Organic light-emitting device using a mixture of electron transporting compounds

1. An organic light-emitting device, comprising:

a first electrode;

a second electrode disposed opposite to the first electrode;

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

an electron-transporting layer disposed between the emission layer and the second electrode; wherein

the electron-transporting layer includes a first electron-transporting material and a second electron-transporting material; and

a lowest unoccupied molecular orbital (LUMO) energy level of the first electron-transporting material (EL 1 ) and a lowest unoccupied molecular orbital (LUMO) energy level of the second electron-transporting material (EL 2 ) satisfy the equation 0.1 eV≦|EL 1 −EL 2 |≦0.3 eV,

wherein the first electron-transporting material and the second electron-transporting material are each independently selected from an amine-based compound represented by Formula 1 and an anthracene-based compound represented by Formula 2:

wherein in Formulae 1 and 2,

groups represented by X 1 and X 2 are each independently selected from a substituted or unsubstituted C 6 -C 60 arylene group and a substituted or unsubstituted C 2 -C 60 heteroarylene group;

m1 and m2 are each independently an integer of 0 to 5;

groups represented by Ar 1 and Ar 2 are each independently selected from a substituted or unsubstituted C 6 -C 60 aryl group and a substituted or unsubstituted C 2 -C 60 heteroaryl group; wherein

at least one of the groups represented by Ar 1 and Ar 2 is selected from i) a pyridyl group, a pyrimidyl group, and a triazinyl group, ii) a pyridyl group, a pyrimidyl group, and a triazinyl group each substituted with at least one of a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group; iii) a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group each substituted with at least one of a pyridyl group, a pyrimidyl group, and a triazinyl group; and iv) a pyridyl group, a pyrimidyl group, and a triazinyl group each substituted with at least one of a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group, which are each substituted with at least one of a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group; and

a group represented by Ar 3 is selected from i) a pyridyl group, a pyrimidyl group, and a triazinyl group, ii) a pyridyl group, a pyrimidyl group, and a triazinyl group each substituted with at least one of a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group; iii) a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group each substituted with at least one of a pyridyl group, a pyrimidyl group, and a triazinyl group; and iv) a pyridyl group, a pyrimidyl group, and a triazinyl group each substituted with at least one of a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group, which are each substituted with at least one of a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group.

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

a highest occupied molecular orbital (HOMO) energy level of the first electron-transporting material (EH 1 ) and the lowest unoccupied molecular orbital (LUMO) energy level of the first electron-transporting material (EL 1 ) satisfy the equation

2.7 eV≦| EL 1 −EH 1 |≦3.2 eV; and

a highest occupied molecular orbital (HOMO) of the second electron-transporting material (EH 2 ) and the lowest unoccupied molecular orbital (LUMO) energy level of the second electron-transporting material (EL 2 ) satisfy the equation,

2.7 eV≦| EL 2 −EH 2 |≦3.2 eV.

3. The organic light-emitting device as claimed in claim 1 , wherein a molecular weight of the first electron-transporting material (MW 1 ) and a molecular weight of the second electron-transporting material (MW 2 ) satisfy the equation, |MW 1 −MW 2 |≦30.

4. The organic light-emitting device as claimed in claim 1 , wherein both of the first electron-transporting material and the second electron-transporting material are each non-metal-atom-containing organic compounds.

5. The organic light-emitting device as claimed in claim 1 , wherein the first electron-transporting material and the second electron-transporting material are each independently selected from a pyridine derivative, a pyrimidine derivative, and a triazine derivative.

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

the LUMO energy level of the EL 1 satisfies the equation 2.6 eV≦|EL 1 |≦2.9 eV; and

the LUMO energy level of the EL 2 satisfies the equation 2.7 eV≦|EL 1 |≦3.0 eV.

