双异质型蓝色OLED器件的研究

Double Heterostructure Blue OLEDs

采用真空蒸镀法制备了ITO/NPB/BAlq3/Alq3/Mg∶Ag(双异质型)和ITO/NPB/BAlq3/Mg∶Ag(传统型)两种结构的蓝色有机电致发光器件(OLED),并研究了器件结构对OLED光电性能的具体影响。实验结果表明,器件结构对OLED的发光光谱没有影响,其谱峰均位于480nm。但是器件结构却显著影响OLED的发光性能,与传统型结构器件相比,双异质型结构OLED的最大发光效率和最大发光亮度分别提高了4.5倍和5.5倍,达到1.90lm/W和10000cd/m2。这是因为双异质型器件结构中引入了电子传输层Alq3和空穴阻挡层BAlq3,从而使得能级匹配更加合理,载流子注入更加平衡的缘故。

Double heterosturcture OLED (ITO/NPB/BAlq_3/Alq_3/Mg∶Ag) and traditional structure OLED (ITO/NPB/BAlq_3/Mg∶Ag) were prepared by vacuum evaporation, and the effect of device structure on the optical and electric performance of the OLED was studied. The experimental results show that electroluminescence of OLEDs is blue and the emission peaks at 480 nm. Compared with the (traditional) structure, the maximum efficiency and luminance of the double heterosturcture are improved to 4.5 times and 5.5 times, respectively, which are 1.90 lm/W and 10 000 cd/m^2. Due to the electron-transporting layer Alq_3 and hole-blocking layer BAlq_3 being used in the double heterosturcture, the energy matching is more reasonable and the carrier injecting is more balanceable.