| 초록 |
High efficiency OLEDs based on phosphorescent, thermally activated delayed fluorescent (TADF) and fluorescent emitters will be presented. We will show that EQEs over 60% is achievable without any extra light extracting structure if OLEDs are fabricated using organic semiconductors with the refractive index of 1.5 and fully horizontal emitting dipoles. We will also show that reverse intersystem crossing (RISC) rate plays an important role to reduce the efficiency roll-off in efficient TADF and fluorescent OLEDs and a couple to methods will be presented to increase the RISC rate in the devices. Finally we will discuss on the ultimate efficiency with OLEDs achievable with light extraction structures including the driving voltage of OLEDs. |
