Jiuxiang Dai

A novel 3D template-catalyzed growth (3D-TCG) method is developed for kilogram-scale production of few-layered 2D nanosheet powders with high efficiency. The template-catalyzed growth mechanism of this approach enables the high-quality and controllable lateral sizes from 100 nm to 10 µm of the products, demonstrating promising viability for large-scale practical applications.

Abstract

Bulk availability of 2D material powders presents broad opportunities for various industrial applications. Particle size and morphology control are critical factors that govern their properties, and in particular, large-scale size-controlled production of 2D materials nanosheets remains extremely challenging. Herein, a novel 3D template-catalyzed growth (3D-TCG) method is demonstrated that allows the mass production of size-tunable 2D hexagonal boron nitride (h-BN) nanosheet powders, a key material in the 2D materials family. Rather than limiting the nanosheet growth on 2D substrate surfaces, this method provides large numbers of active sites distributed in 3D space, leading to the feasibility of scale-up production with excellent product homogeneity and high efficiency. Ultrathin h-BN nanosheets are synthesized with high throughput (kilogram quantities) and lateral sizes that can be tuned from 100 nm to 10 µm with thicknesses of few layers. Their practical application is demonstrated in lithium metal batteries, where the obtained nanosheet powders are processed and roll-to-roll coated on commercial separators (>10 m²). The prototype pouch cell delivers high energy density (501.8 Wh kg⁻¹) and improved cycling stability. The template-based large-scale production strategy can be used to generically produce various types of bulk pristine 2D nanopowders with potential for many large-scale applications.

A modified chemical vapor transport method incorporating a feedback-regulated strategy provides closed-loop control of the growth temperature of MnBi_2nTe_3n+1 family within ± 0.1 °C, which reveals rich magnetic tunability, such as varying antiferromagnetic coupling in MnBi₂Te₄ and inducing magnetic ground state transitions from antiferromagnetism to ferromagnetism in MnBi₄Te₇ and MnBi₆Te₁₀.

Abstract

MnBi_2nTe_3n+1 is a representative family of intrinsic magnetic topological insulators, in which numerous exotic phenomena such as the quantum anomalous Hall effect are expected. The high-quality crystal growth and magnetism manipulation are the most essential processes. Here a modified chemical vapor transport method using a feedback-regulated strategy is developed, which provides the closed-loop control of growth temperature within ± 0.1 °C. Single crystals of MnBi₂Te₄, MnBi₄Te₇, and MnBi₆Te₁₀ are obtained under different temperature intervals respectively, and show variable tunability on magnetism by finely tuning the growth temperatures. Specifically, the cold-end temperatures not only vary the strength of antiferromagnetic coupling in MnBi₂Te₄, but also induce magnetic ground state transitions from antiferromagnetism to ferromagnetism in MnBi₄Te₇ and MnBi₆Te₁₀. In MnBi₂Te₄ with optimized magnetism, quantized transport with Chern insulator state can be easily replicated. These results provide a systematic picture for the crystal growth and the rich magnetic tunability of MnBi_2nTe_3n+1 family, providing richer platforms for the related researches combining magnetism and topological physics.

We found the Ge-Te binary system exhibits three electrical switching transition mechanisms—namely, phasechange memory, ovonic threshold switch, and phase-change switch behaviors. The first two have been successfully utilized in commercialized 3D Xpoint chips, serving as selector and memory cells, respectively. This finding offers a valuable opportunity to explore their interrelationships, which have remained unresolved for the past 60 years.

Abstract

Over the past 60 years, three distinct electrical switching behaviors have been discovered in chalcogenides: ovonic threshold switch (OTS), ovonic memory switch (OMS), and phase-change switch (PCS). The first two have been successfully utilized in commercialized 3D Xpoint chips, serving as selector and memory cells, respectively. However, the relationships among these three behaviors remain unclear. Here, it is demonstrated that the Ge-Te binary system exhibits these three switching mechanisms. Specifically, the switching behavior transforms from PCS-like to OTS-like within the composition range from GeTe₈ to GeTe₆, while the shift from volatile (OTS) to non-volatile switching behavior (OMS) occurs between the compositions GeTe₂ and GeTe. The PCS-to-OTS transition is primarily driven by enhancements in glass-forming ability, with the Turnbull parameter increasing from 0.58 to 0.6, and the crystallization temperature exceeding 145 °C, while the shift from OTS to OMS behavior is largely due to the significantly accelerated crystallization speed, from microseconds to nanoseconds. Most importantly, the GeTe₁₆ PCS stands out, with a large ON current (0.6 mA), low leakage current (<2.5 × 10⁻⁸ A), high endurance (>6 × 10⁹ cycles), and high-temperature back-end-of-line compatibility. The crystalline nature of this PCS material addresses the composition and toxicity issues in conventional OTS materials. Moreover, GeTe₁₆ PCSs have been successfully integrated with GeTe OMSs, forming selector/memory arrays with a read margin of 0.4 V. These findings not only reveal the mechanisms underlying the volatile to non-volatile transition but also provide an alternative solution for high-density 3D memory, potentially replacing the OTS/OMS stack approach.

