A tandem OLED includes an anode, a cathode, and a plurality of organic
electroluminescent units disposed between the anode and the cathode,
wherein each organic electroluminescent unit includes at least one
light-emitting layer, and an intermediate connector disposed between each
adjacent organic electroluminescent unit, wherein the intermediate
connector includes at least a high work function metal layer having a
work function of no less than 4.0 eV and a metal compound layer, wherein
the intermediate connector has a sheet resistance of higher than 100
k.OMEGA. per square, and wherein the high work function metal layer
improves the operational stability of the OLED.