Carbazole-based materials for guest-host electroluminescent systems
AssigneeCanon Kabushiki Kaisha
InventorsTravis P. S. Thoms, Jian-Ping Chen
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Abstract
The invention is directed to guest-host emissive systems suitable for use with organic light emitting devices. In one aspect, the host material comprises a compound having a carbazole core with an electron-donating species bonded to the nitrogen, and aromatic amine groups or carbazole groups bonded to one or more of the carbon atoms. In another aspect, the host material comprises a compound having a single-atom or single-ring core bonded to one or more carbazole moieties, which may themselves be substituted with electron-donating groups. The disclosed host materials have a large band gap potential and high-energy triplet excited states to permit short-wavelength phosphorescent emission by an associated guest material.
Claims16
A guest-host emissive system for use in an organic light emitting device comprising a guest and a host, wherein the host comprises a carbazole-based compound having the following structure:
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- wherein R1 is an electron-donating group,
- and at least one of R2 through R7 is an aromatic amine or carbazole moiety having hole transport capability, and
- wherein the guest is a light emissive compound having smaller band gap than the host.
A guest-host emissive system for use in an organic light emitting device comprising a host and a guest,
- wherein the host comprises a core selected from the group consisting of carbon, benzene, furan, thiophene, pyrrole and tetraphenylmethane, and two or more carbazole groups or carbazole groups substituted with electron-donating groups bonded to said core, and
- wherein the guest is a light emissive material having a smaller band gap potential than the host.
A guest-host emissive system for use in an organic light emitting device comprising a host and a guest,
- wherein the host comprises a compound selected from the group consisting of
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- wherein A is O, S or N, and at least two R are carbazole or substituted carbazole, said guest is a phosphorescent emitter having a wavelength shorter than about 500 nm, and said host has a first excited triplet state higher than said guest.
Dependencies are inferred from the claim text.