Double-Encapsulated Perovskite Nanocrystals Coupled with Spatially Separated Optical Architecture Enabling Low-Crosstalk UV-Excited Full-Color Micro-LED Pixels

Full-color realization remains a critical bottleneck for microlight-emitting diode (Micro-LED) display industrialization. Color conversion avoids complex mass transfer, yet conventional blue-light excitation suffers from leakage that degrades color purity, and all-inorganic perovskite nanocrystals (PNCs) lack sufficient stability. Here, we report a dual-modification strategy combining silica (SiO2) encapsulation with the UV absorber UV-571 to construct CsPbX3@SiO2–UV571 nanocrystals for UV-excited Micro-LED color conversion pixels patterned via electrohydrodynamic (EHD) inkjet printing. The SiO2 shell raises the photoluminescence quantum yield (PLQY) from 67.42% to 82.29% and prolongs the fluorescence lifetime from 9.13 to 49.05 ns; subsequent UV-571 incorporation maintains PLQY at 82.09% while extending the lifetime to 65.16 ns, with markedly improved thermal, solvent, and UV-irradiation stability. Micrometer-scale RGB arrays with sharp boundaries are fabricated via optimized EHD printing. A layered optical structure, placing the UV-571 absorption layer and PNC emissive layer on opposite sides of a glass substrate, effectively suppresses residual UV leakage without sacrificing visible emission. The resulting full-color array achieves gamut area ratios of 133.3% (NTSC) and 99.51% (Rec. 2020). This integrated approach, from material modification to high-precision printing and optical regulation, provides a practical pathway toward reliable full-color Micro-LED displays.