To focus on developing white light-emitting diodes (WLEDs) for lightings with high color rendering index (CRI), low correlated color temperature (CCT), and the displays with wide color gamut, inorganic perovskite quantum dots (QDs) such as CsPbX3 (X = C1, Br, I) were the promising candidate owing to the excellent optoelectronic properties such as high quantum efficiency, narrow emission wavelengths, and tunable emission spectrum. Nevertheless, the CsPbBr3QDs in the form of powders or films had a poor air stability and severe decline of quantum efficiency. Therefore, in this article, a new idea was proposed that 0-D green–red perovskite QDs powders such as Cs4PbBr6 and Cs4Pb(Br0.4I0.6)6 with improved quantum efficiency and long lifetime were first developed by silica-coated method and crystal phase transition in low-temperature synthesis. The quantum efficiency in green Cs4PbBr6 powders could be significantly enhanced from 31.41% to 45.87% and red Cs4Pb(Br0.4I0.6)6 powders was 22.79%. Moreover, the as-prepared perovskite QD powders and commercial YAG phosphors combined with blue chips were applied to high-quality WLEDs for lightings and displays. More importantly, the as-fabricated wide Commission Internationale de l’Eclairage (CIE) color gamut WLEDs for displays possessed 115% National Television System Committee (NTSC) coverage rate and luminous efficiency of 51 lm/W under 20-mA driving current. On the other hand, the constructed WLEDs for high-power lightings would generate a warm white light with a luminous efficiency of 38 lm/W, extremely high CRI of 92.8, and low CCT of 3828 K under 350 mA. Hence, the proposed green–red perovskite QD powders had outstanding potential applications in WLEDs.

中文翻译：

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合成具有长寿命和增强量子效率的二氧化硅涂层 Cs4PbBr6 和 Cs4Pb(Br0.4I0.6)6 量子点，用于 WLED 应用：高 CRI 照明和宽色域显示器


重点开发高显色指数（CRI）、低相关色温（CCT）照明用白光发光二极管（WLED）和宽色域显示器、CsPbX3等无机钙钛矿量子点（QD）（ X = C1, Br, I) 因其优异的光电特性（例如高量子效率、窄发射波长和可调谐发射光谱）而成为有前途的候选者。然而，粉末或薄膜形式的CsPbBr3QDs的空气稳定性较差，量子效率严重下降。因此，本文提出了一种新的想法，即首先通过二氧化硅涂覆方法开发具有提高量子效率和长寿命的0-D绿-红钙钛矿量子点粉末，​​例如Cs4PbBr6和Cs4Pb(Br0.4I0.6)6，低温合成中的晶体相变。绿色Cs4PbBr6粉末的量子效率可以从31.41%显着提高到45.87%，红色Cs4Pb(Br0.4I0.6)6粉末的量子效率为22.79%。此外，所制备的钙钛矿量子点粉末和商用YAG荧光粉与蓝色芯片相结合，应用于高质量的WLED照明和显示器。更重要的是，所制造的显示器用宽色域WLED在20mA驱动电流下具有115%的国家电视系统委员会(NTSC)覆盖率和51lm/W的发光效率。另一方面，所构建的用于高功率照明的 WLED 将产生暖白光，发光效率为 38 lm/W，显色指数高达 92.8，在 350 mA 电流下具有 3828 K 的低色温。因此，所提出的绿-红钙钛矿量子点粉末在 WLED 中具有突出的潜在应用。