Exchange bias (EB) in ferromagnetic/antiferromagnetic materials is a novel idea for high-density spintronic devices. Van der Waals (vdW) heterostructures offer a promising solution, enabling a “Lego” like assembly without interface or adding dopants, opposite to traditional heterostructures. However, in typical vdW heterostructures, the EB effect exists at low temperatures and only one polarity. This work addresses these challenges by using Fe₃GaTe₂/NiPS₃ heterostructures whose EB can survive at higher temperatures and polarities flip. The exchange bias (EB) of the device persists up to 150 K and can have its polarity reversed by altering the stacking direction during fabrication. Simultaneously, an anomalous Hall effect (AHE) with a coercive field of approximately 0.9 T is observed at 5 K and remains detectable up to 300 K. The device further shows the spin-orbit torque (SOT)-induced magnetization switching up to room temperature. Under low field-cooling conditions (e.g., ≥2 mT), we observe an EB field (H_EB) up to 1 mT, which reached 110 mT at 1.5 T. H_EB becomes zero above 150 K, showing a non-discernible EB effect, whereas the AHE persists up to room temperature. Similarly, in the Fe₃GaTe₂/NiPS₃ and NiPS₃/Fe₃GaTe₂, different stacking layers at the interface induce the net magnetic effect and flip the magnetization direction due to magnetic domains at the Fe₃GaTe₂ layer. The results show that strong interlayer coupling within these layers generates significant AHE and high H_EB with blocking temperatures up to 150 K, making it suitable for the new 2D spintronic device applications.

The substitutional doping of two-dimensional (2D) transition metal dichalcogenides (TMDs) is essential for tuning their electronic and optoelectronic properties. However, conventional doping methods often suffer from the edge enrichment by dopant atoms, particularly for rare-earth dopants with large ionic radii, owing to their tendency to migrate toward high-energy edge sites during growth. Herein, we present a seed-mediated, self-driven nucleation strategy that leverages the high surface energy of stepped sapphire substrates to pre-adsorb dopant atoms at the step edges. These sites guide the localized nucleation and incorporation of the dopants, thereby effectively suppressing edge segregation. Using this approach, we synthesized centimeter-scale monolayer Yb-doped WS₂ films with incorporated substitutional atoms, along with other metal-doped WS₂ films. The introduction of mid-gap states near the conduction band in monolayer Yb-doped WS₂ films was further demonstrated by the characterization of the bound exciton emission and electronic density of states. This study broadens the pathways for the controllable synthesis of substitutional 2D materials and extends the potential for developing novel 2D optoelectronic devices.

As dielectric polymers are confined to nanoscale dimensions, anomalous enhancements in electrical resistivity have been widely inferred and exploited in nanocomposites and multilayered structures—yet direct experimental validation of the mechanisms remains elusive. Herein, we unveil the physical origins of this abnormal resistivity at the nanoscale through a model polymer approach. Direct experimental observations on ultrathin polymer films (down to 5 nm) reveal that the size-dependent enhancement in electrical resistivity primarily originates from confined local β-relaxation processes, complementing conventional explanations based on changed molecular packing and density. With this insight, we (i) rationalize the temperature-dependent effects of nanofilling in polymer-nanocomposite dielectrics and (ii) engineer a commercial polymer film with a bulk glass transition temperature of 237 °C that retains stable insulating performance up to 300 °C. These findings provide a unified framework for molecular-dynamics-driven charge transport and offer a strategy to design thermally robust dielectrics for next-generation electronics, power modules, and harsh-environment applications.

