Ngo Loan Thi, Huang Wen-Tse, Verma Hemant, Lin Yen-Huei, Liang Ling-Wei, Fang Chia-Te, Chang Jia-Cheng, Chu Wen-Chung, Su Chaochin, Kaun Chao-Cheng, Liu Ru-Shi
Department of Chemistry, National Taiwan University, Taipei 106, Taiwan.
Nano Science and Technology Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan University, Academia Road 128, Nankang, Taipei 115, Taiwan.
ACS Appl Mater Interfaces. 2024 Dec 4;16(48):66262-66272. doi: 10.1021/acsami.4c15012. Epub 2024 Nov 19.
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 CsPbBr 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(BrI) and green CsPbBr 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 CsPbBr 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 Pb 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.
全无机铅卤化物钙钛矿量子点（PQDs）已成为用于光子和光电器件、太阳能电池及光催化剂的极具前景的材料。然而，由于离子扩散，PQDs存在稳定性和颜色分离问题。目前的策略主要解决绿色CsPbBr PQDs的稳定性问题，由于红色混合卤化物PQDs与绿色PQDs相比稳定性较差，因此对其关注有限。我们的研究提供了一种新的双重保护方法，用于合成高效的绿色和红色混合卤化物PQD薄膜。红色CsPb(BrI)和绿色CsPbBr PQDs嵌入硅树脂，然后与聚甲基丙烯酸甲酯（PMMA）基质结合，形成红色和绿色的PQDs@硅树脂/PMMA薄膜。纯红色PQD聚合物薄膜具有高光致发光量子产率（PLQY）和高稳定性。超亮的绿色CsPbBr PQDs@硅树脂/PMMA薄膜也成功制备，其PLQY超过94%。这些薄膜对热降解和环境降解表现出增强的稳定性，这归因于硅树脂和PMMA基质通过形成Si-卤化物和Pb-O键形成的致密保护层，从而减少了表面缺陷。理论计算表明，硅树脂和PMMA的结合改善了Pb-O相互作用，消除了未配位的Pb并提高了PQD的稳定性。应用于白光发光二极管（WLEDs）时，这些薄膜显示出143.4%的宽色域，表明它们在高效WLED背光方面的潜力。
