Jing Zhang

The research demonstrates the synthesis of Gd³⁺/2D-g-C₃N₄ NS via chemisorption methodology to enhance defect-enriched magnetism and catalytic properties. Spin asymmetry polarizations near the Fermi level, analyzed through PDOS evaluations, confirm the magnetic nature of the synthesized material, validating the room temperature ferromagnetism ascertained using a VSM. The recyclable catalyst exhibits a 98% remediation efficiency for US assisted visible-light-driven photodegradation of methyl orange.

Abstract

Atomically thin two-dimensional (2D) semiconductors have high potential in optoelectronics and magneto-optics appliances due to their tunable band structures and physicochemical stability. The work demonstrates that Gd³⁺ incorporated 2D-g-C₃N₄ nanosheet (Gd³⁺/2D-g-C₃N₄ NS) is synthesized through chemisorption methodology for defect enrichment. The material characterizations reveal that the ion decoration enhances the surface area and defect concentration of the 2D sheet. The experimental observations have been further corroborated with the help of density functional theory (DFT) simulation. Spin asymmetry polarizations near the Fermi level, obtained through the partial density of states (PDOS) analyses, reveal the magnetic nature of the synthesized material, validating the room temperature ferromagnetism obtained through a vibrating-sample magnetometer (VSM). Gd³⁺/2D-g-C₃N₄ NS shows significant enhancement in saturation magnetization (Ms) experimentally and computationally compared to the pristine one. The magnetic catalyst shows 98% remediation efficiency for ultrasound-assisted visible-light-driven photodegradation of methyl orange (MO). The synergistic approach of liquid chromatography-mass spectrometry (LC-MS) analyses and DFT studies elucidates reaction intermediates and unveils the degradation mechanism. Post-characterization studies assure the stability of the magnetic catalyst through optical, chemical, magnetic, and microscopic analyses. So, the synthesized material can be proficiently used as a magnetic nanocatalyst in wastewater treatments and spin-electronics applications.

Large-area Schottky junction of BP/RGO films are fabricated by the developed liquid-phase spin-coating method. The devices exhibit a wide spectrum photodetection from visible of 532 to infrared of 2200 nm with large area uniform. The devices show outstanding photo-response under a high temperature of 400 K with R and D* up to 12 A W⁻¹ and 2.4 × 10⁹ Jones.

Abstract

2D materials-based broadband photodetectors have extensive applications in security monitoring and remote sensing fields, especially in supersonic aircraft that require reliable performance under extreme high-temperature conditions. However, the integration of large-area heterostructures with 2D materials often involves high-temperature deposition methods, and also limited options and size of substrates. Herein, a liquid-phase spin-coating method is presented based on the interface engineering to prepare larger-area Van der Waals heterojunctions of black phosphorus (BP)/reduced graphene oxide (RGO) films at room temperature on arbitrary substrates of any required size. Importantly, this method avoids the common requirement of high-temperature, and prevents the curling or stacking in 2D materials during the liquid-phase film formation. The BP/RGO films-based devices exhibit a wide spectral photo-response, ranging from the visible of 532 nm to infrared range of 2200 nm. Additionally, due to Van der Waals interface of Schottky junction, the array devices provide infrared detection at temperatures up to 400 K, with an outstanding photoresponsivity (R) of 12 A W⁻¹ and a specific detectivity (D*) of ≈2.4 × 10⁹ Jones. This work offers an efficient approach to fabricate large-area 2D Schottky junction films by solution-coating for high-temperature infrared photodetectors.

Nature Chemistry, Published online: 09 April 2024; doi:10.1038/s41557-024-01492-2

Nature, Published online: 10 April 2024; doi:10.1038/s41586-024-07360-w

The large-scale two-dimensional inorganic molecular crystals (2DIMCs) and heterostructures are successfully synthesized, demonstrating superior stability over 80 days in air. The universal growth of 2DIMCs on various substrates enables the construction of 2D BiBr₃/MoS₂ heterostructure with significantly enhanced photoluminescence. This work provides a mature strategy for synthesizing 2DIMC materials toward practical application in electronics and optoelectronics.

