查看更多>>摘要：2D electronic states underline a wide range of exotic phenomena and provide potential for electronic devices. The ability to create and control these states often requires physical thinning or highly perfect interfaces. In this work, the "fractional double perovskite" ATa_2O_6 (A: Eu~(2+)) is synthesized and characterized, where alternating A-site cations and A-site vacancies significantly impact the electronic structure, giving rise to a quasi-2D electronic state within a 3D crystal framework. The intrinsic crystal anisotropy of ATa_2O_6 plays a pivotal role, underscoring how targeted structural modifications can facilitate the emergence of novel quantum states. Utilizing single-crystal synthesis via molecular-beam epitaxy, the crystal and electronic structures of ATa_2O_6 are investigated. X-ray diffraction and electron microscopy reveal the layered A-site ordering. Synchrotron-based diffraction shows the presence of three epitaxial twin variants of ATa_2O_6 domains, with preferential orientation along out-of-plane direction. Angle-resolved photoemission spectroscopy, along with density functional theory calculations, provide direct insight into the electronic structure, unveiling the potential for engineered confined states within bulk materials. These findings highlight ATa_2O_6 as a platform for studying 2D-like electronic phenomena in a 3D context, paving the way for novel device architectures.
查看更多>>摘要：Most physical reservoir computing (RC) systems require complex prep- rocessing steps such as binarization under noise-free conditions and challenging real-time data processing because of latency and increase system complexity. This paper proposes a noise-resistant RC system that reduces the necessity for preprocessing by utilizing a steep-switching memory FET. The proposed device achieved steep-switching characteristics (SS_(PGM) = 19 mV dec~(-1), SS_(ERS) = 23 mV dec~(-1)) by operating in a stable state for a negative capacitance, which is established through the gate-stack of a ferroelectric insulator (CuInP_2S_6) and an insulator (h-BN). Additionally, it shows wide hysteresis (4.72 V) through dipole coupling between CuInP_2S_6 and ferroelectric semiconductor (α-In_2Se_3). Sub-60 mV dec~(-1) characteristics reduce the probability of undefined reservoir state occurrences and demonstrate the ability to filter noisy signals without additional preprocessing. Furthermore, its wide hysteresis-based memory enables non-linear transformations that incorporate temporal information from input signals, facilitating complex tasks such as temporal signal classification. A noise-resistant RC system is developed using steep-switching memory FET and validate its performance using noisy MNIST (15 dB: 95.9%, noise-free: 96.3%) and speech recognition (15 dB: 86.0%, noise-free: 86.7%) tasks, satisfying international noise-tolerance standards. This study highlights the potential of enhancing real-time data processing and system operating efficiency for data-centric computing systems.
查看更多>>摘要：Bismuth telluride (Bi_2Te_3)-based thermoelectrics have emerged as prime candidates for wearable and low-grade heat harvesting. However, the brittleness and insufficient mechanical strength lead to unsatisfactory machinability and flexibility. Here, this study demonstrates grain size- dependent strengthening-to-softening transition in Bi_2Te_3 thin films, achieving a maximum strength of 363 MPa, several times greater than single-crystal bulk counterparts. Remarkably, a novel energy dissipation mechanism mediated by stacking faults-induced ripplocation structures enables an unprecedented tensile ductility of ≈7.3%. High-density stacking faults simultaneously suppress the dominant grain boundary scattering on carrier transport, preserving excellent thermoelectric performance (power factor ≈2760 μW m~(-1) K~(-2) at 550 K). The fabricated Bi_2Te_3-based thin-film devices exhibit superior flexibility (over 10 000 bending cycles), power output, and stability across room-to-medium temperatures. This work establishes a novel microstructural design paradigm for next-generation flexible thermoelectric devices with superior strength-ductility synergy and thermoelectric performance.
