柔性OLED透明导电电极的研究

STUDY ON TRANSPARENT CONDUCTIVE ELECTRODE FOR FLEXIBLE OLED

汪刚

11749080

硕士

力学

王敏

2019-05-28

2019-07-20

哈尔滨工业大学

深圳

显示器，作为人机交互的载体，经过几十年的技术积累，已从最简单的指示灯发展到今天的有机发光二极管显示器（OLED）。相对于目前的主流液晶显示器，OLED具有自发光、耗电量低、响应速度快、可实现柔性等特点，是下一代显示器的不二选择。随着柔性OLED从概念转向产品，其制备技术和多样化应用吸引了众多的关注。作为柔性OLED的重要组成部分，性能优异的透明导电电极更是当前的研究热点。目前研究者提出了多种柔性导电电极，包括导电聚合物、石墨烯、单壁碳纳米管、金属纳米线等，虽然在替代当前主流的OLED阳极材料氧化铟锡（ITO）方面具备一定的潜力，但都存在透光性能和导电性能的相互制约关系。本文主要研究了嵌入式有序金属导电网格的制备及其在OLED中的应用，主要从以下几个方面来进行研究: （1）本文利用电化学辅助剥离技术制备柔性导电电极，相对于前人的其他剥离方法如湿法刻蚀、干法刻蚀、激光辅助剥离技术等，电化学辅助剥离的速度更快，制备的样品表面更光洁，有利于OLED器件的集成。同时，我们也研究了剥离电压、电解液浓度等条件对剥离速率的影响。结果表明：提高剥离电压、增大电解液浓度、减小牺牲层面积可有效提高剥离速率。（2）利用Lift-off技术制备嵌入聚二甲基硅氧烷（PDMS）的有序金属网格，并使用上述剥离技术从不锈钢基底上剥离出Au/PDMS柔性透明导电电极。通过理论设计和实验验证，提出了良好光电性能的柔性透明导电电极的设计准则。同时利用制备的Au/PDMS柔性透明导电电极作为阳极，蒸镀NPB（N,N'-二苯基-N,N'-(1-萘基)-1,1'-联苯-4,4'-二胺）和小分子发光层Alq3（三（8-羟基喹啉）铝）和阴极Al，制备了OLED原型样机，并测试了其发光性能和机械稳定性。（3）为了进一步提高柔性导电电极的可拉伸性，我们提出用U型互联结构金属网格代替直线网格结构。通过模拟分析，我们获得了U型互联结构的特征尺寸与可拉伸性之间的相互关系。利用（2）中的方法，我们分别制备了U型Au网格/PDMS柔性电极和OLED样机，探讨了其光电性能和机械稳定性。

As the carrier of man-machine interaction, Display has developed from the simplest indicator lamp to today's organic light-emitting diode display (OLED) after decades of technical accumulation. Compared with the current mainstream liquid crystal display, OLED has the characteristics of self-luminescence, low power consumption, fast response and flexibility. It is almost the best choice for the next generation of display. With the development of flexible OLED from concept to product, its preparation technology and diversified applications have attracted a lot of attention. As an important part of flexible OLED, transparent conductive electrodes with excellent performance are the current research hotspot. At present, researchers have proposed a variety of flexible conductive electrodes, including conductive polymers, graphene, single-walled carbon nanotubes, metal nanowires and so on, which have good potential to replace the current mainstream OLED anode material, indium tin oxide (ITO). However, there is a mutual restriction between light transmission and conductivity. This paper mainly studies the preparation of em bedded ordered metal conductive grid and its application in OLED, mainly from the following aspects: (1) In this paper, flexible conductive electrodes are fabricated by electrochemical assisted stripping technology. Compared with other stripping methods such as wet etching, dry etching and laser assisted stripping, electrochemical assisted stripping is faster, and the surface of the sample is cleaner, which is conducive to the integration of OLED devices. At the same time, we also studied the influence of stripping voltage and electrolyte concentration on the stripping rate. The results show that bigger stripping voltage, increasing electrolyte concentration and reducing sacrificial layer area can effectively improve the stripping rate. (2) The ordered metal mesh embedded in polydimethylsiloxane (PDMS) was fabricated by Lift-off technology, and Au/PDMS flexible transparent conductive electrodes were stripped from stainless steel substrates by the electrochemical assisted stripping technology. Through theoretical design and experimental verification, the design criteria of flexible transparent conductive electrodes with good photoelectric properties are proposed. At the same time, using the prepared flexible transparent conductive electrode of Au/PDMS as anode, evaporating NPB (N, N'-diphenyl-N, N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine) and small molecular luminescent layer Alq3 (tri (8-hydroxyquinoline) aluminum) and cathode Al, the prototype of OLED was prepared, and its luminescent properties and mechanical stability were tested. (3) In order to further improve the stretchability of flexible conductive electrodes, we propose to use U-shaped interconnected metal grid to instead the linear grid structure. Through simulation analysis, we obtained the relationship between the characteristic size and the stretchability of U-shaped interconnected structures. Using the method of (2) we have fabricated U-shaped Au grid/PDMS flexible electrodes and OLED prototypes, and discussed their photoelectric properties and mechanical stability.

有机发光二极管 柔性透明导电电极 电化学辅助剥离 有限元仿真

organic light emitting diode flexible transparent conductive electrode electrochemical stripping finite element simulation

中文

联合培养

南方科技大学

汪刚. 柔性OLED透明导电电极的研究[D]. 深圳. 哈尔滨工业大学,2019.