High-resolution and spectrally purified 7561-PPI panchromatic micro-LED displays via blue-light-driven color conversion technology

Micro-light-emitting diodes (micro-LEDs), featuring self-emission, high pixel density, wide color saturation, and long operational lifetime, are emerging as a key technology for advanced display applications such as augmented and virtual reality. However, conventional fabrication approaches primarily rely on mass transfer processes that are time-consuming, costly, and yield-limited, posing major challenges to large-scale commercialization. To address these limitations, we present a color conversion-based technique that replaces mass transfer with a highly efficient, stable, and economically viable fine-pitch full-color microarray process. Utilizing high-transparency photoresist hybrids combined with photolithographic patterning, we successfully fabricated color-conversion microarrays of extremely small pixel sizes with customizable layouts. Integrated with a color-purity-enhancement film, the structure effectively reflects unabsorbed blue light while selectively transmitting red and green light, thereby reducing blue-light leakage, improving conversion efficiency, and enhancing color purity. The process eliminates dry etching and protective layer curing, reducing overall process time by more than threefold and significantly increasing fabrication yield. Compared to conventional phosphors, quantum dots, and perovskites, our system offers non-toxicity, rare-earth-free composition, and enhanced optical and economic performance. Furthermore, the introduction of a 3D black matrix structure effectively suppresses optical crosstalk, minimizes angular color shift, and improves pixel resolution and color uniformity. The fabricated 1 × 1 μm pixel microarrays achieve a single-color pixel density of 15,121 PPI and a full-color pixel density of 7,561 PPI. With mixed-size nanoparticles, color conversion efficiencies reach 81.48% for green and 72.40% for red within a 1.5 μm-thick layer, achieving 144.16% of the DCI-P3 gamut area. This work demonstrates a viable approach toward advanced highresolution micro-LED displays.