US 12,089,429 B2
Light-emitting element, light-emitting device, electronic device, and lighting device
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 Jan. 21, 2021, as Appl. No. 17/154,426.
Application 17/154,426 is a continuation of application No. 15/046,875, filed on Feb. 18, 2016, granted, now 10,903,440, issued on Jan. 26, 2021.
Claims priority of application No. 2015-033719 (JP), filed on Feb. 24, 2015.
Prior Publication US 2021/0167313 A1, Jun. 3, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. H10K 50/11 (2023.01); C09K 11/02 (2006.01); C09K 11/06 (2006.01); H10K 50/13 (2023.01); H10K 59/38 (2023.01); H10K 101/10 (2023.01)
CPC H10K 50/11 (2023.02) [C09K 11/02 (2013.01); C09K 11/06 (2013.01); H10K 50/13 (2023.02); C09K 2211/1007 (2013.01); C09K 2211/1011 (2013.01); C09K 2211/1029 (2013.01); C09K 2211/1044 (2013.01); C09K 2211/1059 (2013.01); C09K 2211/185 (2013.01); H10K 59/38 (2023.02); H10K 2101/10 (2023.02)] 18 Claims
OG exemplary drawing
 
1. A light-emitting element comprising:
a pair of electrodes; and
a first light-emitting layer and a second light-emitting layer provided between the pair of electrodes,
wherein the first light-emitting layer comprises a fluorescent material and a first host material,
wherein the second light-emitting layer comprises a material exhibiting thermally activated delayed fluorescence,
wherein the first host material has one of an anthracene skeleton and a tetracene skeleton,
wherein a S1 level of the first host material is higher than the S1 level of the fluorescent material,
wherein that the T1 level of the first host material is lower than the T1 level of the fluorescent material,
wherein light emitted from the first light-emitting layer comprises light emitted from the fluorescent material,
wherein light emitted from the second light-emitting layer comprises light emitted from the material exhibiting thermally activated delayed fluorescence,
wherein a difference in peak wavelength between a first emission spectrum of light from the first light-emitting layer and a second emission spectrum of light from the second light-emitting layer is larger than or equal 0 nm and smaller than or equal to 30 nm, and
wherein a peak wavelength of the first emission spectrum is shorter than or equal a peak wavelength of the second emission spectrum.