectivity in MEA compared to RDE measurements. Unfortunately, the PEMFC performance with the Pt/TiOx/C catalyst was compromised by TiOx dissolution, deduced from voltage loss analysis of the H2/O2 performance curves and by ex-situ SEM/EDX of the MEAs. Finally, the successful mitigation of cathode carbon corrosion was shown over the course of 3200 SUSD cycles, whereby the retention of Pt surface area when using a Pt/TiOx/C anode by far exceeded the improvements expected from the reduced ORR kinetics.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
K Wang, J Huo, L Cao, P Yang, P Müller-Buschbaum, Y Tong, H Wang
Fully Methylammonium-Free Stable Formamidinium Lead Iodide Perovskite Solar Cells Processed under Humid Air Conditions Journal Article
In: ACS Applied Materials & Interfaces, vol. 15, no. 10, pp. 13353-13362, 2023, ISSN: 1944-8244.
Abstract | Links | Tags: Foundry Organic, Solid-Solid
@article{nokey,
title = {Fully Methylammonium-Free Stable Formamidinium Lead Iodide Perovskite Solar Cells Processed under Humid Air Conditions},
author = {K Wang and J Huo and L Cao and P Yang and P M\"{u}ller-Buschbaum and Y Tong and H Wang},
url = {https://doi.org/10.1021/acsami.2c23134},
doi = {10.1021/acsami.2c23134},
issn = {1944-8244},
year = {2023},
date = {2023-02-28},
journal = {ACS Applied Materials \& Interfaces},
volume = {15},
number = {10},
pages = {13353-13362},
abstract = {Fabricating perovskite solar cells (PSCs) in ambient air condition is beneficial for lowering the processing cost and boosting the commercialization. Formamidinium lead iodide (FAPbI3) is an attractive candidate for efficient PSCs; however, it easily suffers from degradation and phase transition in the presence of ambient moisture. Methylammonium (MA) cation is commonly incorporated to stabilize FAPbI3, whereas the residual MA tends to deteriorate the thermal and operational stability. Herein, we report a MA-free strategy to fabricate high-quality α-FAPbI3 films and inverted PSCs under open air conditions with a relative humidity (RH) of 60 ± 10%. The incorporation of phenylethylammonium iodide (PEAI) effectively inhibits the decomposition and phase transition of FAPbI3 during its crystallization in humid air. Accordingly, phase-pure α-FAPbI3 perovskite films with significantly reduced δ-FAPbI3 and PbI2 content are successfully obtained. In addition, introducing PEAI strongly enhances the crystallinity of FAPbI3 perovskite films, thereby yielding enlarged grain sizes and reduced grain boundaries. Defects at the grain boundaries and surface are further passivated by PEAI addition, so that the trap state density is significantly decreased. As a result, the non-radiative recombination is effectively suppressed and the charge carrier transport is promoted. The inverted device optimized with a suitable PEAI concentration exhibits an enhanced power conversion efficiency (PCE) of 17.83%, which significantly surpasses the control device (12.29% PCE). Moreover, the PEAI optimized FAPbI3 PSCs demonstrate strongly improved long-term stability, with nearly 97% PCE maintained after 27-day storage under ambient conditions. This work provides a feasible way to fabricate PSCs in ambient air for promoting their wide range of applications.},
keywords = {Foundry Organic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
S Schneider, E-M Wendinger, V Baran, A-K Hatz, B V Lotsch, M Nentwig, O Oeckler, T Bräuniger, W Schnick
Comprehensive Investigation of Anion Species in Crystalline Li+ ion Conductor Li27−x[P4O7+xN9−x]O3 (x≈1.9(3)) Journal Article
In: Chemistry – A European Journal, vol. 29, no. 27, pp. e202300174, 2023, ISSN: 0947-6539.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Comprehensive Investigation of Anion Species in Crystalline Li+ ion Conductor Li27−x[P4O7+xN9−x]O3 (x≈1.9(3))},
author = {S Schneider and E-M Wendinger and V Baran and A-K Hatz and B V Lotsch and M Nentwig and O Oeckler and T Br\"{a}uniger and W Schnick},
url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.202300174},
doi = {https://doi.org/10.1002/chem.202300174},
issn = {0947-6539},
year = {2023},
date = {2023-02-21},
journal = {Chemistry \textendash A European Journal},
volume = {29},
number = {27},
pages = {e202300174},
abstract = {Abstract The Li+ ion conductor Li27−x[P4O7+xN9−x]O3 (x≈1.9) has been synthesized from P3N5, Li3N and Li2O in a Ta ampoule at 800 °C under Ar atmosphere. The cubic compound crystallizes in space group with a=12.0106(14) r{A} and Z=4. It contains both non-condensed [PO2N2]5− and [PO3N]4− tetrahedra as well as O2− ions, surrounded by Li+ ions. Charge neutrality is achieved by partial occupancy of Li positions, which was refined with neutron powder diffraction data. Measurements of the partial ionic and electronic conductivity show a total ionic conductivity of 6.6×10−8 S cm−1 with an activation energy of 0.46±0.02 eV and a bulk ionic conductivity of 4×10−6 S cm−1 at 25 °C, which is close to the ionic conductivity of amorphous lithium nitridophosphate. This makes Li27−x[P4O7+xN9−x]O3 an interesting candidate for investigation of structural factors affecting ionic conductivity in lithium oxonitridophosphates.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
K Muggli, L Spies, D Bessinger, F Auras, T Bein
Electrically Conductive Carbazole and Thienoisoindigo-Based COFs Showing Fast and Stable Electrochromism Journal Article
In: ACS Nanoscience Au, 2023.
Abstract | Links | Tags: Foundry Organic, Solid-Solid
@article{nokey,
title = {Electrically Conductive Carbazole and Thienoisoindigo-Based COFs Showing Fast and Stable Electrochromism},
author = {K Muggli and L Spies and D Bessinger and F Auras and T Bein},
url = {https://doi.org/10.1021/acsnanoscienceau.2c00049},
doi = {10.1021/acsnanoscienceau.2c00049},
year = {2023},
date = {2023-02-17},
journal = {ACS Nanoscience Au},
abstract = {Thienothiophene thienoisoindigo (ttTII)-based covalent organic frameworks (COFs) have been shown to offer low band gaps and intriguing optical and electrochromic properties. So far, only one tetragonal thienothiophene thienoisoindigo-based COF has been reported showing stable and fast electrochromism and good coloration efficiencies. We have developed two novel COFs using this versatile and nearly linear ttTII building block in a tetragonal and a hexagonal framework geometry to demonstrate their attractive features for optoelectronic applications of thienoisoindigo-based COFs. Both COFs exhibit good electrical conductivities, show promising optical absorption features, are redox-active, and exhibit a strong electrochromic behavior when applying an external electrical stimulus, shifting the optical absorption even farther into the NIR region of the electromagnetic spectrum and achieving absorbance changes of up to 2.5 OD. Cycle-stable cyclic voltammograms with distinct oxidation and reduction waves reveal excellent reversibility and electrochromic switching over 200 cycles and confirm the high stability of the frameworks. Furthermore, high coloration efficiencies in the NIR region and fast switching speeds for coloration/decoloration as fast as 0.75 s/0.37 s for the Cz-ttTII COF and 0.61 s/0.29 s for the TAPB-ttTII COF at 550 nm excitation were observed, outperforming many known electrochromic materials, and offering options for a great variety of applications, such as stimuli-responsive coatings, optical information processing, or thermal control.},
keywords = {Foundry Organic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
K Sun, P Müller-Buschbaum
Shedding Light on the Moisture Stability of Halide Perovskite Thin Films Journal Article
In: Energy Technology, vol. n/a, no. n/a, pp. 2201475, 2023, ISSN: 2194-4288.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Shedding Light on the Moisture Stability of Halide Perovskite Thin Films},
author = {K Sun and P M\"{u}ller-Buschbaum},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/ente.202201475},
doi = {https://doi.org/10.1002/ente.202201475},
issn = {2194-4288},
year = {2023},
date = {2023-02-08},
journal = {Energy Technology},
volume = {n/a},
number = {n/a},
pages = {2201475},
abstract = {To date, remarkable progress has been achieved in the power conversion efficiency of perovskite solar cells (PSCs). Nevertheless, the instability and degradation of PSCs under external stimuli still shadow the prospectus of their commercialization. As a notorious culprit deteriorating the stability of PSCs, moisture-induced degradation is thereby an important aspect. Herein, a comprehensive review of moisture effects on the halide perovskite film, in particular the moisture-induced degradation mechanism and methods toward enhancing the stability, is discussed. In detail, the benefits for perovskite films having a certain amount of water incorporation are elucidated, and the underlying moisture-induced structural degradation and decomposition process of perovskites are summarized. Light is also shed on the methods to enhance the moisture stability of perovskites, particularly a 3D/2D heterostructure. Thereby, this review will enlighten the readers of understanding moisture-induced degradation and the development of stable perovskites.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