查看更多>>摘要：As the only commercial available thermoelectric material, Bi2Te3-based alloys offer exceptional near-room temperature performance, while it is complicated to realize further improvement. Incorporating magnetic impurity is an effective strategy to decouple the relationship between thermal and electrical transport for improved TE performance, while the design of magnetic impurity with precisely tailored chemical components, size, distribution, and crystallinity remains a big challenge. Herein, the amorphous FeO_x layers with weak ferromagnetism are introduced to the grain boundaries of commercial p-type Bi_(0.5)Sb_(1.5)Te_3 materials to improve its TE performance. The special serrated shape and weak-ferromagnetism of the FeO_x layer promote high mobility and Seebeck coefficients of the ALD coated samples. The phonon scattering at the FeO_x layer reduce lattice thermal conductivity by over 30%. Consequently, the optimized sample achieves the maximum and average ZT of 1.42 at 330 K and 1.1 within 300-525 K, respectively, marking increases of 43.7% and 37.5% compared to the matrix. This work delves into the role of thermo-electro-magnetic interactions in ameliorating TE performance and offers inspiration for the development of high-efficiency TE modules.
Ali SoleimaniFarbod AmirghasemiMelissa BanksAbdulrahman Al-Shami...
e13707.1-e13707.17页
查看更多>>摘要：Mastitis occurs when blocked milk ducts lead to inflammation of the breast tissue and can cause significant discomfort for breastfeeding mothers. A key biomarker for mastitis is the altered sodium-to-potassium (Na~+/K~+) ratio in breast milk due to tight junction dysfunction. In this work, MAMAWEL is introduced, the first potentiometric sensor designed for at-home mastitis diagnosis. This device integrates Na~+ and K~+ sensors with an ionic-liquid-based reference electrode, enabling early detection of mastitis before clinical symptoms arise. To ensure reliable, calibration-free operation, 2,2,6,6-tetramethylpiperidinyloxy (TEMPO) is incorporated, a redox buffer that establishes a thermodynamically controlled interface, enhancing sensor reproducibility. Comparative analysis with commercially available sensors demonstrates that MAMAWEL effectively differentiates between healthy and mastitis-affected milk samples, achieving a concentration estimation error margin of less than 10%. Designed for both wearable and point-of-care applications, MAMAWEL has the potential to transform early mastitis detection, reducing maternal discomfort and promoting breastfeeding health.
查看更多>>摘要：While self-assembled monolayers (SAMs) have demonstrated remarkable success in iodide-based perovskite solar cells (PSCs), their application in bromide-based PSCs is fundamentally constrained by poor crystallization behavior and interfacial energy level misalignment. To overcome these limitations, the SAMs of (3-(3,7-bis(diphenylphosphoryl)-10H-phenoxazin- 10-yl)propyl) phosphonic acid (3,7-POPA) are designed and synthesized to address these challenges in FAPbBr_3-based PSCs. 3,7-POPA not only facilitates oriented crystallization of perovskite and defect minimization but also optimizes energy level alignment at the hole-selective interface, thereby significantly enhancing hole extraction efficiency. Consequently, optimized FAPbBr_3-based PSCs achieve a power conversion efficiency (PCE) of 10.79% with a record open circuit voltage (Voc) of 1.51 V. Remarkably, after operating at maximum power point for 1000 h, the encapsulated device maintains 90% of its initial PCE. The novel SAM-based hole transport strategy simultaneously resolves crystallization, defect, and energy-level challenges in Br-based PSCs, achieving record efficiency and stability for high-performance PSCs.
查看更多>>摘要：Hafnium oxide (HfO2)-based ferroelectric thin films, particularly Hf_(0.5)Zr_(0.5)O_2 (HZO), have emerged as promising candidates for next-generation nonvolatile memory due to their stable ferroelectricity at sub-10 nm thicknesses. While HZO thin films have been widely studied, nanoscale ferroelectric architectures such as nanodots remain largely unexplored, especially in the context of po- larization switching and domain wall dynamics. Here, the switching behavior and domain wall migration kinetics in epitaxial HZO nanodots with diameters of 30, 40, and 50 nm and thicknesses of 7, 10, and 13 nm are systematically investigated, using time-resolved piezoresponse force microscopy. The domain wall velocity is found to increase with nanodot diameter but decrease with thickness, ranging from 1.2 to 2.1 m s~(-1). A maximum velocity of 2.3 m s~(-1) is ob- served in a 10 nm thick HZO thin film. The piezoelectric response also improves with increasing aspect ratio, consistent with enhanced depolarization fields. Activation electric fields, determined via Merz's law, increase with decreasing nanodot thickness and diameter, reaching 6.65 MV cm~(-1) in the thinnest con- figuration. These behaviors are attributed to electrostatic boundary effects and depolarization charges surrounding the switching region. These results pro- vide critical insights into ferroelectric scaling limits and offer design guidelines for high-density, energy-efficient ferroelectric memory and logic devices.
