Ultrahigh-resolution quantum-dot light-emitting diodes

With the ever-growing demand for a greater number of pixels, next-generation displays have challenging requirements for resolution as well as colour gamut. Here, to meet this need, quantum-dot light-emitting diodes (QLEDs) with an ultrahigh pixel resolution of 9,072–25,400 pixels per inch are realized via transfer printing combined with the Langmuir–Blodgett film technology. To reduce the leakage current of the devices, a honeycomb-patterned layer of wide-bandgap quantum dots is embedded between the light-emitting quantum-dot pixels as a non-emitting charge barrier layer. Red and green QLEDs are demonstrated. Notably, the red devices achieve a brightness of up to 262,400 cd m −2 at an applied voltage of 8 V and a peak external quantum efficiency of 14.72%. This work provides a promising way for achieving ultrahigh-resolution QLED devices with high performance. The demonstration of high-resolution quantum-dot light-emitting diodes by transfer printing could prove useful for next-generation displays.