表面配体功能化和可控聚合构建高效稳定CsPbX3量子点及其发光性能调控

Lead halide CsPbX3(X=Cl,Br,I) type perovskite nanocrystals (NCs) have stimulated intense research in the field of quantum light-emitting diodes (QLED), lasers and solar cells, predominantly because of their exceptional optoelectronic characteristics. However, the luminescent properties and potential optoelectronic applications of CsPbX3 NCs are primarily limited by major material instability arising from the ionic nature of the NC lattice. Herein, the aim of the proposal is to construct efficient and stable CsPbX3 quantum dots by surface ligand functionalization and controllable polymerization. And first step of this proposal is to realize the functionalized CsPbX3 NCs by systematically controlling the synthetic conditions and hydrocarbon chain composition of carboxylic acids and amines based surfactant ligands with varying chains length and polymerizable double bond. Consequently, we will reveal the dependence of CsPbX3 nanocrystal morphologies and optical properties on the structures of ligands, and further confirm the distribution of ligands on surfaces. The functionalized ligand on NCs surface will undergo UV-initiated self-crosslinking of the surface ligands on NCs or copolymerization with POSS based monomers. The relationship and effects between the reactive time/component content and polymerization process will be carried out by dynamic sampling. And the copolymerization strategy would feature homogenously encapsulated NCs in the POSS-based polymer matrix, and we will further reveal the forming mechanism. The related factors of the morphologies/sizes/microstructures, the distribution of the surface ligands, POSS composition, high stabilities and optical properties will be analyzed correlatively. Then, the morphology and optical properties will be recorded and analyzed by orthogonal method, which will be employed as the criteria for the design and selection of target objects with controllable, high optoelectronic properties and stable structure. According to the chemical analysis results collectively, the mechanism of highly stable and durable properties will be proposed. This novel strategy will provide new research ideas and methods for enriching and developing the synthetic method of extremely stable and durable CsPbX3 NCs, which exhibit vital theoretical value and practical significance.

新型全无机钙钛矿(CsPbX3,X=Cl,Br,I)量子点因诸多优异特性，已在QLED、激光、太阳能电池等领域成为前沿研究热点。但该量子点属于离子型晶体，在潮湿空气中易于解离致使其荧光特性严重受阻，已成为研究深入发展的瓶颈。本项目拟通过表面配体功能化和可控聚合构建高效稳定钙钛矿量子点，利用不同链长含双键羧基/氨基类配体实现CsPbX3量子点可控制备，考察量子点表面配体分布；进而自由基引发诱导表面活性配体自交联或与疏水性POSS基单体共聚，动态监控时间/组分含量等对聚合反应影响，实现聚合物有效包裹，揭示形成机理；关联形貌/尺寸/结构-表面配体-POSS组分-稳定性-光学性能，采用正交法，对目标物光学性能进行表征，筛选出一些性能优异目标物，探寻高抗水抗热稳定性制备规律和保护机制，研究结果将为丰富和发展高稳定性CsPbX3量子点的制备提供新的思路和方法，具有重要的理论价值和实际研究意义。

新型全无机钙钛矿(CsPbX3, X=Cl, Br, I)量子点因诸多优异特性，已在QLED、激光、太阳能电池等领域成为前沿研究热点。但该量子点自身形成能量较低，且属于离子型晶体，在潮湿空气中易于解离致使其荧光特性严重受阻，已成为研究深入发展的瓶颈。近来研究人员通过大空间位阻配体表面调控、元素掺杂、无机组分或有机聚合物包覆等方法，大幅度提高了其稳定性，但仍存在一些问题，如成本高、操作繁琐、重复性差、产率低、相分离比较明显、表面钝化和稳定性间的构效关系相对模糊以及性能并不理想等问题，很难达到CsPbX3量子点的光电产业化，亟待进一步开发研究新型高产率、高性能和高稳定性CsPbX3材料。.本项目正是以CsPbX3量子点极差的稳定性为着眼点，研究了光照、极性溶剂和温度等对量子点的形貌、晶体结构和光学性能的影响，揭示了相关影响因素对量子点的影响机制。通过结合表面配体调控（不同链长含双键羧基/氨基类配体），原位聚合和界面疏水聚合物层包裹等策略，成功构筑了多种形貌可控、高产率、高性能和高稳定性的钙钛矿量子点材料（钙钛矿基疏水性POSS聚合物，钙钛矿基高交联聚合物和钙钛矿基丙烯酸酯凝胶等）。通过关联形貌/尺寸/晶体结构-配体分布-疏水聚合物-稳定性-光学性能，揭示了高稳定性目标物的制备规律和保护机制，并筛选出一些性能优异的目标物。项目还研究了高稳定性钙钛矿量子点材料的自愈合和拉伸特性，以及在荧光防伪和WLED等光电领域应用。本项目的研究进一步丰富了结构可控、高产率、高性能和高稳定性CsPbX3量子点的制备过程，为钙钛矿量子点的针对性保护提供了理论指导，也为最终实现其在QLED、激光、太阳能电池等领域的经济、高效和稳定性应用和工业化量产奠定基础，具有重要的理论价值和实际研究意义。