Light-emitting element, light-emitting device, and electronic device
View Patent ↗Disclosed is a light-emitting element with a good carrier balance and manufacturing method thereof which does not require the formation of the heterostructure. The light-emitting element includes an organic compound film containing a first organic compound as the main component (base material) between an anode and a cathode, wherein the organic compound film is provided in contact with the anode and with the cathode. The first organic compound further includes a light-emitting region to which a light-emitting substance is added and includes a hole-transport region to which a hole-trapping substance is added and/or an electron-transport region to which an electron-trapping substance is added. The hole-transport region is located between the light-emitting region and the anode, and the electron-transport region is located between the light-emitting region and the cathode.
1. A light-emitting element comprising:
an anode;
a first layer over and in contact with the anode, the first layer comprising a first organic compound;
an organic compound layer over and in contact with the first layer;
a second layer over and in contact with the organic compound layer, the second layer comprising the first organic compound; and
a cathode over and in contact with the second layer,
wherein:
the organic compound layer comprises a first region, a light-emitting region over and in contact with the first region, and a second region over and in contact with the light-emitting region;
the first region comprises the first organic compound and a hole-trapping substance;
the light-emitting region comprises the first organic compound and a light-emitting substance; and
the second region comprises the first organic compound and an electron-trapping substance.
2. The light-emitting element according to claim 1 ,
wherein the light-emitting substance is a phosphorescent compound.
3. The light-emitting element according to claim 1 ,
wherein a HOMO level of the hole-trapping substance is higher than a HOMO level of the first organic compound by 0.2 eV or more.
4. The light-emitting element according to claim 1 ,
wherein a LUMO level of the electron-trapping substance is lower than a LUMO level of the first organic compound by 0.2 eV or more.
5. A lighting apparatus comprising a light-emitting element, the light-emitting element comprising:
an anode;
a first layer over and in contact with the anode, the first layer comprising a first organic compound;
an organic compound layer over and in contact with the first layer;
a second layer over and in contact with the organic compound layer, the second layer comprising the first organic compound; and
a cathode over and in contact with the second layer,
wherein:
the organic compound layer comprises a first region, a light-emitting region over and in contact with the first region, and a second region over and in contact with the light-emitting region;
the first region comprises the first organic compound and a hole-trapping substance;
the light-emitting region comprises the first organic compound and a light-emitting substance; and
the second region comprises the first organic compound and an electron-trapping substance.
6. The lighting apparatus according to claim 5 ,
wherein the light-emitting substance is a phosphorescent compound.
7. The lighting apparatus according to claim 5 ,
wherein a HOMO level of the hole-trapping substance is higher than a HOMO level of the first organic compound by 0.2 eV or more.
8. The lighting apparatus according to claim 5 ,
wherein a LUMO level of the electron-trapping substance is lower than a LUMO level of the first organic compound by 0.2 eV or more.
9. A light-emitting element comprising:
an anode;
a first layer over and in contact with the anode, the first layer comprising a first organic compound;
an organic compound layer over and in contact with the first layer;
a second layer over and in contact with the organic compound layer, the second layer comprising the first organic compound; and
a cathode over and in contact with the second layer,
wherein:
the organic compound layer comprises a first region, a light-emitting region over and in contact with the first region, and a second region over and in contact with the light-emitting region;
the first region comprises the first organic compound and a hole-trapping substance;
the light-emitting region comprises the first organic compound and a light-emitting substance;
the second region comprises the first organic compound and an electron-trapping substance; and
the first organic compound is an anthracene derivative.
10. The light-emitting element according to claim 9 ,
wherein the light-emitting substance is a phosphorescent compound.
11. The light-emitting element according to claim 9 ,
wherein a HOMO level of the hole-trapping substance is higher than a HOMO level of the first organic compound by 0.2 eV or more.
12. The light-emitting element according to claim 9 ,
wherein a LUMO level of the electron-trapping substance is lower than a LUMO level of the first organic compound by 0.2 eV or more.
13. A lighting apparatus comprising a light-emitting element, the light-emitting element comprising:
an anode;
a first layer over and in contact with the anode, the first layer comprising a first organic compound;
an organic compound layer over and in contact with the first layer;
a second layer over and in contact with the organic compound layer, the second layer comprising the first organic compound; and
a cathode over and in contact with the second layer,
wherein:
the organic compound layer comprises a first region, a light-emitting region over and in contact with the first region, and a second region over and in contact with the light-emitting region;
the first region comprises the first organic compound and a hole-trapping substance;
the light-emitting region comprises the first organic compound and a light-emitting substance;
the second region comprises the first organic compound and an electron-trapping substance;
the first organic compound is an anthracene derivative.
14. The lighting apparatus according to claim 13 ,
wherein the light-emitting substance is a phosphorescent compound.
15. The lighting apparatus according to claim 13 ,
wherein a HOMO level of the hole-trapping substance is higher than a HOMO level of the first organic compound by 0.2 eV or more.
16. The lighting apparatus according to claim 13 ,
wherein a LUMO level of the electron-trapping substance is lower than a LUMO level of the first organic compound by 0.2 eV or more.