挤出法制备钙钛矿量子点/聚合物复合膜及其显示应用研究

Perovskite quantum dots have the advantages of low cost, simple preparation process and high photoluminescence performance. They are a new type of display materials with growth potential as well as an important research direction for China to break through the foreign patent blockade of display materials. In order to solve the problem of poor stability of perovskite quantum dots and promote its commercial application in QLED backlight display, this project proposes the study of in-situ preparation of perovskite quantum dots/polymer composite luminescent film by extrusion method and studied its application in display. Firstly, the interaction mechanism between the raw materials of the synthetic perovskite quantum dots and the polymer matrix material was studied. The conditions and laws required for the raw material to be dispersed in the matrix at a molecular level during the preparation of the composite by the extrusion method were mastered. Then, the composite luminescent film with high stability, quantum yield of >80% and tunable emission wavelength in the visible light range was in situ prepared by the extrusion method after optimizing the preparation conditions. Thirdly, a water and oxygen barrier film and the perovskite quantum dots/polymer composite luminescent film were simultaneously extruded by using a multi-layer co-extrusion method. The in-situ encapsulation of the perovskite quantum dots/polymer composite luminescent film can stabilize the perovskite quantum dots and meet the engineering application requirements. Finally, the as-prepared green light and red light emitting perovskite quantum dots/polymer composite luminescent film were used to assemble a display prototype for the measurement of the color performance and display stability.

钙钛矿量子点具有成本低、制备工艺简单、发光性能好等特点，是一类具有成长潜力的新型显示材料，是我国突破国外显示材料专利封锁的重要研究方向。为了解决钙钛矿量子点稳定性差的问题，推动量子点背光显示的商业化应用，本项目提出挤出法原位制备钙钛矿量子点/聚合物复合发光薄膜及其在液晶显示背光应用的课题。首先，研究合成钙钛矿量子点的原料与基质材料之间的相互作用机理，掌握挤出法制备复合材料时原料在基质中达到分子级分散所需的条件和规律。然后，通过优化制备条件，使用挤出法原位制备出高稳定性、荧光量子产率>80%、发光波长在可见光范围内可调的复合发光薄膜。再使用多层共挤法将水、氧阻隔膜与钙钛矿量子点/聚合物复合发光薄膜同时挤出，实现对钙钛矿量子点/聚合物复合发光薄膜的原位封装，使其稳定性达到工程应用要求。最后使用制备的绿光和红光发射钙钛矿量子点/聚合物复合发光薄膜组装显示样机，测试其色彩表现性能和显示稳定性。

钙钛矿量子点具有成本低、制备工艺简单、发光性能好等特点，是一类具有成长潜力的新型显示材料，是我国突破国外显示材料专利封锁的重要研究方向。为了解决钙钛矿量子点稳定性差和批量生产的问题，推动量子点背光显示的商业化应用，本项目提出挤出法原位制备钙钛矿量子点/聚合物复合发光薄膜及其在液晶显示背光应用的课题。.研究发现前驱体原料的原始分散性对产物的发光性能影响不大，原因是挤出过程温度较高，聚合物已处于熔融状态，前驱体原料可在挤出过程中均匀分散到聚合物基质中。聚合物基质含有的官能团对产物的发光性能和稳定性影响大，聚合物基质的极性越小，产品的综合性能越好。研究了前驱体、聚合物基质种类、挤出工艺条件等方面对产物的影响，开发出了荧光量子产率>80%的红光和绿光发射钙钛矿量子点扩散板。通过更换不同厚度的模头，可制备出宽幅0.6 m，厚度100~1000 μm的钙钛矿量子点扩散板，满足LCD背光显示的需求。研究了不同挤出工艺和不同阻水、阻氧性能聚合物材料对钙钛矿量子点扩散板稳定性的影响。研究表明可以使用分别具有阻水、阻氧能力的聚合物叠层共挤后达到需要的阻水、阻氧率即可满足钙钛矿量子点扩散板商用对稳定性的需求。使用多层共挤技术将红光、绿光发射的量子点扩散板与封装材料复合，得到红、绿双光色发射的钙钛矿量子点扩散板。该扩散板在65°C95%RH环境中老化1000 h亮度衰减<10%，40°C蓝光辐照（450 nm，3.8 mW/cm2）环境中老化1000 h亮度衰减<10%，信赖性符合商用要求。最后，将扩散板与蓝光Mini LED集成，实现了色域面积为NTSC 1931标准125%、DCI-P3标准95%的LCD背光模组。.挤出法原位制备钙钛矿量子点/聚合物扩散板技术具有零排放、低成本、高性能的优势，并且具有完全自主知识产权，相较于目前广泛使用的CdSe量子点膜/板材料有很强的竞争优势，有望成为下一代主流量子点背光产品。