Ultrafast Thermodynamic Control for Stable and Efficient Mixed Halide Perovskite Nanocrystals

Low photoluminescence quantum yield (PLQY) and spectra instability, the two most difficult challenges in blue‐emitting CsPbBr x Cl 3− x NCs, have not yet been solved. Quickly controlling the reaction thermodynamics is crucial to enhance crystallinity, thus PLQY and spectra stability, but it has been ignored until now. An ultrafast thermodynamic control (UTC) strategy is designed by utilizing liquid nitrogen to instantaneously freeze the superior...