Publications

@article{nokey,

title = {Selective area growth of GaN nanowires and nanofins by molecular beam epitaxy on heteroepitaxial diamond (001) substrates},

author = {F Pantle and F Becker and M Kraut and S W\"{o}rle and T Hoffmann and S Artmeier and M Stutzmann},

url = {http://dx.doi.org/10.1039/D1NA00221J},

doi = {10.1039/D1NA00221J},

year  = {2021},

date = {2021-05-05},

journal = {Nanoscale Advances},

volume = {3},

number = {13},

pages = {3835-3845},

abstract = {GaN-on-diamond is a promising route towards reliable high-power transistor devices with outstanding performances due to better heat management, replacing common GaN-on-SiC technologies. Nevertheless, the implementation of GaN-on-diamond remains challenging. In this work, the selective area growth of GaN nanostructures on cost-efficient, large-scale available heteroepitaxial diamond (001) substrates by means of plasma-assisted molecular beam epitaxy is investigated. Additionally, we discuss the influence of an AlN buffer on the morphology of the GaN nanostructures. The nanowires and nanofins are characterized by a very high selectivity and controllable dimensions. Low temperature photoluminescence measurements are used to evaluate their structural quality. The growth of two GaN crystal domains, which are in-plane rotated against each other by 30°, is observed. The favoring of a certain domain is determined by the off-cut direction of the diamond substrates. By X-ray diffraction we show that the GaN nanostructures grow perpendicular to the diamond surface on off-cut diamond (001) substrates, which is in contrast to the growth on diamond (111), where the nanostructures are aligned with the substrate lattice. Polarity-selective wet chemical etching and Kelvin probe force microscopy reveal that the GaN nanostructures grow solely in the Ga-polar direction. This is a major advantage compared to the growth on diamond (111) and enables the application of GaN nanostructures on cost-efficient diamond for high-power/high-frequency applications.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Review on physical impedance models in modern battery research},

author = {R R Gaddam and L Katzenmeier and X Lamprecht and A S Bandarenka},

url = {http://dx.doi.org/10.1039/D1CP00673H},

doi = {10.1039/D1CP00673H},

issn = {1463-9076},

year  = {2021},

date = {2021-05-04},

journal = {Physical Chemistry Chemical Physics},

volume = {23},

number = {23},

pages = {12926-12944},

abstract = {Electrochemical impedance spectroscopy (EIS) is a versatile tool to understand complex processes in batteries. This technique can investigate the effects of battery components like the electrode and electrolyte, electrochemical reactions, interfaces, and interphases forming in the electrochemical systems. The interpretation of the EIS data is typically made using models expressed in terms of the so-called electrical equivalent circuits (EECs) to fit the impedance spectra. Therefore, the EECs must unambiguously represent the electrochemistry of the system. EEC models with a physical significance are more relevant than the empirical ones with their inherent imperfect description of the ongoing processes. This review aims to present the readers with the importance of physical EEC modeling within the context of battery research. A general introduction to EIS and EEC models along with a brief description of the mathematical formalism is provided, followed by showcasing the importance of physical EEC models for EIS on selected examples from the research on traditional, aqueous, and newer all-solid-state battery systems.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Conformational Control of Chemical Reactivity for Surface-Confined Ru-Porphyrins},

author = {P Knecht and J Reichert and P S Deimel and P Feulner and F Haag and F Allegretti and M Garnica and M Schwarz and W Auw\"{a}rter and P T P Ryan and T-L Lee and D A Duncan and A P Seitsonen and J V Barth and A C Papageorgiou},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202104075},

doi = {https://doi.org/10.1002/anie.202104075},

issn = {1433-7851},

year  = {2021},

date = {2021-05-03},

journal = {Angewandte Chemie International Edition},

volume = {60},

number = {30},

pages = {16561-16567},

abstract = {Abstract We assess the crucial role of tetrapyrrole flexibility in the CO ligation to distinct Ru-porphyrins supported on an atomistically well-defined Ag(111) substrate. Our systematic real-space visualisation and manipulation experiments with scanning tunnelling microscopy directly probe the ligation, while bond-resolving atomic force microscopy and X-ray standing-wave measurements characterise the geometry, X-ray and ultraviolet photoelectron spectroscopy the electronic structure, and temperature-programmed desorption the binding strength. Density-functional-theory calculations provide additional insight into the functional interface. We unambiguously demonstrate that the substituents regulate the interfacial conformational adaptability, either promoting or obstructing the uptake of axial CO adducts.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Global Property Prediction: A Benchmark Study on Open-Source, Perovskite-like Datasets},

author = {F Mayr and A Gagliardi},

url = {https://doi.org/10.1021/acsomega.1c00991},

doi = {10.1021/acsomega.1c00991},

year  = {2021},

date = {2021-05-03},

journal = {ACS Omega},

volume = {6},

number = {19},

pages = {12722-12732},

abstract = {Screening combinatorial space for novel materials, such as perovskite-like ones for photovoltaics, has resulted in a high amount of simulated high-throughput data and analysis thereof. This study proposes a comprehensive comparison of structural fingerprint-based machine learning models on seven open-source databases of perovskite-like materials to predict band gaps and energies. It shows that none of the given methods, including graph neural networks, are able to capture arbitrary databases evenly, while underlining that commonly used metrics are highly database-dependent in typical workflows. In addition, the applicability of variance selection and autoencoders to significantly reduce fingerprint size indicates that models built with common fingerprints only rely on a submanifold of the available fingerprint space.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Controlling exciton many-body states by the electric-field effect in monolayer $mathrmMoS_2$},

author = {J Klein and A H\"{o}tger and M Florian and A Steinhoff and A Delhomme and T Taniguchi and K Watanabe and F Jahnke and A W Holleitner and M Potemski and C Faugeras and J J Finley and A V Stier},

url = {https://link.aps.org/doi/10.1103/PhysRevResearch.3.L022009},

doi = {10.1103/PhysRevResearch.3.L022009},

year  = {2021},

date = {2021-04-30},

journal = {Physical Review Research},

volume = {3},

number = {2},

pages = {L022009},

abstract = {We report magneto-optical spectroscopy of gated monolayer 

MoS2 in high magnetic fields up to 28T and obtain new insights on the many-body interaction of neutral and charged excitons with the resident charges of distinct spin and valley texture. For neutral excitons at low electron doping, we observe a nonlinear valley Zeeman shift due to dipolar spin-interactions that depends sensitively on the local carrier concentration. As the Fermi energy increases to dominate over the other relevant energy scales in the system, the magneto-optical response depends on the occupation of the fully spin-polarized Landau levels (LL) in both K/K′ valleys. This manifests itself in a many-body state. Our experiments demonstrate that the exciton in monolayer semiconductors is only a single particle boson close to charge neutrality. We find that away from charge neutrality it smoothly transitions into polaronic states with a distinct spin-valley flavor that is defined by the LL quantized spin and valley texture.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Anapole-Assisted Absorption Engineering in Arrays of Coupled Amorphous Gallium Phosphide Nanodisks},

author = {L H\"{u}ttenhofer and A Tittl and L K\"{u}hner and E Cort\'{e}s and S A Maier},

url = {https://doi.org/10.1021/acsphotonics.1c00238},

doi = {10.1021/acsphotonics.1c00238},

year  = {2021},

date = {2021-04-26},

journal = {ACS Photonics},

abstract = {Broadband solar light harvesting plays a crucial role for efficient energy conversion. Anapole excitations and associated absorption engineering in dielectric nanoresonators are a focus of nanophotonic research due to the intricate combination of nonradiating modes and strong electromagnetic field confinement in the underlying material. The arising high field strengths are used for enhanced second-harmonic generation and photocatalysis, where devices require large areas with closely spaced nanoresonators for sizable photonic yields. However, most anapole studies have so far been carried out at the single-particle level, neglecting the influence of anapole\textendashanapole interactions. Here, we present a systematic study of coupling mechanisms in rectangular arrays of amorphous GaP nanodisks that support anapole excitations at 600 nm, which is within the lossy spectral regime of the material. Our experimental findings show that maximum visible light extinction by the array and maximum absorption in the GaP are not achieved by the densest packing of resonators. Counterintuitively, increasing the array periodicities such that collective effects spectrally overlap with the anapole excitation of a single particle leads to an absorption enhancement of up to 300% compared to a single disk. An analysis of coupling in one- and two-dimensional arrays with polarization-dependent measurements and numerical simulations allows us to discriminate between coupling interactions parallel and perpendicular to the polarization axis and evaluate their strengths. Utilizing a multipolar decomposition of excitations in single nanodisks embedded in one-dimensional arrays, we can attribute the coupling to enhanced electric and toroidal dipoles under variation of the interparticle spacing. Our results provide a fundamental understanding of tailored light absorption in coupled anapole resonators and reveal important design guidelines for advanced metasurface approaches in a wide range of energy conversion applications.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Photovoltaic Cells Based on Ternary P3HT:PCBM:Ruthenium(II) Complex Bearing 8-(diphenylphosphino)quinoline Active Layer},

