The precise stacking of different two-dimensional (2D) structures such as graphene and MoS₂ has reinvigorated the field of 2D materials, revealing exotic phenomena at their interfaces^1,2. These unique interfaces are typically constructed using mechanical or deposition-based methods to build a heterostructure one monolayer at a time^2,3. By contrast, self-assembly is a scalable technique, where complex materials can selectively form in solution^4,5,6. Here we show a synthetic strategy for the self-assembly of layered perovskite–non-perovskite heterostructures into large single crystals in aqueous solution. Using bifunctional organic molecules as directing groups, we have isolated six layered heterostructures that form as an interleaving of perovskite slabs with a different inorganic lattice, previously unknown to crystallize with perovskites. In many cases, these intergrown lattices are 2D congeners of canonical inorganic structure types. To our knowledge, these compounds are the first layered perovskite heterostructures formed using organic templates and characterized by single-crystal X-ray diffraction. Notably, this interleaving of inorganic structures can markedly transform the band structure. Optical data and first principles calculations show that substantive coupling between perovskite and intergrowth layers leads to new electronic transitions distributed across both sublattices. Given the technological promise of halide perovskites⁴, this intuitive synthetic route sets a foundation for the directed synthesis of richly structured complex semiconductors that self-assemble in water.

不同二维 (2D) 结构（如石墨烯和 MoS ₂ ）的精确堆叠重振了二维材料领域，揭示了其界面^1,2的奇异现象。这些独特的界面通常使用机械或基于沉积的方法构建，以一次构建一个单层的异质结构^2,3。相比之下，自组装是一种可扩展的技术，复杂的材料可以在溶液中选择性地形成^4,5,6. 在这里，我们展示了一种在水溶液中将层状钙钛矿-非钙钛矿异质结构自组装成大单晶的合成策略。使用双功能有机分子作为导向基团，我们分离出六层异质结构，这些异质结构形成为具有不同无机晶格的钙钛矿板的交错，以前不知道用钙钛矿结晶。在许多情况下，这些共生晶格是典型无机结构类型的二维同源物。据我们所知，这些化合物是第一个使用有机模板形成的层状钙钛矿异质结构，并以单晶 X 射线衍射为特征。值得注意的是，这种无机结构的交错可以显着改变能带结构。光学数据和第一性原理计算表明，钙钛矿和共生层之间的实质性耦合导致新的电子跃迁分布在两个亚晶格中。鉴于卤化物钙钛矿的技术前景^{如图 4}所示，这种直观的合成路线为定向合成在水中自组装的结构丰富的复杂半导体奠定了基础。