Abstract

In contrast to conventional atomic crystals, two-dimensional inorganic molecular crystals (2DIMCs) possess a unique crystal structure composed of small molecules held together by van der Waals force. Such distinctive structure grants them specific chemical and physical properties highly suitable for electronic and optoelectronic applications. However, the synthesis of 2DIMCs has posed significant challenges due to the inherent issues such as uncontrollable growth orientation stemming from their natural crystalline isotropy and poor stability resulting from the weak intermolecular connections. Addressing these obstacles, the preparation of large-scale and highly-stable 2DIMC BiBr_3, and its heterostructure are reported here by developing crystallization orientation engineering strategies. This approach has successfully yielded centimeter-scale 2DIMC BiBr₃ with a clean and dense surface, showcasing exceptional long-term air-stability exceeding 80 days. Furthermore, the universal growth of large-scale 2DIMC BiBr₃ is demonstrated on diverse substrates, including SiO₂, Al₂O₃, and MoS₂ monolayers. Notably, the resultant 2D BiBr₃/MoS₂ heterostructure exhibits remarkable photoluminescence enhancement. This contribution paves a universal avenue for the mature synthesis of large-scale 2DIMCs with superior stability, holding great promise for prompting their integration in practical electronic and optoelectronic devices.

Fractal engineering opens new avenues to fabricate highly efficient 2D laser protection materials, with Fractal NbSe₂ demonstrating giant and broadband laser attenuation behaviors at a huge nonlinear absorption coefficient of 9.7 × 10⁻⁴ m W⁻¹ and an ultralow starting threshold of 5 mJ cm⁻² at 532 nm.

Abstract

The compelling demand for laser protection both for civil and defense use calls for new-generation nonlinear optical materials. Chemical vapor deposition (CVD) techniques provide extra tricks to modulate crystal optical nonlinearity through fractal growth. The synthesized 2D NbSe₂ and its fractal structures exhibit giant, broadband laser attenuation behaviors extending into the near Infrared (NIR) range. Particularly, the optical limiting performance generally correlates with the fractal dimension, where Fractal NbSe₂ demonstrates enhanced third-order optical nonlinearity at a huge nonlinear absorption coefficient of 9.7 × 10⁻⁴ m W⁻¹ and an ultralow starting threshold of 5 mJ cm⁻² at 532 nm. Various techniques include femtosecond spectroscopy, Density functional theory (DFT) calculation and Kelvin probe force microscopy disclose the origin of the strong nonlinearity of the 2D NbSe₂ crystals, and suggest the formation of edge states and overall faster carrier dynamics, larger surface contact potential difference NbSe₂ fractals contribute to their even augmented nonlinear responses. Fractal engineering thus opens new avenues to fabricate highly efficient laser protection materials, and the blocking of intense beam (a large attenuation factor over 13.3 dB at 532 nm) while allowing transmission of weak one (a high linear optical transmittance over 80%) fulfills the much desired “smart” defense.

2D Memtransistors

Memtransistors based on 2D materials offer a promising avenue for neuromorphic and brain-inspired computing, as they bypass the limitations of two-terminal non-volatile memory devices by leveraging the gate control through the third terminal. In article number 2308129, Saptarshi Das and Akshay Wali discuss their operational principles and potential applications in neuromorphic, probabilistic, information security, and edge-sensing applications.

A four-level encoding physically unclonable function (PUF) is constructed based on diamond's carbon–carbon single bond, defect luminescence structures, spin structures, and electron energy distribution structures. This PUF realizes fast authentication with encoding capacity up to 2^4×10 000/(100pixels)². The PUF is independent of physical structure parameters, therefore cannot be cloned by nanofabrication. It provides new paradigms for high secure PUFs with high encoding capacity.

Abstract

The multilevel encoding (MLE) scheme is an effective method for improving the anticounterfeiting encryption capabilities of physically unclonable functions (PUFs). However, owing to the correlation between encoding layers, the encoding capacity (EC) is difficult to improve by orders of magnitude. Herein, four noncorrelated structures in the diamond crystal structure (carbon–carbon single bond, defect luminescence structures, spin structures, and electron energy distribution structures) are considered for MLE. First, the microdiamonds containing nitrogen-vacancy (NV) color centers are embedded into polydimethylsiloxane (PDMS) to fabricate PUFs. Using an optical imaging system, four codable images of four noncorrelated structures are read. The noncorrelation of the four-level encoding structure is verified by calculating the Hamming distance (0.496 ± 0.02). The results show that EC exponentially improves to 2^4×10 000/(100 pixels)². Furthermore, the encoding method based on the energy level does not depend on physical structure parameters, such as the size and position of the spin structure. Thus, it is protected from structural modeling attacks, resulting in high security. Moreover, PUF labels based on PDMS flexible substrates can be employed for various flexible applications. In the proposed scheme, the information is encrypted by a four-level two-dimensional (2D) barcode and decoded by self-developed PUF authentication software. The proposed scheme presents a way for developing next-generation PUFs with super-high EC.

