A novel charge generation unit comprising of CsN3: Bphen/Al/HAT-CN was employed to fabricate an efficient tandem white organic light-emitting device. In normal direction, the maximum efficiencies are 45.4 cd/A and 28.5 lm/W, respectively. When the operating current density varies from 10 mA/cm2 to 30 mA/cm2, there are nearly no variations in color coordinates and the correlated color temperature slightly changes from 3 135 K to 3 147 K. The emissions are all within the defined warm white region, as is beneficial to the alleviation of blue-light hazards. As the viewing angles increases from 0 to 60° no obvious shift of the emission peaks was observed and the color coordinates and slight variation of(0.02, 0.03) in color coordinates was occurred. Moreover, the emission pattern was very closed to the desirable Lambertian distribution.