单分散高稳定性钙钛矿量子点的制备及其应用探索研究

Owing to the excellent optical properties, perovskite quntum dots (PQDs) have attracted much attention and exhibited possible applications in areas including lighting, display, biolabeling and biodetction. However, the stability of PQDs is one of the biggest challenges for their practical applications. In this project, we plan to prepare the crosslinked-PS-coated mesoporous silica nanospheres and then use them as nanoreactors for in-situ synthesis of PQDs in the channels of mSiO2. The as-prepared nanocomposites have advantages of being stable in moisture environments, water and even biological buffers, so the corresponding applications in WLED and biolabeling will be explored. In this process, the mSiO2 was used as a hard template for coating crosslinked PS to achieve the monodisperse and smaller-sized nanoparticles. On the other hand, as a soft matter, PS can be controlled for swelling or shrinking in different solvents, which in favor of opening the pores for filling precursor solution or closing it to form protection layer. We hope that the stability of PQDs will be greatly improved by SiO2 framework and PS encapsulation. Simultaneously, the convenient surface modification on PS shell may endow the nanoparticles with desired water dispersity and functionalities. Therefore, fabrication of monodisperse,stable PQDs and simultaneous keeping their excellent optical properties is very significant for their practicle applications.

钙钛矿量子点（PQDs）优异的光学性质使其在照明、显示、生物标记、荧光检测等领域具有良好的应用前景，成为新一代发光材料的研究热点之一。然而，这类材料对于环境的超级敏感性成为发展的瓶颈。本项目拟制备交联的聚苯乙烯(PS)包覆的介孔二氧化硅微球，并作为纳米反应器在氧化硅的孔道中原位合成PQDs，获得在水和生物溶液中稳定的单分散纳米复合微球，并探索其在白光LED和生物标记方面的应用。本项目的创新之处在于利用介孔SiO2作为硬模板，在表面聚合交联的PS，以确保其小的尺寸和单分散性，而PS作为软物质可以通过溶剂控制其溶胀和收缩，实现在孔道中引入量子点前驱体溶液并原位自组装生成PQDs后封闭孔道，以大大提升量子点的稳定性。同时，PS表面可以进一步修饰以提高水中的分散性及引入需要的功能性分子。制备单分散高度稳定的钙钛矿量子点同时能保持其优异的光学性质，对于这类的材料走向实际应用具有重要意义。

金属卤化物钙钛矿材料因其优异的光学性质成为照明和显示领域的研究热点。虽然钙钛矿材料在光电领域具有巨大的应用潜力并取得很大进展，目前仍面临许多问题，其中最为突出的是含铅化合物毒性大，对生态环境造成潜在的污染和破坏，另外这类材料对于环境超级敏感，在潮湿和紫外光照射等条件下易于降解，这些问题大大限制了其实际应用。本项目中，我们主要针对这些问题对材料进行设计并获得一定程度的提升，具体包括以下几个方面：.1. 通过制备无机复合材料、高分子复合材料等方法使嵌入其中的钙钛矿量子点的稳定性得到了大幅提升；.2. 合成了无铅的、PLQY高达84.7%的Cs2Na0.6Ag0.4InCl6：Bi3+/Yb3+双钙钛矿材料；.3. 光引发的配体交联结合全溶液加工方法制备发光LED；.4. 通过高分子配体诱导或溶剂诱导的方法实现了钙钛矿量子点的荧光变色。