Green Photolithography of Perovskite Nanocrystals: In Situ Silica Encapsulation for Stable Micro-LED Displays

Photolithographic patterning of perovskite nanocrystals (PeNCs) is pivotal for realizing color-conversion schemes in full-color Micro-LED displays; however, this process is currently hindered by severe material degradation and a pervasive reliance on toxic organic solvents. Herein, we propose a robust PeNC photoresist strategy designed for compatibility with eco-friendly green solvents, specifically enabling the use of benign ethanol as a developer for high-resolution patterning. By synthesizing PeNCs directly within isobornyl acrylate (IBOA) monomers and engineering an in situ SiO 2 encapsulation layer via hydrolysis, we achieve superior material stability. Remarkably, the resulting PeNC@SiO 2 /IBOA composites retain bright fluorescence after 3480 h of ethanol immersion, whereas uncoated controls quench completely within 96 h. Leveraging this stability, we successfully patterned color conversion pixels with dimensions of 20 µm × 10 µm via photolithography with green solvent ethanol as the developer, which retain 80.3% of their initial photoluminescence quantum yield (PLQY) post-lithography. The successful fabrication of highly uniform red, green, and blue (RGB) pixel arrays demonstrates the significant potential of this green, high-performance lithography strategy of PeNCs for next-generation Micro-LED displays.