Light-emitting element, light-emitting device, and display device
A light-emitting element with which a reduction in power consumption and an improvement in productivity of a display device can be achieved is provided. A technique of manufacturing a display device with high productivity is provided. The light-emitting element includes an electrode having a reflective property, and a first light-emitting layer, a charge generation layer, a second light-emitting layer, and an electrode having a light-transmitting property stacked in this order over the electrode having a reflective property. The optical path length between the electrode having a reflective property and the first light-emitting layer is one-quarter of the peak wavelength of the emission spectrum of the first light-emitting layer. The optical path length between the electrode having a reflective property and the second light-emitting layer is three-quarters of the peak wavelength of the emission spectrum of the second light-emitting layer.
1. A light-emitting device comprising at least three light-emitting elements, each of the three light-emitting elements comprising:
an electrode having a reflective property;
a stacked structure over the electrode having a reflective property, the stacked structure comprising:
a first light-emitting layer over the electrode having a reflective property;
a first charge generation layer over the first light-emitting layer; and
a second light-emitting layer over the first charge generation layer, the second light-emitting layer comprising a first layer and a second layer; and
an electrode having a light-transmitting property over the second light-emitting layer,
wherein an optical path length between the electrode having a reflective property and the first light-emitting layer is one-quarter of a peak wavelength of an emission spectrum of the first light-emitting layer,
wherein an optical path length between the electrode having a reflective property and the second light-emitting layer is three-quarters of a peak wavelength of an emission spectrum of the second light-emitting layer,
wherein the first layer comprising a first compound, a second compound, and a phosphorescent compound,
wherein the second layer comprising the first compound and the phosphorescent compound,
wherein the three light-emitting elements are adjacent to each other, and
wherein the stacked structure is continued from one of the three light-emitting elements to the adjacent light-emitting element.
2. The light-emitting device according to claim 1 , wherein colors of light emitted from the first light-emitting layer and the second light-emitting layer are different.
3. The light-emitting device according to claim 1 , wherein the light-emitting element emits white light.
4. The light-emitting device according to claim 1 , further comprising:
a first substrate provided with the electrode having a reflective property; and
a second substrate over the electrode having a light-transmitting property,
wherein the second substrate is a light-transmitting substrate.
5. The light-emitting device according to claim 1 , further comprising:
a second charge generation layer over the second light-emitting layer; and
a third light-emitting layer between the second charge generation layer and the electrode having a light-transmitting property,
wherein an optical path length between the electrode having a reflective property and the third light-emitting layer is five-quarters of a peak wavelength of an emission spectrum of the third light-emitting layer.
6. The light-emitting device according to claim 5 , wherein colors of light emitted from the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer are different.
7. The light-emitting device according to claim 1 , further comprising:
a hole-injection layer between the electrode having a reflective property and the first light-emitting layer; and
a second charge generation layer between the second light-emitting layer and the electrode having a light-transmitting property,
wherein the hole-injection layer comprises a first organic compound and an inorganic compound,
wherein the first charge generation layer comprises the first organic compound and the inorganic compound, and
wherein the second charge generation layer comprises a second organic compound and the inorganic compound.
