SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4312-8
Carbazole phosphonic acid-based self-assembled molecules (SAMs) serve as effective hole-selective contacts in organic solar cells (OSCs), yet their molecular packing and aggregation behavior during solution processing remain difficult to control, limiting hole transport and device durability. This study introduces a polymer-templated self-assembly strategy to regulate molecular organization by one-step spin-coating a blend of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz) and PEDOT:PSS. The polycationic PEDOT+ framework acts as a template, providing supplementary anchoring interactions that promote ordered molecular arrangement and suppress unfavorable agglomeration. Pronounced face-on orientation and enhanced structural coherence of 2PACz within the polymer matrix are evidenced. The templated ordering improves vertical charge transport, interfacial homogeneity, and film morphology. In binary OSCs based on PM6:BTP-eC9, the hybrid hole transport layers (HTLs) yield a champion power conversion efficiency (PCE) of 20.26%, with an open-circuit voltage (VOC) of 0.874 V, a short-circuit current (JSC) of 28.97 mA cm-2, and a fill factor (FF) of 80.02%. Devices incorporating hybrid HTLs exhibit exceptional operational stability, retaining over 90% of initial PCE (T90) after 405 h of continuous operation at the maximum power point (MPP). This work establishes polymer-directed SAM assembly as a scalable route to simultaneously optimize nanoscale molecular packing, interfacial energetics, and long-term device stability for high-performance OSCs.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4057-4
The escalating use of ionizing radiation in medical and industrial applications necessitates lead-free, flexible, and sustainable shielding materials. Current development relies on empirical trial-and-error, which is inefficient. This study introduces a machine learning-assisted Monte Carlo simulation strategy for rapid optimization of metal filler compositions for X-ray attenuation across 40–120 kV. Guided by this AI-driven approach, polyvinyl alcohol (PVA)-based gels containing uniformly dispersed Bi/W/Gd2O3 nanoparticles were developed, forming within 1 minute at -20°C using a PVA-DMSO/H2O co-solvent system. The optimized gel with 50 wt% metal loading exhibits exceptional mechanical properties: tensile strength of 1.76 MPa, toughness of 6.3 MJ m−3, and elongation of 600%. It achieves >98% X-ray shielding efficiency at 5 mm thickness, outperforming lead composites at 120 kV. The physically cross-linked network provides recyclability and anti-freezing capability, retaining flexibility at -50°C. This work establishes a data-driven paradigm for designing high-performance radiation-shielding materials, demonstrating AI's potential to accelerate materials discovery and enable scalable fabrication of eco-friendly protective systems.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4016-3
Rare earth-based electromagnetic wave (EMW) absorbing materials are promising due to their strong dielectric and magnetic loss capabilities, yet effective enrichment and utilization of rare earth ions remain challenging. Here, an anionic imidazolium-based metal-organic framework (MOF), MOZ-200, is employed to enrich multiple rare earth ions (La3+, Ce3+, Pr3+, Nd3+, Y3+) via host-guest interactions. The anionic framework uniformly confines these ions, which are converted in situ into highly dispersed high-entropy rare earth alloy nanoparticles during carbonization. The resulting HE@C composites feature a conductive, graphitized carbon matrix with abundant multi-scale polarization centers and heterogeneous interfaces, enhancing dipole polarization, interface polarization, and conductive loss. Consequently, the material achieves excellent EMW absorption in the Ku band, with a minimum reflection loss of -79.20 dB and a maximum effective absorption bandwidth of 5.23 GHz. Integrated into a polyurethane matrix, a multifunctional flexible device is realized, offering EMW absorption, photothermal heating, microwave de-icing, and hydrophobicity. This work provides a feasible strategy for rare earth ion utilization and advances the design of flexible multifunctional EMW absorbing materials.