An OLED includes an anode, a light-emitting layer disposed over the anode,
and a first electron-injecting layer disposed over the light-emitting
layer, wherein the first electron-injecting layer includes at least one
organic host material having a reduction potential less than -1.0 V vs. a
Saturated Calomel Electrode and at least one dopant material capable of
reducing the organic host material. The OLED also includes a second
electron-injecting layer disposed in contact with the first
electron-injecting layer, wherein the second electron-injecting layer
includes at least one organic material having a reduction potential
greater than -1.0 V vs. a Saturated Calomel Electrode, and a cathode
disposed over the second electron-injecting layer.