A purely organic D-π-A-π-D emitter with thermally activated delayed fluorescence and room temperature phosphorescence for near-white OLED

摘要

A purely organic D-π-A-π-D type emitter showing thermally activated delayed fluorescence(TADF)and room temperature phosphorescence(RTP)was designed and synthesized by utilizing the benzophenone as an acceptor and the N-phenyl-2-napthylamine as a donor moiety.It exhibits considerable TADF character in doped PMMA film and room temperature phosphorescence with a long lifetime of 74 ms at466 nm in solid state.The devices with the configuration of ITO/Mo_(2) O_(3)(4 nm)/mCP(30 nm)/mCP:x wt%NP2 BP/TmTyPB(60 nm)/LiF(1.5 nm)/AI(100 nm)were prepared by vacuum evaporation to explore their electroluminescent performance.Intere stingly,the non-doped device has obtained near-white emission with a fluorescence emission peak at 475 nm and a phosphore scence emission peak at 563 nm having the CIE coordinate of(0.23,0.32)and the maximum external quantum efficiency of 1.09%.