Publications

@article{nokey,

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

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

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

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

issn = {1385-8947},

year  = {2022},

date = {2022-09-06},

urldate = {2022-09-06},

journal = {Chemical Engineering Journal},

volume = {429},

pages = {132295},

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

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

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

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

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

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

issn = {2195-1071},

year  = {2022},

date = {2022-06-17},

journal = {Advanced Optical Materials},

volume = {n/a},

number = {n/a},

pages = {2200204},

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

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

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

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

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

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

issn = {2367-198X},

year  = {2022},

date = {2022-05-31},

journal = {Solar RRL},

volume = {n/a},

number = {n/a},

pages = {2200373},

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

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

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

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

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

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

year  = {2022},

date = {2022-05-24},

journal = {arXiv preprint arXiv:2205.12178},

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

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {All-optical nanoscopic spatial control of molecular reaction yields on nanoparticles},

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

url = {http://opg.optica.org/optica/abstract.cfm?URI=optica-9-5-551},

doi = {10.1364/OPTICA.453915},

year  = {2022},

date = {2022-05-20},

journal = {Optica},

volume = {9},

number = {5},

pages = {551-560},

abstract = {Molecular adsorbate reactions on nanoparticles play a fundamental role in areas such as nano-photocatalysis, atmospheric, and astrochemistry. They can be induced, enhanced, and controlled by field localization and enhancement on the nanoparticle surface. In particular, the ability to perform highly controlled near-field-mediated reactions is key to deepening our understanding of surface photoactivity on nanosystems. Here, using reaction nanoscopy, we experimentally demonstrate all-optical nanoscopic control of surface reaction yields by tailoring the near fields on nanoparticles with waveform-controlled linear and bicircular two-color laser pulses, respectively. We observe site-selective proton emission from the dissociative ionization of adsorbate molecules on SiO2 nanoparticles as a function of the polarization and relative phase of the two-color pulses. The angularly resolved close-to-uniform mapping between the surface reaction yields and the measured ion momentum enables the observation and spatial control of molecular reactions on the nanoparticle surface with nanoscopic resolution. The experimental results are modeled and reproduced qualitatively by classical trajectory Monte Carlo simulations. Our work paves the way toward reliable all-optical control of photocatalytic chemical reactions on nanoscale surfaces.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Effect of Solvent Vapor Annealing on Diblock Copolymer-Templated Mesoporous Si/Ge/C Thin Films: Implications for Li-Ion Batteries},

author = {C L Weindl and C E Fajman and M A Giebel and K S Wienhold and S Yin and T Tian and C Geiger and L P Kreuzer and M Schwartzkopf and S V Roth and T F F\"{a}ssler and P M\"{u}ller-Buschbaum},

url = {https://doi.org/10.1021/acsanm.2c01191},

doi = {10.1021/acsanm.2c01191},

year  = {2022},

date = {2022-05-17},

journal = {ACS Applied Nano Materials},

volume = {5},

number = {5},

pages = {7278-7287},

abstract = {Although amphiphilic diblock copolymer templating of inorganic materials such as TiO2 is already well investigated, sol\textendashgel synthesis routines for porous silicon and germanium are relatively rare. Therefore, especially in the field of Li-ion batteries, novel synthesis routines with the possibility to tune the silicon and germanium ratio and the morphology in the nanometer regime are of high interest. Here, we demonstrate a synthesis method that allows a change of morphology and elemental composition with minimal effort. We evidence a morphological transformation in the nanometer regime with real space (scanning electron microscopy) and complementary reciprocal space analysis methods (grazing-incidence small-angle X-ray scattering). Although energy-dispersive X-ray spectroscopy (EDS) reveals a considerable amount of oxygen in the thin film, crystalline Ge in the bulk is detected with powder X-ray diffraction (PXRD) and Raman spectroscopy. Due to the system’s simplicity, chemical mass production options such as roll-to-roll or slot-die printing can also be considered high-yield methods compared to standard synthesis routines.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Gold\textendashrhodium nanoflowers for the plasmon enhanced ethanol electrooxidation under visible light for tuning the activity and selectivity},

author = {M P S Rodrigues and A H B Dourado and K Krischer and S I C Torresi},

url = {https://www.sciencedirect.com/science/article/pii/S0013468622006016},

doi = {https://doi.org/10.1016/j.electacta.2022.140439},

issn = {0013-4686},

year  = {2022},

date = {2022-05-12},

journal = {Electrochimica Acta},

volume = {420},

pages = {140439},

abstract = {Direct ethanol fuel cells (DEFCs) are a promising power source, but the low selectivity to ethanol complete oxidation is still challenging. The localized surface plasmon resonance (LSPR) excitation has been reported to accelerate and drive several chemical reactions, including the ethanol oxidation reaction (EOR), coming as a strategy to improve catalysts performance. Nonetheless, metallic nanoparticles (NPs) that present the LSPR excitation in the visible range are known for leading to the incomplete oxidation of ethanol. Thus, we report here the application of gold-rhodium nanoflowers (Au@Rh NFs) towards the plasmon-enhanced EOR. These hybrid materials consist of a Au spherical nucleus covered by Rh branches shell, combining plasmonic and catalytic properties. Firstly, the Au@Rh NFs metallic ratio was investigated in dark conditions to obtain an optimal catalyst. Experiments were also performed under light irradiation. Our data demonstrated an improvement of 352% in current density and 36% in selectivity to complete ethanol oxidation under 533 nm laser incidence. Moreover, the current density showed a linear increase with the laser power density, indicating a photochemical effect and thus enhancement due to the LSPR properties.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Inverse Multislice Ptychography by Layer-wise Optimisation and Sparse Matrix Decomposition},

author = {A Bangun and O Melnyk and B M\"{a}rz and B Diederichs and A Clausen and D Weber and F Filbir and K M\"{u}ller-Caspary},

url = {https://arxiv.org/abs/2205.03902},

doi = {https://doi.org/10.48550/arXiv.2205.03902},

year  = {2022},

date = {2022-05-08},

journal = {arXiv preprint arXiv:2205.03902},

abstract = {We propose algorithms based on an optimisation method for inverse multislice ptychography in, e.g. electron microscopy. The multislice method is widely used to model the interaction between relativistic electrons and thick specimens. Since only the intensity of diffraction patterns can be recorded, the challenge in applying inverse multislice ptychography is to uniquely reconstruct the electrostatic potential in each slice up to some ambiguities. In this conceptual study, we show that a unique separation of atomic layers for simulated data is possible when considering a low acceleration voltage. We also introduce an adaptation for estimating the illuminating probe. For the sake of practical application, we finally present slice reconstructions using experimental 4D scanning transmission electron microscopy (STEM) data.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Electronic and Optical Properties of Eu2+-Activated Narrow-Band Phosphors for Phosphor-Converted Light-Emitting Diode Applications: Insights from a Theoretical Spectroscopy Perspective},

author = {R Shafei and D Maganas and P J Strobel and P J Schmidt and W Schnick and F Neese},

url = {https://doi.org/10.1021/jacs.2c00218},

doi = {10.1021/jacs.2c00218},

issn = {0002-7863},

year  = {2022},

date = {2022-04-26},

journal = {Journal of the American Chemical Society},

volume = {144},

number = {18},

pages = {8038-8053},

abstract = {In this work, we present a computational protocol that is able to predict the experimental absorption and emission spectral shapes of Eu2+-doped phosphors. The protocol is based on time-dependent density functional theory and operates in conjunction with an excited-state dynamics approach. It is demonstrated that across the study set consisting of representative examples of nitride, oxo-nitride, and oxide Eu2+-doped phosphors, the energy distribution and the band shape of the emission spectrum are related to the nature of the 4f\textendash5d transitions that are probed in the absorption process. Since the 4f orbitals are very nearly nonbonding, the decisive quantity is the covalency of the 5d acceptor orbitals that become populated in the electronically excited state that leads to emission. The stronger the (anti) bonding interaction between the lanthanide and the ligands is in the excited state, the larger will be the excited state distortion. Consequently, the corresponding emission will get broader due to the vibronic progression that is induced by the structural distortion. In addition, the energy separation of the absorption bands that are dominated by states with valence 4f\textendash5d and a metal to ligand charge transfer character defines a measure for the thermal quenching of the studied Eu2+-doped phosphors. Based on this analysis, simple descriptors are identified that show a strong correlation with the energy position and bandwidth of the experimental emission bands without the need for elaborate calculations. Overall, we believe that this study serves as an important reference for designing new Eu2+-doped phosphors with desired photoluminescence properties.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Solution-based synthesis of wafer-scale epitaxial BiVO4 thin films exhibiting high structural and optoelectronic quality},

author = {V F Kunzelmann and C-M Jiang and I Ihrke and E Sirotti and T Rieth and A Henning and J Eichhorn and I D Sharp},

