Publications

@article{nokey,

title = {Ionic liquids tailoring crystal orientation and electronic properties for stable perovskite solar cells},

author = {Y Zou and J Eichhorn and S Rieger and Y Zheng and S Yuan and L Wolz and L V Spanier and J E Heger and S Yin and C R Everett and L Dai and M Schwartzkopf and C Mu and S V Roth and I D Sharp and C-C Chen and J Feldmann and S D Stranks and P M\"{u}ller-Buschbaum},

url = {https://www.sciencedirect.com/science/article/pii/S2211285523002860},

doi = {https://doi.org/10.1016/j.nanoen.2023.108449},

issn = {2211-2855},

year  = {2023},

date = {2023-04-21},

journal = {Nano Energy},

volume = {112},

pages = {108449},

abstract = {The crystallization behavior of perovskite films has a profound influence on the resulting defect densities, charge carrier dynamics and photovoltaic performance. Herein, we introduce ionic liquids into the perovskite component to tailor the crystal growth of perovskite films from a disordered to a preferential corner-up orientation and accordingly increase the charge carrier mobility to accelerate electron transport and extraction. Using time-resolved measurements, we probe the charge carrier generation, transport and recombination behavior in these films and related devices. We find the ionic liquid-containing samples exhibit lower defects, faster charge carrier transport and suppressed non-radiative recombination, contributing to higher efficiency and fill factor. Via operando grazing-incidence small- and wide-angle X-ray scattering measurements, we observe a light-induced lattice compression and grain fragmentation in the control devices, whereas the ionic liquid-containing devices exhibit a slight light-induced crystal reconstitution and stronger tolerance against illumination. Under ambient conditions, the non-encapsulated device with the pyrrolidinium-based ionic compound (Pyr14BF4) maintains 97% of its initial efficiency after 4368 h.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Formation of active sites on transition metals through reaction-driven migration of surface atoms},

author = {L Xu and K G Papanikolaou and B A J Lechner and L Je and G A Somorjai and M Salmeron and M Mavrikakis},

url = {https://www.science.org/doi/abs/10.1126/science.add0089},

doi = {doi:10.1126/science.add0089},

year  = {2023},

date = {2023-04-06},

urldate = {2023-04-06},

journal = {Science},

volume = {380},

number = {6640},

pages = {70-76},

abstract = {Adopting low-index single-crystal surfaces as models for metal nanoparticle catalysts has been questioned by the experimental findings of adsorbate-induced formation of subnanometer clusters on several single-crystal surfaces. We used density functional theory calculations to elucidate the conditions that lead to cluster formation and show how adatom formation energies enable efficient screening of the conditions required for adsorbate-induced cluster formation. We studied a combination of eight face-centered cubic transition metals and 18 common surface intermediates and identified systems relevant to catalytic reactions, such as carbon monoxide (CO) oxidation and ammonia (NH3) oxidation. We used kinetic Monte Carlo simulations to elucidate the CO-induced cluster formation process on a copper surface. Scanning tunneling microscopy of CO on a nickel (111) surface that contains steps and dislocations points to the structure sensitivity of this phenomenon. Metal-metal bond breaking that leads to the evolution of catalyst structures under realistic reaction conditions occurs much more broadly than previously thought. In heterogeneous catalysis, it is often assumed that adsorbates have minimal effects on the bonding between surface metal atoms at low temperatures and pressures. Xu et al. used density functional theory to find conditions in which adsorbed molecules can scavenge transition metal atoms by breaking bonds at the surface. These atoms can then form clusters, as observed in kinetic Monte Carlo simulations of carbon monoxide on copper and in scanning tunneling microscopy studies of carbon monoxide on a Ni(111) surface containing steps and dislocations. The reaction mechanisms of several catalytic systems may be dominated by in situ adsorbate-induced active site formation. \textemdashPDS Metal atoms freed from transition metal surfaces during reaction can then form clusters that are catalytically active.},

keywords = {Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@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}

}

@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}

}

@article{nokey,

title = {Elucidating the Roles of Nafion/Solvent Formulations in Copper-Catalyzed CO2 Electrolysis},

author = {P Ding and H An and P Zellner and T Guan and J Gao and P M\"{u}ller-Buschbaum and B M Weckhuysen and W Van Der Stam and I D Sharp},

