Organic light emitting diode

1. An organic electroluminescent device comprising:

an anode;

a cathode;

a light emitting layer provided between the anode and the cathode;

a first p-type organic material layer provided between the light emitting layer and the cathode;

a first n-type organic material layer provided between the light emitting layer and the first p-type organic material layer; and

a light scattering layer provided between the light emitting layer and the cathode,

wherein the light scattering layer is the first p-type organic material layer, or is provided between the first p-type organic material layer and the first n-type organic material layer, and

wherein the light scattering layer comprises a polycyclic condensed ring compound and an aryl amine compound.

2. The organic electroluminescent device of claim 1 , further comprising:

a first electric charge transporting passage provided between the light emitting layer and the cathode; and

a second electric charge transporting passage provided between the light emitting layer and the anode,

wherein the first electric charge transporting passage comprises the first p-type organic material layer associated with the cathode; and the first n-type organic material layer provided between the first p-type organic material layer and the light emitting layer.

3. The organic electroluminescent device of claim 1 , further comprising:

a buffer layer provided between the light emitting layer and the cathode,

wherein the buffer layer includes: the first p-type organic material layer associated with the cathode; and the first n-type organic material layer provided between the first p-type organic material layer and the light emitting layer.

4. The organic electroluminescent device of claim 1 , wherein the light scattering layer comprises a light scattering structure provided in or on a surface of the layer.

5. The organic electroluminescent device of claim 4 , wherein the light scattering layer is formed of an organic material.

6. The organic electroluminescent device of claim 4 , wherein the light scattering structure is a particle structure formed by constituting a cluster of organic material molecules.

7. The organic electroluminescent device of claim 4 , wherein the light scattering structure is formed by depositing an organic material.

8. The organic electroluminescent device of claim 6 , wherein a particle diameter of the particle is from 0.5 micron to 30 micron.

9. The organic electroluminescent device of claim 6 , wherein a degree of roughness of the particle structure is from 2 nm to 50 nm.

10. The organic electroluminescent device of claim 1 , wherein the aryl amine compound comprises a compound of the following Formula 1:

in Formula 1, Ar 1 , Ar 2 , and Ar 3 are each independently hydrogen or a hydrocarbon group.

11. The organic electroluminescent device of claim 10 , wherein the aryl amine compound comprises NPB (N,N′-bis(naphthyl)-N,N′-bis(phenyl)benzidine).

12. The organic electroluminescent device of claim 1 , wherein the polycyclic condensed ring compound comprises a compound of the following Formula 2:

in Formula 2, R 1b to R 6b are each hydrogen, a halogen atom, nitrile (—CN), nitro (—NO 2 ), sulfonyl (—SO 2 R), sulfoxide (—SOR), sulfonamide (—SO 2 NR), sulfonate (—SO 3 R), trifluoromethyl (—CF 3 ), ester (—COOR), amide (—CONHR or —CONRR′), a substituted or unsubstituted straight or branched C 1 to C 12 alkoxy, a substituted or unsubstituted straight or branched C 1 to C 12 alkyl, a substituted or unsubstituted straight or branched C 2 to C 12 alkenyl, a substituted or unsubstituted aromatic or non-aromatic heterocyclic ring, a substituted or unsubstituted aryl, a substituted or unsubstituted mono- or di-aryl amine, or a substituted or unsubstituted aralkyl amine, wherein R and R′ are each a substituted or unsubstituted C 1 to C 60 alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted 5- to 7-membered heterocyclic ring.

13. The organic electroluminescent device of claim 12 , wherein the Formula 2 is selected from the following Formulas 2-1 to 2-6:

14. The organic electroluminescent device of claim 1 , wherein a weight ratio of a content of the polycyclic condensed compound to a content of the aryl amine compound in the light scattering layer is from 1/7 to 5/7.