author = {S Akel and M A Sharif and R Al-Esseili and M A Al-Wahish and H A Hodali and P M\"{u}ller-Buschbaum and L Schmidt-Mende and M Al-Hussein},

url = {https://www.sciencedirect.com/science/article/pii/S0927775721005549},

doi = {https://doi.org/10.1016/j.colsurfa.2021.126685},

issn = {0927-7757},

year  = {2021},

date = {2021-04-24},

urldate = {2021-04-24},

journal = {Colloids and Surfaces A: Physicochemical and Engineering Aspects},

pages = {126685},

abstract = {ABSTRACT Optical, morphological and photovoltaic properties are investigated for ternary solar cells containing a traditional poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl-C61-butyric-acid-methyl ester (P3HT:PCBM) bulkheterojunction (BHJ) active layer modified with different concentrations of a novel ruthenium complex [Ru(N-P)2(O-O)], where N-P abbreviates 8-(diphenylphosphino)quinolone and O-O = oxalate dianion. At a low concentration of the Ru-complex (2.5wt. %) the device efficiency is improved by 50% compared with the reference binary devices at ambient conditions. This substantial efficiency enhancement is attributed to the role of the Ru-complex in improving light absorption over a wavelength range of (295-800nm) in combination with a better matching of the energy levels of the ternary blend system. Moreover, at low concentration, the Ru-complex has a positive impact on the morphology of the active layer in the device. The inclusion of Ru-complex increases the P3HT crystallinity substantially with virtually no effect on the size and orientation of the crystalline lamellae. The enhancement in device efficiency becomes less pronounced with increasing the concentration of the Ru-complex due to the formation of several micron-size domains of [Ru(N-P)2(O-O)] in the ternary active layers. These large domains negatively affect the optical properties and morphology, thus inhibiting efficient charge generation and transport in the corresponding solar cells.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Hot electron physics and applications},

author = {L V Besteiro and E Cort\'{e}s and S Ishii and P Narang and R F Oulton},

url = {https://aip.scitation.org/doi/abs/10.1063/5.0050796},

doi = {10.1063/5.0050796},

year  = {2021},

date = {2021-04-19},

journal = {Journal of Applied Physics},

volume = {129},

number = {15},

pages = {150401},

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

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Bright single photon emitters with enhanced quantum efficiency in a two-dimensional semiconductor coupled with dielectric nano-antennas},

author = {L Sortino and P G Zotev and C L Phillips and A J Brash and J Cambiasso and E Marensi and A M Fox and S A Maier and R Sapienza and A I Tartakovskii},

year  = {2021},

date = {2021-04-05},

journal = {arXiv preprint arXiv:2103.16986},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Ultrafine TiO2 Nanoparticle Supported Nitrogen-Rich Graphitic Porous Carbon as an Efficient Anode Material for Potassium-Ion Batteries},

author = {D P Dubal and A Schneemann and V Ranc and \v{S} Kment and O Tomanec and M Petr and H Kmentova and M Otyepka and R Zbo\v{r}il and R A Fischer and K Jayaramulu},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aesr.202100042},

doi = {https://doi.org/10.1002/aesr.202100042},

issn = {2699-9412},

year  = {2021},

date = {2021-03-17},

journal = {Advanced Energy and Sustainability Research},

volume = {2},

number = {9},

pages = {2100042},

abstract = {Potassium-ion batteries (KIBs) have attracted enormous attention as a next-generation energy storage system due to their low cost, fast ionic conductivity within electrolytes, and high operating voltage. However, developing suitable electrode materials to guarantee high-energy output and structural stability to ensure long cycling performance remains a critical challenge. Herein, anatase TiO2 nanoparticles are encapsulated in nitrogen-rich graphitic carbon (TiO2@NGC) with hierarchical pores and high surface area (250 m2 g−1) using the Ti-based metal\textendashorganic framework NH2-MIL-125 (Ti8O8(OH)4(NH2-bdc)6 with NH2-bdc2− = 2-amino-1,4-benzenedicarboxylate) as a sacrificial template. Serving as the anode material in a K-ion half-cell, TiO2@NGC delivers a high capacity of 228 mA h g−1 with remarkable cycling performance (negligible loss over 2000 cycles with more than 98% Coulombic efficiency). The charge-storing mechanism is underpinned using ex situ characterization techniques such as ex situ X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. It is revealed that the original TiO2 phase gets transformed to the anorthic Ti7O13 and monoclinic K2Ti4O9 phase after the first charge/discharge cycle, which further initiates the charge storage process via the conversion reactions.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Assembly and Manipulation of a Prototypical N-Heterocyclic Carbene with a Metalloporphyrin Pedestal on a Solid Surface},

author = {P Knecht and B Zhang and J Reichert and D A Duncan and M Schwarz and F Haag and P T P Ryan and T-L Lee and P S Deimel and P Feulner and F Allegretti and W Auw\"{a}rter and G M\'{e}dard and A P Seitsonen and J V Barth and A C Papageorgiou},

url = {https://doi.org/10.1021/jacs.1c01229},

doi = {10.1021/jacs.1c01229},

issn = {0002-7863},

year  = {2021},

date = {2021-03-11},

journal = {Journal of the American Chemical Society},

volume = {143},

number = {11},

pages = {4433-4439},

abstract = {The controlled arrangement of N-heterocyclic carbenes (NHCs) on solid surfaces is a current challenge of surface functionalization. We introduce a strategy of using Ru porphyrins in order to control both the orientation and lateral arrangement of NHCs on a planar surface. The coupling of the NHC to the Ru porphyrin is a facile process which takes place on the interface: we apply NHCs as functional, robust pillars on well-defined, preassembled Ru porphyrin monolayers on silver and characterize these interfaces with atomic precision via a battery of experimental techniques and theoretical considerations. The NHCs assemble at room temperature modularly and reversibly on the Ru porphyrin arrays. We demonstrate a selective and complete functionalization of the Ru centers. With its binding, the NHC modifies the interaction of the Ru porphyrin with the Ag surface, displacing the Ru atom by 1 r{A} away from the surface. This arrangement of NHCs allows us to address individual ligands by controlled manipulation with the tip of a scanning tunneling microscope, creating patterned structures on the nanometer scale.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Phase formation through synthetic control: polymorphism in the sodium-ion solid electrolyte Na4P2S6},

author = {T Scholz and C Schneider and R Eger and V Duppel and I Moudrakovski and A Schulz and J Nuss and B V Lotsch},

url = {http://dx.doi.org/10.1039/D0TA11008F},

doi = {10.1039/D0TA11008F},

issn = {2050-7488},

year  = {2021},

date = {2021-03-10},

journal = {Journal of Materials Chemistry A},

volume = {9},

number = {13},

pages = {8692-8703},

abstract = {The development of all-solid-state sodium batteries for scalable energy storage solutions requires fast sodium conducting solid electrolytes. To fast-track their discovery, candidate materials need to be identified that are synthesized from abundant resources via cheap and green synthesis routes. Their ion conducting mechanism has to be understood and adapted to meet the stringent requirements for long-term operation in all-solid-state batteries. Here, structure and properties of the sodium hexathiohypodiphosphate Na4P2S6 obtained by two different synthesis methods are compared: a solid-state reaction and a precipitation route from aqueous solution. Combined investigations using powder X-ray diffraction (PXRD), precession electron diffraction (PED), differential scanning calorimetry (DSC), solid-state nuclear magnetic resonance spectroscopy (ssNMR), and Raman spectroscopy reveal that the solid-state synthesized material is characterized by a Na+ and vacancy disorder-driven enantiotropic phase transition at 160 °C (α- to β-Na4P2S6), which is accompanied by a symmetry change of the P2S64− anion. Precipitated Na4P2S6 already crystallizes in a β-like polymorph at room temperature, likely assisted by inter- and intralayer defects. Bond-valence and nudged elastic band (NEB) calculations were employed to identify a low energy, 2D conduction network in β-Na4P2S6, suggesting facile 2D long-range Na+ diffusion. Electrochemical impedance spectroscopy reveals a higher ionic conductivity at room temperature in precipitated β-like Na4P2S6 (2 × 10−6 S cm−1) compared to the solid-state α polymorph (7 × 10−7 S cm−1). The activation energy is around 0.4 eV for both materials. The findings highlight that even subtle structural changes can significantly impact the sodium-ion diffusion in solid electrolytes and at the same time reveal an intricate interplay between phase formation and synthetic control.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Role of cation-mediated recombination in perovskite solar cells},

