Functional Ligand-Modified Perovskite Quantum Dots for Stable Full-Color Microarrays via Photopolymerization
功能性配体修饰的钙钛矿量子点，用于通过光聚合获得稳定的全色微阵列

Colloidal lead-halide perovskite quantum dots (PQDs; ${\mathrm{APbX}}_3$${\mathrm{APbX}}_3$APbX_(3)\mathrm{APbX}_{3}, where A represents ${\mathrm{CH}}_3{\mathrm{NH}}_3{}^{+},{\mathrm{CHN}}_2{\mathrm{H}}_4{}^{+}$${\mathrm{CH}}_3{\mathrm{NH}}_3{}^{+},{\mathrm{CHN}}_2{\mathrm{H}}_4{}^{+}$CH_(3)NH_(3)^(+),CHN_(2)H_(4)^(+)\mathrm{CH}_{3} \mathrm{NH}_{3}{ }^{+}, \mathrm{CHN}_{2} \mathrm{H}_{4}{ }^{+}, or ${\mathrm{Cs}}^{+}$${\mathrm{Cs}}^{+}$Cs^(+)\mathrm{Cs}^{+}, and X denotes ${\mathrm{Cl}}^{-},{\mathrm{Br}}^{-}$${\mathrm{Cl}}^{-},{\mathrm{Br}}^{-}$Cl^(-),Br^(-)\mathrm{Cl}^{-}, \mathrm{Br}^{-}, or ${\mathrm{I}}^{-}$${\mathrm{I}}^{-}$I^(-)\mathrm{I}^{-}) are notable for their simple synthesis, high absorption coefficients, and outstanding carrier mobility. They have garnered significant interest due to their potential applications in light-emitting diodes, solar cells, and photodetectors. ${}^{[1]}$${}^{[1]}$^([1]){ }^{[1]} In
胶体卤化铅钙钛矿量子点 （PQD; ${\mathrm{APbX}}_3$${\mathrm{APbX}}_3$APbX_(3)\mathrm{APbX}_{3} ，其中 A 代表 ${\mathrm{CH}}_3{\mathrm{NH}}_3{}^{+},{\mathrm{CHN}}_2{\mathrm{H}}_4{}^{+}$${\mathrm{CH}}_3{\mathrm{NH}}_3{}^{+},{\mathrm{CHN}}_2{\mathrm{H}}_4{}^{+}$CH_(3)NH_(3)^(+),CHN_(2)H_(4)^(+)\mathrm{CH}_{3} \mathrm{NH}_{3}{ }^{+}, \mathrm{CHN}_{2} \mathrm{H}_{4}{ }^{+} 、 或 ${\mathrm{Cs}}^{+}$${\mathrm{Cs}}^{+}$Cs^(+)\mathrm{Cs}^{+} ，X 表示 ${\mathrm{Cl}}^{-},{\mathrm{Br}}^{-}$${\mathrm{Cl}}^{-},{\mathrm{Br}}^{-}$Cl^(-),Br^(-)\mathrm{Cl}^{-}, \mathrm{Br}^{-} 、 或 ${\mathrm{I}}^{-}$${\mathrm{I}}^{-}$I^(-)\mathrm{I}^{-} ）以其简单的合成、高吸收系数和出色的载流子迁移率而著称。由于它们在发光二极管、太阳能电池和光电探测器中的潜在应用，它们引起了人们的极大兴趣。 ${}^{[1]}$${}^{[1]}$^([1]){ }^{[1]} 在

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adfm. 202413963
本文作者的 ORCID 识别号可在 https://doi.org/10.1002/adfm 下找到。202413963
DOI: 10.1002/adfm. 202413963
DOI：10.1002/adfm。202413963
comparison to II-VI quantum dots (such as CdSe) and III-V quantum dots (such as InP), PQDs exhibit a notably narrow photoluminescence (PL) emission full width at half maximum (FWHM), rendering them particularly suitable as light-converting materials for liquid crystal displays and microLED displays. ${}^{[2]}$${}^{[2]}$^([2]){ }^{[2]} The integration of red $(R)$$(R)$(R)(R), green ( $G$$G$GG ), and blue (B) PQDs into stable full-color microarrays, in conjunction with blue or UV micro-LED chips, presents significant potential to enhance production efficiency while simultaneously reducing the complexity and costs associated with the manufacturing of micro-LED devices. ${}^{[22,3]}$${}^{[22,3]}$^([22,3]){ }^{[22,3]}
与 II-VI 量子点（如 CdSe）和 III-V 量子点（如 InP）相比，PQD 表现出明显狭窄的半峰全宽光致发光 （PL） 发射 FWHM，使其特别适合作为液晶显示器和 microLED 显示器的光转换材料。 ${}^{[2]}$${}^{[2]}$^([2]){ }^{[2]} 将红色 $(R)$$(R)$(R)(R) 、绿色 （ $G$$G$GG ） 和蓝色 （B） PQD 集成到稳定的全彩微阵列中，与蓝色或紫外线 micro-LED 芯片相结合，在提高生产效率的同时降低与 micro-LED 器件制造相关的复杂性和成本方面具有巨大潜力。 ${}^{[22,3]}$${}^{[22,3]}$^([22,3]){ }^{[22,3]}