url = {http://dx.doi.org/10.1039/D1TA10732A},

doi = {10.1039/D1TA10732A},

issn = {2050-7488},

year  = {2022},

date = {2022-04-22},

journal = {Journal of Materials Chemistry A},

abstract = {We demonstrate a facile approach to solution-based synthesis of wafer-scale epitaxial bismuth vanadate (BiVO4) thin films by spin-coating on yttria-stabilized zirconia. Epitaxial growth proceeds via solid-state transformation of initially formed polycrystalline films, driven by interface energy minimization. The (010)-oriented BiVO4 films are smooth and compact, possessing remarkably high structural quality across complete 2′′ wafers. Optical absorption is characterized by a sharp onset with a low sub-band gap response, confirming that the structural order of the films results in correspondingly high optoelectronic quality. This combination of structural and optoelectronic quality enables measurements that reveal a strong optical anisotropy of BiVO4, which leads to significantly increased in-plane optical constants near the fundamental band edge that are of particular importance for maximizing light harvesting in semiconductor photoanodes. Temperature-dependent transport measurements confirm a thermally activated hopping barrier of ∼570 meV, consistent with small electron polaron conduction. This simple approach for synthesis of high-quality epitaxial BiVO4, without the need for complex deposition equipment, enables a broadly accessible materials base to accelerate research aimed at understanding and optimizing photoelectrochemical energy conversion mechanisms.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Li+ Conductivity of Space Charge Layers Formed at Electrified Interfaces Between a Model Solid-State Electrolyte and Blocking Au-Electrodes},

author = {L Katzenmeier and L Carstensen and A S Bandarenka},

url = {https://doi.org/10.1021/acsami.2c00650},

doi = {10.1021/acsami.2c00650},

issn = {1944-8244},

year  = {2022},

date = {2022-04-06},

journal = {ACS Applied Materials \& Interfaces},

volume = {14},

number = {13},

pages = {15811-15817},

abstract = {The formation of space charge layers in solid-state ion conductors has been investigated as early as the 1980s. With the advent of all-solid-state batteries as an alternative to traditional Li-ion batteries, possibly improving performance and safety, the phenomenon of space charge formation caught the attention of researchers as a possible origin for the observed high interfacial resistance. Following classical space charge theory, such high resistances result from the formation of the depletion layers. These layers of up to hundreds of nanometers in thickness are almost free of mobile cations. With the prediction of a Debye-like screening effect, the thickness of the depletion layer is expected to scale with the square root of the absolute temperature. In this work, we studied the temperature dependence of the depletion layer properties in model solid Ohara LICGC Li+ conducting electrolytes using electrochemical impedance spectroscopy. We show that the activation energy inside the depletion layer increases to ca 0.42 eV compared to ca 0.39 eV in the bulk electrolyte. Moreover, the proportionality between temperature and depletion layer thickness, correlating to the Debye length, is tested and validated.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Time-Resolved Orientation and Phase Analysis of Lead Halide Perovskite Film Annealing Probed by In Situ GIWAXS},

author = {M A Reus and L K Reb and A F Weinzierl and C L Weindl and R Guo and T Xiao and M Schwartzkopf and A Chumakov and S V Roth and P M\"{u}ller-Buschbaum},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202102722},

doi = {https://doi.org/10.1002/adom.202102722},

issn = {2195-1071},

year  = {2022},

date = {2022-04-03},

journal = {Advanced Optical Materials},

volume = {n/a},

number = {n/a},

pages = {2102722},

abstract = {Abstract Scalable thin-film deposition methods are increasingly important for hybrid lead halide perovskite thin films. Understanding the structure evolution during non-equilibrium processes helps to find suitable materials and processing parameters to produce films with well-performing optoelectronic properties. Here, spin-cast and slot-die coated bilayers of lead iodide (PbI2) and methylammonium iodide (MAI) are investigated by in situ grazing-incidence wide-angle X-ray scattering during the thermal annealing process, which converts the bilayer into methylammonium lead iodide (MAPI). Photoluminescence (PL) and UV/Vis measurements show increasing crystallinity during the annealing process and a slight PL red-shift of the spin-cast film, attributed to crystallite coalescence that is not prominent for the slot-die coated film. The disintegration of the solvent-precursor complex (MA)2(Pb3I8) ⋅ 2 DMSO and conversion into perovskite are followed in situ and differences in the morphology and time evolution are observed. In both, spin-cast and slot-die coated thin-films, the isotropic orientation is dominant, however, in the slot-die coated films, the perovskite crystallites have an additional face-on orientation ((110) parallel to substrate) that is not detected in spin-cast films. An Avrami model is applied for the perovskite crystal growth that indicates reduced dimensionality of the growth for the printed thin films.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Band gap and electronic structure of defects in the ternary nitride BP3N6: experiment and theory},

author = {T De Boer and M F A Fattah and M R Amin and S J Ambach and S Vogel and W Schnick and A Moewes},

url = {https://doi.org/10.1039/D1TC06009K},

doi = {10.1039/D1TC06009K},

issn = {2050-7526},

year  = {2022},

date = {2022-03-28},

urldate = {2022-03-28},

journal = {Journal of Materials Chemistry C},

volume = {10},

pages = {6429-6434},

abstract = {Recent advances in methods to access nitride systems by a high-pressure high-temperature approach have made possible the one-step synthesis of mixed ternary non-metal nitrides. As a prerequisite to use in a practical device, it is important to understand important bulk electronic properties, such as the band gap, as well as characterizing the presence and effect of defects that are present. In this work, the novel ternary nitride BP3N6 is studied using techniques sensitive to the partial electronic density of states, specifically X-ray absorption spectroscopy and X-ray emission spectroscopy. Complementary full-potential all-electron density functional theory (DFT) calculations allow important bulk electronic parameters, such as the band gap, to be elucidated. The band gap of BP3N6 has been determined to be 3.9 ± 0.2 eV and 4.1 ± 0.4 eV at the B K- and N K-edges, respectively. This is close to a theoretical value of 4.3 eV predicted by the PBEsol exchange\textendashcorrelation functional and considerably less than a value of 5.8 eV predicted by the modified Becke\textendashJohnson exchange\textendashcorrelation functional. X-Ray excited optical luminescence (XEOL) measurements are performed to interrogate the presence of point defects in this system. Together with DFT calculations, these measurements reveal the presence of nitrogen vacancies which lead to multiple mid-gap trap states.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Self-doping behavior and cation disorder in MgSnN2},

author = {D Han and S S Rudel and W Schnick and H Ebert},

url = {https://link.aps.org/doi/10.1103/PhysRevB.105.125202},

doi = {10.1103/PhysRevB.105.125202},

year  = {2022},

date = {2022-03-28},

journal = {Physical Review B},

volume = {105},

number = {12},

pages = {125202},

abstract = {Investigations on II−Sn−N2(II=Mg, Ca) have been started very recently compared to the intense research of Zn−IV−N2 (IV=Si, Ge, Sn). In this work, we study the phase stability of MgSnN2 and ZnSnN2 in wurtzite and rocksalt phases by first principles calculations. The calculated phase diagram agrees with the experimental observation; i.e., MgSnN2 can form in the wurtzite and rocksalt phases while ZnSnN2 only crystallizes in the wurtzite phase. Due to the higher ionicity of Mg-N bonds compared to Sn-N bonds and Zn-N bonds, wurtzite-type 

MgSnN2 appears under Mg-rich conditions. The defect properties and doping behavior of MgSnN2 in the wurtzite phase are further investigated. We find that MgSnN2 exhibits self-doped n-type conductivity, and donor-type antisite defect SnMg is the primary source of free electrons. The high possibility of forming the stoichiometry-preserving MgSn+SnMg defect complex leads to our study of cation disorder in MgSnN2 by using the cluster expansion method with first principles calculations. It is found that cation disorder in MgSnN2 induces a band-gap reduction because of a violation of the octet rule. The local disorder, namely, forming (4,0) or (0,4) tetrahedra, leads to an appreciable band-gap reduction and hinders the enhancement of the optical absorption.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Process-aid solid engineering triggers delicately modulation of Y-series non-fullerene acceptor for efficient organic solar cells},

author = {X Song and K Zhang and R Guo and K Sun and Z Zhou and S Huang and L Huber and M Reus and J Zhou and M Schwartzkopf and S V Roth and W Liu and Y Liu and W Zhu and P M\"{u}ller-Buschbaum},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202200907},

doi = {https://doi.org/10.1002/adma.202200907},

issn = {0935-9648},

year  = {2022},

date = {2022-03-22},

journal = {Advanced Materials},

volume = {n/a},

number = {n/a},

pages = {2200907},

abstract = {Abstract Volatile solids with symmetric π-backbone have been intensively implemented on manipulating the nanomorphology for improving the operability and stability of organic solar cells. However, due to the isotropic stacking, the announced solids with symmetric geometry cannot modify the microscopic phase separation and component distribution collaboratively, which would constrain the promotion of exciton splitting and charge collection efficiency. Inspired by the superiorities of asymmetric configuration, a novel process-aid solid (PAS) engineering is proposed. By coupling with BTP core unit in Y-series molecule, an asymmetric, volatile 1, 3-dibromo-5-chlorobenzene (DBCl) solid can induce the anisotropic dipole direction, elevated dipole moment, and interlaminar interaction spontaneously. Due to the synergetic effects on the favorable phase separation and desired component distribution, the PAS treated devices feature the evident improvement of exciton splitting, charge transport, and collection, accompanied by the suppressed trap-assisted recombination. Consequently, we achieve an impressive fill factor of 80.2% with maximum power conversion efficiency (PCE) of 18.5% in the PAS treated device. More strikingly, the PAS treated devices demonstrate a promising thickness-tolerance character, where a record PCE of 17.0% is yielded in PAS devices with a 300 nm thickness photoactive layer, which represents the highest PCE for thick-film OSCs. This article is protected by copyright. All rights reserved},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Hydrophobic Graphene Quantum Dots for Defect Passivation and Enhanced Moisture Stability of CH3NH3PbI3 Perovskite Solar Cells},

