The development of blue luminescent materials plays a crucial role in the organic light-emitting diodes (OLEDs) industry. It can not only be used as a high-efficiency luminescent material, but also as a host or sensitizer of fluorescence and phosphorescence, until it has indelible value for the development of white light devices. In this work, two sky-blue luminescent materials (mCP-BP-DMAC and DCB-BP-DMAC) are synthesized and characterized. They exhibit excellent thermal and electrochemical stabilities, strong aggregation-induced delayed fluorescence and bipolar carrier transport ability, and behavior efficiently in nondoped and doped bottom-emitting OLEDs with high external quantum efficiencies (ηexts) of up to 26.6% and small efficiency roll-offs. Efficient top-emitting OLEDs employing mCP-BP-DMAC and DCB-BP-DMAC as emitters are also achieved, providing sky-blue lights with high color purity and impressive ηexts over 30%. In addition, hybrid white OLEDs with stable emission color and high color rendering index are fabricated based on a single emissive layer consisting of orange-red phosphorescent Ir(MDQ)2acac dopant and sky-blue mCP-BP-DMAC and DCB-BP-DMAC hosts, furnishing excellent ηexts of up to 24.1% and small efficiency roll-offs.These results demonstrate mCP-BP-DMAC and DCB-BP-DMAC are outstanding luminescent and host materials with great application potentials in display and lighting devices.
Master student Xing Wu in our group is the first author of this article, and this work has been published on Chemical Engineering Journal (DOI: 10.1016/j.cej.2022.138919).