Unfortunately, the intrinsic ionic characteristics and low formation energy of PQDs render them susceptible to degradation in aqueous environments and in the presence of oxygen, UV light, heat, and polar solvents. ${}^{[4]}$${}^{[4]}$^([4]){ }^{[4]} The polar solvents found in commercial photoresists and during postprocessing can lead to the decomposition of PQDs, making them generally incompatible with traditional photolithography techniques. ${}^{[36,5]}$${}^{[36,5]}$^([36,5]){ }^{[36,5]} Conversely, colloidal PQDs are thought to possess two distinct surface terminations: cesium bromide and lead bromide. Oleic acid (OA) and oleylamine ( OAm ) are the predominant surface ligands that passivate surface defects. ${}^{[6]}$${}^{[6]}$^([6]){ }^{[6]} However, the dynamic nature of the adsorption and desorption of OA and OAm on the surface results in the dissociation and loss of the ligands during separation, purification, and storage, compromising their colloidal stability. Furthermore, the detachment of the surface ligands can increase surface defects, which act as trap sites for charge carriers and excitons generated via photoexcitation or electrical injection. ${}^{[6]}$${}^{[6]}$^([6]){ }^{[6]} This phenomenon induces non-radiative recombination, significantly diminishing the photoluminescence quantum yield (PLQY) of PQDs. ${}^{[7]}$${}^{[7]}$^([7]){ }^{[7]} Therefore, it is essential to develop customized methodologies for patterning stable PQD microarrays using electrohydrodynamic jet (E-jet) printing, direct lithography, or transfer printing technologies while considering the unique properties of PQDs. ${}^{[3b,d,8]}$${}^{[3b,d,8]}$^([3b,d,8]){ }^{[3 b, d, 8]}
不幸的是，PQD 的固有离子特性和低形成能使其在水性环境以及氧气、紫外线、热和极性溶剂存在下容易降解。 ${}^{[4]}$${}^{[4]}$^([4]){ }^{[4]} 商业光刻胶和后处理过程中的极性溶剂会导致 PQD 分解，使其通常与传统的光刻技术不兼容。 ${}^{[36,5]}$${}^{[36,5]}$^([36,5]){ }^{[36,5]} 相反，胶体 PQD 被认为具有两种不同的表面末端：溴化铯和溴化铅。油酸 （OA） 和油胺 （OAm ） 是钝化表面缺陷的主要表面配体。 ${}^{[6]}$${}^{[6]}$^([6]){ }^{[6]} 然而，OA 和 OAm 在表面吸附和解吸的动态性质导致配体在分离、纯化和储存过程中解离和丢失，从而损害其胶体稳定性。此外，表面配体的分离会增加表面缺陷，这些缺陷充当通过光激发或电注入产生的载流子和激子的陷阱位点。 ${}^{[6]}$${}^{[6]}$^([6]){ }^{[6]} 这种现象会诱导非辐射复合，显著降低 PQD 的光致发光量子产率 （PLQY）。 ${}^{[7]}$${}^{[7]}$^([7]){ }^{[7]} 因此，在考虑 PQD 的独特特性的同时，必须开发定制方法，使用电动流体喷射 （E-jet） 打印、直接光刻或转移印刷技术对稳定的 PQD 微阵列进行图案化。 ${}^{[3b,d,8]}$${}^{[3b,d,8]}$^([3b,d,8]){ }^{[3 b, d, 8]}

A method for generating patterned PQDs involves crosslinking small molecule ligands on the surface of the PQDs by exposure to high-energy radiation or UV light. ${}^{[9]}$${}^{[9]}$^([9]){ }^{[9]} When exposed to cleaning solvents, the resulting insolubility of the irradiated regions facilitates the formation of fluorescent microarrays. In early 2016, Prato and co-workers employed low-flux X-rays
生成图案化 PQD 的方法包括通过暴露于高能辐射或紫外线来交联 PQD 表面的小分子配体。 ${}^{[9]}$${}^{[9]}$^([9]){ }^{[9]} 当暴露于清洁溶剂中时，由此产生的辐照区域的不溶性有助于形成荧光微阵列。2016 年初，Prato 和同事使用了低通量 X 射线
( ${10}^{11}$${10}^{11}$10^(11)10^{11} photons $/{\mathrm{mm}}^2\cdot \mathrm{s}$$/{\mathrm{mm}}^2\cdot \mathrm{s}$//mm^(2)*s/ \mathrm{mm}^{2} \cdot \mathrm{~s} ) to promote the cross-linking of carboncarbon double bonds ( $\mathrm{C}=\mathrm{C}$$\mathrm{C}=\mathrm{C}$C=C\mathrm{C}=\mathrm{C} ) between adjacent OA and OAm on the surface of ${\mathrm{CsPbBr}}_3\mathrm{PQDs}$${\mathrm{CsPbBr}}_3\mathrm{PQDs}$CsPbBr_(3)PQDs\mathrm{CsPbBr}_{3} \mathrm{PQDs} (CPB PQDs), thereby creating a hexagonal aperture cellular network pattern. ${}^{[9c]}$${}^{[9c]}$^([9c]){ }^{[9 c]} Oh et al. synthesized small molecules containing azide functional groups to serve as ligands for PQDs and created PQD microarrays by photocrosslinking of azide groups. ${}^{[9a]}$${}^{[9a]}$^([9a]){ }^{[9 a]} However, the azide group and independent $\mathrm{C}=\mathrm{C}$$\mathrm{C}=\mathrm{C}$C=C\mathrm{C}=\mathrm{C} bonds in small molecule ligands exhibit lower reactivity, which can result in insufficient cross-linking when low doses of radiation are applied. Conversely, high doses of radiation may compromise the structural integrity of PQDs and lead to a reduction in their PL properties. ${}^{[5,9,10]}$${}^{[5,9,10]}$^([5,9,10]){ }^{[5,9,10]} Ehrler’s team found that high doses of electron-beam radiation could significantly diminish the PL characteristics of OA and OAm-modified PQDs. ${}^{[9b]}$${}^{[9b]}$^([9b]){ }^{[9 b]} Furthermore, the cross-linking of small molecule ligands is believed to provide minimal protection for PQDs against moisture and thermal exposure from the external environment. This is attributed to the unlikely formation of dense molecular shells on the surface of PQDs resulting from such cross-linking. ${}^{[11]}$${}^{[11]}$^([11]){ }^{[11]}
（ ${10}^{11}$${10}^{11}$10^(11)10^{11} 光子 $/{\mathrm{mm}}^2\cdot \mathrm{s}$$/{\mathrm{mm}}^2\cdot \mathrm{s}$//mm^(2)*s/ \mathrm{mm}^{2} \cdot \mathrm{~s} ）促进 ${\mathrm{CsPbBr}}_3\mathrm{PQDs}$${\mathrm{CsPbBr}}_3\mathrm{PQDs}$CsPbBr_(3)PQDs\mathrm{CsPbBr}_{3} \mathrm{PQDs} （CPB PQDs） 表面相邻 OA 和 OAm 之间碳碳双键 （ $\mathrm{C}=\mathrm{C}$$\mathrm{C}=\mathrm{C}$C=C\mathrm{C}=\mathrm{C} ） 的交联，从而形成六边形孔径蜂窝网络模式。 ${}^{[9c]}$${}^{[9c]}$^([9c]){ }^{[9 c]} Oh 等人合成了含有叠氮化物官能团的小分子作为 PQD 的配体，并通过叠氮化物基团的光交联创建了 PQD 微阵列。 ${}^{[9a]}$${}^{[9a]}$^([9a]){ }^{[9 a]} 然而，小分子配体中的叠氮化物基团和独立 $\mathrm{C}=\mathrm{C}$$\mathrm{C}=\mathrm{C}$C=C\mathrm{C}=\mathrm{C} 键表现出较低的反应性，这可能导致在施加低剂量辐射时交联不足。相反，高剂量的辐射可能会损害 PQD 的结构完整性，并导致其 PL 特性降低。 ${}^{[5,9,10]}$${}^{[5,9,10]}$^([5,9,10]){ }^{[5,9,10]} Ehrler 的团队发现，高剂量的电子束辐射可以显着降低 OA 和 OAm 修饰的 PQD 的 PL 特性。 ${}^{[9b]}$${}^{[9b]}$^([9b]){ }^{[9 b]} 此外，小分子配体的交联被认为为 PQD 提供最低限度的保护，使其免受外部环境的水分和热暴露。这归因于这种交联导致 PQD 表面不太可能形成致密的分子壳。 ${}^{[11]}$${}^{[11]}$^([11]){ }^{[11]}

