Nanoscale transfer-printed full-colour ultrahigh-resolution quantum dot LEDs

Full-colour ultrahigh-resolution quantum dot light-emitting diodes (URQLEDs) with high efficiency and stability are required for next-generation near-eye displays^1-3. However, existing quantum dot (QD) patterning techniques struggle to simultaneously achieve submicrometre pixel sizes, full-colour integration and high device performance. Here we report a dual-action force dynamics (DAFD) strategy using a hard silicon template as a nanoimprinting stamp, combined with integral inverted transfer printing. This approach enables red-green-blue (RGB) full-colour QD pixel arrays with densities in the range 9,072-25,400 pixels per inch (PPI), maintaining high-fidelity pattern replication with a conservative transfer yield >99.9%. The method is compatible with both CdSe/ZnS and perovskite QDs on rigid and flexible substrates. Beyond patterning, we identify and address a previously underappreciated bottleneck in ultrahigh-resolution devices-electric-field non-uniformity arising from pixel microstructures. Matching the dielectric constant of the leakage-current-blocking layer to that of the QDs by means of TiO₂ nanoparticle incorporation yields a more uniform electric-field distribution, effectively suppressing edge effects and enhancing both efficiency and operational stability. Red URQLEDs at 12,700 PPI achieved a peak external quantum efficiency (EQE) of 26.1% and an operational lifetime T₉₅@1,000 cd m^-2 of 65,190 h. Comparable enhancements in device performance were obtained for green and blue URQLEDs, with EQE improvements of 124% and 119%, respectively. RGB-pixelated white URQLEDs reached a peak EQE of 10.1%. By integrating these URQLEDs with complementary metal-oxide-semiconductor (CMOS) integrated circuits, we demonstrated solution-processed active-matrix URQLED animated displays.