Organic light-emitting device

1. An organic light-emitting device, comprising:

a first electrode;

a second electrode facing the first electrode;

an emission layer between the first electrode and the second electrode;

a hole control layer between the first electrode and the emission layer;

an electron control layer between the emission layer and the second electrode; and

a capping layer on the second electrode,

wherein the emission layer includes a first sub-emission layer, a second sub-emission layer, and a third sub-emission layer,

wherein at least one of the first to the third sub-emission layers includes a hole-transporting host, an electron-transporting host, and a light-emitting dopant,

wherein the hole-transporting host and the electron-transporting host form an exciplex, and

wherein the light-emitting dopant emits phosphorescent light and thermally activated delayed fluorescence light.

2. The organic light-emitting device as claimed in claim 1 ,

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

3. The organic light-emitting device as claimed in claim 1 ,

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

4. The organic light-emitting device as claimed in claim 1 ,

wherein a highest occupied molecular orbital (HOMO) energy level of the hole-transporting host is −5.4 eV, and

a lowest unoccupied molecular orbital (LUMO) energy level of the hole-transporting host is −2.4 eV.

5. The organic light-emitting device as claimed in claim 1 ,

wherein a highest occupied molecular orbital (HOMO) energy level of the electron-transporting host is −5.8 eV, and

a lowest unoccupied molecular orbital (LUMO) energy level of the electron-transporting host is −2.7 eV.

6. The organic light-emitting device as claimed in claim 1 ,

wherein the electron-transporting host is an organometallic complex, a spirofluorene-based compound, an oxidazole-based compound, a phenanthroline-based compound, a triazine-based compound, or a triazole-based compound.

7. The organic light-emitting device as claimed in claim 1 ,

wherein the electron control layer includes:

an electron transport layer; and

an electron injection layer on the electron transport layer, and

wherein the electron injection layer includes LiF, LiQ, Li 2 O, BaO, NaCl, Yb, CsF, RbCl, or RbI.

8. The organic light-emitting device as claimed in claim 1 ,

wherein the hole control layer includes:

a hole injection layer; and

a hole transport layer on the hole injection layer,

wherein the hole injection layer includes p-type dopant, and

wherein the p-type dopant is one selected from a quinone derivative, a metal oxide, and a cyano group-containing compound.

9. The organic light-emitting device 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 organic light-emitting device as claimed in claim 1 ,

wherein the first electrode comprise at least one selected from Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, In, Sn, Zn, a compound of two or more thereof, a mixture of two or more thereof, and oxides thereof.

11. The organic light-emitting device as claimed in claim 1 ,

wherein the second electrode comprise at least one selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF/Ca, LiF/Al, Mo, Ti, In, Sn, Zn, a compound of two or more thereof, a mixture of two or more thereof, and oxides thereof.

12. An organic light-emitting device, comprising:

a first electrode;

a second electrode facing the first electrode;

an emission layer between the first electrode and the second electrode;

a hole control layer between the first electrode and the emission layer;

an electron control layer between the emission layer and the second electrode; and

a capping layer on the second electrode,

wherein the emission layer includes:

a first sub-emission layer including a first light-emitting dopant;

a second sub-emission layer including a second light-emitting dopant; and

a third sub-emission layer including a third light-emitting dopant;

at least portions of the first to third sub-emission layers do not overlap one another,

at least one of the first sub-emission layer and the second sub-emission layer includes a mixed hole-transporting host and an electron-transporting host which form an exciplex.

13. The organic light-emitting device as claimed in claim 12 ,

wherein a triplet energy of the exciplex is equal to or greater than respective triplet energies of the first light-emitting dopant and the second light-emitting dopant.

14. The organic light-emitting device as claimed in claim 12 , wherein a triplet energy of the exciplex is about 2.5 eV to about 2.8 eV.

15. The organic light-emitting device as claimed in claim 12 ,

wherein the first light-emitting dopant is a red light-emitting dopant, the second light-emitting dopant is a green light-emitting dopant, and the third light-emitting dopant is a blue light-emitting dopant.

16. The organic light-emitting device as claimed in claim 15 , wherein the first light-emitting dopant and the second light-emitting dopant emit phosphorescent light, and the third light-emitting dopant emits fluorescence light.

17. The organic light-emitting device as claimed in claim 12 ,

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