Conventional Raman spectroscopy faces inherent limitations in detecting interlayer layer-breathing (LB) vibrations with inherently weak electron-phonon coupling or Raman inactivity in two-dimensional materials, hindering insights into interfacial coupling and stacking dynamics. Here, we demonstrate a universal plasmon-enhanced Raman spectroscopy strategy using gold or silver nanocavities to strongly enhance and detect LB modes in multilayer graphene, hBN, and their van der Waals heterostructures. Plasmonic nanocavities even modify the linear and circular polarization selection rules of the LB vibrations. By developing an electric-field-modulated interlayer bond polarizability model, we quantitatively explain the observed intensity profiles and reveal the synergistic roles of localized plasmonic field enhancement and interfacial polarizability modulation. This model successfully describes the behavior of plasmon-enhanced LB vibrations across different material systems and nanocavity geometries. This work not only overcomes traditional detection barriers but also provides a quantitative framework for probing interlayer interactions, offering a versatile platform for investigating hidden interfacial phonons and advancing the characterization of layered quantum materials.

Abstract Metamaterials have been widely used in the field of terahertz (THz) to enhance the interaction between THz waves and materials. The 2D heterojunctions are deposited by two or more layers of different 2D materials, showing excellent optoelectronic properties. Among them, the heterojunction composed of graphene and molybdenum disulfide (MoS2) presents unique photoelectric characteristics and adjustable bandgap characteristics. In this paper, a broadband THz complementary metamaterial absorber based on graphene and MoS2 heterojunction is proposed and investigated. Through simulations, it has been found that the surface plasmon resonance assists the absorber to achieve more than 90% absorption in the frequency range of 2.1-3.9 THz at 0.9 eV graphene Fermi level. Meanwhile, the absorber shows the ability in absorption modulation. By adjusting the Fermi level of graphene, a maximum modulation depth of 75% and a maximum center frequency modulation depth of 13% can be obtained. This work has practical significance and value for the development of 2D heterojunction-based metamaterial in the development of multifunctional THz devices and provides a novel design strategy for terahertz broadband metamaterial absorbers and modulators.

Rapid and quantitative characterization of atomic defects in two-dimensional (2D) semiconductors and transistors is crucial for growth optimization and understanding of device behavior. However, such defect metrology remains challenging due to limitations of existing characterization methods, which are generally destructive and slow or lack the necessary sensitivity. Here, we use nondestructive lateral force microscopy (LFM) to directly map surface defects in monolayer WSe2 and WS2 on different growth substrates (SiO2 and sapphire), as well as in WSe2 transistors. Through LFM measurements on various WSe2 layers, we show that this technique can detect defect densities well below the range of typical Raman measurements on this material. We also demonstrate mapping of spatial variation of defect density within as-grown WSe2 and that the LFM technique can detect defects on suspended and polymer-supported monolayers, expanding the application space. Applied to WSe2 transistors, LFM uncovers defect densities over double that of similar as-grown films, suggesting that defects can be introduced by common fabrication processes. This work demonstrates the applications of LFM as a nondestructive defect characterization method for monitoring 2D material growth and device fabrication.

We investigate the magnetic exchange interaction, magnetic anisotropy (MAE), and magnetocaloric effect (MCE) of ternary transition metal chalcogenides A2MX4 (A = Ti or V; M = W or Mo; X = S or Se). We find that Ti2WS4 and Ti2WSe4 exhibit large entropy changes of 5.97 and 5.51 μJ m-2 K-1, respectively, under a magnetic field near room temperature. Analysis based on perturbation theory indicates that strong second-nearest-neighbor exchange coupling plays an important role in MCE, along with a large MAE of ∼10 meV that is attributed to the coupling contributions of dx2-y2 and dz2 orbitals of the W atom. Moreover, strain and carrier doping effectively modulate the MAE and Curie temperature, leading to remarkable enhancement of the MCE. This work provides important insights into the design of two-dimensional materials with enhanced MCE and is expected to facilitate further advancements in room-temperature magnetic refrigeration for practical applications.

