Ligand-variant Two-Dimensional Halide Perovskite Lateral Heterostructure

The perovskite heterostructure is a novel semiconducting building block that contains multiple spatially organized functionalities within individual particles. The structurally tunable organic ligands in a two-dimensional (2D) perovskite heterostructure play a central role enhancing the stability and affecting the optical properties. Here, we report the synthesis of ligand-variant 2D perovskite lateral heterostructure nanocrystals, based on the sequential solvent evaporation strategy. The fabricated 2D perovskite heterostructures can tolerate large lattice mismatch in the vertical orientation as much as 16.5 percent. The synthesis strategy can be expanded to various combinations of ligands and halides, yielding a clear interface and tailorable electronic structure. This work presents an important step to further the understanding of the interfacial structure of the 2D perovskite heterostructure and the design of perovskite nanodevices with tailored optoelectronic properties. Halide perovskites are novel types of semiconductors that have received extensive research because of the excellent optoelectronic properties such as defect tolerance, long carrier diffusion length, and bright photoluminescence. The heterostructure of halide perovskites is a developing platform in the fundamental research on novel optical properties as well as the development of semiconductor nanodevices. To date, the synthesis of halide perovskite heterostructures has found difficulty due to the highly mobile ion diffusion. Two-dimensional perovskites (2DPs), due to the slow ion diffusion caused by reduced dimensionality and rigid ligands, have been investigated as the basic building block for halide perovskite heterostructures. Herein, we studied the synthesis of 2DP heterostructures with different ligands across the heterojunction. The organic ligands with varying lengths create a large mismatch between the core and the shell of said heterostructure. Interestingly, the large mismatch could be tolerated due to the flexibility of the halide perovskite lattice, which makes our method adaptable for expanded library ligands and halide combinations.