溶液加工型叠层结构有机电致发光器件研究

Research and industry development of solution-processed organic light-emitting diodes (OLEDs) have attracted much attention because of their advantages, such as low-cost, large-area and simplified fabrication process. At present, the device efficiency of solution-processed OLEDs is significantly lower than that of the vacuum-processed counterparts, and still has a distance from the practical application. Therefore, it is exceedingly important to improve the device efficiency of solution-processed OLEDs. Tandem OLEDs are usually constructed by vertically connecting several individual electroluminescent units in series via charge generation layers. The luminance and efficiency of tandem OLEDs under the same current ccould be doubled. Therefore, it has important significance to study how to fabricate tandem OLEDs by solution-processing. Based on the needs, we intend to carry out experimental research on the solution-processed tandem OLEDs. In this project, the construction and performance optimization of the solution processed tandem OLEDs will be proposed. The charge generation layers with a P/N junction structure used for the highly efficient tandem OLEDs will be fabricated by solution-processing. The materials, structures and work mechanisms of the charge generation layers will be studied. The charge generation and charge injection will be solved through the structural design and optimization of the charge generation layers. The tandem OLEDs will be fabricated by contact transfer printing technolegy.The performance of tandem devices and related work mechanisms will be systematic investigated. Based on above research results, the fabrication technologies and physics models of solution-processed tandem OLEDs can be constructed. A number of low-cost, high-efficiency OLEDs will be achieved. The successful project implementation will offer an important theoretical and practical foundation for development of highly efficient OLEDs based on solution-processing. It also provides some theoretical guidance for the industry development of low-cost and high efficiency trinted organic optoelectronic devices.

溶液过程制备有机电致发光器件（OLED）具有制备工艺简单、大面积、成本低的优势，其研究和产业化发展受到人们的广泛关注，目前器件的效率距实用化仍有一定的距离，需要进一步的提升。叠层结构OLED器件可以实现在相同电流驱动下器件亮度和效率的倍增，是一种提高器件效率的有效途径。本项目提出溶液加工型叠层OLED的构筑与性能优化研究，溶液过程制备用于实现高效叠层OLED的新型P/N结载流子产生层，结合接触转印技术构筑叠层OLED器件。重点研究构成P/N结载流子产生层的材料体系及其工作机制，并通过结构设计与优化，解决电荷产生和电荷注入两个关键问题；结合接触转印技术制备叠层OLED器件，从多层器件制备与优化以及相关工作机理分析进行深入系统研究，探索构筑叠层器件的新方法，实现高效率的叠层OLED器件的构筑。项目的实施将为新结构载流子产生层设计与工作机制分析以及低成本印刷型高效OLED器件发展提供重要的指导。

溶液过程构筑叠层结构有机电致发光器件(OLED)是实现低成本、高效率器件的有效途径。项目针对溶液加工叠层OLED器件发展面临的关键问题，围绕P-型和N-型金属氧化物纳米薄膜制备，P/N结电荷产生层(CGL)设计与制备，叠层OLED构筑与优化以及相关工作机理分析进行深入系统的研究，探索制备低成本、高效率叠层OLED器件的新方法和新途径。主要研究结果包括：（1）设计制备了AMT/ZnO、NiOx/ZnO、HAT-CN/NPB、C60/HAT-CN/NPB、HAT-CN/MoO3/NPB、m-MTDATA/C60、NPB/MoO3和C60/NPB:MoO3等多种类型的CGL，通过电流-电压(I-V)、电容-电压(C-V)、电容-频率(C-F)等特性详细研究了各类CGL的载流子产生、分离和取出机制，在此基础上制备了一系列叠层OLED器件，红、蓝、白光叠层OLED器件的效率分别为48 cd/A，58 cd/A和120 cd/A；（2）采用N型掺杂层和单分子层Arg分别修饰溶胶-凝胶制备的ZnO纳米薄膜，其表面功函数为2.35 eV，有效降低了电子注入势垒，发展了一系列低驱动电压、高效率、长寿命的倒置结构OLED器件，器件在1700 cd/m2亮度下的半衰期寿命为3600小时；同时采用NPB/MoO3/Al/LiF、AMT/ZnO/PEI和NiOx/ZnO/PEI等CGL为电子注入层，构筑了一系列倒置结构OLED器件，发现这些电子注入层不依赖阴极的功函数，而且器件寿命显著提高，实现了高效、稳定的倒置OLED器件；（3）在此基础上，提出了溶液加工型叠层OLED的设计与优化，利用设计的新型P/N结CGL，再结合接触转印技术实现高效叠层OLED器件制备；研究了Si衬底和PDMS表面处理以及转印过程中的压力、剥离速度、温度等对转印薄膜的均匀性和形貌的影响，优化转印工艺关键参数，获得高质量的转印薄膜，为溶液方法构筑高性能叠层OLED器件打下基础。