According to previous studies, the stability of PQDs can be improved in PQD/polymer composites, such as $\mathrm{CsPbBr}{}_3/$$\mathrm{CsPbBr}{}_3/$CsPbBr_(3)//\mathrm{CsPbBr}{ }_{3} / polystyrene, ${\mathrm{CsPbBr}}_3/$${\mathrm{CsPbBr}}_3/$CsPbBr_(3)//\mathrm{CsPbBr}_{3} / poly(styrene-ethylene-butylenestyrene), ${\mathrm{CsPbBr}}_3/$${\mathrm{CsPbBr}}_3/$CsPbBr_(3)//\mathrm{CsPbBr}_{3} / hydroxypropyl cellulose, and $\mathrm{CsPbBr}/$$\mathrm{CsPbBr}/$CsPbBr//\mathrm{CsPbBr} / poly (methyl methacrylate). ${}^{[12]}$${}^{[12]}$^([12]){ }^{[12]} These composites are generally produced by blending PQDs or their precursors with polymer solutions or monomers. The resulting dense polymer network serves as a physical barrier, shielding the PQDs from various external environmental factors. ${}^{[12b,e,13]}$${}^{[12b,e,13]}$^([12 b,e,13]){ }^{[12 b, e, 13]} Furthermore, the polymerization of PQDs converts colloidal PQDs directly into solid-state luminescent materials, facilitating the manufacturing of lightemitting devices. ${}^{[12c,d,14]}$${}^{[12c,d,14]}$^([12 c,d,14]){ }^{[12 c, d, 14]} Nonetheless, there has been limited investigation and few successful approaches for applying these composites in inkjet printing to create microarrays. One significant reason is that the as-prepared PQD/polymer composites are large in size and unsuitable for creating microarrays through E-jet printing and lithography. Several studies utilized polymer molecules containing ligand-grafting and photo-crosslinking units as ligands for PQDs. ${}^{[3a,7,15]}$${}^{[3a,7,15]}$^([3a,7,15]){ }^{[3 a, 7,15]} These PQDs with small particle sizes modified with these polymer ligands exhibited enhanced stability and were conducive to inkjet printing or photolithography. The cross-linking reactions between the polymer ligands, initiated by UV radiation, produced a cross-linked polymer matrix that was resistant to removal by cleaning solvents, resulting in the formation of PQD/polymer microarrays. For instance, Ko et al. synthesized poly(2-cinnamoyloxyethylmethacrylate) polymer ligands for PQDs with ammonium halides as terminal groups. The cross-linking of cinnamoyl groups on the ligands facilitated the creation of $RGB$$RGB$RGBR G B PQDs microarrays via direct photolithography. ${}^{[3\mathrm{a}]}$${}^{[3\mathrm{a}]}$^([3a]){ }^{[3 \mathrm{a}]} However, the development of polymer ligands often involves a complex chemical synthesis process, which presents challenges for preparation due to the stringent experimental conditions required. Moreover, limited attention has been given to the PL properties and stability of PQD/polymer composites stemming from the polymer ligands, both of which are crucial for display quality and the long-term performance of optoelectronic devices. Therefore, there is an urgent need for a new design strategy to produce stable PQD/polymer composites with high PLQY to make full-color microarrays.
根据以往的研究，PQD/聚合物复合材料中的稳定性可以提高，例如 $\mathrm{CsPbBr}{}_3/$$\mathrm{CsPbBr}{}_3/$CsPbBr_(3)//\mathrm{CsPbBr}{ }_{3} / 聚苯乙烯、 ${\mathrm{CsPbBr}}_3/$${\mathrm{CsPbBr}}_3/$CsPbBr_(3)//\mathrm{CsPbBr}_{3} / 聚苯乙烯-乙烯-丁烯酯、 ${\mathrm{CsPbBr}}_3/$${\mathrm{CsPbBr}}_3/$CsPbBr_(3)//\mathrm{CsPbBr}_{3} / 羟丙基纤维素和 $\mathrm{CsPbBr}/$$\mathrm{CsPbBr}/$CsPbBr//\mathrm{CsPbBr} / 聚甲基丙烯酸甲酯。 ${}^{[12]}$${}^{[12]}$^([12]){ }^{[12]} 这些复合材料通常是通过将 PQD 或其前驱体与聚合物溶液或单体混合来生产的。由此产生的致密聚合物网络用作物理屏障，保护 PQD 免受各种外部环境因素的影响。 ${}^{[12b,e,13]}$${}^{[12b,e,13]}$^([12 b,e,13]){ }^{[12 b, e, 13]} 此外，PQD 的聚合将胶体 PQD 直接转化为固态发光材料，从而促进发光器件的制造。 ${}^{[12c,d,14]}$${}^{[12c,d,14]}$^([12 c,d,14]){ }^{[12 c, d, 14]} 尽管如此，将这些复合材料应用于喷墨打印以制造微阵列的研究有限，成功的方法也很少。一个重要原因是所制备的 PQD/聚合物复合材料尺寸较大，不适合通过电子喷墨打印和光刻技术创建微阵列。几项研究利用含有配体接枝和光交联单元的聚合物分子作为 PQD 的配体。 ${}^{[3a,7,15]}$${}^{[3a,7,15]}$^([3a,7,15]){ }^{[3 a, 7,15]} 这些用这些聚合物配体修饰的小粒径 PQD 表现出增强的稳定性，有利于喷墨打印或光刻。由紫外线辐射引发的聚合物配体之间的交联反应产生了抗清洗溶剂去除的交联聚合物基质，从而形成 PQD/聚合物微阵列。例如，Ko 等人合成了以卤化铵为末端基团的 PQD 的聚（2-肉纳米氧基甲基丙烯酸乙酯）聚合物配体。 配体上肉桂酰基的交联促进了通过直接光刻法创建 $RGB$$RGB$RGBR G B PQD 微阵列。 ${}^{[3\mathrm{a}]}$${}^{[3\mathrm{a}]}$^([3a]){ }^{[3 \mathrm{a}]} 然而，聚合物配体的开发通常涉及复杂的化学合成过程，由于所需的实验条件严格，这给制备带来了挑战。此外，对聚合物配体产生的 PQD/聚合物复合材料的 PL 性能和稳定性的关注有限，这两者都对光电器件的显示质量和长期性能至关重要。因此，迫切需要一种新的设计策略来生产具有高 PLQY 的稳定 PQD/聚合物复合材料，以制备全彩微阵列。

