Covalent Dual-Shell-Encapsulated Perovskite Quantum Dots for Blue-Light-Resistant, Highly Stable Pixel Fabrication

Perovskite quantum dots (PQDs) are promising candidates for next-generation displays but suffer from poor stability during manufacturing and application. Owing to their intrinsic soft lattice and weak surface ligand-lattice bonding, PQDs degrade easily under light, heat, humidity, and oxygen. Herein, we propose an inorganic–organic covalently bonded dual-shell encapsulation strategy for PQDs. An inorganic inner shell locks the crystal surface to ensure structural stability, while the inorganic shell links to an organic acrylate polymer shell via Si–O–Si bonds to improve dispersion and chemical cross-linking, thereby enhancing the encapsulation of individual PQDs. Benefiting from this strategy, PQDs retain more than 90% of their pristine fluorescence lifetime and maintain stable colloidal dispersion even after 30 days of storage in polar solvents. Under 75% relative humidity, ambient air, and 10,000 cd/m 2 blue light irradiation for 100 h, the fluorescence intensity of the prepared PQD film remained at 96.081 ± 0.019%, compared to 40.037 ± 0.024% for the pristine sample group, indicating enhanced blue light resistance. Carboxylic acid groups in the organic shell precisely passivate surface defects, boosting the photoluminescence quantum yield (PLQY) from 59.1% to 98.3%. Utilizing alkenyl double bonds in surface ligands and their photoinitiated cross-linking, 5 μm high-resolution pixel patterning is achieved. The PQD-based color conversion layer exhibits excellent stability, delivering a brightness of 1,468,161.5 cd/m 2 under excitation from a 445 nm blue-light chip and a 67.7-year operational lifetime at 100 cd/cm 2, which is 100-fold longer than that of unencapsulated PQDs. This strategy enables the practical application of PQDs in high-resolution backlight displays.