A low-cost, ultrathin, fast-response, and large-scale millimeter-wave beamforming array is reported relying on metasurface concepts combined together with ultrathin liquid crystals. The demonstrated device, characterized by its remarkable beamforming flexibility, real-time tunability, and extensive degrees of freedom, stands to pave the way for sophisticated wavefront modulation and revolutionize the way liquid crystals can be exploited for tailoring electromagnetic waves.

Abstract

The rapid advancement of prevailing communication/sensing technologies necessitates cost-effective millimeter-wave arrays equipped with a massive number of phase-shifting cells to perform complicated beamforming tasks. Conventional approaches employing semiconductor switch/varactor components or tunable materials encounter obstacles such as quantization loss, high cost, high complexity, and limited adaptability for realizing large-scale arrays. Here, a low-cost, ultrathin, fast-response, and large-scale solution relying on metasurface concepts combined together with liquid crystal (LC) materials requiring a layer thickness of only 5 µm is reported. Rather than immersing resonant structures in LCs, a joint material-circuit-based strategy is devised, via integrating deep-subwavelength-thick LCs into slow-wave structures, to achieve constitutive metacells with continuous phase shifting and stable reflectivity. An LC-facilitated reconfigurable metasurface sub-system containing more than 2300 metacells is realized with its unprecedented comprehensive wavefront manipulation capacity validated through various beamforming functions, including beam focusing/steering, reconfigurable vortex beams, and tunable holograms, demonstrating a milli-second-level function-switching speed. The proposed methodology offers a paradigm shift for modulating electromagnetic waves in a non-resonating broadband fashion with fast-response and low-cost properties by exploiting functionalized LC-enabled metasurfaces. Moreover, this extremely agile metasurface-enabled antenna technology will facilitate a transformative impact on communication/sensing systems and empower new possibilities for wavefront engineering and diffractive wave calculation/inference.

Leveraging Gd’s magnetocaloric effect to absorb frictional heat enables the triboelectric nanogenerator to sustain output performance in long-term operation. Harnessing the magnetization effect of Gd to concentrate the magnetic field results in a significant enhancement in the electromagnetic generator’s outputs. The interaction of the internal components achieves a synergistic effect where 1 + 1 > 2, providing a general solution for self-reinforcing hybrid generators.

Abstract

Triboelectric-electromagnetic hybrid nanogenerator (TEHG) has emerged as a promising technology for distributed energy harvesting. However, currently reported hybrid generators are straightforward combinations of two functional components. Moreover, inevitable heat from friction intensifies material abrasion and degrades the performance of polymer-based triboelectric nanogenerators (TENGs). Here, a self-reinforcing TEHG (SR-TEHG) that harnesses the magnetocaloric and magnetization effects of gadolinium (Gd), is proposed. The synergy between TENG and electromagnetic generator (EMG) renders them an indivisible unit. Leveraging Gd's magnetocaloric effect, an efficient heat transfer mechanism is constructed to cool the tribolayer and strengthen the device's electrical stability. After 80 h of continuous operation, the optimized TENG occupies a charge decay rate of only 0.32% per hour, significantly outperforming most existing TENGs. Additionally, Gd's magnetization effect boosts the power of EMG by ≈80.84%. This work provides a universal solution in hybrid generators where internal components reinforce each other, achieving a synergistic effect of 1 + 1 > 2.

Nature Communications, Published online: 08 April 2024; doi:10.1038/s41467-024-47224-5

Nature Physics, Published online: 04 April 2024; doi:10.1038/s41567-024-02465-5

The SC-YAG:Tb@YAG:Pr-SCF double-layer phosphor is investigated toward advanced, wide-range luminescence thermometry. The synergy of Pr³⁺ and Tb³⁺ luminescence properties allowed for temperature measurement over 13–650 K with high relative sensitivity, not lower than 0.5 % K⁻¹ and mostly above 1% K⁻¹.