author = {E Khorshidi and B Rezaei and D Bl\"{a}tte and A Buyruk and M A Reus and J Hanisch and B B\"{o}ller and P M\"{u}ller-Buschbaum and T Ameri},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/solr.202200023},

doi = {https://doi.org/10.1002/solr.202200023},

issn = {2367-198X},

year  = {2022},

date = {2022-03-19},

journal = {Solar RRL},

volume = {n/a},

number = {n/a},

pages = {2200023},

abstract = {Passivating the defects and grain boundaries (GBs) of perovskite films at the interface by interface engineering is a promising route to achieve efficient and stable perovskite solar cells (PSCs). Herein, a new type of graphene, that is, hydrophobic graphene quantum dots (HGQDs) containing amide linkages, which consist of carbonyl and dodecyl amine groups, is successfully used as a bifunctional interface modifier to engineer the interface of the perovskite/hole transport layer. A comprehensive characterization including X-ray photoelectron spectroscopy, Fourier-transform photocurrent spectroscopy, Raman spectroscopy, photoluminescence spectroscopy, and space-charge-limited current measurements is performed to identify the underlying passivation mechanisms. It can be demonstrated that the HGQDs, due to the bifunctional groups containing N and O atoms, effectively passivate the uncoordinated Pb2+ ions at the perovskite film surface and GBs and consequently induce a lower trap state density. Moreover, HGQDs enhance the quality of the perovskite film which reduces the charge recombination at the interface. Therefore, the power conversion efficiency of PSCs treated with HGQDs is significantly increased from 16.00% to 18.30%, mainly based on the improved open-circuit voltage and fill factor. Importantly, the HGQDs featuring hydrophobicity due to alkyl chains significantly enhance moisture stability.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Electron\textendashHole Binding Governs Carrier Transport in Halide Perovskite Nanocrystal Thin Films},

author = {M F Lichtenegger and J Drewniok and A Bornschlegl and C Lampe and A Singldinger and N A Henke and A S Urban},

url = {https://doi.org/10.1021/acsnano.2c00369},

doi = {10.1021/acsnano.2c00369},

issn = {1936-0851},

year  = {2022},

date = {2022-03-18},

journal = {ACS Nano},

abstract = {Two-dimensional halide perovskite nanoplatelets (NPLs) have exceptional light-emitting properties, including wide spectral tunability, ultrafast radiative decays, high quantum yields (QY), and oriented emission. Due to the high binding energies of electron\textendashhole pairs, excitons are generally considered the dominant species responsible for carrier transfer in NPL films. To realize efficient devices, it is imperative to understand how exciton transport progresses therein. We employ spatially and temporally resolved optical microscopy to map exciton diffusion in perovskite nanocrystal (NC) thin films between 15 °C and 55 °C. At room temperature (RT), we find the diffusion length to be inversely correlated to the thickness of the nanocrystals (NCs). With increasing temperatures, exciton diffusion declines for all NC films, but at different rates. This leads to specific temperature turnover points, at which thinner NPLs exhibit higher diffusion lengths. We attribute this anomalous diffusion behavior to the coexistence of excitons and free electron hole-pairs inside the individual NCs within our temperature range. The organic ligand shell surrounding the NCs prevents charge transfer. Accordingly, any time an electron\textendashhole pair spends in the unbound state reduces the FRET-mediated inter-NC transfer rates and, consequently, the overall diffusion. These results clarify how exciton diffusion progresses in strongly confined halide perovskite NC films, emphasizing critical considerations for optoelectronic devices.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Anharmonic Lattice Dynamics in Sodium Ion Conductors},

author = {T M Brenner and M Grumet and P Till and M Asher and W G Zeier and D A Egger and O Yaffe},

url = {https://arxiv.org/abs/2203.07955},

doi = {https://doi.org/10.48550/arXiv.2203.07955},

year  = {2022},

date = {2022-03-15},

journal = {arXiv preprint arXiv:2203.07955},

abstract = {We employ THz-range temperature-dependent Raman spectroscopy and first-principles lattice-dynamical calculations to show that the undoped sodium ion conductors Na3PS4 and isostructural Na3PSe4 both exhibit anharmonic lattice dynamics. The anharmonic effects in the compounds involve coupled host lattice -- Na+ ion dynamics that drive the tetragonal-to-cubic phase transition in both cases, but with a qualitative difference in the anharmonic character of the transition. Na3PSe4 shows almost purely displacive character with the soft modes disappearing in the cubic phase as the change of symmetry shifts these modes to the Raman-inactive Brillouin zone boundary. Na3PS4 instead shows order-disorder character in the cubic phase, with the soft modes persisting through the phase transition and remaining active in Raman in the cubic phase, violating Raman selection rules for that phase. Our findings highlight the important role of coupled host lattice -- mobile ion dynamics in vibrational instabilities that are coincident with the exceptional conductivity in these Na+ ion conductors.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Tuning the feature size of nanoimprinting stamps: A method to enhance the flexibility of nanoimprint lithography},

author = {M Golibrzuch and T L Maier and M J Feil and K Krischer and M Becherer},

url = {https://aip.scitation.org/doi/abs/10.1063/5.0079282},

doi = {10.1063/5.0079282},

year  = {2022},

date = {2022-03-09},

journal = {Journal of Applied Physics},

volume = {131},

number = {12},

pages = {124301},

abstract = {In the field of nanoimprinting lithography, fabricating large-area imprinting stamps is often the most time- and resource-consuming step. Specifically in research, it is often not reasonable to produce a new imprinting stamp for each new experimental configuration. Therefore, the lack of flexibility in feature sizes makes prototyping and tailoring the feature sizes according to their application challenging. To overcome these restrictions, we developed an imprinting stamp reproduction and tuning method which enables the size of the features of existing imprinting stamps to be tuned within nanometer precision. For replication, we first fabricate a chromium nanoisland array on silicon dioxide using the to-be tuned imprinting stamp. Then, the silicon dioxide is anisotropically etched in a reactive ion etching process with chromium as a hard mask. The formed replica of the imprinting stamp is subsequently tuned in an isotropic etching step with hydrofluoric acid. The method enables us to tune the size of the features of our nanoimprinting stamps within nanometer precision without influencing their shape with a yield above 96%. The tuned stamps are then used to fabricate metal nanoisland arrays with the respective tuned sizes. To evaluate the influence of the feature sizes, we exemplarily study the plasmonic resonance of gold nanoisland arrays fabricated using stamps with different feature diameters. Here, we see a good agreement between measured and simulated plasmonic resonance wavelengths of the samples. Hence, with the tuning method, we can tailor specific size-dependent properties of our nanoisland arrays according to individual experiments and applications.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Revealing Donor\textendashAcceptor Interaction on the Printed Active Layer Morphology and the Formation Kinetics for Nonfullerene Organic Solar Cells at Ambient Conditions},

author = {X Jiang and P Chotard and K Luo and F Eckmann and S Tu and M A Reus and S Yin and J Reitenbach and C L Weindl and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202103977},

doi = {https://doi.org/10.1002/aenm.202103977},

issn = {1614-6832},

year  = {2022},

date = {2022-02-27},

journal = {Advanced Energy Materials},

volume = {n/a},

number = {n/a},

pages = {2103977},

abstract = {Abstract Slot-die coating is a powerful method for upscaling the production of organic solar cells (OSCs) with low energy consumption print processes at ambient conditions. Herein, chlorobenzene (CB) and chloroform (CF) are compared as host solvents for printing films of the neat novel fused-ring unit based wide-bandgap donor polymer (PDTBT2T-FTBDT), the small molecule nonfullerene acceptor based on a fused ring with a benzothiadiazole core (BTP-4F) as well as the respective PDTBT2T-FTBDT:BTP-4F blend films at room temperature in air. Using CF printing of the PDTBT2T-FTBDT:BTP-4F active layer, OSCs with a high power conversion efficiency of up to 13.2% are reached in ambient conditions. In comparison to CB printed blend films, the active layer printed out of CF has a superior morphology, a smoother film surface and a more pronounced face-on orientation of the crystallites, which altogether result in an enhanced exciton dissociation, a superior charge transport, and suppressed nonradiative charge carrier recombination. Based on in situ studies of the slot-die coating process of PDTBT2T-FTBDT, BTP-4F, and PDTBT2T-FTBDT:BTP-4F films, the details of the film formation kinetics are clarified, which cause the superior behavior for CF compared to CB printing due to balancing the aggregation and crystallization of donor and acceptor.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Modification of the Electrochemical Surface Oxide Formation and the Hydrogen Oxidation Activity of Ruthenium by Strong Metal Support Interactions},