The cobalt-free spinel LiNi_0.5Mn_1.5O₄ (LNMO) emerges as a high voltage and high energy density cathode candidate for next generation batteries, yet its practical application is challenged by intrinsic Mn dissolution, oxygen vacancy-driven structural degradation, and unstable electrode-electrolyte interphase. Herein, we demonstrate a reactive selenium (Se)-induced near-surface reconstruction strategy, which integrates SeO_x coating and Se element doping into the near-surface of LNMO through a one-step vapor-phase selenization process, stabilizing both the electrode-electrolyte interphase and the bulk lattice. During electrochemical cycling, the nanoscale-thick SeO_x coating layer evolves into a Li₂SeO_x-rich interfacial layer, facilitating rapid Li⁺ transport and enhancing mechanical resilience to suppress interfacial degradation caused by volume changes. Concurrently, near-surface Se doping forms O-transition metal (TM)-Se bonds that narrow the bandgap between Mn 3d and O 2p orbitals, thereby stabilizing lattice oxygen, suppressing Mn dissociation and structural deterioration. The near-surface reconstructed Se-LNMO cathode exhibits exceptional long-term cycling stability at high rates with a 0.018% capacity decay rate per cycle after 2000 cycles at 5C, outperforming previously reported LNMO materials. This simple yet effective “all-in-one” reactive Se infusion strategy serves as a universal paradigm for stabilizing high-voltage cathodes, opening up new avenues for the design of novel high-energy-density cathode materials.

All-inorganic halide perovskite cesium lead iodide (CsPbI₃) has emerged as a promising semiconductor and optoelectronic material. However, its optically active black phases easily transform into the non-optically active yellow phase, limiting practical applications. Here, strain variations during phase transitions in CsPbI₃ are investigated using a strain/order parameter coupling model, based on lattice parameters measured over the temperature range of 100–650 K. Structural and thermal analyses suggest that the large positive (e₁–e₂) strain is the primary driver responsible for the transformation of black CsPbI₃ into the yellow phase. The impact of this strain on the phase stability of CsPbI₃-based films is further validated by comparing films on different substrates and with varying compositions. Our findings uncover the key metric that determines the phase stability of CsPbI₃, providing insights for the design of stable, optically active all-inorganic halide perovskite.

The need for rapid and comprehensive health monitoring is especially critical during health crises involving chronic diseases of epidemic proportions or infectious disease outbreaks. Sweat testing offers a rapid, in situ, and noninvasive alternative to traditional blood testing, minimizing discomfort and cross-infection risks. However, the development and commercialization of simple, highly scalable, and power-free sweat sensing devices have been slow and challenging. Here, we design a miniaturized, modular, and skin-interfaced sweat sensing patch for rapid and efficient large-scale health monitoring and diagnosis through multimodal laser sensing. The patch's workflow involves sweat collection via a microfluidics-based collection module, followed by sweat sensing and artificial intelligence (AI)-assisted diagnosis. The sweat sensing module, prepared by coating silver nanowires on filter paper, enables rapid detection of multi-analytes (e.g., glucose, lactate, urea, sodium, potassium, and lead) using multimodal laser sensing techniques (that combine surface-enhanced Raman spectroscopy with nano-enhanced laser-induced breakdown spectroscopy). Furthermore, the multispectral data, analyzed with AI assistance, can rapidly and efficiently detect abnormalities in sweat components for quick diagnosis. Our volunteer trials also show that real-world health monitoring is feasible. Overall, this straightforward and cost-effective patch, integrated with multimodal laser sensing, can potentially enable large-scale health monitoring and diagnosis.

Advancing complementary metal–oxide–semiconductor (CMOS) technology into the sub-1-nm Ångström-scale technology nodes is expected to involve alternative semiconductor materials as silicon transistors encounter severe performance degradation at physical gate lengths below 10 nm. Two-dimensional (2D) semiconductors have emerged as strong candidates for overcoming the short-channel effects due to their atomically thin bodies that significantly improves the gate control in aggressively scaled field-effect transistors (FETs). Among the growing library of 2D materials, MA{\hspace{0.17em}}_2Z{\hspace{0.17em}}_4 family has attracted increasing attention for its remarkable ambient stability, suitable bandgaps, and favorable carrier transport characteristics. While experimental realization of sub-10-nm 2D FETs remains technologically demanding, computational device simulations using first-principles density functional theory combined with nonequilibrium Green's function transport simulations provide a powerful and cost-effective route for assessing the performance limits and optimal design of ultrascaled FET. This review consolidates the current progress in the computational design of MA{\hspace{0.17em}}_2Z{\hspace{0.17em}}_4 family FETs. We review the physical properties of MoSi{\hspace{0.17em}}_2N{\hspace{0.17em}}_4 that makes them compelling candidates for transistor applications, and the simulated device performance and optimization strategy of MA{\hspace{0.17em}}_2Z{\hspace{0.17em}}_4 family FETs. Finally, we discuss the key challenges and research gaps, as well as the future directions of MA{\hspace{0.17em}}_2Z{\hspace{0.17em}}_4 family FET research toward the Ångström-scale CMOS era.

