Light-emitting element
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorSatoshi Seo
Life of this patent
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Abstract
Provided is a light-emitting element with high external quantum efficiency and a low drive voltage. The light-emitting element includes a light-emitting layer which contains a phosphorescent compound and a material exhibiting thermally activated delayed fluorescence between a pair of electrodes, wherein a peak of a fluorescence spectrum and/or a peak of a phosphorescence spectrum of the material exhibiting thermally activated delayed fluorescence overlap(s) with a lowest-energy-side absorption band in an absorption spectrum of the phosphorescent compound, and wherein the phosphorescent compound exhibits phosphorescence in the light-emitting layer by voltage application between the pair of electrodes.
Claims34
A light-emitting element comprising:
- a pair of electrodes;
- and
- a light-emitting layer between the pair of electrodes,
- wherein the light-emitting layer comprises a phosphorescent compound and a thermally activated delayed fluorescence material, and
- wherein a peak of a fluorescence spectrum of the thermally activated delayed fluorescence material overlaps with a lowest-energy-side absorption band in an absorption spectrum of the phosphorescent compound.
A light-emitting element comprising:
- a pair of electrodes;
- and
- a light-emitting layer between the pair of electrodes,
- wherein the light-emitting layer comprises a phosphorescent compound and a thermally activated delayed fluorescence material, and
- wherein a peak of a phosphorescence spectrum of the thermally activated delayed fluorescence material overlaps with a lowest-energy-side absorption band in an absorption spectrum of the phosphorescent compound.
A light-emitting element comprising:
- a pair of electrodes;
- and
- a light-emitting layer between the pair of electrodes,
- wherein the light-emitting layer comprises a phosphorescent compound and a thermally activated delayed fluorescence material, and
- wherein a peak of a fluorescence spectrum and a peak of a phosphorescence spectrum of the thermally activated delayed fluorescence material overlaps with a lowest-energy-side absorption band in an absorption spectrum of the phosphorescent compound.
Dependencies are inferred from the claim text.