Highly efficient stacked organic light-emitting devices(OLEDs) have been fabricated using Mg:Alq3:BCP/WO3 as a novel intermediate layer,which connects two identical emissive units.The stacked OLEDs consisting of NPB/Alq3 exhibited high current efficiency and brightness characteristics over conventional single-unit device.At 200 mA/cm2,the current efficiency of the stacked OLEDs using the intermediate layers of Mg:Alq3:BCP/WO3 were about 6.85 cd/A,doubling that of the conventional device.The results may prove the method to be effective to enhance the current efficiency and brightness of OLEDs.