Study In Structure, EL And Mechanism Of Doped OLED

Organic light-emitting device (OLED) is a promising candidate for next generation flat plane display (FPD). On the other hand, white organic light-emitting device (WOLED) has been attracting considerable attention recently due to their potential applications as backlights for liquid crystal displays, full-color displays, and even general lighting.The efficiency, stability and emission color can be improved by doping dye into suitable host. Usually, the AlQ cation is unstable and served as a quenching center in AlQ-based device. Thus, the efficiency and stability are decreased. In this thesis, DCJTB, C-545T, TBP and Rubrene are doped into NPB host respectively. TPBI acts as an electron-transporting and hole-blocking layer. The results show that the EL efficiencies of these devices can be improved by decreasing the thickness of NPB host, which attributed to the enhanced recombination and improved energy transfer efficiency in narrow confined recombination zone.An efficient WOLED is obtained by doping Rubrene into a thin layer of NPB host. The emission color is undependent on the bias, which is due to two factors, one is the blue emission will be enhanced with the increasing bias, the other is the yellow emission will also be enhanced...