7. The organic light-emitting device as claimed in claim 1 , wherein the first electron-transporting material and the second electron-transporting material are each independently selected from Compounds 1 to 15:

8. An organic light-emitting device, comprising:

a first electrode;

a second electrode disposed opposite to the first electrode;

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

an electron-transporting layer disposed between the emission layer and the second electrode, wherein

the electron-transporting layer includes a first electron-transporting material and a second electron-transporting material,

the first electron-transporting material and the second electron-transporting material are each independently selected from an amine-based compound represented by Formula 1 and an anthracene-based compound represented by Formula 2,

the first electron-transporting material and the second electron-transporting material are different:

wherein Formulae 1 and 2, groups represented by X 1 and X 2 are each independently selected from a substituted or unsubstituted C 6 -C 60 arylene group and a substituted or unsubstituted C 2 -C 60 heteroarylene group;

m1 and m2 are each independently an integer of 0 to 5;

groups represented by Ar 1 and Ar 2 are each independently selected from a substituted or unsubstituted C 6 -C 60 aryl group and a substituted or unsubstituted C 2 -C 60 heteroaryl group; wherein

at least one of the groups represented by Ar 1 and Ar 2 is selected from i) a pyridyl group, a pyrimidyl group, and a triazinyl group, ii) a pyridyl group, a pyrimidyl group, and a triazinyl group each substituted with at least one of a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group; iii) a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group each substituted with at least one of a pyridyl group, a pyrimidyl group, and a triazinyl group; and iv) a pyridyl group, a pyrimidyl group, and a triazinyl group each substituted with at least one of a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group, which are each substituted with at least one of a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group; and

a group represented by Ar 3 is selected from i) a pyridyl group, a pyrimidyl group, and a triazinyl group, ii) a pyridyl group, a pyrimidyl group, and a triazinyl group each substituted with at least one of a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group; iii) a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group each substituted with at least one of a pyridyl group, a pyrimidyl group, and a triazinyl group; and iv) a pyridyl group, a pyrimidyl group, and a triazinyl group each substituted with at least one of a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group, which are each substituted with at least one of a C 6 -C 60 aryl group and a C 2 -C 60 heteroaryl group.

9. The organic light-emitting device as claimed in claim 8 , wherein groups represented by X 1 and X 2 are each independently selected from a substituted or unsubstituted a phenylene group, a substituted or unsubstituted a naphthylene group, a substituted or unsubstituted an anthrylene group, a substituted or unsubstituted pyridinylene group, a substituted or unsubstituted pyrimidinylene group, and a substituted or unsubstituted triazolylene group.

10. The organic light-emitting device as claimed in claim 8 , wherein m1 and m2 are each independently an integer of 1 or 2.

11. The organic light-emitting device as claimed in claim 8 , wherein moieties represented by (X 1 ) m1 and (X 2 ) m2 are each independently selected from Formulae 3-1 to 3-4:

wherein groups represented by Z 1 to Z 8 are each independently selected from a hydrogen atom; a deuterium atom; —F; —Cl; —Br; —I; —CN; a hydroxyl group; —NO 2 ; a C 1 -C 20 alkyl group; a C 1 -C 20 alkoxy group; a C 1 -C 20 alkyl group and a C 1 -C 20 alkoxy group each substituted with at least one of a deuterium atom, —F, —Cl, —Br, —I, —CN, a hydroxyl group, and —NO 2 ; a C 6 -C 20 aryl group; a C 2 -C 20 heteroaryl group; and a C 6 -C 20 aryl group and a C 2 -C 20 heteroaryl group each substituted with at least one of a deuterium atom, —F, —Cl, —Br, —I, —CN, a hydroxyl group, —NO 2 , a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, a C 6 -C 20 aryl group, and a C 2 -C 20 heteroaryl group;

* is a bonding site to anthracene of Formulae 1 and 2; and

** is a bonding site to a nitrogen atom of Formula 1 or a bonding site to a group represented by Ar 3 of Formula 2.

12. The organic light-emitting device as claimed in claim 8 , wherein groups represented by Ar 1 and Ar 2 are each independently represented by any one selected from Formulae 4-1 to 4-9, provided that at least one of groups represented by An and Ar e is represented by any one of Formulae 4-1 to 4-6:

wherein groups represented by Y 1 to Y 8 are each independently selected from a hydrogen atom, a phenyl group, a naphthyl group, a pyridyl group, a pyrimidyl group and a triazinyl group; wherein

* is a bonding site to a nitrogen atom of Formula 1.

