Quantum dots with photopolymerisable ligands for green-solvent direct photolithography

Abstract

Recent advances in direct photolithography have enabled high-resolution patterning of quantum dots (QDs), offering a promising route toward next-generation display technologies. However, previous reported photopatterning strategies still rely on toxic organic solvents, which have severe environmental and industrial implications. Herein, we present a dual-ligand QD platform comprising a methacrylate-containing monomeric dispersing ligand that exhibits excellent compatibility with industrial green solvents and a benzophenone-based photoinitiating ligand that can initiate methacrylate polymerisation under i-line irradiation. This combination allows QDs to be dispersed in environmentally benign solvents, such as propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, 1-methoxy-2-propanol, and triethylene glycol monomethyl ether, while enabling fast, efficient, and non-destructive direct photolithography using standard i-line ultraviolet exposure. As a result, reliable 2 µm-resolution QD patterns can be achieved without compromising the intrinsic photoluminescence or electrical characteristics of the QDs.