Methylammonium Cation-Regulated Controllable Preparation of CsPbBr Perovskite Quantum Dots in Polystyrene Fiber with Enhanced Water and UV Light Stabilities.

In situ fabrication of lead halide perovskite quantum dots (PQDs) is important for narrow-band emitters for LED displays due to the simple work procedure and convenient usability; however, the growth of PQDs is not readily controllable in the preparation, resulting in low quantum efficiency and environmental instability of PQDs. Here, we demonstrate an effective strategy to controllably prepare CsPbBr PQDs in polystyrene (PS) under the regulation of methylammonium bromide (MABr) via electrostatic spinning and thermal annealing techniques. MA slowed down the growth of CsPbBr PQDs and acted as a surface defect passivation reagent, which was proved by Gibbs free energy simulation, static fluorescence spectra, transmission electron microscopy, and time-resolved photoluminescence (PL) decay spectra.