Abstract

The SC-YAG:Tb@YAG:Pr-SCF composite epitaxial structure consisting of a 1 mm thick single crystal substrate of YAG:Tb garnet and a thin (9 µm) single crystalline film of YAG:Pr garnet is fabricated, and its luminescent properties are examined toward luminescence thermometry. The possibility to efficiently excite, individually or simultaneously, the Tb³⁺ and Pr³⁺ dopants by their intense allowed 4f→5d transitions is executed to reach relative thermal sensitivity higher than 1% K⁻¹ over the range of temperatures as wide as 100–625 K and above 0.5% K⁻¹ over 13–650 K. The obtained results demonstrate that using intra- and inter-configurational emission transitions of Pr³⁺ and other lanthanides makes it possible to design wide-range luminescence thermometers with high sensitivity spanning the entire operating limits.

A skin-inspired, flexible, breathable, and highly-sensitive textile-based pressure sensor is fabricated via a facile screen-printing and bionic microengineering strategy. This bionic textile-based sensor demonstrates excellent pressure sensing performance benefiting from the bionic intermittent structure. The sensor can also detect a wide range of human motion, and recognize pressure distribution via the electronic skin fabricated by sensor arrays.

Abstract

Wearable pressure sensors have attracted great interest due to their potential applications in healthcare monitoring and human-machine interaction. However, it is still a critical challenge to simultaneously achieve high sensitivity, low detection limit, fast response, and outstanding breathability for wearable electronics due to the difficulty in constructing microstructure on a porous substrate. Inspired by the spinosum microstructure of human skin for highly-sensitive tactile perception, a biomimetic flexible pressure sensor is designed and fabricated by assembling MXene-based sensing electrode and MXene-based interdigitated electrode. The product biomimetic sensor exhibits good flexibility and suitable air permeability (165.6 mm s⁻¹), comparable to the typical air permeable garments. Benefiting from the two-stage amplification effect of the bionic intermittent structure, the product bionic sensor exhibits an ultrahigh sensitivity (1368.9 kPa⁻¹), ultrafast response (20 ms), low detection limit (1 Pa), and high-linearity response (R² = 0.997) across the entire sensing range. Moreover, the pressure sensor can detect a wide range of human motion in real-time through intimate skin contact, providing essential data for biomedical monitoring and personal medical diagnosis. This principle lays a foundation for the development of human skin-like high-sensitivity, fast-response tactile sensors.

A 2D selector based on Gr/hBN/WSe₂ heterostructure exhibits high bipolar nonlinearity at room temperature. Profit for well-designed band alignment and proper tunneling barrier, the selector undergoes direct tunneling at low bias while Fowler–Nordheim tunneling at high bias. This proof-of-concept demonstration opens up a new paradigm for promoting 2D 1S1R arrays for memory applications.

Abstract

The integration of one-selector-one-resistor crossbar arrays requires the selectors featured with high nonlinearity and bipolarity to prevent leakage currents and any crosstalk among distinct cells. However, a selector with sufficient nonlinearity especially in the frame of device miniaturization remains scarce, restricting the advance of high-density storage devices. Herein, a high-performance memory selector is reported by constructing a graphene/hBN/WSe₂ heterostructure. Within the temperature range of 300–80 K, the nonlinearity of this selector varies from ≈10³ – ≈10⁴ under forward bias, and increases from ≈300 – ≈10⁵ under reverse bias, the highest reported nonlinearity among 2D selectors. This improvement is ascribed to direct tunneling at low bias and Fowler–Nordheim tunneling at high bias. The tunneling current versus voltage curves exhibit excellent bipolarity behavior because of the comparable hole and electron tunneling barriers, and the charge transport polarity can be effectively tuned from N-type or P-type to bipolar by simply changing source-drain bias. In addition, the conceptual memory selector exhibits no sign of deterioration after 70 000 switching cycles, paving the way for assembling 2D selectors into modern memory devices.

Nature Synthesis, Published online: 03 April 2024; doi:10.1038/s44160-024-00520-w

Nature, Published online: 03 April 2024; doi:10.1038/s41586-024-07209-2

A facile strategy is proposed to anchor single-atom nanozyme-like lanthanum moieties on graphene nanocages, showing significantly enhanced dielectric loss performance due to unique five-coordinated configurations. The nanocages-based multifunctional film is fabricated and has outstanding electromagnetic wave absorption performance, outperforming most reported carbon-based films. This work provides crucial insights into the spatially coordinated environment of metal single-atom on the dielectric property.