H Zhu, Q Wang, K Sun, W Chen, J Tang, J Hao, Z Wang, J Sun, W C H Choy, P Müller-Buschbaum, X W Sun, D Wu, K Wang
In: ACS Applied Materials & Interfaces, vol. 15, no. 7, pp. 9978-9986, 2023, ISSN: 1944-8244.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Solvent Modulation of Chiral Perovskite Films Enables High Circularly Polarized Luminescence Performance from Chiral Perovskite/Quantum Dot Composites},
author = {H Zhu and Q Wang and K Sun and W Chen and J Tang and J Hao and Z Wang and J Sun and W C H Choy and P M\"{u}ller-Buschbaum and X W Sun and D Wu and K Wang},
url = {https://doi.org/10.1021/acsami.2c20716},
doi = {10.1021/acsami.2c20716},
issn = {1944-8244},
year = {2023},
date = {2023-02-08},
journal = {ACS Applied Materials \& Interfaces},
volume = {15},
number = {7},
pages = {9978-9986},
abstract = {Materials with circularly polarized luminescence (CPL) activity are promising in many chiroptoelectronics fields, such as for biological probes, asymmetric photosynthesis, information storage, spintronic devices, and so on. Promoting the value of the dissymmetry factor (glum) for the CPL-active materials based on chiral perovskite draws increasing attention since a higher glum value indicates better CPL. In this work, we find that, after being treated with a facile solvent modulation strategy, the chirality of 2D chiral perovskite films has been enhanced a lot, which we attribute to an increased lattice distortion degree. By forming chiral perovskite/quantum dot (QD) composites, the CPL-active material is successfully obtained. The calculated maximum |glum| of these composites increased over 4 times after solvent modulation treatment (1.53 × 10\textendash3 for the pristine sample of R-DMF and 6.91 × 10\textendash3 for R-NMP) at room temperature. Moreover, the enhancement of the CPL intensity is ascribed to two aspects: one is the generation and transportation of spin-polarized charge carriers from chiral perovskite films to combine in the QD layer, and the other is the solvent modulation strategy to enlarge the lattice distortion of chiral perovskite films. This facile route provides an effective way to construct CPL-active materials. More importantly, this kind of composite material (chiral perovskite film/QD layer) can be easily applied for fabricating circularly polarized light-emitting diode devices for electroluminescence.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
J Ye, A Ren, L Dai, T Baikie, R Guo, D Pal, S Gorgon, J E Heger, J Huang, Y Sun
Direct Linearly-Polarised Electroluminescence from Perovskite Nanoplatelet Superlattices Journal Article
In: arXiv preprint arXiv:2302.03582, 2023.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Direct Linearly-Polarised Electroluminescence from Perovskite Nanoplatelet Superlattices},
author = {J Ye and A Ren and L Dai and T Baikie and R Guo and D Pal and S Gorgon and J E Heger and J Huang and Y Sun},
url = {https://arxiv.org/abs/2302.03582},
doi = {https://doi.org/10.48550/arXiv.2302.0358},
year = {2023},
date = {2023-02-07},
journal = {arXiv preprint arXiv:2302.03582},
abstract = {Polarised light is critical for a wide range of applications, but is usually generated by filtering unpolarised light, which leads to significant energy losses and requires additional optics. Herein, the direct emission of linearly-polarised light is achieved from light-emitting diodes (LEDs) made of CsPbI3 perovskite nanoplatelet superlattices. Through use of solvents with different vapour pressures, the self-assembly of perovskite nanoplatelets is achieved to enable fine control over the orientation (either face-up or edge-up) and therefore the transition dipole moment. As a result of the highly-uniform alignment of the nanoplatelets, as well as their strong quantum and dielectric confinement, large exciton fine-structure splitting is achieved at the film level, leading to pure-red LEDs exhibiting a high degree of linear polarisation of 74.4% without any photonic structures. This work unveils the possibilities of perovskite nanoplatelets as a highly promising source of linearly-polarised electroluminescence, opening up the development of next-generation 3D displays and optical communications from this highly versatile, solution-processable system.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
I Abdelwahab, B Tilmann, X Zhao, I Verzhbitskiy, R Berté, G Eda, W L Wilson, G Grinblat, L De S. Menezes, K P Loh, S A Maier
Highly Efficient Sum-Frequency Generation in Niobium Oxydichloride NbOCl2 Nanosheets Journal Article
In: Advanced Optical Materials, vol. 11, no. 7, pp. 2202833, 2023, ISSN: 2195-1071.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Highly Efficient Sum-Frequency Generation in Niobium Oxydichloride NbOCl2 Nanosheets},
author = {I Abdelwahab and B Tilmann and X Zhao and I Verzhbitskiy and R Bert\'{e} and G Eda and W L Wilson and G Grinblat and L De S. Menezes and K P Loh and S A Maier},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202202833},
doi = {https://doi.org/10.1002/adom.202202833},
issn = {2195-1071},
year = {2023},
date = {2023-02-05},
journal = {Advanced Optical Materials},
volume = {11},
number = {7},
pages = {2202833},
abstract = {Abstract Parametric infrared (IR) upconversion is a process in which low-frequency IR photons are upconverted into high-frequency ultraviolet/visible photons through a nonlinear optical process. It is of paramount importance for a wide range of security, material science, and healthcare applications. However, in general, the efficiencies of upconversion processes are typically extremely low for nanometer-scale materials due to the short penetration depth of the excitation fields. Here, parametric IR upconversion processes, including frequency doubling and sum-frequency generation, are studied in layered van der Waals NbOCl2. An upconversion efficiency of up to 0.004% is attained for the NbOCl2 nanosheets, orders of magnitude higher than previously reported values for nonlinear layered materials. The upconverted signal is sensitive to layer numbers, crystal orientation, excitation wavelength, and temperature, and it can be utilized as an optical cross-correlator for ultrashort pulse characterization.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
A Stefancu, J Gargiulo, G Laufersky, B Auguié, V Chiş, E C Le Ru, M Liu, N Leopold, E Cortés
Interface-Dependent Selectivity in Plasmon-Driven Chemical Reactions Journal Article
In: ACS Nano, vol. 17, no. 3, pp. 3119-3127, 2023, ISSN: 1936-0851.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Interface-Dependent Selectivity in Plasmon-Driven Chemical Reactions},
author = {A Stefancu and J Gargiulo and G Laufersky and B Augui\'{e} and V Chi\c{s} and E C Le Ru and M Liu and N Leopold and E Cort\'{e}s},
url = {https://doi.org/10.1021/acsnano.2c12116},
doi = {10.1021/acsnano.2c12116},
issn = {1936-0851},
year = {2023},
date = {2023-02-01},
journal = {ACS Nano},
volume = {17},
number = {3},
pages = {3119-3127},
abstract = {Plasmonic nanoparticles can drive chemical reactions powered by sunlight. These processes involve the excitation of surface plasmon resonances (SPR) and the subsequent charge transfer to adsorbed molecular orbitals. Nonetheless, controlling the flow of energy and charge from SPR to adsorbed molecules is still difficult to predict or tune. Here, we show the crucial role of halide ions in modifying the energy landscape of a plasmon-driven chemical reaction by carefully engineering the nanoparticle\textendashmolecule interface. By doing so, the selectivity of plasmon-driven chemical reactions can be controlled, either enhancing or inhibiting the metal\textendashmolecule charge and energy transfer or by regulating the vibrational pumping rate. These results provide an elegant method for controlling the energy flow from plasmonic nanoparticles to adsorbed molecules, in situ, and selectively targeting chemical bonds by changing the chemical nature of the metal\textendashmolecule interface.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
J E Heger, W Chen, H Zhong, T Xiao, C Harder, F C Apfelbeck, A F Weinzierl, R Boldt, L Schraa, E Euchler, A K Sambale, K Schneider, M Schwartzkopf, S V Roth, P Müller-Buschbaum
Superlattice deformation in quantum dot films on flexible substrates via uniaxial strain Journal Article
In: Nanoscale Horizons, vol. 8, no. 3, pp. 383-395, 2023, ISSN: 2055-6756.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Superlattice deformation in quantum dot films on flexible substrates via uniaxial strain},
author = {J E Heger and W Chen and H Zhong and T Xiao and C Harder and F C Apfelbeck and A F Weinzierl and R Boldt and L Schraa and E Euchler and A K Sambale and K Schneider and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},
url = {http://dx.doi.org/10.1039/D2NH00548D},
doi = {10.1039/D2NH00548D},
issn = {2055-6756},
year = {2023},
date = {2023-01-23},
journal = {Nanoscale Horizons},
volume = {8},
number = {3},
pages = {383-395},
