Mixed-host-emitting layer for high-efficiency organic light-emitting diodes

The external quantum efficiency of organic light-emitting diodes (OLEDs) has been greatly improved in the last decade by engineering the device architecture of the emitting layer. Several approaches have been used to enhance the quantum efficiency of OLEDs by engineering the emitting layer, and of these the most effective is the use of a mixed-host-emitting layer structure. The quantum efficiency of OLEDs can be improved by more than 30% with the use of the mixed-host-emitting layer. In this paper, the recent progress in the device performances of OLEDs through the use of the mixed-host-emitting layer is reviewed.