12‐3: High‐Resolution, Intermixing‐Free Quantum Dot Patterning Technology for Electroluminescent Display Applications

Patterning of the quantum dot (QD) layer with resolutions of 4,200 pixels per inch (ppi) is achieved by using the transfer printing technique which effectively prevents intermixing between QDs and the underlying hole transport layer. As a result, the peak external quantum efficiencies of QD light‐emitting diodes (QLEDs) are significantly improved: 16.0% for red, 5.1% for green, and 5.8% for blue, outperforming those achieved by using spin‐coated QDs. The result demonstrates that the QD transfer printing process is a promising fabrication process for highly efficient, high‐resolution QLEDs.