Metal lead halide perovskite quantum dots (PeQDs) are recognized for their exceptional optoelectronic properties, making them promising candidates for use in solar cells, lighting, display technologies, and anticounterfeiting devices. However, their instability, combined with synthesis and storage methods that involve hazardous solvents, has limited their potential for commercial application.
To address these challenges, a solvent-free method for the fabrication of high-quality green and red CsPbX₃ PeQD (X = Br, I) ink was developed. Within a fluidic system, PeQDs with super-high photoluminescence quantum yields were obtained (92% for red CsPb(Br,I)₃ and nearly 100% for green CsPbBr₃). A uniform, nonsolvent PeQD ink was fabricated by modifying the surface of the as-formed PeQDs with a combination of trimethoxysilane and 3-(trimethoxysilyl)propyl methacrylate silane coupling agents, forming PeQDs@silane. These modified quantum dots were then dispersed in a UV-curable 1,6-hexanediol diacrylate monomer.
Bright and stable green and red emissions were exhibited by the solvent-free PeQD ink, with long-term photoluminescence stability retained—100% PL intensity after 115 days for CsPbBr₃ and 78 days for CsPb(Br,I)₃. Highly uniform and luminous films for LED backlighting and patterns for micro-LED applications were enabled by this environmentally friendly ink. Color coordinates near the red and green reference values were achieved, and a color gamut coverage of 100.28% relative to Rec. 2020 was demonstrated by the PeQD films. Overall, a scalable and environmentally safer alternative to conventional solvent-based PeQD inks was provided by this method.
