Discovering Structure-Adaptive Oxides for Embedded Epitaxial Growth of Perovskite Nanocrystals

Developing heterostructures presents a promising approach to enhance the performance of lead halide perovskite CsPbX₃ (X = Cl, Br, I) nanocrystals (NCs) for optoelectronic applications. Given their rich variety and extreme stability, oxide crystals are appealing candidates for integration with CsPbX₃ to expand their applications. However, heterostructural modification of CsPbX₃ with oxides remains a daunting challenge due to the substantial lattice mismatch. This study presents a strategy for constructing CsPbBr₃-in-oxide heterostructures under substantially mismatched lattice parameters by leveraging the structure-adaptive feature of rationally selected host materials. Our investigations reveal that complex oxide crystals comprising appropriate combinations of large and small cations can accommodate considerable misfit strain, thereby facilitating the epitaxial growth of dispersed CsPbBr₃ NCs within the crystal lattice. Notably, the oxide matrix can effectively protect the CsPbBr₃ NCs against water and heat, simultaneously enabling extended optical tuning through lanthanide doping. These findings provide valuable insights into heterostructural engineering of functional materials, thus representing a novel paradigm for the development and application of perovskite nanocrystal-based materials.