为提升OLED器件(结构为Ag/NPB/Alq3/LiF/Al)的性能,采用紫外光(UV)对银(Ag)阳极进行改性,探究阳极改性对器件性能的影响。研究结果表明:UV改性Ag阳极的时长为50s时,器件性能最佳,启亮电压从20 V降低到6 V,最大亮度从101.6cd/m^2提高到5609.2cd/m^2,电流效率得到很大提升,且改性前后其发光峰的位置没有改变。UV改性使Ag阳极表面氧化生成氧化物,该氧化物薄层可作为空穴注入层,能够有效提高界面功函数,大大降低空穴注入势垒,提高了载流子注入能力,使绿光OLED器件的发光性能得到改善。这种利用UV改性Ag阳极的方法工艺简单,能有效降低空穴注入势垒,对提高该类柔性OLED器件的性能具有一定应用价值。
In ordered to get better performance of the OLED device based on the structure of Ag/NPB/Alq3/LiF/Al, ultraviolet (UV) radiation was used to modify the silver (Ag) anode. The results show that the performance of the device with the anode modified for 50 s by UV is the best, the turn-on voltage is reduced from 20 V to 6 V, the maximum brightness increases from 101.6 cd/m^2 to 5 609.2 cd/m^2 , current efficiency is also improved, and the luminescence peak position shows no chang after the modification. UV radiation generated oxidation on Ag anode surface, this thin oxide layer can play the role of hole-injection layer, and it effectively improves work function of the anode interface. This greatly reduces the hole-injection barrier, improves the ability of carrier injection, thus great performance improvements of the green OLEDs are obtained. This method is simple and effective in reducing the hole injection barrier, thus it has a certain significance for improving the performance of this kind of flexible OLED devices.