Nature Synthesis, Published online: 01 April 2025; doi:10.1038/s44160-025-00795-7

Unusually stacked hexagonal boron nitride

npj 2D Materials and Applications, Published online: 02 April 2025; doi:10.1038/s41699-025-00545-5

Two-dimensional C₂₀-based monolayers and heterostructures for photocatalytic overall water splitting

Nature Communications, Published online: 31 March 2025; doi:10.1038/s41467-025-58226-2

The kagome lattice is known to host a rich array of correlated phenomena, but thus far the number of examples of truly two dimensional kagome systems are limited. Here, Pan, Xiong, Dai, Zhang, and coauthors present a two-dimensional Mo-Te compound with a kagome superlattice structure, and multiple kagome bands driven correlated states.

2D van der Waals (vdW) heterostructures emerges as a groundbreaking candidate for future integrated circuits due to their tunable band structures, atomically sharp interfaces, and seamless compatibility with CMOS technologies. Despite their promise, existing synthesis methods, such as mechanical transfer and vapor-phase conversion, struggle to achieve the high-quality, scalable production for practical applications. In response to these longstanding challenges, our study for the first time unveils the direct epitaxial growth of wafer-scale 2D vdW heterostructures (MoS₂/SnS₂) with exceptional quality and uniformity. This achievement is made possible through fundamentally enhancing the adsorption interactions between intermediates and the underlying material. The heterostructures display pristine, defect-free interfaces, consistent crystal orientation, and wafer-level thickness uniformity. The Raman peak shifts of MoS₂ and SnS₂ are contained to below 0.5 cm⁻¹ across the entire wafer, with intensity deviations maintained within an impressive 2%, and thickness uniformity surpassing 99.5%. Owing to their exceptional crystallinity and interface quality, the heterostructures demonstrate extraordinary electron and hole transfer capabilities, showcasing a prominent rectification effect and an astounding responsivity of 6.28× 10³ A/W, averaged from 30 devices. Our study signifies a pivotal advancement for the integration of 2D materials into semiconductor technologies, paving the way for next-generation integrated circuits.

Nature Synthesis, Published online: 28 March 2025; doi:10.1038/s44160-025-00773-z

The theory-guided synthesis of a tungsten-based W2TiC2Tx MXene from a non-MAX nanolaminated ternary carbide (W,Ti)4C4−y is reported. The tungsten-rich basal plane of the W2TiC2Tx MXene is then examined for the electrocatalytic hydrogen evolution reaction using a combined experimental and theoretical approach.

Nature Materials, Published online: 28 March 2025; doi:10.1038/s41563-025-02194-x

Fracture behaviours in multilayer h-BN, involving interlayer-friction toughening and edge-reconstruction embrittlement, are identified through in situ experiments and theoretical analyses.

A versatile assembly method is developed to uniformly assemble 2D single-crystal copper nanosheets (Cu NS) onto substrates with complex shapes via ultrasonication process. This technique leverages cavitation effects to deposit monolayer Cu NS films with minimal overlap. The assembly is optimized by tuning solvent polarity and substrate surface energy. Demonstrated applications include a resistive heater, highlighting the potential in flexible electronics.

Abstract

Scalable and cost-effective fabrication of conductive films on substrates with complex geometries is crucial for industrial applications in electronics. Herein, an ultrasonic-driven omni-directional and selective assembly technique is introduced for the uniform deposition of 2D single-crystalline copper nanosheets (Cu NS) onto various substrates. This method leverages cavitation-induced forces to propel Cu NS onto hydrophilic surfaces, enabling the formation of monolayer films with largely monolayer films with some degree of nanosheet overlap. The assembly process is influenced by solvent polarity, nanosheet concentration, and ultrasonic parameters, with non-polar solvents significantly enhancing Cu NS adsorption onto hydrophilic substrates. Furthermore, selective assembly is achieved by patterning hydrophobic and hydrophilic regions on the substrate, ensuring precise localization of Cu NS films. The practical potential of this approach is demonstrated by fabricating a Cu NS-coated capillary tube heater, which exhibits excellent heating performance at low operating voltages. This ultrasonic-driven and selective assembly method offers a scalable and versatile solution for producing conductive films with tailored geometries, unlocking new possibilities for applications in flexible electronics, energy storage, and wearable devices with complex structural requirements.

