Patent ID: 7867630

Claim:
A white organic electroluminescent (EL) device comprising: a first electrode; a second electrode; a first polymer light-emitting layer disposed between the first electrode and the second electrode, a highest occupied molecular orbital (HOMO) energy level of the first polymer light-emitting layer being between 5.0 eV and 5.4 eV, an energy band gap of the first polymer light-emitting layer being between 1.9 eV and 2.2 eV; and a second polymer light-emitting layer disposed between the first polymer light-emitting layer and the second electrode, a highest occupied molecular orbital (HOMO) energy level of the second polymer light-emitting layer being no less than the HOMO energy level of the first polymer light-emitting layer, an energy band gap of the second polymer light-emitting layer being no less than 2.5 eV.