Direct Photo‐Patterning of Ultra‐Bright and Stable Quantum Dot Light‐Emitting Diodes Using Small‐Molecule Crosslinkers

ABSTRACT Direct optical lithography of colloidal quantum dots (QDs) offers distinct advantages, including high throughput, process simplicity, and uniform pattern profiles, making it a promising technique for high‐resolution displays. However, a significant challenge remains in achieving ultra‐bright and stable patterned QD light‐emitting diodes (QLEDs) suitable for practical applications using this technology. Here, we present a straightforward direct photo‐patterning method based on a small‐molecule cross‐linked network that preserves the photoluminescence and electroluminescence performance of QDs. This approach enables the fabrication of high‐resolution patterns with a critical dimension of 2 µm (∼6,350 pixels per inch) without requiring pre‐patterning of QDs before small‐molecule crosslinking. The resulting QLED demonstrate a ultra‐high brightness exceeding 1 000 000 cd/m ² , a high external quantum efficiency of ∼18% at 100 000 cd/m ² , and a long T ₉₅ lifetime of >12,000 h at 1000 cd/m ² . To the best of our knowledge, both the device brightness and T ₉₅ lifetime represent the best performance results reported so far based on direct optical lithography technology. This method holds significant potential for ultra‐high‐brightness, long‐lasting displays, particularly augmented reality applications tailored to outdoor scenarios.