Engineering Supramolecular Metal-Organic Frameworks for Stable and Efficient Perovskite Quantum Dots by Defect Passivation and Heterostructure Construction.

Inorganic lead halide perovskite quantum dots (PQDs) feature exceptional optoelectronic properties but suffer from poor stability, limiting their commercial viability. This study employs a mechanochemical synthesis route utilizing shared cesium ion to synthesize CsPbBr PQDs within supramolecular γ-cyclodextrin metal-organic frameworks (γ-CD-MOFs). The resulting CsPbBr@γ-CD-MOFs achieves high photoluminescence quantum yield (73%) alongside exceptional thermal, photochemical, and environmental stabilities. Mechanistic investigations reveal synergistic augmentation effects: multianchored defect passivation via γ-CD hydroxyl groups, enhanced radiative recombination through type-I heterojunction-driven directional carrier injection, and suppression of ion migration and phase separation by MOFs' physical barriers and interfacial chemical bonds. The composite was successfully applied in white light-emitting diodes, boasting color rendering index of 90.1 and color gamut coverage of 115%. Furthermore, benefiting from the good biocompatibility imparted by γ-CD-MOFs, the composite serves as fluorescent probe for specific labeling and imaging of lysosomes in living cells. This supramolecular-MOFs strategy provides design principles for developing stable, efficient, and biologically compatible PQDs, accelerating their optoelectronic and bioimaging applications.