空穴注入结构对有机电致发光器件性能影响

Influence of Hole Injection Structures on Organic Electroluminescent Devices

分别以CuPc、C60和C60/CuPc为空穴注入结构制备了ITO/HIL/NPB/Alq3/LiF/Al结构有机电致发光器件(HIL是空穴注入层)。相比于单层C60注入层器件,由于C60/CuPc结构器件中增加了CuPc作为空穴传输的能量阶梯,器件的电流密度和亮度分别被提高了96%和142%(10V电压下)。尽管CuPc器件的电流密度和亮度最大,但是C60/CuPc结构器件因改善了空穴和电子的注入平衡,器件的效率得到提高,最大效率为2.8cd/A。C60厚度从2nm增加到5nm后,器件性能急剧降低。

Organic electroluminescent devices using CuPc and fullerene C60 as hole-injecting buffer layer were prepared.The structure of the devices is ITO/HIL/NPB/Alq3/LiF/Al(HIL is hole injecting layer).Compared with the device with C60 buffer,the device with C60/CuPc buffer has higher properties,which current density and luminance are increased about 96% and 142% at 10V,respectively.Due to the better balance hole and electron concentrations,the device with C60/CuPc buffer provides the higher efficiency than the device with CuPc buffer,which maximum efficiency is 2.8 cd/A.The characteristics of the devices are sensitive to the thickness of C60.