Journal of Materials Chemistry C最新文献

Despite rapid advances in organic neuromorphic electronics, achieving linear and stable synaptic plasticity in organic electrochemical transistors (OECTs) remains challenging. Here, we show that imposing high alignment and nanoscale confinement in poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene] (PBTTT-C₁₄) conjugated polymer nanowires (NWs)—organized as a fin architecture—directly enhances ion–polymer interactions and regulates ion transport, thereby improving OECT functionality relevant to neuromorphic computing. Uniform, highly aligned NWs are formed by solution nanomolding using a polydimethylsiloxane (PDMS) mold. The resulting fin-structured OECTs (FinOECTs) exhibit a μC* value, where μC* is the product of the volumetric capacitance (C*) and charge carrier mobility (μ), of 10.24 F V⁻¹ s⁻¹ cm⁻¹, approximately twofold higher than those of film-based control devices. Structural analysis confirms increased crystallinity (coherence length 508.9 Å) and tighter π–π stacking, consistent with confinement-driven ordering that supports efficient mixed conduction. Most importantly, the alignment-driven fin geometry yields highly linear synaptic responses in both long-term potentiation (LTP) and long-term depression (LTD) (R² of 0.997), by moderating otherwise rapid ion diffusion at the NW–ion–gel interface. The devices also exhibit robust long-term memory (LTM), retaining 46.16% of the excitatory postsynaptic current after 1000 s. Finally, FinOECT-based reservoir computing attains a structural similarity index of 0.80 on a 16 × 16 pattern recognition task. These results establish highly-aligned polymeric NW fin architectures as a materials- and structure-level route for linear, durable and energy-efficient OECT-based neuromorphic computing systems.

Ordered self-assembled carbon nanotube (CNT) films exhibit outstanding anisotropic optoelectronic properties, subwavelength-scale thickness and high stability making them promising candidates for next-generation polarization photodetectors. The degree of alignment is a critical structural parameter for CNTs due to their exceptionally high aspect ratio and intrinsically one-dimensional nature. To investigate the polarization properties of self-assembled CNT films as a function of their alignment, we fabricated films with controlled alignment by modulating the density of active catalyst particles, with consideration of the crowding effect among adjacent CNTs during growth. Subsequently, the optical performance of the CNT films was evaluated under polarized light at a wavelength of 632 nm. The results indicate that as the degree of orientation, quantified by the Chebyshev orientation parameter (COP), increases from 0.26 to 0.53, both the transmittance and the extinction ratio of a 700 nm-thick film increase significantly. Notably, when the COP reaches 0.61, the extinction ratio attains a remarkable value of 700. Under oblique incidence, the extinction ratio steadily increases with the incident angle, while the transmittance remains nearly constant. This unique phenomenon is attributed to the anisotropic structure of the film, where lateral alignment exhibits superior performance compared to top-surface alignment.

The coupling between visible (Vis) color modulation and infrared (IR) electrochromic (EC) performance in IR EC materials has long posed a critical challenge. Herein, inspired by geometric dimensionality evolution (points to lines to surfaces), we design a dual-band decoupled EC layer (D-ECL) with “pixelated” partitioning of Vis and IR modulation regions via an interdigitated electrode. Comprising polyaniline and Prussian blue, its dual-modulation regions enable both combinations of multiple Vis color/IR emissivity states and “smooth fusion” of interdigitated stripes at distances beyond visual angular resolution limits, achieving “physically separate yet perceptually fused” Vis/IR camouflage by hiding real contours. D-ECL-integrated dual-band decoupled EC film (D-ECF), adapting to diverse temporal/regional conditions, effectively decouples Vis reflectance and IR emissivity modulation for enhanced tuning freedom, offering a new strategy for adaptive multispectral camouflage and dynamic thermal management.