url = {https://doi.org/10.1021/acscatal.2c05235},

doi = {10.1021/acscatal.2c05235},

year  = {2023},

date = {2023-04-05},

journal = {ACS Catalysis},

pages = {5336-5347},

abstract = {Nafion ionomer, composed of hydrophobic perfluorocarbon backbones and hydrophilic sulfonic acid side chains, is the most widely used additive for preparing catalyst layers (CLs) for electrochemical CO2 reduction, but its impact on the performance of CO2 electrolysis remains poorly understood. Here, we systematically investigate the role of the catalyst ink formulation on CO2 electrolysis using commercial CuO nanoparticles as the model pre-catalyst. We find that the presence of Nafion is essential for achieving stable product distributions due to its ability to stabilize the catalyst morphology under reaction conditions. Moreover, the Nafion content and solvent composition (water/alcohol fraction) regulate the internal structure of Nafion coatings, as well as the catalyst morphology, thereby significantly impacting CO2 electrolysis performance, resulting in variations of C2+ product Faradaic efficiency (FE) by >3×, with C2+ FE ranging from 17 to 54% on carbon paper substrates. Using a combination of ellipsometry and in situ Raman spectroscopy during CO2 reduction, we find that such selectivity differences stem from changes to the local reaction microenvironment. In particular, the combination of high water/alcohol ratios and low Nafion fractions in the catalyst ink results in stable and favorable microenvironments, increasing the local CO2/H2O concentration ratio and promoting high CO surface coverage to facilitate C2+ production in long-term CO2 electrolysis. Therefore, this work provides insights into the critical role of Nafion binders and underlines the importance of optimizing Nafion/solvent formulations as a means of enhancing the performance of electrochemical CO2 reduction systems.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@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}

}

@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}

}

@article{nokey,

title = {Electron Tunneling at Electrocatalytic Interfaces},

author = {M R Nouri and R M Kluge and R W Haid and J Fortmann and A Ludwig and A S Bandarenka and V Alexandrov},

url = {https://doi.org/10.1021/acs.jpcc.3c00207},

doi = {10.1021/acs.jpcc.3c00207},

issn = {1932-7447},

year  = {2023},

date = {2023-03-27},

journal = {The Journal of Physical Chemistry C},

volume = {127},

number = {13},

pages = {6321-6327},

abstract = {It was recently proposed that tunneling current fluctuations in electrochemical scanning tunneling microscopy (EC-STM) can be used to map the electrocatalytic activity of surfaces with high spatial resolution. However, the relation between the increased noise in the electron tunneling signal and the local reactivity for such complex electrode/electrolyte interfaces is only explained qualitatively or hypothetically. Herein, we employ electron transport calculations to examine tunneling at Pt surfaces under the conditions of the oxygen reduction reaction as a case study. By computing current\textendashvoltage characteristics, we reveal that the tunneling barrier strongly depends on the chemical identity of the adsorbed reaction intermediate as well as on the orientation of the average dipole moment of water species mediating electron tunneling. Our theoretical results combined with EC-STM measurements suggest that detecting reaction intermediates at electrified interfaces in operando conditions is possible based on tunneling noise amplitudes. This study also aims to stimulate further explorations of tunneling-based electron-proton transfers to enable quantum electrocatalysis beyond conventional approaches.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Large-area synthesis of high electrical performance MoS2 by a commercially scalable atomic layer deposition process},

author = {N Aspiotis and K Morgan and B M\"{a}rz and K M\"{u}ller-Caspary and M Ebert and E Weatherby and M E Light and C-C Huang and D W Hewak and S Majumdar and I Zeimpekis},

url = {https://doi.org/10.1038/s41699-023-00379-z},

doi = {10.1038/s41699-023-00379-z},

issn = {2397-7132},

year  = {2023},

date = {2023-03-27},

journal = {npj 2D Materials and Applications},

volume = {7},

number = {1},

pages = {18},

abstract = {This work demonstrates a large area process for atomically thin 2D semiconductors to unlock the technological upscale required for their commercial uptake. The new atomic layer deposition (ALD) and conversion technique yields large area performance uniformity and tunability. Like graphene, 2D Transition Metal Dichalcogenides (TMDCs) are prone to upscaling challenges limiting their commercial uptake. They are challenging to grow uniformly on large substrates and to transfer on alternative substrates while they often lack in large area electrical performance uniformity. The scalable ALD process of this work enables uniform growth of 2D TMDCs on large area with independent control of layer thickness, stoichiometry and crystallinity while allowing chemical free transfers to application substrates. Field effect transistors (FETs) fabricated on flexible substrates using the process present a field effect mobility of up to 55 cm2/Vs, subthreshold slope down to 80 mV/dec and on/off ratios of 107. In addition, non-volatile memory transistors using ferroelectric FETs (FeFETs) operating at ±5 V with on/off ratio of 107 and a memory window of 3.25 V are demonstrated. These FeFETs demonstrate state-of-the-art performance with multiple state switching, suitable for one-transistor non-volatile memory and for synaptic transistors revealing the applicability of the process to flexible neuromorphic applications.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Transient absorption spectroscopy based on uncompressed hollow core fiber white light proves pre-association between a radical ion photocatalyst and substrate},

author = {A Kumar and P Malevich and L Mewes and S Wu and J P Barham and J Hauer},