abstract = {The superlattice in a quantum dot (QD) film on a flexible substrate deformed by uniaxial strain shows a phase transition in unit cell symmetry. With increasing uniaxial strain, the QD superlattice unit cell changes from tetragonal to cubic to tetragonal phase as measured with in situ grazing-incidence small-angle X-ray scattering (GISAXS). The respective changes in the optoelectronic coupling are probed with photoluminescence (PL) measurements. The PL emission intensity follows the phase transition due to the resulting changing inter-dot distances. The changes in PL intensity accompany a redshift in the emission spectrum, which agrees with the F\"{o}rster resonance energy transfer (FRET) theory. The results are essential for a fundamental understanding of the impact of strain on the performance of flexible devices based on QD films, such as wearable electronics and next-generation solar cells on flexible substrates.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
C Lampe, I Kouroudis, M Harth, S Martin, A Gagliardi, A S Urban
Rapid Data-Efficient Optimization of Perovskite Nanocrystal Syntheses through Machine Learning Algorithm Fusion Journal Article
In: Advanced Materials, vol. n/a, no. n/a, pp. 2208772, 2023, ISSN: 0935-9648.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Rapid Data-Efficient Optimization of Perovskite Nanocrystal Syntheses through Machine Learning Algorithm Fusion},
author = {C Lampe and I Kouroudis and M Harth and S Martin and A Gagliardi and A S Urban},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202208772},
doi = {https://doi.org/10.1002/adma.202208772},
issn = {0935-9648},
year = {2023},
date = {2023-01-21},
journal = {Advanced Materials},
volume = {n/a},
number = {n/a},
pages = {2208772},
abstract = {Abstract With the demand for renewable energy and efficient devices rapidly increasing, a need arises to find and optimize novel (nano)materials. With sheer limitless possibilities for material combinations and synthetic procedures, obtaining novel, highly functional materials has been a tedious trial and error process. Recently, machine learning has emerged as a powerful tool to help optimize syntheses; however, most approaches require a substantial amount of input data, limiting their pertinence. Here, we merge three well-known machine-learning models with Bayesian Optimization into one to optimize the synthesis of CsPbBr3 nanoplatelets with limited data demand. The algorithm can accurately predict the photoluminescence emission maxima of nanoplatelet dispersions using only the three precursor ratios as input parameters. This allowed us to fabricate previously unobtainable 7 and 8 monolayer-thick nanoplatelets. Moreover, the algorithm dramatically improved the homogeneity of 2-6 monolayer-thick nanoplatelet dispersions, as evidenced by narrower and more symmetric photoluminescence spectra. Decisively, only 200 total syntheses were required to achieve this vast improvement, highlighting how rapidly material properties can be optimized. The algorithm is highly versatile and can incorporate additional synthetic parameters. Accordingly, it is readily applicable to other less-explored nanocrystal syntheses and can help rapidly identify and improve exciting compositions' quality. This article is protected by copyright. All rights reserved},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
F Treber, K Frank, B Nickel, C Lampe, A S Urban
Lead-free, luminescent perovskite nanocrystals obtained through ambient condition synthesis Journal Article
In: arXiv preprint arXiv:2301.08936, 2023.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Lead-free, luminescent perovskite nanocrystals obtained through ambient condition synthesis},
author = {F Treber and K Frank and B Nickel and C Lampe and A S Urban},
url = {https://arxiv.org/abs/2301.08936},
doi = {https://doi.org/10.48550/arXiv.2301.08936},
year = {2023},
date = {2023-01-21},
journal = {arXiv preprint arXiv:2301.08936},
abstract = {Heterovalent substitution of toxic lead is an increasingly popular design strategy to obtain environmentally sustainable variants of the exciting material class of halide perovskites. Perovskite nanocrystals (NCs) obtained through solution-based methods exhibit exceedingly high optical quality. Unfortunately, most of these synthesis routes still require reaction under inert gas and at very high temperatures. Herein we present a novel synthesis routine for lead-free double perovskite NCs. We combine hot injection and ligand-assisted reprecipitation (LARP) methods to achieve a low-temperature and ambient atmosphere-based synthesis for manganese-doped Cs_2NaBiCl_6 NCs. Mn incorporation is critical for the otherwise non-emissive material, with a 9:1 Bi:Mn precursor ratio maximizing the bright orange photoluminescence (PL) and quantum yield (QY). Higher temperatures slightly increased the material's performance, yet NCs synthesized at room temperature were still emissive, highlighting the versatility of the synthetic approach. Furthermore, the NCs show excellent long-term stability in ambient conditions, facilitating additional investigations and energy-related applications.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
Y Huang, T Xiao, S Chen, Z Xie, J Zheng, J Zhu, Y Su, W Chen, K Liu, M Tang, P Müller-Buschbaum, L Li
All-optical controlled-NOT logic gate achieving directional asymmetric transmission based on metasurface doublet Journal Article
In: Opto-Electronic Advances, pp. 220073-1-220073-9, 2023, ISSN: 2096-4579.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {All-optical controlled-NOT logic gate achieving directional asymmetric transmission based on metasurface doublet},
author = {Y Huang and T Xiao and S Chen and Z Xie and J Zheng and J Zhu and Y Su and W Chen and K Liu and M Tang and P M\"{u}ller-Buschbaum and L Li},
url = {http://www.oejournal.org//article/doi/10.29026/oea.2023.220073},
doi = {10.29026/oea.2023.220073},
issn = {2096-4579},
year = {2023},
date = {2023-01-18},
journal = {Opto-Electronic Advances},
pages = {220073-1-220073-9},
abstract = {Optical logic gates play important roles in all-optical logic circuits, which lie at the heart of the next-generation optical computing technology. However, the intrinsic contradiction between compactness and robustness hinders the development in this field. Here, we propose a simple design principle that can possess multiple-input-output states according to the incident circular polarization and direction based on the metasurface doublet, which enables controlled-NOT logic gates in infrared region. Therefore, the directional asymmetric electromagnetic transmission can be achieved. As a proof of concept, a spin-dependent Janus metasurface is designed and experimentally verified that four distinct images corresponding to four input states can be captured in the far-field. In addition, since the design method is derived from geometric optics, it can be easily applied to other spectra. We believe that the proposed metasurface doublet may empower many potential applications in chiral imaging, chiroptical spectroscopy and optical computing.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
X Jiang, S Grott, V Körstgens, K S Wienhold, Z Li, J Zhang, C R Everett, M Schwartzkopf, S V Roth, P Müller-Buschbaum
In: Solar RRL, vol. 7, no. 6, pp. 2201077, 2023, ISSN: 2367-198X.
Abstract | Links | Tags: Foundry Organic, Solid-Solid
@article{nokey,
title = {Film Formation Kinetics of Polymer Donor and Nonfullerene Acceptor Active Layers During Printing Out of 1,2,4-Trimethylbenzene in Ambient Conditions},
author = {X Jiang and S Grott and V K\"{o}rstgens and K S Wienhold and Z Li and J Zhang and C R Everett and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/solr.202201077},
doi = {https://doi.org/10.1002/solr.202201077},
issn = {2367-198X},
year = {2023},
date = {2023-01-13},
journal = {Solar RRL},
volume = {7},
number = {6},
pages = {2201077},
abstract = {Slot-die coating is a promising upscaling fabrication method to promote commercialization in the field of organic solar cells. Herein, the nonfullerene active layer blend of a conjugated polymer PffBT4T-2OD and a small molecule acceptor EH-IDTBR, which is printed out of the nonhalogenated solvent 1,2,4-trimethylbenzene, is studied. The film formation kinetics of the active layer PffBT4T-2OD:EH-IDTBR is probed in terms of the temporal evolutions in morphology as well as molecular conformation and aggregation as revealed by in situ grazing-incidence small angle X-ray scattering and UV\textendashvis spectroscopy during the film printing process. A five-regime mesoscale domain growth process is observed in the active layer from the liquid state to the final dry state. The solvent evaporation-induced domain growth is accompanied with molecular stacking in a distinct J-type aggregation of the acceptor and a slight H-type aggregation of the donor molecules. The printed active layers exhibit an edge-on dominated PffBT4T-2OD and a face-on dominated EH-IDTBR crystallite structure. Compared to the neat PffBT4T-2OD and EH-IDTBR films, in the active layer, the crystallite structure deviates slightly in lattice spacing.},
keywords = {Foundry Organic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
F A Freire-Moschovitis, R Rizzato, A Pershin, M R Schepp, R D Allert, L M Todenhagen, M S Brandt, Á Gali, D B Bucher
Sensing Diamagnetic Electrolytes with Spin Defects in Diamond Journal Article
In: arXiv preprint arXiv:2301.04952, 2023.
