US 11,895,908 B2
Light-emitting element, display device, electronic device, and lighting device
Takahiro Ishisone, Kanagawa (JP); Shunsuke Hosoumi, Kanagawa (JP); Tatsuyoshi Takahashi, Kanagawa (JP); and Satoshi Seo, Kanagawa (JP)
Assigned to Semiconductor Energy Laboratory Co., Ltd., Kanagawa-ken (JP)
Filed by SEMICONDUCTOR ENERGY LABORATORY CO., LTD., Atsugi (JP)
Filed on Apr. 5, 2022, as Appl. No. 17/713,931.
Application 17/713,931 is a continuation of application No. 16/737,989, filed on Jan. 9, 2020, granted, now 11,322,689.
Application 16/737,989 is a continuation of application No. 15/958,665, filed on Apr. 20, 2018, granted, now 10,811,611, issued on Oct. 20, 2020.
Application 15/958,665 is a continuation of application No. 15/062,606, filed on Mar. 7, 2016, granted, now 9,954,177, issued on Apr. 24, 2018.
Claims priority of application No. 2015-046376 (JP), filed on Mar. 9, 2015.
Prior Publication US 2022/0238810 A1, Jul. 28, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H10K 85/60 (2023.01); H10K 50/11 (2023.01); H10K 50/19 (2023.01); H10K 101/00 (2023.01)
CPC H10K 85/611 (2023.02) [H10K 50/11 (2023.02); H10K 50/19 (2023.02); H10K 2101/90 (2023.02)] 8 Claims
OG exemplary drawing
 
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.