A novel nicotinonitrile derivative as an excellent multifunctional blue fluorophore for highly efficient hybrid white organic light-emitting devices

摘要

A novel nicotinonitrile derivative CZN has been designed with the aim of developing excellent multifunctional blue fluorophores for hybrid white organic light-emitting devices (WOLEDs) by introducing the nicotinonitrile group as the electron acceptor. CZN shows highly efficient blue fluorescence and its non-doped blue OLED delivers an external quantum efficiency (EQE) as high as 4.6%. Meanwhile, CZN is a promising host for phosphorescent OLEDs, realizing high EQEs of 22.8%, 24.8% and 19.9% for yellow, orange and deep-red phosphorescence, respectively. By using CZN as the blue emitter and the host simultaneously, a hybrid white OLED has been achieved with a forward-viewing EQE of 17.2%. These results indicate that the nicotinonitrile unit is an excellent building block for developing new multifunctional compounds as both blue fluorescent emitters and phosphorescent hosts for efficient hybrid WOLEDs.