Image display device
View Patent ↗An organic EL element has a capping layer formed on a cathode layer. The capping layer contains a pigment that absorbs light that has a wavelength that is different from a wavelength of the light emitted from a light emitting layer, and has a reflectance that is higher at interface in multi-layered structure than a reflectance of the light emitted from the light emitting layer. The capping layer prevents incident light from outside from returning to the outside of the organic EL element.
1. A light emitting element comprising:
a multi-layered structure including a first electrode layer, a second electrode layer and a light emitting layer between the first and the second electrode layers; and
an absorbing layer that is arranged on a side of the light emitting layer from which light is emitted, wherein the absorbing layer has a higher refractive index than at least one layer of the multi-layered structure, and absorbs a different wavelength from light emitted from the light emitting layer,
wherein the absorbing layer contains an additive absorbing the light having a different wavelength from the light emitted from the light emitting layer;
wherein the additive comprises a Nile Red pigment.
2. The light emitting element according to claim 1 , wherein the light emitted from the light emitting layer passes through the absorbing layer.
3. The light emitting element according to claim 1 , wherein the light emitting layer emits light of red color or blue color; wherein a wavelength of the light absorbed in the absorbing layer is from 500 nm to 560 nm.
4. The light emitting element according to claim 1 , wherein the absorbing layer has a higher refractive index than all layers of the multi-layered structure.
5. The light emitting element according to claim 1 , wherein the absorbing layer comprises ZnS, TiO 2 or ITO.
6. The light emitting element according to claim 1 , wherein a concentration of the Nile Red pigment additive is from 5% to 10%.
7. An image display device comprising a plurality of the light emitting elements according to claim 1 .
8. The light emitting element according to claim 1 , wherein the reflectance of the absorbing layer is lower than 0.54.
9. The light emitting element according to claim 1 , wherein the reflectance of the absorbing layer is lower than 0.4.
10. A light emitting element comprising:
a substrate;
a first multi-layered structure on the substrate, including a first electrode layer, a second electrode layer and a light emitting layer between the first and the second electrode layers; and
a second multi-layered structure on the first multi-layered structure, including a absorbing layer and a high-refraction layer, the absorbing layer absorbing light of a different wavelength from light emitted from the light emitting layer, the high-refraction layer having a higher refractive index than at least one layer of the first multi-layered structure,
wherein the absorbing layer contains an additive absorbing the light having a different wavelength from the light emitted from the light emitting layer;
wherein the additive comprises a Nile Red pigment.
11. The light emitting element according to claim 10 , wherein a combined thickness of the absorbing layer and the high-refraction layer is from 60 nm to 90 nm.
12. The light emitting element according to claim 10 , wherein a concentration of the Nile Red pigment additive is from 5% to 10%.
13. An image display device comprising a plurality of the light emitting elements according to claim 10 .
14. A light emitting element comprising:
a substrate;
a multi-layered structure on the substrate, including a first electrode layer, a second electrode layer and a light emitting layer between the first and second electrode layers; and
an absorbing layer arranged on the multi-layered structure, having a higher refractive index than at least one layer of the multi-layered structure, the absorbing layer absorbing light of a different wavelength from light emitted from the light emitting layer,
wherein the absorbing layer contains an additive absorbing the light emitting layer, the additive comprising a Nile Red pigment.
15. The light emitting element according to claim 14 , wherein the light emitted from the light emitting layer passes through the absorbing layer.
16. The light emitting element according to claim 14 , wherein the light emitting layer emits light of red color or blue color; wherein a wavelength of the light absorbed in the absorbing layer is from 500 nm to 560 nm.
17. The light emitting element according to claim 14 , wherein the absorbing layer has a higher refractive index than all layers of the multi-layered structure.
18. The light emitting element according to claim 14 , wherein the absorbing layer comprises ZnS, TiO 2 , or ITO.
19. An image display device comprising a plurality of the light emitting elements according to claim 14 .
20. The light emitting element according to claim 14 , where a concentration of the Nile Red pigment additive is from 5% to 10%.
21. A light emitting element comprising;
a multi-layered structure including a first electrode layer, a second electrode layer and a light emitting layer between the first and the second electrode layers; and
an absorbing layer that is arranged on a side of the light emitting layer from which light is emitted, wherein the absorbing layer has a higher refractive index than at least one layer of the multi-layered structure, and contains a Nile Red pigment absorbing a different wavelength of the light from the light emitted from the light emitting layer.