CPC H10K 50/11 (2023.02) [F21S 43/145 (2018.01); H04N 23/53 (2023.01); H10K 50/131 (2023.02); H10K 50/19 (2023.02); H10K 59/12 (2023.02); H10K 77/111 (2023.02); H10K 85/622 (2023.02); H10K 85/623 (2023.02); H10K 85/624 (2023.02); H10K 85/626 (2023.02); H10K 85/633 (2023.02); H10K 85/6574 (2023.02); H10K 85/6576 (2023.02); H10K 2101/30 (2023.02); H10K 2101/40 (2023.02); H10K 2102/311 (2023.02)] | 25 Claims |
1. An organic EL device comprising at least:
an anode;
a first light-emitting layer;
an intermediate layer;
a second light-emitting layer; and
a cathode in this order,
the intermediate layer being located between the first light-emitting layer and the second light-emitting layer,
wherein the first light-emitting layer contains a first host and a first dopant,
the second light-emitting layer contains a second host and a second dopant,
the intermediate layer contains an aromatic hydrocarbon compound,
the following relationship (a) is satisfied between the first host and the first dopant,
the following relationship (b) is satisfied between the second host and the second dopant,
the following relationship (c) is satisfied between the hydrocarbon compound of the intermediate layer and the first host, and
the following relationship (d) is satisfied between the second host and the hydrocarbon compound of the intermediate layer,
(a) LUMO (H1)>LUMO (D1)
(b) LUMO (H2)>LUMO (D2)
(c) HOMO (H1)≥HOMO (IL)
(d) HOMO (H2)>HOMO (IL)
wherein LUMO (H1), LUMO (D1), LUMO (H2), and LUMO (D2) in (a) to (d) denote LUMO energy levels of the first host, the first dopant, the second host, and the second dopant, respectively, and HOMO (H1), HOMO (H2), and HOMO (IL) denote HOMO energy levels of the first host, the second host, and the intermediate layer material, respectively.
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