Research on breakthroughs in the synthesis and characterization of graphene [...]

Control over the nucleation and growth of two-dimensional (2D) materials is essential for their scalable manufacturing. We report in situ atomic-scale observations of molybdenum disulfide (MoS2) nucleation and growth through chemical vapor deposition (CVD) using environmental transmission electron microscopy. Coupled with molecular dynamics simulations, our observations reveal the formation of a 2D amorphous structure at the initial nucleation stage, which undergoes an in-plane structural ordering transition into a crystalline nucleus once a critical size is reached. We further captured nuclei merging and oriented attachment processes in the early growth stage, which likely contributed to 2D single-crystal fabrication. These findings unveil the atomistic structural evolution in MoS2 nucleation and growth under CVD condition, providing mechanistic insight for the controlled synthesis of high-quality 2D crystals and informing broader strategies for covalently bonded material systems.

The curved magnetism is of great importance in flexomagnetic devices. CrI3, a two-dimensional magnetic material, has emerged as promising platforms for spintronic and quantum applications. Here we studied the impact of bending strain on the magnetic and electronic properties of monolayer CrI3using density functional theory. It was found that under small bending within a bending curvature of 0.033 Å-1, the monolayer CrI3is stable at a ferromagnetic state. Further increasing the bending curvature will trigger a transition to from the ferromagnetic state to antiferromagnetic state due to bending-engineered interatomic distances and magnetic exchange coupling coefficients. Besides, band gap of monolayer CrI3can be also effectively tailored under bending, which clearly decreases with the bending curvature. These results can serve as theoretical references for flexible electronic and magnetic devices in two-dimensional magnetic materials.

Extensive efforts have been made to fabricate complex 3D thermal management materials from hexagonal boron nitride (h-BN) using 3D printing and templating. However, these techniques are often energy-intensive, time-consuming, and inherently limited in scalability, owing to prolonged processing times and low throughput. Herein, we report a cold, rapid, and scalable stamping approach for constructing intricate, large-area h-BN-based thermal architectures. This strategy relies on forming highly viscoelastic h-BN doughs achieved through developing a para-aramid (p-aramid) fiber network and densification via a bimodal alumina mixture. The p-aramid network maximizes viscoelasticity with a minimal binder content (5.1 wt.%), enabling the doughs to exhibit pronounced plasticity during stamping while maintaining solid-like behavior after relaxation. Consequently, the doughs conform precisely to complex stamp geometries within 2 s under ambient conditions, preserving their high structural integrity. Scalability is demonstrated by stamping various 3D geometries exceeding 10cm, including cubes, cylinders, annular sectors, and honeycombs. Furthermore, the fiber-reinforced structures exhibit enhanced thermal conductivity (TC) and fatigue resistance under extreme temperatures (- 50°C and 200°C). Notably, the resulting architectures substantially improve the TC of the polymer composites when used as internal frameworks. This low-energy stamping strategy represents a paradigm shift in the processing of advanced thermal materials.

