Effective intermediate electrode layers comprising of Li F (1 nm )/ Ca (25 nm )/ Ag (15 nm ) or Li F (1 nm )/ Al (3 nm )/ Au (15 nm ) were studied in stacked organic light-emitting devices (OLEDs). Stacked OLEDs with two identical emissive units consisting of NPB / Al q ₃ : C545T/BCP exhibited superior luminous efficiency-current density characteristics over conventional single-unit devices. At 20 mA / cm ² , the luminous efficiency of the stacked OLEDs using the intermediate layers of Li F / Ca / Ag and Li F / Al / Au were about 19.6 cd / A and 17.5 cd / A , respectively, almost doubling that of the corresponding control devices, as expected.