Simultaneous Microstructure Visualization and Trap State Discrimination in Perovskite Films Via Time-Gated...

The exceptional performance of hybrid perovskites stems from their long-range carrier transport and high defect tolerance. However, their intrinsic polycrystalline nature induces pronounced microstructural heterogeneity, leading to localized variations in trap-state distributions and carrier dynamics. Here, we develop a time-gated fluorescence lifetime imaging microscopy strategy for simultaneous microstructure visualization and trap state discrimination with a single photoluminescence decay data set. By applying time gates, a decay process is temporally separated into fast decay, transition, and trap-dominated stages. The fast decay stage visualizes microstructures with improved tolerance to excitation intensity by suppressing trap-assisted decay contributions. Conversely, the subsequent two stages uncover "dynamic boundaries" with enhanced emission compared to the surroundings. Log-log analysis also shows a power-law decay in these dynamic regions, enabling discrimination of a shallow-trap-dominated nature. This noninvasive and intuitive approach correlates microstructure with trap energetics, offering critical insights for optimizing passivation engineering in perovskite optoelectronics.