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Ultrathin terahertz (THz) absorbing films are critical as building blocks for THz devices and systems. Although few-layer Ti₃C₂T_x MXene assemblies have approached the terahertz (THz) intrinsic absorption limit, it remains important to explore the THz intrinsic absorbing properties of other MXenes, which may elucidate the mechanism of THz-matter interactions for the future guidance of material design. In this study, eight representative MXenes with different M-sites were systematically analyzed. Surprisingly, the Ti₂CT_x thin film with direct current (DC) conductivity 26 times lower than that of the Ti₃C₂T_x film possessed similar high THz absorbing properties. Due to the significantly lower electron concentration of Ti₂CT_x compared to that of Ti₃C₂T_x, we concluded that the exceptional THz intrinsic absorption of Ti₂CT_x stemmed from its high terahertz electron mobility (μ_THz), which was attributed to its low electron effective mass (m*). Because the THz intrinsic absorption was determined by THz conductivity, which was proportional to the ratio of electron density (n) to electron effective mass (m*), we proposed that optimizing n/m* was crucial for achieving high THz intrinsic absorption in MXenes. This study not only explored the underlying THz-matter interaction mechanism in MXenes but also provided guidance for designing high THz absorption materials.

Nuclear radiation detectors are critical to transient nuclear reaction imaging, medical diagnostic imaging, security checks, industry inspection, and so forth, with many potential uses limited by scintillator dimensions. Current scintillator crystals are limited by the long-standing issues of hetero-crystalline formation and consequently inferior crystal dimensions and quality. Particularly, the hybrid organic–inorganic perovskites (HOIPs) exhibit scintillation capability under X-ray and fast neutrons within a single framework, owing to the presence of heavy elements and high hydrogen density groups, respectively. However, the achievement of high-performance and large-area imaging by HOIPs scintillators is impeded by the crystal growth technology. Herein, we propose an optimal crystal growth strategy and obtain an inch-sized high-quality (PEA)₂PbBr₄ single crystals (SCs) with a record dimension of 4.60 cm × 3.80 cm × 0.19 cm. Their application as synergistic scintillators in high-energy rays and charged particles detection are investigated, which exhibit high light yield (38 600 photons MeV⁻¹) and ultra-fast decay times that are 4.89, 27.98, and 3.84 ns under the 375-nm laser, γ-ray, and α particles, respectively. Moreover, the (PEA)₂PbBr₄ SCs demonstrate a remarkably high spatial resolution of 23.2 lp mm⁻¹ (at MTF = 20%) for X-ray and 2.00 lp mm⁻¹ for fast neutrons, surpassing the reported perovskites scintillators.

The practical application of lithium-sulfur (Li-S) batteries is seriously impeded by the notorious shuttle effect and sluggish reaction kinetics. Herein, we develop an advanced sulfur electrocatalyst that integrates single-atom Co-N₄ moieties with Co nanoclusters on N-rich hollow carbon nanospheres (Co-ACSA@NC). The proximity of single atoms and nanoclusters establishes a synergistic “pincer” interaction with polysulfides through dual modes of coordinate and chemical bonding. Moreover, electron donation from the Co nanocluster enhances the bonding between polysulfide and Co-N₄, further improving the immobilization and catalytic conversion of sulfur species. The hollow and porous carbon support not only exposes the abundant active sites efficiently, but also serves as a confined nanoreactor for well-tamed sulfur reactions. As a result, the S/Co-ACSA@NC cathode exhibits excellent cyclability over 500 cycles with minimal attenuation of 0.018% per cycle. A high areal capacity of 11.15 mAh cm⁻² can be obtained even under high sulfur loading (13.1 mg cm⁻²) and lean electrolyte (E/S = 4.0 μL mg⁻¹), while a 2.38-Ah pouch cell is also demonstrated with a commendable energy density over 307.7 Wh kg⁻¹. This work offers a unique “pincer” catalysis strategy for boosting sulfur electrochemistry, paving the way to high-performance and practically viable Li-S batteries.

