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Hydrogen-Bonded Organic Framework Enables Phase-Pure Layered Tin Perovskite Nanowires for Room-Temperature Lasing

Anisotropic diffusion of hydrogen dopants in crystalline InAlZnO

Hydrogen incorporation strongly affects carrier density and reliability in oxide semiconductors, yet its behavior in the crystalline indium–aluminum–zinc oxide has not been fully established. Using first-principles calculations, stable hydrogen incorporation sites and their migration characteristics were systematically examined. Hydrogen preferentially occupies oxygen atoms coordinated by three zinc atoms, which remain stable against dissociation with barriers exceeding 0.5 eV. In contrast to the crystalline indium–gallium–zinc oxide, where gallium and zinc readily intermix, the crystalline indium–aluminum–zinc oxide contains a distinct planar aluminum–oxygen layer that acts as a vertical diffusion barrier. Penetration across this dense hexagonal layer requires hydroxyl rotation rather than conventional dissociation–migration, leading to substantially higher activation energies. The combination of site selectivity and anisotropic migration enables confinement of hydrogen dopants within a sub-unit cell thickness, providing a pathway to localized conductivity enhancement while maintaining the wide bandgap and low carrier density of the bulk material.

Computational Elucidation of the Mechanism by which a Pericyclase Controls Periselectivity in the Biosynthesis of Natural Product (−)-PF-1018

Optical conductivity and tunable linear dichroism of surface states in strained three-dimensional topological insulators

We theoretically investigate the influence of anisotropic shear strain on the optical conductivity and linear dichroism of surface states in three-dimensional topological insulators. By employing an effective two-band Hamiltonian that incorporates strain-induced modifications, we demonstrate that the applied strain significantly deforms the Dirac cone, leading to pronounced anisotropy in the Fermi velocities and optical conductivities. The resulting linear dichroism is shown to be highly tunable with the magnitude and direction of strain, notably enabling reversible control through dichroism sign inversion. Polar plots of angle-resolved optical conductivity clearly reveal the selective enhancement or suppression of polarized light absorption along specific crystallographic orientations for various strain configurations. These findings suggest the potential for mechanical modulation of polarization-sensitive absorption in three-dimensional topological insulators.

Coexistence of Ohmic Contact and Fermi Level Pinning at 2D Electride/2D Semiconductor Interfaces

Magneto-mechanical–thermal coupling regulation of Weyl surface state topological transport in three-dimensional magnetoelastic phononic crystals

Weyl phononic crystals (PCs), as a key platform for topological states, feature doubly degenerate Weyl points of band structures in three-dimensional (3D) space. Their investigation has expanded from electronic systems to classical waves, including electromagnetic, acoustic, and elastic waves, and has drawn extensive attention. However, elastic wave systems are limited by fixed structures, making the active modulation of topological surface states challenging. To overcome these limitations, we design a tunable 3D Weyl magnetoelastic PC composed of magnetostrictive materials integrated with an elastic substrate. Based on the magneto-mechanical–thermal coupled constitutive relation of magnetostrictive materials, we have achieved the spatial inversion symmetry breaking under the collaborative regulation of magnetic and thermal fields, and observed the elastic wave Weyl points and their frequency-tunable characteristics. We further examine the robust transport of Weyl surface states under waveguide and defect conditions, as well as layer-selective transmission achieved through boundary condition design. This work provides a new route for dynamic regulation of elastic wave topological transport and offers significant potential for the development of customizable topological devices.

Oxo Ligand Insertion into Fe–C Bonds as a Platform for Oxygen Atom Insertion Catalysis

Effect of stoichiometry on thermodynamic and thermal transport properties of entropy-stabilized oxide MgCoNiCuZnO5

