High-Concentration Perovskite Quantum Dots Photoresist Utilizing BMEP Monomer^†

Quantum dot color conversion (QDCC) technology holds significant promise for next-generation virtual reality/augmented reality displays due to its low cost, high efficiency, and high resolution. However, its advancement is impeded by two primary challenges: the need for high blue light absorption and photo conversion efficiency, and the difficulty of achieving high-resolution patterning of the color conversion layer. This study addresses these challenges by developing a novel bis(2-methacryloxyethyl) phosphate (BMEP)- based photoresist incorporating a high concentration (30 wt%) of perovskite quantum dots (PQDs). The marked superiority of BMEP fundamentally arises from its unique dual functionality. The phosphate group in BMEP exhibits strong affinity for undercoordinated Pb²⁺ sites on nascent PQD surfaces, providing exceptional passivation of surface defects and effectively suppressing ion migration. Concurrently, the photopolymerizable methacrylate end groups of BMEP enable the formation of a densely cross-linked network upon UV exposure, which creates a pronounced spatial confinement effect, physically restricting uncontrolled growth and agglomeration of PQDs. By optimizing exposure time, anti-solvent selection, and annealing parameters, monodisperse PQDs were obtained, resulting in a high blue-light absorption of 99.45% in a 6.3 μm thick film and a high photo conversion efficiency exceeding 41%. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses confirmed that BMEP suppresses PQDs growth distortion through spatial confinement. Using in situ photolithography, red, green, and blue pixel arrays were fabricated, exhibiting photoluminescence quantum yield larger than 80% and covering 91.37% of the Rec. 2020 color gamut. This work introduces a novel strategy for designing high-concentration PQDs photoresists, advancing the development of high-resolution, wide-color-gamut QDs displays.