High-efficiency and high-stability phosphorescent OLED based on new Ir complex

Multi-layer phosphorescent OLED with (tpbi)2Ir(acac) was fabricated which has the structure: ITO/CuPc (40 nm)/α-NPD (45 nm)/CBP: (tpbi)2Ir(acac) (3%, 30 nm)/BCP (20 nm)/Alq3 (20 nm)/LiF (1 nm)/Al (100 nm). Absorption spectra, phosphorescence lifetime of Ir complex, and I-V-L characteristic of the device was tested. The current of the device under low applied voltage conforms to the Richaardon-Schotty emission, and shows linear relationship under high voltage. Gauss peak fit shows the OLED spectra to be composed of α-NPD peak(450 nm), (tpbi)2Ir(acac) main peak(518 nm) and shoulder peak(543 nm). Maximum power efficiency of PHOLED is 12.1 lm/W (at 6V) with luminance 136 cd/m2, and the maximum luminance is 13500 cd/m2 with power efficiency 0.584 lm/W.