Abstract | Links | Tags: Solid-Solid
@article{nokey,
title = {Sensing Diamagnetic Electrolytes with Spin Defects in Diamond},
author = {F A Freire-Moschovitis and R Rizzato and A Pershin and M R Schepp and R D Allert and L M Todenhagen and M S Brandt and \'{A} Gali and D B Bucher},
url = {https://arxiv.org/abs/2301.04952v1},
doi = {https://doi.org/10.48550/arXiv.2301.04952},
year = {2023},
date = {2023-01-12},
journal = {arXiv preprint arXiv:2301.04952},
abstract = {Quantum sensing with spin defects in diamond, such as the nitrogen vacancy (NV) center, enables the detection of various chemical species on the nanoscale. Molecules or ions with unpaired electronic spins are typically probed by their influence on the NV-center's spin relaxation. Whereas it is well-known that paramagnetic ions reduce the NV-center's relaxation time T1, here we report on the opposite effect for diamagnetic ions. We demonstrate that millimolar concentrations of aqueous diamagnetic electrolyte solutions increase the T1 time of near-surface NV-center ensembles compared to pure water. To elucidate the underlying mechanism of this surprising effect, single and double quantum NV experiments are performed, which indicate a reduction of magnetic and electric noise in the presence of diamagnetic electrolytes. In combination with ab initio simulations, we propose that a change in the interfacial band bending due to the formation of an electric double layer leads to a stabilization of fluctuating charges at the interface of an oxygen-terminated diamond. This work not only helps to understand noise sources in quantum systems but also broadens the application space of quantum sensors towards electrolyte sensing in cell biology, neuroscience and electrochemistry.},
keywords = {Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
Y Long, J He, H Zhang, Y Chen, K Liu, J Fu, H Li, L Zhu, Z Lin, A Stefancu, E Cortes, M Zhu, M Liu
Highly selective monomethylation of amines with CO2/H2 via Ag/Al2O3 as catalyst Journal Article
In: Chemistry – A European Journal, vol. n/a, no. n/a, 2023, ISSN: 0947-6539.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Highly selective monomethylation of amines with CO2/H2 via Ag/Al2O3 as catalyst},
author = {Y Long and J He and H Zhang and Y Chen and K Liu and J Fu and H Li and L Zhu and Z Lin and A Stefancu and E Cortes and M Zhu and M Liu},
url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.202203152},
doi = {https://doi.org/10.1002/chem.202203152},
issn = {0947-6539},
year = {2023},
date = {2023-01-10},
journal = {Chemistry \textendash A European Journal},
volume = {n/a},
number = {n/a},
abstract = {The selective synthesis of monomethylated amines with CO2 is particularly challenging because the formation of tertiary amines is thermodynamically more favorable. Here we explore a new strategy for the controllable synthesis of N-monomethylated amines from primary amines and CO2/H2. Our first-principle calculations reveal that the dissociation of H2 via an heterolytic route reduces the reactivity of methylated amines and thus inhibit successive methylation. In-situ DRIFTS prove the process of formation and decomposition of ammonium salt by secondary amine reversible binding with H+ on the Ag/Al2O3 catalyst, thereby reducing its reactivity. Meanwhile, the energy barrier for rate-determining step of monomehylation was much lower than that of over methylation (0.34 eV vs 0.58 eV) means amines monomethylation in preference to successive methylation. Under optimal reaction conditions, a variety of amines conversion to corresponding monomethylated amines in good to excellent yields, and more than 90% yield of product obtained.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
A T S Freiberg, S Qian, J Wandt, H A Gasteiger, E J Crumlin
In: ACS Applied Materials & Interfaces, vol. 15, no. 3, pp. 4743-4754, 2023, ISSN: 1944-8244.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Surface Oxygen Depletion of Layered Transition Metal Oxides in Li-Ion Batteries Studied by Operando Ambient Pressure X-ray Photoelectron Spectroscopy},
author = {A T S Freiberg and S Qian and J Wandt and H A Gasteiger and E J Crumlin},
url = {https://doi.org/10.1021/acsami.2c19008},
doi = {10.1021/acsami.2c19008},
issn = {1944-8244},
year = {2023},
date = {2023-01-09},
journal = {ACS Applied Materials \& Interfaces},
volume = {15},
number = {3},
pages = {4743-4754},
abstract = {A new operando spectro-electrochemical setup was developed to study oxygen depletion from the surface of layered transition metal oxide particles at high degrees of delithiation. An NCM111 working electrode was paired with a chemically delithiated LiFePO4 counter electrode in a fuel cell-inspired membrane electrode assembly (MEA). A propylene carbonate-soaked Li-ion conducting ionomer served as an electrolyte, providing both good electrochemical performance and direct probing of the NCM111 particles during cycling by ambient pressure X-ray photoelectron spectroscopy. The irreversible emergence of an oxygen-depleted phase in the O 1s spectra of the layered oxide particles was observed upon the first delithiation to high state-of-charge, which is in excellent agreement with oxygen release analysis via mass spectrometry analysis of such MEAs. By comparing the metal oxide-based O 1s spectral features to the Ni 2p3/2 intensity, we can calculate the transition metal-to-oxygen ratio of the metal oxide close to the particle surface, which shows good agreement with the formation of a spinel-like stoichiometry as an oxygen-depleted phase. This new setup enables a deeper understanding of interfacial changes of layered oxide-based cathode active materials for Li-ion batteries upon cycling.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
Y Wang, J Xue, H Zhong, C R Everett, X Jiang, M A Reus, A Chumakov, S V Roth, M A Adedeji, N Jili, K Zhou, G Lu, Z Tang, G T Mola, P Müller-Buschbaum, W Ma
In: Advanced Energy Materials, vol. n/a, no. n/a, pp. 2203496, 2023, ISSN: 1614-6832.
Abstract | Links | Tags: Foundry Organic, Solid-Solid
@article{nokey,
title = {Control of the Crystallization and Phase Separation Kinetics in Sequential Blade-Coated Organic Solar Cells by Optimizing the Upper Layer Processing Solvent},
author = {Y Wang and J Xue and H Zhong and C R Everett and X Jiang and M A Reus and A Chumakov and S V Roth and M A Adedeji and N Jili and K Zhou and G Lu and Z Tang and G T Mola and P M\"{u}ller-Buschbaum and W Ma},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202203496},
doi = {https://doi.org/10.1002/aenm.202203496},
issn = {1614-6832},
year = {2023},
date = {2023-01-01},
journal = {Advanced Energy Materials},
volume = {n/a},
number = {n/a},
pages = {2203496},
abstract = {Abstract Sequential deposition of the active layer in organic solar cells (OSCs) is favorable to circumvent the existing drawbacks associated with controlling the microstructure in bulk-heterojunction (BHJ) device fabrication. However, how the processing solvents impact on the morphology during sequential deposition processes is still poorly understood. Herein, high-efficiency OSCs are fabricated by a sequential blade coating (SBC) through optimization of the morphology evolution process induced by processing solvents. It is demonstrated that the device performance is highly dependent on the processing solvent of the upper layer. In situ morphology characterizations reveal that an obvious liquid\textendashsolid phase separation can be identified during the chlorobenzene processing of the D18 layer, corresponding to larger phase separation. During chloroform (CF) processing of the D18 layer, a proper aggregation rate of Y6 and favorable intermixing of lower and upper layers results in the enhanced crystallinity of the acceptor. This facilitates efficient exciton dissociation and charge transport with an inhibited charge recombination in the D18/CF-based devices, contributing to a superior performance of 17.23%. These results highlight the importance of the processing solvent for the upper layer in the SBC strategy and suggest the great potential of achieving optimized morphology and high-efficiency OSCs using the SBC strategy.},
keywords = {Foundry Organic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
A Bornschlegl, M Lichtenegger, L Luber, C Lampe, M Bodnarchuk, M Kovalenko, A S Urban
Dark-Bright Exciton Splitting Dominates Low-Temperature Diffusion in Halide Perovskite Nanocrystal Assemblies Miscellaneous
2023.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@misc{nokey,
title = {Dark-Bright Exciton Splitting Dominates Low-Temperature Diffusion in Halide Perovskite Nanocrystal Assemblies},
author = {A Bornschlegl and M Lichtenegger and L Luber and C Lampe and M Bodnarchuk and M Kovalenko and A S Urban},
url = {http://europepmc.org/abstract/PPR/PPR596764
https://doi.org/10.21203/rs.3.rs-2450378/v1},
doi = {10.21203/rs.3.rs-2450378/v1},
year = {2023},
date = {2023-01-01},
urldate = {2023-01-01},
publisher = {Research Square},
abstract = {Semiconductor nanocrystals could replace conventional bulk materials completely in displays and light-emitting diodes. However, the organic ligands enabling their unique optical properties, prevent current flow in nanocrystal films, leaving energy transfer as the only means of injecting or extracting carriers. Here, we investigate exciton diffusion in halide perovskite superlattices - nearly perfect 3D nanocrystal assemblies. This high degree of order is not as crucial as the individual nanocrystal size, which affects transport differently depending on temperature. Up to 70 K, a confinement-induced splitting of excitonic energies, especially for the smallest nanocrystals, traps excitons into dark levels, suppressing diffusion. At intermediate temperatures, the distance of individual FRET steps corresponding to nanocrystal size enhances diffusion in the larger nanocrystals. This trend is reversed, as exciton dissociation and carrier trapping in less strongly confined nanocrystals become dominant up to room temperature. Our results reveal that transport must be factored strongly into nanocrystal design strategies for future optoelectronic applications.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {misc}
