CPC H10K 50/131 (2023.02) [H10K 50/11 (2023.02); H10K 50/13 (2023.02); H10K 85/342 (2023.02); H10K 85/633 (2023.02); H10K 2101/10 (2023.02); H10K 2101/27 (2023.02); H10K 2101/40 (2023.02)] | 15 Claims |
1. A light-emitting device comprising:
a first electrode comprising indium and tin;
a first light-emitting layer over the first electrode;
a second light-emitting layer over the first light-emitting layer;
a third light-emitting layer over the second light-emitting layer;
a first layer comprising lithium fluoride;
a second electrode over the third light-emitting layer and in contact with the first layer, the second electrode comprising aluminum;
an electron-transport material, a Group 1 metal or a compound of the Group 1 metal, a hole-transport material, and a first organic compound which are between the second light-emitting layer and the third light-emitting layer; and
a second layer between the first light-emitting layer and the second light-emitting layer, the second layer comprising at least one of the electron-transport material, the Group 1 metal or the compound of the Group 1 metal, the hole-transport material, and the first organic compound,
wherein the first organic compound comprises at least one of a halogen group and a cyano group,
wherein the first light-emitting layer comprises a first host material and a first fluorescent material,
wherein the second light-emitting layer comprises a second organic compound, a third organic compound which forms an exciplex together with the second organic compound, and an iridium compound,
wherein the third light-emitting layer comprises a second host material and a second fluorescent material,
wherein an emission spectrum peak of the exciplex overlaps with an adsorption band on a longest wavelength side in an absorption spectrum of the iridium compound,
wherein the first fluorescent material and the second fluorescent material are the same material,
wherein the second organic compound is one of a triazole derivative, a dibenzofuran derivative, a pyrimidine derivative, a triazine derivative, a pyridine derivative, a bipyridine derivative, and a phenanthroline derivative,
wherein the first host material is an anthracene derivative or a tetracene derivative,
wherein the light-emitting device is configured to emit white light,
wherein a level of the lowest triplet excited state of the first fluorescent material is higher than a level of the lowest triplet excited state of the first host material, and
wherein a level of the lowest singlet excited state of the first host material is higher than a level of the lowest singlet excited state of the first fluorescent material.
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