Photocleavable\nLigand-Induced Direct Photolithography\nof InP-Based Quantum Dots

Direct photolithography, which utilizes\nphotosensitive\nquantum\ndot (QD) inks, is a powerful patterning method for implementing next-generation\nhigh-resolution QD displays. However, the chemical reactions occurring\nduring the photoinduced solubility change process can damage the QDs’\nsurface, especially for InP QDs. In this study, we focus on a cleavable\nligand-induced direct photolithography (CLIP) technique utilizing\nspecially designed 3-((but-3-enoyloxy)methyl)-2-nitrobenzoic acid\n(BNA) ligands. The BNA ligand, composed of a carboxylic acid and an <i>ortho</i>-nitrobenzyl ester, facilitates ligand exchange and\nphotocleavage reactions and induces a significant solubility difference\nupon ultraviolet (UV) irradiation, enabling patterning at a low UV\ndose while maintaining 75% of the original photoluminescence quantum\nyields of InP/ZnSe/ZnS QDs. This method can generate high-resolution,\nmulticolor patterns while enhancing electrical conductivity after\nthe patterning process, making it suitable for QD light-emitting diodes\n(LEDs). Our study represents a pioneering effort in CLIP for InP core/shell\nQDs, which could also be widely applicable to colloidal nanomaterials\nand devices.