Lattice distortion in a crystal can have a strong effect on its thermal transport properties. Herein, using a neuroevolution machine learning potential and molecular dynamics simulations, we demonstrate that the lattice thermal conductivity of MgCoNiCuZnO5 (J14) decreases from κ≃2.60±0.20 W m−1 K−1 at 300 K to κ≃2.07±0.05 W m−1 K−1 at 900 K, consistent with experimental findings. Our simulations indicate that the reduction in lattice thermal conductivity as a function of temperature in J14 is due to a decreased mean free path of propagons. Next, we investigated the bounds on κ when reducing or increasing distortions. This is done by varying stoichiometry to make atomic size distribution of transition metal elements more or less uniform: the composition of zinc and nickel in J14 was varied by 30% to make atomic sizes more and less uniform, respectively. While adding more Zn increases distortions, adding Ni reduces it. As a result, we find that the related changes in the thermal conductivity with 30% more zinc (Mg0.2Co0.2Ni0.14Cu0.2Zn0.26O) and 30% more nickel (Mg0.2Co0.2Ni0.26Cu0.2Zn0.14O) are, respectively, 2.54±0.20 and 2.77±0.20 W m−1 K−1 at room temperature. This shows that there is indeed a correlation between the amount of distortions and the thermal conductivity in these compounds. We see larger mean free paths (MFPs) in the less distorted (30% Ni) compound, while MFPs in the more distorted compound are shorter. The MFPs are associated with phonon-like vibrational modes (also called propagons). These results imply that the propagons are mostly responsible for the changes in thermal conductivity. This is supported by the slight decrease in the thermal conductivity with temperature, implying the important contribution of propagons in thermal transport in these distorted high-entropy materials. The neuroevolution machine learning interatomic potential implemented in Graphics Processing Unit Molecular Dynamics is a reliable tool to investigate thermal transport in disordered systems beyond the perturbative approach.

Tandem Photocatalytic CO ₂ -to-C ₂ H ₄ Conversion through an Intracellularly Interfaced Quantum Dot-Molecular Catalyst-Bacteria Biohybrid

Poole–Frenkel emission and bulk charge trapping in AlON deposited on GaN and comparison to Al2O3

The leakage conduction mechanisms in AlON dielectric deposited on GaN are identified and compared to the findings for Al2O3. Poole–Frenkel emission from similar trap energy levels was identified in both atomic layer deposited AlON and Al2O3¸ despite at different electric field ranges, while Fowler–Nordheim tunneling dominated the leakage current characteristics for Al2O3 at average electric field values. It is concluded that the differences observed in the leakage characteristics for these dielectrics are likely a result of the slightly larger conduction band offset between AlON and GaN. The identification of the same trap state energy level responsible for Poole–Frenkel emission in AlON and Al2O3 means that this trap state does not originate from the presence of nitrogen in the dielectric and is related to AlOx compounds and the deposition method. Bulk charge trapping is shown to play a major role in the leakage characteristics of AlON from average to high electric fields, which shifts the transfer characteristics from a certain electric field onward and causes hysteresis. These results provide valuable insights into the development of insulated gate architectures on GaN using the promising dielectric material AlON as the gate oxide.

Efficient Surface to Bulk Catalysis in the Reverse Water–Gas Shift Reaction by the FeO _<i>x</i> /Fe ₃ C Catalyst

Investigation of transverse magnetotransport in the diluted magnetic semiconductor Hg1−xFexTe

In the diluted magnetic semiconductor Hg1−xFexTe with a low iron content (x ≤ 0.3 at. %), the Hall effect and transverse magnetoresistance were investigated over the temperature range of (1.8–150) K in magnetic fields up to 13 T. At low temperatures, p-type conductivity was observed, resulting from a resonant acceptor state located ≈7.5 meV below valence band maximum. It was found that the magnetic field dependence of the transverse magnetoresistance exhibits features indicative of the formation of an energy gap at the center of the Brillouin zone, induced by the p–d-exchange interaction between impurity holes and the magnetic moments localized on the iron ions. Estimates were made for the effective exchange interaction integral and the exchange gap in a Hg1−xFexTe sample with maximum iron content. Our findings provide support for the occurrence of hole spin polarization in Hg1−xFexTe.

