摘要
The development and enrichment of organic materials with narrowband emission in longer wavelength regions beyond 515 nm still remains a great challenge.Herein,a synthetic methodology for narrowband emission materials has been proposed to functionalize multiple resonance(MR)skeletons and generate a universal building block,namely,the key intermediate DtCzB-Bpin,which can be utilized to construct multifarious thermally activated delayed fluorescence(TADF)materials with high color purity through a simple one-step Suzuki coupling reaction.Based on this unique synthetic strategy,a series of efficient narrowband green TADF emitters has been constructed by localized attachment of 1,3,5-triazine and pyrimidine derivatives-based acceptors onto B–N-containing MR frameworks with 1,3-bis(3,6-di-tertbutylcarbazol-9-yl)benzene(DtCz)as the ligand.The precise modulation of the acceptor is an intelligent approach to achieve bathochromic shift and narrowband emission simultaneously.The DtCzB-TPTRZbased organic light-emitting diode(OLED)exhibits pure green emission with Commission Internationale de L’Eclairage(CIE)coordinates of(0.23,0.68),a maximum external quantum efficiency(EQE)of 30.6%,and relatively low efficiency roll-off.
基金
supported by the National Natural Science Foundation of China(no.21935005)
the National Key R&D Program of China(no.2020YFA0714601)
Program for JLU Science and Technology Innovative Research Team(no.2019TD-33).