Volumetric muscle loss (VML) leads to severe skeletal muscle dysfunction. While muscle tissue engineering offers a promising strategy, challenges persist due to insufficient neuromuscular innervation and poor reconstruction of neuromuscular junctions (NMJs). Conductive hydrogels can mimic the electrophysiological microenvironment and thus promote structural and functional regeneration, yet commonly used conductive materials still suffer from poor hydrophilicity, non-degradability, and potential cytotoxicity, while their underlying mechanisms remain unclear. Ti3C2Tx MXene, a class of two-dimensional nanomaterials with high conductivity and biocompatibility, shows potential for repairing electroactive tissues. In this study, we developed a novel biomimetic electroactive hydrogel by incorporating Ti3C2Tx MXene nanosheets into adipose-derived decellularized extracellular matrix (adECM). This study aimed to investigate the effects and mechanisms of MXene/adECM hydrogel on muscle regeneration and innervation. MXene/adECM hydrogel demonstrated excellent biocompatibility, biodegradability, and conductivity. Compared to the adECM hydrogel, the incorporation of MXene promoted myogenesis, along with increased expression of Desmin, MyoD1, and Myf5. Furthermore, the MXene/adECM hydrogel at the optimal concentration increased the average neurite length by 47.29μm (p < 0.05) relative to the adECM group. Transcriptomic analysis combined with a neuromuscular co-culture system indicated that the MXene/adECM hydrogel promoted the formation of neuromuscular junctions (NMJs). The incorporation of MXene upregulated the expression of specific voltage-gated calcium channels at the motor endplate, with transcript levels of Cacna1a and Cacna1s increased to 2.1-fold and 3.1-fold, respectively. It was further observed that calcium signaling was enhanced in the MXene/adECM group, with the peak calcium signal intensity being 2.40 times that of the adECM group. In vivo rat VML model confirmed that, compared to the adECM hydrogel, the MXene/adECM hydrogel promoted an increase in regenerated muscle fiber area, reduced collagen deposition, and elevated the fluorescence intensity of CD31 and Tuj. The co-localization percentage of presynaptic and postsynaptic NMJ markers increased from 27.85 ± 8.69% to 42.21 ± 15.52%. Gait analysis showed significant improvements in print area, swing/stance ratio, and movement velocity. In the MXene/adECM group, the isometric tetanic force (ITF) upon sciatic nerve stimulation was significantly higher than that of the adECM group (0.082 ± 0.012N vs. 0.057 ± 0.014N, p < 0.05), approaching the level of the uninjured group. Together, these findings demonstrate that the incorporation of MXenes into adECM provides a promising strategy that integrates microenvironmental support with endogenous electrical cues to modulate calcium influx and promote NMJ formation, offering a new paradigm for the treatment of VML.

Objectives . The aim of this study is to develop and demonstrate an effective method for obtaining large-area, high-quality monolayers of molybdenum disulfide (MoS 2 ) on the surface of ferroelectric lead zirconate titanate (PZT) films which exhibit pronounced granularity and texturing. Conventional mechanical exfoliation techniques are inefficient for transferring two-dimensional materials onto nonplanar surfaces. This is due to local height variations and substrate granularity which hinder the formation of continuous monolayers and high-defect-density transferred structures. A particular challenge is the transfer onto functional substrates with surface topography characterized by heterogeneities ranging from tens of nanometers to micrometers. Methods . A gold-assisted exfoliation (GAE) method was employed, including: magnetron sputtering of a 50 nm gold film; mechanical delamination of monolayers using thermally cleavable tape; and subsequent gold etching. The characterization was performed using X-ray diffraction, optical confocal microscopy, atomic force microscopy, and second harmonic generation techniques. The efficiency of the transfer process was compared for Si/SiO 2 and PZT substrates. Results . MoS 2 crystallites with areas up to 3000 µm 2 were obtained on PZT and over 65000 µm 2 on standard Si/SiO 2 substrates, both of which exhibit minimal defect densities. Conventional mechanical exfoliation is shown to be unable to ensure transfer onto textured surfaces, whereas the GAE method preserves the monolayer character of the transferred crystallites even on nonplanar substrates. Conclusions . This work demonstrates for the first time the possibility of obtaining large-area, high-quality MoS 2 monolayers on substrates with pronounced grainy and textured structures, such as ferroelectric PZT films, using the gold-assisted exfoliation method. The work also shows that gold-assisted exfoliation is an effective technique for fabricating extended two-dimensional films with controlled morphological and structural properties, including on substrates previously considered unsuitable for such applications.

Synergistic integration of atomic-scale doping and Moiré superlattices opens up new possibilities for manipulating the electrical characteristics of two-dimensional (2D) materials. Here, we report the first thorough first-principles investigation of site-specific chemical doping-based quantum capacitance (CQ) modulation in Moiré-patterned bilayer MoS2 (mBL-MoS2). Periodic potential fluctuations caused by a 21.79° interlayer twist change the density of states close to the Fermi level. By performing transition-metal-site substitution (Mo → Nb) and chalcogen-site substitution (S → Se), further improvements are achieved. Nb doping, which induces a semiconductor-to-metal transition, greatly enhances electronic delocalization and quantum capacitance, whereas Se doping has a comparatively smaller impact owing to its isoelectronic nature with S. The structural and electronic tunability of these systems is confirmed by a comprehensive analysis that includes electronic structure, differential and integral CQ calculations, electron localization function (ELF) mapping, Bader charge analysis, phonon stability, and work function evaluation. The superior charge storage capacity of Nb-doped mBL-MoS2 in the low-bias domain is demonstrated by benchmarking against other 2D materials. These results show how Moiré engineering and chemical doping can work together to create a new design framework for CQ-dominated supercapacitor electrodes.

