Optimizing the Development Process in Direct Photolithography for Efficient PeLEDs

ABSTRACT High‐resolution perovskite nanocrystals light‐emitting diodes (PeLEDs) show great potential for near‐eye and metaverse displays due to their exceptional optoelectronic performance. Direct photolithography stands as a leading approach for high‐resolution pixelation, but patterned devices still suffer from severe performance deterioration. Herein, by integrating high‐efficient perovskite nanocrystals and damage‐free carbene‐based crosslinkers, we reveal the development process as a critical yet overlooked factor influencing pixelated device performance remarkably. The interfacial adhesion between perovskite nanocrystals and the hole transport layer (HTL) dictates both patterning fidelity and residual‐induced background emission. Excessively strong adhesion leads to incomplete development, while weak adhesion compromises pattern integrity. Additionally, conventional developers cause unselective dissolution damage, inevitably degrading the optoelectronic properties of crosslinked perovskite nanocrystals. By synergistically optimizing the HTL to regulate adhesion strength and tailoring the developer with butyric acid for in situ perovskite nanocrystals surface passivation, we minimize development‐induced damage while maintaining clean pattern definition. This integrated optimization yields high‐resolution (5080 PPI) PeLED arrays with a record external quantum efficiency of 20% and a peak luminance of 3061 cd m − 2 , providing a novel perspective toward high‐resolution PeLEDs.