Science China Materials最新文献

Developing an economically efficient process to fabricate thermoelectric materials with remarkable figures of merit is essential for expanding its commercial application. Herein, a self-created extensional rheological technology is used to fabricate high-quality thermoelectric cooling materials. Pyrrole monomers are grown on the Ni_0.49Cu_0.59, and subsequently, uniformly dispersed within the polyethylene (PE) under an extensional flow field, establishing a continuous conductive network. The PE/polypyrrole@constantan (PE/Ppy@Ni_0.49Cu_0.59) composite exhibits an electrical conductivity of 1699.8 S cm⁻², a thermal conductivity of 13.9 W m⁻¹ K⁻¹, and a thermoelectric figure of merit (ZT) of 0.16 at 25 °C. Integrated with PE/Ppy@iron, the thermoelectric device exhibited a temperature reduction of 0.4 °C under a 30 V/0.3 A direct current excitation. To enhance performance, the application of square-wave pulsed currents effectively stabilized the thermoelectric cooling efficiency at its optimum level. Furthermore, the implementation of a custom-designed thermal insulation system significantly mitigated parasitic heat loss to the ambient environment. Collectively, these engineered enhancements achieved a total temperature reduction of 1.6 °C. This study provides an effective approach to fabricating thermoelectric materials, and it is promising to realize low-cost, large-scale commercialization of thermoelectric cooling.

Perovskite solar cells provide an economically viable and highly efficient pathway to harness solar energy. However, the instability of the organic component in hybrid perovskites presents a fundamental challenge that constrains the longevity and performance of perovskite photovoltaics. In this study, we introduce a molecular deuteration strategy to stabilize FAPbI₃ perovskite by replacing the active hydrogen in the N–H bond with its heavier isotope, deuterium. The reduced ground-state energy of the isotopic N–D bond induces a deuteration kinetic isotope effect, which significantly decreases the rate constant of the deprotonation reaction from 5.15 × 10⁻⁸ to 2.42 × 10⁻⁸ s⁻¹. Solar cells fabricated using deuterated FAPbI₃ thin films achieve a power conversion efficiency of 25.08% and exhibit a T₉₇ lifetime of 1264 h under continuous one-sun illumination at 55 °C. This approach paves the way for developing inherently stable perovskite materials and extending the operational lifespan of solar cell devices.

The 12-lead electrocardiogram (ECG) plays a crucial role in the initial diagnosis of cardiac conditions. However, reports on ECG monitoring utilizing neuromorphic hardware indicate that monitoring multi-lead ECG signals and generating conclusive assessment results necessitate multiple array circuits and two operational processes, which present challenges regarding device consistency and accuracy. In this study, we propose a neuromorphic parallel computing hardware architecture based on quantum dot synaptic transistors. Leveraging the trap effect and surface electric field effect inherent to quantum dots, our approach enables 12-lead ECG monitoring within a single array circuit, eliminating the need for twelve separate circuits. This system can concurrently process multiple ECG signals and produce final result outputs without reliance on external computing or control circuits. Furthermore, the training accuracy achieved for classifying various ECG signals exceeds 98%.

Porous membranes with superhydrophobic surfaces have been developed to prevent pore wetting during membrane distillation (MD) for the desalination of hypersaline wastewater. However, these superhydrophobic MD membranes often suffer from scaling and pore wetting during prolonged operation due to the depletion of surface-trapped air cushions. This degradation is attributed to the enhancement of surface hydrophobicity rather than bulk hydrophobicity throughout the membrane. In this work, we simultaneously enhance the hydrophobicity of both the membrane surfaces and pore surfaces of porous membranes by constructing nanostructures using hydrophobic nanoparticles. The resulting membranes exhibit a 31.3% increase in the specific liquid entry pressure of water (reaching 0.109 bar µm⁻¹) compared to membranes with only surface superhydrophobicity, indicating improved resistance to pore wetting. As a result, these membranes exhibit stable permeate flux (16.2 kg m⁻² h⁻¹) and high salt rejection (>99.9%) when treating 70 °C brines (105 g L⁻¹) in MD. The high pore wetting resistance against gypsum-containing saline is further demonstrated through cyclic MD desalination over 30 h, indicating strong potential on the development of high-performance MD membranes for hypersaline wastewater treatment.

Intramolecular noncovalent conformational locks (NoCLs) have emerged as an important strategy for developing high-performance organic/polymeric semiconductors (OPSs) via suppressing the non-radiative decay. Despite extensive investigation into the impact of NoCLs on small molecules, elucidating their influence on the physicochemical properties of conjugated polymers (CPs) remains a critical challenge. By employing a combination of theoretical and experimental methods, it is revealed that the incorporation of NoCLs increases the rigidity of the polymer chain, enhances intermolecular interactions, promotes the formation of pre-aggregates of optimal length, and improves charge transport, providing valuable insights for designing high-performance CPs.

