Stable colour conversion layer with enhanced conversion efficiency by incorporating nanoparticles for micro-LED display application

Abstract

Due to their promising optical performance, micro-light emitting diodes (micro-LEDs) based on colour conversion layer (CCL) have garnered significant attention as the next-generation display technology. However, fabricating CCL with excellent conversion efficiency (CE) with minimal blue light leakage for miniaturized sub-pixel designing is still in its infancy. Herein, we have demonstrated CCL of a thickness (<3.5 μm) based on an organic-inorganic hybrid system incorporated with Titanium dioxide (TiO2) and Zinc Oxide (ZnO) Nanoparticles (NPs) with high CE. The inclusion of the NPs enhances the absorption of blue light within the CCL. We further combined the CCL with a colour purification filter to mitigate blue light leakage, which recycles blue light and suppresses blue light loss, resulting in improved CE. Specifically, we achieved a CE of 83.80 % for the green CCL and 66.97 % for the red CCL. Subsequently, full-colour arrays with a pixel size of 4 μm × 4 μm were successfully patterned and fabricated based on reduced thickness and improved optical performance using NP-doped CCL. This paves the way for cost-effective higher-resolution micro-LED displays for various applications.