Fabrication of in situ polymer-encapsulated stable perovskite patterns of arbitrary shapes and pixel arrays with a resolution of 80 nm is reported by the femtosecond (fs) laser (800 nm) super-resolution writing technique. The two-photon absorption-induced laser ablation is attributed to the achieved feature sizes as small as λ/10. Furthermore, the fabrication of dynamic 3D codes at the micro- and nanoscale is demonstrated.

Abstract

Laser direct writing enables precise tailoring and patterning of semiconductor materials at the micro-and nanoscale, which is crucial for optoelectronic devices. However, the resolution of laser writing is limited by the diameter of the Airy disk. Herein, a femtosecond (fs) laser super-resolution writing (FsLSRW) technique is demonstrated for subwavelength patterning of stable perovskite nanostructures, achieving feature sizes as small as λ/10, with the line width reaching 80 nm. By leveraging the fs-laser's flexible, precise, and non-thermal diffused patterning capabilities, multicolor perovskite patterns are successfully produced with arbitrary design and pixel arrays. The multicolor perovskite patterns exhibit high hydrolytic, oxidative, and thermal stability due to their encapsulation in a polymer matrix. Furthermore, through precise adjustment of the laser focus plane, the writing of different information is demonstrated on two distinct spatial planes within a double-layer stacked perovskite composite film, enabling the production of dynamic 3D codes at the micro- and nanoscale. The high-efficiency and precision of FsLSRW technology pave a novel path for perovskite devices in fields such as information security, data storage, and optical encryption.

Reversible stepless multiple shape memory polymer comprising amorphous region as switching phase is prepared. Owing to the absence of phase transition during actuation, the reversible shape memory polymer (RSMP) comprising the amorphous region as the switching phase has an unfixed actuation temperature, adjustable stepless reversible deformation, substantially more temporary shapes, and a higher working density than conventional RSMPs.

Abstract

Soft robots are an emerging type of robot that frequently comprises flexible or elastic materials and provide novel solutions to the challenges that cannot be satisfactorily addressed using conventional rigid robots. Soft robots based on reversible shape memory polymers (RSMPs) have attracted considerable attention owing to their reversible deformations under external stimuli. However, their activation temperature (phase transition temperature) is fixed. After activation, the mechanical properties of RSMPs considerably deteriorate because of the phase transition upon heating, leading to a low work density. These drawbacks substantially limit the practical and widespread application of RSMPs in soft robots. Herein, reversible stepless multiple shape memory polymers (SMPs) are proposed in which the amorphous region serves as a novel switching phase. Compared with the RSMPs comprising crystalline region and liquid crystalline phase as the switching phase, the prepared reversible stepless multiple SMP possesses a nonfixed activation temperature, reversible stepless multiple shape memory effect, high work density, and wide polymer selection range. Furthermore, the as-developed polymer is used to create a bionic moving robot and soft actuator. The prepared soft actuator can drive an elevating stage up and down and trigger a soft lens set to change its focal length.

As Moore's law approaches its physical limits, carbon nanotube (CNT) 3D integrated circuits (ICs) emerge as a promising alternative due to the miniaturization, high mobility, and low power consumption. CNT 3D ICs in optoelectronics, memory, and monolithic ICs are reviewed while addressing challenges in fabrication, design, and integration. Synergies with chiplet technology can enable high-performance and ultradense ICs for future demands.

Abstract

As Moore's law approaches its physical limits, 3D integrated circuit (3D IC) technology has emerged as a crucial way to increase chip integration density. Due to their small size, high carrier mobility, and low power consumption, carbon nanotube field-effect transistors (CNTFETs) offer a promising way to overcome the limitations imposed by Moore's law. The evolution of ICs and 3D integration technologies for the post-Moore era, such as chiplets and multilayer stacking are reviewed, and the potential applications and value of CNTFETs in 3D optoelectronics, memory, and monolithic 3D ICs are explored. The prospects of novel device structures like FinFETs and gate-all-around FETs are also discussed. CNT 3D ICs have tremendous potential for these applications, but challenges remain in material fabrication, device performance, and 3D structure design. Researchers are actively exploring solutions such as optimizing fabrication processes, developing new materials, and innovative logic design methodologies. Notably, the integration of CNTFETs with chiplet technology promises more efficient and flexible chip design and manufacturing, catering to the future demand for high-performance, low-power, and high-density ICs.

Light: Science & Applications, Published online: 27 March 2025; doi:10.1038/s41377-025-01806-0

Nature, Published online: 26 March 2025; doi:10.1038/s41586-025-08742-4

A standard commercial CMOS FET can exhibit synaptic-like long-term potentiation and depression or neuron-like leaky-integrate-and-fire and adaptive frequency-bursting behaviour when biased in a specific but unconventional way.