Given that ligands play a vital role in passivating surface defects in PQDs and enhancing PQDs stability and scalability, ${}^{[16]}$${}^{[16]}$^([16]){ }^{[16]} developing functional ligands for stable PQD/polymer microarrays deserves more attention. The specific functional groups within the ligand molecules can establish physical or chemical interactions between PQDs and the surrounding polymer matrix, thereby enhancing the performance of the PQDs. Conversely, a reduced number of functional groups can lead to severe selfabsorption quenching, ${}^{[12e,16c]}$${}^{[12e,16c]}$^([12 e,16 c]){ }^{[12 e, 16 c]} which is often attributed to the uneven distribution or aggregation of PQDs within the polymer and induces a significant decrease in the PL intensity of the PQD/polymer composite, even a complete loss of the intensity.
鉴于配体在钝化 PQD 中的表面缺陷和增强 PQD 的稳定性和可扩展性方面起着至关重要的作用， ${}^{[16]}$${}^{[16]}$^([16]){ }^{[16]} 因此开发用于稳定 PQD/聚合物微阵列的功能性配体值得更多关注。配体分子内的特定官能团可以在 PQD 与周围的聚合物基体之间建立物理或化学相互作用，从而提高 PQD 的性能。相反，官能团数量的减少会导致严重的自吸收淬灭， ${}^{[12e,16c]}$${}^{[12e,16c]}$^([12 e,16 c]){ }^{[12 e, 16 c]} 这通常归因于 PQD 在聚合物内的分布或聚集不均匀，并导致 PQD/聚合物复合材料的 PL 强度显着降低， 甚至完全失去了强度。

