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On February 6, 2025, the internationally renowned academic journal Nature published a groundbreaking study titled "Metal-Halide Porous Framework Superlattices" by Prof. Yong CUI’s group and collaborators. The research was primarily conducted at the School of Chemistry and Chemical Engineering, the Frontiers Science Center for Transformative Molecules, and the State Key Laboratory of Metal Matrix Composites at Shanghai Jiao Tong University (SJTU). Doctoral student Wenqiang ZHANG is listed as the first author, while Prof. Yong CUI from SJTU, Prof. Xiangfeng DUAN from UCLA, and Prof. Yihan ZHU from Zhejiang University of Technology acting as corresponding authors. The study also benefited greatly from the substantial contributions of Prof. Dehui LI from Huazhong University of Science and Technology, Prof. Jianwen JIANG from the National University of Singapore, and Prof. Qun ZHANG from the University of Science and Technology of China in the fields of chiral optics, molecular dynamics simulations, and ultrafast spectroscopy, respectively.

Superlattice materials, characterized by their tunable periodic potential landscapes and precise layered structures, exhibit adjustable electronic and optical properties, making them widely applicable in areas such as two-dimensional electron gases, high-electron-mobility transistors, and quantum cascade lasers. Traditional growth techniques, such as molecular beam epitaxy and chemical vapor deposition, enable sub-nanometer thickness control but limit further advancements in superlattice materials. Currently, superlattice materials are transitioning from traditional semiconductor superlattices to self-assembled systems composed of multi-scale building blocks, including nanoparticles, nanowires, nanosheets, and molecules. However, self-assembled superlattices are often constrained using building units of the same dimension or complementary topologies, limiting their structural diversity and functional tunability. Heterogeneous/multi-dimensional superlattices, assembled from building units of different dimensions, offer novel electronic, optical, and quantum properties, significantly enriching the superlattice family. Particularly, chiral superlattice materials hold immense potential in chiral optics, chiral electronics, and chiral superconductors. Nevertheless, the precise synthesis and atomic-level structural characterization of single-crystalline, multi-dimensional superlattices remain challenging due to structural disorder at the interfaces of building units. Thus, developing new synthetic strategies to achieve the preparation and structural resolution of single-crystalline superlattices is a critical challenge in interdisciplinary fields such as coordination chemistry, synthetic chemistry, and materials chemistry.

Prof. Yong CUI’s group has long been dedicated to research on chiral aggregation and crystallization, focusing on innovations in heterogeneous asymmetric catalysis, chiral separation, and optoelectronic functional materials and devices. By developing novel chiral porous materials, the team has driven rapid progress in related fields (Nat. Synth., 2025, 4, 43–52; Nat. Chem., 2024, 16, 1398–1407; Nature, 2022, 602, 606–611; Chem. Rev., 2022, 122, 9078–9144; J. Am. Chem. Soc., 2024, 146, 31807–31815). To address the scientific challenges in single-crystalline superlattice research, the team proposed a "MOF template" strategy. Utilizing Zr-MOF coordination templates and the guiding role of unsaturated coordination nodes in zirconium clusters, they successfully synthesized a series of highly ordered single-crystalline porous superlattice frameworks. By in situ confined growth of metal halides (e.g., PbI₂, PbBr₂, CdI₂, and NiBr₂) within three-dimensional Zr-MOF frameworks, the team achieved precise integration with the MOF lattice, resulting in multi-dimensional single-crystalline superlattice frameworks. Additionally, the study realized chiral transformation and chiral optical functional modulation, opening new avenues for the construction and application of chiral materials.

Fig. 1: Structural characterizations of multi-dimensional PbI₂@MOF superlattices.

The research team demonstrated that the pore environment of MOFs (e.g., cavity size, shape, and direction of adjacent binding sites) plays a critical role in tuning the dimensionality of metal-halide sublattices (zero-dimensional, one-dimensional, and two-dimensional). These superlattice crystals were characterized using single-crystal X-ray diffraction (SC-XRD) and low-dose high-resolution transmission electron microscopy (HR-TEM) (Fig. 2), confirming the high-order superlattice structure with precise atomic coordinates.

Fig. 2: Low-dose cryogenic HR-TEM images of PbI₂@MOF superlattices.

To further explore the confined nucleation and growth mechanism, the team conducted time-dependent nucleation control experiments to monitor the in situ growth of PbI₂ within MOFs. Using PCN-606 as an example, as shown in Fig. 3, the formation process of PbI₂ sublattices was precisely monitored through SC-XRD data, evolving from partially filled zero-dimensional nanoclusters (PbI₂@PCN-606-I, II, III) or one-dimensional nanosheets (PbI₂@PCN-606-IV) to fully filled two-dimensional nanolayers (PbI₂@PCN-606-V).

Fig. 3: Monitoring of the intermediates during the stepwise growth.

Leveraging the optoelectronic properties of PbI₂-based materials and the porous nature of single-crystalline PbI₂@MOF superlattices, the authors introduced organic amine ligands into the porous superlattice framework via a simple molecular diffusion method, forming organic-inorganic hybrid perovskite-like structures. This modification altered the electronic band structure, charge carrier dynamics, and photoluminescence properties of the superlattices. Under the modification of different amine molecules, the perovskite-like superlattices exhibited dimension-dependent photoluminescence and chirality-induced circularly polarized luminescence (Fig. 4). Notably, the chiral polarization ratio (P) reached up to 29%, the highest value reported for organic-inorganic lead iodide hybrid materials, which is crucial for the development of spintronic devices and advanced photonic systems. This structure/dimension-dependent optoelectronic performance holds significant potential for advancing optoelectronics, with applications in quantum computing, secure communications, and high-efficiency displays.

Fig. 4: Preparation and optical characterizations of amine-modified perovskite-like PbI₂@MOFs superlattices.

In summary, this study employed a coordination template-driven in situ assembly strategy, utilizing Zr-MOF templates to achieve the directed nucleation and growth of metal-halide sublattices, successfully constructing a series of novel multi-dimensional single-crystalline porous superlattice frameworks. Through precise single-crystal structural analysis, the complex structure of the superlattices and its relationship with functionality were revealed, further elucidating the confined in situ growth mechanism and significantly enhancing superlattice stability. The study also successfully introduced chiral amines to prepare chiral perovskite-like superlattices, achieving chiral transformation and chiral luminescence functional modulation. Given the diversity of MOF templates and inorganic building units, this research establishes a new platform for constructing high-order single-crystalline porous superlattices, surpassing traditional crystalline solids and providing new insights and foundational strategies for tuning the chiral, electronic, optical, and quantum properties of superlattice materials.

This work was financially supported by the National Key Basic Research Program of China, the National Nature Science Foundation of China, and the Key Project of Basic Research of Shanghai.

Link to original article: https://doi.org/10.1038/s41586-024-08447-0

Translator: Chenyun SUN

Reviser: Xiaoke HU