author = {A Singh and W Kaiser and A Gagliardi},

url = {https://www.sciencedirect.com/science/article/pii/S0927024820305092},

doi = {https://doi.org/10.1016/j.solmat.2020.110912},

issn = {0927-0248},

year  = {2021},

date = {2021-03-01},

journal = {Solar Energy Materials and Solar Cells},

volume = {221},

pages = {110912},

abstract = {The origin of the hysteresis in the current\textendashvoltage (J\textendashV) characteristics in perovskite solar cells (PSCs) is one of the most debated topics of recent years. Hysteretic effects are connected with the slow redistribution of ionic defects during the voltage sweep. Existing literature focuses on the potential screening due to accumulated ions, solely, while neglecting the possibility of charge trapping and subsequent recombination via ions. We investigate the role of cation-mediated recombination of ions using time-dependent drift\textendashdiffusion simulations in MAPbI3 PSCs. Slow-moving cations are considered as traps for the electrons. Trapped electrons can subsequently recombine non-radiatively with holes. We analyze the role of the cation-mediated trapping and its parameters (capture coefficient, cation energy, ion mobility) as well as the scan rate on the device performance. For shallow cation energies, a decrease in open-circuit voltage and slight enhancement in hysteresis is observed. Deep cation energies lead to a substantial deterioration of device performance and large hysteresis enhancement. The presented study emphasizes the importance of considering the interaction of ions with charge carriers beyond the simple electrostatic models to improve our understanding of PSCs.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Properties of the Space Charge Layers Formed in Li-Ion Conducting Glass Ceramics},

author = {L Katzenmeier and S Helmer and S Braxmeier and E Knobbe and A S Bandarenka},

url = {https://doi.org/10.1021/acsami.0c21304},

doi = {10.1021/acsami.0c21304},

issn = {1944-8244},

year  = {2021},

date = {2021-02-03},

journal = {ACS Applied Materials \& Interfaces},

volume = {13},

number = {4},

pages = {5853-5860},

abstract = {For years, the space charge layer formation in Li-conducting solid electrolytes and its relevance to so-called all solid-state batteries have been controversially discussed from experimental and theoretical perspectives. In this work, we observe the phenomenon of space charge layer formation using impedance spectroscopy at different electrode polarizations. We analyze the properties of these space charge layers using a physical equivalent circuit describing the response of the solid electrolytes and solid/solid electrified interfaces under blocking conditions. The elements corresponding to the interfacial layers are identified and analyzed with different electrode metals and applied biases. The effective thickness of the space charge layer was calculated to be ∼60 nm at a bias potential of 1 V. In addition, it was possible to estimate the relative permittivity of the electrolytes, specific resistance of the space charge layer, and the effective thickness of the electric double layer (∼0.7 nm).},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Electronic properties of semiconducting Zn(Si, Ge, Sn)N2 alloys},

author = {M Ogura and D Han and M M Pointner and L S Junkers and S S Rudel and W Schnick and H Ebert},

url = {https://link.aps.org/doi/10.1103/PhysRevMaterials.5.024601},

doi = {10.1103/PhysRevMaterials.5.024601},

year  = {2021},

date = {2021-02-02},

urldate = {2021-02-02},

journal = {Physical Review Materials},

volume = {5},

number = {2},

pages = {024601},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Examination of possible high-pressure candidates of SnTiO3: The search for novel ferroelectric materials},

author = {F Pielnhofer and L Diehl and A Jim\'{e}nez-Solano and A Bussmann-Holder and J C Sch\"{o}n and B V Lotsch},

url = {https://aip.scitation.org/doi/abs/10.1063/5.0029968},

doi = {10.1063/5.0029968},

year  = {2021},

date = {2021-02-02},

journal = {APL Materials},

volume = {9},

number = {2},

pages = {021103},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Origin of Hole Transport in Small Molecule Dilute Donor Solar Cells},

author = {W Kaiser and L N S Murthy and C-L Chung and K-T Wong and J W P Hsu and A Gagliardi},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aesr.202000042},

doi = {https://doi.org/10.1002/aesr.202000042},

issn = {2699-9412},

year  = {2021},

date = {2021-02-01},

journal = {Advanced Energy and Sustainability Research},

volume = {2},

number = {3},

pages = {2000042},

abstract = {Dilute donor organic solar cells (OSCs) are a promising technology to circumvent the trade-off between open-circuit voltage (Voc) and short-circuit current density (Jsc). The origin of hole transport in OSCs with donor concentrations below the percolation threshold is diversely discussed in the community. Herein, both hole back transfer and long-range hopping (tunneling) are analyzed as possible mechanisms of photocurrent in small molecule dilute donor OSCs using kinetic Monte Carlo (kMC) simulations. In contrast to previous kMC studies, the driving force for exciton dissociation is accounted for. As a study system, nitrogen-bridged terthiophene (NBTT) molecules in a [6,6]-phenyl-C70-butyric acid methyl ester (PC71BM) matrix are investigated. The simulations show that hole back transfer from the small molecule donor to the fullerene matrix explains the measured concentration dependences of the photocurrents as well as the Jsc dependence on the light intensity for donor concentrations below 5 wt%. For 5 wt%, distances between NBTT molecules decrease to reasonable ranges that long-range hopping or tunneling cannot be discounted. Compared with polymer donors, larger hole localization is observed. The results emphasize that the barrier for hole back transfer is not only due to the highest occupied molecular orbital (HOMO) offset, but also by hole localization.},

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

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Identification of Potential Optoelectronic Applications for Metal Thiophosphates},

author = {D Han and H Ebert},

url = {https://doi.org/10.1021/acsami.0c17818},

doi = {10.1021/acsami.0c17818},

issn = {1944-8244},

year  = {2021},

date = {2021-01-27},

urldate = {2021-01-27},

journal = {ACS Applied Materials \& Interfaces},

volume = {13},

number = {3},

pages = {3836-3844},

abstract = {Metal thiophosphates are a large family of compounds that received far less attention than conventional chalcogenides. Recently, however, metal thiophosphates arouse research interest in regard of energy harvesting and conversion due to their structural and chemical diversity. Nevertheless, there remain many unexplored metal thiophosphates. Here, we performed a comprehensive investigation on the electronic and optoelectronic properties of a series of metal thiophosphates using first-principles calculations and identified several highly promising compounds as p-type transparent conductors, photovoltaic absorbers, and single visible-light-driven photocatalysts for water splitting. Our investigation reveals the intrinsic features of a series of typical metal thiophosphates, identifies their new optoelectronic applications, and validates that metal thiophosphates are promising materials deserving exploration.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Gate-Switchable Arrays of Quantum Light Emitters in Contacted Monolayer MoS2 van der Waals Heterodevices},

author = {A H\"{o}tger and J Klein and K Barthelmi and L Sigl and F Sigger and W M\"{a}nner and S Gyger and M Florian and M Lorke and F Jahnke and T Taniguchi and K Watanabe and K D J\"{o}ns and U Wurstbauer and C Kastl and K M\"{u}ller and J J Finley and A W Holleitner},

url = {https://doi.org/10.1021/acs.nanolett.0c04222},

doi = {10.1021/acs.nanolett.0c04222},

issn = {1530-6984},

year  = {2021},

date = {2021-01-27},

journal = {Nano Letters},

volume = {21},

number = {2},

pages = {1040-1046},

abstract = {We demonstrate electrostatic switching of individual, site-selectively generated matrices of single photon emitters (SPEs) in MoS2 van der Waals heterodevices. We contact monolayers of MoS2 in field-effect devices with graphene gates and hexagonal boron nitride as the dielectric and graphite as bottom gates. After the assembly of such gate-tunable heterodevices, we demonstrate how arrays of defects, that serve as quantum emitters, can be site-selectively generated in the monolayer MoS2 by focused helium ion irradiation. The SPEs are sensitive to the charge carrier concentration in the MoS2 and switch on and off similar to the neutral exciton in MoS2 for moderate electron doping. The demonstrated scheme is a first step for producing scalable, gate-addressable, and gate-switchable arrays of quantum light emitters in MoS2 heterostacks.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Engineering the Luminescence and Generation of Individual Defect Emitters in Atomically Thin MoS2},

author = {J Klein and L Sigl and S Gyger and K Barthelmi and M Florian and S Rey and T Taniguchi and K Watanabe and F Jahnke and C Kastl and V Zwiller and K D J\"{o}ns and K M\"{u}ller and U Wurstbauer and J J Finley and A W Holleitner},

url = {https://doi.org/10.1021/acsphotonics.0c01907},

doi = {10.1021/acsphotonics.0c01907},

year  = {2021},

date = {2021-01-21},

journal = {ACS Photonics},

abstract = {We demonstrate the on-demand creation and positioning of photon emitters in atomically thin MoS2 with very narrow ensemble broadening and negligible background luminescence. Focused helium-ion beam irradiation creates 100s to 1000s of such mono-typical emitters at specific positions in the MoS2 monolayers. Individually measured photon emitters show antibunching behavior with a g2(0) ∼ 0.23 and 0.27. From a statistical analysis, we extract the creation yield of the He-ion induced photon emitters in MoS2 as a function of the exposed area, as well as the total yield of single emitters as a function of the number of He ions when single spots are irradiated by He ions. We reach probabilities as high as 18% for the generation of individual and spectrally clean photon emitters per irradiated single site. Our results firmly establish 2D materials as a platform for photon emitters with unprecedented control of position as well as photophysical properties owing to the all-interfacial nature.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Synergistic Interplay between Asymmetric Backbone Conformation, Molecular Aggregation, and Charge-Carrier Dynamics in Fused-Ring Electron Acceptor-Based Bulk Heterojunction Solar Cells},

author = {X Song and L Hou and R Guo and Q Wei and L Yang and X Jiang and S Tu and A Zhang and Z Kan and W Tang and G Xing and P M\"{u}ller-Buschbaum},

