Highly Luminescent Photo‐Crosslinkable Perovskite Nanocrystals: Advancing Direct Optical Patterning, 3D Painting, and Backlight Displays

ABSTRACT Perovskite nanocrystals (NCs) are highly attractive for high‐definition displays. And yet, the weakly bound conventional surface ligands on perovskite NCs leads to the poor processibility, impeding their practical application. Herein, bis(2‐methacryloxyethyl)phosphate (BMP) was employed as a functional ligand to prepare BMP‐modified CsPbBr 3 (BMP‐CPB) NCs with exceptional optical properties and photo‐crosslinking capability. The phosphate group strongly coordinates with the surface Pb atoms, while the methacrylate groups undergo photo‐crosslinking reaction. Upon ultraviolet light irradiation, free radicals initiate addition reactions across the C═C bonds of BMP ligands, ultimately leading to the formation of a 3D cross‐linked polymer network. Accordingly, BMP‐CPB NCs show high processability compatible with photopatterning, screen printing, and 3D printing. The superior processibility and outstanding optical properties endow them with great potential in optoelectronic devices, the BMP‐CPB‐based light‐emitting diodes (LEDs) achieved a maximum luminance of 51181.04 cd/m 2 and an external quantum efficiency (EQE) of 18.6%. The BMP‐CsPbX 3 ‐based white LED emits bright white light, achieving a high luminous efficiency of 58.6 lm/W and a wide color gamut covering 124% of National Television System Committee (NTSC) standard. Taking WLED array as backlight source, the constructed liquid‐crystal display (LCD) prototype device demonstrates the significant potential of BMP‐CPB NCs in high‐quality display technologies.