url = {https://aip.scitation.org/doi/abs/10.1063/5.0142225},

doi = {10.1063/5.0142225},

year  = {2023},

date = {2023-03-24},

journal = {The Journal of Chemical Physics},

volume = {158},

number = {14},

pages = {144201},

abstract = {We present a hollow-core fiber (HCF) based transient absorption experiment, with capabilities beyond common titanium:sapphire based setups. By spectral filtering of the HCF spectrum, we provide pump pulses centered at 425 nm with several hundred nJ of pulse energy at the sample position. By employing the red edge of the HCF output for seeding CaF2, we obtain smooth probing spectra in the range between 320 and 900 nm. We demonstrate the capabilities of our experiment by following the ultrafast relaxation dynamics of a radical cationic photocatalyst to prove its pre-association with an arene substrate, a phenomenon that was not detectable previously by steady-state spectroscopic techniques. The detected preassembly rationalizes the successful participation of radical ionic photocatalysts in single electron transfer reactions, a notion that has been subject to controversy in recent years.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {A re-useable microreactor for dynamic and sensitive photocatalytic measurements: Exemplified by the photoconversion of ethanol on Pt-loaded titania P25},

author = {C C Aletsee and D Hochfilzer and A Kwiatkowski and M Becherer and J Kibsgaard and I Chorkendorff and M Tschurl and U Heiz},

url = {https://aip.scitation.org/doi/abs/10.1063/5.0134287},

doi = {10.1063/5.0134287},

year  = {2023},

date = {2023-03-23},

journal = {Review of Scientific Instruments},

volume = {94},

number = {3},

pages = {033909},

abstract = {Despite numerous advancements in synthesizing photoactive materials, the evaluation of their catalytic performance remains challenging since their fabrication often involves tedious strategies, yielding only low quantities in the μ-gram scale. In addition, these model catalysts exhibit different forms, such as powders or film(-like) structures grown on various supporting materials. Herein, we present a versatile gas phase μ-photoreactor, compatible with different catalyst morphologies, which is, in contrast to existing systems, re-openable and \textendashuseable, allowing not only post-characterization of the photocatalytic material but also enabling catalyst screening studies in short experimental time intervals. Sensitive and time-resolved reaction monitoring at ambient pressure is realized by a lid-integrated capillary, transmitting the entire gas flow from the reactor chamber to a quadrupole mass spectrometer. Due to the microfabrication of the lid from borosilicate as base material, 88% of the geometrical area can be illuminated by a light source, further enhancing sensitivity. Gas dependent flow rates through the capillary were experimentally determined to be 1015\textendash1016 molecules s−1, and in combination with a reactor volume of 10.5 μl, this results in residence times below 40 s. Furthermore, the reactor volume can easily be altered by adjusting the height of the polymeric sealing material. The successful operation of the reactor is demonstrated by selective ethanol oxidation over Pt-loaded TiO2 (P25), which serves to exemplify product analysis from dark-illumination difference spectra.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Solution-processed NiPS3 thin films from Liquid Exfoliated Inks with Long-Lived Spin-Entangled Excitons},

author = {A Shcherbakov and K Synnatschke and S Bodnar and J Zerhoch and L Eyre and F Rauh and M W Heindl and S Liu and J Konecny and I D Sharp},

url = {https://arxiv.org/abs/2303.11788},

doi = {https://doi.org/10.48550/arXiv.2303.11788},

year  = {2023},

date = {2023-03-21},

journal = {arXiv preprint arXiv:2303.11788},

abstract = {Antiferromagnets are promising materials for future opto-spintronic applications since they show spin dynamics in the THz range and no net magnetization. Recently, layered van der Waals (vdW) antiferromagnets have been reported, which combine low-dimensional excitonic properties with complex spin-structure. While various methods for the fabrication of vdW 2D crystals exist, formation of large area and continuous thin films is challenging because of either limited scalability, synthetic complexity, or low opto-spintronic quality of the final material. Here, we fabricate centimeter-scale thin films of the van der Waals 2D antiferromagnetic material NiPS3, which we prepare using a crystal ink made from liquid phase exfoliation (LPE). We perform statistical atomic force microscopy (AFM) and scanning electron microscopy (SEM) to characterize and control the lateral size and number of layers through this ink-based fabrication. Using ultrafast optical spectroscopy at cryogenic temperatures, we resolve the dynamics of photoexcited excitons. We find antiferromagnetic spin arrangement and spin-entangled Zhang-Rice multiplet excitons with lifetimes in the nanosecond range, as well as ultranarrow emission linewidths, despite the disordered nature of our films. Thus, our findings demonstrate scalable thin-film fabrication of high-quality NiPS3, which is crucial for translating this 2D antiferromagnetic material into spintronic and nanoscale memory devices and further exploring its complex spin-light coupled states.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Interpreting Ultrafast Electron Transfer on Surfaces with a Converged First-Principles Newns-Anderson Chemisorption Function},