Abstract

Single-atom (SA) nanozymes have unprecedented physicochemical performance due to their integrated merits of both atomically dispersed metal atoms and bio-enzymes. However, the structure-function relationship between the SA nanozyme-like structure and its dielectric performance is still unclear. Furthermore, controllable synthesis of SA nanozyme-like structures remains challenging due to their unique five-coordinated configurations. Here, a dicyandiamide-mediated pyrolysis strategy is proposed to anchor five nitrogen-coordinated lanthanum (La)–N₅ moieties on interconnected N-doped graphene nanocages (La-N₅/ING). Theoretical predictions indicate that the spatially coordinated La–N₅ moieties exhibit significantly enhanced conduction loss and polarization loss compared to La–N₄ moieties, as evidenced by the experimental results. Moreover, the polydimethylsiloxane-coated chemically cross-linked film constructed by the La-N₅/ING and aramid nanofibers has outstanding electromagnetic wave (EMW) absorption performance with an effective absorption bandwidth (EAB₁₀) of 6.24 GHz at a thickness of merely 2.0 mm, outperforming those of most reported carbon-based films. Importantly, the film also has excellent flexibility, hydrophobicity, mechanical strength, and structural stability, ensuring its application potential in practical environments. These findings provide crucial insights into the microscopic environment of SA on the dielectric properties of their host materials, and a critical method for the preparation of multifunctional films with spatial coordinated SA.

Currently, the methods for preparing phosphorene (such as black phosphorene, blue phosphorene, and violet phosphorene) mainly include mechanical exfoliation, liquid-phase exfoliation, electrochemical exfoliation, chemical vapor deposition (CVD), pulsed laser deposition, thermal thinning and so on. Here, the current development status, advantages, and disadvantages of these phosphorene preparation methods is summarized.

Abstract

Phosphorene, a 2D(two-dimensional) material, holds immense promise in various applications due to its unique properties. Here, a comprehensive overview of their recent synthesis progresses, with a specific focus on three phosphorene varieties: black phosphorene, blue phosphorene, and violet phosphorene is provided. Black phosphorene, given its versatile properties, is extensively studied, but the challenges persist in achieving scalable production with high quality and controllable thicknesses. The synthesis of blue phosphorene involves epitaxial methods but results in relatively small structures, limiting its practical applications. Notably, the successful synthesis of violet phosphorene remains limited, achieved only through mechanical and liquid-phase exfoliation (LPE) methods. Despite significant progression in phosphorene synthesis, a critical need is emphasized for a cost-effective and easily controllable method capable of efficiently managing the thickness of phosphorene. The challenges, such as scalability issues and the presence of impurities, highlight the complexity of phosphorene preparation methods. The review emphasizes the importance of continued scientific engagement to overcome these obstacles and advance the research topic. In essence, while phosphorene shows great potential, unlocking its full range of applications requires further research and innovation in synthesis methodologies.

This work provides an insightful and timely review of the recent trends in GeTe thermoelectrics in terms of physical and chemical fundamentals, advanced methodologies, and material and device aspects, inspiring future research in theoretical, experimental, and computational branches envisaging practical applications.

Abstract

Germanium telluride (GeTe) with ultrafast ferroelectric transition, Rashba-like electronic transport, and anomalous phonon anharmonicity are historically studied for potential memorizing and thermoelectric applications. Due to recent breakthroughs in spintronics, valleytronics, orbitronics, pre-eminent GeTe thermoelectrics have re-attracted enormous interest from both academia and industries, with increasing reports of significant figure-of-merit over 2.7 and the maximum efficiency of up to 17.0%. Here, the emerging trends in advancing GeTe thermoelectrics, starting from fundamentals of phase transformation, crystal structure, bonding mechanisms, and transport characteristics, with a highlight on the roles of Ge_4s ² lone pairs, are timely overviewed. Technical insights in synthesis, characterization, property measurement, and computation are then summarized. After that, several innovative strategies for increasing the figure-of-merit, including entropy engineering, nanostructuring, and hybridization, which will further benefit near-room-temperature and n-type performance, are examined. Moreover, high-density and high-efficiency devices with broad working temperatures are discussed as a result of rational configurational and interfacial design. In the end, perspective remarks on the challenges and outlook envisaging for next-generation GeTe thermoelectrics, which will play a prominent role in future energy and environmental landscapes, are provided.

