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 study 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 was 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.