| CPC H10K 50/121 (2023.02) [C07F 15/0033 (2013.01); C09K 11/06 (2013.01); H10K 50/11 (2023.02); H10K 50/15 (2023.02); H10K 50/16 (2023.02); H10K 59/12 (2023.02); H10K 59/38 (2023.02); H10K 59/40 (2023.02); C09K 2211/1007 (2013.01); C09K 2211/1011 (2013.01); C09K 2211/1059 (2013.01); C09K 2211/185 (2013.01); H10K 85/342 (2023.02); H10K 85/615 (2023.02); H10K 85/633 (2023.02); H10K 85/636 (2023.02); H10K 85/654 (2023.02); H10K 85/657 (2023.02); H10K 85/6572 (2023.02); H10K 85/6576 (2023.02); H10K 2101/10 (2023.02); H10K 2101/30 (2023.02); H10K 2101/40 (2023.02); H10K 2101/80 (2023.02); H10K 2101/90 (2023.02)] | 10 Claims |

|
1. A light-emitting element comprising:
a first electrode;
a light-emitting layer over the first electrode, the light-emitting layer comprising a first organic compound, a second organic compound and a phosphorescent material; and
a second electrode over the light-emitting layer,
wherein the first organic compound comprises a triazine skeleton,
wherein the second organic compound comprises a carbazol-3-yl group,
wherein the first organic compound and the second organic compound form an exciplex,
wherein the phosphorescent material has a lower triplet excitation energy level than each of the first organic compound and the second organic compound,
wherein a lowest unoccupied molecular orbital level of the first organic compound is lower than a lowest unoccupied molecular orbital level of the second organic compound,
wherein a highest occupied molecular orbital level of the first organic compound is lower than a highest occupied molecular orbital level of the second organic compound,
wherein a highest occupied molecular orbital level of the phosphorescent material is higher than the highest occupied molecular orbital level of the second organic compound, and
wherein an energy difference between a lowest unoccupied molecular orbital level of the phosphorescent material and the highest occupied molecular orbital level of the phosphorescent material is larger than an energy difference between the lowest unoccupied molecular orbital level of the first organic compound and the highest occupied molecular orbital level of the second organic compound.
|