Journal of Materials Chemistry C最新文献

The rapid development of flexible electronics presents more urgent demands for high-performance devices, such as flexible transistors, as they are essential units for various flexible circuits and systems. Among various device fabrication methods, the emerging all-printing preparation route can integrate different core materials and efficiently maintain their performance while reducing cost and environmental damage, thereby attracting increased attention. Here, we propose a bottom-up printing fabrication strategy to construct a flexible field-effect transistor using the burgeoning two-dimensional semiconductor tellurene as the channel material, graphene as the electrode, and Al₂O₃ as the gate dielectric. This fabrication process operates efficiently and conveniently, and is environmentally friendly, enabling an on/off ratio of over 10². Benefiting from the effective gate modulation of Al₂O₃ and the light response of tellurene, the flexible transistor can function as a fully flexible artificial synaptic device, demonstrating typical postsynaptic current and plasticity characteristics. Especially when photostimulation is changed, modulation of synaptic plasticity can be observed, indicating its broad applicability in future neuromorphic computing technology. These results provide a printable tellurene-based flexible transistor and may promote the development of flexible electronic devices in future information technology and bionic intelligence.

As the permanent magnet material with the highest maximum energy product, NdFeB faces urgent demands in new energy vehicles and wind power generation, while conventional manufacturing processes encounter limitations in fabricating its complex geometries. Laser powder bed fusion technology offers an innovative solution for the precision manufacturing of NdFeB magnets owing to its high design flexibility and near-net-shaping capabilities. This review systematically summarizes the research advancements in LPBF-fabricated NdFeB permanent magnets over the past decade. First, it elucidates the synergistic mechanisms between the laser energy density and spot diameter, clarifying their impacts on the melt pool morphology and relative density. The defect suppression mechanisms are thoroughly investigated through scan strategy optimization, melt pool remelting, and substrate preheating. Subsequently, the mechanisms of heat treatment and hot isostatic pressing processes for regulating the microstructures and enhancing the magnetic properties are analyzed. Current achievements in the magnetic and mechanical performance of LPBF-processed NdFeB are systematically summarized, with a particular emphasis on the correlation between microstructural evolution and magnetic behavior. Finally, by addressing existing bottlenecks in magnetic property regulation, this review proposes a coordinated development strategy combining powder material design and process innovation, providing theoretical foundations and technical pathways for the additive manufacturing of high-performance NdFeB magnets with complex architectures.

Perovskites can be fabricated into anisotropic nanostructures, which have been reported to produce polarization in photoluminescence (PL). These structures are promising for creating polarized light sources. Here, bulk-like CsPbBr₃ nanorods (NRs) with two sizes are synthesized using liquid nitrogen freezing. The use of low-boiling-point solvents enables the self-assembly of the NRs. Surprisingly, the degree of polarization of the S-NRs is higher at room temperature, and S-NRs embedded on Light-emitting diode (LED) chips demonstrate promising potential as circularly polarized luminescence (CPL) emitters. The novel phenomena from the CsPbBr₃ NRs demonstrated that direct fabrication of directionally aligned nanostructures by solution processing can induce “intrinsic” chirality and achieve high polarization emission in LED devices.

With the miniaturization of semiconductor devices, the metals used as interconnect materials are affected by the significant “resistivity size effect.” The increase in resistivity owing to the resistivity size effect can directly degrade the performance of semiconductor devices. To solve this problem, the atomic layer deposition (ALD) of Ru has been actively studied to deposit high-quality Ru thin films that can maintain low resistivity even at thin thicknesses. Although ALD is an excellent method for depositing nanoscale thin films, the actual quality of the films deposited by ALD is greatly influenced by the properties of the precursor. We employed a newly developed zero-valent Ru precursor, stabilized by a combination of neutral open and closed ligands, to deposit high-quality Ru thin films using ALD. The Ru thin films deposited by the new Ru precursor exhibit improved growth characteristics compared to conventional high-oxidation-state Ru precursors and Ru precursors composed of closed ligands. In addition, Ru thin films could be deposited with outstanding conformality, even on trench substrates with a high aspect ratio. Consequently, high-quality Ru films for next-generation interconnect materials were successfully deposited by ALD using a new zero-valent Ru precursor containing an open ligand.

Chirality strongly influences the self-assembly of soft matter systems, yielding new superstructures with numerous potential applications. Here, two series of 4-cyanoresorcinol-based bent-core liquid crystals (BCLCs) in which molecular chirality is provided by the introduction of a branched (S)-2-alkyloxypropyl end chain at both or only one end of the aromatic core have been synthesized and characterized to study the effects of chain branching and molecular chirality on liquid crystalline (LC) self-assembly. Two new LC phases with tilted and twisted arrangements of the molecules, restricted rotation around the long axis, preferred face-to-face stacking of the polyaromatic cores, and only a short correlation length of lamellar ordering were discovered; one is achiral and isotropic (M_Iso) while the other is chiral and low birefringent (M_L*). With decreasing density of the chain branching (i.e., stereogenic centers), the achiral M_Iso phase is replaced by the birefringent heliconical M_L* phase, an amorphous type III blue phase (BPIII), a heliconical tilted smectic phase (SmC*), and a chiral cybotactic nematic phase composed of SmC* clusters (N_CybC*). In this N_CybC* phase, the twist is heliconical, in contrast to the conventional non-cybotactic chiral nematics where it is helical. The heliconical twist is favored and the helical twist is suppressed by the emergence and growth of SmC-type cybotactic clusters. At the transition to a denser, face-to-face-packed core, saddle-splay emerges, and helical twist can become stronger, supporting layer deformation and causing a transition from the heliconical SmC* via M_L* to the achiral M_Iso phase as the density of chain-branched stereogenic centers increases and temperature decreases.

