Recent Advances in Solution-Processable Dendrimers for Highly Efficient Phosphorescent Organic Light-Emitting Diodes (PHOLEDs)

Phosphorescent dendrimers together with dendritic host materials have inherent advantages in achieving highly efficient phosphorescent organic light-emitting diodes (PHOLEDs) with low-cost, solution-processed device fabrication. Recently, much research effort has been devoted to developing these dendritic materials in the field of electroluminescence (EL). In this Focus Review, the major advances in this line of research are summarized and discussed. The crucial roles played by these dendritic organic electronic materials in coping with the key issues in the field of PHOLEDs have been specially emphasized. These include alleviating the triplet-triplet annihilation effect through the site-isolation effect associated with the dendritic structures, promoting charge-carrier injection/transporting ability and ambipolar properties through functionalized dendrons, fulfilling simple PHOLEDs with high EL efficiencies, obtaining self-hosting phosphorescent emitters, and avoiding undesired energy transfer process from phosphorescent cores to the dendrons. In addition, the future perspectives and ongoing challenges of this research frontier are also highlighted.