Efficient white organic light-emitting diodes based on an orange iridium phosphorescent complex

Stable and efficient white light emission is obtained by mixing blue fluorescence and orange phosphorescence. The introduction of double exciton blocking layers brings about well confinement of both charge-carriers and excitons in the emission layer. By systematically adjusting blue fluorescent and orange phosphorescent emission layers thickness, carriers in emission zone are balanced, and electrically generated excitons can be efficiently utilized. One white device with power efficiency of 14.4 lm/W at 100 cd/m2 has excellently stable spectra. The improvement of performance is attributed to efficient utilization of the excitons and more balance of charge-carriers in emission layer.