Organic light emitting diode having low driving voltage, high brightness, and excellent light emitting efficiencies

1. An organic electroluminescent device comprising:

an anode;

a cathode;

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

a first organic material layer being in physical contact with the anode and doped with a p-type dopant; and

a second organic material layer being in physical contact with the cathode and doped with a p-type dopant,

wherein a concentration of the p-type dopant in the first organic material layer is 50% by weight or more and less than 100% by weight.

2. The organic electroluminescent device of claim 1 , wherein when the concentration of the p-type dopant in the first organic material layer is A % by weight and a concentration of the p-type dopant in the second organic material layer is B % by weight, A−B≧B.

3. The organic electroluminescent device of claim 1 , wherein when the concentration of the p-type dopant in the first organic material layer is A % by weight and a concentration of the p-type dopant in the second organic material layer is B % by weight, A−B≧1.5 B.

4. The organic electroluminescent device of claim 1 , wherein when the concentration of the p-type dopant in the first organic material layer is A % by weight and a concentration of the p-type dopant in the second organic material layer is B % by weight, A−B≧2 B.

5. The organic electroluminescent device of claim 1 , wherein the p-type dopant of the first organic material layer and the p-type dopant of the second organic material layer are a compound of the following Formula 1:

in Formula 1, R 1b to R 6b are each hydrogen, a halogen atom, nitrite (—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.

6. The organic electroluminescent device of claim 1 , wherein in the first organic material layer and the second organic material layer, an organic material doped with the p-type dopant is a compound of the following Formula 2:

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

7. The organic electroluminescent device of claim 6 , wherein the p-type dopant in the second organic material layer is a compound of the following Formula 1, and a weight ratio of the compound of the following Formula 1 and the compound of the above Formula 2 is from 1:9 to 5:5;

in Formula 1, 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.

8. The organic electroluminescent device of claim 1 , wherein an electron injection or transporting layer is provided between the second organic material layer and the light emitting layer.

9. The organic electroluminescent device of claim 8 , wherein the electron injection or transporting layer is a first n-type organic material layer which is in contact with the second organic material layer.

10. The organic electroluminescent device of claim 9 , wherein the first n-type organic material layer is formed of a compound of the following Formula 1:

in Formula 1, 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.

11. The organic electroluminescent device of claim 9 , wherein the p-type dopant of the first organic material layer, the p-type dopant of the second organic material layer, and a material for the first n-type organic material layer are the same as each other.

12. The organic electroluminescent device of claim 11 , wherein the p-type dopant of the first organic material layer, the p-type dopant of the second organic material layer, and a material for the first n-type organic material layer are a compound of the following Formula 1:

in Formula 1, 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 9 , wherein a second n-type organic material layer is provided between the first n-type organic material layer and the light emitting layer.

14. The organic electroluminescent device of claim 13 , wherein the second n-type organic material layer is n-type doped.

15. The organic electroluminescent device of claim 14 , wherein a third n-type organic material layer is provided between the second n-type organic material layer and the light emitting layer.

16. The organic electroluminescent device of claim 1 , wherein a fourth n-type organic material layer is provided between the first organic material layer and the anode.

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

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

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

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

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