Iron as a Sulfidation-Resistant Current Collector for Negative Electrode in Sulfide-Based All-Solid-Batteries.

The demand for all-solid-state batteries (ASSBs) featuring credible LiPSCl argyrodite (LPSCl) electrolytes is increasing, driving interest in exploring suitable current collectors for ASSBs. Copper (Cu), used as a current collector in traditional lithium-ion batteries, exhibits significant instability in LPSCl-ASSBs. In this study, the effectiveness of iron (Fe) is systematically investigated as an alternative current collector in LPSCl-ASSBs and compare its performance to that of Cu.

Band Alignment Transition and Enhanced Performance in Vertical SnS/MoS van der Waals Photodetectors.

The strong light-matter interaction and naturally passivated surfaces of van der Waals materials make heterojunctions of such materials ideal candidates for high-performance photodetectors. In this study, we fabricated SnS/MoS van der Waals heterojunctions and investigated their photoelectric properties. Using an applied gate voltage, we can effectively alter the band arrangement and achieve a transition in type II and type I junctions.

Enhanced NO Sensitivity of Vertically Stacked van der Waals Heterostructure Gas Sensor and Its Remarkable Electric and Mechanical Tunability.

Nanodevices based on van der Waals heterostructures have been predicted, and shown, to have unprecedented operational principles and functionalities that hold promise for highly sensitive and selective gas sensors with rapid response times and minimal power consumption. In this study, we fabricated gas sensors based on vertical MoS/WS van der Waals heterostructures and investigated their gas sensing capabilities. Compared with individual MoS or WS gas sensors, the MoS/WS van der Waals heterostructure gas sensors are shown to have enhanced sensitivity, faster response times, rapid recovery, and a notable selectivity, especially toward NO.

Miniaturized spectrometer with intrinsic long-term image memory.

Miniaturized spectrometers have great potential for use in portable optoelectronics and wearable sensors. However, current strategies for miniaturization rely on von Neumann architectures, which separate the spectral sensing, storage, and processing modules spatially, resulting in high energy consumption and limited processing speeds due to the storage-wall problem. Here, we present a miniaturized spectrometer that utilizes a single SnS/ReSe van der Waals heterostructure, providing photodetection, spectrum reconstruction, spectral imaging, long-term image memory, and signal processing capabilities.

Slab gliding, a hidden factor that induces irreversibility and redox asymmetry of lithium-rich layered oxide cathodes.

Lithium-rich layered oxides, despite their potential as high-energy-density cathode materials, are impeded by electrochemical performance deterioration upon anionic redox. Although this deterioration is believed to primarily result from structural disordering, our understanding of how it is triggered and/or occurs remains incomplete. Herein, we propose a theoretical picture that clarifies the irreversible transformation and redox asymmetry of lithium-rich layered oxides by introducing a series of global and local dynamic structural evolution processes involving slab gliding and transition-metal migration.

Field Effect Transistor Gas Sensors Based on Mechanically Exfoliated Van der Waals Materials.

The high surface-to-volume ratio and flatness of mechanically exfoliated van der Waals (vdW) layered materials make them an ideal platform to investigate the Langmuir absorption model. In this work, we fabricated field effect transistor gas sensors, based on a variety of mechanically exfoliated vdW materials, and investigated their electrical field-dependent gas sensing properties. The good agreement between the experimentally extracted intrinsic parameters, such as equilibrium constant and adsorption energy, and theoretically predicted values suggests validity of the Langmuir absorption model for vdW materials.

Growth, structure, phase transition, thermal properties, and structural dynamics of organic-inorganic hybrid [NH(CH)NH]ZnCl crystal.

In this study, the physicochemical properties of [NH(CH)NH]ZnCl crystals were investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis, and nuclear magnetic resonance (NMR). The crystals at 300 K had a monoclinic structure with C2/c space group and lattice constants are a = 21.4175 Å, b = 7.

Light-Tunable Polarity and Erasable Physisorption-Induced Memory Effect in Vertically Stacked InSe/SnS Self-Powered Photodetector.

van der Waals heterojunctions with tunable polarity are being actively explored for more Moore and more-than-Moore device applications, as they can greatly simplify circuit design. However, inadequate control over the multifunctional operational states is still a challenge in their development. Here, we show that a vertically stacked InSe/SnS van der Waals heterojunction exhibits type-II band alignment, and its polarity can be tuned by an external electric field and by the wavelength and intensity of an illuminated light source.

