Dimensionality-Induced Transition from Degenerate to Nondegenerate States in Nb-Doped WSe.

Substitutional doping in transition-metal dichalcogenides (TMDCs) is a pivotal strategy for tuning their electronic and optical properties, enabling their integration into next-generation electronic and optoelectronic devices. This study examines the critical doping levels at which doped TMDCs transition from nondegenerate to degenerate semiconductors, comparing three-dimensional (3D) bulk TMDCs with their two-dimensional (2D) counterparts. Through systematic characterization of Nb-doped WSe, we demonstrate that, although high Nb-doped WSe bulk samples (Nb density: 3.

Visualization of sucrose distribution biosynthesized in vitro from external [1-C]sorbitol in apple (Malus domestica) fruit utilizing MALDI-TOF MSI.

To clarify the cause of graded distribution of sucrose in apple fruit flesh, a quarter cut of young apple fruit was cultured for 72 h on agar-solidified MS medium supplemented with 0.5 M [1-C]sorbitol, with the longitudinal or horizontal cut face being attached with the medium, and distribution of C-labelled sucrose in a specimen obtained by slicing the fruit along with the cut face was visualized utilizing MALDI-TOF MSI. Heat map images on the distribution of the peaks of sorbitol containing C-atom indicated that external [1-C]sorbitol had penetrated evenly into the tissue.

Polysaccharides from a Fermented Beverage Induce Nitric Oxide and Cytokines in Murine Macrophage Cell Line.

Super Ohtaka, a fermented beverage of plant extracts, is prepared from approximately 50 kinds of fruits and vegetables. Natural fermentation is mainly performed by lactic acid bacteria ( spp.) and yeast ( spp.

Reactions of (mesityl)(methyl)silylene complexes with pyridine--oxide ( = 1 and 0): formation of silanone complexes and a disiloxanyloxy complex.

Silanones (OSiR), a heavier congener of ketones (RCO), are highly reactive species that are readily converted to oligomeric siloxane (O-SiR). Coordination of silanones to the transition-metal fragments to afford silanone-coordinated complexes is a reliable silanone stabilization method. Recently, our group reported the synthesis, structures, and reactivity of dimesityl-substituted silanone complexes Cp*(OC)M{OSiMes(L)}(SiMe) (M = W, Mo, L: Lewis base, Cp*: η-CMe, Mes: 2,4,6-MeCH).

Single-Gate MoS Tunnel FET with a Thickness-Modulated Homojunction.

Two-dimensional (2D) materials stand as a promising platform for tunnel field-effect transistors (TFETs) in the pursuit of low-power electronics for the Internet of Things era. This promise arises from their dangling bond-free van der Waals heterointerface. Nevertheless, the attainment of high device performance is markedly impeded by the requirement of precise control over the 2D assembly with multiple stacks of different layers.

p-Type Conversion of WS and WSe by Position-Selective Oxidation Doping and Its Application in Top Gate Transistors.

For the complementary operation of two-dimensional (2D) material-based field-effect transistors (FETs), high-performance p-type FETs are essential. In this study, we applied surface charge-transfer doping from WO, which has a large work function of ∼6.5 eV, selectively to the access region of WS and WSe by covering the channel region with -BN.

Fermi Pressure and Coulomb Repulsion Driven Rapid Hot Plasma Expansion in a van der Waals Heterostructure.

Transition metal dichalcogenide heterostructures provide a versatile platform to explore electronic and excitonic phases. As the excitation density exceeds the critical Mott density, interlayer excitons are ionized into an electron-hole plasma phase. The transport of the highly non-equilibrium plasma is relevant for high-power optoelectronic devices but has not been carefully investigated previously.

Multilayer In-Plane Heterostructures Based on Transition Metal Dichalcogenides for Advanced Electronics.

In-plane heterostructures of transition metal dichalcogenides (TMDCs) have attracted much attention for high-performance electronic and optoelectronic devices. To date, mainly monolayer-based in-plane heterostructures have been prepared by chemical vapor deposition (CVD), and their optical and electrical properties have been investigated. However, the low dielectric properties of monolayers prevent the generation of high concentrations of thermally excited carriers from doped impurities.

