Two-inch wafer-scale manufacturing of Micro-QLED for AR microdisplay application

Micrometre-sized quantum -dot light -emitting diodes ( Micro-QLEDs) have been successfully demonstrated as a promising technology for augmented reality (AR) microdisplay applications. To facilitate industrial application s, we develop ed a two -inch wafer -scale fabrication process for Micro-QLEDs, including the fabrication of a photolithography template, spin-coating fabrication of a QLED, and dicing of a 2-inch wafer into 0.46-inch M icro-QLED panels. Considering the challenge posed by the limited droplet spreading of quantum dots during spin -coating fabrication, we introduced a binary solvent of hexane and octane to achieve a wafer-scale spreading area. In situ high-speed microscopic observations revealed the critical role of Marangoni flow in determining the dynamics of a three-phase contact line. We further designed a 2- inch wafer-scale fabrication process for Micro-QLEDs with an active emitting area of 1600 mm 2, which provides fifteen microdisplay panels with a 0.46-inch Micro-QLED per wafer, achieving a resolution of 2510 pixels per inch (a pixel size range of 4 – 50 μm). In addition, the red, green, and blue Micro-QLED wafers had high external quantum efficiencies of 22.8%, 20.8%, and 1.4%, respectively. The 2-inch wafer- scale fabrication process for Micro-QLEDs provides a feasible method for the industrialisation of Micro-QLED technology.