author = {B M St\"{u}hmeier and R J Schuster and L Hartmann and S Selve and H A El-Sayed and H A Gasteiger },

url = {http://iopscience.iop.org/article/10.1149/1945-7111/ac58c9},

doi = {https://doi.org/10.1149/1945-7111/ac58c9},

issn = {1945-7111},

year  = {2022},

date = {2022-02-25},

urldate = {2022-02-25},

journal = {Journal of The Electrochemical Society},

abstract = {A major hurdle for the wide spread commercialization of proton exchange membrane based fuel cells (PEMFCs) and water electrolyzers are the durability and high cost of noble metal catalysts. Here, alternative support materials might offer advantages, as they can alter the properties of a catalyst by means of a strong metal support interaction (SMSI) that has been shown to prevent platinum oxidation and suppress the oxygen reduction reaction on titanium oxide supported platinum nanoparticles deposited on a carbon support (Pt/TiOx/C). Herein, we report a novel Ru/TiOx/C catalyst that according to tomographic transmission electron microscopy analysis consists of partially encapsulated Ru particles in a Ru/TiOx-composite matrix supported on a carbon support. It is shown by cyclic voltammetry and X-ray photoelectron spectroscopy that ruthenium oxidation is mitigated by an SMSI between Ru and TiOx after reductive heat-treatment (Ru/TiOx/C400°C,H2 ). As a result, the catalyst is capable of oxidizing hydrogen up to the onset of oxygen evolution reaction, in stark contrast to a Ru/C reference catalyst. PEMFC-based hydrogen pump measurements confirmed the stabilization of the hydrogen oxidation reaction (HOR) activity on Ru/TiOx/C400°C,H2 and showed a ≈3 fold higher HOR activity compared to Ru/C, albeit roughly two orders of magnitude less active than Pt/C.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Discovery of Two Polymorphs of TiP4N8 Synthesized from Binary Nitrides},

author = {L Eisenburger and V Weippert and C Paulmann and D Johrendt and O Oeckler and W Schnick},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202202014},

doi = {https://doi.org/10.1002/anie.202202014},

issn = {1433-7851},

year  = {2022},

date = {2022-02-18},

journal = {Angewandte Chemie International Edition},

volume = {n/a},

number = {n/a},

pages = {e202202014},

abstract = {Abstract TiP4N8 was obtained from the binary nitrides TiN and P3N5 upon addition of NH4F as a mineralizer at 8 GPa and 1400 °C. An intricate interplay of disorder and polymorphism was elucidated by in situ temperature-dependent single-crystal X-ray diffraction, STEM-HAADF, and the investigation of annealed samples. This revealed two polymorphs, which consist of dense networks of PN4 tetrahedra (degree of condensation κ=0.5) and either augmented triangular TiN7 prisms or triangular TiN6 prisms for α- and β-TiP4N8, respectively. The structures of TiP4N8 exhibit body-centered tetragonal (bct) framework topology. DFT calculations confirm the measured band gaps of α- and β-TiP4N8 (1.6\textendash1.8 eV) and predict the thermochemistry of the polymorphs in agreement with the experiments.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Vertical Cu Nanoneedle Arrays Enhance the Local Electric Field Promoting C2 Hydrocarbons in the CO2 Electroreduction},

author = {Y Zhou and Y Liang and J Fu and K Liu and Q Chen and X Wang and H Li and L Zhu and J Hu and H Pan and M Miyauchi and L Jiang and E Cort\'{e}s and M Liu},

url = {https://doi.org/10.1021/acs.nanolett.1c04653},

doi = {10.1021/acs.nanolett.1c04653},

issn = {1530-6984},

year  = {2022},

date = {2022-02-15},

journal = {Nano Letters},

abstract = {Electrocatalytic reduction of CO2 to multicarbon products is a potential strategy to solve the energy crisis while achieving carbon neutrality. To improve the efficiency of multicarbon products in Cu-based catalysts, optimizing the *CO adsorption and reducing the energy barrier for carbon\textendashcarbon (C\textendashC) coupling are essential features. In this work, a strong local electric field is obtained by regulating the arrangement of Cu nanoneedle arrays (CuNNAs). CO2 reduction performance tests indicate that an ordered nanoneedle array reaches a 59% Faraday efficiency for multicarbon products (FEC2) at −1.2 V (vs RHE), compared to a FEC2 of 20% for a disordered nanoneedle array (CuNNs). As such, the very high and local electric fields achieved by an ordered Cu nanoneedle array leads to the accumulation of K+ ions, which benefit both *CO adsorption and C\textendashC coupling. Our results contribute to the design of highly efficient catalysts for multicarbon products.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Single-photon emitters in layered van der Waals materials},

author = {S Michaelis De Vasconcellos and D Wigger and U Wurstbauer and A W Holleitner and R Bratschitsch and T Kuhn},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/pssb.202100566},

doi = {https://doi.org/10.1002/pssb.202100566},

issn = {0370-1972},

year  = {2022},

date = {2022-01-28},

journal = {physica status solidi (b)},

volume = {n/a},

number = {n/a},

abstract = {Single-photon emitters have recently been discovered in various atomically thin materials. Their properties, controllability, and the possibility of their monolithic integration in electronic and photonic device structures makes them attractive candidates for a wide range of applications in quantum information and communication, and also in other fields of physics and technology. In this review article an overview of single-photon emitters in layered van der Waals materials and their physical properties is given, theoretical concepts for the modeling of their level structure and their coupling to phonons are presented, and techniques for the creation and localization of these emitters in the host material are described. Perspectives for their application in various fields, such as their coupling to photonic resonators and waveguides, their control by external electric fields or strain, and their integration in optomechanical devices are discussed. Finally, functionalities relying on properties beyond single-photon emission are briefly addressed. This article is protected by copyright. All rights reserved.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Surface NMR using quantum sensors in diamond},

author = {K S Liu and A Henning and M W Heindl and R D Allert and J D Bartl and I D Sharp and R Rizzato and D B Bucher},

url = {https://www.pnas.org/doi/abs/10.1073/pnas.2111607119 %X Many of the functions and applications of materials in catalysis, energy conversion, drug delivery, bioanalysis, and electronics are based on their interfacial properties and structures. The characterization of their molecular properties under ambient or chemically reactive conditions is a fundamental scientific challenge. Here, we develop a surface-sensitive magnetic resonance technique that combines the nanoscale-sensing capabilities of defects in diamond with a high precision and versatile protocol for diamond surface modification. We demonstrate the functionality of this method for probing the molecular properties and kinetics at surfaces and interfaces under ambient conditions. NMR is a noninvasive, molecular-level spectroscopic technique widely used for chemical characterization. However, it lacks the sensitivity to probe the small number of spins at surfaces and interfaces. Here, we use nitrogen vacancy (NV) centers in diamond as quantum sensors to optically detect NMR signals from chemically modified thin films. To demonstrate the method’s capabilities, aluminum oxide layers, common supports in catalysis and materials science, are prepared by atomic layer deposition and are subsequently functionalized by phosphonate chemistry to form self-assembled monolayers. The surface NV-NMR technique detects spatially resolved NMR signals from the monolayer, indicates chemical binding, and quantifies molecular coverage. In addition, it can monitor in real time the formation kinetics at the solid\textendashliquid interface. With our approach, we show that NV quantum sensors are a surface-sensitive NMR tool with femtomole sensitivity for in situ analysis in catalysis, materials, and biological research.},

doi = {doi:10.1073/pnas.2111607119},

year  = {2022},

date = {2022-01-26},

journal = {Proceedings of the National Academy of Sciences},

volume = {119},

number = {5},

pages = {e2111607119},

abstract = {NMR is a noninvasive, molecular-level spectroscopic technique widely used for chemical characterization. However, it lacks the sensitivity to probe the small number of spins at surfaces and interfaces. Here, we use nitrogen vacancy (NV) centers in diamond as quantum sensors to optically detect NMR signals from chemically modified thin films. To demonstrate the method’s capabilities, aluminum oxide layers, common supports in catalysis and materials science, are prepared by atomic layer deposition and are subsequently functionalized by phosphonate chemistry to form self-assembled monolayers. The surface NV-NMR technique detects spatially resolved NMR signals from the monolayer, indicates chemical binding, and quantifies molecular coverage. In addition, it can monitor in real time the formation kinetics at the solid\textendashliquid interface. With our approach, we show that NV quantum sensors are a surface-sensitive NMR tool with femtomole sensitivity for in situ analysis in catalysis, materials, and biological research.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Depositing Molecular Graphene Nanoribbons on Ag(111) by Electrospray - Controlled Ion Beam Deposition: Self-assembly and On-Surface Transformations},

author = {W Ran and A Walz and K Stoiber and P Knecht and H Xu and A C Papageorgiou and A Huettig and D Cortizo-Lacalle and J P Mora-Fuentes and A Mateo-Alonso and H Schlichting and J Reichert and J V Barth},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202111816},

