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US 8,076,681 B2Granted
White organic electroluminescent device
AssigneeCanon Kabushiki Kaisha
InventorsToshifumi Mori, Koichi Suzuki, Akira Tsuboyama, Satoru Shiobara, Kenichi Ikari
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Abstract
A high-efficiency, white organic electroluminescent device has such a structure that its emission layer is obtained by laminating sub-emission layers of red, green, and blue, respectively. The green sub-emission layer contacting a hole transport layer has a delayed fluorescent material, and the red sub-emission layer has a phosphorescent light emitting material.
Claims4
A white organic electroluminescent device for emitting white light, the device comprising:
- a substrate;
- an anode placed;
- a hole transport layer;
- an emission layer having a red sub-emission layer, a green sub-emission layer, and a blue sub-emission layer;
- and
- a cathode,
- the anode, the hole transport layer, the emission layer and the cathode being placed on the substrate,
- wherein:
- the green sub-emission layer is placed to be in contact with the hole transport layer;
- the red sub-emission layer is placed to be in contact with the green sub-emission layer;
- the blue sub-emission layer is placed to be in contact with the red sub-emission layer;
- the green sub-emission layer comprises a delayed fluorescent material;
- the red sub-emission layer comprises a phosphorescent light emitting material;
- a highest occupied molecular orbital (HOMO) of the delayed fluorescent material is deeper than an HOMO of a material of the hole transport layer;
- and
- the HOMO of the delayed fluorescent material is shallower than an HOMO of the phosphorescent light emitting material.
13 more elements
Dependencies are inferred from the claim text.