Imbibition-induced selective wetting of liquid metal.

Herein, we present the imbibition-induced, spontaneous, and selective wetting characteristics of gallium-based liquid metal alloys on a metallized surface with micro-scale topographical features. Gallium-based liquid metal alloys are fascinating materials that have enormous surface tension; therefore, they are difficult to pattern into films. The complete wetting of eutectic alloy of gallium and indium is realized on microstructured copper surfaces in the presence of HCl vapor, which removes the native oxide from the liquid metal alloy.

Grain Growth Behavior and Electrical Properties of 0.96(KNa)NbSbO-0.04Bi(NaK)ZrO Ceramics.

This study investigated the causes of microstructural changes and the resultant electrical properties according to the sintering temperature of 0.96(KNa)NbSbO-0.04Bi(NaK)ZrO lead-free ceramics by analyzing the correlation between vacancy concentrations and 2D nucleation.

Efficient Suppression of Charge Recombination in Self-Powered Photodetectors with Band-Aligned Transferred van der Waals Metal Electrodes.

Recombination of photogenerated electron-hole pairs dominates the photocarrier lifetime and then influences the performance of photodetectors and solar cells. In this work, we report the design and fabrication of band-aligned van der Waals-contacted photodetectors with atomically sharp and flat metal-semiconductor interfaces through transferred metal integration. A unity factor α is achieved, which is essentially independent of the wavelength of the light, from ultraviolet to near-infrared, indicating effective suppression of charge recombination by the device.

Abnormally High-Lithium Storage in Pure Crystalline C Nanoparticles.

Li intercalates into a pure face-centered-cubic (fcc) C structure instead of being adsorbed on a single C molecule. This hinders the excess storage of Li ions in Li-ion batteries, thereby limiting their applications. However, the associated electrochemical processes and mechanisms have not been investigated owing to the low electrochemical reactivity and poor crystallinity of the C powder.

Nanoporous Silver Telluride for Active Hydrogen Evolution.

Silver-based nanomaterials have been versatile building blocks of various photoassisted energy applications; however, they have demonstrated poor electrochemical catalytic performance and stability, in particular, in acidic environments. Here we report a stable and high-performance electrochemical catalyst of silver telluride (AgTe) for the hydrogen evolution reaction (HER), which was synthesized with a nanoporous structure by an electrochemical synthesis method. X-ray spectroscopy techniques on the nanometer scale and high-resolution transmission electron microscopy revealed an orthorhombic structure of nanoporous AgTe with precise lattice constants.

Phase Transition-Induced Temperature-Dependent Phonon Shifts in Molybdenum Disulfide Monolayers Interfaced with a Vanadium Dioxide Film.

We report the optical phonon shifts induced by phase transition effects of vanadium dioxide (VO) in monolayer molybdenum disulfide (MoS) when interfacing with a VO film showing a metal-insulator transition coupled with structural phase transition (SPT). To this end, the monolayer MoS directly synthesized on a SiO/Si substrate by chemical vapor deposition was first transferred onto a VO/c-AlO substrate in which the VO film was prepared by a sputtering method. We compared the MoS interfaced with the VO film with the as-synthesized MoS by using Raman spectroscopy.

Mitrofanovite, Layered Platinum Telluride, for Active Hydrogen Evolution.

Two-dimensional (2D) layered catalysts have been considered as a class of ideal catalysts for hydrogen evolution reaction (HER) because of their abundant active sites with almost zero Gibbs energy change for hydrogen adsorption. Despite the promising performance, the design of stable and economic electrochemical catalyst based on 2D materials remains to be resolved for industrial-scale hydrogen production. Here, we report layered platinum tellurides, mitrofanovite PtTe, which serves as an efficient and stable catalyst for HER with an overpotential of 39.

High Magnetic Field Sensitivity in Ferromagnetic-Ferroelectric Composite with High Mechanical Quality Factor.

In this study, composite devices were fabricated using ferromagnetic FeSiB-based alloys (Metglas) and ferroelectric ceramics, and their magnetic field sensitivity was evaluated. Sintered 0.95Pb(ZrTi)O-0.

