Patent ID: 11895908
Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
Field: nan (nan)
Classification: CPC H | IPC H

Claim 0:
1. A light-emitting element comprising:
a light-emitting layer comprising:
a first substance;
a second substance; and
a third substance,

wherein the third substance is a fluorescent compound,
wherein emission of a mixture of the first substance and the second substance includes a delayed fluorescence component at room temperature,
wherein a peak of the emission of the mixture overlaps with an absorption band on a lowest energy side of the third substance,
wherein a highest occupied molecular orbital level of the first substance is higher than a highest occupied molecular orbital level of the second substance,
wherein a lowest unoccupied molecular orbital level of the first substance is higher than a lowest unoccupied molecular orbital level of the second substance, and
wherein a lifetime of the delayed fluorescence component is 10 ns or longer and 50 μs or shorter.