Near-field radiative heat transfer (NFRHT) provides a powerful route to surpass the blackbody radiation limit by exploiting surface polaritonic modes in nanostructured materials. We propose and analyze a reconfigurable platform for tailoring NFRHT using coupled plasmon-phonon polaritons sustained by n-doped indium arsenide (n-InAs)/hexagonal boron nitride (hBN) heterostructures. Within the hBN reststrahlen bands, the spectral heat flux shows narrow high-Q peaks locked to the hyperbolic phonon polariton branches. Increasing the carrier density in n-InAs greatly boosts these peaks with a minimal frequency shift, indicating that hyperbolic phonon polaritons set the resonance while plasmons mainly enhance coupling. Momentum-resolved maps of the photon-transmission coefficient reveal iso-frequency contours that evolve from quasi-isotropic rings at zero field to anisotropic lobes with higher doping. Introducing a modest in-plane magnetic field B skews these contours, breaks the k_x → − symmetry, and funnels energy into preferred quadrants, thereby enabling reversible, nonreciprocal heat routing that complements carrier-density control. Our findings highlight a versatile approach to tailoring thermal radiation in planar systems, paving the way for advanced applications in thermal management, energy harvesting and nanoscale optoelectronic devices.

Metal bis(dithiolene) complexes have attracted considerable attention since their discovery, owing to their characteristic two-step redox behavior, square-planar coordination geometry, and strong metal–ligand dπ–pπ conjugation, which together endow them with remarkable physical and chemical properties. While early investigations focused on their fundamental coordination chemistry, recent efforts have shifted toward leveraging these complexes in functional organic materials, particularly in optoelectronics and thermoelectrics. This review begins by detailing the three pivotal stages in crafting one-dimensional metal bis(dithiolene) chains: (1) generation of the active dithiolene ligand, (2) metal–ligand coordination, and (3) oxidation. We offer a comparative analysis of the three principal ligand precursor classes: benzoin/benzil derivatives, 1,3-dithiol-2-one/1,3-dithiole-2-thione derivatives, and thiol/thioether derivatives, highlighting their synthetic considerations. Finally, we discuss the emerging applications of these complexes in organic thermoelectric devices (OTEs) and organic thin-film transistors (OTFTs), underscoring recent breakthroughs and charting future research directions.

Breaking optical reciprocity at room temperature in a fully dielectric platform remains a demanding yet impactful goal for integrated photonics. In this work we design and numerically demonstrate a lithography-defined, all-oxide metastructure that merges ferrimagnetic CoFe₂O₄ nanodisks with Mn-doped ZnO (ZnO:Mn) nanodisks, separated by a sub-2 nm Al₂O₃ spacer. This geometry, refined through detailed parameter sweeps and alignment tolerances captured in our original design notes, supports hybrid magneto-exciton polaritons with Rabi splittings up to 120 meV and cooperativity factors exceeding 5 at 300 K—without cryogenics or metallic losses. Finite-difference time-domain and micromagnetic simulations, combined with coupled-mode modelling, reveal broadband (>20 nm) bias-tunable nonreciprocal transmission windows whose spectral positions can be engineered via geometry, Mn content, and interlayer spacing. Our findings validate the concept sketched in the initial design drafts: an oxide-exclusive, CMOS-compatible platform delivering bias-reconfigurable spin–photon coupling, scalable fabrication, and chemical-thermal stability. The approach bridges fundamental magneto-optical physics with practical on-chip implementations, offering a clear pathway toward energy-efficient isolators, routers, and phase-controlled photonic components operating at ambient conditions.

Topological insulators with tunable properties have emerged as promising candidates for exploring exotic physical phenomena and innovating topological spintronic devices. Here, we predict a monolayer NiAl₂Se₄ using first-principles calculations and the dynamical, thermal, and mechanical stabilities are systematically evaluated. The monolayer NiAl₂Se₄ exhibits a noncollinear 120° antiferromagnetic ground state with an indirect band gap of 1.23 eV, which remains robust under various strains and U values. Through hole-doping in monolayer NiAl₂Se₄, the antiferromagnetic state could change to a ferromagnetic state. Intriguingly, the ferromagnetic monolayer NiAl₂Se₄ with 1.0 hole-doping per unit cell and 8.5% tensile strain exhibits topological band structures, hosting the quantum anomalous Hall effect with a high Chern number of C = 2. The Chern number originates from the Berry curvatures around both the non-Dirac Γ point and Dirac K/K′ points. These findings highlight the potential of monolayer NiAl₂Se₄ for applications in topological spintronics.