Dielectrophoretic Manipulation of Janus Particle in Conductive Media for Biomedical Applications.

Janus particles are applied to many fields including biomedical applications. To expand the usability of Janus particles, a technique to manipulate the particle movement is required. A dielectrophoresis (DEP) method can be a promising candidate; however, independent manipulation or separation of Janus particle by DEP is still challenging.

Charge density waves and degenerate modes in exfoliated monolayer 2H-TaS.

Charge density waves spontaneously breaking lattice symmetry through periodic lattice distortion, and electron-electron and electron-phonon inter-actions, can lead to a new type of electronic band structure. Bulk 2H-TaS is an archetypal transition metal dichalcogenide supporting charge density waves with a phase transition at 75 K. Here, it is shown that charge density waves can exist in exfoliated monolayer 2H-TaS and the transition temperature can reach 140 K, which is much higher than that in the bulk.

Strategy to control magnetic coercivity by elucidating crystallization pathway-dependent microstructural evolution of magnetite mesocrystals.

Mesocrystals are assemblies of smaller crystallites and have attracted attention because of their nonclassical crystallization pathway and emerging collective functionalities. Understanding the mesocrystal crystallization mechanism in chemical routes is essential for precise control of size and microstructure, which influence the function of mesocrystals. However, microstructure evolution from the nucleus stage through various crystallization pathways remains unclear.

Sub-millimeter size high mobility single crystal MoSe monolayers synthesized by NaCl-assisted chemical vapor deposition.

Monolayer MoSe is a transition metal dichalcogenide with a narrow bandgap, high optical absorbance and large spin-splitting energy, giving it great promise for applications in the field of optoelectronics. Producing monolayer MoSe films in a reliable and scalable manner is still a challenging task as conventional chemical vapor deposition (CVD) or exfoliation based techniques are limited due to the small domains/nanosheet sizes obtained. Here, based on NaCl assisted CVD, we demonstrate the simple and stable synthesis of sub-millimeter size single-crystal MoSe monolayers with mobilities ranging from 38 to 8 cm V s.

Realizing Vibrant and High-Contrast Reflective Structural Colors from Lossy Metals Supporting Dielectric Gratings.

Despite their distinctive chemical properties, lossy metals are generally avoided in the design of structural colors because the optical losses can degrade the color vibrancy. Herein, we demonstrate a strategy that allows lossy metals supporting near-wavelength dielectric gratings to achieve high color vibrancy by benefiting from the optical loss rather than suffering from it. By exciting the grating rotated 45° relative to the incident field, s-polarized (s-pol) and p-polarized (p-pol) light each excites a spectrally distinct resonance, described by a treatment of coupled waveguide-array modes, that retards the phase over the wavelength.

Long-term observation of Magnetospirillum gryphiswaldense in a microfluidic channel.

We controlled and observed individual magneto-tactic bacteria (Magnetospirillum gryphiswaldense) inside a [Formula: see text]-high microfluidic channel for over 4 h. After a period of constant velocity, the duration of which varied between bacteria, all observed bacteria showed a gradual decrease in their velocity of about [Formula: see text]. After coming to a full stop, different behaviour was observed, ranging from rotation around the centre of mass synchronous with the direction of the external magnetic field, to being completely immobile.

Strategy for Fabricating Wafer-Scale Platinum Disulfide.

PtS is a newly developed group 10 2D layered material with high carrier mobility, wide band gap tunability, strongly bound excitons, symmetrical metallic and magnetic edge states, and ambient stability, making it attractive in nanoelectronic, optoelectronic, and spintronic fields. To the aim of application, a large-scale synthesis is necessary. For transition-metal dichalcogenide (TMD) compounds, a thermally assisted conversion method has been widely used to fabricate wafer-scale thin films.

Photo-enhanced gas sensing of SnS with nanoscale defects.

Recently a SnS based NO gas sensor with a 30 ppb detection limit was demonstrated but this required high operation temperatures. Concurrently, SnS grown by chemical vapor deposition is known to naturally contain nanoscale defects, which could be exploited. Here, we significantly enhance the performance of a NO gas sensor based on SnS with nanoscale defects by photon illumination, and a detection limit of 2.