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We demonstrate high-efficiency white light emission from a phosphorescent organic light-emitting device with greenish-blue and red emissive layers. Bis 2-3, 5-bistrifluoromethylphenyl-pyridinato-N, C2 iridiumIIIpicolinate (CF3ppy) 2Irpic and bis 2-2-benzo (4, 5-a) thienylpyridinato-N, C3 iridiumIIIacetylacetonate were employed for the greenish-blue and red phosphorescent materials for the emissive layers. To enhance the emission efficiency of (CF3ppy) 2Irpic, 4, 4-bis (9-carbazolyl)-2, 2-dimethyl-biphenyl was used as the charge-transporting host. White light emission was obtained by controlling the layer thickness and the concentration of each phosphorescent material in the emissive layers. A maximum external quantum efficiency of 12%, a luminance efficiency of 18 cd/A, and a maximum power efficiency of 10 lm/W were achieved at a current density of 0.01 mA/cm2. This high efficiency is primarily attributed to …