有机电致发光器件的阴极研究

STUDY ON THE CATHODE OF ORGANIC LIGHT -EMITTING DIODES

介绍了用Al/LiF双层阴极和发光层Alq3制成的有机电致发光器件(OLED),研究了绝缘层LiF对电子注入所起的作用。实验发现,LiF的引入对电子注入起到了显著的促进作用,当LiF层取最佳厚度1nm时,器件发光亮度和效率得到了明显提高,达到了14700cd·m-2和3.117cd·A-1。此外还研究了不同厚度Al阴极对OLED器件性能的影响,实验表明,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100nm的最佳厚度。

The effect of the bilayer cathode Al/LiF on electron injection in a organic hght-emitring diode is presented. The devices have a Al/LiF bilayer as a cathode and a Alq3 as a light-emitting layer. It is shown that in our experiments, the electron injection was improved by inserting the insulating layer LiF between Al and Alq3. Compared to the devices with Mg ; Ag/Ag as a cathode, its luminance and efficiency were greatly improved, reaching 14 700cd · m^-2 and 3. 117 cd · A^-1. With increasing the thickness of the insulting layer, the external quantum efficiency and luminance were increasing at first. As the thickness arrived to about 1 nm, they began to decrease. So the optimum thickness for LiF was 1 nm. In addition, it is found that the optimum thickness for Al cathode is 100 nm.