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US 9,871,219 B2Granted
Organic light emitting devices
AssigneeUniversal Display Corporation
InventorsYeh-Jiun Tung, Michael S. Weaver, Michael Hack, James R. Esler
Life of this patent
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Abstract
The present invention provides an emissive region in organic light emitting devices having a combined emission from at least two emissive materials, a fluorescent blue emissive material and a phosphorescent emissive material. The emissive region may further comprise additional fluorescent or phosphorescent emissive materials. Preferably, the emissive region has three different emissive materials—a red emissive material, a green emissive material and a blue emissive material. Organic light emitting devices incorporating the emissive region provides a high color-stability of the light emission over a wide range of currents or luminances.
Claims13
An organic light emitting device comprising:
- a cathode;
- a first emissive layer comprising a fluorescent blue emitting material as a dopant in a host material;
- a spacer layer;
- a second emissive layer comprising a phosphorescent emitting material as a dopant in a host material;
- and
- an anode;
- wherein, the spacer layer is between the first emissive layer and the second emissive layer, the spacer layer inhibits quenching of the triplet excitons in the second emissive layer;
- an interface between the spacer layer and one of the first and second emissive layers forming a heterojunction;
- and the spacer layer comprises a material that has a triplet energy that is higher than the triplet energy of the phosphorescent emitting material;
- wherein one of the following is true:
- (a) the second emissive layer comprises a phosphorescent green emitting material and a phosphorescent red emitting material;
- (b) the second emissive layer comprises a phosphorescent green emitting material and the organic light emitting device further comprises a third emissive layer comprising a phosphorescent red emitting material;
- or
- (c) the first emissive layer further comprising a fluorescent green emitting material;
- and the second emissive layer comprising a phosphorescent red emitting material;
- and
- wherein a combined emission of the emitting materials gives a white emission from the device.
14 more elements
An organic light emitting device comprising in order:
- a cathode;
- a first emissive layer comprising a fluorescent blue emitting material as a dopant in a host material;
- a spacer layer;
- a second emissive layer comprising a phosphorescent emitting material as a dopant in a host material;
- and
- an anode;
- wherein the spacer layer inhibits quenching of the triplet excitons in the second emissive layer;
- an interface between the spacer layer and one of the first and second emissive layers forming a heterojunction;
- and
- the spacer layer comprises a material that has a triplet energy that is higher than the triplet energy of the phosphorescent emitting material;
- and
- wherein one of the following is true:
- (a) the second emissive layer comprises a phosphorescent green emitting material and a phosphorescent red emitting material;
- (b) the second emissive layer comprises a phosphorescent green emitting material and the organic light emitting device further comprises a third emissive layer comprising a phosphorescent red emitting material;
- or
- (c) the first emissive layer further comprises a fluorescent green emitting material;
- and the second emissive layer comprising a phosphorescent red emitting material;
- and
- when a voltage is applied across the device light is emitted from the emitting materials.
16 more elements
A consumer product comprising an organic light emitting device comprising:
- a cathode;
- a first emissive layer comprising a fluorescent blue emitting material as a dopant in a host material;
- a spacer layer;
- a second emissive layer comprising a phosphorescent emitting material as a dopant in a host material;
- and
- an anode;
- wherein, the spacer layer is between the first emissive layer and the second emissive layer, the spacer layer inhibits quenching of the triplet excitons in the second emissive layer;
- an interface between the spacer layer and one of the first and second emissive layers forming a heterojunction;
- and the spacer layer comprises a material that has a triplet energy that is higher than the triplet energy of the phosphorescent emitting material;
- wherein one of the following is true:
- (a) the second emissive layer comprises a phosphorescent green emitting material and a phosphorescent red emitting material;
- (b) the second emissive layer comprises a phosphorescent green emitting material and the organic light emitting device further comprises a third emissive layer comprising a phosphorescent red emitting material;
- or
- (c) the first emissive layer further comprising a fluorescent green emitting material;
- and the second emissive layer comprising a phosphorescent red emitting material;
- and
- wherein a combined emission of the emitting materials gives a white emission from the device.
14 more elements
Dependencies are inferred from the claim text.