doi = {https://doi.org/10.1002/anie.202111816},

issn = {1433-7851},

year  = {2022},

date = {2022-01-25},

journal = {Angewandte Chemie International Edition},

volume = {n/a},

number = {n/a},

abstract = {The chemical processing of low dimensional carbon nanostructures is crucial for their integration in future devices. Here we apply a new methodology in atomically precise engineering by combining multistep solution synthesis of N-doped molecular graphene nanoribbons (GNRs) with mass-selected ultra-high vacuum electrospray - controlled ion beam deposition on surfaces and real space visualisation by scanning tunnelling microscopy. We demonstrate how this method yields solely a controllable amount of single, otherwise unsublimable, GNRs of 2.9 nm length on a planar Ag(111) surface. This methodology allows for further processing by employing on-surface synthesis protocols and exploiting the reactivity of the substrate. Following multiple chemical transformations, the GNRs provide reactive building blocks to form extended, metal-organic coordination polymers.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Electronically Tunable Transparent Conductive Thin Films for Scalable Integration of 2D Materials with Passive 2D\textendash3D Interfaces},

author = {T Gr\"{u}nleitner and A Henning and M Bissolo and A Kleibert and C F Vaz and A V Stier and J J Finley and I D Sharp},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202111343},

doi = {https://doi.org/10.1002/adfm.202111343},

issn = {1616-301X},

year  = {2022},

date = {2022-01-22},

journal = {Advanced Functional Materials},

volume = {n/a},

number = {n/a},

pages = {2111343},

abstract = {Abstract A novel transparent conductive support structure for scalable integration of 2D materials is demonstrated, providing an electronically passive 2D\textendash3D interface while also enabling facile interfacial charge transport. This structure, which comprises an evaporated nanocrystalline carbon (nc-C) film beneath nanometer-thin atomic layer deposited AlOx, is thermally stable and allows direct chemical vapor deposition of 2D materials onto the surface. The combination of spatial uniformity, enhanced charge screening, and low interface defect concentrations yields a tenfold enhancement of MoS2 photoluminescence intensity compared to flakes on conventional Si/SiO2, while also retaining the strong optical contrast for monolayer flakes. Tunneling across the ultrathin AlOx enables facile interfacial charge injection, which is utilized for high-resolution scanning electron microscopy and photoemission electron microscopy with no detectable charging. Thus, this combination of scalable fabrication and electronic conductivity across a weakly interacting 2D\textendash3D interface opens up new opportunities for device integration and characterization of 2D materials.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Optical dipole orientation of interlayer excitons in MoSe2-WSe2 heterostacks},

author = {L Sigl and M Troue and M Katzer and M Selig and F Sigger and J Kiemle and M Brotons-Gisbert and K Watanabe and T Taniguchi and B D Gerardot and A Knorr and U Wurstbauer and A W Holleitner},

url = {https://link.aps.org/doi/10.1103/PhysRevB.105.035417},

doi = {10.1103/PhysRevB.105.035417},

year  = {2022},

date = {2022-01-14},

urldate = {2022-01-14},

journal = {Physical Review B},

volume = {105},

number = {3},

pages = {035417},

abstract = {We report on the far-field photoluminescence intensity distribution of interlayer excitons in 

MoSe2WSe2 heterostacks as measured by back focal plane imaging in the temperature range between 1.7 and 20 K. By comparing the data with an analytical model describing the dipolar emission pattern in a dielectric environment, we are able to obtain the relative contributions of the in- and out-of-plane transition dipole moments associated to the interlayer exciton photon emission. We determine the transition dipole moments for all observed interlayer exciton transitions to be (99±1)% in plane for R- and H-type stacking, independent of the excitation power and therefore the density of the exciton ensemble in the experimentally examined range. Finally, we discuss the limitations of the presented measurement technique to observe correlation effects in exciton ensembles.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Designing multifunctional CoOx layers for efficient and stable electrochemical energy conversion},

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

doi = {10.26434/chemrxiv-2022-23ck4},

year  = {2022},

date = {2022-01-13},

urldate = {2022-01-13},

journal = {Cambridge: Cambridge Open Engage},

abstract = {Disordered and porous metal oxides are promising as earth-abundant and cost-effective alternatives to noble-metal electrocatalysts. Herein, we leverage non-saturated oxidation in plasma-enhanced atomic layer deposition to tune structural, mechanical, and optical properties of biphasic CoOx thin films, thereby tailoring their catalytic activities and chemical stabilities. To optimize the resulting film properties, we systematically vary the oxygen plasma power and exposure time in the deposition process. We find that short exposure times and low plasma powers incompletely oxidize the cobaltocene precursor to Co(OH)2 and result in the incorporation of carbon impurities. These Co(OH)2 films are highly porous and catalytically active, but their electrochemical stability is impacted by poor adhesion to the substrate. In contrast, long exposure times and high plasma powers completely oxidize the precursor to form Co3O4, reduce the carbon impurity incorporation, and improve the film crystallinity. While the resulting Co3O4 films are highly stable under electrochemical conditions, they are characterized by low oxygen evolution reaction activities. To overcome these competing properties, we applied the established relation between deposition parameters and functional film properties to design bilayer films exhibiting simultaneously improved electrochemical performance and chemical stability. The resulting biphasic films combine a highly active Co(OH)2 surface with a stable Co3O4 interface layer. In addition, these coatings exhibit minimal light absorption, thus rendering them well suited as protective catalytic layers on semiconductor light absorbers for application in photoelectrochemical devices.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {CO2-Activation by size-selected tantalum cluster cations (Ta1\textendash16+): thermalization governing reaction selectivity},

author = {N Levin and J T Margraf and J Lengyel and K Reuter and M Tschurl and U Heiz},

url = {http://dx.doi.org/10.1039/D1CP04469A},

doi = {10.1039/D1CP04469A},

issn = {1463-9076},

year  = {2022},

date = {2022-01-06},

urldate = {2022-01-06},

journal = {Physical Chemistry Chemical Physics},

volume = {24},

number = {4},

pages = {2623-2629},

abstract = {The reactions of tantalum cluster cations of different sizes toward carbon dioxide are studied in an ion trap under multi-collisional conditions. For all sizes studied, consecutive reactions with several CO2 molecules are observed. This reveals two different pathways, namely oxide formation and the pickup of an entire molecule. Supported by calculations of the thermochemistry of TanO+ formation upon reaction with CO2, changes in the branching ratios at a particular cluster size are related to heat effects due to the vibrational heat capacity of the clusters and the exothermicity of the reaction.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {The Influence of CsBr on Crystal Orientation and Optoelectronic Properties of MAPbI3-Based Solar Cells},

author = {Y Zou and S Yuan and A Buyruk and J Eichhorn and S Yin and M A Reus and T Xiao and S Pratap and S Liang and C L Weindl and W Chen and C Mu and I D Sharp and T Ameri and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},

url = {https://doi.org/10.1021/acsami.1c22184},

doi = {10.1021/acsami.1c22184},

issn = {1944-8244},

year  = {2022},

date = {2022-01-06},

urldate = {2022-01-06},

journal = {ACS Applied Materials \& Interfaces},

volume = {14},

pages = {2958},

abstract = {Crystal orientations are closely related to the behavior of photogenerated charge carriers and are vital for controlling the optoelectronic properties of perovskite solar cells. Herein, we propose a facile approach to reveal the effect of lattice plane orientation distribution on the charge carrier kinetics via constructing CsBr-doped mixed cation perovskite phases. With grazing-incidence wide-angle X-ray scattering measurements, we investigate the crystallographic properties of mixed perovskite films at the microscopic scale and reveal the effect of the extrinsic CsBr doping on the stacking behavior of the lattice planes. Combined with transient photocurrent, transient photovoltage, and space-charge-limited current measurements, the transport dynamics and recombination of the photogenerated charge carriers are characterized. It is demonstrated that CsBr compositional engineering can significantly affect the perovskite crystal structure in terms of the orientation distribution of crystal planes and passivation of trap-state densities, as well as simultaneously facilitate the photogenerated charge carrier transport across the absorber and its interfaces. This strategy provides unique insight into the underlying relationship between the stacking pattern of crystal planes, photogenerated charge carrier transport, and optoelectronic properties of solar cells.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {In Situ GISAXS Observation and Large Area Homogeneity Study of Slot-Die Printed PS-b-P4VP and PS-b-P4VP/FeCl3 Thin Films},

author = {S Yin and T Tian and C L Weindl and K S Wienhold and Q Ji and Y Cheng and Y Li and C M Papadakis and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},

