Ultrastable and highly efficient green-emitting perovskite quantum dot composites for Mini-LED displays or backlights

Although tremendous efforts have been made to enhance the stability of lead halide perovskite quantum dots (PeQDs), they cannot meet the long-term requirements of photoelectric devices due to their poor reliability when attacked by multiple factors. Herein, we report ultrastable CsPbBr 3 :Sr/PbBr(OH)/molecular sieve composites with a high photoluminescence quantum yield of 75% and high overall stability when exposed to water, blue light and heat, owing to (i) the increased formation energy of CsPbBr 3 PeQDs by Sr doping and (ii) good encapsulation by PbBr(OH) and molecular sieves. These composites maintain 54% of their initial intensity after being aged at 85 °C and 150 mW cm −2 for 720 min, which is superior to commercial green CdSe-based QDs. These promising composites are then used to produce Mini-LED backlights with a high luminous efficacy of 86 lm/W and a color area of ~124% of the National Television Standards Committee or 93% of the Rec. 2020 standards by combining them with red CdSe/CdS/ZnS QDs and a blue Mini-LED chip. We believe that highly reliable PeQDs can be achieved by building well-designed composite structures, thus enabling them to be practically applied in emerging lighting and displays.