双层阴极结构BaO/Al聚合物电致发光器件电子注入的研究  

Study of Electron Injection of Polymer Light-emitting Devices with a Bilayer Cathode of BaO/Al

作　　者：张伟[1] 黄美纯[1] 刘银春[2] 许运华[3] 曾永志[1] 

机构地区：[1]厦门大学物理学系,福建厦门361005 [2]福建农林大学,福建福州360000 [3]华南理工大学高分子光电材料及器件研究所,广东广州510640

出　　处：《厦门大学学报（自然科学版）》2005年第B06期326-329,共4页Journal of Xiamen University：Natural Science

基　　金：国家科技部863计划(2001AA313070)资助

摘　　要：介绍了用双层阴极BaO/Al和发光层MEHPPV制成的聚合物电致发光器件(PLEDs),研究了绝缘层BaO对电子注入所起的作用.实验发现,BaO对电子的注入起到显著的促进作用,与直接用Al做阴极的器件对比,其发光亮度和效率分别提高了20倍和10倍,达到了1250cd/m2和0.4%.同时也研究了不同厚度的绝缘层BaO对电子注入的影响,随着厚度的增加,外部量子效率和亮度先增加后减少,存在一个约为1nm的最佳厚度.另外,国外用绝缘层LiF和CsF做成器件,与他们的实验结果对比,发现是绝缘层BaO增强了电子的注入,而不是BaO分解得到的金属Ba.The effect of the bilayer cathode BaO/Al on electron injection in a polymer light-emitting diode (PLED) device is presented.The devices have a BaO/Al bilayer as a cathode and a MEH-PPV as a light-emitting layer.It is shown that in our experiments,the electron injection was improved by inserting the insulating layer BaO between Al and MEH-PPV.The luminance and efficiency were 20 and 10 times to the devices with single only Al as a cathode,reaching 1 250 cd/m2 and 0.4%.We also investigated the dependence of electron injection on the thickness of the BaO layer.With increasing the thickness of the insulating layer,the external quantum efficiency and luminance were increasing at first.As the thickness arrived to about 1nm,they began to decrease.So the optimum thickness for BaO layer was 1 nm.In addition,our results on BaO have been compared with some of LiF and CsF as the insulating layer fabricated by the other research group.It proved that the electron injection enhancement depends on the insulating BaO layer and not due to the metallic Ba decomposed from BaO.

关 键 词：聚合物电致发光器件 电子注入 BAO AL 阴极结构 绝缘层 实验发现 发光亮度 量子效率 最佳厚度 PPV MEH 发光层 CSF LiF 

分 类 号：TN383.1[电子电信—物理电子学] TS247[轻工技术与工程—制糖工程]