}
J Wang, G Ni, W Liao, K Liu, J Chen, F Liu, Z Zhang, M Jia, J Li, J Fu, E Pensa, L Jiang, Z Bian, E Cortes, M Liu
Subsurface Engineering Induced Fermi Level De-pinning in Metal Oxide Semiconductors for Photoelectrochemical Water Splitting Journal Article
In: Angewandte Chemie International Edition, vol. n/a, no. n/a, 2022, ISSN: 1433-7851.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Subsurface Engineering Induced Fermi Level De-pinning in Metal Oxide Semiconductors for Photoelectrochemical Water Splitting},
author = {J Wang and G Ni and W Liao and K Liu and J Chen and F Liu and Z Zhang and M Jia and J Li and J Fu and E Pensa and L Jiang and Z Bian and E Cortes and M Liu},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202217026},
doi = {https://doi.org/10.1002/anie.202217026},
issn = {1433-7851},
year = {2022},
date = {2022-12-28},
journal = {Angewandte Chemie International Edition},
volume = {n/a},
number = {n/a},
abstract = {Photoelectrochemical (PEC) water splitting is a promising approach for renewable solar light conversion. However, surface Fermi level pinning (FLP), caused by surface trap states, severely restricts the PEC activities. Theoretical calculations indicate subsurface oxygen vacancy (sub-Ov) could release the FLP and retain the active structure. A series of metal oxide semiconductors with sub-Ov were prepared through precisely regulated spin-coating and calcination. Etching X-ray photoelectron spectroscopy (XPS), scanning transmission electron microscopy (STEM), and electron energy loss spectra (EELS) demonstrated Ov located at sub ~2-5 nm region. Mott-Schottky and open circuit photovoltage results confirmed the surface trap states elimination and Fermi level de-pinning. Thus, superior PEC performances of 5.1, 3.4, and 2.1 mA cm-2 at 1.23 V vs. RHE were achieved on BiVO4, Bi2O3, TiO2 with outstanding stability for 72 h, outperforming most reported works under the identical conditions.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
W Liao, K Liu, J Wang, A Stefancu, Q Chen, K Wu, Y Zhou, H Li, L Mei, M Li, J Fu, M Miyauchi, E Cortés, M Liu
Boosting Nitrogen Activation via Ag Nanoneedle Arrays for Efficient Ammonia Synthesis Journal Article
In: ACS Nano, 2022, ISSN: 1936-0851.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Boosting Nitrogen Activation via Ag Nanoneedle Arrays for Efficient Ammonia Synthesis},
author = {W Liao and K Liu and J Wang and A Stefancu and Q Chen and K Wu and Y Zhou and H Li and L Mei and M Li and J Fu and M Miyauchi and E Cort\'{e}s and M Liu},
url = {https://doi.org/10.1021/acsnano.2c08853},
doi = {10.1021/acsnano.2c08853},
issn = {1936-0851},
year = {2022},
date = {2022-12-16},
journal = {ACS Nano},
abstract = {Electrocatalytic N2 reduction reaction (eNRR) provides a promising carbon-neutral and sustainable ammonia-synthesizing alternative to the Haber-Bosch process. However, the nonpolar N2 has significant thermodynamic stability and requires ultrahigh energy to break down the N≡N bond. Here, we report the construction of local enhanced electric fields (LEEFs) by Ag nanoneedle arrays to promote N≡N fracture thus assisting the eNRR. The LEEFs could induce charge polarization on nitrogen atoms and reduce the energy barrier in the N2 first-protonation step. The detected N─N and N─H intermediates prove the cleavage of the N≡N bond and the hydrogenation of N2 by LEEFs. The increased LEEFs lead to logarithmic growth rates for the targeted eNRR and exponential growth rates for the unavoidable competitive hydrogen evolution reaction. Thus, regulation and tuning of LEEFs to ∼4 × 104 kV m\textendash1 endows the raise of eNRR to the summit, achieving high ammonia selectivity with a Faradaic efficiency of 72.3 ± 4.0%.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
J Lenz, M Statz, K Watanabe, T Taniguchi, F Ortmann, R T Weitz
Charge transport in single polymer fiber transistors in the sub 100 nm regime: temperature dependence and Coulomb blockade Journal Article
In: Journal of Physics: Materials, 2022, ISSN: 2515-7639.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Charge transport in single polymer fiber transistors in the sub 100 nm regime: temperature dependence and Coulomb blockade},
author = {J Lenz and M Statz and K Watanabe and T Taniguchi and F Ortmann and R T Weitz},
url = {https://iopscience.iop.org/article/10.1088/2515-7639/aca82f/meta},
doi = {10.1088/2515-7639/aca82f},
issn = {2515-7639},
year = {2022},
date = {2022-12-15},
journal = {Journal of Physics: Materials},
abstract = {Even though charge transport in semiconducting polymers is of relevance for a number of potential applications in (opto-)electronic devices, the fundamental mechanism of how charges are transported through organic polymers that are typically characterized by a complex nanostructure is still open. One of the challenges which we address here, is how to gain controllable experimental access to charge transport at the sub-100 nm lengthscale. To this end charge transport in single poly(diketopyrrolopyrrole-terthiophene) fiber transistors, employing two different solid gate dielectrics, a hybrid Al2O3/self-assembled monolayer and hexagonal boron nitride, is investigated in the sub-50 nm regime using electron-beam contact patterning. The electrical characteristics exhibit near ideal behavior at room temperature which demonstrates the general feasibility of the nanoscale contacting approach, even though the channels are only a few nanometers in width. At low temperatures, we observe nonlinear behavior in the current\textendashvoltage characteristics in the form of Coulomb diamonds which can be explained by the formation of an array of multiple quantum dots at cryogenic temperatures.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
J Gargiulo, M Herran, I Violi, A Sousa-Castillo, L Martinez, S Ezendam, M Barella, H Giesler, R Grzeschik, S Schluecker, S A Maier, F Stefani, E Cortes
Single particle thermometry in bimetallic plasmonic nanostuctures Miscellaneous
2022.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@misc{nokey,
title = {Single particle thermometry in bimetallic plasmonic nanostuctures},
author = {J Gargiulo and M Herran and I Violi and A Sousa-Castillo and L Martinez and S Ezendam and M Barella and H Giesler and R Grzeschik and S Schluecker and S A Maier and F Stefani and E Cortes},
url = {http://europepmc.org/abstract/PPR/PPR584599
https://doi.org/10.21203/rs.3.rs-2233698/v1},
doi = {10.21203/rs.3.rs-2233698/v1},
year = {2022},
date = {2022-12-01},
urldate = {2022-12-01},
publisher = {Research Square},
abstract = {Localized surface plasmons are lossy and generate heat. However, accurate measurement of the temperature of metallic nanoparticles under illumination remains an open challenge, creating difficulties in the interpretation of results across plasmonic applications. Particularly, there is a quest for understanding the role of temperature in plasmon-assisted catalysis. Bimetallic nanoparticles combining plasmonic with catalytic metals are raising increasing interest in artificial photosynthesis and the production of solar fuels. Here, we perform single-particle nanothermometry measurements to investigate the link between morphology and thermal performance of colloidal Au/Pd nanoparticles with two different configurations: Au core \textendash Pd shell and Au core- Pd satellites. It is observed that the inclusion of Pd as a shell strongly reduces the photothermal response in comparison to the bare cores, while the inclusion of Pd as satellites keeps photothermal properties almost unaffected. These results contribute to a better understanding of energy conversion processes in plasmon-assisted catalysis.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {misc}
}
A Weis, P Ganswindt, W Kaiser, H Illner, C Maheu, N Glück, P Dörflinger, M Armer, V Dyakonov, J P Hofmann, E Mosconi, F De Angelis, T Bein
Heterovalent Tin Alloying in Layered MA3Sb2I9 Thin Films: Assessing the Origin of Enhanced Absorption and Self-Stabilizing Charge States Journal Article
In: The Journal of Physical Chemistry C, vol. 126, no. 49, pp. 21040-21049, 2022, ISSN: 1932-7447.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Heterovalent Tin Alloying in Layered MA3Sb2I9 Thin Films: Assessing the Origin of Enhanced Absorption and Self-Stabilizing Charge States},
author = {A Weis and P Ganswindt and W Kaiser and H Illner and C Maheu and N Gl\"{u}ck and P D\"{o}rflinger and M Armer and V Dyakonov and J P Hofmann and E Mosconi and F De Angelis and T Bein},
url = {https://doi.org/10.1021/acs.jpcc.2c06106},
doi = {10.1021/acs.jpcc.2c06106},
issn = {1932-7447},
year = {2022},
date = {2022-11-30},
journal = {The Journal of Physical Chemistry C},
volume = {126},
number = {49},
pages = {21040-21049},
abstract = {Heteroatom alloying of lead-free perovskite derivatives is a highly promising route to tailor their optoelectronic properties and stability for multiple applications. Here, we demonstrate the facile solution-based synthesis of Sn-alloyed layered MA3Sb2I9 thin films by precursor engineering, combining acetate and halide salts. An increasing concentration of tin halides in different oxidation states leads to a strong boost in absorption over the whole visible spectrum. We demonstrate phase-pure synthesis and elucidate the heterovalent incorporation of Sn into the MA3Sb2I9 lattice, proving the formation of additional electronic states in the bandgap by theoretical calculations. On this basis, we dissect the strong absorption increase into three components that we attribute to intervalence and heteroatom-induced interband absorption. Finally, we show the charge-stabilizing effect of the system through robustness toward precursors in mixed oxidation states and trace the improved ambient stability of this material back to this feature.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
