Light-emitting element, light-emitting device, display device, and electronic apparatus
A light-emitting element includes: an anode; a cathode; a light-emitting layer which is provided between the anode and the cathode and emits light as the anode and the cathode are electrically connected to each other; and an organic layer which is provided between the anode and the light-emitting layer to come in contact with both layers. The organic layer has a first function of transporting holes and a second function of preventing electrons infiltrating from the light-emitting layer from staying in the organic layer.
1. A light-emitting element comprising:
an anode;
a cathode;
a light-emitting layer disposed between the anode and the cathode, the light-emitting layer configured to emit light if the anode and the cathode are electrically connected to each other; and
an organic layer disposed between and contacting the anode and the light-emitting layer, the organic layer having a first function of transporting holes and a second function of preventing electrons infiltrating from the light-emitting layer from staying in the organic layer, the entirety of the organic layer contains an electron-transporting material that has a property of transporting electrons and accordingly exhibits the second function, and a content of the electron-transporting material in the organic layer is equal to or greater than 40 wt % and equal to or smaller than 70 wt %.
2. The light-emitting element according to claim 1 , wherein the organic layer exhibits a function of blocking electrons by the first function.
3. The light-emitting element according to claim 1 , wherein the organic layer contains an amine-based material and accordingly exhibits the first function.
4. The light-emitting element according claim 1 , wherein the electron-transporting material is an acene-based material.
5. The light-emitting element according to claim 4 , wherein the acene-based material is made of at least one of an anthracene-based material and a naphthacene-based material.
6. The light-emitting element according claim 1 ,
wherein the organic layer includes a hole injection layer which is provided between the anode and the light-emitting layer to come in contact with the anode and contains a hole-injecting material, and a hole transport layer which is provided between the hole injection layer and the light-emitting layer to come in contact with both layers and contains a hole-transporting material, and
the electron-transporting material is contained in each of the hole injection layer and the hole transport layer.
7. The light-emitting element according to claim 1 ,
wherein the organic layer includes a hole injection layer which is provided between the anode and the light-emitting layer to come in contact with both layers and contains a hole-injecting material, and
the electron-transporting material is contained in the hole injection layer.
8. The light-emitting element according to claim 1 ,
wherein the organic layer includes a hole transport layer which is provided between the anode and the light-emitting layer to come in contact with both layers and contains a hole-transporting material, and
the electron-transporting material is contained in the hole transport layer.
9. The light-emitting element according to claim 1 , wherein the organic layer contains an electron-trapping material having a property of trapping electrons and accordingly exhibits the second function.
10. The light-emitting element according to claim 9 , wherein the electron-trapping material is an acene-based material.
11. The light-emitting element according to claim 9 , wherein the organic layer has an electron neutralization layer containing a hole-transporting material and the electron-trapping material.
12. The light-emitting element according to claim 11 ,
wherein the organic layer further includes a hole injection layer provided between the anode and the light-emitting layer and a hole transport layer provided between the hole injection layer and the light-emitting layer, and
the electron neutralization layer is provided between the hole transport layer and the light-emitting layer to come in contact with the light-emitting layer.
13. The light-emitting element according to claim 11 ,
wherein the organic layer further includes a hole injection layer provided between the anode and the light-emitting layer and a hole transport layer provided between the hole injection layer and the light-emitting layer, and
the electron neutralization layer is provided between the hole injection layer and the hole transport layer to come in contact with both the layers.
14. The light-emitting element according to claim 13 , wherein the hole transport layer has a function of blocking electrons.
15. A light-emitting device including the light-emitting element according to claim 1 .
16. A display device including the light-emitting device according to claim 15 .
17. An electronic apparatus including the display device according to claim 16 .