Effect of silica encapsulation on the stability and photoluminescence emission of FA_xCs_1-xPbX₃ quantum dots for white mini light emitting diodes

Development of wide-color gamut white light-emitting diodes (WLEDs) for displays, with nitride-based phosphors and conventional core-shell quantum dots (QDs) such as InP, CdSe, and all-inorganic CsPbI₃ perovskite quantum dots due to their excellent optoelectronic properties performance, is an excellent candidate for new optoelectronic applications. However, in backlight applications, the color gamut of perovskite quantum dots will be reduced due to the matching degree of color filter, which will limit its application in wide color gamut. To address these issues, in this paper, we propose a novel approach, namely, formamidine acetate (FA⁺) cationic doping, in CsPbI₃ system synthesized at room temperature by organic-inorganic ligand passivation method which can effectively maintain structural stability. At the same time, the PL emission band of CsPbI₃ is increased by doping FA ⁺ cations and the color gamut range is improved. We will discuss this change in detail, and quantum dot films using spin coating method can be maintained for a month in atmospheric conditions. For practical applications, the color gamut range can reach 133%. Therefore, our proposed perovskite quantum dots, FA_xCs_1-xPbI₃, have great potential for application in wide color gamut displays.