As MOSFET dimensions approach their physical limits, conventional gate dielectrics struggle at the nanoscale to simultaneously deliver high breakdown strength and low power consumption. To address this challenge, an ethylene-glycol-chelated sol–gel route was employed to deposit high-κ strontium titanate (SrTiO₃) films on p-type highly doped silicon. The resulting films exhibit a relatively high breakdown field of 11.04 MV cm⁻¹ at 2.5 nm. Using the optimized dielectric, back-gated MoS₂ field-effect transistors were fabricated, which show a low subthreshold swing of ∼0.23 V dec⁻¹, gate leakage on the order of ∼10⁻¹¹ A, and an on/off ratio of ∼10⁶, confirming the feasibility of sol–gel STO as a high-κ gate insulator for 2D devices. These results establish a solution-processed STO platform that is compatible with silicon and amenable to integration with both 2D and oxide electronics.

A commercial battery separator (Celgard) cannot inhibit the penetration of dendrites and the shuttle of sodium polysulfides (NaPSs) due to its permeable porous structure, which seriously threatens the performance and service safety of room-temperature sodium–sulfur (RT Na–S) batteries. In this work, a fluorinated polyimide and polyether copolymer (FPI-PEO) membrane was prepared by electrospinning, and then an FPI-PEO/Celgard/FPI-PEO sandwich structure was constructed using Celgard. By introducing fluorinated groups and polyether segments and constructing a fiber structure and a three-dimensional network structure, the wettability of the electrolyte was improved, and the flexibility of FPI-PEO and the mechanical strength of Celgard were combined to resist the penetration of sodium dendrites. Meanwhile, an electronegative environment was constructed on both sides of Celgard to inhibit the shuttle of sodium polysulfides (NaPSs). The results show that the FPI-PEO/Celgard/FPI-PEO separator inhibits the shuttle of NaPSs and exhibits excellent ability to resist dendrites. The battery assembled with the FPI-PEO/Celgard/FPI-PEO separator exhibits excellent cycling stability. After 2000 cycles at 3 A g⁻¹, the capacity still remained at 515 mA h g⁻¹. In addition, the FPI-PEO/Celgard/FPI-PEO separator exhibits excellent safety performance. This work provides a new and meaningful method for developing RT Na–S battery separators that resist dendrite piercing and inhibit polysulfide shuttle.

Conventional anticounterfeiting has gradually lost its credibility due to the improvement in sophisticated forging methods. There is a growing need to fabricate new anticounterfeiting platforms with multi-mode authentication. In next-generation shape memory-assisted anticounterfeiting polymeric materials, stimuli-induced shape changing, as a result of the shape memory effect, is utilized as one security mode, and other smart phenomena are considered another alarm modes. These systems are divided into different categories, such as shape memory and luminescent-based, shape memory and chromic-based, and shape memory and lithography-based dual-mode anticounterfeiting structures. In these systems, fluorescence emission, photochromism, and thermochromism have received increasing attention. Time is also used as other authentication mode in these systems, which are named dynamic anticounterfeiting systems. The time-dependent nature of the shape memory effect could serve as a dynamic alarm mode that can increase the effectiveness and applicability of the shape memory-assisted anticounterfeiting systems. New perspectives and ideas are proposed for future studies, which can improve the anti-forging level of the prepared materials. Using different stimuli-induced chromism, fluorescent and phosphorescent abilities, various shape memory behaviors, such as triple shape memory effect, and fibrous structures with different morphologies, such as layer-by-layer and core–shell, can significantly complicate the faking process of these systems.

Correction for ‘Mechanofluorochromism and self-recovery of alkylsilylpyrene-1-carboxamides’ by Yuichi Hirai et al., J. Mater. Chem. C, 2024, 12, 1952–1957, https://doi.org/10.1039/D3TC03968D.

Two-dimensional (2D) materials with engineered heterojunctions offer exciting opportunities for next-generation optoelectronic devices. However, achieving high-speed and ambient-stable photodetectors remains challenging. Here, we report a novel heterostructure photodetector based on p-type Ti₃C₂ MXene decorated on vertically aligned n-type SnS₂ nanosheets grown via chemical vapor deposition. This Ti₃C₂/SnS₂ hybrid structure forms a nanoscale p–n junction network with built-in electric fields that significantly enhance photocarrier separation and suppress recombination. The resulting device operates without gate bias and demonstrates a responsivity of 1.34 A W⁻¹, a detectivity of 9.91 × 10¹¹ Jones, and an ultrafast response time of 0.15 ms under visible light illumination. Electrochemical impedance analysis confirms efficient interfacial charge transfer, while the device maintains stable operation over 300 cycles and even after prolonged ambient exposure, highlighting excellent environmental robustness. Comparative analysis with the existing TMD and MXene-based photodetectors establishes the superiority of our approach in simultaneously achieving high speed, sensitivity, and stability. This work offers a scalable platform for developing high-performance 2D material heterojunction devices and sets a new benchmark for MXene-integrated optoelectronics.