Dual ligand exchange of Cd‐free quantum dots and optimal control of ink formulation for improving the performance of all‐inkjet‐printed quantum dot light‐emitting diodes

Abstract Quantum dot light‐emitting diodes (QD‐LEDs) have received significant attention as a next‐generation display technology aimed at large‐size panel production with lower manufacturing costs and excellent picture quality. Here, we demonstrated all‐inkjet‐printed 12.4‐in. full‐color QD‐LED display with the 182‐ppi resolution. The efficiency and lifetime of inkjet‐printed QD‐LEDs were improved through the ligand exchange of Cd‐free quantum dots (QDs), red and green InP and blue ZnSeTe QDs, and optimal control of ink formulation. Dual ligands enhanced colloidal stability and carrier transport properties. The introduction of appropriate additives in the mixed solvent system improved the inkjet processibility and the morphology of inkjet‐printed layers.