Multiscale Dynamics from Picoseconds to Milliseconds: Bridging Spin Coherence and Metastable Photocharging in CsPbX₃ Perovskite Quantum Dots

All-inorganic lead halide perovskite quantum dots (PQDs) have attracted significant attention due to their exceptional optoelectronic properties and unique spin-related behaviors. This study investigates the interplay between hole spin coherence and photocharging processes in solution-processed CsPbCl₃ PQDs by using time-resolved Faraday rotation spectroscopy. Our research reveals a room-temperature hole spin dephasing time of ∼60 ps and a hole g factor of ∼1.73. Photocharging dynamics are probed via a spin detection technique based on a prepump–pump–probe methodology, uncovering biphasic formation kinetics with time constants of 54 and 327 ps and three lifetimes of 62 μs, 335 μs, and >1 ms for the photocharged states. These multiscale dynamics are similarly observed in CsPbBr₃ PQDs. This study provides a quantitative framework linking spin coherence to photocharging processes, deepening the understanding of spin–charge correlations in lead halide perovskites, and offering practical guidelines for optimizing quantum coherence in solution-processed nanomaterials.