url = {https://doi.org/10.1021/acsami.1c19797},

doi = {10.1021/acsami.1c19797},

issn = {1944-8244},

year  = {2022},

date = {2022-01-04},

urldate = {2022-01-04},

journal = {ACS Applied Materials \& Interfaces},

abstract = {Mesoporous hematite (α-Fe2O3) thin films with high surface-to-volume ratios show great potential as photoelectrodes or electrochemical electrodes in energy conversion and storage. In the present work, with the assistance of an up-scalable slot-die coating technique, locally highly ordered α-Fe2O3 thin films are successfully printed based on the amphiphilic diblock copolymer poly(styrene-b-4-vinylpyridine) (PS-b-P4VP) as a structure-directing agent. Pure PS-b-P4VP films are printed under the same conditions for comparison. The micellization of the diblock copolymer in solution, the film formation process of the printed thin films, the homogeneity of the dry films in the lateral and vertical direction as well as the morphological and compositional information on the calcined hybrid PS-b-P4VP/FeCl3 thin film are investigated. Because of convection during the solvent evaporation process, a similar dimple-type structure of vertically aligned cylindrical PS domains in a P4VP matrix developed for both printed PS-b-P4VP and hybrid PS-b-P4VP/FeCl3 thin films. The coordination effect between the Fe3+ ions and the vinylpyridine groups significantly affects the attachment ability of the P4VP chains to the silicon substrate. Accordingly, distinct feature sizes and homogeneity in the lateral direction, as well as the thicknesses in the perpendicular direction, are demonstrated in the two printed films. By removing the polymer template from the hybrid PS-b-P4VP/FeCl3 film at high temperature, a locally highly ordered mesoporous α-Fe2O3 film is obtained. Thus, a facile and up-scalable printing technique is presented for producing homogeneous mesoporous α-Fe2O3 thin films.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Tuning the Optical Properties of a MoSe2 Monolayer Using Nanoscale Plasmonic Antennas},

author = {M M Petri\'{c} and M Kremser and M Barbone and A Nolinder and A Lyamkina and A V Stier and M Kaniber and K M\"{u}ller and J J Finley},

url = {https://doi.org/10.1021/acs.nanolett.1c02676},

doi = {10.1021/acs.nanolett.1c02676},

issn = {1530-6984},

year  = {2022},

date = {2022-01-03},

journal = {Nano Letters},

volume = {22},

number = {2},

pages = {561-569},

abstract = {Nanoplasmonic systems combined with optically active two-dimensional materials provide intriguing opportunities to explore and control light\textendashmatter interactions at extreme subwavelength length scales approaching the exciton Bohr radius. Here, we present room- and cryogenic-temperature investigations of a MoSe2 monolayer on individual gold dipole nanoantennas. By controlling nanoantenna size, the dipolar resonance is tuned relative to the exciton achieving a total tuning of ∼130 meV. Differential reflectance measurements performed on >100 structures reveal an apparent avoided crossing between exciton and dipolar mode and an exciton\textendashplasmon coupling constant of g = 55 meV, representing g/(ℏωX) ≥ 3% of the transition energy. This places our hybrid system in the intermediate-coupling regime where spectra exhibit a characteristic Fano-like shape. We demonstrate active control by varying the polarization of the excitation light to programmably suppress coupling to the dipole mode. We further study the emerging optical signatures of the monolayer localized at dipole nanoantennas at 10 K.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Order-Disorder Transition driven Superionic Conduction in the New Plastic Polymorph of Na4P2S6},

author = {T Scholz and C Schneider and M W Terban and Z Deng and R Eger and M Etter and R E Dinnebier and P Canepa and B V Lotsch},

url = {https://chemrxiv.org/engage/chemrxiv/article-details/61b9af53f52bc46cf0c11492},

doi = {10.26434/chemrxiv-2021-7r31q},

year  = {2021},

date = {2021-12-21},

abstract = {Sodium thiophophates are promising materials for large-scale energy storage applications benefiting from high ionic conductivities and the-political abundance of the elements. A representative of this class is Na4P2S6, which currently shows two known polymorphs\textendashα and β. This work describes a third polymorph of Na4P2S6, γ, that forms above 580◦C, exhibits fast ion conduction with low activation energy, and is mechanically soft. Based on high-temperature diffraction, pair distribution function analysis, thermal analysis, impedance spectroscopy, and ab initio molecular dynamic calculations, γ-Na4P2S6 is identified to be a plastic crystal, characterized by dynamic orientational disorder of the P2S64\textendash anions on a translationally fixed body centered cubic lattice. The prospect of stabilizing plastic crystals at operating temperatures of solid-state batteries and benefiting from their high ionic conductivities as well as mechanical properties could have a strong impact in the field of solid-state battery chemistry.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Detecting a Hierarchy of Deep-Level Defects in the Model Semiconductor ZnSiN2},

author = {T De Boer and J H\"{a}usler and P Strobel and T D Boyko and S S Rudel and W Schnick and A Moewes},

url = {https://doi.org/10.1021/acs.jpcc.1c08115},

doi = {10.1021/acs.jpcc.1c08115},

issn = {1932-7447},

year  = {2021},

date = {2021-12-15},

journal = {The Journal of Physical Chemistry C},

abstract = {Recent developments in the materials synthesis of the Zn\textendashIV\textendashN2 system, including the alloy-free band gap tuning and synthesis of freestanding single crystals, reveal a system with potentially very broad applications. For that, important basic properties of these materials, such as the electronic band gap and the characteristics of defects, must be well understood, which has therefore become an urgent problem. In this work, X-ray absorption spectroscopy, X-ray emission spectroscopy, and density functional theory are utilized to characterize ZnSiN2. Excellent agreement between theory and experiment is obtained, with the band gap of ZnSiN2 determined to be 4.7 ± 0.3 eV. X-ray-excited optical luminescence spectroscopy is used to determine the presence of two deep-level defects, which are identified as due to the presence of nitrogen vacancies.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Surface-confined formation of conjugated porphyrin-based nanostructures on Ag(111)},

author = {N Cao and A Riss and E Corral-Rascon and A Meindl and W Auw\"{a}rter and M O Senge and M Ebrahimi and J V Barth},

url = {http://dx.doi.org/10.1039/D1NR06451G},

doi = {10.1039/D1NR06451G},

issn = {2040-3364},

year  = {2021},

date = {2021-11-25},

journal = {Nanoscale},

volume = {13},

number = {47},

pages = {19884-19889},

abstract = {Porphyrin-based oligomers were synthesized from the condensation of adsorbed 4-benzaldehyde-substituted porphyrins through the formation of CC linkages, following a McMurry-type coupling scheme. Scanning tunneling microscopy, non-contact atomic force microscopy, and X-ray photoelectron spectroscopy data evidence both the dissociation of aldehyde groups and the formation of CC linkages. Our approach provides a path for the on-surface synthesis of porphyrin-based oligomers coupled by CC bridges \textendash as a means to create functional conjugated nanostructures.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {On the Role of Long-Range Electrostatics in Machine-Learned Interatomic Potentials for Complex Battery Materials},

author = {C G Staacke and H H Heenen and C Scheurer and G Cs\'{a}nyi and K Reuter and J T Margraf},

url = {https://doi.org/10.1021/acsaem.1c02363},

doi = {10.1021/acsaem.1c02363},

year  = {2021},

date = {2021-11-22},

journal = {ACS Applied Energy Materials},

volume = {4},

number = {11},

pages = {12562-12569},

abstract = {Modeling complex energy materials such as solid-state electrolytes (SSEs) realistically at the atomistic level strains the capabilities of state-of-the-art theoretical approaches. On one hand, the system sizes and simulation time scales required are prohibitive for first-principles methods such as the density functional theory. On the other hand, parameterizations for empirical potentials are often not available, and these potentials may ultimately lack the desired predictive accuracy. Fortunately, modern machine learning (ML) potentials are increasingly able to bridge this gap, promising first-principles accuracy at a much reduced computational cost. However, the local nature of these ML potentials typically means that long-range contributions arising, for example, from electrostatic interactions are neglected. Clearly, such interactions can be large in polar materials such as electrolytes, however. Herein, we investigate the effect that the locality assumption of ML potentials has on lithium mobility and defect formation energies in the SSE Li7P3S11. We find that neglecting long-range electrostatics is unproblematic for the description of lithium transport in the isotropic bulk. In contrast, (field-dependent) defect formation energies are only adequately captured by a hybrid potential combining ML and a physical model of electrostatic interactions. Broader implications for ML-based modeling of energy materials are discussed.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Modular Assembly of Vibrationally and Electronically Coupled Rhenium Bipyridine Carbonyl Complexes on Silicon},

author = {J D Bartl and C Thomas and A Henning and M F Ober and G Savasci and B Yazdanshenas and P S Deimel and E Magnano and F Bondino and P Zeller and L Gregoratti and M Amati and C Paulus and F Allegretti and A Cattani-Scholz and J V Barth and C Ochsenfeld and B Nickel and I D Sharp and M Stutzmann and B Rieger},

