Arylfluorene based universal hosts for solution-processed RGB and white phosphorescent organic light-emitting devices

A series of solution-processible arylfluorenes (AFs)/carbazole hybrid compounds (SmeFCz, DMeFCz, SMeOFCz, DMeOFCz, SFFCz and DFFCz) have been designed and synthesized via a simple one-step reaction. These compounds exhibit good thermal stability, excellent solubility and high triplet energy levels, which can be used as universal hosts for solution-processed phosphorescent organic light-emitting devices (PhOLEDs). Employing the developed materials, highly efficient blue (DMeFCz:CE_max: 20.0 cd A^-1, EQE_max: 10.0%), green (DMeFCz:CE_max: 26.0 cd A^-1, EQE_max: 7.8%) and red (SMeFCz:CE_max: 13.7 cd A^-1, EQE_max: 8.2%) PhOLEDs fabricated by spin-coating in different device configurations have been demonstrated. Furthermore, complementary-color, single-emitting layer white phosphorescent device were also obtained. The SMeOFCz-based white device exhibited highly efficient white-light emission with a maximum efficiency of 27.1 cd A^-1 (EQE of 12.0%). The state-of-art performance indicates that AFs/carbazole hybrid hosts have a favorable prospect for applications in solution-processed full-color displays and white PhOLEDs.