Suppressing Thermal- and Light-Induced Photoluminescence Quenching in Perovskite Quantum Dots Through Fluoride Post-Treatment.

Perovskite quantum dots (QDs) hold promise for next-generation display applications but suffer from stability challenges, particularly thermal- and light-induced photoluminescence (PL) quenching. Here, a fluoride post-treatment (FPT) strategy is developed to address this challenge for CsPbBr QDs embedded in silica matrices (CsPbBr/silica composites). The FPT enables epitaxial growth of BaF shells on CsPbBr surfaces via thermally driven fluoride ion diffusion, which passivates surfaces and suppresses thermal- and light-induced defects in CsPbBr. The FPT-treated CsPbBr/silica composites exhibit a high PL quantum yield of 94.5%, a complete PL recovery after a thermal cycling (up to 403 K), and retain 95.6% of their initial PL intensity after 1055 h with intense blue light irradiation (350 mW cm). To the best of the knowledge, these FPT-treated CsPbBr/silica composites represent the most stable CsPbBr emitters under light aging. Theoretical calculations reveal that the BaF shells elevate the formation energy of bromine vacancies and anchor [PbBr] octahedra in CsPbBr, thereby inhibiting defect generation. A liquid crystal display (LCD) equipped with these composites achieves a 120% national television system committee color gamut. This work provides a robust route to stabilize CsPbBr QDs for high-performance LCD applications.