Author(s): Livio Nicola Carenza, Josep-Maria Armengol-Collado, Dimitrios Krommydas, and Luca Giomi

Quasi-long-ranged order is the hallmark of two-dimensional liquid crystals. At equilibrium, this property implies that the correlation function of the local orientational order parameter decays with distance as a power law: i.e., ∼|r|−ηp, with ηp a temperature-dependent exponent. While in general no…

[Phys. Rev. Lett. 134, 128304] Published Thu Mar 27, 2025

Nature Electronics, Published online: 27 March 2025; doi:10.1038/s41928-025-01372-8

Solution-processed 2D materials could be of use in the development of large-area electronic applications, but the performance of devices based on such materials remains an issue.

Nature Communications, Published online: 26 March 2025; doi:10.1038/s41467-025-57991-4

The authors report upconversion in few-layer transition metal dichalcogenides, and attribute it to a resonant exciton-exciton annihilation involving a pair of dark excitons with opposite momenta, followed by the spontaneous emission of upconverted bright excitons.

A LiNO₃-assisted confined flux growth method for synthesizing 2D LaOCl nanosheets is developed within a controlled low-temperature range. The crystal quality and dielectric properties are thoroughly characterized, and its performance is demonstrated in devices as both gate dielectric and tunneling layer. With its ability to grow at low temperatures, LaOCl emerges as a strong contender for next-generation dielectric materials.

Abstract

2D semiconductors are widely regarded as the future of highly integrated circuits, but their commercialization is hindered by the lack of suitable gate dielectrics that meet stringent performance and processing requirements. In this study, a novel LiNO₃-assisted Confined Flux Growth (CFG) method is presented that enables the synthesis of high-quality 2D LaOCl nanosheets at remarkably low temperatures (250–350 °C). The synthesized LaOCl not only shows an exciting coexistence of wide bandgap (≈5.54 eV) and high dielectric constant (≈13.8) but also can form high-quality van der Waals interfaces with 2D semiconductors. Compared to traditional methods, the CFG approach significantly reduces thermal budget, providing opportunities for facile integration with the traditional semiconductor industry. Furthermore, the multifunctional application of LaOCl is demonstrated in 2D transistors. The MoS₂ field-effect transistors (FET) gated by LaOCl exhibit excellent gate control (on/off ratio >10⁸) and low interfacial trap density. The floating-gate devices with LaOCl as the tunneling layer show an extremely large storage window (≈91%) and stable storage characteristics. These findings establish 2D LaOCl as a transformative dielectric material, paving the way for next-generation multifunctional 2D electronic devices.

A microsized perovskite oxide Ce_0.266W_0.1Nb_0.9O₃ is engineered as an anode material for high-rate, long-life Li⁺ storage, demonstrating impressive performance by maintaining both high areal capacity and high rate capability, even at high mass loadings. This outstanding electrochemical behavior is primarily attributed to the nanoscale circuitry formed by an atomic-scale short-range order structure.

Abstract

High-rate materials necessitate the rapid transportation of both electrons and ions, a requirement that becomes especially challenging at practical mass loadings (>10 mg cm²). To address this challenge, a material is designed with an architecture having atomic-scale short-range order. This design establishes internal nanoscale circuitry at the particle level, which facilitates rapid electronic and ionic transport within micrometer-sized niobium tungsten oxides. The architecture features alternating cerium-depleted and cerium-enriched regions. The continuous cerium-enriched regions with enhanced conductivity provide multilane highways for electron mobility by functioning as electron-conducting wires that significantly boost the overall conductivity. The cerium-depleted regions effectively mitigate electrostatic repulsion and promote rapid ion transport through ion-conducting channels. These structural characteristics provide a continuous network that supports both electrical migration and chemical diffusion to amplify the areal capacity and rate capability even at high mass loadings. These findings not only expand the fundamental understanding of the design of optimal host lattices for advanced energy storage systems but also of the practical application of microsized high-rate electrode materials.

Author(s): Junlei Zhao, Javier García Fernández, Alexander Azarov, Ru He, Øystein Prytz, Kai Nordlund, Mengyuan Hua, Flyura Djurabekova, and Andrej Kuznetsov

Disordering of solids often leads to amorphization, but polymorph transitions, facilitated by favorable atomic rearrangements, may temporarily help to maintain long-range periodicity in the solid state. In far-from-equilibrium situations, such as atomic collision cascades, these rearrangements may n…

[Phys. Rev. Lett. 134, 126101] Published Tue Mar 25, 2025