A 4.7-inch 650 PPI AMQLED display prepared by direct photolithography

In this work, a highly efficient photosensitive quantum dot (QD) system was designed. The optimized photosensitive QD system had high photoluminescence quantum yield and colloidal stability. By direct photolithography, RGB pixel arrays with a single sub-pixel size of 39 μm × 5 μm were successfully prepared. Further, the full-color QLED device was realized. There were no residual QD emission peaks from neighboring sub-pixels observed in the electroluminescence spectra. Experience on the full-color QLED device guided the successful preparation of a 4.7-inch 650 PPI active matrix QLED prototype. The active matrix QLED prototype could display clear and complete pictures. The color gamut reached 85% of the BT2020 standard. This is the first active matrix QLED prototype prepared with a record-high resolution by direct photolithography, which promoted the development of QLED display technology.