Pure white phosphorescent organic light-emitting diodes using a phosphine oxide derivative as a high triplet energy host material

Pure white phosphorescent organic light-emitting diodes were developed using a high triplet energy (3.02 eV) host material (PPO1) with a carbazole and a phosphine oxide unit. Deep blue emitting tris((3,5-difluoro-4-cyanophenyl)pyridine) iridium was doped into the wide triplet bandgap PPO1 host material and the blue emitting layer was combined with a red/green phosphorescent emitting layer. The doping concentration, thickness of the emitting layer and the electron transport material were managed to optimize the device performance of the white device. A pure white color with a color coordinate of (0.29,0.33) and a high current efficiency of 27.2 cd/A was achieved from the white organic light-emitting diodes with the PPO1 host after optimization.