Photoelectric memristors have shown great potential for future machine visions, via integrating sensing, memory, and computing (namely “all-in-one”) functions in a single device. However, their hard-to-tune photoresponse behavior necessitates extra function modules for signal encoding and modality conversion, impeding such integration. Here, we report an all-in-one memristor with Cs₂AgBiBr₆ perovskite, where the Br vacancy doping-endowed tunable energy band enables tunable photoresponsivity (TPR) behavior. As a result, the memristor showed a large tunable ratio of 35.9 dB, while its photoresponsivity presented a maximum of 2.7 × 10³ mA W⁻¹ and a long-term memory behavior with over 10⁴ s, making it suitable for realizing all-in-one processing tasks. By mapping the algorithm parameters onto the photoresponsivity, we successfully performed both recognition and processing tasks based on the TPR memristor array. Remarkably, compared with conventional complementary metal–oxide–semiconductor counterparts, our demonstrations provided comparable performance but had ~133-fold and ~299-fold reductions in energy consumption, respectively. Our work could facilitate the development of all-in-one smart devices for next-generation machine visions.

The simultaneous enhancement of magnetic and dielectric properties in nanomaterials is becoming increasingly important for achieving exceptional microwave absorption performance. However, the engineering strategies for modulating electromagnetic responses remain challenging, and the underlying magnetic-dielectric loss mechanisms are not yet fully understood. In this study, we constructed novel dual-coupling networks through the tightly packed Fe₃O₄@C spindles, which exhibit both dielectric and magnetic dissipation effects. During the spray-drying process, vigorous self-assembly facilitated the formation of hierarchical microspheres composed of nanoscale core-shell ferromagnetic units. Numerous heterogeneous interfaces and abundant magnetic domains were produced in these microspheres. The integrated dielectric/magnetic coupling networks, formed by discontinuous carbon layers and closely arranged Fe₃O₄ spindles, contribute to strong absorption through intense interfacial polarization and magnetic interactions. The mechanisms behind both magnetic and dielectric losses are elucidated through Lorentz electron holography and micromagnetic simulations. Consequently, the hierarchical microspheres demonstrate excellent low-frequency absorption performance, achieving an effective absorption bandwidth of 3.52 GHz, covering the entire C-band from 4 to 8 GHz. This study reveals that dual-coupling networks engineering is an effective strategy for synergistically enhancing electromagnetic responses and improving the absorption performance of magnetic nanomaterials.

Prof. Yichun Liu et al. develop F&Al co-doped ZnO transparent conductive films that withstand temperatures above 500 °C and are ideal for extreme optoelectronic devices.

Covalent organic frameworks (COFs) feature π-conjugated structure, high porosity, structural regularity, large specific surface area, and good stability, being considered as ideal platform for photocatalytic application. Although single COFs have achieved significant progress in photocatalysis benefiting from their distinctive properties, the COFs-based hybrids provide an extraordinary opportunity to achieve superior photocatalytic performance. From the perspective of carrier transfer mechanism, a systematic summary of hybrids based on COFs and other functional materials (metal single atoms, metal clusters/nanoparticles, inorganic semiconductors, metal–organic frameworks, and other polymers) can offer valuable guidance for the design of COFs-based hybrids. In this review, the photocatalytic mechanism for hybrid materials (such as Schottky junction, type II heterojunction, Z-scheme heterojunction, and S-scheme heterojunction) is briefly introduced. Subsequently, the performance of COFs-based hybrids in photocatalytic water splitting, CO₂ reduction, and pollutant degradation are comprehensively reviewed. Specifically, the carrier separation and transfer in different types of hybrids are highlighted. Finally, the challenges and prospects of COFs-based hybrids for photocatalysis are envisaged. The insights presented in this review are expected to be helpful in the rational design of COFs-based hybrids to obtain outstanding photocatalytic activity.