Mono-2-(methacryloyloxy)ethyl succinate (MMeS) is a linear, short-chain organic molecule comprising ten carbon atoms, characterized by a carboxyl group and a methacrylate group at each terminus. The carboxyl group in MMeS facilitates the passivation of surface atoms in PQDs, while the methacrylate group can react with other matrix molecules. In this study, we propose a robust methodology for fabricating stable PQD/polymer microarrays. MMeS and 1,6-hexanediol diacrylate (HDDA) were selected as the ligands for PQDs and the monomer, respectively. We synthesized MMeS-modified ${\mathrm{CsPbBr}}_3$${\mathrm{CsPbBr}}_3$CsPbBr_(3)\mathrm{CsPbBr}_{3} PQDs (M-CPB PQDs) with PLQY of $85\mathrm{\%}$$85\mathrm{\%}$85%85 \% and produced MMeS-modified ${\mathrm{CsPbBr}}_3$${\mathrm{CsPbBr}}_3$CsPbBr_(3)\mathrm{CsPbBr}_{3} $\mathrm{PQD}/$$\mathrm{PQD}/$PQD//\mathrm{PQD} / polymer (M-H-CPB) composite via the photopolymerization of M-CPB PQDs with HDDA. We also investigated the PL properties and the water and thermal stability of M-H-CPB. Unsurprisingly, M-H-CPB achieved a high PLQY of $73.1\mathrm{\%}$$73.1\mathrm{\%}$73.1%73.1 \% in solid form, and the PL intensity of M-H-CPB retained $72\mathrm{\%}$$72\mathrm{\%}$72%72 \% of its initial value after 17 days of continuous water immersion, representing the best water stability and one of the highest PLQYs in PQD/polymer composites. We deduced that the copolymerization of the acrylate group in HDDA with the methacrylate group in MMeS enhances the dispersion of CPB PQDs within the polymer matrix and also mitigates the detachment of MMeS from the surface of CPB PQDs (Figure 1a). This process improves the PL and thermal resistance properties of CPB PQDs in the $\mathrm{M}-\mathrm{H}-\mathrm{CPB}$$\mathrm{M}-\mathrm{H}-\mathrm{CPB}$M-H-CPB\mathrm{M}-\mathrm{H}-\mathrm{CPB} composite. The resulting polymer effectively inhibits water-induced degradation of CPB PQDs. Finally, full-color patterns generated from MMeS-modified $RGB$$RGB$RGBR G B PQDs demonstrate the potential for developing full-color displays in micro-LED technology.
单-2-（甲基丙烯酰氧基）琥珀酸乙酯 （MMeS） 是一种线性短链有机分子，由 10 个碳原子组成，其特征是每个末端都有一个羧基和一个甲基丙烯酸酯基团。MMeS 中的羧基有助于 PQD 中表面原子的钝化，而甲基丙烯酸酯基团可以与其他基质分子反应。在这项研究中，我们提出了一种制造稳定 PQD /聚合物微阵列的稳健方法。MMeS 和 1,6-己二醇二丙烯酸酯 （HDDA） 分别被选为 PQD 和单体的配体。我们合成了具有 PLQY 的 MMeS 改性 ${\mathrm{CsPbBr}}_3$${\mathrm{CsPbBr}}_3$CsPbBr_(3)\mathrm{CsPbBr}_{3} 的 PQD （M-CPB PQDs），并通过 M-CPB PQD 与 HDDA 的光聚合生产了 MMeS 改性 ${\mathrm{CsPbBr}}_3$${\mathrm{CsPbBr}}_3$CsPbBr_(3)\mathrm{CsPbBr}_{3} $\mathrm{PQD}/$$\mathrm{PQD}/$PQD//\mathrm{PQD} / 的聚合物 （M-H-CPB） 复合材料。 $85\mathrm{\%}$$85\mathrm{\%}$85%85 \% 我们还研究了 M-H-CPB 的 PL 特性以及水和热稳定性。不出所料，M-H-CPB $73.1\mathrm{\%}$$73.1\mathrm{\%}$73.1%73.1 \% 在固体形式下实现了较高的 PLQY，并且在连续浸水 17 天后，M-H-CPB 的 PL 强度仍保持 $72\mathrm{\%}$$72\mathrm{\%}$72%72 \% 其初始值，代表了最好的水稳定性，是 PQD/聚合物复合材料中最高的 PLQY 之一。我们推断，HDDA 中的丙烯酸酯基团与 MMeS 中的甲基丙烯酸酯基团的共聚增强了 CPB PQD 在聚合物基体中的分散，并且还减轻了 MMeS 从 CPB PQD 表面的分离（图 1a）。该工艺改善了复合材料中 $\mathrm{M}-\mathrm{H}-\mathrm{CPB}$$\mathrm{M}-\mathrm{H}-\mathrm{CPB}$M-H-CPB\mathrm{M}-\mathrm{H}-\mathrm{CPB} CPB PQD 的 PL 和热阻性能。所得聚合物可有效抑制水诱导的 CPB PQD 降解。最后，由 MMeS 修饰 $RGB$$RGB$RGBR G B 的 PQD 生成的全彩图案展示了在 micro-LED 技术中开发全彩显示器的潜力。

As previously noted, an appropriate ligand is vital for developing high-performance PQD/polymer composites for optoelectronic applications. To investigate the binding affinity of MMeS to the surface of PQDs, we employed density functional theory (DFT) to compute the binding energy $\left(E_{\mathrm{b}}\right)$$\left(E_{\mathrm{b}}\right)$(E_(b))\left(E_{\mathrm{b}}\right) between MMeS and CPB PQDs, utilizing a slab model to represent the surface. ${}^{[17]}$${}^{[17]}$^([17]){ }^{[17]} We also utilized OA as a comparative reference. Figures 1b,1c illustrate the optimized atomic structures of OA and MMeS as capping ligands on CPB PQDs and their respective binding energies. MMeS establishes $\mathrm{Pb}-\mathrm{O}$$\mathrm{Pb}-\mathrm{O}$Pb-O\mathrm{Pb}-\mathrm{O} covalent bonds on the ${\mathrm{CsPbBr}}_3$${\mathrm{CsPbBr}}_3$CsPbBr_(3)\mathrm{CsPbBr}_{3} surface at a $\mathrm{Pb}-\mathrm{O}$$\mathrm{Pb}-\mathrm{O}$Pb-O\mathrm{Pb}-\mathrm{O} bond distance $\left(d_{\mathrm{Pb}-\mathrm{O}}\right)$$\left(d_{\mathrm{Pb}-\mathrm{O}}\right)$(d_(Pb-O))\left(d_{\mathrm{Pb}-\mathrm{O}}\right) of $2.508\text{Å}$$2.508\text{Å}$2.508"Å"2.508 \AA, exhibiting an $E_{\mathrm{b}}$$E_{\mathrm{b}}$E_(b)E_{\mathrm{b}} of -0.771 eV . This interaction is more robust than that of OA , which has a $d_{\mathrm{Pb}-\mathrm{O}}$$d_{\mathrm{Pb}-\mathrm{O}}$d_(Pb-O)d_{\mathrm{Pb}-\mathrm{O}} of $2.917\text{Å}$$2.917\text{Å}$2.917"Å"2.917 \AA and an $E_{\mathrm{b}}$$E_{\mathrm{b}}$E_(b)E_{\mathrm{b}} of -0.668 eV . These findings theoretically reveal that MMeS could be a more stable ligand than OA for CPB PQDs.
如前所述，合适的配体对于开发用于光电应用的高性能 PQD/聚合物复合材料至关重要。为了研究 MMeS 与 PQD 表面的结合亲和力，我们采用密度泛函理论 （DFT） 来计算 MMeS 和 CPB PQD 之间的结合能 $\left(E_{\mathrm{b}}\right)$$\left(E_{\mathrm{b}}\right)$(E_(b))\left(E_{\mathrm{b}}\right) ，利用平板模型来表示表面。 ${}^{[17]}$${}^{[17]}$^([17]){ }^{[17]} 我们还使用 OA 作为比较参考。图 1b、1c 说明了 OA 和 MMeS 作为 CPB PQD 上的加帽配体的优化原子结构及其各自的结合能。MMeS 在 ${\mathrm{CsPbBr}}_3$${\mathrm{CsPbBr}}_3$CsPbBr_(3)\mathrm{CsPbBr}_{3} 表面上以键 $\mathrm{Pb}-\mathrm{O}$$\mathrm{Pb}-\mathrm{O}$Pb-O\mathrm{Pb}-\mathrm{O} 距离 $\left(d_{\mathrm{Pb}-\mathrm{O}}\right)$$\left(d_{\mathrm{Pb}-\mathrm{O}}\right)$(d_(Pb-O))\left(d_{\mathrm{Pb}-\mathrm{O}}\right) $2.508\text{Å}$$2.508\text{Å}$2.508"Å"2.508 \AA 建立 $\mathrm{Pb}-\mathrm{O}$$\mathrm{Pb}-\mathrm{O}$Pb-O\mathrm{Pb}-\mathrm{O} 共价键， $E_{\mathrm{b}}$$E_{\mathrm{b}}$E_(b)E_{\mathrm{b}} 表现出 -0.771 eV 。这种交互比 OA 的交互更稳健，OA 的 a $d_{\mathrm{Pb}-\mathrm{O}}$$d_{\mathrm{Pb}-\mathrm{O}}$d_(Pb-O)d_{\mathrm{Pb}-\mathrm{O}} 为 $2.917\text{Å}$$2.917\text{Å}$2.917"Å"2.917 \AA $E_{\mathrm{b}}$$E_{\mathrm{b}}$E_(b)E_{\mathrm{b}} -0.668 eV 。这些发现从理论上揭示了 MMeS 可能是 CPB PQD 的比 OA 更稳定的配体。

