High-Stability Thick-Shell CdZnSeS/CdZnS/ZnS Green-Alloy Quantum Dots in Photoluminescent Diffuser-Plate Masterbatches

As a core component of emerging quantum-dot display technology, the stability of quantum-dot materials is crucial to determining the performance of quantum-dot photoluminescent diffuser plates. This study successfully synthesized high-stability thick-shell CdZnSeS/CdZnS/ZnS core–shell structured green-alloy quantum dots suitable for photoluminescent diffuser plates, providing an innovative solution for performance breakthroughs in this field. Through orthogonal experimental design, the synthesis parameters of the CdZnSeS alloy core were precisely optimized to achieve an ideal balance in emission wavelength, full width at half maximum (FWHM), and quantum yield (QY). Furthermore, by systematically adjusting ligands and synthesis parameters, a thick-shell CdZnSeS/CdZnS/ZnS core–shell structure was constructed, significantly improving the stability of the quantum dots. Critically, the replacement of the original oleic-acid ligands with tetradecylphosphonic-acid (TDPA) ligands at high temperature doubled the stability of the quantum-dot diffuser plates. Under extreme accelerated-aging conditions such as intense blue light, high temperature, and high humidity, the T90 lifetime of the diffuser plate exceeded 1000 h, and the xy chromaticity coordinate shift was strictly controlled within 1%, fully meeting the stringent commercial requirements. This achievement not only overcomes the stability bottleneck of quantum dots in the application of photoluminescent diffuser plates but also paves the way for their large-scale commercialization, promising to promote the development of display technology toward higher color gamut and longer lifetimes.