Zinc Phosphate Passivation Enables Photostable Pixelated Quantum Dot Color Conversion Layers for Display Applications

Quantum dots (QDs) converted to micro light-emitting diodes (LEDs) have emerged as a promising technology for next-generation display devices. However, their commercial application has been hindered by the susceptibility of QDs to photodegradation when directly exposed to an open environment. Here, we develop functional ligand zinc bis[2-(methacryloyloxy)ethyl] phosphate (Zn(BMEP)₂) to passivate QD surface anions through a phosphine-mediated surface reaction. This approach improves QD solubility and stability in commercial photoresists (PR) and solvents, enabling QD photoresist (QDPR) micropatterns with 5 μm pixel sizes, distinct structure, and high color conversion efficiency. The -ZnBMEP passivation significantly enhances the efficiency and photostability of QDs, providing remarkable protection against air, heat, and UV light exposure. The barrier-free QDPR demonstrated an impressive lifetime (L90 > 300 h) under accelerated photoaging in air, far surpassing traditional QDPRs. This modification method holds great promise for advancing the reliability and performance of QD-converted micro-LEDs, paving the way for high-performance, long-lasting display devices.