Organic light-emitting device

1. A light-emitting display apparatus, comprising:

a timing controller;

a scan driver;

a source driver; and

a light-emitting display panel including a light-emitting device and defining a first pixel area, a second pixel area, and a third pixel area,

wherein the light-emitting device comprises:

a first electrode;

a hole control layer on the first electrode;

an emission layer on the hole control layer;

an electron control layer on the emission layer;

a second electrode on the electron control layer; and

a capping layer on the second electrode,

the emission layer comprises a plurality of sub-emission layers comprising a first sub-emission layer corresponding to the first pixel area, a second sub-emission layer corresponding to the second pixel area, and a third sub-emission layer corresponding to the third pixel area,

the first sub-emission layer comprises a first hole-transporting host, a first electron-transporting host, and a first color light-emitting dopant,

the second sub-emission layer comprises a second hole-transporting host, a second electron-transporting host, and a second color light-emitting dopant,

the third sub-emission layer comprises a third hole-transporting host, a third electron-transporting host, and a third color light-emitting dopant, and

at least one of the first color light-emitting dopant, the second color light-emitting dopant, and the third color light-emitting dopant emits thermally activated delayed fluorescence (TADF) light.

2. The light-emitting display apparatus as claimed in claim 1 ,

wherein a difference between a lowest unoccupied molecular orbital (LUMO) energy level of the first hole-transporting host and a LUMO energy level of the first electron-transporting host is about 0.2 eV or more.

3. The light-emitting display apparatus as claimed in claim 2 ,

wherein the first hole-transporting host and the first electron-transporting host form a first exciplex,

the first color light-emitting dopant emits phosphorescent light; and

a triplet energy of the first exciplex is equal to or greater than a triplet energy of the first color light-emitting dopant.

4. The light-emitting display apparatus as claimed in claim 3 ,

wherein the triplet energy of the first exciplex is about 2.4 eV to about 3.0 eV.

5. The light-emitting display apparatus as claimed in claim 1 ,

wherein a difference between a lowest unoccupied molecular orbital (LUMO) energy level of the second hole-transporting host and a LUMO energy level of the second electron-transporting host is about 0.2 eV or more.

6. The light-emitting display apparatus as claimed in claim 5 ,

wherein the second hole-transporting host and the second electron-transporting host form a second exciplex,

the second color light-emitting dopant emits phosphorescent light; and

a triplet energy of the second exciplex is equal to or greater than a triplet energy of the second color light-emitting dopant.

7. The light-emitting display apparatus as claimed in claim 6 ,

wherein the triplet energy of the second exciplex is about 2.4 eV to about 3.0 eV.

8. The light-emitting display apparatus as claimed in claim 1 ,

wherein the third hole-transporting host and the third electron-transporting host form a third exciplex,

the third color light-emitting dopant emits thermally activated delayed fluorescence (TADF) light, and

a difference between a triplet energy level of the third exciplex and a singlet energy level of the third color light-emitting dopant is about −0.1 eV to about 0.1 eV.

9. The light-emitting display apparatus as claimed in claim 1 ,

wherein the capping layer includes at least one of an amine compound, a carbazole compound, or a naphthalene compound.

10. The light-emitting display apparatus as claimed in claim 1 ,

wherein a thickness of the first sub-emission layer is thicker than a thickness of the second sub-emission layer, and

the thickness of the second sub-emission layer is thicker than a thickness of the third sub-emission layer.

11. The light-emitting display apparatus as claimed in claim 1 ,

wherein the emission layer further includes an auxiliary layer that disposed between the hole control layer and the plurality of sub-emission layers.

12. The light-emitting display apparatus as claimed in claim 11 ,

wherein the auxiliary layer comprises:

a first auxiliary layer disposed between the hole control layer and the first sub-emission layer;

a second auxiliary layer disposed between the hole control layer and the second sub-emission layer; and

a third auxiliary layer disposed between the hole control layer and the third sub-emission layer.

13. The light-emitting display apparatus as claimed in claim 12 , wherein

the first auxiliary layer disposed on the hole control layer corresponding to the first pixel area;

the second auxiliary layer disposed on the hole control layer corresponding to the second pixel area; and

the third auxiliary layer disposed on the hole control layer corresponding to the third pixel area.

14. The light-emitting display apparatus as claimed in claim 13 ,

wherein a thickness of the first auxiliary layer is thicker than a thickness of the second auxiliary layer, and

a thickness of the second auxiliary layer is thicker than a thickness of the third auxiliary layer.

15. The light-emitting display apparatus as claimed in claim 12 , wherein

the first auxiliary layer disposed on the second auxiliary layer corresponding to the first pixel area;

the second auxiliary layer disposed on the third auxiliary layer corresponding to the first pixel area and the second pixel area; and

the third auxiliary layer disposed on the hole control layer corresponding to the first pixel area, the second pixel area and the third pixel area.