MMeS-modified PQDs MMeS 修饰的 PQD
$✓$$✓$✓\checkmark Passivate PQDs by carboxyl group rovide further reaction sites
$✓$$✓$✓\checkmark 通过羧基钝化 PQD 以开发更多反应位点
by methacrylate group 按甲基丙烯酸酯组

$✓$$✓$✓\checkmark Protect PQDs from corrosion by environmental factors
$✓$$✓$✓\checkmark 保护 PQD 免受环境因素的腐蚀

$E_{\mathrm{b}}=-0.668\mathrm{eV}$$E_{\mathrm{b}}=-0.668\mathrm{eV}$E_(b)=-0.668eVE_{\mathrm{b}}=-0.668 \mathrm{eV}

$E_{\mathrm{b}}=-0.771\mathrm{eV}$$E_{\mathrm{b}}=-0.771\mathrm{eV}$E_(b)=-0.771eVE_{\mathrm{b}}=-0.771 \mathrm{eV}

Figure 1. a) Schematic representation of the photopolymerization process involving MMeS-modified PQDs in conjunction with HDDA, emphasizing the impact of PQDs modification on their dispersion within cross-linked polymer matrices. Calculated structures and binding energies associated with the adsorption of b) OA and c) MMeS on CPB PQDs, respectively.
图 1.a） 涉及 MMeS 修饰的 PQD 与 HDDA 结合的光聚合过程的示意图，强调了 PQD 修饰对其在交联聚合物基质中的分散性的影响。分别计算与 CPB PQD 上 b） OA 和 c） MMeS 吸附相关的结构和结合能。

