Polymer light-emitting diodes (PLEDs) have drawn tremendous research interest in both academia and industry due to their potential applications in large-area flat panel display and solid-state lighting. With excellent properties of low-cost, lightweight, flexible and large-scale manufacture by using solution processing approaches, such as spin-coating, ink-jet printing and roll-to-roll, PLEDs have gotten more and more attention. Compared with fluorescent PLEDs, which use only singlet excitons for light emission, phosphorescent PLEDs can utilize both singlet and triplet excitons for light emission, which increases the quantum efficiency of PLEDs. Theoretically, the quantum efficiency of phosphorescent PLEDs can be higher than that of fluorescent PLEDs by four times and an external quantum efficiency over 20% can be obtained. Iridium complex-containing phosphorescent materials have been successfully developed and applied in high performance solution-processed PLEDs. Among them, the iridium complexes are covalently bonded into the polymer main chain or onto side chain, which can effectively avoid the phase separation and dopant aggregation. Thus, efficient electrophosphorescent devices based on these materials with reduced efficiency loss could be expected. More recently, solution-processed supramolecular polymers with iridium complexes were also successfully demonstrated and show promising application potential for high performance solution processed PLEDs. Therefore, we review the recent progress of iridium complex-based electrophosphorescent polymers materials in this paper. The synthesis, structural characterization and optoelectronic properties of iridium-based electrophosphorescent materials, including the liner polymers and supramolecular polymers are mainly summarized, and the influence of polymer structure on the material properties is also discussed.

Contents
1 Introduction
2 Electrophosphorescent polymers
2.1 Red electrophosphorescent polymers
2.2 Green electrophosphorescent polymers
2.3 Blue electrophosphorescent polymers
2.4 White electrophosphorescent polymers
3 Electrophosphorescent supramolecular polymers
4 Conclusion