Quantum Nanoplatelet Pixelation at 3000 PPI for Enhanced Color Conversion in Microdisplay Applications: Direct Integration on MicroLEDs

ABSTRACT High‐brightness, full‐color microdisplays with sub‐5 µm pixel pitch are key for next‐generation augmented and virtual reality applications. While blue InGaN/GaN µLEDs offer excellent luminance, the integration of efficient red and green emission remains a major challenge in the realization of full color microLED displays. Using color converters such as quantum dots or perovskites is a promising approach, but current pixelation methods for these nanomaterials often suffer from limited resolution, significant material waste, and optical degradation during or after the process. Herein, we introduce a scalable directed‐assembly method for fabricating red‐ and green‐converter 3D micro‐subpixels based on pure colloidal quantum nanoplatelets. This method, compatible with non‐polar solvent dispersions, enables the high‐resolution fabrication of micro‐subpixels of 3.5 µm (corresponding to ∼3000 PPI in RGB configuration) in width and over 1.3 µm in thickness, achieving more than 75% blue light absorption efficiency without requiring much thicker polymer matrices or nanocomposites. Integration on 8 µm × 8 µm InGaN/GaN µLED arrays demonstrates homogeneous large‐area coverage, high structural fidelity, and promising electro‐optical performance with external photoluminescent quantum yield of red micro‐subpixel reaching ∼71%. The process is compatible with 200 mm CMOS‐type processes and offers a compelling pathway toward next‐generation high‐brightness, high‐resolution full‐color microdisplays.