No abstract

No abstract

Phosphorescent materials are crucial to improve the luminescence and efficiency of organic light emitting diodes, because its internal quantum efficiency can almost up to 100%. So the studying of optical and electrical properties of phosphorescent materials is propitious to the further development of phosphorescent OLED. Phosphorescent materials were generally doped into different host materials as emitting components, not only played an important role in emitting light but also had a great influence on carrier transport properties. (t-bt) 2 Ir(acac) was a common yellow phosphorescent material. The optical and electrical properties of the blue DPVBi-based devices, adding (t-bt) 2 Ir(acac) in different position, have studied. The results showed (t-bt) 2 Ir(acac) has remarkable hole-trapping ability.Especially the ultrathin structure device, compared to the device without (t-bt) 2 Ir(acac), had increased the luminance by about 60%, and the efficiency by about 97%.