High pixel resolution is critical for next-generation quantum-dot light-emitting diode (QLED) display technologies. Although advances in quantum-dot patterning have improved resolution, the reduction in pixel size often degrades emission efficiency and pattern uniformity. Here we develop a nanoimprint strategy using nanohole-array moulds to fabricate nano-QLEDs via capillary action-induced self-assembly of quantum dots. We realize pixels as small as sub-100 nm with ultrahigh pixel resolution up to 169,333 pixels per inch over an electroluminescent area of 4 mm 2 . Benefiting from the closely packed light-emitting quantum-dot monolayers, our nano-QLEDs show minimal performance degradation upon reducing the pixel size. Notably, the smallest red, green and blue nano-QLEDs maintain average external quantum efficiencies of 17.0%, 10.5% and 5.7%, respectively. We also demonstrate fabrication on flexible substrates as well as an active-matrix display by imprinting micro-QLEDs on a thin-film-transistor backplane, showing images and videos with a resolution of 100 pixels × 180 pixels. This work provides a powerful method for fabricating ultrahigh-resolution nano-QLED arrays with high external quantum efficiency for next-generation displays.
Cao et al. (Fri,) studied this question.