Ultrahigh-Resolution Transfer Patterning of Quantum Dot Light-Emitting Diodes via Soft-Contact Polymer Interface Engineering.

Quantum dot (QD) light-emitting diodes (QLEDs) with high resolution are ideal candidates for next-generation display technologies. Transfer printing offers a route for precise QD patterning, but scaling QLEDs to the nanoscale often degrades pattern uniformity due to uneven stress distribution in conventional transfer printing methods. Here, we report a soft-contact-assisted transfer printing strategy to reduce stress nonuniformity for the fabrication of ultrahigh-resolution QLEDs with uniformly closed-packed QD patterns via polymer interface engineering. Pixels as small as 200 nm are achieved, with an ultrahigh resolution of up to 42,333 pixels per inch (PPI). The resulting red nano-QLEDs deliver impressive peak external quantum efficiencies (EQEs) of 18.6%. Notably, the high-fidelity transfer minimizes performance trade-offs during scaling, allowing nanometer-scale QLEDs to largely retain the efficiency of their micrometer-scale counterparts. This approach enables high-yield fabrication of high-performance nano-QLED arrays, providing a viable route for next-generation high-density visualization.