| 作者： | Yuan Liu, Feng Liang, Lin-Song Cui, Xiao-Bo Shi, Zhao-Kui Wang* and Liang-Sheng Liao* |
| 单位： | Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, China |
| 摘要： | The authors demonstrate a simple but effective way to manage exciton, reduce the efficiency roll-off, enhance color stability and improve the lifetime of hybrid white organic light-emitting diodes (WOLEDs) simultaneously. Red and green phosphorescent emitting layers (EMLs) are connected by a mixed fluorescent blue emitting layer (MBL), which is composed of two self-host fluorescent materials of N,N'-di-1-naphthalenyl-N,N'-diphenyl-[1,1':4',1'''-quaterphenyl]-4, 4'''-diamine(4P-NPD) and bis [2-(2-hydroxyphenyl)-pyridine] beryllium (Bepp2). By adjusting the mixture ratio and the thickness of MBL, the intensity of blue and green emissions can be tuned independently. A maximum power efficiency of 41.1 lm W-1 and external quantum efficiency (EQE) of 15.8% is obtained without any out-coupling schemes or doping strategies. In addition, the device shows a stable electroluminescence spectrum with Commission International de L’Eclairage (CIE) coordinates of (0.47, 0.43) in the practical range of 1000-5000 cd m-2. Furthermore, the fuzzy interfaces between MBL and phosphorescent EMLs, and the wide distribution of charges and excitons, result in a prolonged device lifetime. |