Synthesis and structure of a pyridine-stabilized silanone molybdenum complex and its reactions with PMe and acetone.

Silanones (OSiR) are highly reactive species that readily convert to oligomeric siloxane (O-SiR). The coordination of silanones to transition metal fragments to afford silanone-coordinated complexes is a reliable silanone stabilization method. Herein, a pyridine-stabilized silanone molybdenum complex Cp*(OC)Mo{OSiMes(py)}(SiMe) (2b, Cp*: η-CMe, Mes: 2,4,6-MeCH, and py: pyridine) was synthesized by reacting the silyl(silylene) complex Cp*(OC)Mo(SiMes)(SiMe) (4b) with pyridine--oxide in pyridine.

Emergence of Interlayer Coherence in Twist-Controlled Graphene Double Layers.

We report enhanced interlayer tunneling with reduced linewidth at zero interlayer bias in a twist-controlled double monolayer graphene heterostructure in the quantum Hall regime, when the top (ν_{T}) and bottom (ν_{B}) layer filling factors are near ν_{T}=±1/2,±3/2 and ν_{B}=±1/2,±3/2, and the total filling factor ν=±1 or ±3. The zero-bias interlayer conductance peaks are stable against variations of layer filling factor, and signal the emergence of interlayer phase coherence. Our results highlight twist control as a key attribute in revealing interlayer coherence using tunneling.

Diffused Beam Energy to Dope van der Waals Electronics and Boost Their Contact Barrier Lowering.

Contact engineering of two-dimensional semiconductors is a central issue for performance improvement of micro-/nanodevices based on these materials. Unfortunately, the various methods proposed to improve the Schottky barrier height normally require the use of high temperatures, chemical dopants, or complex processes. This work demonstrates that diffused electron beam energy (DEBE) treatment can simultaneously reduce the Schottky barrier height and enable the direct writing of electrical circuitry on van der Waals semiconductors.

Reversible Charge-Polarity Control for Multioperation-Mode Transistors Based on van der Waals Heterostructures.

Van der Waals (vdW) heterostructures-in which layered materials are purposely selected to assemble with each other-allow unusual properties and different phenomena to be combined and multifunctional electronics to be created, opening a new chapter for the spread of internet-of-things applications. Here, an O -ultrasensitive MoTe material and an O -insensitive SnS material are integrated to form a vdW heterostructure, allowing the realization of charge-polarity control for multioperation-mode transistors through a simple and effective rapid thermal annealing strategy under dry-air and vacuum conditions. The charge-polarity control (i.

Ultrafast Operation of 2D Heterostructured Nonvolatile Memory Devices Provided by the Strong Short-Time Dielectric Breakdown Strength of -BN.

Recently, the ultrafast operation (∼20 ns) of a two-dimensional (2D) heterostructured nonvolatile memory (NVM) device was demonstrated, attracting considerable attention. However, there is no consensus on its physical origin. In this study, various 2D NVM device structures are compared.

Functional characterization and vacuolar localization of fructan exohydrolase derived from onion (Allium cepa).

Fructans such as inulin and levan accumulate in certain taxonomic groups of plants and are a reserve carbohydrate alternative to starch. Onion (Allium cepa L.) is a typical plant species that accumulates fructans, and it synthesizes inulin-type and inulin neoseries-type fructans in the bulb.

C-O and C-C bond cleavage of α,β-unsaturated esters with the assistance of a gallane(pyridyl)iron complex.

Selective fragmentation of α,β-unsaturated esters into CC, CO, and OR fragments was investigated with the assistance of a gallane(pyridyl)iron complex Cp*(OC)Fe{(η-HGaMes)(η-2-CHN)} (1, Cp*: η-CMe, Mes: 2,4,6-MeCH). The reaction of 1 with methyl acrylate in CD afforded vinyliron complex Cp*(OC)Fe(CHCH) (2) and 4-membered GaO cyclic gallane [MesGaOMe] (3). The C-O and C-C bonds in -butyl acrylate were cleaved by the reaction with complex 1, producing complex 2 and pyridine-coordinated gallane Mes(-BuO)Ga(pyridine) (4).

