SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4269-4
Self-assembled molecular interlayers (SAMs) are promising hole-selective contacts for high-efficiency organic solar cells (OSCs) due to their well-defined energy alignment and minimal parasitic absorption. However, their intrinsically limited mechanical robustness often leads to structural degradation and performance loss under mechanical deformation, restricting their application in flexible devices. Here, we report a nanoparticle-reinforced self-assembled composite interface that simultaneously enhances mechanical reliability and optoelectronic performance. Uniformly dispersed SiO2 nanoparticles are introduced as high-modulus reinforcing building blocks without disturbing molecular self-assembly. In contrast to NiOx nanoparticles, which suffer from aggregation and parasitic absorption, SiO2 nanoparticles exhibit excellent dispersion and optical transparency, enabling formation of a structurally compatible hybrid interface. Mechanistic studies reveal that SiO2 nanoparticles redistribute interfacial stress and form dynamic hydrogen-bond networks with phosphonic acid groups of 2PACz, providing efficient energy dissipation during cyclic deformation. Meanwhile, modulation of interfacial polarity extends the crystallization time window of the active layer, resulting in enhanced molecular ordering and improved charge transport. As a result, devices based on the SiO2/2PACz composite interface achieve a power conversion efficiency of 20.14% for rigid devices and 19.30% for flexible devices, placing the flexible devices among the highest-performing flexible OSCs reported to date, while retaining over 90% of their initial efficiency after repeated bending cycles. This work establishes a general strategy for overcoming the trade-off between electronic selectivity and mechanical robustness in ultrathin self-assembled molecular interfaces, providing design insights for high-performance flexible organic optoelectronics.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3487-x
Continuous carbon fiber-reinforced ZrB2-SiC ceramic matrix composites are promising thermal protection materials for hypersonic vehicles and reusable spacecraft. Although injection-assisted vacuum impregnation (IVI) offers advantages such as shorter processing cycles, lower costs, and reduced fiber damage compared to conventional methods, phenolic/acetone-based IVI systems yield composites (designated as CPS) with limited ceramic contents. To address this, an aqueous slurry-based IVI approach was developed, producing composites designated as CHS. After a single IVI cycle, CHS achieved a ZrB2 phase volume fraction of 25 vol.%, 47% higher than CPS, while reducing processing time by 49%. After chemical vapor infiltration, CVI-CHS composite exhibited a room-temperature compressive strength of 106.78±10.53 MPa, representing a 28% improvement over CVI-CPS. Crack propagation analysis revealed discontinuous zigzag patterns under compression, dominated by fiber bridging and pull-out energy dissipation mechanisms. Flexural results revealed both composites retain considerable strength (111.15±12.46 and 83.15±12.03 MPa) along with low flexural modulus (13.00±2.41 and 13.52±6.99 GPa) and high strain tolerance (1.32%±0.018% and 1.07%±0.34%). It is attributed to the anisotropy of fiber preforms and the elastic modulus mismatch among different phases, which hindered effective constraint of fibers by the matrix and, in turn, facilitated mitigation of stress concentration. Additionally, CVI-CPS demonstrated superior X-band electromagnetic interference (EMI) shielding (34–36 dB) compared to CVI-CHS (22–27 dB), resulting from synergistic effects between pyrolitic and deposited carbon in the matrix of the former. Both composites showed enhanced EMI shielding efficiency with increasing temperature up to 600°C. This eco-friendly aqueous IVI strategy enables high-performance, cost-effective thermal protection materials with higher ceramic loading and tunable multifunctional properties.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3995-6
The deployment of single-site metal catalytic nodes into zirconium-based metal-organic frameworks (Zr-MOFs) offers vast advantages in catalytic recyclability, product separation, and mechanistic analysis, underscoring their paramount significance in heterogeneous catalysis. Nonetheless, their occupation within pores/channels usually diminishes mass transfer and catalytic efficiency during reactions such as the hydroboration of carbonyl compounds, especially for bulkier substrates. To address this issue, three microporous single-site Ti(IV) embedded Zr-MOFs with sequentially extended ligand arms are novelly synthesized to enable precise pore modulation ranging from 9.04, 10.12, to 11.18 Å. The catalytic performance is investigated using eight carbonyl compounds of varying sizes and four additional larger-scale substrates, which demonstrates that the catalytic efficiency is increased through pore size regulation, yet still away from optimal catalytic performance. Then a further strategy was shifted to the linker installation of linear dicarboxylate ligands chelated single-site Ti(IV) within coordination-unsaturated windows of mesoporous Zr-MOFs, and the result elucidates that the obtained catalyst exhibits superior catalytic efficiency (all exceeding 90%) while preserving the inherent mesoporosity of Zr-MOFs with a pore size of approximately 21.73 Å. We believe this research provides critical guidance for future research on structural design and catalytic optimization of MOFs, opening new avenues in heterogeneous catalysis.