url = {https://doi.org/10.1021/jacs.1c09061},

doi = {10.1021/jacs.1c09061},

issn = {0002-7863},

year  = {2021},

date = {2021-11-12},

urldate = {2021-11-12},

journal = {Journal of the American Chemical Society},

volume = {143},

pages = {19505},

abstract = {Hybrid inorganic/organic heterointerfaces are promising systems for next-generation photocatalytic, photovoltaic, and chemical-sensing applications. Their performance relies strongly on the development of robust and reliable surface passivation and functionalization protocols with (sub)molecular control. The structure, stability, and chemistry of the semiconductor surface determine the functionality of the hybrid assembly. Generally, these modification schemes have to be laboriously developed to satisfy the specific chemical demands of the semiconductor surface. The implementation of a chemically independent, yet highly selective, standardized surface functionalization scheme, compatible with nanoelectronic device fabrication, is of utmost technological relevance. Here, we introduce a modular surface assembly (MSA) approach that allows the covalent anchoring of molecular transition-metal complexes with sub-nanometer precision on any solid material by combining atomic layer deposition (ALD) and selectively self-assembled monolayers of phosphonic acids. ALD, as an essential tool in semiconductor device fabrication, is used to grow conformal aluminum oxide activation coatings, down to sub-nanometer thicknesses, on silicon surfaces to enable a selective step-by-step layer assembly of rhenium(I) bipyridine tricarbonyl molecular complexes. The modular surface assembly of molecular complexes generates precisely structured spatial ensembles with strong intermolecular vibrational and electronic coupling, as demonstrated by infrared spectroscopy, photoluminescence, and X-ray photoelectron spectroscopy analysis. The structure of the MSA can be chosen to avoid electronic interactions with the semiconductor substrate to exclusively investigate the electronic interactions between the surface-immobilized molecular complexes.},

keywords = {Foundry Inorganic, Foundry Organic, Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Optical dipole orientation of interlayer excitons in MoSe2-WSe2 heterostacks},

author = {L Sigl and M Troue and M Katzer and M Selig and F Sigger and J Kiemle and M Brotons-Gisbert and K Watanabe and T Taniguchi and B D Gerardot},

year  = {2021},

date = {2021-11-02},

journal = {Cond-Mat. Mes-Hall},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Bifurcations of Clusters and Collective Oscillations in Networks of Bistable Units},

author = {M Salman and C Bick and K Krischer},

year  = {2021},

date = {2021-10-28},

journal = {arXiv preprint arXiv:2110.15004},

abstract = {We investigate dynamics and bifurcations in a mathematical model that captures electrochemical experiments on arrays of microelectrodes. In isolation, each individual microelectrode is described by a one-dimensional unit with a bistable current-potential response. When an array of such electrodes is coupled by controlling the total electric current, the common electric potential of all electrodes oscillates in some interval of the current. These coupling-induced collective oscillations of bistable one-dimensional units are captured by the model. Moreover, any equilibrium is contained in a cluster subspace, where the electrodes take at most three distinct states. We systematically analyze the dynamics and bifurcations of the model equations: We consider the dynamics on cluster subspaces of successively increasing dimension and analyze the bifurcations occurring therein. Most importantly, the system exhibits an equivariant transcritical bifurcation of limit cycles. From this bifurcation, several limit cycles branch, one of which is stable for arbitrarily many bistable units.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Cation disorder in stoichiometric MgSnN2 and ambipolar self-doping behavior in off-stoichiometric MgSnN2},

author = {D Han and S S Rudel and W Schnick and H Ebert},

year  = {2021},

date = {2021-10-27},

journal = {arXiv preprint arXiv:2110.14289},

abstract = {Investigations on II-Sn-N2 (II = Mg, Ca) have been started very recently compared to the intense research of the Zn-IV-N2 (IV = Si, Ge, Sn). In this work, we perform a comprehensive study of cation disorder in stoichiometric MgSnN2 and crystal structure characteristic, doping behavior of off-stoichiometric Mg1+xSn1-xN2 (x = -0.8, -0.6, -0.5, -0.4, -0.2, 0.2, 0.4, 0.5, 0.6, 0.8) by using the cluster expansion method and first principles calculations. It is found that cation disorder in stoichiometric MgSnN2 induces a band gap reduction because of a violation of the octet rule. Moreover, the local disorder, namely forming (4,0) or (0,4) tetrahedra, would lead to an appreciable band gap reduction and hinder the enhancement of the optical absorption. An off-stoichiometric Mg/Sn ratio can strongly affect the morphology of Mg1+xSn1-xN2 samples due to the higher ionicity of the Mg-N bonds in comparison with Zn-N bonds. Furthermore, Mg1+xSn1-xN2 compounds show an ambipolar self-doping behavior, i.e., Mg-rich Mg1+xSn1-xN2 show p-type doping while Sn-rich ones exhibit n-type doping owing to the formation of acceptor-type antisite defect MgSn or donor-type antisite defect SnMg, respectively.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Metasurface Photoelectrodes for Enhanced Solar Fuel Generation},

author = {L H\"{u}ttenhofer and M Golibrzuch and O Bienek and F J Wendisch and R Lin and M Becherer and I D Sharp and S A Maier and E Cort\'{e}s},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202102877},

doi = {https://doi.org/10.1002/aenm.202102877},

issn = {1614-6832},

year  = {2021},

date = {2021-10-27},

journal = {Advanced Energy Materials},

volume = {11},

number = {46},

pages = {2102877},

abstract = {Abstract Tailoring optical properties in photocatalysts by nanostructuring them can help increase solar light harvesting efficiencies in a wide range of materials. Whereas plasmon resonances are widely employed in metallic catalysts for this purpose, latest advances of nonradiative, dielectric nanophotonics also enable light confinement and enhanced visible light absorption in semiconductors. Here, a design procedure for large-scale nanofabrication of semiconductor photoelectrodes using imprint lithography is developed. Anapole excitations and metasurface lattice resonances are combined to enhance the absorption of the model material, amorphous gallium phosphide (a-GaP), over the visible spectrum. It is shown that cost-effective, high sample throughput is achieved while retaining the precise signature of the engineered photonic states. Photoelectrochemical measurements under hydrogen evolution reaction conditions and sunlight illumination reveal the contributions of the respective resonances and demonstrate an overall photocurrent enhancement of 5.7, compared to a planar film. These results are supported by optical and numerical analysis of single nanodisks and of the upscaled metasurface.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {The Flexible On-Surface Self-Assembly of a Low-Symmetry Mabiq Ligand: An Unconventional Metal-Assisted Phase Transformation on Ag(111)},

author = {F Haag and P S Deimel and P Knecht and L Niederegger and K Seufert and M G. Cuxart and Y Bao and A C Papageorgiou and M Muntwiler and W Auw\"{a}rter and C R Hess and J V Barth and F Allegretti},

url = {https://doi.org/10.1021/acs.jpcc.1c07400},

doi = {10.1021/acs.jpcc.1c07400},

issn = {1932-7447},

year  = {2021},

date = {2021-10-12},

journal = {The Journal of Physical Chemistry C},

volume = {125},

number = {42},

pages = {23178-23191},

abstract = {The self-assembly of metal\textendashorganic complexes and networks of increasing complexity on solid surfaces is important for their application in a variety of fields, such as catalysis, sensing, and molecular magnetism. Here, we have selected a low-symmetry, free-base macrocyclic biquinazoline ligand, H-Mabiq, which upon metalation has the potential to incorporate cations in two different coordination sites, affording multi-valency and multi-electron transfer capacity. We show that H-Mabiq molecules readily self-assemble onto the Ag(111) surface at room temperature, forming a well-ordered monolayer of closely packed molecules. Upon increasing the temperature, a new phase with a different long-range order and molecular packing is obtained. By means of scanning tunneling microscopy and photoelectron spectroscopy, we show that this new phase is characterized by a distinctive silver-bridged dimeric motif, entailing a Ag adatom accommodated at the peripheral coordination site of two opposing H-Mabiq molecules. Thus, the present work reveals the ability of the bio-inspired Mabiq ligands to form surface-confined two-dimensional assemblies incorporating metal adatoms. The results bode promise for the use of metal-containing Mabiq compounds to engineer regular bimetallic arrays with atomic precision.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Ion Dynamics and Polymorphism in Cu20Te11Cl3},

author = {A Vogel and T Nilges},

url = {https://doi.org/10.1021/acs.inorgchem.1c01764},

doi = {10.1021/acs.inorgchem.1c01764},

issn = {0020-1669},

year  = {2021},

date = {2021-10-04},

journal = {Inorganic Chemistry},

volume = {60},

number = {20},

pages = {15233-15241},

abstract = {Coinage metal polychalcogenide halides are an intriguing class of materials, and many representatives are solid ion conductors and thermoelectric materials. The materials show high ion mobility, polymorphism, and various attractive interactions in the cation and anion substructures. Especially the latter feature leads to complex electronic structures and the occurrence of charge-density waves (CDWs) and, as a result, the first p\textendashn\textendashp switching materials. During our systematic investigations for new p\textendashn\textendashn switching materials in the Cu\textendashTe\textendashCl phase diagram, we were able to isolate polymorphic Cu20Te11Cl3, which we characterized structurally and with regard to its electronic and thermoelectric properties. Cu20Te11Cl3 is trimorphic, with phase transitions occurring at 288 and 450 K. The crystal structures of two polymorphs, the α phase, stable above 450 K, and the β polymorph (288\textendash450 K), are reported, and the complex structure chemistry featuring twinning upon a phase change is illustrated. We identified a dynamic cation substructure and a static anion substructure for all polymorphs, characterizing Cu20Te11Cl3 as a solid Cu-ion conductor. Temperature-dependent measurements of the Seebeck coefficient and total conductivity were performed and substantiated a linear response of the Seebeck coefficient, a lack of CDWs, and no p\textendashn\textendashp switching. Reasons for a lack of CDWs in Cu20Te11Cl3 are discussed and illustrated in the context of existing p\textendashn\textendashp switching materials.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Degradation mechanisms of perovskite solar cells under vacuum and one atmosphere of nitrogen},

