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

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.