Highly Luminescent and Water-Resistant CsPbBr3-CsPb2Br5 Perovskite Nanocrystals Coordinated with Partially Hydrolyzed Poly(methyl methacrylate) and Polyethylenimine
Highly Luminescent and Water-Resistant CsPbBr3-CsPb2Br5 Perovskite Nanocrystals Coordinated with Partially Hydrolyzed Poly(methyl methacrylate) and Polyethylenimine
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部分水解聚甲基丙烯酸甲酯和聚乙烯亚胺配位的高发光防水CsPbBr3-CsPb2Br5钙钛矿纳米晶
DOI：
10.1021/acsnano.9b04179
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发表时间：
2019-09-01
期刊：
影响因子：
17.1
通讯作者：
Eychmueller, Alexander
中科院分区：
文献类型：
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作者：
Jiang, Guocan;Guhrenz, Chris;Eychmueller, Alexander
所有无机卤化铅钙钛矿纳米晶体（PNC）通常遭受对湿气和UV辐射的差的稳定性以及在热处理期间的降解。PNC的稳定性可以通过聚合物包封而显著增强，通常伴随着由于高动态油胺/油酸（奥拉/OA）配体的损失而导致的光致发光量子产率（PLQY）的降低。在此，我们提出了一个解决这个问题的方案，利用部分水解的聚（甲基丙烯酸甲酯）（h-PMMA）和高度支化的聚（乙烯亚胺）（b-PEI）作为双配体稳定的PNC已经在机械化学合成（研磨）。h-PMMA的疏水性聚合物赋予所得NC-聚合物复合材料优异的成膜性能和水稳定性。反过来，b-PEI在PNC的表面上形成富含氨基的强结合配体层，这是PLQY和所得材料稳定性的显著改善的原因。此外，b-PEI的引入促进了从CsPbBr 3到CsPb 2Br 5的部分相转化，从而获得具有核-壳结构的CsPbBr 3/CsPb 2Br 5纳米晶体。制备的PNC溶液可直接作为油墨加工，而它们的PLQY仅从胶体溶液中的75%略微下降到膜中的65%。此外，最终的PNC-聚合物膜表现出优异的耐水、热和紫外光照射的稳定性。这些上级性质使我们能够制造具有h-PMMA/b-PEI稳定的PNC的概念证明薄膜OLED，作为易于加工的窄发射颜色转换复合材料。
All inorganic lead halide perovskite nano-crystals (PNCs) typically suffer from poor stability against moisture and UV radiation as well as degradation during thermal treatment. The stability of PNCs can be significantly enhanced through polymer encapsulation, often accompanied by a decrease of photoluminescence quantum yield (PLQY) due to the loss of highly dynamic oleylamine/oleic acid (OLA/OA) ligands. Herein, we propose a solution for this problem by utilizing partially hydrolyzed poly(methyl methacrylate) (h-PMMA) and highly branched poly(ethylenimine) (b-PEI) as double ligands stabilizing the PNCs already during the mechanochemical synthesis (grinding). The hydrophobic polymer of h-PMMA imparts excellent film-forming properties and water stability to the resulting NC-polymer composite. In its own turn, the b-PEI forms an amino-rich, strongly binding ligand layer on the surface of the PNCs being responsible for the significant improvement of the PLQY and the stability of the resulting material. Moreover, the introduction of b-PEI promotes a partial phase conversion from CsPbBr3 to CsPb2Br5 to obtain CsPbBr3/CsPb2Br5 nanocrystals with a core-shell-like structure. As-prepared PNCs solutions are directly processable as inks, while their PLQY drops only slightly from 75% in colloidal solution to 65% in films. Moreover, the final PNC-polymer film exhibits excellent stability against water, heat, and ultraviolet light irradiation. These superior properties allowed us to fabricate a proof of concept thin film OLED with h-PMMA/b-PEI-stabilized PNCs as an easily processable, narrowly emitting color conversion composite material.