url = {https://doi.org/10.1021/acsami.0c19700},

doi = {10.1021/acsami.0c19700},

issn = {1944-8244},

year  = {2021},

date = {2021-01-20},

urldate = {2021-01-20},

journal = {ACS Applied Materials \& Interfaces},

volume = {13},

number = {2},

pages = {2961-2970},

abstract = {Asymmetric fused-ring electron acceptors (a-FREAs) have proved to be a promising type of electron acceptor for high-performance organic solar cells (OSCs). However, the relationship among molecular structures of a-FREAs and their nanoscale morphology, charge-carrier dynamics, and device performance remains unclear. In this contribution, two FREAs differing in conjugated backbone geometry with an asymmetric conformation (IPT-2F) or symmetric one (INPIC-2F) are selected to systematically explore the superiorities of the asymmetric conformation. Despite the frailer extinction coefficient and weaker crystallinity, IPT-2F shows stronger dipole interactions in the asymmetrical backbone, which would induce a closer lamellar packing than that of the symmetrical counterpart. Using PBDB-T as the electron donor, the IPT-2F-based OSCs achieve the best power conversion efficiency of 14.0%, which is ca. 67% improvement compared to the INPIC-2F-based ones (8.37%), resulting from a simultaneously increased short-circuited current density (Jsc) and fill factor. Systematical investigations on optoelectronic and morphological properties show that the asymmetric conformation-structured IPT-2F exhibits better miscibility with the polymer donor to induce a favorable blend ordering with small domain sizes and suitable phase separation compared to the INPIC-2F symmetric molecule. This facilitates an efficient charge generation and transport, inhibits charge-carrier recombination, and promotes valid charge extraction in IPT-2F-based devices.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {3D Deep Learning Enables Accurate Layer Mapping of 2D Materials},

author = {X Dong and H Li and Z Jiang and T Gr\"{u}nleitner and \.{I} G\"{u}ler and J Dong and K Wang and M H K\"{o}hler and M Jakobi and B H Menze and A K Yetisen and I D Sharp and A V Stier and J J Finley and A W Koch},

url = {https://doi.org/10.1021/acsnano.0c09685},

doi = {10.1021/acsnano.0c09685},

issn = {1936-0851},

year  = {2021},

date = {2021-01-19},

journal = {ACS Nano},

volume = {15},

number = {2},

pages = {3139-3151},

abstract = {Layered, two-dimensional (2D) materials are promising for next-generation photonics devices. Typically, the thickness of mechanically cleaved flakes and chemical vapor deposited thin films is distributed randomly over a large area, where accurate identification of atomic layer numbers is time-consuming. Hyperspectral imaging microscopy yields spectral information that can be used to distinguish the spectral differences of varying thickness specimens. However, its spatial resolution is relatively low due to the spectral imaging nature. In this work, we present a 3D deep learning solution called DALM (deep-learning-enabled atomic layer mapping) to merge hyperspectral reflection images (high spectral resolution) and RGB images (high spatial resolution) for the identification and segmentation of MoS2 flakes with mono-, bi-, tri-, and multilayer thicknesses. DALM is trained on a small set of labeled images, automatically predicts layer distributions and segments individual layers with high accuracy, and shows robustness to illumination and contrast variations. Further, we show its advantageous performance over the state-of-the-art model that is solely based on RGB microscope images. This AI-supported technique with high speed, spatial resolution, and accuracy allows for reliable computer-aided identification of atomically thin materials.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Raman spectrum of Janus transition metal dichalcogenide monolayers WSSe and MoSSe},

author = {M M Petri\'{c} and M Kremser and M Barbone and Y Qin and Y Sayyad and Y Shen and S Tongay and J J Finley and A R Botello-M\'{e}ndez and K M\"{u}ller},

url = {https://link.aps.org/doi/10.1103/PhysRevB.103.035414},

doi = {10.1103/PhysRevB.103.035414},

year  = {2021},

date = {2021-01-15},

journal = {Physical Review B},

volume = {103},

number = {3},

pages = {035414},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Charged Exciton Kinetics in Monolayer MoSe2 near Ferroelectric Domain Walls in Periodically Poled LiNbO3},

author = {P Soubelet and J Klein and J Wierzbowski and R Silvioli and F Sigger and A V Stier and K Gallo and J J Finley},

url = {https://doi.org/10.1021/acs.nanolett.0c03810},

doi = {10.1021/acs.nanolett.0c03810},

issn = {1530-6984},

year  = {2021},

date = {2021-01-11},

journal = {Nano Letters},

volume = {21},

number = {2},

pages = {959-966},

abstract = {Monolayer semiconducting transition metal dichalcogenides are a strongly emergent platform for exploring quantum phenomena in condensed matter, building novel optoelectronic devices with enhanced functionalities. Because of their atomic thickness, their excitonic optical response is highly sensitive to their dielectric environment. In this work, we explore the optical properties of monolayer thick MoSe2 straddling domain wall boundaries in periodically poled LiNbO3. Spatially resolved photoluminescence experiments reveal spatial sorting of charge and photogenerated neutral and charged excitons across the boundary. Our results reveal evidence for extremely large in-plane electric fields of ≃4000 kV/cm at the domain wall whose effect is manifested in exciton dissociation and routing of free charges and trions toward oppositely poled domains and a nonintuitive spatial intensity dependence. By modeling our result using drift-diffusion and continuity equations, we obtain excellent qualitative agreement with our observations and have explained the observed spatial luminescence modulation using realistic material parameters.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Growth dynamics and compositional structure in periodic InAsSb nanowire arrays on Si (111) grown by selective area molecular beam epitaxy},

author = {D Ruhstorfer and A Lang and S Matich and M D\"{o}blinger and H Riedl and J J Finley and G Koblm\"{u}ller},

issn = {0957-4484},

year  = {2021},

date = {2021-01-08},

journal = {Nanotechnology},

volume = {32},

number = {13},

pages = {135604},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Layer-by-Layer Spray-Coating of Cellulose Nanofibrils and Silver Nanoparticles for Hydrophilic Interfaces},

author = {Q Chen and C J Brett and A Chumakov and M Gensch and M Schwartzkopf and V K\"{o}rstgens and L D S\"{o}derberg and A Plech and P Zhang and P M\"{u}ller-Buschbaum and S V Roth},

url = {https://doi.org/10.1021/acsanm.0c02819},

doi = {10.1021/acsanm.0c02819},

year  = {2021},

date = {2021-01-05},

urldate = {2021-01-05},

journal = {ACS Applied Nano Materials},

volume = {4},

number = {1},

pages = {503-513},

abstract = {Silver nanoparticles (AgNPs) and AgNP-based composite materials have attracted growing interest due to their structure-dependent optical, electrical, catalytic, and stimuli-responsive properties. For practical applications, polymeric materials are often combined with AgNPs to provide flexibility and offer a scaffold for homogenous distribution of the AgNPs. However, the control over the assembly process of AgNPs on polymeric substrates remains a big challenge. Herein, we report the fabrication of AgNP/cellulose nanofibril (CNF) thin films via layer-by-layer (LBL) spray-coating. The morphology and self-assembly of AgNPs with increasing number of spray cycles are characterized by atomic force microscopy (AFM), grazing-incidence small-angle X-ray scattering (GISAXS), and grazing-incidence wide-angle X-ray scattering (GIWAXS). We deduce that an individual AgNP (radius = 15 ± 3 nm) is composed of multiple nanocrystallites (diameter = 2.4 ± 0.9 nm). Our results suggest that AgNPs are assembled into large agglomerates on SiO2 substrates during spray-coating, which is disadvantageous for AgNP functionalization. However, the incorporation of CNF substrates contributes to a more uniform distribution of AgNP agglomerates and individual AgNPs by its network structure and by absorbing the partially dissolved AgNP agglomerates. Furthermore, we demonstrate that the spray-coating of the AgNP/CNF mixture results in similar topography and agglomeration patterns of AgNPs compared to depositing AgNPs onto a precoated CNF thin film. Contact-angle measurements and UV/vis spectroscopy suggest that the deposition of AgNPs onto or within CNFs could increase the hydrophilicity of AgNP-containing surfaces and the localized surface plasmon resonance (LSPR) intensity of AgNP compared to AgNPs sprayed on SiO2 substrates, suggesting their potential applications in antifouling coatings or label-free biosensors. Thereby, our approach provides a platform for a facile and scalable production of AgNP/CNF films with a low agglomeration rate by two different methods as follows: (1) multistep layer-by-layer (LBL) spray-coating and (2) direct spray-coating of the AgNP/CNF mixture. We also demonstrate the ability of CNFs as a flexible framework for directing the uniform assembly of AgNPs with tailorable wettability and plasmonic properties.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {A Solution-Processable Polymer-Based Thin-Film Thermoelectric Generator},

author = {R M Kluge and N Saxena and P M\"{u}ller-Buschbaum},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aesr.202000060},

doi = {https://doi.org/10.1002/aesr.202000060},

issn = {2699-9412},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Advanced Energy and Sustainability Research},

