Light-emitting element, display module, lighting module, light-emitting device, display device, electronic device, and lighting device
A light-emitting element with improved heat resistance is provided without losing its advantages such as thinness, lightness, and low power consumption. A light-emitting element is provided which includes a first electrode, a second electrode, and an EL layer between the first electrode and the second electrode, in which the EL layer includes a layer containing a condensed aromatic compound or a condensed heteroaromatic compound, and a layer containing 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen) in contact with the layer containing the condensed aromatic compound or the condensed heteroaromatic compound.
1. A light-emitting element comprising:
a first electrode;
a second electrode; and
an EL layer between the first electrode and the second electrode, the EL layer comprising:
a first layer comprising one of a condensed aromatic compound and a condensed heteroaromatic compound; and
a second layer comprising NBPhen, the second layer in contact with the first layer,
wherein the condensed heteroaromatic compound is different from NBPhen.
2. The light-emitting element according to claim 1 ,
wherein the condensed heteroaromatic compound comprises a condensed ring skeleton, and
wherein the condensed ring skeleton includes two nitrogen atoms.
3. The light-emitting element according to claim 1 , wherein the light-emitting element is capable of emitting phosphorescent light.
4. The light-emitting element according to claim 1 , wherein the first layer further comprises an iridium complex.
5. The light-emitting element according to claim 1 , wherein a part of the first layer comprises an iridium complex.
6. The light-emitting element according to claim 1 , wherein the second layer comprises chlorine at 1.0×10 −2 g/kg or less.
7. The light-emitting element according to claim 1 ,
wherein the second layer comprises an impurity at 1.7×10 −1 g/kg or less, and
wherein the impurity is a chlorine mono-substituted derivative of NBPhen.
8. A light-emitting device comprising:
the light-emitting element according to claim 1 ; and
a unit for controlling the light-emitting element.
9. A lighting device comprising:
the light-emitting element according to claim 1 ; and
a unit for controlling the light-emitting element.
10. An electronic device comprising the light-emitting element according to claim 1 .
11. A light-emitting element comprising:
a first electrode;
a second electrode; and
an EL layer between the first electrode and the second electrode, the EL layer comprising:
a first layer comprising one of a condensed aromatic compound and a condensed heteroaromatic compound; and
a second layer comprising NBPhen, the second layer in contact with the first layer,
wherein each of the condensed aromatic compound and the condensed heteroaromatic compound comprises a condensed ring skeleton including three or more rings, and
wherein the condensed heteroaromatic compound is different from NBPhen.
12. The light-emitting element according to claim 11 , wherein the condensed ring skeleton includes two nitrogen atoms.
13. The light-emitting element according to claim 11 , wherein the light-emitting element is capable of emitting phosphorescent light.
14. The light-emitting element according to claim 11 , wherein the first layer further comprises an iridium complex.
15. The light-emitting element according to claim 11 , wherein a part of the first layer comprises an iridium complex.
16. The light-emitting element according to claim 11 , wherein the second layer comprises chlorine at 1.0×10 −2 g/kg or less.
17. The light-emitting element according to claim 11 ,
wherein the second layer comprises an impurity at 1.7×10 −1 g/kg or less, and
wherein the impurity is a chlorine mono-substituted derivative of NBPhen.
18. A light-emitting device comprising:
the light-emitting element according to claim 11 ; and
a unit for controlling the light-emitting element.
19. A lighting device comprising:
the light-emitting element according to claim 11 ; and
a unit for controlling the light-emitting element.
20. An electronic device comprising the light-emitting element according to claim 11 .