SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4288-1
The high-temperature oxidation resistance of Cr2AlC MAX phase ceramics is severely compromised by rapid Al depletion and the formation of a brittle sub-surface Cr7C3 layer. This study elucidates how trace Y2O3 doping (0.25 and 0.5 wt.%) modulates the oxidation behavior of Cr2AlC at 1100 °C. The incorporation of 0.5 wt.% Y2O3 significantly suppresses the parabolic rate constant compared to undoped counterparts. This kinetic suppression is attributed to the Reactive Element Effect (REE), where Y3+ segregation at α-Al2O3 grain boundaries inhibits outward Al3+ diffusion, shifting the scale growth mechanism to inward oxygen diffusion control. Consequently, this retarded Al consumption prevents the decomposition of the Cr2AlC substrate into Cr7C3. While undoped specimens fail due to volume contraction and Kirkendall voiding associated with the Cr7C3 interlayer, specimens with the most effective doping content within the investigated range maintain a stable, atomically sharp α-Al2O3/Cr2AlC interface devoid of voids and decomposition products. The superior adhesion of this interface is attributed to three synergistic factors: the elimination of volumetric mismatch induced by phase transformation, the mechanical interlocking provided by Y-rich oxide pegs, and the intrinsically higher interfacial bonding strength of the α-Al2O3/Cr2AlC system as confirmed by DFT calculations. These findings provide a mechanistic framework for designing oxidation-resistant MAX phase ceramics via reactive element doping.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3630-2
This study demonstrates a dual-interface engineering approach for performance enhancement in perovskite-silicon tandem solar cells. By applying ethylenediamine dihydroiodide (EDAI2) to simultaneously modify both top and bottom interfaces of wide-bandgap perovskite layers, we achieve synergistic defect suppression and charge transport optimization. Time-resolved photoluminescence characterization reveals extended carrier lifetimes and improved spatial homogeneity in dual-modified perovskite films. The optimized single-junction wide-bandgap (>1.66 eV) perovskite solar cells attain a champion efficiency of 22.75% with enhanced operational stability. Implemented in perovskite-silicon tandem configuration, the devices achieve over 31% power conversion efficiency, validating the effectiveness of organic ligand-mediated dual-interface engineering in regulating carrier dynamics and advancing perovskite-based tandem photovoltaics.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4173-x
Ferroelectric memory, with its promise of low power consumption, high writing speed and exceptional endurance, requires the scaling of ferroelectric films to ultrathin dimensions—often just a few atomic layers thick. However, such extreme thinning risks destabilizing or even erasing electric polarization, mainly due to the detrimental depolarization field. Remarkably, certain ferroelectrics exhibit an intrinsic immunity to this effect, as predicted theoretically and confirmed experimentally. Examples include improper ferroelectrics, hyper ferroelectrics, engineered heterostructures, and low-dimensional van der Waals ferroelectrics. This review systematically examines these unique materials, unravelling the fundamental physics behind their polarization robustness and the mechanisms enabling them to resist the depolarization field. By bridging theory with experimental advances, we aim to inspire the design of next-generation ferroelectrics capable of overcoming critical challenges encountered in practical ferroelectric memory devices.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4117-y
Real-time, in situ imaging of hydrogen peroxide (H2O2), a key reactive oxygen species implicated in various diseases, remains challenging due to limitations of existing probes, such as short emission wavelengths and reliance on external excitation. To address these issues, we developed an H2O2-triggered near-infrared (NIR) chemiluminescence (CL) nanoprobe with aggregation-induced emission (AIE) characteristics for in vivo inflammation imaging and tumor theranostics. This nanoprobe, denoted as CPPO@TN NPs, was constructed by co-encapsulating a tailored AIE photosensitizer (TN) with strong NIR emission and high singlet oxygen (1O2) generation, a H2O2-responsive chemiluminescent substrate (CPPO), and soybean oil (as a retarder) within F-127 micelles. Upon encountering H2O2, the nanoprobe undergoes a persistent chemically initiated electron exchange luminescence (CIEEL) process that activates AIEgens, resulting in intense NIR chemiluminescence and sustained 1O2 production without the need for external irradiation. Leveraging this mechanism, CPPO@TN NPs achieved highly sensitive and specific imaging of drug-induced liver injury and peritonitis in murine models, with exceptional tissue penetration and signal-to-noise ratio. Furthermore, the nanoprobe facilitated effective self-luminescent imaging and photodynamic therapy of tumors, significantly inhibiting tumor growth in a 4T1 tumor-bearing mouse model. This platform provides an external light excitation-free theranostic strategy for H2O2-associated diseases.