author = {R Guo and D Han and W Chen and L Dai and K Ji and Q Xiong and S Li and L K Reb and M A Scheel and S Pratap and N Li and S Yin and T Xiao and S Liang and A L Oechsle and C L Weindl and M Schwartzkopf and H Ebert and P Gao and K Wang and M Yuan and N C Greenham and S D Stranks and S V Roth and R H Friend and P M\"{u}ller-Buschbaum},

url = {https://doi.org/10.1038/s41560-021-00912-8},

doi = {10.1038/s41560-021-00912-8},

issn = {2058-7546},

year  = {2021},

date = {2021-10-01},

urldate = {2021-10-01},

journal = {Nature Energy},

volume = {6},

number = {10},

pages = {977-986},

abstract = {Extensive studies have focused on improving the operational stability of perovskite solar cells, but few have surveyed the fundamental degradation mechanisms. One aspect overlooked in earlier works is the effect of the atmosphere on device performance during operation. Here we investigate the degradation mechanisms of perovskite solar cells operated under vacuum and under a nitrogen atmosphere using synchrotron radiation-based operando grazing-incidence X-ray scattering methods. Unlike the observations described in previous reports, we find that light-induced phase segregation, lattice shrinkage and morphology deformation occur under vacuum. Under nitrogen, only lattice shrinkage appears during the operation of solar cells, resulting in better device stability. The different behaviour under nitrogen is attributed to a larger energy barrier for lattice distortion and phase segregation. Finally, we find that the migration of excessive PbI2 to the interface between the perovskite and the hole transport layer degrades the performance of devices under vacuum or under nitrogen.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {The Effect of Photoinduced Surface Oxygen Vacancies on the Charge Carrier Dynamics in TiO2 Films},

author = {O E Dagdeviren and D Glass and R Sapienza and E Cort\'{e}s and S A Maier and I P Parkin and P Gr\"{u}tter and R Quesada-Cabrera},

url = {https://doi.org/10.1021/acs.nanolett.1c02853},

doi = {10.1021/acs.nanolett.1c02853},

issn = {1530-6984},

year  = {2021},

date = {2021-09-28},

journal = {Nano Letters},

volume = {21},

number = {19},

pages = {8348-8354},

abstract = {Metal-oxide semiconductors (MOS) are widely utilized for catalytic and photocatalytic applications in which the dynamics of charged carriers (e.g., electrons, holes) play important roles. Under operation conditions, photoinduced surface oxygen vacancies (PI-SOV) can greatly impact the dynamics of charge carriers. However, current knowledge regarding the effect of PI-SOV on the dynamics of hole migration in MOS films, such as titanium dioxide, is solely based upon volume-averaged measurements and/or vacuum conditions. This limits the basic understanding of hole-vacancy interactions, as they are not capable of revealing time-resolved variations during operation. Here, we measured the effect of PI-SOV on the dynamics of hole migration using time-resolved atomic force microscopy. Our findings demonstrate that the time constant associated with hole migration is strongly affected by PI-SOV, in a reversible manner. These results will nucleate an insightful understanding of the physics of hole dynamics and thus enable emerging technologies, facilitated by engineering hole-vacancy interactions.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Real-time observation of nucleation and growth of Au on CdSe quantum dot templates},

author = {N Paul and J Huang and C Liu and T Lin and C Ouyang and Z Liu and C Chen and Z Chen and Z Weng and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum and A Paul},

url = {https://doi.org/10.1038/s41598-021-97485-z},

doi = {10.1038/s41598-021-97485-z},

issn = {2045-2322},

year  = {2021},

date = {2021-09-21},

journal = {Scientific Reports},

volume = {11},

number = {1},

pages = {18777},

abstract = {Semiconductor quantum dot (QD) arrays can be useful for optical devices such as lasers, solar cells and light-emitting diodes. As the size distribution influences the band-gap, it is worthwhile to investigate QDs prepared using different solvents because each of them could influence the overall morphology differently, depending on the ligand network around individual QDs. Here, we follow the nucleation and growth of gold (Au) on CdSe QD arrays to investigate the influence of surface ligands and thereby realized interparticle distance between QDs on Au growth behaviour. We particularly emphasize on the monolayer stage as the Au decoration on individual QDs is expected at this stage. Therefore, we sputter-deposit Au on each QD array to investigate the morphological evolution in real-time using time-resolved grazing-incidence small-angle X-ray scattering (GISAXS). The growth kinetics - independent of the template - signifies that the observed template-mediated nucleation is limited only to the very first few monolayers. Delicate changes in the Au growth morphology are seen in the immediate steps following the initial replicated decoration of the QD arrays. This is followed by a subsequent clustering and finally a complete Au coverage of the QD arrays.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Non-Local Exciton-Photon Interactions in Hybrid High-Q Nanocavities with Embedded hBN-Encapsulated MoS2 Monolayers},

author = {C Qian and V Villafa\~{n}e and P Soubelet and A H\"{o}tger and T Taniguchi and K Watanabe and N P Wilson and A V Stier and A W Holleitner and J J Finley},

url = {https://arxiv.org/abs/2107.04387},

doi = {arXiv:2107.04387v2},

year  = {2021},

date = {2021-09-20},

journal = {arXiv preprint arXiv:2107.04387},

abstract = {Atomically thin semiconductors can be readily integrated into a wide range of nanophotonic architectures for applications in quantum photonics and novel optoelectronic devices. We report the observation of non-local interactions of textitfree trions in pristine hBN/MoS2/hBN heterostructures coupled to single mode (Q >104) quasi 0D nanocavities. The high excitonic and photonic quality of the interaction system stem from our integrated nanofabrication approach simultaneously with the hBN encapsulation and the maximized local cavity field amplitude within the MoS2 monolayer. We observe a non-monotonic temperature dependence of the cavity-trion interaction strength, consistent with the non-local light-matter interactions in which the free trion diffuse over lengthscales comparable to the cavity mode volume. Our approach can be generalized to other optically active 2D materials, opening the way towards harnessing novel light-matter interaction regimes for applications in quantum photonics.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Acoustic Coupling between Plasmonic Nanoantennas: Detection and Directionality of Surface Acoustic Waves},

author = {M Poblet and R Bert\'{e} and H D Boggiano and Y Li and E Cort\'{e}s and G Grinblat and S A Maier and A V Bragas},

url = {https://doi.org/10.1021/acsphotonics.1c00741},

doi = {10.1021/acsphotonics.1c00741},

year  = {2021},

date = {2021-09-17},

urldate = {2021-09-17},

journal = {ACS Photonics},

abstract = {Hypersound waves can be efficient mediators between optical signals at the nanoscale. Having phase velocities several orders of magnitude lower than the speed of light, they propagate with much shorter wavelengths and can be controlled, directed, and even focused in a very small region of space. This work shows how two optical nanoantennas can be coupled through an acoustic wave that propagates with a certain directionality. An “emitter” antenna is first optically excited to generate acoustic coherent phonons that launch surface acoustic waves through the underlying substrate. These waves travel until they are mechanically detected by a “receiver” nanoantenna whose oscillation produces a detectable optical signal. Generation and detection are studied in detail, and new designs are proposed to improve the directionality of the hypersonic surface acoustic wave.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Multistate Nonvolatile Metamirrors with Tunable Optical Chirality},

author = {Y Huang and T Xiao and Z Xie and J Zheng and Y Su and W Chen and K Liu and M Tang and J Zhu and P M\"{u}ller-Buschbaum and L Li},

url = {https://doi.org/10.1021/acsami.1c14204},

doi = {10.1021/acsami.1c14204},

issn = {1944-8244},

year  = {2021},

date = {2021-09-14},

urldate = {2021-09-14},

journal = {ACS Applied Materials \& Interfaces},

abstract = {Compared with conventional mirrors that behave as isotropic electromagnetic (EM) reflectors, metamirrors composed of periodically aligned artificial meta-atoms exhibit increased degrees of freedom for EM manipulations. However, the functionality of most metamirrors is fixed by design, and how to achieve active EM control is still elusive. Here, we propose a multistate metamirror based on the nonvolatile phase change material Ge2Sb2Te5 (GST) with four distinct functionalities that can be realized in the infrared region by exploiting the temperature-activated phase transition. When varying the crystallinity of GST, the metamirror has the capability to perform as a right-handed circular polarization chiral mirror, a narrowband achiral mirror, a left-handed circular polarization chiral mirror, or a broadband achiral mirror, respectively. The inner physics is further explained by the construction or cancellation of extrinsic two-dimensional chirality. As a proof of concept, experimental verification is carried out and the measured results agree well with their simulated counterparts. Such a multifunctional tunable metamirror could address a wide range of applications from sensing and spectroscopy to analytical chemistry and imaging.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}