We synthesized M-CPB PQDs using a ligand-assisted reprecipitation technique. ${}^{[18]}$${}^{[18]}$^([18]){ }^{[18]} A precursor solution containing CsBr , ${\mathrm{PbBr}}_2$${\mathrm{PbBr}}_2$PbBr_(2)\mathrm{PbBr}_{2}, OAm, and MMeS was prepared in DMF at ambient temperature, and then M-CPB PQDs occurred via precipitation by adding xylene. This approach not only streamlines the synthesis process but also mitigates the occurrence of surface defects associated with ligand exchange. ${}^{[19]}$${}^{[19]}$^([19]){ }^{[19]} The high reactivity of the C $=\mathrm{C}$$=\mathrm{C}$=C=\mathrm{C} double bonds in methacrylate and acrylate monomers facilitates their rapid photopolymerization upon exposure to UV light, forming functional polymeric materials. ${}^{[20]}$${}^{[20]}$^([20]){ }^{[20]} We synthesized the M-H-CPB composite by combining M-CPB PQDs, HDDA, and a photoinitiator TPO, followed by 3 min of UV irradiation. This process enabled the $\mathrm{C}=\mathrm{C}$$\mathrm{C}=\mathrm{C}$C=C\mathrm{C}=\mathrm{C} double bonds in the methacrylate group of MMeS to participate in the copolymerization reaction with the $\mathrm{C}=\mathrm{C}$$\mathrm{C}=\mathrm{C}$C=C\mathrm{C}=\mathrm{C} double bonds in the acrylate group of HDDA. The resulting M-H-CPB composite exhibiteda characteristic of a green and transparent solid with bright and uniform green fluorescence (Figure S1a, Supporting Information). In contrast, a 60 min UV irradiation of M-CPB PQDs in xylene yielded only a yellow-green colloidal solution emitting green light (Figure S1b, Supporting Information). We irradiated an xylene solution of MMeS with 365 nm UV light for 60 min . Subsequent gel permeation chromatography analysis of this solution revealed a high molecular weight of $707\mathrm{g}{\mathrm{mol}}^{-1}$$707\mathrm{g}{\mathrm{mol}}^{-1}$707gmol^(-1)707 \mathrm{~g} \mathrm{~mol}^{-1} (Figure S2, Supporting Information). The calculated average degree of polymerization was determined to be 3.07 , indicating that MMeS primarily polymerized into a trimeric form via the methacrylate moiety. This finding suggests that during the irradiation of M-CPB PQDs in xylene, in situ photo-induced ligand cross-linking occurred, resulting in the formation of the trimeric form of MMeS-modified ${\mathrm{CsPbBr}}_3$${\mathrm{CsPbBr}}_3$CsPbBr_(3)\mathrm{CsPbBr}_{3} PQDs (Mc-CPB PQDs).
我们使用配体辅助重沉淀技术合成了 M-CPB PQDs。 ${}^{[18]}$${}^{[18]}$^([18]){ }^{[18]} 在室温下在 DMF 中制备含有 CsBr 、 ${\mathrm{PbBr}}_2$${\mathrm{PbBr}}_2$PbBr_(2)\mathrm{PbBr}_{2} OAm 和 MMeS 的前驱体溶液，然后通过添加二甲苯沉淀产生 M-CPB PQDs。这种方法不仅简化了合成过程，还减少了与配体交换相关的表面缺陷的发生。 ${}^{[19]}$${}^{[19]}$^([19]){ }^{[19]} 甲基丙烯酸酯和丙烯酸酯单体中的 C $=\mathrm{C}$$=\mathrm{C}$=C=\mathrm{C} 双键的高反应性促进了它们在紫外光照射下快速光聚合，形成功能性聚合物材料。 ${}^{[20]}$${}^{[20]}$^([20]){ }^{[20]} 我们通过组合 M-CPB PQDs、hdda 和光引发剂 TPO，然后进行 3 分钟的紫外线照射来合成 M-H-CPB 复合材料。这个过程使 MMeS 的甲基丙烯酸酯基团中的 $\mathrm{C}=\mathrm{C}$$\mathrm{C}=\mathrm{C}$C=C\mathrm{C}=\mathrm{C} 双键与 HDDA 的丙烯酸酯基团中的 $\mathrm{C}=\mathrm{C}$$\mathrm{C}=\mathrm{C}$C=C\mathrm{C}=\mathrm{C} 双键参与共聚反应。所得的 M-H-CPB 复合材料表现出绿色透明固体的特征，具有明亮均匀的绿色荧光（图 S1a，支持信息）。相比之下，在二甲苯中对 M-CPB PQD 进行 60 分钟的紫外线照射，仅产生发出绿光的黄绿色胶体溶液（图 S1b，支持信息）。我们用 365 nm 紫外光照射 MMeS 的二甲苯溶液 60 分钟。随后对该溶液进行的凝胶渗透色谱分析显示，其分子量很高 $707\mathrm{g}{\mathrm{mol}}^{-1}$$707\mathrm{g}{\mathrm{mol}}^{-1}$707gmol^(-1)707 \mathrm{~g} \mathrm{~mol}^{-1} （图 S2，支持信息）。计算的平均聚合度确定为 3.07 ，表明 MMeS 主要通过甲基丙烯酸酯部分聚合成三聚体形式。 这一发现表明，在二甲苯中照射 M-CPB PQD 期间，发生原位光诱导配体交联，导致形成 MMeS 修饰 ${\mathrm{CsPbBr}}_3$${\mathrm{CsPbBr}}_3$CsPbBr_(3)\mathrm{CsPbBr}_{3} 的 PQD （Mc-CPB PQDs） 的三聚体形式。