volume = {2},

number = {1},

pages = {2000060},

abstract = {Thermoelectric modules are capable of transforming thermal energy into electrical power. Implementing earth-abundant and cost-effective organic materials, they can contribute to an eco-friendly way of energy production out of low-grade waste heat and natural heat sources via the Seebeck effect. Moreover, the flexibility of organic materials can allow for adaption to curved surfaces such as the human skin and wearable electronics. Herein, a solution-processable thermoelectric generator (TEG) using exclusively polymers as active materials is presented. The high-mobility n-type polymer poly[[N,N-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5-(2,2-bithiophene)] (P(NDI2OD-T2)) and the widely studied p-type polymer blend poly(3,4-ethylene-dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) are combined into a thin-film TEG. The presented device design is not limited to this system but is applicable to any pair of organic materials processable from solution and can be easily upscaled to fully flexible devices via, e.g., printing and roll-to-roll processing.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Morphology Control in 2D Carbon Nitrides: Impact of Particle Size on Optoelectronic Properties and Photocatalysis},

author = {J Kr\"{o}ger and A Jim\'{e}nez-Solano and G Savasci and V W H Lau and V Duppel and I Moudrakovski and K K\"{u}ster and T Scholz and A Gouder and M-L Schreiber and F Podjaski and C Ochsenfeld and B V Lotsch},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202102468},

doi = {https://doi.org/10.1002/adfm.202102468},

issn = {1616-301X},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Advanced Functional Materials},

volume = {31},

number = {28},

pages = {2102468},

abstract = {Abstract The carbon nitride poly(heptazine imide), PHI, has recently emerged as a powerful 2D carbon nitride photocatalyst with intriguing charge storing ability. Yet, insights into how morphology, particle size, and defects influence its photophysical properties are virtually absent. Here, ultrasonication is used to systematically tune the particle size as well as concentration of surface functional groups and study their impact. Enhanced photocatalytic activity correlates with an optimal amount of those defects that create shallow trap states in the optical band gap, promoting charge percolation, as evidenced by time-resolved photoluminescence spectroscopy, charge transport studies, and quantum-chemical calculations. Excessive amounts of terminal defects can act as recombination centers and hence, decrease the photocatalytic activity for hydrogen evolution. Re-agglomeration of small particles can, however, partially restore the photocatalytic activity. The type and amount of trap states at the surface can also influence the deposition of the co-catalyst Pt, which is used in hydrogen evolution experiments. Optimized conditions entail improved Pt distribution, as well as enhanced wettability and colloidal stability. A description of the interplay between these effects is provided to obtain a holistic picture of the size\textendashproperty\textendashactivity relationship in nanoparticulate PHI-type carbon nitrides that can likely be generalized to related photocatalytic systems.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {In Situ Study of Order Formation in Mesoporous Titania Thin Films Templated by a Diblock Copolymer during Slot-Die Printing},

author = {N Li and W Chen and L Song and R Guo and M A Scheel and D Yang and V K\"{o}rstgens and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},

url = {https://doi.org/10.1021/acsami.0c18851},

doi = {10.1021/acsami.0c18851},

issn = {1944-8244},

year  = {2020},

date = {2020-12-09},

urldate = {2020-12-09},

journal = {ACS Applied Materials \& Interfaces},

volume = {12},

number = {51},

pages = {57627-57637},

abstract = {Slot-die printing, a large-scale deposition technique, is applied to fabricate mesoporous titania films. Printing is interesting, for example, for scaling up solar cells where titania films with an interconnected mesoporous network and a large surface-to-volume ratio are desired as photoanodes. A fundamental understanding of the structure evolution during printing is of high significance in tailoring these films. In this work, we provide important insights into the self-assembly of the slot-die-printed titania/polystyrene-block-poly(ethylene oxide) (PS-b-PEO) micelles into ordered hybrid structures in real time via in situ grazing-incidence small-angle X-ray scattering (GISAXS). GISAXS allows for tracking both vertical and lateral structure development of the film formation process. In the hybrid film, a face-centered cubic (FCC) structure is preferentially formed at the interfaces with air and with the substrate, while a defect-rich mixed FCC and body-centered cubic (BCC) structure forms in the bulk. After calcination, the surface and inner morphologies of the obtained nanostructured titania films are compared with the spin-coated analogues. In the printed films, the initially formed nanoscale structure of the hybrid film is preserved, and the resulting mesoporous titania film shows a superior order as compared with the spin-coated thin films which can be beneficial for future applications.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Spray-deposited PbS colloidal quantum dot solid for near-infrared photodetectors},

author = {W Chen and H Tang and Y Chen and J E Heger and N Li and L P Kreuzer and Y Xie and D Li and C Anthony and Z Pikramenou and K W Ng and X W Sun and K Wang and P M\"{u}ller-Buschbaum},

url = {https://www.sciencedirect.com/science/article/pii/S2211285520308326},

doi = {https://doi.org/10.1016/j.nanoen.2020.105254},

issn = {2211-2855},

year  = {2020},

date = {2020-12-01},

urldate = {2020-12-01},

journal = {Nano Energy},

volume = {78},

pages = {105254},

abstract = {Colloidal PbS quantum dots (QDs) are promising candidates for various optoelectronic applications based on solution-processed thin-film techniques. In this work, a versatile layer-by-layer (LBL) spray deposition of the QDs is introduced aiming for a future large-scale fabrication process of optoelectronic devices. As compared to spin-coated QD solids, a smaller inter-dot distance and a better-ordered superlattice stacking behavior of the QDs are found in the spray-deposited QD solids as confirmed by grazing-incidence small-angle X-ray scattering (GISAXS). The spectral mapping combined time-resolved photoluminescence analysis indicates a longer charge carrier lifetime and better order of the energy state distribution of the spray-deposited QD solid comparing with the spin-coated one. Thus, photodetectors based on spray deposition of QD solids demonstrate an excellent device performance, with the responsivity achieving 365.1 A/W and the detectivity reaching up to 1.4 × 1012 Jones under an illumination power of 63.5 μW/cm2 at a wavelength of 1250 nm. The spray-deposited device performances indicate a great potential of spray deposition of large sized QDs in large-scale fabrications for optoelectronics using longer wavelengths.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Optoelectronic Properties of Cs2AgBiBr6 Thin Films: The Influence of Precursor Stoichiometry},

author = {M T Sirtl and M Armer and L K Reb and R Hooijer and P D\"{o}rflinger and M A Scheel and K Tvingstedt and P Rieder and N Gl\"{u}ck and P Pandit and S V Roth and P M\"{u}ller-Buschbaum and V Dyakonov and T Bein},

url = {https://doi.org/10.1021/acsaem.0c01308},

doi = {10.1021/acsaem.0c01308},

year  = {2020},

date = {2020-11-25},

journal = {ACS Applied Energy Materials},

abstract = {Lead-free double perovskites have recently attracted growing attention as possible alternatives to lead-based halide perovskites in photovoltaics and other optoelectronic applications. The most prominent compound Cs2AgBiBr6, however, presents issues such as a rather large and indirect band gap, high exciton binding energies, and poor charge carrier transport, especially in thin films. In order to address some of these challenges, we systematically modified the stoichiometry of the precursors used for the synthesis of thin films toward a BiBr3-deficient system. In combination with a stoichiometric excess of AgBr, we obtained highly oriented double perovskite thin films. These modifications directly boost the lifetime of the charge carriers up to 500 ns as observed by time-resolved photoluminescence spectroscopy. Moreover, time-resolved microwave conductivity studies revealed an increase of the charge carrier mobility from 3.5 to around ∼5 cm2/(V s). Solar cells comprising the modified films as planar active layers reached power conversion efficiency (PCE) values up to 1.11%, exceeding the stoichiometric reference film (∼0.97%), both on average and with champion cells. The results in this work underline the importance of controlling the nanomorphology of the bulk film. We anticipate that control of precursor stoichiometry will also offer a promising approach for enhancing the efficiency of other perovskite photovoltaic absorber materials and thin films.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Photophysics and Electronic Structure of Lateral Graphene/MoS2 and Metal/MoS2 Junctions},

author = {S Subramanian and Q T Campbell and S K Moser and J Kiemle and P Zimmermann and P Seifert and F Sigger and D Sharma and H Al-Sadeg and M Labella and D Waters and R M Feenstra and R J Koch and C Jozwiak and A Bostwick and E Rotenberg and I Dabo and A W Holleitner and T E Beechem and U Wurstbauer and J A Robinson},

