Institute of Chemistry

Chiral framework materials offer a promising platform for exploring circularly polarized lasing. However, the creation of chirality in current optical gain framework materials relies on the chirality transfer, which suffers from weak chiral light-matter interactions and thus limits the dissymmetry factors of circularly polarized laser emission. Here, we propose to synthesize homochiral metal-organic frameworks (MOF) from chiral optical gain molecules to enhance chiral light-matter interactions, enabling circularly polarized lasing with large dissymmetry factors. The MOFs are grown controllably into 1D microcrystals to function as Fabry-Pérot cavities providing optical feedback for laser oscillations. In addition, the chiral optical gain molecules in the frameworks exhibit high luminescence efficiencies of ∼88% because the rigid frameworks effectively suppress nonradiative decay, resulting in low-threshold lasing. More importantly, the homochiral optical gain frameworks can enhance chiral light-matter interactions, which allows for circularly polarized laser emission with dissymmetry factors larger than 1.0. Our work establishes a homochiral framework material platform for exploring high-performance circularly polarized lasing.

Polymer thermoelectrics offer an inherently soft, cost-effective, and lightweight solution to convert ubiquitous heat sources into sustainable electricity. However, their realistic applications are hindered by insufficient performance and the scaling complexity. We introduce irregular hierarchical-porous thermoelectric polymers, featuring irregularly shaped and distributed pores with diameters that range from less than 10 nanometers to micrometers. This porous structure not only enhances multiple phonon-like scattering, achieving a 72% reduction in lattice thermal conductivity, but also unexpectedly improves charge transport through nanoconfinement-enhanced crystallization. The optimized film yields a benchmark figure-of-merit <i>zT</i> of 1.64 at 343 kelvin. Moreover, this method is compatible with easy-to-process spray-coating techniques.

Control of chiral assembly across length scales is desirable but challenging. Herein, we demonstrate controllable construction of microscopic chiral twists through hierarchical assembly of enantiomeric styrylpyridinium-derived glutamide amphiphiles (L/D-SPG). By combining variable-temperature spectroscopy with in-situ real-time optical microscopic observation, the dynamic chirality transfer process across spatial and length scales during assembly is elucidated. It is revealed that hydrophobic interactions between alkyl chains and intermolecular hydrogen bonds dominate the initial assembly of SPG oligomers, which subsequently elongate into microscopic twists through synergistic action of multiple non-covalent bonds under stereochemical control. The coherent cross-length-scale chirality transfer drives a dramatic amplification of chiroptical signals, evolving from undetectable circularly polarized luminescence (CPL) in the monomeric state and weak CPL with a small luminescence dissymmetry factor (|glum | = 2.8 × 10-3) in the non-hierarchical nanostructures to a |glum| value of 0.11 among single-component supramolecular gel systems. This work not only provides a direct spatiotemporal observation of chirality transfer from molecular to micron scales, but also establishes a supramolecular design strategy for high-performance CPL materials through optimized hierarchical organization.

Metal-organic framework (MOF) heterostructures featuring tunable morphologies and compositions have shown great promise for applications in high-throughput sensing, anti-counterfeiting, and information encryption. Nevertheless, the precise engineering of heterogeneous architectures with multi-dimensional building units remains challenging, primarily hindered by an insufficient understanding of the growth dynamics between modules of different dimensionality. Here, we demonstrate a facet-selective epitaxial growth approach for architecting spatially defined dimensional heterostructures via crystalline plane-selective reactivity control. The intrinsically higher surface energy at the tips of 1D microrods facilitates the nucleation of 2D modules on the terminal facets, thereby yielding dumbbell-like heterostructures. Conversely, by selectively enhancing the reaction activity on the body regions of the 1D templates, preferential nucleation and growth at the central areas over the tips were effectively achieved, which enables the controlled formation of periodic modular architectures through systematic regulation of surface energies. The facet-selective epitaxial growth paradigm establishes a pathway for synthesizing hierarchical dimensional heterostructures with tailored architectures, which show great promise for applications in advanced optoelectronics, anti-counterfeiting systems, and information encryption technologies.

Perovskite solar cells have achieved remarkable progress in photovoltaic efficiency. However, interfacial defects at the buried and upper interfaces of perovskite layer remain a critical challenge, leading to charge recombination, ion migration, and iodine oxidation. To address this, we propose a novel all-in-one modification strategy employing ammonia borane (BNH6) as a multifunctional complex. By incorporating BNH6 at both buried and upper interfaces simultaneously, we achieve dual-interfacial defect passivation and iodide oxidation suppression through three key mechanisms: (1) hydrolysis-induced interaction with SnO2, (2) coordination with Pb2+, and (3) inhibition of I- oxidation. This approach significantly enhances device performance, yielding a champion power conversion efficiency (PCE) of 26.43% (certified 25.98%). Furthermore, the unencapsulated device demonstrates prominent enhanced operation stability, maintaining 90% of its initial PCE after 500h under continuous illumination. Notably, our strategy eliminates the need for separate interface treatments, streamlining fabrication and offering a scalable route toward high-performance perovskite photovoltaics.

A series of non-fullerene acceptors with different side-chain lengths are designed. The side-chain length has remarkable impacts on fractal dimensions of the acceptors, leading to a big difference in efficiencies of organic solar cells.