Ion-conducting oxide (ICO) electrolytes have contributed to the advancement of various electrochemical devices, from lithium-ion batteries to electrochemical sensors. Notably, the ICOs have also been used as solid electrolytes for printed thin film transistors (TFTs). However, the printed TFT technology typically aims for flexible electronic applications, where the high process temperature of ICOs creates a big hindrance. In this regard, in the present study, we propose and demonstrate an extremely low-temperature processable (∼120 °C) solid electrolyte in the form of hydrated lithium phosphate (Li₃PO₄). The fully inkjet-printed TFTs fabricated with amorphous indium gallium oxide (a-IGO) as the semiconductor material demonstrate excellent transistor performance parameters, such as high on–off ratio, high width-normalized on-current density (I_D,ON/W), and width-normalized transconductance (g_m/W) of 3.8 × 10⁸, 63.2 µA µm⁻¹, and 39.4 µS µm⁻¹, respectively, and a subthreshold slope close to the Boltzmann limit (61 mV decade⁻¹). The maximum and average linear field-effect mobility of the TFTs are estimated to be 42.8 and 28.9 cm² V⁻¹ s⁻¹, respectively. The unipolar, depletion-load-type pseudo-CMOS inverters demonstrate rail-to-rail switching for supply voltages from 0.5 to 2 V, with a signal gain up to 33.4 V/V. The present results demonstrate the emergence of a novel low-temperature processed ICO-based solid electrolyte for printed TFTs to be used in various printable, wearable, and portable electronic applications.

Defect engineering in semiconductors is one of the most effective techniques to enhance the sensitivity of the surface-enhanced Raman scattering (SERS) effect in semiconductor substrates. By carefully tailoring the oxygen vacancies in a wide bandgap semiconductor, such as Nb₂O₅, the charge transfer processes can be optimized to strengthen the chemical enhancement mechanism (CM). In the present study, oxygen vacancies were incorporated into 2D Nb₂O₅ nanosheets via a cost-effective UV-ozone treatment and were further integrated with plasmonic Ag, Au nanoparticles (NPs) to harness the synergistic effect of electromagnetic (EM) and CM enhancement mechanisms to contribute towards a superior SERS performance. An extraordinary enhancement factor of 6.75 × 10⁸ with a detection limit of 10⁻¹⁰ M was achieved with Ag nanoparticle decorated Nb₂O₅ nanosheets after UV-ozone treatment, for the detection of malachite green (MG) molecules. Remarkably, the same substrates were also effective for the sensitive detection of the antibiotic ciprofloxacin (CIP). The excitation wavelength has a major impact, which has been chosen in a way to maximize the contributions of both mechanisms. Furthermore, density functional theory (DFT) calculations and finite element method (FEM)-based simulations were employed to unravel the underlying mechanisms and to delineate their individual contributions to the overall SERS enhancement. This work paves a practical and scalable pathway to engineer highly sensitive and stable SERS substrates, underscoring the potential of defect-tailored metal–semiconductor hybrids for applications in environmental monitoring, food safety, and analytical sensing.

Copper-based organic–inorganic hybrid metal halides (OIMHs) have garnered extensive attention in X-ray imaging because of their flexible structural adaptability, efficient light emission, and strong X-ray absorption. Despite the growth of highly efficient luminescent crystals, the fabrication process of X-ray imaging films remains a critical step that can significantly affect the X-ray image resolution. The fabrication process of conventional X-ray imaging films involves grinding and mixing with a transparent, flexible polymer material to uniformly incorporate OIMH crystals into the polymer matrix. However, during the mixing process, the OIMH crystals tend to aggregate into large particles, which results in light reflection during luminescence and limits the X-ray image resolution. In this study, we address the abovementioned issue and demonstrate the fabrication of 0D copper halide (C₁₉H₁₈P)₂CuI₃@polymethyl methacrylate (PMMA) scintillation films using an in situ fabrication method. The in situ grown (C₁₉H₁₈P)₂CuI₃@PMMA scintillator film exhibits cyan emission with a high photoluminescence quantum yield of 82%, a high light yield of 26 800 photons MeV⁻¹, and excellent X-ray imaging with a high resolution of 11 lp mm⁻¹. Therefore, this in situ fabrication technique enables the production of large-area, low-cost X-ray imaging films with high light yield and high X-ray image resolution.