author = {S Ghan and E Diesen and C Kunkel and K Reuter and H Oberhofer},

url = {https://arxiv.org/abs/2303.11412},

doi = {https://doi.org/10.48550/arXiv.2303.11412},

year  = {2023},

date = {2023-03-20},

journal = {arXiv preprint arXiv:2303.11412},

abstract = {We study the electronic coupling between an adsorbate and a metal surface by calculating tunneling matrix elements Had directly from first principles. For this we employ a projection of the Kohn-Sham Hamiltonian upon a diabatic basis using a version of the popular Projection-Operator Diabatization approach. An appropriate integration of couplings over the Brillouin zone allows the first calculation of a size-convergent Newns-Anderson chemisorption function, a coupling-weighted density of states measuring the line broadening of an adsorbate frontier state upon adsorption. This broadening corresponds to the experimentally-observed lifetime of an electron in the state, which we confirm for core-excited Ar∗(2p−13/24s) atoms on a number of transition metal (TM) surfaces. Yet, beyond just lifetimes, the chemisorption function is highly interpretable and encodes rich information on orbital phase interactions on the surface. The model thus captures and elucidates key aspects of the electron transfer process. Finally, a decomposition into angular momentum components reveals the hitherto unresolved role of the hybridized d-character of the TM surface in the resonant electron transfer, and elucidates the coupling of the adsorbate to the surface bands over the entire energy scale.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Improved In Situ Characterization of Electrochemical Interfaces Using Metasurface-Driven Surface-Enhanced IR Absorption Spectroscopy},

author = {L M Berger and M Duportal and L D S Menezes and E Cort\'{e}s and S A Maier and A Tittl and K Krischer},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202300411},

doi = {https://doi.org/10.1002/adfm.202300411},

issn = {1616-301X},

year  = {2023},

date = {2023-03-20},

journal = {Advanced Functional Materials},

volume = {n/a},

number = {n/a},

pages = {2300411},

abstract = {Abstract Electrocatalysis plays a crucial role in realizing the transition toward a zero-carbon future, driving research directions from green hydrogen generation to carbon dioxide reduction. Surface-enhanced infrared absorption spectroscopy (SEIRAS) is a suitable method for investigating electrocatalytic processes because it can monitor with chemical specificity the mechanisms of the reactions. However, it remains difficult to detect many relevant aspects of electrochemical reactions such as short-lived intermediates. Herein, an integrated nanophotonic-electrochemical SEIRAS platform is developed and experimentally realized for the in situ investigation of molecular signal traces emerging during electrochemical experiments. A platinum nano-slot metasurface featuring strongly enhanced electromagnetic near fields is implemented and spectrally targets the weak vibrational mode of the adsorbed carbon monoxide at ≈2033 cm−1. The metasurface-driven resonances can be tuned over a broad range in the mid-infrared spectrum and provide high molecular sensitivity. Compared to conventional unstructured platinum films, this nanophotonic-electrochemical platform delivers a 27-fold improvement of the experimentally detected characteristic absorption signals, enabling the detection of new species with weak signals, fast conversions, or low surface concentrations. By providing a deeper understanding of catalytic reactions, the nanophotonic-electrochemical platform is anticipated to open exciting perspectives for electrochemical SEIRAS, surface-enhanced Raman spectroscopy, and other fields of chemistry such as photoelectrocatalysis.},

keywords = {Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@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}

}

@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}

}

@article{nokey,

title = {Imaging local diffusion in microstructures using NV-based pulsed field gradient NMR},

author = {R Allert and N Neuling and K Briegel},

url = {https://arxiv.org/abs/2303.03516},

doi = {https://doi.org/10.48550/arXiv.2303.03516},

year  = {2023},

date = {2023-03-06},

journal = {arXiv preprint arXiv:2303.03516},

abstract = {Understanding diffusion in microstructures plays a crucial role in many scientific fields, including neuroscience, cancer- or energy research. While magnetic resonance methods are the gold standard for quantitative diffusion measurements, they lack sensitivity in resolving and measuring diffusion within individual microstructures. Here, we introduce nitrogen-vacancy (NV) center based nuclear magnetic resonance (NMR) spectroscopy as a novel tool to probe diffusion in individual structures on microscopic length scales. We have developed a novel experimental scheme combining pulsed gradient spin echo (PGSE) with optically detected NV-NMR, which allows for the quantification of molecular diffusion and flow within nano-to-picoliter sample volumes. We demonstrate correlated optical imaging with spatially resolved PGSE NV-NMR experiments to probe anisotropic water diffusion within a model microstructure. Our method will extend the current capabilities of investigating diffusion processes to the microscopic length scale with the potential of probing single-cells, tissue microstructures, or ion mobility in thin film materials for battery applications.},

keywords = {Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@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}