Mist chemical vapor deposition of crystalline MoSatomic layer films using sequential mist supply mode and its application in field-effect transistors.

Molybdenum disulfide (MoS) mono/bilayer have been systematically investigated using atmospheric-pressure mist chemical vapor deposition (mist CVD) from (NH)MoSdissolved in N-methyl-2-pyrrolidone as a precursor. Film deposition was performed by alternating MoSmist storage within a closed chamber and mist exhaust, i.e.

Material and Device Structure Designs for 2D Memory Devices Based on the Floating Gate Voltage Trajectory.

Two-dimensional heterostructures have been extensively investigated as next-generation nonvolatile memory (NVM) devices. In the past decade, drastic performance improvements and further advanced functionalities have been demonstrated. However, this progress is not sufficiently supported by the understanding of their operations, obscuring the material and device structure design policy.

Twist Angle-Dependent Interlayer Exciton Lifetimes in van der Waals Heterostructures.

In van der Waals (vdW) heterostructures formed by stacking two monolayers of transition metal dichalcogenides, multiple exciton resonances with highly tunable properties are formed and subject to both vertical and lateral confinement. We investigate how a unique control knob, the twist angle between the two monolayers, can be used to control the exciton dynamics. We observe that the interlayer exciton lifetimes in MoSe_{2}/WSe_{2} twisted bilayers (TBLs) change by one order of magnitude when the twist angle is varied from 1° to 3.

Enhanced Exciton-Exciton Collisions in an Ultraflat Monolayer MoSe Prepared through Deterministic Flattening.

Squeezing bubbles and impurities out of interlayer spaces by applying force through a few-layer graphene capping layer leads to van der Waals heterostructures with the ultraflat structure free from random electrostatic potential arising from charged impurities. Without the graphene capping layer, a squeezing process with an AFM tip induces applied-force-dependent charges of Δ ∼ 2 × 10 cm μN, resulting in the significant intensity of trions in photoluminescence spectra of MoSe at low temperature. We found that a hBN/MoSe/hBN prepared with the "graphene-capping-assisted AFM nano-squeezing method" shows a strong excitonic emission with negligible trion peak, and the residual line width of the exciton peak is only 2.

All 2D Heterostructure Tunnel Field-Effect Transistors: Impact of Band Alignment and Heterointerface Quality.

Van der Waals heterostructures are the ideal material platform for tunnel field-effect transistors (TFETs) because a band-to-band tunneling (BTBT) dominant current is feasible at room temperature (RT) because of ideal, dangling bond-free heterointerfaces. However, achieving subthreshold swing (SS) values lower than 60 mV dec of the Boltzmann limit is still challenging. In this work, we systematically studied the band alignment and heterointerface quality in n-MoS channel heterostructure TFETs.

Decreased expression of fructosyltransferase genes in asparagus roots may contribute to efficient fructan degradation during asparagus spear harvesting.

Asparagus (Asparagus officinalis L.) accumulates inulin and inulin neoseries-type fructans in root, which are synthesized by three fructosyltransferases-sucrose:sucrose 1-fructosyltransferase (1-SST, EC 2.4.

Facile and Reversible Carrier-Type Manipulation of Layered MoTe Toward Long-Term Stable Electronics.

Flexible manipulation of the carrier transport behaviors in two-dimensional materials determines their values of practical application in logic circuits. Here, we demonstrated the carrier-type manipulation in field-effect transistors (FETs) containing α-phase molybdenum ditelluride (MoTe) by a rapid thermal annealing (RTA) process in dry air for hole-dominated and electron-beam (EB) treatment for electron-dominated FETs. EB treatment induced a distinct shift of the transfer curve by around 135 V compared with that of the FET-processed RTA treatment, indicating that the carrier density of the EB-treated FET was enhanced by about 1 order of magnitude.