Owing to the severe electromagnetic wave (EMW) pollution and the increasingly intricate operating environments, an excellent EMW absorber with multiple functions has become imperative. Nevertheless, achieving the seamless co-existence of disparate functional features in deliberately engineered EMW absorbers remains a formidable challenge. Herein, 3D/0D–1D hierarchical carbon/Ni nanoparticles-carbon noncoils (CNCs) composite foams can be precisely synthesized through a simple freeze-drying process, carbonization treatment, and chemical vapor deposition process successively. The outcomes reveal that incorporating 1D CNCs into 3D/0D carbon/Ni nanoparticles composite foams successfully constructs multi-dimensional, multi-interfacial and multi-path structures. This significantly improves the impedance matching characteristics of 3D/0D–1D hierarchical carbon/Ni nanoparticles-CNCs composite foams and enhances their polarization loss and conduction loss capabilities. Consequently, the complementarity in structure and composition endows the 3D/0D–1D hierarchical carbon/Ni nanoparticles-CNCs composite foams with outstanding EMW absorption properties with a minimum reflection loss value of −52.91 dB and a broad effective absorption bandwidth of 6.0 GHz. Moreover, this synergistic effect equips 3D/0D–1D hierarchical carbon/Ni nanoparticles-CNCs composite foams with remarkable radar stealth capabilities, outstanding corrosion resistance, excellent Joule heating performance, and exceptional thermal insulation. This makes them highly promising for applications in complex and variable environments.

Perovskite quantum dots (QDs) confined within solid matrices via calcination methods exhibit superior environmental stability compared to colloidal perovskite QDs. However, matrix-confined perovskite QDs generally display lower photoluminescence quantum yield (PLQY) than their colloidal counterparts, especially in the case of blue-emitting mixed-halide CsPb(Cl/Br)₃ QDs. Here, we identify residual tensile stress, originating from the mismatch in thermal expansion coefficients between the perovskite and the matrix, as a key factor responsible for the suppressed luminous efficiency in silica-confined CsPb(Cl/Br)₃ QDs. Furthermore, we demonstrate that a simple hydrothermal treatment enables stress release in these silica-confined QDs, leading to a significant enhancement in their PLQY. The resulting stress-free silica-confined CsPb(Cl/Br)₃ QDs exhibit record-high PLQYs among reported blue-emitting perovskite QDs synthesized via calcination methods, even approaching the PLQY of colloidal QDs. In addition, we find that stress release effectively suppresses both photoinduced halide segregation and thermal-induced emission quenching in these silica-confined CsPb(Cl/Br)₃ QDs. This work provides a new perspective for achieving blue-emitting perovskite QDs with high PLQY and stability.

With organic solar cells surpassing 20% efficiency, the focus is shifting toward understanding the more complex mechanisms in ternary blends. This work investigates the distinct working principles of ternary organic solar cells based on a polymer donor (D) and a nonfullerene acceptor (NFA), with a fullerene acceptor (FA) as the third component. A systematic comparison between ternary D:NFA:FA systems, with different components and compositions, and D:NFA:NFA systems was conducted. In all systems, the open-circuit voltage increased with a higher fullerene ratio, correlating with the fullerene's LUMO position, indicating its involvement in charge transfer (CT) state formation. Various analytical methods and simulations reveal that the investigated D:NFA:FA systems follow an alloy model, where the CT state is delocalized over both acceptors, even in systems with strong surface energy differences between the acceptors. Notably, recombination behavior is largely unaffected by the nature of the third component and is primarily linked to the CT state energy. Based on the internal quantum efficiency characteristics, we propose that the positive effect of fullerenes as third components arises not from reduced nonradiative recombination as often suggested but from more efficient exciton splitting.