Artificial intelligence (AI) advancements are driving the need for highly parallel and energy-efficient computing analogous to the human brain and visual system. Inspired by the human brain, resistive random-access memories (ReRAMs) have recently emerged as an essential component of the intelligent circuitry architecture for developing high-performance neuromorphic computing systems. This occurs due to their fast switching with ultralow power consumption, high ON/OFF ratio, excellent data retention, good endurance, and even great possibilities for altering resistance analogous to their biological counterparts for neuromorphic computing applications. Additionally, with the advantages of photoelectric dual modulation of resistive switching, ReRAMs allow optically inspired artificial neural networks and reconfigurable logic operations, promoting innovative in-memory computing technology for neuromorphic computing and image recognition tasks. Optoelectronic neuromorphic computing architectured ReRAMs can simulate neural functionalities, such as light-triggered long-term/short-term plasticity. They can be used in intelligent robotics and bionic neurological optoelectronic systems. Metal oxide (MOx)–polymer hybrid nanocomposites can be beneficial as an active layer of the bistable metal–insulator–metal ReRAM devices, which hold promise for developing high-performance memory technology. This review explores the state of the art for developing memory storage, advancement in materials, and switching mechanisms for selecting the appropriate materials as active layers of ReRAMs to boost the ON/OFF ratio, flexibility, and memory density while lowering programming voltage. Furthermore, material design cum-synthesis strategies that greatly influence the overall performance of MOx–polymer hybrid nanocomposite ReRAMs and their performances are highlighted. Additionally, the recent progress of multifunctional optoelectronic MOx–polymer hybrid composites-based ReRAMs are explored as artificial synapses for neural networks to emulate neuromorphic visualization and memorize information. Finally, the challenges, limitations, and future outlooks of the fabrication of MOx–polymer hybrid composite ReRAMs over the conventional von Neumann computing systems are discussed.

Chemical vapor deposition (CVD)-gown graphene has tremendous potential as a transparent electrode for the next generation of flexible optoelectronics such as organic light-emitting diodes (OLEDs). A semiconductor coating is critical to improve the work function but usually makes graphene rougher and more conductive, which increases leakage, and then significantly restrict device efficiency improvement and worsens reliability. Here an insulating polyimide bearing carbazole-substituted triphenylamine units and bis(trifluoromethyl)phenyl groups (CzTPA PI/2CF₃) with high thermal stability is synthesized to passivate graphene. The similar surface free energy allows the uniform coating of CzTPA PI/2CF₃/N-methylpyrrolidone on graphene. Despite of a slight decrease in conductivity, CzTPA PI/2CF₃ passivation enables a substantial reduction in surface roughness and improvement in work function. By using such CzTPA PI/2CF₃-passivated graphene as anode, a flexible green OLED is demonstrated with a maximum current, power, and external quantum efficiencies of 88.4 cd A⁻¹, 115.7 lm W⁻¹, and 24.8%, respectively, which are among the best of the reported results. Moreover, the CzTPA PI/2CF₃ passivation enhances the device reliability with extending half-life and reducing dispersion coefficient of efficiency. The study promotes the practical use of graphene transparent electrodes for flexible optoelectronics.

Biologically inspired neuromorphic perceptual systems have great potential for efficient processing of multisensory signals from the physical world. Recently, artificial neurons constructed by memristor have been developed with good biological plausibility and density, but the filament-type memristor is limited by undesirable temporal and spatial variations, high electroforming voltage and limited reproducibility and the Mott insulator type memristor suffer from large driving current. Here, we propose a novel antiferroelectric artificial neuron (AFEAN) based on the intrinsic polarization and depolarization of AgNbO₃ (ANO) antiferroelectric (AFE) films to address these challenges. The antiferroelectric memristor exhibits low power consumption (8.99 nW), excellent durability (~10⁵) and high stability. Using such an AFEAN, a spike-based antiferroelectric neuromorphic perception system (AFENPS) has been designed, which can encode light level and temperature signals into spikes, and further construct a spiking neural network (SNN) (784 × 196 × 10) for optical image classification and thermal imaging classification, achieving 95.34% and 95.76% recognition accuracy on the MNIST dataset, respectively. This work paves the way for the simulation of spiking neurons using antiferroelectric materials and promising a promising method for the development of highly efficient hardware for neuromorphic perception systems.