Surface Fluorination and Liquid-Bridge Assembly of Perovskite Quantum Dots for High-Resolution Displays
Colloidal lead halide perovskite quantum dots (Pe-QDs) have achieved external quantum efficiencies exceeding 20% in red, green, and blue light-emitting diodes (LEDs), yet their integration into high-resolution displays is impeded by two persistent bottlenecks: the intrinsic ionic lability of Pe-QDs, which compromises structural and environmental stability, and the absence of mild, high-fidelity patterning techniques that avoid ligand detachment and surface defect formation. This work addresses both obstacles through a dual strategy. First, a ligand-fluoride co-stabilization method yields shape-defined, colloidally stable rhombic dodecahedral CsPbBr3 Pe-QDs; subsequent fluorine surface reconstruction using tetrabutylammonium fluoride (TBAF) enhances ligand binding affinity, producing BHOA+F CsPbBr3 Pe-QDs with a photoluminescent quantum yield (PLQY) of 94.6%. Accelerated ageing, ultraviolet irradiation, and thermal cycling tests confirm improved structural and environmental stability. Second, capillary liquid-bridge confined assembly enables reproducible, scalable fabrication of pixelated Pe-QDs with in-plane long-range order, vertical confinement, and precise spatial patterning. The resulting pixelated Pe-QDs LEDs exhibit high efficiency, sufficient brightness, and long operational stability, with the approach generalizable across red, green, and blue Pe-QDs for wide color gamut displays. This combination of surface fluorination and liquid-bridge assembly represents a landmark achievement in high-resolution display technology.