Film Formation of Two-Dimensional Hybrid Perovskite using Resonant Infrared Matrix-Assisted Pulsed Laser Evaporation

Resonant infrared, matrix-assisted pulsed laser evaporation (RIR-MAPLE) is a versatile technique for depositing hybrid organic-inorganic perovskites (HOIPs) and has previously been used to deposit two-dimensional (2D) and three-dimensional HOIPs. This work investigates the growth mechanisms of 2D phenethylammonium lead iodide [(PEA)₂PbI₄] thin films deposited by RIR-MAPLE, focusing on their early nucleation and film formation processes. By varying deposition times and substrate surface properties, the evolution of the crystal structure, surface morphology, and optical properties of (PEA)₂PbI₄ films were characterized. Standard characterization techniques provided critical insights but lacked sensitivity to capture early-stage nucleation and excited-state dynamics. Fluorescence lifetime imaging microscopy addressed this gap, revealing three distinct excited-state processes and their spatial distribution during film growth. These findings connect how the underlying surface properties and the RIR-MAPLE deposition method affect the resulting pure 2D (PEA)₂PbI₄ film morphology and spatially-resolved excited-state relaxation dynamics.