基于纳米材料的OLED器件透明柔性电极研究

发布时间：2018-04-24 03:01

本文选题：有机电致发光器件(OLED) + 银(Ag)　；参考：《合肥工业大学》2017年硕士论文

【摘要】：随着透明柔性有机电致发光显示器件(organic light emitting devices,OLED)从概念转向产品,其制备技术、产品应用多元化在未来都会有很大发展。而电极是其结构中非常重要的一部分,所以开发性能稳定的透明柔性电极具有一定的科研价值。本文研究的可用于OLED器件的透明柔性电极主要有以下三个部分:(1)采用紫外光(UV)改性银(Ag)阳极的方法,改善透明Ag阳极与其他功能层的注入势垒,并研究了不同时长UV改性Ag阳极对结构为Ag/N,N′-二苯基-N,N′-(1-萘基)-1,1′-联苯-4,4′-二胺(NPB)/8-羟基喹啉铝(Alq3)/氟化锂(Li F)/铝(Al)的OLED器件性能的影响。Ag阳极改性后,表面产生银氧化层(Ag~((Ⅰ))Ag~((Ⅲ))O_2),实际工作阳极为Ag/Ag~((Ⅰ))Ag~((Ⅲ))O_2。此时阳极面电阻为1.8Ω/cm~2,功函数为5.17 eV,阳极和有机物界面处的空穴注入势垒从原来的0.80 eV降低到0.53eV,这相较于未改性的Ag阳极,大幅降低了空穴注入势垒,使该绿光OLED器件的性能得到很大提升。其中最优器件的改性时长为50 s,最大亮度从101.6 cd/m~2提高到5609.2 cd/m~2,启亮电压从20 V降低到6 V,电流效率得到很大提高。对进一步改善采用Ag作为阳极的透明柔性OLED器件性能有一定的应用前景。(2)用超薄层Al/LiF修饰Ag、Ag/氧化钼(MoO3)/Ag、金(Au)等透明阳极结构代替Al制作了可用于OLED的透明阴极,制成了双面出光的微细尺寸OLED器件。还分析并验证了Al/Li F修饰功函数较高的阳极电极能够做阴极的原因为:Al和LiF在被蒸镀为阴极修饰层时,两者膜层比较薄,会在蒸镀后与Alq3形成解离的阴离子,形成离子的漂移,提高了阴极的电子注入能力及其传输能力。这对制备透明柔性三基色的白光OLED器件具有基础指导意义。(3)利用喷涂的方法制作了基于纳米银线(AgNWs)材料的透明柔性电极,并引入聚乙烯吡咯烷酮(PVP)修饰层提升电极薄膜的机械弯曲能力及电学性能。然后通过优化喷涂浓度、层数及热处理时间制作了PVP/AgNWs透明柔性导电薄膜。薄膜在可见光波段380 nm—780 nm时透过率范围在53.4%—67.9%,面电阻为30Ω/cm~2。在弯曲测试中,经过500次弯曲,面电阻几乎不发生改变,显示出了优良的稳定性。经过180 s的超声,表面膜依然完整,且能够保持优异的导电性能。在空气中放置1000 h后,导电薄膜的表面电阻从30Ω/cm~2增加到36Ω/cm~2。在进一步的脱膜工艺的优化中,大幅度降低其表面粗糙度,后续可以通过引入修饰层,进一步提升了OLED器件的性能。
[Abstract]:With the transition from concept to product of transparent flexible organic electroluminescent display device (Ole), its preparation technology and product application diversification will have great development in the future. The electrode is a very important part of its structure, so the development of transparent flexible electrode with stable performance has certain scientific research value. In this paper, the transparent flexible electrode used in OLED devices is mainly composed of the following three parts: 1) the method of using UV (UV) modified silver silver anode to improve the injection barrier between transparent Ag anode and other functional layers. The effect of UV modified Ag anode on the properties of OLED devices with Ag- / N- (N-) -diphenyl-N- (N-) -diphenyl-N- (1)-1-naphthyl-(1)-1-(1)-(1)-(1)-(1) -biphenyl-4- (4)-diphenyl-4-aniline-diphenyl-4-aniline-diphenyl-4-hydroxyquinoline aluminum (Alq3 / 8-hydroxyquinoline aluminum)-Alq3 / LiF / Al) has been studied after the modification of Ag anode. A silver oxide layer is formed on the surface. The anode surface resistance is 1.8 惟 / cm ~ (-2), the work function is 5.17 EV, and the hole injection barrier at the anode and organic interface is reduced from 0.80 EV to 0.53 EV. Compared with the unmodified Ag anode, the hole injection barrier is greatly reduced. The performance of the green OLED device is greatly improved. The modification time of the optimal device is 50 s, the maximum brightness is increased from 101.6 cd/m~2 to 5609.2 CD / m ~ (2), the starting voltage is reduced from 20 V to 6 V, and the current efficiency is greatly improved. The properties of transparent flexible OLED devices using Ag as anode have a certain application prospect. (2) transparent anode structures such as ultrathin layer Al/LiF modified Ag-Ag / Moo _ 3 / Ag, au _ au) have been used to prepare transparent cathode for OLED instead of Al. A micro-size OLED device with double-sided light was fabricated. It is also analyzed and verified that the anode electrode with higher Al/Li F modification work function can be used as cathode. The reason is that when Al/Li Al and LiF are evaporated as cathodic modified layer, the film is thin, which will form dissociated anions with Alq3 after evaporation and form ion drift. The electron injection ability and the transmission ability of the cathode are improved. This is of fundamental guiding significance for the preparation of transparent flexible trichromatic white OLED devices. The transparent flexible electrodes based on nanocrystalline silver wire (AgNWs) materials have been fabricated by spraying method. Polyvinylpyrrolidone (PVP) modified layer was introduced to improve the mechanical bending and electrical properties of the film. Then the transparent and flexible conductive PVP/AgNWs thin films were prepared by optimizing the spraying concentration, the number of layers and the heat treatment time. The transmittance of the film is in the range of 53.4- 67.9 at 380 nm-780 nm, and the surface resistance is 30 惟 / cm ~ (-2). In the bending test, after 500 times of bending, the surface resistance is almost unchanged, showing good stability. After 180 s of ultrasound, the surface film is still intact and can maintain excellent conductivity. After being placed in air for 1000 h, the surface resistance of the conductive film increases from 30 惟 / cm ~ (2) to 36 惟 / cm ~ (2). In the further optimization of defilm process, the surface roughness can be greatly reduced, and the performance of OLED devices can be further improved by the introduction of modified layer.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN873.3

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