Butterfly-shaped tetrasubstituted carbazole derivatives as a new class of hosts for highly efficient solution-processable green phosphorescent organic light-emitting diodes.

A new bromination method, where butterfly-shaped tetrasubstituted carbazole derivatives TSPFCz and TTPhCz have been designed and synthesized, which possess the twist butterfly skeletons and exhibit excellent thermal and morphological stabilities, has been adopted. By utilizing these novel compounds as host materials, high efficiency solution-processed green phosphorescent organic light-emitting diodes (PhOLEDs) have been achieved.