Highly stable and luminescent silica-coated perovskite quantum dots at nanoscale-particle level via nonpolar solvent synthesis
Highly stable and luminescent silica-coated perovskite quantum dots at nanoscale-particle level via nonpolar solvent synthesis
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通过非极性溶剂合成在纳米级颗粒水平上高度稳定和发光的二氧化硅涂覆的钙钛矿量子点
DOI：
10.1016/j.cej.2020.128001
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发表时间：
2021-03-01
影响因子：
15.1
通讯作者：
Liu, Yichun
中科院分区：
文献类型：
--
作者：
Gao, Fei;Yang, Weiqiang;Liu, Yichun
目前，具有优异光电性能的全无机卤化铅钙钛矿（CsPbBr3，X=Cl、Br和I）量子点（QD）的光学稳定性和毒性不佳是其实际应用的主要障碍。本工作通过非极性溶剂合成将CsPbBr3量子点组装到SiO2壳中，成功制备了单分散CsPbBr3@SiO2纳米复合材料（NCs），其光致发光量子产率（PLQY）接近87%。此外，引入的疏水性多支链三辛基氧化膦（TOPO）有效抑制了四乙氧基硅烷（TEOS）的水解速率，从而形成了纳米级颗粒水平的核@壳NC。受益于 TOPO 和 SiO2 壳层的保护，与裸露的钙钛矿量子点相比，CsPbBr3@SiO2 NCs 对热处理、紫外线照射和水的稳定性显着提高。值得注意的是，不同钙钛矿量子点之间的阴离子交换反应被完全抑制。为了提高碘取代钙钛矿量子点的稳定性并扩大发射波长，通过类似策略也成功制备了PLQY为75%的CsPbBr0.6I2.4@SiO2 NCs。白光发光二极管 (WLED) 的设计是将 CsPbBr3@SiO2 NC 与 CsPbBr0.6I2.4@SiO2 NC 结合到蓝色 GaN 芯片上。这些 WLED 实现了高显色指数 90 和发光效率 80 lm W-1 的明亮白光，表明合成的钙钛矿 NC 在显示器和固态照明方面具有巨大的潜力。
Currently, unsatisfactory optical stability and toxicity of all-inorganic lead halide pemvskite (CsPbBr3, X = Cl, Br, and I) quantum dots (QDs) with excellent photoelectric properties is a major obstacle for their practical application. In this work, the CsPbBr3 QDs were assembled into SiO2 shell via nonpolar solvent synthesis, and monodisperse CsPbBr3@SiO2 nanocomposites (NCs) with high photoluminescence quantum yield (PLQY) of similar to 87% were successfully prepared. Moreover, the introduced hydrophobic and multibranched trioctylphosphine oxide (TOPO) effectively suppressed the hydrolysis rate of tetraethoxysilane (TEOS), resulting in the formation of core@shell NCs at a nanoscale-particle level. Benefiting from the protection of TOPO and SiO2 shell, the CsPbBr3@SiO2 NCs exhibit remarkably improved stability against thermal treatment, UV irradiation and water compared to the bare perovskite-QDs. Notably, the anion-exchange reaction among different perovskite-QDs was completely inhibited. To improve stability of iodide-substituted perovskite-QDs and expand emission wavelength, the CsPbBr0.6I2.4@SiO2 NCs with PLQY of 75% were also successfully prepared by similar strategy. White light-emitting-diodes (WLEDs) were designed by combining CsPbBr3@SiO2 NCs with CsPbBr0.6I2.4@SiO2 NCs onto blue GaN chips. Bright white-light with high color-rendering index of 90 and luminous efficiency of 80 lm W-1 were achieved from these WLEDs, indicating the synthesized perovskite NCs possess huge potentiality in displays and solid-state lighting.