Low-voltage driving three-peak white organic light emitting diodes with color conversion hole injection layer based on host-guest energy transfer

We report a highly chromatic stable white organic light-emitting device (WOLED) with three peaks at 470, 5 10, and 600nm, which is produced by a greenish-blue-emitting layer and a color conversion hole injection layer (CC-HIL) doped with a red dye. The host material in CC-HIL can absorb electroluminescence emission and transfer energy to the dye guest as determined on the basis of host-guest energy transfer. The voltage to drive the device is only 12 V at a current density of 1.0 A/cm(2) and the external quantum efficiency reaches 3.5%. The WOLED was demonstrated to maintain chromatic stability under current densities of up to 1.0A/cm(2) and long operation.