}

@article{nokey,

title = {On-surface synthesis of enetriynes},

author = {N Cao and B Yang and A Riss and J Rosen and J Bj\"{o}rk and J V Barth},

url = {https://doi.org/10.1038/s41467-023-36828-y},

doi = {10.1038/s41467-023-36828-y},

issn = {2041-1723},

year  = {2023},

date = {2023-03-06},

journal = {Nature Communications},

volume = {14},

number = {1},

pages = {1255},

abstract = {Belonging to the enyne family, enetriynes comprise a distinct electron-rich all-carbon bonding scheme. However, the lack of convenient synthesis protocols limits the associated application potential within, e.g., biochemistry and materials science. Herein we introduce a pathway for highly selective enetriyne formation via tetramerization of terminal alkynes on a Ag(100) surface. Taking advantage of a directing hydroxyl group, we steer molecular assembly and reaction processes on square lattices. Induced by O2 exposure the terminal alkyne moieties deprotonate and organometallic bis-acetylide dimer arrays evolve. Upon subsequent thermal annealing tetrameric enetriyne-bridged compounds are generated in high yield, readily self-assembling into regular networks. We combine high-resolution scanning probe microscopy, X-ray photoelectron spectroscopy and density functional theory calculations to examine the structural features, bonding characteristics and the underlying reaction mechanism. Our study introduces an integrated strategy for the precise fabrication of functional enetriyne species, thus providing access to a distinct class of highly conjugated π-system compounds.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Anharmonic Fluctuations Govern the Band Gap of Halide Perovskites},

author = {S A Seidl and X Zhu and G Reuveni and S Aharon and C Gehrmann and S Caicedo-D\'{a}vila and O Yaffe and D A Egger},

url = {https://arxiv.org/abs/2303.01603},

doi = {https://doi.org/10.48550/arXiv.2303.01603},

year  = {2023},

date = {2023-03-02},

journal = {arXiv preprint arXiv:2303.01603},

abstract = {We determine the impact of anharmonic thermal vibrations on the fundamental band gap of CsPbBr3, a prototypical model system for the broader class of halide perovskite semiconductors. Through first-principles molecular dynamics and stochastic calculations, we find that anharmonic fluctuations are a key effect in the electronic structure of these materials. We present experimental and theoretical evidence that important characteristics, such as a mildly changing band-gap value across a temperature range that includes phase-transitions, cannot be explained by harmonic phonons thermally perturbing an average crystal structure and symmetry. Instead, the thermal characteristics of the electronic structure are microscopically connected to anharmonic vibrational contributions to the band gap that reach a fairly large magnitude of 450 meV at 425 K.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Correlative analysis on InGaN/GaN nanowires: structural and optical properties of self-assembled short-period superlattices},

author = {M Alonso-Orts and R H\"{o}tzel and T Grieb and M Auf Der Maur and M Ries and F Nippert and B M\"{a}rz and K M\"{u}ller-Caspary and M R Wagner and A Rosenauer and M Eickhoff},

url = {https://doi.org/10.1186/s11671-023-03808-6},

doi = {10.1186/s11671-023-03808-6},

issn = {2731-9229},

year  = {2023},

date = {2023-03-01},

journal = {Discover Nano},

volume = {18},

number = {1},

pages = {27},

abstract = {The influence of self-assembled short-period superlattices (SPSLs) on the structural and optical properties of InGaN/GaN nanowires (NWs) grown by PAMBE on Si (111) was investigated by STEM, EDXS, µ-PL analysis and k·p simulations. STEM analysis on single NWs indicates that in most of the studied nanostructures, SPSLs self-assemble during growth. The SPSLs display short-range ordering of In-rich and In-poor InxGa1-xN regions with a period of 2\textendash3 nm that are covered by a GaN shell and that transition to a more homogenous InxGa1-xN core. Polarization- and temperature-resolved PL analysis performed on the same NWs shows that they exhibit a strong parallel polarized red-yellow emission and a predominantly perpendicular polarized blue emission, which are ascribed to different In-rich regions in the nanostructures. The correlation between STEM, µ-PL and k·p simulations provides better understanding of the rich optical emission of complex III-N nanostructures and how they are impacted by structural properties, yielding the significant impact of strain on self-assembly and spectral emission.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@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}

}

@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}

}

@article{nokey,

title = {Systematic Errors of Electric Field Measurements in Ferroelectrics by Unit Cell Averaged Momentum Transfers in STEM},

author = {A Strauch and B M\"{a}rz and T Denneulin and M Cattaneo and A Rosenauer and K M\"{u}ller-Caspary},

url = {https://doi.org/10.1093/micmic/ozad016},

doi = {10.1093/micmic/ozad016},

issn = {1431-9276},

year  = {2023},

date = {2023-02-23},

journal = {Microscopy and Microanalysis},

volume = {29},

number = {2},

pages = {499-511},

abstract = {When using the unit cell average of first moment data from four-dimensional scanning transmission electron microscopy (4D-STEM) to characterize ferroelectric materials, a variety of sources of systematic errors needs to be taken into account. In particular, these are the magnitude of the acceleration voltage, STEM probe semi-convergence angle, sample thickness, and sample tilt out of zone axis. Simulations show that a systematic error of calculated electric fields using the unit cell averaged momentum transfer originates from violation of point symmetry within the unit cells. Thus, values can easily exceed those of potential polarization-induced electric fields in ferroelectrics. Importantly, this systematic error produces deflection gradients between different domains seemingly representing measured fields. However, it could be shown that for PbZr0.2Ti0.8O3, many adjacent domains exhibit a relative crystallographic mistilt and in-plane rotation. The experimental results show that the method gives qualitative domain contrast. Comparison of the calculated electric field with the systematic error showed that the domain contrast of the unit cell averaged electric fields is mainly caused by dynamical scattering effects and the electric field plays only a minor role, if present at all.},

keywords = {Foundry Inorganic},

pubstate = {published},

tppubtype = {article}

}

@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 = {n/a},

number = {n/a},

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 I 3d 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}