url = {https://doi.org/10.1021/acsnano.0c02527},

doi = {10.1021/acsnano.0c02527},

issn = {1936-0851},

year  = {2020},

date = {2020-11-16},

journal = {ACS Nano},

abstract = {Integration of semiconducting transition metal dichalcogenides (TMDs) into functional optoelectronic circuitries requires an understanding of the charge transfer across the interface between the TMD and the contacting material. Here, we use spatially resolved photocurrent microscopy to demonstrate electronic uniformity at the epitaxial graphene/molybdenum disulfide (EG/MoS2) interface. A 10× larger photocurrent is extracted at the EG/MoS2 interface when compared to the metal (Ti/Au)/MoS2 interface. This is supported by semi-local density functional theory (DFT), which predicts the Schottky barrier at the EG/MoS2 interface to be ∼2× lower than that at Ti/MoS2. We provide a direct visualization of a 2D material Schottky barrier through combination of angle-resolved photoemission spectroscopy with spatial resolution selected to be ∼300 nm (nano-ARPES) and DFT calculations. A bending of ∼500 meV over a length scale of ∼2\textendash3 μm in the valence band maximum of MoS2 is observed via nano-ARPES. We explicate a correlation between experimental demonstration and theoretical predictions of barriers at graphene/TMD interfaces. Spatially resolved photocurrent mapping allows for directly visualizing the uniformity of built-in electric fields at heterostructure interfaces, providing a guide for microscopic engineering of charge transport across heterointerfaces. This simple probe-based technique also speaks directly to the 2D synthesis community to elucidate electronic uniformity at domain boundaries alongside morphological uniformity over large areas.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Photophysics and Electronic Structure of Lateral Graphene/MoS2 and Metal/MoS2 Junctions},

author = {S Subramanian and Q T Campbell and S K Moser and J Kiemle and P Zimmermann and P Seifert and F Sigger and D Sharma and H Al-Sadeg and M Labella and D Waters and R M Feenstra and R J Koch and C Jozwiak and A Bostwick and E Rotenberg and I Dabo and A W Holleitner and T E Beechem and U Wurstbauer and J A Robinson},

url = {https://doi.org/10.1021/acsnano.0c02527},

doi = {10.1021/acsnano.0c02527},

issn = {1936-0851},

year  = {2020},

date = {2020-11-16},

journal = {ACS Nano},

volume = {14},

number = {12},

pages = {16663-16671},

abstract = {Integration of semiconducting transition metal dichalcogenides (TMDs) into functional optoelectronic circuitries requires an understanding of the charge transfer across the interface between the TMD and the contacting material. Here, we use spatially resolved photocurrent microscopy to demonstrate electronic uniformity at the epitaxial graphene/molybdenum disulfide (EG/MoS2) interface. A 10× larger photocurrent is extracted at the EG/MoS2 interface when compared to the metal (Ti/Au)/MoS2 interface. This is supported by semi-local density functional theory (DFT), which predicts the Schottky barrier at the EG/MoS2 interface to be ∼2× lower than that at Ti/MoS2. We provide a direct visualization of a 2D material Schottky barrier through combination of angle-resolved photoemission spectroscopy with spatial resolution selected to be ∼300 nm (nano-ARPES) and DFT calculations. A bending of ∼500 meV over a length scale of ∼2\textendash3 μm in the valence band maximum of MoS2 is observed via nano-ARPES. We explicate a correlation between experimental demonstration and theoretical predictions of barriers at graphene/TMD interfaces. Spatially resolved photocurrent mapping allows for directly visualizing the uniformity of built-in electric fields at heterostructure interfaces, providing a guide for microscopic engineering of charge transport across heterointerfaces. This simple probe-based technique also speaks directly to the 2D synthesis community to elucidate electronic uniformity at domain boundaries alongside morphological uniformity over large areas.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Room-Temperature Synthesis of 2D Janus Crystals and their Heterostructures},

author = {D B Trivedi and G Turgut and Y Qin and M Y Sayyad and D Hajra and M Howell and L Liu and S Yang and N H Patoary and H Li and M M Petri\'{c} and M Meyer and M Kremser and M Barbone and G Soavi and A V Stier and K M\"{u}ller and S Yang and I S Esqueda and H Zhuang and J J Finley and S Tongay},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202006320},

doi = {https://doi.org/10.1002/adma.202006320},

issn = {0935-9648},

year  = {2020},

date = {2020-11-11},

journal = {Advanced Materials},

volume = {32},

number = {50},

pages = {2006320},

abstract = {Abstract Janus crystals represent an exciting class of 2D materials with different atomic species on their upper and lower facets. Theories have predicted that this symmetry breaking induces an electric field and leads to a wealth of novel properties, such as large Rashba spin\textendashorbit coupling and formation of strongly correlated electronic states. Monolayer MoSSe Janus crystals have been synthesized by two methods, via controlled sulfurization of monolayer MoSe2 and via plasma stripping followed thermal annealing of MoS2. However, the high processing temperatures prevent growth of other Janus materials and their heterostructures. Here, a room-temperature technique for the synthesis of a variety of Janus monolayers with high structural and optical quality is reported. This process involves low-energy reactive radical precursors, which enables selective removal and replacement of the uppermost chalcogen layer, thus transforming classical transition metal dichalcogenides into a Janus structure. The resulting materials show clear mixed character for their excitonic transitions, and more importantly, the presented room-temperature method enables the demonstration of first vertical and lateral heterojunctions of 2D Janus TMDs. The results present significant and pioneering advances in the synthesis of new classes of 2D materials, and pave the way for the creation of heterostructures from 2D Janus layers.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Electron tunneling at the molecularly thin 2D perovskite and graphene van der Waals interface},

author = {K Leng and L Wang and Y Shao and I Abdelwahab and G Grinblat and I Verzhbitskiy and R Li and Y Cai and X Chi and W Fu and P Song and A Rusydi and G Eda and S A Maier and K P Loh},

url = {https://doi.org/10.1038/s41467-020-19331-6},

doi = {10.1038/s41467-020-19331-6},

issn = {2041-1723},

year  = {2020},

date = {2020-10-30},

journal = {Nature Communications},

volume = {11},

number = {1},

pages = {5483},

abstract = {Quasi-two-dimensional perovskites have emerged as a new material platform for optoelectronics on account of its intrinsic stability. A major bottleneck to device performance is the high charge injection barrier caused by organic molecular layers on its basal plane, thus the best performing device currently relies on edge contact. Herein, by leveraging on van der Waals coupling and energy level matching between two-dimensional Ruddlesden-Popper perovskite and graphene, we show that the plane-contacted perovskite and graphene interface presents a lower barrier than gold for charge injection. Electron tunneling across the interface occurs via a gate-tunable, direct tunneling-to-field emission mechanism with increasing bias, and photoinduced charge transfer occurs at femtosecond timescale (~50 fs). Field effect transistors fabricated on molecularly thin Ruddlesden-Popper perovskite using graphene contact exhibit electron mobilities ranging from 0.1 to 0.018 cm2V−1s−1 between 1.7 to 200 K. Scanning tunneling spectroscopy studies reveal layer-dependent tunneling barrier and domain size on few-layered Ruddlesden-Popper perovskite.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Collective oscillations of globally coupled bistable, nonresonant components},

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

url = {https://link.aps.org/doi/10.1103/PhysRevResearch.2.043125},

doi = {10.1103/PhysRevResearch.2.043125},

year  = {2020},

date = {2020-10-23},

journal = {Physical Review Research},

volume = {2},

number = {4},

pages = {043125},

abstract = {Bistable microelectrodes with an S-shaped current-voltage characteristic have recently been shown to oscillate under current control, when connected in parallel. In other systems with equivalently coupled bistable components, such oscillatory instabilities have not been reported. In this paper, we derive a general criterion for when an ensemble of coupled bistable components may become oscillatorily unstable. Using a general model, we perform a stability analysis of the ensemble equilibria, in which the components always group in three or fewer clusters. Based thereon, we give a necessary condition for the occurrence of collective oscillations. Moreover, we demonstrate that stable oscillations may persist for an arbitrarily large number of components, even though, as we show, any equilibrium with two or more components on the middle, autocatalytic branch is unstable.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Hydrogel-supported graphitic carbon nitride nanosheets loaded with Pt atoms as a novel self-water-storage photocatalyst for H2 evolution},

author = {L Lei and W Wang and C Wang and H Fan and A K Yadav and N Hu and Q Zhong and P M\"{u}ller-Buschbaum},

url = {http://dx.doi.org/10.1039/D0TA07805K},

doi = {10.1039/D0TA07805K},

issn = {2050-7488},

year  = {2020},

date = {2020-10-21},

urldate = {2020-10-21},

journal = {Journal of Materials Chemistry A},

volume = {8},

number = {45},

pages = {23812-23819},

abstract = {Graphitic carbon nitride (g-C3N4) exhibits an excellent photocatalytic performance as a powder, especially under visible light irradiation. However, it encounters great challenges for practical applications. For instance, to avoid aggregation and precipitation, a continuous stirring process is required for the bare g-C3N4 powder during the photocatalytic reaction. In addition, recycling of the powder photocatalyst is complicated and usually not environment friendly. To overcome these drawbacks, we present a hybrid materials. This material combines g-C3N4 nanosheets loaded with cocatalyst Pt atoms (CN) with a polymer hydrogel. In the ready-to-use photocatalyst, CN is well distributed in the hydrogel matrix. Water stored in the hydrogel can serve as a water reservoir for the photocatalytic water splitting. Due to the intermolecular interactions between CN and the hydrogel, a 3D network with a small-sized nanostructure is formed, which enhances the light absorption and the charge carrier separation. As a result, the H2 evolution rate is 7437 μmol h−1 g−1, which is 130% higher than that of the bare CN powder in water. Furthermore, the hydrogel-supported CN is able to function under ambient environment conditions without any significant reduction of the photocatalytic performance, as compared to the bare CN powder. In the hybrid material, the combination of hydrogel and CN provides a possibility for the photocatalyst to work without a water environment and accomplish an efficient H2 evolution.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Internal nanoscale architecture and charge carrier dynamics of wide bandgap non-fullerene bulk heterojunction active layers in organic solar cells},