S Yin, Y Zou, M A Reus, X Jiang, S Tu, T Tian, R Qi, Z Xu, S Liang, Y Cheng, J E Heger, M Schwartzkopf, S V Roth, P Müller-Buschbaum
Tailored fabrication of quasi-isoporous and double layered α-Fe2O3 thin films and their application in photovoltaic devices Journal Article
In: Chemical Engineering Journal, pp. 140135, 2022, ISSN: 1385-8947.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Tailored fabrication of quasi-isoporous and double layered α-Fe2O3 thin films and their application in photovoltaic devices},
author = {S Yin and Y Zou and M A Reus and X Jiang and S Tu and T Tian and R Qi and Z Xu and S Liang and Y Cheng and J E Heger and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},
url = {https://www.sciencedirect.com/science/article/pii/S1385894722056157},
doi = {https://doi.org/10.1016/j.cej.2022.140135},
issn = {1385-8947},
year = {2022},
date = {2022-11-21},
journal = {Chemical Engineering Journal},
pages = {140135},
abstract = {A series of α-Fe2O3 thin films with distinct morphologies are prepared via a facile polystyrene-block-polyethylene oxide templated sol\textendashgel method. By tailoring the poor solvent contents and FeCl3-to-polymer weight ratio in the sol\textendashgel solutions, quasi-isoporous α-Fe2O3 thin films with different substructures and thicknesses are obtained. Via a thermal annealing post-treatment, double layered structures are induced by a synergistic dewetting and Oswald ripening effect. Special focus is set on the α-Fe2O3 thin films prepared with no annealing/annealing-medium FeCl3 concentration, as they possess uniform periodic structures, which is suitable to be used as hole blocking modification layer of perovskite solar cells (PSCs). An improved power conversion efficiency (PCE) is obtained when the double layered α-Fe2O3 thin film is applied as the hole blocking modification layer for PSCs. The improved PCE primarily originates from the increased VOC, which probably benefits from the synergistic effect of the suppressed charge carrier recombination at the interfaces, the enhanced light transmittance as well as the superior electron extraction capacity.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
S B Kalkan, E Najafidehaghani, Z Gan, J Drewniok, M F Lichtenegger, U Hübner, A S Urban, A George, A Turchanin, B Nickel
High-Performance Monolayer MoS2 Field-Effect Transistors on Cyclic Olefin Copolymer-Passivated SiO2 Gate Dielectric Journal Article
In: Advanced Optical Materials, vol. n/a, no. n/a, pp. 2201653, 2022, ISSN: 2195-1071.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {High-Performance Monolayer MoS2 Field-Effect Transistors on Cyclic Olefin Copolymer-Passivated SiO2 Gate Dielectric},
author = {S B Kalkan and E Najafidehaghani and Z Gan and J Drewniok and M F Lichtenegger and U H\"{u}bner and A S Urban and A George and A Turchanin and B Nickel},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202201653},
doi = {https://doi.org/10.1002/adom.202201653},
issn = {2195-1071},
year = {2022},
date = {2022-11-18},
journal = {Advanced Optical Materials},
volume = {n/a},
number = {n/a},
pages = {2201653},
abstract = {Abstract Trap states of the semiconductor/gate dielectric interface give rise to a pronounced subthreshold behavior in field-effect transistors (FETs) diminishing and masking intrinsic properties of 2D materials. To reduce the well-known detrimental effect of SiO2 surface traps, this work spin-coated an ultrathin (≈5 nm) cyclic olefin copolymer (COC) layer onto the oxide and this hydrophobic layer acts as a surface passivator. The chemical resistance of COC allows to fabricate monolayer MoS2 FETs on SiO2 by standard cleanroom processes. This way, the interface trap density is lowered and stabilized almost fivefold, to around 5 × 1011 cm−2 eV−1, which enables low-voltage FETs even on 300 nm thick SiO2. In addition to this superior electrical performance, the photoresponsivity of the MoS2 devices on passivated oxide is also enhanced by four orders of magnitude compared to nonpassivated MoS2 FETs. Under these conditions, negative photoconductivity and a photoresponsivity of 3 × 107 A W−1 is observed which is a new highest value for MoS2. These findings indicate that the ultrathin COC passivation of the gate dielectric enables to probe exciting properties of the atomically thin 2D semiconductor, rather than interface trap dominated effects.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
S Schneider, L G Balzat, B V Lotsch, W Schnick
Structure Determination of the Crystalline LiPON Model Structure Li5+xP2O6−xN1+x with x≈0.9 Journal Article
In: Chemistry – A European Journal, vol. 29, no. 9, pp. e202202984, 2022, ISSN: 0947-6539.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Structure Determination of the Crystalline LiPON Model Structure Li5+xP2O6−xN1+x with x≈0.9},
author = {S Schneider and L G Balzat and B V Lotsch and W Schnick},
url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.202202984},
doi = {https://doi.org/10.1002/chem.202202984},
issn = {0947-6539},
year = {2022},
date = {2022-11-16},
journal = {Chemistry \textendash A European Journal},
volume = {29},
number = {9},
pages = {e202202984},
abstract = {Abstract Non-crystalline lithium oxonitridophosphate (LiPON) is used as solid electrolyte in all-solid-state batteries. Crystalline lithium oxonitridophosphates are important model structures to retrieve analytical information that can be used to understand amorphous phases better. The new crystalline lithium oxonitridophosphate Li5+xP2O6−xN1+x was synthesized as an off-white powder by ampoule synthesis at 750\textendash800 °C under Ar atmosphere. It crystallizes in the monoclinic space group P21/c with a=15.13087(11) r{A}},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
A N Koya, M Romanelli, J Kuttruff, N Henriksson, A Stefancu, G Grinblat, A De Andres, F Schnur, M Vanzan, M Marsili
Advances in ultrafast plasmonics Journal Article
In: arXiv preprint arXiv:2211.08241, 2022.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Advances in ultrafast plasmonics},
author = {A N Koya and M Romanelli and J Kuttruff and N Henriksson and A Stefancu and G Grinblat and A De Andres and F Schnur and M Vanzan and M Marsili},
url = {https://arxiv.org/abs/2211.08241},
doi = {https://doi.org/10.48550/arXiv.2211.08241},
year = {2022},
date = {2022-11-15},
journal = {arXiv preprint arXiv:2211.08241},
abstract = {In the past twenty years, we have reached a broad understanding of many light-driven phenomena in nanoscale systems. The temporal dynamics of the excited states are instead quite challenging to explore, and, at the same time, crucial to study for understanding the origin of fundamental physical and chemical processes. In this review we examine the current state and prospects of ultrafast phenomena driven by plasmons both from a fundamental and applied point of view. This research area is referred to as ultrafast plasmonics and represents an outstanding playground to tailor and control fast optical and electronic processes at the nanoscale, such as ultrafast optical switching, single photon emission and strong coupling interactions to tailor photochemical reactions. Here, we provide an overview of the field, and describe the methodologies to monitor and control nanoscale phenomena with plasmons at ultrafast timescales in terms of both modeling and experimental characterization. Various directions are showcased, among others recent advances in ultrafast plasmon-driven chemistry and multi-functional plasmonics, in which charge, spin, and lattice degrees of freedom are exploited to provide active control of the optical and electronic properties of nanoscale materials. As the focus shifts to the development of practical devices, such as all-optical transistors, we also emphasize new materials and applications in ultrafast plasmonics and highlight recent development in the relativistic realm. The latter is a promising research field with potential applications in fusion research or particle and light sources providing properties such as attosecond duration.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
D Han, M-H Du, M Huang, S Wang, G Tang, T Bein, H Ebert
In: Physical Review Materials, vol. 6, no. 11, pp. 114601, 2022.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Ground-state structures, electronic structure, transport properties and optical properties of Ca-based anti-Ruddlesden-Popper phase oxide perovskites},
author = {D Han and M-H Du and M Huang and S Wang and G Tang and T Bein and H Ebert},
url = {https://link.aps.org/doi/10.1103/PhysRevMaterials.6.114601},
doi = {10.1103/PhysRevMaterials.6.114601},
year = {2022},
date = {2022-11-07},
journal = {Physical Review Materials},
volume = {6},
number = {11},
pages = {114601},
abstract = {Anti-Ruddlesden-Popper (ARP) phase oxide perovskites Ca4OA2 (A=P, As, Sb, Bi) have recently attracted great interest in the field of ferroelectrics and thermoelectrics, whereas their optoelectronic application is limited by their indirect band gaps. In this work, we introduce A-site anion ordering in Ca4OA2 (A=P, As, Sb, Bi), and find that it induces an indirect-to-direct band gap transition. Using first-principles calculations, we study the ground-state structures, electronic structure, transport properties and optical properties of anion-ordered ARP phase oxide perovskites Ca4OAA′. Based on analyses of the lattice dynamics, the ground-state structures of Ca4OAsSb and Ca4OAsBi are identified in P4/nmm symmetry and those of Ca4OPSb and Ca4OPBi are in the I222 symmetry. In contrast to the Ruddlesden-Popper (RP) phase oxide and halide counterparts, Ca4OAA′ (AA′=PSb, PBi, AsSb, AsBi) show larger band dispersion along the out-of-plane direction, smaller band gaps and highly enhanced out-of-plane mobilities, which results from the short interlayer distances and the enhanced covalency of the pnictides. Although the out-of-plane mobilities of these n=1 ARP phase perovskites highly increase, the comparatively strong polar optical phonon scattering limits the further enhancement of their mobilities. Furthermore, compared to RP phase halide Cs2PbI2Cl2, Ca4OAA′ show strong optical absorption around the band edges, and their optical absorption coefficients can reach 10^5 cm−1 within the visible light region due to small band gaps. This study reveals that these ARP phase oxide perovskites exhibit the potential for optoelectronic applications.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
