| CPC C07D 491/048 (2013.01) [C07D 519/00 (2013.01); H10K 85/657 (2023.02); H10K 85/6572 (2023.02); H10K 85/6574 (2023.02); H10K 85/6576 (2023.02); H10K 50/11 (2023.02); H10K 50/166 (2023.02); H10K 59/87 (2023.02); H10K 2101/10 (2023.02); H10K 2101/90 (2023.02); H10K 2102/351 (2023.02)] | 18 Claims |

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1. A light-emitting device comprising an electroluminescent layer between an anode and a cathode,
wherein the electroluminescent layer comprises:
a first layer;
a second layer between the first layer and the cathode and in contact with the first layer;
a third layer between the second layer and the cathode and in contact with the second layer; and
a fourth layer between the cathode and the third layer and in contact with the third layer and the cathode,
wherein the second layer has a largest thickness in the electroluminescent layer,
wherein the second layer comprises a light-emitting substance, a first organic compound and a second organic compound,
wherein the first layer comprises the first organic compound,
wherein the third layer comprises a third organic compound,
wherein the fourth layer comprises a compound comprising an alkali metal,
wherein the third organic compound is different from the first organic compound and the second organic compound,
wherein the second organic compound has a structure in which an aromatic ring is fused to a furan ring of a furodiazine skeleton, and
wherein the second layer is a light-emitting layer.
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