Abstract
In this thesis, we synthesized two novel p - type of charge generation materials, one is composed of a ferrocene core and bis(biphenyl) group, and the other is composed of a ferrocene core and bis(biphenyl)amino group. The molecular design not only enhances the thermal property and the carrier mobility of ferrocene, but also maintains its electrochemical stability. In cooperation with C60 as charge generation layer (CGL) in tandem OLED, the CGL could generate and inject charge into the adjacent electron or hole injection layers efficiently due to the small energy gap between the HOMO levels of ferrocene derivatives and the LUMO level of C60. Applications of this CGL in tandem R,G,B devices, it shows high performance with maximum EQE of 50.4 %, 59.5 %, 58.2 % and maximum current efficiency of 53.1 cd/A, 238.4 cd/A, 156.6 cd/A and maximum power efficiency of 33.3 lm/W, 135.9 lm/W, 54.6 lm/W, respectively. Remarkably, the efficiency roll – off of the devices is low and the power efficiency of the green device is among the best of Ir(ppy)3 – based green devices. Next, we applied the ferrocene derivatives with a new n – type CGL, pyrazine quinoxaline derivatives, PQDMN. With the malononitile and Cyanide functional group, PQDMN could have low LUMO level as 4.2 eV and the aromatic ring could adjust the molecular interaction which enhances thermal stability and carrier transporting capability. The tandem R, G, B devices exhibit high efficiencies of maximum EQE of 51.2 %, 59.7 %, 68.0 % and maximum current efficiency of 52.7 cd/A, 232.6 cd/A, 195.7 cd/A and maximum power efficiency of 29.6 lm/W, 132.7 lm/W, 65.5 lm/W, respectively. Especially, the power efficiency of the blue device is among the best of FIrpic – based blue devices. In the last chapter, we applied these two sets of CGL in white phosphorescent OLED, since we have developed such highly efficient RGB devices. The two- color tandem WOLED constructed with C60 / Fc07 CGL reveals a maximum EQE as high as 49.9 %, a maximum current efficiency of 150.6 cd/A and a maximum power efficiency of 49.6 lm/W, with a stable CIE coordination (0.31, 0.39) from the luminance of 500 ~ 3000 cd/m2. As for PQDMN / Fc07, the white device gives a maximum EQE as high as 53.4 %, a maximum current efficiency of 150.5 cd/A and a maximum power efficiency of 62.8 lm/W, with a stable CIE coordination (0.31, 0.41) from the luminance of 500 ~ 3000 cd/m2.