SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3582-9
Perovskite quantum dots (PQDs) hold great potential for brain-like neuromorphic computing. However, the development of PQDs-based synaptic devices is hindered by interfacial defects and limited stability. Here, we demonstrate a high-performance Cs2AgBiBr6 QDs/organic single crystal heterojunction synaptic device, fabricated via a novel space-confined vertical growth technique combined with a polymer-free transfer process. Vertically grown organic single crystals enable superior carrier mobility and facilitate the formation of low-defect interfaces with PQDs. The heterojunction exhibits remarkable photosensitivity (7.22 × 10^5 at 425 nm) and detectivity (2.15 × 10^15 Jones), owing to the strong optical absorption of PQDs coupled with the superior charge transport characteristics of organic single crystals. Notably, the device achieves dual-functional light adaptation, emulating synaptic behaviour under blue light while exhibiting photo-switching under green/red light. This unique capability enables smart blue-light hazard protection. This work not only provides a versatile platform for high-performance PQDs-based synaptic devices but also advances the development of brain-inspired neuromorphic systems for next-generation computing and intelligent sensing.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3885-8
Photocatalytic production of hydrogen peroxide (H2O2) via oxygen reduction reaction (ORR) and water oxidation reaction (WOR) from water and air offers a sustainable alternative to conventional anthraquinone processes. However, the intrinsic kinetic mismatch—fast ORR (microseconds to milliseconds) versus sluggish WOR (seconds)—limits overall efficiency. Here, we report aliphatic acylhydrazone covalent organic frameworks (AA-COFs) synthesized by coupling aliphatic hydrazides with benzotrithiophene motifs via acylhydrazone linkages. The pore walls are decorated with abundant S, O, and N heteroatoms, enhancing affinity toward both O2 and H2O, thereby improving the kinetics of both half-reactions. Through single-carbon atomic engineering, the optimized AA-COF achieves a trade-off between ORR and WOR kinetics, enabling efficient overall H2O2 photosynthesis from water and air without sacrificial agents. The material exhibits a H2O2 production rate of 4777 μmol g−1 h−1 and an O2 utilization/conversion efficiency of 99.3%. This work demonstrates that rational design of heteroatom-rich COFs can synchronize ORR and WOR, overcoming a major bottleneck in artificial photosynthesis.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3332-4
Current high-performance inorganic scintillators, including ceramics and perovskites, suffer from complex manufacturing, environmental toxicity, self-absorption, and stability issues, while organic alternatives exhibit weak X-ray absorption and inefficient triplet exciton utilization. Lanthanide ions offer high energy conversion efficiency and tunable luminescence, yet organolanthanide molecules remain underexplored due to limited understanding of excitonic dynamics. This work introduces a molecular design strategy achieving ultrabright scintillation through lanthanide-assisted near-unity triplet exciton recycling. By engineering organic ligands to reclaim energy lost during secondary X-ray relaxation, radioluminescence (RL) enhancements exceeding three orders of magnitude are demonstrated relative to existing organic and commercial inorganic scintillators. Precise alignment of ligand triplet energy levels with emissive states of Eu3+ and Tb3+ enables near-unity energy transfer efficiency (>99%) via resonance energy transfer. Europium complexes with aromatic diketones, particularly 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione (NTA), exhibit superior RL intensity due to a tailored triplet energy of 19,600 cm−1, slightly exceeding the 5D0 level of Eu3+ (17,200 cm−1), suppressing back-transfer and yielding 100-fold RL enhancement over EuCl3. Coordination saturation with DPEPO and PHEN further optimizes exciton confinement, achieving a 1000-fold RL enhancement for Eu(NTA)3DPEPO. Mechanistic studies reveal that f-f transition systems achieve >99% triplet exciton recycling via Dexter-mediated energy transfer, whereas d-f systems (Ce3+, Eu2+) rely on direct 5d-4f excitation with high PLQY (~100%) but limited X-ray sensitivity due to narrow ligand absorption (<250 nm) and ultrafast decay (50 ns). These findings establish triplet exciton harvesting, not PLQY, as the key determinant of scintillation performance.