In Fourier transform infrared (FT-IR) spectra, M-CPB PQDs exhibited a characteristic absorption peak corresponding to the $\mathrm{C}=\mathrm{C}$$\mathrm{C}=\mathrm{C}$C=C\mathrm{C}=\mathrm{C} stretching vibration of MMeS ligand at $1614{\mathrm{cm}}^{-1}$$1614{\mathrm{cm}}^{-1}$1614cm^(-1)1614 \mathrm{~cm}^{-1} (Figure 2a). ${}^{[21]}$${}^{[21]}$^([21]){ }^{[21]} Following exposure of M-CPB PQDs to 365 nm UV light for 60 min , which resulted in the formation of McCPB PQDs, a notable reduction in the intensity of this absorption peak was observed (Figure 2a). This attenuation suggests decreased $\mathrm{C}=\mathrm{C}$$\mathrm{C}=\mathrm{C}$C=C\mathrm{C}=\mathrm{C} content, likely due to interrelated chemical reactions involving MMeS. In the system comprising M-CPB PQDs, HDDA, and TPO, the peaks at 1614 and $1637{\mathrm{cm}}^{-1}$$1637{\mathrm{cm}}^{-1}$1637cm^(-1)1637 \mathrm{~cm}^{-1} before UV irradiation can be attributed to the $\mathrm{C}=\mathrm{C}$$\mathrm{C}=\mathrm{C}$C=C\mathrm{C}=\mathrm{C} double bonds present
在傅里叶变换红外 （FT-IR） 光谱中，M-CPB PQD 表现出对应于 $\mathrm{C}=\mathrm{C}$$\mathrm{C}=\mathrm{C}$C=C\mathrm{C}=\mathrm{C} MMeS 配体拉伸振动的 $1614{\mathrm{cm}}^{-1}$$1614{\mathrm{cm}}^{-1}$1614cm^(-1)1614 \mathrm{~cm}^{-1} 特征吸收峰（图 2a）。 ${}^{[21]}$${}^{[21]}$^([21]){ }^{[21]} 在 M-CPB PQD 暴露于 365 nm 紫外光 60 分钟后，导致 McCPB PQD 的形成，观察到该吸收峰的强度显着降低（图 2a）。这种衰减表明含量降低 $\mathrm{C}=\mathrm{C}$$\mathrm{C}=\mathrm{C}$C=C\mathrm{C}=\mathrm{C} ，可能是由于涉及 MMeS 的相互关联的化学反应。在包含 M-CPB PQD、HDDA 和 TPO 的系统中，1614 处和 $1637{\mathrm{cm}}^{-1}$$1637{\mathrm{cm}}^{-1}$1637cm^(-1)1637 \mathrm{~cm}^{-1} 紫外线照射前的峰可归因于存在的 $\mathrm{C}=\mathrm{C}$$\mathrm{C}=\mathrm{C}$C=C\mathrm{C}=\mathrm{C} 双键
in MMeS and HDDA, respectively (Figure 2d). After UV irradiation, these two peaks progressively diminished, nearly vanishing after 3 min , indicating that MMeS participated in a copolymerization reaction with HDDA and completed within this timeframe.
分别在 MMeS 和 HDDA 中（图 2d）。紫外照射后，这两个峰逐渐减小，3 min后几乎消失，表明MMeS参与了与HDDA的共聚反应，并在此时间范围内完成。
Transmission electron microscopy (TEM) images revealed that M-CPB PQDs exhibited unaggregated cubic morphologies (Figure 2b). In contrast, OA-modified ${\mathrm{CsPbBr}}_3$${\mathrm{CsPbBr}}_3$CsPbBr_(3)\mathrm{CsPbBr}_{3} PQDs (OA-CPB PQDs) synthesized using the same methodology also displayed a cubic structure (Figure S3, Supporting Information). This observation indicates that incorporating short-chain ligand MMeS did not alter the morphology of CPB PQDs. The average particle size of M-CPB PQDs was determined to be 10.8 nm (Figure S4b, Supporting Information), which is smaller than that of OACPB PQDs with an average particle size of 11.3 nm (Figure S4a, Supporting Information). This difference in size may be attributed to the short-chain ligand enhancing the diffusion coefficient and solubility of the solute, thereby facilitating an accelerated growth rate and process. ${}^{[22]}$${}^{[22]}$^([22]){ }^{[22]} The high-resolution transmission electron microscopy (HR-TEM) images in Figures 2c and f clearly show the lattice striations on the crystal surfaces of M-CPB (110) and Mc-CPB (110), with an interplanar spacing of 0.39 and 0.40 nm , respectively. The average inter-dot distances between adjacent quantum dots in M-CPB and Mc-CPB PQDs were measured at 1.79 and 1.36 nm , respectively (Figure S5, Supporting Information). This reduction in distance within Mc-CPB PQDs is attributed to the cross-linking of ligands between neighboring quantum dots, which enhances intermolecular interactions and decreases the separation between the quantum dots. These findings are consistent with the results reported in the existing literature. ${}^{[11,16a,23]}$${}^{[11,16a,23]}$^([11,16 a,23]){ }^{[11,16 a, 23]} Importantly, the TEM image of the M-H-CPB composite reveals a uniform dispersion of CPB PQDs within the synthesized polymer matrix, with no observable aggregation of PQDs (Figure 2h). Additionally, lattice fringes on the crystal surface of CPB PQDs (220) in M-H-CPB can be observed, displaying an interplanar spacing of 0.21 nm (Figure 2i). In contrast, a significant accumulation of CPB PQDs is observed in the OA-H-CPB composite (Figure S6, Supporting Information) prepared under the same conditions as the M-H-CPB composite. This observation suggests that the in situ cross-linking of MMeS with HDDA effectively facilitates the uniform encapsulation of PQDs within the polymer matrix.
透射电子显微镜 （TEM） 图像显示 M-CPB PQD 表现出未聚集的立方形态（图 2b）。相比之下，使用相同方法合成的 OA 修饰 ${\mathrm{CsPbBr}}_3$${\mathrm{CsPbBr}}_3$CsPbBr_(3)\mathrm{CsPbBr}_{3} 的 PQD （O-CPB PQD） 也显示出立方结构（图 S3，支持信息）。这一观察结果表明，掺入短链配体 MMeS 不会改变 CPB PQD 的形态。确定 M-CPB PQD 的平均粒径为 10.8 nm（图 S4b，支持信息），小于平均粒径为 11.3 nm 的 OACPB PQD（图 S4a，支持信息）。这种大小的差异可能归因于短链配体增强了溶质的扩散系数和溶解度，从而促进了加速生长速率和过程。 ${}^{[22]}$${}^{[22]}$^([22]){ }^{[22]} 图 2c 和 f 中的高分辨率透射电子显微镜 （HR-TEM） 图像清楚地显示了 M-CPB （110） 和 Mc-CPB （110） 晶体表面的晶格条纹，面间距分别为 0.39 和 0.40 nm。M-CPB 和 Mc-CPB PQD 中相邻量子点之间的平均点间距离分别在 1.79 和 1.36 nm 处测量（图 S5，支持信息）。Mc-CPB PQD 内距离的缩短归因于相邻量子点之间配体的交联，这增强了分子间相互作用并减少了量子点之间的分离。这些发现与现有文献中报告的结果一致。 ${}^{[11,16a,23]}$${}^{[11,16a,23]}$^([11,16 a,23]){ }^{[11,16 a, 23]} 重要的是，M-H-CPB 复合材料的 TEM 图像显示 CPB PQD 在合成的聚合物基质中均匀分散，没有观察到的 PQD 聚集（图 2h）。 此外，在 M-H-CPB 中，可以观察到 CPB PQD （220） 晶体表面的晶格条纹，显示 0.21 nm 的面间距（图 2i）。相比之下，在与 M-H-CPB 复合材料相同的条件下制备的 OA-H-CPB 复合材料（图 S6，支持信息）中观察到 CPB PQD 的显着积累。这一观察结果表明，MMeS 与 HDDA 的原位交联有效地促进了 PQD 在聚合物基质内的均匀封装。