Jayabharathi Jayaraman, Goperundevi Gnanasekaran, Thanikachalam Venugopal, Panimozhi Sekar
Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu, India.
ACS Omega. 2019 Sep 9;4(12):15030-15042. doi: 10.1021/acsomega.9b01815. eCollection 2019 Sep 17.
Two efficient fluorescent molecules, viz., ()-2-(2-4-(1-2,3-dihydrobenzo[][1,4]dioxin-5-yl)-4,5-diphenyl--imidazole-2-yl)-[1,1-biphenyl]-4-yl)vinyl-1-yl(naphthalene-1-yl)-1-phenanthro[9,10-]imidazole (DDIBNPPI) and ()-4-(2-(2-(-4'-1(2,3-dihyderobenzo[][1,4]dioxin-5-yl)-4,5-diphenyl-1-imidazole-2-yl)-[1,1'-biphenyl]-4-yl)vinyl)-1-phenanthr[9,10-d]imidazole-1-yl)-1-napthronitrile (DDIBPPIN), were designed and synthesized. DDIBNPPI and DDIBPPIN were obtained by rupturing the covalent bond of phenanthrimidazole core to prevent aggregation-induced quenching. In DDIBPPIN, naphthonitrile group was incorporated into azomethine nitrogen of phenanthrimidazole to enhance charge-transfer ability. The DDIBPPIN/CBP:DDIBPPIN-based device shows blue emission with η (current efficiency) of 4.91/4.10 cd/A, η (power efficiency) of 4.56/3.84 lm/W, and η (external quantum efficiency) of 5.11/5.96%. The η (exciton utilization efficiency) values of DDIPNPPI and DDIBPPIN are of 27.0 and 30.3%, respectively. The DDIPNPPI and DDIBPPIN materials employed as a host to fabricate green and red phosphorescent organic light-emitting diodes. The red/white devices (with 0.4% dopant concentration) with DDIBPPIN:Ir(MDQ)(acac) exhibit maximum of 69889/26319 cd/m, η of 19.6/16.6%, η of 34.6/35.6 cd/A, and η of 35.8/36.6 lm/W. The device with DDIBPPIN:Ir(ppy)/DDIPNPPI:Ir(ppy) exhibits green emission [Commission Internationale de l'Eclairage (0.30,0.60)/(0.30,0.60)] with maximum of 69906/69482 cd/m, η of 17.9/17.0%, η of 59.8/58.6 cd/A, and η of 63.6/61.3 lm/W. The white device using DDIBPPI:Ir(ppy) (with 0.4% dopant concentration) exhibits maximum L of 22152 cd/m, η of 15.8%, η of 31.4 cd/A, and η of 36.1 lm/W.
设计并合成了两种高效荧光分子，即()-2-(2-4-(1-2,3-二氢苯并[][1,4]二氧杂环戊烯-5-基)-4,5-二苯基--咪唑-2-基)-[1,1-联苯]-4-基)乙烯基-1-基(萘-1-基)-1-菲并[9,10-]咪唑(DDIBNPPI)和()-4-(2-(2-(-4'-1(2,3-二氢苯并[][1,4]二氧杂环戊烯-5-基)-4,环戊烯-5-基)-4,5-二苯基-1-咪唑-2-基)-[1,1'-联苯]-4-基)乙烯基)-1-菲并[9,10-d]咪唑-1-基)-1-萘腈(DDIBPPIN)。通过断裂菲并咪唑核的共价键获得DDIBNPPI和DDIBPPIN，以防止聚集诱导猝灭。在DDIBPPIN中，萘腈基团被引入菲并咪唑的甲亚胺氮中以增强电荷转移能力。基于DDIBPPIN/CBP:DDIBPPIN的器件发出蓝色光，电流效率(η)为4.91/4.10 cd/A，功率效率(η)为4.56/3.84 lm/W，外量子效率(η)为5.11/5.96%。DDIPNPPI和DDIBPPIN的激子利用效率(η)值分别为27.0%和30.3%。DDIPNPPI和DDIBPPIN材料用作主体来制备绿色和红色磷光有机发光二极管。具有DDIBPPIN:Ir(MDQ)(acac)的红色/白色器件(掺杂剂浓度为0.4%)的最大亮度为69889/26319 cd/m²，效率(η)为19.6/16.6%，电流效率(η)为34.6/35.6 cd/A，功率效率(η)为35.8/36.6 lm/W。具有DDIBPPIN:Ir(ppy)/DDIPNPPI:Ir(ppy)的器件发出绿色光[国际照明委员会(CIE)(0.30,0.60)/(0.30,0.60)]，最大亮度为69906/69482 cd/m²，效率(η)为17.9/17.0%，电流效率(η)为59.8/58.6 cd/A，功率效率(η)为63.6/61.3 lm/W。使用DDIBPPI:Ir(ppy)(掺杂剂浓度为0.4%)的白色器件的最大亮度为22152 cd/m²，效率(η)为15.8%，电流效率(η)为31.4 cd/A，功率效率(η)为36.1 lm/W。