13. The organic light-emitting device as claimed in claim 8 , wherein a group represented by Ar 3 is selected from i) a pyridyl group, a pyrimidyl group, and a triazinyl group; ii) a pyridyl group, a pyrimidyl group, and a triazinyl group each substituted with at least one of a phenyl group, a naphthyl group, a pyridyl group, a pyrimidyl group, and a triazinyl group; iii) a phenyl group, a naphthyl group, a pyridyl group, a pyrimidyl group, and a triazinyl group each substituted with at least one of a pyridyl group, a pyrimidyl group, and a triazinyl group; and iv) a pyridyl group, a pyrimidyl group, and a triazinyl group each substituted with at least one of a phenyl group, a naphthyl group, a pyridyl group, a pyrimidyl group, and a triazinyl group, which are each substituted with at least one of a phenyl group, a naphthyl group, a pyridyl group, a pyrimidyl group, and a triazinyl group.

14. The organic light-emitting device as claimed in claim 8 , wherein a group represented by Ar 3 is represented by any one of Formulae 4-1 to 4-6:

wherein groups represented by Y 1 to Y 8 are each independently selected from a hydrogen atom, a phenyl group, a naphthyl group, a pyridyl group, a pyrimidyl group, and a triazinyl group; and * is a bonding site to a nitrogen atom of Formula 1.

15. The organic light-emitting device as claimed in claim 8 , wherein the first electron-transporting material and the second electron-transporting material are each independently selected from Compounds 1 to 15:

16. The organic light-emitting device as claimed in claim 8 , wherein a lowest unoccupied molecular orbital energy level (LUMO) of the first electron-transporting material (EL 1 ) and a lowest unoccupied molecular orbital (LUMO) energy level of the second electron-transporting material (EL 2 ) satisfy the equation, 0.1 eV≦|EL 1 −EL 2 |≦0.3 eV.

17. The organic light-emitting device as claimed in claim 16 , wherein:

the LUMO energy level of the EL 1 satisfies the equation 2.6 eV≦|EL 1 |≦2.9 eV; and

the LUMO energy level of the EL 2 satisfies the equation 2.7 eV≦|EL 1 |≦3.0 eV.

18. The organic light-emitting device as claimed in claim 8 , wherein a highest occupied molecular orbital (HOMO) energy level of the first electron-transporting material (EH 1 ) and a lowest unoccupied molecular orbital (LUMO) energy level of the first electron-transporting material (EL 1 ) satisfy the equation, 2.7 eV≦|EL 1 −EH 1 |≦3.2 eV; and

a highest occupied molecular orbital (HOMO) energy level of the second electron-transporting material (EH 2 ) and a lowest unoccupied molecular orbital (LUMO) of the second electron-transporting material (EL 2 ) satisfy 2.7 eV≦|EL 2 −EH 2 |≦3.2 eV.

19. The organic light-emitting device as claimed in claim 8 , wherein:

i) the first electron-transporting material is at least one selected from amine-based compounds represented by Formula 1 and the second electron-transporting material is at least one selected from the amine-based compounds represented by Formula 1;

ii) the first electron-transporting material is at least one selected from the amine-based compounds represented by Formula 1 and the second electron-transporting material is at least one selected from anthracene-based compounds represented by Formula 2; or

iii) the first electron-transporting material is at least one selected from the anthracene-based compounds represented by Formula 2 and the second electron-transporting material is at least one selected from the anthracene-based compounds represented by Formula 2.

20. The organic light-emitting device as claimed in claim 8 , wherein:

i) the first electron-transporting material and the second electron-transporting material are each independently at least one selected from Compounds 1 to 5;

ii) the first electron-transporting material is at least one selected from Compounds 1 to 5 and the second electron-transporting material is at least one selected from Compounds 6 to 10;

iii) the first electron-transporting material is at least one selected from Compounds 1 to 5 and the second electron-transporting material is at least one selected from Compounds 11 to 15;

iv) the first electron-transporting material and the second electron-transporting material are each independently at least one selected from Compounds 6 to 10;

v) the first electron-transporting material is at least one selected from Compounds 6 to 10 and the second electron-transporting material is at least one selected from Compounds 11 to 15; or

vi) the first electron-transporting material and the second electron-transporting material are each independently at least one selected from Compounds 11 to 15,