Light-emitting device and lighting device
View Patent ↗A light-emitting device which has various emission colors and can be manufactured efficiently and easily is provided. A first conductive layer formed of a semi-transmissive and semi-reflective conductive film is provided in a first light-emitting element region, so that the intensity of light in a specific wavelength region is increased with a cavity effect. As a result, the light-emitting device as a whole can emit desired light. When the first conductive layer is formed using a material with low electric resistance, voltage drop in a transparent conductive layer in the light-emitting device can be prevented. Accordingly, a light-emitting device with less emission unevenness can be manufactured. By applying such a structure to a white-light-emitting device, desired white light emission or white light emission with an excellent color rendering property can be obtained. Further, a large-area lighting device including a white-light-emitting device with less emission unevenness can be provided.
1. A light-emitting device comprising:
a reflective electrode;
an EL layer over the reflective electrode;
a transparent conductive layer comprising indium oxide over the EL layer; and
a first conductive layer having a semi-transmissive and semi-reflective property,
wherein the first conductive layer is in contact with a first part of a top surface of the transparent conductive layer in a first region,
wherein the first conductive layer is not in contact with a second part of the top surface of the transparent conductive layer in a second region, and
wherein the EL layer is in contact with the transparent conductive layer in the first region and the second region.
2. The light-emitting device according to claim 1 ,
wherein an electric resistance of the first conductive layer is lower than an electric resistance of the transparent conductive layer.
3. The light-emitting device according to claim 1 ,
wherein an optical path length is adjusted so that an intensity of light in a specific wavelength region is relatively increased due to the first conductive layer, and
wherein an emission color of the first region and an emission color of the second region are complementary colors.
4. The light-emitting device according to claim 1 ,
wherein an optical path length is adjusted so that an intensity of blue light is relatively increased due to the first conductive layer.
5. The light-emitting device according to claim 1 ,
wherein a lens array is provided over the transparent conductive layer and the first conductive layer.
6. The light-emitting device according to claim 1 ,
wherein the first conductive layer comprises an alloy of magnesium and silver or an alloy of magnesium and indium.
7. The light-emitting device according to claim 1 ,
wherein the first conductive layer comprises an element belonging to Group 1 or Group 2 of the periodic table and aluminum.
8. The light-emitting device according to claim 1 ,
wherein the light-emitting device further comprises a second conductive layer between the reflective electrode and the EL layer.
9. The light-emitting device according to claim 1 ,
wherein the first conductive layer has a stripe shape or a grid shape.
10. A lighting device comprising the light-emitting device according to claim 1 .
11. The light-emitting device according to claim 1 ,
wherein the first conductive layer is in contact with a third part of the top surface of the transparent conductive layer in a third region,
wherein the EL layer is in contact with the transparent conductive layer in the third region, and
wherein the second region is between the first region and the third region.
12. A light-emitting device comprising:
a reflective electrode;
an EL layer over the reflective electrode, the EL layer comprising a first EL layer emitting blue light, a second EL layer emitting green light, and a third EL layer emitting red light overlapping with one another;
a transparent conductive layer comprising indium oxide over the EL layer; and
a first conductive layer having a semi-transmissive and semi-reflective property,
wherein the first conductive layer is in contact with a first part of a top surface of the transparent conductive layer in a first region,
wherein the first conductive layer is not in contact with a second part of the top surface of the transparent conductive layer in a second region, and
wherein the EL layer is in contact with the transparent conductive layer in the first region and the second region.
13. The light-emitting device according to claim 12 ,
wherein an electric resistance of the first conductive layer is lower than an electric resistance of the transparent conductive layer.
14. The light-emitting device according to claim 12 ,
wherein an optical path length is adjusted so that an intensity of light in a specific wavelength region is relatively increased due to the first conductive layer, and
wherein an emission color of the first region and an emission color of the second region are complementary colors.
15. The light-emitting device according to claim 12 ,
wherein an optical path length is adjusted so that an intensity of the blue light is relatively increased due to the first conductive layer.
16. The light-emitting device according to claim 12 ,
wherein a lens array is provided over the transparent conductive layer and the first conductive layer.
17. The light-emitting device according to claim 12 ,
wherein the first conductive layer comprises an alloy of magnesium and silver or an alloy of magnesium and indium.
18. The light-emitting device according to claim 12 ,
wherein the first conductive layer comprises an element belonging to Group 1 or Group 2 of the periodic table and aluminum
19. The light-emitting device according to claim 12 ,
wherein the light-emitting device further comprises a second conductive layer between the reflective electrode and one of the first EL layer, the second EL layer, and the third EL layer.
20. The light-emitting device according to claim 12 ,
wherein the first conductive layer has a stripe shape or a grid shape.
21. A lighting device comprising the light-emitting device according to claim 12 .
22. The light-emitting device according to claim 12 ,
wherein the first EL layer emits a light having an emission spectrum in which an intensity at a wavelength of 450 nm to 485 nm is higher than that at the other wavelengths of visible light, the second EL layer emits a light having an emission spectrum in which an intensity at a wavelength of 500 nm to 565 nm is higher than that at the other wavelengths of visible light, and the third EL layer emits a light having an emission spectrum in which an intensity at a wavelength of 600 nm to 740 nm is higher than that at the other wavelengths of visible light.
23. The light-emitting device according to claim 12 ,
wherein the first conductive layer is in contact with a third part of the top surface of the transparent conductive layer in a third region,
wherein the EL layer is in contact with the transparent conductive layer in the third region, and
wherein the second region is between the first region and the third region.