有机薄膜电致发光器件（OLED）研究和研制

【作者】 陶海华；

【导师】 姚宁； 张兵临；

【作者基本信息】 郑州大学 ， 凝聚态物理， 2004， 硕士

【摘要】 有机薄膜电致发光器件(OLED)自20世纪80年代末成为电子显示领域一颗耀眼的明星。它具有低压直流驱动、主动发光、色彩饱和度好、视角宽等一系列优点，在照明光源、光电耦合器和平板显示等光电领域具有诱人的前景。目前，OLED在小型平板显示领域如汽车仪表、手机屏和数码相机显示屏等方面已经投入商用。然而，OLED还存在一些问题，特别是在稳定性和寿命方面仍有待提高。 本文鉴于高分子聚合物在稳定性方面所特有的优势，研制了高分子聚合物掺杂小分子荧光材料的OLED。采用直流磁控反应溅射法沉积阳极ITO薄膜，旋涂法沉积有机膜，直流磁控溅射法或真空蒸镀法沉积Al阴极，制备了8-羟基喹啉铝(AlQ)绿色OLED。并在此基础上对一些制备参数进行优化，得到最大发光亮度为18.8cd／m~2的OLED。 本文首先探讨了在转速固定的情况下双层结构器件中空穴传输层PVK含量以及发光层中聚乙烯基咔唑(PVK)、AIQ和2-(4-联苯基)-5-(4-丁基苯基)-1，3，4-噁二唑(PBD)各物质配比对器件性能的影响，通过观察和比较器件的亮度、稳定性，确定了空穴传输层和发光层中各种物质的最佳含量。 本文还研究了Al阴极厚度和ITO阳极表面处理对器件性能的影响。实验结果表明：Al阴极存在最佳厚度使OLED的发光亮度和稳定性达到最优化；ITO阳极表面处理改变了薄膜表面形貌，提高了OLED的亮度、稳定性和流明效率。 再者，本文研究了器件结构对OLED性能的影响。实验结果表明，单层结构器件性能最差，双层结构器件性能次之，三层结构器件性能最佳。论文还探讨了三层结构器件性能的优化。 本文的创新之处在于：具体探讨了真空蒸镀法和直流磁控溅射法沉积Al阴极对双层器件性能的影响，并对造成这种差异的原因进行了具体分析和探讨。更多还原

【Abstract】 Organic light-emitting diodes (OLED) have become a shining star in the electronic display field since the end of the 1980s. This technology exhibits bright prospect in photoelectricity field due to its advantages of low DC drive voltage, active luminescence, excellent hue saturation, wide visual angle, etc. Nowadays, small-area OLED have been commercially produced in the area of mobile meters, screens of mobile phones and digital cameras, etc. However, some problems, especially on stability and lifetime, still need to resolve.In respect of the excellent stability of polymer, the OLED using polymer doped with small molecular materials is fabricated. The anode is fabricated by direct current (DC) reaction sputtering method. The cathode is fabricated by DC sputtering method or vacuum vaporization method. The organic films are deposited by spin-casting method. Finally, the relatively stable OLED with maximum luminance of 18.8cd/m2 emitting green color resulting from 8-tris-hydroxyquino-line aluminum (A1Q) is obtained.Firstly, the effect of the ratio of poly-(N-vinylcarbazole) (PVK):A1Q: 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-l,3,4-oxadiazole (PBD) in emitting layer (EML) and PVK content in hole transport layer (HTL) on dual OLED property is discussed at the relatively invariable spin speed. The optimized contents of different organic materials are confirmed by comparing the observational luminance and stability of OLED with each other.Then the effect of the Al cathode thickness and the ITO anode surface procession on OLED property is explored. The result shows that the optimized thickness of Al cathode can result in better luminance and stability, while the excessively thin or thick Al film will degenerate the property of OLED.Next, the effect of the device structure on the property of OLED is discussed. The results show that the optimized dual-layer structure device is superior to the single-layer one, while inferior to the optimized three-layer one. The optimization of three-layer structure device is also discussed.The effect of different deposition methods of Al cathode is also studied novelly. Itshows that the optimized dual-layer device with Al cathode deposited by the vacuum vaporization method has lower dark electric current and luminescence turn-on voltage than that deposited by DC magnetron sputtering method. The mechanism of these phenomena is discussed in detail.更多还原