Synergistic Self‐Crystallization and Surface Passivation Enable Enhanced Thermostability and Photostability of Pure‐Green CsPbBr 3 Quantum‐Dot Glasses for Backlit Displays

CsPbBr 3 perovskites quantum dots (QDs) have garnered significant attention as next‐generation green emitter materials due to their high photoluminescence quantum yield (PLQY) and exceptional narrow band emission. However, their performance is still largely constrained by their photostability and thermostability. Here, we report a synergistic strategy of in situ self‐crystallization and surface passivation of CsPbBr 3 QDs in phosphosilicate glass (QDs@glass) by introducing Al 2 O 3 . During the reaction, Al 2 O 3 modified the glass network structure, which not only triggered the self‐crystallization growth of the CsPbBr 3 QDs but was also associated with changes in the local Pb coordination and defect environment involving phosphate‐derived oxygen species, thereby reducing non‐radiative recombination and contributing to the enhanced stability of the CsPbBr 3 QDs@glass. The optimized CsPbBr 3 QDs@glass retains 64.0 ± 2.6% (mean ± SD, n = 3) of its initial photoluminescence intensity at 100°C, while the integrated green‐emission intensity of a single COB‐packaged device remains close to its initial level during a 1440 h continuous‐operation test. The material was further demonstrated in an LCD backlight, achieving a wide color gamut of 90.52% Rec.2020. Our findings provide an interesting idea for constructing surface passivation on quantum dots inside inorganic glasses and will further promote the commercial use of CsPbBr 3 perovskites QDs.