Dual‐Strategy Direct Photocatalytic Patterning for Efficient Perovskite Nanocrystal LED Displays

Abstract

Abstract Achieving nondestructive, high‐resolution patterning of perovskite nanocrystals (PeNCs) is essential for next‐generation near‐eye displays. However, the intrinsic instability of PeNCs renders conventional patterning methods detrimental to their optical and electrical properties. Herein, a dual strategy is reported that enables both high‐resolution patterning and the fabrication of efficient light‐emitting diodes (LEDs). The first strategy involves an advanced direct photocatalytic patterning method. Thiol crosslinkers are systematically investigated and identified 1,8‐octanedithiol and 1,10‐decanedithiol as optimal candidates due to their solvent compatibility, colloidal stability, and ability to achieve nondestructive patterning with high resolution and fidelity. The second strategy introduces a film‐state ligand exchange (FLE) process to enhance the optical and electrical properties of patterned PeNC films. Replacing long‐chain ligands with short‐chain ammonium halides results in denser surface passivation and enhanced charge transport capability. Dual strategy enabled high‐performance crosslinked PeNC‐LEDs, including a maximum external quantum efficiency of 14.7% and luminance of ≈25,400 cd m −2 for green CsPbBr 3 LEDs, representing the highest values reported for green CsPbBr 3 PeNC‐LEDs obtained via direct optical patterning. Furthermore, FLE enabled post‐patterning halide exchange, representing the first demonstration of a red crosslinked CsPbBr x I 3−x PeNC‐LED via direct optical patterning. This study establishes molecular and lithographic design principles for integrating colloidal nanocrystals into next‐generation displays and optoelectronics.