Extremely high pixel density color conversion micro-LED displays with high efficiency and wide color gamut coverage

Abstract

With the vigorous development of display technology, micro light-emitting diode (Micro-LED) display has become the most potential technology in the future. Its characteristics include high resolution, long life, wide color gamut, high contrast, fast response, small pixel size and low power consumption. The technical bottleneck of Micro-LED display is the mass transfer, so we use semiconductor lithography process to replace it for much lower cost and higher production speed. We propose color conversion technology to achieve higher efficiency and light intensity than mass transfer. In this study, we used a waterproof and viscous organic material Polyvinyl Butyral Resin (PVB) as the main material to synthesize rare-earth-free color conversion luminescent materials, which contain 4-(dicyanomethylene)-2-tert-butyl-6- (1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran (DCJTB) for red light and 3-(2-Benzothiazolyl)-7-(diethylamino) coumarin (Coumarin 6) for green light with very high quantum yield (~90%). Through semiconductor process technology, we have realized the fabrication of extremely small size 4μm × 4μm display arrays. The single-color pixel density can reach 5080 pixels per inch (PPI), and the full-color pixel density reaches up to 2540 PPI, with a display color gamut covering approximately 92.3% of the digital cinema initiatives - protocol 3 (DCI-P3) standard. This research achievement offers a promising technique for manufacturing the next generation of Micro-LED displays with extremely high PPI. These advancements in display technology bring tremendous potential for various applications, ranging from consumer electronics products to augmented reality and beyond.