Nondestructive direct photolithography of colloidal quantum dots enabled by benzophenone-based crosslinkers

Quantum dot light-emitting diodes (QLEDs) have emerged as a leading platform for next-generation display technologies, gaining substantial research attention in recent years. Among various patterning strategies, direct photolithography offers distinct advantages through its high resolution, throughput, and process simplicity. However, current direct photolithography approaches face critical limitations in resolution and device performance, primarily arising from surface defect generation and photodamage of quantum dots (QDs) caused by deep-ultraviolet exposure and photochemical byproducts. To overcome these challenges, we present a novel benzophenone-derived photosensitive crosslinker featuring a byproduct-free C–H insertion mechanism with native ligands of QDs. Through precise structure design, the photo-absorption of the crosslinker extends to 365 nm, allowing the long-awaited QD patterning under standard i-line photolithography conditions. The developed crosslinker achieves unprecedented patterning resolution (pixel size ≈500 nm) with preserved photoluminescent characteristics. Corresponding QLED devices demonstrate remarkable performance enhancements, including a maximum external quantum efficiency (EQE) of 16.48% and a T₉₅ operational lifetime of 2258.3 hours (approximately 2.1 times longer than pristine devices). These advancements establish a promising pathway toward high-resolution and high-performance QLEDs, thereby accelerating the commercialization of high-end optoelectronic devices.