author = {X Jiang and H Kim and P S Deimel and W Chen and W Cao and D Yang and S Yin and R Schaffrinna and F Allegretti and J V Barth and M Schwager and H Tang and K Wang and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},

url = {http://dx.doi.org/10.1039/D0TA09671G},

doi = {10.1039/D0TA09671G},

issn = {2050-7488},

year  = {2020},

date = {2020-10-19},

journal = {Journal of Materials Chemistry A},

volume = {8},

number = {44},

pages = {23628-23636},

abstract = {Bulk heterojunction (BHJ) organic solar cells have gained increasing attention in the past few years. In this work, active layers of a wide-bandgap polymer donor with benzodithiophene units PBDB-T-2F and a non-fullerene small molecule acceptor IT-M are assembled into photovoltaic devices with different amounts of solvent additive 1,8-diiodooctane (DIO). The influence of DIO on the nanoscale film morphology and crystalline structure as well as the charge carrier dynamics of the active layers are investigated by combining grazing-incidence small-angle X-ray scattering (GISAXS), grazing-incidence wide-angle X-ray scattering (GIWAXS), X-ray reflectivity (XRR), UV-visible (UV-vis) absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), time-resolved photoluminescence (TRPL) and space charge limited current measurements, which are correlated with the corresponding performance of the solar cells. At 0.5 vol% DIO addition, the wide-bandgap non-fullerene organic solar cells show the best performance due to high open-circuit voltage and short-circuit current resulting from an improved charge carrier management due to the optimal inner nanoscale morphology of the active layers in terms of surface enrichment, crystallinity and crystalline orientation.},

keywords = {Foundry Organic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Light\textendashMatter Interaction in Quantum Confined 2D Polar Metals},

author = {K Nisi and S Subramanian and W He and K A Ulman and H El-Sherif and F Sigger and M Lassauni\`{e}re and M T Wetherington and N Briggs and J Gray and A W Holleitner and N Bassim and S Y Quek and J A Robinson and U Wurstbauer},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202005977},

doi = {https://doi.org/10.1002/adfm.202005977},

issn = {1616-301X},

year  = {2020},

date = {2020-10-15},

urldate = {2020-10-15},

journal = {Advanced Functional Materials},

volume = {n/a},

number = {n/a},

pages = {2005977},

abstract = {Abstract This work is a systematic experimental and theoretical study of the in-plane dielectric functions of 2D gallium and indium films consisting of two or three atomic metal layers confined between silicon carbide and graphene with a corresponding bonding gradient from covalent to metallic to van der Waals type. k-space resolved free electron and bound electron contributions to the optical response are identified, with the latter pointing towards the existence of thickness dependent quantum confinement phenomena. The resonance energies in the dielectric functions and the observed epsilon near-zero behavior in the near infrared to visible spectral range, are dependent on the number of atomic metal layers and properties of the metal involved. A model-based spectroscopic ellipsometry approach is used to estimate the number of atomic metal layers, providing a convenient route over expensive invasive characterization techniques. A strong thickness and metal choice dependence of the light\textendashmatter interaction makes these half van der Waals 2D polar metals attractive for quantum engineered metal films, tunable (quantum-)plasmonics and nano-photonics.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Formation and stability of small polarons at the lithium-terminated Li4Ti5O12 (LTO) (111) surface},

author = {M Kick and C Scheurer and H Oberhofer},

url = {https://aip.scitation.org/doi/abs/10.1063/5.0021443},

doi = {10.1063/5.0021443},

year  = {2020},

date = {2020-10-08},

journal = {The Journal of Chemical Physics},

volume = {153},

number = {14},

pages = {144701},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Nanoscale patterning at the Si/SiO2/graphene interface by focused He+ beam},

author = {A B\"{o}ttcher and R Schwaiger and T M Pazdera and D Exner and J Hauns and D Strelnikov and S Lebedkin and R Gr\"{o}ger and F Esch and B A J Lechner},

url = {https://iopscience.iop.org/article/10.1088/1361-6528/abb5cf/meta?casa_token=0ch84-BOwLoAAAAA:0ibNutoV58k0ONYDhRhhBtMaAbaDMOWEDghZKBvbCABbhx1dGH2gGSD1baUoc-Zosx5xyOGgxg},

doi = {10.1088/1361-6528/abb5cf},

issn = {0957-4484},

year  = {2020},

date = {2020-10-06},

urldate = {2020-10-06},

journal = {Nanotechnology},

volume = {31},

number = {50},

pages = {505302},

abstract = {We have studied the capability of He+ focused ion beam (He+-FIB) patterning to fabricate defect arrays on the Si/SiO2/Graphene interface using a combination of atomic force microscopy (AFM) and Raman imaging to probe damage zones. In general, an amorphized 'blister' region of cylindrical symmetry results upon exposing the surface to the stationary focused He+ beam. The topography of the amorphized region depends strongly on the ion dose, DS, (ranging from 103 to 107ions/spot) with craters and holes observed at higher doses. Furthermore, the surface morphology depends on the distance between adjacent irradiated spots, LS. Increasing the dose leads to (enhanced) subsurface amorphization and a local height increase relative to the unexposed regions. At the highest areal ion dose, the average height of a patterned area also increases as ∼1/LS. Correspondingly, in optical micrographs, the µm2-sized patterned surface regions change appearance. These phenomena can be explained by implantation of the He+ ions into the subsurface layers, formation of helium nanobubbles, expansion and modification of the dielectric constant of the patterned material. The corresponding modifications of the terminating graphene monolayer have been monitored by micro Raman imaging. At low ion doses, DS, the graphene becomes modified by carbon atom defects which perturb the 2D lattice (as indicated by increasing D/G Raman mode ratio). Additional x-ray photoionization spectroscopy (XPS) measurements allow us to infer that for moderate ion doses, scattering of He+ ions by the subsurface results in the oxidation of the graphene network. For largest doses and smallest LS values, the He+ beam activates extensive Si/SiO2/C bond rearrangement and a multicomponent material possibly comprising SiC and silicon oxycarbides, SiOC, is observed. We also infer parameter ranges for He+-FIB patterning defect arrays of potential use for pinning transition metal nanoparticles in model studies of heterogeneous catalysis.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Ultrathin catalyst-free InAs nanowires on silicon with distinct 1D sub-band transport properties},

author = {F Del Giudice and J Becker and C De Rose and M D\"{o}blinger and D Ruhstorfer and L Suomenniemi and J Treu and H Riedl and J J Finley and G Koblm\"{u}ller},

url = {http://dx.doi.org/10.1039/D0NR05666A},

doi = {10.1039/D0NR05666A},

issn = {2040-3364},

year  = {2020},

date = {2020-10-01},

journal = {Nanoscale},

volume = {12},

number = {42},

pages = {21857-21868},

abstract = {Ultrathin InAs nanowires (NW) with a one-dimensional (1D) sub-band structure are promising materials for advanced quantum-electronic devices, where dimensions in the sub-30 nm diameter limit together with post-CMOS integration scenarios on Si are much desired. Here, we demonstrate two site-selective synthesis methods that achieve epitaxial, high aspect ratio InAs NWs on Si with ultrathin diameters below 20 nm. The first approach exploits direct vapor\textendashsolid growth to tune the NW diameter by interwire spacing, mask opening size and growth time. The second scheme explores a unique reverse-reaction growth by which the sidewalls of InAs NWs are thermally decomposed under controlled arsenic flux and annealing time. Interesting kinetically limited dependencies between interwire spacing and thinning dynamics are found, yielding diameters as low as 12 nm for sparse NW arrays. We clearly verify the 1D sub-band structure in ultrathin NWs by pronounced conductance steps in low-temperature transport measurements using back-gated NW-field effect transistors. Correlated simulations reveal single- and double degenerate conductance steps, which highlight the rotational hexagonal symmetry and reproduce the experimental traces in the diffusive 1D transport limit. Modelling under the realistic back-gate configuration further evidences regimes that lead to asymmetric carrier distribution and breakdown of the degeneracy depending on the gate bias.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Mesoporous GeOx/Ge/C as a Highly Reversible Anode Material with High Specific Capacity for Lithium-Ion Batteries},

author = {N Hohn and X Wang and M A Giebel and S Yin and D M\"{u}ller and A E Hetzenecker and L Bie\ssmann and L P Kreuzer and G E M\"{o}hl and H Yu and J G C Veinot and T F F\"{a}ssler and Y-J Cheng and P M\"{u}ller-Buschbaum},

