In the past few years, many kinds of host materials such as polymers, large molecules, and small molecules were demonstrated for solution-processable TADF-OLEDs. Among them, uniform molecular dyad can be easily synthesized and purified. Owing to large...
In the past few years, many kinds of host materials such as polymers, large molecules, and small molecules were demonstrated for solution-processable TADF-OLEDs. Among them, uniform molecular dyad can be easily synthesized and purified. Owing to large molecular weight, it can provide good film forming property via solution-process. In molecular dyad structure, we can introduce donor and acceptor moieties, which can be isolated through a non-conjugated cyclohexane spacer. Our objective is to maintain intrinsic molecular properties of donor and acceptor and to give bipolar electronic nature. In this work, a bipolar molecular dyad (e.g. BCzTC) having a cyclohexane spacer was synthesized and applied to TADF-OLEDs. The device performances were compared to those of devices made with corresponding p-type, n-type, and mixed hosts. The OLED devices made with BCzTC as a bipolar host and t4CzIPN as an emitter showed an high external quantum efficiency (EQE) and low roll-off behaviors.