Partial Desolvation Causes Lithium Structural Transport in Liquid and Gel Polymer Electrolytes

Liquid movement driven by surface charge accumulation and Debye length dependence via experimental validation

This study focuses on the driving mechanism of the plasma-induced liquid flow (PILF) in electrolyte solutions. The examination was conducted by means of systematic analysis for the liquid flow induced in KCl solutions with a concentration ranging from 10−5 to 100 mol/l by a pin-to-liquid DBD reactor. Through a series of experimental examinations, we systematically verified and excluded the contributions of thermal effects, ionic wind, and the applied electric field. We found that a maximum temperature rise of only 8 °C corresponded to a negligible change in liquid properties, and the specific flow pattern cannot be repeated by the impingement of helium. These findings confirm that the occurrence of plasma discharge is the key factor for initiating the liquid flow. These findings lead to the proposal of a driving mechanism, which is a surface tension gradient caused by charge accumulation and the disruption of hydrogen bond network. As the range of electrical effect for charged particles depends on the Debye length of the electrolyte solution and decreases with electrolyte concentration, a negative dependency between the PILF velocity and the electrolyte concentration was anticipated and confirmed (e.g., 7.36 mm/s for the case of [KCl] = 10−5 mol/l vs 0.62 mm/s for [KCl] = 100 mol/l). Additionally, as this mechanism relies on the existence of hydrogen bonds, a negligible flow was predicted in non-polar liquids. This prediction was experimentally validated in the experiment using non-polar and low-viscosity silicone oil.

Enantioselective Total Synthesis of (+)-Fusicoccadiene via Photocatalytic Polyene Isomerization

On the importance of Ni–Au–Ga interdiffusion in the formation of a Ni–Au/p-GaN ohmic contact

High-resolution transmission electron microscopy (TEM) coupled to energy dispersive X-ray spectroscopy (EDX) is used to clarify the exact role of Ni–Au–Ga interdiffusion mechanisms taking place during rapid thermal annealing under an oxygen atmosphere of a Ni–Au/p-GaN contact. It is shown that oxygen-assisted, Ni diffusion to the top surface of the metallic contact through the formation of a nickel oxide (NiOx) is accompanied by Au diffusion down to the GaN surface and by Ga out-diffusion through the GaN/metal interface. Electrical characterizations of the contact by a transmission line method show that an ohmic contact is obtained as soon as a thin, Au–Ga interfacial layer is formed, even after complete diffusion of Ni or NiOx to the top surface of the contact. Our results clarify that the presence of Ni or NiOx at the interface is not the main origin of the ohmic-like behavior in such contacts. Auto-cleaning of the interface during the interdiffusion process may play a role, but TEM-EDX analysis evidences that the creation of Ga vacancies associated with the formation of a Ga–Au interfacial layer is crucial for reducing the Schottky barrier height and maximizing the amount of current flowing through the contact.

Ligand-Relay Strategy Enabling Copper-Catalyzed C–C/C–O/C–N Cascade Trifunctionalization of Internal Alkynes and Propargylic Sites: Synthesis of Benzofuran-β-Lactams

Effect of superlattice period length on thermoelectric performance: A case study of monolayer CrS2, CrSe2, and CrS2/CrSe2 lateral superlattice

Two-dimensional (2D) lateral superlattice is a promising route to tailor thermoelectric properties, yet the impact of superlattice period length on the modulation of phonon and electronic transport remains insufficiently characterized. Using a monolayer CrS2/CrSe2 superlattice as a model system, we combine density-functional theory with a machine-learning potential to quantify the period-dependent thermoelectric properties. Due to the reduced phonon group velocities and shortened phonon lifetimes, our calculation results reveal that the room-temperature lattice thermal conductivity (κp) of short-period superlattice (SS) and long-period superlattice (LS) structures along the modulation direction is reduced by 71.3% and 82.9%, respectively, compared with that of the pristine CrS2. Moreover, the interface-induced charge redistribution in LS disrupts electronic transport continuity, suppressing electrical conductivity (σ). By contrast, SS retains more extended charge states while maintaining σ with reduced κp. As a result, the ZT value of SS (∼0.39) is higher than that of LS (∼0.21) at 600 K, despite LS having a lower κp. This work emphasizes the importance of co-optimizing phonon and electronic transport in superlattice structures by tuning the superlattice period, providing engineering strategies for designing 2D superlattice thermoelectric materials.

Machine Learning-Guided Discovery of Sterically Protected High Triplet Exciplex Hosts for Ultra-Bright Green OLEDs

Commonalities in gene expression and methylation changes across two rat models of acquired epilepsy