Novel light-emitting electrophosphorescent copolymers based on carbazole with an Ir complex on the backbone
作者:Hongyu Zhen、Jie Luo、Wei Yang、Qiliang Chen、Lei Ying、Zou Jianhua、Hongbin Wu、Yong Cao
DOI:10.1039/b618990c
日期:——
Novel light-emitting phosphorescent polymers based on 3,6-carbazole with an iridium complex on the backbone were synthesized by Suzuki polycondensation of A-A and B-B type monomers. Three difluoro-substituted phenylpyridine iridium complexes with different ancillary ligands (FIrptz, FIrpic and FIrtmd) were introduced into the poly(3,6-carbazole) (PCz) backbone, causing distinct differences in the photo- and electroluminescence properties. The PL efficiency of PCz-FIrtmd5 is as high as 62% compared with the value of 9% of the fluorene-alt-carbazole-based copolymer (PFCz-FIrtmd5), which indicated that the 3,6-carbazole unit was suitable to serve as the host for a green electrophosphorescent polymer. The ancillary ligand of bicycloiridium complexes also affects the device performance based on chelating copolymers. The best device performances were obtained from copolymer PCz-FIrtmd5 with the maximal luminous efficiency of 4.4 cd A−1 and a luminance of 453 mA cm−2 at a current density of 10.3 mA cm−2 with the configuration: ITO/PEDOT/polymer + PBD(30 wt%)/Ba/Al.
基于3,6-咔唑的发光磷光聚合物与铱络合物在主链上,通过A-A和B-B型单体的铃木聚缩合反应合成。引入了三种不同辅助配体的二氟取代苯基吡啶铱络合物(FIrptz、FIrpic和FIrtmd)到聚(3,6-咔唑)(PCz)主链中,导致其光学和电致发光性质的显著差异。与氟烯-咔唑共聚物(PFCz-FIrtmd5)9%的光致发光效率相比,PCz-FIrtmd5的光致发光效率高达62%,这表明3,6-咔唑单元适合作为绿色电磷光聚合物的主机。双环铱络合物的辅助配体也会影响基于螯合共聚物的器件性能。共聚物PCz-FIrtmd5显示出最佳的器件性能,最大发光效率为4.4 cd A−1,在电流密度为10.3 mA cm−2时,亮度达到453 mA cm−2,结构配置为:ITO/PEDOT/聚合物 + PBD(30 wt%)/Ba/Al。