url = {https://doi.org/10.1021/acsami.0c13560},

doi = {10.1021/acsami.0c13560},

issn = {1944-8244},

year  = {2020},

date = {2020-09-21},

journal = {ACS Applied Materials \& Interfaces},

volume = {12},

number = {41},

pages = {47002-47009},

abstract = {Nanostructured Ge is considered a highly promising material for Li-ion battery applications as Ge offers high specific capacity and Li-ion diffusivity, while inherent mesoporous nanostructures can contribute resistance against capacity fading as typically induced by high volume expansion in bulk Ge films. Mesoporous GeOx/Ge/C films are synthesized using K4Ge9 Zintl clusters as a Ge precursor and the amphiphilic diblock copolymer polystyrene-block-polyethylene oxide as a templating tool. As compared to a reference sample without post-treatment, enhanced surface-to-volume ratios are achieved through post-treatment with a poor-good azeotrope solvent mixture. High capacities of over 2000 mA h g\textendash1 are obtained with good stability over 300 cycles. Information from morphological and compositional characterization for both reference and post-treated sample suggests that the good electrochemical performance originates from reversible GeO2 conversion reactions.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Electrical control of single-photon emission in highly charged individual colloidal quantum dots},

author = {S Morozov and E L Pensa and A H Khan and A Polovitsyn and E Cort\'{e}s and S A Maier and S Vezzoli and I Moreels and R Sapienza},

url = {https://pubmed.ncbi.nlm.nih.gov/32948584/},

doi = {10.1126/sciadv.abb1821},

issn = {2375-2548},

year  = {2020},

date = {2020-09-18},

urldate = {2020-09-18},

journal = {Sci Adv},

volume = {6},

number = {38},

abstract = {Electron transfer to an individual quantum dot promotes the formation of charged excitons with enhanced recombination pathways and reduced lifetimes. Excitons with only one or two extra charges have been observed and exploited for very efficient lasing or single-quantum dot light-emitting diodes. Here, by room-temperature time-resolved experiments on individual giant-shell CdSe/CdS quantum dots, we show the electrochemical formation of highly charged excitons containing more than 12 electrons and 1 hole. We report the control over intensity blinking, along with a deterministic manipulation of quantum dot photodynamics, with an observed 210-fold increase in the decay rate, accompanied by 12-fold decrease in the emission intensity, while preserving single-photon emission characteristics. These results pave the way for deterministic control over the charge state, and room-temperature decay rate engineering for colloidal quantum dot-based classical and quantum communication technologies.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {In situ Grazing-Incidence Small-Angle X-ray Scattering Observation of Gold Sputter Deposition on a PbS Quantum Dot Solid},

author = {W Chen and S Liang and F C L\"{o}hrer and S J Schaper and N Li and W Cao and L P Kreuzer and H Liu and H Tang and V K\"{o}rstgens and M Schwartzkopf and K Wang and X W Sun and S V Roth and P M\"{u}ller-Buschbaum},

url = {https://doi.org/10.1021/acsami.0c12732},

doi = {10.1021/acsami.0c12732},

issn = {1944-8244},

year  = {2020},

date = {2020-09-17},

urldate = {2020-09-17},

journal = {ACS Applied Materials \& Interfaces},

volume = {12},

number = {41},

pages = {46942-46952},

abstract = {For PbS quantum dot (QD)-based optoelectronic devices, gold is the most frequently used electrode material. In most device architectures, gold is in direct contact with the QD solid. To better understand the formation of the interface between gold and a close-packed QD layer at an early stage, in situ grazing-incidence small-angle X-ray scattering is used to observe the gold sputter deposition on a 1,2-ethanedithiol (EDT)-treated PbS QD solid. In the kinetics of gold layer growth, the forming and merging of small gold clusters (radius less than 1.6 nm) are observed at the early stages. The thereby formed medium gold clusters (radius between 1.9\textendash2.4 nm) are influenced by the QDs’ templating effect. Furthermore, simulations suggest that the medium gold clusters grow preferably along the QDs’ boundaries rather than as a top coating of the QDs. When the thickness of the sputtered gold layer reaches 6.25 nm, larger gold clusters with a radius of 5.3 nm form. Simultaneously, a percolation layer with a thickness of 2.5 nm is established underneath the gold clusters. This fundamental understanding of the QD\textendashgold interface formation will help to control the implementation of sputtered gold electrodes on close-packed QD solids in device manufacturing processes.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Perovskite and Organic Solar Cells on a Rocket Flight},

author = {L K Reb and M B\"{o}hmer and B Predeschly and S Grott and C L Weindl and G I Ivandekic and R Guo and C Drei\ssigacker and R Gernh\"{a}user and A Meyer and P M\"{u}ller-Buschbaum},

url = {https://www.sciencedirect.com/science/article/pii/S2542435120303226},

doi = {https://doi.org/10.1016/j.joule.2020.07.004},

issn = {2542-4351},

year  = {2020},

date = {2020-09-16},

urldate = {2020-09-16},

journal = {Joule},

volume = {4},

number = {9},

pages = {1880-1892},

abstract = {Summary Perovskite and organic solar cells possess a revolutionary potential for space applications. The thin-film solar cells can be processed onto thin polymer foils that enable an exceptional specific power, i.e., obtainable electric power per mass, being superior to their inorganic counterparts. However, research toward space applications was mainly restricted to terrestrial conditions so far. Here, we report the launch of perovskite and organic solar cells of different architectures on a suborbital rocket flight. This is an in situ demonstration of their functionality and power generation under space conditions. We measured solar cell current-voltage characteristics in variable illumination states due to different rocket orientations during flight. Under strong solar irradiance, the solar cells perform efficiently, and they even produce power with weak diffuse light reflected from Earth’s surface. These results highlight both the suitability for near-Earth applications as well as the potential for deep-space missions for these innovative technologies.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Direct Detection of Optical Forces of Magnetic Nature in Dielectric Nanoantennas},

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

url = {https://doi.org/10.1021/acs.nanolett.0c03157},

doi = {10.1021/acs.nanolett.0c03157},

issn = {1530-6984},

year  = {2020},

date = {2020-09-16},

urldate = {2020-09-16},

journal = {Nano Letters},

volume = {20},

number = {10},

pages = {7627-7634},

abstract = {Optical forces on nanostructures are usually characterized by their interaction with the electric field component of the light wave, given that most materials present negligible magnetic response at optical frequencies. This is not the case however of a high-refractive-index dielectric nanoantenna, which has been recently shown to efficiently support both electric and magnetic optical modes. In this work, we use a photoinduced force microscopy configuration to measure optically induced forces produced by a germanium nanoantenna on a surrounding silicon near-field probe. We reveal the spatial distribution, character, and magnitude of the generated forces when exciting the nanoantenna at its anapole state condition. We retrieve optical force maps showing values of up to 20 pN, which are found to be mainly magnetic in nature, according to our numerical simulations. The results of this investigation open new pathways for the study, detection, and generation of magnetic light forces at the nanometer scale.},

keywords = {Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Stepping Out of Equilibrium: The Quest for Understanding the Role of Non-Equilibrium (Thermo-)Dynamics in Electronic and Electrochemical Processes},

author = {W Kaiser and A Gagliardi},

url = {https://www.mdpi.com/1099-4300/22/9/1013},

issn = {1099-4300},

year  = {2020},

date = {2020-09-10},

journal = {Entropy},

volume = {22},

number = {9},

pages = {1013},

abstract = {This editorial aims to interest researchers and inspire novel research on the topic of non-equilibrium Thermodynamics and Monte Carlo for Electronic and Electrochemical Processes. We present a brief outline on recent progress and challenges in the study of non-equilibrium dynamics and thermodynamics using numerical Monte Carlo simulations. The aim of this special issue is to collect recent advances and novel techniques of Monte Carlo methods to study non-equilibrium electronic and electrochemical processes at the nanoscale.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Nickel clusters on TiO2(110): thermal chemistry and photocatalytic hydrogen evolution of methanol},

author = {M Eder and C Courtois and T Kratky and S G\"{u}nther and M Tschurl and U Heiz},

url = {http://dx.doi.org/10.1039/D0CY01465F},

doi = {10.1039/D0CY01465F},

issn = {2044-4753},

year  = {2020},

date = {2020-09-09},

journal = {Catalysis Science \& Technology},

volume = {10},

number = {22},

pages = {7630-7639},

abstract = {In heterogeneous photocatalysis, noble metals such as Au, Pt, or Pd are most commonly used as co-catalysts to facilitate H2 evolution, yet their costs are problematic for applications on a large scale. In this work, we show that the cheaper, more abundant transition metal nickel as co-catalyst material reacts accordingly, when being deposited as small clusters onto rutile TiO2. Different to noble metal systems the photocatalysts undergo photocorrosion, depicted in a declining activity during the photoreforming of methanol. The reaction being performed in an ultra-high vacuum environment allows for a more detailed elucidation of the deactivation processes. Supported by reactivity studies under different conditions, Auger electron spectroscopy reveals that coking of the clusters occurs, while nickel oxide formation is not observed. The study thus shows that nickel co-catalysts are indeed prospective systems for the photocatalytic hydrogen evolution reaction, similar to platinum clusters, but instead may also feature unexpected photon-driven deactivation pathways.},

keywords = {Foundry Inorganic, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}