ABSTRACT On‐chip integration of 2D materials provides a promising route toward next‐generation integrated optical devices with performance beyond existing limits. Here, significantly enhanced spectral broadening induced by self‐phase modulation (SPM) is experimentally demonstrated in silicon nitride (Si 3 N 4 ) waveguides integrated with 2D monolayer molybdenum disulfide (MoS 2 ) films. Monolayer MoS 2 films with ultrahigh optical nonlinearity are synthesized via low‐pressure chemical vapor deposition (LPCVD) and subsequently transferred onto Si 3 N 4 waveguides, with precise control of the film coating length and placement achieved by selectively opening windows on the chip silica upper cladding. Detailed SPM measurements at telecom wavelengths are performed using fabricated waveguides with various MoS 2 film coating lengths. Compared to devices without MoS 2 , increased spectral broadening of sub‐picosecond optical pulses is observed for the hybrid devices, achieving a broadening factor of up to ∼2.4 for a device with a 1.4‐mm‐long MoS 2 film. Theoretical fitting of the experimental results further reveals an increase of up to ∼27 fold in the nonlinear parameter (γ) for the hybrid MoS 2 /Si 3 N 4 waveguides and an equivalent Kerr coefficient ( n 2 ) of MoS 2 nearly 5 orders of magnitude higher than Si 3 N 4 . These results confirm the effectiveness of on‐chip integration of 2D MoS 2 films to enhance the nonlinear optical performance of integrated photonic devices.

The design and synthesis of biomimetic molecules, guided by the principles of molecular architectonics, represent significant advancements in the development of functional materials. This approach facilitates the systematic investigation of how amino acid sequences influence the structural and functional properties of oligopeptides. In this study, we present the design and synthesis of decapeptides with opposite polarity, consisting of specific periodic amino acid sequences such as W5K5 (W: tryptophan, K: lysine) and W5E5 (W: tryptophan, E: glutamic acid), which spontaneously assemble into peptide nanoparticles in aqueous media. A 1:1 mixture of these peptides undergoes coassembly in a phosphate buffer, transitioning from nanoparticles to hierarchical architecture, specifically two-dimensional (2D) sheets with lateral dimension of several micrometers. The assembly process is driven by electrostatic interactions between oppositely charged decapeptides and the uniform distribution of hydrophobic and hydrophilic moieties. The formation and stability of these 2D sheets were studied by using various microscopy and spectroscopy techniques. The 2D peptide assemblies, with their large surface area and structural flexibility, demonstrate significant potential for biological applications, such as DNA interaction. Understanding and optimizing DNA-peptide interactions are essential for advancing applications in gene delivery, biosensing, and nanobiotechnology. This study investigates how coassembled 2D peptide nanostructures can enhance DNA-binding interactions. The coassembled 2D sheets exhibited markedly higher DNA interaction efficiency compared to individual peptide nanoparticles. This study offers a straightforward yet innovative strategy for fabricating peptide-based 2D materials via molecular assembly, providing a promising platform for advancements in DNA nanotechnology and related fields.

