Light-emitting element, light-emitting device, electronic device, and lighting device
Provided is a light-emitting device which can emit monochromatic light with high purity due to a microcavity effect and which can emit white light in the case of a combination of monochromatic light. Provided is a high-definition light-emitting device. Provided is a light-emitting device with low power consumption. In a light-emitting device with a white-color filter top emission structure, one pixel is formed of four sub-pixels of RBGY, an EL layer includes a first light-emitting substance which emits blue light and a second light-emitting substance which emits light corresponding to a complementary color of blue, and a semi-transmissive and semi-reflective electrode (an upper electrode) is formed so as to cover an edge portion of the EL layer.
1. A light-emitting device comprising:
a first light-emitting element comprising a first reflective electrode, a first transparent conductive film, an EL layer, and a semi-transmissive and semi-reflective electrode;
a second light-emitting element comprising a second reflective electrode, a second transparent conductive film, the EL layer, and the semi-transmissive and semi-reflective electrode;
a third light-emitting element comprising a third reflective electrode, a third transparent conductive film, the EL layer, and the semi-transmissive and semi-reflective electrode;
a fourth light-emitting element comprising a fourth reflective electrode, a fourth transparent conductive film, the EL layer, and the semi-transmissive and semi-reflective electrode;
a first color filter over the first light-emitting element;
a second color filter over the second light-emitting element; and
a third color filter over the third light-emitting element,
wherein the EL layer includes a first light-emitting substance which emits blue light and a second light-emitting substance which emits light corresponding to a complementary color of blue,
wherein an optical path length between the fourth reflective electrode and the semi-transmissive and semi-reflective electrode is set so as to intensify the light corresponding to the complementary color of blue,
wherein the semi-transmissive and semi-reflective electrode covers an edge portion of the EL layer, and
wherein the fourth light-emitting element does not overlap with a color filter.
2. The light-emitting device according to claim 1 ,
wherein the first transparent conductive film is in contact with the first reflective electrode between the first reflective electrode and the EL layer,
wherein the second transparent conductive film is in contact with the second reflective electrode between the second reflective electrode and the EL layer,
wherein the third transparent conductive film is in contact with the third reflective electrode between the third reflective electrode and the EL layer, and
wherein the fourth transparent conductive film is in contact with the fourth reflective electrode between the fourth reflective electrode and the EL layer.
3. The light-emitting device according to claim 1 ,
wherein the first light-emitting element emits red light,
wherein the second light-emitting element emits green light, and
wherein the third light-emitting element emits blue light.
4. The light-emitting device according to claim 1 ,
wherein the first light-emitting substance has an emission spectrum peak within a range of greater than or equal to 420 nm and less than or equal to 480 nm, and
wherein the second light-emitting substance has an emission spectrum peak within a range of greater than or equal to 540 nm and less than or equal to 580 nm.
5. The light-emitting device according to claim 1 ,
wherein an optical path length between the first reflective electrode and the semi-transmissive and semi-reflective electrode is set so as to intensify red light,
wherein an optical path length between the second reflective electrode and the semi-transmissive and semi-reflective electrode is set so as to intensify green light, and
wherein an optical path length between the third reflective electrode and the semi-transmissive and semi-reflective electrode is set so as to intensify blue light.
6. The light-emitting device according to claim 1 , wherein the edge portion of the EL layer includes a side surface of the EL layer.
7. The light-emitting device according to claim 1 , further comprising a first flexible substrate and a second flexible substrate.
8. The light-emitting device according to claim 1 , further comprising a partition covering an edge portion of the first reflective electrode, wherein the partition includes a curved upper surface.
9. A light-emitting device comprising:
a first light-emitting element comprising a first reflective electrode, a first transparent conductive film, an EL layer, and a semi-transmissive and semi-reflective electrode;
a second light-emitting element comprising a second reflective electrode, a second transparent conductive film, the EL layer, and the semi-transmissive and semi-reflective electrode;
a third light-emitting element comprising a third reflective electrode, a third transparent conductive film, the EL layer, and the semi-transmissive and semi-reflective electrode;
a fourth light-emitting element comprising a fourth reflective electrode, a fourth transparent conductive film, the EL layer, and the semi-transmissive and semi-reflective electrode;
a first color filter over the first light-emitting element;
a second color filter over the second light-emitting element; and
a third color filter over the third light-emitting element,
wherein the EL layer includes a first light-emitting substance which emits blue light and a second light-emitting substance which emits yellow light,
wherein an optical path length between the fourth reflective electrode and the semi-transmissive and semi-reflective electrode is set so as to intensify the yellow light,
wherein the semi-transmissive and semi-reflective electrode covers an edge portion of the EL layer, and
wherein the fourth light-emitting element does not overlap with a color filter.
10. The light-emitting device according to claim 9 ,
wherein the first transparent conductive film is in contact with the first reflective electrode between the first reflective electrode and the EL layer,
wherein the second transparent conductive film is in contact with the second reflective electrode between the second reflective electrode and the EL layer,
wherein the third transparent conductive film is in contact with the third reflective electrode between the third reflective electrode and the EL layer, and
wherein the fourth transparent conductive film is in contact with the fourth reflective electrode between the fourth reflective electrode and the EL layer.
11. The light-emitting device according to claim 9 ,
wherein the first light-emitting element emits red light,
wherein the second light-emitting element emits green light, and
wherein the third light-emitting element emits blue light.
12. The light-emitting device according to claim 9 ,
wherein the first light-emitting substance has an emission spectrum peak within a range of greater than or equal to 420 nm and less than or equal to 480 nm, and
wherein the second light-emitting substance has an emission spectrum peak within a range of greater than or equal to 540 nm and less than or equal to 580 nm.
13. The light-emitting device according to claim 9 ,
wherein an optical path length between the first reflective electrode and the semi-transmissive and semi-reflective electrode is set so as to intensify red light,
wherein an optical path length between the second reflective electrode and the semi-transmissive and semi-reflective electrode is set so as to intensify green light, and
wherein an optical path length between the third reflective electrode and the semi-transmissive and semi-reflective electrode is set so as to intensify blue light.
14. The light-emitting device according to claim 9 , wherein the edge portion of the EL layer includes a side surface of the EL layer.
15. The light-emitting device according to claim 9 , further comprising a first flexible substrate and a second flexible substrate.
16. The light-emitting device according to claim 9 , further comprising a partition covering an edge portion of the first reflective electrode, wherein the partition includes a curved upper surface.