CPC H10K 85/611 (2023.02) [H10K 50/11 (2023.02); H10K 50/19 (2023.02); H10K 2101/90 (2023.02)] | 8 Claims |
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.
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