查看更多>>摘要：The efficiency of water electrolysis is constrained by the substantial energy requirements of the anodic oxygen evolution reaction (OER) process. It is crucial to solve the issue for efficient and energy-efficient device manufacture. Geometric distortion in transition metal complexes significantly affects their performance. The Jahn-Teller (J.T.) distortion is a geometric distortion that results in various electronic and structural alterations in transition metal complexes. Recently, there have been notable studies that emphasize the significance of the existence and suppression of the J.T. distortion and its influence on OER activity. Degenerated electronic states in metal centers such as Mn3+, Co3+, and Cu2+ induce asymmetric ligand coordination, resulting in distortion, which stabilizes the reactive intermediates on the catalyst surface. This review examines several types of materials exhibiting J.T. distortion and their influence on OER activity. The experimental and theoretical examination of the J.T. distortion has also been discussed in length. The molecular orbital diagram has been employed for a clearer and enhanced comprehension of the distortion in the transition metal compounds. This review offers a detailed overview of the J.T. distortion and its implications for oxygen electrocatalysis, serving as a foundational reference for researchers in the field of electrocatalysis.
Min Young SungTae Jin JangSang Yoon SongChang-Gi Lee...
e15593.1-e15593.10页
查看更多>>摘要：Metallic materials for aerospace and liquid hydrogen technologies need to maintain high strength and ductility under cryogenic conditions. However, conventional strengthening strategies typically increase defect density and promote strain localization, resulting in a strength-ductility trade-off. This limitation becomes more critical at ultralow temperatures, where it facilitates discontinuous plastic flow and abrupt stress drops, substantially increasing the risk of premature failure. Here, a Co_(36)Ni_(46)Mo_(11)Al_7 medium-entropy is devel- oped, exhibiting an exceptional combination of tensile strength (2.1 GPa), high ductility (48%), and remarkably low stress drops of ≈99 MPa at 4.2 K. This bal- ance is enabled by two key mechanisms: enhanced lattice friction through com- positional tuning and the introduction of coherent L1_2 nanoprecipitates. These features effectively impede dislocation motion while promoting Hirth lock formation, thereby suppressing strain localization. Crucially, cryogenic loading- unloading-reloading tests, rarely performed at 4.2 K, reveal low back stress, directly indicating minimal dislocation accumulation despite the high strength. The findings highlight how dislocation-precipitate interactions can decouple strength from back stress accumulation, enabling a rare combination of ultra- high strength and suppressed discontinuous plastic flow. This approach estab- lishes a robust alloy design strategy for overcoming the long-standing conflict between strength, ductility, and mechanical stability in cryogenic environments.
查看更多>>摘要：Sulfide-based all-solid-state lithium-sulfur batteries (ASSLSBs) hold immense promise for next-generation energy-storage due to their high theoretical energy density and enhanced safety. However, fatigue issues such as electrolyte cracking and interfacial damage caused by big volume changes of both elec- trodes and mechanical stress remain critical challenges. Herein, the distinct alternative against monotonical stress evolution is first analyzed in ASSLSBs employing pre-lithiated silicon-based anodes versus conventional lithium metal by using in-situ pressure-detection techniques. Notably, the pre-lithiated silicon-based system demonstrates an alternating stress dominance pattern that effectively stabilizes mechanical responses through stress cancellation effects. Moreover, the investigation shows that the stress-buffering effect of pre- lithiated silicon-based stems from the phase transition dynamics of intermedi- ate Li_(21)Si_5 during lithiation. The finite element modeling and micro-structural morphology analysis is employed to link phase transformation kinetics directly to mechanical stress modulation. This unique characteristic proves crucial in suppressing crack propagation within electrolytes while maintaining stable electrode/electrolyte interfaces. Consequently, the full-cell using pre-lithiated silicon-based achieves stable cycling performance with high S loading (4.5 mg cm~(−2)) at 0.5C (∼3.6 mA cm~(−2)), which outperforms conventional solid-state lithium-sulfur batteries. The discovered chemo-mechanical coupling principles provide new insights for developing high-stability ASSLSBs, particularly in mitigating interfacial degradation induced by large volume changes.
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Wiley