Organic light-emitting device and method
AssigneesCambridge Display Technology Limited, Sumitomo Chemical Company, Limited
InventorsSimon King, Martina Pintani, Matthew Roberts, Michael Cass
Life of this patent
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Abstract
Composition for use in an organic light-emitting device, the composition having a fluorescent light-emitting material and a triplet-accepting material subject to the following energetic scheme: 2×T1A>S1A>S1E, or T1A+T1E>S1A>S1E in which: T1A represents a triplet excited state energy level of the triplet-accepting material; TIE represents a triplet excited state energy level of the light-emitting material; S1A represents a singlet excited state energy level of the triplet-accepting material; and S1E represents a singlet excited state energy level of the light-emitting material; and in which light emitted by the composition upon excitation includes delayed fluorescence.
Claims20
A composition for use in an organic light-emitting device, comprising a fluorescent light-emitting material and a triplet-accepting oligomer or polymer comprising a repeat unit of formula (IIb):
- (TAU-Spacer)m (IIb)
- wherein TAU is a triplet-accepting unit, Spacer is a substituted phenylene, biphenylene, or fluorene spacer group, and m is at least 2, the triplet-accepting oligomer or polymer is physically mixed with the fluorescent light-emitting material, and wherein:
- 2×T1A≧S1A>S1E, or T1A+T1E>S1A>S1E
- in which:
- T1A represents a triplet excited state energy level of the triplet-accepting oligomer or polymer;
- T1E represents a triplet excited state energy level of the fluorescent light-emitting material;
- S1A a represents a singlet excited state energy level of the triplet-accepting oligomer or polymer;
- and
- S1E represents a singlet excited state energy level of the fluorescent light-emitting material;
- wherein the triplet accepting oligomer or polymer has an excited triplet state energy level lower than that of the fluorescent light-emitting material, and wherein light emitted by the composition upon excitation includes delayed fluorescence.
A method of emitting light, comprising:
- applying a voltage to an organic light-emitting device comprising an anode, a cathode, and a light-emitting layer between the anode and the cathode such that light is emitted from the light-emitting layer, wherein the light-emitting layer comprises a composition comprising a physical mixture of a fluorescent light-emitting material and a triplet-accepting oligomer or polymer of formula (IIb):
- (TAU-Spacer)m (IIb)
- wherein TAU is a triplet accepting unit, Spacer is a substituted phenylene, biphenylene, or fluorene spacer group, and m is at least 2,
- wherein the triplet accepting oligomer or polymer has an excited triplet state energy level lower than that of the fluorescent light-emitting material, and wherein at least a portion of the emitted light comprises delayed fluorescence.
Dependencies are inferred from the claim text.