The rapid development of thin-film light emitting devices (LED) technologies has recently been associated with the superior optoelectronic properties of luminescent materials based on lead halide perovskite nanocrystals (NCs) due to their narrow emission line with high color purity. However, the large surface area of NCs leads to the need to use solvating ligands to prevent their agglomeration, which limits their use in optoelectronics. Here we develop a class of modular polyfluorene (PF) copolymer with 4-hydroxyphenyl-, diethylamino- and diethoxyphosphoryl- groups designed to stabilize perovskite NCs. We show that as-synthesized CsPbBr NCs can easily be mixed with custom-designed PFs resulting in polymer/NCs composite that shows efficient Förster energy transfer (FRET) from PF to NC with green photoluminescence (PL). We also found that the NCs composite studied here can be used as an effective emissive layer in LED due to the strong interaction between polymer host and perovskite NCs providing an efficient charge transfer from the PF matrice to the NC emitter. The fabricated LED show excellent performance with a highest current efficiency of ∼25.2 cd A. Our approach provides a low-cost and efficient way for light-emitting optoelectronic applications based on perovskite NCs.

中文翻译：

---

用于发光器件的具有 CsPbX3 钙钛矿纳米晶体的高发光聚芴基复合材料

薄膜发光器件（LED）技术的快速发展最近与基于卤化铅钙钛矿纳米晶体（NC）的发光材料的优异光电特性相关，因为它们具有窄发射线和高色纯度。然而，NCs的大表面积导致需要使用溶剂化配体来防止其团聚，这限制了它们在光电子学中的应用。在这里，我们开发了一类具有 4-羟基苯基、二乙氨基和二乙氧基磷酰基的模块化聚芴 (PF) 共聚物，旨在稳定钙钛矿 NC。我们表明，合成的 CsPbBr NC 可以很容易地与定制设计的 PF 混合，形成聚合物/NC 复合材料，该复合材料显示出从 PF 到 NC 的高效福斯特能量转移 (FRET)，并具有绿色光致发光 (PL)。我们还发现，这里研究的 NC 复合材料可以用作 LED 中的有效发射层，因为聚合物主体和钙钛矿 NC 之间的强相互作用提供了从 PF 矩阵到 NC 发射器的有效电荷转移。所制造的 LED 表现出优异的性能，最高电流效率为 ∼25.2 cd A。我们的方法为基于钙钛矿 NC 的发光光电应用提供了一种低成本且高效的方法。