Jayabharathi Jayaraman, Thanikachalam Venugopal, Sundari Ganapathy Abirama
Department of Chemistry, Annamalai University Annamalainagar-608002 Tamilnadu India
RSC Adv. 2019 Feb 26;9(12):6658-6680. doi: 10.1039/c9ra00135b. eCollection 2019 Feb 22.
A series of efficient electroluminescent materials with dual carrier transport properties shows enhanced singlet exciton utilization ( ) due to small singlet-triplet splitting (Δ ). The strong orbital-coupling transitions of -(4-(1-(1-(2,3-dihydrobenzo[][1,4]dioxin-6-yl)-4,5-diphenyl-1-imidazol-2-yl)naphthalen-4-yl)phenyl)--phenyl benzenamine (DDPB) exhibit deep blue emission at 435 nm (CIEy, 0.07) with an external quantum efficiency of 2.01%. The electroluminescent efficiencies of 2-(1-(9-carbazol-9-yl)naphthalen-4-yl)-1-(2,3-dihydrobenzo[][1,4]dioxin-6-yl)-1-phenanthro[9,10-]imidazole (CDDPI) ( - 3992 cd m; - 3.01%; - 2.56 cd A; - 2.12 lm W) are higher than those of the -(4-(1-(1-(2,3-dihydrobenzo[][1,4]dioxin-6-yl)--phenanthro[9,10-]imidazole-2-yl)naphthalen-4-yl)phenyl)--phenylbenzenamine (DBDPA) based device ( - 3015 cd m; - 2.85%; - 2.01 cd A; - 1.92 lm W). The blue emissive materials CDDPI and DBDPA are used as a host to construct green and red phosphorescent OLEDs: the green device based on CDDPI:Ir(ppy) exhibits higher efficiencies ( - 8812 cd m; - 19.0%; - 27.5 cd A; - 33.0 lm W) at 2.7 V and the red device based on CDDPI:Ir(MQ)(acac) exhibits a maximum luminance of 39 661 cd m with excellent EL efficiencies [ - 19.2%; - 27.9 cd A; - 29.2 lm W; CIE (0.64, 0.34)] compared with those of the DBDPA:Ir(MQ)(acac) based device [ - 37 621 cd m; - 18.5%; - 25.2 cd A; - 25.8 lm W; CIE (0.64, 0.34)].
一系列具有双载流子传输特性的高效电致发光材料由于单重态-三重态分裂小（Δ）而显示出增强的单重态激子利用率。-（4-（1-（1-（2,3-二氢苯并[][1,4]二恶英-6-基）-4,5-二苯基-1-咪唑-2-基）萘-4-基）苯基）- -苯基苯甲胺（DDPB）的强轨道耦合跃迁在435 nm（CIEy，0.07）处呈现深蓝色发射，外量子效率为2.01%。2-（1-（9-咔唑-9-基）萘-4-基）-1-（2,3-二氢苯并[][1,4]二恶英-6-基）-1-菲并[9,10-]咪唑（CDDPI）的电致发光效率（ - 3992 cd m； - 3.01%； - 2.56 cd A； - 2.12 lm W）高于基于-（4-（1-（1-（2,3-二氢苯并[][1,4]二恶英-6-基）- -菲并[9,10-]咪唑-2-基）萘-4-基）苯基）- -苯基苯甲胺（DBDPA）的器件（ - 3015 cd m； - 2.85%； - 2.01 cd A； - 1.92 lm W）。蓝色发光材料CDDPI和DBDPA用作主体来构建绿色和红色磷光OLED：基于CDDPI：Ir（ppy）的绿色器件在2.7 V时表现出更高的效率（ - 8812 cd m； - 19.0%； - 27.5 cd A； - 33.0 lm W），基于CDDPI：Ir（MQ）（acac）的红色器件与基于DBDPA：Ir（MQ）（acac）的器件相比，具有39661 cd m的最大亮度和优异的电致发光效率[ - 19.2%； - 27.9 cd A； - 29.2 lm W；CIE（0.64, 0.34）] [ - 37621 cd m； - 18.5%； - 25.2 cd A； - 25.8 lm W；CIE（0.64, 0.34）]。
