Light-emitting device
View Patent ↗To provide a long lifetime light-emitting element, in particular, to provide a long lifetime white light-emitting element, and to provide a light-emitting element having high luminous efficiency, in particular, to provide a white light-emitting element having high luminous efficiency. In a light-emitting element having, between an anode and a cathode, a first light-emitting layer containing a first light-emitting substance and a second light-emitting layer containing a second light-emitting substance which is provided to be in contact with the first light-emitting layer, the first light-emitting layer is divided into a layer provided on the anode side and a layer provided on the cathode side. At this time, a host material having a hole-transporting property is used for the layer provided on the anode side, and a host material having an electron-transporting property is used for the layer provided on the cathode side.
1. A light-emitting device comprising:
an anode;
a cathode;
a first layer provided between the anode and the cathode, the first layer comprising a first organic compound and a first light-emitting substance;
a second layer provided between the first layer and the cathode, and in direct contact with the first layer, the second layer comprising a second organic compound and the first light-emitting substance; and
a third layer provided between the second layer and the cathode, and in direct contact with the second layer, the third layer comprising the second organic compound and a second light-emitting substance,
wherein the first organic compound is different from the second organic compound,
wherein the first organic compound has a hole-transporting property, and
wherein the second organic compound has an electron-transporting property.
2. The light-emitting device according to claim 1 ,
wherein a first emission peak wavelength of the first light-emitting substance is in a first range of greater than or equal to 400 nm and less than 480 nm, and
wherein a second emission peak wavelength of the second light-emitting substance is in a second range of greater than or equal to 540 nm and less than 600 nm.
3. The light-emitting device according to claim 1 , wherein the first organic compound is tricyclic, tetracyclic, pentacyclic, or hexacyclic condensed aromatic compound.
4. The light-emitting device according to claim 1 , wherein the first organic compound is anthracene derivative.
5. The light-emitting device according to claim 1 , wherein a thickness of the second layer is greater than or equal to 1 nm and less than or equal to 20 nm.
6. The light-emitting device according to claim 1 , wherein the first layer has a hole-transporting property and the second layer and the third layer have an electron-transporting property.
7. The light-emitting device according to claim 1 , wherein the light-emitting device is a lightning device.
8. A light-emitting device comprising:
an anode;
a cathode;
a first layer provided between the anode and the cathode, the first layer comprising a first organic compound and a first light-emitting substance;
a second layer provided between the first layer and the cathode, and in direct contact with the first layer, the second layer comprising a second organic compound and the first light-emitting substance; and
a third layer provided between the second layer and the cathode, and in direct contact with the second layer, the third layer comprising the second organic compound and a second light-emitting substance,
wherein the first organic compound is different from the second organic compound,
wherein the first organic compound has a hole-transporting property,
wherein the second organic compound has an electron-transporting property,
wherein a first content of the first organic compound in the first layer is greater than or equal to 50 wt % and less than or equal to 99.9 wt %,
wherein a second content of the second organic compound in the second layer is greater than or equal to 50 wt % and less than or equal to 99.9 wt %, and
wherein a third content of the second organic compound in the third layer is greater than or equal to 50 wt % and less than or equal to 99.9 wt %.
9. The light-emitting device according to claim 8 ,
wherein a first emission peak wavelength of the first light-emitting substance is in a first range of greater than or equal to 400 nm and less than 480 nm, and
wherein a second emission peak wavelength of the second light-emitting substance is in a second range of greater than or equal to 540 nm and less than 600 nm.
10. The light-emitting device according to claim 8 , wherein the first organic compound is tricyclic, tetracyclic, pentacyclic, or hexacyclic condensed aromatic compound.
11. The light-emitting device according to claim 8 , wherein the first organic compound is anthracene derivative.
12. The light-emitting device according to claim 8 , wherein a thickness of the second layer is greater than or equal to 1 nm and less than or equal to 20 nm.
13. The light-emitting device according to claim 8 , wherein the first layer and the second layer have a hole-transporting property and the third layer has an electron-transporting property.
14. The light-emitting device according to claim 8 , wherein the light-emitting device is a lightning device.
15. A light-emitting device comprising:
an anode;
a cathode;
a first layer provided between the anode and the cathode, the first layer comprising a first organic compound and a first light-emitting substance;
a second layer provided between the first layer and the cathode, and in direct contact with the first layer, the second layer comprising the first organic compound and a second light-emitting substance; and
a third layer provided between the second layer and the cathode, and in direct contact with the second layer, the third layer comprising a second organic compound and the second light-emitting substance,
wherein the second organic compound is different from the first organic compound,
wherein the first layer and the second layer have a hole-transporting property, and
wherein the third layer has an electron-transporting property.
16. The light-emitting device according to claim 15 ,
wherein a first emission peak wavelength of the first light-emitting substance is in a first range of greater than or equal to 540 nm and less than 600 nm, and
wherein a second emission peak wavelength of the second light-emitting substance is in a second range of greater than or equal to 400 nm and less than 480 nm.
17. The light-emitting device according to claim 15 ,
wherein the first organic compound has a hole-transporting property, and
wherein the second organic compound has an electron-transporting property.
18. The light-emitting device according to claim 15 , wherein the first organic compound is tricyclic, tetracyclic, pentacyclic, or hexacyclic condensed aromatic compounds.
19. The light-emitting device according to claim 15 , wherein the first organic compound is anthracene derivatives.
20. The light-emitting device according to claim 15 , wherein a thickness of the second layer is greater than or equal to 1 nm and less than or equal to 20 nm.
21. The light-emitting device according to claim 15 , wherein the light-emitting device is a lightning device.
22. A light-emitting device comprising:
an anode;
a cathode;
a first layer provided between the anode and the cathode, the first layer comprising a first organic compound and a first light-emitting substance;
a second layer provided between the first layer and the cathode, and in direct contact with the first layer, the second layer comprising the first organic compound and a second light-emitting substance; and
a third layer provided between the second layer and the cathode, and in direct contact with the second layer, the third layer comprising a second organic compound and the second light-emitting substance,
wherein the second organic compound is different from the first organic compound,
wherein the first organic compound has a hole-transporting property,
wherein the second organic compound has an electron-transporting property,
wherein a first content of the first organic compound in the first layer is greater than or equal to 50 wt % and less than or equal to 99.9 wt %,
wherein a second content of the first organic compound in the second layer is greater than or equal to 50 wt % and less than or equal to 99.9 wt %, and
wherein a third content of the second organic compound in the third layer is greater than or equal to 50 wt % and less than or equal to 99.9 wt %.
23. The light-emitting device according to claim 22 ,
wherein a first emission peak wavelength of the first light-emitting substance is in a first range of greater than or equal to 540 nm and less than 600 nm, and
wherein a second emission peak wavelength of the second light-emitting substance is in a second range of greater than or equal to 400 nm and less than 480 nm.
24. The light-emitting device according to claim 22 ,
wherein the first organic compound is tricyclic, tetracyclic, pentacyclic, or hexacyclic condensed aromatic compounds.
25. The light-emitting device according to claim 22 ,
wherein the first organic compound is anthracene derivatives.
26. The light-emitting device according to claim 22 , wherein a thickness of the second layer is greater than or equal to 1 nm and less than or equal to 20 nm.
27. The light-emitting device according to claim 22 , wherein the first layer and the second layer have a hole-transporting property and the third layer has an electron-transporting property.
28. The light-emitting device according to claim 22 , wherein the light-emitting device is a lightning device.