A novel 2D/3D integrated dual-channel device artificial tetrachromatic synaptic device by stacking WSe₂/h-BN/Graphene on a GaN substrate is proposed to provide a promising avenue for the development of next-generation artificial visual perception systems. Moreover, the device exhibits remarkable performances under electrical and optical stimulation, owing to the enhanced charge-pumping effect of the GaN layer.

Abstract

The development of artificial tetrachromatic vision holds great potential to enhance human color perception and discrimination, thereby enabling more effective navigation in diverse environments. Herein, an artificial tetrachromatic synaptic device is presented built upon 2D-3D vertically stacked semiconductors composed of tungsten diselenide (WSe₂)-gallium nitride (GaN) configuration, forming a dual-channel floating gate transistor (FGT). Under the concerted influence of electrical and optical stimulation, the device successfully mimics fundamental tetrachromatic synaptic behaviors, including short-term potentiation (STP), weak long-term potentiation (wLTP), long-term potentiation (LTP), paired-pulse facilitation (PPF), spike number-dependent plasticity (SNDP), and spike rate-dependent plasticity (SRDP). Notably, the plasticity of the device can be further modulated under ultraviolet (UV) stimulation, providing insights into the modulation of synaptic plasticity through the photogenerated carrier dynamics in the GaN channel. These results imply that WSe₂-GaN-based FGT architecture with dual-channel characteristics seamlessly integrates optical sensing and synaptic simulation functionalities, representing a promising avenue for the development of next-generation artificial visual perception systems (AVPS), with a particular advantage for the pursuit of high-performance artificial tetrachromatic neuromorphic computing applications of the future.

Conventional security inks printed on the data page surface are vulnerable to counterfeiters and can be chemically deciphered. To address this issue, high-quality multicolored fluorescent patterns inside the polymer matrices for the first time are photochemically printed. Moreover, these patterns are chemically indecipherable, offering a superior way to fight against document fraud.

Abstract

Conventional security inks, generally directly printed on the data page surface, are vulnerable to counterfeiters, thereby raising the risk of chemical structural deciphering. In fact, polymer film-based data pages with customized patterns embedded within polymer matrix, rather than printed on the surface, emerge as a promising solution. Therefore, the key lies in developing fluorophores offering light dose-controlled fluorescent color inside polymer matrices. Though conventional fluorophores often suffer from photobleaching and uncontrolled photoreactions, disqualifying them for this purpose. Herein a diphenanthridinylfumaronitrile-based phototransformers (trans-D5) that undergoes photoisomerization and subsequent photocyclization during photopolymerization of the precursor, successively producing cis- and cyclo-D5 with stepwise redshifted solid-state emissions is developed. The resulting cyclo-D5 exhibits up to 172 nm emission redshift in rigidifying polymer matrices, while trans-D5 experiences a slightly blueshifted emission (≈28 nm), cis-D5 undergoes a modest redshift (≈14 nm). The markedly different rigidochromic behaviors of three D5 molecules within polymer matrices enable multicolor photochemical printing with a broad hue ranging from 38 to 10 via an anticlockwise direction in Munsell color space, yielding indecipherable fluorescent patterns in polymer films. This work provides a new method for document protection and implements advanced security features that are unattainable with conventional inks.

Orbital Gauge Field

In article number 2310010, Xian-Min Jin and co-workers realize an orbital gauge field to transmit high-dimensional quantum states. The orbital gauge field is constructed by a rotational defect on an atom-like lattice and shows a generalized and appealing perspective to control the behaviors of particles. The Hall-like transport of high-dimensional quantum states with protected orbital angular momentum represents a step towards generalized and large-scale quantum engineering.

Optical Encryption

Both wavelength-tunable coloration and light intensity-tunable photoluminescence are independent and reliably manipulated in a rewritable dual-responsive encryption display based on block copolymer self-assembly. The display has the benefit of being a direct and intuitive identification of encrypted information by the human eye, enabling high information security and anti-counterfeiting. More details can be found in article number 2310130 by Cheolmin Park and co-workers.

The diverse organic cations of organic–inorganic 2D perovskites endow them tunable optoelectronic characteristics. 2D perovskites have achieved great progress in the field of radiation detection in the past five years. The progress of 2D perovskites is systematically reviewed in X-rays, γ-rays, α-particles, β-particles, and neutrons, and an outlook on the future development is made.

