High-Stability Quantum Dot-Converted 3-in-1 Full-Color Mini-Light-Emitting Diodes Passivated With Low-Temperature Atomic Layer Deposition

In this study, we demonstrate a 3-in-1 mini-light emitting diodes (LEDs) with ${160} \times {65}\,\,\mu \text{m}^{{2}}$ mini-LED subpixel chip size. Blue mini-LEDs are combining with red and green quantum dots (QDs) by using ink-jet printing technique to achieve a full-color and high-quality mini-LEDs array in the form of a monolithic chip. Subsequently, low-temperature passivated by atomic layer deposition (ALD) at 50 °C is used to effectively avoid the photo-oxidation and maintain the color purity, 99.5% National Television Standards Committee (NTSC) and 89.6% of Rec. 2020 color gamut of red as well as green QDs (GQDs) during 300 h reliability test under 50 °C/50% relative humidity (RH) condition. The environment stability L50 of both samples is 6761 and 5889 h for red and green QDs. Finally, we advocate the potential of the demonstrated highly stable full-color QD mini-LEDs to be applied in the display technology. This research also meets the requirement for a simple QD deposition method which is expected to achieve a breakthrough.