Hybrid OLED having phosphorescent and fluorescent emitters
First Claim
1. 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 the first emissive layer forms 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 a combined emission of the emitting materials gives a white emission from the device.
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Abstract
The present invention provides 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 device may further comprise additional fluorescent or phosphorescent emissive materials. In preferred embodiments, the invention provides OLEDs having three different emissive materials—a red emissive material, a green emissive material and a blue emissive material. The invention provides a device architecture which is optimized for efficiency and lifetime by using a combination of fluorescent and phosphorescent emitters. Further, in preferred embodiments the device architecture provides a high color-stability of the light emission over a wide range of currents or luminances.
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Citations
30 Claims
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1. An organic light emitting device comprising:
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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 the first emissive layer forms 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 a combined emission of the emitting materials gives a white emission from the device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. An organic light emitting device comprising in order:
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a cathode; a first emissive layer comprising a fluorescent emitting material; a spacer layer; a second emissive layer comprising a phosphorescent emitting 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 the first emissive layer forms 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 when a voltage is applied across the device light is emitted from the emitting materials. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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Specification