Regulating the morphology of two-dimensional perovskite single-crystals via high-throughput experimentations

Controllable solution-based synthesis of semiconducting micro-structured materials with tailored morphologies and specific properties is crucial for the development of cost-effective microelectronic devices. Here, we present a high-throughput solvent evaporation crystallization experimental approach that integrates in-situ absorption spectroscopy and molecular dynamics simulations to systematically explore ligand-mediated crystallization dynamics in 2D perovskite single crystals. Based on automated experimental platform, 98 synthesis conditions were systematically investigated, including 9 alkyl ammonium ligands, 5 aromatic ammonium ligands, and varying precursor solution dilutions. We establish a clear correlation between organic molecular structure and perovskite morphology, showing that shorter ligands promote 1D nanowire formation, while longer ligands favor 2D nanosheet growth. In-situ spectroscopy and molecular simulations reveal that larger ligands induce conformational changes within the perovskite lattice, shifting crystallization from direct nucleation to lamellar exfoliation. Transmission electron microscopy (TEM) and density functional theory (DFT) calculations confirm that such transition is driven by enhanced solute-solvent binding energy, which modulates the crystallization pathway of lead halide intermediates. Our findings provide valuable insights into solution-phase crystallization kinetics and offer a rational strategy for designing perovskite materials with tailored optoelectronic properties, facilitating their scalable integration into advanced semiconductor applications.