SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4263-3
Monolayer black phosphorus (phosphorene) exhibits a direct bandgap and strong in-plane anisotropy, making it a promising candidate for near-infrared (NIR) optoelectronic devices. However, the precise modulation of its excitonic emission via anisotropic strain remains insufficiently understood, particularly regarding the contrasting strain responses of phosphorene versus transition metal dichalcogenides (TMDs). Here, we combine experimental characterization with tight-binding (TB) modeling to elucidate the strain-dependent bandgap evolution in phosphorene. Using a four-band TB model, we derive the bandgap at the Γ point as E_g^BP = 4t1 + 2t2 + 4t3 + 2t5, with hopping parameters t1 = -1.220 eV, t2 = 3.665 eV, t3 = -0.205 eV, t4 = -0.105 eV, and t5 = -0.055 eV. Under tensile strain along the zigzag (ZZ) direction, the interatomic distance associated with t1 increases, reducing the magnitude of |t1|. Since t1 is negative, the bandgap increases, contrary to the behavior of monolayer MoS2, where tensile strain decreases the bandgap due to positive hopping parameters t11, t22, and t12. This anisotropic strain response enables selective tuning of NIR exciton emission. Our findings provide a quantitative framework for strain engineering in phosphorene-based NIR devices, highlighting the critical role of hopping parameter signs in determining bandgap modulation.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4315-2
High-temperature X-ray imaging demands scintillators with high crystallinity, efficient scintillation, and robust thermal stability, yet suitable materials remain scarce. Here, we report an ultra-high-crystallinity transparent glass-ceramic (GC) scintillator strategically designed via controllable heat-treatment-induced crystallization. A sequential precipitation method is employed, where cubic CaF2 nanocrystals initially form, subsequently promoting heterogeneous nucleation and growth of hexagonal BaAl2Si2O8. Intrinsic nanoscale phase separation into F-rich and O-rich domains significantly reduces atomic diffusion distances, yielding an unprecedented crystallinity of up to 97.6%. Notably, defect traps (oxygen vacancy defects, likely located within the lattice or at crystalline/amorphous interfaces) enable efficient carrier capture and thermally stimulated release, contributing to remarkable resistance to thermal quenching. Consequently, the GC scintillator maintains 90.6% of its integrated X-ray excited luminescence (XEL) intensity at 300 °C, with the integrated XEL intensity reaching 94.2% of commercial Bi4Ge3O12 (BGO) at room temperature. This enables stable high-temperature X-ray imaging with a spatial resolution of ~10.4 lp mm−1 up to 225 °C. This work provides a versatile pathway for developing high-sensitivity scintillators for extreme-environment X-ray imaging.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3642-4
High-density glass scintillators are promising alternatives to crystals for next-generation radiation detection due to their low cost, excellent physical and chemical stability, and processability. In this study, a series of Ce3+-activated gadolinium gallium borosilicate (GGBS x) glasses were synthesized via vacuum melt-quenching. With increasing Gd2O3 content, glass density increased from 5.86 to 6.05 g/cm3, and molar volume from 36.43 to 39.79 cm3/mol. Extended X-ray absorption fine structure (EXAFS) analysis revealed that in GGBS 1 glass, Ce3+ exclusively adopts a hexahedral [CeO6] configuration, while Gd3+ exhibits both hexahedral and octahedral coordination with a bond length of 2.35±0.1 Å and Debye-Waller factor σ2 of 0.0122±0.0015 Å2. As Gd2O3 content increased, shallow trap depth rose from 0.804 to 0.858 eV, while deep trap depth first increased from 0.948 to 1.434 eV then decreased to 1.010 eV. GGBS 1 glass exhibited high transmittance (~80%) in the visible range and a photoluminescence quantum yield of 78.4%. Under X-ray irradiation, its X-ray excited luminescence intensity reached 128.5% of that of Bi4Ge3O12 (BGO) crystal, with a spatial resolution of 29.1 lp/mm, approaching the highest reported for glass scintillators. Under γ-ray excitation, it achieved a light yield of 1058 photons/MeV and an energy resolution of 23.7% at 662 keV. These results indicate that GGBS 1 glass scintillator warrants further development for applications in X-ray imaging and γ-ray spectroscopy.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3692-9
Doping is essential for modulating semiconductor conductivity, forming p–n junctions, and reducing contact resistance. However, organic semiconductors (OSCs) face challenges in achieving precise regional doping due to uncontrollable dopant diffusion and poor process compatibility. This highlight discusses a breakthrough light-triggered strategy for spatially controlled n-type doping in OSCs, developed by Pei's Group. The method employs inert photoactivable dopants (iPADs) that are thermally stable but undergo rapid 6π-electrocyclization upon UV irradiation, transforming into potent n-dopants (PADs). These PADs irreversibly dope n-type OSCs via hydride transfer. With a high activation barrier (>28 kcal mol−1), the reaction is thermally suppressed even at 120°C, enabling orthogonal control: doping occurs only where