All-inorganic lead halide perovskite quantum dots (PQDs) have emerged as highly promising materials for photonic and optoelectronic devices, solar cells, and photocatalysts. However, PQDs encounter instability and color separation issues because of ion diffusion. Current strategies mainly address stability in green CsPbBr₃ PQDs, with limited focus on the red-mixed halide PQDs because of their inferior stability compared with green PQDs. Our study provides a new dual-protection methodology for synthesizing high-efficiency green and red mixed-halide PQD films. Red CsPb(Br_0.4I_0.6)₃ and green CsPbBr₃ PQDs are embedded with silicone resin and then incorporated with poly(methyl methacrylate) (PMMA) matrix to form red and green PQDs@silicone/PMMA films. The high photoluminescence quantum yield (PLQY) and great stability are recorded for the pure-red PQD polymer film. The ultrabright green CsPbBr₃ PQDs@silicone/PMMA film was also successfully fabricated with an outstanding PLQY beyond 94%. These films exhibited enhanced stability against thermal and environmental degradation, attributed to the dense protective layer of silicone resin and PMMA matrices by the formation of Si–halide and Pb–O bonds, thereby reducing surface defects. Theoretical calculations reveal that combining silicone resin and PMMA improves Pb–O interactions, eliminating uncoordinated Pb²⁺ and enhancing PQD stability. Applied to white light-emitting diodes (WLEDs), these films demonstrated a broad color gamut of 143.4%, indicating their potential for efficient WLED backlighting.

中文翻译：

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用于 LED 背光的具有超高效率和稳定性的混合保护钙钛矿量子点薄膜


全无机卤化铅钙钛矿量子点 （PQD） 已成为光子和光电器件、太阳能电池和光催化剂的非常有前途的材料。然而，由于离子扩散，PQD 会遇到不稳定和分色问题。目前的策略主要解决绿色 CsPbBr₃ PQD 的稳定性，而对红浆混卤 PQD 的关注有限，因为它们的稳定性低于绿色 PQD。本研究为合成高效绿光和红光混卤 PQD 薄膜提供了一种新的双重保护方法。红色 CsPb（Br_0.4I_0.6）₃ 和绿色 CsPbBr₃ PQD 嵌入硅树脂，然后与聚甲基丙烯酸甲酯 （PMMA） 基体掺入，形成红色和绿色 PQDs@silicone/PMMA 薄膜。纯红色 PQD 聚合物薄膜具有高光致发光量子产率 （PLQY） 和良好的稳定性。超亮绿色 CsPbBr₃ PQDs@silicone/PMMA 薄膜也成功制造，PLQY 超过 94%。这些薄膜表现出更强的抗热和环境降解稳定性，这归因于硅树脂和 PMMA 基体的致密保护层通过形成硅-卤化物和 Pb-O 键，从而减少了表面缺陷。理论计算表明，硅树脂和 PMMA 的结合可以改善 Pb-O 相互作用，消除不配位的 Pb²⁺ 并增强 PQD 的稳定性。应用于白光发光二极管 （WLED），这些薄膜表现出 143.4% 的宽色域，表明它们在高效 WLED 背光方面的潜力。