Patent ID: 7776457

Claim:
An organic electroluminescent (EL) device, comprising a first electrode functioning as an anode and a second electrode functioning as a cathode; and light emitting layer disposed between the first electrode and the second electrode, the light emitting layer comprising a first light emitting layer and a second light emitting layer, a portion of the second light emitting layer extending continuously over the entire the first light emitting layer so as to contact the entire first light emitting layer, the first light emitting layer being between the first electrode and the second light emitting layer, the first light emitting layer comprising a host material and at least one phosphorescent dopant, the host material comprising a hole transport material and an electron transport material, the second light emitting layer having a highest occupied molecular orbital (HOMO) value greater than a highest occupied molecular orbital value (HOMO) of the first light emitting layer.