Stacked white organic light emitting devices consisting of separate red, green, and blue elements

We demonstrate a white organic light-emitting device where individual red, green, and blue (R, G, and B) phosphorescent organic light-emitting devices are vertically stacked and electrically interconnected by a compound MoO3/Li-doped charge generation layer. For the order of B, G, and R cells positioned relative to the indium tin oxide anode, the device yields a peak total external quantum efficiency (EQE) and power efficiency (PE) of eta(ext)=(36 +/- 2)% at a current density of J=82 mu A/cm(2) and eta(p)=21 +/- 1 lm/W at J=17 mu A/cm(2), respectively. The EQE and PE of the device roll off to (32 +/- 2)% and 13 +/- 1 lm/W at 1000 cd/m(2), corresponding to J=2 mA/cm(2). At this luminance, the device shows Commission Internationale de L'Eclairage chromaticity coordinates of (0.45, 0.36) and a color rendering index of 63.