J Wang, T Weber, A Aigner, S A Maier, A Tittl
Mirror-coupled plasmonic bound states in the continuum for tunable perfect absorption Journal Article
In: arXiv preprint arXiv:2211.03673, 2022.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Mirror-coupled plasmonic bound states in the continuum for tunable perfect absorption},
author = {J Wang and T Weber and A Aigner and S A Maier and A Tittl},
url = {https://arxiv.org/abs/2211.03673},
doi = {https://doi.org/10.48550/arXiv.2211.03673},
year = {2022},
date = {2022-11-07},
journal = {arXiv preprint arXiv:2211.03673},
abstract = {Tailoring critical light-matter coupling is a fundamental challenge of nanophotonics, impacting diverse fields from higher harmonic generation and energy conversion to surface-enhanced spectroscopy. Plasmonic perfect absorbers (PAs), where resonant antennas couple to their mirror images in adjacent metal films, have been instrumental for obtaining different coupling regimes by tuning the antenna-film distance. However, for on-chip uses, the ideal PA gap size can only match one wavelength, and wide range multispectral approaches remain challenging. Here, we introduce a new paradigm for plasmonic PAs by combining mirror-coupled resonances with the unique loss engineering capabilities of plasmonic bound states in the continuum (BICs). Our BIC-driven PA platform leverages the asymmetry of the constituent meta-atoms as an additional degree of freedom for reaching the critical coupling (CC) condition, delivering resonances with unity absorbance and high quality factors approaching 100 in the mid-infrared. Such a platform holds flexible tuning knobs including asymmetry parameter, dielectric gap, and geometrical scaling factor to precisely control the coupling condition, resonance frequency, and selective enhancement of magnetic and electric fields while maintaining CC. We demonstrate a pixelated PA metasurface with optimal absorption over a broad range of mid-infrared frequencies (950 ~ 2000 1/cm) using only a single spacer layer thickness and apply it for multispectral surface-enhanced molecular spectroscopy in tailored coupling regimes. Our concept greatly expands the capabilities and flexibility of traditional gap-tuned PAs, opening new perspectives for miniaturized sensing platforms towards on-chip and in-situ detection.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
N Li, S Pratap, V Körstgens, S Vema, L Song, S Liang, A Davydok, C Krywka, P Müller-Buschbaum
Mapping structure heterogeneities and visualizing moisture degradation of perovskite films with nano-focus WAXS Journal Article
In: Nature Communications, vol. 13, no. 1, pp. 6701, 2022, ISSN: 2041-1723.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Mapping structure heterogeneities and visualizing moisture degradation of perovskite films with nano-focus WAXS},
author = {N Li and S Pratap and V K\"{o}rstgens and S Vema and L Song and S Liang and A Davydok and C Krywka and P M\"{u}ller-Buschbaum},
url = {https://doi.org/10.1038/s41467-022-34426-y},
doi = {10.1038/s41467-022-34426-y},
issn = {2041-1723},
year = {2022},
date = {2022-11-05},
journal = {Nature Communications},
volume = {13},
number = {1},
pages = {6701},
abstract = {Extensive attention has focused on the structure optimization of perovskites, whereas rare research has mapped the structure heterogeneity within mixed hybrid perovskite films. Overlooked aspects include material and structure variations as a function of depth. These depth-dependent local structure heterogeneities dictate their long-term stabilities and efficiencies. Here, we use a nano-focused wide-angle X-ray scattering method for the mapping of film heterogeneities over several micrometers across lateral and vertical directions. The relative variations of characteristic perovskite peak positions show that the top film region bears the tensile strain. Through a texture orientation map of the perovskite (100) peak, we find that the perovskite grains deposited by sequential spray-coating grow along the vertical direction. Moreover, we investigate the moisture-induced degradation products in the perovskite film, and the underlying mechanism for its structure-dependent degradation. The moisture degradation along the lateral direction primarily initiates at the perovskite-air interface and grain boundaries. The tensile strain on the top surface has a profound influence on the moisture degradation.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
M Nuber, L V Spanier, S Roth, G N Vayssilov, R Kienberger, P Müller-Buschbaum, H Iglev
In: The Journal of Physical Chemistry Letters, pp. 10418-10423, 2022.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Picosecond Charge-Transfer-State Dynamics in Wide Band Gap Polymer\textendashNon-Fullerene Small-Molecule Blend Films Investigated via Transient Infrared Spectroscopy},
author = {M Nuber and L V Spanier and S Roth and G N Vayssilov and R Kienberger and P M\"{u}ller-Buschbaum and H Iglev},
url = {https://doi.org/10.1021/acs.jpclett.2c02864},
doi = {10.1021/acs.jpclett.2c02864},
year = {2022},
date = {2022-11-03},
journal = {The Journal of Physical Chemistry Letters},
pages = {10418-10423},
abstract = {Organic solar cells based on wide band gap polymers and nonfullerene small-molecule acceptors have demonstrated remarkably good device performances. Nevertheless, a thorough understanding of the charge-transfer process in these materials has not been achieved yet. In this study, we use Fano resonance signals caused by the interaction of broad electronic charge carrier absorption and the molecular vibrations of the electron acceptor molecule to monitor the charge-transfer state dynamics. In our time-resolved infrared spectroscopy experiments, we find that in the small-molecule acceptor, they have additional dynamics on the order of a few picoseconds. A change in the solvent used in thin film deposition, leading to different morphologies, influences this time further. We interpret our findings as the dynamics of the charge-transfer state at the interface of the electron donor and the electron- acceptor. The additional mid-infrared transient signal is generated in this state, as both electron and hole polarons can interact with small-molecule acceptor vibrational modes.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
R Berté, T Weber, L D S Menezes, L Kühner, A Aigner, M Barkey, F J Wendisch, Y S Kivshar, A Tittl, S A Maier
Permittivity-asymmetric quasi-bound states in the continuum Journal Article
In: arXiv preprint arXiv:2211.01176, 2022.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Permittivity-asymmetric quasi-bound states in the continuum},
author = {R Bert\'{e} and T Weber and L D S Menezes and L K\"{u}hner and A Aigner and M Barkey and F J Wendisch and Y S Kivshar and A Tittl and S A Maier},
url = {https://arxiv.org/abs/2211.01176},
doi = {https://doi.org/10.48550/arXiv.2211.01176},
year = {2022},
date = {2022-11-02},
journal = {arXiv preprint arXiv:2211.01176},
abstract = {Broken symmetries lie at the heart of nontrivial physical phenomena. Breaking the in-plane geometrical symmetry of optical systems allows to access a set of electromagnetic states termed symmetry-protected quasi-bound states in the continuum (qBICs). Here we demonstrate, theoretically, numerically and experimentally, that such optical states can also be accessed in metasurfaces by breaking the in-plane symmetry in the permittivity of the comprising materials, showing a remarkable equivalence to their geometrically-asymmetric counterparts. However, while the physical size of atoms imposes a limit on the lowest achievable geometrical asymmetry, weak permittivity modulations due to carrier doping and electro-optical Pockels and Kerr effects, usually considered insignificant, open up the possibility of infinitesimal permittivity asymmetries for on-demand, and dynamically tuneable optical resonances of extremely high quality factors. We probe the excitation of permittivity-asymmetric qBICs (ε-qBICs) using a prototype Si/TiO2 metasurface, in which the asymmetry in the unit cell is provided by the refractive index contrast of the dissimilar materials, surpassing any unwanted asymmetries from nanofabrication defects or angular deviations of light from normal incidence. ε-qBICs can also be excited in 1D gratings, where quality-factor enhancement and tailored interference phenomena via the interplay of geometrical and permittivity asymmetries are numerically demonstrated. The emergence of ε-qBICs in systems with broken symmetries in their permittivity may enable to test time-energy uncertainties in quantum mechanics, and lead to a whole new class of low-footprint optical and optoelectronic devices, from arbitrarily narrow filters and topological sources, biosensing and ultrastrong light-matter interaction platforms, to tuneable optical switches.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
F Sigger, I Amersdorffer, A Hötger, M Nutz, J Kiemle, T Taniguchi, K Watanabe, M Förg, J Noe, J J Finley, A Högele, A W Holleitner, T Hümmer, D Hunger, C Kastl
Ultra-Sensitive Extinction Measurements of Optically Active Defects in Monolayer MoS2 Journal Article
