We fabricated phosphorescent organic light-emitting diodes(Ph OLEDs) using thermally activated delayed fluorescence(TADF) material 10,10’-(4,4’-sulfonylbis(4,1-phenylene)) bis(9,9-dimethyl-9,10-dihydroacridine)(DMAC...We fabricated phosphorescent organic light-emitting diodes(Ph OLEDs) using thermally activated delayed fluorescence(TADF) material 10,10’-(4,4’-sulfonylbis(4,1-phenylene)) bis(9,9-dimethyl-9,10-dihydroacridine)(DMAC-DPS) with low concentration, which showed better performance compared with 1,3-bis(carbazole-9-yl) benzene(m CP) based devices. When the concentration of DMAC-DPS was 1 wt%, the driving voltage of the device was only 3.3 V at 1 000 cd/m2, and the efficiency and lifetime of the device were effectively improved compared with those of m CP based devices. The result indicated that DMAC-DPS could effectively improve the performance of phosphorescent devices. We believe that the better device performance can be attributed to the optimization of the energy transfer process in the emitter layer and lifetime of triplet excitons by DMAC-DPS. The study may provide a simple and effective strategy to achieve high-performance OLEDs.展开更多
Energy transfer process and direct charge trapping are two main emission mechanisms in phosphorescent organic light-emitting diodes(Ph OLEDs)with host-guest system.Here,to investigate the relationship between luminesc...Energy transfer process and direct charge trapping are two main emission mechanisms in phosphorescent organic light-emitting diodes(Ph OLEDs)with host-guest system.Here,to investigate the relationship between luminescence mechanism and performances in host-guest system thoroughly,we demonstrated a green Ph OLED using 1,3-bis(carbazole-9-yl)benzene(m CP)as the host and the phosphorescent dye fac-tris(2-phenylpyridine)iridium(fac-Ir(ppy)3)as the guest,where the dopant concentration was variable.It had achieved maximum current efficiency and external quantum efficiency of 84.71 cd/A and 24.5%at 5 wt%dopant concentration,respectively.The intrinsic emission mechanisms in the system have been discussed in detail.Moreover,by analyzing the constant current electroluminescence(EL)and the transient EL,the main cause of relationship between dopant concentration and luminescence mechanism has been revealed and the origin of the high performance is also unveiled.展开更多
基金supported by the National Natural Science Foundation of China(No.51573036)the Fundamental Research Funds for the Central Universities of China(No.JD2016JGPY0007)the Industry-University-Research Cooperation Project of Aviation Industry Corporation of China(No.CXY2013HFGD20)
文摘We fabricated phosphorescent organic light-emitting diodes(Ph OLEDs) using thermally activated delayed fluorescence(TADF) material 10,10’-(4,4’-sulfonylbis(4,1-phenylene)) bis(9,9-dimethyl-9,10-dihydroacridine)(DMAC-DPS) with low concentration, which showed better performance compared with 1,3-bis(carbazole-9-yl) benzene(m CP) based devices. When the concentration of DMAC-DPS was 1 wt%, the driving voltage of the device was only 3.3 V at 1 000 cd/m2, and the efficiency and lifetime of the device were effectively improved compared with those of m CP based devices. The result indicated that DMAC-DPS could effectively improve the performance of phosphorescent devices. We believe that the better device performance can be attributed to the optimization of the energy transfer process in the emitter layer and lifetime of triplet excitons by DMAC-DPS. The study may provide a simple and effective strategy to achieve high-performance OLEDs.
基金supported by the Fundamental Research Funds for the Central Universities of China(No.JD2019JGPY0020)the National Natural Science Foundation of China(No.51573036)the Industry-University-Research Cooperation Project of Aviation Industry Corporation of China(No.CXY2013HFGD20)。
文摘Energy transfer process and direct charge trapping are two main emission mechanisms in phosphorescent organic light-emitting diodes(Ph OLEDs)with host-guest system.Here,to investigate the relationship between luminescence mechanism and performances in host-guest system thoroughly,we demonstrated a green Ph OLED using 1,3-bis(carbazole-9-yl)benzene(m CP)as the host and the phosphorescent dye fac-tris(2-phenylpyridine)iridium(fac-Ir(ppy)3)as the guest,where the dopant concentration was variable.It had achieved maximum current efficiency and external quantum efficiency of 84.71 cd/A and 24.5%at 5 wt%dopant concentration,respectively.The intrinsic emission mechanisms in the system have been discussed in detail.Moreover,by analyzing the constant current electroluminescence(EL)and the transient EL,the main cause of relationship between dopant concentration and luminescence mechanism has been revealed and the origin of the high performance is also unveiled.