This study employed an integrated experimental–computational methodology to investigate the critical role of the layer-stacking sequence in the acoustic performance of multi-layer porous materials for vehicle NVH applications. The acoustic properties of four distinct single-layer materials were first characterized via impedance tube measurements. A finite element simulation model based on the Johnson–Champoux–Allard (JCA) theory was subsequently developed in COMSOL Multiphysics 6.2 and rigorously validated. Leveraging this validated model, a systematic analysis was conducted on six different layer sequences under a fixed total thickness of 30 mm. The simulation results showed excellent agreement with experimental data, with a root-mean-square error (RMSE) below 5%. It was demonstrated that the stacking sequence significantly governed the mid-to-high frequency sound absorption behavior, which was strongly correlated with the modulation of the real and imaginary parts of the normalized surface acoustic impedance. This study thus demonstrated that the layer sequence—a previously underexplored design factor—critically determines the absorption performance of multi-layer materials at a fixed total thickness. A full design-space analysis revealed that performance shifts are governed by changes in interfacial acoustic impedance. This physics-driven insight provides a practical framework for tailoring absorbers to specific frequency bands, offering a viable path toward lightweight acoustic solutions for electric vehicle applications.

Rashba-type spin-orbit coupling is an important physical phenomenon for spintronic device applications. The size of Rashba splitting is generally enhanced by increasing inversion symmetry breaking, typically by increasing the spontaneous polarization of ferroelectric materials. Here, we identify an intriguing mechanism to enhance Rashba splitting by topological band inversion induced by strain. Using density functional theory, we show that monolayer quasi-1D ferroelectric chalcogenides BaTiSe3 and BaZrSe3 exhibit in-plane polarization, giving rise to Rashba splitting in the valence and conduction band edges with a persistent spin texture. Remarkably, under 1% compressive biaxial strain, the Rashba parameter and splitting energy of monolayer BaZrSe3 are enhanced to ∼3.0 eV Å and ∼60 meV, respectively, among the highest in 2D materials, and concurrently, a giant Berry curvature is induced, which is ∼1400 Å2 in magnitude. Our analysis shows that these enhancements result from a generic mechanism of strain-induced phase transition from semiconductor to topological insulator, which in turn changes interband transitions. Our findings manifest a unique strain-induced interplay between topology and ferroelectricity, and the integration of topological bands with Rashba splitting may provide promising applications to advancing spintronics technology.

ABSTRACT Lattice deformation is a powerful way to engineer the properties of 2D materials, making their precise measurement an important challenge for both fundamental science and technological applications. Here, we demonstrate that boron‐vacancy () color centers in hexagonal boron nitride (hBN) enable quantitative strain sensing with sub‐micrometer spatial resolution. Using this approach, we precisely quantify the strain‐induced shift of the Raman mode in a multilayer hBN flake under uniaxial stress, establishing centers as a new tool for strain metrology in van der Waals heterostructures. Beyond strain sensing, our work also highlights the unique multimodal sensing functionalities offered by centers, which will be valuable for future studies of strain‐engineered 2D materials.

Two-dimensional (2D) antimony-based materials have garnered significant interest due to their intrinsic structural anisotropy, tunable electronic band structures, and superior carrier transport properties, rendering them highly promising for next-generation microelectronic and optoelectronic applications. Nevertheless, research on ternary antimony-based compounds remains at an early stage, despite their compositional versatility and potential for synergistically modulating electronic and optical properties through element-specific engineering. Here, we report a novel 2D ternary antimony chalcogenide oxide, Sb2S2O, which features a low-symmetry layered structure and pronounced in-plane anisotropy. The layered Sb2S2O crystals exhibit excellent broadband photoresponse performance across the 254-940 nm range, achieving a remarkable responsivity of 11.3 A W-1 and a specific detectivity of 6.5 × 1011 Jones. Moreover, the photodetectors demonstrate polarization-angle-dependent sensitivity spanning 266-808 nm, with the structural anisotropy of Sb2S2O giving rise to a maximum dichroic ratio of approximately 1.48 at 633 nm. Notably, modulation of the polarization angle enables dynamic control over the spatial distribution of photoexcited carriers and the interfacial potential landscape, thereby allowing efficient tuning of the device's optical response. This polarization-dependent tunability further allows the photodetector to operate in a dual-mode configuration for intelligent imaging, simultaneously achieving high-sensitivity detection and programmable contrast enhancement. The integration of deep learning algorithms with the multifunctional optoelectronic characteristics of Sb2S2O positions this material as a promising candidate for next-generation intelligent photodetection and adaptive vision technologies.