8. The light-emitting device according to claim 1 , wherein the light-emitting device is a display device.
9. A lighting device comprising the three light-emitting elements according to claim 1 .
10. A light-emitting device comprising:
a first light-emitting element, the first light-emitting element comprising:
an electrode having a reflective property;
a stacked structure over the electrode having a reflective property, the stacked structure comprising:
a first light-emitting layer over the electrode having a reflective property;
a first charge generation layer over the first light-emitting layer; and
a second light-emitting layer over the first charge generation layer, the second light-emitting layer comprising a first layer and a second layer; and
an electrode having a light-transmitting property over the second light-emitting layer;
a first color filter layer over the first light-emitting element;
a second light-emitting element adjacent to the first light-emitting element; and
a second color filter layer over the second light-emitting element,
wherein an optical path length between the electrode having a reflective property and the first light-emitting layer is one-quarter of a peak wavelength of an emission spectrum of the first light-emitting layer,
wherein an optical path length between the electrode having a reflective property and the second light-emitting layer is three-quarters of a peak wavelength of an emission spectrum of the second light-emitting layer,
wherein the first color filter layer transmits light with a peak wavelength of the emission spectrum of the first light-emitting layer,
wherein the second color filter layer transmits light with a peak wavelength of the emission spectrum of the second light-emitting layer,
wherein the first layer comprising a first compound, a second compound, and a phosphorescent compound,
wherein the second layer comprising the first compound and the phosphorescent compound, and
wherein the stacked structure is continued from the first light-emitting element to the second light-emitting element.
11. The light-emitting device according to claim 10 , wherein colors of light emitted from the first light-emitting layer and the second light-emitting layer are different.
12. The light-emitting device according to claim 10 , further comprising:
a first substrate provided with the first light-emitting element and the second light-emitting element; and
a second substrate provided with the first color filter layer and the second color filter layer, wherein the second substrate is a light-transmitting substrate.
13. The light-emitting device according to claim 10 , further comprising:
a hole-injection layer between the electrode having a reflective property and the first light-emitting layer; and
a second charge generation layer between the second light-emitting layer and the electrode having a light-transmitting property,
wherein the hole-injection layer comprises a first organic compound and an inorganic compound,
wherein the first charge generation layer comprises the first organic compound and the inorganic compound, and
wherein the second charge generation layer comprises a second organic compound and the inorganic compound.
14. The light-emitting device according to claim 10 , wherein the light-emitting device is a display device.
15. A light-emitting device comprising:
a plurality of light-emitting elements, the plurality of light-emitting elements each comprising:
an electrode having a reflective property;
a stacked structure over the electrode having a reflective property, the stacked structure comprising:
a first light-emitting layer over the electrode having a reflective property;
a first charge generation layer over the first light-emitting layer;
a second light-emitting layer over the first charge generation layer, the second light-emitting layer comprising a first layer and a second layer;
a second charge generation layer over the second light-emitting layer; and
a third light-emitting layer over the second charge generation layer; and
an electrode having a light-transmitting property over the third light-emitting layer; and
a plurality of color filter layers provided over the plurality of light-emitting elements,
wherein an optical path length between the electrode having a reflective property and the first light-emitting layer is one-quarter of a peak wavelength of an emission spectrum of the first light-emitting layer,
wherein an optical path length between the electrode having a reflective property and the second light-emitting layer is three-quarters of a peak wavelength of an emission spectrum of the second light-emitting layer,
wherein an optical path length between the electrode having a reflective property and the third light-emitting layer is five-quarters of a peak wavelength of an emission spectrum of the third light-emitting layer, and
wherein the plurality of color filter layers comprise at least:
a first color filter layer transmitting light with a peak wavelength of the emission spectrum of the first light-emitting layer;
a second color filter layer transmitting light with a peak wavelength of the emission spectrum of the second light-emitting layer;
a third color filter layer transmitting light with a peak wavelength of the emission spectrum of the third light-emitting layer,
wherein the first layer comprising a first compound, a second compound, and a phosphorescent compound,
wherein the second layer comprising the first compound and the phosphorescent compound, and
wherein the stacked structure is continued from one of the plurality of light-emitting elements to the other of the plurality of light-emitting elements.
16. The light-emitting device according to claim 15 , wherein colors of light emitted from the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer are different.
17. The light-emitting device according to claim 15 , further comprising:
a first substrate provided with the plurality of light-emitting elements; and
a second substrate provided with the plurality of color filter layers,
wherein the second substrate is a light-transmitting substrate.
18. The light-emitting device according to claim 15 , wherein the light-emitting device is a display device.
19. The light-emitting device according to claim 5 ,
wherein white light is extracted from the light-emitting device without providing a color filter layer.