}

@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}

}

@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}

}

@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}

}

@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}

}

@article{nokey,

title = {Thermal site energy fluctuations in photosystem I: new insights from MD/QM/MM calculations},

author = {S Reiter and F L Kiss and J Hauer and R De Vivie-Riedle},

url = {http://dx.doi.org/10.1039/D2SC06160K},

doi = {10.1039/D2SC06160K},

issn = {2041-6520},

year  = {2023},

date = {2023-02-06},

journal = {Chemical Science},

volume = {14},

number = {12},

pages = {3117-3131},

abstract = {Cyanobacterial photosystem I (PSI) is one of the most efficient photosynthetic machineries found in nature. Due to the large scale and complexity of the system, the energy transfer mechanism from the antenna complex to the reaction center is still not fully understood. A central element is the accurate evaluation of the individual chlorophyll excitation energies (site energies). Such an evaluation must include a detailed treatment of site specific environmental influences on structural and electrostatic properties, but also their evolution in the temporal domain, because of the dynamic nature of the energy transfer process. In this work, we calculate the site energies of all 96 chlorophylls in a membrane-embedded model of PSI. The employed hybrid QM/MM approach using the multireference DFT/MRCI method in the QM region allows to obtain accurate site energies under explicit consideration of the natural environment. We identify energy traps and barriers in the antenna complex and discuss their implications for energy transfer to the reaction center. Going beyond previous studies, our model also accounts for the molecular dynamics of the full trimeric PSI complex. Via statistical analysis we show that the thermal fluctuations of single chlorophylls prevent the formation of a single prominent energy funnel within the antenna complex. These findings are also supported by a dipole exciton model. We conclude that energy transfer pathways may form only transiently at physiological temperatures, as thermal fluctuations overcome energy barriers. The set of site energies provided in this work sets the stage for theoretical and experimental studies on the highly efficient energy transfer mechanisms in PSI.},

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

pubstate = {published},

tppubtype = {article}

}

@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}

}

@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}

}

@article{nokey,

title = {Mechanisms of Degradation of Na2Ni[Fe(CN)6] Functional Electrodes in Aqueous Media: A Combined Theoretical and Experimental Study},

author = {X Lamprecht and I Evazzade and I Ungerer and L Hromadko and J M Macak and A S Bandarenka and V Alexandrov},

url = {https://doi.org/10.1021/acs.jpcc.2c08222},

doi = {10.1021/acs.jpcc.2c08222},

issn = {1932-7447},

year  = {2023},

date = {2023-01-30},

journal = {The Journal of Physical Chemistry C},

volume = {127},

number = {5},

pages = {2204-2214},

abstract = {Prussian blue analogues (PBAs) are versatile functional materials with numerous applications ranging from electrocatalysis and batteries to sensors and electrochromic devices. Their electrochemical performance involving long-term cycling stability strongly depends on the electrolyte composition. In this work, we use density functional theory calculations and experiments to elucidate the mechanisms of degradation of model Na2Ni[Fe(CN)6] functional electrodes in aqueous electrolytes. Next to the solution pH and cation concentration, we identify anion adsorption as a major driving force for electrode dissolution. Notably, the nature of adsorbed anions can control the mass and charge transfer mechanisms during metal cation intercalation as well as the electrode degradation rate. We find that weakly adsorbing anions, such as NO3\textendash, impede the degradation, while strongly adsorbing anions, such as SO42\textendash, accelerate it. The results of this study provide practical guidelines for electrolyte optimization and can likely be extrapolated to the whole family of PBAs operating in aqueous media.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Ligand Chemistry of Inorganic Lead Halide Perovskite Nanocrystals},

author = {N Fiuza-Maneiro and K Sun and I L\'{o}pez-Fern\'{a}ndez and S G\'{o}mez-Gra\~{n}a and P M\"{u}ller-Buschbaum and L Polavarapu},

