Light-emitting device, light-emitting apparatus, electronic device, and lighting device
Provided is a light-emitting device that can have sufficient device characteristics even with a smaller number of stacked layers in an EL layer and a thicker light-emitting layer than a conventional one by using, as an organic compound used for the EL layer of the light-emitting device, a material that can increase not only a property of carrier transport to the light-emitting layer but also a property of carrier injection from an electrode.
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.
2. The light-emitting device according to claim 1 ,
wherein the compound comprising an alkali metal is an organic compound.
3. The light-emitting device according to claim 1 ,
wherein the fourth layer further comprises the first organic compound.
4. The light-emitting device according to claim 1 ,
wherein the aromatic ring in the structure included in the second organic compound is a naphthalene ring.
5. The light-emitting device according to claim 4 ,
wherein the furodiazine skeleton in the second organic compound is a furopirazine skeleton or a furopyrimidine skeleton.
6. The light-emitting device according to claim 1 ,
wherein the first organic compound is represented by any one of Formulae (G1), (G2) and (G3),
wherein Ar 1 represents a substituted or unsubstituted aromatic ring,
wherein each of R 1 to R 6 independently represents hydrogen or a group having 1 to 100 carbon atoms in total, and
wherein each of at least one of R 1 and R 2 , at least one of R 3 and R 4 , and at least one of R 5 and R 6 has a hole-transport skeleton.
7. The light-emitting device according to claim 1 ,
wherein the first organic compound is represented by any one Formulae (G1), (G2) and (G3),
wherein Ar 1 represents any one of substituted or unsubstituted benzene, substituted or unsubstituted naphthalene, substituted or unsubstituted phenanthrene, and substituted or unsubstituted chrysene,
wherein each of R 1 to R 6 independently represents hydrogen or a group having 1 to 100 carbon atoms in total, and
each of at least one of R 1 and R 2 , at least one of R 3 and R 4 , and at least one of R 5 and R 6 has a hole-transport skeleton.
8. The light-emitting device according to claim 6 ,
wherein Ar 1 represents any one of Formulae (t2), (t3) and (t4),
wherein each of R 11 to R 36 independently represents any one of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted monocyclic saturated hydrocarbon group having 3 to 7 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaromatic hydrocarbon group having 3 to 12 carbon atoms, and
wherein * represents a portion bonded to the furan ring in Formulae (G1) to (G3).
9. The light-emitting device according to claim 6 ,
wherein the group having 1 to 100 carbon atoms in each of R 1 to R 6 of Formulae (G1) to (G3), represents one of or a combination of an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a substituted or unsubstituted polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms, and a substituted or unsubstituted heteroaromatic hydrocarbon group having 3 to 12 carbon atoms.
10. The light-emitting device according to claim 6 ,
wherein the group having 1 to 100 carbon atoms in each of R 1 to R 6 of Formulae (G1) to (G3), has any one of a pyrrole ring structure, a furan ring structure and a thiophene ring structure through one of a substituted or unsubstituted phenylene group and a substituted or unsubstituted biphenylene group.
11. The light-emitting device according to claim 6 ,
wherein the group having 1 to 100 carbon atoms in each of R 1 to R 6 of Formulae (G1) to (G3), has a structure represented by any one of Formulae (Ht-1) to (Ht-26) through one of a substituted or unsubstituted phenylene group and a substituted or unsubstituted biphenylene group,
wherein Q represents oxygen or sulfur,
wherein each of R 100 to R 169 represents 1 to 4 substituents and independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms, and
wherein Ar 1 represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms.
12. The light-emitting device according to claim 1 , wherein the light-emitting substance is a phosphorescent material.
13. The light-emitting device according to claim 1 , wherein the first organic compound is a carbazole derivative.
14. The light-emitting device according to claim 13 , wherein the carbazole derivative is a bicarbazole derivative.
15. The light-emitting device according to claim 1 , wherein the first layer is a hole-transport layer.
16. A light-emitting apparatus comprising:
the light-emitting device according to claim 1 ; and
a flexible printed circuit.
17. An electronic device comprising:
the light-emitting apparatus according to claim 16 ; and
at least one of a microphone, a camera, an operation button, an external connection portion and a speaker.
18. A lighting device comprising:
the light-emitting device according to claim 1 ; and
at least one of a housing and a cover.