15. The organic electroluminescent device of claim 4 , wherein the light scattering layer comprises a compound of the following Formula 3:

in Formula 3,

R 1c to R 6c are the same as or different from each other, are each independently a hydrogen atom; a C 1 to C 30 alkyl group which is unsubstituted or substituted with one or more groups selected from the group consisting of a halogen atom, an amino group, a nitrile group, a nitro group, a C 1 to C 30 alkyl group, a C 2 to C 30 alkenyl group, a C 1 to C 30 alkoxy group, a C 3 to C 30 cycloalkyl group, a C 3 to C 30 heterocycloalkyl group, a C 6 to C 30 aryl group, and a C 2 to C 30 heteroaryl group; a C 3 to C 30 cycloalkyl group which is unsubstituted or substituted with one or more groups selected from the group consisting of a halogen atom, an amino group, a nitrile group, a nitro group, a C 1 to C 30 alkyl group, a C 2 to C 30 alkenyl group, a C 1 to C 30 alkoxy group, a C 3 to C 30 cycloalkyl group, a C 3 to C 30 heterocycloalkyl group, a C 6 to C 30 aryl group, and a C 2 to C 30 heteroaryl group; a C 6 to C 30 aryl group which is unsubstituted or substituted with one or more groups selected from the group consisting of a halogen atom, an amino group, a nitrile group, a nitro group, a C 1 to C 30 alkyl group, a C 2 to C 30 alkenyl group, a C 1 to C 30 alkoxy group, a C 3 to C 30 cycloalkyl group, a C 3 to C 30 heterocycloalkyl group, a C 6 to C 30 aryl group, and a C 2 to C 30 heteroaryl group; or a C 2 to C 30 heteroaryl group which is unsubstituted or substituted with one or more groups selected from the group consisting of a halogen atom, an amino group, a nitrile group, a nitro group, a C 1 to C 30 alkyl group, a C 2 to C 30 alkenyl group, a C 1 to C 30 alkoxy group, a C 3 to C 30 cycloalkyl group, a C 3 to C 30 heterocycloalkyl group, a C 6 to C 30 aryl group, and a C 2 to C 30 heteroaryl group, and are able to form an aliphatic, aromatic, aliphatic hetero, or aromatic hetero condensation ring or a spiro bond in conjunction with an adjacent group, and n and m are each an integer from 0 to 4.

16. The organic electroluminescent device of claim 15 , wherein the compound of Formula 3 is represented by any one of the following Formulas 3-1 to 3-5:

17. The organic electroluminescent device of claim 2 , wherein a work function of the cathode is at a HOMO energy level or less of the first p-type organic material layer.

18. The organic electroluminescent device of claim 2 , wherein a difference between the HOMO energy level of the first p-type organic material layer and a LUMO energy level of the first n-type organic material layer is 2 eV or less.

19. The organic electroluminescent device of claim 2 , further comprising:

a second n-type organic material layer provided between the first n-type organic material layer and the light emitting layer.

20. The organic electroluminescent device of claim 19 , wherein the second n-type organic material layer is doped with an n-type dopant.

21. The organic electroluminescent device of claim 19 , further comprising:

a third n-type organic material layer provided between the second n-type organic material layer and the light emitting layer.

22. The organic electroluminescent device of claim 2 , wherein the cathode is in contact with the first p-type organic material layer.

23. The organic electroluminescent device of claim 2 , wherein the first n-type organic material layer and the first p-type organic material layer form an NP junction.

24. The organic electroluminescent device of claim 2 , further comprising:

a second p-type organic material layer provided between the light emitting layer and the anode.

25. The organic electroluminescent device of claim 24 , further comprising:

a fourth n-type organic material layer provided between the anode and the second p-type organic material layer.

26. The organic electroluminescent device of claim 25 , wherein the second p-type organic material layer and the fourth n-type organic material layer form an NP junction.

27. The organic electroluminescent device of claim 1 , further comprising:

a substrate provided on a surface opposite to a substrate on which the organic material layer of the cathode or the anode is provided; and

a light extraction layer provided between the cathode or the anode and the substrate, or on a surface opposite to a surface on which the anode or the cathode of the substrate is provided.

28. The organic electroluminescent device of claim 1 , wherein the organic electroluminescent device is a flexible organic electroluminescent device.

29. A display comprising the organic electroluminescent device of claim 1 .

30. An illumination apparatus comprising the organic electroluminescent device of claim 1 .

31. The organic electroluminescent device of claim 1 , wherein the first p-type organic material layer is non-doped.