url = {https://doi.org/10.1021/acsenergylett.2c02363},

doi = {10.1021/acsenergylett.2c02363},

year  = {2023},

date = {2023-01-26},

journal = {ACS Energy Letters},

pages = {1152-1191},

abstract = {Lead halide perovskite nanocrystals (LHP NCs) have emerged as next-generation semiconductor materials with outstanding optical and optoelectronic properties. Because of the high surface-to-volume ratio, the optical and optoelectronic performance and the colloidal stability of LHP NCs largely depend on their surface chemistry, especially the ligands and surface termination. On one hand, the capping ligands improve the colloidal stability and luminescence; on the other hand the highly dynamic binding nature of ligands is detrimental to the colloidal stability and photoluminescence of LHP NCs. In addition, the surface functionalization with desired molecules induces new functionalities such as chirality, light harvesting, and triplet sensitization through energy/electron transfer or use as X-ray detectors. In this review, we present the current understanding of an atomic view of the surface chemistry of colloidal LHP NCs, including crystal termination, vacancies, and different types of capping ligands. Furthermore, we discuss the ligand-induced functionalities, including photocatalysis and chirality.},

keywords = {Foundry Inorganic, Foundry Organic},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Does cluster encapsulation inhibit sintering? Stabilization of size-selected Pt clusters on Fe $ _3 $ O $ _4 $(001) by SMSI},

author = {S Kaiser and J Plansky and M Krinninger and A Shavorskiy and S Zhu and U Heiz and F Esch and B A J Lechner},

url = {https://arxiv.org/abs/2301.10845},

doi = {https://doi.org/10.48550/arXiv.2301.10845},

year  = {2023},

date = {2023-01-25},

urldate = {2023-01-25},

journal = {arXiv preprint arXiv:2301.10845},

abstract = {The metastability of supported metal nanoparticles limits their application in heterogeneous catalysis at elevated temperatures due to their tendency to sinter. One strategy to overcome these thermodynamic limits on reducible oxide supports is encapsulation via strong metal-support interaction (SMSI). While annealing-induced encapsulation is a well-explored phenomenon for extended nanoparticles, it is as yet unknown whether the same mechanisms hold for sub-nanometer clusters, where concomitant sintering and alloying might play a significant role. In this article, we explore the encapsulation and stability of size-selected Pt5, Pt10 and Pt19 clusters deposited on Fe3O4(001). In a multimodal approach using temperature-programmed desorption (TPD), x-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM), we demonstrate that SMSI indeed leads to the formation of a defective, FeO-like conglomerate encapsulating the clusters. By stepwise annealing up to 1023 K, we observe the succession of encapsulation, cluster coalescence and Ostwald ripening, resulting in square-shaped crystalline Pt particles, independent of the initial cluster sizes. The respective sintering onset temperatures scale with the cluster footprint and thus size. Remarkably, while small encapsulated clusters can still diffuse as a whole, atom detachment and thus Ostwald ripening are successfully suppressed up to 823 K, i.e. 200 K above the H\"{u}ttig temperature that indicates the thermodynamic stability limit.},

keywords = {Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@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}

}

@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}

}

@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}

}

@article{nokey,

title = {Shrinking gate fluorescence correlation spectroscopy yields equilibrium constants and separates photophysics from structural dynamics},

author = {T Schr\"{o}der and J Bohlen and S E Ochmann and P Sch\"{u}ler and S Krause and D C Lamb and P Tinnefeld},

url = {https://www.pnas.org/doi/abs/10.1073/pnas.2211896120},

doi = {doi:10.1073/pnas.2211896120},

year  = {2023},

date = {2023-01-18},

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

volume = {120},

number = {4},

pages = {e2211896120},

abstract = {Fluorescence correlation spectroscopy is a versatile tool for studying fast conformational changes of biomolecules especially when combined with F\"{o}rster resonance energy transfer (FRET). Despite the many methods available for identifying structural dynamics in FRET experiments, the determination of the forward and backward transition rate constants and thereby also the equilibrium constant is difficult when two intensity levels are involved. Here, we combine intensity correlation analysis with fluorescence lifetime information by including only a subset of photons in the autocorrelation analysis based on their arrival time with respect to the excitation pulse (microtime). By fitting the correlation amplitude as a function of microtime gate, the transition rate constants from two fluorescence-intensity level systems and the corresponding equilibrium constants are obtained. This shrinking-gate fluorescence correlation spectroscopy (sg-FCS) approach is demonstrated using simulations and with a DNA origami-based model system in experiments on immobilized and freely diffusing molecules. We further show that sg-FCS can distinguish photophysics from dynamic intensity changes even if a dark quencher, in this case graphene, is involved. Finally, we unravel the mechanism of a FRET-based membrane charge sensor indicating the broad potential of the method. With sg-FCS, we present an algorithm that does not require prior knowledge and is therefore easily implemented when an autocorrelation analysis is carried out on time-correlated single-photon data.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@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}