and when light is applied. This approach achieves down to 1 μm spatial resolution, far surpassing physical masking methods. The method's universality accommodates diverse n-type OSCs (LUMO: −3.7 to −4.7 eV) with conductivity enhancements up to nine orders of magnitude (exceeding 30 S cm−1 in some systems). Doping levels, conductivity, and Fermi energy are tunable via UV dose and dopant concentration. The doped regions exhibit robust stability and withstand subsequent thermal processing, aligning with large-scale and flexible manufacturing. In organic field-effect transistors, precise spatial doping significantly enhances carrier mobility, reduces contact resistance to one-sixth of its original value, and effectively lowers surface trap density, providing critical support for device miniaturization and high-density integration.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3966-0
The development of low platinum-loading catalysts for the economically viable hydrogen evolution reaction (HER) remains challenging. Herein, a precursor dilution strategy is used to fabricate Pt nanoclusters anchored on Ni-embedded porous carbon microspheres. The approach begins with the facile synthesis of Zn/Ni-based coordination polymers (Ni-BTC-Zn) due to the isomorphic substitution of Zn2+ and Ni2+. During pyrolysis, the evaporation of zinc species results in a highly porous carbon structure with well-dispersed nickel nanoparticles. Subsequent solvothermal treatment allows for the uniform deposition of Pt nanoclusters to form the final bimetallic PtNi catalysts (PtNi-BTC-C). Among them, the optimized PtNi-BTC-C10 exhibits exceptional alkaline HER performance, requiring an overpotential of only 41 mV to achieve 10 mA cm−2 and a low Tafel slope of 31.1 mV dec−1. It also demonstrates outstanding durability with a current retention of 90.7% after 70 h, far exceeding Pt/C. Extensive characterization confirms that moderate Zn dilution optimally modulates the Ni particle size and dispersion, leading to maximized active sites and enhanced charge transfer. Combined with DFT calculations, the Pt-Ni-cluster model for PtNi-BTC-C10 possesses an optimized electronic structure with a shifted d-band center, which facilitates water dissociation and optimizes H* desorption with the most favorable energetics (0.262 eV). This work provides a fundamental understanding of precursor dilution engineering and offers a versatile pathway for designing advanced noble-metal-based bimetallic electrocatalysts.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3861-4
Multi-resonance thermally activated delayed fluorescence (MR-TADF) emitters are pivotal for achieving high color purity and 100% internal quantum efficiency in organic light-emitting diodes (OLEDs). However, extending emission to the red region (>600 nm) remains challenging due to limited MR cores and the synthetic complexity of fused-ring extensions. Here, we report a novel strategy that breaks the fused ring by employing a linear conjugated diene linker between nitrogen and carbonyl moieties, enabling simultaneous introduction of three MR units in one step with high yield. Two emitters, NF-CON1 and NF-CON2, exhibit pure-red emission at 620 nm with narrow full-width at half-maximum (FWHM) below 35 nm in dilute toluene, small Stokes shifts of 26 nm, and weak solvatochromic shifts (~25 nm from toluene to ethanol), confirming the MR-characteristic short-range charge transfer. The emitters show low reorganization energies (0.209 eV for NF-CON1 and 0.194 eV for NF-CON2), singlet-triplet energy gaps of ~0.2 eV, and high reverse intersystem crossing rates of ~3.0×10^5 s^-1. In doped films with m-MTDATA, delayed lifetimes of 31–40 μs are achieved. These properties, combined with high oscillator strengths, ensure efficient RISC and high IQE. The facile synthesis and solution-processability of this MR-TADF skeleton address the bottlenecks of cost and scalability, offering a promising route for practical pure-red OLEDs.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3551-5
Flexible photonic crystal (PC) materials exhibit exceptional optical properties but suffer structural degradation under repeated mechanical stress, leading to photonic band gap impairment and limited sustainability. This study introduces a self-healing thermoplastic polyurethane (STPU) with an inverse-opal PC structure, inspired by natural structural coloration and self-healing mechanisms. Synergistic dynamic covalent disulfide bonds and hydrogen bonds enable reversible mechanical adjustment, yielding a tensile strength of 26.76 MPa and elongation at break of 2000%. The inverse opal structure facilitates reversible color transitions in response to solvents (water, ethanol) and mechanical strain (0–70%) via lattice spacing modulation. Incorporating an interpenetrating network of polyacrylamide hydrogel and carbon nanotubes enhances strain sensitivity and structural color stability. The material demonstrates broad potential in flexible sensors, adaptive optical devices, bioinspired robotic skins, and dynamic anti-counterfeiting encryption, overcoming traditional PC limitations such as high fragility and single functionality. This strategy advances durable intelligent sensing materials with enhanced environmental adaptability and multifunctional integration.