Two-dimensional (2D) metal oxide semiconductor-based gas sensors usually suffer from limited sensitivity and sluggish recovery at ppb levels due to the intrinsic interlayer restacking and poor out-of-plane charge transport. Herein, TiO2 nanotubular arrays (NTAs) acting as a scaffold were applied to grown 2D highly dispersed curved BiOBr nanosheets to form heterojunctions, thereby achieving full surface utilization in gaseous sensing reactions. Positron annihilation lifetime spectroscopy verified the presence of three types of defects (VO, VBr, and VBrBiBr) in the as-formed BiOBr nanosheets; Monte Carlo simulations further revealed that these curved nanosheets exhibited a substantially increased target collision frequency and higher adsorption probability compared to planar structures. Using gaseous NO2 molecules as the model target, the interface-defect-morphology synergistic effect enabled the resulting BiOBr/TiO2 NTA composite to exhibit high activity in NO2 sensing reactions even at room temperature, with a detection linear range from 1 ppb to 10 ppm (LOD = 0.12 ppb), sensitive response, excellent selectivity, satisfactory humidity tolerance, and superior operational stability (>60 days). In situ Raman analysis demonstrated that vacancy-mediated NO2 adsorption contributed to the excellent sensing performance, which was further confirmed by strong NO2 adsorption energy (-2.553 eV) and midgap defect state-triggered efficient charge transfer. This work not only provides an effective route for designing gas sensing materials but also paves a new way for preparing 2D materials with abundant active surfaces for catalytic applications.

To address the clinical urgency of simultaneously monitoring multiple biomarkers in chronic wound infections, this study presents the innovative development of an electrochemical sensor based on a MWCNTs/MXene/PVA composite hydrogel. A dual-channel conductive network is constructed via the electrostatic self-assembly of the two-dimensional material MXene and multi-walled carbon nanotubes (MWCNTs). This strategy not only enhances the charge transfer efficiency but also effectively suppresses the aggregation of MWCNTs and exposes the electrocatalytic active sites. Additionally, the thermal annealing process is incorporated to facilitate the ordered arrangement of polyvinyl alcohol (PVA) nanocrystalline domains, strengthening the hydrogen bond-mediated interfacial adhesion and resolving the issues of hydrogel swelling and delamination. The detection limit (LOD) of the optimized sensor (MWCNTs0.6/MXene0.4/PVA) for pyocyanin (PCN) within complex biological matrices, including phosphate-buffered saline (PBS), Luria–Bertani (LB) broth, and saliva, was decreased to a range of 0.84~0.98 μM. Leveraging the disparities in the characteristic oxidation potentials (ΔE &gt; 0.3 V) of PCN, uric acid (UA), and histamine (HA) in simulated wound exudate (SWE), the multi-component synchronous detection functionality of the non-specific sensor was expanded for the first time. This study offers a high-precision and multi-parameter integrated approach for point-of-care testing (POCT) of wound infections.

Near-infrared and short-wave infrared dual-band detection has emerged as a pivotal enabling technology in across diverse applications spanning material identification, biological diagnostics, and machine vision. Current dual-band device architectures based on vertically stacked photodetectors such as those employing two-dimensional materials or back-illuminated colloidal quantum dots remain constrained by limited large-area manufacturability and incompatibility with standard readout integrated circuits. Here, we report a top-illuminated p-i-n-i-p dual-band photodetector using two distinct sizes of solution-processed PbS colloidal quantum dots, which enables bias-switchable spectral response between near-infrared and short-wave infrared regimes. The device achieves a specific detectivity exceeding 1×1011 cm·Hz1/2·W-1 in both bands, with short-wave infrared crosstalk of 0.5% and near-infrared crosstalk of 7.7%. The successful fabrication of a monolithic integrated 128×128 dual-band focal plane array showcases a functional dual-band infrared imager. This work establishes a scalable and silicon-compatible platform toward high-performance, low-cost dual-band infrared imagers.