Abstract

2D perovskites have greatly improved moisture stability owing to the large organic cations embedded in the inorganic octahedral structure, which also suppresses the ions migration and reduces the dark current. The suppression of ions migration by 2D perovskites effectively suppresses excessive device noise and baseline drift and shows excellent potential in the direct X-ray detection field. In addition, 2D perovskites have gradually emerged with many unique properties, such as anisotropy, tunable bandgap, high photoluminescence quantum yield, and wide range exciton binding energy, which continuously promote the development of 2D perovskites in ionizing radiation detection. This review aims to systematically summarize the advances and progress of 2D halide perovskite semiconductor and scintillator ionizing radiation detectors, including reported alpha (α) particle, beta (β) particle, neutron, X-ray, and gamma (γ) ray detection. The unique structural features of 2D perovskites and their advantages in X-ray detection are discussed. Development directions are also proposed to overcome the limitations of 2D halide perovskite radiation detectors.

Porous carbonaceous sphere derived from cobalt metal–organic frameworks is suggested to develop multimodal electro-ionic and magnetoactive soft actuators with expanded bandwidth and strong force actuation. These actuators are then utilized to demonstrate the high-frequency motion of a balancing bird and a dynamic eagle robot having a magneto-responsive claw.

Abstract

The advancement of active electrode materials is essential to meet the demand for multifaceted soft robotic interactions. In this study, a new type of porous carbonaceous sphere (PCS) for a multimodal soft actuator capable of both magnetoactive and electro-ionic responses is reported. The PCS, derived from the simultaneous oxidative and reductive breakdown of specially designed cobalt-based metal–organic frameworks (Co-MOFs) with varying metal-to-ligand ratios, exhibits a high specific surface area of 529 m² g⁻¹ and a saturated magnetization of 142.7 Am² kg⁻¹. The size of the PCS can be controlled through the Ostwald ripening mechanism, while the porous structure can be regulated by adjusting the metal-to-ligand mol ratio. Its exceptional compatibility with poly(3,4-ethylene-dioxythiophene)-poly(styrenesulfonate) enables the creation of uniform electrode, crucial for producing soft actuators that work in both magnetic and electrical fields. Operated at an ultralow voltage of 1 V, the PCS-based actuator generates a blocking force of 47.5 mN and exhibits significant bending deflection even at an oscillation frequency of 10 Hz. Employing this simultaneous multimodal actuation ensures the dynamic and complex motions of a balancing bird robot and a dynamic eagle robot. This advancement marks a significant step toward the realization of more dynamic and versatile soft robotic systems.

Through the concept of pneumatic multiscale shape morphing and reverse engineering, the MXene-enabled pneumatic matrix demonstrates unprecedented radar-infrared compatible camouflage, including dynamic adaptability, multispectral compatibility, multi-pixel programmability, multi-modal switching, high responsiveness, performance robustness, and weak angular dependence. The approach establishes an upgradable solution and realistic platform for smart electromagnetic sheath and advanced electromagnetic functional materials.

Abstract

Achieving radar-infrared compatible camouflage with dynamic adaptability has been a long-sought goal, but faces significant challenges owing to the limited dispersion relations of conventional material systems operating in different wavelength ranges. Here, this work proposes the concept of pneumatic multiscale shape morphing and design a periodically arranged pneumatic unit consisting of MXene-based morphable conductors and intake platforms. During gas actuation, the morphable conductor transforms centimeter-scale 2D flat sheets into 3D balloon shapes to enhance microwave absorption behavior, and also reconfigures micrometer-scale MXene wrinkles into smooth planes in combination with cavity-induced low heat transfer to minimize infrared (IR) signatures. Through theory-guided reverse engineering, the final pneumatic matrix shows remarkable frequency tunability (2.64–18.0 GHz), moderate IR emissivity regulation (0.14 at 7–16.5 µm), rapid responsiveness (≈30 ms), wide-angle operation (>45^°), and excellent environmental tolerance. Additionally, the multiplexed pneumatic matrix enables over 14 programmable coding sequences that independently alter thermal radiation without compromising radar stealth, and allows multimodal camouflage switching between three distinct compatible states. The approach may facilitate the evolution of camouflage techniques and electromagnetic functional materials toward multispectral, adaptability and intelligence.