In: The Journal of Physical Chemistry Letters, pp. 10291-10296, 2022.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Ultra-Sensitive Extinction Measurements of Optically Active Defects in Monolayer MoS2},
author = {F Sigger and I Amersdorffer and A H\"{o}tger and M Nutz and J Kiemle and T Taniguchi and K Watanabe and M F\"{o}rg and J Noe and J J Finley and A H\"{o}gele and A W Holleitner and T H\"{u}mmer and D Hunger and C Kastl},
url = {https://doi.org/10.1021/acs.jpclett.2c02386},
doi = {10.1021/acs.jpclett.2c02386},
year = {2022},
date = {2022-10-28},
journal = {The Journal of Physical Chemistry Letters},
pages = {10291-10296},
abstract = {We utilize cavity-enhanced extinction spectroscopy to directly quantify the optical absorption of defects in MoS2 generated by helium ion bombardment. We achieve hyperspectral imaging of specific defect patterns with a detection limit below 0.01% extinction, corresponding to a detectable defect density below 1 × 1011 cm\textendash2. The corresponding spectra reveal a broad subgap absorption, being consistent with theoretical predictions related to sulfur vacancy-bound excitons in MoS2. Our results highlight cavity-enhanced extinction spectroscopy as efficient means for the detection of optical transitions in nanoscale thin films with weak absorption, applicable to a broad range of materials.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
A Vogel, A Rabenbauer, P Deng, R Steib, T Böger, W G Zeier, R Siegel, J Senker, D Daisenberger, K Nisi, A W Holleitner, J Venturini, T Nilges
A Switchable One-Compound Diode Journal Article
In: Advanced Materials, vol. n/a, no. n/a, pp. 2208698, 2022, ISSN: 0935-9648.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {A Switchable One-Compound Diode},
author = {A Vogel and A Rabenbauer and P Deng and R Steib and T B\"{o}ger and W G Zeier and R Siegel and J Senker and D Daisenberger and K Nisi and A W Holleitner and J Venturini and T Nilges},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202208698},
doi = {https://doi.org/10.1002/adma.202208698},
issn = {0935-9648},
year = {2022},
date = {2022-10-25},
journal = {Advanced Materials},
volume = {n/a},
number = {n/a},
pages = {2208698},
abstract = {Abstract A diode or transistor requires the combination of p- and n-type semiconductors or at least the defined formation of such areas within a given compound. This is a prerequisite for any IT application, energy conversion technology, and electronic semiconductor devices. Since 2009, when the first pnp-switchable compound Ag10Te4Br3 was described, it is in principle possible to fabricate a diode from a single material without adjusting the semiconduction type by a defined doping level. After this discovery, a handful of other materials that are capable of reversibly switching between these two semiconducting stages was reported. In all cases, a structural phase transition accompanied by a dynamic change of charge carriers or a charge density wave (CDW) within certain substructures are responsible for this effect. Unfortunately, a certain feature hinders the application of this phenomenon in convenient devices, namely the pnp-switching temperature, which generally occurs well above room temperature, between 364 and 580 K. This effect is far removed from a suitable operation temperature at ambient conditions. Here, we report on Ag18Cu3Te11Cl3, a room temperature pnp-switching material, and the realization of the first single-material position-independent diode. The title compound shows the highest ever reported Seebeck coefficient drop that takes place within a few Kelvin at room temperature. Combined with its reasonably low thermal conductivity, this material offers great application potential within an easily accessible and applicable temperature window. Ag18Cu3Te11Cl3 and pnp-switching materials have the potential for applications and processes where diodes, transistors, or any defined charge separation with junction formation are utilized. This article is protected by copyright. All rights reserved},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
K Birkmeier, T Hertel, A Hartschuh
Probing the ultrafast dynamics of excitons in single semiconducting carbon nanotubes Journal Article
In: Nature Communications, vol. 13, no. 1, pp. 6290, 2022, ISSN: 2041-1723.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {Probing the ultrafast dynamics of excitons in single semiconducting carbon nanotubes},
author = {K Birkmeier and T Hertel and A Hartschuh},
url = {https://doi.org/10.1038/s41467-022-33941-2},
doi = {10.1038/s41467-022-33941-2},
issn = {2041-1723},
year = {2022},
date = {2022-10-21},
journal = {Nature Communications},
volume = {13},
number = {1},
pages = {6290},
abstract = {Excitonic states govern the optical spectra of low-dimensional semiconductor nanomaterials and their dynamics are key for a wide range of applications, such as in solar energy harvesting and lighting. Semiconducting single-walled carbon nanotubes emerged as particularly rich model systems for one-dimensional nanomaterials and as such have been investigated intensively in the past. The exciton decay dynamics in nanotubes has been studied mainly by transient absorption and time-resolved photoluminescence spectroscopy. Since different transitions are monitored with these two techniques, developing a comprehensive model to reconcile different data sets, however, turned out to be a challenge and remarkably, a uniform description seems to remain elusive. In this work, we investigate the exciton decay dynamics in single carbon nanotubes using transient interferometric scattering and time-resolved photoluminescence microscopy with few-exciton detection sensitivity and formulate a unified microscopic model by combining unimolecular exciton decay and ultrafast exciton-exciton annihilation on a time-scale down to 200 fs.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
A Mancini, L Nan, F J Wendisch, R Berté, H Ren, E Cortés, S A Maier
Near-Field Retrieval of the Surface Phonon Polariton Dispersion in Free-Standing Silicon Carbide Thin Films Journal Article
In: ACS Photonics, 2022.
Abstract | Links | Tags: Foundry Inorganic, Solid-Solid
@article{nokey,
title = {Near-Field Retrieval of the Surface Phonon Polariton Dispersion in Free-Standing Silicon Carbide Thin Films},
author = {A Mancini and L Nan and F J Wendisch and R Bert\'{e} and H Ren and E Cort\'{e}s and S A Maier},
url = {https://doi.org/10.1021/acsphotonics.2c01270},
doi = {10.1021/acsphotonics.2c01270},
year = {2022},
date = {2022-10-20},
journal = {ACS Photonics},
abstract = {Surface phonon polaritons (SPhPs) are mixed light-matter states originating from strong coupling of photons with lattice vibrations. Thin films of polar dielectrics feature a splitting of the SPhP branch due to the hybridization of the top and bottom interface modes. Recently, enhanced in-plane thermal conductivity and near-field energy transfer have been experimentally demonstrated in free-standing polar films. These effects are determined by the SPhP dispersion in these systems, which, however, is yet to be reported experimentally. In this work, we retrieve the SPhP dispersion in silicon carbide free-standing membranes few hundreds of nanometers thick through near-field spectroscopy. We find several branches in the experimental dispersion, which we rationalize as multiple reflections of tip and edge launched SPhPs, in good agreement with theoretical predictions. Our work paves the way to employ large-area free-standing membranes as a platform for phonon polaritonics, with foreseeable applications in the field of thermal management at the nanoscale.},
keywords = {Foundry Inorganic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
L Kühner, L Sortino, B Tilmann, T Weber, K Watanabe, T Taniguchi, S A Maier, A Tittl
High-Q nanophotonics over the full visible spectrum enabled by hexagonal boron nitride metasurfaces Journal Article
In: arXiv preprint arXiv:2210.11314, 2022.
Abstract | Links | Tags: Molecularly-Functionalized, Solid-Solid
@article{nokey,
title = {High-Q nanophotonics over the full visible spectrum enabled by hexagonal boron nitride metasurfaces},
author = {L K\"{u}hner and L Sortino and B Tilmann and T Weber and K Watanabe and T Taniguchi and S A Maier and A Tittl},
url = {https://arxiv.org/abs/2210.11314},
doi = {https://doi.org/10.48550/arXiv.2210.11314},
year = {2022},
date = {2022-10-20},
journal = {arXiv preprint arXiv:2210.11314},
abstract = {All-dielectric optical metasurfaces with high quality (Q) factors have so far been hampered by the lack of simultaneously lossless and high refractive index (RI) materials over the full visible spectrum. To achieve broad spectral coverage, the use of low-index materials is, in fact, unavoidable due to the inverse correlation between the band-gap energy (and therefore the optical losses) and the RI. However, for Mie resonant photonics, smaller RIs are associated with reduced Q factors and mode volume confinement. In this work, we leverage symmetry-broken bound states in the continuum (BICs) to efficiently suppress radiation losses from the low-index (n~2) van der Waals material hexagonal boron nitride (hBN), realizing metasurfaces with high-Q resonances over the complete visible spectrum. In particular, we analyze the rational use of low and high RI materials as resonator components and harness our insights to experimentally demonstrate sharp BIC resonances with Q factors above 300, spanning wavelengths between 400 nm and 1000 nm from a single hBN flake. Moreover, we utilize the enhanced electric near-fields to demonstrate second harmonic generation (SHG) with enhancement factors above 102. Our results provide a theoretical and experimental framework for the implementation of low RI materials as photonic media for metaoptics.},
keywords = {Molecularly-Functionalized, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}