The activity and stability of single-atom catalysts (SACs) are intimately associated with the structure of supports. Herein, by employing a van der Waals (vdW) heterostructure support, we construct a highly active and durable Pt SAC for hydrogen evolution reaction (HER). The unique support consists of monolayer MoS₂ attaching on hierarchical N-doped carbon nanocages (hNCNC), on which Pt presents as individual single atoms on the hNCNC and as island-like single-atom layers on the MoS₂. The optimized Pt₁-MoS₂/hNCNC demonstrates low overpotential (11 mV at 10 mA cm⁻²) and high mass activity (5.6 A mg_Pt⁻¹ at −20 mV) in 0.5 M H₂SO₄ solution, outperforming commercial Pt/C. Impressively, the Pt₁-MoS₂/hNCNC exhibits improved long-term stability in proton exchange membrane water electrolyzer relative to commercial Pt/C. The excellent HER performance is attributed to the regulated electronic structure, robust interaction of Pt atoms with MoS₂/hNCNC and facilitated charge transfer. This study establishes an innovative strategy to develop a highly active and durable Pt SAC using vdW heterostructure supports.

Thick-film organic solar cells (OSCs) are critical for large-scale manufacturing, yet they face persistent challenges of severe energy loss and complex morphology control. The integration of molecular design and device engineering is widely recognized as a promising strategy to address these bottlenecks. Here, we report the synthesis of a fluoropolymer PF8 and its application in combination with fluorous solvent vapor annealing (FSVA) post-treatment to fabricate high-performance thick-film OSCs. The fluorination strategy and FSVA process synergistically enhance the polymer’s crystallinity and induce an intrinsic fibrous morphology. As a result, the FSVA-treated PF8:L8BO device with a thickness of 110 nm achieves a power conversion efficiency (PCE) of 18.89%. Notably, even when the film thickness is increased to 300 and 500 nm, the devices maintain high efficiencies of 17.54% and 15.59%, respectively. More importantly, the 300-nm FSVA-treated blend films exhibit enhanced packing order and well-defined fibrillar morphology, leading to suppressed non-radiative recombination and efficient charge transport along the fiber network. This study demonstrates the potential of combining fluoropolymers with fluorous solvent-based device engineering for advanced thick-film optoelectronic applications, providing a viable pathway for scalable OSC manufacturing.

Natural surfaces with heterogeneous wettability inspire innovations in functional materials. Lubricant-infused slipperiness and heterogeneous three-dimensional (3D) micro-textures are emerging performers, displaying diversified interface features and spatial topologies. However, how to construct well-defined heterogeneous wettability on 3D micro-textures to create stable heterogeneous slippery surfaces remains challenging. Here, a 3D micro-heterogeneous wetting surface, featuring a lubricant sea dotted with superhydrophilic micro-islands, was fabricated via an innovative method without costly techniques. Tunable micro-island dimensions are supported for stable lubricant retention and programmable slipperiness. The flexibility and vertical heterogeneity enable the film advanced functions of deformation-responsive convertible adhesion and high-performance water collection. This work can greatly boost interfacial materials and extend their application in intelligent microfluidics and sustainable systems.

Two-dimensional (2D) BiOBr has garnered significant interest due to its exceptional optoelectronic properties. Currently, reported 2D BiOBr primarily exhibits n-type conductivity. However, in the field of optoelectronics, particularly within complementary metal oxide semiconductor (CMOS) integrated circuits, there is an urgent demand for high-quality p-type 2D semiconductors. In this study, we present the synthesis of high-quality, large-scale p-type 2D BiOBr crystals using chemical potential modulation chemical vapor deposition (CPMCVD). Notably, the conduction polarity of 2D BiOBr can be precisely controlled by modulating the oxygen chemical potential during the synthesis process. Density functional theory (DFT) calculations indicate that high oxygen chemical potential promotes the formation of bismuth vacancies in 2D BiOBr, resulting in p-type conductivity. Conversely, as the oxygen chemical potential decreases, oxygen vacancies become the predominant defects, leading to n-type BiOBr. Furthermore, both p-type and n-type high-performance field-effect transistors (FETs) based on 2D BiOBr have been fabricated. The p-type FETs exhibit a superior hole mobility of 26.28 cm² V⁻¹ s⁻¹ and on/off ratio exceeding 10⁴. The n-type FETs demonstrate an electron mobility of 59.59 cm² V⁻¹ s⁻¹, surpassing those reported for most n-type FETs. This breakthrough in the precise control of conduction polarity in 2D BiOBr using CPMCVD not only represents a significant milestone but also greatly expands its potential applications in advancing CMOS technology.

Two-dimensional metal halide perovskites (2D MHPs) have garnered significant attention for their promising optoelectronic properties, driven by strong excitonic effects and structural tunability. Their photoelectric properties are directly determined by their exciton behavior. Here, we investigate the impact of halogen doping on exciton dynamics and emission characteristics in PEA₂Pb(Br_1−xCl_x)₄. Systematic Cl-doping engineering induces a remarkable spectral evolution, characterized by a transition from blue emission to white-light emission. This transformation correlates with a unique switching behavior between extrinsic and intrinsic self-trapped exciton (STE) states, as revealed through combined analysis of excited-state transitions and carrier dynamics. Temperature-dependent photoluminescence studies coupled with lattice distortion analysis demonstrate that doping induces subtle structural perturbations within the inorganic framework. These minimal lattice modifications fundamentally reconfigure excitonic behavior. The doping-dependent competition between intrinsic polaronic self-trapping and defect-mediated trapping mechanisms accounts for the observed spectral broadening. Specifically, Cl incorporation below 0.2 preferentially enhances intrinsic STE formation through lattice softening, while higher doping levels introduce defect-assisted trapping pathways. This dual-channel trapping model, validated by temperature-activated detrapping kinetics and transient absorption spectroscopy, provides new insights into defect engineering strategies for tailoring emission characteristics in low-dimensional hybrid perovskites.