High-Efficiency Green Electrophosphorescent Hyperbranched Copolymers based on 3,6-Carbazole-co-2,6-Pyridine with Iridium Complex

摘要

Electrophosphorescent polymers have attracted great scientific and commercial attention because of their high quantum efficiency and the ease of fabrication by utilization of printing techniques. It would be interesting to investigate the main-chain type chalating polymer with phosphorescent metal complex as a repeat unit incorporated into a conjugated main chain. In this case, the conjugated segments play both roles: a ligand and a host for the energy transfer system. The high-efficiency energy transfer from the polymer host to the triplet metal complex in polymer main chain via an efficient intramolecular energy transfer would be expected. On the other hand, the carbazole segments are used as a polymer backbone because the HOMO level of carbazole-based copolymers can be tuned by the substitution at the 3-, 6- and 9- position, while the triplet level remains sufficiently high to accommodate even blue triplet emitters.