}

@article{nokey,

title = {The neglected influence of zinc oxide light-soaking on stability measurements of inverted organic solar cells},

author = {M G\"{u}nther and S Lotfi and S S Rivas and D Bl\"{a}tte and J P Hofmann and T Bein and T Ameri},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202209768},

doi = {https://doi.org/10.1002/adfm.202209768},

issn = {1616-301X},

year  = {2023},

date = {2023-01-15},

journal = {Advanced Functional Materials},

volume = {33},

number = {13},

pages = {2209768},

abstract = {Abstract Although zinc oxide (ZnO) is one of the most commonly used materials for electron transport layers in organic solar cells (OSCs), it also comes with disadvantages such as the so-called light-soaking issues, i.e., its need for exposure to UV light to reach its full potential in OSCs. Here, the impact of ZnO light-soaking issues on stability measurements of OSCs is investigated. It is found that in the absence of UV light a reversible degradation occurs, which is independent of the used active layer material and accelerates at higher temperatures but can be undone with a short UV exposure. This reversible aging is attributed to the re-adsorption of oxygen, which for manufacturing reasons is trapped at the interface of ZnO, even in an oxygen-free environment. This oxygen can be removed with a UV pretreatment of the ZnO but at the expense of device efficiency and production that has to take place in an oxygen-free environment. This study establishes that stability measurements of ZnO-containing OSCs must be performed exclusively with a light source including a UV part since the usage of a simple white light source \textendash as often reported in the literature \textendash can lead to erroneous results.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@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}

}

@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}

}

@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}

}

@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}

}

@article{nokey,

title = {Covalent Organic Framework Thin-Film Photodetectors from Solution-Processable Porous Nanospheres},

author = {S Bag and H S Sasmal and S P Chaudhary and K Dey and D Bl\"{a}tte and R Guntermann and Y Zhang and M Polo\v{z}ij and A Kuc and A Shelke and R K Vijayaraghavan and T G Ajithkumar and S Bhattacharyya and T Heine and T Bein and R Banerjee},

url = {https://doi.org/10.1021/jacs.2c09838},

doi = {10.1021/jacs.2c09838},

issn = {0002-7863},

year  = {2023},

date = {2023-01-09},

journal = {Journal of the American Chemical Society},

volume = {145},

number = {3},

pages = {1649-1659},

abstract = {The synthesis of homogeneous covalent organic framework (COF) thin films on a desired substrate with decent crystallinity, porosity, and uniform thickness has great potential for optoelectronic applications. We have used a solution-processable sphere transmutation process to synthesize 300 ± 20 nm uniform COF thin films on a 2 × 2 cm2 TiO2-coated fluorine-doped tin oxide (FTO) surface. This process controls the nucleation of COF crystallites and molecular morphology that helps the nanospheres to arrange periodically to form homogeneous COF thin films. We have synthesized four COF thin films (TpDPP, TpEtBt, TpTab, and TpTta) with different functional backbones. In a close agreement between the experiment and density functional theory, the TpEtBr COF film showed the lowest optical band gap (2.26 eV) and highest excited-state lifetime (8.52 ns) among all four COF films. Hence, the TpEtBr COF film can participate in efficient charge generation and separation. We constructed optoelectronic devices having a glass/FTO/TiO2/COF-film/Au architecture, which serves as a model system to study the optoelectronic charge transport properties of COF thin films under dark and illuminated conditions. Visible light with a calibrated intensity of 100 mW cm\textendash2 was used for the excitation of COF thin films. All of the COF thin films exhibit significant photocurrent after illumination with visible light in comparison to the dark. Hence, all of the COF films behave as good photoactive substrates with minimal pinhole defects. The fabricated out-of-plane photodetector device based on the TpEtBr COF thin film exhibits high photocurrent density (2.65 ± 0.24 mA cm\textendash2 at 0.5 V) and hole mobility (8.15 ± 0.64 ×10\textendash3 cm2 V\textendash1 S\textendash1) compared to other as-synthesized films, indicating the best photoactive characteristics.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Gold Nanorod DNA Origami Antennas for 3 Orders of Magnitude Fluorescence Enhancement in NIR},

author = {K Trofymchuk and K Ko\l\k{a}taj and V Glembockyte and F Zhu and G P Acuna and T Liedl and P Tinnefeld},

url = {https://doi.org/10.1021/acsnano.2c09577},

doi = {10.1021/acsnano.2c09577},

issn = {1936-0851},

year  = {2023},

date = {2023-01-03},

journal = {ACS Nano},

volume = {17},

number = {2},

pages = {1327-1334},

abstract = {DNA origami has taken a leading position in organizing materials at the nanoscale for various applications such as manipulation of light by exploiting plasmonic nanoparticles. We here present the arrangement of gold nanorods in a plasmonic nanoantenna dimer enabling up to 1600-fold fluorescence enhancement of a conventional near-infrared (NIR) dye positioned at the plasmonic hotspot between the nanorods. Transmission electron microscopy, dark-field spectroscopy, and fluorescence analysis together with numerical simulations give us insights on the heterogeneity of the observed enhancement values. The size of our hotspot region is ∼12 nm, granted by using the recently introduced design of NAnoantenna with Cleared HotSpot (NACHOS), which provides enough space for placing of tailored bioassays. Additionally, the possibility to synthesize nanoantennas in solution might allow for production upscaling.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@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}

}

@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}

}